---

yaml
---
r: 273815
b: refs/heads/master
c: 6dd9ad7
h: refs/heads/master
i:
  273813: f0ceca1
  273811: f371116
  273807: f78d240
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 334c2b0b8b2ab186fa198413386cba41fffcb4f2
+refs/heads/master: 6dd9ad7df2019b1e33a372a501907db293ebcd0d

trunk/block/blk-core.c

@@ -407,8 +407,13 @@ void blk_cleanup_queue(struct request_queue *q)
 	spin_unlock_irq(lock);
 	mutex_unlock(&q->sysfs_lock);
 
-	/* drain all requests queued before DEAD marking */
-	blk_drain_queue(q, true);
+	/*
+	 * Drain all requests queued before DEAD marking.  The caller might
+	 * be trying to tear down @q before its elevator is initialized, in
+	 * which case we don't want to call into draining.
+	 */
+	if (q->elevator)
+		blk_drain_queue(q, true);
 
 	/* @q won't process any more request, flush async actions */
 	del_timer_sync(&q->backing_dev_info.laptop_mode_wb_timer);