nvme: introduce struct nvme_request

This adds a shared per-request structure for all NVMe I/O.  This structure
is embedded as the first member in all NVMe transport drivers request
private data and allows to implement common functionality between the
drivers.

The first use is to replace the current abuse of the SCSI command
passthrough fields in struct request for the NVMe command passthrough,
but it will grow a field more fields to allow implementing things
like common abort handlers in the future.

The passthrough commands are handled by having a pointer to the SQE
(struct nvme_command) in struct nvme_request, and the union of the
possible result fields, which had to be turned from an anonymous
into a named union for that purpose.  This avoids having to pass
a reference to a full CQE around and thus makes checking the result
a lot more lightweight.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Jens Axboe <axboe@fb.com>

1 files changed, 7 insertions, 7 deletions

diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c
index 9a97ae67e656..f4088198cd0d 100644
--- a/drivers/nvme/target/fabrics-cmd.c
+++ b/drivers/nvme/target/fabrics-cmd.c
@@ -69,7 +69,7 @@ static void nvmet_execute_prop_get(struct nvmet_req *req)
 		}
 	}
 
-	req->rsp->result64 = cpu_to_le64(val);
+	req->rsp->result.u64 = cpu_to_le64(val);
 	nvmet_req_complete(req, status);
 }
 
@@ -125,7 +125,7 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
 	d = kmap(sg_page(req->sg)) + req->sg->offset;
 
 	/* zero out initial completion result, assign values as needed */
-	req->rsp->result = 0;
+	req->rsp->result.u32 = 0;
 
 	if (c->recfmt != 0) {
 		pr_warn("invalid connect version (%d).\n",
@@ -138,7 +138,7 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
 		pr_warn("connect attempt for invalid controller ID %#x\n",
 			d->cntlid);
 		status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
-		req->rsp->result = IPO_IATTR_CONNECT_DATA(cntlid);
+		req->rsp->result.u32 = IPO_IATTR_CONNECT_DATA(cntlid);
 		goto out;
 	}
 
@@ -155,7 +155,7 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
 
 	pr_info("creating controller %d for NQN %s.\n",
 			ctrl->cntlid, ctrl->hostnqn);
-	req->rsp->result16 = cpu_to_le16(ctrl->cntlid);
+	req->rsp->result.u16 = cpu_to_le16(ctrl->cntlid);
 
 out:
 	kunmap(sg_page(req->sg));
@@ -173,7 +173,7 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
 	d = kmap(sg_page(req->sg)) + req->sg->offset;
 
 	/* zero out initial completion result, assign values as needed */
-	req->rsp->result = 0;
+	req->rsp->result.u32 = 0;
 
 	if (c->recfmt != 0) {
 		pr_warn("invalid connect version (%d).\n",
@@ -191,14 +191,14 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
 	if (unlikely(qid > ctrl->subsys->max_qid)) {
 		pr_warn("invalid queue id (%d)\n", qid);
 		status = NVME_SC_CONNECT_INVALID_PARAM | NVME_SC_DNR;
-		req->rsp->result = IPO_IATTR_CONNECT_SQE(qid);
+		req->rsp->result.u32 = IPO_IATTR_CONNECT_SQE(qid);
 		goto out_ctrl_put;
 	}
 
 	status = nvmet_install_queue(ctrl, req);
 	if (status) {
 		/* pass back cntlid that had the issue of installing queue */
-		req->rsp->result16 = cpu_to_le16(ctrl->cntlid);
+		req->rsp->result.u16 = cpu_to_le16(ctrl->cntlid);
 		goto out_ctrl_put;
 	}