X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=fs%2Fbtrfs%2Fvolumes.c;h=cc1cc355904576bc5a1ee08f169cf287b6cc3ffb;hb=6db4a7335dd701a0e20275440ee057d3db2a7ae3;hp=dd644d7677821ab90544db5f8fbd0b763dde389f;hpb=62fb50ab7c903357c92cef2f7677235b92ac575f;p=cascardo%2Flinux.git

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index dd644d767782..cc1cc3559045 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -344,6 +344,9 @@ loop_lock:
 		pending = pending->bi_next;
 		cur->bi_next = NULL;
 
+		/*
+		 * atomic_dec_return implies a barrier for waitqueue_active
+		 */
 		if (atomic_dec_return(&fs_info->nr_async_bios) < limit &&
 		    waitqueue_active(&fs_info->async_submit_wait))
 			wake_up(&fs_info->async_submit_wait);