nvmf: add free_req function pointer.

At times, it may be necessary to free requests without completing them.
For example, when freeing a qpair, one needs to free the AER sent from
the host before deleting the qpair. It is important not to send a
completion for the AER because:
1. According to the spec, this will trigger the host to send another AER
2. No Asynchronous Events have occured, so we should not complete the
AER.

Change-Id: I92e163f0fed0ee2bc942569a647cb3c1967edec9
Signed-off-by: Seth Howell <seth.howell@intel.com>
Reviewed-on: https://review.gerrithub.io/419732
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>

lib/nvmf/nvmf_internal.h

@@ -268,6 +268,7 @@ int spdk_nvmf_poll_group_pause_subsystem(struct spdk_nvmf_poll_group *group,
 int spdk_nvmf_poll_group_resume_subsystem(struct spdk_nvmf_poll_group *group,
 		struct spdk_nvmf_subsystem *subsystem);
 void spdk_nvmf_request_exec(struct spdk_nvmf_request *req);
+int spdk_nvmf_request_free(struct spdk_nvmf_request *req);
 int spdk_nvmf_request_complete(struct spdk_nvmf_request *req);
 
 void spdk_nvmf_get_discovery_log_page(struct spdk_nvmf_tgt *tgt,

lib/nvmf/rdma.c

@@ -2390,6 +2390,29 @@ spdk_nvmf_rdma_poll_group_remove(struct spdk_nvmf_transport_poll_group *group,
 	return 0;
 }
 
+static int
+spdk_nvmf_rdma_request_free(struct spdk_nvmf_request *req)
+{
+	struct spdk_nvmf_rdma_request	*rdma_req = SPDK_CONTAINEROF(req, struct spdk_nvmf_rdma_request, req);
+	struct spdk_nvmf_rdma_transport	*rtransport = SPDK_CONTAINEROF(req->qpair->transport,
+			struct spdk_nvmf_rdma_transport, transport);
+
+	if (rdma_req->data_from_pool) {
+		/* Put the buffer/s back in the pool */
+		for (uint32_t i = 0; i < rdma_req->req.iovcnt; i++) {
+			spdk_mempool_put(rtransport->data_buf_pool, rdma_req->data.buffers[i]);
+			rdma_req->req.iov[i].iov_base = NULL;
+			rdma_req->data.buffers[i] = NULL;
+		}
+		rdma_req->data_from_pool = false;
+	}
+	rdma_req->req.length = 0;
+	rdma_req->req.iovcnt = 0;
+	rdma_req->req.data = NULL;
+	spdk_nvmf_rdma_request_set_state(rdma_req, RDMA_REQUEST_STATE_FREE);
+	return 0;
+}
+
 static int
 spdk_nvmf_rdma_request_complete(struct spdk_nvmf_request *req)
 {
@@ -2606,6 +2629,7 @@ const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
 	.poll_group_remove = spdk_nvmf_rdma_poll_group_remove,
 	.poll_group_poll = spdk_nvmf_rdma_poll_group_poll,
 
+	.req_free = spdk_nvmf_rdma_request_free,
 	.req_complete = spdk_nvmf_rdma_request_complete,
 
 	.qpair_fini = spdk_nvmf_rdma_close_qpair,

lib/nvmf/request.c

@@ -45,6 +45,35 @@
 #include "spdk_internal/assert.h"
 #include "spdk_internal/log.h"
 
+static void
+spdk_nvmf_qpair_request_cleanup(struct spdk_nvmf_qpair *qpair)
+{
+	if (qpair->state == SPDK_NVMF_QPAIR_DEACTIVATING) {
+		assert(qpair->state_cb != NULL);
+
+		if (TAILQ_EMPTY(&qpair->outstanding)) {
+			qpair->state_cb(qpair->state_cb_arg, 0);
+		}
+	} else {
+		assert(qpair->state == SPDK_NVMF_QPAIR_ACTIVE);
+	}
+}
+
+int
+spdk_nvmf_request_free(struct spdk_nvmf_request *req)
+{
+	struct spdk_nvmf_qpair *qpair = req->qpair;
+
+	TAILQ_REMOVE(&qpair->outstanding, req, link);
+	if (spdk_nvmf_transport_req_free(req)) {
+		SPDK_ERRLOG("Unable to free transport level request resources.\n");
+	}
+
+	spdk_nvmf_qpair_request_cleanup(qpair);
+
+	return 0;
+}
+
 int
 spdk_nvmf_request_complete(struct spdk_nvmf_request *req)
 {
@@ -67,16 +96,7 @@ spdk_nvmf_request_complete(struct spdk_nvmf_request *req)
 		SPDK_ERRLOG("Transport request completion error!\n");
 	}
 
-	if (qpair->state == SPDK_NVMF_QPAIR_DEACTIVATING) {
+	spdk_nvmf_qpair_request_cleanup(qpair);
-		assert(qpair->state_cb != NULL);
-
-		if (TAILQ_EMPTY(&qpair->outstanding)) {
-
-			qpair->state_cb(qpair->state_cb_arg, 0);
-		}
-	} else {
-		assert(qpair->state == SPDK_NVMF_QPAIR_ACTIVE);
-	}
 
 	return 0;
 }

lib/nvmf/transport.c

@@ -160,6 +160,12 @@ spdk_nvmf_transport_poll_group_poll(struct spdk_nvmf_transport_poll_group *group
 	return group->transport->ops->poll_group_poll(group);
 }
 
+int
+spdk_nvmf_transport_req_free(struct spdk_nvmf_request *req)
+{
+	return req->qpair->transport->ops->req_free(req);
+}
+
 int
 spdk_nvmf_transport_req_complete(struct spdk_nvmf_request *req)
 {

lib/nvmf/transport.h

@@ -114,6 +114,12 @@ struct spdk_nvmf_transport_ops {
 	 */
 	int (*poll_group_poll)(struct spdk_nvmf_transport_poll_group *group);
 
+	/*
+	 * Free the request without sending a response
+	 * to the originator. Release memory tied to this request.
+	 */
+	int (*req_free)(struct spdk_nvmf_request *req);
+
 	/*
 	 * Signal request completion, which sends a response
 	 * to the originator.
@@ -160,6 +166,8 @@ int spdk_nvmf_transport_poll_group_remove(struct spdk_nvmf_transport_poll_group
 
 int spdk_nvmf_transport_poll_group_poll(struct spdk_nvmf_transport_poll_group *group);
 
+int spdk_nvmf_transport_req_free(struct spdk_nvmf_request *req);
+
 int spdk_nvmf_transport_req_complete(struct spdk_nvmf_request *req);
 
 void spdk_nvmf_transport_qpair_fini(struct spdk_nvmf_qpair *qpair);

test/unit/lib/nvmf/ctrlr.c/ctrlr_ut.c

@@ -128,7 +128,7 @@ DEFINE_STUB(spdk_nvmf_request_complete,
 	    (struct spdk_nvmf_request *req),
 	    -1);
 
-DEFINE_STUB(spdk_nvmf_request_abort,
+DEFINE_STUB(spdk_nvmf_request_free,
 	    int,
 	    (struct spdk_nvmf_request *req),
 	    -1);

test/unit/lib/nvmf/request.c/request_ut.c

@@ -44,6 +44,12 @@ void spdk_trace_record(uint16_t tpoint_id, uint16_t poller_id, uint32_t size,
 {
 }
 
+int
+spdk_nvmf_transport_req_free(struct spdk_nvmf_request *req)
+{
+	return 0;
+}
+
 int
 spdk_nvmf_transport_req_complete(struct spdk_nvmf_request *req)
 {