--- /dev/null
+diff --git a/Documentation/ABI/testing/debugfs-aufs b/Documentation/ABI/testing/debugfs-aufs
+new file mode 100644
+index 0000000..4110b94
+--- /dev/null
++++ b/Documentation/ABI/testing/debugfs-aufs
+@@ -0,0 +1,40 @@
++What: /debug/aufs/si_<id>/
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ Under /debug/aufs, a directory named si_<id> is created
++ per aufs mount, where <id> is a unique id generated
++ internally.
++
++What: /debug/aufs/si_<id>/xib
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ It shows the consumed blocks by xib (External Inode Number
++ Bitmap), its block size and file size.
++ When the aufs mount option 'noxino' is specified, it
++ will be empty. About XINO files, see
++ Documentation/filesystems/aufs/aufs.5 in detail.
++
++What: /debug/aufs/si_<id>/xino0, xino1 ... xinoN
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ It shows the consumed blocks by xino (External Inode Number
++ Translation Table), its link count, block size and file
++ size.
++ When the aufs mount option 'noxino' is specified, it
++ will be empty. About XINO files, see
++ Documentation/filesystems/aufs/aufs.5 in detail.
++
++What: /debug/aufs/si_<id>/xigen
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ It shows the consumed blocks by xigen (External Inode
++ Generation Table), its block size and file size.
++ If CONFIG_AUFS_EXPORT is disabled, this entry will not
++ be created.
++ When the aufs mount option 'noxino' is specified, it
++ will be empty. About XINO files, see
++ Documentation/filesystems/aufs/aufs.5 in detail.
+diff --git a/Documentation/ABI/testing/sysfs-aufs b/Documentation/ABI/testing/sysfs-aufs
+new file mode 100644
+index 0000000..ca49330
+--- /dev/null
++++ b/Documentation/ABI/testing/sysfs-aufs
+@@ -0,0 +1,25 @@
++What: /sys/fs/aufs/si_<id>/
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ Under /sys/fs/aufs, a directory named si_<id> is created
++ per aufs mount, where <id> is a unique id generated
++ internally.
++
++What: /sys/fs/aufs/si_<id>/br0, br1 ... brN
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ It shows the abolute path of a member directory (which
++ is called branch) in aufs, and its permission.
++
++What: /sys/fs/aufs/si_<id>/xi_path
++Date: March 2009
++Contact: J. R. Okajima <hooanon05@yahoo.co.jp>
++Description:
++ It shows the abolute path of XINO (External Inode Number
++ Bitmap, Translation Table and Generation Table) file
++ even if it is the default path.
++ When the aufs mount option 'noxino' is specified, it
++ will be empty. About XINO files, see
++ Documentation/filesystems/aufs/aufs.5 in detail.
+diff --git a/Documentation/filesystems/aufs/README b/Documentation/filesystems/aufs/README
+new file mode 100644
+index 0000000..ed68e31
+--- /dev/null
++++ b/Documentation/filesystems/aufs/README
+@@ -0,0 +1,256 @@
++
++Aufs2 -- advanced multi layered unification filesystem version 2
++http://aufs.sf.net
++Junjiro R. Okajima
++
++
++0. Introduction
++----------------------------------------
++In the early days, aufs was entirely re-designed and re-implemented
++Unionfs Version 1.x series. After many original ideas, approaches,
++improvements and implementations, it becomes totally different from
++Unionfs while keeping the basic features.
++Recently, Unionfs Version 2.x series begin taking some of the same
++approaches to aufs1's.
++Unionfs is being developed by Professor Erez Zadok at Stony Brook
++University and his team.
++
++This version of AUFS, aufs2 has several purposes.
++- to be reviewed easily and widely.
++- to make the source files simpler and smaller by dropping several
++ original features.
++
++Note: it becomes clear that "Aufs was rejected. Let's give it up."
++According to Christoph Hellwig, linux rejects all union-type filesystems
++but UnionMount.
++<http://marc.info/?l=linux-kernel&m=123938533724484&w=2>
++
++Through this work, I found some bad things in aufs1 source code and
++fixed them. Some of the dropped features will be reverted in the future,
++but not all I'm afraid.
++Aufs2 supports linux-2.6.27 and later. If you want older kernel version
++support, try aufs1 from CVS on SourceForge.
++
++
++1. Features
++----------------------------------------
++- unite several directories into a single virtual filesystem. The member
++ directory is called as a branch.
++- you can specify the permission flags to the branch, which are 'readonly',
++ 'readwrite' and 'whiteout-able.'
++- by upper writable branch, internal copyup and whiteout, files/dirs on
++ readonly branch are modifiable logically.
++- dynamic branch manipulation, add, del.
++- etc...
++
++Also there are many enhancements in aufs1, such as:
++- keep inode number by external inode number table
++- keep the timestamps of file/dir in internal copyup operation
++- seekable directory, supporting NFS readdir.
++- support mmap(2) including /proc/PID/exe symlink, without page-copy
++- whiteout is hardlinked in order to reduce the consumption of inodes
++ on branch
++- do not copyup, nor create a whiteout when it is unnecessary
++- revert a single systemcall when an error occurs in aufs
++- remount interface instead of ioctl
++- maintain /etc/mtab by an external command, /sbin/mount.aufs.
++- loopback mounted filesystem as a branch
++- kernel thread for removing the dir who has a plenty of whiteouts
++- support copyup sparse file (a file which has a 'hole' in it)
++- default permission flags for branches
++- selectable permission flags for ro branch, whether whiteout can
++ exist or not
++- export via NFS.
++- support <sysfs>/fs/aufs and <debugfs>/aufs.
++- support multiple writable branches, some policies to select one
++ among multiple writable branches.
++- a new semantics for link(2) and rename(2) to support multiple
++ writable branches.
++- no glibc changes are required.
++- pseudo hardlink (hardlink over branches)
++- allow a direct access manually to a file on branch, e.g. bypassing aufs.
++ including NFS or remote filesystem branch.
++- and more...
++
++Currently these features are dropped temporary from this version, aufs2.
++See design/08plan.txt in detail.
++- test only the highest one for the directory permission (dirperm1)
++- show whiteout mode (shwh)
++- copyup on open (coo=)
++- nested mount, i.e. aufs as readonly no-whiteout branch of another aufs
++ (robr)
++- statistics of aufs thread (/sys/fs/aufs/stat)
++- delegation mode (dlgt)
++ a delegation of the internal branch access to support task I/O
++ accounting, which also supports Linux Security Modules (LSM) mainly
++ for Suse AppArmor.
++- intent.open/create (file open in a single lookup)
++
++Features or just an idea in the future (see also design/*.txt),
++- reorder the branch index without del/re-add.
++- permanent xino files for NFSD
++- an option for refreshing the opened files after add/del branches
++- 'move' policy for copy-up between two writable branches, after
++ checking free space.
++- O_DIRECT
++- light version, without branch manipulation. (unnecessary?)
++- copyup in userspace
++- inotify in userspace
++- readv/writev
++- xattr, acl
++
++
++2. Download
++----------------------------------------
++Kindly one of aufs user, the Center for Scientific Computing and Free
++Software (C3SL), Federal University of Parana offered me a public GIT
++tree space.
++
++There are three GIT trees, aufs2-2.6, aufs2-standalone and aufs2-util.
++While the aufs2-util is always necessary, you need either of aufs2-2.6
++or aufs2-standalone.
++
++The aufs2-2.6 tree includes the whole linux-2.6 GIT tree,
++git://git.kernel.org/.../torvalds/linux-2.6.git.
++And you cannot select CONFIG_AUFS_FS=m for this version, eg. you cannot
++build aufs2 as an externel kernel module.
++If you already have linux-2.6 GIT tree, you may want to pull and merge
++the "aufs2" branch from this tree.
++
++On the other hand, the aufs2-standalone tree has only aufs2 source files
++and a necessary patch, and you can select CONFIG_AUFS_FS=m. In other
++words, the aufs2-standalone tree is generated from aufs2-2.6 tree by,
++- extract new files and modifications.
++- generate a single patch file from modifications.
++- generate a ChangeLog file from git-log.
++- commit the files newly and no log messages. this is not git-pull.
++
++Both of aufs2-2.6 and aufs2-standalone trees have a branch whose name is
++in form of "aufs2-xx" where "xx" represents the linux kernel version,
++"linux-2.6.xx".
++
++o aufs2-2.6 tree
++$ git clone --reference /your/linux-2.6/git/tree \
++ http://git.c3sl.ufpr.br/pub/scm/aufs/aufs2-2.6.git \
++ aufs2-2.6.git
++- if you don't have linux-2.6 GIT tree, then remove "--reference ..."
++$ cd aufs2-2.6.git
++$ git checkout origin/aufs2-xx # for instance, aufs2-27 for linux-2.6.27
++ # aufs2 (no -xx) for the latest -rc version.
++
++o aufs2-standalone tree
++$ git clone http://git.c3sl.ufpr.br/pub/scm/aufs/aufs2-standalone.git \
++ aufs2-standalone.git
++$ cd aufs2-standalone.git
++$ git checkout origin/aufs2-xx # for instance, aufs2-27 for linux-2.6.27
++ # aufs2 (no -xx) for the latest -rc version.
++- apply "aufs2-standalone.patch" to your kernel source files.
++
++o aufs2-util tree
++$ git clone http://git.c3sl.ufpr.br/pub/scm/aufs/aufs2-util.git \
++ aufs2-util.git
++$ cd aufs2-util.git
++- no particular tag/branch currently.
++
++
++3. Configuration and Compilation
++----------------------------------------
++For aufs2-2.6 tree,
++- enable CONFIG_EXPERIMENTAL and CONFIG_AUFS_FS.
++- set other aufs configurations if necessary.
++
++For aufs2-standalone tree,
++- enable CONFIG_EXPERIMENTAL and CONFIG_AUFS_FS, you can select =m.
++- edit fs/aufs/config.mk and set other aufs configurations if necessary.
++
++And then,
++- build your kernel (or a module) by "make"
++- install it and reboot your system
++- read README in aufs2-util, build and install it
++
++
++4. Usage
++----------------------------------------
++At first, make sure aufs2-util are installed, and please read the aufs
++manual, ./Documentation/filesystems/aufs/aufs.5.
++$ man -l aufs.5
++
++And then,
++$ mkdir /tmp/rw /tmp/aufs
++# mount -t aufs -o br=/tmp/rw:${HOME}=ro none /tmp/aufs
++
++Here is another example. The result is equivalent.
++# mount -t aufs -o br=/tmp/rw:${HOME} none /tmp/aufs
++ Or
++# mount -t aufs -o br:/tmp/rw none /tmp/aufs
++# mount -o remount,append:${HOME} /tmp/aufs
++
++Then, you can see whole tree of your home dir through /tmp/aufs. If
++you modify a file under /tmp/aufs, the one on your home directory is
++not affected, instead the same named file will be newly created under
++/tmp/rw. And all of your modification to a file will be applied to
++the one under /tmp/rw. This is called the file based Copy on Write
++(COW) method.
++Aufs mount options are described in aufs.5.
++
++Additionally, there are some sample usages of aufs which are a
++diskless system with network booting, and LiveCD over NFS.
++See sample dir in CVS tree on SourceForge.
++
++
++5. Contact
++----------------------------------------
++When you have any problems or strange behaviour in aufs, please let me
++know with:
++- /proc/mounts (instead of the output of mount(8))
++- /sys/module/aufs/*
++- /sys/fs/aufs/* (if you have them)
++- /debug/aufs/* (if you have them)
++- linux kernel version
++ if your kernel is not plain, for example modified by distributor,
++ the url where i can download its source is necessary too.
++- aufs version which was printed at loading the module or booting the
++ system, instead of the date you downloaded.
++- configuration (define/undefine CONFIG_AUFS_xxx)
++- kernel configuration or /proc/config.gz (if you have it)
++- behaviour which you think to be incorrect
++- actual operation, reproducible one is better
++- mailto: aufs-users at lists.sourceforge.net
++
++Usually, I don't watch the Public Areas(Bugs, Support Requests, Patches,
++and Feature Requests) on SourceForge. Please join and write to
++aufs-users ML.
++
++
++6. Acknowledgements
++----------------------------------------
++Thanks to everyone who have tried and are using aufs, whoever
++have reported a bug or any feedback.
++
++Especially donors:
++Tomas Matejicek(slax.org) made a donation (much more than once).
++Dai Itasaka made a donation (2007/8).
++Chuck Smith made a donation (2008/4, 10 and 12).
++Henk Schoneveld made a donation (2008/9).
++Chih-Wei Huang, ASUS, CTC donated Eee PC 4G (2008/10).
++Francois Dupoux made a donation (2008/11).
++Bruno Cesar Ribas and Luis Carlos Erpen de Bona, C3SL serves public GIT
++tree (2009/2).
++William Grant made a donation (2009/3).
++
++Thank you very much.
++Donations are always, including future donations, very important and
++helpful for me to keep on developing aufs.
++
++
++7.
++----------------------------------------
++If you are an experienced user, no explanation is needed. Aufs is
++just a linux filesystem.
++
++
++Enjoy!
++
++# Local variables: ;
++# mode: text;
++# End: ;
+diff --git a/Documentation/filesystems/aufs/aufs.5 b/Documentation/filesystems/aufs/aufs.5
+new file mode 100644
+index 0000000..0b9732f
+--- /dev/null
++++ b/Documentation/filesystems/aufs/aufs.5
+@@ -0,0 +1,1681 @@
++.ds AUFS_VERSION aufs2
++.ds AUFS_XINO_FNAME .aufs.xino
++.ds AUFS_XINO_DEFPATH /tmp/.aufs.xino
++.ds AUFS_DIRWH_DEF 3
++.ds AUFS_WH_PFX .wh.
++.ds AUFS_WH_PFX_LEN 4
++.ds AUFS_WKQ_NAME aufsd
++.ds AUFS_NWKQ_DEF 4
++.ds AUFS_WH_DIROPQ .wh..wh..opq
++.ds AUFS_WH_BASE .wh..wh.aufs
++.ds AUFS_WH_PLINKDIR .wh..wh.plnk
++.ds AUFS_BRANCH_MAX 127
++.ds AUFS_MFS_SECOND_DEF 30
++.ds AUFS_RDBLK_DEF 512
++.ds AUFS_RDHASH_DEF 32
++.\".so aufs.tmac
++.
++.eo
++.de TQ
++.br
++.ns
++.TP \$1
++..
++.de Bu
++.IP \(bu 4
++..
++.ec
++.\" end of macro definitions
++.
++.\" ----------------------------------------------------------------------
++.TH aufs 5 \*[AUFS_VERSION] Linux "Linux Aufs User\[aq]s Manual"
++.SH NAME
++aufs \- advanced multi layered unification filesystem. version \*[AUFS_VERSION]
++
++.\" ----------------------------------------------------------------------
++.SH DESCRIPTION
++Aufs is a stackable unification filesystem such as Unionfs, which unifies
++several directories and provides a merged single directory.
++In the early days, aufs was entirely re-designed and re-implemented
++Unionfs Version 1.x series. After
++many original ideas, approaches and improvements, it
++becomes totally different from Unionfs while keeping the basic features.
++See Unionfs Version 1.x series for the basic features.
++Recently, Unionfs Version 2.x series begin taking some of same
++approaches to aufs\[aq]s.
++
++.\" ----------------------------------------------------------------------
++.SH MOUNT OPTIONS
++At mount-time, the order of interpreting options is,
++.RS
++.Bu
++simple flags, except xino/noxino and udba=inotify
++.Bu
++branches
++.Bu
++xino/noxino
++.Bu
++udba=inotify
++.RE
++
++At remount-time,
++the options are interpreted in the given order,
++e.g. left to right.
++.RS
++.Bu
++create or remove
++whiteout-base(\*[AUFS_WH_BASE]) and
++whplink-dir(\*[AUFS_WH_PLINKDIR]) if necessary
++.RE
++.
++.TP
++.B br:BRANCH[:BRANCH ...] (dirs=BRANCH[:BRANCH ...])
++Adds new branches.
++(cf. Branch Syntax).
++
++Aufs rejects the branch which is an ancestor or a descendant of another
++branch. It is called overlapped. When the branch is loopback-mounted
++directory, aufs also checks the source fs-image file of loopback
++device. If the source file is a descendant of another branch, it will
++be rejected too.
++
++After mounting aufs or adding a branch, if you move a branch under
++another branch and make it descendant of another branch, aufs will not
++work correctly.
++.
++.TP
++.B [ add | ins ]:index:BRANCH
++Adds a new branch.
++The index begins with 0.
++Aufs creates
++whiteout-base(\*[AUFS_WH_BASE]) and
++whplink-dir(\*[AUFS_WH_PLINKDIR]) if necessary.
++
++If there is the same named file on the lower branch (larger index),
++aufs will hide the lower file.
++You can only see the highest file.
++You will be confused if the added branch has whiteouts (including
++diropq), they may or may not hide the lower entries.
++.\" It is recommended to make sure that the added branch has no whiteout.
++
++Even if a process have once mapped a file by mmap(2) with MAP_SHARED
++and the same named file exists on the lower branch,
++the process still refers the file on the lower(hidden)
++branch after adding the branch.
++If you want to update the contents of a process address space after
++adding, you need to restart your process or open/mmap the file again.
++.\" Usually, such files are executables or shared libraries.
++(cf. Branch Syntax).
++.
++.TP
++.B del:dir
++Removes a branch.
++Aufs does not remove
++whiteout-base(\*[AUFS_WH_BASE]) and
++whplink-dir(\*[AUFS_WH_PLINKDIR]) automatically.
++For example, when you add a RO branch which was unified as RW, you
++will see whiteout-base or whplink-dir on the added RO branch.
++
++If a process is referencing the file/directory on the deleting branch
++(by open, mmap, current working directory, etc.), aufs will return an
++error EBUSY.
++.
++.TP
++.B mod:BRANCH
++Modifies the permission flags of the branch.
++Aufs creates or removes
++whiteout-base(\*[AUFS_WH_BASE]) and/or
++whplink-dir(\*[AUFS_WH_PLINKDIR]) if necessary.
++
++If the branch permission is been changing \[oq]rw\[cq] to \[oq]ro\[cq], and a process
++is mapping a file by mmap(2)
++.\" with MAP_SHARED
++on the branch, the process may or may not
++be able to modify its mapped memory region after modifying branch
++permission flags.
++(cf. Branch Syntax).
++.
++.TP
++.B append:BRANCH
++equivalent to \[oq]add:(last index + 1):BRANCH\[cq].
++(cf. Branch Syntax).
++.
++.TP
++.B prepend:BRANCH
++equivalent to \[oq]add:0:BRANCH.\[cq]
++(cf. Branch Syntax).
++.
++.TP
++.B xino=filename
++Use external inode number bitmap and translation table.
++When CONFIG_AUFS_EXPORT is enabled, external inode generation table too.
++It is set to
++<FirstWritableBranch>/\*[AUFS_XINO_FNAME] by default, or
++\*[AUFS_XINO_DEFPATH].
++Comma character in filename is not allowed.
++
++The files are created per an aufs and per a branch filesystem, and
++unlinked. So you
++cannot find this file, but it exists and is read/written frequently by
++aufs.
++(cf. External Inode Number Bitmap, Translation Table and Generation Table).
++
++If you enable CONFIG_SYSFS, the path of xino files are not shown in
++/proc/mounts (and /etc/mtab), instead it is shown in
++<sysfs>/fs/aufs/si_<id>/xi_path.
++Otherwise, it is shown in /proc/mounts unless it is not the default
++path.
++.
++.TP
++.B noxino
++Stop using external inode number bitmap and translation table.
++
++If you use this option,
++Some applications will not work correctly.
++.\" And pseudo link feature will not work after the inode cache is
++.\" shrunk.
++(cf. External Inode Number Bitmap, Translation Table and Generation Table).
++.
++.TP
++.B trunc_xib
++Truncate the external inode number bitmap file. The truncation is done
++automatically when you delete a branch unless you do not specify
++\[oq]notrunc_xib\[cq] option.
++(cf. External Inode Number Bitmap, Translation Table and Generation Table).
++.
++.TP
++.B notrunc_xib
++Stop truncating the external inode number bitmap file when you delete
++a branch.
++(cf. External Inode Number Bitmap, Translation Table and Generation Table).
++.
++.TP
++.B create_policy | create=CREATE_POLICY
++.TQ
++.B copyup_policy | copyup | cpup=COPYUP_POLICY
++Policies to select one among multiple writable branches. The default
++values are \[oq]create=tdp\[cq] and \[oq]cpup=tdp\[cq].
++link(2) and rename(2) systemcalls have an exception. In aufs, they
++try keeping their operations in the branch where the source exists.
++(cf. Policies to Select One among Multiple Writable Branches).
++.
++.TP
++.B verbose | v
++Print some information.
++Currently, it is only busy file (or inode) at deleting a branch.
++.
++.TP
++.B noverbose | quiet | q | silent
++Disable \[oq]verbose\[cq] option.
++This is default value.
++.
++.TP
++.B sum
++df(1)/statfs(2) returns the total number of blocks and inodes of
++all branches.
++Note that there are cases that systemcalls may return ENOSPC, even if
++df(1)/statfs(2) shows that aufs has some free space/inode.
++.
++.TP
++.B nosum
++Disable \[oq]sum\[cq] option.
++This is default value.
++.
++.TP
++.B dirwh=N
++Watermark to remove a dir actually at rmdir(2) and rename(2).
++
++If the target dir which is being removed or renamed (destination dir)
++has a huge number of whiteouts, i.e. the dir is empty logically but
++physically, the cost to remove/rename the single
++dir may be very high.
++It is
++required to unlink all of whiteouts internally before issuing
++rmdir/rename to the branch.
++To reduce the cost of single systemcall,
++aufs renames the target dir to a whiteout-ed temporary name and
++invokes a pre-created
++kernel thread to remove whiteout-ed children and the target dir.
++The rmdir/rename systemcall returns just after kicking the thread.
++
++When the number of whiteout-ed children is less than the value of
++dirwh, aufs remove them in a single systemcall instead of passing
++another thread.
++This value is ignored when the branch is NFS.
++The default value is \*[AUFS_DIRWH_DEF].
++.\" .
++.\" .TP
++.\" .B rdcache=N
++.
++.TP
++.B rdblk=N
++Specifies a size of internal VDIR block which is allocated at a time in
++byte.
++The VDIR block will be allocated several times when necessary. If your
++directory has millions of files, you may want to expand this size.
++The default value is defined as \*[AUFS_RDBLK_DEF].
++The size has to be lager than NAME_MAX (usually 255) and kmalloc\-able
++(the maximum limit depends on your system. at least 128KB is available
++for every system).
++(cf. Virtual or Vertical Directory Block).
++.
++.TP
++.B rdhash=N
++Specifies a size of internal VDIR hash table which is used to compare
++the file names under the same named directory on multiple branches.
++The VDIR hash table will be allocated in readdir(3)/getdents(2),
++rmdir(2) and rename(2) for the existing target directory. If your
++directory has millions of files, you may want to expand this size.
++The default value is defined as \*[AUFS_RDHASH_DEF].
++The size has to be lager than zero, and it will be multiplied by 4 or 8
++(for 32\-bit and 64\-bit respectively, currently). The result must be
++kmalloc\-able
++(the maximum limit depends on your system. at least 128KB is available
++for every system).
++(cf. Virtual or Vertical Directory Block).
++.
++.TP
++.B plink
++.TQ
++.B noplink
++Specifies to use \[oq]pseudo link\[cq] feature or not.
++The default is \[oq]plink\[cq] which means use this feature.
++(cf. Pseudo Link)
++.
++.TP
++.B clean_plink
++Removes all pseudo-links in memory.
++In order to make pseudo-link permanent, use
++\[oq]auplink\[cq] utility just before one of these operations,
++unmounting aufs,
++using \[oq]ro\[cq] or \[oq]noplink\[cq] mount option,
++deleting a branch from aufs,
++adding a branch into aufs,
++or changing your writable branch as readonly.
++If you installed both of /sbin/mount.aufs and /sbin/umount.aufs, and your
++mount(8) and umount(8) support them,
++\[oq]auplink\[cq] utility will be executed automatically and flush pseudo-links.
++(cf. Pseudo Link)
++.
++.TP
++.B udba=none | reval | inotify
++Specifies the level of UDBA (User\[aq]s Direct Branch Access) test.
++(cf. User\[aq]s Direct Branch Access and Inotify Limitation).
++.
++.TP
++.B diropq=whiteouted | w | always | a
++Specifies whether mkdir(2) and rename(2) dir case make the created directory
++\[oq]opaque\[cq] or not.
++In other words, to create \[oq]\*[AUFS_WH_DIROPQ]\[cq] under the created or renamed
++directory, or not to create.
++When you specify diropq=w or diropq=whiteouted, aufs will not create
++it if the
++directory was not whiteouted or opaqued. If the directory was whiteouted
++or opaqued, the created or renamed directory will be opaque.
++When you specify diropq=a or diropq==always, aufs will always create
++it regardless
++the directory was whiteouted/opaqued or not.
++The default value is diropq=w, it means not to create when it is unnecessary.
++If you define CONFIG_AUFS_COMPAT at aufs compiling time, the default will be
++diropq=a.
++You need to consider this option if you are planning to add a branch later
++since \[oq]diropq\[cq] affects the same named directory on the added branch.
++.
++.TP
++.B warn_perm
++.TQ
++.B nowarn_perm
++Adding a branch, aufs will issue a warning about uid/gid/permission of
++the adding branch directory,
++when they differ from the existing branch\[aq]s. This difference may or
++may not impose a security risk.
++If you are sure that there is no problem and want to stop the warning,
++use \[oq]nowarn_perm\[cq] option.
++The default is \[oq]warn_perm\[cq] (cf. DIAGNOSTICS).
++
++.\" ----------------------------------------------------------------------
++.SH Module Parameters
++.TP
++.B nwkq=N
++The number of kernel thread named \*[AUFS_WKQ_NAME].
++
++Those threads stay in the system while the aufs module is loaded,
++and handle the special I/O requests from aufs.
++The default value is \*[AUFS_NWKQ_DEF].
++
++The special I/O requests from aufs include a part of copy-up, lookup,
++directory handling, pseudo-link, xino file operations and the
++delegated access to branches.
++For example, Unix filesystems allow you to rmdir(2) which has no write
++permission bit, if its parent directory has write permission bit. In aufs, the
++removing directory may or may not have whiteout or \[oq]dir opaque\[cq] mark as its
++child. And aufs needs to unlink(2) them before rmdir(2).
++Therefore aufs delegates the actual unlink(2) and rmdir(2) to another kernel
++thread which has been created already and has a superuser privilege.
++
++If you enable CONFIG_SYSFS, you can check this value through
++<sysfs>/module/aufs/parameters/nwkq.
++
++.
++.TP
++.B brs=1 | 0
++Specifies to use the branch path data file under sysfs or not.
++
++If the number of your branches is large or their path is long
++and you meet the limitation of mount(8) ro /etc/mtab, you need to
++enable CONFIG_SYSFS and set aufs module parameter brs=1.
++
++When this parameter is set as 1, aufs does not show \[oq]br:\[cq] (or dirs=)
++mount option through /proc/mounts (and /etc/mtab). So you can
++keep yourself from the page limitation of
++mount(8) or /etc/mtab.
++Aufs shows branch paths through <sysfs>/fs/aufs/si_XXX/brNNN.
++Actually the file under sysfs has also a size limitation, but I don\[aq]t
++think it is harmful.
++
++There is one more side effect in setting 1 to this parameter.
++If you rename your branch, the branch path written in /etc/mtab will be
++obsoleted and the future remount will meet some error due to the
++unmatched parameters (Remember that mount(8) may take the options from
++/etc/mtab and pass them to the systemcall).
++If you set 1, /etc/mtab will not hold the branch path and you will not
++meet such trouble. On the other hand, the entires for the
++branch path under sysfs are generated dynamically. So it must not be obsoleted.
++But I don\[aq]t think users want to rename branches so often.
++
++If CONFIG_SYSFS is disable, this paramater is always set to 0.
++.
++.TP
++.B sysrq=key
++Specifies MagicSysRq key for debugging aufs.
++You need to enable both of CONFIG_MAGIC_SYSRQ and CONFIG_AUFS_DEBUG.
++Currently this is for developers only.
++The default is \[oq]a\[cq].
++.
++.TP
++.B debug= 0 | 1
++Specifies disable(0) or enable(1) debug print in aufs.
++This parameter can be changed dynamically.
++You need to enable CONFIG_AUFS_DEBUG.
++Currently this is for developers only.
++The default is \[oq]0\[cq] (disable).
++
++.\" ----------------------------------------------------------------------
++.SH Entries under Sysfs and Debugfs
++See linux/Documentation/ABI/*/{sys,debug}fs-aufs.
++
++.\" ----------------------------------------------------------------------
++.SH Branch Syntax
++.TP
++.B dir_path[ =permission [ + attribute ] ]
++.TQ
++.B permission := rw | ro | rr
++.TQ
++.B attribute := wh | nolwh
++dir_path is a directory path.
++The keyword after \[oq]dir_path=\[cq] is a
++permission flags for that branch.
++Comma, colon and the permission flags string (including \[oq]=\[cq])in the path
++are not allowed.
++
++Any filesystem can be a branch, But some are not accepted such like
++sysfs, procfs and unionfs.
++If you specify such filesystems as an aufs branch, aufs will return an error
++saying it is unsupported.
++
++Cramfs in linux stable release has strange inodes and it makes aufs
++confused. For example,
++.nf
++$ mkdir -p w/d1 w/d2
++$ > w/z1
++$ > w/z2
++$ mkcramfs w cramfs
++$ sudo mount -t cramfs -o ro,loop cramfs /mnt
++$ find /mnt -ls
++ 76 1 drwxr-xr-x 1 jro 232 64 Jan 1 1970 /mnt
++ 1 1 drwxr-xr-x 1 jro 232 0 Jan 1 1970 /mnt/d1
++ 1 1 drwxr-xr-x 1 jro 232 0 Jan 1 1970 /mnt/d2
++ 1 1 -rw-r--r-- 1 jro 232 0 Jan 1 1970 /mnt/z1
++ 1 1 -rw-r--r-- 1 jro 232 0 Jan 1 1970 /mnt/z2
++.fi
++
++All these two directories and two files have the same inode with one
++as their link count. Aufs cannot handle such inode correctly.
++Currently, aufs involves a tiny workaround for such inodes. But some
++applications may not work correctly since aufs inode number for such
++inode will change silently.
++If you do not have any empty files, empty directories or special files,
++inodes on cramfs will be all fine.
++
++A branch should not be shared as the writable branch between multiple
++aufs. A readonly branch can be shared.
++
++The maximum number of branches is configurable at compile time.
++The current value is \*[AUFS_BRANCH_MAX] which depends upon
++configuration.
++
++When an unknown permission or attribute is given, aufs sets ro to that
++branch silently.
++
++.SS Permission
++.
++.TP
++.B rw
++Readable and writable branch. Set as default for the first branch.
++If the branch filesystem is mounted as readonly, you cannot set it \[oq]rw.\[cq]
++.\" A filesystem which does not support link(2) and i_op\->setattr(), for
++.\" example FAT, will not be used as the writable branch.
++.
++.TP
++.B ro
++Readonly branch and it has no whiteouts on it.
++Set as default for all branches except the first one. Aufs never issue
++both of write operation and lookup operation for whiteout to this branch.
++.
++.TP
++.B rr
++Real readonly branch, special case of \[oq]ro\[cq], for natively readonly
++branch. Assuming the branch is natively readonly, aufs can optimize
++some internal operation. For example, if you specify \[oq]udba=inotify\[cq]
++option, aufs does not set inotify for the things on rr branch.
++Set by default for a branch whose fs-type is either \[oq]iso9660\[cq],
++\[oq]cramfs\[cq] or \[oq]romfs\[cq].
++
++When your branch exists on slower device and you have some
++capacity on your hdd, you may want to try ulobdev tool in ULOOP sample.
++It can cache the contents of the real devices on another faster device,
++so you will be able to get the better access performance.
++The ulobdev tool is for a generic block device, and the ulohttp is for a
++filesystem image on http server.
++If you want to spin down your hdd to save the
++battery life or something, then you may want to use ulobdev to save the
++access to the hdd, too.
++See $AufsCVS/sample/uloop in detail.
++
++.SS Attribute
++.
++.TP
++.B wh
++Readonly branch and it has/might have whiteouts on it.
++Aufs never issue write operation to this branch, but lookup for whiteout.
++Use this as \[oq]<branch_dir>=ro+wh\[cq].
++.
++.TP
++.B nolwh
++Usually, aufs creates a whiteout as a hardlink on a writable
++branch. This attributes prohibits aufs to create the hardlinked
++whiteout, including the source file of all hardlinked whiteout
++(\*[AUFS_WH_BASE].)
++If you do not like a hardlink, or your writable branch does not support
++link(2), then use this attribute.
++But I am afraid a filesystem which does not support link(2) natively
++will fail in other place such as copy-up.
++Use this as \[oq]<branch_dir>=rw+nolwh\[cq].
++Also you may want to try \[oq]noplink\[cq] mount option, while it is not recommended.
++
++.\" .SS FUSE as a branch
++.\" A FUSE branch needs special attention.
++.\" The struct fuse_operations has a statfs operation. It is OK, but the
++.\" parameter is struct statvfs* instead of struct statfs*. So almost
++.\" all user\-space implementaion will call statvfs(3)/fstatvfs(3) instead of
++.\" statfs(2)/fstatfs(2).
++.\" In glibc, [f]statvfs(3) issues [f]statfs(2), open(2)/read(2) for
++.\" /proc/mounts,
++.\" and stat(2) for the mountpoint. With this situation, a FUSE branch will
++.\" cause a deadlock in creating something in aufs. Here is a sample
++.\" scenario,
++.\" .\" .RS
++.\" .\" .IN -10
++.\" .Bu
++.\" create/modify a file just under the aufs root dir.
++.\" .Bu
++.\" aufs aquires a write\-lock for the parent directory, ie. the root dir.
++.\" .Bu
++.\" A library function or fuse internal may call statfs for a fuse branch.
++.\" The create=mfs mode in aufs will surely call statfs for each writable
++.\" branches.
++.\" .Bu
++.\" FUSE in kernel\-space converts and redirects the statfs request to the
++.\" user\-space.
++.\" .Bu
++.\" the user\-space statfs handler will call [f]statvfs(3).
++.\" .Bu
++.\" the [f]statvfs(3) in glibc will access /proc/mounts and issue
++.\" stat(2) for the mountpoint. But those require a read\-lock for the aufs
++.\" root directory.
++.\" .Bu
++.\" Then a deadlock occurs.
++.\" .\" .RE 1
++.\" .\" .IN
++.\"
++.\" In order to avoid this deadlock, I would suggest not to call
++.\" [f]statvfs(3) from fuse. Here is a sample code to do this.
++.\" .nf
++.\" struct statvfs stvfs;
++.\"
++.\" main()
++.\" {
++.\" statvfs(..., &stvfs)
++.\" or
++.\" fstatvfs(..., &stvfs)
++.\" stvfs.f_fsid = 0
++.\" }
++.\"
++.\" statfs_handler(const char *path, struct statvfs *arg)
++.\" {
++.\" struct statfs stfs
++.\"
++.\" memcpy(arg, &stvfs, sizeof(stvfs))
++.\"
++.\" statfs(..., &stfs)
++.\" or
++.\" fstatfs(..., &stfs)
++.\"
++.\" arg->f_bfree = stfs.f_bfree
++.\" arg->f_bavail = stfs.f_bavail
++.\" arg->f_ffree = stfs.f_ffree
++.\" arg->f_favail = /* any value */
++.\" }
++.\" .fi
++
++.\" ----------------------------------------------------------------------
++.SH External Inode Number Bitmap, Translation Table and Generation Table (xino)
++Aufs uses one external bitmap file and one external inode number
++translation table files per an aufs and per a branch
++filesystem by default.
++Additionally when CONFIG_AUFS_EXPORT is enabled, one external inode
++generation table is added.
++The bitmap (and the generation table) is for recycling aufs inode number
++and the others
++are a table for converting an inode number on a branch to
++an aufs inode number. The default path
++is \[oq]first writable branch\[cq]/\*[AUFS_XINO_FNAME].
++If there is no writable branch, the
++default path
++will be \*[AUFS_XINO_DEFPATH].
++.\" A user who executes mount(8) needs the privilege to create xino
++.\" file.
++
++If you enable CONFIG_SYSFS, the path of xino files are not shown in
++/proc/mounts (and /etc/mtab), instead it is shown in
++<sysfs>/fs/aufs/si_<id>/xi_path.
++Otherwise, it is shown in /proc/mounts unless it is not the default
++path.
++
++Those files are always opened and read/write by aufs frequently.
++If your writable branch is on flash memory device, it is recommended
++to put xino files on other than flash memory by specifying \[oq]xino=\[cq]
++mount option.
++
++The
++maximum file size of the bitmap is, basically, the amount of the
++number of all the files on all branches divided by 8 (the number of
++bits in a byte).
++For example, on a 4KB page size system, if you have 32,768 (or
++2,599,968) files in aufs world,
++then the maximum file size of the bitmap is 4KB (or 320KB).
++
++The
++maximum file size of the table will
++be \[oq]max inode number on the branch x size of an inode number\[cq].
++For example in 32bit environment,
++
++.nf
++$ df -i /branch_fs
++/dev/hda14 2599968 203127 2396841 8% /branch_fs
++.fi
++
++and /branch_fs is an branch of the aufs. When the inode number is
++assigned contiguously (without \[oq]hole\[cq]), the maximum xino file size for
++/branch_fs will be 2,599,968 x 4 bytes = about 10 MB. But it might not be
++allocated all of disk blocks.
++When the inode number is assigned discontinuously, the maximum size of
++xino file will be the largest inode number on a branch x 4 bytes.
++Additionally, the file size is limited to LLONG_MAX or the s_maxbytes
++in filesystem\[aq]s superblock (s_maxbytes may be smaller than
++LLONG_MAX). So the
++support-able largest inode number on a branch is less than
++2305843009213693950 (LLONG_MAX/4\-1).
++This is the current limitation of aufs.
++On 64bit environment, this limitation becomes more strict and the
++supported largest inode number is less than LLONG_MAX/8\-1.
++
++The xino files are always hidden, i.e. removed. So you cannot
++do \[oq]ls \-l xino_file\[cq].
++If you enable CONFIG_DEBUG_FS, you can check these information through
++<debugfs>/aufs/<si_id>/{xib,xi[0-9]*,xigen}. xib is for the bitmap file,
++xi0 ix for the first branch, and xi1 is for the next. xigen is for the
++generation table.
++xib and xigen are in the format of,
++
++.nf
++<blocks>x<block size> <file size>
++.fi
++
++Note that a filesystem usually has a
++feature called pre-allocation, which means a number of
++blocks are allocated automatically, and then deallocated
++silently when the filesystem thinks they are unnecessary.
++You do not have to be surprised the sudden changes of the number of
++blocks, when your filesystem which xino files are placed supports the
++pre-allocation feature.
++
++The rests are hidden xino file information in the format of,
++
++.nf
++<file count>, <blocks>x<block size> <file size>
++.fi
++
++If the file count is larger than 1, it means some of your branches are
++on the same filesystem and the xino file is shared by them.
++Note that the file size may not be equal to the actual consuming blocks
++since xino file is a sparse file, i.e. a hole in a file which does not
++consume any disk blocks.
++
++Once you unmount aufs, the xino files for that aufs are totally gone.
++It means that the inode number is not permanent across umount or
++shutdown.
++
++The xino files should be created on the filesystem except NFS.
++If your first writable branch is NFS, you will need to specify xino
++file path other than NFS.
++Also if you are going to remove the branch where xino files exist or
++change the branch permission to readonly, you need to use xino option
++before del/mod the branch.
++
++The bitmap file can be truncated.
++For example, if you delete a branch which has huge number of files,
++many inode numbers will be recycled and the bitmap will be truncated
++to smaller size. Aufs does this automatically when a branch is
++deleted.
++You can truncate it anytime you like if you specify \[oq]trunc_xib\[cq] mount
++option. But when the accessed inode number was not deleted, nothing
++will be truncated.
++If you do not want to truncate it (it may be slow) when you delete a
++branch, specify \[oq]notrunc_xib\[cq] after \[oq]del\[cq] mount option.
++
++If you do not want to use xino, use noxino mount option. Use this
++option with care, since the inode number may be changed silently and
++unexpectedly anytime.
++For example,
++rmdir failure, recursive chmod/chown/etc to a large and deep directory
++or anything else.
++And some applications will not work correctly.
++.\" When the inode number has been changed, your system
++.\" can be crazy.
++If you want to change the xino default path, use xino mount option.
++
++After you add branches, the persistence of inode number may not be
++guaranteed.
++At remount time, cached but unused inodes are discarded.
++And the newly appeared inode may have different inode number at the
++next access time. The inodes in use have the persistent inode number.
++
++When aufs assigned an inode number to a file, and if you create the
++same named file on the upper branch directly, then the next time you
++access the file, aufs may assign another inode number to the file even
++if you use xino option.
++Some applications may treat the file whose inode number has been
++changed as totally different file.
++
++.\" ----------------------------------------------------------------------
++.SH Pseudo Link (hardlink over branches)
++Aufs supports \[oq]pseudo link\[cq] which is a logical hard-link over
++branches (cf. ln(1) and link(2)).
++In other words, a copied-up file by link(2) and a copied-up file which was
++hard-linked on a readonly branch filesystem.
++
++When you have files named fileA and fileB which are
++hardlinked on a readonly branch, if you write something into fileA,
++aufs copies-up fileA to a writable branch, and write(2) the originally
++requested thing to the copied-up fileA. On the writable branch,
++fileA is not hardlinked.
++But aufs remembers it was hardlinked, and handles fileB as if it existed
++on the writable branch, by referencing fileA\[aq]s inode on the writable
++branch as fileB\[aq]s inode.
++
++Once you unmount aufs, the plink info for that aufs kept in memory are totally
++gone.
++It means that the pseudo-link is not permanent.
++If you want to make plink permanent, try \[oq]auplink\[cq] utility just before
++one of these operations,
++unmounting your aufs,
++using \[oq]ro\[cq] or \[oq]noplink\[cq] mount option,
++deleting a branch from aufs,
++adding a branch into aufs,
++or changing your writable branch to readonly.
++
++This utility will reproduces all real hardlinks on a writable branch by linking
++them, and removes pseudo-link info in memory and temporary link on the
++writable branch.
++Since this utility access your branches directly, you cannot hide them by
++\[oq]mount \-\-bind /tmp /branch\[cq] or something.
++
++If you are willing to rebuild your aufs with the same branches later, you
++should use auplink utility before you umount your aufs.
++If you installed both of /sbin/mount.aufs and /sbin/umount.aufs, and your
++mount(8) and umount(8) support them,
++\[oq]auplink\[cq] utility will be executed automatically and flush pseudo-links.
++
++.nf
++# auplink /your/aufs/root flush
++# umount /your/aufs/root
++or
++# auplink /your/aufs/root flush
++# mount -o remount,mod:/your/writable/branch=ro /your/aufs/root
++or
++# auplink /your/aufs/root flush
++# mount -o remount,noplink /your/aufs/root
++or
++# auplink /your/aufs/root flush
++# mount -o remount,del:/your/aufs/branch /your/aufs/root
++or
++# auplink /your/aufs/root flush
++# mount -o remount,append:/your/aufs/branch /your/aufs/root
++.fi
++
++The plinks are kept both in memory and on disk. When they consumes too much
++resources on your system, you can use the \[oq]auplink\[cq] utility at anytime and
++throw away the unnecessary pseudo-links in safe.
++
++Additionally, the \[oq]auplink\[cq] utility is very useful for some security reasons.
++For example, when you have a directory whose permission flags
++are 0700, and a file who is 0644 under the 0700 directory. Usually,
++all files under the 0700 directory are private and no one else can see
++the file. But when the directory is 0711 and someone else knows the 0644
++filename, he can read the file.
++
++Basically, aufs pseudo-link feature creates a temporary link under the
++directory whose owner is root and the permission flags are 0700.
++But when the writable branch is NFS, aufs sets 0711 to the directory.
++When the 0644 file is pseudo-linked, the temporary link, of course the
++contents of the file is totally equivalent, will be created under the
++0711 directory. The filename will be generated by its inode number.
++While it is hard to know the generated filename, someone else may try peeping
++the temporary pseudo-linked file by his software tool which may try the name
++from one to MAX_INT or something.
++In this case, the 0644 file will be read unexpectedly.
++I am afraid that leaving the temporary pseudo-links can be a security hole.
++It makes sense to execute \[oq]auplink /your/aufs/root flush\[cq]
++periodically, when your writable branch is NFS.
++
++When your writable branch is not NFS, or all users are careful enough to set 0600
++to their private files, you do not have to worry about this issue.
++
++If you do not want this feature, use \[oq]noplink\[cq] mount option.
++
++.SS The behaviours of plink and noplink
++This sample shows that the \[oq]f_src_linked2\[cq] with \[oq]noplink\[cq] option cannot follow
++the link.
++
++.nf
++none on /dev/shm/u type aufs (rw,xino=/dev/shm/rw/.aufs.xino,br:/dev/shm/rw=rw:/dev/shm/ro=ro)
++$ ls -li ../r?/f_src_linked* ./f_src_linked* ./copied
++ls: ./copied: No such file or directory
++15 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked
++15 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked2
++22 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ./f_src_linked
++22 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ./f_src_linked2
++$ echo abc >> f_src_linked
++$ cp f_src_linked copied
++$ ls -li ../r?/f_src_linked* ./f_src_linked* ./copied
++15 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked
++15 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked2
++36 -rw-r--r-- 2 jro jro 6 Dec 22 11:03 ../rw/f_src_linked
++53 -rw-r--r-- 1 jro jro 6 Dec 22 11:03 ./copied
++22 -rw-r--r-- 2 jro jro 6 Dec 22 11:03 ./f_src_linked
++22 -rw-r--r-- 2 jro jro 6 Dec 22 11:03 ./f_src_linked2
++$ cmp copied f_src_linked2
++$
++
++none on /dev/shm/u type aufs (rw,xino=/dev/shm/rw/.aufs.xino,noplink,br:/dev/shm/rw=rw:/dev/shm/ro=ro)
++$ ls -li ../r?/f_src_linked* ./f_src_linked* ./copied
++ls: ./copied: No such file or directory
++17 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked
++17 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked2
++23 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ./f_src_linked
++23 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ./f_src_linked2
++$ echo abc >> f_src_linked
++$ cp f_src_linked copied
++$ ls -li ../r?/f_src_linked* ./f_src_linked* ./copied
++17 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked
++17 -rw-r--r-- 2 jro jro 2 Dec 22 11:03 ../ro/f_src_linked2
++36 -rw-r--r-- 1 jro jro 6 Dec 22 11:03 ../rw/f_src_linked
++53 -rw-r--r-- 1 jro jro 6 Dec 22 11:03 ./copied
++23 -rw-r--r-- 2 jro jro 6 Dec 22 11:03 ./f_src_linked
++23 -rw-r--r-- 2 jro jro 6 Dec 22 11:03 ./f_src_linked2
++$ cmp copied f_src_linked2
++cmp: EOF on f_src_linked2
++$
++.fi
++
++.\"
++.\" If you add/del a branch, or link/unlink the pseudo-linked
++.\" file on a branch
++.\" directly, aufs cannot keep the correct link count, but the status of
++.\" \[oq]pseudo-linked.\[cq]
++.\" Those files may or may not keep the file data after you unlink the
++.\" file on the branch directly, especially the case of your branch is
++.\" NFS.
++
++If you add a branch which has fileA or fileB, aufs does not follow the
++pseudo link. The file on the added branch has no relation to the same
++named file(s) on the lower branch(es).
++If you use noxino mount option, pseudo link will not work after the
++kernel shrinks the inode cache.
++
++This feature will not work for squashfs before version 3.2 since its
++inode is tricky.
++When the inode is hardlinked, squashfs inodes has the same inode
++number and correct link count, but the inode memory object is
++different. Squashfs inodes (before v3.2) are generated for each, even
++they are hardlinked.
++
++.\" ----------------------------------------------------------------------
++.SH User\[aq]s Direct Branch Access (UDBA)
++UDBA means a modification to a branch filesystem manually or directly,
++e.g. bypassing aufs.
++While aufs is designed and implemented to be safe after UDBA,
++it can make yourself and your aufs confused. And some information like
++aufs inode will be incorrect.
++For example, if you rename a file on a branch directly, the file on
++aufs may
++or may not be accessible through both of old and new name.
++Because aufs caches various information about the files on
++branches. And the cache still remains after UDBA.
++
++Aufs has a mount option named \[oq]udba\[cq] which specifies the test level at
++access time whether UDBA was happened or not.
++.
++.TP
++.B udba=none
++Aufs trusts the dentry and the inode cache on the system, and never
++test about UDBA. With this option, aufs runs fastest, but it may show
++you incorrect data.
++Additionally, if you often modify a branch
++directly, aufs will not be able to trace the changes of inodes on the
++branch. It can be a cause of wrong behaviour, deadlock or anything else.
++
++It is recommended to use this option only when you are sure that
++nobody access a file on a branch.
++It might be difficult for you to achieve real \[oq]no UDBA\[cq] world when you
++cannot stop your users doing \[oq]find / \-ls\[cq] or something.
++If you really want to forbid all of your users to UDBA, here is a trick
++for it.
++With this trick, users cannot see the
++branches directly and aufs runs with no problem, except \[oq]auplink\[cq] utility.
++But if you are not familiar with aufs, this trick may make
++yourself confused.
++
++.nf
++# d=/tmp/.aufs.hide
++# mkdir $d
++# for i in $branches_you_want_to_hide
++> do
++> mount -n --bind $d $i
++> done
++.fi
++
++When you unmount the aufs, delete/modify the branch by remount, or you
++want to show the hidden branches again, unmount the bound
++/tmp/.aufs.hide.
++
++.nf
++# umount -n $branches_you_want_to_unbound
++.fi
++
++If you use FUSE filesystem as an aufs branch which supports hardlink,
++you should not set this option, since FUSE makes inode objects for
++each hardlinks (at least in linux\-2.6.23). When your FUSE filesystem
++maintains them at link/unlinking, it is equivalent
++to \[oq]direct branch access\[cq] for aufs.
++
++.
++.TP
++.B udba=reval
++Aufs tests only the existence of the file which existed. If
++the existed file was removed on the branch directly, aufs
++discard the cache about the file and
++re-lookup it. So the data will be updated.
++This test is at minimum level to keep the performance and ensure the
++existence of a file.
++This is default and aufs runs still fast.
++
++This rule leads to some unexpected situation, but I hope it is
++harmless. Those are totally depends upon cache. Here are just a few
++examples.
++.
++.RS
++.Bu
++If the file is cached as negative or
++not-existed, aufs does not test it. And the file is still handled as
++negative after a user created the file on a branch directly. If the
++file is not cached, aufs will lookup normally and find the file.
++.
++.Bu
++When the file is cached as positive or existed, and a user created the
++same named file directly on the upper branch. Aufs detects the cached
++inode of the file is still existing and will show you the old (cached)
++file which is on the lower branch.
++.
++.Bu
++When the file is cached as positive or existed, and a user renamed the
++file by rename(2) directly. Aufs detects the inode of the file is
++still existing. You may or may not see both of the old and new files.
++Todo: If aufs also tests the name, we can detect this case.
++.RE
++
++If your outer modification (UDBA) is rare and you can ignore the
++temporary and minor differences between virtual aufs world and real
++branch filesystem, then try this mount option.
++.
++.TP
++.B udba=inotify
++Aufs sets \[oq]inotify\[cq] to all the accessed directories on its branches
++and receives the event about the dir and its children. It consumes
++resources, cpu and memory. And I am afraid that the performance will be
++hurt, but it is most strict test level.
++There are some limitations of linux inotify, see also Inotify
++Limitation.
++So it is recommended to leave udba default option usually, and set it
++to inotify by remount when you need it.
++
++When a user accesses the file which was notified UDBA before, the cached data
++about the file will be discarded and aufs re-lookup it. So the data will
++be updated.
++When an error condition occurs between UDBA and aufs operation, aufs
++will return an error, including EIO.
++To use this option, you need to enable CONFIG_INOTIFY and
++CONFIG_AUFS_UDBA_INOTIFY.
++
++To rename/rmdir a directory on a branch directory may reveal the same named
++directory on the lower branch. Aufs tries re-lookuping the renamed
++directory and the revealed directory and assigning different inode
++number to them. But the inode number including their children can be a
++problem. The inode numbers will be changed silently, and
++aufs may produce a warning. If you rename a directory repeatedly and
++reveal/hide the lower directory, then aufs may confuse their inode
++numbers too. It depends upon the system cache.
++
++When you make a directory in aufs and mount other filesystem on it,
++the directory in aufs cannot be removed expectedly because it is a
++mount point. But the same named directory on the writable branch can
++be removed, if someone wants. It is just an empty directory, instead
++of a mount point.
++Aufs cannot stop such direct rmdir, but produces a warning about it.
++
++If the pseudo-linked file is hardlinked or unlinked on the branch
++directly, its inode link count in aufs may be incorrect. It is
++recommended to flush the psuedo-links by auplink script.
++
++.\" ----------------------------------------------------------------------
++.SH Linux Inotify Limitation
++Unfortunately, current inotify (linux\-2.6.18) has some limitations,
++and aufs must derive it.
++
++.SS IN_ATTRIB, updating atime
++When a file/dir on a branch is accessed directly, the inode atime (access
++time, cf. stat(2)) may or may not be updated. In some cases, inotify
++does not fire this event. So the aufs inode atime may remain old.
++
++.SS IN_ATTRIB, updating nlink
++When the link count of a file on a branch is incremented by link(2)
++directly,
++inotify fires IN_CREATE to the parent
++directory, but IN_ATTRIB to the file. So the aufs inode nlink may
++remain old.
++
++.SS IN_DELETE, removing file on NFS
++When a file on a NFS branch is deleted directly, inotify may or may
++not fire
++IN_DELETE event. It depends upon the status of dentry
++(DCACHE_NFSFS_RENAMED flag).
++In this case, the file on aufs seems still exists. Aufs and any user can see
++the file.
++
++.SS IN_IGNORED, deleted rename target
++When a file/dir on a branch is unlinked by rename(2) directly, inotify
++fires IN_IGNORED which means the inode is deleted. Actually, in some
++cases, the inode survives. For example, the rename target is linked or
++opened. In this case, inotify watch set by aufs is removed by VFS and
++inotify.
++And aufs cannot receive the events anymore. So aufs may show you
++incorrect data about the file/dir.
++
++.\" ----------------------------------------------------------------------
++.SH Virtual or Vertical Directory Block (VDIR)
++In order to provide the merged view of file listing, aufs builds
++internal direcotry block on memory. For readdir, aufs performs readdir()
++internally for each dir on branches, merges their entries with
++eliminating the whiteout\-ed ones, and sets it to the opened file (dir)
++object. So the file object has its entry list until it is closed. The
++entry list will be updated when the file position is zero (by
++rewinddir(3)) and becomes obsoleted.
++
++Some people may call it can be a security hole or invite DoS attack
++since the opened and once readdir\-ed dir (file object) holds its entry
++list and becomes a pressure for system memory. But I would say it is similar
++to files under /proc or /sys. The virtual files in them also holds a
++memory page (generally) while they are opened. When an idea to reduce
++memory for them is introduced, it will be applied to aufs too.
++
++The dynamically allocated memory block for the name of entries has a
++unit of \*[AUFS_RDBLK_DEF] bytes by default.
++During building dir blocks, aufs creates hash list (hashed and divied by
++\*[AUFS_RDHASH_DEF] by default) and judging whether
++the entry is whiteouted by its upper branch or already listed.
++
++These values are suitable for normal environments. But you may have
++millions of files or very long filenames under a single direcotry. For
++such cases, you may need to customize these values by spicifying rdblk=
++and rdhash= aufs mount options.
++
++For instance, there are 97 files under my /bin, and the total name
++length is 597 bytes.
++
++.nf
++$ \\ls -1 /bin | wc
++ 97 97 597
++.fi
++
++Strictly speaking, 97 end\-of\-line codes are
++included. But it is OK since aufs VDIR also stores the name length in 1
++byte. In this case, you do not need to customize the default values. 597 bytes
++filenames will be stored in 2 VDIR memory blocks (597 <
++\*[AUFS_RDBLK_DEF] x 2).
++And 97 filenames are distributed among \*[AUFS_RDHASH_DEF] lists, so one
++list will point 4 names in average. To judge the names is whiteouted or
++not, the number of comparision will be 4. 2 memory allocations
++and 4 comparison costs low (even if the directory is opened for a long
++time). So you do not need to customize.
++
++If your directory has millions of files, the you will need to specify
++rdblk= and rdhash=.
++
++.nf
++$ ls -U /mnt/rotating-rust | wc -l
++1382438
++.fi
++
++In this case, assuming the average length of filenames is 6, in order to
++get better time performance I would
++recommend to set $((128*1024)) or $((64*1024)) for rdblk, and
++$((8*1024)) or $((4*1024)) for rdhash.
++You can change these values of the active aufs mount by "mount -o
++remount".
++
++This customization is not for
++reducing the memory space, but for reducing time for the number of memory
++allocation and the name comparison. The larger value is faster, in
++general. Of course, you will need system memory. This is a generic
++"time\-vs\-space" problem.
++
++.\" ----------------------------------------------------------------------
++.SH Copy On Write, or aufs internal copyup and copydown
++Every stackable filesystem which implements copy\-on\-write supports the
++copyup feature. The feature is to copy a file/dir from the lower branch
++to the upper internally. When you have one readonly branch and one
++upper writable branch, and you append a string to a file which exists on
++the readonly branch, then aufs will copy the file from the readonly
++branch to the writable branch with its directory hierarchy. It means one
++write(2) involves several logical/internal mkdir(2), creat(2), read(2),
++write(2) and close(2) systemcalls
++before the actual expected write(2) is performed. Sometimes it may take
++a long time, particulary when the file is very large.
++If CONFIG_AUFS_DEBUG is enabled, aufs produces a message saying \[oq]copying
++a large file.\[cq]
++
++You may see the message when you change the xino file path or
++truncate the xino/xib files. Sometimes those files can be large and may
++take a long time to handle them.
++
++.\" ----------------------------------------------------------------------
++.SH Policies to Select One among Multiple Writable Branches
++Aufs has some policies to select one among multiple writable branches
++when you are going to write/modify something. There are two kinds of
++policies, one is for newly create something and the other is for
++internal copy-up.
++You can select them by specifying mount option \[oq]create=CREATE_POLICY\[cq]
++or \[oq]cpup=COPYUP_POLICY.\[cq]
++These policies have no meaning when you have only one writable
++branch. If there is some meaning, it must hurt the performance.
++
++.SS Exceptions for Policies
++In every cases below, even if the policy says that the branch where a
++new file should be created is /rw2, the file will be created on /rw1.
++.
++.Bu
++If there is a readonly branch with \[oq]wh\[cq] attribute above the
++policy-selected branch and the parent dir is marked as opaque,
++or the target (creating) file is whiteouted on the ro+wh branch, then
++the policy will be ignored and the target file will be created on the
++nearest upper writable branch than the ro+wh branch.
++.RS
++.nf
++/aufs = /rw1 + /ro+wh/diropq + /rw2
++/aufs = /rw1 + /ro+wh/wh.tgt + /rw2
++.fi
++.RE
++.
++.Bu
++If there is a writable branch above the policy-selected branch and the
++parent dir is marked as opaque or the target file is whiteouted on the
++branch, then the policy will be ignored and the target file will be
++created on the highest one among the upper writable branches who has
++diropq or whiteout. In case of whiteout, aufs removes it as usual.
++.RS
++.nf
++/aufs = /rw1/diropq + /rw2
++/aufs = /rw1/wh.tgt + /rw2
++.fi
++.RE
++.
++.Bu
++link(2) and rename(2) systemcalls are exceptions in every policy.
++They try selecting the branch where the source exists as possible since
++copyup a large file will take long time. If it can\[aq]t be, ie. the
++branch where the source exists is readonly, then they will follow the
++copyup policy.
++.
++.Bu
++There is an exception for rename(2) when the target exists.
++If the rename target exists, aufs compares the index of the branches
++where the source and the target are existing and selects the higher
++one. If the selected branch is readonly, then aufs follows the copyup
++policy.
++
++.SS Policies for Creating
++.
++.TP
++.B create=tdp | top\-down\-parent
++Selects the highest writable branch where the parent dir exists. If
++the parent dir does not exist on a writable branch, then the internal
++copyup will happen. The policy for this copyup is always \[oq]bottom-up.\[cq]
++This is the default policy.
++.
++.TP
++.B create=rr | round\-robin
++Selects a writable branch in round robin. When you have two writable
++branches and creates 10 new files, 5 files will be created for each
++branch.
++mkdir(2) systemcall is an exception. When you create 10 new directories,
++all are created on the same branch.
++.
++.TP
++.B create=mfs[:second] | most\-free\-space[:second]
++Selects a writable branch which has most free space. In order to keep
++the performance, you can specify the duration (\[oq]second\[cq]) which makes
++aufs hold the index of last selected writable branch until the
++specified seconds expires. The first time you create something in aufs
++after the specified seconds expired, aufs checks the amount of free
++space of all writable branches by internal statfs call
++and the held branch index will be updated.
++The default value is \*[AUFS_MFS_SECOND_DEF] seconds.
++.
++.TP
++.B create=mfsrr:low[:second]
++Selects a writable branch in most-free-space mode first, and then
++round-robin mode. If the selected branch has less free space than the
++specified value \[oq]low\[cq] in bytes, then aufs re-tries in round-robin mode.
++.\" \[oq]G\[cq], \[oq]M\[cq] and \[oq]K\[cq] (case insensitive) can be followed after \[oq]low.\[cq] Or
++Try an arithmetic expansion of shell which is defined by POSIX.
++For example, $((10 * 1024 * 1024)) for 10M.
++You can also specify the duration (\[oq]second\[cq]) which is equivalent to
++the \[oq]mfs\[cq] mode.
++.
++.TP
++.B create=pmfs[:second]
++Selects a writable branch where the parent dir exists, such as tdp
++mode. When the parent dir exists on multiple writable branches, aufs
++selects the one which has most free space, such as mfs mode.
++
++.SS Policies for Copy-Up
++.
++.TP
++.B cpup=tdp | top\-down\-parent
++Equivalent to the same named policy for create.
++This is the default policy.
++.
++.TP
++.B cpup=bup | bottom\-up\-parent
++Selects the writable branch where the parent dir exists and the branch
++is nearest upper one from the copyup-source.
++.
++.TP
++.B cpup=bu | bottom\-up
++Selects the nearest upper writable branch from the copyup-source,
++regardless the existence of the parent dir.
++
++.\" ----------------------------------------------------------------------
++.SH Exporting Aufs via NFS
++Aufs is supporting NFS-exporting.
++Since aufs has no actual block device, you need to add NFS \[oq]fsid\[cq] option at
++exporting. Refer to the manual of NFS about the detail of this option.
++
++There are some limitations or requirements.
++.RS
++.Bu
++The branch filesystem must support NFS-exporting.
++.Bu
++NFSv2 is not supported. When you mount the exported aufs from your NFS
++client, you will need to some NFS options like v3 or nfsvers=3,
++especially if it is nfsroot.
++.Bu
++If the size of the NFS file handle on your branch filesystem is large,
++aufs will
++not be able to handle it. The maximum size of NFSv3 file
++handle for a filesystem is 64 bytes. Aufs uses 24 bytes for 32bit
++system, plus 12 bytes for 64bit system. The rest is a room for a file
++handle of a branch filesystem.
++.Bu
++The External Inode Number Bitmap, Translation Table and Generation Table
++(xino) is
++required since NFS file
++handle is based upon inode number. The mount option \[oq]xino\[cq] is enabled
++by default.
++The external inode generation table and its debugfs entry
++(<debugfs>/aufs/si_*/xigen) is created when CONFIG_AUFS_EXPORT is
++enabled even if you don\[aq]t export aufs actually.
++The size of the external inode generation table grows only, never be
++truncated. You might need to pay attention to the free space of the
++filesystem where xino files are placed. By default, it is the first
++writable branch.
++.Bu
++The branch filesystems must be accessible, which means \[oq]not hidden.\[cq]
++It means you need to \[oq]mount \-\-move\[cq] when you use initramfs and
++switch_root(8), or chroot(8).
++.RE
++
++.\" ----------------------------------------------------------------------
++.SH Dentry and Inode Caches
++If you want to clear caches on your system, there are several tricks
++for that. If your system ram is low,
++try \[oq]find /large/dir \-ls > /dev/null\[cq].
++It will read many inodes and dentries and cache them. Then old caches will be
++discarded.
++But when you have large ram or you do not have such large
++directory, it is not effective.
++
++If you want to discard cache within a certain filesystem,
++try \[oq]mount \-o remount /your/mntpnt\[cq]. Some filesystem may return an error of
++EINVAL or something, but VFS discards the unused dentry/inode caches on the
++specified filesystem.
++
++.\" ----------------------------------------------------------------------
++.SH Compatible/Incompatible with Unionfs Version 1.x Series
++If you compile aufs with \-DCONFIG_AUFS_COMPAT, dirs= option and =nfsro
++branch permission flag are available. They are interpreted as
++br: option and =ro flags respectively.
++ \[oq]debug\[cq], \[oq]delete\[cq], \[oq]imap\[cq] options are ignored silently. When you
++compile aufs without \-DCONFIG_AUFS_COMPAT, these three options are
++also ignored, but a warning message is issued.
++
++Ignoring \[oq]delete\[cq] option, and to keep filesystem consistency, aufs tries
++writing something to only one branch in a single systemcall. It means
++aufs may copyup even if the copyup-src branch is specified as writable.
++For example, you have two writable branches and a large regular file
++on the lower writable branch. When you issue rename(2) to the file on aufs,
++aufs may copyup it to the upper writable branch.
++If this behaviour is not what you want, then you should rename(2) it
++on the lower branch directly.
++
++And there is a simple shell
++script \[oq]unionctl\[cq] under sample subdirectory, which is compatible with
++unionctl(8) in
++Unionfs Version 1.x series, except \-\-query action.
++This script executes mount(8) with \[oq]remount\[cq] option and uses
++add/del/mod aufs mount options.
++If you are familiar with Unionfs Version 1.x series and want to use unionctl(8), you can
++try this script instead of using mount \-o remount,... directly.
++Aufs does not support ioctl(2) interface.
++This script is highly depending upon mount(8) in
++util\-linux\-2.12p package, and you need to mount /proc to use this script.
++If your mount(8) version differs, you can try modifying this
++script. It is very easy.
++The unionctl script is just for a sample usage of aufs remount
++interface.
++
++Aufs uses the external inode number bitmap and translation table by
++default.
++
++The default branch permission for the first branch is \[oq]rw\[cq], and the
++rest is \[oq]ro.\[cq]
++
++The whiteout is for hiding files on lower branches. Also it is applied
++to stop readdir going lower branches.
++The latter case is called \[oq]opaque directory.\[cq] Any
++whiteout is an empty file, it means whiteout is just an mark.
++In the case of hiding lower files, the name of whiteout is
++\[oq]\*[AUFS_WH_PFX]<filename>.\[cq]
++And in the case of stopping readdir, the name is
++\[oq]\*[AUFS_WH_PFX]\*[AUFS_WH_PFX].opq\[cq] or
++\[oq]\*[AUFS_WH_PFX]__dir_opaque.\[cq] The name depends upon your compile
++configuration
++CONFIG_AUFS_COMPAT.
++.\" All of newly created or renamed directory will be opaque.
++All whiteouts are hardlinked,
++including \[oq]<writable branch top dir>/\*[AUFS_WH_BASE].\[cq]
++
++The hardlink on an ordinary (disk based) filesystem does not
++consume inode resource newly. But in linux tmpfs, the number of free
++inodes will be decremented by link(2). It is recommended to specify
++nr_inodes option to your tmpfs if you meet ENOSPC. Use this option
++after checking by \[oq]df \-i.\[cq]
++
++When you rmdir or rename-to the dir who has a number of whiteouts,
++aufs rename the dir to the temporary whiteouted-name like
++\[oq]\*[AUFS_WH_PFX]<dir>.<random hex>.\[cq] Then remove it after actual operation.
++cf. mount option \[oq]dirwh.\[cq]
++
++.\" ----------------------------------------------------------------------
++.SH Incompatible with an Ordinary Filesystem
++stat(2) returns the inode info from the first existence inode among
++the branches, except the directory link count.
++Aufs computes the directory link count larger than the exact value usually, in
++order to keep UNIX filesystem semantics, or in order to shut find(1) mouth up.
++The size of a directory may be wrong too, but it has to do no harm.
++The timestamp of a directory will not be updated when a file is
++created or removed under it, and it was done on a lower branch.
++
++The test for permission bits has two cases. One is for a directory,
++and the other is for a non-directory. In the case of a directory, aufs
++checks the permission bits of all existing directories. It means you
++need the correct privilege for the directories including the lower
++branches.
++The test for a non-directory is more simple. It checks only the
++topmost inode.
++
++statfs(2) returns the information of the first branch info except
++namelen when \[oq]nosum\[cq] is specified (the default). The namelen is
++decreased by the whiteout prefix length. And the block size may differ
++from st_blksize which is obtained by stat(2).
++
++Remember, seekdir(3) and telldir(3) are not defined in POSIX. They may
++not work as you expect. Try rewinddir(3) or re-open the dir.
++
++The whiteout prefix (\*[AUFS_WH_PFX]) is reserved on all branches. Users should
++not handle the filename begins with this prefix.
++In order to future whiteout, the maxmum filename length is limited by
++the longest value \- \*[AUFS_WH_PFX_LEN]. It may be a violation of POSIX.
++
++If you dislike the difference between the aufs entries in /etc/mtab
++and /proc/mounts, and if you are using mount(8) in util\-linux package,
++then try ./mount.aufs utility. Copy the script to /sbin/mount.aufs.
++This simple utility tries updating
++/etc/mtab. If you do not care about /etc/mtab, you can ignore this
++utility.
++Remember this utility is highly depending upon mount(8) in
++util\-linux\-2.12p package, and you need to mount /proc.
++
++Since aufs uses its own inode and dentry, your system may cache huge
++number of inodes and dentries. It can be as twice as all of the files
++in your union.
++It means that unmounting or remounting readonly at shutdown time may
++take a long time, since mount(2) in VFS tries freeing all of the cache
++on the target filesystem.
++
++When you open a directory, aufs will open several directories
++internally.
++It means you may reach the limit of the number of file descriptor.
++And when the lower directory cannot be opened, aufs will close all the
++opened upper directories and return an error.
++
++The sub-mount under the branch
++of local filesystem
++is ignored.
++For example, if you have mount another filesystem on
++/branch/another/mntpnt, the files under \[oq]mntpnt\[cq] will be ignored by aufs.
++It is recommended to mount the sub-mount under the mounted aufs.
++For example,
++
++.nf
++# sudo mount /dev/sdaXX /ro_branch
++# d=another/mntpnt
++# sudo mount /dev/sdbXX /ro_branch/$d
++# mkdir -p /rw_branch/$d
++# sudo mount -t aufs -o br:/rw_branch:/ro_branch none /aufs
++# sudo mount -t aufs -o br:/rw_branch/${d}:/ro_branch/${d} none /aufs/another/$d
++.fi
++
++There are several characters which are not allowed to use in a branch
++directory path and xino filename. See detail in Branch Syntax and Mount
++Option.
++
++The file-lock which means fcntl(2) with F_SETLK, F_SETLKW or F_GETLK, flock(2)
++and lockf(3), is applied to virtual aufs file only, not to the file on a
++branch. It means you can break the lock by accessing a branch directly.
++TODO: check \[oq]security\[cq] to hook locks, as inotify does.
++
++The I/O to the named pipe or local socket are not handled by aufs, even
++if it exists in aufs. After the reader and the writer established their
++connection if the pipe/socket are copied-up, they keep using the old one
++instead of the copied-up one.
++
++The fsync(2) and fdatasync(2) systemcalls return 0 which means success, even
++if the given file descriptor is not opened for writing.
++I am afraid this behaviour may violate some standards. Checking the
++behaviour of fsync(2) on ext2, aufs decided to return success.
++
++If you want to use disk-quota, you should set it up to your writable
++branch since aufs does not have its own block device.
++
++When your aufs is the root directory of your system, and your system
++tells you some of the filesystem were not unmounted cleanly, try these
++procedure when you shutdown your system.
++.nf
++# mount -no remount,ro /
++# for i in $writable_branches
++# do mount -no remount,ro $i
++# done
++.fi
++If your xino file is on a hard drive, you also need to specify
++\[oq]noxino\[cq] option or \[oq]xino=/your/tmpfs/xino\[cq] at remounting root
++directory.
++
++To rename(2) directory may return EXDEV even if both of src and tgt
++are on the same aufs. When the rename-src dir exists on multiple
++branches and the lower dir has child(ren), aufs has to copyup all his
++children. It can be recursive copyup. Current aufs does not support
++such huge copyup operation at one time in kernel space, instead
++produces a warning and returns EXDEV.
++Generally, mv(1) detects this error and tries mkdir(2) and
++rename(2) or copy/unlink recursively. So the result is harmless.
++If your application which issues rename(2) for a directory does not
++support EXDEV, it will not work on aufs.
++Also this specification is applied to the case when the src directroy
++exists on the lower readonly branch and it has child(ren).
++
++If a sudden accident such like a power failure happens during aufs is
++performing, and regular fsck for branch filesystems is completed after
++the disaster, you need to extra fsck for aufs writable branches. It is
++necessary to check whether the whiteout remains incorrectly or not,
++eg. the real filename and the whiteout for it under the same parent
++directory. If such whiteout remains, aufs cannot handle the file
++correctly.
++To check the consistency from the aufs\[aq] point of view, you can use a
++simple shell script called /sbin/auchk. Its purpose is a fsck tool for
++aufs, and it checks the illegal whiteout, the remained
++pseudo-links and the remained aufs-temp files. If they are found, the
++utility reports you and asks whether to delete or not.
++It is recommended to execute /sbin/auchk for every writable branch
++filesystem before mouting aufs if the system experienced crash.
++
++
++.\" ----------------------------------------------------------------------
++.SH EXAMPLES
++The mount options are interpreted from left to right at remount-time.
++These examples
++shows how the options are handled. (assuming /sbin/mount.aufs was
++installed)
++
++.nf
++# mount -v -t aufs br:/day0:/base none /u
++none on /u type aufs (rw,xino=/day0/.aufs.xino,br:/day0=rw:/base=ro)
++# mount -v -o remount,\\
++ prepend:/day1,\\
++ xino=/day1/xino,\\
++ mod:/day0=ro,\\
++ del:/day0 \\
++ /u
++none on /u type aufs (rw,xino=/day1/xino,br:/day1=rw:/base=ro)
++.fi
++
++.nf
++# mount -t aufs br:/rw none /u
++# mount -o remount,append:/ro /u
++different uid/gid/permission, /ro
++# mount -o remount,del:/ro /u
++# mount -o remount,nowarn_perm,append:/ro /u
++#
++(there is no warning)
++.fi
++
++.\" If you want to expand your filesystem size, aufs may help you by
++.\" adding an writable branch. Since aufs supports multiple writable
++.\" branches, the old writable branch can be being writable, if you want.
++.\" In this example, any modifications to the files under /ro branch will
++.\" be copied-up to /new, but modifications to the files under /rw branch
++.\" will not.
++.\" And the next example shows the modifications to the files under /rw branch
++.\" will be copied-up to /new/a.
++.\"
++.\" Todo: test multiple writable branches policy. cpup=nearest, cpup=exist_parent.
++.\"
++.\" .nf
++.\" # mount -v -t aufs br:/rw:/ro none /u
++.\" none on /u type aufs (rw,xino=/rw/.aufs.xino,br:/rw=rw:/ro=ro)
++.\" # mkfs /new
++.\" # mount -v -o remount,add:1:/new=rw /u
++.\" none on /u type aufs (rw,xino=/rw/.aufs.xino,br:/rw=rw:/new=rw:/ro=ro)
++.\" .fi
++.\"
++.\" .nf
++.\" # mount -v -t aufs br:/rw:/ro none /u
++.\" none on /u type aufs (rw,xino=/rw/.aufs.xino,br:/rw=rw:/ro=ro)
++.\" # mkfs /new
++.\" # mkdir /new/a new/b
++.\" # mount -v -o remount,add:1:/new/b=rw,prepend:/new/a,mod:/rw=ro /u
++.\" none on /u type aufs (rw,xino=/rw/.aufs.xino,br:/new/a=rw:/rw=ro:/new/b=rw:/ro=ro)
++.\" .fi
++
++When you use aufs as root filesystem, it is recommended to consider to
++exclude some directories. For example, /tmp and /var/log are not need
++to stack in many cases. They do not usually need to copyup or to whiteout.
++Also the swapfile on aufs (a regular file, not a block device) is not
++supported.
++In order to exclude the specific dir from aufs, try bind mounting.
++
++And there is a good sample which is for network booted diskless machines. See
++sample/ in detail.
++
++.\" ----------------------------------------------------------------------
++.SH DIAGNOSTICS
++When you add a branch to your union, aufs may warn you about the
++privilege or security of the branch, which is the permission bits,
++owner and group of the top directory of the branch.
++For example, when your upper writable branch has a world writable top
++directory,
++a malicious user can create any files on the writable branch directly,
++like copyup and modify manually. I am afraid it can be a security
++issue.
++
++When you mount or remount your union without \-o ro common mount option
++and without writable branch, aufs will warn you that the first branch
++should be writable.
++
++.\" It is discouraged to set both of \[oq]udba\[cq] and \[oq]noxino\[cq] mount options. In
++.\" this case the inode number under aufs will always be changed and may
++.\" reach the end of inode number which is a maximum of unsigned long. If
++.\" the inode number reaches the end, aufs will return EIO repeatedly.
++
++When you set udba other than inotify and change something on your
++branch filesystem directly, later aufs may detect some mismatches to
++its cache. If it is a critical mismatch, aufs returns EIO.
++
++When an error occurs in aufs, aufs prints the kernel message with
++\[oq]errno.\[cq] The priority of the message (log level) is ERR or WARNING which
++depends upon the message itself.
++You can convert the \[oq]errno\[cq] into the error message by perror(3),
++strerror(3) or something.
++For example, the \[oq]errno\[cq] in the message \[oq]I/O Error, write failed (\-28)\[cq]
++is 28 which means ENOSPC or \[oq]No space left on device.\[cq]
++
++When CONFIG_AUFS_BR_RAMFS is enabled, you can specify ramfs as an aufs
++branch. Since ramfs is simple, it does not set the maximum link count
++originally. In aufs, it is very dangerous, particulary for
++whiteouts. Finally aufs sets the maxmimum link count for ramfs. Tha
++value is 32000 which is borrowed from ext2.
++
++
++.\" .SH Current Limitation
++.
++.\" ----------------------------------------------------------------------
++.\" SYNOPSIS
++.\" briefly describes the command or function\[aq]s interface. For commands, this
++.\" shows the syntax of the command and its arguments (including options); bold-
++.\" face is used for as-is text and italics are used to indicate replaceable
++.\" arguments. Brackets ([]) surround optional arguments, vertical bars (|) sep-
++.\" arate choices, and ellipses (...) can be repeated. For functions, it shows
++.\" any required data declarations or #include directives, followed by the func-
++.\" tion declaration.
++.
++.\" DESCRIPTION
++.\" gives an explanation of what the command, function, or format does. Discuss
++.\" how it interacts with files and standard input, and what it produces on
++.\" standard output or standard error. Omit internals and implementation
++.\" details unless they\[aq]re critical for understanding the interface. Describe
++.\" the usual case; for information on options use the OPTIONS section. If
++.\" there is some kind of input grammar or complex set of subcommands, consider
++.\" describing them in a separate USAGE section (and just place an overview in
++.\" the DESCRIPTION section).
++.
++.\" RETURN VALUE
++.\" gives a list of the values the library routine will return to the caller and
++.\" the conditions that cause these values to be returned.
++.
++.\" EXIT STATUS
++.\" lists the possible exit status values or a program and the conditions that
++.\" cause these values to be returned.
++.
++.\" USAGE
++.\" describes the grammar of any sublanguage this implements.
++.
++.\" FILES
++.\" lists the files the program or function uses, such as configuration files,
++.\" startup files, and files the program directly operates on. Give the full
++.\" pathname of these files, and use the installation process to modify the
++.\" directory part to match user preferences. For many programs, the default
++.\" installation location is in /usr/local, so your base manual page should use
++.\" /usr/local as the base.
++.
++.\" ENVIRONMENT
++.\" lists all environment variables that affect your program or function and how
++.\" they affect it.
++.
++.\" SECURITY
++.\" discusses security issues and implications. Warn about configurations or
++.\" environments that should be avoided, commands that may have security impli-
++.\" cations, and so on, especially if they aren\[aq]t obvious. Discussing security
++.\" in a separate section isn\[aq]t necessary; if it\[aq]s easier to understand, place
++.\" security information in the other sections (such as the DESCRIPTION or USAGE
++.\" section). However, please include security information somewhere!
++.
++.\" CONFORMING TO
++.\" describes any standards or conventions this implements.
++.
++.\" NOTES
++.\" provides miscellaneous notes.
++.
++.\" BUGS
++.\" lists limitations, known defects or inconveniences, and other questionable
++.\" activities.
++
++.SH COPYRIGHT
++Copyright \(co 2005\-2009 Junjiro R. Okajima
++
++.SH AUTHOR
++Junjiro R. Okajima
++
++.\" SEE ALSO
++.\" lists related man pages in alphabetical order, possibly followed by other
++.\" related pages or documents. Conventionally this is the last section.
+diff --git a/Documentation/filesystems/aufs/design/01intro.txt b/Documentation/filesystems/aufs/design/01intro.txt
+new file mode 100644
+index 0000000..4955fdc
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/01intro.txt
+@@ -0,0 +1,128 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++Introduction
++----------------------------------------
++
++aufs [ei ju: ef es] | [a u f s]
++1. abbrev. for "advanced multi-layered unification filesystem".
++2. abbrev. for "another unionfs".
++3. abbrev. for "auf das" in German which means "on the" in English.
++ Ex. "Butter aufs Brot"(G) means "butter onto bread"(E).
++ But "Filesystem aufs Filesystem" is hard to understand.
++
++AUFS is a filesystem with features:
++- multi layered stackable unification filesystem, the member directory
++ is called as a branch.
++- branch permission and attribute, 'readonly', 'real-readonly',
++ 'readwrite', 'whiteout-able', 'link-able whiteout' and their
++ combination.
++- internal "file copy-on-write".
++- logical deletion, whiteout.
++- dynamic branch manipulation, adding, deleting and changing permission.
++- allow bypassing aufs, user's direct branch access.
++- external inode number translation table and bitmap which maintains the
++ persistent aufs inode number.
++- seekable directory, including NFS readdir.
++- file mapping, mmap and sharing pages.
++- pseudo-link, hardlink over branches.
++- loopback mounted filesystem as a branch.
++- several policies to select one among multiple writable branches.
++- revert a single systemcall when an error occurs in aufs.
++- and more...
++
++
++Multi Layered Stackable Unification Filesystem
++----------------------------------------------------------------------
++Most people already knows what it is.
++It is a filesystem which unifies several directories and provides a
++merged single directory. When users access a file, the access will be
++passed/re-directed/converted (sorry, I am not sure which English word is
++correct) to the real file on the member filesystem. The member
++filesystem is called 'lower filesystem' or 'branch' and has a mode
++'readonly' and 'readwrite.' And the deletion for a file on the lower
++readonly branch is handled by creating 'whiteout' on the upper writable
++branch.
++
++On LKML, there have been discussions about UnionMount (Jan Blunck and
++Bharata B Rao) and Unionfs (Erez Zadok). They took different approaches
++to implement the merged-view.
++The former tries putting it into VFS, and the latter implements as a
++separate filesystem.
++(If I misunderstand about these implementations, please let me know and
++I shall correct it. Because it is a long time ago when I read their
++source files last time).
++UnionMount's approach will be able to small, but may be hard to share
++branches between several UnionMount since the whiteout in it is
++implemented in the inode on branch filesystem and always
++shared. According to Bharata's post, readdir does not seems to be
++finished yet.
++Unionfs has a longer history. When I started implementing a stacking filesystem
++(Aug 2005), it already existed. It has virtual super_block, inode,
++dentry and file objects and they have an array pointing lower same kind
++objects. After contributing many patches for Unionfs, I re-started my
++project AUFS (Jun 2006).
++
++In AUFS, the structure of filesystem resembles to Unionfs, but I
++implemented my own ideas, approaches and enhancements and it became
++totally different one.
++
++
++Several characters/aspects of aufs
++----------------------------------------------------------------------
++
++Aufs has several characters or aspects.
++1. a filesystem, callee of VFS helper
++2. sub-VFS, caller of VFS helper for branches
++3. a virtual filesystem which maintains persistent inode number
++4. reader/writer of files on branches such like an application
++
++1. Caller of VFS Helper
++As an ordinary linux filesystem, aufs is a callee of VFS. For instance,
++unlink(2) from an application reaches sys_unlink() kernel function and
++then vfs_unlink() is called. vfs_unlink() is one of VFS helper and it
++calls filesystem specific unlink operation. Actually aufs implements the
++unlink operation but it behaves like a redirector.
++
++2. Caller of VFS Helper for Branches
++aufs_unlink() passes the unlink request to the branch filesystem as if
++it were called from VFS. So the called unlink operation of the branch
++filesystem acts as usual. As a caller of VFS helper, aufs should handle
++every necessary pre/post operation for the branch filesystem.
++- acquire the lock for the parent dir on a branch
++- lookup in a branch
++- revalidate dentry on a branch
++- mnt_want_write() for a branch
++- vfs_unlink() for a branch
++- mnt_drop_write() for a branch
++- release the lock on a branch
++
++3. Persistent Inode Number
++One of the most important issue for a filesystem is to maintain inode
++numbers. This is particularly important to support exporting a
++filesystem via NFS. Aufs is a virtual filesystem which doesn't have a
++backend block device for its own. But some storage is necessary to
++maintain inode number. It may be a large space and may not suit to keep
++in memory. Aufs rents some space from its first writable branch
++filesystem (by default) and creates file(s) on it. These files are
++created by aufs internally and removed soon (currently) keeping opened.
++Note: Because these files are removed, they are totally gone after
++ unmounting aufs. It means the inode numbers are not persistent
++ across unmount or reboot. I have a plan to make them really
++ persistent which will be important for aufs on NFS server.
++
++4. Read/Write Files Internally (copy-on-write)
++Because a branch can be readonly, when you write a file on it, aufs will
++"copy-up" it to the upper writable branch internally. And then write the
++originally requested thing to the file. Generally kernel doesn't
++open/read/write file actively. In aufs, even a single write may cause a
++internal "file copy". This behaviour is very similar to cp(1) command.
++
++Some people may think it is better to pass such work to user space
++helper, instead of doing in kernel space. Actually I am still thinking
++about it. But currently I have implemented it in kernel space.
+diff --git a/Documentation/filesystems/aufs/design/02struct.txt b/Documentation/filesystems/aufs/design/02struct.txt
+new file mode 100644
+index 0000000..6db666b
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/02struct.txt
+@@ -0,0 +1,205 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++Basic Aufs Internal Structure
++
++Superblock/Inode/Dentry/File Objects
++----------------------------------------------------------------------
++As like an ordinary filesystem, aufs has its own
++superblock/inode/dentry/file objects. All these objects have a
++dynamically allocated array and store the same kind of pointers to the
++lower filesystem, branch.
++For example, when you build a union with one readwrite branch and one
++readonly, mounted /au, /rw and /ro respectively.
++- /au = /rw + /ro
++- /ro/fileA exists but /rw/fileA
++
++Aufs lookup operation finds /ro/fileA and gets dentry for that. These
++pointers are stored in a aufs dentry. The array in aufs dentry will be,
++- [0] = NULL
++- [1] = /ro/fileA
++
++This style of an array is essentially same to the aufs
++superblock/inode/dentry/file objects.
++
++Because aufs supports manipulating branches, ie. add/delete/change
++dynamically, these objects has its own generation. When branches are
++changed, the generation in aufs superblock is incremented. And a
++generation in other object are compared when it is accessed.
++When a generation in other objects are obsoleted, aufs refreshes the
++internal array.
++
++
++Superblock
++----------------------------------------------------------------------
++Additionally aufs superblock has some data for policies to select one
++among multiple writable branches, XIB files, pseudo-links and kobject.
++See below in detail.
++About the policies which supports copy-down a directory, see policy.txt
++too.
++
++
++Branch and XINO(External Inode Number Translation Table)
++----------------------------------------------------------------------
++Every branch has its own xino (external inode number translation table)
++file. The xino file is created and unlinked by aufs internally. When two
++members of a union exist on the same filesystem, they share the single
++xino file.
++The struct of a xino file is simple, just a sequence of aufs inode
++numbers which is indexed by the lower inode number.
++In the above sample, assume the inode number of /ro/fileA is i111 and
++aufs assigns the inode number i999 for fileA. Then aufs writes 999 as
++4(8) bytes at 111 * 4(8) bytes offset in the xino file.
++
++When the inode numbers are not contiguous, the xino file will be sparse
++which has a hole in it and doesn't consume as much disk space as it
++might appear. If your branch filesystem consumes disk space for such
++holes, then you should specify 'xino=' option at mounting aufs.
++
++Also a writable branch has three kinds of "whiteout bases". All these
++are existed when the branch is joined to aufs and the names are
++whiteout-ed doubly, so that users will never see their names in aufs
++hierarchy.
++1. a regular file which will be linked to all whiteouts.
++2. a directory to store a pseudo-link.
++3. a directory to store an "orphan-ed" file temporary.
++
++1. Whiteout Base
++ When you remove a file on a readonly branch, aufs handles it as a
++ logical deletion and creates a whiteout on the upper writable branch
++ as a hardlink of this file in order not to consume inode on the
++ writable branch.
++2. Pseudo-link Dir
++ See below, Pseudo-link.
++3. Step-Parent Dir
++ When "fileC" exists on the lower readonly branch only and it is
++ opened and removed with its parent dir, and then user writes
++ something into it, then aufs copies-up fileC to this
++ directory. Because there is no other dir to store fileC. After
++ creating a file under this dir, the file is unlinked.
++
++Because aufs supports manipulating branches, ie. add/delete/change
++dynamically, a branch has its own id. When the branch order changes, aufs
++finds the new index by searching the branch id.
++
++
++Pseudo-link
++----------------------------------------------------------------------
++Assume "fileA" exists on the lower readonly branch only and it is
++hardlinked to "fileB" on the branch. When you write something to fileA,
++aufs copies-up it to the upper writable branch. Additionally aufs
++creates a hardlink under the Pseudo-link Directory of the writable
++branch. The inode of a pseudo-link is kept in aufs super_block as a
++simple list. If fileB is read after unlinking fileA, aufs returns
++filedata from the pseudo-link instead of the lower readonly
++branch. Because the pseudo-link is based upon the inode, to keep the
++inode number by xino (see above) is important.
++
++All the hardlinks under the Pseudo-link Directory of the writable branch
++should be restored in a proper location later. Aufs provides a utility
++to do this. The userspace helpers executed at remounting and unmounting
++aufs by default.
++
++
++XIB(external inode number bitmap)
++----------------------------------------------------------------------
++Addition to the xino file per a branch, aufs has an external inode number
++bitmap in a superblock object. It is also a file such like a xino file.
++It is a simple bitmap to mark whether the aufs inode number is in-use or
++not.
++To reduce the file I/O, aufs prepares a single memory page to cache xib.
++
++Aufs implements a feature to truncate/refresh both of xino and xib to
++reduce the number of consumed disk blocks for these files.
++
++
++Virtual or Vertical Dir
++----------------------------------------------------------------------
++In order to support multiple layers (branches), aufs readdir operation
++constructs a virtual dir block on memory. For readdir, aufs calls
++vfs_readdir() internally for each dir on branches, merges their entries
++with eliminating the whiteout-ed ones, and sets it to file (dir)
++object. So the file object has its entry list until it is closed. The
++entry list will be updated when the file position is zero and becomes
++old. This decision is made in aufs automatically.
++
++The dynamically allocated memory block for the name of entries has a
++unit of 512 bytes (by default) and stores the names contiguously (no
++padding). Another block for each entry is handled by kmem_cache too.
++During building dir blocks, aufs creates hash list and judging whether
++the entry is whiteouted by its upper branch or already listed.
++
++Some people may call it can be a security hole or invite DoS attack
++since the opened and once readdir-ed dir (file object) holds its entry
++list and becomes a pressure for system memory. But I'd say it is similar
++to files under /proc or /sys. The virtual files in them also holds a
++memory page (generally) while they are opened. When an idea to reduce
++memory for them is introduced, it will be applied to aufs too.
++
++
++Workqueue
++----------------------------------------------------------------------
++Aufs sometimes requires privilege access to a branch. For instance,
++in copy-up/down operation. When a user process is going to make changes
++to a file which exists in the lower readonly branch only, and the mode
++of one of ancestor directories may not be writable by a user
++process. Here aufs copy-up the file with its ancestors and they may
++require privilege to set its owner/group/mode/etc.
++This is a typical case of a application character of aufs (see
++Introduction).
++
++Aufs uses workqueue synchronously for this case. It creates its own
++workqueue. The workqueue is a kernel thread and has privilege. Aufs
++passes the request to call mkdir or write (for example), and wait for
++its completion. This approach solves a problem of a signal handler
++simply.
++If aufs didn't adopt the workqueue and changed the privilege of the
++process, and if the mkdir/write call arises SIGXFSZ or other signal,
++then the user process might gain a privilege or the generated core file
++was owned by a superuser. But I have a plan to switch to a new
++credential approach which will be introduced in linux-2.6.29.
++
++Also aufs uses the system global workqueue ("events" kernel thread) too
++for asynchronous tasks, such like handling inotify, re-creating a
++whiteout base and etc. This is unrelated to a privilege.
++Most of aufs operation tries acquiring a rw_semaphore for aufs
++superblock at the beginning, at the same time waits for the completion
++of all queued asynchronous tasks.
++
++
++Whiteout
++----------------------------------------------------------------------
++The whiteout in aufs is very similar to Unionfs's. That is represented
++by its filename. UnionMount takes an approach of a file mode, but I am
++afraid several utilities (find(1) or something) will have to support it.
++
++Basically the whiteout represents "logical deletion" which stops aufs to
++lookup further, but also it represents "dir is opaque" which also stop
++lookup.
++
++In aufs, rmdir(2) and rename(2) for dir uses whiteout alternatively.
++In order to make several functions in a single systemcall to be
++revertible, aufs adopts an approach to rename a directory to a temporary
++unique whiteouted name.
++For example, in rename(2) dir where the target dir already existed, aufs
++renames the target dir to a temporary unique whiteouted name before the
++actual rename on a branch and then handles other actions (make it opaque,
++update the attributes, etc). If an error happens in these actions, aufs
++simply renames the whiteouted name back and returns an error. If all are
++succeeded, aufs registers a function to remove the whiteouted unique
++temporary name completely and asynchronously to the system global
++workqueue.
++
++
++Copy-up
++----------------------------------------------------------------------
++It is a well-known feature or concept.
++When user modifies a file on a readonly branch, aufs operate "copy-up"
++internally and makes change to the new file on the upper writable branch.
++When the trigger systemcall does not update the timestamps of the parent
++dir, aufs reverts it after copy-up.
+diff --git a/Documentation/filesystems/aufs/design/03lookup.txt b/Documentation/filesystems/aufs/design/03lookup.txt
+new file mode 100644
+index 0000000..36ddac7
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/03lookup.txt
+@@ -0,0 +1,95 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++Lookup in a Branch
++----------------------------------------------------------------------
++Since aufs has a character of sub-VFS (see Introduction), it operates
++lookup for branches as VFS does. It may be a heavy work. Generally
++speaking struct nameidata is a bigger structure and includes many
++information. But almost all lookup operation in aufs is the simplest
++case, ie. lookup only an entry directly connected to its parent. Digging
++down the directory hierarchy is unnecessary.
++
++VFS has a function lookup_one_len() for that use, but it is not usable
++for a branch filesystem which requires struct nameidata. So aufs
++implements a simple lookup wrapper function. When a branch filesystem
++allows NULL as nameidata, it calls lookup_one_len(). Otherwise it builds
++a simplest nameidata and calls lookup_hash().
++Here aufs applies "a principle in NFSD", ie. if the filesystem supports
++NFS-export, then it has to support NULL as a nameidata parameter for
++->create(), ->lookup() and ->d_revalidate(). So the lookup wrapper in
++aufs tests if ->s_export_op in the branch is NULL or not.
++
++When a branch is a remote filesystem, aufs trusts its ->d_revalidate().
++For d_revalidate, aufs implements three levels of revalidate tests. See
++"Revalidate Dentry and UDBA" in detail.
++
++
++Loopback Mount
++----------------------------------------------------------------------
++Basically aufs supports any type of filesystem and block device for a
++branch (actually there are some exceptions). But it is prohibited to add
++a loopback mounted one whose backend file exists in a filesystem which is
++already added to aufs. The reason is to protect aufs from a recursive
++lookup. If it was allowed, the aufs lookup operation might re-enter a
++lookup for the loopback mounted branch in the same context, and will
++cause a deadlock.
++
++
++Revalidate Dentry and UDBA (User's Direct Branch Access)
++----------------------------------------------------------------------
++Generally VFS helpers re-validate a dentry as a part of lookup.
++0. digging down the directory hierarchy.
++1. lock the parent dir by its i_mutex.
++2. lookup the final (child) entry.
++3. revalidate it.
++4. call the actual operation (create, unlink, etc.)
++5. unlock the parent dir
++
++If the filesystem implements its ->d_revalidate() (step 3), then it is
++called. Actually aufs implements it and checks the dentry on a branch is
++still valid.
++But it is not enough. Because aufs has to release the lock for the
++parent dir on a branch at the end of ->lookup() (step 2) and
++->d_revalidate() (step 3) while the i_mutex of the aufs dir is still
++held by VFS.
++If the file on a branch is changed directly, eg. bypassing aufs, after
++aufs released the lock, then the subsequent operation may cause
++something unpleasant result.
++
++This situation is a result of VFS architecture, ->lookup() and
++->d_revalidate() is separated. But I never say it is wrong. It is a good
++design from VFS's point of view. It is just not suitable for sub-VFS
++character in aufs.
++
++Aufs supports such case by three level of revalidation which is
++selectable by user.
++1. Simple Revalidate
++ Addition to the native flow in VFS's, confirm the child-parent
++ relationship on the branch just after locking the parent dir on the
++ branch in the "actual operation" (step 4). When this validation
++ fails, aufs returns EBUSY. ->d_revalidate() (step 3) in aufs still
++ checks the validation of the dentry on branches.
++2. Monitor Changes Internally by Inotify
++ Addition to above, in the "actual operation" (step 4) aufs re-lookup
++ the dentry on the branch, and returns EBUSY if it finds different
++ dentry.
++ Additionally, aufs sets the inotify watch for every dir on branches
++ during it is in cache. When the event is notified, aufs registers a
++ function to kernel 'events' thread by schedule_work(). And the
++ function sets some special status to the cached aufs dentry and inode
++ private data. If they are not cached, then aufs has nothing to
++ do. When the same file is accessed through aufs (step 0-3) later,
++ aufs will detect the status and refresh all necessary data.
++ In this mode, aufs has to ignore the event which is fired by aufs
++ itself.
++3. No Extra Validation
++ This is the simplest test and doesn't add any additional revalidation
++ test, and skip therevalidatin in step 4. It is useful and improves
++ aufs performance when system surely hide the aufs branches from user,
++ by over-mounting something (or another method).
+diff --git a/Documentation/filesystems/aufs/design/04branch.txt b/Documentation/filesystems/aufs/design/04branch.txt
+new file mode 100644
+index 0000000..78432c5
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/04branch.txt
+@@ -0,0 +1,67 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++Branch Manipulation
++
++Since aufs supports dynamic branch manipulation, ie. add/remove a branch
++and changing its permission/attribute, there are a lot of works to do.
++
++
++Add a Branch
++----------------------------------------------------------------------
++o Confirm the adding dir exists outside of aufs, including loopback
++ mount.
++- and other various attributes...
++o Initialize the xino file and whiteout bases if necessary.
++ See struct.txt.
++
++o Check the owner/group/mode of the directory
++ When the owner/group/mode of the adding directory differs from the
++ existing branch, aufs issues a warning because it may impose a
++ security risk.
++ For example, when a upper writable branch has a world writable empty
++ top directory, a malicious user can create any files on the writable
++ branch directly, like copy-up and modify manually. If something like
++ /etc/{passwd,shadow} exists on the lower readonly branch but the upper
++ writable branch, and the writable branch is world-writable, then a
++ malicious guy may create /etc/passwd on the writable branch directly
++ and the infected file will be valid in aufs.
++ I am afraid it can be a security issue, but nothing to do except
++ producing a warning.
++
++
++Delete a Branch
++----------------------------------------------------------------------
++o Confirm the deleting branch is not busy
++ To be general, there is one merit to adopt "remount" interface to
++ manipulate branches. It is to discard caches. At deleting a branch,
++ aufs checks the still cached (and connected) dentries and inodes. If
++ there are any, then they are all in-use. An inode without its
++ corresponding dentry can be alive alone (for example, inotify case).
++
++ For the cached one, aufs checks whether the same named entry exists on
++ other branches.
++ If the cached one is a directory, because aufs provides a merged view
++ to users, as long as one dir is left on any branch aufs can show the
++ dir to users. In this case, the branch can be removed from aufs.
