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| author | David Sterba <dsterba@suse.com> | 2015-02-16 19:36:47 +0100 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2015-10-10 18:40:04 +0200 |
| commit | a83342aa0c8f0ca90057d3837ae8d198186e5153 (patch) | |
| tree | 723d60098638e0f048ae630399d2f77d0e1a0c9d /fs/btrfs/locking.c | |
| parent | 33a9eca7e4a4c2c17aebbb11f0e506a48ebc30c9 (diff) | |
btrfs: add comments to barriers before waitqueue_active
Reduce number of undocumented barriers out there.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/locking.c')
| -rw-r--r-- | fs/btrfs/locking.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/locking.c b/fs/btrfs/locking.c index d7e6baf1b205..03f8630dbaf2 100644 --- a/fs/btrfs/locking.c +++ b/fs/btrfs/locking.c @@ -280,6 +280,9 @@ void btrfs_tree_unlock(struct extent_buffer *eb) if (blockers) { WARN_ON(atomic_read(&eb->spinning_writers)); atomic_dec(&eb->blocking_writers); + /* + * Make sure counter is updated before we wake up waiters. + */ smp_mb(); if (waitqueue_active(&eb->write_lock_wq)) wake_up(&eb->write_lock_wq); |