Merge branch 'for-linus' of git://git.kernel.dk/linux-block

* 'for-linus' of git://git.kernel.dk/linux-block:
  cfq-iosched: fix use-after-free of cfqq

block/cfq-iosched.c

@@ -3117,18 +3117,17 @@ cfq_should_preempt(struct cfq_data *cfqd, struct cfq_queue *new_cfqq,
  */
 static void cfq_preempt_queue(struct cfq_data *cfqd, struct cfq_queue *cfqq)
 {
-	struct cfq_queue *old_cfqq = cfqd->active_queue;
-
 	cfq_log_cfqq(cfqd, cfqq, "preempt");
-	cfq_slice_expired(cfqd, 1);
 
 	/*
 	 * workload type is changed, don't save slice, otherwise preempt
 	 * doesn't happen
 	 */
-	if (cfqq_type(old_cfqq) != cfqq_type(cfqq))
+	if (cfqq_type(cfqd->active_queue) != cfqq_type(cfqq))
 		cfqq->cfqg->saved_workload_slice = 0;
 
+	cfq_slice_expired(cfqd, 1);
+
 	/*
 	 * Put the new queue at the front of the of the current list,
 	 * so we know that it will be selected next.