blk-mq: Avoid that request queue removal can trigger list corruption

KAGA-KOKO · axboe · commit aba7afc5671c · 2017-11-10T19:53:25.000-07:00
Avoid that removal of a request queue sporadically triggers the
following warning:

list_del corruption. next-&gt;prev should be ffff8807d649b970, but was 6b6b6b6b6b6b6b6b
WARNING: CPU: 3 PID: 342 at lib/list_debug.c:56 __list_del_entry_valid+0x92/0xa0
Call Trace:
 process_one_work+0x11b/0x660
 worker_thread+0x3d/0x3b0
 kthread+0x129/0x140
 ret_from_fork+0x27/0x40

Signed-off-by: Bart Van Assche &lt;bart.vanassche@wdc.com&gt;
Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Hannes Reinecke &lt;hare@suse.com&gt;
Cc: Johannes Thumshirn &lt;jthumshirn@suse.de&gt;
Signed-off-by: Jens Axboe &lt;axboe@kernel.dk&gt;
diff --git a/block/blk-core.c b/block/blk-core.c
@@ -339,6 +339,7 @@ void blk_sync_queue(struct request_queue *q)
 		struct blk_mq_hw_ctx *hctx;
 		int i;
 
+		cancel_delayed_work_sync(&q->requeue_work);
 		queue_for_each_hw_ctx(q, hctx, i)
 			cancel_delayed_work_sync(&hctx->run_work);
 	} else {
