rpc: Add NVMf transport statistics to nvmf_get_stats RPC method

This patch adds transport part to nvmf_get_stats RPC method and basic
infrastructure to report NVMf transport specific statistics.

Signed-off-by: Evgeniy Kochetov <evgeniik@mellanox.com>
Change-Id: Ie83b34f4ed932dd5f6d6e37897cf45228114bd88
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/452299
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

CHANGELOG.md

@@ -60,6 +60,8 @@ updated the related rpc function nvmf_create_transport to make this
 configurable parameter available to users. The `dif_insert_or_strip` is relevant
 for TCP transport for now and used to configure the DIF strip and insert.
 
+Added infrastructure to retrieve NVMf transport statistics.
+
 ### notify
 
 The function `spdk_notify_get_types()` and `spdk_notify_get_events()` were

doc/jsonrpc.md

@@ -4173,7 +4173,12 @@ Example response:
         "name": "app_thread",
         "admin_qpairs": 1,
         "io_qpairs": 4,
-        "pending_bdev_io": 1721
+        "pending_bdev_io": 1721,
+        "transports": [
+          {
+            "trtype": "RDMA"
+          }
+        ]
       }
     ]
   }

include/spdk/nvmf.h

@@ -85,6 +85,15 @@ struct spdk_nvmf_poll_group_stat {
 	uint64_t pending_bdev_io;
 };
 
+struct spdk_nvmf_transport_poll_group_stat {
+	spdk_nvme_transport_type_t trtype;
+	union {
+		struct {
+			int dummy;
+		} rdma;
+	};
+};
+
 /**
  * Construct an NVMe-oF target.
  *
@@ -866,6 +875,40 @@ int spdk_nvmf_transport_listen(struct spdk_nvmf_transport *transport,
 void
 spdk_nvmf_tgt_transport_write_config_json(struct spdk_json_write_ctx *w, struct spdk_nvmf_tgt *tgt);
 
+
+/**
+ * \brief Get current transport poll group statistics.
+ *
+ * This function allocates memory for statistics and returns it
+ * in \p stat parameter. Caller must free this memory with
+ * spdk_nvmf_transport_poll_group_free_stat() when it is not needed
+ * anymore.
+ *
+ * \param tgt The NVMf target.
+ * \param transport The NVMf transport.
+ * \param stat Output parameter that will contain pointer to allocated statistics structure.
+ *
+ * \return 0 upon success.
+ * \return -ENOTSUP if transport does not support statistics.
+ * \return -EINVAL if any of parameters is NULL.
+ * \return -ENOENT if transport poll group is not found.
+ * \return -ENOMEM if memory allocation failed.
+ */
+int
+spdk_nvmf_transport_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
+					struct spdk_nvmf_transport *transport,
+					struct spdk_nvmf_transport_poll_group_stat **stat);
+
+/**
+ * Free statistics memory previously allocated with spdk_nvmf_transport_poll_group_get_stat().
+ *
+ * \param transport The NVMf transport.
+ * \param stat Pointer to transport poll group statistics structure.
+ */
+void
+spdk_nvmf_transport_poll_group_free_stat(struct spdk_nvmf_transport *transport,
+		struct spdk_nvmf_transport_poll_group_stat *stat);
+
 #ifdef SPDK_CONFIG_RDMA
 /**
  * \brief Set the global hooks for the RDMA transport, if necessary.

lib/event/subsystems/nvmf/nvmf_rpc.c

@@ -1608,11 +1608,29 @@ rpc_nvmf_get_stats_done(struct spdk_io_channel_iter *i, int status)
 	free(ctx);
 }
 
+static void
+write_nvmf_transport_stats(struct spdk_json_write_ctx *w,
+			   struct spdk_nvmf_transport_poll_group_stat *stat)
+{
+	spdk_json_write_object_begin(w);
+	spdk_json_write_named_string(w, "trtype",
+				     spdk_nvme_transport_id_trtype_str(stat->trtype));
+	switch (stat->trtype) {
+	case SPDK_NVME_TRANSPORT_RDMA:
+	default:
+		break;
+	}
+	spdk_json_write_object_end(w);
+}
+
 static void
 rpc_nvmf_get_stats(struct spdk_io_channel_iter *i)
 {
 	struct rpc_nvmf_get_stats_ctx *ctx = spdk_io_channel_iter_get_ctx(i);
+	struct spdk_nvmf_transport *transport;
 	struct spdk_nvmf_poll_group_stat stat;
+	struct spdk_nvmf_transport_poll_group_stat *trstat;
+	int rc;
 
 	if (0 == spdk_nvmf_poll_group_get_stat(g_spdk_nvmf_tgt, &stat)) {
 		spdk_json_write_object_begin(ctx->w);
@@ -1620,6 +1638,22 @@ rpc_nvmf_get_stats(struct spdk_io_channel_iter *i)
 		spdk_json_write_named_uint32(ctx->w, "admin_qpairs", stat.admin_qpairs);
 		spdk_json_write_named_uint32(ctx->w, "io_qpairs", stat.io_qpairs);
 		spdk_json_write_named_uint64(ctx->w, "pending_bdev_io", stat.pending_bdev_io);
+
+		spdk_json_write_named_array_begin(ctx->w, "transports");
+		transport = spdk_nvmf_transport_get_first(g_spdk_nvmf_tgt);
+		while (transport) {
+			rc = spdk_nvmf_transport_poll_group_get_stat(g_spdk_nvmf_tgt, transport, &trstat);
+			if (0 == rc) {
+				write_nvmf_transport_stats(ctx->w, trstat);
+				spdk_nvmf_transport_poll_group_free_stat(transport, trstat);
+			} else if (-ENOTSUP != rc) {
+				SPDK_ERRLOG("Failed to get poll group statistics for transport %s, errno %d\n",
+					    spdk_nvme_transport_id_trtype_str(spdk_nvmf_get_transport_type(transport)),
+					    rc);
+			}
+			transport = spdk_nvmf_transport_get_next(transport);
+		}
+		spdk_json_write_array_end(ctx->w);
 		spdk_json_write_object_end(ctx->w);
 	}
 

