nvme: avoid to use blk_mq_abort_requeue_list()

NVMe may add request into requeue list simply and not kick off the
requeue if hw queues are stopped. Then blk_mq_abort_requeue_list()
is called in both nvme_kill_queues() and nvme_ns_remove() for
dealing with this issue.

Unfortunately blk_mq_abort_requeue_list() is absolutely a
race maker, for example, one request may be requeued during
the aborting. So this patch just calls blk_mq_kick_requeue_list() in
nvme_kill_queues() to handle this issue like what nvme_start_queues()
does. Now all requests in requeue list when queues are stopped will be
handled by blk_mq_kick_requeue_list() when queues are restarted, either
in nvme_start_queues() or in nvme_kill_queues().

Cc: stable@vger.kernel.org
Reported-by: Zhang Yi <yizhan@redhat.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -2098,7 +2098,6 @@ static void nvme_ns_remove(struct nvme_ns *ns)
 		if (ns->ndev)
 			nvme_nvm_unregister_sysfs(ns);
 		del_gendisk(ns->disk);
-		blk_mq_abort_requeue_list(ns->queue);
 		blk_cleanup_queue(ns->queue);
 	}
 
@@ -2436,7 +2435,6 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl)
 			continue;
 		revalidate_disk(ns->disk);
 		blk_set_queue_dying(ns->queue);
-		blk_mq_abort_requeue_list(ns->queue);
 
 		/*
 		 * Forcibly start all queues to avoid having stuck requests.
@@ -2444,6 +2442,9 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl)
 		 * when the final removal happens.
 		 */
 		blk_mq_start_hw_queues(ns->queue);
+
+		/* draining requests in requeue list */
+		blk_mq_kick_requeue_list(ns->queue);
 	}
 	mutex_unlock(&ctrl->namespaces_mutex);
 }