- added description of djurban's branch

[packages/kernel.git] / 2.6.0-t10-POSIX_message_queues-2of2-lkml.patch

diff -urN 2.6.0-test10-orig_2/arch/i386/kernel/entry.S 2.6.0-test10-patched_2/arch/i386/kernel/entry.S
--- 2.6.0-test10-orig_2/arch/i386/kernel/entry.S	2003-11-24 16:28:52.000000000 +0100
+++ 2.6.0-test10-patched_2/arch/i386/kernel/entry.S	2003-11-24 16:46:44.000000000 +0100
@@ -882,5 +882,12 @@
 	.long sys_utimes
  	.long sys_fadvise64_64
 	.long sys_ni_syscall	/* sys_vserver */
+	.long sys_mq_open
+	.long sys_mq_unlink	/* 275 */
+	.long sys_mq_timedsend
+	.long sys_mq_timedreceive
+	.long sys_mq_notify
+	.long sys_mq_getattr
+	.long sys_mq_setattr
 
 syscall_table_size=(.-sys_call_table)
diff -urN 2.6.0-test10-orig_2/CREDITS 2.6.0-test10-patched_2/CREDITS
--- 2.6.0-test10-orig_2/CREDITS	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/CREDITS	2003-11-21 16:48:21.000000000 +0100
@@ -289,6 +289,15 @@
 S: Terni 05100
 S: Italy
 
+N: Krzysztof Benedyczak
+E: golbi@mat.uni.torun.pl
+W: http://www.mat.uni.torun.pl/~golbi
+D: POSIX message queues fs (with M. Wronski)
+S: ul. Podmiejska 52
+S: Radunica
+S: 83-000 Pruszcz Gdanski
+S: Poland
+
 N: Randolph Bentson
 E: bentson@grieg.seaslug.org
 W: http://www.aa.net/~bentson/
@@ -3475,6 +3484,14 @@
 S: Beaverton, OR 97005
 S: USA
 
+N: Michal Wronski
+E: wrona@mat.uni.torun.pl
+W: http://www.mat.uni.torun.pl/~wrona
+D: POSIX message queues fs (with K. Benedyczak)
+S: ul. Teczowa 23/12
+S: 80-680 Gdansk-Sobieszewo
+S: Poland
+
 N: Frank Xia
 E: qx@math.columbia.edu
 D: Xiafs filesystem [defunct]
diff -urN 2.6.0-test10-orig_2/Documentation/filesystems/proc.txt 2.6.0-test10-patched_2/Documentation/filesystems/proc.txt
--- 2.6.0-test10-orig_2/Documentation/filesystems/proc.txt	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/Documentation/filesystems/proc.txt	2003-11-24 17:37:30.000000000 +0100
@@ -38,6 +38,7 @@
   2.8	/proc/sys/net/ipv4 - IPV4 settings
   2.9	Appletalk
   2.10	IPX
+  2.11	/proc/sys/fs/mqueue - POSIX message queues filesystem
 
 ------------------------------------------------------------------------------
 Preface
@@ -1805,6 +1806,30 @@
 gives the  destination  network, the router node (or Directly) and the network
 address of the router (or Connected) for internal networks.
 
+2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem
+----------------------------------------------------------
+
+The "mqueue"  filesystem provides  the necessary kernel features to enable the
+creation of a  user space  library that  implements  the  POSIX message queues
+API (as noted by the  MSG tag in the  POSIX 1003.1-2001 version  of the System
+Interfaces specification.)
+
+The "mqueue" filesystem contains values for determining/setting  the amount of
+resources used by the file system.
+
+/proc/sys/fs/mqueue/queues_max is a read/write  file for  setting/getting  the
+maximum number of message queues allowed on the system.
+
+/proc/sys/fs/mqueue/msg_max  is  a  read/write file  for  setting/getting  the
+maximum number of messages in a queue value.  In fact it is the limiting value
+for another (user) limit which is set in mq_open invocation. This attribute of
+a queue must be less or equal then msg_max.
+
+/proc/sys/fs/mqueue/msgsize_max is  a read/write  file for setting/getting the
+maximum  message size value (it is every  message queue's attribute set during
+its creation).
+
+
 ------------------------------------------------------------------------------
 Summary
 ------------------------------------------------------------------------------
diff -urN 2.6.0-test10-orig_2/fs/Kconfig 2.6.0-test10-patched_2/fs/Kconfig
--- 2.6.0-test10-orig_2/fs/Kconfig	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/fs/Kconfig	2003-11-21 16:59:14.000000000 +0100
@@ -893,6 +893,23 @@
 	  To compile this as a module, choose M here: the module will be called
 	  ramfs.
 
+config POSIX_MQUEUE_FS
+	bool "POSIX Message Queues"
+	---help---
+	  POSIX variant of message queues is a part of IPC. In POSIX message
+	  queues every message has a priority which decides about succession
+	  of receiving it by a process. If you want to compile and run
+	  programs written e.g. for Solaris with use of its POSIX message
+	  queues (functions mq_*) say Y here. To use this feature you will
+	  also need mqueue library, available from
+	  <http://www.mat.uni.torun.pl/~wrona/posix_ipc/>
+
+	  POSIX message queues are visible as a filesystem called 'mqueue'
+	  and can be mounted somewhere if you want to do filesystem
+	  operations on message queues.
+
+	  If unsure, say N.
+
 endmenu
 
 menu "Miscellaneous filesystems"
diff -urN 2.6.0-test10-orig_2/include/asm-generic/siginfo.h 2.6.0-test10-patched_2/include/asm-generic/siginfo.h
--- 2.6.0-test10-orig_2/include/asm-generic/siginfo.h	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/include/asm-generic/siginfo.h	2003-11-21 16:48:21.000000000 +0100
@@ -118,6 +118,7 @@
 #define __SI_FAULT	(3 << 16)
 #define __SI_CHLD	(4 << 16)
 #define __SI_RT		(5 << 16)
+#define __SI_MESGQ	(6 << 16)
 #define __SI_CODE(T,N)	((T) | ((N) & 0xffff))
 #else
 #define __SI_KILL	0
@@ -126,6 +127,7 @@
 #define __SI_FAULT	0
 #define __SI_CHLD	0
 #define __SI_RT		0
+#define __SI_MESGQ	0
 #define __SI_CODE(T,N)	(N)
 #endif
 
@@ -137,7 +139,7 @@
 #define SI_KERNEL	0x80		/* sent by the kernel from somewhere */
 #define SI_QUEUE	-1		/* sent by sigqueue */
 #define SI_TIMER __SI_CODE(__SI_TIMER,-2) /* sent by timer expiration */
-#define SI_MESGQ	-3		/* sent by real time mesq state change */
+#define SI_MESGQ __SI_CODE(__SI_MESGQ,-3) /* sent by real time mesq state change */
 #define SI_ASYNCIO	-4		/* sent by AIO completion */
 #define SI_SIGIO	-5		/* sent by queued SIGIO */
 #define SI_TKILL	-6		/* sent by tkill system call */
diff -urN 2.6.0-test10-orig_2/include/asm-i386/unistd.h 2.6.0-test10-patched_2/include/asm-i386/unistd.h
--- 2.6.0-test10-orig_2/include/asm-i386/unistd.h	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/include/asm-i386/unistd.h	2003-11-21 16:48:21.000000000 +0100
@@ -279,8 +279,15 @@
 #define __NR_utimes		271
 #define __NR_fadvise64_64	272
 #define __NR_vserver		273
-
-#define NR_syscalls 274
+#define __NR_mq_open 		274
+#define __NR_mq_unlink		(__NR_mq_open+1)
+#define __NR_mq_timedsend	(__NR_mq_open+2)
+#define __NR_mq_timedreceive	(__NR_mq_open+3)
+#define __NR_mq_notify		(__NR_mq_open+4)
+#define __NR_mq_getattr		(__NR_mq_open+5)
+#define __NR_mq_setattr		(__NR_mq_open+6)
+
+#define NR_syscalls 281
 