++ Otherwise aufs rejects deleting the branch.
++
++ If any file on the deleting branch is opened by aufs, then aufs
++ rejects deleting.
++
++
++Modify the Permission of a Branch
++----------------------------------------------------------------------
++o Re-initialize or remove the xino file and whiteout bases if necessary.
++ See struct.txt.
++
++o rw --> ro: Confirm the modifying branch is not busy
++ Aufs rejects the request if any of these conditions are true.
++ - a file on the branch is mmap-ed.
++ - a regular file on the branch is opened for write and there is no
++ same named entry on the upper branch.
+diff --git a/Documentation/filesystems/aufs/design/05wbr_policy.txt b/Documentation/filesystems/aufs/design/05wbr_policy.txt
+new file mode 100644
+index 0000000..d9720ca
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/05wbr_policy.txt
+@@ -0,0 +1,57 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++
++Policies to Select One among Multiple Writable Branches
++----------------------------------------------------------------------
++When the number of writable branch is more than one, aufs has to decide
++the target branch for file creation or copy-up. By default, the highest
++writable branch which has the parent (or ancestor) dir of the target
++file is chosen (top-down-parent policy).
++By user's request, aufs implements some other policies to select the
++writable branch, for file creation two policies, round-robin and
++most-free-space policies. For copy-up three policies, top-down-parent,
++bottom-up-parent and bottom-up policies.
++
++As expected, the round-robin policy selects the branch in circular. When
++you have two writable branches and creates 10 new files, 5 files will be
++created for each branch. mkdir(2) systemcall is an exception. When you
++create 10 new directories, all will be created on the same branch.
++And the most-free-space policy selects the one which has most free
++space among the writable branches. The amount of free space will be
++checked by aufs internally, and users can specify its time interval.
++
++The policies for copy-up is more simple,
++top-down-parent is equivalent to the same named on in create policy,
++bottom-up-parent selects the writable branch where the parent dir
++exists and the nearest upper one from the copyup-source,
++bottom-up selects the nearest upper writable branch from the
++copyup-source, regardless the existence of the parent dir.
++
++There are some rules or exceptions to apply these policies.
++- If there is a readonly branch above the policy-selected branch and
++ the parent dir is marked as opaque (a variation of whiteout), or the
++ target (creating) file is whiteout-ed on the upper readonly branch,
++ then the result of the policy is ignored and the target file will be
++ created on the nearest upper writable branch than the readonly branch.
++- If there is a writable branch above the policy-selected branch and
++ the parent dir is marked as opaque or the target file is whiteouted
++ on the branch, then the result of the policy is ignored and the target
++ file will be created on the highest one among the upper writable
++ branches who has diropq or whiteout. In case of whiteout, aufs removes
++ it as usual.
++- link(2) and rename(2) systemcalls are exceptions in every policy.
++ They try selecting the branch where the source exists as possible
++ since copyup a large file will take long time. If it can't be,
++ ie. the branch where the source exists is readonly, then they will
++ follow the copyup policy.
++- There is an exception for rename(2) when the target exists.
++ If the rename target exists, aufs compares the index of the branches
++ where the source and the target exists and selects the higher
++ one. If the selected branch is readonly, then aufs follows the
++ copyup policy.
+diff --git a/Documentation/filesystems/aufs/design/06fmode_exec.txt b/Documentation/filesystems/aufs/design/06fmode_exec.txt
+new file mode 100644
+index 0000000..b172cd1
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/06fmode_exec.txt
+@@ -0,0 +1,24 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++FMODE_EXEC and deny_write()
++----------------------------------------------------------------------
++Generally Unix prevents an executing file from writing its filedata.
++In linux it is implemented by deny_write() and allow_write().
++When a file is executed by exec() family, open_exec() (and sys_uselib())
++they opens the file and calls deny_write(). If the file is aufs's virtual
++one, it has no meaning. The file which deny_write() is really necessary
++is the file on a branch. But the FMODE_EXEC flag is not passed to
++->open() operation. So aufs adopt a dirty trick.
++
++- in order to get FMODE_EXEC, aufs ->lookup() and ->d_revalidate() set
++ nd->intent.open.file->private_data to nd->intent.open.flags temporary.
++- in aufs ->open(), when FMODE_EXEC is set in file->private_data, it
++ calls deny_write() for the file on a branch.
++- when the aufs file is released, allow_write() for the file on a branch
++ is called.
+diff --git a/Documentation/filesystems/aufs/design/07mmap.txt b/Documentation/filesystems/aufs/design/07mmap.txt
+new file mode 100644
+index 0000000..d751c42
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/07mmap.txt
+@@ -0,0 +1,44 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++mmap(2) -- File Memory Mapping
++----------------------------------------------------------------------
++In aufs, the file-mapped pages are shared between the file on a branch
++and the virtual one in aufs by overriding vm_operation, particularly
++->fault().
++
++In aufs_mmap(),
++- get and store vm_ops of the real file on a branch.
++- map the file of aufs by generic_file_mmap() and set aufs's vm
++ operations.
++
++In aufs_fault(),
++- get the file of aufs from the passed vma, sleep if needed.
++- get the real file on a branch from the aufs file.
++- a race may happen. for instance a multithreaded library. so some lock
++ is implemented.
++- call ->fault() in the previously stored vm_ops with setting the
++ real file on a branch to vm_file.
++- restore vm_file and wake_up if someone else got sleep.
++
++When a branch is added to or deleted from aufs, the same-named file may
++unveil and its contents will be replaced by the new one when a process
++read(2) through previously opened file.
++(Some users may not want to refresh the filedata. For such users, I
++have a plan to implement a mount option 'refrof' which decides to
++refresh the opened files or not. See plan.txt too.)
++In this case, an already mapped file will not be updated since the
++contents are a part of a process already and it should not be changed by
++aufs branch manipulation. (Even if MAP_SHARED is specified, currently).
++Of course, in case of the deleting branch has a busy file, it cannot be
++deleted from the union.
++
++In Unionfs, it took an approach which the memory pages mapped to
++filedata are copied from the lower (real) file into the Unionfs's
++virtual one and handles it by address_space operations. Recently Unionfs
++changed it to this approach which aufs adopted since Jul 2006.
+diff --git a/Documentation/filesystems/aufs/design/08export.txt b/Documentation/filesystems/aufs/design/08export.txt
+new file mode 100644
+index 0000000..8a7b9e5
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/08export.txt
+@@ -0,0 +1,51 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++
++Export Aufs via NFS
++----------------------------------------------------------------------
++Here is an approach.
++- like xino/xib, add a new file 'xigen' which stores aufs inode
++ generation.
++- iget_locked(): initialize aufs inode generation for a new inode, and
++ store it in xigen file.
++- destroy_inode(): increment aufs inode generation and store it in xigen
++ file. it is necessary even if it is not unlinked, because any data of
++ inode may be changed by UDBA.
++- encode_fh(): for a root dir, simply return FILEID_ROOT. otherwise
++ build file handle by
++ + branch id (4 bytes)
++ + superblock generation (4 bytes)
++ + inode number (4 or 8 bytes)
++ + parent dir inode number (4 or 8 bytes)
++ + inode generation (4 bytes))
++ + return value of exportfs_encode_fh() for the parent on a branch (4
++ bytes)
++ + file handle for a branch (by exportfs_encode_fh())
++- fh_to_dentry():
++ + find the index of a branch from its id in handle, and check it is
++ still exist in aufs.
++ + 1st level: get the inode number from handle and search it in cache.
++ + 2nd level: if not found, get the parent inode number from handle and
++ search it in cache. and then open the parent dir, find the matching
++ inode number by vfs_readdir() and get its name, and call
++ lookup_one_len() for the target dentry.
++ + 3rd level: if the parent dir is not cached, call
++ exportfs_decode_fh() for a branch and get the parent on a branch,
++ build a pathname of it, convert it a pathname in aufs, call
++ path_lookup(). now aufs gets a parent dir dentry, then handle it as
++ the 2nd level.
++ + to open the dir, aufs needs struct vfsmount. aufs keeps vfsmount
++ for every branch, but not itself. to get this, (currently) aufs
++ searches in current->nsproxy->mnt_ns list. it may not be a good
++ idea, but I didn't get other approach.
++ + test the generation of the gotten inode.
++- every inode operation: they may get EBUSY due to UDBA. in this case,
++ convert it into ESTALE for NFSD.
++- readdir(): call lockdep_on/off() because filldir in NFSD calls
++ lookup_one_len(), vfs_getattr(), encode_fh() and others.
+diff --git a/Documentation/filesystems/aufs/design/99plan.txt b/Documentation/filesystems/aufs/design/99plan.txt
+new file mode 100644
+index 0000000..3167d0e
+--- /dev/null
++++ b/Documentation/filesystems/aufs/design/99plan.txt
+@@ -0,0 +1,125 @@
++
++# Copyright (C) 2005-2009 Junjiro R. Okajima
++#
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 2 of the License, or
++# (at your option) any later version.
++
++Plan
++
++Restoring some features which was implemented in aufs1.
++They were dropped in aufs2 in order to make source files simpler and
++easier to be reviewed.
++
++
++Test Only the Highest One for the Directory Permission (dirperm1 option)
++----------------------------------------------------------------------
++Let's try case study.
++- aufs has two branches, upper readwrite and lower readonly.
++ /au = /rw + /ro
++- "dirA" exists under /ro, but /rw. and its mode is 0700.
++- user invoked "chmod a+rx /au/dirA"
++- then "dirA" becomes world readable?
++
++In this case, /ro/dirA is still 0700 since it exists in readonly branch,
++or it may be a natively readonly filesystem. If aufs respects the lower
++branch, it should not respond readdir request from other users. But user
++allowed it by chmod. Should really aufs rejects showing the entries
++under /ro/dirA?
++
++To be honest, I don't have a best solution for this case. So I
++implemented 'dirperm1' and 'nodirperm1' option in aufs1, and leave it to
++users.
++When dirperm1 is specified, aufs checks only the highest one for the
++directory permission, and shows the entries. Otherwise, as usual, checks
++every dir existing on all branches and rejects the request.
++
++As a side effect, dirperm1 option improves the performance of aufs
++because the number of permission check is reduced.
++
++
++Show Whiteout Mode (shwh)
++----------------------------------------------------------------------
++Generally aufs hides the name of whiteouts. But in some cases, to show
++them is very useful for users. For instance, creating a new middle layer
++(branch) by merging existing layers.
++
++(borrowing aufs1 HOW-TO from a user, Michael Towers)
++When you have three branches,
++- Bottom: 'system', squashfs (underlying base system), read-only
++- Middle: 'mods', squashfs, read-only
++- Top: 'overlay', ram (tmpfs), read-write
++
++The top layer is loaded at boot time and saved at shutdown, to preserve
++the changes made to the system during the session.
++When larger changes have been made, or smaller changes have accumulated,
++the size of the saved top layer data grows. At this point, it would be
++nice to be able to merge the two overlay branches ('mods' and 'overlay')
++and rewrite the 'mods' squashfs, clearing the top layer and thus
++restoring save and load speed.
++
++This merging is simplified by the use of another aufs mount, of just the
++two overlay branches using the 'shwh' option.
++# mount -t aufs -o ro,shwh,br:/livesys/overlay=ro+wh:/livesys/mods=rr+wh \
++ aufs /livesys/merge_union
++
++A merged view of these two branches is then available at
++/livesys/merge_union, and the new feature is that the whiteouts are
++visible!
++Note that in 'shwh' mode the aufs mount must be 'ro', which will disable
++writing to all branches. Also the default mode for all branches is 'ro'.
++It is now possible to save the combined contents of the two overlay
++branches to a new squashfs, e.g.:
++# mksquashfs /livesys/merge_union /path/to/newmods.squash
++
++This new squashfs archive can be stored on the boot device and the
++initramfs will use it to replace the old one at the next boot.
++
++
++Being Another Aufs's Readonly Branch (robr)
++----------------------------------------------------------------------
++Aufs1 allows aufs to be another aufs's readonly branch.
++This feature was developed by a user's request. But it may not be used
++currecnly.
++
++
++Copy-up on Open (coo=)
++----------------------------------------------------------------------
++By default the internal copy-up is executed when it is really necessary.
++It is not done when a file is opened for writing, but when write(2) is
++done. Users who have many (over 100) branches want to know and analyse
++when and what file is copied-up. To insert a new upper branch which
++contains such files only may improve the performance of aufs.
++
++Aufs1 implemented "coo=none | leaf | all" option.
++
++
++Refresh the Opened File (refrof)
++----------------------------------------------------------------------
++This option is implemented in aufs1 but incomplete.
++
++When user reads from a file, he expects to get its latest filedata
++generally. If the file is removed and a new same named file is created,
++the content he gets is unchanged, ie. the unlinked filedata.
++
++Let's try case study again.
++- aufs has two branches.
++ /au = /rw + /ro
++- "fileA" exists under /ro, but /rw.
++- user opened "/au/fileA".
++- he or someone else inserts a branch (/new) between /rw and /ro.
++ /au = /rw + /new + /ro
++- the new branch has "fileA".
++- user reads from the opened "fileA"
++- which filedata should aufs return, from /ro or /new?
++
++Some people says it has to be "from /ro" and it is a semantics of Unix.
++The others say it should be "from /new" because the file is not removed
++and it is equivalent to the case of someone else modifies the file.
++
++Here again I don't have a best and final answer. I got an idea to
++implement 'refrof' and 'norefrof' option. When 'refrof' (REFResh the
++Opened File) is specified (by default), aufs returns the filedata from
++/new.
++Otherwise from /new.
+diff --git a/fs/Kconfig b/fs/Kconfig
+index 93945dd..75156dd 100644
+--- a/fs/Kconfig
++++ b/fs/Kconfig
+@@ -222,6 +222,7 @@ source "fs/qnx4/Kconfig"
+ source "fs/romfs/Kconfig"
+ source "fs/sysv/Kconfig"
+ source "fs/ufs/Kconfig"
++source "fs/aufs/Kconfig"
+
+ endif # MISC_FILESYSTEMS
+
+diff --git a/fs/Makefile b/fs/Makefile
+index dc20db3..a4e9a65 100644
+--- a/fs/Makefile
++++ b/fs/Makefile
+@@ -124,3 +124,4 @@ obj-$(CONFIG_DEBUG_FS) += debugfs/
+ obj-$(CONFIG_OCFS2_FS) += ocfs2/
+ obj-$(CONFIG_BTRFS_FS) += btrfs/
+ obj-$(CONFIG_GFS2_FS) += gfs2/
++obj-$(CONFIG_AUFS_FS) += aufs/
+diff --git a/fs/aufs/Kconfig b/fs/aufs/Kconfig
+new file mode 100644
+index 0000000..04b2060
+--- /dev/null
++++ b/fs/aufs/Kconfig
+@@ -0,0 +1,109 @@
++config AUFS_FS
++ bool "Aufs (Advanced multi layered unification filesystem) support"
++ depends on EXPERIMENTAL
++ help
++ Aufs is a stackable unification filesystem such as Unionfs,
++ which unifies several directories and provides a merged single
++ directory.
++ In the early days, aufs was entirely re-designed and
++ re-implemented Unionfs Version 1.x series. Introducing many
++ original ideas, approaches and improvements, it becomes totally
++ different from Unionfs while keeping the basic features.
++
++if AUFS_FS
++choice
++ prompt "Maximum number of branches"
++ default AUFS_BRANCH_MAX_127
++ help
++ Specifies the maximum number of branches (or member directories)
++ in a single aufs. The larger value consumes more system
++ resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_127
++ bool "127"
++ help
++ Specifies the maximum number of branches (or member directories)
++ in a single aufs. The larger value consumes more system
++ resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_511
++ bool "511"
++ help
++ Specifies the maximum number of branches (or member directories)
++ in a single aufs. The larger value consumes more system
++ resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_1023
++ bool "1023"
++ help
++ Specifies the maximum number of branches (or member directories)
++ in a single aufs. The larger value consumes more system
++ resources and has a minor impact to performance.
++config AUFS_BRANCH_MAX_32767
++ bool "32767"
++ help
++ Specifies the maximum number of branches (or member directories)
++ in a single aufs. The larger value consumes more system
++ resources and has a minor impact to performance.
++endchoice
++
++config AUFS_HINOTIFY
++ bool "Use inotify to detect actions on a branch"
++ depends on INOTIFY
++ help
++ If you want to modify files on branches directly, eg. bypassing aufs,
++ and want aufs to detect the changes of them fully, then enable this
++ option and use 'udba=inotify' mount option.
++ It will have a negative impact to the performance.
++ See detail in aufs.5.
++
++config AUFS_EXPORT
++ bool "NFS-exportable aufs"
++ depends on EXPORTFS = y
++ help
++ If you want to export your mounted aufs via NFS, then enable this
++ option. There are several requirements for this configuration.
++ See detail in aufs.5.
++
++config AUFS_BR_RAMFS
++ bool "Ramfs (initramfs/rootfs) as an aufs branch"
++ help
++ If you want to use ramfs as an aufs branch fs, then enable this
++ option. Generally tmpfs is recommended.
++ Aufs prohibited them to be a branch fs by default, because
++ initramfs becomes unusable after switch_root or something
++ generally. If you sets initramfs as an aufs branch and boot your
++ system by switch_root, you will meet a problem easily since the
++ files in initramfs may be inaccessible.
++ Unless you are going to use ramfs as an aufs branch fs without
++ switch_root or something, leave it N.
++
++config AUFS_DEBUG
++ bool "Debug aufs"
++ help
++ Enable this to compile aufs internal debug code.
++ It will have a negative impact to the performance.
++
++config AUFS_MAGIC_SYSRQ
++ bool
++ depends on AUFS_DEBUG && MAGIC_SYSRQ
++ default y
++ help
++ Automatic configuration for internal use.
++ When aufs supports Magic SysRq, enabled automatically.
++
++config AUFS_BDEV_LOOP
++ bool
++ depends on BLK_DEV_LOOP
++ default y
++ help
++ Automatic configuration for internal use.
++ Convert =[ym] into =y.
++
++config AUFS_INO_T_64
++ bool
++ depends on AUFS_EXPORT
++ depends on 64BIT && !(ALPHA || S390)
++ default y
++ help
++ Automatic configuration for internal use.
++ /* typedef unsigned long/int __kernel_ino_t */
++ /* alpha and s390x are int */
++endif
+diff --git a/fs/aufs/Makefile b/fs/aufs/Makefile
+new file mode 100644
+index 0000000..477d245
+--- /dev/null
++++ b/fs/aufs/Makefile
+@@ -0,0 +1,21 @@
++
++include ${srctree}/${src}/magic.mk
++
++obj-$(CONFIG_AUFS_FS) += aufs.o
++aufs-y := module.o sbinfo.o super.o branch.o xino.o sysaufs.o opts.o \
++ wkq.o vfsub.o dcsub.o \
++ cpup.o whout.o plink.o wbr_policy.o \
++ dinfo.o dentry.o \
++ finfo.o file.o f_op.o \
++ dir.o vdir.o \
++ iinfo.o inode.o i_op.o i_op_add.o i_op_del.o i_op_ren.o \
++ ioctl.o
++
++# all are boolean
++aufs-$(CONFIG_SYSFS) += sysfs.o
++aufs-$(CONFIG_DEBUG_FS) += dbgaufs.o
++aufs-$(CONFIG_AUFS_BDEV_LOOP) += loop.o
++aufs-$(CONFIG_AUFS_HINOTIFY) += hinotify.o
++aufs-$(CONFIG_AUFS_EXPORT) += export.o
++aufs-$(CONFIG_AUFS_DEBUG) += debug.o
++aufs-$(CONFIG_AUFS_MAGIC_SYSRQ) += sysrq.o
+diff --git a/fs/aufs/aufs.h b/fs/aufs/aufs.h
+new file mode 100644
+index 0000000..132e84e
+--- /dev/null
++++ b/fs/aufs/aufs.h
+@@ -0,0 +1,44 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * all header files
++ */
++
++#ifndef __AUFS_H__
++#define __AUFS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/bug.h>
++
++#include "debug.h"
++
++#include "branch.h"
++#include "cpup.h"
++#include "dcsub.h"
++#include "dbgaufs.h"
++#include "dentry.h"
++#include "dir.h"
++#include "file.h"
++#include "fstype.h"
++#include "inode.h"
++#include "loop.h"
++#include "module.h"
++#include "opts.h"
++#include "rwsem.h"
++#include "spl.h"
++#include "super.h"
++#include "sysaufs.h"
++#include "vfsub.h"
++#include "whout.h"
++#include "wkq.h"
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_H__ */
+diff --git a/fs/aufs/branch.c b/fs/aufs/branch.c
+new file mode 100644
+index 0000000..7ef8a18
+--- /dev/null
++++ b/fs/aufs/branch.c
+@@ -0,0 +1,946 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * branch management
++ */
++
++#include "aufs.h"
++
++/*
++ * free a single branch
++ */
++static void au_br_do_free(struct au_branch *br)
++{
++ int i;
++ struct au_wbr *wbr;
++
++ if (br->br_xino.xi_file)
++ fput(br->br_xino.xi_file);
++ mutex_destroy(&br->br_xino.xi_nondir_mtx);
++
++ AuDebugOn(atomic_read(&br->br_count));
++
++ wbr = br->br_wbr;
++ if (wbr) {
++ for (i = 0; i < AuBrWh_Last; i++)
++ dput(wbr->wbr_wh[i]);
++ AuDebugOn(atomic_read(&wbr->wbr_wh_running));
++ au_rwsem_destroy(&wbr->wbr_wh_rwsem);
++ }
++
++ /* some filesystems acquire extra lock */
++ lockdep_off();
++ mntput(br->br_mnt);
++ lockdep_on();
++
++ kfree(wbr);
++ kfree(br);
++}
++
++/*
++ * frees all branches
++ */
++void au_br_free(struct au_sbinfo *sbinfo)
++{
++ aufs_bindex_t bmax;
++ struct au_branch **br;
++
++ bmax = sbinfo->si_bend + 1;
++ br = sbinfo->si_branch;
++ while (bmax--)
++ au_br_do_free(*br++);
++}
++
++/*
++ * find the index of a branch which is specified by @br_id.
++ */
++int au_br_index(struct super_block *sb, aufs_bindex_t br_id)
++{
++ aufs_bindex_t bindex, bend;
++
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex <= bend; bindex++)
++ if (au_sbr_id(sb, bindex) == br_id)
++ return bindex;
++ return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * add a branch
++ */
++
++static int test_overlap(struct super_block *sb, struct dentry *h_d1,
++ struct dentry *h_d2)
++{
++ if (unlikely(h_d1 == h_d2))
++ return 1;
++ return !!au_test_subdir(h_d1, h_d2)
++ || !!au_test_subdir(h_d2, h_d1)
++ || au_test_loopback_overlap(sb, h_d1, h_d2)
++ || au_test_loopback_overlap(sb, h_d2, h_d1);
++}
++
++/*
++ * returns a newly allocated branch. @new_nbranch is a number of branches
++ * after adding a branch.
++ */
++static struct au_branch *au_br_alloc(struct super_block *sb, int new_nbranch,
++ int perm)
++{
++ struct au_branch *add_branch;
++ struct dentry *root;
++
++ root = sb->s_root;
++ add_branch = kmalloc(sizeof(*add_branch), GFP_NOFS);
++ if (unlikely(!add_branch))
++ goto out;
++
++ add_branch->br_wbr = NULL;
++ if (au_br_writable(perm)) {
++ /* may be freed separately at changing the branch permission */
++ add_branch->br_wbr = kmalloc(sizeof(*add_branch->br_wbr),
++ GFP_NOFS);
++ if (unlikely(!add_branch->br_wbr))
++ goto out_br;
++ }
++
++ if (unlikely(au_sbr_realloc(au_sbi(sb), new_nbranch)
++ || au_di_realloc(au_di(root), new_nbranch)
++ || au_ii_realloc(au_ii(root->d_inode), new_nbranch)))
++ goto out_wbr;
++ return add_branch; /* success */
++
++ out_wbr:
++ kfree(add_branch->br_wbr);
++ out_br:
++ kfree(add_branch);
++ out:
++ return ERR_PTR(-ENOMEM);
++}
++
++/*
++ * test if the branch permission is legal or not.
++ */
++static int test_br(struct inode *inode, int brperm, char *path)
++{
++ int err;
++
++ err = 0;
++ if (unlikely(au_br_writable(brperm) && IS_RDONLY(inode))) {
++ AuErr("write permission for readonly mount or inode, %s\n",
++ path);
++ err = -EINVAL;
++ }
++
++ return err;
++}
++
++/*
++ * returns:
++ * 0: success, the caller will add it
++ * plus: success, it is already unified, the caller should ignore it
++ * minus: error
++ */
++static int test_add(struct super_block *sb, struct au_opt_add *add, int remount)
++{
++ int err;
++ aufs_bindex_t bend, bindex;
++ struct dentry *root;
++ struct inode *inode, *h_inode;
++
++ root = sb->s_root;
++ bend = au_sbend(sb);
++ if (unlikely(bend >= 0
++ && au_find_dbindex(root, add->path.dentry) >= 0)) {
++ err = 1;
++ if (!remount) {
++ err = -EINVAL;
++ AuErr("%s duplicated\n", add->pathname);
++ }
++ goto out;
++ }
++
++ err = -ENOSPC; /* -E2BIG; */
++ if (unlikely(AUFS_BRANCH_MAX <= add->bindex
++ || AUFS_BRANCH_MAX - 1 <= bend)) {
++ AuErr("number of branches exceeded %s\n", add->pathname);
++ goto out;
++ }
++
++ err = -EDOM;
++ if (unlikely(add->bindex < 0 || bend + 1 < add->bindex)) {
++ AuErr("bad index %d\n", add->bindex);
++ goto out;
++ }
++
++ inode = add->path.dentry->d_inode;
++ err = -ENOENT;
++ if (unlikely(!inode->i_nlink)) {
++ AuErr("no existence %s\n", add->pathname);
++ goto out;
++ }
++
++ err = -EINVAL;
++ if (unlikely(inode->i_sb == sb)) {
++ AuErr("%s must be outside\n", add->pathname);
++ goto out;
++ }
++
++ if (unlikely(au_test_fs_unsuppoted(inode->i_sb))) {
++ AuErr("unsupported filesystem, %s (%s)\n",
++ add->pathname, au_sbtype(inode->i_sb));
++ goto out;
++ }
++
++ err = test_br(add->path.dentry->d_inode, add->perm, add->pathname);
++ if (unlikely(err))
++ goto out;
++
++ if (bend < 0)
++ return 0; /* success */
++
++ err = -EINVAL;
++ for (bindex = 0; bindex <= bend; bindex++)
++ if (unlikely(test_overlap(sb, add->path.dentry,
++ au_h_dptr(root, bindex)))) {
++ AuErr("%s is overlapped\n", add->pathname);
++ goto out;
++ }
++
++ err = 0;
++ if (au_opt_test(au_mntflags(sb), WARN_PERM)) {
++ h_inode = au_h_dptr(root, 0)->d_inode;
++ if ((h_inode->i_mode & S_IALLUGO) != (inode->i_mode & S_IALLUGO)
++ || h_inode->i_uid != inode->i_uid
++ || h_inode->i_gid != inode->i_gid)
++ AuWarn("uid/gid/perm %s %u/%u/0%o, %u/%u/0%o\n",
++ add->pathname,
++ inode->i_uid, inode->i_gid,
++ (inode->i_mode & S_IALLUGO),
++ h_inode->i_uid, h_inode->i_gid,
++ (h_inode->i_mode & S_IALLUGO));
++ }
++
++ out:
++ return err;
++}
++
++/*
++ * initialize or clean the whiteouts for an adding branch
++ */
++static int au_br_init_wh(struct super_block *sb, struct au_branch *br,
++ int new_perm, struct dentry *h_root)
++{
++ int err, old_perm;
++ aufs_bindex_t bindex;
++ struct mutex *h_mtx;
++ struct au_wbr *wbr;
++ struct au_hinode *hdir;
++
++ wbr = br->br_wbr;
++ old_perm = br->br_perm;
++ br->br_perm = new_perm;
++ hdir = NULL;
++ h_mtx = NULL;
++ bindex = au_br_index(sb, br->br_id);
++ if (0 <= bindex) {
++ hdir = au_hi(sb->s_root->d_inode, bindex);
++ au_hin_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++ } else {
++ h_mtx = &h_root->d_inode->i_mutex;
++ mutex_lock_nested(h_mtx, AuLsc_I_PARENT);
++ }
++ if (!wbr)
++ err = au_wh_init(h_root, br, sb);
++ else {
++ wbr_wh_write_lock(wbr);
++ err = au_wh_init(h_root, br, sb);
++ wbr_wh_write_unlock(wbr);
++ }
++ if (hdir)
++ au_hin_imtx_unlock(hdir);
++ else
++ mutex_unlock(h_mtx);
++ br->br_perm = old_perm;
++
++ if (!err && wbr && !au_br_writable(new_perm)) {
++ kfree(wbr);
++ br->br_wbr = NULL;
++ }
++
++ return err;
++}
++
++static int au_wbr_init(struct au_branch *br, struct super_block *sb,
++ int perm, struct path *path)
++{
++ int err;
++ struct au_wbr *wbr;
++
++ wbr = br->br_wbr;
++ init_rwsem(&wbr->wbr_wh_rwsem);
++ memset(wbr->wbr_wh, 0, sizeof(wbr->wbr_wh));
++ atomic_set(&wbr->wbr_wh_running, 0);
++ wbr->wbr_bytes = 0;
++
++ err = au_br_init_wh(sb, br, perm, path->dentry);
++
++ return err;
++}
++
++/* intialize a new branch */
++static int au_br_init(struct au_branch *br, struct super_block *sb,
++ struct au_opt_add *add)
++{
++ int err;
++
++ err = 0;
++ memset(&br->br_xino, 0, sizeof(br->br_xino));
++ mutex_init(&br->br_xino.xi_nondir_mtx);
++ br->br_perm = add->perm;
++ br->br_mnt = add->path.mnt; /* set first, mntget() later */
++ atomic_set(&br->br_count, 0);
++ br->br_xino_upper = AUFS_XINO_TRUNC_INIT;
++ atomic_set(&br->br_xino_running, 0);
++ br->br_id = au_new_br_id(sb);
++
++ if (au_br_writable(add->perm)) {
++ err = au_wbr_init(br, sb, add->perm, &add->path);
++ if (unlikely(err))
++ goto out;
++ }
++
++ if (au_opt_test(au_mntflags(sb), XINO)) {
++ err = au_xino_br(sb, br, add->path.dentry->d_inode->i_ino,
++ au_sbr(sb, 0)->br_xino.xi_file, /*do_test*/1);
++ if (unlikely(err)) {
++ AuDebugOn(br->br_xino.xi_file);
++ goto out;
++ }
++ }
++
++ sysaufs_br_init(br);
++ mntget(add->path.mnt);
++
++ out:
++ return err;
++}
++
++static void au_br_do_add_brp(struct au_sbinfo *sbinfo, aufs_bindex_t bindex,
++ struct au_branch *br, aufs_bindex_t bend,
++ aufs_bindex_t amount)
++{
++ struct au_branch **brp;
++
++ brp = sbinfo->si_branch + bindex;
++ memmove(brp + 1, brp, sizeof(*brp) * amount);
++ *brp = br;
++ sbinfo->si_bend++;
++ if (unlikely(bend < 0))
++ sbinfo->si_bend = 0;
++}
++
++static void au_br_do_add_hdp(struct au_dinfo *dinfo, aufs_bindex_t bindex,
++ aufs_bindex_t bend, aufs_bindex_t amount)
++{
++ struct au_hdentry *hdp;
++
++ hdp = dinfo->di_hdentry + bindex;
++ memmove(hdp + 1, hdp, sizeof(*hdp) * amount);
++ au_h_dentry_init(hdp);
++ dinfo->di_bend++;
++ if (unlikely(bend < 0))
++ dinfo->di_bstart = 0;
++}
++
++static void au_br_do_add_hip(struct au_iinfo *iinfo, aufs_bindex_t bindex,
++ aufs_bindex_t bend, aufs_bindex_t amount)
++{
++ struct au_hinode *hip;
++
++ hip = iinfo->ii_hinode + bindex;
++ memmove(hip + 1, hip, sizeof(*hip) * amount);
++ hip->hi_inode = NULL;
++ au_hin_init(hip, NULL);
++ iinfo->ii_bend++;
++ if (unlikely(bend < 0))
++ iinfo->ii_bstart = 0;
++}
++
++static void au_br_do_add(struct super_block *sb, struct dentry *h_dentry,
++ struct au_branch *br, aufs_bindex_t bindex)
++{
++ struct dentry *root;
++ struct inode *root_inode;
++ aufs_bindex_t bend, amount;
++
++ root = sb->s_root;
++ root_inode = root->d_inode;
++ au_plink_block_maintain(sb);
++ bend = au_sbend(sb);
++ amount = bend + 1 - bindex;
++ au_br_do_add_brp(au_sbi(sb), bindex, br, bend, amount);
++ au_br_do_add_hdp(au_di(root), bindex, bend, amount);
++ au_br_do_add_hip(au_ii(root_inode), bindex, bend, amount);
++ au_set_h_dptr(root, bindex, dget(h_dentry));
++ au_set_h_iptr(root_inode, bindex, au_igrab(h_dentry->d_inode),
++ /*flags*/0);
++}
++
++int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount)
++{
++ int err;
++ unsigned long long maxb;
++ aufs_bindex_t bend, add_bindex;
++ struct dentry *root, *h_dentry;
++ struct inode *root_inode;
++ struct au_branch *add_branch;
++
++ root = sb->s_root;
++ root_inode = root->d_inode;
++ IMustLock(root_inode);
++ err = test_add(sb, add, remount);
++ if (unlikely(err < 0))
++ goto out;
++ if (err) {
++ err = 0;
++ goto out; /* success */
++ }
++
++ bend = au_sbend(sb);
++ add_branch = au_br_alloc(sb, bend + 2, add->perm);
++ err = PTR_ERR(add_branch);
++ if (IS_ERR(add_branch))
++ goto out;
++
++ err = au_br_init(add_branch, sb, add);
++ if (unlikely(err)) {
++ au_br_do_free(add_branch);
++ goto out;
++ }
++
++ add_bindex = add->bindex;
++ h_dentry = add->path.dentry;
++ if (!remount)
++ au_br_do_add(sb, h_dentry, add_branch, add_bindex);
++ else {
++ sysaufs_brs_del(sb, add_bindex);
++ au_br_do_add(sb, h_dentry, add_branch, add_bindex);
++ sysaufs_brs_add(sb, add_bindex);
++ }
++
++ if (!add_bindex)
++ au_cpup_attr_all(root_inode, /*force*/1);
++ else
++ au_add_nlink(root_inode, h_dentry->d_inode);
++ maxb = h_dentry->d_sb->s_maxbytes;
++ if (sb->s_maxbytes < maxb)
++ sb->s_maxbytes = maxb;
++
++ /*
++ * this test/set prevents aufs from handling unnecesary inotify events
++ * of xino files, in a case of re-adding a writable branch which was
++ * once detached from aufs.
++ */
++ if (au_xino_brid(sb) < 0
++ && au_br_writable(add_branch->br_perm)
++ && !au_test_fs_bad_xino(h_dentry->d_sb)
++ && add_branch->br_xino.xi_file
++ && add_branch->br_xino.xi_file->f_dentry->d_parent == h_dentry)
++ au_xino_brid_set(sb, add_branch->br_id);
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * delete a branch
++ */
++
++/* to show the line number, do not make it inlined function */
++#define AuVerbose(do_info, fmt, args...) do { \
++ if (do_info) \
++ AuInfo(fmt, ##args); \
++} while (0)
++
++/*
++ * test if the branch is deletable or not.
++ */
++static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
++ unsigned int sigen)
++{
++ int err, i, j, ndentry;
++ aufs_bindex_t bstart, bend;
++ unsigned char verbose;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++ struct dentry *d;
++ struct inode *inode;
++
++ err = au_dpages_init(&dpages, GFP_NOFS);
++ if (unlikely(err))
++ goto out;
++ err = au_dcsub_pages(&dpages, root, NULL, NULL);
++ if (unlikely(err))
++ goto out_dpages;
++
++ verbose = !!au_opt_test(au_mntflags(root->d_sb), VERBOSE);
++ for (i = 0; !err && i < dpages.ndpage; i++) {
++ dpage = dpages.dpages + i;
++ ndentry = dpage->ndentry;
++ for (j = 0; !err && j < ndentry; j++) {
++ d = dpage->dentries[j];
++ AuDebugOn(!atomic_read(&d->d_count));
++ inode = d->d_inode;
++ if (au_digen(d) == sigen && au_iigen(inode) == sigen)
++ di_read_lock_child(d, AuLock_IR);
++ else {
++ di_write_lock_child(d);
++ err = au_reval_dpath(d, sigen);
++ if (!err)
++ di_downgrade_lock(d, AuLock_IR);
++ else {
++ di_write_unlock(d);
++ break;
++ }
++ }
++
++ bstart = au_dbstart(d);
++ bend = au_dbend(d);
++ if (bstart <= bindex
++ && bindex <= bend
++ && au_h_dptr(d, bindex)
++ && (!S_ISDIR(inode->i_mode) || bstart == bend)) {
++ err = -EBUSY;
++ AuVerbose(verbose, "busy %.*s\n", AuDLNPair(d));
++ }
++ di_read_unlock(d, AuLock_IR);
++ }
++ }
++
++ out_dpages:
++ au_dpages_free(&dpages);
++ out:
++ return err;
++}
++
++static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
++ unsigned int sigen)
++{
++ int err;
++ struct inode *i;
++ aufs_bindex_t bstart, bend;
++ unsigned char verbose;
++
++ err = 0;
++ verbose = !!au_opt_test(au_mntflags(sb), VERBOSE);
++ list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
++ AuDebugOn(!atomic_read(&i->i_count));
++ if (!list_empty(&i->i_dentry))
++ continue;
++
++ if (au_iigen(i) == sigen)
++ ii_read_lock_child(i);
++ else {
++ ii_write_lock_child(i);
++ err = au_refresh_hinode_self(i, /*do_attr*/1);
++ if (!err)
++ ii_downgrade_lock(i);
++ else {
++ ii_write_unlock(i);
++ break;
++ }
++ }
++
++ bstart = au_ibstart(i);
++ bend = au_ibend(i);
++ if (bstart <= bindex
++ && bindex <= bend
++ && au_h_iptr(i, bindex)
++ && (!S_ISDIR(i->i_mode) || bstart == bend)) {
++ err = -EBUSY;
++ AuVerbose(verbose, "busy i%lu\n", i->i_ino);
++ ii_read_unlock(i);
++ break;
++ }
++ ii_read_unlock(i);
++ }
++
++ return err;
++}
++
++static int test_children_busy(struct dentry *root, aufs_bindex_t bindex)
++{
++ int err;
++ unsigned int sigen;
++
++ sigen = au_sigen(root->d_sb);
++ DiMustNoWaiters(root);
++ IiMustNoWaiters(root->d_inode);
++ di_write_unlock(root);
++ err = test_dentry_busy(root, bindex, sigen);
++ if (!err)
++ err = test_inode_busy(root->d_sb, bindex, sigen);
++ di_write_lock_child(root); /* aufs_write_lock() calls ..._child() */
++
++ return err;
++}
++
++static void au_br_do_del_brp(struct au_sbinfo *sbinfo,
++ const aufs_bindex_t bindex,
++ const aufs_bindex_t bend)
++{
++ struct au_branch **brp, **p;
++
++ brp = sbinfo->si_branch + bindex;
++ if (bindex < bend)
++ memmove(brp, brp + 1, sizeof(*brp) * (bend - bindex));
++ sbinfo->si_branch[0 + bend] = NULL;
++ sbinfo->si_bend--;
++
++ p = krealloc(sbinfo->si_branch, sizeof(*p) * bend, GFP_NOFS);
++ if (p)
++ sbinfo->si_branch = p;
++}
++
++static void au_br_do_del_hdp(struct au_dinfo *dinfo, const aufs_bindex_t bindex,
++ const aufs_bindex_t bend)
++{
++ struct au_hdentry *hdp, *p;
++
++ hdp = dinfo->di_hdentry + bindex;
++ if (bindex < bend)
++ memmove(hdp, hdp + 1, sizeof(*hdp) * (bend - bindex));
++ dinfo->di_hdentry[0 + bend].hd_dentry = NULL;
++ dinfo->di_bend--;
++
++ p = krealloc(dinfo->di_hdentry, sizeof(*p) * bend, GFP_NOFS);
++ if (p)
++ dinfo->di_hdentry = p;
++}
++
++static void au_br_do_del_hip(struct au_iinfo *iinfo, const aufs_bindex_t bindex,
++ const aufs_bindex_t bend)
++{
++ struct au_hinode *hip, *p;
++
++ hip = iinfo->ii_hinode + bindex;
++ if (bindex < bend)
++ memmove(hip, hip + 1, sizeof(*hip) * (bend - bindex));
++ iinfo->ii_hinode[0 + bend].hi_inode = NULL;
++ au_hin_init(iinfo->ii_hinode + bend, NULL);
++ iinfo->ii_bend--;
++
++ p = krealloc(iinfo->ii_hinode, sizeof(*p) * bend, GFP_NOFS);
++ if (p)
++ iinfo->ii_hinode = p;
++}
++
++static void au_br_do_del(struct super_block *sb, aufs_bindex_t bindex,
++ struct au_branch *br)
++{
++ aufs_bindex_t bend;
++ struct au_sbinfo *sbinfo;
++ struct dentry *root;
++ struct inode *inode;
++
++ root = sb->s_root;
++ inode = root->d_inode;
++ au_plink_block_maintain(sb);
++ sbinfo = au_sbi(sb);
++ bend = sbinfo->si_bend;
++
++ dput(au_h_dptr(root, bindex));
++ au_hiput(au_hi(inode, bindex));
++ au_br_do_free(br);
++
++ au_br_do_del_brp(sbinfo, bindex, bend);
++ au_br_do_del_hdp(au_di(root), bindex, bend);
++ au_br_do_del_hip(au_ii(inode), bindex, bend);
++}
++
++int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount)
++{
++ int err, rerr, i;
++ unsigned int mnt_flags;
++ aufs_bindex_t bindex, bend, br_id;
++ unsigned char do_wh, verbose;
++ struct au_branch *br;
++ struct au_wbr *wbr;
++
++ err = 0;
++ bindex = au_find_dbindex(sb->s_root, del->h_path.dentry);
++ if (bindex < 0) {
++ if (remount)
++ goto out; /* success */
++ err = -ENOENT;
++ AuErr("%s no such branch\n", del->pathname);
++ goto out;
++ }
++ AuDbg("bindex b%d\n", bindex);
++
++ err = -EBUSY;
++ mnt_flags = au_mntflags(sb);
++ verbose = !!au_opt_test(mnt_flags, VERBOSE);
++ bend = au_sbend(sb);
++ if (unlikely(!bend)) {
++ AuVerbose(verbose, "no more branches left\n");
++ goto out;
++ }
++ br = au_sbr(sb, bindex);
++ i = atomic_read(&br->br_count);
++ if (unlikely(i)) {
++ AuVerbose(verbose, "%d file(s) opened\n", i);
++ goto out;
++ }
++
++ wbr = br->br_wbr;
++ do_wh = wbr && (wbr->wbr_whbase || wbr->wbr_plink || wbr->wbr_orph);
++ if (do_wh) {
++ for (i = 0; i < AuBrWh_Last; i++) {
++ dput(wbr->wbr_wh[i]);
++ wbr->wbr_wh[i] = NULL;
++ }
++ }
++
++ err = test_children_busy(sb->s_root, bindex);
++ if (unlikely(err)) {
++ if (do_wh)
++ goto out_wh;
++ goto out;
++ }
++
++ err = 0;
++ br_id = br->br_id;
++ if (!remount)
++ au_br_do_del(sb, bindex, br);
++ else {
++ sysaufs_brs_del(sb, bindex);
++ au_br_do_del(sb, bindex, br);
++ sysaufs_brs_add(sb, bindex);
++ }
++
++ if (!bindex)
++ au_cpup_attr_all(sb->s_root->d_inode, /*force*/1);
++ else
++ au_sub_nlink(sb->s_root->d_inode, del->h_path.dentry->d_inode);
++ if (au_opt_test(mnt_flags, PLINK))
++ au_plink_half_refresh(sb, br_id);
++
++ if (sb->s_maxbytes == del->h_path.dentry->d_sb->s_maxbytes) {
++ bend--;
++ sb->s_maxbytes = 0;
++ for (bindex = 0; bindex <= bend; bindex++) {
++ unsigned long long maxb;
++
++ maxb = au_sbr_sb(sb, bindex)->s_maxbytes;
++ if (sb->s_maxbytes < maxb)
++ sb->s_maxbytes = maxb;
++ }
++ }
++
++ if (au_xino_brid(sb) == br->br_id)
++ au_xino_brid_set(sb, -1);
++ goto out; /* success */
++
++ out_wh:
++ /* revert */
++ rerr = au_br_init_wh(sb, br, br->br_perm, del->h_path.dentry);
++ if (rerr)
++ AuWarn("failed re-creating base whiteout, %s. (%d)\n",
++ del->pathname, rerr);
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * change a branch permission
++ */
++
++static int do_need_sigen_inc(int a, int b)
++{
++ return au_br_whable(a) && !au_br_whable(b);
++}
++
++static int need_sigen_inc(int old, int new)
++{
++ return do_need_sigen_inc(old, new)
++ || do_need_sigen_inc(new, old);
++}
++
++static int au_br_mod_files_ro(struct super_block *sb, aufs_bindex_t bindex)
++{
++ int err;
++ unsigned long n, ul, bytes, files;
++ aufs_bindex_t bstart;
++ struct file *file, *hf, **a;
++ const int step_bytes = 1024, /* memory allocation unit */
++ step_files = step_bytes / sizeof(*a);
++
++ err = -ENOMEM;
++ n = 0;
++ bytes = step_bytes;
++ files = step_files;
++ a = kmalloc(bytes, GFP_NOFS);
++ if (unlikely(!a))
++ goto out;
++
++ /* no need file_list_lock() since sbinfo is locked? defered? */
++ list_for_each_entry(file, &sb->s_files, f_u.fu_list) {
++ if (special_file(file->f_dentry->d_inode->i_mode))
++ continue;
++
++ AuDbg("%.*s\n", AuDLNPair(file->f_dentry));
++ fi_read_lock(file);
++ if (unlikely(au_test_mmapped(file))) {
++ err = -EBUSY;
++ FiMustNoWaiters(file);
++ fi_read_unlock(file);
++ goto out_free;
++ }
++
++ bstart = au_fbstart(file);
++ if (!S_ISREG(file->f_dentry->d_inode->i_mode)
++ || !(file->f_mode & FMODE_WRITE)
++ || bstart != bindex) {
++ FiMustNoWaiters(file);
++ fi_read_unlock(file);
++ continue;
++ }
++
++ hf = au_h_fptr(file, bstart);
++ FiMustNoWaiters(file);
++ fi_read_unlock(file);
++
++ if (n < files)
++ a[n++] = hf;
++ else {
++ void *p;
++
++ err = -ENOMEM;
++ bytes += step_bytes;
++ files += step_files;
++ p = krealloc(a, bytes, GFP_NOFS);
++ if (p) {
++ a = p;
++ a[n++] = hf;
++ } else
++ goto out_free;
++ }
++ }
++
++ err = 0;
++ for (ul = 0; ul < n; ul++) {
++ /* todo: already flushed? */
++ /* cf. fs/super.c:mark_files_ro() */
++ hf = a[ul];
++ hf->f_mode &= ~FMODE_WRITE;
++ if (!file_check_writeable(hf)) {
++ file_release_write(hf);
++ mnt_drop_write(hf->f_vfsmnt);
++ }
++ }
++
++ out_free:
++ kfree(a);
++ out:
++ return err;
++}
++
++int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
++ int *do_update)
++{
++ int err, rerr;
++ aufs_bindex_t bindex;
++ struct dentry *root;
++ struct au_branch *br;
++
++ root = sb->s_root;
++ au_plink_block_maintain(sb);
++ bindex = au_find_dbindex(root, mod->h_root);
++ if (bindex < 0) {
++ if (remount)
++ return 0; /* success */
++ err = -ENOENT;
++ AuErr("%s no such branch\n", mod->path);
++ goto out;
++ }
++ AuDbg("bindex b%d\n", bindex);
++
++ err = test_br(mod->h_root->d_inode, mod->perm, mod->path);
++ if (unlikely(err))
++ goto out;
++
++ br = au_sbr(sb, bindex);
++ if (br->br_perm == mod->perm)
++ return 0; /* success */
++
++ if (au_br_writable(br->br_perm)) {
++ /* remove whiteout base */
++ err = au_br_init_wh(sb, br, mod->perm, mod->h_root);
++ if (unlikely(err))
++ goto out;
++
++ if (!au_br_writable(mod->perm)) {
++ /* rw --> ro, file might be mmapped */
++ DiMustNoWaiters(root);
++ IiMustNoWaiters(root->d_inode);
++ di_write_unlock(root);
++ err = au_br_mod_files_ro(sb, bindex);
++ /* aufs_write_lock() calls ..._child() */
++ di_write_lock_child(root);
++
++ if (unlikely(err)) {
++ rerr = -ENOMEM;
++ br->br_wbr = kmalloc(sizeof(*br->br_wbr),
++ GFP_NOFS);
++ if (br->br_wbr)
++ rerr = au_br_init_wh
++ (sb, br, br->br_perm,
++ mod->h_root);
++ if (unlikely(rerr)) {
++ AuIOErr("nested error %d (%d)\n",
++ rerr, err);
++ br->br_perm = mod->perm;
++ }
++ }
++ }
++ } else if (au_br_writable(mod->perm)) {
++ /* ro --> rw */
++ err = -ENOMEM;
++ br->br_wbr = kmalloc(sizeof(*br->br_wbr), GFP_NOFS);
++ if (br->br_wbr) {
++ struct path path = {
++ .mnt = br->br_mnt,
++ .dentry = mod->h_root
++ };
++
++ err = au_wbr_init(br, sb, mod->perm, &path);
++ if (unlikely(err)) {
++ kfree(br->br_wbr);
++ br->br_wbr = NULL;
++ }
++ }
++ }
++
++ if (!err) {
++ *do_update |= need_sigen_inc(br->br_perm, mod->perm);
++ br->br_perm = mod->perm;
++ }
++
++ out:
++ return err;
++}
+diff --git a/fs/aufs/branch.h b/fs/aufs/branch.h
+new file mode 100644
+index 0000000..e448692
+--- /dev/null
++++ b/fs/aufs/branch.h
+@@ -0,0 +1,207 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * branch filesystems and xino for them
++ */
++
++#ifndef __AUFS_BRANCH_H__
++#define __AUFS_BRANCH_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/mount.h>
++#include <linux/sysfs.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++#include "super.h"
++
++/* ---------------------------------------------------------------------- */
++
++/* a xino file */
++struct au_xino_file {
++ struct file *xi_file;
++ struct mutex xi_nondir_mtx;
++
++ /* todo: make xino files an array to support huge inode number */
++
++#ifdef CONFIG_DEBUG_FS
++ struct dentry *xi_dbgaufs;
++#endif
++};
++
++/* members for writable branch only */
++enum {AuBrWh_BASE, AuBrWh_PLINK, AuBrWh_ORPH, AuBrWh_Last};
++struct au_wbr {
++ struct rw_semaphore wbr_wh_rwsem;
++ struct dentry *wbr_wh[AuBrWh_Last];
++ atomic_t wbr_wh_running;
++#define wbr_whbase wbr_wh[AuBrWh_BASE] /* whiteout base */
++#define wbr_plink wbr_wh[AuBrWh_PLINK] /* pseudo-link dir */
++#define wbr_orph wbr_wh[AuBrWh_ORPH] /* dir for orphans */
++
++ /* mfs mode */
++ unsigned long long wbr_bytes;
++};
++
++/* protected by superblock rwsem */
++struct au_branch {
++ struct au_xino_file br_xino;
++
++ aufs_bindex_t br_id;
++
++ int br_perm;
++ struct vfsmount *br_mnt;
++ atomic_t br_count;
++
++ struct au_wbr *br_wbr;
++
++ /* xino truncation */
++ blkcnt_t br_xino_upper; /* watermark in blocks */
++ atomic_t br_xino_running;
++
++#ifdef CONFIG_SYSFS
++ /* an entry under sysfs per mount-point */
++ char br_name[8];
++ struct attribute br_attr;
++#endif
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* branch permission and attribute */
++enum {
++ AuBrPerm_RW, /* writable, linkable wh */
++ AuBrPerm_RO, /* readonly, no wh */
++ AuBrPerm_RR, /* natively readonly, no wh */
++
++ AuBrPerm_RWNoLinkWH, /* un-linkable whiteouts */
++
++ AuBrPerm_ROWH, /* whiteout-able */
++ AuBrPerm_RRWH, /* whiteout-able */
++
++ AuBrPerm_Last
++};
++
++static inline int au_br_writable(int brperm)
++{
++ return brperm == AuBrPerm_RW || brperm == AuBrPerm_RWNoLinkWH;
++}
++
++static inline int au_br_whable(int brperm)
++{
++ return brperm == AuBrPerm_RW
++ || brperm == AuBrPerm_ROWH
++ || brperm == AuBrPerm_RRWH;
++}
++
++static inline int au_br_rdonly(struct au_branch *br)
++{
++ return ((br->br_mnt->mnt_sb->s_flags & MS_RDONLY)
++ || !au_br_writable(br->br_perm))
++ ? -EROFS : 0;
++}
++
++static inline int au_br_hinotifyable(int brperm __maybe_unused)
++{
++#ifdef CONFIG_AUFS_HINOTIFY
++ return brperm != AuBrPerm_RR && brperm != AuBrPerm_RRWH;
++#else
++ return 0;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* branch.c */
++struct au_sbinfo;
++void au_br_free(struct au_sbinfo *sinfo);
++int au_br_index(struct super_block *sb, aufs_bindex_t br_id);
++struct au_opt_add;
++int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount);
++struct au_opt_del;
++int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount);
++struct au_opt_mod;
++int au_br_mod(struct super_block *sb, struct au_opt_mod *mod, int remount,
++ int *do_update);
++
++/* xino.c */
++static const loff_t au_loff_max = LLONG_MAX;
++
++int au_xib_trunc(struct super_block *sb);
++ssize_t xino_fread(au_readf_t func, struct file *file, void *buf, size_t size,
++ loff_t *pos);
++ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
++ loff_t *pos);
++struct file *au_xino_create2(struct file *base_file, struct file *copy_src);
++struct file *au_xino_create(struct super_block *sb, char *fname, int silent);
++ino_t au_xino_new_ino(struct super_block *sb);
++int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t ino);
++int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t ino);
++int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t *ino);
++int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t hino,
++ struct file *base_file, int do_test);
++int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex);
++
++struct au_opt_xino;
++int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount);
++void au_xino_clr(struct super_block *sb);
++struct file *au_xino_def(struct super_block *sb);
++int au_xino_path(struct seq_file *seq, struct file *file);
++
++/* ---------------------------------------------------------------------- */
++
++/* Superblock to branch */
++static inline
++aufs_bindex_t au_sbr_id(struct super_block *sb, aufs_bindex_t bindex)
++{
++ return au_sbr(sb, bindex)->br_id;
++}
++
++static inline
++struct vfsmount *au_sbr_mnt(struct super_block *sb, aufs_bindex_t bindex)
++{
++ return au_sbr(sb, bindex)->br_mnt;
++}
++
++static inline
++struct super_block *au_sbr_sb(struct super_block *sb, aufs_bindex_t bindex)
++{
++ return au_sbr_mnt(sb, bindex)->mnt_sb;
++}
++
++static inline void au_sbr_put(struct super_block *sb, aufs_bindex_t bindex)
++{
++ atomic_dec(&au_sbr(sb, bindex)->br_count);
++}
++
++static inline int au_sbr_perm(struct super_block *sb, aufs_bindex_t bindex)
++{
++ return au_sbr(sb, bindex)->br_perm;
++}
++
++static inline int au_sbr_whable(struct super_block *sb, aufs_bindex_t bindex)
++{
++ return au_br_whable(au_sbr_perm(sb, bindex));
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * wbr_wh_read_lock, wbr_wh_write_lock
++ * wbr_wh_read_unlock, wbr_wh_write_unlock, wbr_wh_downgrade_lock
++ */
++AuSimpleRwsemFuncs(wbr_wh, struct au_wbr *wbr, &wbr->wbr_wh_rwsem);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_BRANCH_H__ */
+diff --git a/fs/aufs/cpup.c b/fs/aufs/cpup.c
+new file mode 100644
+index 0000000..91808b1
+--- /dev/null
++++ b/fs/aufs/cpup.c
+@@ -0,0 +1,1028 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * copy-up functions, see wbr_policy.c for copy-down
++ */
++
++#include <linux/fs_stack.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++void au_cpup_attr_flags(struct inode *dst, struct inode *src)
++{
++ const unsigned int mask = S_DEAD | S_SWAPFILE | S_PRIVATE
++ | S_NOATIME | S_NOCMTIME;
++
++ dst->i_flags |= src->i_flags & ~mask;
++ if (au_test_fs_notime(dst->i_sb))
++ dst->i_flags |= S_NOATIME | S_NOCMTIME;
++}
++
++void au_cpup_attr_timesizes(struct inode *inode)
++{
++ struct inode *h_inode;
++
++ h_inode = au_h_iptr(inode, au_ibstart(inode));
++ fsstack_copy_attr_times(inode, h_inode);
++ vfsub_copy_inode_size(inode, h_inode);
++}
++
++void au_cpup_attr_nlink(struct inode *inode, int force)
++{
++ struct inode *h_inode;
++ struct super_block *sb;
++ aufs_bindex_t bindex, bend;
++
++ sb = inode->i_sb;
++ bindex = au_ibstart(inode);
++ h_inode = au_h_iptr(inode, bindex);
++ if (!force
++ && !S_ISDIR(h_inode->i_mode)
++ && au_opt_test(au_mntflags(sb), PLINK)
++ && au_plink_test(inode))
++ return;
++
++ inode->i_nlink = h_inode->i_nlink;
++
++ /*
++ * fewer nlink makes find(1) noisy, but larger nlink doesn't.
++ * it may includes whplink directory.
++ */
++ if (S_ISDIR(h_inode->i_mode)) {
++ bend = au_ibend(inode);
++ for (bindex++; bindex <= bend; bindex++) {
++ h_inode = au_h_iptr(inode, bindex);
++ if (h_inode)
++ au_add_nlink(inode, h_inode);
++ }
++ }
++}
++
++void au_cpup_attr_changeable(struct inode *inode)
++{
++ struct inode *h_inode;
++
++ h_inode = au_h_iptr(inode, au_ibstart(inode));
++ inode->i_mode = h_inode->i_mode;
++ inode->i_uid = h_inode->i_uid;
++ inode->i_gid = h_inode->i_gid;
++ au_cpup_attr_timesizes(inode);
++ au_cpup_attr_flags(inode, h_inode);
++}
++
++void au_cpup_igen(struct inode *inode, struct inode *h_inode)
++{
++ struct au_iinfo *iinfo = au_ii(inode);
++
++ iinfo->ii_higen = h_inode->i_generation;
++ iinfo->ii_hsb1 = h_inode->i_sb;
++}
++
++void au_cpup_attr_all(struct inode *inode, int force)
++{
++ struct inode *h_inode;
++
++ h_inode = au_h_iptr(inode, au_ibstart(inode));
++ au_cpup_attr_changeable(inode);
++ if (inode->i_nlink > 0)
++ au_cpup_attr_nlink(inode, force);
++ inode->i_rdev = h_inode->i_rdev;
++ inode->i_blkbits = h_inode->i_blkbits;
++ au_cpup_igen(inode, h_inode);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* Note: dt_dentry and dt_h_dentry are not dget/dput-ed */
++
++/* keep the timestamps of the parent dir when cpup */
++void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
++ struct path *h_path)
++{
++ struct inode *h_inode;
++
++ dt->dt_dentry = dentry;
++ dt->dt_h_path = *h_path;
++ h_inode = h_path->dentry->d_inode;
++ dt->dt_atime = h_inode->i_atime;
++ dt->dt_mtime = h_inode->i_mtime;
++ /* smp_mb(); */
++}
++
++void au_dtime_revert(struct au_dtime *dt)
++{
++ struct iattr attr;
++ int err;
++
++ attr.ia_atime = dt->dt_atime;
++ attr.ia_mtime = dt->dt_mtime;
++ attr.ia_valid = ATTR_FORCE | ATTR_MTIME | ATTR_MTIME_SET
++ | ATTR_ATIME | ATTR_ATIME_SET;
++
++ err = vfsub_notify_change(&dt->dt_h_path, &attr);
++ if (unlikely(err))
++ AuWarn("restoring timestamps failed(%d). ignored\n", err);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static noinline_for_stack
++int cpup_iattr(struct dentry *dst, aufs_bindex_t bindex, struct dentry *h_src)
++{
++ int err, sbits;
++ struct iattr ia;
++ struct path h_path;
++ struct inode *h_isrc;
++
++ h_path.dentry = au_h_dptr(dst, bindex);
++ h_path.mnt = au_sbr_mnt(dst->d_sb, bindex);
++ h_isrc = h_src->d_inode;
++ ia.ia_valid = ATTR_FORCE | ATTR_MODE | ATTR_UID | ATTR_GID
++ | ATTR_ATIME | ATTR_MTIME
++ | ATTR_ATIME_SET | ATTR_MTIME_SET;
++ ia.ia_mode = h_isrc->i_mode;
++ ia.ia_uid = h_isrc->i_uid;
++ ia.ia_gid = h_isrc->i_gid;
++ ia.ia_atime = h_isrc->i_atime;
++ ia.ia_mtime = h_isrc->i_mtime;
++ sbits = !!(ia.ia_mode & (S_ISUID | S_ISGID));
++ au_cpup_attr_flags(h_path.dentry->d_inode, h_isrc);
++ err = vfsub_notify_change(&h_path, &ia);
++
++ /* is this nfs only? */
++ if (!err && sbits && au_test_nfs(h_path.dentry->d_sb)) {
++ ia.ia_valid = ATTR_FORCE | ATTR_MODE;
++ ia.ia_mode = h_isrc->i_mode;
++ err = vfsub_notify_change(&h_path, &ia);
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_copy_file(struct file *dst, struct file *src, loff_t len,
++ char *buf, unsigned long blksize)
++{
++ int err;
++ size_t sz, rbytes, wbytes;
++ unsigned char all_zero;
++ char *p, *zp;
++ struct mutex *h_mtx;
++ /* reduce stack usage */
++ struct iattr *ia;
++
++ zp = page_address(ZERO_PAGE(0));
++ if (unlikely(!zp))
++ return -ENOMEM; /* possible? */
++
++ err = 0;
++ all_zero = 0;
++ while (len) {
++ AuDbg("len %lld\n", len);
++ sz = blksize;
++ if (len < blksize)
++ sz = len;
++
++ rbytes = 0;
++ /* todo: signal_pending? */
++ while (!rbytes || err == -EAGAIN || err == -EINTR) {
++ rbytes = vfsub_read_k(src, buf, sz, &src->f_pos);
++ err = rbytes;
++ }
++ if (unlikely(err < 0))
++ break;
++
++ all_zero = 0;
++ if (len >= rbytes && rbytes == blksize)
++ all_zero = !memcmp(buf, zp, rbytes);
++ if (!all_zero) {
++ wbytes = rbytes;
++ p = buf;
++ while (wbytes) {
++ size_t b;
++
++ b = vfsub_write_k(dst, p, wbytes, &dst->f_pos);
++ err = b;
++ /* todo: signal_pending? */
++ if (unlikely(err == -EAGAIN || err == -EINTR))
++ continue;
++ if (unlikely(err < 0))
++ break;
++ wbytes -= b;
++ p += b;
++ }
++ } else {
++ loff_t res;
++
++ AuLabel(hole);
++ res = vfsub_llseek(dst, rbytes, SEEK_CUR);
++ err = res;
++ if (unlikely(res < 0))
++ break;
++ }
++ len -= rbytes;
++ err = 0;
++ }
++
++ /* the last block may be a hole */
++ if (!err && all_zero) {
++ AuLabel(last hole);
++
++ err = 1;
++ if (au_test_nfs(dst->f_dentry->d_sb)) {
++ /* nfs requires this step to make last hole */
++ /* is this only nfs? */
++ do {
++ /* todo: signal_pending? */
++ err = vfsub_write_k(dst, "\0", 1, &dst->f_pos);
++ } while (err == -EAGAIN || err == -EINTR);
++ if (err == 1)
++ dst->f_pos--;
++ }
++
++ if (err == 1) {
++ ia = (void *)buf;
++ ia->ia_size = dst->f_pos;
++ ia->ia_valid = ATTR_SIZE | ATTR_FILE;
++ ia->ia_file = dst;
++ h_mtx = &dst->f_dentry->d_inode->i_mutex;
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD2);
++ err = vfsub_notify_change(&dst->f_path, ia);
++ mutex_unlock(h_mtx);
++ }
++ }
++
++ return err;
++}
++
++int au_copy_file(struct file *dst, struct file *src, loff_t len)
++{
++ int err;
++ unsigned long blksize;
++ unsigned char do_kfree;
++ char *buf;
++
++ err = -ENOMEM;
++ blksize = dst->f_dentry->d_sb->s_blocksize;
++ if (!blksize || PAGE_SIZE < blksize)
++ blksize = PAGE_SIZE;
++ AuDbg("blksize %lu\n", blksize);
++ do_kfree = (blksize != PAGE_SIZE && blksize >= sizeof(struct iattr *));
++ if (do_kfree)
++ buf = kmalloc(blksize, GFP_NOFS);
++ else
++ buf = (void *)__get_free_page(GFP_NOFS);
++ if (unlikely(!buf))
++ goto out;
++
++ if (len > (1 << 22))
++ AuDbg("copying a large file %lld\n", (long long)len);
++
++ src->f_pos = 0;
++ dst->f_pos = 0;
++ err = au_do_copy_file(dst, src, len, buf, blksize);
++ if (do_kfree)
++ kfree(buf);
++ else
++ free_page((unsigned long)buf);
++
++ out:
++ return err;
++}
++
++/*
++ * to support a sparse file which is opened with O_APPEND,
++ * we need to close the file.
++ */
++static int au_cp_regular(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len)
++{
++ int err, i;
++ enum { SRC, DST };
++ struct {
++ aufs_bindex_t bindex;
++ unsigned int flags;
++ struct dentry *dentry;
++ struct file *file;
++ void *label, *label_file;
++ } *f, file[] = {
++ {
++ .bindex = bsrc,
++ .flags = O_RDONLY | O_NOATIME | O_LARGEFILE,
++ .file = NULL,
++ .label = &&out,
++ .label_file = &&out_src
++ },
++ {
++ .bindex = bdst,
++ .flags = O_WRONLY | O_NOATIME | O_LARGEFILE,
++ .file = NULL,
++ .label = &&out_src,
++ .label_file = &&out_dst
++ }
++ };
++ struct super_block *sb;
++
++ /* bsrc branch can be ro/rw. */
++ sb = dentry->d_sb;
++ f = file;
++ for (i = 0; i < 2; i++, f++) {
++ f->dentry = au_h_dptr(dentry, f->bindex);
++ f->file = au_h_open(dentry, f->bindex, f->flags, /*file*/NULL);
++ err = PTR_ERR(f->file);
++ if (IS_ERR(f->file))
++ goto *f->label;
++ err = -EINVAL;
++ if (unlikely(!f->file->f_op))
++ goto *f->label_file;
++ }
++
++ /* try stopping to update while we copyup */
++ IMustLock(file[SRC].dentry->d_inode);
++ err = au_copy_file(file[DST].file, file[SRC].file, len);
++
++ out_dst:
++ fput(file[DST].file);
++ au_sbr_put(sb, file[DST].bindex);
++ out_src:
++ fput(file[SRC].file);
++ au_sbr_put(sb, file[SRC].bindex);
++ out:
++ return err;
++}
++
++static int au_do_cpup_regular(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len,
++ struct inode *h_dir, struct path *h_path)
++{
++ int err, rerr;
++ loff_t l;
++
++ err = 0;
++ l = i_size_read(au_h_iptr(dentry->d_inode, bsrc));
++ if (len == -1 || l < len)
++ len = l;
++ if (len)
++ err = au_cp_regular(dentry, bdst, bsrc, len);
++ if (!err)
++ goto out; /* success */
++
++ rerr = vfsub_unlink(h_dir, h_path, /*force*/0);
++ if (rerr) {
++ AuIOErr("failed unlinking cpup-ed %.*s(%d, %d)\n",
++ AuDLNPair(h_path->dentry), err, rerr);
++ err = -EIO;
++ }
++
++ out:
++ return err;
++}
++
++static int au_do_cpup_symlink(struct path *h_path, struct dentry *h_src,
++ struct inode *h_dir)
++{
++ int err, symlen;
++ mm_segment_t old_fs;
++ char *sym;
++
++ err = -ENOSYS;
++ if (unlikely(!h_src->d_inode->i_op->readlink))
++ goto out;
++
++ err = -ENOMEM;
++ sym = __getname();
++ if (unlikely(!sym))
++ goto out;
++
++ old_fs = get_fs();
++ set_fs(KERNEL_DS);
++ symlen = h_src->d_inode->i_op->readlink(h_src, (char __user *)sym,
++ PATH_MAX);
++ err = symlen;
++ set_fs(old_fs);
++
++ if (symlen > 0) {
++ sym[symlen] = 0;
++ err = vfsub_symlink(h_dir, h_path, sym);
++ }
++ __putname(sym);
++
++ out:
++ return err;
++}
++
++/* return with the lower dst inode is locked */
++static noinline_for_stack
++int cpup_entry(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++ struct dentry *dst_parent)
++{
++ int err;
++ umode_t mode;
++ unsigned int mnt_flags;
++ unsigned char isdir;
++ const unsigned char do_dt = !!au_ftest_cpup(flags, DTIME);
++ struct au_dtime dt;
++ struct path h_path;
++ struct dentry *h_src, *h_dst, *h_parent;
++ struct inode *h_inode, *h_dir;
++ struct super_block *sb;
++
++ /* bsrc branch can be ro/rw. */
++ h_src = au_h_dptr(dentry, bsrc);
++ h_inode = h_src->d_inode;
++ AuDebugOn(h_inode != au_h_iptr(dentry->d_inode, bsrc));
++
++ /* try stopping to be referenced while we are creating */
++ h_dst = au_h_dptr(dentry, bdst);
++ h_parent = h_dst->d_parent; /* dir inode is locked */
++ h_dir = h_parent->d_inode;
++ IMustLock(h_dir);
++ AuDebugOn(h_parent != h_dst->d_parent);
++
++ sb = dentry->d_sb;
++ h_path.mnt = au_sbr_mnt(sb, bdst);
++ if (do_dt) {
++ h_path.dentry = h_parent;
++ au_dtime_store(&dt, dst_parent, &h_path);
++ }
++ h_path.dentry = h_dst;
++
++ isdir = 0;
++ mode = h_inode->i_mode;
++ switch (mode & S_IFMT) {
++ case S_IFREG:
++ /* try stopping to update while we are referencing */
++ IMustLock(h_inode);
++ err = vfsub_create(h_dir, &h_path, mode | S_IWUSR);
++ if (!err)
++ err = au_do_cpup_regular
++ (dentry, bdst, bsrc, len,
++ au_h_iptr(dst_parent->d_inode, bdst), &h_path);
++ break;
++ case S_IFDIR:
++ isdir = 1;
++ err = vfsub_mkdir(h_dir, &h_path, mode);
++ if (!err) {
++ /*
++ * strange behaviour from the users view,
++ * particularry setattr case
++ */
++ if (au_ibstart(dst_parent->d_inode) == bdst)
++ au_cpup_attr_nlink(dst_parent->d_inode,
++ /*force*/1);
++ au_cpup_attr_nlink(dentry->d_inode, /*force*/1);
++ }
++ break;
++ case S_IFLNK:
++ err = au_do_cpup_symlink(&h_path, h_src, h_dir);
++ break;
++ case S_IFCHR:
++ case S_IFBLK:
++ AuDebugOn(!capable(CAP_MKNOD));
++ /*FALLTHROUGH*/
++ case S_IFIFO:
++ case S_IFSOCK:
++ err = vfsub_mknod(h_dir, &h_path, mode, h_inode->i_rdev);
++ break;
++ default:
++ AuIOErr("Unknown inode type 0%o\n", mode);
++ err = -EIO;
++ }
++
++ mnt_flags = au_mntflags(sb);
++ if (!au_opt_test(mnt_flags, UDBA_NONE)
++ && !isdir
++ && au_opt_test(mnt_flags, XINO)
++ && h_inode->i_nlink == 1
++ /* todo: unnecessary? */
++ /* && dentry->d_inode->i_nlink == 1 */
++ && bdst < bsrc
++ && !au_ftest_cpup(flags, KEEPLINO))
++ au_xino_write0(sb, bsrc, h_inode->i_ino, /*ino*/0);
++ /* ignore this error */
++
++ if (do_dt)
++ au_dtime_revert(&dt);
++ return err;
++}
++
++/*
++ * copyup the @dentry from @bsrc to @bdst.
++ * the caller must set the both of lower dentries.
++ * @len is for truncating when it is -1 copyup the entire file.
++ * in link/rename cases, @dst_parent may be different from the real one.
++ */
++static int au_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++ struct dentry *dst_parent)
++{
++ int err, rerr;
++ aufs_bindex_t old_ibstart;
++ unsigned char isdir, plink;
++ struct au_dtime dt;
++ struct path h_path;
++ struct dentry *h_src, *h_dst, *h_parent;
++ struct inode *dst_inode, *h_dir, *inode;
++ struct super_block *sb;
++
++ AuDebugOn(bsrc <= bdst);
++
++ sb = dentry->d_sb;
++ h_path.mnt = au_sbr_mnt(sb, bdst);
++ h_dst = au_h_dptr(dentry, bdst);
++ h_parent = h_dst->d_parent; /* dir inode is locked */
++ h_dir = h_parent->d_inode;
++ IMustLock(h_dir);
++
++ h_src = au_h_dptr(dentry, bsrc);
++ inode = dentry->d_inode;
++
++ if (!dst_parent)
++ dst_parent = dget_parent(dentry);
++ else
++ dget(dst_parent);
++
++ plink = !!au_opt_test(au_mntflags(sb), PLINK);
++ dst_inode = au_h_iptr(inode, bdst);
++ if (dst_inode) {
++ if (unlikely(!plink)) {
++ err = -EIO;
++ AuIOErr("i%lu exists on a upper branch "
++ "but plink is disabled\n", inode->i_ino);
++ goto out;
++ }
++
++ if (dst_inode->i_nlink) {
++ const int do_dt = au_ftest_cpup(flags, DTIME);
++
++ h_src = au_plink_lkup(inode, bdst);
++ err = PTR_ERR(h_src);
++ if (IS_ERR(h_src))
++ goto out;
++ if (unlikely(!h_src->d_inode)) {
++ err = -EIO;
++ AuIOErr("i%lu exists on a upper branch "
++ "but plink is broken\n", inode->i_ino);
++ dput(h_src);
++ goto out;
++ }
++
++ if (do_dt) {
++ h_path.dentry = h_parent;
++ au_dtime_store(&dt, dst_parent, &h_path);
++ }
++ h_path.dentry = h_dst;
++ err = vfsub_link(h_src, h_dir, &h_path);
++ if (do_dt)
++ au_dtime_revert(&dt);
++ dput(h_src);
++ goto out;
++ } else
++ /* todo: cpup_wh_file? */
++ /* udba work */
++ au_update_brange(inode, 1);
++ }
++
++ old_ibstart = au_ibstart(inode);
++ err = cpup_entry(dentry, bdst, bsrc, len, flags, dst_parent);
++ if (unlikely(err))
++ goto out;
++ dst_inode = h_dst->d_inode;
++ mutex_lock_nested(&dst_inode->i_mutex, AuLsc_I_CHILD2);
++
++ err = cpup_iattr(dentry, bdst, h_src);
++ isdir = S_ISDIR(dst_inode->i_mode);
++ if (!err) {
++ if (bdst < old_ibstart)
++ au_set_ibstart(inode, bdst);
++ au_set_h_iptr(inode, bdst, au_igrab(dst_inode),
++ au_hi_flags(inode, isdir));
++ mutex_unlock(&dst_inode->i_mutex);
++ if (!isdir
++ && h_src->d_inode->i_nlink > 1
++ && plink)
++ au_plink_append(inode, bdst, h_dst);
++ goto out; /* success */
++ }
++
++ /* revert */
++ h_path.dentry = h_parent;
++ mutex_unlock(&dst_inode->i_mutex);
++ au_dtime_store(&dt, dst_parent, &h_path);
++ h_path.dentry = h_dst;
++ if (!isdir)
++ rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
++ else
++ rerr = vfsub_rmdir(h_dir, &h_path);
++ au_dtime_revert(&dt);
++ if (rerr) {
++ AuIOErr("failed removing broken entry(%d, %d)\n", err, rerr);
++ err = -EIO;
++ }
++
++ out:
++ dput(dst_parent);
++ return err;
++}
++
++struct au_cpup_single_args {
++ int *errp;
++ struct dentry *dentry;
++ aufs_bindex_t bdst, bsrc;
++ loff_t len;
++ unsigned int flags;
++ struct dentry *dst_parent;
++};
++
++static void au_call_cpup_single(void *args)
++{
++ struct au_cpup_single_args *a = args;
++ *a->errp = au_cpup_single(a->dentry, a->bdst, a->bsrc, a->len,
++ a->flags, a->dst_parent);
++}
++
++int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++ struct dentry *dst_parent)
++{
++ int err, wkq_err;
++ umode_t mode;
++ struct dentry *h_dentry;
++
++ h_dentry = au_h_dptr(dentry, bsrc);
++ mode = h_dentry->d_inode->i_mode & S_IFMT;
++ if ((mode != S_IFCHR && mode != S_IFBLK)
++ || capable(CAP_MKNOD))
++ err = au_cpup_single(dentry, bdst, bsrc, len, flags,
++ dst_parent);
++ else {
++ struct au_cpup_single_args args = {
++ .errp = &err,
++ .dentry = dentry,
++ .bdst = bdst,
++ .bsrc = bsrc,
++ .len = len,
++ .flags = flags,
++ .dst_parent = dst_parent
++ };
++ wkq_err = au_wkq_wait(au_call_cpup_single, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ return err;
++}
++
++/*
++ * copyup the @dentry from the first active lower branch to @bdst,
++ * using au_cpup_single().
++ */
++static int au_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ unsigned int flags)
++{
++ int err;
++ aufs_bindex_t bsrc, bend;
++
++ bend = au_dbend(dentry);
++ for (bsrc = bdst + 1; bsrc <= bend; bsrc++)
++ if (au_h_dptr(dentry, bsrc))
++ break;
++
++ err = au_lkup_neg(dentry, bdst);
++ if (!err) {
++ err = au_cpup_single(dentry, bdst, bsrc, len, flags, NULL);
++ if (!err)
++ return 0; /* success */
++
++ /* revert */
++ au_set_h_dptr(dentry, bdst, NULL);
++ au_set_dbstart(dentry, bsrc);
++ }
++
++ return err;
++}
++
++struct au_cpup_simple_args {
++ int *errp;
++ struct dentry *dentry;
++ aufs_bindex_t bdst;
++ loff_t len;
++ unsigned int flags;
++};
++
++static void au_call_cpup_simple(void *args)
++{
++ struct au_cpup_simple_args *a = args;
++ *a->errp = au_cpup_simple(a->dentry, a->bdst, a->len, a->flags);
++}
++
++int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ unsigned int flags)
++{
++ int err, wkq_err;
++ unsigned char do_sio;
++ struct dentry *parent;
++ struct inode *h_dir;
++
++ parent = dget_parent(dentry);
++ h_dir = au_h_iptr(parent->d_inode, bdst);
++ do_sio = !!au_test_h_perm_sio(h_dir, MAY_EXEC | MAY_WRITE);
++ if (!do_sio) {
++ /*
++ * testing CAP_MKNOD is for generic fs,
++ * but CAP_FSETID is for xfs only, currently.
++ */
++ umode_t mode = dentry->d_inode->i_mode;
++ do_sio = (((mode & (S_IFCHR | S_IFBLK))
++ && !capable(CAP_MKNOD))
++ || ((mode & (S_ISUID | S_ISGID))
++ && !capable(CAP_FSETID)));
++ }
++ if (!do_sio)
++ err = au_cpup_simple(dentry, bdst, len, flags);
++ else {
++ struct au_cpup_simple_args args = {
++ .errp = &err,
++ .dentry = dentry,
++ .bdst = bdst,
++ .len = len,
++ .flags = flags
++ };
++ wkq_err = au_wkq_wait(au_call_cpup_simple, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ dput(parent);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * copyup the deleted file for writing.
++ */
++static int au_do_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst,
++ struct dentry *wh_dentry, struct file *file,
++ loff_t len)
++{
++ int err;
++ aufs_bindex_t bstart;
++ struct au_dinfo *dinfo;
++ struct dentry *h_d_dst, *h_d_start;
++
++ dinfo = au_di(dentry);
++ bstart = dinfo->di_bstart;
++ h_d_dst = dinfo->di_hdentry[0 + bdst].hd_dentry;
++ dinfo->di_bstart = bdst;
++ dinfo->di_hdentry[0 + bdst].hd_dentry = wh_dentry;
++ h_d_start = dinfo->di_hdentry[0 + bstart].hd_dentry;
++ if (file)
++ dinfo->di_hdentry[0 + bstart].hd_dentry
++ = au_h_fptr(file, au_fbstart(file))->f_dentry;
++ err = au_cpup_single(dentry, bdst, bstart, len, !AuCpup_DTIME,
++ /*h_parent*/NULL);
++ if (!err && file) {
++ err = au_reopen_nondir(file);
++ dinfo->di_hdentry[0 + bstart].hd_dentry = h_d_start;
++ }
++ dinfo->di_hdentry[0 + bdst].hd_dentry = h_d_dst;
++ dinfo->di_bstart = bstart;
++
++ return err;
++}
++
++static int au_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ struct file *file)
++{
++ int err;
++ struct au_dtime dt;
++ struct dentry *parent, *h_parent, *wh_dentry;
++ struct au_branch *br;
++ struct path h_path;
++
++ br = au_sbr(dentry->d_sb, bdst);
++ parent = dget_parent(dentry);
++ h_parent = au_h_dptr(parent, bdst);
++ wh_dentry = au_whtmp_lkup(h_parent, br, &dentry->d_name);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out;
++
++ h_path.dentry = h_parent;
++ h_path.mnt = br->br_mnt;
++ au_dtime_store(&dt, parent, &h_path);
++ err = au_do_cpup_wh(dentry, bdst, wh_dentry, file, len);
++ if (unlikely(err))
++ goto out_wh;
++
++ dget(wh_dentry);
++ h_path.dentry = wh_dentry;
++ err = vfsub_unlink(h_parent->d_inode, &h_path, /*force*/0);
++ if (unlikely(err)) {
++ AuIOErr("failed remove copied-up tmp file %.*s(%d)\n",
++ AuDLNPair(wh_dentry), err);
++ err = -EIO;
++ }
++ au_dtime_revert(&dt);
++ au_set_hi_wh(dentry->d_inode, bdst, wh_dentry);
++
++ out_wh:
++ dput(wh_dentry);
++ out:
++ dput(parent);
++ return err;
++}
++
++struct au_cpup_wh_args {
++ int *errp;
++ struct dentry *dentry;
++ aufs_bindex_t bdst;
++ loff_t len;
++ struct file *file;
++};
++
++static void au_call_cpup_wh(void *args)
++{
++ struct au_cpup_wh_args *a = args;
++ *a->errp = au_cpup_wh(a->dentry, a->bdst, a->len, a->file);
++}
++
++int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ struct file *file)
++{
++ int err, wkq_err;
++ struct dentry *parent, *h_orph, *h_parent, *h_dentry;
++ struct inode *dir, *h_dir, *h_tmpdir, *h_inode;
++ struct au_wbr *wbr;
++
++ parent = dget_parent(dentry);
++ dir = parent->d_inode;
++ h_orph = NULL;
++ h_parent = NULL;
++ h_dir = au_igrab(au_h_iptr(dir, bdst));
++ h_tmpdir = h_dir;
++ if (!h_dir->i_nlink) {
++ wbr = au_sbr(dentry->d_sb, bdst)->br_wbr;
++ h_orph = wbr->wbr_orph;
++
++ h_parent = dget(au_h_dptr(parent, bdst));
++ au_set_h_dptr(parent, bdst, NULL);
++ au_set_h_dptr(parent, bdst, dget(h_orph));
++ h_tmpdir = h_orph->d_inode;
++ au_set_h_iptr(dir, bdst, NULL, 0);
++ au_set_h_iptr(dir, bdst, au_igrab(h_tmpdir), /*flags*/0);
++
++ /* this temporary unlock is safe */
++ if (file)
++ h_dentry = au_h_fptr(file, au_fbstart(file))->f_dentry;
++ else
++ h_dentry = au_h_dptr(dentry, au_dbstart(dentry));
++ h_inode = h_dentry->d_inode;
++ IMustLock(h_inode);
++ mutex_unlock(&h_inode->i_mutex);
++ mutex_lock_nested(&h_tmpdir->i_mutex, AuLsc_I_PARENT2);
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ }
++
++ if (!au_test_h_perm_sio(h_tmpdir, MAY_EXEC | MAY_WRITE))
++ err = au_cpup_wh(dentry, bdst, len, file);
++ else {
++ struct au_cpup_wh_args args = {
++ .errp = &err,
++ .dentry = dentry,
++ .bdst = bdst,
++ .len = len,
++ .file = file
++ };
++ wkq_err = au_wkq_wait(au_call_cpup_wh, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ if (h_orph) {
++ mutex_unlock(&h_tmpdir->i_mutex);
++ au_set_h_iptr(dir, bdst, NULL, 0);
++ au_set_h_iptr(dir, bdst, au_igrab(h_dir), /*flags*/0);
++ au_set_h_dptr(parent, bdst, NULL);
++ au_set_h_dptr(parent, bdst, h_parent);
++ }
++ iput(h_dir);
++ dput(parent);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * generic routine for both of copy-up and copy-down.
