diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 41a3ccf..8f660dd 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1315,6 +1315,8 @@
 		.reason			= reason,
 	};
 
+	if (sb->s_bdi == &noop_backing_dev_info)
+		return;
 	WARN_ON(!rwsem_is_locked(&sb->s_umount));
 	bdi_queue_work(sb->s_bdi, &work);
 	wait_for_completion(&done);
@@ -1398,6 +1400,9 @@
 		.reason		= WB_REASON_SYNC,
 	};
 
+	/* Nothing to do? */
+	if (sb->s_bdi == &noop_backing_dev_info)
+		return;
 	WARN_ON(!rwsem_is_locked(&sb->s_umount));
 
 	bdi_queue_work(sb->s_bdi, &work);
diff --git a/fs/sync.c b/fs/sync.c
index 11e3d1c..b3d2a00 100644
--- a/fs/sync.c
+++ b/fs/sync.c
@@ -29,13 +29,6 @@
  */
 static int __sync_filesystem(struct super_block *sb, int wait)
 {
-	/*
-	 * This should be safe, as we require bdi backing to actually
-	 * write out data in the first place
-	 */
-	if (sb->s_bdi == &noop_backing_dev_info)
-		return 0;
-
 	if (sb->s_qcop && sb->s_qcop->quota_sync)
 		sb->s_qcop->quota_sync(sb, -1, wait);