 /* user-visible error numbers are in the range -1 - -124: see <asm-i386/errno.h> */
 
diff -urN 2.6.0-test10-orig_2/include/linux/mqueue.h 2.6.0-test10-patched_2/include/linux/mqueue.h
--- 2.6.0-test10-orig_2/include/linux/mqueue.h	1970-01-01 01:00:00.000000000 +0100
+++ 2.6.0-test10-patched_2/include/linux/mqueue.h	2003-11-24 16:37:46.000000000 +0100
@@ -0,0 +1,64 @@
+/* Copyright (C) 2003 Krzysztof Benedyczak & Michal Wronski
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   It is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this software; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _LINUX_MQUEUE_H
+#define _LINUX_MQUEUE_H
+
+#define MQ_PRIO_MAX 	32768
+
+typedef int mqd_t;
+
+struct mq_attr {
+	long	mq_flags;	/* message queue flags			*/
+	long	mq_maxmsg;	/* maximum number of messages		*/
+	long	mq_msgsize;	/* maximum message size			*/
+	long	mq_curmsgs;	/* number of messages currently queued	*/
+};
+
+#ifdef __KERNEL__
+#include <linux/types.h>
+#include <linux/time.h>
+#include <linux/signal.h>
+#include <linux/linkage.h>
+
+asmlinkage long sys_mq_open(const char __user *name, int oflag, mode_t mode, struct mq_attr __user *attr);
+asmlinkage long sys_mq_unlink(const char __user *name);
+asmlinkage long mq_timedsend(mqd_t mqdes, const char __user *msg_ptr, size_t msg_len, unsigned int msg_prio, const struct timespec __user *abs_timeout);
+asmlinkage ssize_t mq_timedreceive(mqd_t mqdes, char __user *msg_ptr, size_t msg_len, unsigned int __user *msg_prio, const struct timespec __user *abs_timeout);
+asmlinkage long mq_notify(mqd_t mqdes, const struct sigevent __user *notification);
+asmlinkage long mq_getattr(mqd_t mqdes, struct mq_attr __user *mqstat);
+asmlinkage long mq_setattr(mqd_t mqdes, const struct mq_attr __user *mqstat, struct mq_attr __user *omqstat);
+
+#else
+
+#include <signal.h>
+#include <fcntl.h>
+#include <time.h>
+
+mqd_t mq_open(const char *name, int oflag, /* mode_t mode, struct mq_attr *attr */ ...);
+int mq_close(mqd_t mqdes);
+int mq_unlink(const char *name);
+int mq_send(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned int msg_prio);
+int mq_timedsend(mqd_t mqdes, const char *msg_ptr, size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout);
+ssize_t mq_receive(mqd_t mqdes, char *msg_ptr, size_t msg_len, unsigned int *msg_prio);
+ssize_t mq_timedreceive(mqd_t mqdes, char *__restrict msg_ptr, size_t msg_len, unsigned int *__restrict msg_prio, const struct timespec *__restrict abs_timeout);
+int mq_notify(mqd_t mqdes, const struct sigevent *notification);
+int mq_getattr(mqd_t mqdes, struct mq_attr *mqstat);
+int mq_setattr(mqd_t mqdes, const struct mq_attr *__restrict mqstat, struct mq_attr *__restrict omqstat);
+#endif
+
+#endif
diff -urN 2.6.0-test10-orig_2/ipc/Makefile 2.6.0-test10-patched_2/ipc/Makefile
--- 2.6.0-test10-orig_2/ipc/Makefile	2003-11-07 17:07:13.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/Makefile	2003-11-21 16:48:21.000000000 +0100
@@ -5,3 +5,4 @@
 obj-y   := util.o
 
