nvme: move the dying queue check from cancel to completion

With multipath we don't want a hard DNR bit on a request that is cancelled
by a controller reset, but instead want to be able to retry it on another
patch.  To archive this don't always set the DNR bit when the queue is
dying in nvme_cancel_request, but defer that decision to
nvme_req_needs_retry.  Note that it applies to any command there and not
just cancelled commands, but one the queue is dying that is the right
thing to do anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/nvme/host/core.c

@@ -172,6 +172,8 @@ static inline bool nvme_req_needs_retry(struct request *req)
 		return false;
 	if (nvme_req(req)->retries >= nvme_max_retries)
 		return false;
+	if (blk_queue_dying(req->q))
+		return false;
 	return true;
 }
 
@@ -189,18 +191,13 @@ EXPORT_SYMBOL_GPL(nvme_complete_rq);
 
 void nvme_cancel_request(struct request *req, void *data, bool reserved)
 {
-	int status;
-
 	if (!blk_mq_request_started(req))
 		return;
 
 	dev_dbg_ratelimited(((struct nvme_ctrl *) data)->device,
 				"Cancelling I/O %d", req->tag);
 
-	status = NVME_SC_ABORT_REQ;
-	if (blk_queue_dying(req->q))
-		status |= NVME_SC_DNR;
-	nvme_req(req)->status = status;
+	nvme_req(req)->status = NVME_SC_ABORT_REQ;
 	blk_mq_complete_request(req);
 
 }