++ */
++/* cf. revalidate function in file.c */
++int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst,
++ int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
++ struct dentry *h_parent, void *arg),
++ void *arg)
++{
++ int err;
++ struct au_pin pin;
++ struct dentry *d, *parent, *h_parent, *real_parent;
++
++ err = 0;
++ parent = dget_parent(dentry);
++ if (IS_ROOT(parent))
++ goto out;
++
++ au_pin_init(&pin, dentry, bdst, AuLsc_DI_PARENT2, AuLsc_I_PARENT2,
++ au_opt_udba(dentry->d_sb), AuPin_MNT_WRITE);
++
++ /* do not use au_dpage */
++ real_parent = parent;
++ while (1) {
++ dput(parent);
++ parent = dget_parent(dentry);
++ h_parent = au_h_dptr(parent, bdst);
++ if (h_parent)
++ goto out; /* success */
++
++ /* find top dir which is necessary to cpup */
++ do {
++ d = parent;
++ dput(parent);
++ parent = dget_parent(d);
++ di_read_lock_parent3(parent, !AuLock_IR);
++ h_parent = au_h_dptr(parent, bdst);
++ di_read_unlock(parent, !AuLock_IR);
++ } while (!h_parent);
++
++ if (d != real_parent)
++ di_write_lock_child3(d);
++
++ /* somebody else might create while we were sleeping */
++ if (!au_h_dptr(d, bdst) || !au_h_dptr(d, bdst)->d_inode) {
++ if (au_h_dptr(d, bdst))
++ au_update_dbstart(d);
++
++ au_pin_set_dentry(&pin, d);
++ err = au_do_pin(&pin);
++ if (!err) {
++ err = cp(d, bdst, h_parent, arg);
++ au_unpin(&pin);
++ }
++ }
++
++ if (d != real_parent)
++ di_write_unlock(d);
++ if (unlikely(err))
++ break;
++ }
++
++ out:
++ dput(parent);
++ return err;
++}
++
++static int au_cpup_dir(struct dentry *dentry, aufs_bindex_t bdst,
++ struct dentry *h_parent __maybe_unused ,
++ void *arg __maybe_unused)
++{
++ return au_sio_cpup_simple(dentry, bdst, -1, AuCpup_DTIME);
++}
++
++int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++ return au_cp_dirs(dentry, bdst, au_cpup_dir, NULL);
++}
++
++int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++ int err;
++ struct dentry *parent;
++ struct inode *dir;
++
++ parent = dget_parent(dentry);
++ dir = parent->d_inode;
++ err = 0;
++ if (au_h_iptr(dir, bdst))
++ goto out;
++
++ di_read_unlock(parent, AuLock_IR);
++ di_write_lock_parent(parent);
++ /* someone else might change our inode while we were sleeping */
++ if (!au_h_iptr(dir, bdst))
++ err = au_cpup_dirs(dentry, bdst);
++ di_downgrade_lock(parent, AuLock_IR);
++
++ out:
++ dput(parent);
++ return err;
++}
+diff --git a/fs/aufs/cpup.h b/fs/aufs/cpup.h
+new file mode 100644
+index 0000000..240014a
+--- /dev/null
++++ b/fs/aufs/cpup.h
+@@ -0,0 +1,68 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * copy-up/down functions
++ */
++
++#ifndef __AUFS_CPUP_H__
++#define __AUFS_CPUP_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++
++void au_cpup_attr_flags(struct inode *dst, struct inode *src);
++void au_cpup_attr_timesizes(struct inode *inode);
++void au_cpup_attr_nlink(struct inode *inode, int force);
++void au_cpup_attr_changeable(struct inode *inode);
++void au_cpup_igen(struct inode *inode, struct inode *h_inode);
++void au_cpup_attr_all(struct inode *inode, int force);
++
++/* ---------------------------------------------------------------------- */
++
++/* cpup flags */
++#define AuCpup_DTIME 1 /* do dtime_store/revert */
++#define AuCpup_KEEPLINO (1 << 1) /* do not clear the lower xino,
++ for link(2) */
++#define au_ftest_cpup(flags, name) ((flags) & AuCpup_##name)
++#define au_fset_cpup(flags, name) { (flags) |= AuCpup_##name; }
++#define au_fclr_cpup(flags, name) { (flags) &= ~AuCpup_##name; }
++
++int au_copy_file(struct file *dst, struct file *src, loff_t len);
++int au_sio_cpup_single(struct dentry *dentry, aufs_bindex_t bdst,
++ aufs_bindex_t bsrc, loff_t len, unsigned int flags,
++ struct dentry *dst_parent);
++int au_sio_cpup_simple(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ unsigned int flags);
++int au_sio_cpup_wh(struct dentry *dentry, aufs_bindex_t bdst, loff_t len,
++ struct file *file);
++
++int au_cp_dirs(struct dentry *dentry, aufs_bindex_t bdst,
++ int (*cp)(struct dentry *dentry, aufs_bindex_t bdst,
++ struct dentry *h_parent, void *arg),
++ void *arg);
++int au_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++int au_test_and_cpup_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++
++/* ---------------------------------------------------------------------- */
++
++/* keep timestamps when copyup */
++struct au_dtime {
++ struct dentry *dt_dentry;
++ struct path dt_h_path;
++ struct timespec dt_atime, dt_mtime;
++};
++void au_dtime_store(struct au_dtime *dt, struct dentry *dentry,
++ struct path *h_path);
++void au_dtime_revert(struct au_dtime *dt);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_CPUP_H__ */
+diff --git a/fs/aufs/dbgaufs.c b/fs/aufs/dbgaufs.c
+new file mode 100644
+index 0000000..cb04b5d
+--- /dev/null
++++ b/fs/aufs/dbgaufs.c
+@@ -0,0 +1,304 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * debugfs interface
++ */
++
++#include <linux/debugfs.h>
++#include "aufs.h"
++
++#ifndef CONFIG_SYSFS
++#error DEBUG_FS depends upon SYSFS
++#endif
++
++static struct dentry *dbgaufs;
++static const mode_t dbgaufs_mode = S_IRUSR | S_IRGRP | S_IROTH;
++
++/* 20 is max digits length of ulong 64 */
++struct dbgaufs_arg {
++ int n;
++ char a[20 * 4];
++};
++
++/*
++ * common function for all XINO files
++ */
++static int dbgaufs_xi_release(struct inode *inode __maybe_unused,
++ struct file *file)
++{
++ kfree(file->private_data);
++ return 0;
++}
++
++static int dbgaufs_xi_open(struct file *xf, struct file *file, int do_fcnt)
++{
++ int err;
++ struct kstat st;
++ struct dbgaufs_arg *p;
++
++ err = -ENOMEM;
++ p = kmalloc(sizeof(*p), GFP_NOFS);
++ if (unlikely(!p))
++ goto out;
++
++ err = 0;
++ p->n = 0;
++ file->private_data = p;
++ if (!xf)
++ goto out;
++
++ err = vfs_getattr(xf->f_vfsmnt, xf->f_dentry, &st);
++ if (!err) {
++ if (do_fcnt)
++ p->n = snprintf
++ (p->a, sizeof(p->a), "%ld, %llux%lu %lld\n",
++ (long)file_count(xf), st.blocks, st.blksize,
++ (long long)st.size);
++ else
++ p->n = snprintf(p->a, sizeof(p->a), "%llux%lu %lld\n",
++ st.blocks, st.blksize,
++ (long long)st.size);
++ AuDebugOn(p->n >= sizeof(p->a));
++ } else {
++ p->n = snprintf(p->a, sizeof(p->a), "err %d\n", err);
++ err = 0;
++ }
++
++ out:
++ return err;
++
++}
++
++static ssize_t dbgaufs_xi_read(struct file *file, char __user *buf,
++ size_t count, loff_t *ppos)
++{
++ struct dbgaufs_arg *p;
++
++ p = file->private_data;
++ return simple_read_from_buffer(buf, count, ppos, p->a, p->n);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int dbgaufs_xib_open(struct inode *inode, struct file *file)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++ struct super_block *sb;
++
++ sbinfo = inode->i_private;
++ sb = sbinfo->si_sb;
++ si_noflush_read_lock(sb);
++ err = dbgaufs_xi_open(sbinfo->si_xib, file, /*do_fcnt*/0);
++ si_read_unlock(sb);
++ return err;
++}
++
++static const struct file_operations dbgaufs_xib_fop = {
++ .open = dbgaufs_xib_open,
++ .release = dbgaufs_xi_release,
++ .read = dbgaufs_xi_read
++};
++
++/* ---------------------------------------------------------------------- */
++
++#define DbgaufsXi_PREFIX "xi"
++
++static int dbgaufs_xino_open(struct inode *inode, struct file *file)
++{
++ int err;
++ long l;
++ struct au_sbinfo *sbinfo;
++ struct super_block *sb;
++ struct file *xf;
++ struct qstr *name;
++
++ err = -ENOENT;
++ xf = NULL;
++ name = &file->f_dentry->d_name;
++ if (unlikely(name->len < sizeof(DbgaufsXi_PREFIX)
++ || memcmp(name->name, DbgaufsXi_PREFIX,
++ sizeof(DbgaufsXi_PREFIX) - 1)))
++ goto out;
++ err = strict_strtol(name->name + sizeof(DbgaufsXi_PREFIX) - 1, 10, &l);
++ if (unlikely(err))
++ goto out;
++
++ sbinfo = inode->i_private;
++ sb = sbinfo->si_sb;
++ si_noflush_read_lock(sb);
++ if (l <= au_sbend(sb)) {
++ xf = au_sbr(sb, (aufs_bindex_t)l)->br_xino.xi_file;
++ err = dbgaufs_xi_open(xf, file, /*do_fcnt*/1);
++ } else
++ err = -ENOENT;
++ si_read_unlock(sb);
++
++ out:
++ return err;
++}
++
++static const struct file_operations dbgaufs_xino_fop = {
++ .open = dbgaufs_xino_open,
++ .release = dbgaufs_xi_release,
++ .read = dbgaufs_xi_read
++};
++
++void dbgaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++ aufs_bindex_t bend;
++ struct au_branch *br;
++ struct au_xino_file *xi;
++
++ if (!au_sbi(sb)->si_dbgaufs)
++ return;
++
++ bend = au_sbend(sb);
++ for (; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ xi = &br->br_xino;
++ if (xi->xi_dbgaufs) {
++ debugfs_remove(xi->xi_dbgaufs);
++ xi->xi_dbgaufs = NULL;
++ }
++ }
++}
++
++void dbgaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++ struct au_sbinfo *sbinfo;
++ struct dentry *parent;
++ struct au_branch *br;
++ struct au_xino_file *xi;
++ aufs_bindex_t bend;
++ char name[sizeof(DbgaufsXi_PREFIX) + 5]; /* "xi" bindex NULL */
++
++ sbinfo = au_sbi(sb);
++ parent = sbinfo->si_dbgaufs;
++ if (!parent)
++ return;
++
++ bend = au_sbend(sb);
++ for (; bindex <= bend; bindex++) {
++ snprintf(name, sizeof(name), DbgaufsXi_PREFIX "%d", bindex);
++ br = au_sbr(sb, bindex);
++ xi = &br->br_xino;
++ AuDebugOn(xi->xi_dbgaufs);
++ xi->xi_dbgaufs = debugfs_create_file(name, dbgaufs_mode, parent,
++ sbinfo, &dbgaufs_xino_fop);
++ /* ignore an error */
++ if (unlikely(!xi->xi_dbgaufs))
++ AuWarn1("failed %s under debugfs\n", name);
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_EXPORT
++static int dbgaufs_xigen_open(struct inode *inode, struct file *file)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++ struct super_block *sb;
++
++ sbinfo = inode->i_private;
++ sb = sbinfo->si_sb;
++ si_noflush_read_lock(sb);
++ err = dbgaufs_xi_open(sbinfo->si_xigen, file, /*do_fcnt*/0);
++ si_read_unlock(sb);
++ return err;
++}
++
++static const struct file_operations dbgaufs_xigen_fop = {
++ .open = dbgaufs_xigen_open,
++ .release = dbgaufs_xi_release,
++ .read = dbgaufs_xi_read
++};
++
++static int dbgaufs_xigen_init(struct au_sbinfo *sbinfo)
++{
++ int err;
++
++ err = -EIO;
++ sbinfo->si_dbgaufs_xigen = debugfs_create_file
++ ("xigen", dbgaufs_mode, sbinfo->si_dbgaufs, sbinfo,
++ &dbgaufs_xigen_fop);
++ if (sbinfo->si_dbgaufs_xigen)
++ err = 0;
++
++ return err;
++}
++#else
++static int dbgaufs_xigen_init(struct au_sbinfo *sbinfo)
++{
++ return 0;
++}
++#endif /* CONFIG_AUFS_EXPORT */
++
++/* ---------------------------------------------------------------------- */
++
++void dbgaufs_si_fin(struct au_sbinfo *sbinfo)
++{
++ debugfs_remove_recursive(sbinfo->si_dbgaufs);
++ sbinfo->si_dbgaufs = NULL;
++ kobject_put(&sbinfo->si_kobj);
++}
++
++int dbgaufs_si_init(struct au_sbinfo *sbinfo)
++{
++ int err;
++ char name[SysaufsSiNameLen];
++
++ err = -ENOENT;
++ if (!dbgaufs) {
++ AuErr1("/debug/aufs is uninitialized\n");
++ goto out;
++ }
++
++ err = -EIO;
++ sysaufs_name(sbinfo, name);
++ sbinfo->si_dbgaufs = debugfs_create_dir(name, dbgaufs);
++ if (unlikely(!sbinfo->si_dbgaufs))
++ goto out;
++ kobject_get(&sbinfo->si_kobj);
++
++ sbinfo->si_dbgaufs_xib = debugfs_create_file
++ ("xib", dbgaufs_mode, sbinfo->si_dbgaufs, sbinfo,
++ &dbgaufs_xib_fop);
++ if (unlikely(!sbinfo->si_dbgaufs_xib))
++ goto out_dir;
++
++ err = dbgaufs_xigen_init(sbinfo);
++ if (!err)
++ goto out; /* success */
++
++ out_dir:
++ dbgaufs_si_fin(sbinfo);
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void dbgaufs_fin(void)
++{
++ debugfs_remove(dbgaufs);
++}
++
++int __init dbgaufs_init(void)
++{
++ int err;
++
++ err = -EIO;
++ dbgaufs = debugfs_create_dir(AUFS_NAME, NULL);
++ if (dbgaufs)
++ err = 0;
++ return err;
++}
+diff --git a/fs/aufs/dbgaufs.h b/fs/aufs/dbgaufs.h
+new file mode 100644
+index 0000000..dfb0f0a
+--- /dev/null
++++ b/fs/aufs/dbgaufs.h
+@@ -0,0 +1,68 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * debugfs interface
++ */
++
++#ifndef __DBGAUFS_H__
++#define __DBGAUFS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++
++struct au_sbinfo;
++#ifdef CONFIG_DEBUG_FS
++/* dbgaufs.c */
++void dbgaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
++void dbgaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
++void dbgaufs_si_fin(struct au_sbinfo *sbinfo);
++int dbgaufs_si_init(struct au_sbinfo *sbinfo);
++void dbgaufs_fin(void);
++int __init dbgaufs_init(void);
++
++#else
++
++static inline
++void dbgaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++ /* empty */
++}
++
++static inline
++void dbgaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++ /* empty */
++}
++
++static inline
++void dbgaufs_si_fin(struct au_sbinfo *sbinfo)
++{
++ /* empty */
++}
++
++static inline
++int dbgaufs_si_init(struct au_sbinfo *sbinfo)
++{
++ return 0;
++}
++
++#define dbgaufs_fin() do {} while (0)
++
++static inline
++int __init dbgaufs_init(void)
++{
++ return 0;
++}
++#endif /* CONFIG_DEBUG_FS */
++
++#endif /* __KERNEL__ */
++#endif /* __DBGAUFS_H__ */
+diff --git a/fs/aufs/dcsub.c b/fs/aufs/dcsub.c
+new file mode 100644
+index 0000000..e4597e4
+--- /dev/null
++++ b/fs/aufs/dcsub.c
+@@ -0,0 +1,214 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sub-routines for dentry cache
++ */
++
++#include "aufs.h"
++
++static void au_dpage_free(struct au_dpage *dpage)
++{
++ int i;
++ struct dentry **p;
++
++ p = dpage->dentries;
++ for (i = 0; i < dpage->ndentry; i++)
++ dput(*p++);
++ free_page((unsigned long)dpage->dentries);
++}
++
++int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp)
++{
++ int err;
++ void *p;
++
++ err = -ENOMEM;
++ dpages->dpages = kmalloc(sizeof(*dpages->dpages), gfp);
++ if (unlikely(!dpages->dpages))
++ goto out;
++
++ p = (void *)__get_free_page(gfp);
++ if (unlikely(!p))
++ goto out_dpages;
++
++ dpages->dpages[0].ndentry = 0;
++ dpages->dpages[0].dentries = p;
++ dpages->ndpage = 1;
++ return 0; /* success */
++
++ out_dpages:
++ kfree(dpages->dpages);
++ out:
++ return err;
++}
++
++void au_dpages_free(struct au_dcsub_pages *dpages)
++{
++ int i;
++ struct au_dpage *p;
++
++ p = dpages->dpages;
++ for (i = 0; i < dpages->ndpage; i++)
++ au_dpage_free(p++);
++ kfree(dpages->dpages);
++}
++
++static int au_dpages_append(struct au_dcsub_pages *dpages,
++ struct dentry *dentry, gfp_t gfp)
++{
++ int err, sz;
++ struct au_dpage *dpage;
++ void *p;
++
++ dpage = dpages->dpages + dpages->ndpage - 1;
++ sz = PAGE_SIZE / sizeof(dentry);
++ if (unlikely(dpage->ndentry >= sz)) {
++ AuLabel(new dpage);
++ err = -ENOMEM;
++ sz = dpages->ndpage * sizeof(*dpages->dpages);
++ p = au_kzrealloc(dpages->dpages, sz,
++ sz + sizeof(*dpages->dpages), gfp);
++ if (unlikely(!p))
++ goto out;
++
++ dpages->dpages = p;
++ dpage = dpages->dpages + dpages->ndpage;
++ p = (void *)__get_free_page(gfp);
++ if (unlikely(!p))
++ goto out;
++
++ dpage->ndentry = 0;
++ dpage->dentries = p;
++ dpages->ndpage++;
++ }
++
++ dpage->dentries[dpage->ndentry++] = dget(dentry);
++ return 0; /* success */
++
++ out:
++ return err;
++}
++
++int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
++ au_dpages_test test, void *arg)
++{
++ int err;
++ struct dentry *this_parent = root;
++ struct list_head *next;
++ struct super_block *sb = root->d_sb;
++
++ err = 0;
++ spin_lock(&dcache_lock);
++ repeat:
++ next = this_parent->d_subdirs.next;
++ resume:
++ if (this_parent->d_sb == sb
++ && !IS_ROOT(this_parent)
++ && atomic_read(&this_parent->d_count)
++ && this_parent->d_inode
++ && (!test || test(this_parent, arg))) {
++ err = au_dpages_append(dpages, this_parent, GFP_ATOMIC);
++ if (unlikely(err))
++ goto out;
++ }
++
++ while (next != &this_parent->d_subdirs) {
++ struct list_head *tmp = next;
++ struct dentry *dentry = list_entry(tmp, struct dentry,
++ d_u.d_child);
++ next = tmp->next;
++ if (/*d_unhashed(dentry) || */!dentry->d_inode)
++ continue;
++ if (!list_empty(&dentry->d_subdirs)) {
++ this_parent = dentry;
++ goto repeat;
++ }
++ if (dentry->d_sb == sb
++ && atomic_read(&dentry->d_count)
++ && (!test || test(dentry, arg))) {
++ err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++ if (unlikely(err))
++ goto out;
++ }
++ }
++
++ if (this_parent != root) {
++ next = this_parent->d_u.d_child.next;
++ this_parent = this_parent->d_parent; /* dcache_lock is locked */
++ goto resume;
++ }
++ out:
++ spin_unlock(&dcache_lock);
++ return err;
++}
++
++int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
++ int do_include, au_dpages_test test, void *arg)
++{
++ int err;
++
++ err = 0;
++ spin_lock(&dcache_lock);
++ if (do_include && (!test || test(dentry, arg))) {
++ err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++ if (unlikely(err))
++ goto out;
++ }
++ while (!IS_ROOT(dentry)) {
++ dentry = dentry->d_parent; /* dcache_lock is locked */
++ if (!test || test(dentry, arg)) {
++ err = au_dpages_append(dpages, dentry, GFP_ATOMIC);
++ if (unlikely(err))
++ break;
++ }
++ }
++
++ out:
++ spin_unlock(&dcache_lock);
++
++ return err;
++}
++
++struct dentry *au_test_subdir(struct dentry *d1, struct dentry *d2)
++{
++ struct dentry *trap, **dentries;
++ int err, i, j;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++
++ trap = ERR_PTR(-ENOMEM);
++ err = au_dpages_init(&dpages, GFP_NOFS);
++ if (unlikely(err))
++ goto out;
++ err = au_dcsub_pages_rev(&dpages, d1, /*do_include*/1, NULL, NULL);
++ if (unlikely(err))
++ goto out_dpages;
++
++ trap = d1;
++ for (i = 0; !err && i < dpages.ndpage; i++) {
++ dpage = dpages.dpages + i;
++ dentries = dpage->dentries;
++ for (j = 0; !err && j < dpage->ndentry; j++) {
++ struct dentry *d;
++
++ d = dentries[j];
++ err = (d == d2);
++ if (!err)
++ trap = d;
++ }
++ }
++ if (!err)
++ trap = NULL;
++
++ out_dpages:
++ au_dpages_free(&dpages);
++ out:
++ return trap;
++}
+diff --git a/fs/aufs/dcsub.h b/fs/aufs/dcsub.h
+new file mode 100644
+index 0000000..89a7745
+--- /dev/null
++++ b/fs/aufs/dcsub.h
+@@ -0,0 +1,43 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sub-routines for dentry cache
++ */
++
++#ifndef __AUFS_DCSUB_H__
++#define __AUFS_DCSUB_H__
++
++#ifdef __KERNEL__
++
++#include <linux/dcache.h>
++
++struct au_dpage {
++ int ndentry;
++ struct dentry **dentries;
++};
++
++struct au_dcsub_pages {
++ int ndpage;
++ struct au_dpage *dpages;
++};
++
++/* ---------------------------------------------------------------------- */
++
++int au_dpages_init(struct au_dcsub_pages *dpages, gfp_t gfp);
++void au_dpages_free(struct au_dcsub_pages *dpages);
++typedef int (*au_dpages_test)(struct dentry *dentry, void *arg);
++int au_dcsub_pages(struct au_dcsub_pages *dpages, struct dentry *root,
++ au_dpages_test test, void *arg);
++int au_dcsub_pages_rev(struct au_dcsub_pages *dpages, struct dentry *dentry,
++ int do_include, au_dpages_test test, void *arg);
++struct dentry *au_test_subdir(struct dentry *d1, struct dentry *d2);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DCSUB_H__ */
+diff --git a/fs/aufs/debug.c b/fs/aufs/debug.c
+new file mode 100644
+index 0000000..de38931
+--- /dev/null
++++ b/fs/aufs/debug.c
+@@ -0,0 +1,416 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * debug print functions
++ */
++
++#include "aufs.h"
++
++int aufs_debug;
++MODULE_PARM_DESC(debug, "debug print");
++module_param_named(debug, aufs_debug, int, S_IRUGO | S_IWUSR | S_IWGRP);
++
++char *au_plevel = KERN_DEBUG;
++#define dpri(fmt, arg...) do { \
++ if (au_debug_test()) \
++ printk("%s" fmt, au_plevel, ##arg); \
++} while (0)
++
++/* ---------------------------------------------------------------------- */
++
++void au_dpri_whlist(struct au_nhash *whlist)
++{
++ unsigned long ul, n;
++ struct hlist_head *head;
++ struct au_vdir_wh *tpos;
++ struct hlist_node *pos;
++
++ n = whlist->nh_num;
++ head = whlist->nh_head;
++ for (ul = 0; ul < n; ul++) {
++ hlist_for_each_entry(tpos, pos, head, wh_hash)
++ dpri("b%d, %.*s, %d\n",
++ tpos->wh_bindex,
++ tpos->wh_str.len, tpos->wh_str.name,
++ tpos->wh_str.len);
++ head++;
++ }
++}
++
++void au_dpri_vdir(struct au_vdir *vdir)
++{
++ unsigned long ul;
++ union au_vdir_deblk_p p;
++ unsigned char *o;
++
++ if (!vdir || IS_ERR(vdir)) {
++ dpri("err %ld\n", PTR_ERR(vdir));
++ return;
++ }
++
++ dpri("deblk %u, nblk %lu, deblk %p, last{%lu, %p}, ver %lu\n",
++ vdir->vd_deblk_sz, vdir->vd_nblk, vdir->vd_deblk,
++ vdir->vd_last.ul, vdir->vd_last.p.deblk, vdir->vd_version);
++ for (ul = 0; ul < vdir->vd_nblk; ul++) {
++ p.deblk = vdir->vd_deblk[ul];
++ o = p.deblk;
++ dpri("[%lu]: %p\n", ul, o);
++ }
++}
++
++static int do_pri_inode(aufs_bindex_t bindex, struct inode *inode,
++ struct dentry *wh)
++{
++ char *n = NULL;
++ int l = 0;
++
++ if (!inode || IS_ERR(inode)) {
++ dpri("i%d: err %ld\n", bindex, PTR_ERR(inode));
++ return -1;
++ }
++
++ /* the type of i_blocks depends upon CONFIG_LSF */
++ BUILD_BUG_ON(sizeof(inode->i_blocks) != sizeof(unsigned long)
++ && sizeof(inode->i_blocks) != sizeof(u64));
++ if (wh) {
++ n = (void *)wh->d_name.name;
++ l = wh->d_name.len;
++ }
++
++ dpri("i%d: i%lu, %s, cnt %d, nl %u, 0%o, sz %llu, blk %llu,"
++ " ct %lld, np %lu, st 0x%lx, f 0x%x, g %x%s%.*s\n",
++ bindex,
++ inode->i_ino, inode->i_sb ? au_sbtype(inode->i_sb) : "??",
++ atomic_read(&inode->i_count), inode->i_nlink, inode->i_mode,
++ i_size_read(inode), (unsigned long long)inode->i_blocks,
++ (long long)timespec_to_ns(&inode->i_ctime) & 0x0ffff,
++ inode->i_mapping ? inode->i_mapping->nrpages : 0,
++ inode->i_state, inode->i_flags, inode->i_generation,
++ l ? ", wh " : "", l, n);
++ return 0;
++}
++
++void au_dpri_inode(struct inode *inode)
++{
++ struct au_iinfo *iinfo;
++ aufs_bindex_t bindex;
++ int err;
++
++ err = do_pri_inode(-1, inode, NULL);
++ if (err || !au_test_aufs(inode->i_sb))
++ return;
++
++ iinfo = au_ii(inode);
++ if (!iinfo)
++ return;
++ dpri("i-1: bstart %d, bend %d, gen %d\n",
++ iinfo->ii_bstart, iinfo->ii_bend, au_iigen(inode));
++ if (iinfo->ii_bstart < 0)
++ return;
++ for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend; bindex++)
++ do_pri_inode(bindex, iinfo->ii_hinode[0 + bindex].hi_inode,
++ iinfo->ii_hinode[0 + bindex].hi_whdentry);
++}
++
++static int do_pri_dentry(aufs_bindex_t bindex, struct dentry *dentry)
++{
++ struct dentry *wh = NULL;
++
++ if (!dentry || IS_ERR(dentry)) {
++ dpri("d%d: err %ld\n", bindex, PTR_ERR(dentry));
++ return -1;
++ }
++ /* do not call dget_parent() here */
++ dpri("d%d: %.*s?/%.*s, %s, cnt %d, flags 0x%x\n",
++ bindex,
++ AuDLNPair(dentry->d_parent), AuDLNPair(dentry),
++ dentry->d_sb ? au_sbtype(dentry->d_sb) : "??",
++ atomic_read(&dentry->d_count), dentry->d_flags);
++ if (bindex >= 0 && dentry->d_inode && au_test_aufs(dentry->d_sb)) {
++ struct au_iinfo *iinfo = au_ii(dentry->d_inode);
++ if (iinfo)
++ wh = iinfo->ii_hinode[0 + bindex].hi_whdentry;
++ }
++ do_pri_inode(bindex, dentry->d_inode, wh);
++ return 0;
++}
++
++void au_dpri_dentry(struct dentry *dentry)
++{
++ struct au_dinfo *dinfo;
++ aufs_bindex_t bindex;
++ int err;
++
++ err = do_pri_dentry(-1, dentry);
++ if (err || !au_test_aufs(dentry->d_sb))
++ return;
++
++ dinfo = au_di(dentry);
++ if (!dinfo)
++ return;
++ dpri("d-1: bstart %d, bend %d, bwh %d, bdiropq %d, gen %d\n",
++ dinfo->di_bstart, dinfo->di_bend,
++ dinfo->di_bwh, dinfo->di_bdiropq, au_digen(dentry));
++ if (dinfo->di_bstart < 0)
++ return;
++ for (bindex = dinfo->di_bstart; bindex <= dinfo->di_bend; bindex++)
++ do_pri_dentry(bindex, dinfo->di_hdentry[0 + bindex].hd_dentry);
++}
++
++static int do_pri_file(aufs_bindex_t bindex, struct file *file)
++{
++ char a[32];
++
++ if (!file || IS_ERR(file)) {
++ dpri("f%d: err %ld\n", bindex, PTR_ERR(file));
++ return -1;
++ }
++ a[0] = 0;
++ if (bindex < 0
++ && file->f_dentry
++ && au_test_aufs(file->f_dentry->d_sb)
++ && au_fi(file))
++ snprintf(a, sizeof(a), ", mmapped %d", au_test_mmapped(file));
++ dpri("f%d: mode 0x%x, flags 0%o, cnt %ld, pos %llu%s\n",
++ bindex, file->f_mode, file->f_flags, (long)file_count(file),
++ file->f_pos, a);
++ if (file->f_dentry)
++ do_pri_dentry(bindex, file->f_dentry);
++ return 0;
++}
++
++void au_dpri_file(struct file *file)
++{
++ struct au_finfo *finfo;
++ aufs_bindex_t bindex;
++ int err;
++
++ err = do_pri_file(-1, file);
++ if (err || !file->f_dentry || !au_test_aufs(file->f_dentry->d_sb))
++ return;
++
++ finfo = au_fi(file);
++ if (!finfo)
++ return;
++ if (finfo->fi_bstart < 0)
++ return;
++ for (bindex = finfo->fi_bstart; bindex <= finfo->fi_bend; bindex++) {
++ struct au_hfile *hf;
++
++ hf = finfo->fi_hfile + bindex;
++ do_pri_file(bindex, hf ? hf->hf_file : NULL);
++ }
++}
++
++static int do_pri_br(aufs_bindex_t bindex, struct au_branch *br)
++{
++ struct vfsmount *mnt;
++ struct super_block *sb;
++
++ if (!br || IS_ERR(br))
++ goto out;
++ mnt = br->br_mnt;
++ if (!mnt || IS_ERR(mnt))
++ goto out;
++ sb = mnt->mnt_sb;
++ if (!sb || IS_ERR(sb))
++ goto out;
++
++ dpri("s%d: {perm 0x%x, cnt %d, wbr %p}, "
++ "%s, dev 0x%02x%02x, flags 0x%lx, cnt(BIAS) %d, active %d, "
++ "xino %d\n",
++ bindex, br->br_perm, atomic_read(&br->br_count), br->br_wbr,
++ au_sbtype(sb), MAJOR(sb->s_dev), MINOR(sb->s_dev),
++ sb->s_flags, sb->s_count - S_BIAS,
++ atomic_read(&sb->s_active), !!br->br_xino.xi_file);
++ return 0;
++
++ out:
++ dpri("s%d: err %ld\n", bindex, PTR_ERR(br));
++ return -1;
++}
++
++void au_dpri_sb(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++ aufs_bindex_t bindex;
++ int err;
++ /* to reuduce stack size */
++ struct {
++ struct vfsmount mnt;
++ struct au_branch fake;
++ } *a;
++
++ /* this function can be called from magic sysrq */
++ a = kzalloc(sizeof(*a), GFP_ATOMIC);
++ if (unlikely(!a)) {
++ dpri("no memory\n");
++ return;
++ }
++
++ a->mnt.mnt_sb = sb;
++ a->fake.br_perm = 0;
++ a->fake.br_mnt = &a->mnt;
++ a->fake.br_xino.xi_file = NULL;
++ atomic_set(&a->fake.br_count, 0);
++ smp_mb(); /* atomic_set */
++ err = do_pri_br(-1, &a->fake);
++ kfree(a);
++ dpri("dev 0x%x\n", sb->s_dev);
++ if (err || !au_test_aufs(sb))
++ return;
++
++ sbinfo = au_sbi(sb);
++ if (!sbinfo)
++ return;
++ dpri("nw %d, gen %u, kobj %d\n",
++ atomic_read(&sbinfo->si_nowait.nw_len), sbinfo->si_generation,
++ atomic_read(&sbinfo->si_kobj.kref.refcount));
++ for (bindex = 0; bindex <= sbinfo->si_bend; bindex++)
++ do_pri_br(bindex, sbinfo->si_branch[0 + bindex]);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_dbg_sleep_jiffy(int jiffy)
++{
++ while (jiffy)
++ jiffy = schedule_timeout_uninterruptible(jiffy);
++}
++
++void au_dbg_iattr(struct iattr *ia)
++{
++#define AuBit(name) if (ia->ia_valid & ATTR_ ## name) \
++ dpri(#name "\n")
++ AuBit(MODE);
++ AuBit(UID);
++ AuBit(GID);
++ AuBit(SIZE);
++ AuBit(ATIME);
++ AuBit(MTIME);
++ AuBit(CTIME);
++ AuBit(ATIME_SET);
++ AuBit(MTIME_SET);
++ AuBit(FORCE);
++ AuBit(ATTR_FLAG);
++ AuBit(KILL_SUID);
++ AuBit(KILL_SGID);
++ AuBit(FILE);
++ AuBit(KILL_PRIV);
++ AuBit(OPEN);
++ AuBit(TIMES_SET);
++#undef AuBit
++ dpri("ia_file %p\n", ia->ia_file);
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_dbg_verify_dir_parent(struct dentry *dentry, unsigned int sigen)
++{
++ struct dentry *parent;
++
++ parent = dget_parent(dentry);
++ AuDebugOn(!S_ISDIR(dentry->d_inode->i_mode)
++ || IS_ROOT(dentry)
++ || au_digen(parent) != sigen);
++ dput(parent);
++}
++
++void au_dbg_verify_nondir_parent(struct dentry *dentry, unsigned int sigen)
++{
++ struct dentry *parent;
++
++ parent = dget_parent(dentry);
++ AuDebugOn(S_ISDIR(dentry->d_inode->i_mode)
++ || au_digen(parent) != sigen);
++ dput(parent);
++}
++
++void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen)
++{
++ int err, i, j;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++ struct dentry **dentries;
++
++ err = au_dpages_init(&dpages, GFP_NOFS);
++ AuDebugOn(err);
++ err = au_dcsub_pages_rev(&dpages, parent, /*do_include*/1, NULL, NULL);
++ AuDebugOn(err);
++ for (i = dpages.ndpage - 1; !err && i >= 0; i--) {
++ dpage = dpages.dpages + i;
++ dentries = dpage->dentries;
++ for (j = dpage->ndentry - 1; !err && j >= 0; j--)
++ AuDebugOn(au_digen(dentries[j]) != sigen);
++ }
++ au_dpages_free(&dpages);
++}
++
++void au_dbg_verify_hf(struct au_finfo *finfo)
++{
++ struct au_hfile *hf;
++ aufs_bindex_t bend, bindex;
++
++ if (finfo->fi_bstart >= 0) {
++ bend = finfo->fi_bend;
++ for (bindex = finfo->fi_bstart; bindex <= bend; bindex++) {
++ hf = finfo->fi_hfile + bindex;
++ AuDebugOn(hf->hf_file || hf->hf_br);
++ }
++ }
++}
++
++void au_dbg_verify_kthread(void)
++{
++ if (au_test_wkq(current)) {
++ au_dbg_blocked();
++ BUG();
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_debug_sbinfo_init(struct au_sbinfo *sbinfo __maybe_unused)
++{
++#ifdef AuForceNoPlink
++ au_opt_clr(sbinfo->si_mntflags, PLINK);
++#endif
++#ifdef AuForceNoXino
++ au_opt_clr(sbinfo->si_mntflags, XINO);
++#endif
++#ifdef AuForceNoRefrof
++ au_opt_clr(sbinfo->si_mntflags, REFROF);
++#endif
++#ifdef AuForceHinotify
++ au_opt_set_udba(sbinfo->si_mntflags, UDBA_HINOTIFY);
++#endif
++}
++
++int __init au_debug_init(void)
++{
++ aufs_bindex_t bindex;
++ struct au_vdir_destr destr;
++
++ bindex = -1;
++ AuDebugOn(bindex >= 0);
++
++ destr.len = -1;
++ AuDebugOn(destr.len < NAME_MAX);
++
++#ifdef CONFIG_4KSTACKS
++ AuWarn("CONFIG_4KSTACKS is defined.\n");
++#endif
++
++#ifdef AuForceNoBrs
++ sysaufs_brs = 0;
++#endif
++
++ return 0;
++}
+diff --git a/fs/aufs/debug.h b/fs/aufs/debug.h
+new file mode 100644
+index 0000000..36ff0ea
+--- /dev/null
++++ b/fs/aufs/debug.h
+@@ -0,0 +1,243 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * debug print functions
++ */
++
++#ifndef __AUFS_DEBUG_H__
++#define __AUFS_DEBUG_H__
++
++#ifdef __KERNEL__
++
++#include <linux/delay.h>
++#include <linux/fs.h>
++#include <linux/kd.h>
++#include <linux/vt_kern.h>
++#include <linux/sysrq.h>
++#include <linux/aufs_type.h>
++
++#ifdef CONFIG_AUFS_DEBUG
++#define AuDebugOn(a) BUG_ON(a)
++
++/* module parameter */
++extern int aufs_debug;
++static inline void au_debug(int n)
++{
++ aufs_debug = n;
++ smp_mb();
++}
++
++static inline int au_debug_test(void)
++{
++ return aufs_debug;
++}
++#else
++#define AuDebugOn(a) do {} while (0)
++#define au_debug() do {} while (0)
++static inline int au_debug_test(void)
++{
++ return 0;
++}
++#endif /* CONFIG_AUFS_DEBUG */
++
++/* ---------------------------------------------------------------------- */
++
++/* debug print */
++
++#define AuDpri(lvl, fmt, arg...) \
++ printk(lvl AUFS_NAME " %s:%d:%s[%d]: " fmt, \
++ __func__, __LINE__, current->comm, current->pid, ##arg)
++#define AuDbg(fmt, arg...) do { \
++ if (au_debug_test()) \
++ AuDpri(KERN_DEBUG, fmt, ##arg); \
++} while (0)
++#define AuLabel(l) AuDbg(#l "\n")
++#define AuInfo(fmt, arg...) AuDpri(KERN_INFO, fmt, ##arg)
++#define AuWarn(fmt, arg...) AuDpri(KERN_WARNING, fmt, ##arg)
++#define AuErr(fmt, arg...) AuDpri(KERN_ERR, fmt, ##arg)
++#define AuIOErr(fmt, arg...) AuErr("I/O Error, " fmt, ##arg)
++#define AuWarn1(fmt, arg...) do { \
++ static unsigned char _c; \
++ if (!_c++) \
++ AuWarn(fmt, ##arg); \
++} while (0)
++
++#define AuErr1(fmt, arg...) do { \
++ static unsigned char _c; \
++ if (!_c++) \
++ AuErr(fmt, ##arg); \
++} while (0)
++
++#define AuIOErr1(fmt, arg...) do { \
++ static unsigned char _c; \
++ if (!_c++) \
++ AuIOErr(fmt, ##arg); \
++} while (0)
++
++#define AuUnsupportMsg "This operation is not supported." \
++ " Please report this application to aufs-users ML."
++#define AuUnsupport(fmt, args...) do { \
++ AuErr(AuUnsupportMsg "\n" fmt, ##args); \
++ dump_stack(); \
++} while (0)
++
++#define AuTraceErr(e) do { \
++ if (unlikely((e) < 0)) \
++ AuDbg("err %d\n", (int)(e)); \
++} while (0)
++
++#define AuTraceErrPtr(p) do { \
++ if (IS_ERR(p)) \
++ AuDbg("err %ld\n", PTR_ERR(p)); \
++} while (0)
++
++/* dirty macros for debug print, use with "%.*s" and caution */
++#define AuLNPair(qstr) (qstr)->len, (qstr)->name
++#define AuDLNPair(d) AuLNPair(&(d)->d_name)
++
++/* ---------------------------------------------------------------------- */
++
++struct au_sbinfo;
++struct au_finfo;
++#ifdef CONFIG_AUFS_DEBUG
++extern char *au_plevel;
++struct au_nhash;
++void au_dpri_whlist(struct au_nhash *whlist);
++struct au_vdir;
++void au_dpri_vdir(struct au_vdir *vdir);
++void au_dpri_inode(struct inode *inode);
++void au_dpri_dentry(struct dentry *dentry);
++void au_dpri_file(struct file *filp);
++void au_dpri_sb(struct super_block *sb);
++
++void au_dbg_sleep_jiffy(int jiffy);
++void au_dbg_iattr(struct iattr *ia);
++
++void au_dbg_verify_dir_parent(struct dentry *dentry, unsigned int sigen);
++void au_dbg_verify_nondir_parent(struct dentry *dentry, unsigned int sigen);
++void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen);
++void au_dbg_verify_hf(struct au_finfo *finfo);
++void au_dbg_verify_kthread(void);
++
++int __init au_debug_init(void);
++void au_debug_sbinfo_init(struct au_sbinfo *sbinfo);
++#define AuDbgWhlist(w) do { \
++ AuDbg(#w "\n"); \
++ au_dpri_whlist(w); \
++} while (0)
++
++#define AuDbgVdir(v) do { \
++ AuDbg(#v "\n"); \
++ au_dpri_vdir(v); \
++} while (0)
++
++#define AuDbgInode(i) do { \
++ AuDbg(#i "\n"); \
++ au_dpri_inode(i); \
++} while (0)
++
++#define AuDbgDentry(d) do { \
++ AuDbg(#d "\n"); \
++ au_dpri_dentry(d); \
++} while (0)
++
++#define AuDbgFile(f) do { \
++ AuDbg(#f "\n"); \
++ au_dpri_file(f); \
++} while (0)
++
++#define AuDbgSb(sb) do { \
++ AuDbg(#sb "\n"); \
++ au_dpri_sb(sb); \
++} while (0)
++
++#define AuDbgSleep(sec) do { \
++ AuDbg("sleep %d sec\n", sec); \
++ ssleep(sec); \
++} while (0)
++
++#define AuDbgSleepJiffy(jiffy) do { \
++ AuDbg("sleep %d jiffies\n", jiffy); \
++ au_dbg_sleep_jiffy(jiffy); \
++} while (0)
++
++#define AuDbgIAttr(ia) do { \
++ AuDbg("ia_valid 0x%x\n", (ia)->ia_valid); \
++ au_dbg_iattr(ia); \
++} while (0)
++#else
++static inline void au_dbg_verify_dir_parent(struct dentry *dentry,
++ unsigned int sigen)
++{
++ /* empty */
++}
++static inline void au_dbg_verify_nondir_parent(struct dentry *dentry,
++ unsigned int sigen)
++{
++ /* empty */
++}
++static inline void au_dbg_verify_gen(struct dentry *parent, unsigned int sigen)
++{
++ /* empty */
++}
++static inline void au_dbg_verify_hf(struct au_finfo *finfo)
++{
++ /* empty */
++}
++static inline void au_dbg_verify_kthread(void)
++{
++ /* empty */
++}
++
++static inline int au_debug_init(void)
++{
++ return 0;
++}
++static inline void au_debug_sbinfo_init(struct au_sbinfo *sbinfo)
++{
++ /* empty */
++}
++#define AuDbgWhlist(w) do {} while (0)
++#define AuDbgVdir(v) do {} while (0)
++#define AuDbgInode(i) do {} while (0)
++#define AuDbgDentry(d) do {} while (0)
++#define AuDbgFile(f) do {} while (0)
++#define AuDbgSb(sb) do {} while (0)
++#define AuDbgSleep(sec) do {} while (0)
++#define AuDbgSleepJiffy(jiffy) do {} while (0)
++#define AuDbgIAttr(ia) do {} while (0)
++#endif /* CONFIG_AUFS_DEBUG */
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_MAGIC_SYSRQ
++int __init au_sysrq_init(void);
++void au_sysrq_fin(void);
++
++#ifdef CONFIG_HW_CONSOLE
++#define au_dbg_blocked() do { \
++ WARN_ON(1); \
++ handle_sysrq('w', vc_cons[fg_console].d->vc_tty); \
++} while (0)
++#else
++#define au_dbg_blocked() do {} while (0)
++#endif
++
++#else
++static inline int au_sysrq_init(void)
++{
++ return 0;
++}
++#define au_sysrq_fin() do {} while (0)
++#define au_dbg_blocked() do {} while (0)
++#endif /* CONFIG_AUFS_MAGIC_SYSRQ */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DEBUG_H__ */
+diff --git a/fs/aufs/dentry.c b/fs/aufs/dentry.c
+new file mode 100644
+index 0000000..f36956a
+--- /dev/null
++++ b/fs/aufs/dentry.c
+@@ -0,0 +1,858 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * lookup and dentry operations
++ */
++
++#include "aufs.h"
++
++static void au_h_nd(struct nameidata *h_nd, struct nameidata *nd)
++{
++ if (nd) {
++ *h_nd = *nd;
++
++ /*
++ * gave up supporting LOOKUP_CREATE/OPEN for lower fs,
++ * due to whiteout and branch permission.
++ */
++ h_nd->flags &= ~(/*LOOKUP_PARENT |*/ LOOKUP_OPEN | LOOKUP_CREATE
++ | LOOKUP_FOLLOW);
++ /* unnecessary? */
++ h_nd->intent.open.file = NULL;
++ } else
++ memset(h_nd, 0, sizeof(*h_nd));
++}
++
++struct au_lkup_one_args {
++ struct dentry **errp;
++ struct qstr *name;
++ struct dentry *h_parent;
++ struct au_branch *br;
++ struct nameidata *nd;
++};
++
++struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent,
++ struct au_branch *br, struct nameidata *nd)
++{
++ struct dentry *h_dentry;
++ int err;
++ struct nameidata h_nd;
++
++ if (au_test_fs_null_nd(h_parent->d_sb))
++ return vfsub_lookup_one_len(name->name, h_parent, name->len);
++
++ au_h_nd(&h_nd, nd);
++ h_nd.path.dentry = h_parent;
++ h_nd.path.mnt = br->br_mnt;
++
++ err = __lookup_one_len(name->name, &h_nd.last, NULL, name->len);
++ h_dentry = ERR_PTR(err);
++ if (!err) {
++ path_get(&h_nd.path);
++ h_dentry = vfsub_lookup_hash(&h_nd);
++ path_put(&h_nd.path);
++ }
++
++ return h_dentry;
++}
++
++static void au_call_lkup_one(void *args)
++{
++ struct au_lkup_one_args *a = args;
++ *a->errp = au_lkup_one(a->name, a->h_parent, a->br, a->nd);
++}
++
++#define AuLkup_ALLOW_NEG 1
++#define au_ftest_lkup(flags, name) ((flags) & AuLkup_##name)
++#define au_fset_lkup(flags, name) { (flags) |= AuLkup_##name; }
++#define au_fclr_lkup(flags, name) { (flags) &= ~AuLkup_##name; }
++
++struct au_do_lookup_args {
++ unsigned int flags;
++ mode_t type;
++ struct nameidata *nd;
++};
++
++/*
++ * returns positive/negative dentry, NULL or an error.
++ * NULL means whiteout-ed or not-found.
++ */
++static struct dentry*
++au_do_lookup(struct dentry *h_parent, struct dentry *dentry,
++ aufs_bindex_t bindex, struct qstr *wh_name,
++ struct au_do_lookup_args *args)
++{
++ struct dentry *h_dentry;
++ struct inode *h_inode, *inode;
++ struct qstr *name;
++ struct au_branch *br;
++ int wh_found, opq;
++ unsigned char wh_able;
++ const unsigned char allow_neg = !!au_ftest_lkup(args->flags, ALLOW_NEG);
++
++ name = &dentry->d_name;
++ wh_found = 0;
++ br = au_sbr(dentry->d_sb, bindex);
++ wh_able = !!au_br_whable(br->br_perm);
++ if (wh_able)
++ wh_found = au_wh_test(h_parent, wh_name, br, /*try_sio*/0);
++ h_dentry = ERR_PTR(wh_found);
++ if (!wh_found)
++ goto real_lookup;
++ if (unlikely(wh_found < 0))
++ goto out;
++
++ /* We found a whiteout */
++ /* au_set_dbend(dentry, bindex); */
++ au_set_dbwh(dentry, bindex);
++ if (!allow_neg)
++ return NULL; /* success */
++
++ real_lookup:
++ h_dentry = au_lkup_one(name, h_parent, br, args->nd);
++ if (IS_ERR(h_dentry))
++ goto out;
++
++ h_inode = h_dentry->d_inode;
++ if (!h_inode) {
++ if (!allow_neg)
++ goto out_neg;
++ } else if (wh_found
++ || (args->type && args->type != (h_inode->i_mode & S_IFMT)))
++ goto out_neg;
++
++ if (au_dbend(dentry) <= bindex)
++ au_set_dbend(dentry, bindex);
++ if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
++ au_set_dbstart(dentry, bindex);
++ au_set_h_dptr(dentry, bindex, h_dentry);
++
++ inode = dentry->d_inode;
++ if (!h_inode || !S_ISDIR(h_inode->i_mode) || !wh_able
++ || (inode && !S_ISDIR(inode->i_mode)))
++ goto out; /* success */
++
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ opq = au_diropq_test(h_dentry, br);
++ mutex_unlock(&h_inode->i_mutex);
++ if (opq > 0)
++ au_set_dbdiropq(dentry, bindex);
++ else if (unlikely(opq < 0)) {
++ au_set_h_dptr(dentry, bindex, NULL);
++ h_dentry = ERR_PTR(opq);
++ }
++ goto out;
++
++ out_neg:
++ dput(h_dentry);
++ h_dentry = NULL;
++ out:
++ return h_dentry;
++}
++
++/*
++ * returns the number of lower positive dentries,
++ * otherwise an error.
++ * can be called at unlinking with @type is zero.
++ */
++int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
++ struct nameidata *nd)
++{
++ int npositive, err;
++ aufs_bindex_t bindex, btail, bdiropq;
++ unsigned char isdir;
++ struct qstr whname;
++ struct au_do_lookup_args args = {
++ .flags = 0,
++ .type = type,
++ .nd = nd
++ };
++ const struct qstr *name = &dentry->d_name;
++ struct dentry *parent;
++ struct inode *inode;
++
++ err = -EPERM;
++ parent = dget_parent(dentry);
++ if (unlikely(!strncmp(name->name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)))
++ goto out;
++
++ err = au_wh_name_alloc(&whname, name);
++ if (unlikely(err))
++ goto out;
++
++ inode = dentry->d_inode;
++ isdir = !!(inode && S_ISDIR(inode->i_mode));
++ if (!type)
++ au_fset_lkup(args.flags, ALLOW_NEG);
++
++ npositive = 0;
++ btail = au_dbtaildir(parent);
++ for (bindex = bstart; bindex <= btail; bindex++) {
++ struct dentry *h_parent, *h_dentry;
++ struct inode *h_inode, *h_dir;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (h_dentry) {
++ if (h_dentry->d_inode)
++ npositive++;
++ if (type != S_IFDIR)
++ break;
++ continue;
++ }
++ h_parent = au_h_dptr(parent, bindex);
++ if (!h_parent)
++ continue;
++ h_dir = h_parent->d_inode;
++ if (!h_dir || !S_ISDIR(h_dir->i_mode))
++ continue;
++
++ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++ h_dentry = au_do_lookup(h_parent, dentry, bindex, &whname,
++ &args);
++ mutex_unlock(&h_dir->i_mutex);
++ err = PTR_ERR(h_dentry);
++ if (IS_ERR(h_dentry))
++ goto out_wh;
++ au_fclr_lkup(args.flags, ALLOW_NEG);
++
++ if (au_dbwh(dentry) >= 0)
++ break;
++ if (!h_dentry)
++ continue;
++ h_inode = h_dentry->d_inode;
++ if (!h_inode)
++ continue;
++ npositive++;
++ if (!args.type)
++ args.type = h_inode->i_mode & S_IFMT;
++ if (args.type != S_IFDIR)
++ break;
++ else if (isdir) {
++ /* the type of lower may be different */
++ bdiropq = au_dbdiropq(dentry);
++ if (bdiropq >= 0 && bdiropq <= bindex)
++ break;
++ }
++ }
++
++ if (npositive) {
++ AuLabel(positive);
++ au_update_dbstart(dentry);
++ }
++ err = npositive;
++ if (unlikely(!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE)
++ && au_dbstart(dentry) < 0))
++ /* both of real entry and whiteout found */
++ err = -EIO;
++
++ out_wh:
++ kfree(whname.name);
++ out:
++ dput(parent);
++ return err;
++}
++
++struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent,
++ struct au_branch *br)
++{
++ struct dentry *dentry;
++ int wkq_err;
++
++ if (!au_test_h_perm_sio(parent->d_inode, MAY_EXEC))
++ dentry = au_lkup_one(name, parent, br, /*nd*/NULL);
++ else {
++ struct au_lkup_one_args args = {
++ .errp = &dentry,
++ .name = name,
++ .h_parent = parent,
++ .br = br,
++ .nd = NULL
++ };
++
++ wkq_err = au_wkq_wait(au_call_lkup_one, &args);
++ if (unlikely(wkq_err))
++ dentry = ERR_PTR(wkq_err);
++ }
++
++ return dentry;
++}
++
++/*
++ * lookup @dentry on @bindex which should be negative.
++ */
++int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ int err;
++ struct dentry *parent, *h_parent, *h_dentry;
++ struct qstr *name;
++
++ name = &dentry->d_name;
++ parent = dget_parent(dentry);
++ h_parent = au_h_dptr(parent, bindex);
++ h_dentry = au_sio_lkup_one(name, h_parent,
++ au_sbr(dentry->d_sb, bindex));
++ err = PTR_ERR(h_dentry);
++ if (IS_ERR(h_dentry))
++ goto out;
++ if (unlikely(h_dentry->d_inode)) {
++ err = -EIO;
++ AuIOErr("b%d %.*s should be negative.\n",
++ bindex, AuDLNPair(h_dentry));
++ dput(h_dentry);
++ goto out;
++ }
++
++ if (bindex < au_dbstart(dentry))
++ au_set_dbstart(dentry, bindex);
++ if (au_dbend(dentry) < bindex)
++ au_set_dbend(dentry, bindex);
++ au_set_h_dptr(dentry, bindex, h_dentry);
++ err = 0;
++
++ out:
++ dput(parent);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* subset of struct inode */
++struct au_iattr {
++ unsigned long i_ino;
++ /* unsigned int i_nlink; */
++ uid_t i_uid;
++ gid_t i_gid;
++ u64 i_version;
++/*
++ loff_t i_size;
++ blkcnt_t i_blocks;
++*/
++ umode_t i_mode;
++};
++
++static void au_iattr_save(struct au_iattr *ia, struct inode *h_inode)
++{
++ ia->i_ino = h_inode->i_ino;
++ /* ia->i_nlink = h_inode->i_nlink; */
++ ia->i_uid = h_inode->i_uid;
++ ia->i_gid = h_inode->i_gid;
++ ia->i_version = h_inode->i_version;
++/*
++ ia->i_size = h_inode->i_size;
++ ia->i_blocks = h_inode->i_blocks;
++*/
++ ia->i_mode = (h_inode->i_mode & S_IFMT);
++}
++
++static int au_iattr_test(struct au_iattr *ia, struct inode *h_inode)
++{
++ return ia->i_ino != h_inode->i_ino
++ /* || ia->i_nlink != h_inode->i_nlink */
++ || ia->i_uid != h_inode->i_uid
++ || ia->i_gid != h_inode->i_gid
++ || ia->i_version != h_inode->i_version
++/*
++ || ia->i_size != h_inode->i_size
++ || ia->i_blocks != h_inode->i_blocks
++*/
++ || ia->i_mode != (h_inode->i_mode & S_IFMT);
++}
++
++static int au_h_verify_dentry(struct dentry *h_dentry, struct dentry *h_parent,
++ struct au_branch *br)
++{
++ int err;
++ struct au_iattr ia;
++ struct inode *h_inode;
++ struct dentry *h_d;
++ struct super_block *h_sb;
++
++ err = 0;
++ memset(&ia, -1, sizeof(ia));
++ h_sb = h_dentry->d_sb;
++ h_inode = h_dentry->d_inode;
++ if (h_inode)
++ au_iattr_save(&ia, h_inode);
++ else if (au_test_nfs(h_sb) || au_test_fuse(h_sb))
++ /* nfs d_revalidate may return 0 for negative dentry */
++ /* fuse d_revalidate always return 0 for negative dentry */
++ goto out;
++
++ /* main purpose is namei.c:cached_lookup() and d_revalidate */
++ h_d = au_lkup_one(&h_dentry->d_name, h_parent, br, /*nd*/NULL);
++ err = PTR_ERR(h_d);
++ if (IS_ERR(h_d))
++ goto out;
++
++ err = 0;
++ if (unlikely(h_d != h_dentry
++ || h_d->d_inode != h_inode
++ || (h_inode && au_iattr_test(&ia, h_inode))))
++ err = au_busy_or_stale();
++ dput(h_d);
++
++ out:
++ AuTraceErr(err);
++ return err;
++}
++
++int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir,
++ struct dentry *h_parent, struct au_branch *br)
++{
++ int err;
++
++ err = 0;
++ if (udba == AuOpt_UDBA_REVAL) {
++ IMustLock(h_dir);
++ err = (h_dentry->d_parent->d_inode != h_dir);
++ } else if (udba == AuOpt_UDBA_HINOTIFY)
++ err = au_h_verify_dentry(h_dentry, h_parent, br);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void au_do_refresh_hdentry(struct au_hdentry *p, struct au_dinfo *dinfo,
++ struct dentry *parent)
++{
++ struct dentry *h_d, *h_dp;
++ struct au_hdentry tmp, *q;
++ struct super_block *sb;
++ aufs_bindex_t new_bindex, bindex, bend, bwh, bdiropq;
++
++ bend = dinfo->di_bend;
++ bwh = dinfo->di_bwh;
++ bdiropq = dinfo->di_bdiropq;
++ for (bindex = dinfo->di_bstart; bindex <= bend; bindex++, p++) {
++ h_d = p->hd_dentry;
++ if (!h_d)
++ continue;
++
++ h_dp = dget_parent(h_d);
++ if (h_dp == au_h_dptr(parent, bindex)) {
++ dput(h_dp);
++ continue;
++ }
++
++ new_bindex = au_find_dbindex(parent, h_dp);
++ dput(h_dp);
++ if (dinfo->di_bwh == bindex)
++ bwh = new_bindex;
++ if (dinfo->di_bdiropq == bindex)
++ bdiropq = new_bindex;
++ if (new_bindex < 0) {
++ au_hdput(p);
++ p->hd_dentry = NULL;
++ continue;
++ }
++
++ /* swap two lower dentries, and loop again */
++ q = dinfo->di_hdentry + new_bindex;
++ tmp = *q;
++ *q = *p;
++ *p = tmp;
++ if (tmp.hd_dentry) {
++ bindex--;
++ p--;
++ }
++ }
++
++ sb = parent->d_sb;
++ dinfo->di_bwh = -1;
++ if (bwh >= 0 && bwh <= au_sbend(sb) && au_sbr_whable(sb, bwh))
++ dinfo->di_bwh = bwh;
++
++ dinfo->di_bdiropq = -1;
++ if (bdiropq >= 0
++ && bdiropq <= au_sbend(sb)
++ && au_sbr_whable(sb, bdiropq))
++ dinfo->di_bdiropq = bdiropq;
++
++ bend = au_dbend(parent);
++ p = dinfo->di_hdentry;
++ for (bindex = 0; bindex <= bend; bindex++, p++)
++ if (p->hd_dentry) {
++ dinfo->di_bstart = bindex;
++ break;
++ }
++
++ p = dinfo->di_hdentry + bend;
++ for (bindex = bend; bindex >= 0; bindex--, p--)
++ if (p->hd_dentry) {
++ dinfo->di_bend = bindex;
++ break;
++ }
++}
++
++/*
++ * returns the number of found lower positive dentries,
++ * otherwise an error.
++ */
++int au_refresh_hdentry(struct dentry *dentry, mode_t type)
++{
++ int npositive, err;
++ unsigned int sigen;
++ aufs_bindex_t bstart;
++ struct au_dinfo *dinfo;
++ struct super_block *sb;
++ struct dentry *parent;
++
++ sb = dentry->d_sb;
++ AuDebugOn(IS_ROOT(dentry));
++ sigen = au_sigen(sb);
++ parent = dget_parent(dentry);
++ AuDebugOn(au_digen(parent) != sigen
++ || au_iigen(parent->d_inode) != sigen);
++
++ dinfo = au_di(dentry);
++ err = au_di_realloc(dinfo, au_sbend(sb) + 1);
++ npositive = err;
++ if (unlikely(err))
++ goto out;
++ au_do_refresh_hdentry(dinfo->di_hdentry + dinfo->di_bstart, dinfo,
++ parent);
++
++ npositive = 0;
++ bstart = au_dbstart(parent);
++ if (type != S_IFDIR && dinfo->di_bstart == bstart)
++ goto out_dgen; /* success */
++
++ npositive = au_lkup_dentry(dentry, bstart, type, /*nd*/NULL);
++ if (npositive < 0)
++ goto out;
++ if (dinfo->di_bwh >= 0 && dinfo->di_bwh <= dinfo->di_bstart)
++ d_drop(dentry);
++
++ out_dgen:
++ au_update_digen(dentry);
++ out:
++ dput(parent);
++ AuTraceErr(npositive);
++ return npositive;
++}
++
++static noinline_for_stack
++int au_do_h_d_reval(struct dentry *h_dentry, struct nameidata *nd,
++ struct dentry *dentry, aufs_bindex_t bindex)
++{
++ int err, valid;
++ int (*reval)(struct dentry *, struct nameidata *);
++
++ err = 0;
++ reval = NULL;
++ if (h_dentry->d_op)
++ reval = h_dentry->d_op->d_revalidate;
++ if (!reval)
++ goto out;
++
++ AuDbg("b%d\n", bindex);
++ if (au_test_fs_null_nd(h_dentry->d_sb))
++ /* it may return tri-state */
++ valid = reval(h_dentry, NULL);
++ else {
++ struct nameidata h_nd;
++ int locked;
++ struct dentry *parent;
++
++ au_h_nd(&h_nd, nd);
++ parent = nd->path.dentry;
++ locked = (nd && nd->path.dentry != dentry);
++ if (locked)
++ di_read_lock_parent(parent, AuLock_IR);
++ BUG_ON(bindex > au_dbend(parent));
++ h_nd.path.dentry = au_h_dptr(parent, bindex);
++ BUG_ON(!h_nd.path.dentry);
++ h_nd.path.mnt = au_sbr(parent->d_sb, bindex)->br_mnt;
++ path_get(&h_nd.path);
++ valid = reval(h_dentry, &h_nd);
++ path_put(&h_nd.path);
++ if (locked)
++ di_read_unlock(parent, AuLock_IR);
++ }
++
++ if (unlikely(valid < 0))
++ err = valid;
++ else if (!valid)
++ err = -EINVAL;
++
++ out:
++ AuTraceErr(err);
++ return err;
++}
++
++/* todo: remove this */
++static int h_d_revalidate(struct dentry *dentry, struct inode *inode,
++ struct nameidata *nd, int do_udba)
++{
++ int err;
++ umode_t mode, h_mode;
++ aufs_bindex_t bindex, btail, bstart, ibs, ibe;
++ unsigned char plus, unhashed, is_root, h_plus;
++ struct inode *first, *h_inode, *h_cached_inode;
++ struct dentry *h_dentry;
++ struct qstr *name, *h_name;
++
++ err = 0;
++ plus = 0;
++ mode = 0;
++ first = NULL;
++ ibs = -1;
++ ibe = -1;
++ unhashed = !!d_unhashed(dentry);
++ is_root = !!IS_ROOT(dentry);
++ name = &dentry->d_name;
++
++ /*
++ * Theoretically, REVAL test should be unnecessary in case of INOTIFY.
++ * But inotify doesn't fire some necessary events,
++ * IN_ATTRIB for atime/nlink/pageio
++ * IN_DELETE for NFS dentry
++ * Let's do REVAL test too.
++ */
++ if (do_udba && inode) {
++ mode = (inode->i_mode & S_IFMT);
++ plus = (inode->i_nlink > 0);
++ first = au_h_iptr(inode, au_ibstart(inode));
++ ibs = au_ibstart(inode);
++ ibe = au_ibend(inode);
++ }
++
++ bstart = au_dbstart(dentry);
++ btail = bstart;
++ if (inode && S_ISDIR(inode->i_mode))
++ btail = au_dbtaildir(dentry);
++ for (bindex = bstart; bindex <= btail; bindex++) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!h_dentry)
++ continue;
++
++ AuDbg("b%d, %.*s\n", bindex, AuDLNPair(h_dentry));
++ h_name = &h_dentry->d_name;
++ if (unlikely(do_udba
++ && !is_root
++ && (unhashed != !!d_unhashed(h_dentry)
++ || name->len != h_name->len
++ || memcmp(name->name, h_name->name, name->len))
++ )) {
++ AuDbg("unhash 0x%x 0x%x, %.*s %.*s\n",
++ unhashed, d_unhashed(h_dentry),
++ AuDLNPair(dentry), AuDLNPair(h_dentry));
++ goto err;
++ }
++
++ err = au_do_h_d_reval(h_dentry, nd, dentry, bindex);
++ if (unlikely(err))
++ /* do not goto err, to keep the errno */
++ break;
++
++ /* todo: plink too? */
++ if (!do_udba)
++ continue;
++
++ /* UDBA tests */
++ h_inode = h_dentry->d_inode;
++ if (unlikely(!!inode != !!h_inode))
++ goto err;
++
++ h_plus = plus;
++ h_mode = mode;
++ h_cached_inode = h_inode;
++ if (h_inode) {
++ h_mode = (h_inode->i_mode & S_IFMT);
++ h_plus = (h_inode->i_nlink > 0);
++ }
++ if (inode && ibs <= bindex && bindex <= ibe)
++ h_cached_inode = au_h_iptr(inode, bindex);
++
++ if (unlikely(plus != h_plus
++ || mode != h_mode
++ || h_cached_inode != h_inode))
++ goto err;
++ continue;
++
++ err:
++ err = -EINVAL;
++ break;
++ }
++
++ return err;
++}
++
++static int simple_reval_dpath(struct dentry *dentry, unsigned int sigen)
++{
++ int err;
++ struct dentry *parent;
++ struct inode *inode;
++
++ inode = dentry->d_inode;
++ if (au_digen(dentry) == sigen && au_iigen(inode) == sigen)
++ return 0;
++
++ parent = dget_parent(dentry);
++ di_read_lock_parent(parent, AuLock_IR);
++ AuDebugOn(au_digen(parent) != sigen
++ || au_iigen(parent->d_inode) != sigen);
++ au_dbg_verify_gen(parent, sigen);
++
++ /* returns a number of positive dentries */
++ err = au_refresh_hdentry(dentry, inode->i_mode & S_IFMT);
++ if (err >= 0)
++ err = au_refresh_hinode(inode, dentry);
++
++ di_read_unlock(parent, AuLock_IR);
++ dput(parent);
++ return err;
++}
++
++int au_reval_dpath(struct dentry *dentry, unsigned int sigen)
++{
++ int err;
++ struct dentry *d, *parent;
++ struct inode *inode;
++
++ if (!au_ftest_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS))
++ return simple_reval_dpath(dentry, sigen);
++
++ /* slow loop, keep it simple and stupid */
++ /* cf: au_cpup_dirs() */
++ err = 0;
++ parent = NULL;
++ while (au_digen(dentry) != sigen
++ || au_iigen(dentry->d_inode) != sigen) {
++ d = dentry;
++ while (1) {
++ dput(parent);
++ parent = dget_parent(d);
++ if (au_digen(parent) == sigen
++ && au_iigen(parent->d_inode) == sigen)
++ break;
++ d = parent;
++ }
++
++ inode = d->d_inode;
++ if (d != dentry)
++ di_write_lock_child(d);
++
++ /* someone might update our dentry while we were sleeping */
++ if (au_digen(d) != sigen || au_iigen(d->d_inode) != sigen) {
++ di_read_lock_parent(parent, AuLock_IR);
++ /* returns a number of positive dentries */
++ err = au_refresh_hdentry(d, inode->i_mode & S_IFMT);
++ if (err >= 0)
++ err = au_refresh_hinode(inode, d);
++ di_read_unlock(parent, AuLock_IR);
++ }
++
++ if (d != dentry)
++ di_write_unlock(d);
++ dput(parent);
++ if (unlikely(err))
++ break;
++ }
++
++ return err;
++}
++
++/*
++ * if valid returns 1, otherwise 0.
++ */
++static int aufs_d_revalidate(struct dentry *dentry, struct nameidata *nd)
++{
++ int valid, err;
++ unsigned int sigen;
++ unsigned char do_udba;
++ struct super_block *sb;
++ struct inode *inode;
++
++ err = -EINVAL;
++ sb = dentry->d_sb;
++ inode = dentry->d_inode;
++ aufs_read_lock(dentry, AuLock_FLUSH | AuLock_DW);
++ sigen = au_sigen(sb);
++ if (au_digen(dentry) != sigen) {
++ AuDebugOn(IS_ROOT(dentry));
++ if (inode)
++ err = au_reval_dpath(dentry, sigen);
++ if (unlikely(err))
++ goto out_dgrade;
++ AuDebugOn(au_digen(dentry) != sigen);
++ }
++ if (inode && au_iigen(inode) != sigen) {
++ AuDebugOn(IS_ROOT(dentry));
++ err = au_refresh_hinode(inode, dentry);
++ if (unlikely(err))
++ goto out_dgrade;
++ AuDebugOn(au_iigen(inode) != sigen);
++ }
++ di_downgrade_lock(dentry, AuLock_IR);
++
++ AuDebugOn(au_digen(dentry) != sigen);
++ AuDebugOn(inode && au_iigen(inode) != sigen);
++ err = -EINVAL;
++ do_udba = !au_opt_test(au_mntflags(sb), UDBA_NONE);
++ if (do_udba && inode) {
++ aufs_bindex_t bstart = au_ibstart(inode);
++
++ if (bstart >= 0
++ && au_test_higen(inode, au_h_iptr(inode, bstart)))
++ goto out;
++ }
++
++ err = h_d_revalidate(dentry, inode, nd, do_udba);
++ if (unlikely(!err && do_udba && au_dbstart(dentry) < 0))
++ /* both of real entry and whiteout found */
++ err = -EIO;
++ goto out;
++
++ out_dgrade:
++ di_downgrade_lock(dentry, AuLock_IR);
++ out:
++ au_store_oflag(nd, inode);
++ aufs_read_unlock(dentry, AuLock_IR);
++ AuTraceErr(err);
++ valid = !err;
++ if (!valid)
++ AuDbg("%.*s invalid\n", AuDLNPair(dentry));
++ return valid;
++}
++
++static void aufs_d_release(struct dentry *dentry)
++{
++ struct au_dinfo *dinfo;
++ aufs_bindex_t bend, bindex;
++
++ dinfo = dentry->d_fsdata;
++ if (!dinfo)
++ return;
++
++ /* dentry may not be revalidated */
++ bindex = dinfo->di_bstart;
++ if (bindex >= 0) {
++ struct au_hdentry *p;
++
++ bend = dinfo->di_bend;
++ p = dinfo->di_hdentry + bindex;
++ while (bindex++ <= bend) {
++ if (p->hd_dentry)
++ au_hdput(p);
++ p++;
++ }
++ }
++ kfree(dinfo->di_hdentry);
++ au_rwsem_destroy(&dinfo->di_rwsem);
++ au_cache_free_dinfo(dinfo);
++ au_hin_di_reinit(dentry);
++}
++
++struct dentry_operations aufs_dop = {
++ .d_revalidate = aufs_d_revalidate,
++ .d_release = aufs_d_release
++};
+diff --git a/fs/aufs/dentry.h b/fs/aufs/dentry.h
+new file mode 100644
+index 0000000..8708db8
+--- /dev/null
++++ b/fs/aufs/dentry.h
+@@ -0,0 +1,213 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * lookup and dentry operations
++ */
++
++#ifndef __AUFS_DENTRY_H__
++#define __AUFS_DENTRY_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/namei.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++/* make a single member structure for future use */
++/* todo: remove this structure */
++struct au_hdentry {
++ struct dentry *hd_dentry;
++};
++
++struct au_dinfo {
++ atomic_t di_generation;
++
++ struct rw_semaphore di_rwsem;
++ aufs_bindex_t di_bstart, di_bend, di_bwh, di_bdiropq;
++ struct au_hdentry *di_hdentry;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* dentry.c */
++extern struct dentry_operations aufs_dop;
++struct au_branch;
++struct dentry *au_lkup_one(struct qstr *name, struct dentry *h_parent,
++ struct au_branch *br, struct nameidata *nd);
++struct dentry *au_sio_lkup_one(struct qstr *name, struct dentry *parent,
++ struct au_branch *br);
++int au_h_verify(struct dentry *h_dentry, unsigned int udba, struct inode *h_dir,
++ struct dentry *h_parent, struct au_branch *br);
++
++int au_lkup_dentry(struct dentry *dentry, aufs_bindex_t bstart, mode_t type,
++ struct nameidata *nd);
++int au_lkup_neg(struct dentry *dentry, aufs_bindex_t bindex);
++int au_refresh_hdentry(struct dentry *dentry, mode_t type);
++int au_reval_dpath(struct dentry *dentry, unsigned int sigen);
++
++/* dinfo.c */
++int au_alloc_dinfo(struct dentry *dentry);
++int au_di_realloc(struct au_dinfo *dinfo, int nbr);
++
++void di_read_lock(struct dentry *d, int flags, unsigned int lsc);
++void di_read_unlock(struct dentry *d, int flags);
++void di_downgrade_lock(struct dentry *d, int flags);
++void di_write_lock(struct dentry *d, unsigned int lsc);
++void di_write_unlock(struct dentry *d);
++void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir);
++void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir);
++void di_write_unlock2(struct dentry *d1, struct dentry *d2);
++
++struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex);
++aufs_bindex_t au_dbtail(struct dentry *dentry);
++aufs_bindex_t au_dbtaildir(struct dentry *dentry);
++
++void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_dentry);
++void au_update_digen(struct dentry *dentry);
++void au_update_dbrange(struct dentry *dentry, int do_put_zero);
++void au_update_dbstart(struct dentry *dentry);
++void au_update_dbend(struct dentry *dentry);
++int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_dinfo *au_di(struct dentry *dentry)
++{
++ return dentry->d_fsdata;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for dinfo */
++enum {
++ AuLsc_DI_CHILD, /* child first */
++ AuLsc_DI_CHILD2, /* rename(2), link(2), and cpup at hinotify */
++ AuLsc_DI_CHILD3, /* copyup dirs */
++ AuLsc_DI_PARENT,
++ AuLsc_DI_PARENT2,
++ AuLsc_DI_PARENT3
++};
++
++/*
++ * di_read_lock_child, di_write_lock_child,
++ * di_read_lock_child2, di_write_lock_child2,
++ * di_read_lock_child3, di_write_lock_child3,
++ * di_read_lock_parent, di_write_lock_parent,
++ * di_read_lock_parent2, di_write_lock_parent2,
++ * di_read_lock_parent3, di_write_lock_parent3,
++ */
++#define AuReadLockFunc(name, lsc) \
++static inline void di_read_lock_##name(struct dentry *d, int flags) \
++{ di_read_lock(d, flags, AuLsc_DI_##lsc); }
++
++#define AuWriteLockFunc(name, lsc) \
++static inline void di_write_lock_##name(struct dentry *d) \
++{ di_write_lock(d, AuLsc_DI_##lsc); }
++
++#define AuRWLockFuncs(name, lsc) \
++ AuReadLockFunc(name, lsc) \
++ AuWriteLockFunc(name, lsc)
++
++AuRWLockFuncs(child, CHILD);
++AuRWLockFuncs(child2, CHILD2);
++AuRWLockFuncs(child3, CHILD3);
++AuRWLockFuncs(parent, PARENT);
++AuRWLockFuncs(parent2, PARENT2);
++AuRWLockFuncs(parent3, PARENT3);
++
++#undef AuReadLockFunc
++#undef AuWriteLockFunc
++#undef AuRWLockFuncs
++
++#define DiMustNoWaiters(d) AuRwMustNoWaiters(&au_di(d)->di_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: memory barrier? */
++static inline unsigned int au_digen(struct dentry *d)
++{
++ return atomic_read(&au_di(d)->di_generation);
++}
++
++static inline void au_h_dentry_init(struct au_hdentry *hdentry)
++{
++ hdentry->hd_dentry = NULL;
++}
++
++static inline void au_hdput(struct au_hdentry *hd)
++{
++ dput(hd->hd_dentry);
++}
++
++static inline aufs_bindex_t au_dbstart(struct dentry *dentry)
++{
++ return au_di(dentry)->di_bstart;
++}
++
++static inline aufs_bindex_t au_dbend(struct dentry *dentry)
++{
++ return au_di(dentry)->di_bend;
++}
++
++static inline aufs_bindex_t au_dbwh(struct dentry *dentry)
++{
++ return au_di(dentry)->di_bwh;
++}
++
++static inline aufs_bindex_t au_dbdiropq(struct dentry *dentry)
++{
++ return au_di(dentry)->di_bdiropq;
++}
++
++/* todo: hard/soft set? */
++static inline void au_set_dbstart(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ au_di(dentry)->di_bstart = bindex;
++}
++
++static inline void au_set_dbend(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ au_di(dentry)->di_bend = bindex;
++}
++
++static inline void au_set_dbwh(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ /* dbwh can be outside of bstart - bend range */
++ au_di(dentry)->di_bwh = bindex;
++}
++
++static inline void au_set_dbdiropq(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ au_di(dentry)->di_bdiropq = bindex;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_HINOTIFY
++static inline void au_digen_dec(struct dentry *d)
++{
++ atomic_dec(&au_di(d)->di_generation);
++}
++
++static inline void au_hin_di_reinit(struct dentry *dentry)
++{
++ dentry->d_fsdata = NULL;
++}
++#else
++static inline void au_hin_di_reinit(struct dentry *dentry __maybe_unused)
++{
++ /* empty */
++}
++#endif /* CONFIG_AUFS_HINOTIFY */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DENTRY_H__ */
+diff --git a/fs/aufs/dinfo.c b/fs/aufs/dinfo.c
+new file mode 100644
+index 0000000..b0645aa
+--- /dev/null
++++ b/fs/aufs/dinfo.c
+@@ -0,0 +1,351 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * dentry private data
++ */
++
++#include "aufs.h"
++
++int au_alloc_dinfo(struct dentry *dentry)
++{
++ struct au_dinfo *dinfo;
++ struct super_block *sb;
++ int nbr;
++
++ dinfo = au_cache_alloc_dinfo();
++ if (unlikely(!dinfo))
++ goto out;
++
++ sb = dentry->d_sb;
++ nbr = au_sbend(sb) + 1;
++ if (nbr <= 0)
++ nbr = 1;
++ dinfo->di_hdentry = kcalloc(nbr, sizeof(*dinfo->di_hdentry), GFP_NOFS);
++ if (unlikely(!dinfo->di_hdentry))
++ goto out_dinfo;
++
++ atomic_set(&dinfo->di_generation, au_sigen(sb));
++ /* smp_mb(); */ /* atomic_set */
++ init_rwsem(&dinfo->di_rwsem);
++ down_write_nested(&dinfo->di_rwsem, AuLsc_DI_CHILD);
++ dinfo->di_bstart = -1;
++ dinfo->di_bend = -1;
++ dinfo->di_bwh = -1;
++ dinfo->di_bdiropq = -1;
++
++ dentry->d_fsdata = dinfo;
++ dentry->d_op = &aufs_dop;
++ return 0; /* success */
++
++ out_dinfo:
++ au_cache_free_dinfo(dinfo);
++ out:
++ return -ENOMEM;
++}
++
++int au_di_realloc(struct au_dinfo *dinfo, int nbr)
++{
++ int err, sz;
++ struct au_hdentry *hdp;
++
++ err = -ENOMEM;
++ sz = sizeof(*hdp) * (dinfo->di_bend + 1);
++ if (!sz)
++ sz = sizeof(*hdp);
++ hdp = au_kzrealloc(dinfo->di_hdentry, sz, sizeof(*hdp) * nbr, GFP_NOFS);
++ if (hdp) {
++ dinfo->di_hdentry = hdp;
++ err = 0;
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void do_ii_write_lock(struct inode *inode, unsigned int lsc)
++{
++ switch (lsc) {
++ case AuLsc_DI_CHILD:
++ ii_write_lock_child(inode);
++ break;
++ case AuLsc_DI_CHILD2:
++ ii_write_lock_child2(inode);
++ break;
++ case AuLsc_DI_CHILD3:
++ ii_write_lock_child3(inode);
++ break;
++ case AuLsc_DI_PARENT:
++ ii_write_lock_parent(inode);
++ break;
++ case AuLsc_DI_PARENT2:
++ ii_write_lock_parent2(inode);
++ break;
++ case AuLsc_DI_PARENT3:
++ ii_write_lock_parent3(inode);
++ break;
++ default:
++ BUG();
++ }
++}
++
++static void do_ii_read_lock(struct inode *inode, unsigned int lsc)
++{
++ switch (lsc) {
++ case AuLsc_DI_CHILD:
++ ii_read_lock_child(inode);
++ break;
++ case AuLsc_DI_CHILD2:
++ ii_read_lock_child2(inode);
++ break;
++ case AuLsc_DI_CHILD3:
++ ii_read_lock_child3(inode);
++ break;
++ case AuLsc_DI_PARENT:
++ ii_read_lock_parent(inode);
++ break;
++ case AuLsc_DI_PARENT2:
++ ii_read_lock_parent2(inode);
++ break;
++ case AuLsc_DI_PARENT3:
++ ii_read_lock_parent3(inode);
++ break;
++ default:
++ BUG();
++ }
++}
++
++void di_read_lock(struct dentry *d, int flags, unsigned int lsc)
++{
++ down_read_nested(&au_di(d)->di_rwsem, lsc);
++ if (d->d_inode) {
++ if (au_ftest_lock(flags, IW))
++ do_ii_write_lock(d->d_inode, lsc);
++ else if (au_ftest_lock(flags, IR))
++ do_ii_read_lock(d->d_inode, lsc);
++ }
++}
++
++void di_read_unlock(struct dentry *d, int flags)
++{
++ if (d->d_inode) {
++ if (au_ftest_lock(flags, IW))
++ ii_write_unlock(d->d_inode);
++ else if (au_ftest_lock(flags, IR))
++ ii_read_unlock(d->d_inode);
++ }
++ up_read(&au_di(d)->di_rwsem);
++}
++
++void di_downgrade_lock(struct dentry *d, int flags)
++{
++ downgrade_write(&au_di(d)->di_rwsem);
++ if (d->d_inode && au_ftest_lock(flags, IR))
++ ii_downgrade_lock(d->d_inode);
++}
++
++void di_write_lock(struct dentry *d, unsigned int lsc)
++{
++ down_write_nested(&au_di(d)->di_rwsem, lsc);
++ if (d->d_inode)
++ do_ii_write_lock(d->d_inode, lsc);
++}
++
++void di_write_unlock(struct dentry *d)
++{
++ if (d->d_inode)
++ ii_write_unlock(d->d_inode);
++ up_write(&au_di(d)->di_rwsem);
++}
++
++void di_write_lock2_child(struct dentry *d1, struct dentry *d2, int isdir)
++{
++ AuDebugOn(d1 == d2
++ || d1->d_inode == d2->d_inode
++ || d1->d_sb != d2->d_sb);
++
++ if (isdir && au_test_subdir(d1, d2)) {
++ di_write_lock_child(d1);
++ di_write_lock_child2(d2);
++ } else {
++ /* there should be no races */
++ di_write_lock_child(d2);
++ di_write_lock_child2(d1);
++ }
++}
++
++void di_write_lock2_parent(struct dentry *d1, struct dentry *d2, int isdir)
++{
++ AuDebugOn(d1 == d2
++ || d1->d_inode == d2->d_inode
++ || d1->d_sb != d2->d_sb);
++
++ if (isdir && au_test_subdir(d1, d2)) {
++ di_write_lock_parent(d1);
++ di_write_lock_parent2(d2);
++ } else {
++ /* there should be no races */
++ di_write_lock_parent(d2);
++ di_write_lock_parent2(d1);
++ }
++}
++
++void di_write_unlock2(struct dentry *d1, struct dentry *d2)
++{
++ di_write_unlock(d1);
++ if (d1->d_inode == d2->d_inode)
++ up_write(&au_di(d2)->di_rwsem);
++ else
++ di_write_unlock(d2);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *au_h_dptr(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ struct dentry *d;
++
++ if (au_dbstart(dentry) < 0 || bindex < au_dbstart(dentry))
++ return NULL;
++ AuDebugOn(bindex < 0);
++ d = au_di(dentry)->di_hdentry[0 + bindex].hd_dentry;
++ AuDebugOn(d && (atomic_read(&d->d_count) <= 0));
++ return d;
++}
++
++aufs_bindex_t au_dbtail(struct dentry *dentry)
++{
++ aufs_bindex_t bend, bwh;
++
++ bend = au_dbend(dentry);
++ if (0 <= bend) {
++ bwh = au_dbwh(dentry);
++ if (!bwh)
++ return bwh;
++ if (0 < bwh && bwh < bend)
++ return bwh - 1;
++ }
++ return bend;
++}
++
++aufs_bindex_t au_dbtaildir(struct dentry *dentry)
++{
++ aufs_bindex_t bend, bopq;
++
++ bend = au_dbtail(dentry);
++ if (0 <= bend) {
++ bopq = au_dbdiropq(dentry);
++ if (0 <= bopq && bopq < bend)
++ bend = bopq;
++ }
++ return bend;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_set_h_dptr(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_dentry)
++{
++ struct au_hdentry *hd = au_di(dentry)->di_hdentry + bindex;
++
++ if (hd->hd_dentry)
++ au_hdput(hd);
++ hd->hd_dentry = h_dentry;
++}
++
++void au_update_digen(struct dentry *dentry)
++{
++ atomic_set(&au_di(dentry)->di_generation, au_sigen(dentry->d_sb));
++ /* smp_mb(); */ /* atomic_set */
++}
++
++void au_update_dbrange(struct dentry *dentry, int do_put_zero)
++{
++ struct au_dinfo *dinfo;
++ struct dentry *h_d;
++
++ dinfo = au_di(dentry);
++ if (!dinfo || dinfo->di_bstart < 0)
++ return;
++
++ if (do_put_zero) {
++ aufs_bindex_t bindex, bend;
++
++ bend = dinfo->di_bend;
++ for (bindex = dinfo->di_bstart; bindex <= bend; bindex++) {
++ h_d = dinfo->di_hdentry[0 + bindex].hd_dentry;
++ if (h_d && !h_d->d_inode)
++ au_set_h_dptr(dentry, bindex, NULL);
++ }
++ }
++
++ dinfo->di_bstart = -1;
++ while (++dinfo->di_bstart <= dinfo->di_bend)
++ if (dinfo->di_hdentry[0 + dinfo->di_bstart].hd_dentry)
++ break;
++ if (dinfo->di_bstart > dinfo->di_bend) {
++ dinfo->di_bstart = -1;
++ dinfo->di_bend = -1;
++ return;
++ }
++
++ dinfo->di_bend++;
++ while (0 <= --dinfo->di_bend)
++ if (dinfo->di_hdentry[0 + dinfo->di_bend].hd_dentry)
++ break;
++ AuDebugOn(dinfo->di_bstart > dinfo->di_bend || dinfo->di_bend < 0);
++}
++
++void au_update_dbstart(struct dentry *dentry)
++{
++ aufs_bindex_t bindex, bend;
++ struct dentry *h_dentry;
++
++ bend = au_dbend(dentry);
++ for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!h_dentry)
++ continue;
++ if (h_dentry->d_inode) {
++ au_set_dbstart(dentry, bindex);
++ return;
++ }
++ au_set_h_dptr(dentry, bindex, NULL);
++ }
++}
++
++void au_update_dbend(struct dentry *dentry)
++{
++ aufs_bindex_t bindex, bstart;
++ struct dentry *h_dentry;
++
++ bstart = au_dbstart(dentry);
++ for (bindex = au_dbend(dentry); bindex <= bstart; bindex--) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!h_dentry)
++ continue;
++ if (h_dentry->d_inode) {
++ au_set_dbend(dentry, bindex);
++ return;
++ }
++ au_set_h_dptr(dentry, bindex, NULL);
++ }
++}
++
++int au_find_dbindex(struct dentry *dentry, struct dentry *h_dentry)
++{
++ aufs_bindex_t bindex, bend;
++
++ bend = au_dbend(dentry);
++ for (bindex = au_dbstart(dentry); bindex <= bend; bindex++)
++ if (au_h_dptr(dentry, bindex) == h_dentry)
++ return bindex;
++ return -1;
++}
+diff --git a/fs/aufs/dir.c b/fs/aufs/dir.c
+new file mode 100644
+index 0000000..9fc6196
+--- /dev/null
++++ b/fs/aufs/dir.c
+@@ -0,0 +1,513 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * directory operations
++ */
++
++#include <linux/fs_stack.h>
++#include "aufs.h"
++
++void au_add_nlink(struct inode *dir, struct inode *h_dir)
++{
++ AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
++
++ dir->i_nlink += h_dir->i_nlink - 2;
++ if (h_dir->i_nlink < 2)
++ dir->i_nlink += 2;
++}
++
++void au_sub_nlink(struct inode *dir, struct inode *h_dir)
++{
++ AuDebugOn(!S_ISDIR(dir->i_mode) || !S_ISDIR(h_dir->i_mode));
++
++ dir->i_nlink -= h_dir->i_nlink - 2;
++ if (h_dir->i_nlink < 2)
++ dir->i_nlink -= 2;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int reopen_dir(struct file *file)
++{
++ int err;
++ unsigned int flags;
++ aufs_bindex_t bindex, btail, bstart;
++ struct dentry *dentry, *h_dentry;
++ struct file *h_file;
++
++ /* open all lower dirs */
++ dentry = file->f_dentry;
++ bstart = au_dbstart(dentry);
++ for (bindex = au_fbstart(file); bindex < bstart; bindex++)
++ au_set_h_fptr(file, bindex, NULL);
++ au_set_fbstart(file, bstart);
++
++ btail = au_dbtaildir(dentry);
++ for (bindex = au_fbend(file); btail < bindex; bindex--)
++ au_set_h_fptr(file, bindex, NULL);
++ au_set_fbend(file, btail);
++
++ flags = file->f_flags;
++ for (bindex = bstart; bindex <= btail; bindex++) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!h_dentry)
++ continue;
++ h_file = au_h_fptr(file, bindex);
++ if (h_file)
++ continue;
++
++ h_file = au_h_open(dentry, bindex, flags, file);
++ err = PTR_ERR(h_file);
++ if (IS_ERR(h_file))
++ goto out; /* close all? */
++ au_set_h_fptr(file, bindex, h_file);
++ }
++ au_update_figen(file);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++ err = 0;
++
++ out:
++ return err;
++}
++
++static int do_open_dir(struct file *file, int flags)
++{
++ int err;
++ aufs_bindex_t bindex, btail;
++ struct dentry *dentry, *h_dentry;
++ struct file *h_file;
++
++ err = 0;
++ dentry = file->f_dentry;
++ au_set_fvdir_cache(file, NULL);
++ au_fi(file)->fi_maintain_plink = 0;
++ file->f_version = dentry->d_inode->i_version;
++ bindex = au_dbstart(dentry);
++ au_set_fbstart(file, bindex);
++ btail = au_dbtaildir(dentry);
++ au_set_fbend(file, btail);
++ for (; !err && bindex <= btail; bindex++) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!h_dentry)
++ continue;
++
++ h_file = au_h_open(dentry, bindex, flags, file);
++ if (IS_ERR(h_file)) {
++ err = PTR_ERR(h_file);
++ break;
++ }
++ au_set_h_fptr(file, bindex, h_file);
++ }
++ au_update_figen(file);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++ if (!err)
++ return 0; /* success */
++
++ /* close all */
++ for (bindex = au_fbstart(file); bindex <= btail; bindex++)
++ au_set_h_fptr(file, bindex, NULL);
++ au_set_fbstart(file, -1);
++ au_set_fbend(file, -1);
++ return err;
++}
++
++static int aufs_open_dir(struct inode *inode __maybe_unused,
++ struct file *file)
++{
++ return au_do_open(file, do_open_dir);
++}
++
++static int aufs_release_dir(struct inode *inode __maybe_unused,
++ struct file *file)
++{
++ struct au_vdir *vdir_cache;
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++
++ sb = file->f_dentry->d_sb;
++ si_noflush_read_lock(sb);
++ fi_write_lock(file);
++ vdir_cache = au_fvdir_cache(file);
++ if (vdir_cache)
++ au_vdir_free(vdir_cache);
++ if (au_fi(file)->fi_maintain_plink) {
++ sbinfo = au_sbi(sb);
++ au_fclr_si(sbinfo, MAINTAIN_PLINK);
++ wake_up_all(&sbinfo->si_plink_wq);
++ }
++ fi_write_unlock(file);
++ au_finfo_fin(file);
++ si_read_unlock(sb);
++ return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_do_fsync_dir_no_file(struct dentry *dentry, int datasync)
++{
++ int err;
++ aufs_bindex_t bend, bindex;
++ struct inode *inode;
++ struct super_block *sb;
++
++ err = 0;
++ sb = dentry->d_sb;
++ inode = dentry->d_inode;
++ IMustLock(inode);
++ bend = au_dbend(dentry);
++ for (bindex = au_dbstart(dentry); !err && bindex <= bend; bindex++) {
++ struct path h_path;
++ struct inode *h_inode;
++
++ if (au_test_ro(sb, bindex, inode))
++ continue;
++ h_path.dentry = au_h_dptr(dentry, bindex);
++ if (!h_path.dentry)
++ continue;
++ h_inode = h_path.dentry->d_inode;
++ if (!h_inode)
++ continue;
++
++ /* no mnt_want_write() */
++ /* cf. fs/nsfd/vfs.c and fs/nfsd/nfs4recover.c */
++ /* todo: inotiry fired? */
++ h_path.mnt = au_sbr_mnt(sb, bindex);
++ mutex_lock(&h_inode->i_mutex);
++ err = filemap_fdatawrite(h_inode->i_mapping);
++ AuDebugOn(!h_inode->i_fop);
++ if (!err && h_inode->i_fop->fsync)
++ err = h_inode->i_fop->fsync(NULL, h_path.dentry,
++ datasync);
++ if (!err)
++ err = filemap_fdatawrite(h_inode->i_mapping);
++ if (!err)
++ vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++ mutex_unlock(&h_inode->i_mutex);
++ }
++
++ return err;
++}
++
++static int au_do_fsync_dir(struct file *file, int datasync)
++{
++ int err;
++ aufs_bindex_t bend, bindex;
++ struct file *h_file;
++ struct super_block *sb;
++ struct inode *inode;
++ struct mutex *h_mtx;
++
++ err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1);
++ if (unlikely(err))
++ goto out;
++
++ sb = file->f_dentry->d_sb;
++ inode = file->f_dentry->d_inode;
++ bend = au_fbend(file);
++ for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
++ h_file = au_h_fptr(file, bindex);
++ if (!h_file || au_test_ro(sb, bindex, inode))
++ continue;
++
++ err = vfs_fsync(h_file, h_file->f_dentry, datasync);
++ if (!err) {
++ h_mtx = &h_file->f_dentry->d_inode->i_mutex;
++ mutex_lock(h_mtx);
++ vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++ /*ignore*/
++ mutex_unlock(h_mtx);
++ }
++ }
++
++ out:
++ return err;
++}
++
++/*
++ * @file may be NULL
++ */
++static int aufs_fsync_dir(struct file *file, struct dentry *dentry,
++ int datasync)
++{
++ int err;
++ struct super_block *sb;
++
++ IMustLock(dentry->d_inode);
++
++ err = 0;
++ sb = dentry->d_sb;
++ si_noflush_read_lock(sb);
++ if (file)
++ err = au_do_fsync_dir(file, datasync);
++ else {
++ di_write_lock_child(dentry);
++ err = au_do_fsync_dir_no_file(dentry, datasync);
++ }
++ au_cpup_attr_timesizes(dentry->d_inode);
++ di_write_unlock(dentry);
++ if (file)
++ fi_write_unlock(file);
++
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_readdir(struct file *file, void *dirent, filldir_t filldir)
++{
++ int err;
++ struct dentry *dentry;
++ struct inode *inode;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ inode = dentry->d_inode;
++ IMustLock(inode);
++
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, reopen_dir, /*wlock*/1);
++ if (unlikely(err))
++ goto out;
++ err = au_vdir_init(file);
++ di_downgrade_lock(dentry, AuLock_IR);
++ if (unlikely(err))
++ goto out_unlock;
++
++ if (!au_test_nfsd(current)) {
++ err = au_vdir_fill_de(file, dirent, filldir);
++ fsstack_copy_attr_atime(inode,
++ au_h_iptr(inode, au_ibstart(inode)));
++ } else {
++ /*
++ * nfsd filldir may call lookup_one_len(), vfs_getattr(),
++ * encode_fh() and others.
++ */
++ struct inode *h_inode = au_h_iptr(inode, au_ibstart(inode));
++
++ di_read_unlock(dentry, AuLock_IR);
++ si_read_unlock(sb);
++ lockdep_off();
++ err = au_vdir_fill_de(file, dirent, filldir);
++ lockdep_on();
++ fsstack_copy_attr_atime(inode, h_inode);
++ fi_write_unlock(file);
++
++ AuTraceErr(err);
++ return err;
++ }
++
++ out_unlock:
++ di_read_unlock(dentry, AuLock_IR);
++ fi_write_unlock(file);
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#define AuTestEmpty_WHONLY 1
++#define AuTestEmpty_CALLED (1 << 2)
++#define au_ftest_testempty(flags, name) ((flags) & AuTestEmpty_##name)
++#define au_fset_testempty(flags, name) { (flags) |= AuTestEmpty_##name; }
++#define au_fclr_testempty(flags, name) { (flags) &= ~AuTestEmpty_##name; }
++
++struct test_empty_arg {
++ struct au_nhash *whlist;
++ unsigned int flags;
++ int err;
++ aufs_bindex_t bindex;
++};
++
++static int test_empty_cb(void *__arg, const char *__name, int namelen,
++ loff_t offset __maybe_unused, u64 ino __maybe_unused,
++ unsigned int d_type __maybe_unused)
++{
++ struct test_empty_arg *arg = __arg;
++ char *name = (void *)__name;
++
++ arg->err = 0;
++ au_fset_testempty(arg->flags, CALLED);
++ /* smp_mb(); */
++ if (name[0] == '.'