 obj-$(CONFIG_SYSVIPC) += msg.o sem.o shm.o
+obj-$(CONFIG_POSIX_MQUEUE_FS) += mqueue.o
diff -urN 2.6.0-test10-orig_2/ipc/mqueue.c 2.6.0-test10-patched_2/ipc/mqueue.c
--- 2.6.0-test10-orig_2/ipc/mqueue.c	1970-01-01 01:00:00.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/mqueue.c	2003-11-24 16:37:46.000000000 +0100
@@ -0,0 +1,1260 @@
+/*
+ * POSIX message queues filesystem for Linux.
+ *
+ * Copyright (C) 2003   Krzysztof Benedyczak    (golbi@mat.uni.torun.pl)
+ *                      Michal Wronski          (wrona@mat.uni.torun.pl)
+ *
+ * Spinlocks:           Mohamed Abbas           (abbas.mohamed@intel.com)
+ *
+ * This file is released under the GPL.
+ */
+
+#include <linux/mqueue.h>
+#include <linux/msg.h>
+#include <linux/list.h>
+#include <linux/poll.h>
+#include <linux/init.h>
+#include <linux/pagemap.h>
+#include <linux/file.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/sysctl.h>
+#include "util.h"
+
+#define MQUEUE_MAGIC	0x19800202
+#define DIRENT_SIZE	20
+#define FILENT_SIZE	60
+#define SEND		0
+#define RECV		1
+
+#define ERRNO_OK_SIGNAL		0
+#define ERRNO_OK_THREAD		1
+#define ERRNO_REMOVE_THREAD	2
+
+/* used by sysctl */
+#define FS_MQUEUE 	1
+#define CTL_QUEUESMAX 	2
+#define CTL_MSGMAX 	3
+#define CTL_MSGSIZEMAX 	4
+
+/* default values */
+#define DFLT_QUEUESMAX	64	/* max number of message queues */
+#define DFLT_MSGMAX 	40	/* max number of messages in each queue */
+#define DFLT_MSGSIZEMAX 16384	/* max message size */
+
+struct ext_wait_queue {		/* queue of sleeping tasks */
+	struct task_struct *task;
+	struct list_head list;
+};
+
+struct mqueue_inode_info {
+	struct mq_attr attr;
+	struct msg_msg **messages;
+
+	struct sigevent notify;
+	pid_t notify_task;
+	pid_t notify_owner; /* == tgid of notify_task */
+
+	/* for tasks waiting for free space or message (respectively) */
+	/* this is left mainly because of poll */
+	wait_queue_head_t wait_q[2];
+	/* avoids extra invocations of wake_up */
+	wait_queue_head_t wait_q2[2];
+	struct ext_wait_queue e_wait_q[2];	/* 0=free space   1=message */
+
+	__u32 qsize; /* size of queue in memory (msgs & struct) */
+	spinlock_t lock;
+	struct inode vfs_inode;
+};
+
+static struct inode_operations mqueue_dir_inode_operations;
+static struct file_operations mqueue_file_operations;
+static struct super_operations mqueue_super_ops;
+static inline void remove_notification(struct mqueue_inode_info *info);
+
+static spinlock_t mq_lock;
+static kmem_cache_t *mqueue_inode_cachep;
+static struct vfsmount *mqueue_mnt;
+
+static unsigned int queues_count;
+static unsigned int queues_max 	= DFLT_QUEUESMAX;
+static unsigned int msg_max 	= DFLT_MSGMAX;
+static unsigned int msgsize_max = DFLT_MSGSIZEMAX;
+
+static struct ctl_table_header * mq_sysctl_table;
+
+
+static inline struct mqueue_inode_info *MQUEUE_I(struct inode *ino)
+{
+	return list_entry(ino, struct mqueue_inode_info, vfs_inode);
+}
+
+static struct inode *mqueue_get_inode(struct super_block *sb, int mode)
+{
+	struct inode *inode;
+	struct mqueue_inode_info *ino_extra;
+	struct msg_msg **msgs = NULL;
+	int size = msg_max;
+
+	if ((mode & S_IFMT) == S_IFREG) {
+		msgs = (struct msg_msg **)kmalloc(size * sizeof(struct msg_msg *), GFP_KERNEL);
+		if (!msgs)
+			return NULL;
+	}
+
+	inode = new_inode(sb);
+	if (inode) {
+		inode->i_mode = mode;
+		inode->i_uid = current->fsuid;
+		inode->i_gid = current->fsgid;
+		inode->i_blksize = PAGE_CACHE_SIZE;
+		inode->i_blocks = 0;
+		inode->i_mtime = inode->i_ctime = inode->i_atime = CURRENT_TIME;
+
+		if ((mode & S_IFMT) == S_IFREG) {
+			inode->i_fop = &mqueue_file_operations;
+			inode->i_size = FILENT_SIZE;
+			/* mqueue specific info */
+			ino_extra = MQUEUE_I(inode);
+			spin_lock_init(&(ino_extra->lock));
+			init_waitqueue_head((&(ino_extra->wait_q[0])));
+			init_waitqueue_head((&(ino_extra->wait_q[1])));
+			init_waitqueue_head((&(ino_extra->wait_q2[0])));
+			init_waitqueue_head((&(ino_extra->wait_q2[1])));
+			INIT_LIST_HEAD(&(ino_extra->e_wait_q[0].list));
+			INIT_LIST_HEAD(&(ino_extra->e_wait_q[1].list));
+			ino_extra->notify_task = 0;
+			ino_extra->notify_owner = 0;
+			ino_extra->notify.sigev_signo = 0;
+			ino_extra->notify.sigev_notify = SIGEV_NONE;
+			ino_extra->qsize = sizeof(struct mqueue_inode_info);
+			ino_extra->attr.mq_curmsgs = 0;
+			/* fill up with defaults */
+			ino_extra->attr.mq_maxmsg = size;
+			ino_extra->attr.mq_msgsize = msgsize_max;
+			ino_extra->messages = msgs;
+		} else if ((mode & S_IFMT) == S_IFDIR) {
+			inode->i_nlink++;
+			/* Some things misbehave if size == 0 on a directory */
+			inode->i_size = 2 * DIRENT_SIZE;
+			inode->i_op = &mqueue_dir_inode_operations;
+			inode->i_fop = &simple_dir_operations;
+		}
+	} else if (msgs)
+		kfree(msgs);
+	return inode;
+}
+
+
+static int mqueue_fill_super(struct super_block *sb, void *data, int silent)
+{
+	struct inode *inode;
+
+	sb->s_blocksize = PAGE_CACHE_SIZE;
+	sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
+	sb->s_magic = MQUEUE_MAGIC;
+	sb->s_op = &mqueue_super_ops;
+
+	inode = mqueue_get_inode(sb, S_IFDIR | S_IRWXUGO);
+	if (!inode)
+		return -ENOMEM;
+
+	sb->s_root = d_alloc_root(inode);
+	if (!sb->s_root) {
+		iput(inode);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static struct super_block *mqueue_get_sb(struct file_system_type *fs_type,
+					 int flags, const char *dev_name,
+					 void *data)
+{
+	return get_sb_single(fs_type, flags, data, mqueue_fill_super);
+}
+
+static void init_once(void *foo, kmem_cache_t * cachep, unsigned long flags)
+{
+	struct mqueue_inode_info *p = (struct mqueue_inode_info *) foo;
+
+	if ((flags & (SLAB_CTOR_VERIFY | SLAB_CTOR_CONSTRUCTOR)) == SLAB_CTOR_CONSTRUCTOR)
+		inode_init_once(&p->vfs_inode);
+}
+
+static struct inode *mqueue_alloc_inode(struct super_block *sb)
+{
+	struct mqueue_inode_info *ei;
+
+	ei = (struct mqueue_inode_info *)kmem_cache_alloc(mqueue_inode_cachep, SLAB_KERNEL);
+	if (!ei)
+		return NULL;
+	return &ei->vfs_inode;
+}
+
+static void mqueue_destroy_inode(struct inode *inode)
+{
+	kmem_cache_free(mqueue_inode_cachep, MQUEUE_I(inode));
+}
+
+static void mqueue_delete_inode(struct inode *ino)
+{
+	struct mqueue_inode_info *info;
+	int i;
+
+	if ((ino->i_mode & S_IFMT) == S_IFDIR) {
+		clear_inode(ino);
+		return;
+	}
+	info = MQUEUE_I(ino);
+	spin_lock(&info->lock);
+	for (i = 0; i < info->attr.mq_curmsgs; i++)
+		free_msg(info->messages[i]);
+	kfree(info->messages);
+	spin_unlock(&info->lock);
