nvme: use driver pdu command for passthrough

All nvme transport drivers preallocate an nvme command for each request.
Assume to use that command for nvme_setup_cmd() instead of requiring
drivers pass a pointer to it. All nvme drivers must initialize the
generic nvme_request 'cmd' to point to the transport's preallocated
nvme_command.

The generic nvme_request cmd pointer had previously been used only as a
temporary copy for passthrough commands. Since it now points to the
command that gets dispatched, passthrough commands must directly set it
up prior to executing the request.

Signed-off-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -575,6 +575,9 @@ EXPORT_SYMBOL_NS_GPL(nvme_put_ns, NVME_TARGET_PASSTHRU);
 
 static inline void nvme_clear_nvme_request(struct request *req)
 {
+	struct nvme_command *cmd = nvme_req(req)->cmd;
+
+	memset(cmd, 0, sizeof(*cmd));
 	nvme_req(req)->retries = 0;
 	nvme_req(req)->flags = 0;
 	req->rq_flags |= RQF_DONTPREP;
@@ -593,9 +596,12 @@ static inline void nvme_init_request(struct request *req,
 	else /* no queuedata implies admin queue */
 		req->timeout = NVME_ADMIN_TIMEOUT;
 
+	/* passthru commands should let the driver set the SGL flags */
+	cmd->common.flags &= ~NVME_CMD_SGL_ALL;
+
 	req->cmd_flags |= REQ_FAILFAST_DRIVER;
 	nvme_clear_nvme_request(req);
-	nvme_req(req)->cmd = cmd;
+	memcpy(nvme_req(req)->cmd, cmd, sizeof(*cmd));
 }
 
 struct request *nvme_alloc_request(struct request_queue *q,
@@ -724,14 +730,6 @@ static void nvme_assign_write_stream(struct nvme_ctrl *ctrl,
 		req->q->write_hints[streamid] += blk_rq_bytes(req) >> 9;
 }
 
-static inline void nvme_setup_passthrough(struct request *req,
-		struct nvme_command *cmd)
-{
-	memcpy(cmd, nvme_req(req)->cmd, sizeof(*cmd));
-	/* passthru commands should let the driver set the SGL flags */
-	cmd->common.flags &= ~NVME_CMD_SGL_ALL;
-}
-
 static inline void nvme_setup_flush(struct nvme_ns *ns,
 		struct nvme_command *cmnd)
 {
@@ -886,19 +884,18 @@ void nvme_cleanup_cmd(struct request *req)
 }
 EXPORT_SYMBOL_GPL(nvme_cleanup_cmd);
 
-blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
-		struct nvme_command *cmd)
+blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req)
 {
+	struct nvme_command *cmd = nvme_req(req)->cmd;
 	blk_status_t ret = BLK_STS_OK;
 
 	if (!(req->rq_flags & RQF_DONTPREP))
 		nvme_clear_nvme_request(req);
 
-	memset(cmd, 0, sizeof(*cmd));
 	switch (req_op(req)) {
 	case REQ_OP_DRV_IN:
 	case REQ_OP_DRV_OUT:
-		nvme_setup_passthrough(req, cmd);
+		/* these are setup prior to execution in nvme_init_request() */
 		break;
 	case REQ_OP_FLUSH:
 		nvme_setup_flush(ns, cmd);

drivers/nvme/host/fc.c

@@ -2128,6 +2128,7 @@ nvme_fc_init_request(struct blk_mq_tag_set *set, struct request *rq,
 	op->op.fcp_req.first_sgl = op->sgl;
 	op->op.fcp_req.private = &op->priv[0];
 	nvme_req(rq)->ctrl = &ctrl->ctrl;
+	nvme_req(rq)->cmd = &op->op.cmd_iu.sqe;
 	return res;
 }
 
@@ -2759,8 +2760,6 @@ nvme_fc_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct nvme_fc_ctrl *ctrl = queue->ctrl;
 	struct request *rq = bd->rq;
 	struct nvme_fc_fcp_op *op = blk_mq_rq_to_pdu(rq);
-	struct nvme_fc_cmd_iu *cmdiu = &op->cmd_iu;
-	struct nvme_command *sqe = &cmdiu->sqe;
 	enum nvmefc_fcp_datadir	io_dir;
 	bool queue_ready = test_bit(NVME_FC_Q_LIVE, &queue->flags);
 	u32 data_len;
@@ -2770,7 +2769,7 @@ nvme_fc_queue_rq(struct blk_mq_hw_ctx *hctx,
 	    !nvmf_check_ready(&queue->ctrl->ctrl, rq, queue_ready))
 		return nvmf_fail_nonready_command(&queue->ctrl->ctrl, rq);
 
