Re: [PATCH 16/17] nvme: implement multipath access to nvme subsystems

[Sagi Grimberg]

  static inline bool nvme_req_needs_retry(struct request *req)
  {
        if (blk_noretry_request(req))
@@ -143,6 +204,11 @@ static inline bool nvme_req_needs_retry(struct request 
*req)
  void nvme_complete_rq(struct request *req)
  {
        if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
+               if (nvme_req_needs_failover(req)) {
+                       nvme_failover_req(req);
+                       return;
+               }
+
                nvme_req(req)->retries++;
                blk_mq_requeue_request(req, true);
                return;

Nit, consider having the !nvme_req_needs_failover() case in an else
clause, just a suggestion though.

@@ -171,6 +237,18 @@ void nvme_cancel_request(struct request *req, void *data, 
bool reserved)
  }
  EXPORT_SYMBOL_GPL(nvme_cancel_request);

Question,

Does the statement in nvme_cancel_request:

        if (blk_queue_dying(req->q))
                status |= NVME_SC_DNR;

still holds?