+
+	clear_inode(ino);
+
+	spin_lock(&mq_lock);
+	queues_count--;
+	spin_unlock(&mq_lock);
+}
+
+static int mqueue_unlink(struct inode *dir, struct dentry *dent)
+{
+	struct inode *inode = dent->d_inode;
+	dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+	dir->i_size -= DIRENT_SIZE;
+	inode->i_nlink--;
+	dput(dent);
+	return 0;
+}
+
+static struct dentry *mqueue_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd)
+{
+	if (dentry->d_name.len > NAME_MAX)
+		return ERR_PTR(-ENAMETOOLONG);
+
+	d_add(dentry, NULL);
+	return NULL;
+}
+
+static int mqueue_create(struct inode *dir, struct dentry *dent, int mode, struct nameidata *nd)
+{
+	struct inode *ino;
+	int error;
+
+	spin_lock(&mq_lock);
+	if (queues_count >= queues_max) {
+		error = -ENOSPC;
+		goto out_lock;
+	}
+	queues_count++;
+	spin_unlock(&mq_lock);
+
+	ino = mqueue_get_inode(dir->i_sb, mode);
+	if (!ino) {
+		error = -ENOMEM;
+		spin_lock(&mq_lock);
+		queues_count--;
+		goto out_lock;
+	}
+
+	dir->i_size += DIRENT_SIZE;
+	dir->i_ctime = dir->i_mtime = dir->i_atime = CURRENT_TIME;
+
+	d_instantiate(dent, ino);
+	dget(dent);
+	return 0;
+out_lock:
+	spin_unlock(&mq_lock);
+	return error;
+}
+
+/*
+*	This is routine for system read from queue file.
+*	To avoid mess with doing here some sort of mq_receive we allow
+*	to read only queue size & notification info (the only values
+*	that are interesting from user point of view and aren't accessible
+*	through std routines)
+*/
+static ssize_t mqueue_read_file(struct file *filp, char __user *data,
+				size_t count, loff_t * off)
+{
+	size_t pos;
+	ssize_t retval;
+	char buffer[FILENT_SIZE + 1];
+	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+
+	pos = *off;
+	if ((ssize_t) count < 0)
+		return -EINVAL;
+	if (!count)
+		return 0;
+	if (pos >= FILENT_SIZE)
+		return 0;
+	if (pos + count >= FILENT_SIZE)
+		count = FILENT_SIZE - pos - 1;
+
+	if (!access_ok(VERIFY_WRITE, data, count))
+		return -EFAULT;
+
+	snprintf(buffer, FILENT_SIZE + 1,
+		"QSIZE:%-10u NOTIFY:%-5d SIGNO:%-5d NOTIFY_PID:%-6d\n",
+	 	info->qsize, info->notify.sigev_notify,
+	 	info->notify.sigev_signo, info->notify_owner);
+
+	retval = FILENT_SIZE - *off;
+	if (copy_to_user(data, buffer + pos, retval)) {
+		retval = (ssize_t)-EFAULT;
+		goto out;
+	}
+	*off += retval;
+	filp->f_dentry->d_inode->i_atime = filp->f_dentry->d_inode->i_ctime = CURRENT_TIME;
+out:
+	return retval;
+}
+
+
+static int mqueue_release_file(struct inode *ino, struct file *filp)
+{
+	struct mqueue_inode_info *info = MQUEUE_I(ino);
+
+	spin_lock(&info->lock);
+	if (current->tgid == info->notify_owner)
+		remove_notification(info);
+
+	spin_unlock(&info->lock);
+	return 0;
+}
+
+
+static unsigned int mqueue_poll_file(struct file *filp, struct poll_table_struct *poll_tab)
+{
+	struct mqueue_inode_info *info = MQUEUE_I(filp->f_dentry->d_inode);
+	int retval = 0;
+
+	poll_wait(filp, &info->wait_q[0], poll_tab);
+	poll_wait(filp, &info->wait_q[1], poll_tab);
+
+	spin_lock(&info->lock);
+	if (info->attr.mq_curmsgs)
+		retval = POLLIN | POLLRDNORM;
+
+	if (info->attr.mq_curmsgs < info->attr.mq_maxmsg)
+		retval |= POLLOUT | POLLWRNORM;
+	spin_unlock(&info->lock);
+
+	return retval;
+}
+
+/*
+*  This cut&paste version of wait_event() without event checking & with
+*  exclusive adding to queue.
+*/
+void inline wait_exclusive(wait_queue_head_t * wq,
+			   struct mqueue_inode_info *i)
+{
+	wait_queue_t wait;
+	init_waitqueue_entry(&wait, current);
+
+	add_wait_queue_exclusive(wq, &wait);
+	set_current_state(TASK_UNINTERRUPTIBLE);
+
+	spin_unlock(&i->lock);
+	schedule();
+	spin_lock(&i->lock);
+
+	current->state = TASK_RUNNING;
+	remove_wait_queue(wq, &wait);
+}
+
+/* Removes from info->e_wait_q[sr] current task */
+static void wq_remove(struct mqueue_inode_info *info, int sr)
+{
+	struct ext_wait_queue *ptr;
+
+	if (!list_empty(&(info->e_wait_q[sr].list)))
+		list_for_each_entry(ptr, &(info->e_wait_q[sr].list), list) {
+			if (ptr->task == current) {
+				list_del(&(ptr->list));
+				kfree(ptr);
+				break;
+			}
+		}
+}
+
+/* adds current to info->e_wait_q[sr] before element with smaller prio */
+static inline void wq_add(struct mqueue_inode_info *info, int sr,
+			struct ext_wait_queue *tmp)
+{
+	struct ext_wait_queue *ptr;
+
+	tmp->task = current;
+
+	if (list_empty(&info->e_wait_q[sr].list))
+		list_add(&tmp->list, &info->e_wait_q[sr].list);
+	else {
+		list_for_each_entry(ptr, &info->e_wait_q[sr].list, list)
+			if (ptr->task->static_prio <= current->static_prio) {
+				/* we add before ptr element */
+				__list_add(&tmp->list, ptr->list.prev, &ptr->list);
+				return;
+			}
+		/* we add on tail */
+		list_add_tail(&tmp->list, &info->e_wait_q[sr].list);
+	}
+	return;
+}
+
+/* removes from info->e_wait_q[sr] current task.
+ * Only for wq_sleep(): as we are here current must be one
+ * before-first (last) (meaning first in order as our 'queue' is inversed) */
+static inline void wq_remove_last(struct mqueue_inode_info *info, int sr)
+{
+	struct ext_wait_queue *tmp = list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list);
+	list_del(&(tmp->list));
+	kfree(tmp);
+}
+
+/*
+ * puts current task to sleep
+ * sr: SEND or RECV
+ */
+static int wq_sleep(struct mqueue_inode_info *info, int sr,
+		    signed long timeout, struct ext_wait_queue *wq_ptr)
+{
+	wait_queue_t __wait;
+	long error;
+
+	wq_add(info, sr, wq_ptr);
+
+	init_waitqueue_entry(&__wait, current);
+
+	for (;;) {
+		set_current_state(TASK_INTERRUPTIBLE);
+		if ((current == (list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list))->task)
+			&& ((info->attr.mq_curmsgs > 0 && sr == RECV)
+			|| (info->attr.mq_curmsgs < info->attr.mq_maxmsg && sr == SEND)))
+			break;
+
+		if (signal_pending(current)) {
+			current->state = TASK_RUNNING;
+			wq_remove(info, sr);
+			return -EINTR;
+		}
+
+		spin_unlock(&info->lock);
+		error = schedule_timeout(timeout);
+		spin_lock(&info->lock);
+
+		if ((!error) && (!signal_pending(current))) {
+			wq_remove(info, sr);
+			return -ETIMEDOUT;
+		}
+	}
+	current->state = TASK_RUNNING;
+	wq_remove_last(info, sr);
+
+	return 0;
+}
+
+/* wakes up sleeping task */
+static void wq_wakeup(struct mqueue_inode_info *info, int sr)
+{
+	if (sr == SEND) {
+		/* We can't invoke wake_up for tasks waiting for free space
+		 * if there is less then MAXMSG-1 messages - then wake_up was
+		 * invoked previously (and finished) but mq_sleep() of proper
+		 * (only one) task didn't start to continue running yet,
