From 8b293a26940ddcb5991a4a959accf5cd40e11c39 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Thu, 3 Nov 2011 18:52:11 +0100
Subject: [PATCH] --- yaml --- r: 273815 b: refs/heads/master c:
 6dd9ad7df2019b1e33a372a501907db293ebcd0d h: refs/heads/master i:   273813:
 f0ceca1773b3c7d847d87c55022ba37cc17cc5d7   273811:
 f371116b29874cd6337bf859f5da675f25573c39   273807:
 f78d240958d78d7432774bc8663f1cefea7e9736 v: v3

---
 [refs]                 | 2 +-
 trunk/block/blk-core.c | 9 +++++++--
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index d6604fef7737..ab0385408e14 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 334c2b0b8b2ab186fa198413386cba41fffcb4f2
+refs/heads/master: 6dd9ad7df2019b1e33a372a501907db293ebcd0d
diff --git a/trunk/block/blk-core.c b/trunk/block/blk-core.c
index f65871116404..f43c8a5840ae 100644
--- a/trunk/block/blk-core.c
+++ b/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);