lib/nvmf/rdma.c

@@ -3647,6 +3647,40 @@ spdk_nvmf_rdma_init_hooks(struct spdk_nvme_rdma_hooks *hooks)
 	g_nvmf_hooks = *hooks;
 }
 
+static int
+spdk_nvmf_rdma_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
+				   struct spdk_nvmf_transport_poll_group_stat **stat)
+{
+	struct spdk_io_channel *ch;
+	struct spdk_nvmf_poll_group *group;
+	struct spdk_nvmf_transport_poll_group *tgroup;
+
+	if (tgt == NULL || stat == NULL) {
+		return -EINVAL;
+	}
+
+	ch = spdk_get_io_channel(tgt);
+	group = spdk_io_channel_get_ctx(ch);;
+	TAILQ_FOREACH(tgroup, &group->tgroups, link) {
+		if (SPDK_NVME_TRANSPORT_RDMA == tgroup->transport->ops->type) {
+			*stat = calloc(1, sizeof(struct spdk_nvmf_transport_poll_group_stat));
+			if (!*stat) {
+				SPDK_ERRLOG("Failed to allocate memory for NVMf RDMA statistics\n");
+				return -ENOMEM;
+			}
+			(*stat)->trtype = SPDK_NVME_TRANSPORT_RDMA;
+			return 0;
+		}
+	}
+	return -ENOENT;
+}
+
+static void
+spdk_nvmf_rdma_poll_group_free_stat(struct spdk_nvmf_transport_poll_group_stat *stat)
+{
+	free(stat);
+}
+
 const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
 	.type = SPDK_NVME_TRANSPORT_RDMA,
 	.opts_init = spdk_nvmf_rdma_opts_init,
@@ -3672,6 +3706,8 @@ const struct spdk_nvmf_transport_ops spdk_nvmf_transport_rdma = {
 	.qpair_get_local_trid = spdk_nvmf_rdma_qpair_get_local_trid,
 	.qpair_get_listen_trid = spdk_nvmf_rdma_qpair_get_listen_trid,
 
+	.poll_group_get_stat = spdk_nvmf_rdma_poll_group_get_stat,
+	.poll_group_free_stat = spdk_nvmf_rdma_poll_group_free_stat,
 };
 
 SPDK_LOG_REGISTER_COMPONENT("rdma", SPDK_LOG_RDMA)

lib/nvmf/transport.c

@@ -2,7 +2,7 @@
  *   BSD LICENSE
  *
  *   Copyright (c) Intel Corporation. All rights reserved.
- *   Copyright (c) 2018 Mellanox Technologies LTD. All rights reserved.
+ *   Copyright (c) 2018-2019 Mellanox Technologies LTD. All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -335,3 +335,24 @@ spdk_nvmf_transport_qpair_set_sqsize(struct spdk_nvmf_qpair *qpair)
 
 	return 0;
 }
+
+int
+spdk_nvmf_transport_poll_group_get_stat(struct spdk_nvmf_tgt *tgt,
+					struct spdk_nvmf_transport *transport,
+					struct spdk_nvmf_transport_poll_group_stat **stat)
+{
+	if (transport->ops->poll_group_get_stat) {
+		return transport->ops->poll_group_get_stat(tgt, stat);
+	} else {
+		return -ENOTSUP;
+	}
+}
+
+void
+spdk_nvmf_transport_poll_group_free_stat(struct spdk_nvmf_transport *transport,
+		struct spdk_nvmf_transport_poll_group_stat *stat)
+{
+	if (transport->ops->poll_group_free_stat) {
+		transport->ops->poll_group_free_stat(stat);
+	}
+}

lib/nvmf/transport.h

@@ -1,8 +1,8 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright (c) Intel Corporation.
- *   All rights reserved.
+ *   Copyright (c) Intel Corporation. All rights reserved.
+ *   Copyright (c) 2019 Mellanox Technologies LTD. All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -167,6 +167,17 @@ struct spdk_nvmf_transport_ops {
 	 * set the submission queue size of the queue pair
 	 */
 	int (*qpair_set_sqsize)(struct spdk_nvmf_qpair *qpair);
+
+	/*
+	 * Get transport poll group statistics
+	 */
+	int (*poll_group_get_stat)(struct spdk_nvmf_tgt *tgt,
+				   struct spdk_nvmf_transport_poll_group_stat **stat);
+
+	/*
+	 * Free transport poll group statistics previously allocated with poll_group_get_stat()
+	 */
+	void (*poll_group_free_stat)(struct spdk_nvmf_transport_poll_group_stat *stat);
 };
 
 int spdk_nvmf_transport_stop_listen(struct spdk_nvmf_transport *transport,