+		 * thus we must wait until this task receives IT'S message
+		 */
+		if ((info->attr.mq_curmsgs < info->attr.mq_maxmsg - 1)
+		    && (!list_empty(&info->e_wait_q[sr].list)))
+			wait_exclusive(&(info->wait_q2[sr]), info);
+	} else {
+		/* As above but for tasks waiting for new message */
+		if ((info->attr.mq_curmsgs > 1) && (!list_empty(&info->e_wait_q[sr].list)))
+			wait_exclusive(&(info->wait_q2[sr]), info);
+	}
+	/* We can wake up now - either all are sleeping or queue is empty. */
+	if (!list_empty(&info->e_wait_q[sr].list))
+		wake_up_process((list_entry(info->e_wait_q[sr].list.prev, struct ext_wait_queue, list))->task);
+	/* for poll */
+	wake_up_interruptible(&(info->wait_q[sr]));
+}
+
+
+/* Auxiliary functions to manipulate messages' list */
+static inline void msg_insert(struct msg_msg *ptr, struct mqueue_inode_info *info)
+{
+	int k;
+
+	k = (info->attr.mq_curmsgs)-1;
+	while ((k >= 0) && (info->messages[k]->m_type >= ptr->m_type)) {
+		info->messages[k + 1] = info->messages[k];
+		k--;
+	}
+	(info->attr.mq_curmsgs)++;
+	info->messages[k + 1] = ptr;
+}
+
+static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
+{
+	return info->messages[--(info->attr.mq_curmsgs)];
+}
+
+/*
+ * The next function is only to split too long sys_mq_timedsend
+ */
+static inline void __do_notify(struct mqueue_inode_info *info)
+{
+	struct siginfo sig_i;
+	struct task_struct *p;
+
+	/* notification
+	 * invoked when there is registered process and there isn't process
+	 * waiting synchronously for message AND state of queue changed from
+	 * empty to not empty */
+	if ((info->notify.sigev_notify != SIGEV_NONE) && list_empty(&info->e_wait_q[RECV].list)
+	    && info->attr.mq_curmsgs == 1) {
+
+		sig_i.si_signo = info->notify.sigev_signo;
+		sig_i.si_errno = ERRNO_OK_SIGNAL;
+		sig_i.si_code = SI_MESGQ;
+		sig_i.si_value = info->notify.sigev_value;
+		sig_i.si_pid = current->tgid;
+		sig_i.si_uid = current->uid;
+
+		/* sends signal */
+		if (info->notify.sigev_notify == SIGEV_SIGNAL) {
+			kill_proc_info(info->notify.sigev_signo,
+				       &sig_i, info->notify_task);
+		} else  if (info->notify.sigev_notify == SIGEV_THREAD ||
+			    info->notify.sigev_notify == SIGEV_THREAD_ID) {
+			sig_i.si_errno = ERRNO_OK_THREAD;
+			read_lock(&tasklist_lock);
+			p = find_task_by_pid(info->notify_task);
+			if (p && (p->tgid == info->notify_owner))
+				send_sig_info(info->notify.sigev_signo, &sig_i, p);
+			read_unlock(&tasklist_lock);
+		}
+		/* after notification unregisters process */
+		info->notify_task = 0;
+		info->notify_owner = 0;
+		info->notify.sigev_signo = 0;
+		info->notify.sigev_notify = SIGEV_NONE;
+	}
+}
+
+static inline long prepare_timeout(const struct timespec __user *arg)
+{
+	struct timespec ts, nowts;
+	long timeout;
+
+	if (arg) {
+		if (copy_from_user(&ts, arg, sizeof(struct timespec)))
+			return -EFAULT;
+
+		if (ts.tv_nsec < 0 || ts.tv_sec < 0
+			|| ts.tv_nsec >= NSEC_PER_SEC)
+			return -EINVAL;
+		nowts = CURRENT_TIME;
+		/* first subtract as jiffies can't be too big */
+		ts.tv_sec -= nowts.tv_sec;
+		if (ts.tv_nsec < nowts.tv_nsec) {
+			ts.tv_nsec += NSEC_PER_SEC;
+			ts.tv_sec--;
+		}
+		ts.tv_nsec -= nowts.tv_nsec;
+		if (ts.tv_sec < 0)
+			return 0;
+
+		timeout = timespec_to_jiffies(&ts) + 1;
+	} else
+		return MAX_SCHEDULE_TIMEOUT;
+
+	return timeout;
+}
+
+
+static inline void remove_notification(struct mqueue_inode_info *info)
+{
+	struct siginfo sig_i;
+	struct task_struct *p;
+
+	if (info->notify.sigev_notify == SIGEV_THREAD) {
+		/* cancel waiting thread */
+		sig_i.si_signo = info->notify.sigev_signo;
+		sig_i.si_errno = ERRNO_REMOVE_THREAD;
+		sig_i.si_code = SI_MESGQ;
+		sig_i.si_value = info->notify.sigev_value;
+		sig_i.si_pid = current->tgid;
+		sig_i.si_uid = current->uid;
+
+		read_lock(&tasklist_lock);
+		p = find_task_by_pid(info->notify_task);
+
+		if (p && (p->tgid == info->notify_owner))
+			send_sig_info(info->notify.sigev_signo, &sig_i, p);
+		read_unlock(&tasklist_lock);
+	}
+	info->notify_task = 0;
+	info->notify_owner = 0;
+	info->notify.sigev_signo = 0;
+	info->notify.sigev_notify = SIGEV_NONE;
+}
+
+/*
+ * Invoked when creating a new queue via sys_mq_open
+ */
+static struct file *do_create(struct dentry *dir, struct dentry *dentry,
+	     int oflag, mode_t mode, struct mq_attr __user *u_attr)
+{
+	struct file *filp;
+	struct inode *ino;
+	struct mqueue_inode_info *info;
+	struct msg_msg **msgs = NULL;
+	struct mq_attr attr;
+	int ret;
+
+	if (u_attr != NULL) {
+		if (copy_from_user(&attr, u_attr, sizeof(struct mq_attr)))
+			return ERR_PTR(-EFAULT);
+
+		if (attr.mq_maxmsg <= 0 || attr.mq_msgsize <= 0
+		    || attr.mq_maxmsg > msg_max || attr.mq_msgsize > msgsize_max)
+			return ERR_PTR(-EINVAL);
+		msgs = (struct msg_msg **)kmalloc(attr.mq_maxmsg * sizeof(struct msg_msg *), GFP_KERNEL);
+		if (!msgs)
+			return ERR_PTR(-ENOMEM);
+	}
+
+	ret = vfs_create(dir->d_inode, dentry, mode, NULL);
+	if (ret) {
+		if (msgs)
+			kfree(msgs);
+		return ERR_PTR(ret);
+	}
+
+	ino = dentry->d_inode;
+	info = MQUEUE_I(ino);
+	if (u_attr != NULL) {
+		info->attr.mq_maxmsg = attr.mq_maxmsg;
+		info->attr.mq_msgsize = attr.mq_msgsize;
+		kfree(info->messages);
+		info->messages = msgs;
+	}
+
+	filp = dentry_open(dentry, mqueue_mnt, oflag);
+	if (!IS_ERR(filp))
+		dget(dentry);
+
+	return filp;
+}
+
+/* opens existing queue */
+static struct file *do_open(struct dentry *dentry, int oflag)
+{
+	struct file *filp;
+	static int oflag2acc[O_ACCMODE] = { MAY_READ, MAY_WRITE, MAY_READ | MAY_WRITE };
+
+	if ((oflag & O_ACCMODE) == (O_RDWR | O_WRONLY))
+		return ERR_PTR(-EINVAL);
+
+	if (permission(dentry->d_inode, oflag2acc[oflag & O_ACCMODE], NULL))
+		return ERR_PTR(-EACCES);
+
+	filp = dentry_open(dentry, mqueue_mnt, oflag);
+
+	if (!IS_ERR(filp))
+		dget(dentry);
+
+	return filp;
+}
+
+asmlinkage long sys_mq_open(const char __user *u_name, int oflag, mode_t mode,
+	struct mq_attr __user *attr)
+{
+	struct dentry *dentry;
+	struct file *filp;
+	char   *name;
+	int    fd, error;
+
+	if (IS_ERR(name = getname(u_name)))
+		return PTR_ERR(name);
+
+	fd = get_unused_fd();
+	if (fd < 0)
+		goto out_putname;
+
+	down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	if (IS_ERR(dentry)) {
+		error = PTR_ERR(dentry);
+		goto out_err;
+	}
+	mntget(mqueue_mnt);
+
+	if (oflag & O_CREAT) {
+		if (dentry->d_inode) {	/* entry already exists */
