1 files changed, 1 insertions, 3 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 2d65c52b0944..97baf00b40d1 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1007,9 +1007,7 @@ 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(nr_pages, &root->fs_info->async_delalloc_pages);
-
-        if (atomic_read(&root->fs_info->async_delalloc_pages) <
+        if (atomic_sub_return(nr_pages, &root->fs_info->async_delalloc_pages) <
             5 * 1024 * 1024 &&
             waitqueue_active(&root->fs_info->async_submit_wait))
                 wake_up(&root->fs_info->async_submit_wait);