diff options
| -rw-r--r-- | fs/super.c | 85 | ||||
| -rw-r--r-- | fs/sync.c | 85 | ||||
| -rw-r--r-- | include/linux/fs.h | 3 |
3 files changed, 86 insertions, 87 deletions
diff --git a/fs/super.c b/fs/super.c index c8ce5ed0424..f822c74f25b 100644 --- a/fs/super.c +++ b/fs/super.c @@ -283,42 +283,6 @@ void unlock_super(struct super_block * sb) EXPORT_SYMBOL(lock_super); EXPORT_SYMBOL(unlock_super); -/* - * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0) - * just dirties buffers with inodes so we have to submit IO for these buffers - * via __sync_blockdev(). This also speeds up the wait == 1 case since in that - * case write_inode() functions do sync_dirty_buffer() and thus effectively - * write one block at a time. - */ -static int __fsync_super(struct super_block *sb, int wait) -{ - vfs_dq_sync(sb); - sync_inodes_sb(sb, wait); - lock_super(sb); - if (sb->s_dirt && sb->s_op->write_super) - sb->s_op->write_super(sb); - unlock_super(sb); - if (sb->s_op->sync_fs) - sb->s_op->sync_fs(sb, wait); - return __sync_blockdev(sb->s_bdev, wait); -} - -/* - * Write out and wait upon all dirty data associated with this - * superblock. Filesystem data as well as the underlying block - * device. Takes the superblock lock. - */ -int fsync_super(struct super_block *sb) -{ - int ret; - - ret = __fsync_super(sb, 0); - if (ret < 0) - return ret; - return __fsync_super(sb, 1); -} -EXPORT_SYMBOL_GPL(fsync_super); - /** * generic_shutdown_super - common helper for ->kill_sb() * @sb: superblock to kill @@ -473,55 +437,6 @@ restart: spin_unlock(&sb_lock); } -/* - * Sync all the data for all the filesystems (called by sys_sync() and - * emergency sync) - * - * This operation is careful to avoid the livelock which could easily happen - * if two or more filesystems are being continuously dirtied. s_need_sync - * is used only here. We set it against all filesystems and then clear it as - * we sync them. So redirtied filesystems are skipped. - * - * But if process A is currently running sync_filesystems and then process B - * calls sync_filesystems as well, process B will set all the s_need_sync - * flags again, which will cause process A to resync everything. Fix that with - * a local mutex. - */ -void sync_filesystems(int wait) -{ - struct super_block *sb; - static DEFINE_MUTEX(mutex); - - mutex_lock(&mutex); /* Could be down_interruptible */ - spin_lock(&sb_lock); - list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_flags & MS_RDONLY) - continue; - sb->s_need_sync = 1; - } - -restart: - list_for_each_entry(sb, &super_blocks, s_list) { - if (!sb->s_need_sync) - continue; - sb->s_need_sync = 0; - if (sb->s_flags & MS_RDONLY) - continue; /* hm. Was remounted r/o meanwhile */ - sb->s_count++; - spin_unlock(&sb_lock); - down_read(&sb->s_umount); - if (sb->s_root) - __fsync_super(sb, wait); - up_read(&sb->s_umount); - /* restart only when sb is no longer on the list */ - spin_lock(&sb_lock); - if (__put_super_and_need_restart(sb)) - goto restart; - } - spin_unlock(&sb_lock); - mutex_unlock(&mutex); -} - /** * get_super - get the superblock of a device * @bdev: device to get the superblock for diff --git a/fs/sync.c b/fs/sync.c index be0798cc33d..d5fa7b79982 100644 --- a/fs/sync.c +++ b/fs/sync.c @@ -18,6 +18,91 @@ #define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ SYNC_FILE_RANGE_WAIT_AFTER) +/* + * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0) + * just dirties buffers with inodes so we have to submit IO for these buffers + * via __sync_blockdev(). This also speeds up the wait == 1 case since in that + * case write_inode() functions do sync_dirty_buffer() and thus effectively + * write one block at a time. + */ +static int __fsync_super(struct super_block *sb, int wait) +{ + vfs_dq_sync(sb); + sync_inodes_sb(sb, wait); + lock_super(sb); + if (sb->s_dirt && sb->s_op->write_super) + sb->s_op->write_super(sb); + unlock_super(sb); + if (sb->s_op->sync_fs) + sb->s_op->sync_fs(sb, wait); + return __sync_blockdev(sb->s_bdev, wait); +} + +/* + * Write out and wait upon all dirty data associated with this + * superblock. Filesystem data as well as the underlying block + * device. Takes the superblock lock. + */ +int fsync_super(struct super_block *sb) +{ + int ret; + + ret = __fsync_super(sb, 0); + if (ret < 0) + return ret; + return __fsync_super(sb, 1); +} +EXPORT_SYMBOL_GPL(fsync_super); + +/* + * Sync all the data for all the filesystems (called by sys_sync() and + * emergency sync) + * + * This operation is careful to avoid the livelock which could easily happen + * if two or more filesystems are being continuously dirtied. s_need_sync + * is used only here. We set it against all filesystems and then clear it as + * we sync them. So redirtied filesystems are skipped. + * + * But if process A is currently running sync_filesystems and then process B + * calls sync_filesystems as well, process B will set all the s_need_sync + * flags again, which will cause process A to resync everything. Fix that with + * a local mutex. + */ +static void sync_filesystems(int wait) +{ + struct super_block *sb; + static DEFINE_MUTEX(mutex); + + mutex_lock(&mutex); /* Could be down_interruptible */ + spin_lock(&sb_lock); + list_for_each_entry(sb, &super_blocks, s_list) { + if (sb->s_flags & MS_RDONLY) + continue; + sb->s_need_sync = 1; + } + +restart: + list_for_each_entry(sb, &super_blocks, s_list) { + if (!sb->s_need_sync) + continue; + sb->s_need_sync = 0; + if (sb->s_flags & MS_RDONLY) + continue; /* hm. Was remounted r/o meanwhile */ + sb->s_count++; + spin_unlock(&sb_lock); + down_read(&sb->s_umount); + if (sb->s_root) + __fsync_super(sb, wait); + up_read(&sb->s_umount); + /* restart only when sb is no longer on the list */ + spin_lock(&sb_lock); + if (__put_super_and_need_restart(sb)) + goto restart; + } + spin_unlock(&sb_lock); + mutex_unlock(&mutex); +} + SYSCALL_DEFINE0(sync) { sync_filesystems(0); diff --git a/include/linux/fs.h b/include/linux/fs.h index f00df653cf2..d3f7159993c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1942,7 +1942,6 @@ extern struct super_block *freeze_bdev(struct block_device *); extern void emergency_thaw_all(void); extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); extern int fsync_bdev(struct block_device *); -extern int fsync_super(struct super_block *); extern int fsync_no_super(struct block_device *); #else static inline void bd_forget(struct inode *inode) {} @@ -1959,6 +1958,7 @@ static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb) return 0; } #endif +extern int fsync_super(struct super_block *); extern const struct file_operations def_blk_fops; extern const struct file_operations def_chr_fops; extern const struct file_operations bad_sock_fops; @@ -2077,7 +2077,6 @@ extern int filemap_fdatawrite_range(struct address_space *mapping, extern int vfs_fsync(struct file *file, struct dentry *dentry, int datasync); extern void sync_supers(void); -extern void sync_filesystems(int wait); extern void emergency_sync(void); extern void emergency_remount(void); extern int do_remount_sb(struct super_block *sb, int flags, |