+			filp = (oflag & O_EXCL) ? ERR_PTR(-EEXIST) : do_open(dentry, oflag);
+		} else {
+			filp = do_create(mqueue_mnt->mnt_root, dentry, oflag, mode, attr);
+		}
+	} else
+		filp = (dentry->d_inode) ? do_open(dentry, oflag) : ERR_PTR(-ENOENT);
+
+	dput(dentry);
+
+	if (IS_ERR(filp)) {
+		error = PTR_ERR(filp);
+		goto out_putfd;
+	}
+
+	fd_install(fd, filp);
+	goto out_upsem;
+
+out_putfd:
+	mntput(mqueue_mnt);
+	put_unused_fd(fd);
+out_err:
+	fd = error;
+out_upsem:
+	up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+out_putname:
+	putname(name);
+	return fd;
+}
+
+
+asmlinkage long sys_mq_unlink(const char __user *u_name)
+{
+	int err;
+	char *name;
+	struct dentry *dentry;
+	struct inode *ino = NULL;
+
+	name = getname(u_name);
+	if (IS_ERR(name))
+		return PTR_ERR(name);
+
+	down(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	dentry = lookup_one_len(name, mqueue_mnt->mnt_root, strlen(name));
+	if (IS_ERR(dentry)) {
+		err = PTR_ERR(dentry);
+		goto out_unlock;
+	}
+
+	if (!dentry->d_inode) {
+		err = -ENOENT;
+		goto out_unlock;
+	}
+
+	if (permission(dentry->d_inode, MAY_WRITE, NULL)) {
+		err = -EACCES;
+		goto out_err;
+	}
+	ino = dentry->d_inode;
+	if (ino)
+		atomic_inc(&ino->i_count);
+
+	err = vfs_unlink(dentry->d_parent->d_inode, dentry);
+out_err:
+	dput(dentry);
+
+out_unlock:
+	up(&mqueue_mnt->mnt_root->d_inode->i_sem);
+	putname(name);
+	if (ino)
+		iput(ino);
+
+	return err;
+}
+
+
+static long do_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+	size_t msg_len, unsigned int msg_prio, const long timeout)
+{
+	struct file *filp;
+	struct inode *ino;
+	struct ext_wait_queue *wq_ptr;
+	struct msg_msg *msg_ptr;
+	int ret;
+	struct mqueue_inode_info *info = MQUEUE_I(ino);
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	ino = filp->f_dentry->d_inode;
+	if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+		goto out_fput;
+	info = MQUEUE_I(ino);
+
+	if ((filp->f_flags & O_ACCMODE) == O_RDONLY)
+		goto out_fput;
+
+	/* first try to allocate memory, before doing anything with
+	 * existing queues */
+	msg_ptr = load_msg((void *)u_msg_ptr, msg_len);
+	if (IS_ERR(msg_ptr)) {
+		ret = PTR_ERR(msg_ptr);
+		goto out_fput;
+	}
+
+	/* This memory may be unnecessary but we must alloc it here
+	 * because of spinlock. kfree is called in wq_remove(_last) */
+	wq_ptr = kmalloc(sizeof(struct ext_wait_queue), GFP_KERNEL);
+	if (wq_ptr == NULL) {
+		ret = -ENOMEM;
+		goto out_free;
+	}
+
+	spin_lock(&info->lock);
+
+	if ((filp->f_flags & O_NONBLOCK) && (info->attr.mq_curmsgs == info->attr.mq_maxmsg)) {
+		ret = -EAGAIN;
+		goto out_1unlock;
+	}
+
+	if (msg_len > info->attr.mq_msgsize) {
+		ret = -EMSGSIZE;
+		goto out_1unlock;
+	}
+
+	/* checks if queue is full -> I'm waiting as O_NONBLOCK isn't
+	 * set then. mq_receive wakes up only 1 task */
+	if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
+		ret = wq_sleep(info, SEND, timeout, wq_ptr);
+		if (ret)
+			goto out_1unlock_nofree;
+	} else
+		kfree(wq_ptr);
+
+	/* adds message to the queue */
+	msg_ptr->m_ts = msg_len;
+	msg_ptr->m_type = msg_prio;
+
+	msg_insert(msg_ptr, info);
+
+	info->qsize += msg_len;
+	ino->i_atime = ino->i_mtime = ino->i_ctime = CURRENT_TIME;
+	__do_notify(info);
+
+	/* after sending message we must wake up (ONLY 1 no matter which) */
+	/* task sleeping in wq_wakeup() */
+	wake_up(&(info->wait_q2[SEND]));
+
+	/* wakes up task waiting for message */
+	wq_wakeup(info, RECV);
+
+	spin_unlock(&info->lock);
+	ret = 0;
+	goto out_fput;
+
+	/* I hate this goto convention... */
+out_1unlock:
+	kfree(wq_ptr);
+out_1unlock_nofree:
+	spin_unlock(&info->lock);
+out_free:
+	free_msg(msg_ptr);
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char __user *u_msg_ptr,
+	size_t msg_len, unsigned int msg_prio, const struct timespec __user *u_abs_timeout)
+{
+ 	long timeout;
+
+	if (msg_prio >= (unsigned long) MQ_PRIO_MAX)
+		return -EINVAL;
+
+	if ((timeout = prepare_timeout(u_abs_timeout)) < 0)
+		return timeout;
+	return do_mq_timedsend(mqdes, u_msg_ptr, msg_len, msg_prio, timeout);
+}
+
+
+static ssize_t do_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+	size_t msg_len, unsigned int __user *u_msg_prio, const long timeout)
+{
+	ssize_t ret;
+	struct msg_msg *msg_ptr;
+	struct file *filp;
+	struct inode *ino;
+	struct mqueue_inode_info *info;
+	struct ext_wait_queue *wq_ptr;
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	ino = filp->f_dentry->d_inode;
+	if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+		goto out_fput;
+	info = MQUEUE_I(ino);
+
+	if ((filp->f_flags & O_ACCMODE) == O_WRONLY)
+		goto out_fput;
+
+        /* The same as in send */
+	wq_ptr = kmalloc(sizeof(struct ext_wait_queue), GFP_KERNEL);
+	if (wq_ptr == NULL) {
+		ret = -ENOMEM;
+		goto out_fput;
+	}
+
+	spin_lock(&info->lock);
+
+	/* checks if O_NONBLOCK is set and queue is empty */
+	if ((filp->f_flags & O_NONBLOCK) && (info->attr.mq_curmsgs == 0)) {
+		ret = -EAGAIN;
+		goto out_1unlock;
+	}
+
+	/* checks if buffer is big enough */
+	if (msg_len < info->attr.mq_msgsize) {
+		ret = -EMSGSIZE;
+		goto out_1unlock;
+	}
+
+	/* checks if queue is empty -> as O_NONBLOCK isn't set then
+	 * we must wait */
+	if (info->attr.mq_curmsgs == 0) {
+		ret = wq_sleep(info, RECV, timeout, wq_ptr);
+		if (ret < 0)
+			goto out_unlock_only;
+	} else
+		kfree(wq_ptr);
+
+	msg_ptr = msg_get(info);
+	ret = msg_ptr->m_ts;
+
+	info->qsize -= ret;
+	ino->i_atime = ino->i_mtime = ino->i_ctime = CURRENT_TIME;
+
+	/* after receive we can wakeup 1 task waiting in wq_wakeup */
+	wake_up(&(info->wait_q2[RECV]));
+	/* wakes up task waiting for sending message */
+	wq_wakeup(info, SEND);
+
+	spin_unlock(&info->lock);
+
+	if (u_msg_prio) {
+		if (put_user(msg_ptr->m_type, u_msg_prio)) {
+			ret = -EFAULT;
+			goto out_2free;
+		}
+        }
+	if (store_msg(u_msg_ptr, msg_ptr, msg_ptr->m_ts))
+		ret = -EFAULT;
+
+out_2free:
+	free_msg(msg_ptr);
+	goto out_fput;
+out_1unlock:
+	kfree(wq_ptr);
+out_unlock_only:
+	spin_unlock(&info->lock);
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char __user *u_msg_ptr,
+	size_t msg_len, unsigned int __user *u_msg_prio,
+	const struct timespec __user *u_abs_timeout)
+{
+	long timeout;
+
+	if ((timeout = prepare_timeout(u_abs_timeout)) < 0)
+		return timeout;
+	return do_mq_timedreceive(mqdes, u_msg_ptr, msg_len, u_msg_prio, timeout);
+}
+
+
+/* Notes: the case when user wants us to deregister (with NULL as pointer or SIGEV_NONE)
