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| author | Josef Bacik <jbacik@fusionio.com> | 2012-08-01 15:36:24 -0400 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2012-08-28 16:53:33 -0400 |
| commit | 66657b318e0e443ada229fccd40c8be86cfebdbf (patch) | |
| tree | bf1334fff93556fbc8d82b26a6d5431fd9e74b5c /fs/btrfs/compression.c | |
| parent | 1fa11e265fa2562fb713171b6a58e72bb7afd276 (diff) | |
| download | linux-66657b318e0e443ada229fccd40c8be86cfebdbf.tar.bz2 | |
Btrfs: barrier before waitqueue_active
We need a barrir before calling waitqueue_active otherwise we will miss
wakeups. So in places that do atomic_dec(); then atomic_read() use
atomic_dec_return() which imply a memory barrier (see memory-barriers.txt)
and then add an explicit memory barrier everywhere else that need them.
Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Diffstat (limited to 'fs/btrfs/compression.c')
| -rw-r--r-- | fs/btrfs/compression.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 86eff48dab78..43d1c5a3a030 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -818,6 +818,7 @@ static void free_workspace(int type, struct list_head *workspace) btrfs_compress_op[idx]->free_workspace(workspace); atomic_dec(alloc_workspace); wake: + smp_mb(); if (waitqueue_active(workspace_wait)) wake_up(workspace_wait); } |