diff --git a/[refs] b/[refs]
index 1b223bf5bacc..46dec2479f1b 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d340d2475c6e394013325f83f499594628a9e558
+refs/heads/master: bc178622d40d87e75abc131007342429c9b03351
diff --git a/trunk/fs/btrfs/volumes.c b/trunk/fs/btrfs/volumes.c
index 6b9cff42265d..5989a92236f7 100644
--- a/trunk/fs/btrfs/volumes.c
+++ b/trunk/fs/btrfs/volumes.c
@@ -684,6 +684,12 @@ int btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		__btrfs_close_devices(fs_devices);
 		free_fs_devices(fs_devices);
 	}
+	/*
+	 * Wait for rcu kworkers under __btrfs_close_devices
+	 * to finish all blkdev_puts so device is really
+	 * free when umount is done.
+	 */
+	rcu_barrier();
 	return ret;
 }