+ * and he isn't currently owner of notification will be silently discarded.
+ * It isn't explicitly defined in the POSIX.
+ */
+asmlinkage long sys_mq_notify(mqd_t mqdes, const struct sigevent __user *u_notification)
+{
+	int ret;
+	struct file *filp;
+	struct inode *ino;
+	struct sigevent notification;
+	struct mqueue_inode_info *info;
+
+	if (u_notification != NULL) {
+		if (copy_from_user(&notification, u_notification, sizeof(struct sigevent)))
+			return -EFAULT;
+
+		if (unlikely(notification.sigev_notify != SIGEV_NONE &&
+			     notification.sigev_notify != SIGEV_SIGNAL &&
+			     notification.sigev_notify != SIGEV_THREAD))
+			return -EINVAL;
+	}
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	ino = filp->f_dentry->d_inode;
+	if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+		goto out_fput;
+	info = MQUEUE_I(ino);
+
+	ret = 0;
+	spin_lock(&info->lock);
+
+	if (u_notification == NULL || notification.sigev_notify == SIGEV_NONE) {
+		if (info->notify_owner == current->tgid)
+			remove_notification(info);
+		goto out_unlock;
+	}
+
+	if (info->notify_task) {
+		ret = -EBUSY;
+		goto out_unlock;
+	}
+	/* add notification */
+	if (notification.sigev_signo < 0 || notification.sigev_signo > _NSIG)
+		ret = -EINVAL;
+	else {
+		info->notify_task = current->pid;
+		info->notify_owner = current->tgid;
+		info->notify.sigev_signo = notification.sigev_signo;
+		info->notify.sigev_notify = notification.sigev_notify;
+		info->notify.sigev_value = notification.sigev_value;
+	}
+out_unlock:
+	ino->i_atime = ino->i_ctime = CURRENT_TIME;
+	spin_unlock(&info->lock);
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+asmlinkage long sys_mq_getattr(mqd_t mqdes, struct mq_attr __user *u_mqstat)
+{
+	int ret;
+	struct mq_attr attr;
+	struct file *filp;
+	struct inode *ino;
+	struct mqueue_inode_info *info;
+
+	if (u_mqstat == NULL)
+		return -EINVAL;
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	ino = filp->f_dentry->d_inode;
+	if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+		goto out_fput;
+	info = MQUEUE_I(ino);
+
+	spin_lock(&info->lock);
+	attr = info->attr;
+	attr.mq_flags = filp->f_flags;
+	ino->i_atime = ino->i_ctime = CURRENT_TIME;
+
+	spin_unlock(&info->lock);
+
+	ret = 0;
+	if (copy_to_user(u_mqstat, &attr, sizeof(struct mq_attr)))
+		ret = -EFAULT;
+
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+asmlinkage long sys_mq_setattr(mqd_t mqdes, const struct mq_attr __user *u_mqstat,
+	struct mq_attr __user *u_omqstat)
+{
+	int ret;
+	struct mq_attr mqstat, omqstat;
+	struct file *filp;
+	struct inode *ino;
+	struct mqueue_inode_info *info;
+
+	if (u_mqstat == NULL)
+		return -EINVAL;
+
+	if (copy_from_user(&mqstat, u_mqstat, sizeof (struct mq_attr)))
+		return -EFAULT;
+
+	ret = -EBADF;
+	filp = fget(mqdes);
+	if (!filp)
+		goto out;
+
+	ino = filp->f_dentry->d_inode;
+	if (ino->i_sb->s_magic != MQUEUE_MAGIC)
+		goto out_fput;
+	info = MQUEUE_I(ino);
+
+	spin_lock(&info->lock);
+
+	omqstat = info->attr;
+	omqstat.mq_flags = filp->f_flags;
+
+	if (mqstat.mq_flags & O_NONBLOCK)
+		filp->f_flags |= O_NONBLOCK;
+	else
+		filp->f_flags &= ~O_NONBLOCK;
+
+	ino->i_atime = ino->i_ctime = CURRENT_TIME;
+
+	spin_unlock(&info->lock);
+
+	ret = 0;
+	if (u_omqstat != NULL && copy_to_user(u_omqstat, &omqstat, sizeof(struct mq_attr)))
+		ret = -EFAULT;
+
+out_fput:
+	fput(filp);
+out:
+	return ret;
+}
+
+
+static struct inode_operations mqueue_dir_inode_operations = {
+	.lookup = mqueue_lookup,
+	.create = mqueue_create,
+	.unlink = mqueue_unlink,
+};
+
+static struct file_operations mqueue_file_operations = {
+	.release = mqueue_release_file,
+	.poll = mqueue_poll_file,
+	.read = mqueue_read_file,
+};
+
+static struct super_operations mqueue_super_ops = {
+	.alloc_inode = mqueue_alloc_inode,
+	.destroy_inode = mqueue_destroy_inode,
+	.statfs = simple_statfs,
+	.delete_inode = mqueue_delete_inode,
+	.drop_inode = generic_delete_inode,
+};
+
+static struct file_system_type mqueue_fs_type = {
+	.name = "mqueue",
+	.get_sb = mqueue_get_sb,
+	.kill_sb = kill_litter_super,
+};
+
+static ctl_table mq_sysctls[] = {
+	{
+		.ctl_name	= CTL_QUEUESMAX,
+		.procname	= "queues_max",
+		.data		= &queues_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= CTL_MSGMAX,
+		.procname	= "msg_max",
+		.data		= &msg_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{
+		.ctl_name	= CTL_MSGSIZEMAX,
+		.procname	= "msgsize_max",
+		.data		= &msgsize_max,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec,
+	},
+	{ .ctl_name = 0 }
+};
+
+static ctl_table mq_sysctl_dir[] = {
+	{
+		.ctl_name	= FS_MQUEUE,
+		.procname	= "mqueue",
+		.mode		= 0555,
+		.child		= mq_sysctls,
+	},
+	{ .ctl_name = 0 }
+};
+
+static ctl_table mq_sysctl_root[] = {
+	{
+		.ctl_name	= CTL_FS,
+		.procname	= "fs",
+		.mode		= 0555,
+		.child		= mq_sysctl_dir,
+	},
+	{ .ctl_name = 0 }
+};
+
+
+static int __init init_mqueue_fs(void)
+{
+	int error;
+
+	mqueue_inode_cachep = kmem_cache_create("mqueue_inode_cache",
+		sizeof(struct mqueue_inode_info), 0, SLAB_HWCACHE_ALIGN, init_once, NULL);
+
+	if (mqueue_inode_cachep == NULL)
+		return -ENOMEM;
+
+	mq_sysctl_table = register_sysctl_table(mq_sysctl_root, 0);
+	if (!mq_sysctl_table) {
+		error = -ENOMEM;
+		goto out_inodecache;
+	}
+
+	error = register_filesystem(&mqueue_fs_type);
+	if (error)
+		goto out_inodecache;
+
+	if (IS_ERR(mqueue_mnt = kern_mount(&mqueue_fs_type))) {
+		unregister_filesystem(&mqueue_fs_type);
+		unregister_sysctl_table(mq_sysctl_table);
+		error = PTR_ERR(mqueue_mnt);
+		goto out_inodecache;
+	}
+
+	/* internal initialization - not common for vfs */
+	queues_count = 0;
+	spin_lock_init(&mq_lock);
+
+	return 0;
+
+out_inodecache:
+	if (kmem_cache_destroy(mqueue_inode_cachep))
+		printk(KERN_INFO "mqueue_inode_cache: not all structures were freed\n");
+	return error;
+}
+
+static void __exit exit_mqueue_fs(void)
+{
+	unregister_filesystem(&mqueue_fs_type);
+	unregister_sysctl_table(mq_sysctl_table);
+
+	if (kmem_cache_destroy(mqueue_inode_cachep))
+		printk(KERN_INFO "mqueue_inode_cache: not all structures were freed\n");
+}
+
+__initcall(init_mqueue_fs);
diff -urN 2.6.0-test10-orig_2/ipc/util.c 2.6.0-test10-patched_2/ipc/util.c
--- 2.6.0-test10-orig_2/ipc/util.c	2003-11-21 17:11:17.000000000 +0100
+++ 2.6.0-test10-patched_2/ipc/util.c	2003-11-24 17:47:23.000000000 +0100
@@ -24,10 +24,13 @@
 #include <linux/security.h>
 #include <linux/rcupdate.h>
 #include <linux/workqueue.h>
+#include <linux/mqueue.h>
 
