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| author | Nick Piggin <npiggin@suse.de> | 2009-01-06 14:40:26 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-06 15:59:09 -0800 |
| commit | 856bf4d717feb8c55d4e2f817b71ebb70cfbc67b (patch) | |
| tree | f44790d9b8f42223955d1866645103ac5f9c68a3 | |
| parent | 38f21977663126fef53f5585e7f1653d8ebe55c4 (diff) | |
| download | linux-856bf4d717feb8c55d4e2f817b71ebb70cfbc67b.tar.gz linux-856bf4d717feb8c55d4e2f817b71ebb70cfbc67b.tar.bz2 linux-856bf4d717feb8c55d4e2f817b71ebb70cfbc67b.zip | |
fs: sys_sync fix
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>
| -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 a9ee474f9691..e5eaa62fd17f 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 fb59673c60b1..d7eba77f666e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1133,7 +1133,6 @@ 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 |