diff options
| author | Nick Piggin <npiggin@suse.de> | 2009-01-06 14:40:26 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-01-24 16:41:52 -0800 |
| commit | d2845ee1312cf822ab0d04b91e80a3cfb1d9166f (patch) | |
| tree | a7d6eab81bab1c73b2836c7dab9804c428922f25 | |
| parent | e782d5e42a1ada8df4aa0665d9f21f1ddbc24320 (diff) | |
fs: sys_sync fix
commit 856bf4d717feb8c55d4e2f817b71ebb70cfbc67b upstream.
s_syncing livelock avoidance was breaking data integrity guarantee of
sys_sync, by allowing sys_sync to skip writing or waiting for superblocks
if there is a concurrent sys_sync happening.
This livelock avoidance is much less important now that we don't have the
get_super_to_sync() call after every sb that we sync. This was replaced
by __put_super_and_need_restart.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | fs/fs-writeback.c | 20 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
2 files changed, 1 insertions, 20 deletions
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c index a9ee474f969..e5eaa62fd17 100644 --- a/fs/fs-writeback.c +++ b/fs/fs-writeback.c @@ -652,18 +652,6 @@ void sync_inodes_sb(struct super_block *sb, int wait) sync_sb_inodes(sb, &wbc); } -/* - * Rather lame livelock avoidance. - */ -static void set_sb_syncing(int val) -{ - struct super_block *sb; - spin_lock(&sb_lock); - list_for_each_entry_reverse(sb, &super_blocks, s_list) - sb->s_syncing = val; - spin_unlock(&sb_lock); -} - /** * sync_inodes - writes all inodes to disk * @wait: wait for completion @@ -690,9 +678,6 @@ static void __sync_inodes(int wait) spin_lock(&sb_lock); restart: list_for_each_entry(sb, &super_blocks, s_list) { - if (sb->s_syncing) - continue; - sb->s_syncing = 1; sb->s_count++; spin_unlock(&sb_lock); down_read(&sb->s_umount); @@ -710,13 +695,10 @@ restart: void sync_inodes(int wait) { - set_sb_syncing(0); __sync_inodes(0); - if (wait) { - set_sb_syncing(0); + if (wait) __sync_inodes(1); - } } /** diff --git a/include/linux/fs.h b/include/linux/fs.h index efeff3dd95c..4b9192497b9 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1124,7 +1124,6 @@ struct super_block { struct rw_semaphore s_umount; struct mutex s_lock; int s_count; - int s_syncing; int s_need_sync_fs; atomic_t s_active; #ifdef CONFIG_SECURITY |