-#if defined(CONFIG_SYSVIPC)
-
+#if defined(CONFIG_SYSVIPC) || defined(CONFIG_POSIX_MQUEUE_FS)
 #include "util.h"
+#endif
+
+#if defined(CONFIG_SYSVIPC)
 
 /**
  *	ipc_init	-	initialise IPC subsystem
@@ -612,7 +615,7 @@
 
 #endif /* CONFIG_SYSVIPC */
 
-#ifdef CONFIG_SYSVIPC
+#if defined(CONFIG_POSIX_MQUEUE_FS) || defined(CONFIG_SYSVIPC)
 
 void free_msg(struct msg_msg* msg)
 {
@@ -714,4 +717,51 @@
 	return 0;
 }
 
-#endif /* CONFIG_SYSVIPC */
+#endif /* CONFIG_POSIX_MQUEUE_FS || CONFIG_SYSVIPC */
+
+#if !defined(CONFIG_POSIX_MQUEUE_FS)
+
+/*
+ * Return ENOSYS when posix mqueue filesystem is not compiled in
+ */
+
+asmlinkage long sys_mq_open(const char *name, int oflag, mode_t mode,
+	struct mq_attr *attr)
+{
+	return (mqd_t)-ENOSYS;
+}
+
+asmlinkage long sys_mq_unlink(const char *name)
+{
+	return -ENOSYS;
+}
+
+asmlinkage long sys_mq_timedsend(mqd_t mqdes, const char *msg_ptr,
+	size_t msg_len, unsigned int msg_prio, const struct timespec *abs_timeout)
+{
+	return -ENOSYS;
+}
+
+asmlinkage ssize_t sys_mq_timedreceive(mqd_t mqdes, char *msg_ptr,
+	size_t msg_len, unsigned int *msg_prio, const struct timespec *abs_timeout)
+{
+	return -ENOSYS;
+}
+
+asmlinkage long sys_mq_notify(mqd_t mqdes, const struct sigevent *notification)
+{
+	return -ENOSYS;
+}
+
+asmlinkage long sys_mq_getattr(mqd_t mqdes, struct mq_attr *mqstat)
+{
+	return -ENOSYS;
+}
+
+asmlinkage long sys_mq_setattr(mqd_t mqdes, const struct mq_attr *mqstat,
+	struct mq_attr *omqstat)
+{
+	return -ENOSYS;
+}
+
+#endif /* ! CONFIG_POSIX_MQUEUE_FS */
diff -urN 2.6.0-test10-orig_2/kernel/signal.c 2.6.0-test10-patched_2/kernel/signal.c
--- 2.6.0-test10-orig_2/kernel/signal.c	2003-11-24 16:28:58.000000000 +0100
+++ 2.6.0-test10-patched_2/kernel/signal.c	2003-11-24 16:51:48.000000000 +0100
@@ -2044,6 +2044,7 @@
 		err |= __put_user(from->si_stime, &to->si_stime);
 		break;
 	case __SI_RT: /* This is not generated by the kernel as of now. */
+	case __SI_MESGQ: /* But this is */
 		err |= __put_user(from->si_pid, &to->si_pid);
 		err |= __put_user(from->si_uid, &to->si_uid);
 		err |= __put_user(from->si_int, &to->si_int);