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-rw-r--r--fs/super.c85
-rw-r--r--fs/sync.c85
-rw-r--r--include/linux/fs.h3
3 files changed, 86 insertions, 87 deletions
diff --git a/fs/super.c b/fs/super.c
index c8ce5ed04249..f822c74f25be 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -283,42 +283,6 @@ void unlock_super(struct super_block * sb)
283EXPORT_SYMBOL(lock_super); 283EXPORT_SYMBOL(lock_super);
284EXPORT_SYMBOL(unlock_super); 284EXPORT_SYMBOL(unlock_super);
285 285
286/*
287 * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0)
288 * just dirties buffers with inodes so we have to submit IO for these buffers
289 * via __sync_blockdev(). This also speeds up the wait == 1 case since in that
290 * case write_inode() functions do sync_dirty_buffer() and thus effectively
291 * write one block at a time.
292 */
293static int __fsync_super(struct super_block *sb, int wait)
294{
295 vfs_dq_sync(sb);
296 sync_inodes_sb(sb, wait);
297 lock_super(sb);
298 if (sb->s_dirt && sb->s_op->write_super)
299 sb->s_op->write_super(sb);
300 unlock_super(sb);
301 if (sb->s_op->sync_fs)
302 sb->s_op->sync_fs(sb, wait);
303 return __sync_blockdev(sb->s_bdev, wait);
304}
305
306/*
307 * Write out and wait upon all dirty data associated with this
308 * superblock. Filesystem data as well as the underlying block
309 * device. Takes the superblock lock.
310 */
311int fsync_super(struct super_block *sb)
312{
313 int ret;
314
315 ret = __fsync_super(sb, 0);
316 if (ret < 0)
317 return ret;
318 return __fsync_super(sb, 1);
319}
320EXPORT_SYMBOL_GPL(fsync_super);
321
322/** 286/**
323 * generic_shutdown_super - common helper for ->kill_sb() 287 * generic_shutdown_super - common helper for ->kill_sb()
324 * @sb: superblock to kill 288 * @sb: superblock to kill
@@ -473,55 +437,6 @@ restart:
473 spin_unlock(&sb_lock); 437 spin_unlock(&sb_lock);
474} 438}
475 439
476/*
477 * Sync all the data for all the filesystems (called by sys_sync() and
478 * emergency sync)
479 *
480 * This operation is careful to avoid the livelock which could easily happen
481 * if two or more filesystems are being continuously dirtied. s_need_sync
482 * is used only here. We set it against all filesystems and then clear it as
483 * we sync them. So redirtied filesystems are skipped.
484 *
485 * But if process A is currently running sync_filesystems and then process B
486 * calls sync_filesystems as well, process B will set all the s_need_sync
487 * flags again, which will cause process A to resync everything. Fix that with
488 * a local mutex.
489 */
490void sync_filesystems(int wait)
491{
492 struct super_block *sb;
493 static DEFINE_MUTEX(mutex);
494
495 mutex_lock(&mutex); /* Could be down_interruptible */
496 spin_lock(&sb_lock);
497 list_for_each_entry(sb, &super_blocks, s_list) {
498 if (sb->s_flags & MS_RDONLY)
499 continue;
500 sb->s_need_sync = 1;
501 }
502
503restart:
504 list_for_each_entry(sb, &super_blocks, s_list) {
505 if (!sb->s_need_sync)
506 continue;
507 sb->s_need_sync = 0;
508 if (sb->s_flags & MS_RDONLY)
509 continue; /* hm. Was remounted r/o meanwhile */
510 sb->s_count++;
511 spin_unlock(&sb_lock);
512 down_read(&sb->s_umount);
513 if (sb->s_root)
514 __fsync_super(sb, wait);
515 up_read(&sb->s_umount);
516 /* restart only when sb is no longer on the list */
517 spin_lock(&sb_lock);
518 if (__put_super_and_need_restart(sb))
519 goto restart;
520 }
521 spin_unlock(&sb_lock);
522 mutex_unlock(&mutex);
523}
524
525/** 440/**
526 * get_super - get the superblock of a device 441 * get_super - get the superblock of a device
527 * @bdev: device to get the superblock for 442 * @bdev: device to get the superblock for
diff --git a/fs/sync.c b/fs/sync.c
index be0798cc33d7..d5fa7b79982e 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -18,6 +18,91 @@
18#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \ 18#define VALID_FLAGS (SYNC_FILE_RANGE_WAIT_BEFORE|SYNC_FILE_RANGE_WRITE| \
19 SYNC_FILE_RANGE_WAIT_AFTER) 19 SYNC_FILE_RANGE_WAIT_AFTER)
20 20
21/*
22 * Do the filesystem syncing work. For simple filesystems sync_inodes_sb(sb, 0)
23 * just dirties buffers with inodes so we have to submit IO for these buffers
24 * via __sync_blockdev(). This also speeds up the wait == 1 case since in that
25 * case write_inode() functions do sync_dirty_buffer() and thus effectively
26 * write one block at a time.
