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author | David Sterba <dsterba@suse.com> | 2015-02-16 19:41:40 +0100 |
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committer | David Sterba <dsterba@suse.com> | 2015-10-10 18:42:00 +0200 |
commit | ee86395458072760d62e66aad10a5e9e8902b8cf (patch) | |
tree | b3293bde46967a886b5d066028c5eceebd810dac /fs/btrfs/inode.c | |
parent | 779adf0f647651f5a45eeee3442c881300ce989e (diff) |
btrfs: comment the rest of implicit barriers before waitqueue_active
There are atomic operations that imply the barrier for waitqueue_active
mixed in an if-condition.
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/inode.c')
-rw-r--r-- | fs/btrfs/inode.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 611b66d73e80..7be4abe25e06 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1096,6 +1096,9 @@ static noinline void async_cow_submit(struct btrfs_work *work) nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >> PAGE_CACHE_SHIFT; + /* + * atomic_sub_return implies a barrier for waitqueue_active + */ if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) < 5 * 1024 * 1024 && waitqueue_active(&root->fs_info->async_submit_wait)) |