On 09/27/2016 09:31 AM, Steve Wise wrote:

quoted

@@ -2079,11 +2075,15 @@ EXPORT_SYMBOL_GPL(nvme_kill_queues);
 void nvme_stop_queues(struct nvme_ctrl *ctrl)
 {
 	struct nvme_ns *ns;
+	struct request_queue *q;

 	mutex_lock(&ctrl->namespaces_mutex);
 	list_for_each_entry(ns, &ctrl->namespaces, list) {
-		blk_mq_cancel_requeue_work(ns->queue);
-		blk_mq_stop_hw_queues(ns->queue);
+		q = ns->queue;
+		blk_quiesce_queue(q);
+		blk_mq_cancel_requeue_work(q);
+		blk_mq_stop_hw_queues(q);
+		blk_resume_queue(q);
 	}
 	mutex_unlock(&ctrl->namespaces_mutex);

Hey Bart, should nvme_stop_queues() really be resuming the blk queue?

Hello Steve,

Would you perhaps prefer that blk_resume_queue(q) is called from 
nvme_start_queues()? I think that would make the NVMe code harder to 
review. The above code won't cause any unexpected side effects if an 
NVMe namespace is removed after nvme_stop_queues() has been called and 
before nvme_start_queues() is called. Moving the blk_resume_queue(q) 
call into nvme_start_queues() will only work as expected if no 
namespaces are added nor removed between the nvme_stop_queues() and 
nvme_start_queues() calls. I'm not familiar enough with the NVMe code to 
know whether or not this change is safe ...

Bart.