-	ret = nvme_setup_cmd(ns, rq, sqe);
+	ret = nvme_setup_cmd(ns, rq);
 	if (ret)
 		return ret;
 

drivers/nvme/host/nvme.h

@@ -623,8 +623,7 @@ void nvme_start_freeze(struct nvme_ctrl *ctrl);
 struct request *nvme_alloc_request(struct request_queue *q,
 		struct nvme_command *cmd, blk_mq_req_flags_t flags);
 void nvme_cleanup_cmd(struct request *req);
-blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
-		struct nvme_command *cmd);
+blk_status_t nvme_setup_cmd(struct nvme_ns *ns, struct request *req);
 int nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 		void *buf, unsigned bufflen);
 int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,

drivers/nvme/host/pci.c

@@ -430,6 +430,7 @@ static int nvme_init_request(struct blk_mq_tag_set *set, struct request *req,
 	iod->nvmeq = nvmeq;
 
 	nvme_req(req)->ctrl = &dev->ctrl;
+	nvme_req(req)->cmd = &iod->cmd;
 	return 0;
 }
 
@@ -932,7 +933,7 @@ static blk_status_t nvme_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (unlikely(!test_bit(NVMEQ_ENABLED, &nvmeq->flags)))
 		return BLK_STS_IOERR;
 
-	ret = nvme_setup_cmd(ns, req, cmnd);
+	ret = nvme_setup_cmd(ns, req);
 	if (ret)
 		return ret;
 

drivers/nvme/host/rdma.c

@@ -314,6 +314,7 @@ static int nvme_rdma_init_request(struct blk_mq_tag_set *set,
 			NVME_RDMA_DATA_SGL_SIZE;
 
 	req->queue = queue;
+	nvme_req(rq)->cmd = req->sqe.data;
 
 	return 0;
 }
@@ -2038,7 +2039,7 @@ static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 	struct request *rq = bd->rq;
 	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
 	struct nvme_rdma_qe *sqe = &req->sqe;
-	struct nvme_command *c = sqe->data;
+	struct nvme_command *c = nvme_req(rq)->cmd;
 	struct ib_device *dev;
 	bool queue_ready = test_bit(NVME_RDMA_Q_LIVE, &queue->flags);
 	blk_status_t ret;
@@ -2061,7 +2062,7 @@ static blk_status_t nvme_rdma_queue_rq(struct blk_mq_hw_ctx *hctx,
 	ib_dma_sync_single_for_cpu(dev, sqe->dma,
 			sizeof(struct nvme_command), DMA_TO_DEVICE);
 
-	ret = nvme_setup_cmd(ns, rq, c);
+	ret = nvme_setup_cmd(ns, rq);
 	if (ret)
 		goto unmap_qe;
 

drivers/nvme/host/tcp.c

@@ -417,6 +417,7 @@ static int nvme_tcp_init_request(struct blk_mq_tag_set *set,
 {
 	struct nvme_tcp_ctrl *ctrl = set->driver_data;
 	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);
+	struct nvme_tcp_cmd_pdu *pdu;
 	int queue_idx = (set == &ctrl->tag_set) ? hctx_idx + 1 : 0;
 	struct nvme_tcp_queue *queue = &ctrl->queues[queue_idx];
 	u8 hdgst = nvme_tcp_hdgst_len(queue);
@@ -427,8 +428,10 @@ static int nvme_tcp_init_request(struct blk_mq_tag_set *set,
 	if (!req->pdu)
 		return -ENOMEM;
 
+	pdu = req->pdu;
 	req->queue = queue;
 	nvme_req(rq)->ctrl = &ctrl->ctrl;
+	nvme_req(rq)->cmd = &pdu->cmd;
 
 	return 0;
 }
@@ -2259,7 +2262,7 @@ static blk_status_t nvme_tcp_setup_cmd_pdu(struct nvme_ns *ns,
 	u8 hdgst = nvme_tcp_hdgst_len(queue), ddgst = 0;
 	blk_status_t ret;
 
-	ret = nvme_setup_cmd(ns, rq, &pdu->cmd);
+	ret = nvme_setup_cmd(ns, rq);
 	if (ret)
 		return ret;
 

drivers/nvme/target/loop.c

@@ -141,7 +141,7 @@ static blk_status_t nvme_loop_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (!nvmf_check_ready(&queue->ctrl->ctrl, req, queue_ready))
 		return nvmf_fail_nonready_command(&queue->ctrl->ctrl, req);
 
-	ret = nvme_setup_cmd(ns, req, &iod->cmd);
+	ret = nvme_setup_cmd(ns, req);
 	if (ret)
 		return ret;
 
@@ -205,8 +205,10 @@ static int nvme_loop_init_request(struct blk_mq_tag_set *set,
 		unsigned int numa_node)
 {
 	struct nvme_loop_ctrl *ctrl = set->driver_data;
+	struct nvme_loop_iod *iod = blk_mq_rq_to_pdu(req);
 
 	nvme_req(req)->ctrl = &ctrl->ctrl;
+	nvme_req(req)->cmd = &iod->cmd;
 	return nvme_loop_init_iod(ctrl, blk_mq_rq_to_pdu(req),
 			(set == &ctrl->tag_set) ? hctx_idx + 1 : 0);
 }