nvme: untangle 0 and BLK_MQ_RQ_QUEUE_OK

Let's not depend on any of the BLK_MQ_RQ_QUEUE_* constants having
specific values. No functional change.
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

drivers/nvme/host/core.c

@@ -269,7 +269,7 @@ static inline int nvme_setup_discard(struct nvme_ns *ns, struct request *req,
 	 */
 	req->__data_len = nr_bytes;
 
-	return 0;
+	return BLK_MQ_RQ_QUEUE_OK;
 }
 
 static inline void nvme_setup_rw(struct nvme_ns *ns, struct request *req,
@@ -317,7 +317,7 @@ static inline void nvme_setup_rw(struct nvme_ns *ns, struct request *req,
 int nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 		struct nvme_command *cmd)
 {
-	int ret = 0;
+	int ret = BLK_MQ_RQ_QUEUE_OK;
 
 	if (req->cmd_type == REQ_TYPE_DRV_PRIV)
 		memcpy(cmd, nvme_req(req)->cmd, sizeof(*cmd));

drivers/nvme/host/pci.c

@@ -328,7 +328,7 @@ static int nvme_init_iod(struct request *rq, unsigned size,
 		rq->retries = 0;
 		rq->rq_flags |= RQF_DONTPREP;
 	}
-	return 0;
+	return BLK_MQ_RQ_QUEUE_OK;
 }
 
 static void nvme_free_iod(struct nvme_dev *dev, struct request *req)
@@ -598,17 +598,17 @@ static int nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 	map_len = nvme_map_len(req);
 	ret = nvme_init_iod(req, map_len, dev);
-	if (ret)
+	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		return ret;
 
 	ret = nvme_setup_cmd(ns, req, &cmnd);
-	if (ret)
+	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		goto out;
 
 	if (req->nr_phys_segments)
 		ret = nvme_map_data(dev, req, map_len, &cmnd);
 
-	if (ret)
+	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		goto out;
 
 	cmnd.common.command_id = req->tag;

drivers/nvme/host/rdma.c

@@ -1395,7 +1395,7 @@ static int nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 			sizeof(struct nvme_command), DMA_TO_DEVICE);
 
 	ret = nvme_setup_cmd(ns, rq, c);
-	if (ret)
+	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		return ret;
 
 	c->common.command_id = rq->tag;

drivers/nvme/target/loop.c

@@ -169,7 +169,7 @@ static int nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	int ret;
 
 	ret = nvme_setup_cmd(ns, req, &iod->cmd);
-	if (ret)
+	if (ret != BLK_MQ_RQ_QUEUE_OK)
 		return ret;
 
 	iod->cmd.common.flags |= NVME_CMD_SGL_METABUF;
@@ -179,7 +179,7 @@ static int nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 		nvme_cleanup_cmd(req);
 		blk_mq_start_request(req);
 		nvme_loop_queue_response(&iod->req);
-		return 0;
+		return BLK_MQ_RQ_QUEUE_OK;
 	}
 
 	if (blk_rq_bytes(req)) {
@@ -198,7 +198,7 @@ static int nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	blk_mq_start_request(req);
 
 	schedule_work(&iod->work);
-	return 0;
+	return BLK_MQ_RQ_QUEUE_OK;
 }
 
 static void nvme_loop_submit_async_event(struct nvme_ctrl *arg, int aer_idx)