nvme-fc: quiesce/unquiesce admin_q instead of start/stop its hw queues

unlike blk_mq_stop_hw_queues and blk_mq_start_stopped_hw_queues
quiescing/unquiescing respects the submission path rcu grace.

Also, make sure to unquiesce before cleanup the admin queue.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-By: James Smart <james.smart@broadcom.com>
Signed-off-by: Sagi Grimberg <sagi@grimberg.me>

drivers/nvme/host/fc.c

@@ -1703,6 +1703,7 @@ nvme_fc_ctrl_free(struct kref *ref)
 	list_del(&ctrl->ctrl_list);
 	spin_unlock_irqrestore(&ctrl->rport->lock, flags);
 
+	blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 	blk_cleanup_queue(ctrl->ctrl.admin_q);
 	blk_mq_free_tag_set(&ctrl->admin_tag_set);
 
@@ -2321,7 +2322,7 @@ nvme_fc_create_association(struct nvme_fc_ctrl *ctrl)
 		goto out_delete_hw_queue;
 
 	if (ctrl->ctrl.state != NVME_CTRL_NEW)
-		blk_mq_start_stopped_hw_queues(ctrl->ctrl.admin_q, true);
+		blk_mq_unquiesce_queue(ctrl->ctrl.admin_q);
 
 	ret = nvmf_connect_admin_queue(&ctrl->ctrl);
 	if (ret)
@@ -2475,7 +2476,7 @@ nvme_fc_delete_association(struct nvme_fc_ctrl *ctrl)
 	 * use blk_mq_tagset_busy_itr() and the transport routine to
 	 * terminate the exchanges.
 	 */
-	blk_mq_stop_hw_queues(ctrl->ctrl.admin_q);
+	blk_mq_quiesce_queue(ctrl->ctrl.admin_q);
 	blk_mq_tagset_busy_iter(&ctrl->admin_tag_set,
 				nvme_fc_terminate_exchange, &ctrl->ctrl);