nvme-pci: unquiesce admin queue on shutdown

Just like IO queues, the admin queue also will not be restarted after a
controller shutdown. Unquiesce this queue so that we do not block
request dispatch on a permanently disabled controller.

Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/pci.c

@@ -2437,8 +2437,11 @@ static void nvme_dev_disable(struct nvme_dev *dev, bool shutdown)
 	 * must flush all entered requests to their failed completion to avoid
 	 * deadlocking blk-mq hot-cpu notifier.
 	 */
-	if (shutdown)
+	if (shutdown) {
 		nvme_start_queues(&dev->ctrl);
+		if (dev->ctrl.admin_q && !blk_queue_dying(dev->ctrl.admin_q))
+			blk_mq_unquiesce_queue(dev->ctrl.admin_q);
+	}
 	mutex_unlock(&dev->shutdown_lock);
 }