nvme/tcp: add naive implementation of poll_group api

This implementation simply loops over qpairs calling process_completions.

Signed-off-by: Seth Howell <seth.howell@intel.com>
Change-Id: Ia1f59c13444703e00c6b769d378874f48b9ef03e
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/627
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@mellanox.com>

lib/nvme/nvme_tcp.c

@@ -64,6 +64,10 @@ struct nvme_tcp_ctrlr {
 	struct spdk_nvme_ctrlr			ctrlr;
 };
 
+struct nvme_tcp_poll_group {
+	struct spdk_nvme_transport_poll_group group;
+};
+
 /* NVMe TCP qpair extensions for spdk_nvme_qpair */
 struct nvme_tcp_qpair {
 	struct spdk_nvme_qpair			qpair;
@@ -1709,7 +1713,14 @@ nvme_tcp_admin_qpair_abort_aers(struct spdk_nvme_qpair *qpair)
 static struct spdk_nvme_transport_poll_group *
 nvme_tcp_poll_group_create(void)
 {
-	return NULL;
+	struct nvme_tcp_poll_group *group = calloc(1, sizeof(*group));
+
+	if (group == NULL) {
+		SPDK_ERRLOG("Unable to allocate poll group.\n");
+		return NULL;
+	}
+
+	return &group->group;
 }
 
 static int
@@ -1728,27 +1739,50 @@ static int
 nvme_tcp_poll_group_add(struct spdk_nvme_transport_poll_group *tgroup,
 			struct spdk_nvme_qpair *qpair)
 {
-	return -ENOTSUP;
+	return 0;
 }
 
 static int
 nvme_tcp_poll_group_remove(struct spdk_nvme_transport_poll_group *tgroup,
 			   struct spdk_nvme_qpair *qpair)
 {
-	return -ENOTSUP;
+	return 0;
 }
 
 static int64_t
 nvme_tcp_poll_group_process_completions(struct spdk_nvme_transport_poll_group *tgroup,
 					uint32_t completions_per_qpair, spdk_nvme_disconnected_qpair_cb disconnected_qpair_cb)
 {
-	return -ENOTSUP;
+	struct spdk_nvme_qpair *qpair, *tmp_qpair;
+	int32_t local_completions = 0;
+	int64_t total_completions = 0;
+
+	STAILQ_FOREACH_SAFE(qpair, &tgroup->disconnected_qpairs, poll_group_stailq, tmp_qpair) {
+		disconnected_qpair_cb(qpair, tgroup->group->ctx);
+	}
+
+	STAILQ_FOREACH_SAFE(qpair, &tgroup->connected_qpairs, poll_group_stailq, tmp_qpair) {
+		local_completions = spdk_nvme_qpair_process_completions(qpair, completions_per_qpair);
+		if (local_completions < 0) {
+			disconnected_qpair_cb(qpair, tgroup->group->ctx);
+			local_completions = 0;
+		}
+		total_completions += local_completions;
+	}
+
+	return total_completions;
 }
 
 static int
 nvme_tcp_poll_group_destroy(struct spdk_nvme_transport_poll_group *tgroup)
 {
-	return -ENOTSUP;
+	if (!STAILQ_EMPTY(&tgroup->connected_qpairs) || !STAILQ_EMPTY(&tgroup->disconnected_qpairs)) {
+		return -EBUSY;
+	}
+
+	free(tgroup);
+
+	return 0;
 }
 
 const struct spdk_nvme_transport_ops tcp_ops = {

lib/nvme/nvme_transport.c

@@ -443,7 +443,16 @@ nvme_transport_poll_group_remove(struct spdk_nvme_transport_poll_group *tgroup,
 
 	rc = tgroup->transport->ops.poll_group_remove(tgroup, qpair);
 	if (rc == 0) {
+		if (qpair->poll_group_tailq_head == &tgroup->connected_qpairs) {
+			STAILQ_REMOVE(&tgroup->connected_qpairs, qpair, spdk_nvme_qpair, poll_group_stailq);
+		} else if (qpair->poll_group_tailq_head == &tgroup->disconnected_qpairs) {
+			STAILQ_REMOVE(&tgroup->disconnected_qpairs, qpair, spdk_nvme_qpair, poll_group_stailq);
+		} else {
+			return -ENOENT;
+		}
+
 		qpair->poll_group = NULL;
+		qpair->poll_group_tailq_head = NULL;
 	}
 
 	return rc;

test/unit/lib/nvme/nvme_tcp.c/nvme_tcp_ut.c

@@ -44,6 +44,8 @@ SPDK_LOG_REGISTER_COMPONENT("nvme", SPDK_LOG_NVME);
 
 DEFINE_STUB(nvme_qpair_submit_request,
 	    int, (struct spdk_nvme_qpair *qpair, struct nvme_request *req), 0);
+DEFINE_STUB(spdk_nvme_qpair_process_completions, int32_t, (struct spdk_nvme_qpair *qpair,
+		uint32_t max_completions), 0);
 
 DEFINE_STUB(spdk_sock_set_priority,
 	    int, (struct spdk_sock *sock, int priority), 0);