++ && (namelen == 1 || (name[1] == '.' && namelen == 2)))
++ goto out; /* success */
++
++ if (namelen <= AUFS_WH_PFX_LEN
++ || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++ if (au_ftest_testempty(arg->flags, WHONLY)
++ && !au_nhash_test_known_wh(arg->whlist, name, namelen))
++ arg->err = -ENOTEMPTY;
++ goto out;
++ }
++
++ name += AUFS_WH_PFX_LEN;
++ namelen -= AUFS_WH_PFX_LEN;
++ if (!au_nhash_test_known_wh(arg->whlist, name, namelen))
++ arg->err = au_nhash_append_wh
++ (arg->whlist, name, namelen, arg->bindex);
++
++ out:
++ /* smp_mb(); */
++ AuTraceErr(arg->err);
++ return arg->err;
++}
++
++static int do_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
++{
++ int err;
++ struct file *h_file;
++
++ h_file = au_h_open(dentry, arg->bindex,
++ O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_LARGEFILE,
++ /*file*/NULL);
++ err = PTR_ERR(h_file);
++ if (IS_ERR(h_file))
++ goto out;
++
++ err = 0;
++ if (!au_opt_test(au_mntflags(dentry->d_sb), UDBA_NONE)
++ && !h_file->f_dentry->d_inode->i_nlink)
++ goto out_put;
++
++ do {
++ arg->err = 0;
++ au_fclr_testempty(arg->flags, CALLED);
++ /* smp_mb(); */
++ err = vfsub_readdir(h_file, test_empty_cb, arg);
++ if (err >= 0)
++ err = arg->err;
++ } while (!err && au_ftest_testempty(arg->flags, CALLED));
++
++ out_put:
++ fput(h_file);
++ au_sbr_put(dentry->d_sb, arg->bindex);
++ out:
++ return err;
++}
++
++struct do_test_empty_args {
++ int *errp;
++ struct dentry *dentry;
++ struct test_empty_arg *arg;
++};
++
++static void call_do_test_empty(void *args)
++{
++ struct do_test_empty_args *a = args;
++ *a->errp = do_test_empty(a->dentry, a->arg);
++}
++
++static int sio_test_empty(struct dentry *dentry, struct test_empty_arg *arg)
++{
++ int err, wkq_err;
++ struct dentry *h_dentry;
++ struct inode *h_inode;
++
++ h_dentry = au_h_dptr(dentry, arg->bindex);
++ h_inode = h_dentry->d_inode;
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ err = au_test_h_perm_sio(h_inode, MAY_EXEC | MAY_READ);
++ mutex_unlock(&h_inode->i_mutex);
++ if (!err)
++ err = do_test_empty(dentry, arg);
++ else {
++ struct do_test_empty_args args = {
++ .errp = &err,
++ .dentry = dentry,
++ .arg = arg
++ };
++ unsigned int flags = arg->flags;
++
++ wkq_err = au_wkq_wait(call_do_test_empty, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ arg->flags = flags;
++ }
++
++ return err;
++}
++
++int au_test_empty_lower(struct dentry *dentry)
++{
++ int err;
++ aufs_bindex_t bindex, bstart, btail;
++ struct test_empty_arg arg;
++ struct au_nhash *whlist;
++
++ whlist = au_nhash_alloc(dentry->d_sb, /*bend*/0, GFP_NOFS);
++ err = PTR_ERR(whlist);
++ if (IS_ERR(whlist))
++ goto out;
++
++ bstart = au_dbstart(dentry);
++ arg.whlist = whlist;
++ arg.flags = 0;
++ arg.bindex = bstart;
++ err = do_test_empty(dentry, &arg);
++ if (unlikely(err))
++ goto out_whlist;
++
++ au_fset_testempty(arg.flags, WHONLY);
++ btail = au_dbtaildir(dentry);
++ for (bindex = bstart + 1; !err && bindex <= btail; bindex++) {
++ struct dentry *h_dentry;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (h_dentry && h_dentry->d_inode) {
++ arg.bindex = bindex;
++ err = do_test_empty(dentry, &arg);
++ }
++ }
++
++ out_whlist:
++ au_nhash_wh_free(whlist, /*bend*/0);
++ out:
++ return err;
++}
++
++int au_test_empty(struct dentry *dentry, struct au_nhash *whlist)
++{
++ int err;
++ struct test_empty_arg arg;
++ aufs_bindex_t bindex, btail;
++
++ err = 0;
++ arg.whlist = whlist;
++ arg.flags = AuTestEmpty_WHONLY;
++ btail = au_dbtaildir(dentry);
++ for (bindex = au_dbstart(dentry); !err && bindex <= btail; bindex++) {
++ struct dentry *h_dentry;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (h_dentry && h_dentry->d_inode) {
++ arg.bindex = bindex;
++ err = sio_test_empty(dentry, &arg);
++ }
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++const struct file_operations aufs_dir_fop = {
++ .read = generic_read_dir,
++ .readdir = aufs_readdir,
++ .unlocked_ioctl = aufs_ioctl_dir,
++ .open = aufs_open_dir,
++ .release = aufs_release_dir,
++ .flush = aufs_flush,
++ .fsync = aufs_fsync_dir
++};
+diff --git a/fs/aufs/dir.h b/fs/aufs/dir.h
+new file mode 100644
+index 0000000..f41f050
+--- /dev/null
++++ b/fs/aufs/dir.h
+@@ -0,0 +1,98 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * directory operations
++ */
++
++#ifndef __AUFS_DIR_H__
++#define __AUFS_DIR_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++
++/* ---------------------------------------------------------------------- */
++
++/* need to be faster and smaller */
++
++struct au_nhash {
++ unsigned int nh_num;
++ struct hlist_head *nh_head;
++};
++
++struct au_vdir_destr {
++ unsigned char len;
++ unsigned char name[0];
++} __packed;
++
++struct au_vdir_dehstr {
++ struct hlist_node hash;
++ struct au_vdir_destr *str;
++};
++
++struct au_vdir_de {
++ ino_t de_ino;
++ unsigned char de_type;
++ /* caution: packed */
++ struct au_vdir_destr de_str;
++} __packed;
++
++struct au_vdir_wh {
++ struct hlist_node wh_hash;
++ aufs_bindex_t wh_bindex;
++ struct au_vdir_destr wh_str;
++} __packed;
++
++union au_vdir_deblk_p {
++ unsigned char *deblk;
++ struct au_vdir_de *de;
++};
++
++struct au_vdir {
++ unsigned char **vd_deblk;
++ unsigned long vd_nblk;
++ unsigned int vd_deblk_sz;
++ struct {
++ unsigned long ul;
++ union au_vdir_deblk_p p;
++ } vd_last;
++
++ unsigned long vd_version;
++ unsigned long vd_jiffy;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* dir.c */
++extern const struct file_operations aufs_dir_fop;
++void au_add_nlink(struct inode *dir, struct inode *h_dir);
++void au_sub_nlink(struct inode *dir, struct inode *h_dir);
++int au_test_empty_lower(struct dentry *dentry);
++int au_test_empty(struct dentry *dentry, struct au_nhash *whlist);
++
++/* vdir.c */
++struct au_nhash *au_nhash_alloc(struct super_block *sb, aufs_bindex_t bend,
++ gfp_t gfp);
++void au_nhash_wh_free(struct au_nhash *whlist, aufs_bindex_t bend);
++int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
++ int limit);
++int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int namelen);
++int au_nhash_append_wh(struct au_nhash *whlist, char *name, int namelen,
++ aufs_bindex_t bindex);
++void au_vdir_free(struct au_vdir *vdir);
++int au_vdir_init(struct file *file);
++int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir);
++
++/* ioctl.c */
++long aufs_ioctl_dir(struct file *file, unsigned int cmd, unsigned long arg);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_DIR_H__ */
+diff --git a/fs/aufs/export.c b/fs/aufs/export.c
+new file mode 100644
+index 0000000..7dd7f33
+--- /dev/null
++++ b/fs/aufs/export.c
+@@ -0,0 +1,725 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * export via nfs
++ */
++
++#include <linux/exportfs.h>
++#include <linux/mnt_namespace.h>
++#include <linux/random.h>
++#include "aufs.h"
++
++union conv {
++#ifdef CONFIG_AUFS_INO_T_64
++ __u32 a[2];
++#else
++ __u32 a[1];
++#endif
++ ino_t ino;
++};
++
++static ino_t decode_ino(__u32 *a)
++{
++ union conv u;
++
++ BUILD_BUG_ON(sizeof(u.ino) != sizeof(u.a));
++ u.a[0] = a[0];
++#ifdef CONFIG_AUFS_INO_T_64
++ u.a[1] = a[1];
++#endif
++ return u.ino;
++}
++
++static void encode_ino(__u32 *a, ino_t ino)
++{
++ union conv u;
++
++ u.ino = ino;
++ a[0] = u.a[0];
++#ifdef CONFIG_AUFS_INO_T_64
++ a[1] = u.a[1];
++#endif
++}
++
++/* NFS file handle */
++enum {
++ Fh_br_id,
++ Fh_sigen,
++#ifdef CONFIG_AUFS_INO_T_64
++ /* support 64bit inode number */
++ Fh_ino1,
++ Fh_ino2,
++ Fh_dir_ino1,
++ Fh_dir_ino2,
++#else
++ Fh_ino1,
++ Fh_dir_ino1,
++#endif
++ Fh_igen,
++ Fh_h_type,
++ Fh_tail,
++
++ Fh_ino = Fh_ino1,
++ Fh_dir_ino = Fh_dir_ino1
++};
++
++static int au_test_anon(struct dentry *dentry)
++{
++ return !!(dentry->d_flags & DCACHE_DISCONNECTED);
++}
++
++/* ---------------------------------------------------------------------- */
++/* inode generation external table */
++
++int au_xigen_inc(struct inode *inode)
++{
++ int err;
++ loff_t pos;
++ ssize_t sz;
++ __u32 igen;
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++
++ err = 0;
++ sb = inode->i_sb;
++ if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
++ goto out;
++
++ pos = inode->i_ino;
++ pos *= sizeof(igen);
++ igen = inode->i_generation + 1;
++ sbinfo = au_sbi(sb);
++ sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
++ sizeof(igen), &pos);
++ if (sz == sizeof(igen))
++ goto out; /* success */
++
++ err = sz;
++ if (unlikely(sz >= 0)) {
++ err = -EIO;
++ AuIOErr("xigen error (%zd)\n", sz);
++ }
++
++ out:
++ return err;
++}
++
++int au_xigen_new(struct inode *inode)
++{
++ int err;
++ loff_t pos;
++ ssize_t sz;
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++ struct file *file;
++
++ err = 0;
++ /* todo: dirty, at mount time */
++ if (inode->i_ino == AUFS_ROOT_INO)
++ goto out;
++ sb = inode->i_sb;
++ if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
++ goto out;
++
++ err = -EFBIG;
++ pos = inode->i_ino;
++ if (unlikely(au_loff_max / sizeof(inode->i_generation) - 1 < pos)) {
++ AuIOErr1("too large i%lld\n", pos);
++ goto out;
++ }
++ pos *= sizeof(inode->i_generation);
++
++ err = 0;
++ sbinfo = au_sbi(sb);
++ file = sbinfo->si_xigen;
++ BUG_ON(!file);
++
++ if (i_size_read(file->f_dentry->d_inode)
++ < pos + sizeof(inode->i_generation)) {
++ inode->i_generation = atomic_inc_return(&sbinfo->si_xigen_next);
++ sz = xino_fwrite(sbinfo->si_xwrite, file, &inode->i_generation,
++ sizeof(inode->i_generation), &pos);
++ } else
++ sz = xino_fread(sbinfo->si_xread, file, &inode->i_generation,
++ sizeof(inode->i_generation), &pos);
++ if (sz == sizeof(inode->i_generation))
++ goto out; /* success */
++
++ err = sz;
++ if (unlikely(sz >= 0)) {
++ err = -EIO;
++ AuIOErr("xigen error (%zd)\n", sz);
++ }
++
++ out:
++ return err;
++}
++
++int au_xigen_set(struct super_block *sb, struct file *base)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++ struct file *file;
++
++ sbinfo = au_sbi(sb);
++ file = au_xino_create2(base, sbinfo->si_xigen);
++ err = PTR_ERR(file);
++ if (IS_ERR(file))
++ goto out;
++ err = 0;
++ if (sbinfo->si_xigen)
++ fput(sbinfo->si_xigen);
++ sbinfo->si_xigen = file;
++
++ out:
++ return err;
++}
++
++void au_xigen_clr(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++
++ sbinfo = au_sbi(sb);
++ if (sbinfo->si_xigen) {
++ fput(sbinfo->si_xigen);
++ sbinfo->si_xigen = NULL;
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *decode_by_ino(struct super_block *sb, ino_t ino,
++ ino_t dir_ino)
++{
++ struct dentry *dentry, *d;
++ struct inode *inode;
++ unsigned int sigen;
++
++ dentry = NULL;
++ inode = ilookup(sb, ino);
++ if (!inode)
++ goto out;
++
++ dentry = ERR_PTR(-ESTALE);
++ sigen = au_sigen(sb);
++ if (unlikely(is_bad_inode(inode)
++ || IS_DEADDIR(inode)
++ || sigen != au_iigen(inode)))
++ goto out_iput;
++
++ dentry = NULL;
++ if (!dir_ino || S_ISDIR(inode->i_mode))
++ dentry = d_find_alias(inode);
++ else {
++ spin_lock(&dcache_lock);
++ list_for_each_entry(d, &inode->i_dentry, d_alias)
++ if (!au_test_anon(d)
++ && d->d_parent->d_inode->i_ino == dir_ino) {
++ dentry = dget_locked(d);
++ break;
++ }
++ spin_unlock(&dcache_lock);
++ }
++ if (unlikely(dentry && sigen != au_digen(dentry))) {
++ dput(dentry);
++ dentry = ERR_PTR(-ESTALE);
++ }
++
++ out_iput:
++ iput(inode);
++ out:
++ return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: dirty? */
++/* if exportfs_decode_fh() passed vfsmount*, we could be happy */
++static struct vfsmount *au_mnt_get(struct super_block *sb)
++{
++ struct mnt_namespace *ns;
++ struct vfsmount *pos, *mnt;
++
++ spin_lock(&vfsmount_lock);
++ /* no get/put ?? */
++ AuDebugOn(!current->nsproxy);
++ ns = current->nsproxy->mnt_ns;
++ AuDebugOn(!ns);
++ mnt = NULL;
++ /* the order (reverse) will not be a problem */
++ list_for_each_entry(pos, &ns->list, mnt_list)
++ if (pos->mnt_sb == sb) {
++ mnt = mntget(pos);
++ break;
++ }
++ spin_unlock(&vfsmount_lock);
++ AuDebugOn(!mnt);
++
++ return mnt;
++}
++
++struct au_nfsd_si_lock {
++ const unsigned int sigen;
++ const aufs_bindex_t br_id;
++ unsigned char force_lock;
++};
++
++static aufs_bindex_t si_nfsd_read_lock(struct super_block *sb,
++ struct au_nfsd_si_lock *nsi_lock)
++{
++ aufs_bindex_t bindex;
++
++ si_read_lock(sb, AuLock_FLUSH);
++
++ /* branch id may be wrapped around */
++ bindex = au_br_index(sb, nsi_lock->br_id);
++ if (bindex >= 0 && nsi_lock->sigen + AUFS_BRANCH_MAX > au_sigen(sb))
++ goto out; /* success */
++
++ if (!nsi_lock->force_lock)
++ si_read_unlock(sb);
++ bindex = -1;
++
++ out:
++ return bindex;
++}
++
++struct find_name_by_ino {
++ int called, found;
++ ino_t ino;
++ char *name;
++ int namelen;
++};
++
++static int
++find_name_by_ino(void *arg, const char *name, int namelen, loff_t offset,
++ u64 ino, unsigned int d_type)
++{
++ struct find_name_by_ino *a = arg;
++
++ a->called++;
++ if (a->ino != ino)
++ return 0;
++
++ memcpy(a->name, name, namelen);
++ a->namelen = namelen;
++ a->found = 1;
++ return 1;
++}
++
++static struct dentry *au_lkup_by_ino(struct path *path, ino_t ino,
++ struct au_nfsd_si_lock *nsi_lock)
++{
++ struct dentry *dentry, *parent;
++ struct file *file;
++ struct inode *dir;
++ struct find_name_by_ino arg;
++ int err;
++
++ parent = path->dentry;
++ if (nsi_lock)
++ si_read_unlock(parent->d_sb);
++ path_get(path);
++ file = dentry_open(parent, path->mnt, au_dir_roflags, current_cred());
++ dentry = (void *)file;
++ if (IS_ERR(file))
++ goto out;
++
++ dentry = ERR_PTR(-ENOMEM);
++ arg.name = __getname();
++ if (unlikely(!arg.name))
++ goto out_file;
++ arg.ino = ino;
++ arg.found = 0;
++ do {
++ arg.called = 0;
++ /* smp_mb(); */
++ err = vfsub_readdir(file, find_name_by_ino, &arg);
++ } while (!err && !arg.found && arg.called);
++ dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out_name;
++ dentry = ERR_PTR(-ENOENT);
++ if (!arg.found)
++ goto out_name;
++
++ /* do not call au_lkup_one() */
++ dir = parent->d_inode;
++ mutex_lock(&dir->i_mutex);
++ dentry = vfsub_lookup_one_len(arg.name, parent, arg.namelen);
++ mutex_unlock(&dir->i_mutex);
++ AuTraceErrPtr(dentry);
++ if (IS_ERR(dentry))
++ goto out_name;
++ AuDebugOn(au_test_anon(dentry));
++ if (unlikely(!dentry->d_inode)) {
++ dput(dentry);
++ dentry = ERR_PTR(-ENOENT);
++ }
++
++ out_name:
++ __putname(arg.name);
++ out_file:
++ fput(file);
++ out:
++ if (unlikely(nsi_lock
++ && si_nfsd_read_lock(parent->d_sb, nsi_lock) < 0))
++ if (!IS_ERR(dentry)) {
++ dput(dentry);
++ dentry = ERR_PTR(-ESTALE);
++ }
++ AuTraceErrPtr(dentry);
++ return dentry;
++}
++
++static struct dentry *decode_by_dir_ino(struct super_block *sb, ino_t ino,
++ ino_t dir_ino,
++ struct au_nfsd_si_lock *nsi_lock)
++{
++ struct dentry *dentry;
++ struct path path;
++
++ if (dir_ino != AUFS_ROOT_INO) {
++ path.dentry = decode_by_ino(sb, dir_ino, 0);
++ dentry = path.dentry;
++ if (!path.dentry || IS_ERR(path.dentry))
++ goto out;
++ AuDebugOn(au_test_anon(path.dentry));
++ } else
++ path.dentry = dget(sb->s_root);
++
++ path.mnt = au_mnt_get(sb);
++ dentry = au_lkup_by_ino(&path, ino, nsi_lock);
++ path_put(&path);
++
++ out:
++ AuTraceErrPtr(dentry);
++ return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int h_acceptable(void *expv, struct dentry *dentry)
++{
++ return 1;
++}
++
++static char *au_build_path(struct dentry *h_parent, struct path *h_rootpath,
++ char *buf, int len, struct super_block *sb)
++{
++ char *p;
++ int n;
++ struct path path;
++
++ p = d_path(h_rootpath, buf, len);
++ if (IS_ERR(p))
++ goto out;
++ n = strlen(p);
++
++ path.mnt = h_rootpath->mnt;
++ path.dentry = h_parent;
++ p = d_path(&path, buf, len);
++ if (IS_ERR(p))
++ goto out;
++ if (n != 1)
++ p += n;
++
++ path.mnt = au_mnt_get(sb);
++ path.dentry = sb->s_root;
++ p = d_path(&path, buf, len - strlen(p));
++ mntput(path.mnt);
++ if (IS_ERR(p))
++ goto out;
++ if (n != 1)
++ p[strlen(p)] = '/';
++
++ out:
++ AuTraceErrPtr(p);
++ return p;
++}
++
++static
++struct dentry *decode_by_path(struct super_block *sb, aufs_bindex_t bindex,
++ ino_t ino, __u32 *fh, int fh_len,
++ struct au_nfsd_si_lock *nsi_lock)
++{
++ struct dentry *dentry, *h_parent, *root;
++ struct super_block *h_sb;
++ char *pathname, *p;
++ struct vfsmount *h_mnt;
++ struct au_branch *br;
++ int err;
++ struct path path;
++
++ br = au_sbr(sb, bindex);
++ /* au_br_get(br); */
++ h_mnt = br->br_mnt;
++ h_sb = h_mnt->mnt_sb;
++ /* todo: call lower fh_to_dentry()? fh_to_parent()? */
++ h_parent = exportfs_decode_fh(h_mnt, (void *)(fh + Fh_tail),
++ fh_len - Fh_tail, fh[Fh_h_type],
++ h_acceptable, /*context*/NULL);
++ dentry = h_parent;
++ if (unlikely(!h_parent || IS_ERR(h_parent))) {
++ AuWarn1("%s decode_fh failed, %ld\n",
++ au_sbtype(h_sb), PTR_ERR(h_parent));
++ goto out;
++ }
++ dentry = NULL;
++ if (unlikely(au_test_anon(h_parent))) {
++ AuWarn1("%s decode_fh returned a disconnected dentry\n",
++ au_sbtype(h_sb));
++ goto out_h_parent;
++ }
++
++ dentry = ERR_PTR(-ENOMEM);
++ pathname = (void *)__get_free_page(GFP_NOFS);
++ if (unlikely(!pathname))
++ goto out_h_parent;
++
++ root = sb->s_root;
++ path.mnt = h_mnt;
++ di_read_lock_parent(root, !AuLock_IR);
++ path.dentry = au_h_dptr(root, bindex);
++ di_read_unlock(root, !AuLock_IR);
++ p = au_build_path(h_parent, &path, pathname, PAGE_SIZE, sb);
++ dentry = (void *)p;
++ if (IS_ERR(p))
++ goto out_pathname;
++
++ si_read_unlock(sb);
++ err = vfsub_kern_path(p, LOOKUP_FOLLOW | LOOKUP_DIRECTORY, &path);
++ dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out_relock;
++
++ dentry = ERR_PTR(-ENOENT);
++ AuDebugOn(au_test_anon(path.dentry));
++ if (unlikely(!path.dentry->d_inode))
++ goto out_path;
++
++ if (ino != path.dentry->d_inode->i_ino)
++ dentry = au_lkup_by_ino(&path, ino, /*nsi_lock*/NULL);
++ else
++ dentry = dget(path.dentry);
++
++ out_path:
++ path_put(&path);
++ out_relock:
++ if (unlikely(si_nfsd_read_lock(sb, nsi_lock) < 0))
++ if (!IS_ERR(dentry)) {
++ dput(dentry);
++ dentry = ERR_PTR(-ESTALE);
++ }
++ out_pathname:
++ free_page((unsigned long)pathname);
++ out_h_parent:
++ dput(h_parent);
++ out:
++ /* au_br_put(br); */
++ AuTraceErrPtr(dentry);
++ return dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *
++aufs_fh_to_dentry(struct super_block *sb, struct fid *fid, int fh_len,
++ int fh_type)
++{
++ struct dentry *dentry;
++ __u32 *fh = fid->raw;
++ ino_t ino, dir_ino;
++ aufs_bindex_t bindex;
++ struct au_nfsd_si_lock nsi_lock = {
++ .sigen = fh[Fh_sigen],
++ .br_id = fh[Fh_br_id],
++ .force_lock = 0
++ };
++
++ AuDebugOn(fh_len < Fh_tail);
++
++ dentry = ERR_PTR(-ESTALE);
++ /* branch id may be wrapped around */
++ bindex = si_nfsd_read_lock(sb, &nsi_lock);
++ if (unlikely(bindex < 0))
++ goto out;
++ nsi_lock.force_lock = 1;
++
++ /* is this inode still cached? */
++ ino = decode_ino(fh + Fh_ino);
++ AuDebugOn(ino == AUFS_ROOT_INO);
++ dir_ino = decode_ino(fh + Fh_dir_ino);
++ dentry = decode_by_ino(sb, ino, dir_ino);
++ if (IS_ERR(dentry))
++ goto out_unlock;
++ if (dentry)
++ goto accept;
++
++ /* is the parent dir cached? */
++ dentry = decode_by_dir_ino(sb, ino, dir_ino, &nsi_lock);
++ if (IS_ERR(dentry))
++ goto out_unlock;
++ if (dentry)
++ goto accept;
++
++ /* lookup path */
++ dentry = decode_by_path(sb, bindex, ino, fh, fh_len, &nsi_lock);
++ if (IS_ERR(dentry))
++ goto out_unlock;
++ if (unlikely(!dentry))
++ /* todo?: make it ESTALE */
++ goto out_unlock;
++
++ accept:
++ if (dentry->d_inode->i_generation == fh[Fh_igen])
++ goto out_unlock; /* success */
++
++ dput(dentry);
++ dentry = ERR_PTR(-ESTALE);
++ out_unlock:
++ si_read_unlock(sb);
++ out:
++ AuTraceErrPtr(dentry);
++ return dentry;
++}
++
++#if 0 /* reserved for future use */
++/* support subtreecheck option */
++static struct dentry *aufs_fh_to_parent(struct super_block *sb, struct fid *fid,
++ int fh_len, int fh_type)
++{
++ struct dentry *parent;
++ __u32 *fh = fid->raw;
++ ino_t dir_ino;
++
++ dir_ino = decode_ino(fh + Fh_dir_ino);
++ parent = decode_by_ino(sb, dir_ino, 0);
++ if (IS_ERR(parent))
++ goto out;
++ if (!parent)
++ parent = decode_by_path(sb, au_br_index(sb, fh[Fh_br_id]),
++ dir_ino, fh, fh_len);
++
++ out:
++ AuTraceErrPtr(parent);
++ return parent;
++}
++#endif
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_encode_fh(struct dentry *dentry, __u32 *fh, int *max_len,
++ int connectable)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ struct super_block *sb, *h_sb;
++ struct inode *inode;
++ struct dentry *parent, *h_parent;
++ struct au_branch *br;
++
++ AuDebugOn(au_test_anon(dentry));
++
++ parent = NULL;
++ err = -ENOSPC;
++ if (unlikely(*max_len <= Fh_tail)) {
++ AuWarn1("NFSv2 client (max_len %d)?\n", *max_len);
++ goto out;
++ }
++
++ err = FILEID_ROOT;
++ if (IS_ROOT(dentry)) {
++ AuDebugOn(dentry->d_inode->i_ino != AUFS_ROOT_INO);
++ goto out;
++ }
++
++ err = -EIO;
++ h_parent = NULL;
++ sb = dentry->d_sb;
++ aufs_read_lock(dentry, AuLock_FLUSH | AuLock_IR);
++ parent = dget_parent(dentry);
++ di_read_lock_parent(parent, !AuLock_IR);
++ inode = dentry->d_inode;
++ AuDebugOn(!inode);
++#ifdef CONFIG_AUFS_DEBUG
++ if (unlikely(!au_opt_test(au_mntflags(sb), XINO)))
++ AuWarn1("NFS-exporting requires xino\n");
++#endif
++
++ bend = au_dbtaildir(parent);
++ for (bindex = au_dbstart(parent); bindex <= bend; bindex++) {
++ h_parent = au_h_dptr(parent, bindex);
++ if (h_parent) {
++ dget(h_parent);
++ break;
++ }
++ }
++ if (unlikely(!h_parent))
++ goto out_unlock;
++
++ err = -EPERM;
++ br = au_sbr(sb, bindex);
++ h_sb = br->br_mnt->mnt_sb;
++ if (unlikely(!h_sb->s_export_op)) {
++ AuErr1("%s branch is not exportable\n", au_sbtype(h_sb));
++ goto out_dput;
++ }
++
++ fh[Fh_br_id] = br->br_id;
++ fh[Fh_sigen] = au_sigen(sb);
++ encode_ino(fh + Fh_ino, inode->i_ino);
++ encode_ino(fh + Fh_dir_ino, parent->d_inode->i_ino);
++ fh[Fh_igen] = inode->i_generation;
++
++ *max_len -= Fh_tail;
++ fh[Fh_h_type] = exportfs_encode_fh(h_parent, (void *)(fh + Fh_tail),
++ max_len,
++ /*connectable or subtreecheck*/0);
++ err = fh[Fh_h_type];
++ *max_len += Fh_tail;
++ /* todo: macros? */
++ if (err != 255)
++ err = 99;
++ else
++ AuWarn1("%s encode_fh failed\n", au_sbtype(h_sb));
++
++ out_dput:
++ dput(h_parent);
++ out_unlock:
++ di_read_unlock(parent, !AuLock_IR);
++ dput(parent);
++ aufs_read_unlock(dentry, AuLock_IR);
++ out:
++ if (unlikely(err < 0))
++ err = 255;
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct export_operations aufs_export_op = {
++ .fh_to_dentry = aufs_fh_to_dentry,
++ /* .fh_to_parent = aufs_fh_to_parent, */
++ .encode_fh = aufs_encode_fh
++};
++
++void au_export_init(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++ __u32 u;
++
++ sb->s_export_op = &aufs_export_op;
++ sbinfo = au_sbi(sb);
++ sbinfo->si_xigen = NULL;
++ get_random_bytes(&u, sizeof(u));
++ BUILD_BUG_ON(sizeof(u) != sizeof(int));
++ atomic_set(&sbinfo->si_xigen_next, u);
++}
+diff --git a/fs/aufs/f_op.c b/fs/aufs/f_op.c
+new file mode 100644
+index 0000000..7841d99
+--- /dev/null
++++ b/fs/aufs/f_op.c
+@@ -0,0 +1,556 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * file and vm operations
++ */
++
++#include <linux/fs_stack.h>
++#include <linux/poll.h>
++#include "aufs.h"
++
++/* common function to regular file and dir */
++int aufs_flush(struct file *file, fl_owner_t id)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ struct dentry *dentry;
++ struct file *h_file;
++
++ dentry = file->f_dentry;
++ si_noflush_read_lock(dentry->d_sb);
++ fi_read_lock(file);
++ di_read_lock_child(dentry, AuLock_IW);
++
++ err = 0;
++ bend = au_fbend(file);
++ for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
++ h_file = au_h_fptr(file, bindex);
++ if (!h_file || !h_file->f_op || !h_file->f_op->flush)
++ continue;
++
++ err = h_file->f_op->flush(h_file, id);
++ if (!err)
++ vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++ /*ignore*/
++ }
++ au_cpup_attr_timesizes(dentry->d_inode);
++
++ di_read_unlock(dentry, AuLock_IW);
++ fi_read_unlock(file);
++ si_read_unlock(dentry->d_sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int do_open_nondir(struct file *file, int flags)
++{
++ int err;
++ aufs_bindex_t bindex;
++ struct file *h_file;
++ struct dentry *dentry;
++
++ err = 0;
++ dentry = file->f_dentry;
++ au_fi(file)->fi_h_vm_ops = NULL;
++ bindex = au_dbstart(dentry);
++ /* O_TRUNC is processed already */
++ BUG_ON(au_test_ro(dentry->d_sb, bindex, dentry->d_inode)
++ && (flags & O_TRUNC));
++
++ h_file = au_h_open(dentry, bindex, flags, file);
++ if (IS_ERR(h_file))
++ err = PTR_ERR(h_file);
++ else {
++ au_set_fbstart(file, bindex);
++ au_set_fbend(file, bindex);
++ au_set_h_fptr(file, bindex, h_file);
++ au_update_figen(file);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++ }
++ return err;
++}
++
++static int aufs_open_nondir(struct inode *inode __maybe_unused,
++ struct file *file)
++{
++ return au_do_open(file, do_open_nondir);
++}
++
++static int aufs_release_nondir(struct inode *inode __maybe_unused,
++ struct file *file)
++{
++ struct super_block *sb = file->f_dentry->d_sb;
++
++ si_noflush_read_lock(sb);
++ au_finfo_fin(file);
++ si_read_unlock(sb);
++ return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static ssize_t aufs_read(struct file *file, char __user *buf, size_t count,
++ loff_t *ppos)
++{
++ ssize_t err;
++ struct dentry *dentry;
++ struct file *h_file;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++ if (unlikely(err))
++ goto out;
++
++ h_file = au_h_fptr(file, au_fbstart(file));
++ err = vfsub_read_u(h_file, buf, count, ppos);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++ fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++
++ di_read_unlock(dentry, AuLock_IR);
++ fi_read_unlock(file);
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++static ssize_t aufs_write(struct file *file, const char __user *ubuf,
++ size_t count, loff_t *ppos)
++{
++ ssize_t err;
++ aufs_bindex_t bstart;
++ struct au_pin pin;
++ struct dentry *dentry;
++ struct inode *inode;
++ struct super_block *sb;
++ struct file *h_file;
++ char __user *buf = (char __user *)ubuf;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ inode = dentry->d_inode;
++ mutex_lock(&inode->i_mutex);
++ si_read_lock(sb, AuLock_FLUSH);
++
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++ if (unlikely(err))
++ goto out;
++
++ err = au_ready_to_write(file, -1, &pin);
++ di_downgrade_lock(dentry, AuLock_IR);
++ if (unlikely(err))
++ goto out_unlock;
++
++ bstart = au_fbstart(file);
++ h_file = au_h_fptr(file, bstart);
++ au_unpin(&pin);
++ err = vfsub_write_u(h_file, buf, count, ppos);
++ au_cpup_attr_timesizes(inode);
++ inode->i_mode = h_file->f_dentry->d_inode->i_mode;
++
++ out_unlock:
++ di_read_unlock(dentry, AuLock_IR);
++ fi_write_unlock(file);
++ out:
++ si_read_unlock(sb);
++ mutex_unlock(&inode->i_mutex);
++ return err;
++}
++
++static ssize_t aufs_splice_read(struct file *file, loff_t *ppos,
++ struct pipe_inode_info *pipe, size_t len,
++ unsigned int flags)
++{
++ ssize_t err;
++ struct file *h_file;
++ struct dentry *dentry;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++ if (unlikely(err))
++ goto out;
++
++ err = -EINVAL;
++ h_file = au_h_fptr(file, au_fbstart(file));
++ if (au_test_loopback_kthread()) {
++ file->f_mapping = h_file->f_mapping;
++ smp_mb(); /* unnecessary? */
++ }
++ err = vfsub_splice_to(h_file, ppos, pipe, len, flags);
++ /* todo: necessasry? */
++ /* file->f_ra = h_file->f_ra; */
++ fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++
++ di_read_unlock(dentry, AuLock_IR);
++ fi_read_unlock(file);
++
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++static ssize_t
++aufs_splice_write(struct pipe_inode_info *pipe, struct file *file, loff_t *ppos,
++ size_t len, unsigned int flags)
++{
++ ssize_t err;
++ struct au_pin pin;
++ struct dentry *dentry;
++ struct inode *inode;
++ struct super_block *sb;
++ struct file *h_file;
++
++ dentry = file->f_dentry;
++ inode = dentry->d_inode;
++ mutex_lock(&inode->i_mutex);
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++ if (unlikely(err))
++ goto out;
++
++ err = au_ready_to_write(file, -1, &pin);
++ di_downgrade_lock(dentry, AuLock_IR);
++ if (unlikely(err))
++ goto out_unlock;
++
++ h_file = au_h_fptr(file, au_fbstart(file));
++ au_unpin(&pin);
++ err = vfsub_splice_from(pipe, h_file, ppos, len, flags);
++ au_cpup_attr_timesizes(inode);
++ inode->i_mode = h_file->f_dentry->d_inode->i_mode;
++
++ out_unlock:
++ di_read_unlock(dentry, AuLock_IR);
++ fi_write_unlock(file);
++ out:
++ si_read_unlock(sb);
++ mutex_unlock(&inode->i_mutex);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct file *au_safe_file(struct vm_area_struct *vma)
++{
++ struct file *file;
++
++ file = vma->vm_file;
++ if (file->private_data && au_test_aufs(file->f_dentry->d_sb))
++ return file;
++ return NULL;
++}
++
++static void au_reset_file(struct vm_area_struct *vma, struct file *file)
++{
++ vma->vm_file = file;
++ /* smp_mb(); */ /* flush vm_file */
++}
++
++static int aufs_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
++{
++ int err;
++ static DECLARE_WAIT_QUEUE_HEAD(wq);
++ struct file *file, *h_file;
++ struct au_finfo *finfo;
++
++ /* todo: non-robr mode, user vm_file as it is? */
++ wait_event(wq, (file = au_safe_file(vma)));
++
++ /* do not revalidate, no si lock */
++ finfo = au_fi(file);
++ h_file = finfo->fi_hfile[0 + finfo->fi_bstart].hf_file;
++ AuDebugOn(!h_file || !au_test_mmapped(file));
++
++ fi_write_lock(file);
++ vma->vm_file = h_file;
++ err = finfo->fi_h_vm_ops->fault(vma, vmf);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++ au_reset_file(vma, file);
++ fi_write_unlock(file);
++#if 0 /* def CONFIG_SMP */
++ /* wake_up_nr(&wq, online_cpu - 1); */
++ wake_up_all(&wq);
++#else
++ wake_up(&wq);
++#endif
++
++ return err;
++}
++
++static struct vm_operations_struct aufs_vm_ops = {
++ .fault = aufs_fault
++};
++
++/* ---------------------------------------------------------------------- */
++
++static struct vm_operations_struct *au_vm_ops(struct file *h_file,
++ struct vm_area_struct *vma)
++{
++ struct vm_operations_struct *vm_ops;
++ int err;
++
++ vm_ops = ERR_PTR(-ENODEV);
++ if (!h_file->f_op || !h_file->f_op->mmap)
++ goto out;
++
++ err = h_file->f_op->mmap(h_file, vma);
++ vm_ops = ERR_PTR(err);
++ if (unlikely(err))
++ goto out;
++
++ vm_ops = vma->vm_ops;
++ err = do_munmap(current->mm, vma->vm_start,
++ vma->vm_end - vma->vm_start);
++ if (unlikely(err)) {
++ AuIOErr("failed internal unmapping %.*s, %d\n",
++ AuDLNPair(h_file->f_dentry), err);
++ vm_ops = ERR_PTR(-EIO);
++ }
++
++ out:
++ return vm_ops;
++}
++
++static int aufs_mmap(struct file *file, struct vm_area_struct *vma)
++{
++ int err;
++ unsigned char wlock, mmapped;
++ struct dentry *dentry;
++ struct super_block *sb;
++ struct file *h_file;
++ struct vm_operations_struct *vm_ops;
++
++ dentry = file->f_dentry;
++ mmapped = !!au_test_mmapped(file); /* can be harmless race condition */
++ wlock = !!(file->f_mode & FMODE_WRITE) && (vma->vm_flags & VM_SHARED);
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, wlock | !mmapped);
++ if (unlikely(err))
++ goto out;
++
++ if (wlock) {
++ struct au_pin pin;
++
++ err = au_ready_to_write(file, -1, &pin);
++ di_downgrade_lock(dentry, AuLock_IR);
++ if (unlikely(err))
++ goto out_unlock;
++ au_unpin(&pin);
++ } else if (!mmapped)
++ di_downgrade_lock(dentry, AuLock_IR);
++
++ h_file = au_h_fptr(file, au_fbstart(file));
++ if (au_test_fs_bad_mapping(h_file->f_dentry->d_sb)) {
++ /*
++ * by this assignment, f_mapping will differs from aufs inode
++ * i_mapping.
++ * if someone else mixes the use of f_dentry->d_inode and
++ * f_mapping->host, then a problem may arise.
++ */
++ file->f_mapping = h_file->f_mapping;
++ }
++
++ vm_ops = NULL;
++ if (!mmapped) {
++ vm_ops = au_vm_ops(h_file, vma);
++ err = PTR_ERR(vm_ops);
++ if (IS_ERR(vm_ops))
++ goto out_unlock;
++ }
++
++ /*
++ * unnecessary to handle MAP_DENYWRITE and deny_write_access()?
++ * currently MAP_DENYWRITE from userspace is ignored, but elf loader
++ * sets it. when FMODE_EXEC is set (by open_exec() or sys_uselib()),
++ * both of the aufs file and the lower file is deny_write_access()-ed.
++ * finally I hope we can skip handlling MAP_DENYWRITE here.
++ */
++ err = generic_file_mmap(file, vma);
++ if (unlikely(err))
++ goto out_unlock;
++ vma->vm_ops = &aufs_vm_ops;
++ /* test again */
++ if (!au_test_mmapped(file))
++ au_fi(file)->fi_h_vm_ops = vm_ops;
++
++ vfsub_file_accessed(h_file);
++ fsstack_copy_attr_atime(dentry->d_inode, h_file->f_dentry->d_inode);
++
++ out_unlock:
++ di_read_unlock(dentry, AuLock_IR);
++ if (!wlock && mmapped)
++ fi_read_unlock(file);
++ else
++ fi_write_unlock(file);
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static unsigned int aufs_poll(struct file *file, poll_table *wait)
++{
++ unsigned int mask;
++ int err;
++ struct file *h_file;
++ struct dentry *dentry;
++ struct super_block *sb;
++
++ /* We should pretend an error happened. */
++ mask = POLLERR /* | POLLIN | POLLOUT */;
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++ if (unlikely(err))
++ goto out;
++
++ /* it is not an error if h_file has no operation */
++ mask = DEFAULT_POLLMASK;
++ h_file = au_h_fptr(file, au_fbstart(file));
++ if (h_file->f_op && h_file->f_op->poll)
++ mask = h_file->f_op->poll(h_file, wait);
++
++ di_read_unlock(dentry, AuLock_IR);
++ fi_read_unlock(file);
++
++ out:
++ si_read_unlock(sb);
++ AuTraceErr((int)mask);
++ return mask;
++}
++
++static int aufs_fsync_nondir(struct file *file, struct dentry *dentry,
++ int datasync)
++{
++ int err;
++ struct au_pin pin;
++ struct inode *inode;
++ struct file *h_file;
++ struct super_block *sb;
++
++ inode = dentry->d_inode;
++ IMustLock(file->f_mapping->host);
++ if (inode != file->f_mapping->host) {
++ mutex_unlock(&file->f_mapping->host->i_mutex);
++ mutex_lock(&inode->i_mutex);
++ }
++ IMustLock(inode);
++
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++
++ err = 0; /* -EBADF; */ /* posix? */
++ if (unlikely(!(file->f_mode & FMODE_WRITE)))
++ goto out;
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/1);
++ if (unlikely(err))
++ goto out;
++
++ err = au_ready_to_write(file, -1, &pin);
++ di_downgrade_lock(dentry, AuLock_IR);
++ if (unlikely(err))
++ goto out_unlock;
++ au_unpin(&pin);
++
++ err = -EINVAL;
++ h_file = au_h_fptr(file, au_fbstart(file));
++ if (h_file->f_op && h_file->f_op->fsync) {
++ struct dentry *h_d;
++ struct mutex *h_mtx;
++
++ /*
++ * no filemap_fdatawrite() since aufs file has no its own
++ * mapping, but dir.
++ */
++ h_d = h_file->f_dentry;
++ h_mtx = &h_d->d_inode->i_mutex;
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ err = h_file->f_op->fsync(h_file, h_d, datasync);
++ if (!err)
++ vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL);
++ /*ignore*/
++ au_cpup_attr_timesizes(inode);
++ mutex_unlock(h_mtx);
++ }
++
++ out_unlock:
++ di_read_unlock(dentry, AuLock_IR);
++ fi_write_unlock(file);
++ out:
++ si_read_unlock(sb);
++ if (inode != file->f_mapping->host) {
++ mutex_unlock(&inode->i_mutex);
++ mutex_lock(&file->f_mapping->host->i_mutex);
++ }
++ return err;
++}
++
++static int aufs_fasync(int fd, struct file *file, int flag)
++{
++ int err;
++ struct file *h_file;
++ struct dentry *dentry;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_reval_and_lock_fdi(file, au_reopen_nondir, /*wlock*/0);
++ if (unlikely(err))
++ goto out;
++
++ h_file = au_h_fptr(file, au_fbstart(file));
++ if (h_file->f_op && h_file->f_op->fasync)
++ err = h_file->f_op->fasync(fd, h_file, flag);
++
++ di_read_unlock(dentry, AuLock_IR);
++ fi_read_unlock(file);
++
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++const struct file_operations aufs_file_fop = {
++ /*
++ * while generic_file_llseek/_unlocked() don't use BKL,
++ * don't use it since it operates file->f_mapping->host.
++ * in aufs, it may be a real file and may confuse users by UDBA.
++ */
++ /* .llseek = generic_file_llseek, */
++
++ .read = aufs_read,
++ .write = aufs_write,
++ .poll = aufs_poll,
++ .mmap = aufs_mmap,
++ .open = aufs_open_nondir,
++ .flush = aufs_flush,
++ .release = aufs_release_nondir,
++ .fsync = aufs_fsync_nondir,
++ .fasync = aufs_fasync,
++ .splice_write = aufs_splice_write,
++ .splice_read = aufs_splice_read
++};
+diff --git a/fs/aufs/file.c b/fs/aufs/file.c
+new file mode 100644
+index 0000000..d472587
+--- /dev/null
++++ b/fs/aufs/file.c
+@@ -0,0 +1,557 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * handling file/dir, and address_space operation
++ */
++
++#include <linux/fsnotify.h>
++#include <linux/pagemap.h>
++#include "aufs.h"
++
++/*
++ * a dirty trick for handling deny_write_access().
++ * because FMODE_EXEC flag is not passed to f_op->open(),
++ * set it to file->private_data temporary.
++ */
++void au_store_oflag(struct nameidata *nd, struct inode *inode)
++{
++ if (nd
++ /* && !(nd->flags & LOOKUP_CONTINUE) */
++ && (nd->flags & LOOKUP_OPEN)
++ && (nd->intent.open.flags & vfsub_fmode_to_uint(FMODE_EXEC))
++ && inode
++ && S_ISREG(inode->i_mode)) {
++ /* suppress a warning in lp64 */
++ unsigned long flags = nd->intent.open.flags;
++ nd->intent.open.file->private_data = (void *)flags;
++ /* smp_mb(); */
++ }
++}
++
++/* drop flags for writing */
++unsigned int au_file_roflags(unsigned int flags)
++{
++ flags &= ~(O_WRONLY | O_RDWR | O_APPEND | O_CREAT | O_TRUNC);
++ flags |= O_RDONLY | O_NOATIME;
++ return flags;
++}
++
++/* common functions to regular file and dir */
++struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
++ struct file *file)
++{
++ struct file *h_file;
++ struct dentry *h_dentry;
++ struct inode *h_inode;
++ struct super_block *sb;
++ struct au_branch *br;
++ int err;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ h_inode = h_dentry->d_inode;
++ /* a race condition can happen between open and unlink/rmdir */
++ h_file = ERR_PTR(-ENOENT);
++ if (unlikely((!d_unhashed(dentry) && d_unhashed(h_dentry))
++ || !h_inode))
++ goto out;
++
++ sb = dentry->d_sb;
++ br = au_sbr(sb, bindex);
++ h_file = ERR_PTR(-EACCES);
++ if (file && (file->f_mode & FMODE_EXEC)
++ && (br->br_mnt->mnt_flags & MNT_NOEXEC))
++ goto out;
++
++ /* drop flags for writing */
++ if (au_test_ro(sb, bindex, dentry->d_inode))
++ flags = au_file_roflags(flags);
++ flags &= ~O_CREAT;
++ atomic_inc(&br->br_count);
++ h_file = dentry_open(dget(h_dentry), mntget(br->br_mnt), flags,
++ current_cred());
++ if (IS_ERR(h_file))
++ goto out_br;
++
++ if (file && (file->f_mode & FMODE_EXEC)) {
++ h_file->f_mode |= FMODE_EXEC;
++ err = deny_write_access(h_file);
++ if (unlikely(err)) {
++ fput(h_file);
++ h_file = ERR_PTR(err);
++ goto out_br;
++ }
++ }
++ fsnotify_open(h_dentry);
++ goto out; /* success */
++
++ out_br:
++ atomic_dec(&br->br_count);
++ out:
++ return h_file;
++}
++
++int au_do_open(struct file *file, int (*open)(struct file *file, int flags))
++{
++ int err;
++ struct dentry *dentry;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_finfo_init(file);
++ if (unlikely(err))
++ goto out;
++
++ di_read_lock_child(dentry, AuLock_IR);
++ err = open(file, file->f_flags);
++ di_read_unlock(dentry, AuLock_IR);
++
++ fi_write_unlock(file);
++ if (unlikely(err))
++ au_finfo_fin(file);
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++int au_reopen_nondir(struct file *file)
++{
++ int err;
++ aufs_bindex_t bstart, bindex, bend;
++ struct dentry *dentry;
++ struct file *h_file, *h_file_tmp;
++
++ dentry = file->f_dentry;
++ bstart = au_dbstart(dentry);
++ h_file_tmp = NULL;
++ if (au_fbstart(file) == bstart) {
++ h_file = au_h_fptr(file, bstart);
++ if (file->f_mode == h_file->f_mode)
++ return 0; /* success */
++ h_file_tmp = h_file;
++ get_file(h_file_tmp);
++ au_set_h_fptr(file, bstart, NULL);
++ }
++ AuDebugOn(au_fbstart(file) < bstart
++ || au_fi(file)->fi_hfile[0 + bstart].hf_file);
++
++ h_file = au_h_open(dentry, bstart, file->f_flags & ~O_TRUNC, file);
++ err = PTR_ERR(h_file);
++ if (IS_ERR(h_file))
++ goto out; /* todo: close all? */
++
++ err = 0;
++ au_set_fbstart(file, bstart);
++ au_set_h_fptr(file, bstart, h_file);
++ au_update_figen(file);
++ /* todo: necessary? */
++ /* file->f_ra = h_file->f_ra; */
++
++ /* close lower files */
++ bend = au_fbend(file);
++ for (bindex = bstart + 1; bindex <= bend; bindex++)
++ au_set_h_fptr(file, bindex, NULL);
++ au_set_fbend(file, bstart);
++
++ out:
++ if (h_file_tmp)
++ fput(h_file_tmp);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_reopen_wh(struct file *file, aufs_bindex_t btgt,
++ struct dentry *hi_wh)
++{
++ int err;
++ aufs_bindex_t bstart;
++ struct au_dinfo *dinfo;
++ struct dentry *h_dentry;
++
++ dinfo = au_di(file->f_dentry);
++ bstart = dinfo->di_bstart;
++ dinfo->di_bstart = btgt;
++ h_dentry = dinfo->di_hdentry[0 + btgt].hd_dentry;
++ dinfo->di_hdentry[0 + btgt].hd_dentry = hi_wh;
++ err = au_reopen_nondir(file);
++ dinfo->di_hdentry[0 + btgt].hd_dentry = h_dentry;
++ dinfo->di_bstart = bstart;
++
++ return err;
++}
++
++static int au_ready_to_write_wh(struct file *file, loff_t len,
++ aufs_bindex_t bcpup)
++{
++ int err;
++ struct inode *inode;
++ struct dentry *dentry, *hi_wh;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ inode = dentry->d_inode;
++ hi_wh = au_hi_wh(inode, bcpup);
++ if (!hi_wh)
++ err = au_sio_cpup_wh(dentry, bcpup, len, file);
++ else
++ /* already copied-up after unlink */
++ err = au_reopen_wh(file, bcpup, hi_wh);
++
++ sb = dentry->d_sb;
++ if (!err && inode->i_nlink > 1 && au_opt_test(au_mntflags(sb), PLINK))
++ au_plink_append(inode, bcpup, au_h_dptr(dentry, bcpup));
++
++ return err;
++}
++
++/*
++ * prepare the @file for writing.
++ */
++int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
++{
++ int err;
++ aufs_bindex_t bstart, bcpup;
++ struct dentry *dentry, *parent, *h_dentry;
++ struct inode *h_inode, *inode;
++ struct super_block *sb;
++
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ bstart = au_fbstart(file);
++ inode = dentry->d_inode;
++ err = au_test_ro(sb, bstart, inode);
++ if (!err && (au_h_fptr(file, bstart)->f_mode & FMODE_WRITE)) {
++ err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
++ goto out;
++ }
++
++ /* need to cpup */
++ parent = dget_parent(dentry);
++ di_write_lock_parent(parent);
++ err = AuWbrCopyup(au_sbi(sb), dentry);
++ bcpup = err;
++ if (unlikely(err < 0))
++ goto out_dgrade;
++ err = 0;
++
++ if (!au_h_dptr(parent, bcpup)) {
++ err = au_cpup_dirs(dentry, bcpup);
++ if (unlikely(err))
++ goto out_dgrade;
++ }
++
++ err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ if (unlikely(err))
++ goto out_dgrade;
++
++ h_dentry = au_h_fptr(file, bstart)->f_dentry;
++ h_inode = h_dentry->d_inode;
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ if (d_unhashed(dentry) /* || d_unhashed(h_dentry) */
++ /* || !h_inode->i_nlink */) {
++ err = au_ready_to_write_wh(file, len, bcpup);
++ di_downgrade_lock(parent, AuLock_IR);
++ } else {
++ di_downgrade_lock(parent, AuLock_IR);
++ if (!au_h_dptr(dentry, bcpup))
++ err = au_sio_cpup_simple(dentry, bcpup, len,
++ AuCpup_DTIME);
++ if (!err)
++ err = au_reopen_nondir(file);
++ }
++ mutex_unlock(&h_inode->i_mutex);
++
++ if (!err) {
++ au_pin_set_parent_lflag(pin, /*lflag*/0);
++ goto out_dput; /* success */
++ }
++ au_unpin(pin);
++ goto out_unlock;
++
++ out_dgrade:
++ di_downgrade_lock(parent, AuLock_IR);
++ out_unlock:
++ di_read_unlock(parent, AuLock_IR);
++ out_dput:
++ dput(parent);
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_file_refresh_by_inode(struct file *file, int *need_reopen)
++{
++ int err;
++ aufs_bindex_t bstart;
++ struct au_pin pin;
++ struct au_finfo *finfo;
++ struct dentry *dentry, *parent, *hi_wh;
++ struct inode *inode;
++ struct super_block *sb;
++
++ err = 0;
++ finfo = au_fi(file);
++ dentry = file->f_dentry;
++ sb = dentry->d_sb;
++ inode = dentry->d_inode;
++ bstart = au_ibstart(inode);
++ if (bstart == finfo->fi_bstart)
++ goto out;
++
++ parent = dget_parent(dentry);
++ if (au_test_ro(sb, bstart, inode)) {
++ di_read_lock_parent(parent, !AuLock_IR);
++ err = AuWbrCopyup(au_sbi(sb), dentry);
++ bstart = err;
++ di_read_unlock(parent, !AuLock_IR);
++ if (unlikely(err < 0))
++ goto out_parent;
++ err = 0;
++ }
++
++ di_read_lock_parent(parent, AuLock_IR);
++ hi_wh = au_hi_wh(inode, bstart);
++ if (au_opt_test(au_mntflags(sb), PLINK)
++ && au_plink_test(inode)
++ && !d_unhashed(dentry)) {
++ err = au_test_and_cpup_dirs(dentry, bstart);
++ if (unlikely(err))
++ goto out_unlock;
++
++ /* always superio. */
++ err = au_pin(&pin, dentry, bstart, AuOpt_UDBA_NONE,
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ if (!err)
++ err = au_sio_cpup_simple(dentry, bstart, -1,
++ AuCpup_DTIME);
++ au_unpin(&pin);
++ } else if (hi_wh) {
++ /* already copied-up after unlink */
++ err = au_reopen_wh(file, bstart, hi_wh);
++ *need_reopen = 0;
++ }
++
++ out_unlock:
++ di_read_unlock(parent, AuLock_IR);
++ out_parent:
++ dput(parent);
++ out:
++ return err;
++}
++
++static void au_do_refresh_file(struct file *file)
++{
++ aufs_bindex_t bindex, bend, new_bindex, brid;
++ struct au_hfile *p, tmp, *q;
++ struct au_finfo *finfo;
++ struct super_block *sb;
++
++ sb = file->f_dentry->d_sb;
++ finfo = au_fi(file);
++ p = finfo->fi_hfile + finfo->fi_bstart;
++ brid = p->hf_br->br_id;
++ bend = finfo->fi_bend;
++ for (bindex = finfo->fi_bstart; bindex <= bend; bindex++, p++) {
++ if (!p->hf_file)
++ continue;
++
++ new_bindex = au_br_index(sb, p->hf_br->br_id);
++ if (new_bindex == bindex)
++ continue;
++ if (new_bindex < 0) {
++ au_set_h_fptr(file, bindex, NULL);
++ continue;
++ }
++
++ /* swap two lower inode, and loop again */
++ q = finfo->fi_hfile + new_bindex;
++ tmp = *q;
++ *q = *p;
++ *p = tmp;
++ if (tmp.hf_file) {
++ bindex--;
++ p--;
++ }
++ }
++
++ p = finfo->fi_hfile;
++ if (!au_test_mmapped(file) && !d_unhashed(file->f_dentry)) {
++ bend = au_sbend(sb);
++ for (finfo->fi_bstart = 0; finfo->fi_bstart <= bend;
++ finfo->fi_bstart++, p++)
++ if (p->hf_file) {
++ if (p->hf_file->f_dentry
++ && p->hf_file->f_dentry->d_inode)
++ break;
++ else
++ au_hfput(p, file);
++ }
++ } else {
++ bend = au_br_index(sb, brid);
++ for (finfo->fi_bstart = 0; finfo->fi_bstart < bend;
++ finfo->fi_bstart++, p++)
++ if (p->hf_file)
++ au_hfput(p, file);
++ bend = au_sbend(sb);
++ }
++
++ p = finfo->fi_hfile + bend;
++ for (finfo->fi_bend = bend; finfo->fi_bend >= finfo->fi_bstart;
++ finfo->fi_bend--, p--)
++ if (p->hf_file) {
++ if (p->hf_file->f_dentry
++ && p->hf_file->f_dentry->d_inode)
++ break;
++ else
++ au_hfput(p, file);
++ }
++ AuDebugOn(finfo->fi_bend < finfo->fi_bstart);
++}
++
++/*
++ * after branch manipulating, refresh the file.
++ */
++static int refresh_file(struct file *file, int (*reopen)(struct file *file))
++{
++ int err, need_reopen;
++ struct dentry *dentry;
++ aufs_bindex_t bend, bindex;
++
++ dentry = file->f_dentry;
++ err = au_fi_realloc(au_fi(file), au_sbend(dentry->d_sb) + 1);
++ if (unlikely(err))
++ goto out;
++ au_do_refresh_file(file);
++
++ err = 0;
++ need_reopen = 1;
++ if (!au_test_mmapped(file))
++ err = au_file_refresh_by_inode(file, &need_reopen);
++ if (!err && need_reopen && !d_unhashed(dentry))
++ err = reopen(file);
++ if (!err) {
++ au_update_figen(file);
++ return 0; /* success */
++ }
++
++ /* error, close all lower files */
++ bend = au_fbend(file);
++ for (bindex = au_fbstart(file); bindex <= bend; bindex++)
++ au_set_h_fptr(file, bindex, NULL);
++
++ out:
++ return err;
++}
++
++/* common function to regular file and dir */
++int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
++ int wlock)
++{
++ int err;
++ unsigned int sigen, figen;
++ aufs_bindex_t bstart;
++ unsigned char pseudo_link;
++ struct dentry *dentry;
++
++ err = 0;
++ dentry = file->f_dentry;
++ sigen = au_sigen(dentry->d_sb);
++ fi_write_lock(file);
++ figen = au_figen(file);
++ di_write_lock_child(dentry);
++ bstart = au_dbstart(dentry);
++ pseudo_link = (bstart != au_ibstart(dentry->d_inode));
++ if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
++ if (!wlock) {
++ di_downgrade_lock(dentry, AuLock_IR);
++ fi_downgrade_lock(file);
++ }
++ goto out; /* success */
++ }
++
++ AuDbg("sigen %d, figen %d\n", sigen, figen);
++ if (sigen != au_digen(dentry)
++ || sigen != au_iigen(dentry->d_inode)) {
++ err = au_reval_dpath(dentry, sigen);
++ if (unlikely(err < 0))
++ goto out;
++ AuDebugOn(au_digen(dentry) != sigen
++ || au_iigen(dentry->d_inode) != sigen);
++ }
++
++ err = refresh_file(file, reopen);
++ if (!err) {
++ if (!wlock) {
++ di_downgrade_lock(dentry, AuLock_IR);
++ fi_downgrade_lock(file);
++ }
++ } else {
++ di_write_unlock(dentry);
++ fi_write_unlock(file);
++ }
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* cf. aufs_nopage() */
++/* for madvise(2) */
++static int aufs_readpage(struct file *file __maybe_unused, struct page *page)
++{
++ unlock_page(page);
++ return 0;
++}
++
++/* they will never be called. */
++#ifdef CONFIG_AUFS_DEBUG
++static int aufs_write_begin(struct file *file, struct address_space *mapping,
++ loff_t pos, unsigned len, unsigned flags,
++ struct page **pagep, void **fsdata)
++{ AuUnsupport(); return 0; }
++static int aufs_write_end(struct file *file, struct address_space *mapping,
++ loff_t pos, unsigned len, unsigned copied,
++ struct page *page, void *fsdata)
++{ AuUnsupport(); return 0; }
++static int aufs_writepage(struct page *page, struct writeback_control *wbc)
++{ AuUnsupport(); return 0; }
++static void aufs_sync_page(struct page *page)
++{ AuUnsupport(); }
++
++static int aufs_set_page_dirty(struct page *page)
++{ AuUnsupport(); return 0; }
++static void aufs_invalidatepage(struct page *page, unsigned long offset)
++{ AuUnsupport(); }
++static int aufs_releasepage(struct page *page, gfp_t gfp)
++{ AuUnsupport(); return 0; }
++static ssize_t aufs_direct_IO(int rw, struct kiocb *iocb,
++ const struct iovec *iov, loff_t offset,
++ unsigned long nr_segs)
++{ AuUnsupport(); return 0; }
++#endif /* CONFIG_AUFS_DEBUG */
++
++struct address_space_operations aufs_aop = {
++ .readpage = aufs_readpage,
++#ifdef CONFIG_AUFS_DEBUG
++ .writepage = aufs_writepage,
++ .sync_page = aufs_sync_page,
++ .set_page_dirty = aufs_set_page_dirty,
++ .write_begin = aufs_write_begin,
++ .write_end = aufs_write_end,
++ .invalidatepage = aufs_invalidatepage,
++ .releasepage = aufs_releasepage,
++ .direct_IO = aufs_direct_IO,
++#endif /* CONFIG_AUFS_DEBUG */
++};
+diff --git a/fs/aufs/file.h b/fs/aufs/file.h
+new file mode 100644
+index 0000000..dd9ee61
+--- /dev/null
++++ b/fs/aufs/file.h
+@@ -0,0 +1,148 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * file operations
++ */
++
++#ifndef __AUFS_FILE_H__
++#define __AUFS_FILE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/file.h>
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++struct au_branch;
++struct au_hfile {
++ struct file *hf_file;
++ struct au_branch *hf_br;
++};
++
++struct au_vdir;
++struct au_finfo {
++ atomic_t fi_generation;
++
++ struct rw_semaphore fi_rwsem;
++ struct au_hfile *fi_hfile;
++ aufs_bindex_t fi_bstart, fi_bend;
++
++ union {
++ /* non-dir only */
++ struct vm_operations_struct *fi_h_vm_ops;
++
++ /* dir only */
++ struct {
++ struct au_vdir *fi_vdir_cache;
++ int fi_maintain_plink;
++ };
++ };
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* file.c */
++extern struct address_space_operations aufs_aop;
++void au_store_oflag(struct nameidata *nd, struct inode *inode);
++unsigned int au_file_roflags(unsigned int flags);
++struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
++ struct file *file);
++int au_do_open(struct file *file, int (*open)(struct file *file, int flags));
++int au_reopen_nondir(struct file *file);
++struct au_pin;
++int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin);
++int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
++ int wlock);
++
++/* f_op.c */
++extern const struct file_operations aufs_file_fop;
++int aufs_flush(struct file *file, fl_owner_t id);
++
++/* finfo.c */
++void au_hfput(struct au_hfile *hf, struct file *file);
++void au_set_h_fptr(struct file *file, aufs_bindex_t bindex,
++ struct file *h_file);
++
++void au_update_figen(struct file *file);
++
++void au_finfo_fin(struct file *file);
++int au_finfo_init(struct file *file);
++int au_fi_realloc(struct au_finfo *finfo, int nbr);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_finfo *au_fi(struct file *file)
++{
++ return file->private_data;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * fi_read_lock, fi_write_lock,
++ * fi_read_unlock, fi_write_unlock, fi_downgrade_lock
++ */
++AuSimpleRwsemFuncs(fi, struct file *f, &au_fi(f)->fi_rwsem);
++
++#define FiMustNoWaiters(f) AuRwMustNoWaiters(&au_fi(f)->fi_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++/* todo: hard/soft set? */
++static inline aufs_bindex_t au_fbstart(struct file *file)
++{
++ return au_fi(file)->fi_bstart;
++}
++
++static inline aufs_bindex_t au_fbend(struct file *file)
++{
++ return au_fi(file)->fi_bend;
++}
++
++static inline struct au_vdir *au_fvdir_cache(struct file *file)
++{
++ return au_fi(file)->fi_vdir_cache;
++}
++
++static inline void au_set_fbstart(struct file *file, aufs_bindex_t bindex)
++{
++ au_fi(file)->fi_bstart = bindex;
++}
++
++static inline void au_set_fbend(struct file *file, aufs_bindex_t bindex)
++{
++ au_fi(file)->fi_bend = bindex;
++}
++
++static inline void au_set_fvdir_cache(struct file *file,
++ struct au_vdir *vdir_cache)
++{
++ au_fi(file)->fi_vdir_cache = vdir_cache;
++}
++
++static inline struct file *au_h_fptr(struct file *file, aufs_bindex_t bindex)
++{
++ return au_fi(file)->fi_hfile[0 + bindex].hf_file;
++}
++
++/* todo: memory barrier? */
++static inline unsigned int au_figen(struct file *f)
++{
++ return atomic_read(&au_fi(f)->fi_generation);
++}
++
++static inline int au_test_mmapped(struct file *f)
++{
++ return !!(au_fi(f)->fi_h_vm_ops);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_FILE_H__ */
+diff --git a/fs/aufs/finfo.c b/fs/aufs/finfo.c
+new file mode 100644
+index 0000000..dfb4851
+--- /dev/null
++++ b/fs/aufs/finfo.c
+@@ -0,0 +1,124 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * file private data
++ */
++
++#include "aufs.h"
++
++void au_hfput(struct au_hfile *hf, struct file *file)
++{
++ if (file->f_mode & FMODE_EXEC)
++ allow_write_access(hf->hf_file);
++ fput(hf->hf_file);
++ hf->hf_file = NULL;
++ atomic_dec(&hf->hf_br->br_count);
++ hf->hf_br = NULL;
++}
++
++void au_set_h_fptr(struct file *file, aufs_bindex_t bindex, struct file *val)
++{
++ struct au_finfo *finfo = au_fi(file);
++ struct au_hfile *hf;
++
++ hf = finfo->fi_hfile + bindex;
++ if (hf->hf_file)
++ au_hfput(hf, file);
++ if (val) {
++ hf->hf_file = val;
++ hf->hf_br = au_sbr(file->f_dentry->d_sb, bindex);
++ }
++}
++
++void au_update_figen(struct file *file)
++{
++ atomic_set(&au_fi(file)->fi_generation, au_digen(file->f_dentry));
++ /* smp_mb(); */ /* atomic_set */
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_finfo_fin(struct file *file)
++{
++ struct au_finfo *finfo;
++ aufs_bindex_t bindex, bend;
++
++ fi_write_lock(file);
++ bend = au_fbend(file);
++ bindex = au_fbstart(file);
++ if (bindex >= 0)
++ /*
++ * calls fput() instead of filp_close(),
++ * since no dnotify or lock for the lower file.
++ */
++ for (; bindex <= bend; bindex++)
++ au_set_h_fptr(file, bindex, NULL);
++
++ finfo = au_fi(file);
++ au_dbg_verify_hf(finfo);
++ kfree(finfo->fi_hfile);
++ fi_write_unlock(file);
++ au_rwsem_destroy(&finfo->fi_rwsem);
++ au_cache_free_finfo(finfo);
++}
++
++int au_finfo_init(struct file *file)
++{
++ struct au_finfo *finfo;
++ struct dentry *dentry;
++ unsigned long ul;
++
++ dentry = file->f_dentry;
++ finfo = au_cache_alloc_finfo();
++ if (unlikely(!finfo))
++ goto out;
++
++ finfo->fi_hfile = kcalloc(au_sbend(dentry->d_sb) + 1,
++ sizeof(*finfo->fi_hfile), GFP_NOFS);
++ if (unlikely(!finfo->fi_hfile))
++ goto out_finfo;
++
++ init_rwsem(&finfo->fi_rwsem);
++ down_write(&finfo->fi_rwsem);
++ finfo->fi_bstart = -1;
++ finfo->fi_bend = -1;
++ atomic_set(&finfo->fi_generation, au_digen(dentry));
++ /* smp_mb(); */ /* atomic_set */
++
++ /* cf. au_store_oflag() */
++ /* suppress a warning in lp64 */
++ ul = (unsigned long)file->private_data;
++ file->f_mode |= (vfsub_uint_to_fmode(ul) & FMODE_EXEC);
++ file->private_data = finfo;
++ return 0; /* success */
++
++ out_finfo:
++ au_cache_free_finfo(finfo);
++ out:
++ return -ENOMEM;
++}
++
++int au_fi_realloc(struct au_finfo *finfo, int nbr)
++{
++ int err, sz;
++ struct au_hfile *hfp;
++
++ err = -ENOMEM;
++ sz = sizeof(*hfp) * (finfo->fi_bend + 1);
++ if (!sz)
++ sz = sizeof(*hfp);
++ hfp = au_kzrealloc(finfo->fi_hfile, sz, sizeof(*hfp) * nbr, GFP_NOFS);
++ if (hfp) {
++ finfo->fi_hfile = hfp;
++ err = 0;
++ }
++
++ return err;
++}
+diff --git a/fs/aufs/fstype.h b/fs/aufs/fstype.h
+new file mode 100644
+index 0000000..54896c6
+--- /dev/null
++++ b/fs/aufs/fstype.h
+@@ -0,0 +1,464 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * judging filesystem type
++ */
++
++#ifndef __AUFS_FSTYPE_H__
++#define __AUFS_FSTYPE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/cramfs_fs.h>
++#include <linux/magic.h>
++#include <linux/romfs_fs.h>
++#include <linux/aufs_type.h>
++
++static inline int au_test_aufs(struct super_block *sb)
++{
++ return sb->s_magic == AUFS_SUPER_MAGIC;
++}
++
++static inline const char *au_sbtype(struct super_block *sb)
++{
++ return sb->s_type->name;
++}
++
++static inline int au_test_iso9660(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ROMFS_FS) || defined(CONFIG_ROMFS_FS_MODULE)
++ return sb->s_magic == ROMFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_romfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ISO9660_FS) || defined(CONFIG_ISO9660_FS_MODULE)
++ return sb->s_magic == ISOFS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_cramfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CRAMFS) || defined(CONFIG_CRAMFS_MODULE)
++ return sb->s_magic == CRAMFS_MAGIC;
++#endif
++ return 0;
++}
++
++static inline int au_test_nfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_NFS_FS) || defined(CONFIG_NFS_FS_MODULE)
++ return sb->s_magic == NFS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_fuse(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_FUSE_FS) || defined(CONFIG_FUSE_FS_MODULE)
++ return sb->s_magic == FUSE_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_xfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_XFS_FS) || defined(CONFIG_XFS_FS_MODULE)
++ return sb->s_magic == XFS_SB_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_tmpfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_TMPFS
++ return sb->s_magic == TMPFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_ecryptfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_ECRYPT_FS) || defined(CONFIG_ECRYPT_FS_MODULE)
++ return !strcmp(au_sbtype(sb), "ecryptfs");
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_smbfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SMB_FS) || defined(CONFIG_SMB_FS_MODULE)
++ return sb->s_magic == SMB_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_ocfs2(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_OCFS2_FS) || defined(CONFIG_OCFS2_FS_MODULE)
++ return sb->s_magic == OCFS2_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_ocfs2_dlmfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_OCFS2_FS_O2CB) || defined(CONFIG_OCFS2_FS_O2CB_MODULE)
++ return sb->s_magic == DLMFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_coda(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CODA_FS) || defined(CONFIG_CODA_FS_MODULE)
++ return sb->s_magic == CODA_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_v9fs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_9P_FS) || defined(CONFIG_9P_FS_MODULE)
++ return sb->s_magic == V9FS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_ext4(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_EXT4DEV_FS) || defined(CONFIG_EXT4DEV_FS_MODULE)
++ return sb->s_magic == EXT4_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_sysv(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SYSV_FS) || defined(CONFIG_SYSV_FS_MODULE)
++ return !strcmp(au_sbtype(sb), "sysv");
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_ramfs(struct super_block *sb)
++{
++ return sb->s_magic == RAMFS_MAGIC;
++}
++
++static inline int au_test_ubifs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_UBIFS_FS) || defined(CONFIG_UBIFS_FS_MODULE)
++ return sb->s_magic == UBIFS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_procfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_PROC_FS
++ return sb->s_magic == PROC_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_sysfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_SYSFS
++ return sb->s_magic == SYSFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_configfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CONFIGFS_FS) || defined(CONFIG_CONFIGFS_FS_MODULE)
++ return sb->s_magic == CONFIGFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_minix(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_MINIX_FS) || defined(CONFIG_MINIX_FS_MODULE)
++ return sb->s_magic == MINIX3_SUPER_MAGIC
++ || sb->s_magic == MINIX2_SUPER_MAGIC
++ || sb->s_magic == MINIX2_SUPER_MAGIC2
++ || sb->s_magic == MINIX_SUPER_MAGIC
++ || sb->s_magic == MINIX_SUPER_MAGIC2;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_cifs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_CIFS_FS) || defined(CONFIGCIFS_FS_MODULE)
++ return sb->s_magic == CIFS_MAGIC_NUMBER;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_fat(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_FAT_FS) || defined(CONFIG_FAT_FS_MODULE)
++ return sb->s_magic == MSDOS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_msdos(struct super_block *sb)
++{
++ return au_test_fat(sb);
++}
++
++static inline int au_test_vfat(struct super_block *sb)
++{
++ return au_test_fat(sb);
++}
++
++static inline int au_test_securityfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_SECURITYFS
++ return sb->s_magic == SECURITYFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_squashfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_SQUASHFS) || defined(CONFIG_SQUASHFS_MODULE)
++ return sb->s_magic == SQUASHFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_btrfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_BTRFS_FS) || defined(CONFIG_BTRFS_FS_MODULE)
++ return sb->s_magic == BTRFS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_xenfs(struct super_block *sb __maybe_unused)
++{
++#if defined(CONFIG_XENFS) || defined(CONFIG_XENFS_MODULE)
++ return sb->s_magic == XENFS_SUPER_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++static inline int au_test_debugfs(struct super_block *sb __maybe_unused)
++{
++#ifdef CONFIG_DEBUG_FS
++ return sb->s_magic == DEBUGFS_MAGIC;
++#else
++ return 0;
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * they can't be an aufs branch.
++ */
++static inline int au_test_fs_unsuppoted(struct super_block *sb)
++{
++ return
++#ifndef CONFIG_AUFS_BR_RAMFS
++ au_test_ramfs(sb) ||
++#endif
++ au_test_procfs(sb)
++ || au_test_sysfs(sb)
++ || au_test_configfs(sb)
++ || au_test_debugfs(sb)
++ || au_test_securityfs(sb)
++ || au_test_xenfs(sb)
++ /* || !strcmp(au_sbtype(sb), "unionfs") */
++ || au_test_aufs(sb); /* will be supported in next version */
++}
++
++/*
++ * If the filesystem supports NFS-export, then it has to support NULL as
++ * a nameidata parameter for ->create(), ->lookup() and ->d_revalidate().
++ * We can apply this principle when we handle a lower filesystem.
++ */
++static inline int au_test_fs_null_nd(struct super_block *sb)
++{
++ return !!sb->s_export_op;
++}
++
++static inline int au_test_fs_remote(struct super_block *sb)
++{
++ return !au_test_tmpfs(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++ && !au_test_ramfs(sb)
++#endif
++ && !(sb->s_type->fs_flags & FS_REQUIRES_DEV);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * Note: these functions (below) are created after reading ->getattr() in all
++ * filesystems under linux/fs. it means we have to do so in every update...
++ */
++
++/*
++ * some filesystems require getattr to refresh the inode attributes before
++ * referencing.
++ * in most cases, we can rely on the inode attribute in NFS (or every remote fs)
++ * and leave the work for d_revalidate()
++ */
++static inline int au_test_fs_refresh_iattr(struct super_block *sb)
++{
++ return au_test_nfs(sb)
++ || au_test_fuse(sb)
++ /* || au_test_smbfs(sb) */ /* untested */
++ /* || au_test_ocfs2(sb) */ /* untested */
++ /* || au_test_btrfs(sb) */ /* untested */
++ /* || au_test_coda(sb) */ /* untested */
++ /* || au_test_v9fs(sb) */ /* untested */
++ ;
++}
++
++/*
++ * filesystems which don't maintain i_size or i_blocks.
++ */
++static inline int au_test_fs_bad_iattr_size(struct super_block *sb)
++{
++ return au_test_xfs(sb)
++ /* || au_test_ext4(sb) */ /* untested */
++ /* || au_test_ocfs2(sb) */ /* untested */
++ /* || au_test_ocfs2_dlmfs(sb) */ /* untested */
++ /* || au_test_sysv(sb) */ /* untested */
++ /* || au_test_ubifs(sb) */ /* untested */
++ /* || au_test_minix(sb) */ /* untested */
++ ;
++}
++
++/*
++ * filesystems which don't store the correct value in some of their inode
++ * attributes.
++ */
++static inline int au_test_fs_bad_iattr(struct super_block *sb)
++{
++ return au_test_fs_bad_iattr_size(sb)
++ /* || au_test_cifs(sb) */ /* untested */
++ || au_test_fat(sb)
++ || au_test_msdos(sb)
++ || au_test_vfat(sb);
++}
++
++/* they don't check i_nlink in link(2) */
++static inline int au_test_fs_no_limit_nlink(struct super_block *sb)
++{
++ return au_test_tmpfs(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++ || au_test_ramfs(sb)
++#endif
++ ;
++}
++
++/*
++ * filesystems which sets S_NOATIME and S_NOCMTIME.
++ */
++static inline int au_test_fs_notime(struct super_block *sb)
++{
++ return au_test_nfs(sb)
++ || au_test_fuse(sb)
++ /* || au_test_cifs(sb) */ /* untested */
++ /* || au_test_ubifs(sb) */ /* untested */
++ ;
++}
++
++/*
++ * filesystems which requires replacing i_mapping.
++ */
++static inline int au_test_fs_bad_mapping(struct super_block *sb)
++{
++ return au_test_fuse(sb);
++}
++
++/* temporary support for i#1 in cramfs */
++static inline int au_test_fs_unique_ino(struct inode *inode)
++{
++ if (au_test_cramfs(inode->i_sb))
++ return inode->i_ino != 1;
++ return 1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * the filesystem where the xino files placed must support i/o after unlink and
++ * maintain i_size and i_blocks.
++ */
++static inline int au_test_fs_bad_xino(struct super_block *sb)
++{
++ return au_test_fs_remote(sb)
++ || au_test_fs_bad_iattr_size(sb)
++#ifdef CONFIG_AUFS_BR_RAMFS
++ || !(au_test_ramfs(sb) || au_test_fs_null_nd(sb))
++#else
++ || !au_test_fs_null_nd(sb) /* to keep xino code simple */
++#endif
++ /* don't want unnecessary work for xino */
++ || au_test_aufs(sb)
++ || au_test_ecryptfs(sb);
++}
++
++static inline int au_test_fs_trunc_xino(struct super_block *sb)
++{
++ return au_test_tmpfs(sb)
++ || au_test_ramfs(sb);
++}
++
++/*
++ * test if the @sb is real-readonly.
++ */
++static inline int au_test_fs_rr(struct super_block *sb)
++{
++ return au_test_squashfs(sb)
++ || au_test_iso9660(sb)
++ || au_test_cramfs(sb)
++ || au_test_romfs(sb);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_FSTYPE_H__ */
+diff --git a/fs/aufs/hinotify.c b/fs/aufs/hinotify.c
+new file mode 100644
+index 0000000..af8ebdb
+--- /dev/null
++++ b/fs/aufs/hinotify.c
+@@ -0,0 +1,746 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inotify for the lower directories
++ */
++
++#include "aufs.h"
++
++static const __u32 AuHinMask = (IN_MOVE | IN_DELETE | IN_CREATE);
++static struct inotify_handle *au_hin_handle;
++
++AuCacheFuncs(hinotify, HINOTIFY);
++
++int au_hin_alloc(struct au_hinode *hinode, struct inode *inode,
++ struct inode *h_inode)
++{
++ int err;
++ struct au_hinotify *hin;
++ s32 wd;
++
++ err = -ENOMEM;
++ hin = au_cache_alloc_hinotify();
++ if (hin) {
++ AuDebugOn(hinode->hi_notify);
++ hinode->hi_notify = hin;
++ hin->hin_aufs_inode = inode;
++
++ inotify_init_watch(&hin->hin_watch);
++ wd = inotify_add_watch(au_hin_handle, &hin->hin_watch, h_inode,
++ AuHinMask);
++ if (wd >= 0)
++ return 0; /* success */
++
++ err = wd;
++ put_inotify_watch(&hin->hin_watch);
++ au_cache_free_hinotify(hin);
++ hinode->hi_notify = NULL;
++ }
++
++ return err;
++}
++
++void au_hin_free(struct au_hinode *hinode)
++{
++ int err;
++ struct au_hinotify *hin;
++
++ hin = hinode->hi_notify;
++ if (hin) {
++ err = 0;
++ if (atomic_read(&hin->hin_watch.count))
++ err = inotify_rm_watch(au_hin_handle, &hin->hin_watch);
++ if (unlikely(err))
++ /* it means the watch is already removed */
++ AuWarn("failed inotify_rm_watch() %d\n", err);
++ au_cache_free_hinotify(hin);
++ hinode->hi_notify = NULL;
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_hin_ctl(struct au_hinode *hinode, int do_set)
++{
++ struct inode *h_inode;
++ struct inotify_watch *watch;
++
++ if (!hinode->hi_notify)
++ return;
++
++ h_inode = hinode->hi_inode;
++ IMustLock(h_inode);
++
++ /* todo: try inotify_find_update_watch()? */
++ watch = &hinode->hi_notify->hin_watch;
++ mutex_lock(&h_inode->inotify_mutex);
++ /* mutex_lock(&watch->ih->mutex); */
++ if (do_set) {
++ AuDebugOn(watch->mask & AuHinMask);
++ watch->mask |= AuHinMask;
++ } else {
++ AuDebugOn(!(watch->mask & AuHinMask));
++ watch->mask &= ~AuHinMask;
++ }
++ /* mutex_unlock(&watch->ih->mutex); */
++ mutex_unlock(&h_inode->inotify_mutex);
++}
++
++void au_reset_hinotify(struct inode *inode, unsigned int flags)
++{
++ aufs_bindex_t bindex, bend;
++ struct inode *hi;
++ struct dentry *iwhdentry;
++
++ bend = au_ibend(inode);
++ for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
++ hi = au_h_iptr(inode, bindex);
++ if (!hi)
++ continue;
++
++ /* mutex_lock_nested(&hi->i_mutex, AuLsc_I_CHILD); */
++ iwhdentry = au_hi_wh(inode, bindex);
++ if (iwhdentry)
++ dget(iwhdentry);
++ au_igrab(hi);
++ au_set_h_iptr(inode, bindex, NULL, 0);
++ au_set_h_iptr(inode, bindex, au_igrab(hi),
++ flags & ~AuHi_XINO);
++ iput(hi);
++ dput(iwhdentry);
++ /* mutex_unlock(&hi->i_mutex); */
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int hin_xino(struct inode *inode, struct inode *h_inode)
++{
++ int err;
++ aufs_bindex_t bindex, bend, bfound, bstart;
++ struct inode *h_i;
++
++ err = 0;
++ if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++ AuWarn("branch root dir was changed\n");
++ goto out;
++ }
++
++ bfound = -1;
++ bend = au_ibend(inode);
++ bstart = au_ibstart(inode);
++#if 0 /* reserved for future use */
++ if (bindex == bend) {
++ /* keep this ino in rename case */
++ goto out;
++ }
++#endif
++ for (bindex = bstart; bindex <= bend; bindex++) {
++ if (au_h_iptr(inode, bindex) == h_inode) {
++ bfound = bindex;
++ break;
++ }
++ }
++ if (bfound < 0)
++ goto out;
++
++ for (bindex = bstart; bindex <= bend; bindex++) {
++ h_i = au_h_iptr(inode, bindex);
++ if (!h_i)
++ continue;
++
++ err = au_xino_write0(inode->i_sb, bindex, h_i->i_ino, 0);
++ /* ignore this error */
++ /* bad action? */
++ }
++
++ /* children inode number will be broken */
++
++ out:
++ AuTraceErr(err);
++ return err;
++}
++
++static int hin_gen_tree(struct dentry *dentry)
++{
++ int err, i, j, ndentry;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++ struct dentry **dentries;
++
++ err = au_dpages_init(&dpages, GFP_NOFS);
++ if (unlikely(err))
++ goto out;
++ err = au_dcsub_pages(&dpages, dentry, NULL, NULL);
++ if (unlikely(err))
++ goto out_dpages;
++
++ for (i = 0; i < dpages.ndpage; i++) {
++ dpage = dpages.dpages + i;
++ dentries = dpage->dentries;
++ ndentry = dpage->ndentry;
++ for (j = 0; j < ndentry; j++) {
++ struct dentry *d;
++
++ d = dentries[j];
++ if (IS_ROOT(d))
++ continue;
++
++ d_drop(d);
++ au_digen_dec(d);
++ if (d->d_inode)
++ /* todo: reset children xino?
++ cached children only? */
++ au_iigen_dec(d->d_inode);
++ }
++ }
++
++ out_dpages:
++ au_dpages_free(&dpages);
++
++ /* discard children */
++ dentry_unhash(dentry);
++ dput(dentry);
++ out:
++ return err;
++}
++
++/*
++ * return 0 if processed.
++ */
++static int hin_gen_by_inode(char *name, unsigned int nlen, struct inode *inode,
++ const unsigned int isdir)
++{
++ int err;
++ struct dentry *d;
++ struct qstr *dname;
++
++ err = 1;
++ if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++ AuWarn("branch root dir was changed\n");
++ err = 0;
++ goto out;
++ }
++
++ if (!isdir) {
++ AuDebugOn(!name);
++ au_iigen_dec(inode);
++ spin_lock(&dcache_lock);
++ list_for_each_entry(d, &inode->i_dentry, d_alias) {
++ dname = &d->d_name;
++ if (dname->len != nlen
++ && memcmp(dname->name, name, nlen))
++ continue;
++ err = 0;
++ spin_lock(&d->d_lock);
++ __d_drop(d);
++ au_digen_dec(d);
++ spin_unlock(&d->d_lock);
++ break;
++ }
++ spin_unlock(&dcache_lock);
++ } else {
++ au_fset_si(au_sbi(inode->i_sb), FAILED_REFRESH_DIRS);
++ d = d_find_alias(inode);
++ if (!d) {
++ au_iigen_dec(inode);
++ goto out;
++ }
++
++ dname = &d->d_name;
++ if (dname->len == nlen && !memcmp(dname->name, name, nlen))
++ err = hin_gen_tree(d);
++ dput(d);
++ }
++
++ out:
++ AuTraceErr(err);
++ return err;
++}
++
++static int hin_gen_by_name(struct dentry *dentry, const unsigned int isdir)
++{
++ int err;
++ struct inode *inode;
++
++ inode = dentry->d_inode;
++ if (IS_ROOT(dentry)
++ /* || (inode && inode->i_ino == AUFS_ROOT_INO) */
++ ) {
++ AuWarn("branch root dir was changed\n");
++ return 0;
++ }
++
++ err = 0;
++ if (!isdir) {
++ d_drop(dentry);
++ au_digen_dec(dentry);
++ if (inode)
++ au_iigen_dec(inode);
++ } else {
++ au_fset_si(au_sbi(dentry->d_sb), FAILED_REFRESH_DIRS);
++ if (inode)
++ err = hin_gen_tree(dentry);
++ }
++
++ AuTraceErr(err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* hinotify job flags */
++#define AuHinJob_XINO0 1
++#define AuHinJob_GEN (1 << 1)
++#define AuHinJob_DIRENT (1 << 2)
++#define AuHinJob_ISDIR (1 << 3)
++#define AuHinJob_TRYXINO0 (1 << 4)
++#define AuHinJob_MNTPNT (1 << 5)
++#define au_ftest_hinjob(flags, name) ((flags) & AuHinJob_##name)
++#define au_fset_hinjob(flags, name) { (flags) |= AuHinJob_##name; }
++#define au_fclr_hinjob(flags, name) { (flags) &= ~AuHinJob_##name; }
++
++struct hin_job_args {
++ unsigned int flags;
++ struct inode *inode, *h_inode, *dir, *h_dir;
++ struct dentry *dentry;
++ char *h_name;
++ int h_nlen;
++};
++
++static int hin_job(struct hin_job_args *a)
++{
++ const unsigned int isdir = au_ftest_hinjob(a->flags, ISDIR);
++
++ /* reset xino */
++ if (au_ftest_hinjob(a->flags, XINO0) && a->inode)
++ hin_xino(a->inode, a->h_inode); /* ignore this error */
++
++ if (au_ftest_hinjob(a->flags, TRYXINO0)
++ && a->inode
++ && a->h_inode) {
++ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++ if (!a->h_inode->i_nlink)
++ hin_xino(a->inode, a->h_inode); /* ignore this error */
++ mutex_unlock(&a->h_inode->i_mutex);
++ }
++
++ /* make the generation obsolete */
++ if (au_ftest_hinjob(a->flags, GEN)) {
++ int err = -1;
++ if (a->inode)
++ err = hin_gen_by_inode(a->h_name, a->h_nlen, a->inode,
++ isdir);
++ if (err && a->dentry)
++ hin_gen_by_name(a->dentry, isdir);
++ /* ignore this error */
++ }
++
++ /* make dir entries obsolete */
++ if (au_ftest_hinjob(a->flags, DIRENT) && a->inode) {
++ struct au_vdir *vdir;
++
++ vdir = au_ivdir(a->inode);
++ if (vdir)
++ vdir->vd_jiffy = 0;
++ /* IMustLock(a->inode); */
++ /* a->inode->i_version++; */
++ }
++
++ /* can do nothing but warn */
++ if (au_ftest_hinjob(a->flags, MNTPNT)
++ && a->dentry
++ && d_mountpoint(a->dentry))
++ AuWarn("mount-point %.*s is removed or renamed\n",
++ AuDLNPair(a->dentry));
++
++ return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static char *in_name(u32 mask)
++{
++#ifdef CONFIG_AUFS_DEBUG
++#define test_ret(flag) if (mask & flag) \
++ return #flag;
++ test_ret(IN_ACCESS);
++ test_ret(IN_MODIFY);
++ test_ret(IN_ATTRIB);
++ test_ret(IN_CLOSE_WRITE);
++ test_ret(IN_CLOSE_NOWRITE);
++ test_ret(IN_OPEN);
++ test_ret(IN_MOVED_FROM);
++ test_ret(IN_MOVED_TO);
++ test_ret(IN_CREATE);
++ test_ret(IN_DELETE);
++ test_ret(IN_DELETE_SELF);
++ test_ret(IN_MOVE_SELF);
++ test_ret(IN_UNMOUNT);
++ test_ret(IN_Q_OVERFLOW);
++ test_ret(IN_IGNORED);
++ return "";
++#undef test_ret
++#else
++ return "??";
++#endif
++}
++
++static struct dentry *lookup_wlock_by_name(char *name, unsigned int nlen,
++ struct inode *dir)
++{
++ struct dentry *dentry, *d, *parent;
++ struct qstr *dname;
++
++ parent = d_find_alias(dir);
++ if (!parent)
++ return NULL;
++
++ dentry = NULL;
++ spin_lock(&dcache_lock);
++ list_for_each_entry(d, &parent->d_subdirs, d_u.d_child) {
++ /* AuDbg("%.*s\n", AuDLNPair(d)); */
++ dname = &d->d_name;
++ if (dname->len != nlen || memcmp(dname->name, name, nlen))
++ continue;
++ if (!atomic_read(&d->d_count) || !d->d_fsdata) {
++ spin_lock(&d->d_lock);
++ __d_drop(d);
++ spin_unlock(&d->d_lock);
++ continue;
++ }
++
++ dentry = dget(d);
++ break;
++ }
++ spin_unlock(&dcache_lock);
++ dput(parent);
++
++ if (dentry)
++ di_write_lock_child(dentry);
++
++ return dentry;
++}
++
++static struct inode *lookup_wlock_by_ino(struct super_block *sb,
++ aufs_bindex_t bindex, ino_t h_ino)
++{
++ struct inode *inode;
++ ino_t ino;
++ int err;
++
++ inode = NULL;
++ err = au_xino_read(sb, bindex, h_ino, &ino);
++ if (!err && ino)
++ inode = ilookup(sb, ino);
++ if (!inode)
++ goto out;
++
++ if (unlikely(inode->i_ino == AUFS_ROOT_INO)) {
++ AuWarn("wrong root branch\n");
++ iput(inode);
++ inode = NULL;
++ goto out;
++ }
++
++ ii_write_lock_child(inode);
++
++ out:
++ return inode;
++}
++
++enum { CHILD, PARENT };
++struct postproc_args {
++ struct inode *h_dir, *dir, *h_child_inode;
++ u32 mask;
++ unsigned int flags[2];
++ unsigned int h_child_nlen;
++ char h_child_name[];
++};
++
++static void postproc(void *_args)
++{
++ struct postproc_args *a = _args;
++ struct super_block *sb;
++ aufs_bindex_t bindex, bend, bfound;
++ unsigned char xino, try_iput;
++ int err;
++ struct inode *inode;
++ ino_t h_ino;
++ struct hin_job_args args;
++ struct dentry *dentry;
++ struct au_sbinfo *sbinfo;
++
++ AuDebugOn(!_args);
++ AuDebugOn(!a->h_dir);
++ AuDebugOn(!a->dir);
++ AuDebugOn(!a->mask);
++ AuDbg("mask 0x%x %s, i%lu, hi%lu, hci%lu\n",
++ a->mask, in_name(a->mask), a->dir->i_ino, a->h_dir->i_ino,
++ a->h_child_inode ? a->h_child_inode->i_ino : 0);
++
++ inode = NULL;
++ dentry = NULL;
++ /*
++ * do not lock a->dir->i_mutex here
++ * because of d_revalidate() may cause a deadlock.
++ */
++ sb = a->dir->i_sb;
++ AuDebugOn(!sb);
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!sbinfo);
++ /* big aufs lock */
++ si_noflush_write_lock(sb);
++
++ ii_read_lock_parent(a->dir);
++ bfound = -1;
++ bend = au_ibend(a->dir);
++ for (bindex = au_ibstart(a->dir); bindex <= bend; bindex++)
++ if (au_h_iptr(a->dir, bindex) == a->h_dir) {
++ bfound = bindex;
++ break;
++ }
++ ii_read_unlock(a->dir);
++ if (unlikely(bfound < 0))
++ goto out;
++
++ xino = !!au_opt_test(au_mntflags(sb), XINO);
++ h_ino = 0;
++ if (a->h_child_inode)
++ h_ino = a->h_child_inode->i_ino;
++
++ if (a->h_child_nlen
++ && (au_ftest_hinjob(a->flags[CHILD], GEN)
++ || au_ftest_hinjob(a->flags[CHILD], MNTPNT)))
++ dentry = lookup_wlock_by_name(a->h_child_name, a->h_child_nlen,
++ a->dir);
++ try_iput = 0;
++ if (dentry)
++ inode = dentry->d_inode;
++ if (xino && !inode && h_ino
++ && (au_ftest_hinjob(a->flags[CHILD], XINO0)
++ || au_ftest_hinjob(a->flags[CHILD], TRYXINO0)
++ || au_ftest_hinjob(a->flags[CHILD], GEN))) {
++ inode = lookup_wlock_by_ino(sb, bfound, h_ino);
++ try_iput = 1;
++ }
++
++ args.flags = a->flags[CHILD];
++ args.dentry = dentry;
++ args.inode = inode;
++ args.h_inode = a->h_child_inode;
++ args.dir = a->dir;
++ args.h_dir = a->h_dir;
++ args.h_name = a->h_child_name;
++ args.h_nlen = a->h_child_nlen;
++ err = hin_job(&args);
++ if (dentry) {
++ if (dentry->d_fsdata)
++ di_write_unlock(dentry);
++ dput(dentry);
++ }
++ if (inode && try_iput) {
++ ii_write_unlock(inode);
++ iput(inode);
++ }
++
++ ii_write_lock_parent(a->dir);
++ args.flags = a->flags[PARENT];
++ args.dentry = NULL;
++ args.inode = a->dir;
++ args.h_inode = a->h_dir;
++ args.dir = NULL;
++ args.h_dir = NULL;
++ args.h_name = NULL;
++ args.h_nlen = 0;
++ err = hin_job(&args);
++ ii_write_unlock(a->dir);
++
++ out:
++ au_nwt_done(&sbinfo->si_nowait);
++ si_write_unlock(sb);
++
++ iput(a->h_child_inode);
++ iput(a->h_dir);
++ iput(a->dir);
++ kfree(a);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void aufs_inotify(struct inotify_watch *watch, u32 wd __maybe_unused,
++ u32 mask, u32 cookie __maybe_unused,
++ const char *h_child_name, struct inode *h_child_inode)
++{
++ struct au_hinotify *hinotify;
++ struct postproc_args *args;
++ int len, wkq_err;
++ unsigned char isdir, isroot, wh;
++ char *p;
++ struct inode *dir;
++ unsigned int flags[2];
++
++ /* if IN_UNMOUNT happens, there must be another bug */
++ AuDebugOn(mask & IN_UNMOUNT);
++ if (mask & (IN_IGNORED | IN_UNMOUNT)) {
++ put_inotify_watch(watch);
++ return;
++ }
++#ifdef AuDbgHinotify
++ au_debug(1);
++ if (1 || !h_child_name || strcmp(h_child_name, AUFS_XINO_FNAME)) {
++ AuDbg("i%lu, wd %d, mask 0x%x %s, cookie 0x%x, hcname %s,"
++ " hi%lu\n",
++ watch->inode->i_ino, wd, mask, in_name(mask), cookie,
++ h_child_name ? h_child_name : "",
++ h_child_inode ? h_child_inode->i_ino : 0);
++ WARN_ON(1);
++ }
++ au_debug(0);
++#endif
++
++ hinotify = container_of(watch, struct au_hinotify, hin_watch);
++ AuDebugOn(!hinotify || !hinotify->hin_aufs_inode);
++ dir = igrab(hinotify->hin_aufs_inode);
++ if (!dir)
++ return;
++
++ isroot = (dir->i_ino == AUFS_ROOT_INO);
++ len = 0;
++ wh = 0;
++ if (h_child_name) {
++ len = strlen(h_child_name);
++ if (!memcmp(h_child_name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++ h_child_name += AUFS_WH_PFX_LEN;
++ len -= AUFS_WH_PFX_LEN;
++ wh = 1;
++ }
++ }
++
++ isdir = 0;
++ if (h_child_inode)
++ isdir = !!S_ISDIR(h_child_inode->i_mode);
++ flags[PARENT] = AuHinJob_ISDIR;
++ flags[CHILD] = 0;
++ if (isdir)
++ flags[CHILD] = AuHinJob_ISDIR;
++ switch (mask & IN_ALL_EVENTS) {
++ case IN_MOVED_FROM:
++ case IN_MOVED_TO:
++ AuDebugOn(!h_child_name || !h_child_inode);
++ au_fset_hinjob(flags[CHILD], GEN);
++ au_fset_hinjob(flags[CHILD], XINO0);
++ au_fset_hinjob(flags[CHILD], MNTPNT);
++ au_fset_hinjob(flags[PARENT], DIRENT);
++ break;
++
++ case IN_CREATE:
++ AuDebugOn(!h_child_name || !h_child_inode);
++ au_fset_hinjob(flags[PARENT], DIRENT);
++ au_fset_hinjob(flags[CHILD], GEN);
++ break;
++
++ case IN_DELETE:
++ /*
++ * aufs never be able to get this child inode.
++ * revalidation should be in d_revalidate()
++ * by checking i_nlink, i_generation or d_unhashed().
++ */
++ AuDebugOn(!h_child_name);
++ au_fset_hinjob(flags[PARENT], DIRENT);
++ au_fset_hinjob(flags[CHILD], GEN);
++ au_fset_hinjob(flags[CHILD], TRYXINO0);
++ au_fset_hinjob(flags[CHILD], MNTPNT);
++ break;
++
++ default:
++ AuDebugOn(1);
++ }
++
++ if (wh)
++ h_child_inode = NULL;
++
++ /* iput() and kfree() will be called in postproc() */
++ /*
++ * inotify_mutex is already acquired and kmalloc/prune_icache may lock
++ * iprune_mutex. strange.
++ */
++ lockdep_off();
++ args = kmalloc(sizeof(*args) + len + 1, GFP_NOFS);
++ lockdep_on();
++ if (unlikely(!args)) {
++ AuErr1("no memory\n");
++ iput(dir);
++ return;
++ }
++ args->flags[PARENT] = flags[PARENT];
++ args->flags[CHILD] = flags[CHILD];
++ args->mask = mask;
++ args->dir = dir;
++ args->h_dir = igrab(watch->inode);
++ if (h_child_inode)
++ h_child_inode = igrab(h_child_inode); /* can be NULL */
++ args->h_child_inode = h_child_inode;
++ args->h_child_nlen = len;
++ if (len) {
++ p = (void *)args;
++ p += sizeof(*args);
++ memcpy(p, h_child_name, len + 1);
++ }
++
++ lockdep_off();
++ wkq_err = au_wkq_nowait(postproc, args, dir->i_sb);
++ lockdep_on();
++ if (unlikely(wkq_err))
++ AuErr("wkq %d\n", wkq_err);
++}
++
++static void aufs_inotify_destroy(struct inotify_watch *watch __maybe_unused)
++{
++ return;
++}
++
++static struct inotify_operations aufs_inotify_ops = {
++ .handle_event = aufs_inotify,
++ .destroy_watch = aufs_inotify_destroy
++};
++
++/* ---------------------------------------------------------------------- */
++
++static void au_hin_destroy_cache(void)
++{
++ kmem_cache_destroy(au_cachep[AuCache_HINOTIFY]);
++ au_cachep[AuCache_HINOTIFY] = NULL;
++}
++
++int __init au_hinotify_init(void)
++{
++ int err;
++
++ err = -ENOMEM;
++ au_cachep[AuCache_HINOTIFY] = AuCache(au_hinotify);
++ if (au_cachep[AuCache_HINOTIFY]) {
++ err = 0;
++ au_hin_handle = inotify_init(&aufs_inotify_ops);
++ if (IS_ERR(au_hin_handle)) {
++ err = PTR_ERR(au_hin_handle);
++ au_hin_destroy_cache();
++ }
++ }
++ AuTraceErr(err);
++ return err;
++}
++
++void au_hinotify_fin(void)
++{
++ inotify_destroy(au_hin_handle);
++ if (au_cachep[AuCache_HINOTIFY])
++ au_hin_destroy_cache();
++}
+diff --git a/fs/aufs/i_op.c b/fs/aufs/i_op.c
+new file mode 100644
+index 0000000..a64d6b0
+--- /dev/null
++++ b/fs/aufs/i_op.c
+@@ -0,0 +1,862 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode operations (except add/del/rename)
++ */
++
++#include <linux/device_cgroup.h>
++#include <linux/fs_stack.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++static int h_permission(struct inode *h_inode, int mask,
++ struct vfsmount *h_mnt, int brperm)
++{
++ int err;
++ const unsigned char write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
++
++ err = -EACCES;
++ if ((write_mask && IS_IMMUTABLE(h_inode))
++ || ((mask & MAY_EXEC)
++ && S_ISREG(h_inode->i_mode)
++ && ((h_mnt->mnt_flags & MNT_NOEXEC)
++ || !(h_inode->i_mode & S_IXUGO))))
++ goto out;
++
++ /*
++ * - skip the lower fs test in the case of write to ro branch.
++ * - nfs dir permission write check is optimized, but a policy for
++ * link/rename requires a real check.
++ */
++ if ((write_mask && !au_br_writable(brperm))
++ || (au_test_nfs(h_inode->i_sb) && S_ISDIR(h_inode->i_mode)
++ && write_mask && !(mask & MAY_READ))
++ || !h_inode->i_op->permission) {
++ /* AuLabel(generic_permission); */
++ err = generic_permission(h_inode, mask, NULL);
++ } else {
++ /* AuLabel(h_inode->permission); */
++ err = h_inode->i_op->permission(h_inode, mask);
++ AuTraceErr(err);
++ }
++
++ if (!err)
++ err = devcgroup_inode_permission(h_inode, mask);
++ if (!err)
++ err = security_inode_permission
++ (h_inode, mask & (MAY_READ | MAY_WRITE | MAY_EXEC
++ | MAY_APPEND));
++
++ out:
++ return err;
++}
++
++static int aufs_permission(struct inode *inode, int mask)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ const unsigned char isdir = !!S_ISDIR(inode->i_mode);
++ const unsigned char write_mask = !!(mask & (MAY_WRITE | MAY_APPEND));
++ struct inode *h_inode;
++ struct super_block *sb;
++ struct au_branch *br;
++
++ sb = inode->i_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ ii_read_lock_child(inode);
++
++ if (!isdir || write_mask) {
++ h_inode = au_h_iptr(inode, au_ibstart(inode));
++ AuDebugOn(!h_inode
++ || ((h_inode->i_mode & S_IFMT)
++ != (inode->i_mode & S_IFMT)));
++ err = 0;
++ bindex = au_ibstart(inode);
++ br = au_sbr(sb, bindex);
++ err = h_permission(h_inode, mask, br->br_mnt, br->br_perm);
++
++ if (write_mask && !err) {
++ /* test whether the upper writable branch exists */
++ err = -EROFS;
++ for (; bindex >= 0; bindex--)
++ if (!au_br_rdonly(au_sbr(sb, bindex))) {
++ err = 0;
++ break;
++ }
++ }
++ goto out;
++ }
++
++ /* non-write to dir */
++ err = 0;
++ bend = au_ibend(inode);
++ for (bindex = au_ibstart(inode); !err && bindex <= bend; bindex++) {
++ h_inode = au_h_iptr(inode, bindex);
++ if (h_inode) {
++ AuDebugOn(!S_ISDIR(h_inode->i_mode));
++ br = au_sbr(sb, bindex);
++ err = h_permission(h_inode, mask, br->br_mnt,
++ br->br_perm);
++ }
++ }
++
++ out:
++ ii_read_unlock(inode);
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct dentry *aufs_lookup(struct inode *dir, struct dentry *dentry,
++ struct nameidata *nd)
++{
++ struct dentry *ret, *parent;
++ struct inode *inode, *h_inode;
++ struct mutex *mtx;
++ struct super_block *sb;
++ int err, npositive;
++ aufs_bindex_t bstart;
++
++ /* temporary workaround for a bug in NFSD readdir */
++ if (!au_test_nfsd(current))
++ IMustLock(dir);
++ else
++ WARN_ONCE(!mutex_is_locked(&dir->i_mutex),
++ "a known problem of NFSD readdir since 2.6.28\n");
++
++ sb = dir->i_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++ err = au_alloc_dinfo(dentry);
++ ret = ERR_PTR(err);
++ if (unlikely(err))
++ goto out;
++
++ parent = dentry->d_parent; /* dir inode is locked */
++ di_read_lock_parent(parent, AuLock_IR);
++ npositive = au_lkup_dentry(dentry, au_dbstart(parent), /*type*/0, nd);
++ di_read_unlock(parent, AuLock_IR);
++ err = npositive;
++ ret = ERR_PTR(err);
++ if (unlikely(err < 0))
++ goto out_unlock;
++
++ inode = NULL;
++ if (npositive) {
++ bstart = au_dbstart(dentry);
++ h_inode = au_h_dptr(dentry, bstart)->d_inode;
++ if (!S_ISDIR(h_inode->i_mode)) {
++ /*
++ * stop 'race'-ing between hardlinks under different
++ * parents.
++ */
++ mtx = &au_sbr(sb, bstart)->br_xino.xi_nondir_mtx;
++ mutex_lock(mtx);
++ inode = au_new_inode(dentry, /*must_new*/0);
++ mutex_unlock(mtx);
++ } else
++ inode = au_new_inode(dentry, /*must_new*/0);
++ ret = (void *)inode;
++ }
++ if (IS_ERR(inode))
++ goto out_unlock;
++
++ ret = d_splice_alias(inode, dentry);
++ if (unlikely(IS_ERR(ret) && inode))
++ ii_write_unlock(inode);
++ au_store_oflag(nd, inode);
++
++ out_unlock:
++ di_write_unlock(dentry);
++ out:
++ si_read_unlock(sb);
++ return ret;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_wr_dir_cpup(struct dentry *dentry, struct dentry *parent,
++ const unsigned char add_entry, aufs_bindex_t bcpup,
++ aufs_bindex_t bstart)
++{
++ int err;
++ struct dentry *h_parent;
++ struct inode *h_dir;
++
++ if (add_entry) {
++ au_update_dbstart(dentry);
++ IMustLock(parent->d_inode);
++ } else
++ di_write_lock_parent(parent);
++
++ err = 0;
++ if (!au_h_dptr(parent, bcpup)) {
++ if (bstart < bcpup)
++ err = au_cpdown_dirs(dentry, bcpup);
++ else
++ err = au_cpup_dirs(dentry, bcpup);
++ }
++ if (!err && add_entry) {
++ h_parent = au_h_dptr(parent, bcpup);
++ h_dir = h_parent->d_inode;
++ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++ err = au_lkup_neg(dentry, bcpup);
++ /* todo: no unlock here */
++ mutex_unlock(&h_dir->i_mutex);
++ if (bstart < bcpup && au_dbstart(dentry) < 0) {
++ au_set_dbstart(dentry, 0);
++ au_update_dbrange(dentry, /*do_put_zero*/0);
++ }
++ }
++
++ if (!add_entry)
++ di_write_unlock(parent);
++ if (!err)
++ err = bcpup; /* success */
++
++ return err;
++}
++
++/*
++ * decide the branch and the parent dir where we will create a new entry.
++ * returns new bindex or an error.
++ * copyup the parent dir if needed.
