+ /*
+ * On suspend dm_stop_queue() handles stopping the blk-mq
+ * request_queue BUT: even though the hw_queues are marked
+ * BLK_MQ_S_STOPPED at that point there is still a race that
+ * is allowing block/blk-mq.c to call ->queue_rq against a
+ * hctx that it really shouldn't. The following check guards
+ * against this rarity (albeit _not_ race-free).
+ */
+ if (unlikely(test_bit(BLK_MQ_S_STOPPED, &hctx->state)))
+ return BLK_MQ_RQ_QUEUE_BUSY;
+