nvme: host: unquiesce queue in nvme_kill_queues()

When nvme_kill_queues() is run, queues may be in
quiesced state, so we forcibly unquiesce queues to avoid
blocking dispatch, and I/O hang can be avoided in
remove path.

Peviously we use blk_mq_start_stopped_hw_queues() as
counterpart of blk_mq_quiesce_queue(), now we have
introduced blk_mq_unquiesce_queue(), so use it explicitly.

Cc: linux-nvme@lists.infradead.org
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: Ming Lei

drivers/nvme/host/core.c

@@ -2581,6 +2581,9 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl)
 
 	mutex_lock(&ctrl->namespaces_mutex);
 
+	/* Forcibly unquiesce queues to avoid blocking dispatch */
+	blk_mq_unquiesce_queue(ctrl->admin_q);
+
 	/* Forcibly start all queues to avoid having stuck requests */
 	blk_mq_start_hw_queues(ctrl->admin_q);
 
@@ -2594,6 +2597,9 @@ void nvme_kill_queues(struct nvme_ctrl *ctrl)
 		revalidate_disk(ns->disk);
 		blk_set_queue_dying(ns->queue);
 
+		/* Forcibly unquiesce queues to avoid blocking dispatch */
+		blk_mq_unquiesce_queue(ns->queue);
+
 		/*
 		 * Forcibly start all queues to avoid having stuck requests.
 		 * Note that we must ensure the queues are not stopped