++ */
++int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
++ struct au_wr_dir_args *args)
++{
++ int err;
++ aufs_bindex_t bcpup, bstart, src_bstart;
++ const unsigned char add_entry = !!au_ftest_wrdir(args->flags,
++ ADD_ENTRY);
++ struct super_block *sb;
++ struct dentry *parent;
++ struct au_sbinfo *sbinfo;
++
++ sb = dentry->d_sb;
++ sbinfo = au_sbi(sb);
++ parent = dget_parent(dentry);
++ bstart = au_dbstart(dentry);
++ bcpup = bstart;
++ if (args->force_btgt < 0) {
++ if (src_dentry) {
++ src_bstart = au_dbstart(src_dentry);
++ if (src_bstart < bstart)
++ bcpup = src_bstart;
++ } else if (add_entry) {
++ err = AuWbrCreate(sbinfo, dentry,
++ au_ftest_wrdir(args->flags, ISDIR));
++ bcpup = err;
++ }
++
++ if (bcpup < 0 || au_test_ro(sb, bcpup, dentry->d_inode)) {
++ if (add_entry)
++ err = AuWbrCopyup(sbinfo, dentry);
++ else {
++ if (!IS_ROOT(dentry)) {
++ di_read_lock_parent(parent, !AuLock_IR);
++ err = AuWbrCopyup(sbinfo, dentry);
++ di_read_unlock(parent, !AuLock_IR);
++ } else
++ err = AuWbrCopyup(sbinfo, dentry);
++ }
++ bcpup = err;
++ if (unlikely(err < 0))
++ goto out;
++ }
++ } else {
++ bcpup = args->force_btgt;
++ AuDebugOn(au_test_ro(sb, bcpup, dentry->d_inode));
++ }
++ AuDbg("bstart %d, bcpup %d\n", bstart, bcpup);
++ if (bstart < bcpup)
++ au_update_dbrange(dentry, /*do_put_zero*/1);
++
++ err = bcpup;
++ if (bcpup == bstart)
++ goto out; /* success */
++
++ /* copyup the new parent into the branch we process */
++ err = au_wr_dir_cpup(dentry, parent, add_entry, bcpup, bstart);
++
++ out:
++ dput(parent);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *au_pinned_h_parent(struct au_pin *pin)
++{
++ if (pin && pin->parent)
++ return au_h_dptr(pin->parent, pin->bindex);
++ return NULL;
++}
++
++void au_unpin(struct au_pin *p)
++{
++ if (au_ftest_pin(p->flags, MNT_WRITE))
++ mnt_drop_write(p->h_mnt);
++ if (!p->hdir)
++ return;
++
++ au_hin_imtx_unlock(p->hdir);
++ if (!au_ftest_pin(p->flags, DI_LOCKED))
++ di_read_unlock(p->parent, AuLock_IR);
++ iput(p->hdir->hi_inode);
++ dput(p->parent);
++ p->parent = NULL;
++ p->hdir = NULL;
++ p->h_mnt = NULL;
++}
++
++int au_do_pin(struct au_pin *p)
++{
++ int err;
++ struct super_block *sb;
++ struct dentry *h_dentry, *h_parent;
++ struct au_branch *br;
++ struct inode *h_dir;
++
++ err = 0;
++ sb = p->dentry->d_sb;
++ br = au_sbr(sb, p->bindex);
++ if (IS_ROOT(p->dentry)) {
++ if (au_ftest_pin(p->flags, MNT_WRITE)) {
++ p->h_mnt = br->br_mnt;
++ err = mnt_want_write(p->h_mnt);
++ if (unlikely(err)) {
++ au_fclr_pin(p->flags, MNT_WRITE);
++ goto out_err;
++ }
++ }
++ goto out;
++ }
++
++ h_dentry = NULL;
++ if (p->bindex <= au_dbend(p->dentry))
++ h_dentry = au_h_dptr(p->dentry, p->bindex);
++
++ p->parent = dget_parent(p->dentry);
++ if (!au_ftest_pin(p->flags, DI_LOCKED))
++ di_read_lock(p->parent, AuLock_IR, p->lsc_di);
++
++ h_dir = NULL;
++ h_parent = au_h_dptr(p->parent, p->bindex);
++ p->hdir = au_hi(p->parent->d_inode, p->bindex);
++ if (p->hdir)
++ h_dir = p->hdir->hi_inode;
++
++ /* udba case */
++ if (unlikely(!p->hdir || !h_dir)) {
++ err = au_busy_or_stale();
++ if (!au_ftest_pin(p->flags, DI_LOCKED))
++ di_read_unlock(p->parent, AuLock_IR);
++ dput(p->parent);
++ p->parent = NULL;
++ goto out_err;
++ }
++
++ au_igrab(h_dir);
++ au_hin_imtx_lock_nested(p->hdir, p->lsc_hi);
++
++ if (h_dentry) {
++ err = au_h_verify(h_dentry, p->udba, h_dir, h_parent, br);
++ if (unlikely(err)) {
++ au_fclr_pin(p->flags, MNT_WRITE);
++ goto out_unpin;
++ }
++ }
++
++ if (au_ftest_pin(p->flags, MNT_WRITE)) {
++ p->h_mnt = br->br_mnt;
++ err = mnt_want_write(p->h_mnt);
++ if (unlikely(err)) {
++ au_fclr_pin(p->flags, MNT_WRITE);
++ goto out_unpin;
++ }
++ }
++ goto out; /* success */
++
++ out_unpin:
++ au_unpin(p);
++ out_err:
++ AuErr("err %d\n", err);
++ err = au_busy_or_stale();
++ out:
++ return err;
++}
++
++void au_pin_init(struct au_pin *p, struct dentry *dentry,
++ aufs_bindex_t bindex, int lsc_di, int lsc_hi,
++ unsigned int udba, unsigned char flags)
++{
++ p->dentry = dentry;
++ p->udba = udba;
++ p->lsc_di = lsc_di;
++ p->lsc_hi = lsc_hi;
++ p->flags = flags;
++ p->bindex = bindex;
++
++ p->parent = NULL;
++ p->hdir = NULL;
++ p->h_mnt = NULL;
++}
++
++int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
++ unsigned int udba, unsigned char flags)
++{
++ au_pin_init(pin, dentry, bindex, AuLsc_DI_PARENT, AuLsc_I_PARENT2,
++ udba, flags);
++ return au_do_pin(pin);
++}
++
++/* ---------------------------------------------------------------------- */
++
++#define AuIcpup_DID_CPUP 1
++#define au_ftest_icpup(flags, name) ((flags) & AuIcpup_##name)
++#define au_fset_icpup(flags, name) { (flags) |= AuIcpup_##name; }
++#define au_fclr_icpup(flags, name) { (flags) &= ~AuIcpup_##name; }
++
++struct au_icpup_args {
++ unsigned char flags;
++ unsigned char pin_flags;
++ aufs_bindex_t btgt;
++ struct au_pin pin;
++ struct path h_path;
++ struct inode *h_inode;
++};
++
++static int au_lock_and_icpup(struct dentry *dentry, struct iattr *ia,
++ struct au_icpup_args *a)
++{
++ int err;
++ unsigned int udba;
++ loff_t sz;
++ aufs_bindex_t bstart;
++ struct dentry *hi_wh, *parent;
++ struct inode *inode;
++ struct au_wr_dir_args wr_dir_args = {
++ .force_btgt = -1,
++ .flags = 0
++ };
++
++ di_write_lock_child(dentry);
++ bstart = au_dbstart(dentry);
++ inode = dentry->d_inode;
++ if (S_ISDIR(inode->i_mode))
++ au_fset_wrdir(wr_dir_args.flags, ISDIR);
++ /* plink or hi_wh() case */
++ if (bstart != au_ibstart(inode))
++ wr_dir_args.force_btgt = au_ibstart(inode);
++ err = au_wr_dir(dentry, /*src_dentry*/NULL, &wr_dir_args);
++ if (unlikely(err < 0))
++ goto out_dentry;
++ a->btgt = err;
++ if (err != bstart)
++ au_fset_icpup(a->flags, DID_CPUP);
++
++ err = 0;
++ a->pin_flags = AuPin_MNT_WRITE;
++ parent = NULL;
++ if (!IS_ROOT(dentry)) {
++ au_fset_pin(a->pin_flags, DI_LOCKED);
++ parent = dget_parent(dentry);
++ di_write_lock_parent(parent);
++ }
++
++ udba = au_opt_udba(dentry->d_sb);
++ if (d_unhashed(dentry) || (ia->ia_valid & ATTR_FILE))
++ udba = AuOpt_UDBA_NONE;
++ err = au_pin(&a->pin, dentry, a->btgt, udba, a->pin_flags);
++ if (unlikely(err)) {
++ if (parent) {
++ di_write_unlock(parent);
++ dput(parent);
++ }
++ goto out_dentry;
++ }
++ a->h_path.dentry = au_h_dptr(dentry, bstart);
++ a->h_inode = a->h_path.dentry->d_inode;
++ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++ sz = -1;
++ if ((ia->ia_valid & ATTR_SIZE) && ia->ia_size < i_size_read(a->h_inode))
++ sz = ia->ia_size;
++
++ hi_wh = NULL;
++ if (au_ftest_icpup(a->flags, DID_CPUP) && d_unhashed(dentry)) {
++ hi_wh = au_hi_wh(inode, a->btgt);
++ if (!hi_wh) {
++ err = au_sio_cpup_wh(dentry, a->btgt, sz, /*file*/NULL);
++ if (unlikely(err))
++ goto out_unlock;
++ hi_wh = au_hi_wh(inode, a->btgt);
++ /* todo: revalidate hi_wh? */
++ }
++ }
++
++ if (parent) {
++ au_pin_set_parent_lflag(&a->pin, /*lflag*/0);
++ di_downgrade_lock(parent, AuLock_IR);
++ dput(parent);
++ }
++ if (!au_ftest_icpup(a->flags, DID_CPUP))
++ goto out; /* success */
++
++ if (!d_unhashed(dentry)) {
++ err = au_sio_cpup_simple(dentry, a->btgt, sz, AuCpup_DTIME);
++ if (!err)
++ a->h_path.dentry = au_h_dptr(dentry, a->btgt);
++ } else if (!hi_wh)
++ a->h_path.dentry = au_h_dptr(dentry, a->btgt);
++ else
++ a->h_path.dentry = hi_wh; /* do not dget here */
++
++ out_unlock:
++ mutex_unlock(&a->h_inode->i_mutex);
++ a->h_inode = a->h_path.dentry->d_inode;
++ if (!err) {
++ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++ goto out; /* success */
++ }
++
++ au_unpin(&a->pin);
++
++ out_dentry:
++ di_write_unlock(dentry);
++ out:
++ return err;
++}
++
++static int aufs_setattr(struct dentry *dentry, struct iattr *ia)
++{
++ int err;
++ struct inode *inode;
++ struct super_block *sb;
++ struct file *file;
++ struct au_icpup_args *a;
++
++ err = -ENOMEM;
++ a = kzalloc(sizeof(*a), GFP_NOFS);
++ if (unlikely(!a))
++ goto out;
++
++ inode = dentry->d_inode;
++ IMustLock(inode);
++ sb = dentry->d_sb;
++ si_read_lock(sb, AuLock_FLUSH);
++
++ file = NULL;
++ if (ia->ia_valid & ATTR_FILE) {
++ /* currently ftruncate(2) only */
++ file = ia->ia_file;
++ fi_write_lock(file);
++ ia->ia_file = au_h_fptr(file, au_fbstart(file));
++ }
++
++ if (ia->ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
++ ia->ia_valid &= ~ATTR_MODE;
++
++ err = au_lock_and_icpup(dentry, ia, a);
++ if (unlikely(err < 0))
++ goto out_si;
++ if (au_ftest_icpup(a->flags, DID_CPUP)) {
++ ia->ia_file = NULL;
++ ia->ia_valid &= ~ATTR_FILE;
++ }
++
++ a->h_path.mnt = au_sbr_mnt(sb, a->btgt);
++ if (ia->ia_valid & ATTR_SIZE) {
++ struct file *f;
++
++ if (ia->ia_size < i_size_read(inode)) {
++ /* unmap only */
++ err = vmtruncate(inode, ia->ia_size);
++ if (unlikely(err))
++ goto out_unlock;
++ }
++
++ f = NULL;
++ if (ia->ia_valid & ATTR_FILE)
++ f = ia->ia_file;
++ mutex_unlock(&a->h_inode->i_mutex);
++ err = vfsub_trunc(&a->h_path, ia->ia_size, ia->ia_valid, f);
++ mutex_lock_nested(&a->h_inode->i_mutex, AuLsc_I_CHILD);
++ } else
++ err = vfsub_notify_change(&a->h_path, ia);
++ if (!err)
++ au_cpup_attr_changeable(inode);
++
++ out_unlock:
++ mutex_unlock(&a->h_inode->i_mutex);
++ au_unpin(&a->pin);
++ di_write_unlock(dentry);
++ out_si:
++ if (file) {
++ fi_write_unlock(file);
++ ia->ia_file = file;
++ ia->ia_valid |= ATTR_FILE;
++ }
++ si_read_unlock(sb);
++ kfree(a);
++ out:
++ return err;
++}
++
++static int au_getattr_lock_reval(struct dentry *dentry, unsigned int sigen)
++{
++ int err;
++ struct inode *inode;
++ struct dentry *parent;
++
++ err = 0;
++ inode = dentry->d_inode;
++ di_write_lock_child(dentry);
++ if (au_digen(dentry) != sigen || au_iigen(inode) != sigen) {
++ parent = dget_parent(dentry);
++ di_read_lock_parent(parent, AuLock_IR);
++ /* returns a number of positive dentries */
++ err = au_refresh_hdentry(dentry, inode->i_mode & S_IFMT);
++ if (err > 0)
++ err = au_refresh_hinode(inode, dentry);
++ di_read_unlock(parent, AuLock_IR);
++ dput(parent);
++ if (unlikely(!err))
++ err = -EIO;
++ }
++ di_downgrade_lock(dentry, AuLock_IR);
++
++ return err;
++}
++
++static void au_refresh_iattr(struct inode *inode, struct kstat *st,
++ unsigned int nlink)
++{
++ inode->i_mode = st->mode;
++ inode->i_uid = st->uid;
++ inode->i_gid = st->gid;
++ inode->i_atime = st->atime;
++ inode->i_mtime = st->mtime;
++ inode->i_ctime = st->ctime;
++
++ au_cpup_attr_nlink(inode, /*force*/0);
++ if (S_ISDIR(inode->i_mode)) {
++ inode->i_nlink -= nlink;
++ inode->i_nlink += st->nlink;
++ }
++
++ spin_lock(&inode->i_lock);
++ inode->i_blocks = st->blocks;
++ i_size_write(inode, st->size);
++ spin_unlock(&inode->i_lock);
++}
++
++static int aufs_getattr(struct vfsmount *mnt __maybe_unused,
++ struct dentry *dentry, struct kstat *st)
++{
++ int err;
++ unsigned int mnt_flags;
++ aufs_bindex_t bindex;
++ unsigned char udba_none, positive, did_lock;
++ struct super_block *sb, *h_sb;
++ struct inode *inode;
++ struct vfsmount *h_mnt;
++ struct dentry *h_dentry;
++
++ err = 0;
++ did_lock = 0;
++ sb = dentry->d_sb;
++ inode = dentry->d_inode;
++ si_read_lock(sb, AuLock_FLUSH);
++ if (IS_ROOT(dentry)) {
++ /* lock free root dinfo */
++ h_dentry = dget(au_di(dentry)->di_hdentry->hd_dentry);
++ h_mnt = au_sbr_mnt(sb, 0);
++ goto getattr;
++ }
++
++ did_lock = 1;
++ mnt_flags = au_mntflags(sb);
++ udba_none = !!au_opt_test(mnt_flags, UDBA_NONE);
++
++ /* support fstat(2) */
++ if (!d_unhashed(dentry) && !udba_none) {
++ unsigned int sigen = au_sigen(sb);
++ if (au_digen(dentry) == sigen && au_iigen(inode) == sigen)
++ di_read_lock_child(dentry, AuLock_IR);
++ else {
++ err = au_getattr_lock_reval(dentry, sigen);
++ if (unlikely(err))
++ goto out;
++ }
++ } else
++ di_read_lock_child(dentry, AuLock_IR);
++
++ bindex = au_ibstart(inode);
++ h_mnt = au_sbr_mnt(sb, bindex);
++ h_sb = h_mnt->mnt_sb;
++ if (!au_test_fs_bad_iattr(h_sb) && udba_none)
++ goto out_fill; /* success */
++
++ if (au_dbstart(dentry) == bindex)
++ h_dentry = dget(au_h_dptr(dentry, bindex));
++ else if (au_opt_test(mnt_flags, PLINK) && au_plink_test(inode)) {
++ h_dentry = au_plink_lkup(inode, bindex);
++ if (IS_ERR(h_dentry))
++ goto out_fill; /* pretending success */
++ } else
++ /* illegally overlapped or something */
++ goto out_fill; /* pretending success */
++
++ getattr:
++ positive = !!h_dentry->d_inode;
++ if (positive)
++ err = vfs_getattr(h_mnt, h_dentry, st);
++ dput(h_dentry);
++ if (!err) {
++ if (positive)
++ au_refresh_iattr(inode, st, h_dentry->d_inode->i_nlink);
++ goto out_fill; /* success */
++ }
++ goto out;
++
++ out_fill:
++ generic_fillattr(inode, st);
++ out:
++ if (did_lock)
++ di_read_unlock(dentry, AuLock_IR);
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int h_readlink(struct dentry *dentry, int bindex, char __user *buf,
++ int bufsiz)
++{
++ int err;
++ struct super_block *sb;
++ struct dentry *h_dentry;
++
++ err = -EINVAL;
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (unlikely(/* !h_dentry
++ || !h_dentry->d_inode
++ || !h_dentry->d_inode->i_op
++ || */ !h_dentry->d_inode->i_op->readlink))
++ goto out;
++
++ err = security_inode_readlink(h_dentry);
++ if (unlikely(err))
++ goto out;
++
++ sb = dentry->d_sb;
++ if (!au_test_ro(sb, bindex, dentry->d_inode)) {
++ vfsub_touch_atime(au_sbr_mnt(sb, bindex), h_dentry);
++ fsstack_copy_attr_atime(dentry->d_inode, h_dentry->d_inode);
++ }
++ err = h_dentry->d_inode->i_op->readlink(h_dentry, buf, bufsiz);
++
++ out:
++ return err;
++}
++
++static int aufs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
++{
++ int err;
++
++ aufs_read_lock(dentry, AuLock_IR);
++ err = h_readlink(dentry, au_dbstart(dentry), buf, bufsiz);
++ aufs_read_unlock(dentry, AuLock_IR);
++
++ return err;
++}
++
++static void *aufs_follow_link(struct dentry *dentry, struct nameidata *nd)
++{
++ int err;
++ char *buf;
++ mm_segment_t old_fs;
++
++ err = -ENOMEM;
++ buf = __getname();
++ if (unlikely(!buf))
++ goto out;
++
++ aufs_read_lock(dentry, AuLock_IR);
++ old_fs = get_fs();
++ set_fs(KERNEL_DS);
++ err = h_readlink(dentry, au_dbstart(dentry), (char __user *)buf,
++ PATH_MAX);
++ set_fs(old_fs);
++ aufs_read_unlock(dentry, AuLock_IR);
++
++ if (err >= 0) {
++ buf[err] = 0;
++ /* will be freed by put_link */
++ nd_set_link(nd, buf);
++ return NULL; /* success */
++ }
++ __putname(buf);
++
++ out:
++ path_put(&nd->path);
++ AuTraceErr(err);
++ return ERR_PTR(err);
++}
++
++static void aufs_put_link(struct dentry *dentry __maybe_unused,
++ struct nameidata *nd, void *cookie __maybe_unused)
++{
++ __putname(nd_get_link(nd));
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void aufs_truncate_range(struct inode *inode __maybe_unused,
++ loff_t start __maybe_unused,
++ loff_t end __maybe_unused)
++{
++ AuUnsupport();
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct inode_operations aufs_symlink_iop = {
++ .permission = aufs_permission,
++ .setattr = aufs_setattr,
++ .getattr = aufs_getattr,
++ .readlink = aufs_readlink,
++ .follow_link = aufs_follow_link,
++ .put_link = aufs_put_link
++};
++
++struct inode_operations aufs_dir_iop = {
++ .create = aufs_create,
++ .lookup = aufs_lookup,
++ .link = aufs_link,
++ .unlink = aufs_unlink,
++ .symlink = aufs_symlink,
++ .mkdir = aufs_mkdir,
++ .rmdir = aufs_rmdir,
++ .mknod = aufs_mknod,
++ .rename = aufs_rename,
++
++ .permission = aufs_permission,
++ .setattr = aufs_setattr,
++ .getattr = aufs_getattr
++};
++
++struct inode_operations aufs_iop = {
++ .permission = aufs_permission,
++ .setattr = aufs_setattr,
++ .getattr = aufs_getattr,
++ .truncate_range = aufs_truncate_range
++};
+diff --git a/fs/aufs/i_op_add.c b/fs/aufs/i_op_add.c
+new file mode 100644
+index 0000000..516120d
+--- /dev/null
++++ b/fs/aufs/i_op_add.c
+@@ -0,0 +1,625 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode operations (add entry)
++ */
++
++#include "aufs.h"
++
++/*
++ * final procedure of adding a new entry, except link(2).
++ * remove whiteout, instantiate, copyup the parent dir's times and size
++ * and update version.
++ * if it failed, re-create the removed whiteout.
++ */
++static int epilog(struct inode *dir, aufs_bindex_t bindex,
++ struct dentry *wh_dentry, struct dentry *dentry)
++{
++ int err, rerr;
++ aufs_bindex_t bwh;
++ struct path h_path;
++ struct inode *inode, *h_dir;
++ struct dentry *wh;
++
++ bwh = -1;
++ if (wh_dentry) {
++ h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
++ IMustLock(h_dir);
++ AuDebugOn(au_h_iptr(dir, bindex) != h_dir);
++ bwh = au_dbwh(dentry);
++ h_path.dentry = wh_dentry;
++ h_path.mnt = au_sbr_mnt(dir->i_sb, bindex);
++ err = au_wh_unlink_dentry(au_h_iptr(dir, bindex), &h_path,
++ dentry);
++ if (unlikely(err))
++ goto out;
++ }
++
++ inode = au_new_inode(dentry, /*must_new*/1);
++ if (!IS_ERR(inode)) {
++ d_instantiate(dentry, inode);
++ dir = dentry->d_parent->d_inode; /* dir inode is locked */
++ IMustLock(dir);
++ if (au_ibstart(dir) == au_dbstart(dentry))
++ au_cpup_attr_timesizes(dir);
++ dir->i_version++;
++ return 0; /* success */
++ }
++
++ err = PTR_ERR(inode);
++ if (!wh_dentry)
++ goto out;
++
++ /* revert */
++ /* dir inode is locked */
++ wh = au_wh_create(dentry, bwh, wh_dentry->d_parent);
++ rerr = PTR_ERR(wh);
++ if (IS_ERR(wh)) {
++ AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ err = -EIO;
++ } else
++ dput(wh);
++
++ out:
++ return err;
++}
++
++/*
++ * simple tests for the adding inode operations.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent, int isdir)
++{
++ int err;
++ umode_t h_mode;
++ struct dentry *h_dentry;
++ struct inode *h_inode;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ h_inode = h_dentry->d_inode;
++ if (!dentry->d_inode) {
++ err = -EEXIST;
++ if (unlikely(h_inode))
++ goto out;
++ } else {
++ /* rename(2) case */
++ err = -EIO;
++ if (unlikely(!h_inode || !h_inode->i_nlink))
++ goto out;
++
++ h_mode = h_inode->i_mode;
++ if (!isdir) {
++ err = -EISDIR;
++ if (unlikely(S_ISDIR(h_mode)))
++ goto out;
++ } else if (unlikely(!S_ISDIR(h_mode))) {
++ err = -ENOTDIR;
++ goto out;
++ }
++ }
++
++ err = -EIO;
++ /* expected parent dir is locked */
++ if (unlikely(h_parent != h_dentry->d_parent))
++ goto out;
++ err = 0;
++
++ out:
++ return err;
++}
++
++/*
++ * initial procedure of adding a new entry.
++ * prepare writable branch and the parent dir, lock it,
++ * and lookup whiteout for the new entry.
++ */
++static struct dentry*
++lock_hdir_lkup_wh(struct dentry *dentry, struct au_dtime *dt,
++ struct dentry *src_dentry, struct au_pin *pin,
++ struct au_wr_dir_args *wr_dir_args)
++{
++ struct dentry *wh_dentry, *h_parent;
++ struct super_block *sb;
++ struct au_branch *br;
++ int err;
++ unsigned int udba;
++ aufs_bindex_t bcpup;
++
++ err = au_wr_dir(dentry, src_dentry, wr_dir_args);
++ bcpup = err;
++ wh_dentry = ERR_PTR(err);
++ if (unlikely(err < 0))
++ goto out;
++
++ sb = dentry->d_sb;
++ udba = au_opt_udba(sb);
++ err = au_pin(pin, dentry, bcpup, udba,
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ wh_dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out;
++
++ h_parent = au_pinned_h_parent(pin);
++ if (udba != AuOpt_UDBA_NONE
++ && au_dbstart(dentry) == bcpup) {
++ err = au_may_add(dentry, bcpup, h_parent,
++ au_ftest_wrdir(wr_dir_args->flags, ISDIR));
++ wh_dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out_unpin;
++ }
++
++ br = au_sbr(sb, bcpup);
++ if (dt) {
++ struct path tmp = {
++ .dentry = h_parent,
++ .mnt = br->br_mnt
++ };
++ au_dtime_store(dt, au_pinned_parent(pin), &tmp);
++ }
++
++ wh_dentry = NULL;
++ if (bcpup != au_dbwh(dentry))
++ goto out; /* success */
++
++ wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
++
++ out_unpin:
++ if (IS_ERR(wh_dentry))
++ au_unpin(pin);
++ out:
++ return wh_dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++enum { Mknod, Symlink, Creat };
++struct simple_arg {
++ int type;
++ union {
++ struct {
++ int mode;
++ struct nameidata *nd;
++ } c;
++ struct {
++ const char *symname;
++ } s;
++ struct {
++ int mode;
++ dev_t dev;
++ } m;
++ } u;
++};
++
++static int add_simple(struct inode *dir, struct dentry *dentry,
++ struct simple_arg *arg)
++{
++ int err;
++ aufs_bindex_t bstart;
++ unsigned char created;
++ struct au_dtime dt;
++ struct au_pin pin;
++ struct path h_path;
++ struct dentry *wh_dentry, *parent;
++ struct inode *h_dir;
++ struct au_wr_dir_args wr_dir_args = {
++ .force_btgt = -1,
++ .flags = AuWrDir_ADD_ENTRY
++ };
++
++ IMustLock(dir);
++
++ parent = dentry->d_parent; /* dir inode is locked */
++ aufs_read_lock(dentry, AuLock_DW);
++ di_write_lock_parent(parent);
++ wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL, &pin,
++ &wr_dir_args);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out;
++
++ bstart = au_dbstart(dentry);
++ h_path.dentry = au_h_dptr(dentry, bstart);
++ h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
++ h_dir = au_pinned_h_dir(&pin);
++ switch (arg->type) {
++ case Creat:
++ err = vfsub_create(h_dir, &h_path, arg->u.c.mode);
++ break;
++ case Symlink:
++ err = vfsub_symlink(h_dir, &h_path, arg->u.s.symname);
++ break;
++ case Mknod:
++ err = vfsub_mknod(h_dir, &h_path, arg->u.m.mode, arg->u.m.dev);
++ break;
++ default:
++ BUG();
++ }
++ created = !err;
++ if (!err)
++ err = epilog(dir, bstart, wh_dentry, dentry);
++
++ /* revert */
++ if (unlikely(created && err && h_path.dentry->d_inode)) {
++ int rerr;
++ rerr = vfsub_unlink(h_dir, &h_path, /*force*/0);
++ if (rerr) {
++ AuIOErr("%.*s revert failure(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ err = -EIO;
++ }
++ au_dtime_revert(&dt);
++ d_drop(dentry);
++ }
++
++ au_unpin(&pin);
++ dput(wh_dentry);
++
++ out:
++ if (unlikely(err)) {
++ au_update_dbstart(dentry);
++ d_drop(dentry);
++ }
++ di_write_unlock(parent);
++ aufs_read_unlock(dentry, AuLock_DW);
++ return err;
++}
++
++int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
++{
++ struct simple_arg arg = {
++ .type = Mknod,
++ .u.m = {
++ .mode = mode,
++ .dev = dev
++ }
++ };
++ return add_simple(dir, dentry, &arg);
++}
++
++int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname)
++{
++ struct simple_arg arg = {
++ .type = Symlink,
++ .u.s.symname = symname
++ };
++ return add_simple(dir, dentry, &arg);
++}
++
++int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
++ struct nameidata *nd)
++{
++ struct simple_arg arg = {
++ .type = Creat,
++ .u.c = {
++ .mode = mode,
++ .nd = nd
++ }
++ };
++ return add_simple(dir, dentry, &arg);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_link_args {
++ aufs_bindex_t bdst, bsrc;
++ struct au_pin pin;
++ struct path h_path;
++ struct dentry *src_parent, *parent;
++};
++
++static int au_cpup_before_link(struct dentry *src_dentry,
++ struct au_link_args *a)
++{
++ int err;
++ struct dentry *h_src_dentry;
++ struct mutex *h_mtx;
++
++ di_read_lock_parent(a->src_parent, AuLock_IR);
++ err = au_test_and_cpup_dirs(src_dentry, a->bdst);
++ if (unlikely(err))
++ goto out;
++
++ h_src_dentry = au_h_dptr(src_dentry, a->bsrc);
++ h_mtx = &h_src_dentry->d_inode->i_mutex;
++ err = au_pin(&a->pin, src_dentry, a->bdst,
++ au_opt_udba(src_dentry->d_sb),
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ if (unlikely(err))
++ goto out;
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ err = au_sio_cpup_simple(src_dentry, a->bdst, -1,
++ AuCpup_DTIME /* | AuCpup_KEEPLINO */);
++ mutex_unlock(h_mtx);
++ au_unpin(&a->pin);
++
++ out:
++ di_read_unlock(a->src_parent, AuLock_IR);
++ return err;
++}
++
++static int au_cpup_or_link(struct dentry *src_dentry, struct au_link_args *a)
++{
++ int err;
++ unsigned char plink;
++ struct inode *h_inode, *inode;
++ struct dentry *h_src_dentry;
++ struct super_block *sb;
++
++ plink = 0;
++ h_inode = NULL;
++ sb = src_dentry->d_sb;
++ inode = src_dentry->d_inode;
++ if (au_ibstart(inode) <= a->bdst)
++ h_inode = au_h_iptr(inode, a->bdst);
++ if (!h_inode || !h_inode->i_nlink) {
++ /* copyup src_dentry as the name of dentry. */
++ au_set_dbstart(src_dentry, a->bdst);
++ au_set_h_dptr(src_dentry, a->bdst, dget(a->h_path.dentry));
++ h_inode = au_h_dptr(src_dentry, a->bsrc)->d_inode;
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ err = au_sio_cpup_single(src_dentry, a->bdst, a->bsrc, -1,
++ AuCpup_KEEPLINO, a->parent);
++ mutex_unlock(&h_inode->i_mutex);
++ au_set_h_dptr(src_dentry, a->bdst, NULL);
++ au_set_dbstart(src_dentry, a->bsrc);
++ } else {
++ /* the inode of src_dentry already exists on a.bdst branch */
++ h_src_dentry = d_find_alias(h_inode);
++ if (!h_src_dentry && au_plink_test(inode)) {
++ plink = 1;
++ h_src_dentry = au_plink_lkup(inode, a->bdst);
++ err = PTR_ERR(h_src_dentry);
++ if (IS_ERR(h_src_dentry))
++ goto out;
++
++ if (unlikely(!h_src_dentry->d_inode)) {
++ dput(h_src_dentry);
++ h_src_dentry = NULL;
++ }
++
++ }
++ if (h_src_dentry) {
++ err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
++ &a->h_path);
++ dput(h_src_dentry);
++ } else {
++ AuIOErr("no dentry found for hi%lu on b%d\n",
++ h_inode->i_ino, a->bdst);
++ err = -EIO;
++ }
++ }
++
++ if (!err && !plink)
++ au_plink_append(inode, a->bdst, a->h_path.dentry);
++
++out:
++ return err;
++}
++
++int aufs_link(struct dentry *src_dentry, struct inode *dir,
++ struct dentry *dentry)
++{
++ int err, rerr;
++ struct au_dtime dt;
++ struct au_link_args *a;
++ struct dentry *wh_dentry, *h_src_dentry;
++ struct inode *inode;
++ struct super_block *sb;
++ struct au_wr_dir_args wr_dir_args = {
++ /* .force_btgt = -1, */
++ .flags = AuWrDir_ADD_ENTRY
++ };
++
++ IMustLock(dir);
++ inode = src_dentry->d_inode;
++ IMustLock(inode);
++
++ err = -ENOMEM;
++ a = kzalloc(sizeof(*a), GFP_NOFS);
++ if (unlikely(!a))
++ goto out;
++
++ a->parent = dentry->d_parent; /* dir inode is locked */
++ aufs_read_and_write_lock2(dentry, src_dentry, /*AuLock_FLUSH*/0);
++ a->src_parent = dget_parent(src_dentry);
++ wr_dir_args.force_btgt = au_dbstart(src_dentry);
++
++ di_write_lock_parent(a->parent);
++ wr_dir_args.force_btgt = au_wbr(dentry, wr_dir_args.force_btgt);
++ wh_dentry = lock_hdir_lkup_wh(dentry, &dt, src_dentry, &a->pin,
++ &wr_dir_args);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out_unlock;
++
++ err = 0;
++ sb = dentry->d_sb;
++ a->bdst = au_dbstart(dentry);
++ a->h_path.dentry = au_h_dptr(dentry, a->bdst);
++ a->h_path.mnt = au_sbr_mnt(sb, a->bdst);
++ a->bsrc = au_dbstart(src_dentry);
++ if (au_opt_test(au_mntflags(sb), PLINK)) {
++ if (a->bdst < a->bsrc
++ /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */)
++ err = au_cpup_or_link(src_dentry, a);
++ else {
++ h_src_dentry = au_h_dptr(src_dentry, a->bdst);
++ err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
++ &a->h_path);
++ }
++ } else {
++ /*
++ * copyup src_dentry to the branch we process,
++ * and then link(2) to it.
++ */
++ if (a->bdst < a->bsrc
++ /* && h_src_dentry->d_sb != a->h_path.dentry->d_sb */) {
++ au_unpin(&a->pin);
++ di_write_unlock(a->parent);
++ err = au_cpup_before_link(src_dentry, a);
++ if (!err) {
++ di_write_lock_parent(a->parent);
++ err = au_pin(&a->pin, dentry, a->bdst,
++ au_opt_udba(sb),
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ if (unlikely(err))
++ goto out_wh;
++ }
++ }
++ if (!err) {
++ h_src_dentry = au_h_dptr(src_dentry, a->bdst);
++ err = vfsub_link(h_src_dentry, au_pinned_h_dir(&a->pin),
++ &a->h_path);
++ }
++ }
++ if (unlikely(err))
++ goto out_unpin;
++
++ if (wh_dentry) {
++ a->h_path.dentry = wh_dentry;
++ err = au_wh_unlink_dentry(au_pinned_h_dir(&a->pin), &a->h_path,
++ dentry);
++ if (unlikely(err))
++ goto out_revert;
++ }
++
++ dir->i_version++;
++ if (au_ibstart(dir) == au_dbstart(dentry))
++ au_cpup_attr_timesizes(dir);
++ inc_nlink(inode);
++ inode->i_ctime = dir->i_ctime;
++ if (!d_unhashed(a->h_path.dentry))
++ d_instantiate(dentry, au_igrab(inode));
++ else
++ /* some filesystem calls d_drop() */
++ d_drop(dentry);
++ goto out_unpin; /* success */
++
++ out_revert:
++ rerr = vfsub_unlink(au_pinned_h_dir(&a->pin), &a->h_path, /*force*/0);
++ if (!rerr)
++ goto out_dt;
++ AuIOErr("%.*s reverting failed(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ err = -EIO;
++ out_dt:
++ d_drop(dentry);
++ au_dtime_revert(&dt);
++ out_unpin:
++ au_unpin(&a->pin);
++ out_wh:
++ dput(wh_dentry);
++ out_unlock:
++ if (unlikely(err)) {
++ au_update_dbstart(dentry);
++ d_drop(dentry);
++ }
++ di_write_unlock(a->parent);
++ dput(a->src_parent);
++ aufs_read_and_write_unlock2(dentry, src_dentry);
++ kfree(a);
++ out:
++ return err;
++}
++
++int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
++{
++ int err, rerr;
++ aufs_bindex_t bindex;
++ unsigned char diropq;
++ struct au_pin pin;
++ struct path h_path;
++ struct dentry *wh_dentry, *parent, *opq_dentry;
++ struct mutex *h_mtx;
++ struct super_block *sb;
++ struct au_dtime dt;
++ struct au_wr_dir_args wr_dir_args = {
++ .force_btgt = -1,
++ .flags = AuWrDir_ADD_ENTRY | AuWrDir_ISDIR
++ };
++
++ IMustLock(dir);
++
++ aufs_read_lock(dentry, AuLock_DW);
++ parent = dentry->d_parent; /* dir inode is locked */
++ di_write_lock_parent(parent);
++ wh_dentry = lock_hdir_lkup_wh(dentry, &dt, /*src_dentry*/NULL, &pin,
++ &wr_dir_args);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out;
++
++ sb = dentry->d_sb;
++ bindex = au_dbstart(dentry);
++ h_path.dentry = au_h_dptr(dentry, bindex);
++ h_path.mnt = au_sbr_mnt(sb, bindex);
++ err = vfsub_mkdir(au_pinned_h_dir(&pin), &h_path, mode);
++ if (unlikely(err))
++ goto out_unlock;
++
++ /* make the dir opaque */
++ diropq = 0;
++ h_mtx = &h_path.dentry->d_inode->i_mutex;
++ if (wh_dentry
++ || au_opt_test(au_mntflags(sb), ALWAYS_DIROPQ)) {
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ opq_dentry = au_diropq_create(dentry, bindex);
++ mutex_unlock(h_mtx);
++ err = PTR_ERR(opq_dentry);
++ if (IS_ERR(opq_dentry))
++ goto out_dir;
++ dput(opq_dentry);
++ diropq = 1;
++ }
++
++ err = epilog(dir, bindex, wh_dentry, dentry);
++ if (!err) {
++ inc_nlink(dir);
++ goto out_unlock; /* success */
++ }
++
++ /* revert */
++ if (diropq) {
++ AuLabel(revert opq);
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ rerr = au_diropq_remove(dentry, bindex);
++ mutex_unlock(h_mtx);
++ if (rerr) {
++ AuIOErr("%.*s reverting diropq failed(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ err = -EIO;
++ }
++ }
++
++ out_dir:
++ AuLabel(revert dir);
++ rerr = vfsub_rmdir(au_pinned_h_dir(&pin), &h_path);
++ if (rerr) {
++ AuIOErr("%.*s reverting dir failed(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ err = -EIO;
++ }
++ d_drop(dentry);
++ au_dtime_revert(&dt);
++ out_unlock:
++ au_unpin(&pin);
++ dput(wh_dentry);
++ out:
++ if (unlikely(err)) {
++ au_update_dbstart(dentry);
++ d_drop(dentry);
++ }
++ di_write_unlock(parent);
++ aufs_read_unlock(dentry, AuLock_DW);
++ return err;
++}
+diff --git a/fs/aufs/i_op_del.c b/fs/aufs/i_op_del.c
+new file mode 100644
+index 0000000..a9756ae
+--- /dev/null
++++ b/fs/aufs/i_op_del.c
+@@ -0,0 +1,463 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode operations (del entry)
++ */
++
++#include "aufs.h"
++
++/*
++ * decide if a new whiteout for @dentry is necessary or not.
++ * when it is necessary, prepare the parent dir for the upper branch whose
++ * branch index is @bcpup for creation. the actual creation of the whiteout will
++ * be done by caller.
++ * return value:
++ * 0: wh is unnecessary
++ * plus: wh is necessary
++ * minus: error
++ */
++int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup)
++{
++ int need_wh, err;
++ aufs_bindex_t bstart;
++ struct super_block *sb;
++
++ sb = dentry->d_sb;
++ bstart = au_dbstart(dentry);
++ if (*bcpup < 0) {
++ *bcpup = bstart;
++ if (au_test_ro(sb, bstart, dentry->d_inode)) {
++ err = AuWbrCopyup(au_sbi(sb), dentry);
++ *bcpup = err;
++ if (unlikely(err < 0))
++ goto out;
++ }
++ } else
++ AuDebugOn(bstart < *bcpup
++ || au_test_ro(sb, *bcpup, dentry->d_inode));
++ AuDbg("bcpup %d, bstart %d\n", *bcpup, bstart);
++
++ if (*bcpup != bstart) {
++ err = au_cpup_dirs(dentry, *bcpup);
++ if (unlikely(err))
++ goto out;
++ need_wh = 1;
++ } else {
++ aufs_bindex_t old_bend, new_bend, bdiropq = -1;
++
++ old_bend = au_dbend(dentry);
++ if (isdir) {
++ bdiropq = au_dbdiropq(dentry);
++ au_set_dbdiropq(dentry, -1);
++ }
++ need_wh = au_lkup_dentry(dentry, bstart + 1, /*type*/0,
++ /*nd*/NULL);
++ err = need_wh;
++ if (isdir)
++ au_set_dbdiropq(dentry, bdiropq);
++ if (unlikely(err < 0))
++ goto out;
++ new_bend = au_dbend(dentry);
++ if (!need_wh && old_bend != new_bend) {
++ au_set_h_dptr(dentry, new_bend, NULL);
++ au_set_dbend(dentry, old_bend);
++ }
++ }
++ AuDbg("need_wh %d\n", need_wh);
++ err = need_wh;
++
++ out:
++ return err;
++}
++
++/*
++ * simple tests for the del-entry operations.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent, int isdir)
++{
++ int err;
++ umode_t h_mode;
++ struct dentry *h_dentry, *h_latest;
++ struct inode *h_inode;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ h_inode = h_dentry->d_inode;
++ if (dentry->d_inode) {
++ err = -ENOENT;
++ if (unlikely(!h_inode || !h_inode->i_nlink))
++ goto out;
++
++ h_mode = h_inode->i_mode;
++ if (!isdir) {
++ err = -EISDIR;
++ if (unlikely(S_ISDIR(h_mode)))
++ goto out;
++ } else if (unlikely(!S_ISDIR(h_mode))) {
++ err = -ENOTDIR;
++ goto out;
++ }
++ } else {
++ /* rename(2) case */
++ err = -EIO;
++ if (unlikely(h_inode))
++ goto out;
++ }
++
++ err = -ENOENT;
++ /* expected parent dir is locked */
++ if (unlikely(h_parent != h_dentry->d_parent))
++ goto out;
++ err = 0;
++
++ /*
++ * rmdir a dir may break the consistency on some filesystem.
++ * let's try heavy test.
++ */
++ err = -EACCES;
++ if (unlikely(au_test_h_perm(h_parent->d_inode, MAY_EXEC | MAY_WRITE)))
++ goto out;
++
++ h_latest = au_sio_lkup_one(&dentry->d_name, h_parent,
++ au_sbr(dentry->d_sb, bindex));
++ err = -EIO;
++ if (IS_ERR(h_latest))
++ goto out;
++ if (h_latest == h_dentry)
++ err = 0;
++ dput(h_latest);
++
++ out:
++ return err;
++}
++
++/*
++ * decide the branch where we operate for @dentry. the branch index will be set
++ * @rbcpup. after diciding it, 'pin' it and store the timestamps of the parent
++ * dir for reverting.
++ * when a new whiteout is necessary, create it.
++ */
++static struct dentry*
++lock_hdir_create_wh(struct dentry *dentry, int isdir, aufs_bindex_t *rbcpup,
++ struct au_dtime *dt, struct au_pin *pin)
++{
++ struct dentry *wh_dentry;
++ struct super_block *sb;
++ struct path h_path;
++ int err, need_wh;
++ unsigned int udba;
++ aufs_bindex_t bcpup;
++
++ need_wh = au_wr_dir_need_wh(dentry, isdir, rbcpup);
++ wh_dentry = ERR_PTR(need_wh);
++ if (unlikely(need_wh < 0))
++ goto out;
++
++ sb = dentry->d_sb;
++ udba = au_opt_udba(sb);
++ bcpup = *rbcpup;
++ err = au_pin(pin, dentry, bcpup, udba,
++ AuPin_DI_LOCKED | AuPin_MNT_WRITE);
++ wh_dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out;
++
++ h_path.dentry = au_pinned_h_parent(pin);
++ if (udba != AuOpt_UDBA_NONE
++ && au_dbstart(dentry) == bcpup) {
++ err = au_may_del(dentry, bcpup, h_path.dentry, isdir);
++ wh_dentry = ERR_PTR(err);
++ if (unlikely(err))
++ goto out_unpin;
++ }
++
++ h_path.mnt = au_sbr_mnt(sb, bcpup);
++ au_dtime_store(dt, au_pinned_parent(pin), &h_path);
++ wh_dentry = NULL;
++ if (!need_wh)
++ goto out; /* success, no need to create whiteout */
++
++ wh_dentry = au_wh_create(dentry, bcpup, h_path.dentry);
++ if (!IS_ERR(wh_dentry))
++ goto out; /* success */
++ /* returns with the parent is locked and wh_dentry is dget-ed */
++
++ out_unpin:
++ au_unpin(pin);
++ out:
++ return wh_dentry;
++}
++
++/*
++ * when removing a dir, rename it to a unique temporary whiteout-ed name first
++ * in order to be revertible and save time for removing many child whiteouts
++ * under the dir.
++ * returns 1 when there are too many child whiteout and caller should remove
++ * them asynchronously. returns 0 when the number of children is enough small to
++ * remove now or the branch fs is a remote fs.
++ * otherwise return an error.
++ */
++static int renwh_and_rmdir(struct dentry *dentry, aufs_bindex_t bindex,
++ struct au_nhash *whlist, struct inode *dir)
++{
++ int rmdir_later, err, dirwh;
++ struct dentry *h_dentry;
++ struct super_block *sb;
++
++ sb = dentry->d_sb;
++ h_dentry = au_h_dptr(dentry, bindex);
++ err = au_whtmp_ren(h_dentry, au_sbr(sb, bindex));
++ if (unlikely(err))
++ goto out;
++
++ /* stop monitoring */
++ au_hin_free(au_hi(dentry->d_inode, bindex));
++
++ if (!au_test_fs_remote(h_dentry->d_sb)) {
++ dirwh = au_sbi(sb)->si_dirwh;
++ rmdir_later = (dirwh <= 1);
++ if (!rmdir_later)
++ rmdir_later = au_nhash_test_longer_wh(whlist, bindex,
++ dirwh);
++ if (rmdir_later)
++ return rmdir_later;
++ }
++
++ err = au_whtmp_rmdir(dir, bindex, h_dentry, whlist);
++ if (unlikely(err)) {
++ AuIOErr("rmdir %.*s, b%d failed, %d. ignored\n",
++ AuDLNPair(h_dentry), bindex, err);
++ err = 0;
++ }
++
++ out:
++ return err;
++}
++
++/*
++ * final procedure for deleting a entry.
++ * maintain dentry and iattr.
++ */
++static void epilog(struct inode *dir, struct dentry *dentry,
++ aufs_bindex_t bindex)
++{
++ struct inode *inode;
++
++ /*
++ * even if this is not a dir,
++ * set S_DEAD here since we need to detect the dead inode.
++ */
++ inode = dentry->d_inode;
++ if (!inode->i_nlink)
++ inode->i_flags |= S_DEAD;
++ d_drop(dentry);
++ inode->i_ctime = dir->i_ctime;
++
++ if (atomic_read(&dentry->d_count) == 1) {
++ au_set_h_dptr(dentry, au_dbstart(dentry), NULL);
++ au_update_dbstart(dentry);
++ }
++ if (au_ibstart(dir) == bindex)
++ au_cpup_attr_timesizes(dir);
++ dir->i_version++;
++}
++
++/*
++ * when an error happened, remove the created whiteout and revert everything.
++ */
++static int do_revert(int err, struct inode *dir, aufs_bindex_t bwh,
++ struct dentry *wh_dentry, struct dentry *dentry,
++ struct au_dtime *dt)
++{
++ int rerr;
++ struct path h_path = {
++ .dentry = wh_dentry,
++ .mnt = au_sbr_mnt(dir->i_sb, bwh)
++ };
++
++ rerr = au_wh_unlink_dentry(au_h_iptr(dir, bwh), &h_path, dentry);
++ if (!rerr) {
++ au_set_dbwh(dentry, bwh);
++ au_dtime_revert(dt);
++ return 0;
++ }
++
++ AuIOErr("%.*s reverting whiteout failed(%d, %d)\n",
++ AuDLNPair(dentry), err, rerr);
++ return -EIO;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int aufs_unlink(struct inode *dir, struct dentry *dentry)
++{
++ int err;
++ aufs_bindex_t bwh, bindex, bstart;
++ struct au_dtime dt;
++ struct au_pin pin;
++ struct path h_path;
++ struct inode *inode, *h_dir;
++ struct dentry *parent, *wh_dentry;
++
++ IMustLock(dir);
++ inode = dentry->d_inode;
++ if (unlikely(!inode))
++ return -ENOENT; /* possible? */
++ IMustLock(inode);
++
++ aufs_read_lock(dentry, AuLock_DW);
++ parent = dentry->d_parent; /* dir inode is locked */
++ di_write_lock_parent(parent);
++
++ bstart = au_dbstart(dentry);
++ bwh = au_dbwh(dentry);
++ bindex = -1;
++ wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/0, &bindex, &dt, &pin);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out;
++
++ h_path.mnt = au_sbr_mnt(dentry->d_sb, bstart);
++ h_path.dentry = au_h_dptr(dentry, bstart);
++ dget(h_path.dentry);
++ if (bindex == bstart) {
++ h_dir = au_pinned_h_dir(&pin);
++ err = vfsub_unlink(h_dir, &h_path, /*force*/0);
++ } else {
++ /* dir inode is locked */
++ h_dir = wh_dentry->d_parent->d_inode;
++ IMustLock(h_dir);
++ err = 0;
++ }
++
++ if (!err) {
++ drop_nlink(inode);
++ epilog(dir, dentry, bindex);
++
++ /* update target timestamps */
++ if (bindex == bstart) {
++ vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++ inode->i_ctime = h_path.dentry->d_inode->i_ctime;
++ } else
++ /* todo: this timestamp may be reverted later */
++ inode->i_ctime = h_dir->i_ctime;
++ goto out_unlock; /* success */
++ }
++
++ /* revert */
++ if (wh_dentry) {
++ int rerr;
++
++ rerr = do_revert(err, dir, bwh, wh_dentry, dentry, &dt);
++ if (rerr)
++ err = rerr;
++ }
++
++ out_unlock:
++ au_unpin(&pin);
++ dput(wh_dentry);
++ dput(h_path.dentry);
++ out:
++ di_write_unlock(parent);
++ aufs_read_unlock(dentry, AuLock_DW);
++ return err;
++}
++
++int aufs_rmdir(struct inode *dir, struct dentry *dentry)
++{
++ int err, rmdir_later;
++ aufs_bindex_t bwh, bindex, bstart;
++ struct au_dtime dt;
++ struct au_pin pin;
++ struct inode *inode;
++ struct dentry *parent, *wh_dentry, *h_dentry;
++ struct au_whtmp_rmdir *args;
++
++ IMustLock(dir);
++ inode = dentry->d_inode;
++ err = -ENOENT; /* possible? */
++ if (unlikely(!inode))
++ goto out;
++ IMustLock(inode);
++
++ err = -ENOMEM;
++ args = au_whtmp_rmdir_alloc(dir->i_sb, GFP_NOFS);
++ if (unlikely(!args))
++ goto out;
++
++ aufs_read_lock(dentry, AuLock_DW | AuLock_FLUSH);
++ parent = dentry->d_parent; /* dir inode is locked */
++ di_write_lock_parent(parent);
++ err = au_test_empty(dentry, args->whlist);
++ if (unlikely(err))
++ goto out_args;
++
++ bstart = au_dbstart(dentry);
++ bwh = au_dbwh(dentry);
++ bindex = -1;
++ wh_dentry = lock_hdir_create_wh(dentry, /*isdir*/1, &bindex, &dt, &pin);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out_args;
++
++ h_dentry = au_h_dptr(dentry, bstart);
++ dget(h_dentry);
++ rmdir_later = 0;
++ if (bindex == bstart) {
++ err = renwh_and_rmdir(dentry, bstart, args->whlist, dir);
++ if (err > 0) {
++ rmdir_later = err;
++ err = 0;
++ }
++ } else {
++ /* stop monitoring */
++ au_hin_free(au_hi(inode, bstart));
++
++ /* dir inode is locked */
++ IMustLock(wh_dentry->d_parent->d_inode);
++ err = 0;
++ }
++
++ if (!err) {
++ clear_nlink(inode);
++ au_set_dbdiropq(dentry, -1);
++ epilog(dir, dentry, bindex);
++
++ if (rmdir_later) {
++ au_whtmp_kick_rmdir(dir, bstart, h_dentry, args);
++ args = NULL;
++ }
++
++ goto out_unlock; /* success */
++ }
++
++ /* revert */
++ AuLabel(revert);
++ if (wh_dentry) {
++ int rerr;
++
++ rerr = do_revert(err, dir, bwh, wh_dentry, dentry, &dt);
++ if (rerr)
++ err = rerr;
++ }
++
++ out_unlock:
++ au_unpin(&pin);
++ dput(wh_dentry);
++ dput(h_dentry);
++ out_args:
++ di_write_unlock(parent);
++ aufs_read_unlock(dentry, AuLock_DW);
++ if (args)
++ au_whtmp_rmdir_free(args);
++ out:
++ return err;
++}
+diff --git a/fs/aufs/i_op_ren.c b/fs/aufs/i_op_ren.c
+new file mode 100644
+index 0000000..3617d94
+--- /dev/null
++++ b/fs/aufs/i_op_ren.c
+@@ -0,0 +1,940 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode operation (rename entry)
++ * todo: this is crazy monster
++ */
++
++#include "aufs.h"
++
++enum { AuSRC, AuDST, AuSrcDst };
++enum { AuPARENT, AuCHILD, AuParentChild };
++
++#define AuRen_ISDIR 1
++#define AuRen_ISSAMEDIR (1 << 1)
++#define AuRen_WHSRC (1 << 2)
++#define AuRen_WHDST (1 << 3)
++#define AuRen_MNT_WRITE (1 << 4)
++#define AuRen_DT_DSTDIR (1 << 5)
++#define AuRen_DIROPQ (1 << 6)
++#define AuRen_CPUP (1 << 7)
++#define au_ftest_ren(flags, name) ((flags) & AuRen_##name)
++#define au_fset_ren(flags, name) { (flags) |= AuRen_##name; }
++#define au_fclr_ren(flags, name) { (flags) &= ~AuRen_##name; }
++
++struct au_ren_args {
++ struct {
++ struct dentry *dentry, *h_dentry, *parent, *h_parent,
++ *wh_dentry;
++ struct inode *dir, *inode;
++ struct au_hinode *hdir;
++ struct au_dtime dt[AuParentChild];
++ aufs_bindex_t bstart;
++ } sd[AuSrcDst];
++
++#define src_dentry sd[AuSRC].dentry
++#define src_dir sd[AuSRC].dir
++#define src_inode sd[AuSRC].inode
++#define src_h_dentry sd[AuSRC].h_dentry
++#define src_parent sd[AuSRC].parent
++#define src_h_parent sd[AuSRC].h_parent
++#define src_wh_dentry sd[AuSRC].wh_dentry
++#define src_hdir sd[AuSRC].hdir
++#define src_h_dir sd[AuSRC].hdir->hi_inode
++#define src_dt sd[AuSRC].dt
++#define src_bstart sd[AuSRC].bstart
++
++#define dst_dentry sd[AuDST].dentry
++#define dst_dir sd[AuDST].dir
++#define dst_inode sd[AuDST].inode
++#define dst_h_dentry sd[AuDST].h_dentry
++#define dst_parent sd[AuDST].parent
++#define dst_h_parent sd[AuDST].h_parent
++#define dst_wh_dentry sd[AuDST].wh_dentry
++#define dst_hdir sd[AuDST].hdir
++#define dst_h_dir sd[AuDST].hdir->hi_inode
++#define dst_dt sd[AuDST].dt
++#define dst_bstart sd[AuDST].bstart
++
++ struct dentry *h_trap;
++ struct au_branch *br;
++ struct au_hinode *src_hinode;
++ struct path h_path;
++ struct au_nhash *whlist;
++ aufs_bindex_t btgt;
++
++ unsigned int flags;
++
++ struct au_whtmp_rmdir *thargs;
++ struct dentry *h_dst;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * functions for reverting.
++ * when an error happened in a single rename systemcall, we should revert
++ * everything as if nothing happend.
++ * we don't need to revert the copied-up/down the parent dir since they are
++ * harmless.
++ */
++
++#define RevertFailure(fmt, args...) do { \
++ AuIOErr("revert failure: " fmt " (%d, %d)\n", \
++ ##args, err, rerr); \
++ err = -EIO; \
++} while (0)
++
++static void au_ren_rev_diropq(int err, struct au_ren_args *a)
++{
++ int rerr;
++
++ au_hin_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
++ rerr = au_diropq_remove(a->src_dentry, a->btgt);
++ au_hin_imtx_unlock(a->src_hinode);
++ if (rerr)
++ RevertFailure("remove diropq %.*s", AuDLNPair(a->src_dentry));
++}
++
++
++static void au_ren_rev_rename(int err, struct au_ren_args *a)
++{
++ int rerr;
++
++ a->h_path.dentry = au_lkup_one(&a->src_dentry->d_name, a->src_h_parent,
++ a->br, /*nd*/NULL);
++ rerr = PTR_ERR(a->h_path.dentry);
++ if (IS_ERR(a->h_path.dentry)) {
++ RevertFailure("au_lkup_one %.*s", AuDLNPair(a->src_dentry));
++ return;
++ }
++
++ rerr = vfsub_rename(a->dst_h_dir,
++ au_h_dptr(a->src_dentry, a->btgt),
++ a->src_h_dir, &a->h_path);
++ d_drop(a->h_path.dentry);
++ dput(a->h_path.dentry);
++ /* au_set_h_dptr(a->src_dentry, a->btgt, NULL); */
++ if (rerr)
++ RevertFailure("rename %.*s", AuDLNPair(a->src_dentry));
++}
++
++static void au_ren_rev_cpup(int err, struct au_ren_args *a)
++{
++ int rerr;
++
++ a->h_path.dentry = a->dst_h_dentry;
++ rerr = vfsub_unlink(a->dst_h_dir, &a->h_path, /*force*/0);
++ au_set_h_dptr(a->src_dentry, a->btgt, NULL);
++ au_set_dbstart(a->src_dentry, a->src_bstart);
++ if (rerr)
++ RevertFailure("unlink %.*s", AuDLNPair(a->dst_h_dentry));
++}
++
++
++static void au_ren_rev_whtmp(int err, struct au_ren_args *a)
++{
++ int rerr;
++
++ a->h_path.dentry = au_lkup_one(&a->dst_dentry->d_name, a->dst_h_parent,
++ a->br, /*nd*/NULL);
++ rerr = PTR_ERR(a->h_path.dentry);
++ if (IS_ERR(a->h_path.dentry)) {
++ RevertFailure("lookup %.*s", AuDLNPair(a->dst_dentry));
++ return;
++ }
++ if (a->h_path.dentry->d_inode) {
++ d_drop(a->h_path.dentry);
++ dput(a->h_path.dentry);
++ return;
++ }
++
++ rerr = vfsub_rename(a->dst_h_dir, a->h_dst, a->dst_h_dir, &a->h_path);
++ d_drop(a->h_path.dentry);
++ dput(a->h_path.dentry);
++ if (!rerr) {
++ au_set_h_dptr(a->dst_dentry, a->btgt, NULL);
++ au_set_h_dptr(a->dst_dentry, a->btgt, dget(a->h_dst));
++ } else
++ RevertFailure("rename %.*s", AuDLNPair(a->h_dst));
++}
++
++static void au_ren_rev_whsrc(int err, struct au_ren_args *a)
++{
++ int rerr;
++
++ a->h_path.dentry = a->src_wh_dentry;
++ rerr = au_wh_unlink_dentry(a->src_h_dir, &a->h_path, a->src_dentry);
++ if (rerr)
++ RevertFailure("unlink %.*s", AuDLNPair(a->src_wh_dentry));
++}
++
++static void au_ren_rev_drop(struct au_ren_args *a)
++{
++ struct dentry *d, *h_d;
++ int i;
++ aufs_bindex_t bend, bindex;
++
++ for (i = 0; i < AuSrcDst; i++) {
++ d = a->sd[i].dentry;
++ d_drop(d);
++ bend = au_dbend(d);
++ for (bindex = au_dbstart(d); bindex <= bend; bindex++) {
++ h_d = au_h_dptr(d, bindex);
++ if (h_d)
++ d_drop(h_d);
++ }
++ }
++
++ au_update_dbstart(a->dst_dentry);
++ if (a->thargs)
++ d_drop(a->h_dst);
++}
++#undef RevertFailure
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * when we have to copyup the renaming entry, do it with the rename-target name
++ * in order to minimize the cost (the later actual rename is unnecessary).
++ * otherwise rename it on the target branch.
++ */
++static int au_ren_or_cpup(struct au_ren_args *a)
++{
++ int err;
++ struct dentry *d;
++
++ d = a->src_dentry;
++ if (au_dbstart(d) == a->btgt) {
++ a->h_path.dentry = a->dst_h_dentry;
++ if (au_ftest_ren(a->flags, DIROPQ)
++ && au_dbdiropq(d) == a->btgt)
++ au_fclr_ren(a->flags, DIROPQ);
++ AuDebugOn(au_dbstart(d) != a->btgt);
++ err = vfsub_rename(a->src_h_dir, au_h_dptr(d, a->btgt),
++ a->dst_h_dir, &a->h_path);
++ } else {
++ struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
++
++ au_fset_ren(a->flags, CPUP);
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ au_set_dbstart(d, a->btgt);
++ au_set_h_dptr(d, a->btgt, dget(a->dst_h_dentry));
++ err = au_sio_cpup_single(d, a->btgt, a->src_bstart, -1,
++ !AuCpup_DTIME, a->dst_parent);
++ if (unlikely(err)) {
++ au_set_h_dptr(d, a->btgt, NULL);
++ au_set_dbstart(d, a->src_bstart);
++ }
++ mutex_unlock(h_mtx);
++ }
++
++ return err;
++}
++
++/* cf. aufs_rmdir() */
++static int au_ren_del_whtmp(struct au_ren_args *a)
++{
++ int err;
++ struct inode *dir;
++
++ dir = a->dst_dir;
++ if (!au_nhash_test_longer_wh(a->whlist, a->btgt,
++ au_sbi(dir->i_sb)->si_dirwh)
++ || au_test_fs_remote(a->h_dst->d_sb)) {
++ err = au_whtmp_rmdir(dir, a->btgt, a->h_dst, a->whlist);
++ if (unlikely(err))
++ AuWarn("failed removing whtmp dir %.*s (%d), "
++ "ignored.\n", AuDLNPair(a->h_dst), err);
++ } else {
++ au_nhash_wh_free(a->thargs->whlist, /*bend*/0);
++ a->thargs->whlist = a->whlist;
++ a->whlist = NULL;
++ au_whtmp_kick_rmdir(dir, a->btgt, a->h_dst, a->thargs);
++ dput(a->h_dst);
++ a->thargs = NULL;
++ }
++
++ return 0;
++}
++
++/* make it 'opaque' dir. */
++static int au_ren_diropq(struct au_ren_args *a)
++{
++ int err;
++ struct dentry *diropq;
++
++ err = 0;
++ a->src_hinode = au_hi(a->src_inode, a->btgt);
++ au_hin_imtx_lock_nested(a->src_hinode, AuLsc_I_CHILD);
++ diropq = au_diropq_create(a->src_dentry, a->btgt);
++ au_hin_imtx_unlock(a->src_hinode);
++ if (IS_ERR(diropq))
++ err = PTR_ERR(diropq);
++ dput(diropq);
++
++ return err;
++}
++
++static int do_rename(struct au_ren_args *a)
++{
++ int err;
++ struct dentry *d, *h_d;
++
++ /* prepare workqueue args for asynchronous rmdir */
++ h_d = a->dst_h_dentry;
++ if (au_ftest_ren(a->flags, ISDIR) && h_d->d_inode) {
++ err = -ENOMEM;
++ a->thargs = au_whtmp_rmdir_alloc(a->src_dentry->d_sb, GFP_NOFS);
++ if (unlikely(!a->thargs))
++ goto out;
++ a->h_dst = dget(h_d);
++ }
++
++ /* create whiteout for src_dentry */
++ if (au_ftest_ren(a->flags, WHSRC)) {
++ a->src_wh_dentry
++ = au_wh_create(a->src_dentry, a->btgt, a->src_h_parent);
++ err = PTR_ERR(a->src_wh_dentry);
++ if (IS_ERR(a->src_wh_dentry))
++ goto out_thargs;
++ }
++
++ /* lookup whiteout for dentry */
++ if (au_ftest_ren(a->flags, WHDST)) {
++ h_d = au_wh_lkup(a->dst_h_parent, &a->dst_dentry->d_name,
++ a->br);
++ err = PTR_ERR(h_d);
++ if (IS_ERR(h_d))
++ goto out_whsrc;
++ if (!h_d->d_inode)
++ dput(h_d);
++ else
++ a->dst_wh_dentry = h_d;
++ }
++
++ /* rename dentry to tmpwh */
++ if (a->thargs) {
++ err = au_whtmp_ren(a->dst_h_dentry, a->br);
++ if (unlikely(err))
++ goto out_whdst;
++
++ d = a->dst_dentry;
++ au_set_h_dptr(d, a->btgt, NULL);
++ err = au_lkup_neg(d, a->btgt);
++ if (unlikely(err))
++ goto out_whtmp;
++ a->dst_h_dentry = au_h_dptr(d, a->btgt);
++ }
++
++ /* cpup src */
++ if (a->dst_h_dentry->d_inode && a->src_bstart != a->btgt) {
++ struct mutex *h_mtx = &a->src_h_dentry->d_inode->i_mutex;
++
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ err = au_sio_cpup_simple(a->src_dentry, a->btgt, -1,
++ !AuCpup_DTIME);
++ mutex_unlock(h_mtx);
++ if (unlikely(err))
++ goto out_whtmp;
++ }
++
++ /* rename by vfs_rename or cpup */
++ d = a->dst_dentry;
++ if (au_ftest_ren(a->flags, ISDIR)
++ && (a->dst_wh_dentry
++ || au_dbdiropq(d) == a->btgt
++ /* hide the lower to keep xino */
++ || a->btgt < au_dbend(d)
++ || au_opt_test(au_mntflags(d->d_sb), ALWAYS_DIROPQ)))
++ au_fset_ren(a->flags, DIROPQ);
++ err = au_ren_or_cpup(a);
++ if (unlikely(err))
++ /* leave the copied-up one */
++ goto out_whtmp;
++
++ /* make dir opaque */
++ if (au_ftest_ren(a->flags, DIROPQ)) {
++ err = au_ren_diropq(a);
++ if (unlikely(err))
++ goto out_rename;
++ }
++
++ /* update target timestamps */
++ AuDebugOn(au_dbstart(a->src_dentry) != a->btgt);
++ a->h_path.dentry = au_h_dptr(a->src_dentry, a->btgt);
++ vfsub_update_h_iattr(&a->h_path, /*did*/NULL); /*ignore*/
++ a->src_inode->i_ctime = a->h_path.dentry->d_inode->i_ctime;
++
++ /* remove whiteout for dentry */
++ if (a->dst_wh_dentry) {
++ a->h_path.dentry = a->dst_wh_dentry;
++ err = au_wh_unlink_dentry(a->dst_h_dir, &a->h_path,
++ a->dst_dentry);
++ if (unlikely(err))
++ goto out_diropq;
++ }
++
++ /* remove whtmp */
++ if (a->thargs)
++ au_ren_del_whtmp(a); /* ignore this error */
++
++ err = 0;
++ goto out_success;
++
++ out_diropq:
++ if (au_ftest_ren(a->flags, DIROPQ))
++ au_ren_rev_diropq(err, a);
++ out_rename:
++ if (!au_ftest_ren(a->flags, CPUP))
++ au_ren_rev_rename(err, a);
++ else
++ au_ren_rev_cpup(err, a);
++ out_whtmp:
++ if (a->thargs)
++ au_ren_rev_whtmp(err, a);
++ out_whdst:
++ dput(a->dst_wh_dentry);
++ a->dst_wh_dentry = NULL;
++ out_whsrc:
++ if (a->src_wh_dentry)
++ au_ren_rev_whsrc(err, a);
++ au_ren_rev_drop(a);
++ out_success:
++ dput(a->src_wh_dentry);
++ dput(a->dst_wh_dentry);
++ out_thargs:
++ if (a->thargs) {
++ dput(a->h_dst);
++ au_whtmp_rmdir_free(a->thargs);
++ a->thargs = NULL;
++ }
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * test if @dentry dir can be rename destination or not.
++ * success means, it is a logically empty dir.
++ */
++static int may_rename_dstdir(struct dentry *dentry, struct au_nhash *whlist)
++{
++ return au_test_empty(dentry, whlist);
++}
++
++/*
++ * test if @dentry dir can be rename source or not.
++ * if it can, return 0 and @children is filled.
++ * success means,
++ * - it is a logically empty dir.
++ * - or, it exists on writable branch and has no children including whiteouts
++ * on the lower branch.
++ */
++static int may_rename_srcdir(struct dentry *dentry, aufs_bindex_t btgt)
++{
++ int err;
++ aufs_bindex_t bstart;
++
++ bstart = au_dbstart(dentry);
++ if (bstart != btgt) {
++ struct au_nhash *whlist;
++
++ whlist = au_nhash_alloc(dentry->d_sb, /*bend*/0, GFP_NOFS);
++ err = PTR_ERR(whlist);
++ if (IS_ERR(whlist))
++ goto out;
++ err = au_test_empty(dentry, whlist);
++ au_nhash_wh_free(whlist, /*bend*/0);
++ goto out;
++ }
++
++ if (bstart == au_dbtaildir(dentry))
++ return 0; /* success */
++
++ err = au_test_empty_lower(dentry);
++
++ out:
++ if (err == -ENOTEMPTY) {
++ AuWarn1("renaming dir who has child(ren) on multiple branches,"
++ " is not supported\n");
++ err = -EXDEV;
++ }
++ return err;
++}
++
++/* side effect: sets whlist and h_dentry */
++static int au_ren_may_dir(struct au_ren_args *a)
++{
++ int err;
++ struct dentry *d;
++
++ err = -ENOMEM;
++ d = a->dst_dentry;
++ a->whlist = au_nhash_alloc(d->d_sb, /*bend*/0, GFP_NOFS);
++ if (unlikely(!a->whlist))
++ goto out;
++
++ err = 0;
++ if (au_ftest_ren(a->flags, ISDIR) && a->dst_inode) {
++ au_set_dbstart(d, a->dst_bstart);
++ err = may_rename_dstdir(d, a->whlist);
++ au_set_dbstart(d, a->btgt);
++ }
++ a->dst_h_dentry = au_h_dptr(d, au_dbstart(d));
++ if (unlikely(err))
++ goto out;
++
++ d = a->src_dentry;
++ a->src_h_dentry = au_h_dptr(d, au_dbstart(d));
++ if (au_ftest_ren(a->flags, ISDIR)) {
++ err = may_rename_srcdir(d, a->btgt);
++ if (unlikely(err)) {
++ au_nhash_wh_free(a->whlist, /*bend*/0);
++ a->whlist = NULL;
++ }
++ }
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * simple tests for rename.
++ * following the checks in vfs, plus the parent-child relationship.
++ */
++static int au_may_ren(struct au_ren_args *a)
++{
++ int err, isdir;
++ struct inode *h_inode;
++
++ if (a->src_bstart == a->btgt) {
++ err = au_may_del(a->src_dentry, a->btgt, a->src_h_parent,
++ au_ftest_ren(a->flags, ISDIR));
++ if (unlikely(err))
++ goto out;
++ err = -EINVAL;
++ if (unlikely(a->src_h_dentry == a->h_trap))
++ goto out;
++ }
++
++ err = 0;
++ if (a->dst_bstart != a->btgt)
++ goto out;
++
++ err = -EIO;
++ h_inode = a->dst_h_dentry->d_inode;
++ isdir = !!au_ftest_ren(a->flags, ISDIR);
++ if (!a->dst_dentry->d_inode) {
++ if (unlikely(h_inode))
++ goto out;
++ err = au_may_add(a->dst_dentry, a->btgt, a->dst_h_parent,
++ isdir);
++ } else {
++ if (unlikely(!h_inode || !h_inode->i_nlink))
++ goto out;
++ err = au_may_del(a->dst_dentry, a->btgt, a->dst_h_parent,
++ isdir);
++ if (unlikely(err))
++ goto out;
++ err = -ENOTEMPTY;
++ if (unlikely(a->dst_h_dentry == a->h_trap))
++ goto out;
++ err = 0;
++ }
++
++ out:
++ if (unlikely(err == -ENOENT || err == -EEXIST))
++ err = -EIO;
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * locking order
++ * (VFS)
++ * - src_dir and dir by lock_rename()
++ * - inode if exitsts
++ * (aufs)
++ * - lock all
++ * + src_dentry and dentry by aufs_read_and_write_lock2() which calls,
++ * + si_read_lock
++ * + di_write_lock2_child()
++ * + di_write_lock_child()
++ * + ii_write_lock_child()
++ * + di_write_lock_child2()
++ * + ii_write_lock_child2()
++ * + src_parent and parent
++ * + di_write_lock_parent()
++ * + ii_write_lock_parent()
++ * + di_write_lock_parent2()
++ * + ii_write_lock_parent2()
++ * + lower src_dir and dir by vfsub_lock_rename()
++ * + verify the every relationships between child and parent. if any
++ * of them failed, unlock all and return -EBUSY.
++ */
++static void au_ren_unlock(struct au_ren_args *a)
++{
++ struct super_block *sb;
++
++ sb = a->dst_dentry->d_sb;
++ if (au_ftest_ren(a->flags, MNT_WRITE))
++ mnt_drop_write(a->br->br_mnt);
++ vfsub_unlock_rename(a->src_h_parent, a->src_hdir,
++ a->dst_h_parent, a->dst_hdir);
++}
++
++static int au_ren_lock(struct au_ren_args *a)
++{
++ int err;
++ unsigned int udba;
++
++ err = 0;
++ a->src_h_parent = au_h_dptr(a->src_parent, a->btgt);
++ a->src_hdir = au_hi(a->src_dir, a->btgt);
++ a->dst_h_parent = au_h_dptr(a->dst_parent, a->btgt);
++ a->dst_hdir = au_hi(a->dst_dir, a->btgt);
++ a->h_trap = vfsub_lock_rename(a->src_h_parent, a->src_hdir,
++ a->dst_h_parent, a->dst_hdir);
++ udba = au_opt_udba(a->src_dentry->d_sb);
++ if (au_dbstart(a->src_dentry) == a->btgt)
++ err = au_h_verify(a->src_h_dentry, udba,
++ a->src_h_parent->d_inode, a->src_h_parent,
++ a->br);
++ if (!err && au_dbstart(a->dst_dentry) == a->btgt)
++ err = au_h_verify(a->dst_h_dentry, udba,
++ a->dst_h_parent->d_inode, a->dst_h_parent,
++ a->br);
++ if (!err) {
++ err = mnt_want_write(a->br->br_mnt);
++ if (unlikely(err))
++ goto out_unlock;
++ au_fset_ren(a->flags, MNT_WRITE);
++ goto out; /* success */
++ }
++
++ err = au_busy_or_stale();
++
++ out_unlock:
++ au_ren_unlock(a);
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static void au_ren_refresh_dir(struct au_ren_args *a)
++{
++ struct inode *dir;
++
++ dir = a->dst_dir;
++ dir->i_version++;
++ if (au_ftest_ren(a->flags, ISDIR)) {
++ /* is this updating defined in POSIX? */
++ au_cpup_attr_timesizes(a->src_inode);
++ au_cpup_attr_nlink(dir, /*force*/1);
++ if (a->dst_inode) {
++ clear_nlink(a->dst_inode);
++ au_cpup_attr_timesizes(a->dst_inode);
++ }
++ }
++ if (au_ibstart(dir) == a->btgt)
++ au_cpup_attr_timesizes(dir);
++
++ if (au_ftest_ren(a->flags, ISSAMEDIR))
++ return;
++
++ dir = a->src_dir;
++ dir->i_version++;
++ if (au_ftest_ren(a->flags, ISDIR))
++ au_cpup_attr_nlink(dir, /*force*/1);
++ if (au_ibstart(dir) == a->btgt)
++ au_cpup_attr_timesizes(dir);
++}
++
++static void au_ren_refresh(struct au_ren_args *a)
++{
++ aufs_bindex_t bend, bindex;
++ struct dentry *d, *h_d;
++ struct inode *i, *h_i;
++ struct super_block *sb;
++
++ d = a->src_dentry;
++ au_set_dbwh(d, -1);
++ bend = au_dbend(d);
++ for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
++ h_d = au_h_dptr(d, bindex);
++ if (h_d)
++ au_set_h_dptr(d, bindex, NULL);
++ }
++ au_set_dbend(d, a->btgt);
++
++ sb = d->d_sb;
++ i = a->src_inode;
++ if (au_opt_test(au_mntflags(sb), PLINK) && au_plink_test(i))
++ return; /* success */
++
++ bend = au_ibend(i);
++ for (bindex = a->btgt + 1; bindex <= bend; bindex++) {
++ h_i = au_h_iptr(i, bindex);
++ if (h_i) {
++ au_xino_write0(sb, bindex, h_i->i_ino, 0);
++ /* ignore this error */
++ au_set_h_iptr(i, bindex, NULL, 0);
++ }
++ }
++ au_set_ibend(i, a->btgt);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* mainly for link(2) and rename(2) */
++int au_wbr(struct dentry *dentry, aufs_bindex_t btgt)
++{
++ aufs_bindex_t bdiropq, bwh;
++ struct dentry *parent;
++ struct au_branch *br;
++
++ parent = dentry->d_parent;
++ IMustLock(parent->d_inode); /* dir is locked */
++
++ bdiropq = au_dbdiropq(parent);
++ bwh = au_dbwh(dentry);
++ br = au_sbr(dentry->d_sb, btgt);
++ if (au_br_rdonly(br)
++ || (0 <= bdiropq && bdiropq < btgt)
++ || (0 <= bwh && bwh < btgt))
++ btgt = -1;
++
++ AuDbg("btgt %d\n", btgt);
++ return btgt;
++}
++
++/* sets src_bstart, dst_bstart and btgt */
++static int au_ren_wbr(struct au_ren_args *a)
++{
++ int err;
++ struct au_wr_dir_args wr_dir_args = {
++ /* .force_btgt = -1, */
++ .flags = AuWrDir_ADD_ENTRY
++ };
++
++ a->src_bstart = au_dbstart(a->src_dentry);
++ a->dst_bstart = au_dbstart(a->dst_dentry);
++ if (au_ftest_ren(a->flags, ISDIR))
++ au_fset_wrdir(wr_dir_args.flags, ISDIR);
++ wr_dir_args.force_btgt = a->src_bstart;
++ if (a->dst_inode && a->dst_bstart < a->src_bstart)
++ wr_dir_args.force_btgt = a->dst_bstart;
++ wr_dir_args.force_btgt = au_wbr(a->dst_dentry, wr_dir_args.force_btgt);
++ err = au_wr_dir(a->dst_dentry, a->src_dentry, &wr_dir_args);
++ a->btgt = err;
++
++ return err;
++}
++
++static void au_ren_dt(struct au_ren_args *a)
++{
++ a->h_path.dentry = a->src_h_parent;
++ au_dtime_store(a->src_dt + AuPARENT, a->src_parent, &a->h_path);
++ if (!au_ftest_ren(a->flags, ISSAMEDIR)) {
++ a->h_path.dentry = a->dst_h_parent;
++ au_dtime_store(a->dst_dt + AuPARENT, a->dst_parent, &a->h_path);
++ }
++
++ au_fclr_ren(a->flags, DT_DSTDIR);
++ if (!au_ftest_ren(a->flags, ISDIR))
++ return;
++
++ a->h_path.dentry = a->src_h_dentry;
++ au_dtime_store(a->src_dt + AuCHILD, a->src_dentry, &a->h_path);
++ if (a->dst_h_dentry->d_inode) {
++ au_fset_ren(a->flags, DT_DSTDIR);
++ a->h_path.dentry = a->dst_h_dentry;
++ au_dtime_store(a->dst_dt + AuCHILD, a->dst_dentry, &a->h_path);
++ }
++}
++
++static void au_ren_rev_dt(int err, struct au_ren_args *a)
++{
++ struct dentry *h_d;
++ struct mutex *h_mtx;
++
++ au_dtime_revert(a->src_dt + AuPARENT);
++ if (!au_ftest_ren(a->flags, ISSAMEDIR))
++ au_dtime_revert(a->dst_dt + AuPARENT);
++
++ if (au_ftest_ren(a->flags, ISDIR) && err != -EIO) {
++ h_d = a->src_dt[AuCHILD].dt_h_path.dentry;
++ h_mtx = &h_d->d_inode->i_mutex;
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ au_dtime_revert(a->src_dt + AuCHILD);
++ mutex_unlock(h_mtx);
++
++ if (au_ftest_ren(a->flags, DT_DSTDIR)) {
++ h_d = a->dst_dt[AuCHILD].dt_h_path.dentry;
++ h_mtx = &h_d->d_inode->i_mutex;
++ mutex_lock_nested(h_mtx, AuLsc_I_CHILD);
++ au_dtime_revert(a->dst_dt + AuCHILD);
++ mutex_unlock(h_mtx);
++ }
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++int aufs_rename(struct inode *_src_dir, struct dentry *_src_dentry,
++ struct inode *_dst_dir, struct dentry *_dst_dentry)
++{
++ int err;
++ /* reduce stack space */
++ struct au_ren_args *a;
++
++ IMustLock(_src_dir);
++ IMustLock(_dst_dir);
++
++ err = -ENOMEM;
++ BUILD_BUG_ON(sizeof(*a) > PAGE_SIZE);
++ a = kzalloc(sizeof(*a), GFP_NOFS);
++ if (unlikely(!a))
++ goto out;
++
++ a->src_dir = _src_dir;
++ a->src_dentry = _src_dentry;
++ a->src_inode = a->src_dentry->d_inode;
++ a->src_parent = a->src_dentry->d_parent; /* dir inode is locked */
++ a->dst_dir = _dst_dir;
++ a->dst_dentry = _dst_dentry;
++ a->dst_inode = a->dst_dentry->d_inode;
++ a->dst_parent = a->dst_dentry->d_parent; /* dir inode is locked */
++ if (a->dst_inode) {
++ IMustLock(a->dst_inode);
++ au_igrab(a->dst_inode);
++ }
++
++ err = -ENOTDIR;
++ if (S_ISDIR(a->src_inode->i_mode)) {
++ au_fset_ren(a->flags, ISDIR);
++ if (unlikely(a->dst_inode && !S_ISDIR(a->dst_inode->i_mode)))
++ goto out_free;
++ aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
++ AuLock_DIR | AuLock_FLUSH);
++ } else
++ aufs_read_and_write_lock2(a->dst_dentry, a->src_dentry,
++ AuLock_FLUSH);
++
++ au_fset_ren(a->flags, ISSAMEDIR); /* temporary */
++ di_write_lock_parent(a->dst_parent);
++
++ /* which branch we process */
++ err = au_ren_wbr(a);
++ if (unlikely(err < 0))
++ goto out_unlock;
++ a->br = au_sbr(a->dst_dentry->d_sb, a->btgt);
++ a->h_path.mnt = a->br->br_mnt;
++
++ /* are they available to be renamed */
++ err = au_ren_may_dir(a);
++ if (unlikely(err))
++ goto out_unlock;
++
++ /* prepare the writable parent dir on the same branch */
++ if (a->dst_bstart == a->btgt) {
++ au_fset_ren(a->flags, WHDST);
++ } else {
++ err = au_cpup_dirs(a->dst_dentry, a->btgt);
++ if (unlikely(err))
++ goto out_children;
++ }
++
++ if (a->src_dir != a->dst_dir) {
++ /*
++ * this temporary unlock is safe,
++ * because both dir->i_mutex are locked.
++ */
++ di_write_unlock(a->dst_parent);
++ di_write_lock_parent(a->src_parent);
++ err = au_wr_dir_need_wh(a->src_dentry,
++ au_ftest_ren(a->flags, ISDIR),
++ &a->btgt);
++ di_write_unlock(a->src_parent);
++ di_write_lock2_parent(a->src_parent, a->dst_parent, /*isdir*/1);
++ au_fclr_ren(a->flags, ISSAMEDIR);
++ } else
++ err = au_wr_dir_need_wh(a->src_dentry,
++ au_ftest_ren(a->flags, ISDIR),
++ &a->btgt);
++ if (unlikely(err < 0))
++ goto out_children;
++ if (err)
++ au_fset_ren(a->flags, WHSRC);
++
++ /* lock them all */
++ err = au_ren_lock(a);
++ if (unlikely(err))
++ goto out_children;
++
++ if (!au_opt_test(au_mntflags(a->dst_dir->i_sb), UDBA_NONE)) {
++ err = au_may_ren(a);
++ if (unlikely(err))
++ goto out_hdir;
++ }
++
++ /* store timestamps to be revertible */
++ au_ren_dt(a);
++
++ /* here we go */
++ err = do_rename(a);
++ if (unlikely(err))
++ goto out_dt;
++
++ /* update dir attributes */
++ au_ren_refresh_dir(a);
++
++ /* dput/iput all lower dentries */
++ au_ren_refresh(a);
++
++ goto out_hdir; /* success */
++
++ out_dt:
++ au_ren_rev_dt(err, a);
++ out_hdir:
++ au_ren_unlock(a);
++ out_children:
++ if (a->whlist)
++ au_nhash_wh_free(a->whlist, /*bend*/0);
++ out_unlock:
++ if (unlikely(err && au_ftest_ren(a->flags, ISDIR))) {
++ au_update_dbstart(a->dst_dentry);
++ d_drop(a->dst_dentry);
++ }
++ if (!err) {
++ d_move(a->src_dentry, a->dst_dentry);
++ if (a->dst_inode
++ && (a->dst_inode->i_nlink <= 1
++ || au_ftest_ren(a->flags, ISDIR)))
++ a->dst_inode->i_flags |= S_DEAD;
++ }
++ if (au_ftest_ren(a->flags, ISSAMEDIR))
++ di_write_unlock(a->dst_parent);
++ else
++ di_write_unlock2(a->src_parent, a->dst_parent);
++ aufs_read_and_write_unlock2(a->dst_dentry, a->src_dentry);
++ out_free:
++ iput(a->dst_inode);
++ if (a->thargs)
++ au_whtmp_rmdir_free(a->thargs);
++ kfree(a);
++ out:
++ return err;
++}
+diff --git a/fs/aufs/iinfo.c b/fs/aufs/iinfo.c
+new file mode 100644
+index 0000000..b1cff91
+--- /dev/null
++++ b/fs/aufs/iinfo.c
+@@ -0,0 +1,262 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode private data
++ */
++
++#include "aufs.h"
++
++struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex)
++{
++ struct inode *h_inode;
++
++ h_inode = au_ii(inode)->ii_hinode[0 + bindex].hi_inode;
++ AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
++ return h_inode;
++}
++
++/* todo: hard/soft set? */
++void au_set_ibstart(struct inode *inode, aufs_bindex_t bindex)
++{
++ struct au_iinfo *iinfo = au_ii(inode);
++ struct inode *h_inode;
++
++ iinfo->ii_bstart = bindex;
++ h_inode = iinfo->ii_hinode[bindex + 0].hi_inode;
++ if (h_inode)
++ au_cpup_igen(inode, h_inode);
++}
++
++void au_hiput(struct au_hinode *hinode)
++{
++ au_hin_free(hinode);
++ dput(hinode->hi_whdentry);
++ iput(hinode->hi_inode);
++}
++
++unsigned int au_hi_flags(struct inode *inode, int isdir)
++{
++ unsigned int flags;
++ const unsigned int mnt_flags = au_mntflags(inode->i_sb);
++
++ flags = 0;
++ if (au_opt_test(mnt_flags, XINO))
++ au_fset_hi(flags, XINO);
++ if (isdir && au_opt_test(mnt_flags, UDBA_HINOTIFY))
++ au_fset_hi(flags, HINOTIFY);
++ return flags;
++}
++
++void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
++ struct inode *h_inode, unsigned int flags)
++{
++ struct au_hinode *hinode;
++ struct inode *hi;
++ struct au_iinfo *iinfo = au_ii(inode);
++
++ hinode = iinfo->ii_hinode + bindex;
++ hi = hinode->hi_inode;
++ AuDebugOn(h_inode && atomic_read(&h_inode->i_count) <= 0);
++ AuDebugOn(h_inode && hi);
++
++ if (hi)
++ au_hiput(hinode);
++ hinode->hi_inode = h_inode;
++ if (h_inode) {
++ int err;
++ struct super_block *sb = inode->i_sb;
++ struct au_branch *br;
++
++ if (bindex == iinfo->ii_bstart)
++ au_cpup_igen(inode, h_inode);
++ br = au_sbr(sb, bindex);
++ hinode->hi_id = br->br_id;
++ if (au_ftest_hi(flags, XINO)) {
++ err = au_xino_write(sb, bindex, h_inode->i_ino,
++ inode->i_ino);
++ if (unlikely(err))
++ AuIOErr1("failed au_xino_write() %d\n", err);
++ }
++
++ if (au_ftest_hi(flags, HINOTIFY)
++ && au_br_hinotifyable(br->br_perm)) {
++ err = au_hin_alloc(hinode, inode, h_inode);
++ if (unlikely(err))
++ AuIOErr1("au_hin_alloc() %d\n", err);
++ }
++ }
++}
++
++void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
++ struct dentry *h_wh)
++{
++ struct au_hinode *hinode;
++
++ hinode = au_ii(inode)->ii_hinode + bindex;
++ AuDebugOn(hinode->hi_whdentry);
++ hinode->hi_whdentry = h_wh;
++}
++
++void au_update_iigen(struct inode *inode)
++{
++ atomic_set(&au_ii(inode)->ii_generation, au_sigen(inode->i_sb));
++ /* smp_mb(); */ /* atomic_set */
++}
++
++/* it may be called at remount time, too */
++void au_update_brange(struct inode *inode, int do_put_zero)
++{
++ struct au_iinfo *iinfo;
++
++ iinfo = au_ii(inode);
++ if (!iinfo || iinfo->ii_bstart < 0)
++ return;
++
++ if (do_put_zero) {
++ aufs_bindex_t bindex;
++
++ for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
++ bindex++) {
++ struct inode *h_i;
++
++ h_i = iinfo->ii_hinode[0 + bindex].hi_inode;
++ if (h_i && !h_i->i_nlink)
++ au_set_h_iptr(inode, bindex, NULL, 0);
++ }
++ }
++
++ iinfo->ii_bstart = -1;
++ while (++iinfo->ii_bstart <= iinfo->ii_bend)
++ if (iinfo->ii_hinode[0 + iinfo->ii_bstart].hi_inode)
++ break;
++ if (iinfo->ii_bstart > iinfo->ii_bend) {
++ iinfo->ii_bstart = -1;
++ iinfo->ii_bend = -1;
++ return;
++ }
++
++ iinfo->ii_bend++;
++ while (0 <= --iinfo->ii_bend)
++ if (iinfo->ii_hinode[0 + iinfo->ii_bend].hi_inode)
++ break;
++ AuDebugOn(iinfo->ii_bstart > iinfo->ii_bend || iinfo->ii_bend < 0);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_iinfo_init(struct inode *inode)
++{
++ struct au_iinfo *iinfo;
++ struct super_block *sb;
++ int nbr, i;
++
++ sb = inode->i_sb;
++ iinfo = &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
++ nbr = au_sbend(sb) + 1;
++ if (unlikely(nbr <= 0))
++ nbr = 1;
++ iinfo->ii_hinode = kcalloc(nbr, sizeof(*iinfo->ii_hinode), GFP_NOFS);
++ if (iinfo->ii_hinode) {
++ for (i = 0; i < nbr; i++)
++ iinfo->ii_hinode[i].hi_id = -1;
++
++ atomic_set(&iinfo->ii_generation, au_sigen(sb));
++ /* smp_mb(); */ /* atomic_set */
++ init_rwsem(&iinfo->ii_rwsem);
++ iinfo->ii_bstart = -1;
++ iinfo->ii_bend = -1;
++ iinfo->ii_vdir = NULL;
++ return 0;
++ }
++ return -ENOMEM;
++}
++
++int au_ii_realloc(struct au_iinfo *iinfo, int nbr)
++{
++ int err, sz;
++ struct au_hinode *hip;
++
++ err = -ENOMEM;
++ sz = sizeof(*hip) * (iinfo->ii_bend + 1);
++ if (!sz)
++ sz = sizeof(*hip);
++ hip = au_kzrealloc(iinfo->ii_hinode, sz, sizeof(*hip) * nbr, GFP_NOFS);
++ if (hip) {
++ iinfo->ii_hinode = hip;
++ err = 0;
++ }
++
++ return err;
++}
++
++static int au_iinfo_write0(struct super_block *sb, struct au_hinode *hinode,
++ ino_t ino)
++{
++ int err;
++ aufs_bindex_t bindex;
++ unsigned char locked;
++
++ err = 0;
++ locked = !!si_noflush_read_trylock(sb);
++ bindex = au_br_index(sb, hinode->hi_id);
++ if (bindex >= 0)
++ err = au_xino_write0(sb, bindex, hinode->hi_inode->i_ino, ino);
++ /* error action? */
++ if (locked)
++ si_read_unlock(sb);
++ return err;
++}
++
++void au_iinfo_fin(struct inode *inode)
++{
++ ino_t ino;
++ aufs_bindex_t bend;
++ unsigned char unlinked = !inode->i_nlink || IS_DEADDIR(inode);
++ struct au_iinfo *iinfo;
++ struct au_hinode *hi;
++ struct super_block *sb;
++
++ if (unlinked) {
++ int err = au_xigen_inc(inode);
++ if (unlikely(err))
++ AuWarn1("failed resetting i_generation, %d\n", err);
++ }
++
++ iinfo = au_ii(inode);
++ /* bad_inode case */
++ if (!iinfo)
++ return;
++
++ if (iinfo->ii_vdir)
++ au_vdir_free(iinfo->ii_vdir);
++
++ if (iinfo->ii_bstart >= 0) {
++ sb = inode->i_sb;
++ ino = 0;
++ if (unlinked)
++ ino = inode->i_ino;
++ hi = iinfo->ii_hinode + iinfo->ii_bstart;
++ bend = iinfo->ii_bend;
++ while (iinfo->ii_bstart++ <= bend) {
++ if (hi->hi_inode) {
++ if (unlinked || !hi->hi_inode->i_nlink) {
++ au_iinfo_write0(sb, hi, ino);
++ /* ignore this error */
++ ino = 0;
++ }
++ au_hiput(hi);
++ }
++ hi++;
++ }
++ }
++
++ kfree(iinfo->ii_hinode);
++ au_rwsem_destroy(&iinfo->ii_rwsem);
++}
+diff --git a/fs/aufs/inode.c b/fs/aufs/inode.c
+new file mode 100644
+index 0000000..c4a962b
+--- /dev/null
++++ b/fs/aufs/inode.c
+@@ -0,0 +1,356 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode functions
++ */
++
++#include "aufs.h"
++
++static void au_refresh_hinode_attr(struct inode *inode, int do_version)
++{
++ au_cpup_attr_all(inode, /*force*/0);
++ au_update_iigen(inode);
++ if (do_version)
++ inode->i_version++;
++}
++
++int au_refresh_hinode_self(struct inode *inode, int do_attr)
++{
++ int err;
++ aufs_bindex_t bindex, new_bindex;
++ unsigned char update;
++ struct inode *first;
++ struct au_hinode *p, *q, tmp;
++ struct super_block *sb;
++ struct au_iinfo *iinfo;
++
++ update = 0;
++ sb = inode->i_sb;
++ iinfo = au_ii(inode);
++ err = au_ii_realloc(iinfo, au_sbend(sb) + 1);
++ if (unlikely(err))
++ goto out;
++
++ p = iinfo->ii_hinode + iinfo->ii_bstart;
++ first = p->hi_inode;
++ err = 0;
++ for (bindex = iinfo->ii_bstart; bindex <= iinfo->ii_bend;
++ bindex++, p++) {
++ if (!p->hi_inode)
++ continue;
++
++ new_bindex = au_br_index(sb, p->hi_id);
++ if (new_bindex == bindex)
++ continue;
++
++ if (new_bindex < 0) {
++ update++;
++ au_hiput(p);
++ p->hi_inode = NULL;
++ continue;
++ }
++
++ if (new_bindex < iinfo->ii_bstart)
++ iinfo->ii_bstart = new_bindex;
++ if (iinfo->ii_bend < new_bindex)
++ iinfo->ii_bend = new_bindex;
++ /* swap two lower inode, and loop again */
++ q = iinfo->ii_hinode + new_bindex;
++ tmp = *q;
++ *q = *p;
++ *p = tmp;
++ if (tmp.hi_inode) {
++ bindex--;
++ p--;
++ }
++ }
++ au_update_brange(inode, /*do_put_zero*/0);
++ if (do_attr)
++ au_refresh_hinode_attr(inode, update && S_ISDIR(inode->i_mode));
++
++ out:
++ return err;
++}
++
++int au_refresh_hinode(struct inode *inode, struct dentry *dentry)
++{
++ int err, update;
++ unsigned int flags;
++ aufs_bindex_t bindex, bend;
++ unsigned char isdir;
++ struct inode *first;
++ struct au_hinode *p;
++ struct au_iinfo *iinfo;
++
++ err = au_refresh_hinode_self(inode, /*do_attr*/0);
++ if (unlikely(err))
++ goto out;
++
++ update = 0;
++ iinfo = au_ii(inode);
++ p = iinfo->ii_hinode + iinfo->ii_bstart;
++ first = p->hi_inode;
++ isdir = S_ISDIR(inode->i_mode);
++ flags = au_hi_flags(inode, isdir);
++ bend = au_dbend(dentry);
++ for (bindex = au_dbstart(dentry); bindex <= bend; bindex++) {
++ struct inode *h_i;
++ struct dentry *h_d;
++
++ h_d = au_h_dptr(dentry, bindex);
++ if (!h_d || !h_d->d_inode)
++ continue;
++
++ if (iinfo->ii_bstart <= bindex && bindex <= iinfo->ii_bend) {
++ h_i = au_h_iptr(inode, bindex);
++ if (h_i) {
++ if (h_i == h_d->d_inode)
++ continue;
++ err = -EIO;
++ break;
++ }
++ }
++ if (bindex < iinfo->ii_bstart)
++ iinfo->ii_bstart = bindex;
++ if (iinfo->ii_bend < bindex)
++ iinfo->ii_bend = bindex;
++ au_set_h_iptr(inode, bindex, au_igrab(h_d->d_inode), flags);
++ update = 1;
++ }
++ au_update_brange(inode, /*do_put_zero*/0);
++
++ if (unlikely(err))
++ goto out;
++
++ au_refresh_hinode_attr(inode, update && isdir);
++
++ out:
++ return err;
++}
++
++static int set_inode(struct inode *inode, struct dentry *dentry)
++{
++ int err;
++ unsigned int flags;
++ umode_t mode;
++ aufs_bindex_t bindex, bstart, btail;
++ unsigned char isdir;
++ struct dentry *h_dentry;
++ struct inode *h_inode;
++ struct au_iinfo *iinfo;
++
++ err = 0;
++ isdir = 0;
++ bstart = au_dbstart(dentry);
++ h_inode = au_h_dptr(dentry, bstart)->d_inode;
++ mode = h_inode->i_mode;
++ switch (mode & S_IFMT) {
++ case S_IFREG:
++ btail = au_dbtail(dentry);
++ inode->i_op = &aufs_iop;
++ inode->i_fop = &aufs_file_fop;
++ inode->i_mapping->a_ops = &aufs_aop;
++ break;
++ case S_IFDIR:
++ isdir = 1;
++ btail = au_dbtaildir(dentry);
++ inode->i_op = &aufs_dir_iop;
++ inode->i_fop = &aufs_dir_fop;
++ break;
++ case S_IFLNK:
++ btail = au_dbtail(dentry);
++ inode->i_op = &aufs_symlink_iop;
++ break;
++ case S_IFBLK:
++ case S_IFCHR:
++ case S_IFIFO:
++ case S_IFSOCK:
++ btail = au_dbtail(dentry);
++ inode->i_op = &aufs_iop;
++ init_special_inode(inode, mode, h_inode->i_rdev);
++ break;
++ default:
++ AuIOErr("Unknown file type 0%o\n", mode);
++ err = -EIO;
++ goto out;
++ }
++
++ flags = au_hi_flags(inode, isdir);
++ iinfo = au_ii(inode);
++ iinfo->ii_bstart = bstart;
++ iinfo->ii_bend = btail;
++ for (bindex = bstart; bindex <= btail; bindex++) {
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (h_dentry)
++ au_set_h_iptr(inode, bindex,
++ au_igrab(h_dentry->d_inode), flags);
++ }
++ au_cpup_attr_all(inode, /*force*/1);
++
++ out:
++ return err;
++}
++
++/* successful returns with iinfo write_locked */
++static int reval_inode(struct inode *inode, struct dentry *dentry, int *matched)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ struct inode *h_inode, *h_dinode;
++
++ *matched = 0;
++
++ /*
++ * before this function, if aufs got any iinfo lock, it must be only
++ * one, the parent dir.
++ * it can happen by UDBA and the obsoleted inode number.
