diff -urNp linux-1253/fs/buffer.c linux-1255/fs/buffer.c --- linux-1253/fs/buffer.c +++ linux-1255/fs/buffer.c @@ -366,6 +366,34 @@ void sync_dev(kdev_t dev) fsync_dev(dev); } +int fsync_dev_lockfs(kdev_t dev) +{ + /* you are not allowed to try locking all the filesystems + ** on the system, your chances of getting through without + ** total deadlock are slim to none. + */ + if (!dev) + return fsync_dev(dev) ; + + sync_buffers(dev, 0); + + lock_kernel(); + /* note, the FS might need to start transactions to + ** sync the inodes, or the quota, no locking until + ** after these are done + */ + sync_inodes(dev); + DQUOT_SYNC_DEV(dev); + /* if inodes or quotas could be dirtied during the + ** sync_supers_lockfs call, the FS is responsible for getting + ** them on disk, without deadlocking against the lock + */ + sync_supers_lockfs(dev) ; + unlock_kernel(); + + return sync_buffers(dev, 1) ; +} + asmlinkage long sys_sync(void) { fsync_dev(0); diff -urNp linux-1253/fs/reiserfs/super.c linux-1255/fs/reiserfs/super.c --- linux-1253/fs/reiserfs/super.c +++ linux-1255/fs/reiserfs/super.c @@ -44,7 +44,7 @@ static void reiserfs_write_super_lockfs reiserfs_prepare_for_journal(s, SB_BUFFER_WITH_SB(s), 1); journal_mark_dirty(&th, s, SB_BUFFER_WITH_SB (s)); reiserfs_block_writes(&th) ; - journal_end(&th, s, 1) ; + journal_end_sync(&th, s, 1) ; } s->s_dirt = dirty; unlock_kernel() ; diff -urNp linux-1253/fs/super.c linux-1255/fs/super.c --- linux-1253/fs/super.c +++ linux-1255/fs/super.c @@ -38,6 +38,13 @@ LIST_HEAD(super_blocks); spinlock_t sb_lock = SPIN_LOCK_UNLOCKED; +/* + * lock/unlockfs grab a read lock on s_umount, but you need this lock to + * make sure no lockfs runs are in progress before inserting/removing + * supers from the list. + */ +static DECLARE_MUTEX(lockfs_sem); + /* * Handling of filesystem drivers list. * Rules: @@ -451,6 +458,19 @@ void drop_super(struct super_block *sb) put_super(sb); } +static void write_super_lockfs(struct super_block *sb) +{ + lock_super(sb); + if (sb->s_root && sb->s_op) { + if (sb->s_dirt && sb->s_op->write_super) + sb->s_op->write_super(sb); + if (sb->s_op->write_super_lockfs) { + sb->s_op->write_super_lockfs(sb); + } + } + unlock_super(sb); +} + static inline void write_super(struct super_block *sb) { lock_super(sb); @@ -498,6 +518,39 @@ restart: spin_unlock(&sb_lock); } +/* + * Note: don't check the dirty flag before waiting, we want the lock + * to happen every time this is called. dev must be non-zero + */ +void sync_supers_lockfs(kdev_t dev) +{ + struct super_block * sb; + + down(&lockfs_sem); + if (dev) { + sb = get_super(dev); + if (sb) { + write_super_lockfs(sb); + drop_super(sb); + } + } +} + +void unlockfs(kdev_t dev) +{ + struct super_block * sb; + + if (dev) { + sb = get_super(dev); + if (sb) { + if (sb->s_op && sb->s_op->unlockfs) + sb->s_op->unlockfs(sb) ; + drop_super(sb); + } + } + up(&lockfs_sem); +} + /** * get_super - get the superblock of a device * @dev: device to get the superblock for @@ -741,6 +794,7 @@ static struct super_block *get_sb_bdev(s goto out1; error = -EBUSY; + down(&lockfs_sem); restart: spin_lock(&sb_lock); @@ -751,11 +805,13 @@ restart: if (old->s_type != fs_type || ((flags ^ old->s_flags) & MS_RDONLY)) { spin_unlock(&sb_lock); + up(&lockfs_sem); destroy_super(s); goto out1; } if (!grab_super(old)) goto restart; + up(&lockfs_sem); destroy_super(s); blkdev_put(bdev, BDEV_FS); path_release(&nd); @@ -765,6 +821,7 @@ restart: s->s_bdev = bdev; s->s_flags = flags; insert_super(s, fs_type); + up(&lockfs_sem); if (!fs_type->read_super(s, data, flags & MS_VERBOSE ? 1 : 0)) goto Einval; s->s_flags |= MS_ACTIVE; @@ -872,7 +929,10 @@ void kill_super(struct super_block *sb) if (!deactivate_super(sb)) return; + down(&lockfs_sem); down_write(&sb->s_umount); + up(&lockfs_sem); + sb->s_root = NULL; /* Need to clean after the sucker */ if (fs->fs_flags & FS_LITTER) diff -urNp linux-1253/include/linux/fs.h linux-1255/include/linux/fs.h --- linux-1253/include/linux/fs.h +++ linux-1255/include/linux/fs.h @@ -1275,6 +1275,7 @@ extern void write_inode_now(struct inode extern int sync_buffers(kdev_t, int); extern void sync_dev(kdev_t); extern int fsync_dev(kdev_t); +extern int fsync_dev_lockfs(kdev_t); extern int fsync_super(struct super_block *); extern int fsync_no_super(kdev_t); extern void sync_inodes_sb(struct super_block *); @@ -1291,6 +1292,8 @@ extern int inode_has_buffers(struct inod extern int filemap_fdatasync(struct address_space *); extern int filemap_fdatawait(struct address_space *); extern void sync_supers(kdev_t); +extern void sync_supers_lockfs(kdev_t); +extern void unlockfs(kdev_t); extern int bmap(struct inode *, int); extern int notify_change(struct dentry *, struct iattr *); extern int permission(struct inode *, int); diff -urNp linux-1253/kernel/ksyms.c linux-1255/kernel/ksyms.c --- linux-1253/kernel/ksyms.c +++ linux-1255/kernel/ksyms.c @@ -208,6 +208,8 @@ EXPORT_SYMBOL(invalidate_device); EXPORT_SYMBOL(invalidate_inode_pages); EXPORT_SYMBOL(truncate_inode_pages); EXPORT_SYMBOL(fsync_dev); +EXPORT_SYMBOL_GPL(fsync_dev_lockfs); +EXPORT_SYMBOL_GPL(unlockfs); EXPORT_SYMBOL(fsync_no_super); EXPORT_SYMBOL(permission); EXPORT_SYMBOL(vfs_permission);