nvmf: Delay allocating rdma requests until CONNECT capsule.

The queue type and queue depth are not known until
the connect capsule is processed. Delay allocating more
than 1 recv wqe until then.

Change-Id: I0e68c24bc3d6f37043946de6c2cbcb3198cd5d1b
Signed-off-by: Ben Walker <benjamin.walker@intel.com>

lib/nvmf/rdma.c

@@ -155,6 +155,15 @@ free_rdma_req(struct spdk_nvmf_rdma_request *rdma_req)
 	rte_free(rdma_req);
 }
 
+void
+spdk_nvmf_rdma_free_req(struct spdk_nvmf_request *req)
+{
+	struct spdk_nvmf_rdma_request *rdma_req = get_rdma_req(req);
+
+	STAILQ_REMOVE(&req->conn->rdma.rdma_reqs, rdma_req, spdk_nvmf_rdma_request, link);
+	free_rdma_req(rdma_req);
+}
+
 void
 spdk_nvmf_rdma_free_reqs(struct spdk_nvmf_conn *conn)
 {
@@ -270,8 +279,10 @@ nvmf_rdma_conn_cleanup(struct spdk_nvmf_conn *conn)
 static void
 nvmf_trace_ibv_sge(struct ibv_sge *sg_list)
 {
+	if (sg_list) {
 		SPDK_TRACELOG(SPDK_TRACE_RDMA, "local addr %p length 0x%x lkey 0x%x\n",
 			      (void *)sg_list->addr, sg_list->length, sg_list->lkey);
+	}
 }
 
 static void
@@ -494,6 +505,7 @@ nvmf_rdma_connect(struct rdma_cm_event *event)
 	struct spdk_nvmf_fabric_intf	*fabric_intf;
 	struct rdma_cm_id		*conn_id;
 	struct spdk_nvmf_conn		*conn;
+	struct spdk_nvmf_rdma_request	*rdma_req;
 	struct ibv_device_attr		ibdev_attr;
 	struct sockaddr_in		*addr;
 	struct rdma_conn_param		*host_event_data = NULL;
@@ -591,13 +603,15 @@ nvmf_rdma_connect(struct rdma_cm_event *event)
 
 	STAILQ_INIT(&conn->rdma.rdma_reqs);
 
-	/* Allocate Buffers */
+	/* Allocate 1 buffer suitable for the CONNECT capsule.
-	rc = spdk_nvmf_rdma_alloc_reqs(conn);
+	 * Once that is received, the full queue depth will be allocated.
-	if (rc) {
+	 */
-		SPDK_ERRLOG("Unable to allocate connection RDMA requests\n");
+	rdma_req = alloc_rdma_req(conn);
+	if (nvmf_post_rdma_recv(conn, &rdma_req->req)) {
+		SPDK_ERRLOG("Unable to post connection rx desc\n");
 		goto err1;
 	}
-	SPDK_TRACELOG(SPDK_TRACE_DEBUG, "RDMA requests allocated\n");
+	STAILQ_INSERT_TAIL(&conn->rdma.rdma_reqs, rdma_req, link);
 
 	rc = spdk_nvmf_startup_conn(conn);
 	if (rc) {

lib/nvmf/rdma.h

@@ -81,6 +81,7 @@ int spdk_nvmf_rdma_request_release(struct spdk_nvmf_conn *conn,
 int nvmf_rdma_init(void);
 int spdk_nvmf_rdma_alloc_reqs(struct spdk_nvmf_conn *conn);
 void spdk_nvmf_rdma_free_reqs(struct spdk_nvmf_conn *conn);
+void spdk_nvmf_rdma_free_req(struct spdk_nvmf_request *req);
 void nvmf_rdma_conn_cleanup(struct spdk_nvmf_conn *conn);
 
 int nvmf_acceptor_start(void);

lib/nvmf/request.c

@@ -73,6 +73,21 @@ spdk_nvmf_request_complete(struct spdk_nvmf_request *req)
 int
 spdk_nvmf_request_release(struct spdk_nvmf_request *req)
 {
+	struct spdk_nvme_cmd *cmd = &req->cmd->nvme_cmd;
+	struct spdk_nvmf_capsule_cmd *capsule;
+
+	if (cmd->opc == SPDK_NVME_OPC_FABRIC) {
+		capsule = &req->cmd->nvmf_cmd;
+		if (capsule->fctype == SPDK_NVMF_FABRIC_COMMAND_CONNECT) {
+			/* Special case: connect is always the first capsule and new
+			 * work queue entries are allocated in response to this command.
+			 * Instead of re-posting this entry, just free it.
+			 */
+			spdk_nvmf_rdma_free_req(req);
+			return 0;
+		}
+	}
+
 	return spdk_nvmf_rdma_request_release(req->conn, req);
 }
 
@@ -433,6 +448,13 @@ nvmf_process_connect(struct spdk_nvmf_request *req)
 		}
 	}
 
+	/* Allocate RDMA reqs according to the queue depth and conn type*/
+	if (spdk_nvmf_rdma_alloc_reqs(conn)) {
+		SPDK_ERRLOG("Unable to allocate sufficient RDMA work requests\n");
+		req->rsp->nvme_cpl.status.sc = SPDK_NVME_SC_INTERNAL_DEVICE_ERROR;
+		return true;
+	}
+
 	SPDK_TRACELOG(SPDK_TRACE_NVMF, "connect capsule response: cntlid = 0x%04x\n",
 		      response->status_code_specific.success.cntlid);
 	return true;