++ */
++ err = -EIO;
++ if (unlikely(inode->i_ino == parent_ino(dentry)))
++ goto out;
++
++ ii_write_lock_new_child(inode);
++ if (unlikely(IS_DEADDIR(inode)))
++ goto out_unlock;
++
++ err = 0;
++ h_dinode = au_h_dptr(dentry, au_dbstart(dentry))->d_inode;
++ bend = au_ibend(inode);
++ for (bindex = au_ibstart(inode); bindex <= bend; bindex++) {
++ h_inode = au_h_iptr(inode, bindex);
++ if (h_inode && h_inode == h_dinode) {
++ *matched = 1;
++ err = 0;
++ if (au_iigen(inode) != au_digen(dentry))
++ err = au_refresh_hinode(inode, dentry);
++ break;
++ }
++ }
++
++ out_unlock:
++ if (unlikely(err))
++ ii_write_unlock(inode);
++ out:
++ return err;
++}
++
++/* successful returns with iinfo write_locked */
++/* todo: return with unlocked? */
++struct inode *au_new_inode(struct dentry *dentry, int must_new)
++{
++ struct inode *inode;
++ struct dentry *h_dentry;
++ struct super_block *sb;
++ ino_t h_ino, ino;
++ int err, match;
++ aufs_bindex_t bstart;
++
++ sb = dentry->d_sb;
++ bstart = au_dbstart(dentry);
++ h_dentry = au_h_dptr(dentry, bstart);
++ h_ino = h_dentry->d_inode->i_ino;
++ err = au_xino_read(sb, bstart, h_ino, &ino);
++ inode = ERR_PTR(err);
++ if (unlikely(err))
++ goto out;
++ new_ino:
++ if (!ino) {
++ ino = au_xino_new_ino(sb);
++ if (unlikely(!ino)) {
++ inode = ERR_PTR(-EIO);
++ goto out;
++ }
++ }
++
++ AuDbg("i%lu\n", (unsigned long)ino);
++ inode = au_iget_locked(sb, ino);
++ err = PTR_ERR(inode);
++ if (IS_ERR(inode))
++ goto out;
++
++ AuDbg("%lx, new %d\n", inode->i_state, !!(inode->i_state & I_NEW));
++ if (inode->i_state & I_NEW) {
++ ii_write_lock_new_child(inode);
++ err = set_inode(inode, dentry);
++ unlock_new_inode(inode);
++ if (!err)
++ goto out; /* success */
++
++ iget_failed(inode);
++ ii_write_unlock(inode);
++ goto out_iput;
++ } else if (!must_new) {
++ err = reval_inode(inode, dentry, &match);
++ if (!err)
++ goto out; /* success */
++ else if (match)
++ goto out_iput;
++ }
++
++ if (unlikely(au_test_fs_unique_ino(h_dentry->d_inode)))
++ AuWarn1("Un-notified UDBA or repeatedly renamed dir,"
++ " b%d, %s, %.*s, hi%lu, i%lu.\n",
++ bstart, au_sbtype(h_dentry->d_sb), AuDLNPair(dentry),
++ (unsigned long)h_ino, (unsigned long)ino);
++ ino = 0;
++ err = au_xino_write0(sb, bstart, h_ino, 0);
++ if (!err) {
++ iput(inode);
++ goto new_ino;
++ }
++
++ out_iput:
++ iput(inode);
++ inode = ERR_PTR(err);
++ out:
++ return inode;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
++ struct inode *inode)
++{
++ int err;
++
++ err = au_br_rdonly(au_sbr(sb, bindex));
++
++ /* pseudo-link after flushed may happen out of bounds */
++ if (!err
++ && inode
++ && au_ibstart(inode) <= bindex
++ && bindex <= au_ibend(inode)) {
++ /*
++ * permission check is unnecessary since vfsub routine
++ * will be called later
++ */
++ struct inode *hi = au_h_iptr(inode, bindex);
++ if (hi)
++ err = IS_IMMUTABLE(hi) ? -EROFS : 0;
++ }
++
++ return err;
++}
++
++int au_test_h_perm(struct inode *h_inode, int mask)
++{
++ if (!current_fsuid())
++ return 0;
++ return inode_permission(h_inode, mask);
++}
++
++int au_test_h_perm_sio(struct inode *h_inode, int mask)
++{
++ if (au_test_nfs(h_inode->i_sb)
++ && (mask & MAY_WRITE)
++ && S_ISDIR(h_inode->i_mode))
++ mask |= MAY_READ; /* force permission check */
++ return au_test_h_perm(h_inode, mask);
++}
+diff --git a/fs/aufs/inode.h b/fs/aufs/inode.h
+new file mode 100644
+index 0000000..ffda951
+--- /dev/null
++++ b/fs/aufs/inode.h
+@@ -0,0 +1,471 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * inode operations
++ */
++
++#ifndef __AUFS_INODE_H__
++#define __AUFS_INODE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/inotify.h>
++#include <linux/namei.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++
++struct au_hinotify {
++#ifdef CONFIG_AUFS_HINOTIFY
++ struct inotify_watch hin_watch;
++ struct inode *hin_aufs_inode; /* no get/put */
++#endif
++};
++
++struct au_hinode {
++ struct inode *hi_inode;
++ aufs_bindex_t hi_id;
++#ifdef CONFIG_AUFS_HINOTIFY
++ struct au_hinotify *hi_notify;
++#endif
++
++ /* reference to the copied-up whiteout with get/put */
++ struct dentry *hi_whdentry;
++};
++
++struct au_vdir;
++struct au_iinfo {
++ atomic_t ii_generation;
++ struct super_block *ii_hsb1; /* no get/put */
++
++ struct rw_semaphore ii_rwsem;
++ aufs_bindex_t ii_bstart, ii_bend;
++ __u32 ii_higen;
++ struct au_hinode *ii_hinode;
++ struct au_vdir *ii_vdir;
++};
++
++struct au_icntnr {
++ struct au_iinfo iinfo;
++ struct inode vfs_inode;
++};
++
++/* au_pin flags */
++#define AuPin_DI_LOCKED 1
++#define AuPin_MNT_WRITE (1 << 1)
++#define au_ftest_pin(flags, name) ((flags) & AuPin_##name)
++#define au_fset_pin(flags, name) { (flags) |= AuPin_##name; }
++#define au_fclr_pin(flags, name) { (flags) &= ~AuPin_##name; }
++
++struct au_pin {
++ /* input */
++ struct dentry *dentry;
++ unsigned int udba;
++ unsigned char lsc_di, lsc_hi, flags;
++ aufs_bindex_t bindex;
++
++ /* output */
++ struct dentry *parent;
++ struct au_hinode *hdir;
++ struct vfsmount *h_mnt;
++};
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_iinfo *au_ii(struct inode *inode)
++{
++ struct au_iinfo *iinfo;
++
++ iinfo = &(container_of(inode, struct au_icntnr, vfs_inode)->iinfo);
++ if (iinfo->ii_hinode)
++ return iinfo;
++ return NULL; /* debugging bad_inode case */
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* inode.c */
++int au_refresh_hinode_self(struct inode *inode, int do_attr);
++int au_refresh_hinode(struct inode *inode, struct dentry *dentry);
++struct inode *au_new_inode(struct dentry *dentry, int must_new);
++int au_test_ro(struct super_block *sb, aufs_bindex_t bindex,
++ struct inode *inode);
++int au_test_h_perm(struct inode *h_inode, int mask);
++int au_test_h_perm_sio(struct inode *h_inode, int mask);
++
++/* i_op.c */
++extern struct inode_operations aufs_iop, aufs_symlink_iop, aufs_dir_iop;
++
++/* au_wr_dir flags */
++#define AuWrDir_ADD_ENTRY 1
++#define AuWrDir_ISDIR (1 << 1)
++#define au_ftest_wrdir(flags, name) ((flags) & AuWrDir_##name)
++#define au_fset_wrdir(flags, name) { (flags) |= AuWrDir_##name; }
++#define au_fclr_wrdir(flags, name) { (flags) &= ~AuWrDir_##name; }
++
++struct au_wr_dir_args {
++ aufs_bindex_t force_btgt;
++ unsigned char flags;
++};
++int au_wr_dir(struct dentry *dentry, struct dentry *src_dentry,
++ struct au_wr_dir_args *args);
++
++struct dentry *au_pinned_h_parent(struct au_pin *pin);
++void au_pin_init(struct au_pin *pin, struct dentry *dentry,
++ aufs_bindex_t bindex, int lsc_di, int lsc_hi,
++ unsigned int udba, unsigned char flags);
++int au_pin(struct au_pin *pin, struct dentry *dentry, aufs_bindex_t bindex,
++ unsigned int udba, unsigned char flags) __must_check;
++int au_do_pin(struct au_pin *pin) __must_check;
++void au_unpin(struct au_pin *pin);
++
++/* i_op_add.c */
++int au_may_add(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent, int isdir);
++int aufs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev);
++int aufs_symlink(struct inode *dir, struct dentry *dentry, const char *symname);
++int aufs_create(struct inode *dir, struct dentry *dentry, int mode,
++ struct nameidata *nd);
++int aufs_link(struct dentry *src_dentry, struct inode *dir,
++ struct dentry *dentry);
++int aufs_mkdir(struct inode *dir, struct dentry *dentry, int mode);
++
++/* i_op_del.c */
++int au_wr_dir_need_wh(struct dentry *dentry, int isdir, aufs_bindex_t *bcpup);
++int au_may_del(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent, int isdir);
++int aufs_unlink(struct inode *dir, struct dentry *dentry);
++int aufs_rmdir(struct inode *dir, struct dentry *dentry);
++
++/* i_op_ren.c */
++int au_wbr(struct dentry *dentry, aufs_bindex_t btgt);
++int aufs_rename(struct inode *src_dir, struct dentry *src_dentry,
++ struct inode *dir, struct dentry *dentry);
++
++/* iinfo.c */
++struct inode *au_h_iptr(struct inode *inode, aufs_bindex_t bindex);
++void au_hiput(struct au_hinode *hinode);
++void au_set_ibstart(struct inode *inode, aufs_bindex_t bindex);
++void au_set_hi_wh(struct inode *inode, aufs_bindex_t bindex,
++ struct dentry *h_wh);
++unsigned int au_hi_flags(struct inode *inode, int isdir);
++
++/* hinode flags */
++#define AuHi_XINO 1
++#define AuHi_HINOTIFY (1 << 1)
++#define au_ftest_hi(flags, name) ((flags) & AuHi_##name)
++#define au_fset_hi(flags, name) { (flags) |= AuHi_##name; }
++#define au_fclr_hi(flags, name) { (flags) &= ~AuHi_##name; }
++
++#ifndef CONFIG_AUFS_HINOTIFY
++#undef AuHi_HINOTIFY
++#define AuHi_HINOTIFY 0
++#endif
++
++void au_set_h_iptr(struct inode *inode, aufs_bindex_t bindex,
++ struct inode *h_inode, unsigned int flags);
++
++void au_update_iigen(struct inode *inode);
++void au_update_brange(struct inode *inode, int do_put_zero);
++
++int au_iinfo_init(struct inode *inode);
++void au_iinfo_fin(struct inode *inode);
++int au_ii_realloc(struct au_iinfo *iinfo, int nbr);
++
++/* plink.c */
++void au_plink_block_maintain(struct super_block *sb);
++#ifdef CONFIG_AUFS_DEBUG
++void au_plink_list(struct super_block *sb);
++#else
++static inline void au_plink_list(struct super_block *sb)
++{
++ /* nothing */
++}
++#endif
++int au_plink_test(struct inode *inode);
++struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex);
++void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
++ struct dentry *h_dentry);
++void au_plink_put(struct super_block *sb);
++void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id);
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for iinfo */
++enum {
++ AuLsc_II_CHILD, /* child first */
++ AuLsc_II_CHILD2, /* rename(2), link(2), and cpup at hinotify */
++ AuLsc_II_CHILD3, /* copyup dirs */
++ AuLsc_II_PARENT, /* see AuLsc_I_PARENT in vfsub.h */
++ AuLsc_II_PARENT2,
++ AuLsc_II_PARENT3, /* copyup dirs */
++ AuLsc_II_NEW_CHILD
++};
++
++/*
++ * ii_read_lock_child, ii_write_lock_child,
++ * ii_read_lock_child2, ii_write_lock_child2,
++ * ii_read_lock_child3, ii_write_lock_child3,
++ * ii_read_lock_parent, ii_write_lock_parent,
++ * ii_read_lock_parent2, ii_write_lock_parent2,
++ * ii_read_lock_parent3, ii_write_lock_parent3,
++ * ii_read_lock_new_child, ii_write_lock_new_child,
++ */
++#define AuReadLockFunc(name, lsc) \
++static inline void ii_read_lock_##name(struct inode *i) \
++{ \
++ down_read_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
++}
++
++#define AuWriteLockFunc(name, lsc) \
++static inline void ii_write_lock_##name(struct inode *i) \
++{ \
++ down_write_nested(&au_ii(i)->ii_rwsem, AuLsc_II_##lsc); \
++}
++
++#define AuRWLockFuncs(name, lsc) \
++ AuReadLockFunc(name, lsc) \
++ AuWriteLockFunc(name, lsc)
++
++AuRWLockFuncs(child, CHILD);
++AuRWLockFuncs(child2, CHILD2);
++AuRWLockFuncs(child3, CHILD3);
++AuRWLockFuncs(parent, PARENT);
++AuRWLockFuncs(parent2, PARENT2);
++AuRWLockFuncs(parent3, PARENT3);
++AuRWLockFuncs(new_child, NEW_CHILD);
++
++#undef AuReadLockFunc
++#undef AuWriteLockFunc
++#undef AuRWLockFuncs
++
++/*
++ * ii_read_unlock, ii_write_unlock, ii_downgrade_lock
++ */
++AuSimpleUnlockRwsemFuncs(ii, struct inode *i, &au_ii(i)->ii_rwsem);
++
++#define IiMustNoWaiters(i) AuRwMustNoWaiters(&au_ii(i)->ii_rwsem)
++
++/* ---------------------------------------------------------------------- */
++
++static inline unsigned int au_iigen(struct inode *inode)
++{
++ return atomic_read(&au_ii(inode)->ii_generation);
++}
++
++/* tiny test for inode number */
++/* tmpfs generation is too rough */
++static inline int au_test_higen(struct inode *inode, struct inode *h_inode)
++{
++ struct au_iinfo *iinfo;
++
++ iinfo = au_ii(inode);
++ return !(iinfo->ii_hsb1 == h_inode->i_sb
++ && iinfo->ii_higen == h_inode->i_generation);
++}
++
++static inline struct inode *au_igrab(struct inode *inode)
++{
++ if (inode) {
++ AuDebugOn(!atomic_read(&inode->i_count));
++ atomic_inc(&inode->i_count);
++ }
++ return inode;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline aufs_bindex_t au_ii_br_id(struct inode *inode,
++ aufs_bindex_t bindex)
++{
++ return au_ii(inode)->ii_hinode[0 + bindex].hi_id;
++}
++
++static inline aufs_bindex_t au_ibstart(struct inode *inode)
++{
++ return au_ii(inode)->ii_bstart;
++}
++
++static inline aufs_bindex_t au_ibend(struct inode *inode)
++{
++ return au_ii(inode)->ii_bend;
++}
++
++static inline struct au_vdir *au_ivdir(struct inode *inode)
++{
++ return au_ii(inode)->ii_vdir;
++}
++
++static inline struct dentry *au_hi_wh(struct inode *inode, aufs_bindex_t bindex)
++{
++ return au_ii(inode)->ii_hinode[0 + bindex].hi_whdentry;
++}
++
++static inline void au_set_ibend(struct inode *inode, aufs_bindex_t bindex)
++{
++ au_ii(inode)->ii_bend = bindex;
++}
++
++static inline void au_set_ivdir(struct inode *inode, struct au_vdir *vdir)
++{
++ au_ii(inode)->ii_vdir = vdir;
++}
++
++static inline struct au_hinode *au_hi(struct inode *inode, aufs_bindex_t bindex)
++{
++ return au_ii(inode)->ii_hinode + bindex;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct dentry *au_pinned_parent(struct au_pin *pin)
++{
++ if (pin)
++ return pin->parent;
++ return NULL;
++}
++
++static inline struct inode *au_pinned_h_dir(struct au_pin *pin)
++{
++ if (pin && pin->hdir)
++ return pin->hdir->hi_inode;
++ return NULL;
++}
++
++static inline struct au_hinode *au_pinned_hdir(struct au_pin *pin)
++{
++ if (pin)
++ return pin->hdir;
++ return NULL;
++}
++
++static inline void au_pin_set_dentry(struct au_pin *pin, struct dentry *dentry)
++{
++ if (pin)
++ pin->dentry = dentry;
++}
++
++static inline void au_pin_set_parent_lflag(struct au_pin *pin,
++ unsigned char lflag)
++{
++ if (pin) {
++ /* dirty macros require brackets */
++ if (lflag) {
++ au_fset_pin(pin->flags, DI_LOCKED);
++ } else {
++ au_fclr_pin(pin->flags, DI_LOCKED);
++ }
++ }
++}
++
++static inline void au_pin_set_parent(struct au_pin *pin, struct dentry *parent)
++{
++ if (pin) {
++ dput(pin->parent);
++ pin->parent = dget(parent);
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_HINOTIFY
++/* hinotify.c */
++int au_hin_alloc(struct au_hinode *hinode, struct inode *inode,
++ struct inode *h_inode);
++void au_hin_free(struct au_hinode *hinode);
++void au_hin_ctl(struct au_hinode *hinode, int do_set);
++void au_reset_hinotify(struct inode *inode, unsigned int flags);
++
++int __init au_hinotify_init(void);
++void au_hinotify_fin(void);
++
++static inline
++void au_hin_init(struct au_hinode *hinode, struct au_hinotify *val)
++{
++ hinode->hi_notify = val;
++}
++
++static inline void au_iigen_dec(struct inode *inode)
++{
++ atomic_dec(&au_ii(inode)->ii_generation);
++}
++
++#else
++static inline
++int au_hin_alloc(struct au_hinode *hinode __maybe_unused,
++ struct inode *inode __maybe_unused,
++ struct inode *h_inode __maybe_unused)
++{
++ return -EOPNOTSUPP;
++}
++
++static inline void au_hin_free(struct au_hinode *hinode __maybe_unused)
++{
++ /* nothing */
++}
++
++static inline void au_hin_ctl(struct au_hinode *hinode __maybe_unused,
++ int do_set __maybe_unused)
++{
++ /* nothing */
++}
++
++static inline void au_reset_hinotify(struct inode *inode __maybe_unused,
++ unsigned int flags __maybe_unused)
++{
++ /* nothing */
++}
++
++static inline int au_hinotify_init(void)
++{
++ return 0;
++}
++
++#define au_hinotify_fin() do {} while (0)
++
++static inline
++void au_hin_init(struct au_hinode *hinode __maybe_unused,
++ struct au_hinotify *val __maybe_unused)
++{
++ /* empty */
++}
++#endif /* CONFIG_AUFS_HINOTIFY */
++
++static inline void au_hin_suspend(struct au_hinode *hdir)
++{
++ au_hin_ctl(hdir, /*do_set*/0);
++}
++
++static inline void au_hin_resume(struct au_hinode *hdir)
++{
++ au_hin_ctl(hdir, /*do_set*/1);
++}
++
++static inline void au_hin_imtx_lock(struct au_hinode *hdir)
++{
++ mutex_lock(&hdir->hi_inode->i_mutex);
++ au_hin_suspend(hdir);
++}
++
++static inline void au_hin_imtx_lock_nested(struct au_hinode *hdir,
++ unsigned int sc __maybe_unused)
++{
++ mutex_lock_nested(&hdir->hi_inode->i_mutex, sc);
++ au_hin_suspend(hdir);
++}
++
++static inline void au_hin_imtx_unlock(struct au_hinode *hdir)
++{
++ au_hin_resume(hdir);
++ mutex_unlock(&hdir->hi_inode->i_mutex);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_INODE_H__ */
+diff --git a/fs/aufs/ioctl.c b/fs/aufs/ioctl.c
+new file mode 100644
+index 0000000..ff17d77
+--- /dev/null
++++ b/fs/aufs/ioctl.c
+@@ -0,0 +1,54 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++long aufs_ioctl_dir(struct file *file, unsigned int cmd,
++ unsigned long arg __maybe_unused)
++{
++ long err;
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++
++ err = -EACCES;
++ if (!capable(CAP_SYS_ADMIN))
++ goto out;
++
++ err = 0;
++ sb = file->f_dentry->d_sb;
++ sbinfo = au_sbi(sb);
++ switch (cmd) {
++ case AUFS_CTL_PLINK_MAINT:
++ /*
++ * pseudo-link maintenance mode,
++ * cleared by aufs_release_dir()
++ */
++ si_write_lock(sb);
++ if (!au_ftest_si(sbinfo, MAINTAIN_PLINK)) {
++ au_fset_si(sbinfo, MAINTAIN_PLINK);
++ au_fi(file)->fi_maintain_plink = 1;
++ } else
++ err = -EBUSY;
++ si_write_unlock(sb);
++ break;
++ case AUFS_CTL_PLINK_CLEAN:
++ if (au_opt_test(sbinfo->si_mntflags, PLINK)) {
++ aufs_write_lock(sb->s_root);
++ au_plink_put(sb);
++ aufs_write_unlock(sb->s_root);
++ }
++ break;
++ default:
++ err = -EINVAL;
++ }
++
++ out:
++ return err;
++}
+diff --git a/fs/aufs/loop.c b/fs/aufs/loop.c
+new file mode 100644
+index 0000000..84a940f
+--- /dev/null
++++ b/fs/aufs/loop.c
+@@ -0,0 +1,46 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * support for loopback block device as a branch
++ */
++
++#include <linux/loop.h>
++#include "aufs.h"
++
++/*
++ * test if two lower dentries have overlapping branches.
++ */
++int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_d1,
++ struct dentry *h_d2)
++{
++ struct inode *h_inode;
++ struct loop_device *l;
++
++ h_inode = h_d1->d_inode;
++ if (MAJOR(h_inode->i_sb->s_dev) != LOOP_MAJOR)
++ return 0;
++
++ l = h_inode->i_sb->s_bdev->bd_disk->private_data;
++ h_d1 = l->lo_backing_file->f_dentry;
++ /* h_d1 can be local NFS. in this case aufs cannot detect the loop */
++ if (unlikely(h_d1->d_sb == sb))
++ return 1;
++ return !!au_test_subdir(h_d1, h_d2);
++}
++
++/* true if a kernel thread named 'loop[0-9].*' accesses a file */
++int au_test_loopback_kthread(void)
++{
++ const char c = current->comm[4];
++
++ return current->mm == NULL
++ && '0' <= c && c <= '9'
++ && strncmp(current->comm, "loop", 4) == 0;
++}
+diff --git a/fs/aufs/loop.h b/fs/aufs/loop.h
+new file mode 100644
+index 0000000..1c0ee40
+--- /dev/null
++++ b/fs/aufs/loop.h
+@@ -0,0 +1,41 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * support for loopback mount as a branch
++ */
++
++#ifndef __AUFS_LOOP_H__
++#define __AUFS_LOOP_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++
++#ifdef CONFIG_AUFS_BDEV_LOOP
++/* loop.c */
++int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_d1,
++ struct dentry *h_d2);
++int au_test_loopback_kthread(void);
++#else
++static inline
++int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_d1,
++ struct dentry *h_d2)
++{
++ return 0;
++}
++
++static inline int au_test_loopback_kthread(void)
++{
++ return 0;
++}
++#endif /* BLK_DEV_LOOP */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_LOOP_H__ */
+diff --git a/fs/aufs/magic.mk b/fs/aufs/magic.mk
+new file mode 100644
+index 0000000..6258f57
+--- /dev/null
++++ b/fs/aufs/magic.mk
+@@ -0,0 +1,58 @@
++
++# defined in ${srctree}/fs/fuse/inode.c
++# tristate
++ifdef CONFIG_FUSE_FS
++ccflags-y += -DFUSE_SUPER_MAGIC=0x65735546
++endif
++
++# defined in ${srctree}/fs/ocfs2/ocfs2_fs.h
++# tristate
++ifdef CONFIG_OCFS2_FS
++ccflags-y += -DOCFS2_SUPER_MAGIC=0x7461636f
++endif
++
++# defined in ${srctree}/fs/ocfs2/dlm/userdlm.h
++# tristate
++ifdef CONFIG_OCFS2_FS_O2CB
++ccflags-y += -DDLMFS_MAGIC=0x76a9f425
++endif
++
++# defined in ${srctree}/fs/ramfs/inode.c
++# always true
++ccflags-y += -DRAMFS_MAGIC=0x858458f6
++
++# defined in ${srctree}/fs/cifs/cifsfs.c
++# tristate
++ifdef CONFIG_CIFS_FS
++ccflags-y += -DCIFS_MAGIC_NUMBER=0xFF534D42
++endif
++
++# defined in ${srctree}/fs/xfs/xfs_sb.h
++# tristate
++ifdef CONFIG_XFS_FS
++ccflags-y += -DXFS_SB_MAGIC=0x58465342
++endif
++
++# defined in ${srctree}/fs/configfs/mount.c
++# tristate
++ifdef CONFIG_CONFIGFS_FS
++ccflags-y += -DCONFIGFS_MAGIC=0x62656570
++endif
++
++# defined in ${srctree}/fs/9p/v9fs.h
++# tristate
++ifdef CONFIG_9P_FS
++ccflags-y += -DV9FS_MAGIC=0x01021997
++endif
++
++# defined in ${srctree}/fs/ubifs/ubifs.h
++# tristate
++ifdef CONFIG_UBIFS_FS
++ccflags-y += -DUBIFS_SUPER_MAGIC=0x24051905
++endif
++
++# defined in ${srctree}/fs/debugfs/inode.c
++# boolean
++ifdef CONFIG_DEBUG_FS
++ccflags-y += -DDEBUGFS_MAGIC=0x64626720
++endif
+diff --git a/fs/aufs/module.c b/fs/aufs/module.c
+new file mode 100644
+index 0000000..c2219d3
+--- /dev/null
++++ b/fs/aufs/module.c
+@@ -0,0 +1,164 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * module global variables and operations
++ */
++
++#include <linux/module.h>
++#include <linux/seq_file.h>
++#include "aufs.h"
++
++void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp)
++{
++ if (new_sz <= nused)
++ return p;
++
++ p = krealloc(p, new_sz, gfp);
++ if (p)
++ memset(p + nused, 0, new_sz - nused);
++ return p;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * aufs caches
++ */
++struct kmem_cache *au_cachep[AuCache_Last];
++static int __init au_cache_init(void)
++{
++ au_cachep[AuCache_DINFO] = AuCache(au_dinfo);
++ if (au_cachep[AuCache_DINFO])
++ au_cachep[AuCache_ICNTNR] = AuCache(au_icntnr);
++ if (au_cachep[AuCache_ICNTNR])
++ au_cachep[AuCache_FINFO] = AuCache(au_finfo);
++ if (au_cachep[AuCache_FINFO])
++ au_cachep[AuCache_VDIR] = AuCache(au_vdir);
++ if (au_cachep[AuCache_VDIR])
++ au_cachep[AuCache_DEHSTR] = AuCache(au_vdir_dehstr);
++ if (au_cachep[AuCache_DEHSTR])
++ return 0;
++
++ return -ENOMEM;
++}
++
++static void au_cache_fin(void)
++{
++ int i;
++ for (i = 0; i < AuCache_Last; i++)
++ if (au_cachep[i]) {
++ kmem_cache_destroy(au_cachep[i]);
++ au_cachep[i] = NULL;
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_dir_roflags;
++
++/*
++ * functions for module interface.
++ */
++MODULE_LICENSE("GPL");
++/* MODULE_LICENSE("GPL v2"); */
++MODULE_AUTHOR("Junjiro R. Okajima");
++MODULE_DESCRIPTION(AUFS_NAME
++ " -- Advanced multi layered unification filesystem");
++MODULE_VERSION(AUFS_VERSION);
++
++/* it should be 'byte', but param_set_byte() prints it by "%c" */
++short aufs_nwkq = AUFS_NWKQ_DEF;
++MODULE_PARM_DESC(nwkq, "the number of workqueue thread, " AUFS_WKQ_NAME);
++module_param_named(nwkq, aufs_nwkq, short, S_IRUGO);
++
++/* this module parameter has no meaning when SYSFS is disabled */
++int sysaufs_brs = 1;
++MODULE_PARM_DESC(brs, "use <sysfs>/fs/aufs/si_*/brN");
++module_param_named(brs, sysaufs_brs, int, S_IRUGO);
++
++/* ---------------------------------------------------------------------- */
++
++static char au_esc_chars[0x20 + 3]; /* 0x01-0x20, backslash, del, and NULL */
++
++int au_seq_path(struct seq_file *seq, struct path *path)
++{
++ return seq_path(seq, path, au_esc_chars);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int __init aufs_init(void)
++{
++ int err, i;
++ char *p;
++
++ p = au_esc_chars;
++ for (i = 1; i <= ' '; i++)
++ *p++ = i;
++ *p++ = '\\';
++ *p++ = '\x7f';
++ *p = 0;
++
++ au_dir_roflags = au_file_roflags(O_DIRECTORY | O_LARGEFILE);
++
++ sysaufs_brs_init();
++ au_debug_init();
++
++ err = -EINVAL;
++ if (unlikely(aufs_nwkq <= 0))
++ goto out;
++
++ err = sysaufs_init();
++ if (unlikely(err))
++ goto out;
++ err = au_wkq_init();
++ if (unlikely(err))
++ goto out_sysaufs;
++ err = au_hinotify_init();
++ if (unlikely(err))
++ goto out_wkq;
++ err = au_sysrq_init();
++ if (unlikely(err))
++ goto out_hin;
++ err = au_cache_init();
++ if (unlikely(err))
++ goto out_sysrq;
++ err = register_filesystem(&aufs_fs_type);
++ if (unlikely(err))
++ goto out_cache;
++ pr_info(AUFS_NAME " " AUFS_VERSION "\n");
++ goto out; /* success */
++
++ out_cache:
++ au_cache_fin();
++ out_sysrq:
++ au_sysrq_fin();
++ out_hin:
++ au_hinotify_fin();
++ out_wkq:
++ au_wkq_fin();
++ out_sysaufs:
++ sysaufs_fin();
++ out:
++ return err;
++}
++
++static void __exit aufs_exit(void)
++{
++ unregister_filesystem(&aufs_fs_type);
++ au_cache_fin();
++ au_sysrq_fin();
++ au_hinotify_fin();
++ au_wkq_fin();
++ sysaufs_fin();
++}
++
++module_init(aufs_init);
++module_exit(aufs_exit);
+diff --git a/fs/aufs/module.h b/fs/aufs/module.h
+new file mode 100644
+index 0000000..85e397a
+--- /dev/null
++++ b/fs/aufs/module.h
+@@ -0,0 +1,66 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * module initialization and module-global
++ */
++
++#ifndef __AUFS_MODULE_H__
++#define __AUFS_MODULE_H__
++
++#ifdef __KERNEL__
++
++#include <linux/slab.h>
++
++/* module parameters */
++extern short aufs_nwkq;
++extern int sysaufs_brs;
++
++/* ---------------------------------------------------------------------- */
++
++extern int au_dir_roflags;
++
++void *au_kzrealloc(void *p, unsigned int nused, unsigned int new_sz, gfp_t gfp);
++int au_seq_path(struct seq_file *seq, struct path *path);
++
++/* ---------------------------------------------------------------------- */
++
++/* kmem cache */
++enum {
++ AuCache_DINFO,
++ AuCache_ICNTNR,
++ AuCache_FINFO,
++ AuCache_VDIR,
++ AuCache_DEHSTR,
++#ifdef CONFIG_AUFS_HINOTIFY
++ AuCache_HINOTIFY,
++#endif
++ AuCache_Last
++};
++
++#define AuCache(type) KMEM_CACHE(type, SLAB_RECLAIM_ACCOUNT)
++
++extern struct kmem_cache *au_cachep[];
++
++#define AuCacheFuncs(name, index) \
++static inline void *au_cache_alloc_##name(void) \
++{ return kmem_cache_alloc(au_cachep[AuCache_##index], GFP_NOFS); } \
++static inline void au_cache_free_##name(void *p) \
++{ kmem_cache_free(au_cachep[AuCache_##index], p); }
++
++AuCacheFuncs(dinfo, DINFO);
++AuCacheFuncs(icntnr, ICNTNR);
++AuCacheFuncs(finfo, FINFO);
++AuCacheFuncs(vdir, VDIR);
++AuCacheFuncs(dehstr, DEHSTR);
++
++/* ---------------------------------------------------------------------- */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_MODULE_H__ */
+diff --git a/fs/aufs/opts.c b/fs/aufs/opts.c
+new file mode 100644
+index 0000000..630db0e
+--- /dev/null
++++ b/fs/aufs/opts.c
+@@ -0,0 +1,1478 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * mount options/flags
++ */
++
++#include <linux/types.h> /* a distribution requires */
++#include <linux/parser.h>
++#include "aufs.h"
++
++/* ---------------------------------------------------------------------- */
++
++enum {
++ Opt_br,
++ Opt_add, Opt_del, Opt_mod, Opt_reorder, Opt_append, Opt_prepend,
++ Opt_idel, Opt_imod, Opt_ireorder,
++ Opt_dirwh, Opt_rdcache, Opt_rdblk, Opt_rdhash, Opt_rendir,
++ Opt_xino, Opt_zxino, Opt_noxino,
++ Opt_trunc_xino, Opt_trunc_xino_v, Opt_notrunc_xino,
++ Opt_trunc_xino_path, Opt_itrunc_xino,
++ Opt_trunc_xib, Opt_notrunc_xib,
++ Opt_plink, Opt_noplink, Opt_list_plink,
++ Opt_udba,
++ /* Opt_lock, Opt_unlock, */
++ Opt_cmd, Opt_cmd_args,
++ Opt_diropq_a, Opt_diropq_w,
++ Opt_warn_perm, Opt_nowarn_perm,
++ Opt_wbr_copyup, Opt_wbr_create,
++ Opt_refrof, Opt_norefrof,
++ Opt_verbose, Opt_noverbose,
++ Opt_sum, Opt_nosum, Opt_wsum,
++ Opt_tail, Opt_ignore, Opt_ignore_silent, Opt_err
++};
++
++static match_table_t options = {
++ {Opt_br, "br=%s"},
++ {Opt_br, "br:%s"},
++
++ {Opt_add, "add=%d:%s"},
++ {Opt_add, "add:%d:%s"},
++ {Opt_add, "ins=%d:%s"},
++ {Opt_add, "ins:%d:%s"},
++ {Opt_append, "append=%s"},
++ {Opt_append, "append:%s"},
++ {Opt_prepend, "prepend=%s"},
++ {Opt_prepend, "prepend:%s"},
++
++ {Opt_del, "del=%s"},
++ {Opt_del, "del:%s"},
++ /* {Opt_idel, "idel:%d"}, */
++ {Opt_mod, "mod=%s"},
++ {Opt_mod, "mod:%s"},
++ /* {Opt_imod, "imod:%d:%s"}, */
++
++ {Opt_dirwh, "dirwh=%d"},
++
++ {Opt_xino, "xino=%s"},
++ {Opt_noxino, "noxino"},
++ {Opt_trunc_xino, "trunc_xino"},
++ {Opt_trunc_xino_v, "trunc_xino_v=%d:%d"},
++ {Opt_notrunc_xino, "notrunc_xino"},
++ {Opt_trunc_xino_path, "trunc_xino=%s"},
++ {Opt_itrunc_xino, "itrunc_xino=%d"},
++ /* {Opt_zxino, "zxino=%s"}, */
++ {Opt_trunc_xib, "trunc_xib"},
++ {Opt_notrunc_xib, "notrunc_xib"},
++
++ {Opt_plink, "plink"},
++ {Opt_noplink, "noplink"},
++#ifdef CONFIG_AUFS_DEBUG
++ {Opt_list_plink, "list_plink"},
++#endif
++
++ {Opt_udba, "udba=%s"},
++
++ {Opt_diropq_a, "diropq=always"},
++ {Opt_diropq_a, "diropq=a"},
++ {Opt_diropq_w, "diropq=whiteouted"},
++ {Opt_diropq_w, "diropq=w"},
++
++ {Opt_warn_perm, "warn_perm"},
++ {Opt_nowarn_perm, "nowarn_perm"},
++
++ /* keep them temporary */
++ {Opt_ignore_silent, "coo=%s"},
++ {Opt_ignore_silent, "nodlgt"},
++ {Opt_ignore_silent, "nodirperm1"},
++ {Opt_ignore_silent, "noshwh"},
++ {Opt_ignore_silent, "clean_plink"},
++
++ {Opt_rendir, "rendir=%d"},
++
++ {Opt_refrof, "refrof"},
++ {Opt_norefrof, "norefrof"},
++
++ {Opt_verbose, "verbose"},
++ {Opt_verbose, "v"},
++ {Opt_noverbose, "noverbose"},
++ {Opt_noverbose, "quiet"},
++ {Opt_noverbose, "q"},
++ {Opt_noverbose, "silent"},
++
++ {Opt_sum, "sum"},
++ {Opt_nosum, "nosum"},
++ {Opt_wsum, "wsum"},
++
++ {Opt_rdcache, "rdcache=%d"},
++ {Opt_rdblk, "rdblk=%d"},
++ {Opt_rdhash, "rdhash=%d"},
++
++ {Opt_wbr_create, "create=%s"},
++ {Opt_wbr_create, "create_policy=%s"},
++ {Opt_wbr_copyup, "cpup=%s"},
++ {Opt_wbr_copyup, "copyup=%s"},
++ {Opt_wbr_copyup, "copyup_policy=%s"},
++
++ /* internal use for the scripts */
++ {Opt_ignore_silent, "si=%s"},
++
++ {Opt_br, "dirs=%s"},
++ {Opt_ignore, "debug=%d"},
++ {Opt_ignore, "delete=whiteout"},
++ {Opt_ignore, "delete=all"},
++ {Opt_ignore, "imap=%s"},
++
++ {Opt_err, NULL}
++};
++
++/* ---------------------------------------------------------------------- */
++
++static const char *au_parser_pattern(int val, struct match_token *token)
++{
++ while (token->pattern) {
++ if (token->token == val)
++ return token->pattern;
++ token++;
++ }
++ BUG();
++ return "??";
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t brperms = {
++ {AuBrPerm_RO, AUFS_BRPERM_RO},
++ {AuBrPerm_RR, AUFS_BRPERM_RR},
++ {AuBrPerm_RW, AUFS_BRPERM_RW},
++
++ {AuBrPerm_ROWH, AUFS_BRPERM_ROWH},
++ {AuBrPerm_RRWH, AUFS_BRPERM_RRWH},
++ {AuBrPerm_RWNoLinkWH, AUFS_BRPERM_RWNLWH},
++
++ {AuBrPerm_ROWH, "nfsro"},
++ {AuBrPerm_RO, NULL}
++};
++
++static int br_perm_val(char *perm)
++{
++ int val;
++ substring_t args[MAX_OPT_ARGS];
++
++ val = match_token(perm, brperms, args);
++ return val;
++}
++
++const char *au_optstr_br_perm(int brperm)
++{
++ return au_parser_pattern(brperm, (void *)brperms);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t udbalevel = {
++ {AuOpt_UDBA_REVAL, "reval"},
++ {AuOpt_UDBA_NONE, "none"},
++#ifdef CONFIG_AUFS_HINOTIFY
++ {AuOpt_UDBA_HINOTIFY, "inotify"},
++#endif
++ {-1, NULL}
++};
++
++static int udba_val(char *str)
++{
++ substring_t args[MAX_OPT_ARGS];
++
++ return match_token(str, udbalevel, args);
++}
++
++const char *au_optstr_udba(int udba)
++{
++ return au_parser_pattern(udba, (void *)udbalevel);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static match_table_t au_wbr_create_policy = {
++ {AuWbrCreate_TDP, "tdp"},
++ {AuWbrCreate_TDP, "top-down-parent"},
++ {AuWbrCreate_RR, "rr"},
++ {AuWbrCreate_RR, "round-robin"},
++ {AuWbrCreate_MFS, "mfs"},
++ {AuWbrCreate_MFS, "most-free-space"},
++ {AuWbrCreate_MFSV, "mfs:%d"},
++ {AuWbrCreate_MFSV, "most-free-space:%d"},
++
++ {AuWbrCreate_MFSRR, "mfsrr:%d"},
++ {AuWbrCreate_MFSRRV, "mfsrr:%d:%d"},
++ {AuWbrCreate_PMFS, "pmfs"},
++ {AuWbrCreate_PMFSV, "pmfs:%d"},
++
++ {-1, NULL}
++};
++
++/* cf. linux/lib/parser.c */
++static int au_match_ull(substring_t *s, unsigned long long *result)
++{
++ int err;
++ unsigned int len;
++ char a[32];
++
++ err = -ERANGE;
++ len = s->to - s->from;
++ if (len + 1 <= sizeof(a)) {
++ memcpy(a, s->from, len);
++ a[len] = '\0';
++ err = strict_strtoull(a, 0, result);
++ }
++ return err;
++}
++
++static int au_wbr_mfs_wmark(substring_t *arg, char *str,
++ struct au_opt_wbr_create *create)
++{
++ int err;
++ unsigned long long ull;
++
++ err = 0;
++ if (!au_match_ull(arg, &ull))
++ create->mfsrr_watermark = ull;
++ else {
++ AuErr("bad integer in %s\n", str);
++ err = -EINVAL;
++ }
++
++ return err;
++}
++
++static int au_wbr_mfs_sec(substring_t *arg, char *str,
++ struct au_opt_wbr_create *create)
++{
++ int n, err;
++
++ err = 0;
++ if (!match_int(arg, &n) && 0 <= n)
++ create->mfs_second = n;
++ else {
++ AuErr("bad integer in %s\n", str);
++ err = -EINVAL;
++ }
++
++ return err;
++}
++
++static int au_wbr_create_val(char *str, struct au_opt_wbr_create *create)
++{
++ int err, e;
++ substring_t args[MAX_OPT_ARGS];
++
++ err = match_token(str, au_wbr_create_policy, args);
++ create->wbr_create = err;
++ switch (err) {
++ case AuWbrCreate_MFSRRV:
++ e = au_wbr_mfs_wmark(&args[0], str, create);
++ if (!e)
++ e = au_wbr_mfs_sec(&args[1], str, create);
++ if (unlikely(e))
++ err = e;
++ break;
++ case AuWbrCreate_MFSRR:
++ e = au_wbr_mfs_wmark(&args[0], str, create);
++ if (unlikely(e)) {
++ err = e;
++ break;
++ }
++ /*FALLTHROUGH*/
++ case AuWbrCreate_MFS:
++ case AuWbrCreate_PMFS:
++ create->mfs_second = AUFS_MFS_SECOND_DEF;
++ break;
++ case AuWbrCreate_MFSV:
++ case AuWbrCreate_PMFSV:
++ e = au_wbr_mfs_sec(&args[0], str, create);
++ if (unlikely(e))
++ err = e;
++ break;
++ }
++
++ return err;
++}
++
++const char *au_optstr_wbr_create(int wbr_create)
++{
++ return au_parser_pattern(wbr_create, (void *)au_wbr_create_policy);
++}
++
++static match_table_t au_wbr_copyup_policy = {
++ {AuWbrCopyup_TDP, "tdp"},
++ {AuWbrCopyup_TDP, "top-down-parent"},
++ {AuWbrCopyup_BUP, "bup"},
++ {AuWbrCopyup_BUP, "bottom-up-parent"},
++ {AuWbrCopyup_BU, "bu"},
++ {AuWbrCopyup_BU, "bottom-up"},
++ {-1, NULL}
++};
++
++static int au_wbr_copyup_val(char *str)
++{
++ substring_t args[MAX_OPT_ARGS];
++
++ return match_token(str, au_wbr_copyup_policy, args);
++}
++
++const char *au_optstr_wbr_copyup(int wbr_copyup)
++{
++ return au_parser_pattern(wbr_copyup, (void *)au_wbr_copyup_policy);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static const int lkup_dirflags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
++
++static void dump_opts(struct au_opts *opts)
++{
++#ifdef CONFIG_AUFS_DEBUG
++ /* reduce stack space */
++ union {
++ struct au_opt_add *add;
++ struct au_opt_del *del;
++ struct au_opt_mod *mod;
++ struct au_opt_xino *xino;
++ struct au_opt_xino_itrunc *xino_itrunc;
++ struct au_opt_wbr_create *create;
++ } u;
++ struct au_opt *opt;
++
++ opt = opts->opt;
++ while (opt->type != Opt_tail) {
++ switch (opt->type) {
++ case Opt_add:
++ u.add = &opt->add;
++ AuDbg("add {b%d, %s, 0x%x, %p}\n",
++ u.add->bindex, u.add->pathname, u.add->perm,
++ u.add->path.dentry);
++ break;
++ case Opt_del:
++ case Opt_idel:
++ u.del = &opt->del;
++ AuDbg("del {%s, %p}\n",
++ u.del->pathname, u.del->h_path.dentry);
++ break;
++ case Opt_mod:
++ case Opt_imod:
++ u.mod = &opt->mod;
++ AuDbg("mod {%s, 0x%x, %p}\n",
++ u.mod->path, u.mod->perm, u.mod->h_root);
++ break;
++ case Opt_append:
++ u.add = &opt->add;
++ AuDbg("append {b%d, %s, 0x%x, %p}\n",
++ u.add->bindex, u.add->pathname, u.add->perm,
++ u.add->path.dentry);
++ break;
++ case Opt_prepend:
++ u.add = &opt->add;
++ AuDbg("prepend {b%d, %s, 0x%x, %p}\n",
++ u.add->bindex, u.add->pathname, u.add->perm,
++ u.add->path.dentry);
++ break;
++ case Opt_dirwh:
++ AuDbg("dirwh %d\n", opt->dirwh);
++ break;
++ case Opt_rdcache:
++ AuDbg("rdcache %d\n", opt->rdcache);
++ break;
++ case Opt_rdblk:
++ AuDbg("rdblk %u\n", opt->rdblk);
++ break;
++ case Opt_rdhash:
++ AuDbg("rdhash %u\n", opt->rdhash);
++ break;
++ case Opt_xino:
++ u.xino = &opt->xino;
++ AuDbg("xino {%s %.*s}\n",
++ u.xino->path,
++ AuDLNPair(u.xino->file->f_dentry));
++ break;
++ case Opt_trunc_xino:
++ AuLabel(trunc_xino);
++ break;
++ case Opt_notrunc_xino:
++ AuLabel(notrunc_xino);
++ break;
++ case Opt_trunc_xino_path:
++ case Opt_itrunc_xino:
++ u.xino_itrunc = &opt->xino_itrunc;
++ AuDbg("trunc_xino %d\n", u.xino_itrunc->bindex);
++ break;
++
++ case Opt_noxino:
++ AuLabel(noxino);
++ break;
++ case Opt_trunc_xib:
++ AuLabel(trunc_xib);
++ break;
++ case Opt_notrunc_xib:
++ AuLabel(notrunc_xib);
++ break;
++ case Opt_plink:
++ AuLabel(plink);
++ break;
++ case Opt_noplink:
++ AuLabel(noplink);
++ break;
++ case Opt_list_plink:
++ AuLabel(list_plink);
++ break;
++ case Opt_udba:
++ AuDbg("udba %d, %s\n",
++ opt->udba, au_optstr_udba(opt->udba));
++ break;
++ case Opt_diropq_a:
++ AuLabel(diropq_a);
++ break;
++ case Opt_diropq_w:
++ AuLabel(diropq_w);
++ break;
++ case Opt_warn_perm:
++ AuLabel(warn_perm);
++ break;
++ case Opt_nowarn_perm:
++ AuLabel(nowarn_perm);
++ break;
++ case Opt_refrof:
++ AuLabel(refrof);
++ break;
++ case Opt_norefrof:
++ AuLabel(norefrof);
++ break;
++ case Opt_verbose:
++ AuLabel(verbose);
++ break;
++ case Opt_noverbose:
++ AuLabel(noverbose);
++ break;
++ case Opt_sum:
++ AuLabel(sum);
++ break;
++ case Opt_nosum:
++ AuLabel(nosum);
++ break;
++ case Opt_wsum:
++ AuLabel(wsum);
++ break;
++ case Opt_wbr_create:
++ u.create = &opt->wbr_create;
++ AuDbg("create %d, %s\n", u.create->wbr_create,
++ au_optstr_wbr_create(u.create->wbr_create));
++ switch (u.create->wbr_create) {
++ case AuWbrCreate_MFSV:
++ case AuWbrCreate_PMFSV:
++ AuDbg("%d sec\n", u.create->mfs_second);
++ break;
++ case AuWbrCreate_MFSRR:
++ AuDbg("%llu watermark\n",
++ u.create->mfsrr_watermark);
++ break;
++ case AuWbrCreate_MFSRRV:
++ AuDbg("%llu watermark, %d sec\n",
++ u.create->mfsrr_watermark,
++ u.create->mfs_second);
++ break;
++ }
++ break;
++ case Opt_wbr_copyup:
++ AuDbg("copyup %d, %s\n", opt->wbr_copyup,
++ au_optstr_wbr_copyup(opt->wbr_copyup));
++ break;
++ default:
++ BUG();
++ }
++ opt++;
++ }
++#endif
++}
++
++void au_opts_free(struct au_opts *opts)
++{
++ struct au_opt *opt;
++
++ opt = opts->opt;
++ while (opt->type != Opt_tail) {
++ switch (opt->type) {
++ case Opt_add:
++ case Opt_append:
++ case Opt_prepend:
++ path_put(&opt->add.path);
++ break;
++ case Opt_del:
++ case Opt_idel:
++ path_put(&opt->del.h_path);
++ break;
++ case Opt_mod:
++ case Opt_imod:
++ dput(opt->mod.h_root);
++ break;
++ case Opt_xino:
++ fput(opt->xino.file);
++ break;
++ }
++ opt++;
++ }
++}
++
++static int opt_add(struct au_opt *opt, char *opt_str, unsigned long sb_flags,
++ aufs_bindex_t bindex)
++{
++ int err;
++ struct au_opt_add *add = &opt->add;
++ char *p;
++
++ add->bindex = bindex;
++ add->perm = AuBrPerm_Last;
++ add->pathname = opt_str;
++ p = strchr(opt_str, '=');
++ if (p) {
++ *p++ = 0;
++ if (*p)
++ add->perm = br_perm_val(p);
++ }
++
++ err = vfsub_kern_path(add->pathname, lkup_dirflags, &add->path);
++ if (!err) {
++ if (!p) {
++ add->perm = AuBrPerm_RO;
++ if (au_test_fs_rr(add->path.dentry->d_sb))
++ add->perm = AuBrPerm_RR;
++ else if (!bindex && !(sb_flags & MS_RDONLY))
++ add->perm = AuBrPerm_RW;
++ }
++ opt->type = Opt_add;
++ goto out;
++ }
++ AuErr("lookup failed %s (%d)\n", add->pathname, err);
++ err = -EINVAL;
++
++ out:
++ return err;
++}
++
++static int au_opts_parse_del(struct au_opt_del *del, substring_t args[])
++{
++ int err;
++
++ del->pathname = args[0].from;
++ AuDbg("del path %s\n", del->pathname);
++
++ err = vfsub_kern_path(del->pathname, lkup_dirflags, &del->h_path);
++ if (unlikely(err))
++ AuErr("lookup failed %s (%d)\n", del->pathname, err);
++
++ return err;
++}
++
++#if 0 /* reserved for future use */
++static int au_opts_parse_idel(struct super_block *sb, aufs_bindex_t bindex,
++ struct au_opt_del *del, substring_t args[])
++{
++ int err;
++ struct dentry *root;
++
++ err = -EINVAL;
++ root = sb->s_root;
++ aufs_read_lock(root, AuLock_FLUSH);
++ if (bindex < 0 || au_sbend(sb) < bindex) {
++ AuErr("out of bounds, %d\n", bindex);
++ goto out;
++ }
++
++ err = 0;
++ del->h_path.dentry = dget(au_h_dptr(root, bindex));
++ del->h_path.mnt = mntget(au_sbr_mnt(sb, bindex));
++
++ out:
++ aufs_read_unlock(root, !AuLock_IR);
++ return err;
++}
++#endif
++
++static int au_opts_parse_mod(struct au_opt_mod *mod, substring_t args[])
++{
++ int err;
++ struct path path;
++ char *p;
++
++ err = -EINVAL;
++ mod->path = args[0].from;
++ p = strchr(mod->path, '=');
++ if (unlikely(!p)) {
++ AuErr("no permssion %s\n", args[0].from);
++ goto out;
++ }
++
++ *p++ = 0;
++ err = vfsub_kern_path(mod->path, lkup_dirflags, &path);
++ if (unlikely(err)) {
++ AuErr("lookup failed %s (%d)\n", mod->path, err);
++ goto out;
++ }
++
++ mod->perm = br_perm_val(p);
++ AuDbg("mod path %s, perm 0x%x, %s\n", mod->path, mod->perm, p);
++ mod->h_root = dget(path.dentry);
++ path_put(&path);
++
++ out:
++ return err;
++}
++
++#if 0 /* reserved for future use */
++static int au_opts_parse_imod(struct super_block *sb, aufs_bindex_t bindex,
++ struct au_opt_mod *mod, substring_t args[])
++{
++ int err;
++ struct dentry *root;
++
++ err = -EINVAL;
++ root = sb->s_root;
++ aufs_read_lock(root, AuLock_FLUSH);
++ if (bindex < 0 || au_sbend(sb) < bindex) {
++ AuErr("out of bounds, %d\n", bindex);
++ goto out;
++ }
++
++ err = 0;
++ mod->perm = br_perm_val(args[1].from);
++ AuDbg("mod path %s, perm 0x%x, %s\n",
++ mod->path, mod->perm, args[1].from);
++ mod->h_root = dget(au_h_dptr(root, bindex));
++
++ out:
++ aufs_read_unlock(root, !AuLock_IR);
++ return err;
++}
++#endif
++
++static int au_opts_parse_xino(struct super_block *sb, struct au_opt_xino *xino,
++ substring_t args[])
++{
++ int err;
++ struct file *file;
++
++ file = au_xino_create(sb, args[0].from, /*silent*/0);
++ err = PTR_ERR(file);
++ if (IS_ERR(file))
++ goto out;
++
++ err = -EINVAL;
++ if (unlikely(file->f_dentry->d_sb == sb)) {
++ fput(file);
++ AuErr("%s must be outside\n", args[0].from);
++ goto out;
++ }
++
++ err = 0;
++ xino->file = file;
++ xino->path = args[0].from;
++
++ out:
++ return err;
++}
++
++static
++int au_opts_parse_xino_itrunc_path(struct super_block *sb,
++ struct au_opt_xino_itrunc *xino_itrunc,
++ substring_t args[])
++{
++ int err;
++ aufs_bindex_t bend, bindex;
++ struct path path;
++ struct dentry *root;
++
++ err = vfsub_kern_path(args[0].from, lkup_dirflags, &path);
++ if (unlikely(err)) {
++ AuErr("lookup failed %s (%d)\n", args[0].from, err);
++ goto out;
++ }
++
++ xino_itrunc->bindex = -1;
++ root = sb->s_root;
++ aufs_read_lock(root, AuLock_FLUSH);
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex <= bend; bindex++) {
++ if (au_h_dptr(root, bindex) == path.dentry) {
++ xino_itrunc->bindex = bindex;
++ break;
++ }
++ }
++ aufs_read_unlock(root, !AuLock_IR);
++ path_put(&path);
++
++ if (unlikely(xino_itrunc->bindex < 0)) {
++ AuErr("no such branch %s\n", args[0].from);
++ err = -EINVAL;
++ }
++
++ out:
++ return err;
++}
++
++/* called without aufs lock */
++int au_opts_parse(struct super_block *sb, char *str, struct au_opts *opts)
++{
++ int err, n, token;
++ aufs_bindex_t bindex;
++ unsigned char skipped;
++ struct dentry *root;
++ struct au_opt *opt, *opt_tail;
++ char *opt_str;
++ /* reduce the stack space */
++ union {
++ struct au_opt_xino_itrunc *xino_itrunc;
++ struct au_opt_wbr_create *create;
++ } u;
++ struct {
++ substring_t args[MAX_OPT_ARGS];
++ } *a;
++
++ err = -ENOMEM;
++ a = kmalloc(sizeof(*a), GFP_NOFS);
++ if (unlikely(!a))
++ goto out;
++
++ root = sb->s_root;
++ err = 0;
++ bindex = 0;
++ opt = opts->opt;
++ opt_tail = opt + opts->max_opt - 1;
++ opt->type = Opt_tail;
++ while (!err && (opt_str = strsep(&str, ",")) && *opt_str) {
++ err = -EINVAL;
++ skipped = 0;
++ token = match_token(opt_str, options, a->args);
++ switch (token) {
++ case Opt_br:
++ err = 0;
++ while (!err && (opt_str = strsep(&a->args[0].from, ":"))
++ && *opt_str) {
++ err = opt_add(opt, opt_str, opts->sb_flags,
++ bindex++);
++ if (unlikely(!err && ++opt > opt_tail)) {
++ err = -E2BIG;
++ break;
++ }
++ opt->type = Opt_tail;
++ skipped = 1;
++ }
++ break;
++ case Opt_add:
++ if (unlikely(match_int(&a->args[0], &n))) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ bindex = n;
++ err = opt_add(opt, a->args[1].from, opts->sb_flags,
++ bindex);
++ if (!err)
++ opt->type = token;
++ break;
++ case Opt_append:
++ err = opt_add(opt, a->args[0].from, opts->sb_flags,
++ /*dummy bindex*/1);
++ if (!err)
++ opt->type = token;
++ break;
++ case Opt_prepend:
++ err = opt_add(opt, a->args[0].from, opts->sb_flags,
++ /*bindex*/0);
++ if (!err)
++ opt->type = token;
++ break;
++ case Opt_del:
++ err = au_opts_parse_del(&opt->del, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++#if 0 /* reserved for future use */
++ case Opt_idel:
++ del->pathname = "(indexed)";
++ if (unlikely(match_int(&args[0], &n))) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ err = au_opts_parse_idel(sb, n, &opt->del, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++#endif
++ case Opt_mod:
++ err = au_opts_parse_mod(&opt->mod, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++#ifdef IMOD /* reserved for future use */
++ case Opt_imod:
++ u.mod->path = "(indexed)";
++ if (unlikely(match_int(&a->args[0], &n))) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ err = au_opts_parse_imod(sb, n, &opt->mod, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++#endif
++ case Opt_xino:
++ err = au_opts_parse_xino(sb, &opt->xino, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++
++ case Opt_trunc_xino_path:
++ err = au_opts_parse_xino_itrunc_path
++ (sb, &opt->xino_itrunc, a->args);
++ if (!err)
++ opt->type = token;
++ break;
++
++ case Opt_itrunc_xino:
++ u.xino_itrunc = &opt->xino_itrunc;
++ if (unlikely(match_int(&a->args[0], &n))) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ u.xino_itrunc->bindex = n;
++ aufs_read_lock(root, AuLock_FLUSH);
++ if (n < 0 || au_sbend(sb) < n) {
++ AuErr("out of bounds, %d\n", n);
++ aufs_read_unlock(root, !AuLock_IR);
++ break;
++ }
++ aufs_read_unlock(root, !AuLock_IR);
++ err = 0;
++ opt->type = token;
++ break;
++
++ case Opt_dirwh:
++ if (unlikely(match_int(&a->args[0], &opt->dirwh)))
++ break;
++ err = 0;
++ opt->type = token;
++ break;
++
++ case Opt_rdcache:
++ if (unlikely(match_int(&a->args[0], &opt->rdcache)))
++ break;
++ err = 0;
++ opt->type = token;
++ break;
++ case Opt_rdblk:
++ if (unlikely(match_int(&a->args[0], &n)
++ || n <= 0
++ || n > KMALLOC_MAX_SIZE)) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ if (unlikely(n < NAME_MAX)) {
++ AuErr("rdblk must be larger than %d\n",
++ NAME_MAX);
++ break;
++ }
++ opt->rdblk = n;
++ err = 0;
++ opt->type = token;
++ break;
++ case Opt_rdhash:
++ if (unlikely(match_int(&a->args[0], &n)
++ || n <= 0
++ || n * sizeof(struct hlist_head)
++ > KMALLOC_MAX_SIZE)) {
++ AuErr("bad integer in %s\n", opt_str);
++ break;
++ }
++ opt->rdhash = n;
++ err = 0;
++ opt->type = token;
++ break;
++
++ case Opt_trunc_xino:
++ case Opt_notrunc_xino:
++ case Opt_noxino:
++ case Opt_trunc_xib:
++ case Opt_notrunc_xib:
++ case Opt_plink:
++ case Opt_noplink:
++ case Opt_list_plink:
++ case Opt_diropq_a:
++ case Opt_diropq_w:
++ case Opt_warn_perm:
++ case Opt_nowarn_perm:
++ case Opt_refrof:
++ case Opt_norefrof:
++ case Opt_verbose:
++ case Opt_noverbose:
++ case Opt_sum:
++ case Opt_nosum:
++ case Opt_wsum:
++ err = 0;
++ opt->type = token;
++ break;
++
++ case Opt_udba:
++ opt->udba = udba_val(a->args[0].from);
++ if (opt->udba >= 0) {
++ err = 0;
++ opt->type = token;
++ } else
++ AuErr("wrong value, %s\n", opt_str);
++ break;
++
++ case Opt_wbr_create:
++ u.create = &opt->wbr_create;
++ u.create->wbr_create
++ = au_wbr_create_val(a->args[0].from, u.create);
++ if (u.create->wbr_create >= 0) {
++ err = 0;
++ opt->type = token;
++ } else
++ AuErr("wrong value, %s\n", opt_str);
++ break;
++ case Opt_wbr_copyup:
++ opt->wbr_copyup = au_wbr_copyup_val(a->args[0].from);
++ if (opt->wbr_copyup >= 0) {
++ err = 0;
++ opt->type = token;
++ } else
++ AuErr("wrong value, %s\n", opt_str);
++ break;
++
++ case Opt_ignore:
++ AuWarn("ignored %s\n", opt_str);
++ /*FALLTHROUGH*/
++ case Opt_ignore_silent:
++ skipped = 1;
++ err = 0;
++ break;
++ case Opt_err:
++ AuErr("unknown option %s\n", opt_str);
++ break;
++ }
++
++ if (!err && !skipped) {
++ if (unlikely(++opt > opt_tail)) {
++ err = -E2BIG;
++ opt--;
++ opt->type = Opt_tail;
++ break;
++ }
++ opt->type = Opt_tail;
++ }
++ }
++
++ kfree(a);
++ dump_opts(opts);
++ if (unlikely(err))
++ au_opts_free(opts);
++
++ out:
++ return err;
++}
++
++static int au_opt_wbr_create(struct super_block *sb,
++ struct au_opt_wbr_create *create)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++
++ err = 1; /* handled */
++ sbinfo = au_sbi(sb);
++ if (sbinfo->si_wbr_create_ops->fin) {
++ err = sbinfo->si_wbr_create_ops->fin(sb);
++ if (!err)
++ err = 1;
++ }
++
++ sbinfo->si_wbr_create = create->wbr_create;
++ sbinfo->si_wbr_create_ops = au_wbr_create_ops + create->wbr_create;
++ switch (create->wbr_create) {
++ case AuWbrCreate_MFSRRV:
++ case AuWbrCreate_MFSRR:
++ sbinfo->si_wbr_mfs.mfsrr_watermark = create->mfsrr_watermark;
++ /*FALLTHROUGH*/
++ case AuWbrCreate_MFS:
++ case AuWbrCreate_MFSV:
++ case AuWbrCreate_PMFS:
++ case AuWbrCreate_PMFSV:
++ sbinfo->si_wbr_mfs.mfs_expire = create->mfs_second * HZ;
++ break;
++ }
++
++ if (sbinfo->si_wbr_create_ops->init)
++ sbinfo->si_wbr_create_ops->init(sb); /* ignore */
++
++ return err;
++}
++
++/*
++ * returns,
++ * plus: processed without an error
++ * zero: unprocessed
++ */
++static int au_opt_simple(struct super_block *sb, struct au_opt *opt,
++ struct au_opts *opts)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++
++ err = 1; /* handled */
++ sbinfo = au_sbi(sb);
++ switch (opt->type) {
++ case Opt_udba:
++ sbinfo->si_mntflags &= ~AuOptMask_UDBA;
++ sbinfo->si_mntflags |= opt->udba;
++ opts->given_udba |= opt->udba;
++ break;
++
++ case Opt_plink:
++ au_opt_set(sbinfo->si_mntflags, PLINK);
++ break;
++ case Opt_noplink:
++ if (au_opt_test(sbinfo->si_mntflags, PLINK))
++ au_plink_put(sb);
++ au_opt_clr(sbinfo->si_mntflags, PLINK);
++ break;
++ case Opt_list_plink:
++ if (au_opt_test(sbinfo->si_mntflags, PLINK))
++ au_plink_list(sb);
++ break;
++
++ case Opt_diropq_a:
++ au_opt_set(sbinfo->si_mntflags, ALWAYS_DIROPQ);
++ break;
++ case Opt_diropq_w:
++ au_opt_clr(sbinfo->si_mntflags, ALWAYS_DIROPQ);
++ break;
++
++ case Opt_warn_perm:
++ au_opt_set(sbinfo->si_mntflags, WARN_PERM);
++ break;
++ case Opt_nowarn_perm:
++ au_opt_clr(sbinfo->si_mntflags, WARN_PERM);
++ break;
++
++ case Opt_refrof:
++ au_opt_set(sbinfo->si_mntflags, REFROF);
++ break;
++ case Opt_norefrof:
++ au_opt_clr(sbinfo->si_mntflags, REFROF);
++ break;
++
++ case Opt_verbose:
++ au_opt_set(sbinfo->si_mntflags, VERBOSE);
++ break;
++ case Opt_noverbose:
++ au_opt_clr(sbinfo->si_mntflags, VERBOSE);
++ break;
++
++ case Opt_sum:
++ au_opt_set(sbinfo->si_mntflags, SUM);
++ break;
++ case Opt_wsum:
++ au_opt_clr(sbinfo->si_mntflags, SUM);
++ au_opt_set(sbinfo->si_mntflags, SUM_W);
++ case Opt_nosum:
++ au_opt_clr(sbinfo->si_mntflags, SUM);
++ au_opt_clr(sbinfo->si_mntflags, SUM_W);
++ break;
++
++ case Opt_wbr_create:
++ err = au_opt_wbr_create(sb, &opt->wbr_create);
++ break;
++ case Opt_wbr_copyup:
++ sbinfo->si_wbr_copyup = opt->wbr_copyup;
++ sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + opt->wbr_copyup;
++ break;
++
++ case Opt_dirwh:
++ sbinfo->si_dirwh = opt->dirwh;
++ break;
++
++ case Opt_rdcache:
++ sbinfo->si_rdcache = opt->rdcache * HZ;
++ break;
++ case Opt_rdblk:
++ sbinfo->si_rdblk = opt->rdblk;
++ break;
++ case Opt_rdhash:
++ sbinfo->si_rdhash = opt->rdhash;
++ break;
++
++ case Opt_trunc_xino:
++ au_opt_set(sbinfo->si_mntflags, TRUNC_XINO);
++ break;
++ case Opt_notrunc_xino:
++ au_opt_clr(sbinfo->si_mntflags, TRUNC_XINO);
++ break;
++
++ case Opt_trunc_xino_path:
++ case Opt_itrunc_xino:
++ err = au_xino_trunc(sb, opt->xino_itrunc.bindex);
++ if (!err)
++ err = 1;
++ break;
++
++ case Opt_trunc_xib:
++ au_fset_opts(opts->flags, TRUNC_XIB);
++ break;
++ case Opt_notrunc_xib:
++ au_fclr_opts(opts->flags, TRUNC_XIB);
++ break;
++
++ default:
++ err = 0;
++ break;
++ }
++
++ return err;
++}
++
++/*
++ * returns tri-state.
++ * plus: processed without an error
++ * zero: unprocessed
++ * minus: error
++ */
++static int au_opt_br(struct super_block *sb, struct au_opt *opt,
++ struct au_opts *opts)
++{
++ int err, do_refresh;
++
++ err = 0;
++ switch (opt->type) {
++ case Opt_append:
++ opt->add.bindex = au_sbend(sb) + 1;
++ if (opt->add.bindex < 0)
++ opt->add.bindex = 0;
++ goto add;
++ case Opt_prepend:
++ opt->add.bindex = 0;
++ add:
++ case Opt_add:
++ err = au_br_add(sb, &opt->add,
++ au_ftest_opts(opts->flags, REMOUNT));
++ if (!err) {
++ err = 1;
++ au_fset_opts(opts->flags, REFRESH_DIR);
++ if (au_br_whable(opt->add.perm))
++ au_fset_opts(opts->flags, REFRESH_NONDIR);
++ }
++ break;
++
++ case Opt_del:
++ case Opt_idel:
++ err = au_br_del(sb, &opt->del,
++ au_ftest_opts(opts->flags, REMOUNT));
++ if (!err) {
++ err = 1;
++ au_fset_opts(opts->flags, TRUNC_XIB);
++ au_fset_opts(opts->flags, REFRESH_DIR);
++ au_fset_opts(opts->flags, REFRESH_NONDIR);
++ }
++ break;
++
++ case Opt_mod:
++ case Opt_imod:
++ err = au_br_mod(sb, &opt->mod,
++ au_ftest_opts(opts->flags, REMOUNT),
++ &do_refresh);
++ if (!err) {
++ err = 1;
++ if (do_refresh) {
++ au_fset_opts(opts->flags, REFRESH_DIR);
++ au_fset_opts(opts->flags, REFRESH_NONDIR);
++ }
++ }
++ break;
++ }
++
++ return err;
++}
++
++static int au_opt_xino(struct super_block *sb, struct au_opt *opt,
++ struct au_opt_xino **opt_xino,
++ struct au_opts *opts)
++{
++ int err;
++ aufs_bindex_t bend, bindex;
++ struct dentry *root, *parent, *h_root;
++
++ err = 0;
++ switch (opt->type) {
++ case Opt_xino:
++ err = au_xino_set(sb, &opt->xino,
++ !!au_ftest_opts(opts->flags, REMOUNT));
++ if (unlikely(err))
++ break;
++
++ *opt_xino = &opt->xino;
++ au_xino_brid_set(sb, -1);
++
++ /* safe d_parent access */
++ parent = opt->xino.file->f_dentry->d_parent;
++ root = sb->s_root;
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex <= bend; bindex++) {
++ h_root = au_h_dptr(root, bindex);
++ if (h_root == parent) {
++ au_xino_brid_set(sb, au_sbr_id(sb, bindex));
++ break;
++ }
++ }
++ break;
++
++ case Opt_noxino:
++ au_xino_clr(sb);
++ au_xino_brid_set(sb, -1);
++ *opt_xino = (void *)-1;
++ break;
++ }
++
++ return err;
++}
++
++int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
++ unsigned int pending)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ unsigned char do_plink, skip, do_free;
++ struct au_branch *br;
++ struct au_wbr *wbr;
++ struct dentry *root;
++ struct inode *dir, *h_dir;
++ struct au_sbinfo *sbinfo;
++ struct au_hinode *hdir;
++
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!(sbinfo->si_mntflags & AuOptMask_UDBA));
++
++ if (unlikely(!(sb_flags & MS_RDONLY)
++ && !au_br_writable(au_sbr_perm(sb, 0))))
++ AuWarn("first branch should be rw\n");
++
++ if (au_opt_test((sbinfo->si_mntflags | pending), UDBA_HINOTIFY)
++ && !au_opt_test(sbinfo->si_mntflags, XINO))
++ AuWarn("udba=inotify requires xino\n");
++
++ err = 0;
++ root = sb->s_root;
++ dir = sb->s_root->d_inode;
++ do_plink = !!au_opt_test(sbinfo->si_mntflags, PLINK);
++ bend = au_sbend(sb);
++ for (bindex = 0; !err && bindex <= bend; bindex++) {
++ skip = 0;
++ h_dir = au_h_iptr(dir, bindex);
++ br = au_sbr(sb, bindex);
++ do_free = 0;
++
++ wbr = br->br_wbr;
++ if (wbr)
++ wbr_wh_read_lock(wbr);
++
++ switch (br->br_perm) {
++ case AuBrPerm_RO:
++ case AuBrPerm_ROWH:
++ case AuBrPerm_RR:
++ case AuBrPerm_RRWH:
++ do_free = !!wbr;
++ skip = (!wbr
++ || (!wbr->wbr_whbase
++ && !wbr->wbr_plink
++ && !wbr->wbr_orph));
++ break;
++
++ case AuBrPerm_RWNoLinkWH:
++ /* skip = (!br->br_whbase && !br->br_orph); */
++ skip = (!wbr || !wbr->wbr_whbase);
++ if (skip && wbr) {
++ if (do_plink)
++ skip = !!wbr->wbr_plink;
++ else
++ skip = !wbr->wbr_plink;
++ }
++ break;
++
++ case AuBrPerm_RW:
++ /* skip = (br->br_whbase && br->br_ohph); */
++ skip = (wbr && wbr->wbr_whbase);
++ if (skip) {
++ if (do_plink)
++ skip = !!wbr->wbr_plink;
++ else
++ skip = !wbr->wbr_plink;
++ }
++ break;
++
++ default:
++ BUG();
++ }
++ if (wbr)
++ wbr_wh_read_unlock(wbr);
++
++ if (skip)
++ continue;
++
++ hdir = au_hi(dir, bindex);
++ au_hin_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++ if (wbr)
++ wbr_wh_write_lock(wbr);
++ err = au_wh_init(au_h_dptr(root, bindex), br, sb);
++ if (wbr)
++ wbr_wh_write_unlock(wbr);
++ au_hin_imtx_unlock(hdir);
++
++ if (!err && do_free) {
++ kfree(wbr);
++ br->br_wbr = NULL;
++ }
++ }
++
++ return err;
++}
++
++int au_opts_mount(struct super_block *sb, struct au_opts *opts)
++{
++ int err;
++ unsigned int tmp;
++ aufs_bindex_t bend;
++ struct au_opt *opt;
++ struct au_opt_xino *opt_xino, xino;
++ struct au_sbinfo *sbinfo;
++
++ err = 0;
++ opt_xino = NULL;
++ opt = opts->opt;
++ while (err >= 0 && opt->type != Opt_tail)
++ err = au_opt_simple(sb, opt++, opts);
++ if (err > 0)
++ err = 0;
++ else if (unlikely(err < 0))
++ goto out;
++
++ /* disable xino and udba temporary */
++ sbinfo = au_sbi(sb);
++ tmp = sbinfo->si_mntflags;
++ au_opt_clr(sbinfo->si_mntflags, XINO);
++ au_opt_set_udba(sbinfo->si_mntflags, UDBA_REVAL);
++
++ opt = opts->opt;
++ while (err >= 0 && opt->type != Opt_tail)
++ err = au_opt_br(sb, opt++, opts);
++ if (err > 0)
++ err = 0;
++ else if (unlikely(err < 0))
++ goto out;
++
++ bend = au_sbend(sb);
++ if (unlikely(bend < 0)) {
++ err = -EINVAL;
++ AuErr("no branches\n");
++ goto out;
++ }
++
++ if (au_opt_test(tmp, XINO))
++ au_opt_set(sbinfo->si_mntflags, XINO);
++ opt = opts->opt;
++ while (!err && opt->type != Opt_tail)
++ err = au_opt_xino(sb, opt++, &opt_xino, opts);
++ if (unlikely(err))
++ goto out;
++
++ err = au_opts_verify(sb, sb->s_flags, tmp);
++ if (unlikely(err))
++ goto out;
++
++ /* restore xino */
++ if (au_opt_test(tmp, XINO) && !opt_xino) {
++ xino.file = au_xino_def(sb);
++ err = PTR_ERR(xino.file);
++ if (IS_ERR(xino.file))
++ goto out;
++
++ err = au_xino_set(sb, &xino, /*remount*/0);
++ fput(xino.file);
++ if (unlikely(err))
++ goto out;
++ }
++
++ /* restore udba */
++ sbinfo->si_mntflags &= ~AuOptMask_UDBA;
++ sbinfo->si_mntflags |= (tmp & AuOptMask_UDBA);
++ if (au_opt_test(tmp, UDBA_HINOTIFY)) {
++ struct inode *dir = sb->s_root->d_inode;
++ au_reset_hinotify(dir,
++ au_hi_flags(dir, /*isdir*/1) & ~AuHi_XINO);
++ }
++
++ out:
++ return err;
++}
++
++int au_opts_remount(struct super_block *sb, struct au_opts *opts)
++{
++ int err, rerr;
++ struct inode *dir;
++ struct au_opt_xino *opt_xino;
++ struct au_opt *opt;
++ struct au_sbinfo *sbinfo;
++
++ dir = sb->s_root->d_inode;
++ sbinfo = au_sbi(sb);
++ err = 0;
++ opt_xino = NULL;
++ opt = opts->opt;
++ while (err >= 0 && opt->type != Opt_tail) {
++ err = au_opt_simple(sb, opt, opts);
++ if (!err)
++ err = au_opt_br(sb, opt, opts);
++ if (!err)
++ err = au_opt_xino(sb, opt, &opt_xino, opts);
++ opt++;
++ }
++ if (err > 0)
++ err = 0;
++ AuTraceErr(err);
++ /* go on even err */
++
++ rerr = au_opts_verify(sb, opts->sb_flags, /*pending*/0);
++ if (unlikely(rerr && !err))
++ err = rerr;
++
++ if (au_ftest_opts(opts->flags, TRUNC_XIB)) {
++ rerr = au_xib_trunc(sb);
++ if (unlikely(rerr && !err))
++ err = rerr;
++ }
++
++ /* will be handled by the caller */
++ if (!au_ftest_opts(opts->flags, REFRESH_DIR)
++ && (opts->given_udba || au_opt_test(sbinfo->si_mntflags, XINO)))
++ au_fset_opts(opts->flags, REFRESH_DIR);
++
++ AuDbg("status 0x%x\n", opts->flags);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++unsigned int au_opt_udba(struct super_block *sb)
++{
++ return au_mntflags(sb) & AuOptMask_UDBA;
++}
+diff --git a/fs/aufs/opts.h b/fs/aufs/opts.h
+new file mode 100644
+index 0000000..275702c
+--- /dev/null
++++ b/fs/aufs/opts.h
+@@ -0,0 +1,180 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * mount options/flags
++ */
++
++#ifndef __AUFS_OPTS_H__
++#define __AUFS_OPTS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/namei.h>
++#include <linux/aufs_type.h>
++
++/* ---------------------------------------------------------------------- */
++
++/* mount flags */
++#define AuOpt_XINO 1 /* external inode number bitmap
++ and translation table */
++#define AuOpt_TRUNC_XINO (1 << 1) /* truncate xino files */
++#define AuOpt_UDBA_NONE (1 << 2) /* users direct branch access */
++#define AuOpt_UDBA_REVAL (1 << 3)
++#define AuOpt_UDBA_HINOTIFY (1 << 4)
++#define AuOpt_PLINK (1 << 5) /* pseudo-link */
++#define AuOpt_DIRPERM1 (1 << 6) /* unimplemented */
++#define AuOpt_REFROF (1 << 7) /* unimplemented */
++#define AuOpt_ALWAYS_DIROPQ (1 << 8) /* policy to creating diropq */
++#define AuOpt_SUM (1 << 9) /* summation for statfs(2) */
++#define AuOpt_SUM_W (1 << 10) /* unimplemented */
++#define AuOpt_WARN_PERM (1 << 11) /* warn when add-branch */
++#define AuOpt_VERBOSE (1 << 12) /* busy inode when del-branch */
++
++#ifndef CONFIG_AUFS_HINOTIFY
++#undef AuOpt_UDBA_HINOTIFY
++#define AuOpt_UDBA_HINOTIFY 0
++#endif
++
++#define AuOpt_Def (AuOpt_XINO \
++ | AuOpt_UDBA_REVAL \
++ | AuOpt_PLINK \
++ /* | AuOpt_DIRPERM1 */ \
++ | AuOpt_WARN_PERM)
++#define AuOptMask_UDBA (AuOpt_UDBA_NONE \
++ | AuOpt_UDBA_REVAL \
++ | AuOpt_UDBA_HINOTIFY)
++
++#define au_opt_test(flags, name) (flags & AuOpt_##name)
++#define au_opt_set(flags, name) do { \
++ BUILD_BUG_ON(AuOpt_##name & AuOptMask_UDBA); \
++ ((flags) |= AuOpt_##name); \
++} while (0)
++#define au_opt_set_udba(flags, name) do { \
++ (flags) &= ~AuOptMask_UDBA; \
++ ((flags) |= AuOpt_##name); \
++} while (0)
++#define au_opt_clr(flags, name) { ((flags) &= ~AuOpt_##name); }
++
++/* ---------------------------------------------------------------------- */
++
++/* policies to select one among multiple writable branches */
++enum {
++ AuWbrCreate_TDP, /* top down parent */
++ AuWbrCreate_RR, /* round robin */
++ AuWbrCreate_MFS, /* most free space */
++ AuWbrCreate_MFSV, /* mfs with seconds */
++ AuWbrCreate_MFSRR, /* mfs then rr */
++ AuWbrCreate_MFSRRV, /* mfs then rr with seconds */
++ AuWbrCreate_PMFS, /* parent and mfs */
++ AuWbrCreate_PMFSV, /* parent and mfs with seconds */
++
++ AuWbrCreate_Def = AuWbrCreate_TDP
++};
++
++enum {
++ AuWbrCopyup_TDP, /* top down parent */
++ AuWbrCopyup_BUP, /* bottom up parent */
++ AuWbrCopyup_BU, /* bottom up */
++
++ AuWbrCopyup_Def = AuWbrCopyup_TDP
++};
++
++/* ---------------------------------------------------------------------- */
++
++struct au_opt_add {
++ aufs_bindex_t bindex;
++ char *pathname;
++ int perm;
++ struct path path;
++};
++
++struct au_opt_del {
++ char *pathname;
++ struct path h_path;
++};
++
++struct au_opt_mod {
++ char *path;
++ int perm;
++ struct dentry *h_root;
++};
++
++struct au_opt_xino {
++ char *path;
++ struct file *file;
++};
++
++struct au_opt_xino_itrunc {
++ aufs_bindex_t bindex;
++};
++
++struct au_opt_wbr_create {
++ int wbr_create;
++ int mfs_second;
++ unsigned long long mfsrr_watermark;
++};
++
++struct au_opt {
++ int type;
++ union {
++ struct au_opt_xino xino;
++ struct au_opt_xino_itrunc xino_itrunc;
++ struct au_opt_add add;
++ struct au_opt_del del;
++ struct au_opt_mod mod;
++ int dirwh;
++ int rdcache;
++ unsigned int rdblk;
++ unsigned int rdhash;
++ int udba;
++ struct au_opt_wbr_create wbr_create;
++ int wbr_copyup;
++ };
++};
++
++/* opts flags */
++#define AuOpts_REMOUNT 1
++#define AuOpts_REFRESH_DIR (1 << 1)
++#define AuOpts_REFRESH_NONDIR (1 << 2)
++#define AuOpts_TRUNC_XIB (1 << 3)
++#define au_ftest_opts(flags, name) ((flags) & AuOpts_##name)
++#define au_fset_opts(flags, name) { (flags) |= AuOpts_##name; }
++#define au_fclr_opts(flags, name) { (flags) &= ~AuOpts_##name; }
++
++struct au_opts {
++ struct au_opt *opt;
++ int max_opt;
++
++ unsigned int given_udba;
++ unsigned int flags;
++ unsigned long sb_flags;
++};
++
++/* ---------------------------------------------------------------------- */
++
++const char *au_optstr_br_perm(int brperm);
++const char *au_optstr_udba(int udba);
++const char *au_optstr_wbr_copyup(int wbr_copyup);
++const char *au_optstr_wbr_create(int wbr_create);
++
++void au_opts_free(struct au_opts *opts);
++int au_opts_parse(struct super_block *sb, char *str, struct au_opts *opts);
++int au_opts_verify(struct super_block *sb, unsigned long sb_flags,
++ unsigned int pending);
++int au_opts_mount(struct super_block *sb, struct au_opts *opts);
++int au_opts_remount(struct super_block *sb, struct au_opts *opts);
++
++unsigned int au_opt_udba(struct super_block *sb);
++
++/* ---------------------------------------------------------------------- */
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_OPTS_H__ */
+diff --git a/fs/aufs/plink.c b/fs/aufs/plink.c
+new file mode 100644
+index 0000000..62d258f
+--- /dev/null
++++ b/fs/aufs/plink.c
+@@ -0,0 +1,335 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * pseudo-link
++ */
++
++#include "aufs.h"
++
++/*
++ * during a user process maintains the pseudo-links,
++ * prohibit adding a new plink and branch manipulation.
++ */
++void au_plink_block_maintain(struct super_block *sb)
++{
++ struct au_sbinfo *sbi = au_sbi(sb);
++ /* gave up wake_up_bit() */
++ wait_event(sbi->si_plink_wq, !au_ftest_si(sbi, MAINTAIN_PLINK));
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct pseudo_link {
++ struct list_head list;
++ struct inode *inode;
++};
++
++#ifdef CONFIG_AUFS_DEBUG
++void au_plink_list(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++ struct list_head *plink_list;
++ struct pseudo_link *plink;
++
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++
++ plink_list = &sbinfo->si_plink.head;
++ spin_lock(&sbinfo->si_plink.spin);
++ list_for_each_entry(plink, plink_list, list)
++ AuDbg("%lu\n", plink->inode->i_ino);
++ spin_unlock(&sbinfo->si_plink.spin);
++}
++#endif
++
++/* is the inode pseudo-linked? */
++int au_plink_test(struct inode *inode)
++{
++ int found;
++ struct au_sbinfo *sbinfo;
++ struct list_head *plink_list;
++ struct pseudo_link *plink;
++
++ sbinfo = au_sbi(inode->i_sb);
++ AuDebugOn(!au_opt_test(au_mntflags(inode->i_sb), PLINK));
++
++ found = 0;
++ plink_list = &sbinfo->si_plink.head;
++ spin_lock(&sbinfo->si_plink.spin);
++ list_for_each_entry(plink, plink_list, list)
++ if (plink->inode == inode) {
++ found = 1;
++ break;
++ }
++ spin_unlock(&sbinfo->si_plink.spin);
++ return found;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * generate a name for plink.
++ * the file will be stored under AUFS_WH_PLINKDIR.
++ */
++/* 20 is max digits length of ulong 64 */
++#define PLINK_NAME_LEN ((20 + 1) * 2)
++
++static int plink_name(char *name, int len, struct inode *inode,
++ aufs_bindex_t bindex)
++{
++ int rlen;
++ struct inode *h_inode;
++
++ h_inode = au_h_iptr(inode, bindex);
++ rlen = snprintf(name, len, "%lu.%lu", inode->i_ino, h_inode->i_ino);
++ return rlen;
++}
++
++/* lookup the plink-ed @inode under the branch at @bindex */
++struct dentry *au_plink_lkup(struct inode *inode, aufs_bindex_t bindex)
++{
++ struct dentry *h_dentry, *h_parent;
++ struct au_branch *br;
++ struct inode *h_dir;
++ char a[PLINK_NAME_LEN];
++ struct qstr tgtname = {
++ .name = a
++ };
++
++ br = au_sbr(inode->i_sb, bindex);
++ h_parent = br->br_wbr->wbr_plink;
++ h_dir = h_parent->d_inode;
++ tgtname.len = plink_name(a, sizeof(a), inode, bindex);
++
++ /* always superio. */
++ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_CHILD2);
++ h_dentry = au_sio_lkup_one(&tgtname, h_parent, br);
++ mutex_unlock(&h_dir->i_mutex);
++ return h_dentry;
++}
++
++/* create a pseudo-link */
++static int do_whplink(struct qstr *tgt, struct dentry *h_parent,
++ struct dentry *h_dentry, struct au_branch *br)
++{
++ int err;
++ struct path h_path = {
++ .mnt = br->br_mnt
++ };
++ struct inode *h_dir;
++
++ h_dir = h_parent->d_inode;
++ again:
++ h_path.dentry = au_lkup_one(tgt, h_parent, br, /*nd*/NULL);
++ err = PTR_ERR(h_path.dentry);
++ if (IS_ERR(h_path.dentry))
++ goto out;
++
++ err = 0;
++ /* wh.plink dir is not monitored */
++ if (h_path.dentry->d_inode
++ && h_path.dentry->d_inode != h_dentry->d_inode) {
++ err = vfsub_unlink(h_dir, &h_path, /*force*/0);
++ dput(h_path.dentry);
++ h_path.dentry = NULL;
++ if (!err)
++ goto again;
++ }
++ if (!err && !h_path.dentry->d_inode)
++ err = vfsub_link(h_dentry, h_dir, &h_path);
++ dput(h_path.dentry);
++
++ out:
++ return err;
++}
++
++struct do_whplink_args {
++ int *errp;
++ struct qstr *tgt;
++ struct dentry *h_parent;
++ struct dentry *h_dentry;
++ struct au_branch *br;
++};
++
++static void call_do_whplink(void *args)
++{
++ struct do_whplink_args *a = args;
++ *a->errp = do_whplink(a->tgt, a->h_parent, a->h_dentry, a->br);
++}
++
++static int whplink(struct dentry *h_dentry, struct inode *inode,
++ aufs_bindex_t bindex, struct au_branch *br)
++{
++ int err, wkq_err;
++ struct au_wbr *wbr;
++ struct dentry *h_parent;
++ struct inode *h_dir;
++ char a[PLINK_NAME_LEN];
++ struct qstr tgtname = {
++ .name = a
++ };
++
++ wbr = au_sbr(inode->i_sb, bindex)->br_wbr;
++ h_parent = wbr->wbr_plink;
++ h_dir = h_parent->d_inode;
++ tgtname.len = plink_name(a, sizeof(a), inode, bindex);
++
++ /* always superio. */
++ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_CHILD2);
++ if (!au_test_wkq(current)) {
++ struct do_whplink_args args = {
++ .errp = &err,
++ .tgt = &tgtname,
++ .h_parent = h_parent,
++ .h_dentry = h_dentry,
++ .br = br
++ };
++ wkq_err = au_wkq_wait(call_do_whplink, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ } else
++ err = do_whplink(&tgtname, h_parent, h_dentry, br);
++ mutex_unlock(&h_dir->i_mutex);
++
++ return err;
++}
++
++/* free a single plink */
++static void do_put_plink(struct pseudo_link *plink, int do_del)
++{
++ iput(plink->inode);
++ if (do_del)
++ list_del(&plink->list);
++ kfree(plink);
++}
++
++/*
++ * create a new pseudo-link for @h_dentry on @bindex.
++ * the linked inode is held in aufs @inode.
++ */
++void au_plink_append(struct inode *inode, aufs_bindex_t bindex,
++ struct dentry *h_dentry)
++{
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++ struct list_head *plink_list;
++ struct pseudo_link *plink;
++ int found, err, cnt;
++
++ sb = inode->i_sb;
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++
++ err = 0;
++ cnt = 0;
++ found = 0;
++ plink_list = &sbinfo->si_plink.head;
++ spin_lock(&sbinfo->si_plink.spin);
++ list_for_each_entry(plink, plink_list, list) {
++ cnt++;
++ if (plink->inode == inode) {
++ found = 1;
++ break;
++ }
++ }
++ if (found) {
++ spin_unlock(&sbinfo->si_plink.spin);
++ return;
++ }
++
++ plink = NULL;
++ if (!found) {
++ plink = kmalloc(sizeof(*plink), GFP_ATOMIC);
++ if (plink) {
++ plink->inode = au_igrab(inode);
++ list_add(&plink->list, plink_list);
++ cnt++;
++ } else
++ err = -ENOMEM;
++ }
++ spin_unlock(&sbinfo->si_plink.spin);
++
++ if (!err) {
++ au_plink_block_maintain(sb);
++ err = whplink(h_dentry, inode, bindex, au_sbr(sb, bindex));
++ }
++
++ if (unlikely(cnt > AUFS_PLINK_WARN))
++ AuWarn1("unexpectedly many pseudo links, %d\n", cnt);
++ if (unlikely(err)) {
++ AuWarn("err %d, damaged pseudo link.\n", err);
++ if (!found && plink)
++ do_put_plink(plink, /*do_del*/1);
++ }
++}
++
++/* free all plinks */
++void au_plink_put(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++ struct list_head *plink_list;
++ struct pseudo_link *plink, *tmp;
++
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++
++ plink_list = &sbinfo->si_plink.head;
++ /* no spin_lock since sbinfo is write-locked */
++ list_for_each_entry_safe(plink, tmp, plink_list, list)
++ do_put_plink(plink, 0);
++ INIT_LIST_HEAD(plink_list);
++}
++
++/* free the plinks on a branch specified by @br_id */
++void au_plink_half_refresh(struct super_block *sb, aufs_bindex_t br_id)
++{
++ struct au_sbinfo *sbinfo;
++ struct list_head *plink_list;
++ struct pseudo_link *plink, *tmp;
++ struct inode *inode;
++ aufs_bindex_t bstart, bend, bindex;
++ unsigned char do_put;
++
++ sbinfo = au_sbi(sb);
++ AuDebugOn(!au_opt_test(au_mntflags(sb), PLINK));
++
++ plink_list = &sbinfo->si_plink.head;
++ /* no spin_lock since sbinfo is write-locked */
++ list_for_each_entry_safe(plink, tmp, plink_list, list) {
++ do_put = 0;
++ inode = au_igrab(plink->inode);
++ ii_write_lock_child(inode);
++ bstart = au_ibstart(inode);
++ bend = au_ibend(inode);
++ if (bstart >= 0) {
++ for (bindex = bstart; bindex <= bend; bindex++) {
++ if (!au_h_iptr(inode, bindex)
++ || au_ii_br_id(inode, bindex) != br_id)
++ continue;
++ au_set_h_iptr(inode, bindex, NULL, 0);
++ do_put = 1;
++ break;
++ }
++ } else
++ do_put_plink(plink, 1);
++
++ if (do_put) {
++ for (bindex = bstart; bindex <= bend; bindex++)
++ if (au_h_iptr(inode, bindex)) {
++ do_put = 0;
++ break;
++ }
++ if (do_put)
++ do_put_plink(plink, 1);
++ }
++ ii_write_unlock(inode);
++ iput(inode);
++ }
++}
+diff --git a/fs/aufs/rwsem.h b/fs/aufs/rwsem.h
+new file mode 100644
+index 0000000..d569243
+--- /dev/null
++++ b/fs/aufs/rwsem.h
+@@ -0,0 +1,52 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * simple read-write semaphore wrappers
++ */
++
++#ifndef __AUFS_RWSEM_H__
++#define __AUFS_RWSEM_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++
++#define au_rwsem_destroy(rw) AuDebugOn(rwsem_is_locked(rw))
++#define AuRwMustNoWaiters(rw) AuDebugOn(!list_empty(&(rw)->wait_list))
++
++#define AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
++static inline void prefix##_read_lock(param) \
++{ down_read(rwsem); } \
++static inline void prefix##_write_lock(param) \
++{ down_write(rwsem); } \
++static inline int prefix##_read_trylock(param) \
++{ return down_read_trylock(rwsem); } \
++static inline int prefix##_write_trylock(param) \
++{ return down_write_trylock(rwsem); }
++/* why is not _nested version defined */
++/* static inline void prefix##_read_trylock_nested(param, lsc)
++{ down_write_trylock_nested(rwsem, lsc)); }
++static inline void prefix##_write_trylock_nestd(param, lsc)
++{ down_write_trylock_nested(rwsem, lsc); } */
++
++#define AuSimpleUnlockRwsemFuncs(prefix, param, rwsem) \
++static inline void prefix##_read_unlock(param) \
++{ up_read(rwsem); } \
++static inline void prefix##_write_unlock(param) \
++{ up_write(rwsem); } \
++static inline void prefix##_downgrade_lock(param) \
++{ downgrade_write(rwsem); }
++
++#define AuSimpleRwsemFuncs(prefix, param, rwsem) \
++ AuSimpleLockRwsemFuncs(prefix, param, rwsem) \
++ AuSimpleUnlockRwsemFuncs(prefix, param, rwsem)
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_RWSEM_H__ */
+diff --git a/fs/aufs/sbinfo.c b/fs/aufs/sbinfo.c
+new file mode 100644
+index 0000000..37e0649
+--- /dev/null
++++ b/fs/aufs/sbinfo.c
+@@ -0,0 +1,194 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * superblock private data
++ */
++
++#include "aufs.h"
++
++/*
++ * they are necessary regardless sysfs is disabled.
++ */
++void au_si_free(struct kobject *kobj)
++{
++ struct au_sbinfo *sbinfo;
++ struct super_block *sb;
++
++ sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
++ AuDebugOn(!list_empty(&sbinfo->si_plink.head));
++
++ sb = sbinfo->si_sb;
++ si_write_lock(sb);
++ au_xino_clr(sb);
++ au_br_free(sbinfo);
++ kfree(sbinfo->si_branch);
++ mutex_destroy(&sbinfo->si_xib_mtx);
++ si_write_unlock(sb);
++ au_rwsem_destroy(&sbinfo->si_rwsem);
++
++ kfree(sbinfo);
++}
++
++int au_si_alloc(struct super_block *sb)
++{
++ int err;
++ struct au_sbinfo *sbinfo;
++
++ err = -ENOMEM;
++ sbinfo = kmalloc(sizeof(*sbinfo), GFP_NOFS);
++ if (unlikely(!sbinfo))
++ goto out;
++
++ /* will be reallocated separately */
++ sbinfo->si_branch = kzalloc(sizeof(*sbinfo->si_branch), GFP_NOFS);
++ if (unlikely(!sbinfo->si_branch))
++ goto out_sbinfo;
++
++ memset(&sbinfo->si_kobj, 0, sizeof(sbinfo->si_kobj));
++ err = sysaufs_si_init(sbinfo);
++ if (unlikely(err))
++ goto out_br;
++
++ au_nwt_init(&sbinfo->si_nowait);
++ init_rwsem(&sbinfo->si_rwsem);
++ down_write(&sbinfo->si_rwsem);
++ sbinfo->si_generation = 0;
++ sbinfo->au_si_status = 0;
++ sbinfo->si_bend = -1;
++ sbinfo->si_last_br_id = 0;
++
++ sbinfo->si_wbr_copyup = AuWbrCopyup_Def;
++ sbinfo->si_wbr_create = AuWbrCreate_Def;
++ sbinfo->si_wbr_copyup_ops = au_wbr_copyup_ops + AuWbrCopyup_Def;
++ sbinfo->si_wbr_create_ops = au_wbr_create_ops + AuWbrCreate_Def;
++
++ sbinfo->si_mntflags = AuOpt_Def;
++
++ sbinfo->si_xread = NULL;
++ sbinfo->si_xwrite = NULL;
++ sbinfo->si_xib = NULL;
++ mutex_init(&sbinfo->si_xib_mtx);
++ sbinfo->si_xib_buf = NULL;
++ sbinfo->si_xino_brid = -1;
++ /* leave si_xib_last_pindex and si_xib_next_bit */
++
++ sbinfo->si_rdcache = AUFS_RDCACHE_DEF * HZ;
++ sbinfo->si_rdblk = AUFS_RDBLK_DEF;
++ sbinfo->si_rdhash = AUFS_RDHASH_DEF;
++ sbinfo->si_dirwh = AUFS_DIRWH_DEF;
++
++ au_spl_init(&sbinfo->si_plink);
++ init_waitqueue_head(&sbinfo->si_plink_wq);
++
++ /* leave other members for sysaufs and si_mnt. */
++ sbinfo->si_sb = sb;
++ sb->s_fs_info = sbinfo;
++ au_debug_sbinfo_init(sbinfo);
++ return 0; /* success */
++
++ out_br:
++ kfree(sbinfo->si_branch);
++ out_sbinfo:
++ kfree(sbinfo);
++ out:
++ return err;
++}
++
++int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr)
++{
++ int err, sz;
++ struct au_branch **brp;
++
++ err = -ENOMEM;
++ sz = sizeof(*brp) * (sbinfo->si_bend + 1);
++ if (unlikely(!sz))
++ sz = sizeof(*brp);
++ brp = au_kzrealloc(sbinfo->si_branch, sz, sizeof(*brp) * nbr, GFP_NOFS);
++ if (brp) {
++ sbinfo->si_branch = brp;
++ err = 0;
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++unsigned int au_sigen_inc(struct super_block *sb)
++{
++ unsigned int gen;
++
++ gen = ++au_sbi(sb)->si_generation;
++ au_update_digen(sb->s_root);
++ au_update_iigen(sb->s_root->d_inode);
++ sb->s_root->d_inode->i_version++;
++ return gen;
++}
++
++aufs_bindex_t au_new_br_id(struct super_block *sb)
++{
++ aufs_bindex_t br_id;
++ int i;
++ struct au_sbinfo *sbinfo;
++
++ sbinfo = au_sbi(sb);
++ for (i = 0; i <= AUFS_BRANCH_MAX; i++) {
++ br_id = ++sbinfo->si_last_br_id;
++ if (br_id && au_br_index(sb, br_id) < 0)
++ return br_id;
++ }
++
++ return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* dentry and super_block lock. call at entry point */
++void aufs_read_lock(struct dentry *dentry, int flags)
++{
++ si_read_lock(dentry->d_sb, flags);
++ if (au_ftest_lock(flags, DW))
++ di_write_lock_child(dentry);
++ else
++ di_read_lock_child(dentry, flags);
++}
++
++void aufs_read_unlock(struct dentry *dentry, int flags)
++{
++ if (au_ftest_lock(flags, DW))
++ di_write_unlock(dentry);
++ else
++ di_read_unlock(dentry, flags);
++ si_read_unlock(dentry->d_sb);
++}
++
++void aufs_write_lock(struct dentry *dentry)
++{
++ si_write_lock(dentry->d_sb);
++ di_write_lock_child(dentry);
++}
++
++void aufs_write_unlock(struct dentry *dentry)
++{
++ di_write_unlock(dentry);
++ si_write_unlock(dentry->d_sb);
++}
++
++void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int flags)
++{
++ si_read_lock(d1->d_sb, flags);
++ di_write_lock2_child(d1, d2, au_ftest_lock(flags, DIR));
++}
++
++void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2)
++{
++ di_write_unlock2(d1, d2);
++ si_read_unlock(d1->d_sb);
++}
+diff --git a/fs/aufs/spl.h b/fs/aufs/spl.h
+new file mode 100644
+index 0000000..89ea7a2
+--- /dev/null
++++ b/fs/aufs/spl.h
+@@ -0,0 +1,47 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * simple list protected by a spinlock
++ */
++
++#ifndef __AUFS_SPL_H__
++#define __AUFS_SPL_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++
++struct au_splhead {
++ spinlock_t spin;
++ struct list_head head;
++};
++
++static inline void au_spl_init(struct au_splhead *spl)
++{
++ spin_lock_init(&spl->spin);
++ INIT_LIST_HEAD(&spl->head);
++}
++
++static inline void au_spl_add(struct list_head *list, struct au_splhead *spl)
++{
++ spin_lock(&spl->spin);
++ list_add(list, &spl->head);
++ spin_unlock(&spl->spin);
++}
++
++static inline void au_spl_del(struct list_head *list, struct au_splhead *spl)
++{
++ spin_lock(&spl->spin);
++ list_del(list);
++ spin_unlock(&spl->spin);
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_SPL_H__ */
+diff --git a/fs/aufs/super.c b/fs/aufs/super.c
+new file mode 100644
+index 0000000..0f6ad13
+--- /dev/null
++++ b/fs/aufs/super.c
+@@ -0,0 +1,859 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * mount and super_block operations
++ */
++
++#include <linux/buffer_head.h>
++#include <linux/seq_file.h>
++#include <linux/statfs.h>
++#include "aufs.h"
++
++/*
++ * super_operations
++ */
++static struct inode *aufs_alloc_inode(struct super_block *sb __maybe_unused)
++{
++ struct au_icntnr *c;
++
++ c = au_cache_alloc_icntnr();
++ if (c) {
++ inode_init_once(&c->vfs_inode);
++ c->vfs_inode.i_version = 1; /* sigen(sb); */
++ c->iinfo.ii_hinode = NULL;
++ return &c->vfs_inode;
++ }
++ return NULL;
++}
++
++static void aufs_destroy_inode(struct inode *inode)
++{
++ au_iinfo_fin(inode);
++ au_cache_free_icntnr(container_of(inode, struct au_icntnr, vfs_inode));
++}
++
++struct inode *au_iget_locked(struct super_block *sb, ino_t ino)
++{
++ struct inode *inode;
++ int err;
++
++ inode = iget_locked(sb, ino);
++ if (unlikely(!inode)) {
++ inode = ERR_PTR(-ENOMEM);
++ goto out;
++ }
++ if (!(inode->i_state & I_NEW))
++ goto out;
++
++ err = au_xigen_new(inode);
++ if (!err)
++ err = au_iinfo_init(inode);
++ if (!err)
++ inode->i_version++;
++ else {
++ iget_failed(inode);
++ inode = ERR_PTR(err);
++ }
++
++ out:
++ /* never return NULL */
++ AuDebugOn(!inode);
++ AuTraceErrPtr(inode);
++ return inode;
++}
++
++/* lock free root dinfo */
++static int au_show_brs(struct seq_file *seq, struct super_block *sb)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ struct path path;
++ struct au_hdentry *hd;
++ struct au_branch *br;
++
++ err = 0;
++ bend = au_sbend(sb);
++ hd = au_di(sb->s_root)->di_hdentry;
++ for (bindex = 0; !err && bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ path.mnt = br->br_mnt;
++ path.dentry = hd[bindex].hd_dentry;
++ err = au_seq_path(seq, &path);
++ if (err > 0)
++ err = seq_printf(seq, "=%s",
++ au_optstr_br_perm(br->br_perm));
++ if (!err && bindex != bend)
++ err = seq_putc(seq, ':');
++ }
++
++ return err;
++}
++
++static void au_show_wbr_create(struct seq_file *m, int v,
++ struct au_sbinfo *sbinfo)
++{
++ const char *pat;
++
++ seq_printf(m, ",create=");
++ pat = au_optstr_wbr_create(v);
++ switch (v) {
++ case AuWbrCreate_TDP:
++ case AuWbrCreate_RR:
++ case AuWbrCreate_MFS:
++ case AuWbrCreate_PMFS:
++ seq_printf(m, pat);
++ break;
++ case AuWbrCreate_MFSV:
++ seq_printf(m, /*pat*/"mfs:%lu",
++ sbinfo->si_wbr_mfs.mfs_expire / HZ);
++ break;
++ case AuWbrCreate_PMFSV:
++ seq_printf(m, /*pat*/"pmfs:%lu",
++ sbinfo->si_wbr_mfs.mfs_expire / HZ);
++ break;
++ case AuWbrCreate_MFSRR:
++ seq_printf(m, /*pat*/"mfsrr:%llu",
++ sbinfo->si_wbr_mfs.mfsrr_watermark);
++ break;
++ case AuWbrCreate_MFSRRV:
++ seq_printf(m, /*pat*/"mfsrr:%llu:%lu",
++ sbinfo->si_wbr_mfs.mfsrr_watermark,
++ sbinfo->si_wbr_mfs.mfs_expire / HZ);
++ break;
++ }
++}
++
++static int au_show_xino(struct seq_file *seq, struct vfsmount *mnt)
++{
++#ifdef CONFIG_SYSFS
++ return 0;
++#else
++ int err;
++ const int len = sizeof(AUFS_XINO_FNAME) - 1;
++ aufs_bindex_t bindex, brid;
++ struct super_block *sb;
++ struct qstr *name;
++ struct file *f;
++ struct dentry *d, *h_root;
++
++ err = 0;
++ sb = mnt->mnt_sb;
++ f = au_sbi(sb)->si_xib;
++ if (!f)
++ goto out;
++
++ /* stop printing the default xino path on the first writable branch */
++ h_root = NULL;
++ brid = au_xino_brid(sb);
++ if (brid >= 0) {
++ bindex = au_br_index(sb, brid);
++ h_root = au_di(sb->s_root)->di_hdentry[0 + bindex].hd_dentry;
++ }
++ d = f->f_dentry;
++ name = &d->d_name;
++ /* safe ->d_parent because the file is unlinked */
++ if (d->d_parent == h_root
++ && name->len == len
++ && !memcmp(name->name, AUFS_XINO_FNAME, len))
++ goto out;
++
++ seq_puts(seq, ",xino=");
++ err = au_xino_path(seq, f);
++
++ out:
++ return err;
++#endif
++}
++
++/* seq_file will re-call me in case of too long string */
++static int aufs_show_options(struct seq_file *m, struct vfsmount *mnt)
++{
++ int err, n;
++ unsigned int mnt_flags, v;
++ struct super_block *sb;
++ struct au_sbinfo *sbinfo;
++
++#define AuBool(name, str) do { \
++ v = au_opt_test(mnt_flags, name); \
++ if (v != au_opt_test(AuOpt_Def, name)) \
++ seq_printf(m, ",%s" #str, v ? "" : "no"); \
++} while (0)
++
++#define AuStr(name, str) do { \
++ v = mnt_flags & AuOptMask_##name; \
++ if (v != (AuOpt_Def & AuOptMask_##name)) \
++ seq_printf(m, "," #str "=%s", au_optstr_##str(v)); \
++} while (0)
++
++#define AuUInt(name, str, val) do { \
++ if (val != AUFS_##name##_DEF) \
++ seq_printf(m, "," #str "=%u", val); \
++} while (0)
++
++ /* lock free root dinfo */
++ sb = mnt->mnt_sb;
++ si_noflush_read_lock(sb);
++ sbinfo = au_sbi(sb);
++ seq_printf(m, ",si=%lx", sysaufs_si_id(sbinfo));
++
++ mnt_flags = au_mntflags(sb);
++ if (au_opt_test(mnt_flags, XINO)) {
++ err = au_show_xino(m, mnt);
++ if (unlikely(err))
++ goto out;
++ } else
++ seq_puts(m, ",noxino");
++
++ AuBool(TRUNC_XINO, trunc_xino);
++ AuStr(UDBA, udba);
++ AuBool(PLINK, plink);
++ /* AuBool(DIRPERM1, dirperm1); */
++ /* AuBool(REFROF, refrof); */
++
++ v = sbinfo->si_wbr_create;
++ if (v != AuWbrCreate_Def)
++ au_show_wbr_create(m, v, sbinfo);
++
++ v = sbinfo->si_wbr_copyup;
++ if (v != AuWbrCopyup_Def)
++ seq_printf(m, ",cpup=%s", au_optstr_wbr_copyup(v));
++
++ v = au_opt_test(mnt_flags, ALWAYS_DIROPQ);
++ if (v != au_opt_test(AuOpt_Def, ALWAYS_DIROPQ))
++ seq_printf(m, ",diropq=%c", v ? 'a' : 'w');
++
++ AuUInt(DIRWH, dirwh, sbinfo->si_dirwh);
++
++ n = sbinfo->si_rdcache / HZ;
++ AuUInt(RDCACHE, rdcache, n);
++
++ AuUInt(RDBLK, rdblk, sbinfo->si_rdblk);
++ AuUInt(RDHASH, rdhash, sbinfo->si_rdhash);
++
++ AuBool(SUM, sum);
++ /* AuBool(SUM_W, wsum); */
++ AuBool(WARN_PERM, warn_perm);
++ AuBool(VERBOSE, verbose);
++
++ out:
++ /* be sure to print "br:" last */
++ if (!sysaufs_brs) {
++ seq_puts(m, ",br:");
++ au_show_brs(m, sb);
++ }
++ si_read_unlock(sb);
++ return 0;
++
++#undef Deleted
++#undef AuBool
++#undef AuStr
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* sum mode which returns the summation for statfs(2) */
++
++static u64 au_add_till_max(u64 a, u64 b)
++{
++ u64 old;
++
++ old = a;
++ a += b;
++ if (old < a)
++ return a;
++ return ULLONG_MAX;
++}
++
++static int au_statfs_sum(struct super_block *sb, struct kstatfs *buf)
++{
++ int err;
++ u64 blocks, bfree, bavail, files, ffree;
++ aufs_bindex_t bend, bindex, i;
++ unsigned char shared;
++ struct vfsmount *h_mnt;
++ struct super_block *h_sb;
++
++ blocks = 0;
++ bfree = 0;
++ bavail = 0;
++ files = 0;
++ ffree = 0;
++
++ err = 0;
++ bend = au_sbend(sb);
++ for (bindex = bend; bindex >= 0; bindex--) {
++ h_mnt = au_sbr_mnt(sb, bindex);
++ h_sb = h_mnt->mnt_sb;
++ shared = 0;
++ for (i = bindex + 1; !shared && i <= bend; i++)
++ shared = (au_sbr_sb(sb, i) == h_sb);
++ if (shared)
++ continue;
++
++ /* sb->s_root for NFS is unreliable */
++ err = vfs_statfs(h_mnt->mnt_root, buf);
++ if (unlikely(err))
++ goto out;
++
++ blocks = au_add_till_max(blocks, buf->f_blocks);
++ bfree = au_add_till_max(bfree, buf->f_bfree);
++ bavail = au_add_till_max(bavail, buf->f_bavail);
++ files = au_add_till_max(files, buf->f_files);
++ ffree = au_add_till_max(ffree, buf->f_ffree);
++ }
++
++ buf->f_blocks = blocks;
++ buf->f_bfree = bfree;
++ buf->f_bavail = bavail;
++ buf->f_files = files;
++ buf->f_ffree = ffree;
++
++ out:
++ return err;
++}
++
++static int aufs_statfs(struct dentry *dentry, struct kstatfs *buf)
++{
++ int err;
++ struct super_block *sb;
++
++ /* lock free root dinfo */
++ sb = dentry->d_sb;
++ si_noflush_read_lock(sb);
++ if (!au_opt_test(au_mntflags(sb), SUM))
++ /* sb->s_root for NFS is unreliable */
++ err = vfs_statfs(au_sbr_mnt(sb, 0)->mnt_root, buf);
++ else
++ err = au_statfs_sum(sb, buf);
++ si_read_unlock(sb);
++
++ if (!err) {
++ buf->f_type = AUFS_SUPER_MAGIC;
++ buf->f_namelen -= AUFS_WH_PFX_LEN;
++ memset(&buf->f_fsid, 0, sizeof(buf->f_fsid));
++ }
++ /* buf->f_bsize = buf->f_blocks = buf->f_bfree = buf->f_bavail = -1; */
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* try flushing the lower fs at aufs remount/unmount time */
++
++static void au_fsync_br(struct super_block *sb)
++{
++ aufs_bindex_t bend, bindex;
++ int brperm;
++ struct au_branch *br;
++ struct super_block *h_sb;
++
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex < bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ brperm = br->br_perm;
++ if (brperm == AuBrPerm_RR || brperm == AuBrPerm_RRWH)
++ continue;
++ h_sb = br->br_mnt->mnt_sb;
++ if (bdev_read_only(h_sb->s_bdev))
++ continue;
++
++ lockdep_off();
++ down_write(&h_sb->s_umount);
++ shrink_dcache_sb(h_sb);
++ fsync_super(h_sb);
++ up_write(&h_sb->s_umount);
++ lockdep_on();
++ }
++}
++
++/*
++ * this IS NOT for super_operations.