27 */
28static int __fsync_super(struct super_block *sb, int wait)
29{
30 vfs_dq_sync(sb);
31 sync_inodes_sb(sb, wait);
32 lock_super(sb);
33 if (sb->s_dirt && sb->s_op->write_super)
34 sb->s_op->write_super(sb);
35 unlock_super(sb);
36 if (sb->s_op->sync_fs)
37 sb->s_op->sync_fs(sb, wait);
38 return __sync_blockdev(sb->s_bdev, wait);
39}
40
41/*
42 * Write out and wait upon all dirty data associated with this
43 * superblock. Filesystem data as well as the underlying block
44 * device. Takes the superblock lock.
45 */
46int fsync_super(struct super_block *sb)
47{
48 int ret;
49
50 ret = __fsync_super(sb, 0);
51 if (ret < 0)
52 return ret;
53 return __fsync_super(sb, 1);
54}
55EXPORT_SYMBOL_GPL(fsync_super);
56
57/*
58 * Sync all the data for all the filesystems (called by sys_sync() and
59 * emergency sync)
60 *
61 * This operation is careful to avoid the livelock which could easily happen
62 * if two or more filesystems are being continuously dirtied. s_need_sync
63 * is used only here. We set it against all filesystems and then clear it as
64 * we sync them. So redirtied filesystems are skipped.
65 *
66 * But if process A is currently running sync_filesystems and then process B
67 * calls sync_filesystems as well, process B will set all the s_need_sync
68 * flags again, which will cause process A to resync everything. Fix that with
69 * a local mutex.
70 */
71static void sync_filesystems(int wait)
72{
73 struct super_block *sb;
74 static DEFINE_MUTEX(mutex);
75
76 mutex_lock(&mutex); /* Could be down_interruptible */
77 spin_lock(&sb_lock);
78 list_for_each_entry(sb, &super_blocks, s_list) {
79 if (sb->s_flags & MS_RDONLY)
80 continue;
81 sb->s_need_sync = 1;
82 }
83
84restart:
85 list_for_each_entry(sb, &super_blocks, s_list) {
86 if (!sb->s_need_sync)
87 continue;
88 sb->s_need_sync = 0;
89 if (sb->s_flags & MS_RDONLY)
90 continue; /* hm. Was remounted r/o meanwhile */
91 sb->s_count++;
92 spin_unlock(&sb_lock);
93 down_read(&sb->s_umount);
94 if (sb->s_root)
95 __fsync_super(sb, wait);
96 up_read(&sb->s_umount);
97 /* restart only when sb is no longer on the list */
98 spin_lock(&sb_lock);
99 if (__put_super_and_need_restart(sb))
100 goto restart;
101 }
102 spin_unlock(&sb_lock);
103 mutex_unlock(&mutex);
104}
105
21SYSCALL_DEFINE0(sync) 106SYSCALL_DEFINE0(sync)
22{ 107{
23 sync_filesystems(0); 108 sync_filesystems(0);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f00df653cf2b..d3f7159993cf 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1942,7 +1942,6 @@ extern struct super_block *freeze_bdev(struct block_device *);
1942extern void emergency_thaw_all(void); 1942extern void emergency_thaw_all(void);
1943extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); 1943extern int thaw_bdev(struct block_device *bdev, struct super_block *sb);
1944extern int fsync_bdev(struct block_device *); 1944extern int fsync_bdev(struct block_device *);
1945extern int fsync_super(struct super_block *);
1946extern int fsync_no_super(struct block_device *); 1945extern int fsync_no_super(struct block_device *);
1947#else 1946#else
1948static inline void bd_forget(struct inode *inode) {} 1947static inline void bd_forget(struct inode *inode) {}
@@ -1959,6 +1958,7 @@ static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb)
1959 return 0; 1958 return 0;
1960} 1959}
1961#endif 1960#endif
1961extern int fsync_super(struct super_block *);
1962extern const struct file_operations def_blk_fops; 1962extern const struct file_operations def_blk_fops;
1963extern const struct file_operations def_chr_fops; 1963extern const struct file_operations def_chr_fops;
1964extern const struct file_operations bad_sock_fops; 1964extern const struct file_operations bad_sock_fops;
@@ -2077,7 +2077,6 @@ extern int filemap_fdatawrite_range(struct address_space *mapping,
2077 2077
2078extern int vfs_fsync(struct file *file, struct dentry *dentry, int datasync); 2078extern int vfs_fsync(struct file *file, struct dentry *dentry, int datasync);
2079extern void sync_supers(void); 2079extern void sync_supers(void);
2080extern void sync_filesystems(int wait);
2081extern void emergency_sync(void); 2080extern void emergency_sync(void);
2082extern void emergency_remount(void); 2081extern void emergency_remount(void);
2083extern int do_remount_sb(struct super_block *sb, int flags, 2082extern int do_remount_sb(struct super_block *sb, int flags,