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| author | Wang Shilong <wangsl.fnst@cn.fujitsu.com> | 2014-02-19 19:24:19 +0800 |
|---|---|---|
| committer | Josef Bacik <jbacik@fb.com> | 2014-03-10 15:16:54 -0400 |
| commit | 32a447896c7b4c5cf5502a3ca7f5ef57d498fb03 (patch) | |
| tree | 3ad2fb22832b927c3b7192f6d7f12bc6119ef7c8 /fs/btrfs/scrub.c | |
| parent | c0af8f0b1cf7ec5cde4450be9f8bfeb8c211d40a (diff) | |
| download | linux-32a447896c7b4c5cf5502a3ca7f5ef57d498fb03.tar.bz2 | |
Btrfs: wake up @scrub_pause_wait as much as we can
check if @scrubs_running=@scrubs_paused condition inside wait_event()
is not an atomic operation which means we may inc/dec @scrub_running/
paused at any time. Let's wake up @scrub_pause_wait as much as we can
to let commit transaction blocked less.
An example below:
Thread1 Thread2
|->scrub_blocked_if_needed() |->scrub_pending_trans_workers_inc
|->increase @scrub_paused
|->increase @scrub_running
|->wake up scrub_pause_wait list
|->scrub blocked
|->increase @scrub_paused
Thread3 is commiting transaction which is blocked at btrfs_scrub_pause().
So after Thread2 increase @scrub_paused, we meet the condition
@scrub_paused=@scrub_running, but transaction will be still blocked until
another calling to wake up @scrub_pause_wait.
Signed-off-by: Wang Shilong <wangsl.fnst@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Diffstat (limited to 'fs/btrfs/scrub.c')
| -rw-r--r-- | fs/btrfs/scrub.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index f2f8803ea79c..682ec3fca4a1 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -315,6 +315,16 @@ static void scrub_pending_trans_workers_inc(struct scrub_ctx *sctx) atomic_inc(&fs_info->scrubs_running); atomic_inc(&fs_info->scrubs_paused); mutex_unlock(&fs_info->scrub_lock); + + /* + * check if @scrubs_running=@scrubs_paused condition + * inside wait_event() is not an atomic operation. + * which means we may inc/dec @scrub_running/paused + * at any time. Let's wake up @scrub_pause_wait as + * much as we can to let commit transaction blocked less. + */ + wake_up(&fs_info->scrub_pause_wait); + atomic_inc(&sctx->workers_pending); } |