++ * I guess it will be reverted someday.
++ */
++static void aufs_umount_begin(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++
++ sbinfo = au_sbi(sb);
++ if (!sbinfo)
++ return;
++
++ si_write_lock(sb);
++ au_fsync_br(sb);
++ if (au_opt_test(au_mntflags(sb), PLINK))
++ au_plink_put(sb);
++ if (sbinfo->si_wbr_create_ops->fin)
++ sbinfo->si_wbr_create_ops->fin(sb);
++ si_write_unlock(sb);
++}
++
++/* final actions when unmounting a file system */
++static void aufs_put_super(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++
++ sbinfo = au_sbi(sb);
++ if (!sbinfo)
++ return;
++
++ aufs_umount_begin(sb);
++ dbgaufs_si_fin(sbinfo);
++ kobject_put(&sbinfo->si_kobj);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * refresh dentry and inode at remount time.
++ */
++static int do_refresh(struct dentry *dentry, mode_t type,
++ unsigned int dir_flags)
++{
++ int err;
++ struct dentry *parent;
++
++ di_write_lock_child(dentry);
++ parent = dget_parent(dentry);
++ di_read_lock_parent(parent, AuLock_IR);
++
++ /* returns the number of positive dentries */
++ err = au_refresh_hdentry(dentry, type);
++ if (err >= 0) {
++ struct inode *inode = dentry->d_inode;
++ err = au_refresh_hinode(inode, dentry);
++ if (!err && type == S_IFDIR)
++ au_reset_hinotify(inode, dir_flags);
++ }
++ if (unlikely(err))
++ AuErr("unrecoverable error %d, %.*s\n", err, AuDLNPair(dentry));
++
++ di_read_unlock(parent, AuLock_IR);
++ dput(parent);
++ di_write_unlock(dentry);
++
++ return err;
++}
++
++static int test_dir(struct dentry *dentry, void *arg __maybe_unused)
++{
++ return S_ISDIR(dentry->d_inode->i_mode);
++}
++
++/* gave up consolidating with refresh_nondir() */
++static int refresh_dir(struct dentry *root, unsigned int sigen)
++{
++ int err, i, j, ndentry, e;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++ struct dentry **dentries;
++ struct inode *inode;
++ const unsigned int flags = au_hi_flags(root->d_inode, /*isdir*/1);
++
++ err = 0;
++ list_for_each_entry(inode, &root->d_sb->s_inodes, i_sb_list)
++ if (S_ISDIR(inode->i_mode) && au_iigen(inode) != sigen) {
++ ii_write_lock_child(inode);
++ e = au_refresh_hinode_self(inode, /*do_attr*/1);
++ ii_write_unlock(inode);
++ if (unlikely(e)) {
++ AuDbg("e %d, i%lu\n", e, inode->i_ino);
++ if (!err)
++ err = e;
++ /* go on even if err */
++ }
++ }
++
++ e = au_dpages_init(&dpages, GFP_NOFS);
++ if (unlikely(e)) {
++ if (!err)
++ err = e;
++ goto out;
++ }
++ e = au_dcsub_pages(&dpages, root, test_dir, NULL);
++ if (unlikely(e)) {
++ if (!err)
++ err = e;
++ goto out_dpages;
++ }
++
++ for (i = 0; !e && i < dpages.ndpage; i++) {
++ dpage = dpages.dpages + i;
++ dentries = dpage->dentries;
++ ndentry = dpage->ndentry;
++ for (j = 0; !e && j < ndentry; j++) {
++ struct dentry *d;
++
++ d = dentries[j];
++ au_dbg_verify_dir_parent(d, sigen);
++ if (au_digen(d) != sigen) {
++ e = do_refresh(d, S_IFDIR, flags);
++ if (unlikely(e && !err))
++ err = e;
++ /* break on err */
++ }
++ }
++ }
++
++ out_dpages:
++ au_dpages_free(&dpages);
++ out:
++ return err;
++}
++
++static int test_nondir(struct dentry *dentry, void *arg __maybe_unused)
++{
++ return !S_ISDIR(dentry->d_inode->i_mode);
++}
++
++static int refresh_nondir(struct dentry *root, unsigned int sigen,
++ int do_dentry)
++{
++ int err, i, j, ndentry, e;
++ struct au_dcsub_pages dpages;
++ struct au_dpage *dpage;
++ struct dentry **dentries;
++ struct inode *inode;
++
++ err = 0;
++ list_for_each_entry(inode, &root->d_sb->s_inodes, i_sb_list)
++ if (!S_ISDIR(inode->i_mode) && au_iigen(inode) != sigen) {
++ ii_write_lock_child(inode);
++ e = au_refresh_hinode_self(inode, /*do_attr*/1);
++ ii_write_unlock(inode);
++ if (unlikely(e)) {
++ AuDbg("e %d, i%lu\n", e, inode->i_ino);
++ if (!err)
++ err = e;
++ /* go on even if err */
++ }
++ }
++
++ if (!do_dentry)
++ goto out;
++
++ e = au_dpages_init(&dpages, GFP_NOFS);
++ if (unlikely(e)) {
++ if (!err)
++ err = e;
++ goto out;
++ }
++ e = au_dcsub_pages(&dpages, root, test_nondir, NULL);
++ if (unlikely(e)) {
++ if (!err)
++ err = e;
++ goto out_dpages;
++ }
++
++ for (i = 0; i < dpages.ndpage; i++) {
++ dpage = dpages.dpages + i;
++ dentries = dpage->dentries;
++ ndentry = dpage->ndentry;
++ for (j = 0; j < ndentry; j++) {
++ struct dentry *d;
++
++ d = dentries[j];
++ au_dbg_verify_nondir_parent(d, sigen);
++ inode = d->d_inode;
++ if (inode && au_digen(d) != sigen) {
++ e = do_refresh(d, inode->i_mode & S_IFMT,
++ /*dir_flags*/0);
++ if (unlikely(e && !err))
++ err = e;
++ /* go on even err */
++ }
++ }
++ }
++
++ out_dpages:
++ au_dpages_free(&dpages);
++ out:
++ return err;
++}
++
++static void au_remount_refresh(struct super_block *sb, unsigned int flags)
++{
++ int err;
++ unsigned int sigen;
++ struct au_sbinfo *sbinfo;
++ struct dentry *root;
++ struct inode *inode;
++
++ au_sigen_inc(sb);
++ sigen = au_sigen(sb);
++ sbinfo = au_sbi(sb);
++ au_fclr_si(sbinfo, FAILED_REFRESH_DIRS);
++
++ root = sb->s_root;
++ DiMustNoWaiters(root);
++ inode = root->d_inode;
++ IiMustNoWaiters(inode);
++ au_reset_hinotify(inode, au_hi_flags(inode, /*isdir*/1));
++ di_write_unlock(root);
++
++ err = refresh_dir(root, sigen);
++ if (unlikely(err)) {
++ au_fset_si(sbinfo, FAILED_REFRESH_DIRS);
++ AuWarn("Refreshing directories failed, ignored (%d)\n", err);
++ }
++
++ if (au_ftest_opts(flags, REFRESH_NONDIR)) {
++ err = refresh_nondir(root, sigen, !err);
++ if (unlikely(err))
++ AuWarn("Refreshing non-directories failed, ignored"
++ "(%d)\n", err);
++ }
++
++ /* aufs_write_lock() calls ..._child() */
++ di_write_lock_child(root);
++ au_cpup_attr_all(root->d_inode, /*force*/1);
++}
++
++/* stop extra interpretation of errno in mount(8), and strange error messages */
++static int cvt_err(int err)
++{
++ AuTraceErr(err);
++
++ switch (err) {
++ case -ENOENT:
++ case -ENOTDIR:
++ case -EEXIST:
++ case -EIO:
++ err = -EINVAL;
++ }
++ return err;
++}
++
++static int aufs_remount_fs(struct super_block *sb, int *flags, char *data)
++{
++ int err;
++ struct au_opts opts;
++ struct dentry *root;
++ struct inode *inode;
++ struct au_sbinfo *sbinfo;
++
++ err = 0;
++ root = sb->s_root;
++ if (!data || !*data) {
++ aufs_write_lock(root);
++ err = au_opts_verify(sb, *flags, /*pending*/0);
++ if (!err)
++ au_fsync_br(sb);
++ aufs_write_unlock(root);
++ goto out;
++ }
++
++ err = -ENOMEM;
++ memset(&opts, 0, sizeof(opts));
++ opts.opt = (void *)__get_free_page(GFP_NOFS);
++ if (unlikely(!opts.opt))
++ goto out;
++ opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
++ opts.flags = AuOpts_REMOUNT;
++ opts.sb_flags = *flags;
++
++ /* parse it before aufs lock */
++ err = au_opts_parse(sb, data, &opts);
++ if (unlikely(err))
++ goto out_opts;
++
++ sbinfo = au_sbi(sb);
++ inode = root->d_inode;
++ mutex_lock(&inode->i_mutex);
++ aufs_write_lock(root);
++ au_fsync_br(sb);
++
++ /* au_opts_remount() may return an error */
++ err = au_opts_remount(sb, &opts);
++ au_opts_free(&opts);
++
++ if (au_ftest_opts(opts.flags, REFRESH_DIR)
++ || au_ftest_opts(opts.flags, REFRESH_NONDIR))
++ au_remount_refresh(sb, opts.flags);
++
++ aufs_write_unlock(root);
++ mutex_unlock(&inode->i_mutex);
++
++ out_opts:
++ free_page((unsigned long)opts.opt);
++ out:
++ err = cvt_err(err);
++ AuTraceErr(err);
++ return err;
++}
++
++static struct super_operations aufs_sop = {
++ .alloc_inode = aufs_alloc_inode,
++ .destroy_inode = aufs_destroy_inode,
++ .drop_inode = generic_delete_inode,
++ .show_options = aufs_show_options,
++ .statfs = aufs_statfs,
++ .put_super = aufs_put_super,
++ .remount_fs = aufs_remount_fs
++};
++
++/* ---------------------------------------------------------------------- */
++
++static int alloc_root(struct super_block *sb)
++{
++ int err;
++ struct inode *inode;
++ struct dentry *root;
++
++ err = -ENOMEM;
++ inode = au_iget_locked(sb, AUFS_ROOT_INO);
++ err = PTR_ERR(inode);
++ if (IS_ERR(inode))
++ goto out;
++
++ inode->i_op = &aufs_dir_iop;
++ inode->i_fop = &aufs_dir_fop;
++ inode->i_mode = S_IFDIR;
++ inode->i_nlink = 2;
++ unlock_new_inode(inode);
++
++ root = d_alloc_root(inode);
++ if (unlikely(!root))
++ goto out_iput;
++ err = PTR_ERR(root);
++ if (IS_ERR(root))
++ goto out_iput;
++
++ err = au_alloc_dinfo(root);
++ if (!err) {
++ sb->s_root = root;
++ return 0; /* success */
++ }
++ dput(root);
++ goto out; /* do not iput */
++
++ out_iput:
++ iget_failed(inode);
++ iput(inode);
++ out:
++ return err;
++
++}
++
++static int aufs_fill_super(struct super_block *sb, void *raw_data,
++ int silent __maybe_unused)
++{
++ int err;
++ struct au_opts opts;
++ struct dentry *root;
++ struct inode *inode;
++ char *arg = raw_data;
++
++ if (unlikely(!arg || !*arg)) {
++ err = -EINVAL;
++ AuErr("no arg\n");
++ goto out;
++ }
++
++ err = -ENOMEM;
++ memset(&opts, 0, sizeof(opts));
++ opts.opt = (void *)__get_free_page(GFP_NOFS);
++ if (unlikely(!opts.opt))
++ goto out;
++ opts.max_opt = PAGE_SIZE / sizeof(*opts.opt);
++ opts.sb_flags = sb->s_flags;
++
++ err = au_si_alloc(sb);
++ if (unlikely(err))
++ goto out_opts;
++
++ /* all timestamps always follow the ones on the branch */
++ sb->s_flags |= MS_NOATIME | MS_NODIRATIME;
++ sb->s_op = &aufs_sop;
++ sb->s_magic = AUFS_SUPER_MAGIC;
++ sb->s_maxbytes = 0;
++ au_export_init(sb);
++
++ err = alloc_root(sb);
++ if (unlikely(err)) {
++ si_write_unlock(sb);
++ goto out_info;
++ }
++ root = sb->s_root;
++ inode = root->d_inode;
++
++ /*
++ * actually we can parse options regardless aufs lock here.
++ * but at remount time, parsing must be done before aufs lock.
++ * so we follow the same rule.
++ */
++ ii_write_lock_parent(inode);
++ aufs_write_unlock(root);
++ err = au_opts_parse(sb, arg, &opts);
++ if (unlikely(err))
++ goto out_root;
++
++ /* lock vfs_inode first, then aufs. */
++ mutex_lock(&inode->i_mutex);
++ inode->i_op = &aufs_dir_iop;
++ inode->i_fop = &aufs_dir_fop;
++ aufs_write_lock(root);
++ err = au_opts_mount(sb, &opts);
++ au_opts_free(&opts);
++ if (unlikely(err))
++ goto out_unlock;
++ aufs_write_unlock(root);
++ mutex_unlock(&inode->i_mutex);
++ goto out_opts; /* success */
++
++ out_unlock:
++ aufs_write_unlock(root);
++ mutex_unlock(&inode->i_mutex);
++ out_root:
++ dput(root);
++ sb->s_root = NULL;
++ out_info:
++ kobject_put(&au_sbi(sb)->si_kobj);
++ sb->s_fs_info = NULL;
++ out_opts:
++ free_page((unsigned long)opts.opt);
++ out:
++ AuTraceErr(err);
++ err = cvt_err(err);
++ AuTraceErr(err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int aufs_get_sb(struct file_system_type *fs_type, int flags,
++ const char *dev_name __maybe_unused, void *raw_data,
++ struct vfsmount *mnt)
++{
++ int err;
++ struct super_block *sb;
++
++ /* all timestamps always follow the ones on the branch */
++ /* mnt->mnt_flags |= MNT_NOATIME | MNT_NODIRATIME; */
++ err = get_sb_nodev(fs_type, flags, raw_data, aufs_fill_super, mnt);
++ if (!err) {
++ sb = mnt->mnt_sb;
++ si_write_lock(sb);
++ sysaufs_brs_add(sb, 0);
++ si_write_unlock(sb);
++ }
++ return err;
++}
++
++struct file_system_type aufs_fs_type = {
++ .name = AUFS_FSTYPE,
++ .fs_flags =
++ FS_RENAME_DOES_D_MOVE /* a race between rename and others */
++ | FS_REVAL_DOT, /* for NFS branch and udba */
++ .get_sb = aufs_get_sb,
++ .kill_sb = generic_shutdown_super,
++ /* no need to __module_get() and module_put(). */
++ .owner = THIS_MODULE,
++};
+diff --git a/fs/aufs/super.h b/fs/aufs/super.h
+new file mode 100644
+index 0000000..9897dba
+--- /dev/null
++++ b/fs/aufs/super.h
+@@ -0,0 +1,351 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * super_block operations
++ */
++
++#ifndef __AUFS_SUPER_H__
++#define __AUFS_SUPER_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/kobject.h>
++#include <linux/aufs_type.h>
++#include "rwsem.h"
++#include "spl.h"
++#include "wkq.h"
++
++typedef ssize_t (*au_readf_t)(struct file *, char __user *, size_t, loff_t *);
++typedef ssize_t (*au_writef_t)(struct file *, const char __user *, size_t,
++ loff_t *);
++
++/* policies to select one among multiple writable branches */
++struct au_wbr_copyup_operations {
++ int (*copyup)(struct dentry *dentry);
++};
++
++struct au_wbr_create_operations {
++ int (*create)(struct dentry *dentry, int isdir);
++ int (*init)(struct super_block *sb);
++ int (*fin)(struct super_block *sb);
++};
++
++struct au_wbr_mfs {
++ struct mutex mfs_lock; /* protect this structure */
++ unsigned long mfs_jiffy;
++ unsigned long mfs_expire;
++ aufs_bindex_t mfs_bindex;
++
++ unsigned long long mfsrr_bytes;
++ unsigned long long mfsrr_watermark;
++};
++
++/* sbinfo status flags */
++/*
++ * set true when refresh_dirs() failed at remount time.
++ * then try refreshing dirs at access time again.
++ * if it is false, refreshing dirs at access time is unnecesary
++ */
++#define AuSi_FAILED_REFRESH_DIRS 1
++#define AuSi_MAINTAIN_PLINK (1 << 1) /* ioctl */
++#define au_ftest_si(sbinfo, name) ((sbinfo)->au_si_status & AuSi_##name)
++#define au_fset_si(sbinfo, name) \
++ { (sbinfo)->au_si_status |= AuSi_##name; }
++#define au_fclr_si(sbinfo, name) \
++ { (sbinfo)->au_si_status &= ~AuSi_##name; }
++
++struct au_branch;
++struct au_sbinfo {
++ /* nowait tasks in the system-wide workqueue */
++ struct au_nowait_tasks si_nowait;
++
++ struct rw_semaphore si_rwsem;
++
++ /* branch management */
++ unsigned int si_generation;
++
++ /* see above flags */
++ unsigned char au_si_status;
++
++ aufs_bindex_t si_bend;
++ aufs_bindex_t si_last_br_id;
++ struct au_branch **si_branch;
++
++ /* policy to select a writable branch */
++ unsigned char si_wbr_copyup;
++ unsigned char si_wbr_create;
++ struct au_wbr_copyup_operations *si_wbr_copyup_ops;
++ struct au_wbr_create_operations *si_wbr_create_ops;
++
++ /* round robin */
++ atomic_t si_wbr_rr_next;
++
++ /* most free space */
++ struct au_wbr_mfs si_wbr_mfs;
++
++ /* mount flags */
++ /* include/asm-ia64/siginfo.h defines a macro named si_flags */
++ unsigned int si_mntflags;
++
++ /* external inode number (bitmap and translation table) */
++ au_readf_t si_xread;
++ au_writef_t si_xwrite;
++ struct file *si_xib;
++ struct mutex si_xib_mtx; /* protect xib members */
++ unsigned long *si_xib_buf;
++ unsigned long si_xib_last_pindex;
++ int si_xib_next_bit;
++ aufs_bindex_t si_xino_brid;
++ /* reserved for future use */
++ /* unsigned long long si_xib_limit; */ /* Max xib file size */
++
++#ifdef CONFIG_AUFS_EXPORT
++ /* i_generation */
++ struct file *si_xigen;
++ atomic_t si_xigen_next;
++#endif
++
++ /* vdir parameters */
++ unsigned long si_rdcache; /* max cache time in HZ */
++ unsigned int si_rdblk; /* deblk size */
++ unsigned int si_rdhash; /* hash size */
++
++ /*
++ * If the number of whiteouts are larger than si_dirwh, leave all of
++ * them after au_whtmp_ren to reduce the cost of rmdir(2).
++ * future fsck.aufs or kernel thread will remove them later.
++ * Otherwise, remove all whiteouts and the dir in rmdir(2).
++ */
++ unsigned int si_dirwh;
++
++ /*
++ * rename(2) a directory with all children.
++ */
++ /* reserved for future use */
++ /* int si_rendir; */
++
++ /* pseudo_link list */
++ struct au_splhead si_plink;
++ wait_queue_head_t si_plink_wq;
++
++ /*
++ * sysfs and lifetime management.
++ * this is not a small structure and it may be a waste of memory in case
++ * of sysfs is disabled, particulary when many aufs-es are mounted.
++ * but using sysfs is majority.
++ */
++ struct kobject si_kobj;
++#ifdef CONFIG_DEBUG_FS
++ struct dentry *si_dbgaufs, *si_dbgaufs_xib;
++#ifdef CONFIG_AUFS_EXPORT
++ struct dentry *si_dbgaufs_xigen;
++#endif
++#endif
++
++ /* dirty, necessary for unmounting, sysfs and sysrq */
++ struct super_block *si_sb;
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* policy to select one among writable branches */
++#define AuWbrCopyup(sbinfo, args...) \
++ ((sbinfo)->si_wbr_copyup_ops->copyup(args))
++#define AuWbrCreate(sbinfo, args...) \
++ ((sbinfo)->si_wbr_create_ops->create(args))
++
++/* flags for si_read_lock()/aufs_read_lock()/di_read_lock() */
++#define AuLock_DW 1 /* write-lock dentry */
++#define AuLock_IR (1 << 1) /* read-lock inode */
++#define AuLock_IW (1 << 2) /* write-lock inode */
++#define AuLock_FLUSH (1 << 3) /* wait for 'nowait' tasks */
++#define AuLock_DIR (1 << 4) /* target is a dir */
++#define au_ftest_lock(flags, name) ((flags) & AuLock_##name)
++#define au_fset_lock(flags, name) { (flags) |= AuLock_##name; }
++#define au_fclr_lock(flags, name) { (flags) &= ~AuLock_##name; }
++
++/* ---------------------------------------------------------------------- */
++
++/* super.c */
++extern struct file_system_type aufs_fs_type;
++struct inode *au_iget_locked(struct super_block *sb, ino_t ino);
++
++/* sbinfo.c */
++void au_si_free(struct kobject *kobj);
++int au_si_alloc(struct super_block *sb);
++int au_sbr_realloc(struct au_sbinfo *sbinfo, int nbr);
++
++unsigned int au_sigen_inc(struct super_block *sb);
++aufs_bindex_t au_new_br_id(struct super_block *sb);
++
++void aufs_read_lock(struct dentry *dentry, int flags);
++void aufs_read_unlock(struct dentry *dentry, int flags);
++void aufs_write_lock(struct dentry *dentry);
++void aufs_write_unlock(struct dentry *dentry);
++void aufs_read_and_write_lock2(struct dentry *d1, struct dentry *d2, int isdir);
++void aufs_read_and_write_unlock2(struct dentry *d1, struct dentry *d2);
++
++/* wbr_policy.c */
++extern struct au_wbr_copyup_operations au_wbr_copyup_ops[];
++extern struct au_wbr_create_operations au_wbr_create_ops[];
++int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct au_sbinfo *au_sbi(struct super_block *sb)
++{
++ return sb->s_fs_info;
++}
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_EXPORT
++void au_export_init(struct super_block *sb);
++
++static inline int au_test_nfsd(struct task_struct *tsk)
++{
++ return !tsk->mm && !strcmp(tsk->comm, "nfsd");
++}
++
++int au_xigen_inc(struct inode *inode);
++int au_xigen_new(struct inode *inode);
++int au_xigen_set(struct super_block *sb, struct file *base);
++void au_xigen_clr(struct super_block *sb);
++
++static inline int au_busy_or_stale(void)
++{
++ if (!au_test_nfsd(current))
++ return -EBUSY;
++ return -ESTALE;
++}
++#else
++static inline void au_export_init(struct super_block *sb)
++{
++ /* nothing */
++}
++
++static inline int au_test_nfsd(struct task_struct *tsk)
++{
++ return 0;
++}
++
++static inline int au_xigen_inc(struct inode *inode)
++{
++ return 0;
++}
++
++static inline int au_xigen_new(struct inode *inode)
++{
++ return 0;
++}
++
++static inline int au_xigen_set(struct super_block *sb, struct file *base)
++{
++ return 0;
++}
++
++static inline void au_xigen_clr(struct super_block *sb)
++{
++ /* empty */
++}
++
++static inline int au_busy_or_stale(void)
++{
++ return -EBUSY;
++}
++#endif /* CONFIG_AUFS_EXPORT */
++
++/* ---------------------------------------------------------------------- */
++
++static inline void dbgaufs_si_null(struct au_sbinfo *sbinfo)
++{
++#ifdef CONFIG_DEBUG_FS
++ sbinfo->si_dbgaufs = NULL;
++ sbinfo->si_dbgaufs_xib = NULL;
++#ifdef CONFIG_AUFS_EXPORT
++ sbinfo->si_dbgaufs_xigen = NULL;
++#endif
++#endif
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* lock superblock. mainly for entry point functions */
++/*
++ * si_noflush_read_lock, si_noflush_write_lock,
++ * si_read_unlock, si_write_unlock, si_downgrade_lock
++ */
++AuSimpleLockRwsemFuncs(si_noflush, struct super_block *sb,
++ &au_sbi(sb)->si_rwsem);
++AuSimpleUnlockRwsemFuncs(si, struct super_block *sb, &au_sbi(sb)->si_rwsem);
++
++static inline void si_read_lock(struct super_block *sb, int flags)
++{
++ if (au_ftest_lock(flags, FLUSH))
++ au_nwt_flush(&au_sbi(sb)->si_nowait);
++ si_noflush_read_lock(sb);
++}
++
++static inline void si_write_lock(struct super_block *sb)
++{
++ au_nwt_flush(&au_sbi(sb)->si_nowait);
++ si_noflush_write_lock(sb);
++}
++
++static inline int si_read_trylock(struct super_block *sb, int flags)
++{
++ if (au_ftest_lock(flags, FLUSH))
++ au_nwt_flush(&au_sbi(sb)->si_nowait);
++ return si_noflush_read_trylock(sb);
++}
++
++static inline int si_write_trylock(struct super_block *sb, int flags)
++{
++ if (au_ftest_lock(flags, FLUSH))
++ au_nwt_flush(&au_sbi(sb)->si_nowait);
++ return si_noflush_write_trylock(sb);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static inline aufs_bindex_t au_sbend(struct super_block *sb)
++{
++ return au_sbi(sb)->si_bend;
++}
++
++static inline unsigned int au_mntflags(struct super_block *sb)
++{
++ return au_sbi(sb)->si_mntflags;
++}
++
++static inline unsigned int au_sigen(struct super_block *sb)
++{
++ return au_sbi(sb)->si_generation;
++}
++
++static inline struct au_branch *au_sbr(struct super_block *sb,
++ aufs_bindex_t bindex)
++{
++ return au_sbi(sb)->si_branch[0 + bindex];
++}
++
++static inline void au_xino_brid_set(struct super_block *sb, aufs_bindex_t brid)
++{
++ au_sbi(sb)->si_xino_brid = brid;
++}
++
++static inline aufs_bindex_t au_xino_brid(struct super_block *sb)
++{
++ return au_sbi(sb)->si_xino_brid;
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_SUPER_H__ */
+diff --git a/fs/aufs/sysaufs.c b/fs/aufs/sysaufs.c
+new file mode 100644
+index 0000000..623f2e6
+--- /dev/null
++++ b/fs/aufs/sysaufs.c
+@@ -0,0 +1,95 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sysfs interface and lifetime management
++ * they are necessary regardless sysfs is disabled.
++ */
++
++#include <linux/fs.h>
++#include <linux/random.h>
++#include <linux/sysfs.h>
++#include "aufs.h"
++
++unsigned long sysaufs_si_mask;
++struct kset *sysaufs_ket;
++
++#define AuSiAttr(_name) { \
++ .attr = { .name = __stringify(_name), .mode = 0444 }, \
++ .show = sysaufs_si_##_name, \
++}
++
++static struct sysaufs_si_attr sysaufs_si_attr_xi_path = AuSiAttr(xi_path);
++struct attribute *sysaufs_si_attrs[] = {
++ &sysaufs_si_attr_xi_path.attr,
++ NULL,
++};
++
++static struct sysfs_ops au_sbi_ops = {
++ .show = sysaufs_si_show
++};
++
++static struct kobj_type au_sbi_ktype = {
++ .release = au_si_free,
++ .sysfs_ops = &au_sbi_ops,
++ .default_attrs = sysaufs_si_attrs
++};
++
++/* ---------------------------------------------------------------------- */
++
++int sysaufs_si_init(struct au_sbinfo *sbinfo)
++{
++ int err;
++
++ sbinfo->si_kobj.kset = sysaufs_ket;
++ /* cf. sysaufs_name() */
++ err = kobject_init_and_add
++ (&sbinfo->si_kobj, &au_sbi_ktype, /*&sysaufs_ket->kobj*/NULL,
++ SysaufsSiNamePrefix "%lx", sysaufs_si_id(sbinfo));
++
++ dbgaufs_si_null(sbinfo);
++ if (!err) {
++ err = dbgaufs_si_init(sbinfo);
++ if (unlikely(err))
++ kobject_put(&sbinfo->si_kobj);
++ }
++ return err;
++}
++
++void sysaufs_fin(void)
++{
++ dbgaufs_fin();
++ sysfs_remove_group(&sysaufs_ket->kobj, sysaufs_attr_group);
++ kset_unregister(sysaufs_ket);
++}
++
++int __init sysaufs_init(void)
++{
++ int err;
++
++ do {
++ get_random_bytes(&sysaufs_si_mask, sizeof(sysaufs_si_mask));
++ } while (!sysaufs_si_mask);
++
++ sysaufs_ket = kset_create_and_add(AUFS_NAME, NULL, fs_kobj);
++ err = PTR_ERR(sysaufs_ket);
++ if (IS_ERR(sysaufs_ket))
++ goto out;
++ err = sysfs_create_group(&sysaufs_ket->kobj, sysaufs_attr_group);
++ if (unlikely(err)) {
++ kset_unregister(sysaufs_ket);
++ goto out;
++ }
++
++ err = dbgaufs_init();
++ if (unlikely(err))
++ sysaufs_fin();
++ out:
++ return err;
++}
+diff --git a/fs/aufs/sysaufs.h b/fs/aufs/sysaufs.h
+new file mode 100644
+index 0000000..c1202fa
+--- /dev/null
++++ b/fs/aufs/sysaufs.h
+@@ -0,0 +1,109 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sysfs interface and mount lifetime management
++ */
++
++#ifndef __SYSAUFS_H__
++#define __SYSAUFS_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/sysfs.h>
++#include <linux/aufs_type.h>
++#include "module.h"
++
++struct sysaufs_si_attr {
++ struct attribute attr;
++ int (*show)(struct seq_file *seq, struct super_block *sb);
++};
++
++/* ---------------------------------------------------------------------- */
++
++/* sysaufs.c */
++extern unsigned long sysaufs_si_mask;
++extern struct kset *sysaufs_ket;
++extern struct attribute *sysaufs_si_attrs[];
++int sysaufs_si_init(struct au_sbinfo *sbinfo);
++int __init sysaufs_init(void);
++void sysaufs_fin(void);
++
++/* ---------------------------------------------------------------------- */
++
++/* some people doesn't like to show a pointer in kernel */
++static inline unsigned long sysaufs_si_id(struct au_sbinfo *sbinfo)
++{
++ return sysaufs_si_mask ^ (unsigned long)sbinfo;
++}
++
++#define SysaufsSiNamePrefix "si_"
++#define SysaufsSiNameLen (sizeof(SysaufsSiNamePrefix) + 16)
++static inline void sysaufs_name(struct au_sbinfo *sbinfo, char *name)
++{
++ snprintf(name, SysaufsSiNameLen, SysaufsSiNamePrefix "%lx",
++ sysaufs_si_id(sbinfo));
++}
++
++struct au_branch;
++#ifdef CONFIG_SYSFS
++/* sysfs.c */
++extern struct attribute_group *sysaufs_attr_group;
++
++int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb);
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++ char *buf);
++
++void sysaufs_br_init(struct au_branch *br);
++void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex);
++void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex);
++
++#define sysaufs_brs_init() do {} while (0)
++
++#else
++#define sysaufs_attr_group NULL
++
++static inline
++int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb)
++{
++ return 0;
++}
++
++static inline
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++ char *buf)
++{
++ return 0;
++}
++
++static inline void sysaufs_br_init(struct au_branch *br)
++{
++ /* empty */
++}
++
++static inline void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++ /* nothing */
++}
++
++static inline void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++ /* nothing */
++}
++
++static inline void sysaufs_brs_init(void)
++{
++ sysaufs_brs = 0;
++}
++
++#endif /* CONFIG_SYSFS */
++
++#endif /* __KERNEL__ */
++#endif /* __SYSAUFS_H__ */
+diff --git a/fs/aufs/sysfs.c b/fs/aufs/sysfs.c
+new file mode 100644
+index 0000000..496a2fc
+--- /dev/null
++++ b/fs/aufs/sysfs.c
+@@ -0,0 +1,198 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sysfs interface
++ */
++
++#include <linux/fs.h>
++#include <linux/seq_file.h>
++#include <linux/sysfs.h>
++#include "aufs.h"
++
++static struct attribute *au_attr[] = {
++ NULL, /* need to NULL terminate the list of attributes */
++};
++
++static struct attribute_group sysaufs_attr_group_body = {
++ .attrs = au_attr
++};
++
++struct attribute_group *sysaufs_attr_group = &sysaufs_attr_group_body;
++
++/* ---------------------------------------------------------------------- */
++
++int sysaufs_si_xi_path(struct seq_file *seq, struct super_block *sb)
++{
++ int err;
++
++ err = 0;
++ if (au_opt_test(au_mntflags(sb), XINO)) {
++ err = au_xino_path(seq, au_sbi(sb)->si_xib);
++ seq_putc(seq, '\n');
++ }
++ return err;
++}
++
++/*
++ * the lifetime of branch is independent from the entry under sysfs.
++ * sysfs handles the lifetime of the entry, and never call ->show() after it is
++ * unlinked.
++ */
++static int sysaufs_si_br(struct seq_file *seq, struct super_block *sb,
++ aufs_bindex_t bindex)
++{
++ struct path path;
++ struct dentry *root;
++ struct au_branch *br;
++
++ AuDbg("b%d\n", bindex);
++
++ root = sb->s_root;
++ di_read_lock_parent(root, !AuLock_IR);
++ br = au_sbr(sb, bindex);
++ path.mnt = br->br_mnt;
++ path.dentry = au_h_dptr(root, bindex);
++ au_seq_path(seq, &path);
++ di_read_unlock(root, !AuLock_IR);
++ seq_printf(seq, "=%s\n", au_optstr_br_perm(br->br_perm));
++ return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static struct seq_file *au_seq(char *p, ssize_t len)
++{
++ struct seq_file *seq;
++
++ seq = kzalloc(sizeof(*seq), GFP_NOFS);
++ if (seq) {
++ /* mutex_init(&seq.lock); */
++ seq->buf = p;
++ seq->size = len;
++ return seq; /* success */
++ }
++
++ seq = ERR_PTR(-ENOMEM);
++ return seq;
++}
++
++#define SysaufsBr_PREFIX "br"
++
++/* todo: file size may exceed PAGE_SIZE */
++ssize_t sysaufs_si_show(struct kobject *kobj, struct attribute *attr,
++ char *buf)
++{
++ ssize_t err;
++ long l;
++ aufs_bindex_t bend;
++ struct au_sbinfo *sbinfo;
++ struct super_block *sb;
++ struct seq_file *seq;
++ char *name;
++ struct attribute **cattr;
++
++ sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
++ sb = sbinfo->si_sb;
++ si_noflush_read_lock(sb);
++
++ seq = au_seq(buf, PAGE_SIZE);
++ err = PTR_ERR(seq);
++ if (IS_ERR(seq))
++ goto out;
++
++ name = (void *)attr->name;
++ cattr = sysaufs_si_attrs;
++ while (*cattr) {
++ if (!strcmp(name, (*cattr)->name)) {
++ err = container_of(*cattr, struct sysaufs_si_attr, attr)
++ ->show(seq, sb);
++ goto out_seq;
++ }
++ cattr++;
++ }
++
++ bend = au_sbend(sb);
++ if (!strncmp(name, SysaufsBr_PREFIX, sizeof(SysaufsBr_PREFIX) - 1)) {
++ name += sizeof(SysaufsBr_PREFIX) - 1;
++ err = strict_strtol(name, 10, &l);
++ if (!err) {
++ if (l <= bend)
++ err = sysaufs_si_br(seq, sb, (aufs_bindex_t)l);
++ else
++ err = -ENOENT;
++ }
++ goto out_seq;
++ }
++ BUG();
++
++ out_seq:
++ if (!err) {
++ err = seq->count;
++ /* sysfs limit */
++ if (unlikely(err == PAGE_SIZE))
++ err = -EFBIG;
++ }
++ kfree(seq);
++ out:
++ si_read_unlock(sb);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void sysaufs_br_init(struct au_branch *br)
++{
++ br->br_attr.name = br->br_name;
++ br->br_attr.mode = S_IRUGO;
++ br->br_attr.owner = THIS_MODULE;
++}
++
++void sysaufs_brs_del(struct super_block *sb, aufs_bindex_t bindex)
++{
++ struct au_branch *br;
++ struct kobject *kobj;
++ aufs_bindex_t bend;
++
++ dbgaufs_brs_del(sb, bindex);
++
++ if (!sysaufs_brs)
++ return;
++
++ kobj = &au_sbi(sb)->si_kobj;
++ bend = au_sbend(sb);
++ for (; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ sysfs_remove_file(kobj, &br->br_attr);
++ }
++}
++
++void sysaufs_brs_add(struct super_block *sb, aufs_bindex_t bindex)
++{
++ int err;
++ aufs_bindex_t bend;
++ struct kobject *kobj;
++ struct au_branch *br;
++
++ dbgaufs_brs_add(sb, bindex);
++
++ if (!sysaufs_brs)
++ return;
++
++ kobj = &au_sbi(sb)->si_kobj;
++ bend = au_sbend(sb);
++ for (; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ snprintf(br->br_name, sizeof(br->br_name), SysaufsBr_PREFIX
++ "%d", bindex);
++ err = sysfs_create_file(kobj, &br->br_attr);
++ if (unlikely(err))
++ AuWarn("failed %s under sysfs(%d)\n", br->br_name, err);
++ }
++}
+diff --git a/fs/aufs/sysrq.c b/fs/aufs/sysrq.c
+new file mode 100644
+index 0000000..419ff2c
+--- /dev/null
++++ b/fs/aufs/sysrq.c
+@@ -0,0 +1,106 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * magic sysrq hanlder
++ */
++
++#include <linux/fs.h>
++#include <linux/module.h>
++#include <linux/moduleparam.h>
++/* #include <linux/sysrq.h> */
++#include "aufs.h"
++
++/* ---------------------------------------------------------------------- */
++
++static void sysrq_sb(struct super_block *sb)
++{
++ char *plevel;
++ struct au_sbinfo *sbinfo;
++ struct file *file;
++
++ plevel = au_plevel;
++ au_plevel = KERN_WARNING;
++ au_debug(1);
++
++ sbinfo = au_sbi(sb);
++ pr_warning("si=%lx\n", sysaufs_si_id(sbinfo));
++ pr_warning(AUFS_NAME ": superblock\n");
++ au_dpri_sb(sb);
++ pr_warning(AUFS_NAME ": root dentry\n");
++ au_dpri_dentry(sb->s_root);
++ pr_warning(AUFS_NAME ": root inode\n");
++ au_dpri_inode(sb->s_root->d_inode);
++#if 0
++ struct inode *i;
++ pr_warning(AUFS_NAME ": isolated inode\n");
++ list_for_each_entry(i, &sb->s_inodes, i_sb_list)
++ if (list_empty(&i->i_dentry))
++ au_dpri_inode(i);
++#endif
++ pr_warning(AUFS_NAME ": files\n");
++ list_for_each_entry(file, &sb->s_files, f_u.fu_list)
++ if (!special_file(file->f_dentry->d_inode->i_mode))
++ au_dpri_file(file);
++
++ au_plevel = plevel;
++ au_debug(0);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* module parameter */
++static char *aufs_sysrq_key = "a";
++module_param_named(sysrq, aufs_sysrq_key, charp, S_IRUGO);
++MODULE_PARM_DESC(sysrq, "MagicSysRq key for " AUFS_NAME);
++
++static void au_sysrq(int key __maybe_unused,
++ struct tty_struct *tty __maybe_unused)
++{
++ struct kobject *kobj;
++ struct au_sbinfo *sbinfo;
++
++ /* spin_lock(&sysaufs_ket->list_lock); */
++ list_for_each_entry(kobj, &sysaufs_ket->list, entry) {
++ sbinfo = container_of(kobj, struct au_sbinfo, si_kobj);
++ sysrq_sb(sbinfo->si_sb);
++ }
++ /* spin_unlock(&sysaufs_ket->list_lock); */
++}
++
++static struct sysrq_key_op au_sysrq_op = {
++ .handler = au_sysrq,
++ .help_msg = "Aufs",
++ .action_msg = "Aufs",
++ .enable_mask = SYSRQ_ENABLE_DUMP
++};
++
++/* ---------------------------------------------------------------------- */
++
++int __init au_sysrq_init(void)
++{
++ int err;
++ char key;
++
++ err = -1;
++ key = *aufs_sysrq_key;
++ if ('a' <= key && key <= 'z')
++ err = register_sysrq_key(key, &au_sysrq_op);
++ if (unlikely(err))
++ AuErr("err %d, sysrq=%c\n", err, key);
++ return err;
++}
++
++void au_sysrq_fin(void)
++{
++ int err;
++ err = unregister_sysrq_key(*aufs_sysrq_key, &au_sysrq_op);
++ if (unlikely(err))
++ AuErr("err %d (ignored)\n", err);
++}
+diff --git a/fs/aufs/vdir.c b/fs/aufs/vdir.c
+new file mode 100644
+index 0000000..9c7b64a
+--- /dev/null
++++ b/fs/aufs/vdir.c
+@@ -0,0 +1,796 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * virtual or vertical directory
++ */
++
++#include "aufs.h"
++
++static unsigned int calc_size(int namelen)
++{
++ int sz;
++ const int mask = sizeof(ino_t) - 1;
++
++ BUILD_BUG_ON(sizeof(ino_t) != sizeof(long));
++
++ sz = sizeof(struct au_vdir_de) + namelen;
++ if (sz & mask) {
++ sz += sizeof(ino_t);
++ sz &= ~mask;
++ }
++
++ AuDebugOn(sz % sizeof(ino_t));
++ return sz;
++}
++
++static int set_deblk_end(union au_vdir_deblk_p *p,
++ union au_vdir_deblk_p *deblk_end)
++{
++ if (calc_size(0) <= deblk_end->deblk - p->deblk) {
++ p->de->de_str.len = 0;
++ /* smp_mb(); */
++ return 0;
++ }
++ return -1; /* error */
++}
++
++/* returns true or false */
++static int is_deblk_end(union au_vdir_deblk_p *p,
++ union au_vdir_deblk_p *deblk_end)
++{
++ if (calc_size(0) <= deblk_end->deblk - p->deblk)
++ return !p->de->de_str.len;
++ return 1;
++}
++
++static unsigned char *last_deblk(struct au_vdir *vdir)
++{
++ return vdir->vd_deblk[vdir->vd_nblk - 1];
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * the allocated memory has to be freed by
++ * au_nhash_wh_free() or void au_nhash_de_free().
++ */
++struct au_nhash *au_nhash_alloc(struct super_block *sb, aufs_bindex_t bend,
++ gfp_t gfp)
++{
++ struct au_nhash *nhash;
++ struct hlist_head *head;
++ unsigned int u, n;
++ aufs_bindex_t bindex;
++
++ nhash = kmalloc(sizeof(*nhash) * (bend + 1), gfp);
++ if (unlikely(!nhash))
++ goto out;
++
++ n = au_sbi(sb)->si_rdhash;
++ for (bindex = 0; bindex <= bend; bindex++) {
++ head = kmalloc(sizeof(*nhash->nh_head) * n, gfp);
++ if (unlikely(!head))
++ goto out_free;
++ nhash[bindex].nh_num = n;
++ nhash[bindex].nh_head = head;
++ for (u = 0; u < n; u++)
++ INIT_HLIST_HEAD(head++);
++ }
++ return nhash; /* success */
++
++ out_free:
++ for (bindex--; bindex >= 0; bindex--)
++ kfree(nhash[bindex].nh_head);
++ kfree(nhash);
++ out:
++ return ERR_PTR(-ENOMEM);
++}
++
++static void au_nhash_wh_do_free(struct au_nhash *whlist)
++{
++ unsigned int u, n;
++ struct hlist_head *head;
++ struct au_vdir_wh *tpos;
++ struct hlist_node *pos, *node;
++
++ n = whlist->nh_num;
++ head = whlist->nh_head;
++ for (u = 0; u < n; u++) {
++ hlist_for_each_entry_safe(tpos, pos, node, head, wh_hash) {
++ /* hlist_del(pos); */
++ kfree(tpos);
++ }
++ head++;
++ }
++}
++
++void au_nhash_wh_free(struct au_nhash *whlist, aufs_bindex_t bend)
++{
++ aufs_bindex_t bindex;
++
++ for (bindex = 0; bindex <= bend; bindex++) {
++ au_nhash_wh_do_free(whlist + bindex);
++ kfree(whlist[bindex].nh_head);
++ }
++
++ kfree(whlist);
++}
++
++static void au_nhash_de_do_free(struct au_nhash *delist)
++{
++ unsigned int u, n;
++ struct hlist_head *head;
++ struct au_vdir_dehstr *tpos;
++ struct hlist_node *pos, *node;
++
++ n = delist->nh_num;
++ head = delist->nh_head;
++ for (u = 0; u < n; u++) {
++ hlist_for_each_entry_safe(tpos, pos, node, head, hash) {
++ /* hlist_del(pos); */
++ au_cache_free_dehstr(tpos);
++ }
++ head++;
++ }
++}
++
++static void au_nhash_de_free(struct au_nhash *delist, aufs_bindex_t bend)
++{
++ aufs_bindex_t bindex;
++
++ for (bindex = 0; bindex <= bend; bindex++) {
++ au_nhash_de_do_free(delist + bindex);
++ kfree(delist[bindex].nh_head);
++ }
++
++ kfree(delist);
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_nhash_test_longer_wh(struct au_nhash *whlist, aufs_bindex_t btgt,
++ int limit)
++{
++ int num;
++ unsigned int u, n;
++ struct hlist_head *head;
++ struct au_vdir_wh *tpos;
++ struct hlist_node *pos;
++
++ num = 0;
++ n = whlist->nh_num;
++ head = whlist->nh_head;
++ for (u = 0; u < n; u++) {
++ hlist_for_each_entry(tpos, pos, head, wh_hash)
++ if (tpos->wh_bindex == btgt && ++num > limit)
++ return 1;
++ head++;
++ }
++ return 0;
++}
++
++static struct hlist_head *au_name_hash(struct au_nhash *nhash,
++ const unsigned char *name,
++ unsigned int len)
++{
++ return nhash->nh_head + full_name_hash(name, len) % nhash->nh_num;
++}
++
++/* returns found or not */
++int au_nhash_test_known_wh(struct au_nhash *whlist, char *name, int namelen)
++{
++ struct hlist_head *head;
++ struct au_vdir_wh *tpos;
++ struct hlist_node *pos;
++ struct au_vdir_destr *str;
++
++ head = au_name_hash(whlist, name, namelen);
++ hlist_for_each_entry(tpos, pos, head, wh_hash) {
++ str = &tpos->wh_str;
++ AuDbg("%.*s\n", str->len, str->name);
++ if (str->len == namelen && !memcmp(str->name, name, namelen))
++ return 1;
++ }
++ return 0;
++}
++
++int au_nhash_append_wh(struct au_nhash *whlist, char *name, int namelen,
++ aufs_bindex_t bindex)
++{
++ int err;
++ struct au_vdir_destr *str;
++ struct au_vdir_wh *wh;
++
++ err = -ENOMEM;
++ wh = kmalloc(sizeof(*wh) + namelen, GFP_NOFS);
++ if (unlikely(!wh))
++ goto out;
++
++ err = 0;
++ wh->wh_bindex = bindex;
++ str = &wh->wh_str;
++ str->len = namelen;
++ memcpy(str->name, name, namelen);
++ hlist_add_head(&wh->wh_hash, au_name_hash(whlist, name, namelen));
++ /* smp_mb(); */
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_vdir_free(struct au_vdir *vdir)
++{
++ unsigned char **deblk;
++
++ deblk = vdir->vd_deblk;
++ while (vdir->vd_nblk--)
++ kfree(*deblk++);
++ kfree(vdir->vd_deblk);
++ au_cache_free_vdir(vdir);
++}
++
++static int append_deblk(struct au_vdir *vdir)
++{
++ int err;
++ unsigned long sz, ul;
++ const unsigned int deblk_sz = vdir->vd_deblk_sz;
++ union au_vdir_deblk_p p, deblk_end;
++ unsigned char **o;
++
++ err = -ENOMEM;
++ sz = sizeof(*o) * vdir->vd_nblk;
++ o = au_kzrealloc(vdir->vd_deblk, sz, sz + sizeof(*o), GFP_NOFS);
++ if (unlikely(!o))
++ goto out;
++
++ vdir->vd_deblk = o;
++ p.deblk = kmalloc(deblk_sz, GFP_NOFS);
++ if (p.deblk) {
++ ul = vdir->vd_nblk++;
++ vdir->vd_deblk[ul] = p.deblk;
++ vdir->vd_last.ul = ul;
++ vdir->vd_last.p.deblk = p.deblk;
++ deblk_end.deblk = p.deblk + deblk_sz;
++ err = set_deblk_end(&p, &deblk_end);
++ }
++
++ out:
++ return err;
++}
++
++static struct au_vdir *alloc_vdir(struct super_block *sb)
++{
++ struct au_vdir *vdir;
++ int err;
++
++ err = -ENOMEM;
++ vdir = au_cache_alloc_vdir();
++ if (unlikely(!vdir))
++ goto out;
++
++ vdir->vd_deblk = kzalloc(sizeof(*vdir->vd_deblk), GFP_NOFS);
++ if (unlikely(!vdir->vd_deblk))
++ goto out_free;
++
++ vdir->vd_deblk_sz = au_sbi(sb)->si_rdblk;
++ vdir->vd_nblk = 0;
++ vdir->vd_version = 0;
++ vdir->vd_jiffy = 0;
++ err = append_deblk(vdir);
++ if (!err)
++ return vdir; /* success */
++
++ kfree(vdir->vd_deblk);
++
++ out_free:
++ au_cache_free_vdir(vdir);
++ out:
++ vdir = ERR_PTR(err);
++ return vdir;
++}
++
++static int reinit_vdir(struct au_vdir *vdir)
++{
++ int err;
++ union au_vdir_deblk_p p, deblk_end;
++
++ while (vdir->vd_nblk > 1) {
++ kfree(vdir->vd_deblk[vdir->vd_nblk - 1]);
++ /* vdir->vd_deblk[vdir->vd_nblk - 1] = NULL; */
++ vdir->vd_nblk--;
++ }
++ p.deblk = vdir->vd_deblk[0];
++ deblk_end.deblk = p.deblk + vdir->vd_deblk_sz;
++ err = set_deblk_end(&p, &deblk_end);
++ /* keep vd_dblk_sz */
++ vdir->vd_last.ul = 0;
++ vdir->vd_last.p.deblk = vdir->vd_deblk[0];
++ vdir->vd_version = 0;
++ vdir->vd_jiffy = 0;
++ /* smp_mb(); */
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* returns found(true) or not */
++static int test_known(struct au_nhash *delist, char *name, int namelen)
++{
++ struct hlist_head *head;
++ struct au_vdir_dehstr *tpos;
++ struct hlist_node *pos;
++ struct au_vdir_destr *str;
++
++ head = au_name_hash(delist, name, namelen);
++ hlist_for_each_entry(tpos, pos, head, hash) {
++ str = tpos->str;
++ AuDbg("%.*s\n", str->len, str->name);
++ if (str->len == namelen && !memcmp(str->name, name, namelen))
++ return 1;
++ }
++ return 0;
++
++}
++
++static int append_de(struct au_vdir *vdir, char *name, int namelen, ino_t ino,
++ unsigned int d_type, struct au_nhash *delist)
++{
++ int err;
++ unsigned int sz;
++ const unsigned int deblk_sz = vdir->vd_deblk_sz;
++ union au_vdir_deblk_p p, *room, deblk_end;
++ struct au_vdir_dehstr *dehstr;
++
++ p.deblk = last_deblk(vdir);
++ deblk_end.deblk = p.deblk + deblk_sz;
++ room = &vdir->vd_last.p;
++ AuDebugOn(room->deblk < p.deblk || deblk_end.deblk <= room->deblk
++ || !is_deblk_end(room, &deblk_end));
++
++ sz = calc_size(namelen);
++ if (unlikely(sz > deblk_end.deblk - room->deblk)) {
++ err = append_deblk(vdir);
++ if (unlikely(err))
++ goto out;
++
++ p.deblk = last_deblk(vdir);
++ deblk_end.deblk = p.deblk + deblk_sz;
++ /* smp_mb(); */
++ AuDebugOn(room->deblk != p.deblk);
++ }
++
++ err = -ENOMEM;
++ dehstr = au_cache_alloc_dehstr();
++ if (unlikely(!dehstr))
++ goto out;
++
++ dehstr->str = &room->de->de_str;
++ hlist_add_head(&dehstr->hash, au_name_hash(delist, name, namelen));
++ room->de->de_ino = ino;
++ room->de->de_type = d_type;
++ room->de->de_str.len = namelen;
++ memcpy(room->de->de_str.name, name, namelen);
++
++ err = 0;
++ room->deblk += sz;
++ if (unlikely(set_deblk_end(room, &deblk_end)))
++ err = append_deblk(vdir);
++ /* smp_mb(); */
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_ino(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ unsigned int d_type, ino_t *ino)
++{
++ int err;
++ struct mutex *mtx;
++ const int isdir = (d_type == DT_DIR);
++
++ /* prevent hardlinks from race condition */
++ mtx = NULL;
++ if (!isdir) {
++ mtx = &au_sbr(sb, bindex)->br_xino.xi_nondir_mtx;
++ mutex_lock(mtx);
++ }
++ err = au_xino_read(sb, bindex, h_ino, ino);
++ if (unlikely(err))
++ goto out;
++
++ if (!*ino) {
++ err = -EIO;
++ *ino = au_xino_new_ino(sb);
++ if (unlikely(!*ino))
++ goto out;
++ err = au_xino_write(sb, bindex, h_ino, *ino);
++ if (unlikely(err))
++ goto out;
++ }
++
++ out:
++ if (!isdir)
++ mutex_unlock(mtx);
++ return err;
++}
++
++#define AuFillVdir_CALLED 1
++#define AuFillVdir_WHABLE (1 << 1)
++#define au_ftest_fillvdir(flags, name) ((flags) & AuFillVdir_##name)
++#define au_fset_fillvdir(flags, name) { (flags) |= AuFillVdir_##name; }
++#define au_fclr_fillvdir(flags, name) { (flags) &= ~AuFillVdir_##name; }
++
++struct fillvdir_arg {
++ struct file *file;
++ struct au_vdir *vdir;
++ struct au_nhash *delist;
++ struct au_nhash *whlist;
++ aufs_bindex_t bindex;
++ unsigned int flags;
++ int err;
++};
++
++static int fillvdir(void *__arg, const char *__name, int namelen,
++ loff_t offset __maybe_unused, u64 h_ino,
++ unsigned int d_type)
++{
++ struct fillvdir_arg *arg = __arg;
++ char *name = (void *)__name;
++ struct super_block *sb;
++ struct au_nhash *delist, *whlist;
++ ino_t ino;
++ aufs_bindex_t bindex, bend;
++
++ bend = arg->bindex;
++ arg->err = 0;
++ au_fset_fillvdir(arg->flags, CALLED);
++ /* smp_mb(); */
++ if (namelen <= AUFS_WH_PFX_LEN
++ || memcmp(name, AUFS_WH_PFX, AUFS_WH_PFX_LEN)) {
++ delist = arg->delist;
++ whlist = arg->whlist;
++ for (bindex = 0; bindex < bend; bindex++)
++ if (test_known(delist++, name, namelen)
++ || au_nhash_test_known_wh(whlist + bindex, name,
++ namelen))
++ goto out; /* already exists or whiteouted */
++
++ sb = arg->file->f_dentry->d_sb;
++ arg->err = au_ino(sb, bend, h_ino, d_type, &ino);
++ if (!arg->err)
++ arg->err = append_de(arg->vdir, name, namelen, ino,
++ d_type, arg->delist + bend);
++ } else if (au_ftest_fillvdir(arg->flags, WHABLE)) {
++ name += AUFS_WH_PFX_LEN;
++ namelen -= AUFS_WH_PFX_LEN;
++ whlist = arg->whlist;
++ for (bindex = 0; bindex < bend; bindex++)
++ if (au_nhash_test_known_wh(whlist++, name, namelen))
++ goto out; /* already whiteouted */
++
++ if (!arg->err)
++ arg->err = au_nhash_append_wh
++ (arg->whlist + bend, name, namelen, bend);
++ }
++
++ out:
++ if (!arg->err)
++ arg->vdir->vd_jiffy = jiffies;
++ /* smp_mb(); */
++ AuTraceErr(arg->err);
++ return arg->err;
++}
++
++static int au_do_read_vdir(struct fillvdir_arg *arg)
++{
++ int err;
++ loff_t offset;
++ aufs_bindex_t bend, bindex;
++ struct file *hf, *file;
++ struct super_block *sb;
++
++ err = -ENOMEM;
++ file = arg->file;
++ sb = file->f_dentry->d_sb;
++ bend = au_fbend(file);
++ arg->delist = au_nhash_alloc(sb, bend, GFP_NOFS);
++ if (unlikely(!arg->delist))
++ goto out;
++ arg->whlist = au_nhash_alloc(sb, bend, GFP_NOFS);
++ if (unlikely(!arg->whlist))
++ goto out_delist;
++
++ err = 0;
++ arg->flags = 0;
++ for (bindex = au_fbstart(file); !err && bindex <= bend; bindex++) {
++ hf = au_h_fptr(file, bindex);
++ if (!hf)
++ continue;
++
++ offset = vfsub_llseek(hf, 0, SEEK_SET);
++ err = offset;
++ if (unlikely(offset))
++ break;
++
++ arg->bindex = bindex;
++ au_fclr_fillvdir(arg->flags, WHABLE);
++ if (bindex != bend
++ && au_br_whable(au_sbr_perm(sb, bindex)))
++ au_fset_fillvdir(arg->flags, WHABLE);
++ do {
++ arg->err = 0;
++ au_fclr_fillvdir(arg->flags, CALLED);
++ /* smp_mb(); */
++ err = vfsub_readdir(hf, fillvdir, arg);
++ if (err >= 0)
++ err = arg->err;
++ } while (!err && au_ftest_fillvdir(arg->flags, CALLED));
++ }
++ au_nhash_wh_free(arg->whlist, bend);
++
++ out_delist:
++ au_nhash_de_free(arg->delist, bend);
++ out:
++ return err;
++}
++
++static int read_vdir(struct file *file, int may_read)
++{
++ int err;
++ unsigned long expire;
++ unsigned char do_read;
++ struct fillvdir_arg arg;
++ struct inode *inode;
++ struct au_vdir *vdir, *allocated;
++
++ err = 0;
++ inode = file->f_dentry->d_inode;
++ IMustLock(inode);
++ allocated = NULL;
++ do_read = 0;
++ expire = au_sbi(inode->i_sb)->si_rdcache;
++ vdir = au_ivdir(inode);
++ if (!vdir) {
++ do_read = 1;
++ vdir = alloc_vdir(inode->i_sb);
++ err = PTR_ERR(vdir);
++ if (IS_ERR(vdir))
++ goto out;
++ err = 0;
++ allocated = vdir;
++ } else if (may_read
++ && (inode->i_version != vdir->vd_version
++ || time_after(jiffies, vdir->vd_jiffy + expire))) {
++ do_read = 1;
++ err = reinit_vdir(vdir);
++ if (unlikely(err))
++ goto out;
++ }
++
++ if (!do_read)
++ return 0; /* success */
++
++ arg.file = file;
++ arg.vdir = vdir;
++ err = au_do_read_vdir(&arg);
++ if (!err) {
++ /* file->f_pos = 0; */
++ vdir->vd_version = inode->i_version;
++ vdir->vd_last.ul = 0;
++ vdir->vd_last.p.deblk = vdir->vd_deblk[0];
++ if (allocated)
++ au_set_ivdir(inode, allocated);
++ } else if (allocated)
++ au_vdir_free(allocated);
++
++ out:
++ return err;
++}
++
++static int copy_vdir(struct au_vdir *tgt, struct au_vdir *src)
++{
++ int err, rerr;
++ unsigned long ul, n;
++ const unsigned int deblk_sz = src->vd_deblk_sz;
++
++ AuDebugOn(tgt->vd_nblk != 1);
++
++ err = -ENOMEM;
++ if (tgt->vd_nblk < src->vd_nblk) {
++ unsigned char **p;
++
++ p = au_kzrealloc(tgt->vd_deblk, sizeof(*p) * tgt->vd_nblk,
++ sizeof(*p) * src->vd_nblk, GFP_NOFS);
++ if (unlikely(!p))
++ goto out;
++ tgt->vd_deblk = p;
++ }
++
++ tgt->vd_nblk = src->vd_nblk;
++ tgt->vd_deblk_sz = deblk_sz;
++ memcpy(tgt->vd_deblk[0], src->vd_deblk[0], deblk_sz);
++ /* tgt->vd_last.i = 0; */
++ /* tgt->vd_last.p.deblk = tgt->vd_deblk[0]; */
++ tgt->vd_version = src->vd_version;
++ tgt->vd_jiffy = src->vd_jiffy;
++
++ n = src->vd_nblk;
++ for (ul = 1; ul < n; ul++) {
++ tgt->vd_deblk[ul] = kmalloc(deblk_sz, GFP_NOFS);
++ if (tgt->vd_deblk[ul])
++ memcpy(tgt->vd_deblk[ul], src->vd_deblk[ul], deblk_sz);
++ else
++ goto out;
++ }
++ /* smp_mb(); */
++ return 0; /* success */
++
++ out:
++ rerr = reinit_vdir(tgt);
++ BUG_ON(rerr);
++ return err;
++}
++
++int au_vdir_init(struct file *file)
++{
++ int err;
++ struct inode *inode;
++ struct au_vdir *vdir_cache, *allocated;
++
++ err = read_vdir(file, !file->f_pos);
++ if (unlikely(err))
++ goto out;
++
++ allocated = NULL;
++ vdir_cache = au_fvdir_cache(file);
++ if (!vdir_cache) {
++ vdir_cache = alloc_vdir(file->f_dentry->d_sb);
++ err = PTR_ERR(vdir_cache);
++ if (IS_ERR(vdir_cache))
++ goto out;
++ allocated = vdir_cache;
++ } else if (!file->f_pos && vdir_cache->vd_version != file->f_version) {
++ err = reinit_vdir(vdir_cache);
++ if (unlikely(err))
++ goto out;
++ } else
++ return 0; /* success */
++
++ inode = file->f_dentry->d_inode;
++ err = copy_vdir(vdir_cache, au_ivdir(inode));
++ if (!err) {
++ file->f_version = inode->i_version;
++ if (allocated)
++ au_set_fvdir_cache(file, allocated);
++ } else if (allocated)
++ au_vdir_free(allocated);
++
++ out:
++ return err;
++}
++
++static loff_t calc_offset(struct au_vdir *vdir)
++{
++ loff_t offset;
++ union au_vdir_deblk_p p;
++
++ p.deblk = vdir->vd_deblk[vdir->vd_last.ul];
++ offset = vdir->vd_last.p.deblk - p.deblk;
++ offset += vdir->vd_deblk_sz * vdir->vd_last.ul;
++ return offset;
++}
++
++/* returns true or false */
++static int seek_vdir(struct file *file)
++{
++ int valid;
++ unsigned int deblk_sz;
++ unsigned long ul, n;
++ loff_t offset;
++ union au_vdir_deblk_p p, deblk_end;
++ struct au_vdir *vdir_cache;
++
++ valid = 1;
++ vdir_cache = au_fvdir_cache(file);
++ offset = calc_offset(vdir_cache);
++ AuDbg("offset %lld\n", offset);
++ if (file->f_pos == offset)
++ goto out;
++
++ vdir_cache->vd_last.ul = 0;
++ vdir_cache->vd_last.p.deblk = vdir_cache->vd_deblk[0];
++ if (!file->f_pos)
++ goto out;
++
++ valid = 0;
++ deblk_sz = vdir_cache->vd_deblk_sz;
++ ul = div64_u64(file->f_pos, deblk_sz);
++ AuDbg("ul %lu\n", ul);
++ if (ul >= vdir_cache->vd_nblk)
++ goto out;
++
++ n = vdir_cache->vd_nblk;
++ for (; ul < n; ul++) {
++ p.deblk = vdir_cache->vd_deblk[ul];
++ deblk_end.deblk = p.deblk + deblk_sz;
++ offset = ul;
++ offset *= deblk_sz;
++ while (!is_deblk_end(&p, &deblk_end) && offset < file->f_pos) {
++ unsigned int l;
++
++ l = calc_size(p.de->de_str.len);
++ offset += l;
++ p.deblk += l;
++ }
++ if (!is_deblk_end(&p, &deblk_end)) {
++ valid = 1;
++ vdir_cache->vd_last.ul = ul;
++ vdir_cache->vd_last.p = p;
++ break;
++ }
++ }
++
++ out:
++ /* smp_mb(); */
++ AuTraceErr(!valid);
++ return valid;
++}
++
++int au_vdir_fill_de(struct file *file, void *dirent, filldir_t filldir)
++{
++ int err;
++ unsigned int l, deblk_sz;
++ union au_vdir_deblk_p deblk_end;
++ struct au_vdir *vdir_cache;
++ struct au_vdir_de *de;
++
++ vdir_cache = au_fvdir_cache(file);
++ if (!seek_vdir(file))
++ return 0;
++
++ deblk_sz = vdir_cache->vd_deblk_sz;
++ while (1) {
++ deblk_end.deblk = vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
++ deblk_end.deblk += deblk_sz;
++ while (!is_deblk_end(&vdir_cache->vd_last.p, &deblk_end)) {
++ de = vdir_cache->vd_last.p.de;
++ AuDbg("%.*s, off%lld, i%lu, dt%d\n",
++ de->de_str.len, de->de_str.name, file->f_pos,
++ (unsigned long)de->de_ino, de->de_type);
++ err = filldir(dirent, de->de_str.name, de->de_str.len,
++ file->f_pos, de->de_ino, de->de_type);
++ if (unlikely(err)) {
++ AuTraceErr(err);
++ /* todo: ignore the error caused by udba? */
++ /* return err; */
++ return 0;
++ }
++
++ l = calc_size(de->de_str.len);
++ vdir_cache->vd_last.p.deblk += l;
++ file->f_pos += l;
++ }
++ if (vdir_cache->vd_last.ul < vdir_cache->vd_nblk - 1) {
++ vdir_cache->vd_last.ul++;
++ vdir_cache->vd_last.p.deblk
++ = vdir_cache->vd_deblk[vdir_cache->vd_last.ul];
++ file->f_pos = deblk_sz * vdir_cache->vd_last.ul;
++ continue;
++ }
++ break;
++ }
++
++ /* smp_mb(); */
++ return 0;
++}
+diff --git a/fs/aufs/vfsub.c b/fs/aufs/vfsub.c
+new file mode 100644
+index 0000000..f58d07d
+--- /dev/null
++++ b/fs/aufs/vfsub.c
+@@ -0,0 +1,724 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sub-routines for VFS
++ */
++
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++int vfsub_update_h_iattr(struct path *h_path, int *did)
++{
++ int err;
++ struct kstat st;
++ struct super_block *h_sb;
++
++ /* for remote fs, leave work for its getattr or d_revalidate */
++ /* for bad i_attr fs, handle them in aufs_getattr() */
++ /* still some fs may acquire i_mutex. we need to skip them */
++ err = 0;
++ if (!did)
++ did = &err;
++ h_sb = h_path->dentry->d_sb;
++ *did = (!au_test_fs_remote(h_sb) && au_test_fs_refresh_iattr(h_sb));
++ if (*did)
++ err = vfs_getattr(h_path->mnt, h_path->dentry, &st);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct file *vfsub_filp_open(const char *path, int oflags, int mode)
++{
++ struct file *file;
++
++ lockdep_off();
++ file = filp_open(path, oflags, mode);
++ lockdep_on();
++ if (IS_ERR(file))
++ goto out;
++ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++
++ out:
++ return file;
++}
++
++int vfsub_kern_path(const char *name, unsigned int flags, struct path *path)
++{
++ int err;
++
++ /* lockdep_off(); */
++ err = kern_path(name, flags, path);
++ /* lockdep_on(); */
++ if (!err && path->dentry->d_inode)
++ vfsub_update_h_iattr(path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
++ int len)
++{
++ struct path path = {
++ .mnt = NULL
++ };
++
++ IMustLock(parent->d_inode);
++
++ path.dentry = lookup_one_len(name, parent, len);
++ if (IS_ERR(path.dentry))
++ goto out;
++ if (path.dentry->d_inode)
++ vfsub_update_h_iattr(&path, /*did*/NULL); /*ignore*/
++
++ out:
++ return path.dentry;
++}
++
++struct dentry *vfsub_lookup_hash(struct nameidata *nd)
++{
++ struct path path = {
++ .mnt = nd->path.mnt
++ };
++
++ IMustLock(nd->path.dentry->d_inode);
++
++ path.dentry = lookup_hash(nd);
++ if (!IS_ERR(path.dentry) && path.dentry->d_inode)
++ vfsub_update_h_iattr(&path, /*did*/NULL); /*ignore*/
++
++ return path.dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct dentry *vfsub_lock_rename(struct dentry *d1, struct au_hinode *hdir1,
++ struct dentry *d2, struct au_hinode *hdir2)
++{
++ struct dentry *d;
++
++ lockdep_off();
++ d = lock_rename(d1, d2);
++ lockdep_on();
++ au_hin_suspend(hdir1);
++ if (hdir1 != hdir2)
++ au_hin_suspend(hdir2);
++
++ return d;
++}
++
++void vfsub_unlock_rename(struct dentry *d1, struct au_hinode *hdir1,
++ struct dentry *d2, struct au_hinode *hdir2)
++{
++ au_hin_resume(hdir1);
++ if (hdir1 != hdir2)
++ au_hin_resume(hdir2);
++ lockdep_off();
++ unlock_rename(d1, d2);
++ lockdep_on();
++}
++
++/* ---------------------------------------------------------------------- */
++
++int vfsub_create(struct inode *dir, struct path *path, int mode)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_mknod(path, path->dentry, mode, 0);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ if (au_test_fs_null_nd(dir->i_sb))
++ err = vfs_create(dir, path->dentry, mode, NULL);
++ else {
++ struct nameidata h_nd;
++
++ memset(&h_nd, 0, sizeof(h_nd));
++ h_nd.flags = LOOKUP_CREATE;
++ h_nd.intent.open.flags = O_CREAT
++ | vfsub_fmode_to_uint(FMODE_READ);
++ h_nd.intent.open.create_mode = mode;
++ h_nd.path.dentry = path->dentry->d_parent;
++ h_nd.path.mnt = path->mnt;
++ path_get(&h_nd.path);
++ err = vfs_create(dir, path->dentry, mode, &h_nd);
++ path_put(&h_nd.path);
++ }
++
++ if (!err) {
++ struct path tmp = *path;
++ int did;
++
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = path->dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++int vfsub_symlink(struct inode *dir, struct path *path, const char *symname)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_symlink(path, path->dentry, symname);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ err = vfs_symlink(dir, path->dentry, symname);
++ if (!err) {
++ struct path tmp = *path;
++ int did;
++
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = path->dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++int vfsub_mknod(struct inode *dir, struct path *path, int mode, dev_t dev)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_mknod(path, path->dentry, mode, dev);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ err = vfs_mknod(dir, path->dentry, mode, dev);
++ if (!err) {
++ struct path tmp = *path;
++ int did;
++
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = path->dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++static int au_test_nlink(struct inode *inode)
++{
++ const unsigned int link_max = UINT_MAX >> 1; /* rough margin */
++
++ if (!au_test_fs_no_limit_nlink(inode->i_sb)
++ || inode->i_nlink < link_max)
++ return 0;
++ return -EMLINK;
++}
++
++int vfsub_link(struct dentry *src_dentry, struct inode *dir, struct path *path)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ err = au_test_nlink(src_dentry->d_inode);
++ if (unlikely(err))
++ return err;
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_link(src_dentry, path, path->dentry);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ lockdep_off();
++ err = vfs_link(src_dentry, dir, path->dentry);
++ lockdep_on();
++ if (!err) {
++ struct path tmp = *path;
++ int did;
++
++ /* fuse has different memory inode for the same inumber */
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = path->dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ tmp.dentry = src_dentry;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
++ struct inode *dir, struct path *path)
++{
++ int err;
++ struct path tmp = {
++ .mnt = path->mnt
++ };
++ struct dentry *d;
++
++ IMustLock(dir);
++ IMustLock(src_dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ tmp.dentry = src_dentry->d_parent;
++ err = security_path_rename(&tmp, src_dentry, path, path->dentry);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ lockdep_off();
++ err = vfs_rename(src_dir, src_dentry, dir, path->dentry);
++ lockdep_on();
++ if (!err) {
++ int did;
++
++ tmp.dentry = d->d_parent;
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = src_dentry;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ tmp.dentry = src_dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++int vfsub_mkdir(struct inode *dir, struct path *path, int mode)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_mkdir(path, path->dentry, mode);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ err = vfs_mkdir(dir, path->dentry, mode);
++ if (!err) {
++ struct path tmp = *path;
++ int did;
++
++ vfsub_update_h_iattr(&tmp, &did);
++ if (did) {
++ tmp.dentry = path->dentry->d_parent;
++ vfsub_update_h_iattr(&tmp, /*did*/NULL);
++ }
++ /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++int vfsub_rmdir(struct inode *dir, struct path *path)
++{
++ int err;
++ struct dentry *d;
++
++ IMustLock(dir);
++
++ d = path->dentry;
++ path->dentry = d->d_parent;
++ err = security_path_rmdir(path, path->dentry);
++ path->dentry = d;
++ if (unlikely(err))
++ goto out;
++
++ lockdep_off();
++ err = vfs_rmdir(dir, path->dentry);
++ lockdep_on();
++ if (!err) {
++ struct path tmp = {
++ .dentry = path->dentry->d_parent,
++ .mnt = path->mnt
++ };
++
++ vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
++ }
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
++ loff_t *ppos)
++{
++ ssize_t err;
++
++ err = vfs_read(file, ubuf, count, ppos);
++ if (err >= 0)
++ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++/* todo: kernel_read()? */
++ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count,
++ loff_t *ppos)
++{
++ ssize_t err;
++ mm_segment_t oldfs;
++
++ oldfs = get_fs();
++ set_fs(KERNEL_DS);
++ err = vfsub_read_u(file, (char __user *)kbuf, count, ppos);
++ set_fs(oldfs);
++ return err;
++}
++
++ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
++ loff_t *ppos)
++{
++ ssize_t err;
++
++ lockdep_off();
++ err = vfs_write(file, ubuf, count, ppos);
++ lockdep_on();
++ if (err >= 0)
++ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos)
++{
++ ssize_t err;
++ mm_segment_t oldfs;
++
++ oldfs = get_fs();
++ set_fs(KERNEL_DS);
++ err = vfsub_write_u(file, (const char __user *)kbuf, count, ppos);
++ set_fs(oldfs);
++ return err;
++}
++
++int vfsub_readdir(struct file *file, filldir_t filldir, void *arg)
++{
++ int err;
++
++ lockdep_off();
++ err = vfs_readdir(file, filldir, arg);
++ lockdep_on();
++ if (err >= 0)
++ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++long vfsub_splice_to(struct file *in, loff_t *ppos,
++ struct pipe_inode_info *pipe, size_t len,
++ unsigned int flags)
++{
++ long err;
++
++ lockdep_off();
++ err = do_splice_to(in, ppos, pipe, len, flags);
++ lockdep_on();
++ if (err >= 0)
++ vfsub_update_h_iattr(&in->f_path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
++ loff_t *ppos, size_t len, unsigned int flags)
++{
++ long err;
++
++ lockdep_off();
++ err = do_splice_from(pipe, out, ppos, len, flags);
++ lockdep_on();
++ if (err >= 0)
++ vfsub_update_h_iattr(&out->f_path, /*did*/NULL); /*ignore*/
++ return err;
++}
++
++/* cf. open.c:do_sys_truncate() and do_sys_ftruncate() */
++int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
++ struct file *h_file)
++{
++ int err;
++ struct inode *h_inode;
++
++ h_inode = h_path->dentry->d_inode;
++ if (!h_file) {
++ err = mnt_want_write(h_path->mnt);
++ if (err)
++ goto out;
++ err = inode_permission(h_inode, MAY_WRITE);
++ if (err)
++ goto out_mnt;
++ err = get_write_access(h_inode);
++ if (err)
++ goto out_mnt;
++ err = break_lease(h_inode, vfsub_fmode_to_uint(FMODE_WRITE));
++ if (err)
++ goto out_inode;
++ }
++
++ err = locks_verify_truncate(h_inode, h_file, length);
++ if (!err)
++ err = security_path_truncate(h_path, length, attr);
++ if (!err) {
++ lockdep_off();
++ err = do_truncate(h_path->dentry, length, attr, h_file);
++ lockdep_on();
++ }
++
++ out_inode:
++ if (!h_file)
++ put_write_access(h_inode);
++ out_mnt:
++ if (!h_file)
++ mnt_drop_write(h_path->mnt);
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_vfsub_mkdir_args {
++ int *errp;
++ struct inode *dir;
++ struct path *path;
++ int mode;
++};
++
++static void au_call_vfsub_mkdir(void *args)
++{
++ struct au_vfsub_mkdir_args *a = args;
++ *a->errp = vfsub_mkdir(a->dir, a->path, a->mode);
++}
++
++int vfsub_sio_mkdir(struct inode *dir, struct path *path, int mode)
++{
++ int err, do_sio, wkq_err;
++
++ do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
++ if (!do_sio)
++ err = vfsub_mkdir(dir, path, mode);
++ else {
++ struct au_vfsub_mkdir_args args = {
++ .errp = &err,
++ .dir = dir,
++ .path = path,
++ .mode = mode
++ };
++ wkq_err = au_wkq_wait(au_call_vfsub_mkdir, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ return err;
++}
++
++struct au_vfsub_rmdir_args {
++ int *errp;
++ struct inode *dir;
++ struct path *path;
++};
++
++static void au_call_vfsub_rmdir(void *args)
++{
++ struct au_vfsub_rmdir_args *a = args;
++ *a->errp = vfsub_rmdir(a->dir, a->path);
++}
++
++int vfsub_sio_rmdir(struct inode *dir, struct path *path)
++{
++ int err, do_sio, wkq_err;
++
++ do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
++ if (!do_sio)
++ err = vfsub_rmdir(dir, path);
++ else {
++ struct au_vfsub_rmdir_args args = {
++ .errp = &err,
++ .dir = dir,
++ .path = path
++ };
++ wkq_err = au_wkq_wait(au_call_vfsub_rmdir, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct notify_change_args {
++ int *errp;
++ struct path *path;
++ struct iattr *ia;
++};
++
++static void call_notify_change(void *args)
++{
++ struct notify_change_args *a = args;
++ struct inode *h_inode;
++
++ h_inode = a->path->dentry->d_inode;
++ IMustLock(h_inode);
++
++ *a->errp = -EPERM;
++ if (!IS_IMMUTABLE(h_inode) && !IS_APPEND(h_inode)) {
++ lockdep_off();
++ *a->errp = notify_change(a->path->dentry, a->ia);
++ lockdep_on();
++ if (!*a->errp)
++ vfsub_update_h_iattr(a->path, /*did*/NULL); /*ignore*/
++ }
++ AuTraceErr(*a->errp);
++}
++
++int vfsub_notify_change(struct path *path, struct iattr *ia)
++{
++ int err;
++ struct notify_change_args args = {
++ .errp = &err,
++ .path = path,
++ .ia = ia
++ };
++
++ call_notify_change(&args);
++
++ return err;
++}
++
++int vfsub_sio_notify_change(struct path *path, struct iattr *ia)
++{
++ int err, wkq_err;
++ struct notify_change_args args = {
++ .errp = &err,
++ .path = path,
++ .ia = ia
++ };
++
++ wkq_err = au_wkq_wait(call_notify_change, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct unlink_args {
++ int *errp;
++ struct inode *dir;
++ struct path *path;
++};
++
++static void call_unlink(void *args)
++{
++ struct unlink_args *a = args;
++ struct dentry *d = a->path->dentry;
++ struct inode *h_inode;
++ const int stop_sillyrename = (au_test_nfs(d->d_sb)
++ && atomic_read(&d->d_count) == 1);
++
++ IMustLock(a->dir);
++
++ a->path->dentry = d->d_parent;
++ *a->errp = security_path_unlink(a->path, d);
++ a->path->dentry = d;
++ if (unlikely(*a->errp))
++ return;
++
++ if (!stop_sillyrename)
++ dget(d);
++ h_inode = d->d_inode;
++ if (h_inode)
++ atomic_inc(&h_inode->i_count);
++
++ lockdep_off();
++ *a->errp = vfs_unlink(a->dir, d);
++ lockdep_on();
++ if (!*a->errp) {
++ struct path tmp = {
++ .dentry = d->d_parent,
++ .mnt = a->path->mnt
++ };
++ vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
++ }
++
++ if (!stop_sillyrename)
++ dput(d);
++ if (h_inode)
++ iput(h_inode);
++
++ AuTraceErr(*a->errp);
++}
++
++/*
++ * @dir: must be locked.
++ * @dentry: target dentry.
++ */
++int vfsub_unlink(struct inode *dir, struct path *path, int force)
++{
++ int err;
++ struct unlink_args args = {
++ .errp = &err,
++ .dir = dir,
++ .path = path
++ };
++
++ if (!force)
++ call_unlink(&args);
++ else {
++ int wkq_err;
++
++ wkq_err = au_wkq_wait(call_unlink, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++
++ return err;
++}
+diff --git a/fs/aufs/vfsub.h b/fs/aufs/vfsub.h
+new file mode 100644
+index 0000000..d0172c7
+--- /dev/null
++++ b/fs/aufs/vfsub.h
+@@ -0,0 +1,165 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * sub-routines for VFS
++ */
++
++#ifndef __AUFS_VFSUB_H__
++#define __AUFS_VFSUB_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/fs_stack.h>
++#include <linux/namei.h>
++#include <linux/security.h>
++#include <linux/splice.h>
++
++/* ---------------------------------------------------------------------- */
++
++/* lock subclass for lower inode */
++/* default MAX_LOCKDEP_SUBCLASSES(8) is not enough */
++/* reduce? gave up. */
++enum {
++ AuLsc_I_Begin = I_MUTEX_QUOTA, /* 4 */
++ AuLsc_I_PARENT, /* lower inode, parent first */
++ AuLsc_I_PARENT2, /* copyup dirs */
++ AuLsc_I_CHILD,
++ AuLsc_I_CHILD2,
++ AuLsc_I_End
++};
++
++/* to debug easier, do not make them inlined functions */
++#define MtxMustLock(mtx) AuDebugOn(!mutex_is_locked(mtx))
++#define IMustLock(i) MtxMustLock(&(i)->i_mutex)
++
++/* ---------------------------------------------------------------------- */
++
++static inline void vfsub_copy_inode_size(struct inode *inode,
++ struct inode *h_inode)
++{
++ spin_lock(&inode->i_lock);
++ fsstack_copy_inode_size(inode, h_inode);
++ spin_unlock(&inode->i_lock);
++}
++
++int vfsub_update_h_iattr(struct path *h_path, int *did);
++struct file *vfsub_filp_open(const char *path, int oflags, int mode);
++int vfsub_kern_path(const char *name, unsigned int flags, struct path *path);
++struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
++ int len);
++struct dentry *vfsub_lookup_hash(struct nameidata *nd);
++
++/* ---------------------------------------------------------------------- */
++
++struct au_hinode;
++struct dentry *vfsub_lock_rename(struct dentry *d1, struct au_hinode *hdir1,
++ struct dentry *d2, struct au_hinode *hdir2);
++void vfsub_unlock_rename(struct dentry *d1, struct au_hinode *hdir1,
++ struct dentry *d2, struct au_hinode *hdir2);
++
++int vfsub_create(struct inode *dir, struct path *path, int mode);
++int vfsub_symlink(struct inode *dir, struct path *path,
++ const char *symname);
++int vfsub_mknod(struct inode *dir, struct path *path, int mode, dev_t dev);
++int vfsub_link(struct dentry *src_dentry, struct inode *dir,
++ struct path *path);
++int vfsub_rename(struct inode *src_hdir, struct dentry *src_dentry,
++ struct inode *hdir, struct path *path);
++int vfsub_mkdir(struct inode *dir, struct path *path, int mode);
++int vfsub_rmdir(struct inode *dir, struct path *path);
++
++/* ---------------------------------------------------------------------- */
++
++ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
++ loff_t *ppos);
++ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count,
++ loff_t *ppos);
++ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
++ loff_t *ppos);
++ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count,
++ loff_t *ppos);
++int vfsub_readdir(struct file *file, filldir_t filldir, void *arg);
++
++static inline void vfsub_file_accessed(struct file *h_file)
++{
++ file_accessed(h_file);
++ vfsub_update_h_iattr(&h_file->f_path, /*did*/NULL); /*ignore*/
++}
++
++static inline void vfsub_touch_atime(struct vfsmount *h_mnt,
++ struct dentry *h_dentry)
++{
++ struct path h_path = {
++ .dentry = h_dentry,
++ .mnt = h_mnt
++ };
++ touch_atime(h_mnt, h_dentry);
++ vfsub_update_h_iattr(&h_path, /*did*/NULL); /*ignore*/
++}
++
++long vfsub_splice_to(struct file *in, loff_t *ppos,
++ struct pipe_inode_info *pipe, size_t len,
++ unsigned int flags);
++long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
++ loff_t *ppos, size_t len, unsigned int flags);
++int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
++ struct file *h_file);
++
++/* ---------------------------------------------------------------------- */
++
++static inline loff_t vfsub_llseek(struct file *file, loff_t offset, int origin)
++{
++ loff_t err;
++
++ lockdep_off();
++ err = vfs_llseek(file, offset, origin);
++ lockdep_on();
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* dirty workaround for strict type of fmode_t */
++union vfsub_fmu {
++ fmode_t fm;
++ unsigned int ui;
++};
++
++static inline unsigned int vfsub_fmode_to_uint(fmode_t fm)
++{
++ union vfsub_fmu u = {
++ .fm = fm
++ };
++
++ BUILD_BUG_ON(sizeof(u.fm) != sizeof(u.ui));
++
++ return u.ui;
++}
++
++static inline fmode_t vfsub_uint_to_fmode(unsigned int ui)
++{
++ union vfsub_fmu u = {
++ .ui = ui
++ };
++
++ return u.fm;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int vfsub_sio_mkdir(struct inode *dir, struct path *path, int mode);
++int vfsub_sio_rmdir(struct inode *dir, struct path *path);
++int vfsub_sio_notify_change(struct path *path, struct iattr *ia);
++int vfsub_notify_change(struct path *path, struct iattr *ia);
++int vfsub_unlink(struct inode *dir, struct path *path, int force);
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_VFSUB_H__ */
+diff --git a/fs/aufs/wbr_policy.c b/fs/aufs/wbr_policy.c
+new file mode 100644
+index 0000000..436ebfc
+--- /dev/null
++++ b/fs/aufs/wbr_policy.c
+@@ -0,0 +1,628 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * policies for selecting one among multiple writable branches
++ */
++
++#include <linux/statfs.h>
++#include "aufs.h"
++
++/* subset of cpup_attr() */
++static noinline_for_stack
++int au_cpdown_attr(struct path *h_path, struct dentry *h_src)
++{
++ int err, sbits;
++ struct iattr ia;
++ struct inode *h_isrc;
++
++ h_isrc = h_src->d_inode;
++ ia.ia_valid = ATTR_FORCE | ATTR_MODE | ATTR_UID | ATTR_GID;
++ ia.ia_mode = h_isrc->i_mode;
++ ia.ia_uid = h_isrc->i_uid;
++ ia.ia_gid = h_isrc->i_gid;
++ sbits = !!(ia.ia_mode & (S_ISUID | S_ISGID));
++ au_cpup_attr_flags(h_path->dentry->d_inode, h_isrc);
++ err = vfsub_sio_notify_change(h_path, &ia);
++
++ /* is this nfs only? */
++ if (!err && sbits && au_test_nfs(h_path->dentry->d_sb)) {
++ ia.ia_valid = ATTR_FORCE | ATTR_MODE;
++ ia.ia_mode = h_isrc->i_mode;
++ err = vfsub_sio_notify_change(h_path, &ia);
++ }
++
++ return err;
++}
++
++#define AuCpdown_PARENT_OPQ 1
++#define AuCpdown_WHED (1 << 1)
++#define AuCpdown_MADE_DIR (1 << 2)
++#define AuCpdown_DIROPQ (1 << 3)
++#define au_ftest_cpdown(flags, name) ((flags) & AuCpdown_##name)
++#define au_fset_cpdown(flags, name) { (flags) |= AuCpdown_##name; }
++#define au_fclr_cpdown(flags, name) { (flags) &= ~AuCpdown_##name; }
++
++struct au_cpdown_dir_args {
++ struct dentry *parent;
++ unsigned int flags;
++};
++
++static int au_cpdown_dir_opq(struct dentry *dentry, aufs_bindex_t bdst,
++ struct au_cpdown_dir_args *a)
++{
++ int err;
++ struct dentry *opq_dentry;
++
++ opq_dentry = au_diropq_create(dentry, bdst);
++ err = PTR_ERR(opq_dentry);
++ if (IS_ERR(opq_dentry))
++ goto out;
++ dput(opq_dentry);
++ au_fset_cpdown(a->flags, DIROPQ);
++
++ out:
++ return err;
++}
++
++static int au_cpdown_dir_wh(struct dentry *dentry, struct dentry *h_parent,
++ struct inode *dir, aufs_bindex_t bdst)
++{
++ int err;
++ struct path h_path;
++ struct au_branch *br;
++
++ br = au_sbr(dentry->d_sb, bdst);
++ h_path.dentry = au_wh_lkup(h_parent, &dentry->d_name, br);
++ err = PTR_ERR(h_path.dentry);
++ if (IS_ERR(h_path.dentry))
++ goto out;
++
++ err = 0;
++ if (h_path.dentry->d_inode) {
++ h_path.mnt = br->br_mnt;
++ err = au_wh_unlink_dentry(au_h_iptr(dir, bdst), &h_path,
++ dentry);
++ }
++ dput(h_path.dentry);
++
++ out:
++ return err;
++}
++
++static int au_cpdown_dir(struct dentry *dentry, aufs_bindex_t bdst,
++ struct dentry *h_parent, void *arg)
++{
++ int err, rerr;
++ aufs_bindex_t bend, bopq, bstart;
++ unsigned char parent_opq;
++ struct path h_path;
++ struct dentry *parent;
++ struct inode *h_dir, *h_inode, *inode, *dir;
++ struct au_cpdown_dir_args *args = arg;
++
++ bstart = au_dbstart(dentry);
++ /* dentry is di-locked */
++ parent = dget_parent(dentry);
++ dir = parent->d_inode;
++ h_dir = h_parent->d_inode;
++ AuDebugOn(h_dir != au_h_iptr(dir, bdst));
++ IMustLock(h_dir);
++
++ err = au_lkup_neg(dentry, bdst);
++ if (unlikely(err < 0))
++ goto out;
++ h_path.dentry = au_h_dptr(dentry, bdst);
++ h_path.mnt = au_sbr_mnt(dentry->d_sb, bdst);
++ err = vfsub_sio_mkdir(au_h_iptr(dir, bdst), &h_path,
++ S_IRWXU | S_IRUGO | S_IXUGO);
++ if (unlikely(err))
++ goto out_put;
++ au_fset_cpdown(args->flags, MADE_DIR);
++
++ bend = au_dbend(dentry);
++ bopq = au_dbdiropq(dentry);
++ au_fclr_cpdown(args->flags, WHED);
++ au_fclr_cpdown(args->flags, DIROPQ);
++ if (au_dbwh(dentry) == bdst)
++ au_fset_cpdown(args->flags, WHED);
++ if (!au_ftest_cpdown(args->flags, PARENT_OPQ) && bopq <= bdst)
++ au_fset_cpdown(args->flags, PARENT_OPQ);
++ parent_opq = (au_ftest_cpdown(args->flags, PARENT_OPQ)
++ && args->parent == dentry);
++ h_inode = h_path.dentry->d_inode;
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ if (au_ftest_cpdown(args->flags, WHED)) {
++ err = au_cpdown_dir_opq(dentry, bdst, args);
++ if (unlikely(err)) {
++ mutex_unlock(&h_inode->i_mutex);
++ goto out_dir;
++ }
++ }
++
++ err = au_cpdown_attr(&h_path, au_h_dptr(dentry, bstart));
++ mutex_unlock(&h_inode->i_mutex);
++ if (unlikely(err))
++ goto out_opq;
++
++ if (au_ftest_cpdown(args->flags, WHED)) {
++ err = au_cpdown_dir_wh(dentry, h_parent, dir, bdst);
++ if (unlikely(err))
++ goto out_opq;
++ }
++
++ inode = dentry->d_inode;
++ if (au_ibend(inode) < bdst)
++ au_set_ibend(inode, bdst);
++ au_set_h_iptr(inode, bdst, au_igrab(h_inode),
++ au_hi_flags(inode, /*isdir*/1));
++ goto out; /* success */
++
++ /* revert */
++ out_opq:
++ if (au_ftest_cpdown(args->flags, DIROPQ)) {
++ mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
++ rerr = au_diropq_remove(dentry, bdst);
++ mutex_unlock(&h_inode->i_mutex);
++ if (unlikely(rerr)) {
++ AuIOErr("failed removing diropq for %.*s b%d (%d)\n",
++ AuDLNPair(dentry), bdst, rerr);
++ err = -EIO;
++ goto out;
++ }
++ }
++ out_dir:
++ if (au_ftest_cpdown(args->flags, MADE_DIR)) {
++ rerr = vfsub_sio_rmdir(au_h_iptr(dir, bdst), &h_path);
++ if (unlikely(rerr)) {
++ AuIOErr("failed removing %.*s b%d (%d)\n",
++ AuDLNPair(dentry), bdst, rerr);
++ err = -EIO;
++ }
++ }
++ out_put:
++ au_set_h_dptr(dentry, bdst, NULL);
++ if (au_dbend(dentry) == bdst)
++ au_update_dbend(dentry);
++ out:
++ dput(parent);
++ return err;
++}
++
++int au_cpdown_dirs(struct dentry *dentry, aufs_bindex_t bdst)
++{
++ int err;
++ struct au_cpdown_dir_args args = {
++ .parent = dget_parent(dentry),
++ .flags = 0
++ };
++
++ err = au_cp_dirs(dentry, bdst, au_cpdown_dir, &args);
++ dput(args.parent);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* policies for create */
++
++static int au_wbr_bu(struct super_block *sb, aufs_bindex_t bindex)
++{
++ for (; bindex >= 0; bindex--)
++ if (!au_br_rdonly(au_sbr(sb, bindex)))
++ return bindex;
++ return -EROFS;
++}
++
++/* top down parent */
++static int au_wbr_create_tdp(struct dentry *dentry, int isdir __maybe_unused)
++{
++ int err;
++ aufs_bindex_t bstart, bindex;
++ struct super_block *sb;
++ struct dentry *parent, *h_parent;
++
++ sb = dentry->d_sb;
++ bstart = au_dbstart(dentry);
++ err = bstart;
++ if (!au_br_rdonly(au_sbr(sb, bstart)))
++ goto out;
++
++ err = -EROFS;
++ parent = dget_parent(dentry);
++ for (bindex = au_dbstart(parent); bindex < bstart; bindex++) {
++ h_parent = au_h_dptr(parent, bindex);
++ if (!h_parent || !h_parent->d_inode)
++ continue;
++
++ if (!au_br_rdonly(au_sbr(sb, bindex))) {
++ err = bindex;
++ break;
++ }
++ }
++ dput(parent);
++
++ /* bottom up here */
++ if (unlikely(err < 0))
++ err = au_wbr_bu(sb, bstart - 1);
++
++ out:
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* an exception for the policy other than tdp */
++static int au_wbr_create_exp(struct dentry *dentry)
++{
++ int err;
++ aufs_bindex_t bwh, bdiropq;
++ struct dentry *parent;
++
++ err = -1;
++ bwh = au_dbwh(dentry);
++ parent = dget_parent(dentry);
++ bdiropq = au_dbdiropq(parent);
++ if (bwh >= 0) {
++ if (bdiropq >= 0)
++ err = min(bdiropq, bwh);
++ else
++ err = bwh;
++ AuDbg("%d\n", err);
++ } else if (bdiropq >= 0) {
++ err = bdiropq;
++ AuDbg("%d\n", err);
++ }
++ dput(parent);
++
++ if (err >= 0 && au_br_rdonly(au_sbr(dentry->d_sb, err)))
++ err = -1;
++
++ AuDbg("%d\n", err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* round robin */
++static int au_wbr_create_init_rr(struct super_block *sb)
++{
++ int err;
++
++ err = au_wbr_bu(sb, au_sbend(sb));
++ atomic_set(&au_sbi(sb)->si_wbr_rr_next, -err); /* less important */
++
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++static int au_wbr_create_rr(struct dentry *dentry, int isdir)
++{
++ int err, nbr;
++ unsigned int u;
++ aufs_bindex_t bindex, bend;
++ struct super_block *sb;
++ atomic_t *next;
++
++ err = au_wbr_create_exp(dentry);
++ if (err >= 0)
++ goto out;
++
++ sb = dentry->d_sb;
++ next = &au_sbi(sb)->si_wbr_rr_next;
++ bend = au_sbend(sb);
++ nbr = bend + 1;
++ for (bindex = 0; bindex <= bend; bindex++) {
++ if (!isdir) {
++ err = atomic_dec_return(next) + 1;
++ /* modulo for 0 is meaningless */
++ if (unlikely(!err))
++ err = atomic_dec_return(next) + 1;
++ } else
++ err = atomic_read(next);
++ AuDbg("%d\n", err);
++ u = err;
++ err = u % nbr;
++ AuDbg("%d\n", err);
++ if (!au_br_rdonly(au_sbr(sb, err)))
++ break;
++ err = -EROFS;
++ }
++
++ out:
++ AuDbg("%d\n", err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* most free space */
++static void au_mfs(struct dentry *dentry)
++{
++ struct super_block *sb;
++ struct au_branch *br;
++ struct au_wbr_mfs *mfs;
++ aufs_bindex_t bindex, bend;
++ int err;
++ unsigned long long b, bavail;
++ /* reduce the stack usage */
++ struct kstatfs *st;
++
++ st = kmalloc(sizeof(*st), GFP_NOFS);
++ if (unlikely(!st)) {
++ AuWarn1("failed updating mfs(%d), ignored\n", -ENOMEM);
++ return;
++ }
++
++ bavail = 0;
++ sb = dentry->d_sb;
++ mfs = &au_sbi(sb)->si_wbr_mfs;
++ mfs->mfs_bindex = -EROFS;
++ mfs->mfsrr_bytes = 0;
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ if (au_br_rdonly(br))
++ continue;
++
++ /* sb->s_root for NFS is unreliable */
++ err = vfs_statfs(br->br_mnt->mnt_root, st);
++ if (unlikely(err)) {
++ AuWarn1("failed statfs, b%d, %d\n", bindex, err);
++ continue;
++ }
++
++ /* when the available size is equal, select the lower one */
++ BUILD_BUG_ON(sizeof(b) < sizeof(st->f_bavail)
++ || sizeof(b) < sizeof(st->f_bsize));
++ b = st->f_bavail * st->f_bsize;
++ br->br_wbr->wbr_bytes = b;
++ if (b >= bavail) {
++ bavail = b;
++ mfs->mfs_bindex = bindex;
++ mfs->mfs_jiffy = jiffies;
++ }
++ }
++
++ mfs->mfsrr_bytes = bavail;
++ AuDbg("b%d\n", mfs->mfs_bindex);
++ kfree(st);
++}
++
++static int au_wbr_create_mfs(struct dentry *dentry, int isdir __maybe_unused)
++{
++ int err;
++ struct super_block *sb;
++ struct au_wbr_mfs *mfs;
++
++ err = au_wbr_create_exp(dentry);
++ if (err >= 0)
++ goto out;
++
++ sb = dentry->d_sb;
++ mfs = &au_sbi(sb)->si_wbr_mfs;
++ mutex_lock(&mfs->mfs_lock);
++ if (time_after(jiffies, mfs->mfs_jiffy + mfs->mfs_expire)
++ || mfs->mfs_bindex < 0
++ || au_br_rdonly(au_sbr(sb, mfs->mfs_bindex)))
++ au_mfs(dentry);
++ mutex_unlock(&mfs->mfs_lock);
++ err = mfs->mfs_bindex;
++
++ out:
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++static int au_wbr_create_init_mfs(struct super_block *sb)
++{
++ struct au_wbr_mfs *mfs;
++
++ mfs = &au_sbi(sb)->si_wbr_mfs;
++ mutex_init(&mfs->mfs_lock);
++ mfs->mfs_jiffy = 0;
++ mfs->mfs_bindex = -EROFS;
++
++ return 0;
++}
++
++static int au_wbr_create_fin_mfs(struct super_block *sb __maybe_unused)
++{
++ mutex_destroy(&au_sbi(sb)->si_wbr_mfs.mfs_lock);
++ return 0;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* most free space and then round robin */
++static int au_wbr_create_mfsrr(struct dentry *dentry, int isdir)
++{
++ int err;
++ struct au_wbr_mfs *mfs;
++
++ err = au_wbr_create_mfs(dentry, isdir);
++ if (err >= 0) {
++ mfs = &au_sbi(dentry->d_sb)->si_wbr_mfs;
++ if (mfs->mfsrr_bytes < mfs->mfsrr_watermark)
++ err = au_wbr_create_rr(dentry, isdir);
++ }
++
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++static int au_wbr_create_init_mfsrr(struct super_block *sb)
++{
++ int err;
++
++ au_wbr_create_init_mfs(sb); /* ignore */
++ err = au_wbr_create_init_rr(sb);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* top down parent and most free space */
++static int au_wbr_create_pmfs(struct dentry *dentry, int isdir)
++{
++ int err, e2;
++ unsigned long long b;
++ aufs_bindex_t bindex, bstart, bend;
++ struct super_block *sb;
++ struct dentry *parent, *h_parent;
++ struct au_branch *br;
++
++ err = au_wbr_create_tdp(dentry, isdir);
++ if (unlikely(err < 0))
++ goto out;
++ parent = dget_parent(dentry);
++ bstart = au_dbstart(parent);
++ bend = au_dbtaildir(parent);
++ if (bstart == bend)
++ goto out_parent; /* success */
++
++ e2 = au_wbr_create_mfs(dentry, isdir);
++ if (e2 < 0)
++ goto out_parent; /* success */
++
++ /* when the available size is equal, select upper one */
++ sb = dentry->d_sb;
++ br = au_sbr(sb, err);
++ b = br->br_wbr->wbr_bytes;
++ AuDbg("b%d, %llu\n", err, b);
++
++ for (bindex = bstart; bindex <= bend; bindex++) {
++ h_parent = au_h_dptr(parent, bindex);
++ if (!h_parent || !h_parent->d_inode)
++ continue;
++
++ br = au_sbr(sb, bindex);
++ if (!au_br_rdonly(br) && br->br_wbr->wbr_bytes > b) {
++ b = br->br_wbr->wbr_bytes;
++ err = bindex;
++ AuDbg("b%d, %llu\n", err, b);
++ }
++ }
++
++ out_parent:
++ dput(parent);
++ out:
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* policies for copyup */
++
++/* top down parent */
++static int au_wbr_copyup_tdp(struct dentry *dentry)
++{
++ return au_wbr_create_tdp(dentry, /*isdir, anything is ok*/0);
++}
++
++/* bottom up parent */
++static int au_wbr_copyup_bup(struct dentry *dentry)
++{
++ int err;
++ aufs_bindex_t bindex, bstart;
++ struct dentry *parent, *h_parent;
++ struct super_block *sb;
++
++ err = -EROFS;
++ sb = dentry->d_sb;
++ parent = dget_parent(dentry);
++ bstart = au_dbstart(parent);
++ for (bindex = au_dbstart(dentry); bindex >= bstart; bindex--) {
++ h_parent = au_h_dptr(parent, bindex);
++ if (!h_parent || !h_parent->d_inode)
++ continue;
++
++ if (!au_br_rdonly(au_sbr(sb, bindex))) {
++ err = bindex;
++ break;
++ }
++ }
++ dput(parent);
++
++ /* bottom up here */
++ if (unlikely(err < 0))
++ err = au_wbr_bu(sb, bstart - 1);
++
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++/* bottom up */
++static int au_wbr_copyup_bu(struct dentry *dentry)
++{
++ int err;
++
++ err = au_wbr_bu(dentry->d_sb, au_dbstart(dentry));
++
++ AuDbg("b%d\n", err);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_wbr_copyup_operations au_wbr_copyup_ops[] = {
++ [AuWbrCopyup_TDP] = {
++ .copyup = au_wbr_copyup_tdp
++ },
++ [AuWbrCopyup_BUP] = {
++ .copyup = au_wbr_copyup_bup
++ },
++ [AuWbrCopyup_BU] = {
++ .copyup = au_wbr_copyup_bu
++ }
++};
++
++struct au_wbr_create_operations au_wbr_create_ops[] = {
++ [AuWbrCreate_TDP] = {
++ .create = au_wbr_create_tdp
++ },
++ [AuWbrCreate_RR] = {
++ .create = au_wbr_create_rr,
++ .init = au_wbr_create_init_rr
++ },
++ [AuWbrCreate_MFS] = {
++ .create = au_wbr_create_mfs,
++ .init = au_wbr_create_init_mfs,
++ .fin = au_wbr_create_fin_mfs
++ },
++ [AuWbrCreate_MFSV] = {
++ .create = au_wbr_create_mfs,
++ .init = au_wbr_create_init_mfs,
++ .fin = au_wbr_create_fin_mfs
++ },
++ [AuWbrCreate_MFSRR] = {
++ .create = au_wbr_create_mfsrr,
++ .init = au_wbr_create_init_mfsrr,
++ .fin = au_wbr_create_fin_mfs
++ },
++ [AuWbrCreate_MFSRRV] = {
++ .create = au_wbr_create_mfsrr,
++ .init = au_wbr_create_init_mfsrr,
++ .fin = au_wbr_create_fin_mfs
++ },
++ [AuWbrCreate_PMFS] = {
++ .create = au_wbr_create_pmfs,
++ .init = au_wbr_create_init_mfs,
++ .fin = au_wbr_create_fin_mfs
++ },
++ [AuWbrCreate_PMFSV] = {
++ .create = au_wbr_create_pmfs,
++ .init = au_wbr_create_init_mfs,
++ .fin = au_wbr_create_fin_mfs
++ }
++};
+diff --git a/fs/aufs/whout.c b/fs/aufs/whout.c
+new file mode 100644
+index 0000000..a45e126
+--- /dev/null
++++ b/fs/aufs/whout.c
+@@ -0,0 +1,1030 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * whiteout for logical deletion and opaque directory
++ */
++
++#include <linux/fs.h>
++#include "aufs.h"
++
++#define WH_MASK S_IRUGO
++
++/*
++ * If a directory contains this file, then it is opaque. We start with the
++ * .wh. flag so that it is blocked by lookup.
++ */
++static struct qstr diropq_name = {
++ .name = AUFS_WH_DIROPQ,
++ .len = sizeof(AUFS_WH_DIROPQ) - 1
++};
++
++/*
++ * generate whiteout name, which is NOT terminated by NULL.
++ * @name: original d_name.name
++ * @len: original d_name.len
++ * @wh: whiteout qstr
++ * returns zero when succeeds, otherwise error.
++ * succeeded value as wh->name should be freed by kfree().
++ */
++int au_wh_name_alloc(struct qstr *wh, const struct qstr *name)
++{
++ char *p;
++
++ if (unlikely(name->len > PATH_MAX - AUFS_WH_PFX_LEN))
++ return -ENAMETOOLONG;
++
++ wh->len = name->len + AUFS_WH_PFX_LEN;
++ p = kmalloc(wh->len, GFP_NOFS);
++ wh->name = p;
++ if (p) {
++ memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
++ memcpy(p + AUFS_WH_PFX_LEN, name->name, name->len);
++ /* smp_mb(); */
++ return 0;
++ }
++ return -ENOMEM;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * test if the @wh_name exists under @h_parent.
++ * @try_sio specifies the necessary of super-io.
++ */
++int au_wh_test(struct dentry *h_parent, struct qstr *wh_name,
++ struct au_branch *br, int try_sio)
++{
++ int err;
++ struct dentry *wh_dentry;
++ struct inode *h_dir;
++
++ h_dir = h_parent->d_inode;
++ if (!try_sio)
++ wh_dentry = au_lkup_one(wh_name, h_parent, br, /*nd*/NULL);
++ else
++ wh_dentry = au_sio_lkup_one(wh_name, h_parent, br);
++ err = PTR_ERR(wh_dentry);
++ if (IS_ERR(wh_dentry))
++ goto out;
++
++ err = 0;
++ if (!wh_dentry->d_inode)
++ goto out_wh; /* success */
++
++ err = 1;
++ if (S_ISREG(wh_dentry->d_inode->i_mode))
++ goto out_wh; /* success */
++
++ err = -EIO;
++ AuIOErr("%.*s Invalid whiteout entry type 0%o.\n",
++ AuDLNPair(wh_dentry), wh_dentry->d_inode->i_mode);
++
++ out_wh:
++ dput(wh_dentry);
++ out:
++ return err;
++}
++
++/*
++ * test if the @h_dentry sets opaque or not.
++ */
++int au_diropq_test(struct dentry *h_dentry, struct au_branch *br)
++{
++ int err;
++ struct inode *h_dir;
++
++ h_dir = h_dentry->d_inode;
++ err = au_wh_test(h_dentry, &diropq_name, br,
++ au_test_h_perm_sio(h_dir, MAY_EXEC));
++ return err;
++}
++
++/*
++ * returns a negative dentry whose name is unique and temporary.
++ */
++struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct au_branch *br,
++ struct qstr *prefix)
++{
++#define HEX_LEN 4
++ struct dentry *dentry;
++ int i;
++ char defname[AUFS_WH_PFX_LEN * 2 + DNAME_INLINE_LEN_MIN + 1
++ + HEX_LEN + 1], *name, *p;
++ static unsigned short cnt;
++ struct qstr qs;
++
++ name = defname;
++ qs.len = sizeof(defname) - DNAME_INLINE_LEN_MIN + prefix->len - 1;
++ if (unlikely(prefix->len > DNAME_INLINE_LEN_MIN)) {
++ dentry = ERR_PTR(-ENAMETOOLONG);
++ if (unlikely(qs.len >= PATH_MAX))
++ goto out;
++ dentry = ERR_PTR(-ENOMEM);
++ name = kmalloc(qs.len + 1, GFP_NOFS);
++ if (unlikely(!name))
++ goto out;
++ }
++
++ /* doubly whiteout-ed */
++ memcpy(name, AUFS_WH_PFX AUFS_WH_PFX, AUFS_WH_PFX_LEN * 2);
++ p = name + AUFS_WH_PFX_LEN * 2;
++ memcpy(p, prefix->name, prefix->len);
++ p += prefix->len;
++ *p++ = '.';
++ AuDebugOn(name + qs.len + 1 - p <= HEX_LEN);
++
++ qs.name = name;
++ for (i = 0; i < 3; i++) {
++ sprintf(p, "%.*d", HEX_LEN, cnt++);
++ dentry = au_sio_lkup_one(&qs, h_parent, br);
++ if (IS_ERR(dentry) || !dentry->d_inode)
++ goto out_name;
++ dput(dentry);
++ }
++ /* AuWarn("could not get random name\n"); */
++ dentry = ERR_PTR(-EEXIST);
++ AuDbg("%.*s\n", AuLNPair(&qs));
++ BUG();
++
++ out_name:
++ if (name != defname)
++ kfree(name);
++ out:
++ return dentry;
++#undef HEX_LEN
++}
++
++/*
++ * rename the @h_dentry on @br to the whiteouted temporary name.
++ */
++int au_whtmp_ren(struct dentry *h_dentry, struct au_branch *br)
++{
++ int err;
++ struct path h_path = {
++ .mnt = br->br_mnt
++ };
++ struct inode *h_dir;
++ struct dentry *h_parent;
++
++ h_parent = h_dentry->d_parent; /* dir inode is locked */
++ h_dir = h_parent->d_inode;
++ IMustLock(h_dir);
++
++ h_path.dentry = au_whtmp_lkup(h_parent, br, &h_dentry->d_name);
++ err = PTR_ERR(h_path.dentry);
++ if (IS_ERR(h_path.dentry))
++ goto out;
++
++ /* under the same dir, no need to lock_rename() */
++ err = vfsub_rename(h_dir, h_dentry, h_dir, &h_path);
++ AuTraceErr(err);
++ dput(h_path.dentry);
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * functions for removing a whiteout
++ */
++
++static int do_unlink_wh(struct inode *h_dir, struct path *h_path)
++{
++ int force;
++
++ /*
++ * forces superio when the dir has a sticky bit.
++ * this may be a violation of unix fs semantics.
++ */
++ force = (h_dir->i_mode & S_ISVTX)
++ && h_path->dentry->d_inode->i_uid != current_fsuid();
++ return vfsub_unlink(h_dir, h_path, force);
++}
++
++int au_wh_unlink_dentry(struct inode *h_dir, struct path *h_path,
++ struct dentry *dentry)
++{
++ int err;
++
++ err = do_unlink_wh(h_dir, h_path);
++ if (!err && dentry)
++ au_set_dbwh(dentry, -1);
++
++ return err;
++}
++
++static int unlink_wh_name(struct dentry *h_parent, struct qstr *wh,
++ struct au_branch *br)
++{
++ int err;
++ struct path h_path = {
++ .mnt = br->br_mnt
++ };
++
++ err = 0;
++ h_path.dentry = au_lkup_one(wh, h_parent, br, /*nd*/NULL);
++ if (IS_ERR(h_path.dentry))
++ err = PTR_ERR(h_path.dentry);
++ else {
++ if (h_path.dentry->d_inode
++ && S_ISREG(h_path.dentry->d_inode->i_mode))
++ err = do_unlink_wh(h_parent->d_inode, &h_path);
++ dput(h_path.dentry);
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * initialize/clean whiteout for a branch
++ */
++
++static void au_wh_clean(struct inode *h_dir, struct path *whpath,
++ const int isdir)
++{
++ int err;
++
++ if (!whpath->dentry->d_inode)
++ return;
++
++ err = mnt_want_write(whpath->mnt);
++ if (!err) {
++ if (isdir)
++ err = vfsub_rmdir(h_dir, whpath);
++ else
++ err = vfsub_unlink(h_dir, whpath, /*force*/0);
++ mnt_drop_write(whpath->mnt);
++ }
++ if (unlikely(err))
++ AuWarn("failed removing %.*s (%d), ignored.\n",
++ AuDLNPair(whpath->dentry), err);
++}
++
++static int test_linkable(struct dentry *h_root)
++{
++ struct inode *h_dir = h_root->d_inode;
++
++ if (h_dir->i_op->link)
++ return 0;
++
++ AuErr("%.*s (%s) doesn't support link(2), use noplink and rw+nolwh\n",
++ AuDLNPair(h_root), au_sbtype(h_root->d_sb));
++ return -ENOSYS;
++}
++
++/* todo: should this mkdir be done in /sbin/mount.aufs helper? */
++static int au_whdir(struct inode *h_dir, struct path *path)
++{
++ int err;
++
++ err = -EEXIST;
++ if (!path->dentry->d_inode) {
++ int mode = S_IRWXU;
++
++ if (au_test_nfs(path->dentry->d_sb))
++ mode |= S_IXUGO;
++ err = mnt_want_write(path->mnt);
++ if (!err) {
++ err = vfsub_mkdir(h_dir, path, mode);
++ mnt_drop_write(path->mnt);
++ }
++ } else if (S_ISDIR(path->dentry->d_inode->i_mode))
++ err = 0;
++ else
++ AuErr("unknown %.*s exists\n", AuDLNPair(path->dentry));
++
++ return err;
++}
++
++struct au_wh_base {
++ const struct qstr *name;
++ struct dentry *dentry;
++};
++
++static void au_wh_init_ro(struct inode *h_dir, struct au_wh_base base[],
++ struct path *h_path)
++{
++ h_path->dentry = base[AuBrWh_BASE].dentry;
++ au_wh_clean(h_dir, h_path, /*isdir*/0);
++ h_path->dentry = base[AuBrWh_PLINK].dentry;
++ au_wh_clean(h_dir, h_path, /*isdir*/1);
++ h_path->dentry = base[AuBrWh_ORPH].dentry;
++ au_wh_clean(h_dir, h_path, /*isdir*/1);
++}
++
++/*
++ * returns tri-state,
++ * minus: error, caller should print the mesage
++ * zero: succuess
++ * plus: error, caller should NOT print the mesage
++ */
++static int au_wh_init_rw_nolink(struct dentry *h_root, struct au_wbr *wbr,
++ int do_plink, struct au_wh_base base[],
++ struct path *h_path)
++{
++ int err;
++ struct inode *h_dir;
++
++ h_dir = h_root->d_inode;
++ h_path->dentry = base[AuBrWh_BASE].dentry;
++ au_wh_clean(h_dir, h_path, /*isdir*/0);
++ h_path->dentry = base[AuBrWh_PLINK].dentry;
++ if (do_plink) {
++ err = test_linkable(h_root);
++ if (unlikely(err)) {
++ err = 1;
++ goto out;
++ }
++
++ err = au_whdir(h_dir, h_path);
++ if (unlikely(err))
++ goto out;
++ wbr->wbr_plink = dget(base[AuBrWh_PLINK].dentry);
++ } else
++ au_wh_clean(h_dir, h_path, /*isdir*/1);
++ h_path->dentry = base[AuBrWh_ORPH].dentry;
++ err = au_whdir(h_dir, h_path);
++ if (unlikely(err))
++ goto out;
++ wbr->wbr_orph = dget(base[AuBrWh_ORPH].dentry);
++
++ out:
++ return err;
++}
++
++/*
++ * for the moment, aufs supports the branch filesystem which does not support
++ * link(2). testing on FAT which does not support i_op->setattr() fully either,
++ * copyup failed. finally, such filesystem will not be used as the writable
++ * branch.
++ *
++ * returns tri-state, see above.
++ */
++static int au_wh_init_rw(struct dentry *h_root, struct au_wbr *wbr,
++ int do_plink, struct au_wh_base base[],
++ struct path *h_path)
++{
++ int err;
++ struct inode *h_dir;
++
++ err = test_linkable(h_root);
++ if (unlikely(err)) {
++ err = 1;
++ goto out;
++ }
++
++ /*
++ * todo: should this create be done in /sbin/mount.aufs helper?
++ */
++ err = -EEXIST;
++ h_dir = h_root->d_inode;
++ if (!base[AuBrWh_BASE].dentry->d_inode) {
++ err = mnt_want_write(h_path->mnt);
++ if (!err) {
++ h_path->dentry = base[AuBrWh_BASE].dentry;
++ err = vfsub_create(h_dir, h_path, WH_MASK);
++ mnt_drop_write(h_path->mnt);
++ }
++ } else if (S_ISREG(base[AuBrWh_BASE].dentry->d_inode->i_mode))
++ err = 0;
++ else
++ AuErr("unknown %.*s/%.*s exists\n",
++ AuDLNPair(h_root), AuDLNPair(base[AuBrWh_BASE].dentry));
++ if (unlikely(err))
++ goto out;
++
++ h_path->dentry = base[AuBrWh_PLINK].dentry;
++ if (do_plink) {
++ err = au_whdir(h_dir, h_path);
++ if (unlikely(err))
++ goto out;
++ wbr->wbr_plink = dget(base[AuBrWh_PLINK].dentry);
++ } else
++ au_wh_clean(h_dir, h_path, /*isdir*/1);
++ wbr->wbr_whbase = dget(base[AuBrWh_BASE].dentry);
++
++ h_path->dentry = base[AuBrWh_ORPH].dentry;
++ err = au_whdir(h_dir, h_path);
++ if (unlikely(err))
++ goto out;
++ wbr->wbr_orph = dget(base[AuBrWh_ORPH].dentry);
++
++ out:
++ return err;
++}
++
++/*
++ * initialize the whiteout base file/dir for @br.
++ */
++int au_wh_init(struct dentry *h_root, struct au_branch *br,
++ struct super_block *sb)
++{
++ int err, i;
++ const unsigned char do_plink
++ = !!au_opt_test(au_mntflags(sb), PLINK);
++ struct path path = {
++ .mnt = br->br_mnt
++ };
++ struct inode *h_dir;
++ struct au_wbr *wbr = br->br_wbr;
++ static const struct qstr base_name[] = {
++ [AuBrWh_BASE] = {
++ .name = AUFS_BASE_NAME,
++ .len = sizeof(AUFS_BASE_NAME) - 1
++ },
++ [AuBrWh_PLINK] = {
++ .name = AUFS_PLINKDIR_NAME,
++ .len = sizeof(AUFS_PLINKDIR_NAME) - 1
++ },
++ [AuBrWh_ORPH] = {
++ .name = AUFS_ORPHDIR_NAME,
++ .len = sizeof(AUFS_ORPHDIR_NAME) - 1
++ }
++ };
++ struct au_wh_base base[] = {
++ [AuBrWh_BASE] = {
++ .name = base_name + AuBrWh_BASE,
++ .dentry = NULL
++ },
++ [AuBrWh_PLINK] = {
++ .name = base_name + AuBrWh_PLINK,
++ .dentry = NULL
++ },
++ [AuBrWh_ORPH] = {
++ .name = base_name + AuBrWh_ORPH,
++ .dentry = NULL
++ }
++ };
++
++
++ h_dir = h_root->d_inode;
++ for (i = 0; i < AuBrWh_Last; i++) {
++ /* doubly whiteouted */
++ struct dentry *d;
++
++ d = au_wh_lkup(h_root, (void *)base[i].name, br);
++ err = PTR_ERR(d);
++ if (IS_ERR(d))
++ goto out;
++
++ base[i].dentry = d;
++ AuDebugOn(wbr
++ && wbr->wbr_wh[i]
++ && wbr->wbr_wh[i] != base[i].dentry);
++ }
++
++ if (wbr)
++ for (i = 0; i < AuBrWh_Last; i++) {
++ dput(wbr->wbr_wh[i]);
++ wbr->wbr_wh[i] = NULL;
++ }
++
++ err = 0;
++
++ switch (br->br_perm) {
++ case AuBrPerm_RO:
++ case AuBrPerm_ROWH:
++ case AuBrPerm_RR:
++ case AuBrPerm_RRWH:
++ au_wh_init_ro(h_dir, base, &path);
++ break;
++
++ case AuBrPerm_RWNoLinkWH:
++ err = au_wh_init_rw_nolink(h_root, wbr, do_plink, base, &path);
++ if (err > 0)
++ goto out;
++ else if (err)
++ goto out_err;
++ break;
++
++ case AuBrPerm_RW:
++ err = au_wh_init_rw(h_root, wbr, do_plink, base, &path);
++ if (err > 0)
++ goto out;
++ else if (err)
++ goto out_err;
++ break;
++
++ default:
++ BUG();
++ }
++ goto out; /* success */
++
++ out_err:
++ AuErr("an error(%d) on the writable branch %.*s(%s)\n",
++ err, AuDLNPair(h_root), au_sbtype(h_root->d_sb));
++ out:
++ for (i = 0; i < AuBrWh_Last; i++)
++ dput(base[i].dentry);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++/*
++ * whiteouts are all hard-linked usually.
++ * when its link count reaches a ceiling, we create a new whiteout base
++ * asynchronously.
++ */
++
++struct reinit_br_wh {
++ struct super_block *sb;
++ struct au_branch *br;
++};
++
++static void reinit_br_wh(void *arg)
++{
++ int err;
++ aufs_bindex_t bindex;
++ struct path h_path;
++ struct reinit_br_wh *a = arg;
++ struct au_wbr *wbr;
++ struct inode *dir;
++ struct dentry *h_root;
++ struct au_hinode *hdir;
++
++ err = 0;
++ wbr = a->br->br_wbr;
++ /* big aufs lock */
++ si_noflush_write_lock(a->sb);
++ if (!au_br_writable(a->br->br_perm))
++ goto out;
++ bindex = au_br_index(a->sb, a->br->br_id);
++ if (unlikely(bindex < 0))
++ goto out;
++
++ dir = a->sb->s_root->d_inode;
++ /* ii_read_lock_parent(dir); */
++ hdir = au_hi(dir, bindex);
++ h_root = au_h_dptr(a->sb->s_root, bindex);
++
++ au_hin_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++ wbr_wh_write_lock(wbr);
++ err = au_h_verify(wbr->wbr_whbase, au_opt_udba(a->sb), hdir->hi_inode,
++ h_root, a->br);
++ if (!err) {
++ err = mnt_want_write(a->br->br_mnt);
++ if (!err) {
++ h_path.dentry = wbr->wbr_whbase;
++ h_path.mnt = a->br->br_mnt;
++ err = vfsub_unlink(hdir->hi_inode, &h_path, /*force*/0);
++ mnt_drop_write(a->br->br_mnt);
++ }
++ } else {
++ AuWarn("%.*s is moved, ignored\n", AuDLNPair(wbr->wbr_whbase));
++ err = 0;
++ }
++ dput(wbr->wbr_whbase);
++ wbr->wbr_whbase = NULL;
++ if (!err)
++ err = au_wh_init(h_root, a->br, a->sb);
++ wbr_wh_write_unlock(wbr);
++ au_hin_imtx_unlock(hdir);
++ /* ii_read_unlock(dir); */
++
++ out:
++ if (wbr)
++ atomic_dec(&wbr->wbr_wh_running);
++ atomic_dec(&a->br->br_count);
++ au_nwt_done(&au_sbi(a->sb)->si_nowait);
++ si_write_unlock(a->sb);
++ kfree(arg);
++ if (unlikely(err))
++ AuIOErr("err %d\n", err);
++}
++
++static void kick_reinit_br_wh(struct super_block *sb, struct au_branch *br)
++{
++ int do_dec, wkq_err;
++ struct reinit_br_wh *arg;
++
++ do_dec = 1;
++ if (atomic_inc_return(&br->br_wbr->wbr_wh_running) != 1)
++ goto out;
++
++ /* ignore ENOMEM */
++ arg = kmalloc(sizeof(*arg), GFP_NOFS);
++ if (arg) {
++ /*
++ * dec(wh_running), kfree(arg) and dec(br_count)
++ * in reinit function
++ */
++ arg->sb = sb;
++ arg->br = br;
++ atomic_inc(&br->br_count);
++ wkq_err = au_wkq_nowait(reinit_br_wh, arg, sb);
++ if (unlikely(wkq_err)) {
++ atomic_dec(&br->br_wbr->wbr_wh_running);
++ atomic_dec(&br->br_count);
++ kfree(arg);
++ }
++ do_dec = 0;
++ }
++
++ out:
++ if (do_dec)
++ atomic_dec(&br->br_wbr->wbr_wh_running);
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create the whiteout @wh.
++ */
++static int link_or_create_wh(struct super_block *sb, aufs_bindex_t bindex,
++ struct dentry *wh)
++{
++ int err;
++ struct path h_path = {
++ .dentry = wh
++ };
++ struct au_branch *br;
++ struct au_wbr *wbr;
++ struct dentry *h_parent;
++ struct inode *h_dir;
++
++ h_parent = wh->d_parent; /* dir inode is locked */
++ h_dir = h_parent->d_inode;
++ IMustLock(h_dir);
++
++ br = au_sbr(sb, bindex);
++ h_path.mnt = br->br_mnt;
++ wbr = br->br_wbr;
++ wbr_wh_read_lock(wbr);
++ if (wbr->wbr_whbase) {
++ err = vfsub_link(wbr->wbr_whbase, h_dir, &h_path);
++ if (!err || err != -EMLINK)
++ goto out;
++
++ /* link count full. re-initialize br_whbase. */
++ kick_reinit_br_wh(sb, br);
++ }
++
++ /* return this error in this context */
++ err = vfsub_create(h_dir, &h_path, WH_MASK);
++
++ out:
++ wbr_wh_read_unlock(wbr);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create or remove the diropq.
++ */
++static struct dentry *do_diropq(struct dentry *dentry, aufs_bindex_t bindex,
++ unsigned int flags)
++{
++ struct dentry *opq_dentry, *h_dentry;
++ struct super_block *sb;
++ struct au_branch *br;
++ int err;
++
++ sb = dentry->d_sb;
++ br = au_sbr(sb, bindex);
++ h_dentry = au_h_dptr(dentry, bindex);
++ opq_dentry = au_lkup_one(&diropq_name, h_dentry, br, /*nd*/NULL);
++ if (IS_ERR(opq_dentry))
++ goto out;
++
++ if (au_ftest_diropq(flags, CREATE)) {
++ err = link_or_create_wh(sb, bindex, opq_dentry);
++ if (!err) {
++ au_set_dbdiropq(dentry, bindex);
++ goto out; /* success */
++ }
++ } else {
++ struct path tmp = {
++ .dentry = opq_dentry,
++ .mnt = br->br_mnt
++ };
++ err = do_unlink_wh(au_h_iptr(dentry->d_inode, bindex), &tmp);
++ if (!err)
++ au_set_dbdiropq(dentry, -1);
++ }
++ dput(opq_dentry);
++ opq_dentry = ERR_PTR(err);
++
++ out:
++ return opq_dentry;
++}
++
++struct do_diropq_args {
++ struct dentry **errp;
++ struct dentry *dentry;
++ aufs_bindex_t bindex;
++ unsigned int flags;
++};
++
++static void call_do_diropq(void *args)
++{
++ struct do_diropq_args *a = args;
++ *a->errp = do_diropq(a->dentry, a->bindex, a->flags);
++}
++
++struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
++ unsigned int flags)
++{
++ struct dentry *diropq, *h_dentry;
++
++ h_dentry = au_h_dptr(dentry, bindex);
++ if (!au_test_h_perm_sio(h_dentry->d_inode, MAY_EXEC | MAY_WRITE))
++ diropq = do_diropq(dentry, bindex, flags);
++ else {
++ int wkq_err;
++ struct do_diropq_args args = {
++ .errp = &diropq,
++ .dentry = dentry,
++ .bindex = bindex,
++ .flags = flags
++ };
++
++ wkq_err = au_wkq_wait(call_do_diropq, &args);
++ if (unlikely(wkq_err))
++ diropq = ERR_PTR(wkq_err);
++ }
++
++ return diropq;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * lookup whiteout dentry.
++ * @h_parent: lower parent dentry which must exist and be locked
++ * @base_name: name of dentry which will be whiteouted
++ * returns dentry for whiteout.
++ */
++struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
++ struct au_branch *br)
++{
++ int err;
++ struct qstr wh_name;
++ struct dentry *wh_dentry;
++
++ err = au_wh_name_alloc(&wh_name, base_name);
++ wh_dentry = ERR_PTR(err);
++ if (!err) {
++ wh_dentry = au_lkup_one(&wh_name, h_parent, br, /*nd*/NULL);
++ kfree(wh_name.name);
++ }
++ return wh_dentry;
++}
++
++/*
++ * link/create a whiteout for @dentry on @bindex.
++ */
++struct dentry *au_wh_create(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent)
++{
++ struct dentry *wh_dentry;
++ struct super_block *sb;
++ int err;
++
++ sb = dentry->d_sb;
++ wh_dentry = au_wh_lkup(h_parent, &dentry->d_name, au_sbr(sb, bindex));
++ if (!IS_ERR(wh_dentry) && !wh_dentry->d_inode) {
++ err = link_or_create_wh(sb, bindex, wh_dentry);
++ if (!err)
++ au_set_dbwh(dentry, bindex);
++ else {
++ dput(wh_dentry);
++ wh_dentry = ERR_PTR(err);
++ }
++ }
++
++ return wh_dentry;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* Delete all whiteouts in this directory on branch bindex. */
++static int del_wh_children(struct dentry *h_dentry, struct au_nhash *whlist,
++ aufs_bindex_t bindex, struct au_branch *br)
++{
++ int err;
++ unsigned long ul, n;
++ struct qstr wh_name;
++ char *p;
++ struct hlist_head *head;
++ struct au_vdir_wh *tpos;
++ struct hlist_node *pos;
++ struct au_vdir_destr *str;
++
++ err = -ENOMEM;
++ p = __getname();
++ wh_name.name = p;
++ if (unlikely(!wh_name.name))
++ goto out;
++
++ err = 0;
++ memcpy(p, AUFS_WH_PFX, AUFS_WH_PFX_LEN);
++ p += AUFS_WH_PFX_LEN;
++ n = whlist->nh_num;
++ head = whlist->nh_head;
++ for (ul = 0; !err && ul < n; ul++, head++) {
++ hlist_for_each_entry(tpos, pos, head, wh_hash) {
++ if (tpos->wh_bindex != bindex)
++ continue;
++
++ str = &tpos->wh_str;
++ if (str->len + AUFS_WH_PFX_LEN <= PATH_MAX) {
++ memcpy(p, str->name, str->len);
++ wh_name.len = AUFS_WH_PFX_LEN + str->len;
++ err = unlink_wh_name(h_dentry, &wh_name, br);
++ if (!err)
++ continue;
++ break;
++ }
++ AuIOErr("whiteout name too long %.*s\n",
++ str->len, str->name);
++ err = -EIO;
++ break;
++ }
++ }
++ __putname(wh_name.name);
++
++ out:
++ return err;
++}
++
++struct del_wh_children_args {
++ int *errp;
++ struct dentry *h_dentry;
++ struct au_nhash *whlist;
++ aufs_bindex_t bindex;
++ struct au_branch *br;
++};
++
++static void call_del_wh_children(void *args)
++{
++ struct del_wh_children_args *a = args;
++ *a->errp = del_wh_children(a->h_dentry, a->whlist, a->bindex, a->br);
++}
++
++/* ---------------------------------------------------------------------- */
++
++struct au_whtmp_rmdir *au_whtmp_rmdir_alloc(struct super_block *sb, gfp_t gfp)
++{
++ struct au_whtmp_rmdir *whtmp;
++
++ whtmp = kmalloc(sizeof(*whtmp), gfp);
++ if (unlikely(!whtmp))
++ goto out;
++
++ whtmp->dir = NULL;
++ whtmp->wh_dentry = NULL;
++ whtmp->whlist = au_nhash_alloc(sb, /*bend*/0, gfp);
++ if (unlikely(!whtmp->whlist))
++ goto out_whtmp;
++ return whtmp; /* success */
++
++ out_whtmp:
++ kfree(whtmp);
++ out:
++ return ERR_PTR(-ENOMEM);
++}
++
++void au_whtmp_rmdir_free(struct au_whtmp_rmdir *whtmp)
++{
++ dput(whtmp->wh_dentry);
++ iput(whtmp->dir);
++ au_nhash_wh_free(whtmp->whlist, /*bend*/0);
++ kfree(whtmp);
++}
++
++/*
++ * rmdir the whiteouted temporary named dir @h_dentry.
++ * @whlist: whiteouted children.
++ */
++int au_whtmp_rmdir(struct inode *dir, aufs_bindex_t bindex,
++ struct dentry *wh_dentry, struct au_nhash *whlist)
++{
++ int err;
++ struct path h_tmp;
++ struct inode *wh_inode, *h_dir;
++ struct au_branch *br;
++
++ h_dir = wh_dentry->d_parent->d_inode; /* dir inode is locked */
++ IMustLock(h_dir);
++
++ br = au_sbr(dir->i_sb, bindex);
++ wh_inode = wh_dentry->d_inode;
++ mutex_lock_nested(&wh_inode->i_mutex, AuLsc_I_CHILD);
++
++ /*
++ * someone else might change some whiteouts while we were sleeping.
++ * it means this whlist may have an obsoleted entry.
++ */
++ if (!au_test_h_perm_sio(wh_inode, MAY_EXEC | MAY_WRITE))
++ err = del_wh_children(wh_dentry, whlist, bindex, br);
++ else {
++ int wkq_err;
++ struct del_wh_children_args args = {
++ .errp = &err,
++ .h_dentry = wh_dentry,
++ .whlist = whlist,
++ .bindex = bindex,
++ .br = br
++ };
++
++ wkq_err = au_wkq_wait(call_del_wh_children, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ }
++ mutex_unlock(&wh_inode->i_mutex);
++
++ if (!err) {
++ h_tmp.dentry = wh_dentry;
++ h_tmp.mnt = br->br_mnt;
++ err = vfsub_rmdir(h_dir, &h_tmp);
++ /* d_drop(h_dentry); */
++ }
++
++ if (!err) {
++ if (au_ibstart(dir) == bindex) {
++ au_cpup_attr_timesizes(dir);
++ drop_nlink(dir);
++ }
++ return 0; /* success */
++ }
++
++ AuWarn("failed removing %.*s(%d), ignored\n",
++ AuDLNPair(wh_dentry), err);
++ return err;
++}
++
++static void call_rmdir_whtmp(void *args)
++{
++ int err;
++ struct au_whtmp_rmdir *a = args;
++ struct super_block *sb;
++ struct dentry *h_parent;
++ struct inode *h_dir;
++ struct au_branch *br;
++ struct au_hinode *hdir;
++
++ /* rmdir by nfsd may cause deadlock with this i_mutex */
++ /* mutex_lock(&a->dir->i_mutex); */
++ sb = a->dir->i_sb;
++ si_noflush_read_lock(sb);
++ err = au_test_ro(sb, a->bindex, NULL);
++ if (unlikely(err))
++ goto out;
++
++ err = -EIO;
++ br = au_sbr(sb, a->bindex);
++ ii_write_lock_parent(a->dir);
++ h_parent = dget_parent(a->wh_dentry);
++ h_dir = h_parent->d_inode;
++ hdir = au_hi(a->dir, a->bindex);
++ au_hin_imtx_lock_nested(hdir, AuLsc_I_PARENT);
++ err = au_h_verify(a->wh_dentry, au_opt_udba(sb), h_dir, h_parent, br);
++ if (!err) {
++ err = mnt_want_write(br->br_mnt);
++ if (!err) {
++ err = au_whtmp_rmdir(a->dir, a->bindex, a->wh_dentry,
++ a->whlist);
++ mnt_drop_write(br->br_mnt);
++ }
++ }
++ au_hin_imtx_unlock(hdir);
++ dput(h_parent);
++ ii_write_unlock(a->dir);
++
++ out:
++ /* mutex_unlock(&a->dir->i_mutex); */
++ au_nwt_done(&au_sbi(sb)->si_nowait);
++ si_read_unlock(sb);
++ au_whtmp_rmdir_free(a);
++ if (unlikely(err))
++ AuIOErr("err %d\n", err);
++}
++
++void au_whtmp_kick_rmdir(struct inode *dir, aufs_bindex_t bindex,
++ struct dentry *wh_dentry, struct au_whtmp_rmdir *args)
++{
++ int wkq_err;
++
++ IMustLock(dir);
++
++ /* all post-process will be done in do_rmdir_whtmp(). */
++ args->dir = au_igrab(dir);
++ args->bindex = bindex;
++ args->wh_dentry = dget(wh_dentry);
++ wkq_err = au_wkq_nowait(call_rmdir_whtmp, args, dir->i_sb);
++ if (unlikely(wkq_err)) {
++ AuWarn("rmdir error %.*s (%d), ignored\n",
++ AuDLNPair(wh_dentry), wkq_err);
++ au_whtmp_rmdir_free(args);
++ }
++}
+diff --git a/fs/aufs/whout.h b/fs/aufs/whout.h
+new file mode 100644
+index 0000000..3247a4f
+--- /dev/null
++++ b/fs/aufs/whout.h
+@@ -0,0 +1,79 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * whiteout for logical deletion and opaque directory
++ */
++
++#ifndef __AUFS_WHOUT_H__
++#define __AUFS_WHOUT_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/aufs_type.h>
++#include "dir.h"
++
++/* whout.c */
++int au_wh_name_alloc(struct qstr *wh, const struct qstr *name);
++struct au_branch;
++int au_wh_test(struct dentry *h_parent, struct qstr *wh_name,
++ struct au_branch *br, int try_sio);
++int au_diropq_test(struct dentry *h_dentry, struct au_branch *br);
++struct dentry *au_whtmp_lkup(struct dentry *h_parent, struct au_branch *br,
++ struct qstr *prefix);
++int au_whtmp_ren(struct dentry *h_dentry, struct au_branch *br);
++int au_wh_unlink_dentry(struct inode *h_dir, struct path *h_path,
++ struct dentry *dentry);
++int au_wh_init(struct dentry *h_parent, struct au_branch *br,
++ struct super_block *sb);
++
++/* diropq flags */
++#define AuDiropq_CREATE 1
++#define au_ftest_diropq(flags, name) ((flags) & AuDiropq_##name)
++#define au_fset_diropq(flags, name) { (flags) |= AuDiropq_##name; }
++#define au_fclr_diropq(flags, name) { (flags) &= ~AuDiropq_##name; }
++
++struct dentry *au_diropq_sio(struct dentry *dentry, aufs_bindex_t bindex,
++ unsigned int flags);
++struct dentry *au_wh_lkup(struct dentry *h_parent, struct qstr *base_name,
++ struct au_branch *br);
++struct dentry *au_wh_create(struct dentry *dentry, aufs_bindex_t bindex,
++ struct dentry *h_parent);
++
++/* real rmdir for the whiteout-ed dir */
++struct au_whtmp_rmdir {
++ struct inode *dir;
++ aufs_bindex_t bindex;
++ struct dentry *wh_dentry;
++ struct au_nhash *whlist;
++};
++
++struct au_whtmp_rmdir *au_whtmp_rmdir_alloc(struct super_block *sb, gfp_t gfp);
++void au_whtmp_rmdir_free(struct au_whtmp_rmdir *whtmp);
++int au_whtmp_rmdir(struct inode *dir, aufs_bindex_t bindex,
++ struct dentry *wh_dentry, struct au_nhash *whlist);
++void au_whtmp_kick_rmdir(struct inode *dir, aufs_bindex_t bindex,
++ struct dentry *wh_dentry, struct au_whtmp_rmdir *args);
++
++/* ---------------------------------------------------------------------- */
++
++static inline struct dentry *au_diropq_create(struct dentry *dentry,
++ aufs_bindex_t bindex)
++{
++ return au_diropq_sio(dentry, bindex, AuDiropq_CREATE);
++}
++
++static inline int au_diropq_remove(struct dentry *dentry, aufs_bindex_t bindex)
++{
++ return PTR_ERR(au_diropq_sio(dentry, bindex, !AuDiropq_CREATE));
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_WHOUT_H__ */
+diff --git a/fs/aufs/wkq.c b/fs/aufs/wkq.c
+new file mode 100644
+index 0000000..41e30be
+--- /dev/null
++++ b/fs/aufs/wkq.c
+@@ -0,0 +1,249 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * workqueue for asynchronous/super-io operations
++ * todo: try new dredential scheme
++ */
++
++#include "aufs.h"
++
++/* internal workqueue named AUFS_WKQ_NAME */
++static struct au_wkq {
++ struct workqueue_struct *q;
++
++ /* balancing */
++ atomic_t busy;
++} *au_wkq;
++
++struct au_wkinfo {
++ struct work_struct wk;
++ struct super_block *sb;
++
++ unsigned int flags; /* see wkq.h */
++
++ au_wkq_func_t func;
++ void *args;
++
++ atomic_t *busyp;
++ struct completion *comp;
++};
++
++/* ---------------------------------------------------------------------- */
++
++static int enqueue(struct au_wkq *wkq, struct au_wkinfo *wkinfo)
++{
++ wkinfo->busyp = &wkq->busy;
++ if (au_ftest_wkq(wkinfo->flags, WAIT))
++ return !queue_work(wkq->q, &wkinfo->wk);
++ else
++ return !schedule_work(&wkinfo->wk);
++}
++
++static void do_wkq(struct au_wkinfo *wkinfo)
++{
++ unsigned int idle, n;
++ int i, idle_idx;
++
++ while (1) {
++ if (au_ftest_wkq(wkinfo->flags, WAIT)) {
++ idle_idx = 0;
++ idle = UINT_MAX;
++ for (i = 0; i < aufs_nwkq; i++) {
++ n = atomic_inc_return(&au_wkq[i].busy);
++ if (n == 1 && !enqueue(au_wkq + i, wkinfo))
++ return; /* success */
++
++ if (n < idle) {
++ idle_idx = i;
++ idle = n;
++ }
++ atomic_dec(&au_wkq[i].busy);
++ }
++ } else
++ idle_idx = aufs_nwkq;
++
++ atomic_inc(&au_wkq[idle_idx].busy);
++ if (!enqueue(au_wkq + idle_idx, wkinfo))
++ return; /* success */
++
++ /* impossible? */
++ AuWarn1("failed to queue_work()\n");
++ yield();
++ }
++}
++
++static void wkq_func(struct work_struct *wk)
++{
++ struct au_wkinfo *wkinfo = container_of(wk, struct au_wkinfo, wk);
++
++ wkinfo->func(wkinfo->args);
++ atomic_dec(wkinfo->busyp);
++ if (au_ftest_wkq(wkinfo->flags, WAIT))
++ complete(wkinfo->comp);
++ else {
++ kobject_put(&au_sbi(wkinfo->sb)->si_kobj);
++ module_put(THIS_MODULE);
++ kfree(wkinfo);
++ }
++}
++
++/*
++ * Since struct completion is large, try allocating it dynamically.
++ */
++#if defined(CONFIG_4KSTACKS) || defined(AuTest4KSTACKS)
++#define AuWkqCompDeclare(name) struct completion *comp = NULL
++
++static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
++{
++ *comp = kmalloc(sizeof(**comp), GFP_NOFS);
++ if (*comp) {
++ init_completion(*comp);
++ wkinfo->comp = *comp;
++ return 0;
++ }
++ return -ENOMEM;
++}
++
++static void au_wkq_comp_free(struct completion *comp)
++{
++ kfree(comp);
++}
++
++#else
++
++/* no braces */
++#define AuWkqCompDeclare(name) \
++ DECLARE_COMPLETION_ONSTACK(_ ## name); \
++ struct completion *comp = &_ ## name
++
++static int au_wkq_comp_alloc(struct au_wkinfo *wkinfo, struct completion **comp)
++{
++ wkinfo->comp = *comp;
++ return 0;
++}
++
++static void au_wkq_comp_free(struct completion *comp __maybe_unused)
++{
++ /* empty */
++}
++#endif /* 4KSTACKS */
++
++static void au_wkq_run(struct au_wkinfo *wkinfo)
++{
++ au_dbg_verify_kthread();
++ INIT_WORK(&wkinfo->wk, wkq_func);
++ do_wkq(wkinfo);
++}
++
++int au_wkq_wait(au_wkq_func_t func, void *args)
++{
++ int err;
++ AuWkqCompDeclare(comp);
++ struct au_wkinfo wkinfo = {
++ .flags = AuWkq_WAIT,
++ .func = func,
++ .args = args
++ };
++
++ err = au_wkq_comp_alloc(&wkinfo, &comp);
++ if (!err) {
++ au_wkq_run(&wkinfo);
++ /* no timeout, no interrupt */
++ wait_for_completion(wkinfo.comp);
++ au_wkq_comp_free(comp);
++ }
++
++ return err;
++
++}
++
++int au_wkq_nowait(au_wkq_func_t func, void *args, struct super_block *sb)
++{
++ int err;
++ struct au_wkinfo *wkinfo;
++
++ atomic_inc(&au_sbi(sb)->si_nowait.nw_len);
++
++ /*
++ * wkq_func() must free this wkinfo.
++ * it highly depends upon the implementation of workqueue.
++ */
++ err = 0;
++ wkinfo = kmalloc(sizeof(*wkinfo), GFP_NOFS);
++ if (wkinfo) {
++ wkinfo->sb = sb;
++ wkinfo->flags = !AuWkq_WAIT;
++ wkinfo->func = func;
++ wkinfo->args = args;
++ wkinfo->comp = NULL;
++ kobject_get(&au_sbi(sb)->si_kobj);
++ __module_get(THIS_MODULE);
++
++ au_wkq_run(wkinfo);
++ } else {
++ err = -ENOMEM;
++ atomic_dec(&au_sbi(sb)->si_nowait.nw_len);
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++void au_nwt_init(struct au_nowait_tasks *nwt)
++{
++ atomic_set(&nwt->nw_len, 0);
++ /* smp_mb();*/ /* atomic_set */
++ init_waitqueue_head(&nwt->nw_wq);
++}
++
++void au_wkq_fin(void)
++{
++ int i;
++
++ for (i = 0; i < aufs_nwkq; i++)
++ if (au_wkq[i].q && !IS_ERR(au_wkq[i].q))
++ destroy_workqueue(au_wkq[i].q);
++ kfree(au_wkq);
++}
++
++int __init au_wkq_init(void)
++{
++ int err, i;
++ struct au_wkq *nowaitq;
++
++ /* '+1' is for accounting of nowait queue */
++ err = -ENOMEM;
++ au_wkq = kcalloc(aufs_nwkq + 1, sizeof(*au_wkq), GFP_NOFS);
++ if (unlikely(!au_wkq))
++ goto out;
++
++ err = 0;
++ for (i = 0; i < aufs_nwkq; i++) {
++ au_wkq[i].q = create_singlethread_workqueue(AUFS_WKQ_NAME);
++ if (au_wkq[i].q && !IS_ERR(au_wkq[i].q)) {
++ atomic_set(&au_wkq[i].busy, 0);
++ continue;
++ }
++
++ err = PTR_ERR(au_wkq[i].q);
++ au_wkq_fin();
++ goto out;
++ }
++
++ /* nowait accounting */
++ nowaitq = au_wkq + aufs_nwkq;
++ atomic_set(&nowaitq->busy, 0);
++ nowaitq->q = NULL;
++ /* smp_mb(); */ /* atomic_set */
++
++ out:
++ return err;
++}
+diff --git a/fs/aufs/wkq.h b/fs/aufs/wkq.h
+new file mode 100644
+index 0000000..17d24d8
+--- /dev/null
++++ b/fs/aufs/wkq.h
+@@ -0,0 +1,72 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * workqueue for asynchronous/super-io operations
++ * todo: try new credentials management scheme
++ */
++
++#ifndef __AUFS_WKQ_H__
++#define __AUFS_WKQ_H__
++
++#ifdef __KERNEL__
++
++#include <linux/fs.h>
++#include <linux/sched.h>
++#include <linux/workqueue.h>
++#include <linux/aufs_type.h>
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * in the next operation, wait for the 'nowait' tasks in system-wide workqueue
++ */
++struct au_nowait_tasks {
++ atomic_t nw_len;
++ wait_queue_head_t nw_wq;
++};
++
++/* ---------------------------------------------------------------------- */
++
++typedef void (*au_wkq_func_t)(void *args);
++
++/* wkq flags */
++#define AuWkq_WAIT 1
++#define au_ftest_wkq(flags, name) ((flags) & AuWkq_##name)
++#define au_fset_wkq(flags, name) { (flags) |= AuWkq_##name; }
++#define au_fclr_wkq(flags, name) { (flags) &= ~AuWkq_##name; }
++
++/* wkq.c */
++int au_wkq_wait(au_wkq_func_t func, void *args);
++int au_wkq_nowait(au_wkq_func_t func, void *args, struct super_block *sb);
++void au_nwt_init(struct au_nowait_tasks *nwt);
++int __init au_wkq_init(void);
++void au_wkq_fin(void);
++
++/* ---------------------------------------------------------------------- */
++
++static inline int au_test_wkq(struct task_struct *tsk)
++{
++ return !tsk->mm && !strcmp(tsk->comm, AUFS_WKQ_NAME);
++}
++
++static inline void au_nwt_done(struct au_nowait_tasks *nwt)
++{
++ if (!atomic_dec_return(&nwt->nw_len))
++ wake_up_all(&nwt->nw_wq);
++}
++
++static inline int au_nwt_flush(struct au_nowait_tasks *nwt)
++{
++ wait_event(nwt->nw_wq, !atomic_read(&nwt->nw_len));
++ return 0;
++}
++
++#endif /* __KERNEL__ */
++#endif /* __AUFS_WKQ_H__ */
+diff --git a/fs/aufs/xino.c b/fs/aufs/xino.c
+new file mode 100644
+index 0000000..7d11111
+--- /dev/null
++++ b/fs/aufs/xino.c
+@@ -0,0 +1,1181 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++/*
++ * external inode number translation table and bitmap
++ */
++
++#include <linux/seq_file.h>
++#include <linux/uaccess.h>
++#include "aufs.h"
++
++ssize_t xino_fread(au_readf_t func, struct file *file, void *buf, size_t size,
++ loff_t *pos)
++{
++ ssize_t err;
++ mm_segment_t oldfs;
++
++ oldfs = get_fs();
++ set_fs(KERNEL_DS);
++ do {
++ /* todo: signal_pending? */
++ err = func(file, (char __user *)buf, size, pos);
++ } while (err == -EAGAIN || err == -EINTR);
++ set_fs(oldfs);
++
++#if 0 /* reserved for future use */
++ if (err > 0)
++ fsnotify_access(file->f_dentry);
++#endif
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++static ssize_t do_xino_fwrite(au_writef_t func, struct file *file, void *buf,
++ size_t size, loff_t *pos)
++{
++ ssize_t err;
++ mm_segment_t oldfs;
++
++ oldfs = get_fs();
++ set_fs(KERNEL_DS);
++ lockdep_off();
++ do {
++ /* todo: signal_pending? */
++ err = func(file, (const char __user *)buf, size, pos);
++ } while (err == -EAGAIN || err == -EINTR);
++ lockdep_on();
++ set_fs(oldfs);
++
++#if 0 /* reserved for future use */
++ if (err > 0)
++ fsnotify_modify(file->f_dentry);
++#endif
++
++ return err;
++}
++
++struct do_xino_fwrite_args {
++ ssize_t *errp;
++ au_writef_t func;
++ struct file *file;
++ void *buf;
++ size_t size;
++ loff_t *pos;
++};
++
++static void call_do_xino_fwrite(void *args)
++{
++ struct do_xino_fwrite_args *a = args;
++ *a->errp = do_xino_fwrite(a->func, a->file, a->buf, a->size, a->pos);
++}
++
++ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
++ loff_t *pos)
++{
++ ssize_t err;
++
++ /* todo: signal block and no wkq? */
++ /* todo: new credential scheme */
++ /*
++ * it breaks RLIMIT_FSIZE and normal user's limit,
++ * users should care about quota and real 'filesystem full.'
++ */
++ if (!au_test_wkq(current)) {
++ int wkq_err;
++ struct do_xino_fwrite_args args = {
++ .errp = &err,
++ .func = func,
++ .file = file,
++ .buf = buf,
++ .size = size,
++ .pos = pos
++ };
++
++ wkq_err = au_wkq_wait(call_do_xino_fwrite, &args);
++ if (unlikely(wkq_err))
++ err = wkq_err;
++ } else
++ err = do_xino_fwrite(func, file, buf, size, pos);
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create a new xinofile at the same place/path as @base_file.
++ */
++struct file *au_xino_create2(struct file *base_file, struct file *copy_src)
++{
++ struct file *file;
++ struct dentry *base, *dentry, *parent;
++ struct inode *dir;
++ struct qstr *name;
++ int err;
++
++ base = base_file->f_dentry;
++ parent = base->d_parent; /* dir inode is locked */
++ dir = parent->d_inode;
++ IMustLock(dir);
++
++ file = ERR_PTR(-EINVAL);
++ name = &base->d_name;
++ dentry = vfsub_lookup_one_len(name->name, parent, name->len);
++ if (IS_ERR(dentry)) {
++ file = (void *)dentry;
++ AuErr("%.*s lookup err %ld\n", AuLNPair(name), PTR_ERR(dentry));
++ goto out;
++ }
++
++ /* no need to mnt_want_write() since we call dentry_open() later */
++ err = vfs_create(dir, dentry, S_IRUGO | S_IWUGO, NULL);
++ if (unlikely(err)) {
++ file = ERR_PTR(err);
++ AuErr("%.*s create err %d\n", AuLNPair(name), err);
++ goto out_dput;
++ }
++
++ file = dentry_open(dget(dentry), mntget(base_file->f_vfsmnt),
++ O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE,
++ current_cred());
++ if (IS_ERR(file)) {
++ AuErr("%.*s open err %ld\n", AuLNPair(name), PTR_ERR(file));
++ goto out_dput;
++ }
++
++ err = vfsub_unlink(dir, &file->f_path, /*force*/0);
++ if (unlikely(err)) {
++ AuErr("%.*s unlink err %d\n", AuLNPair(name), err);
++ goto out_fput;
++ }
++
++ if (copy_src) {
++ /* no one can touch copy_src xino */
++ err = au_copy_file(file, copy_src,
++ i_size_read(copy_src->f_dentry->d_inode));
++ if (unlikely(err)) {
++ AuErr("%.*s copy err %d\n", AuLNPair(name), err);
++ goto out_fput;
++ }
++ }
++ goto out_dput; /* success */
++
++ out_fput:
++ fput(file);
++ file = ERR_PTR(err);
++ out_dput:
++ dput(dentry);
++ out:
++ return file;
++}
++
++struct au_xino_lock_dir {
++ struct au_hinode *hdir;
++ struct dentry *parent;
++ struct mutex *mtx;
++};
++
++static void au_xino_lock_dir(struct super_block *sb, struct file *xino,
++ struct au_xino_lock_dir *ldir)
++{
++ aufs_bindex_t brid, bindex;
++
++ ldir->hdir = NULL;
++ bindex = -1;
++ brid = au_xino_brid(sb);
++ if (brid >= 0)
++ bindex = au_br_index(sb, brid);
++ if (bindex >= 0) {
++ ldir->hdir = au_hi(sb->s_root->d_inode, bindex);
++ au_hin_imtx_lock_nested(ldir->hdir, AuLsc_I_PARENT);
++ } else {
++ ldir->parent = dget_parent(xino->f_dentry);
++ ldir->mtx = &ldir->parent->d_inode->i_mutex;
++ mutex_lock_nested(ldir->mtx, AuLsc_I_PARENT);
++ }
++}
++
++static void au_xino_unlock_dir(struct au_xino_lock_dir *ldir)
++{
++ if (ldir->hdir)
++ au_hin_imtx_unlock(ldir->hdir);
++ else {
++ mutex_unlock(ldir->mtx);
++ dput(ldir->parent);
++ }
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* trucate xino files asynchronously */
++
++int au_xino_trunc(struct super_block *sb, aufs_bindex_t bindex)
++{
++ int err;
++ aufs_bindex_t bi, bend;
++ struct au_branch *br;
++ struct file *new_xino, *file;
++ struct super_block *h_sb;
++ struct au_xino_lock_dir ldir;
++
++ err = -EINVAL;
++ bend = au_sbend(sb);
++ if (unlikely(bindex < 0 || bend < bindex))
++ goto out;
++ br = au_sbr(sb, bindex);
++ file = br->br_xino.xi_file;
++ if (!file)
++ goto out;
++
++ au_xino_lock_dir(sb, file, &ldir);
++ /* mnt_want_write() is unnecessary here */
++ new_xino = au_xino_create2(file, file);
++ au_xino_unlock_dir(&ldir);
++ err = PTR_ERR(new_xino);
++ if (IS_ERR(new_xino))
++ goto out;
++ err = 0;
++ fput(file);
++ br->br_xino.xi_file = new_xino;
++
++ h_sb = br->br_mnt->mnt_sb;
++ for (bi = 0; bi <= bend; bi++) {
++ if (unlikely(bi == bindex))
++ continue;
++ br = au_sbr(sb, bi);
++ if (br->br_mnt->mnt_sb != h_sb)
++ continue;
++
++ fput(br->br_xino.xi_file);
++ br->br_xino.xi_file = new_xino;
++ get_file(new_xino);
++ }
++
++ out:
++ return err;
++}
++
++struct xino_do_trunc_args {
++ struct super_block *sb;
++ struct au_branch *br;
++};
++
++static void xino_do_trunc(void *_args)
++{
++ struct xino_do_trunc_args *args = _args;
++ struct super_block *sb;
++ struct au_branch *br;
++ struct inode *dir;
++ int err;
++ aufs_bindex_t bindex;
++
++ err = 0;
++ sb = args->sb;
++ dir = sb->s_root->d_inode;
++ br = args->br;
++
++ si_noflush_write_lock(sb);
++ ii_read_lock_parent(dir);
++ bindex = au_br_index(sb, br->br_id);
++ err = au_xino_trunc(sb, bindex);
++ if (unlikely(err))
++ goto out;
++
++ if (br->br_xino.xi_file->f_dentry->d_inode->i_blocks
++ >= br->br_xino_upper)
++ br->br_xino_upper += AUFS_XINO_TRUNC_STEP;
++
++ out:
++ ii_read_unlock(dir);
++ if (unlikely(err))
++ AuWarn("err b%d, (%d)\n", bindex, err);
++ atomic_dec(&br->br_xino_running);
++ atomic_dec(&br->br_count);
++ au_nwt_done(&au_sbi(sb)->si_nowait);
++ si_write_unlock(sb);
++ kfree(args);
++}
++
++static void xino_try_trunc(struct super_block *sb, struct au_branch *br)
++{
++ struct xino_do_trunc_args *args;
++ int wkq_err;
++
++ if (br->br_xino.xi_file->f_dentry->d_inode->i_blocks
++ < br->br_xino_upper)
++ return;
++
++ if (atomic_inc_return(&br->br_xino_running) > 1)
++ goto out;
++
++ /* lock and kfree() will be called in trunc_xino() */
++ args = kmalloc(sizeof(*args), GFP_NOFS);
++ if (unlikely(!args)) {
++ AuErr1("no memory\n");
++ goto out_args;
++ }
++
++ atomic_inc(&br->br_count);
++ args->sb = sb;
++ args->br = br;
++ wkq_err = au_wkq_nowait(xino_do_trunc, args, sb);
++ if (!wkq_err)
++ return; /* success */
++
++ AuErr("wkq %d\n", wkq_err);
++ atomic_dec(&br->br_count);
++
++ out_args:
++ kfree(args);
++ out:
++ atomic_dec(&br->br_xino_running);
++}
++
++/* ---------------------------------------------------------------------- */
++
++static int au_xino_do_write(au_writef_t write, struct file *file,
++ ino_t h_ino, ino_t ino)
++{
++ loff_t pos;
++ ssize_t sz;
++
++ pos = h_ino;
++ if (unlikely(au_loff_max / sizeof(ino) - 1 < pos)) {
++ AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
++ return -EFBIG;
++ }
++ pos *= sizeof(ino);
++ sz = xino_fwrite(write, file, &ino, sizeof(ino), &pos);
++ if (sz == sizeof(ino))
++ return 0; /* success */
++
++ AuIOErr("write failed (%zd)\n", sz);
++ return -EIO;
++}
++
++/*
++ * write @ino to the xinofile for the specified branch{@sb, @bindex}
++ * at the position of @h_ino.
++ * even if @ino is zero, it is written to the xinofile and means no entry.
++ * if the size of the xino file on a specific filesystem exceeds the watermark,
++ * try truncating it.
++ */
++int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t ino)
++{
++ int err;
++ unsigned int mnt_flags;
++ struct au_branch *br;
++
++ BUILD_BUG_ON(sizeof(long long) != sizeof(au_loff_max)
++ || ((loff_t)-1) > 0);
++
++ mnt_flags = au_mntflags(sb);
++ if (!au_opt_test(mnt_flags, XINO))
++ return 0;
++
++ br = au_sbr(sb, bindex);
++ err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
++ h_ino, ino);
++ if (!err) {
++ if (au_opt_test(mnt_flags, TRUNC_XINO)
++ && au_test_fs_trunc_xino(br->br_mnt->mnt_sb))
++ xino_try_trunc(sb, br);
++ return 0; /* success */
++ }
++
++ AuIOErr("write failed (%d)\n", err);
++ return -EIO;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* aufs inode number bitmap */
++
++static const int page_bits = (int)PAGE_SIZE * BITS_PER_BYTE;
++static ino_t xib_calc_ino(unsigned long pindex, int bit)
++{
++ ino_t ino;
++
++ AuDebugOn(bit < 0 || page_bits <= bit);
++ ino = AUFS_FIRST_INO + pindex * page_bits + bit;
++ return ino;
++}
++
++static void xib_calc_bit(ino_t ino, unsigned long *pindex, int *bit)
++{
++ AuDebugOn(ino < AUFS_FIRST_INO);
++ ino -= AUFS_FIRST_INO;
++ *pindex = ino / page_bits;
++ *bit = ino % page_bits;
++}
++
++static int xib_pindex(struct super_block *sb, unsigned long pindex)
++{
++ int err;
++ loff_t pos;
++ ssize_t sz;
++ struct au_sbinfo *sbinfo;
++ struct file *xib;
++ unsigned long *p;
++
++ sbinfo = au_sbi(sb);
++ MtxMustLock(&sbinfo->si_xib_mtx);
++ AuDebugOn(pindex > ULONG_MAX / PAGE_SIZE
++ || !au_opt_test(sbinfo->si_mntflags, XINO));
++
++ if (pindex == sbinfo->si_xib_last_pindex)
++ return 0;
++
++ xib = sbinfo->si_xib;
++ p = sbinfo->si_xib_buf;
++ pos = sbinfo->si_xib_last_pindex;
++ pos *= PAGE_SIZE;
++ sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
++ if (unlikely(sz != PAGE_SIZE))
++ goto out;
++
++ pos = pindex;
++ pos *= PAGE_SIZE;
++ if (i_size_read(xib->f_dentry->d_inode) >= pos + PAGE_SIZE)
++ sz = xino_fread(sbinfo->si_xread, xib, p, PAGE_SIZE, &pos);
++ else {
++ memset(p, 0, PAGE_SIZE);
++ sz = xino_fwrite(sbinfo->si_xwrite, xib, p, PAGE_SIZE, &pos);
++ }
++ if (sz == PAGE_SIZE) {
++ sbinfo->si_xib_last_pindex = pindex;
++ return 0; /* success */
++ }
++
++ out:
++ AuIOErr1("write failed (%zd)\n", sz);
++ err = sz;
++ if (sz >= 0)
++ err = -EIO;
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t ino)
++{
++ int err, bit;
++ unsigned long pindex;
++ struct au_sbinfo *sbinfo;
++
++ if (!au_opt_test(au_mntflags(sb), XINO))
++ return 0;
++
++ err = 0;
++ if (ino) {
++ sbinfo = au_sbi(sb);
++ xib_calc_bit(ino, &pindex, &bit);
++ AuDebugOn(page_bits <= bit);
++ mutex_lock(&sbinfo->si_xib_mtx);
++ err = xib_pindex(sb, pindex);
++ if (!err) {
++ clear_bit(bit, sbinfo->si_xib_buf);
++ sbinfo->si_xib_next_bit = bit;
++ }
++ mutex_unlock(&sbinfo->si_xib_mtx);
++ }
++
++ if (!err)
++ err = au_xino_write(sb, bindex, h_ino, 0);
++ return err;
++}
++
++/* get an unused inode number from bitmap */
++ino_t au_xino_new_ino(struct super_block *sb)
++{
++ ino_t ino;
++ unsigned long *p, pindex, ul, pend;
++ struct au_sbinfo *sbinfo;
++ struct file *file;
++ int free_bit, err;
++
++ if (!au_opt_test(au_mntflags(sb), XINO))
++ return iunique(sb, AUFS_FIRST_INO);
++
++ sbinfo = au_sbi(sb);
++ mutex_lock(&sbinfo->si_xib_mtx);
++ p = sbinfo->si_xib_buf;
++ free_bit = sbinfo->si_xib_next_bit;
++ if (free_bit < page_bits && !test_bit(free_bit, p))
++ goto out; /* success */
++ free_bit = find_first_zero_bit(p, page_bits);
++ if (free_bit < page_bits)
++ goto out; /* success */
++
++ pindex = sbinfo->si_xib_last_pindex;
++ for (ul = pindex - 1; ul < ULONG_MAX; ul--) {
++ err = xib_pindex(sb, ul);
++ if (unlikely(err))
++ goto out_err;
++ free_bit = find_first_zero_bit(p, page_bits);
++ if (free_bit < page_bits)
++ goto out; /* success */
++ }
++
++ file = sbinfo->si_xib;
++ pend = i_size_read(file->f_dentry->d_inode) / PAGE_SIZE;
++ for (ul = pindex + 1; ul <= pend; ul++) {
++ err = xib_pindex(sb, ul);
++ if (unlikely(err))
++ goto out_err;
++ free_bit = find_first_zero_bit(p, page_bits);
++ if (free_bit < page_bits)
++ goto out; /* success */
++ }
++ BUG();
++
++ out:
++ set_bit(free_bit, p);
++ sbinfo->si_xib_next_bit++;
++ pindex = sbinfo->si_xib_last_pindex;
++ mutex_unlock(&sbinfo->si_xib_mtx);
++ ino = xib_calc_ino(pindex, free_bit);
++ AuDbg("i%lu\n", (unsigned long)ino);
++ return ino;
++ out_err:
++ mutex_unlock(&sbinfo->si_xib_mtx);
++ AuDbg("i0\n");
++ return 0;
++}
++
++/*
++ * read @ino from xinofile for the specified branch{@sb, @bindex}
++ * at the position of @h_ino.
++ * if @ino does not exist and @do_new is true, get new one.
++ */
++int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
++ ino_t *ino)
++{
++ int err;
++ ssize_t sz;
++ loff_t pos;
++ struct file *file;
++ struct au_sbinfo *sbinfo;
++
++ *ino = 0;
++ if (!au_opt_test(au_mntflags(sb), XINO))
++ return 0; /* no xino */
++
++ err = 0;
++ sbinfo = au_sbi(sb);
++ pos = h_ino;
++ if (unlikely(au_loff_max / sizeof(*ino) - 1 < pos)) {
++ AuIOErr1("too large hi%lu\n", (unsigned long)h_ino);
++ return -EFBIG;
++ }
++ pos *= sizeof(*ino);
++
++ file = au_sbr(sb, bindex)->br_xino.xi_file;
++ if (i_size_read(file->f_dentry->d_inode) < pos + sizeof(*ino))
++ return 0; /* no ino */
++
++ sz = xino_fread(sbinfo->si_xread, file, ino, sizeof(*ino), &pos);
++ if (sz == sizeof(*ino))
++ return 0; /* success */
++
++ err = sz;
++ if (unlikely(sz >= 0)) {
++ err = -EIO;
++ AuIOErr("xino read error (%zd)\n", sz);
++ }
++
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* create and set a new xino file */
++
++struct file *au_xino_create(struct super_block *sb, char *fname, int silent)
++{
++ struct file *file;
++ struct dentry *h_parent, *d;
++ struct inode *h_dir;
++ int err;
++
++ /*
++ * at mount-time, and the xino file is the default path,
++ * hinotify is disabled so we have no inotify events to ignore.
++ * when a user specified the xino, we cannot get au_hdir to be ignored.
++ */
++ file = vfsub_filp_open(fname, O_RDWR | O_CREAT | O_EXCL | O_LARGEFILE,
++ S_IRUGO | S_IWUGO);
++ if (IS_ERR(file)) {
++ if (!silent)
++ AuErr("open %s(%ld)\n", fname, PTR_ERR(file));
++ return file;
++ }
++
++ /* keep file count */
++ h_parent = dget_parent(file->f_dentry);
++ h_dir = h_parent->d_inode;
++ mutex_lock_nested(&h_dir->i_mutex, AuLsc_I_PARENT);
++ /* mnt_want_write() is unnecessary here */
++ err = vfsub_unlink(h_dir, &file->f_path, /*force*/0);
++ mutex_unlock(&h_dir->i_mutex);
++ dput(h_parent);
++ if (unlikely(err)) {
++ if (!silent)
++ AuErr("unlink %s(%d)\n", fname, err);
++ goto out;
++ }
++
++ err = -EINVAL;
++ d = file->f_dentry;
++ if (unlikely(sb == d->d_sb)) {
++ if (!silent)
++ AuErr("%s must be outside\n", fname);
++ goto out;
++ }
++ if (unlikely(au_test_fs_bad_xino(d->d_sb))) {
++ if (!silent)
++ AuErr("xino doesn't support %s(%s)\n",
++ fname, au_sbtype(d->d_sb));
++ goto out;
++ }
++ return file; /* success */
++
++ out:
++ fput(file);
++ file = ERR_PTR(err);
++ return file;
++}
++
++/*
++ * find another branch who is on the same filesystem of the specified
++ * branch{@btgt}. search until @bend.
++ */
++static int is_sb_shared(struct super_block *sb, aufs_bindex_t btgt,
++ aufs_bindex_t bend)
++{
++ aufs_bindex_t bindex;
++ struct super_block *tgt_sb = au_sbr_sb(sb, btgt);
++
++ for (bindex = 0; bindex < btgt; bindex++)
++ if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
++ return bindex;
++ for (bindex++; bindex <= bend; bindex++)
++ if (unlikely(tgt_sb == au_sbr_sb(sb, bindex)))
++ return bindex;
++ return -1;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * initialize the xinofile for the specified branch @br
++ * at the place/path where @base_file indicates.
++ * test whether another branch is on the same filesystem or not,
++ * if @do_test is true.
++ */
++int au_xino_br(struct super_block *sb, struct au_branch *br, ino_t h_ino,
++ struct file *base_file, int do_test)
++{
++ int err;
++ ino_t ino;
++ aufs_bindex_t bend, bindex;
++ struct au_branch *shared_br, *b;
++ struct file *file;
++ struct super_block *tgt_sb;
++
++ shared_br = NULL;
++ bend = au_sbend(sb);
++ if (do_test) {
++ tgt_sb = br->br_mnt->mnt_sb;
++ for (bindex = 0; bindex <= bend; bindex++) {
++ b = au_sbr(sb, bindex);
++ if (tgt_sb == b->br_mnt->mnt_sb) {
++ shared_br = b;
++ break;
++ }
++ }
++ }
++
++ if (!shared_br || !shared_br->br_xino.xi_file) {
++ struct au_xino_lock_dir ldir;
++
++ au_xino_lock_dir(sb, base_file, &ldir);
++ /* mnt_want_write() is unnecessary here */
++ file = au_xino_create2(base_file, NULL);
++ au_xino_unlock_dir(&ldir);
++ err = PTR_ERR(file);
++ if (IS_ERR(file))
++ goto out;
++ br->br_xino.xi_file = file;
++ } else {
++ br->br_xino.xi_file = shared_br->br_xino.xi_file;
++ get_file(br->br_xino.xi_file);
++ }
++
++ ino = AUFS_ROOT_INO;
++ err = au_xino_do_write(au_sbi(sb)->si_xwrite, br->br_xino.xi_file,
++ h_ino, ino);
++ if (!err)
++ return 0; /* success */
++
++
++ out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/* trucate a xino bitmap file */
++
++/* todo: slow */
++static int do_xib_restore(struct super_block *sb, struct file *file, void *page)
++{
++ int err, bit;
++ ssize_t sz;
++ unsigned long pindex;
++ loff_t pos, pend;
++ struct au_sbinfo *sbinfo;
++ au_readf_t func;
++ ino_t *ino;
++ unsigned long *p;
++
++ err = 0;
++ sbinfo = au_sbi(sb);
++ p = sbinfo->si_xib_buf;
++ func = sbinfo->si_xread;
++ pend = i_size_read(file->f_dentry->d_inode);
++ pos = 0;
++ while (pos < pend) {
++ sz = xino_fread(func, file, page, PAGE_SIZE, &pos);
++ err = sz;
++ if (unlikely(sz <= 0))
++ goto out;
++
++ err = 0;
++ for (ino = page; sz > 0; ino++, sz -= sizeof(ino)) {
++ if (unlikely(*ino < AUFS_FIRST_INO))
++ continue;
++
++ xib_calc_bit(*ino, &pindex, &bit);
++ AuDebugOn(page_bits <= bit);
++ err = xib_pindex(sb, pindex);
++ if (!err)
++ set_bit(bit, p);
++ else
++ goto out;
++ }
++ }
++
++ out:
++ return err;
++}
++
++static int xib_restore(struct super_block *sb)
++{
++ int err;
++ aufs_bindex_t bindex, bend;
++ void *page;
++
++ err = -ENOMEM;
++ page = (void *)__get_free_page(GFP_NOFS);
++ if (unlikely(!page))
++ goto out;
++
++ err = 0;
++ bend = au_sbend(sb);
++ for (bindex = 0; !err && bindex <= bend; bindex++)
++ if (!bindex || is_sb_shared(sb, bindex, bindex - 1) < 0)
++ err = do_xib_restore
++ (sb, au_sbr(sb, bindex)->br_xino.xi_file, page);
++ else
++ AuDbg("b%d\n", bindex);
++ free_page((unsigned long)page);
++
++ out:
++ return err;
++}
++
++int au_xib_trunc(struct super_block *sb)
++{
++ int err;
++ ssize_t sz;
++ loff_t pos;
++ struct au_xino_lock_dir ldir;
++ struct au_sbinfo *sbinfo;
++ unsigned long *p;
++ struct file *file;
++
++ err = 0;
++ sbinfo = au_sbi(sb);
++ if (!au_opt_test(sbinfo->si_mntflags, XINO))
++ goto out;
++
++ file = sbinfo->si_xib;
++ if (i_size_read(file->f_dentry->d_inode) <= PAGE_SIZE)
++ goto out;
++
++ au_xino_lock_dir(sb, file, &ldir);
++ /* mnt_want_write() is unnecessary here */
++ file = au_xino_create2(sbinfo->si_xib, NULL);
++ au_xino_unlock_dir(&ldir);
++ err = PTR_ERR(file);
++ if (IS_ERR(file))
++ goto out;
++ fput(sbinfo->si_xib);
++ sbinfo->si_xib = file;
++
++ p = sbinfo->si_xib_buf;
++ memset(p, 0, PAGE_SIZE);
++ pos = 0;
++ sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xib, p, PAGE_SIZE, &pos);
++ if (unlikely(sz != PAGE_SIZE)) {
++ err = sz;
++ AuIOErr("err %d\n", err);
++ if (sz >= 0)
++ err = -EIO;
++ goto out;
++ }
++
++ mutex_lock(&sbinfo->si_xib_mtx);
++ /* mnt_want_write() is unnecessary here */
++ err = xib_restore(sb);
++ mutex_unlock(&sbinfo->si_xib_mtx);
++
++out:
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * xino mount option handlers
++ */
++static au_readf_t find_readf(struct file *h_file)
++{
++ const struct file_operations *fop = h_file->f_op;
++
++ if (fop) {
++ if (fop->read)
++ return fop->read;
++ if (fop->aio_read)
++ return do_sync_read;
++ }
++ return ERR_PTR(-ENOSYS);
++}
++
++static au_writef_t find_writef(struct file *h_file)
++{
++ const struct file_operations *fop = h_file->f_op;
++
++ if (fop) {
++ if (fop->write)
++ return fop->write;
++ if (fop->aio_write)
++ return do_sync_write;
++ }
++ return ERR_PTR(-ENOSYS);
++}
++
++/* xino bitmap */
++static void xino_clear_xib(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++
++ sbinfo = au_sbi(sb);
++ sbinfo->si_xread = NULL;
++ sbinfo->si_xwrite = NULL;
++ if (sbinfo->si_xib)
++ fput(sbinfo->si_xib);
++ sbinfo->si_xib = NULL;
++ free_page((unsigned long)sbinfo->si_xib_buf);
++ sbinfo->si_xib_buf = NULL;
++}
++
++static int au_xino_set_xib(struct super_block *sb, struct file *base)
++{
++ int err;
++ loff_t pos;
++ struct au_sbinfo *sbinfo;
++ struct file *file;
++
++ sbinfo = au_sbi(sb);
++ file = au_xino_create2(base, sbinfo->si_xib);
++ err = PTR_ERR(file);
++ if (IS_ERR(file))
++ goto out;
++ if (sbinfo->si_xib)
++ fput(sbinfo->si_xib);
++ sbinfo->si_xib = file;
++ sbinfo->si_xread = find_readf(file);
++ sbinfo->si_xwrite = find_writef(file);
++
++ err = -ENOMEM;
++ if (!sbinfo->si_xib_buf)
++ sbinfo->si_xib_buf = (void *)get_zeroed_page(GFP_NOFS);
++ if (unlikely(!sbinfo->si_xib_buf))
++ goto out_unset;
++
++ sbinfo->si_xib_last_pindex = 0;
++ sbinfo->si_xib_next_bit = 0;
++ if (i_size_read(file->f_dentry->d_inode) < PAGE_SIZE) {
++ pos = 0;
++ err = xino_fwrite(sbinfo->si_xwrite, file, sbinfo->si_xib_buf,
++ PAGE_SIZE, &pos);
++ if (unlikely(err != PAGE_SIZE))
++ goto out_free;
++ }
++ err = 0;
++ goto out; /* success */
++
++ out_free:
++ free_page((unsigned long)sbinfo->si_xib_buf);
++ sbinfo->si_xib_buf = NULL;
++ if (err >= 0)
++ err = -EIO;
++ out_unset:
++ fput(sbinfo->si_xib);
++ sbinfo->si_xib = NULL;
++ sbinfo->si_xread = NULL;
++ sbinfo->si_xwrite = NULL;
++ out:
++ return err;
++}
++
++/* xino for each branch */
++static void xino_clear_br(struct super_block *sb)
++{
++ aufs_bindex_t bindex, bend;
++ struct au_branch *br;
++
++ bend = au_sbend(sb);
++ for (bindex = 0; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ if (!br || !br->br_xino.xi_file)
++ continue;
++
++ fput(br->br_xino.xi_file);
++ br->br_xino.xi_file = NULL;
++ }
++}
++
++static int au_xino_set_br(struct super_block *sb, struct file *base)
++{
++ int err;
++ ino_t ino;
++ aufs_bindex_t bindex, bend, bshared;
++ struct {
++ struct file *old, *new;
++ } *fpair, *p;
++ struct au_branch *br;
++ struct inode *inode;
++ au_writef_t writef;
++
++ err = -ENOMEM;
++ bend = au_sbend(sb);
++ fpair = kcalloc(bend + 1, sizeof(*fpair), GFP_NOFS);
++ if (unlikely(!fpair))
++ goto out;
++
++ inode = sb->s_root->d_inode;
++ ino = AUFS_ROOT_INO;
++ writef = au_sbi(sb)->si_xwrite;
++ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
++ br = au_sbr(sb, bindex);
++ bshared = is_sb_shared(sb, bindex, bindex - 1);
++ if (bshared >= 0) {
++ /* shared xino */
++ *p = fpair[bshared];
++ get_file(p->new);
++ }
++
++ if (!p->new) {
++ /* new xino */
++ p->old = br->br_xino.xi_file;
++ p->new = au_xino_create2(base, br->br_xino.xi_file);
++ err = PTR_ERR(p->new);
++ if (IS_ERR(p->new)) {
++ p->new = NULL;
++ goto out_pair;
++ }
++ }
++
++ err = au_xino_do_write(writef, p->new,
++ au_h_iptr(inode, bindex)->i_ino, ino);
++ if (unlikely(err))
++ goto out_pair;
++ }
++
++ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++) {
++ br = au_sbr(sb, bindex);
++ if (br->br_xino.xi_file)
++ fput(br->br_xino.xi_file);
++ get_file(p->new);
++ br->br_xino.xi_file = p->new;
++ }
++
++ out_pair:
++ for (bindex = 0, p = fpair; bindex <= bend; bindex++, p++)
++ if (p->new)
++ fput(p->new);
++ else
++ break;
++ kfree(fpair);
++ out:
++ return err;
++}
++
++void au_xino_clr(struct super_block *sb)
++{
++ struct au_sbinfo *sbinfo;
++
++ au_xigen_clr(sb);
++ xino_clear_xib(sb);
++ xino_clear_br(sb);
++ sbinfo = au_sbi(sb);
++ /* lvalue, do not call au_mntflags() */
++ au_opt_clr(sbinfo->si_mntflags, XINO);
++}
++
++int au_xino_set(struct super_block *sb, struct au_opt_xino *xino, int remount)
++{
++ int err, skip;
++ struct dentry *parent, *cur_parent;
++ struct qstr *dname, *cur_name;
++ struct file *cur_xino;
++ struct inode *dir;
++ struct au_sbinfo *sbinfo;
++
++ err = 0;
++ sbinfo = au_sbi(sb);
++ parent = dget_parent(xino->file->f_dentry);
++ if (remount) {
++ skip = 0;
++ dname = &xino->file->f_dentry->d_name;
++ cur_xino = sbinfo->si_xib;
++ if (cur_xino) {
++ cur_parent = dget_parent(cur_xino->f_dentry);
++ cur_name = &cur_xino->f_dentry->d_name;
++ skip = (cur_parent == parent
++ && dname->len == cur_name->len
++ && !memcmp(dname->name, cur_name->name,
++ dname->len));
++ dput(cur_parent);
++ }
++ if (skip)
++ goto out;
++ }
++
++ au_opt_set(sbinfo->si_mntflags, XINO);
++ dir = parent->d_inode;
++ mutex_lock_nested(&dir->i_mutex, AuLsc_I_PARENT);
++ /* mnt_want_write() is unnecessary here */
++ err = au_xino_set_xib(sb, xino->file);
++ if (!err)
++ err = au_xigen_set(sb, xino->file);
++ if (!err)
++ err = au_xino_set_br(sb, xino->file);
++ mutex_unlock(&dir->i_mutex);
++ if (!err)
++ goto out; /* success */
++
++ /* reset all */
++ AuIOErr("failed creating xino(%d).\n", err);
++
++ out:
++ dput(parent);
++ return err;
++}
++
++/* ---------------------------------------------------------------------- */
++
++/*
++ * create a xinofile at the default place/path.
++ */
++struct file *au_xino_def(struct super_block *sb)
++{
++ struct file *file;
++ char *page, *p;
++ struct au_branch *br;
++ struct super_block *h_sb;
++ struct path path;
++ aufs_bindex_t bend, bindex, bwr;
++
++ br = NULL;
++ bend = au_sbend(sb);
++ bwr = -1;
++ for (bindex = 0; bindex <= bend; bindex++) {
++ br = au_sbr(sb, bindex);
++ if (au_br_writable(br->br_perm)
++ && !au_test_fs_bad_xino(br->br_mnt->mnt_sb)) {
++ bwr = bindex;
++ break;
++ }
++ }
++
++ if (bwr >= 0) {
++ file = ERR_PTR(-ENOMEM);
++ page = __getname();
++ if (unlikely(!page))
++ goto out;
++ path.mnt = br->br_mnt;
++ path.dentry = au_h_dptr(sb->s_root, bwr);
++ p = d_path(&path, page, PATH_MAX - sizeof(AUFS_XINO_FNAME));
++ file = (void *)p;
++ if (!IS_ERR(p)) {
++ strcat(p, "/" AUFS_XINO_FNAME);
++ AuDbg("%s\n", p);
++ file = au_xino_create(sb, p, /*silent*/0);
++ if (!IS_ERR(file))
++ au_xino_brid_set(sb, br->br_id);
++ }
++ __putname(page);
++ } else {
++ file = au_xino_create(sb, AUFS_XINO_DEFPATH, /*silent*/0);
++ if (IS_ERR(file))
++ goto out;
++ h_sb = file->f_dentry->d_sb;
++ if (unlikely(au_test_fs_bad_xino(h_sb))) {
++ AuErr("xino doesn't support %s(%s)\n",
++ AUFS_XINO_DEFPATH, au_sbtype(h_sb));
++ fput(file);
++ file = ERR_PTR(-EINVAL);
++ }
++ if (!IS_ERR(file))
++ au_xino_brid_set(sb, -1);
++ }
++
++ out:
++ return file;
++}
++
++/* ---------------------------------------------------------------------- */
++
++int au_xino_path(struct seq_file *seq, struct file *file)
++{
++ int err;
++
++ err = au_seq_path(seq, &file->f_path);
++ if (unlikely(err < 0))
++ goto out;
++
++ err = 0;
++#define Deleted "\\040(deleted)"
++ seq->count -= sizeof(Deleted) - 1;
++ AuDebugOn(memcmp(seq->buf + seq->count, Deleted,
++ sizeof(Deleted) - 1));
++#undef Deleted
++
++ out:
++ return err;
++}
+diff --git a/fs/namei.c b/fs/namei.c
+index bbc15c2..db581b4 100644
+--- a/fs/namei.c
++++ b/fs/namei.c
+@@ -1196,7 +1196,7 @@ out:
+ * needs parent already locked. Doesn't follow mounts.
+ * SMP-safe.
+ */
+-static struct dentry *lookup_hash(struct nameidata *nd)
++struct dentry *lookup_hash(struct nameidata *nd)
+ {
+ int err;
+
+@@ -1206,7 +1206,7 @@ static struct dentry *lookup_hash(struct nameidata *nd)
+ return __lookup_hash(&nd->last, nd->path.dentry, nd);
+ }
+
+-static int __lookup_one_len(const char *name, struct qstr *this,
++int __lookup_one_len(const char *name, struct qstr *this,
+ struct dentry *base, int len)
+ {
+ unsigned long hash;
+diff --git a/fs/splice.c b/fs/splice.c
+index 4ed0ba4..2fb3d17 100644
+--- a/fs/splice.c
++++ b/fs/splice.c
+@@ -888,8 +888,8 @@ EXPORT_SYMBOL(generic_splice_sendpage);
+ /*
+ * Attempt to initiate a splice from pipe to file.
+ */
+-static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+- loff_t *ppos, size_t len, unsigned int flags)
++long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
++ loff_t *ppos, size_t len, unsigned int flags)
+ {
+ int ret;
+
+@@ -912,9 +912,9 @@ static long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
+ /*
+ * Attempt to initiate a splice from a file to a pipe.
+ */
+-static long do_splice_to(struct file *in, loff_t *ppos,
+- struct pipe_inode_info *pipe, size_t len,
+- unsigned int flags)
++long do_splice_to(struct file *in, loff_t *ppos,
++ struct pipe_inode_info *pipe, size_t len,
++ unsigned int flags)
+ {
+ int ret;
+
+diff --git a/include/linux/Kbuild b/include/linux/Kbuild
+index 106c3ba..d0c7262 100644
+--- a/include/linux/Kbuild
++++ b/include/linux/Kbuild
+@@ -34,6 +34,7 @@ header-y += atmppp.h
+ header-y += atmsap.h
+ header-y += atmsvc.h
+ header-y += atm_zatm.h
++header-y += aufs_type.h
+ header-y += auto_fs4.h
+ header-y += ax25.h
+ header-y += b1lli.h
+diff --git a/include/linux/aufs_type.h b/include/linux/aufs_type.h
+new file mode 100644
+index 0000000..5c98a5f
+--- /dev/null
++++ b/include/linux/aufs_type.h
+@@ -0,0 +1,100 @@
++/*
++ * Copyright (C) 2005-2009 Junjiro R. Okajima
++ *
++ * This program, aufs is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ */
++
++#ifndef __AUFS_TYPE_H__
++#define __AUFS_TYPE_H__
++
++#include <linux/ioctl.h>
++
++#define AUFS_VERSION "2-29"
++
++/* todo? move this to linux-2.6.19/include/magic.h */
++#define AUFS_SUPER_MAGIC ('a' << 24 | 'u' << 16 | 'f' << 8 | 's')
++
++/* ---------------------------------------------------------------------- */
++
++#ifdef CONFIG_AUFS_BRANCH_MAX_127
++/* some environments treat 'char' as 'unsigned char' by default */
++typedef signed char aufs_bindex_t;
++#define AUFS_BRANCH_MAX 127
++#else
++typedef short aufs_bindex_t;
++#ifdef CONFIG_AUFS_BRANCH_MAX_511
++#define AUFS_BRANCH_MAX 511
++#elif defined(CONFIG_AUFS_BRANCH_MAX_1023)
++#define AUFS_BRANCH_MAX 1023
++#elif defined(CONFIG_AUFS_BRANCH_MAX_32767)
++#define AUFS_BRANCH_MAX 32767
++#endif
++#endif
++
++#ifdef __KERNEL__
++#ifndef AUFS_BRANCH_MAX
++#error unknown CONFIG_AUFS_BRANCH_MAX value
++#endif
++#endif /* __KERNEL__ */
++
++/* ---------------------------------------------------------------------- */
++
++#define AUFS_NAME "aufs"
++#define AUFS_FSTYPE AUFS_NAME
++
++#define AUFS_ROOT_INO 2
++#define AUFS_FIRST_INO 11
++
++#define AUFS_WH_PFX ".wh."
++#define AUFS_WH_PFX_LEN ((int)sizeof(AUFS_WH_PFX) - 1)
++#define AUFS_XINO_FNAME "." AUFS_NAME ".xino"
++#define AUFS_XINO_DEFPATH "/tmp/" AUFS_XINO_FNAME
++#define AUFS_XINO_TRUNC_INIT 64 /* blocks */
++#define AUFS_XINO_TRUNC_STEP 4 /* blocks */
++#define AUFS_DIRWH_DEF 3
++#define AUFS_RDCACHE_DEF 10 /* seconds */
++#define AUFS_RDBLK_DEF 512 /* bytes */
++#define AUFS_RDHASH_DEF 32
++#define AUFS_WKQ_NAME AUFS_NAME "d"
++#define AUFS_NWKQ_DEF 4
++#define AUFS_MFS_SECOND_DEF 30 /* seconds */
++#define AUFS_PLINK_WARN 100 /* number of plinks */
++
++#define AUFS_DIROPQ_NAME AUFS_WH_PFX ".opq" /* whiteouted doubly */
++#define AUFS_WH_DIROPQ AUFS_WH_PFX AUFS_DIROPQ_NAME
++
++#define AUFS_BASE_NAME AUFS_WH_PFX AUFS_NAME
++#define AUFS_PLINKDIR_NAME AUFS_WH_PFX "plnk"
++#define AUFS_ORPHDIR_NAME AUFS_WH_PFX "orph"
++
++/* doubly whiteouted */
++#define AUFS_WH_BASE AUFS_WH_PFX AUFS_BASE_NAME
++#define AUFS_WH_PLINKDIR AUFS_WH_PFX AUFS_PLINKDIR_NAME
++#define AUFS_WH_ORPHDIR AUFS_WH_PFX AUFS_ORPHDIR_NAME
++
++/* branch permission */
++#define AUFS_BRPERM_RW "rw"
++#define AUFS_BRPERM_RO "ro"
++#define AUFS_BRPERM_RR "rr"
++#define AUFS_BRPERM_WH "wh"
++#define AUFS_BRPERM_NLWH "nolwh"
++#define AUFS_BRPERM_ROWH AUFS_BRPERM_RO "+" AUFS_BRPERM_WH
++#define AUFS_BRPERM_RRWH AUFS_BRPERM_RR "+" AUFS_BRPERM_WH
++#define AUFS_BRPERM_RWNLWH AUFS_BRPERM_RW "+" AUFS_BRPERM_NLWH
++
++/* ---------------------------------------------------------------------- */
++
++/* ioctl */
++enum {
++ AuCtl_PLINK_MAINT,
++ AuCtl_PLINK_CLEAN
++};
++
++#define AuCtlType 'A'
++#define AUFS_CTL_PLINK_MAINT _IO(AuCtlType, AuCtl_PLINK_MAINT)
++#define AUFS_CTL_PLINK_CLEAN _IO(AuCtlType, AuCtl_PLINK_CLEAN)
++
++#endif /* __AUFS_TYPE_H__ */
+diff --git a/include/linux/namei.h b/include/linux/namei.h
+index fc2e035..182d43b 100644
+--- a/include/linux/namei.h
++++ b/include/linux/namei.h
+@@ -75,6 +75,9 @@ extern struct file *lookup_instantiate_filp(struct nameidata *nd, struct dentry
+ extern struct file *nameidata_to_filp(struct nameidata *nd, int flags);
+ extern void release_open_intent(struct nameidata *);
+
++extern struct dentry *lookup_hash(struct nameidata *nd);
++extern int __lookup_one_len(const char *name, struct qstr *this,
++ struct dentry *base, int len);
+ extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
+ extern struct dentry *lookup_one_noperm(const char *, struct dentry *);
+
+diff --git a/include/linux/splice.h b/include/linux/splice.h
+index 528dcb9..5123bc6 100644
+--- a/include/linux/splice.h
++++ b/include/linux/splice.h
+@@ -71,4 +71,10 @@ extern ssize_t splice_to_pipe(struct pipe_inode_info *,
+ extern ssize_t splice_direct_to_actor(struct file *, struct splice_desc *,
+ splice_direct_actor *);
+
++extern long do_splice_from(struct pipe_inode_info *pipe, struct file *out,
++ loff_t *ppos, size_t len, unsigned int flags);
++extern long do_splice_to(struct file *in, loff_t *ppos,
++ struct pipe_inode_info *pipe, size_t len,
++ unsigned int flags);
++
+ #endif
projects / packages / kernel.git / commitdiff