X-Git-Url: http://git.efficios.com/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=150a2dfe4675bfbfaf90d5e30b51d54ab6eb284d;hp=184dd494c74cfa29fe3408da36f94085df91b3ca;hb=ffe600149a7608221985751e1bf293234bf2545c;hpb=9a572cf512695118b85db5d9ed1157b3a4aa5b7f

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 184dd494c..150a2dfe4 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -101,11 +101,22 @@ static int build_network_session_path(char *dst, size_t size,
 		goto error;
 	}
 
-	if (strlen(tmp_uurl) > 0) {
+	/*
+	 * Do we have a UST url set. If yes, this means we have both kernel and UST
+	 * to print.
+	 */
+	if (*tmp_uurl != '\0') {
 		ret = snprintf(dst, size, "[K]: %s [data: %d] -- [U]: %s [data: %d]",
 				tmp_urls, kdata_port, tmp_uurl, udata_port);
 	} else {
-		ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, kdata_port);
+		int dport;
+		if (kuri) {
+			dport = kdata_port;
+		} else {
+			/* No kernel URI, use the UST port. */
+			dport = udata_port;
+		}
+		ret = snprintf(dst, size, "%s [data: %d]", tmp_urls, dport);
 	}
 
 error:
@@ -141,6 +152,7 @@ static void list_lttng_channels(int domain, struct ltt_session *session,
 		struct lttng_ht_iter iter;
 		struct ltt_ust_channel *uchan;
 
+		rcu_read_lock();
 		cds_lfht_for_each_entry(session->ust_session->domain_global.channels->ht,
 				&iter.iter, uchan, node.node) {
 			strncpy(channels[i].name, uchan->name, LTTNG_SYMBOL_NAME_LEN);
@@ -160,6 +172,7 @@ static void list_lttng_channels(int domain, struct ltt_session *session,
 			}
 			i++;
 		}
+		rcu_read_unlock();
 		break;
 	}
 	default:
@@ -363,6 +376,8 @@ static int add_uri_to_consumer(struct consumer_output *consumer,
 	case LTTNG_DST_IPV6:
 		DBG2("Setting network URI to consumer");
 
+		consumer->type = CONSUMER_DST_NET;
+
 		/* Set URI into consumer output object */
 		ret = consumer_set_network_uri(consumer, uri);
 		if (ret < 0) {
@@ -422,6 +437,8 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
 
 	assert(session);
 
+	rcu_read_lock();
+
 	if (session->consumer_fds_sent == 0 && session->consumer != NULL) {
 		cds_lfht_for_each_entry(session->consumer->socks->ht, &iter.iter,
 				socket, node.node) {
@@ -429,7 +446,7 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
 			assert(socket->fd >= 0);
 
 			pthread_mutex_lock(socket->lock);
-			ret = kernel_consumer_send_session(socket->fd, session);
+			ret = kernel_consumer_send_session(socket, session);
 			pthread_mutex_unlock(socket->lock);
 			if (ret < 0) {
 				ret = LTTNG_ERR_KERN_CONSUMER_FAIL;
@@ -439,6 +456,7 @@ static int init_kernel_tracing(struct ltt_kernel_session *session)
 	}
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -468,8 +486,14 @@ static int create_connect_relayd(struct consumer_output *output,
 		goto error;
 	}
 
-	/* Connect to relayd so we can proceed with a session creation. */
+	/*
+	 * Connect to relayd so we can proceed with a session creation. This call
+	 * can possibly block for an arbitrary amount of time to set the health
+	 * state to be in poll execution.
+	 */
+	health_poll_entry();
 	ret = relayd_connect(sock);
+	health_poll_exit();
 	if (ret < 0) {
 		ERR("Unable to reach lttng-relayd");
 		ret = LTTNG_ERR_RELAYD_CONNECT_FAIL;
@@ -517,11 +541,22 @@ error:
  */
 static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 		struct lttng_uri *relayd_uri, struct consumer_output *consumer,
-		int consumer_fd)
+		struct consumer_socket *consumer_sock)
 {
 	int ret;
 	struct lttcomm_sock *sock = NULL;
 
+	/* Connect to relayd and make version check if uri is the control. */
+	ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
+	if (ret != LTTNG_OK) {
+		goto close_sock;
+	}
+
+	/* If the control socket is connected, network session is ready */
+	if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
+		session->net_handle = 1;
+	}
+
 	/* Set the network sequence index if not set. */
 	if (consumer->net_seq_index == -1) {
 		/*
@@ -534,20 +569,9 @@ static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 				uatomic_read(&relayd_net_seq_idx));
 	}
 
-	/* Connect to relayd and make version check if uri is the control. */
-	ret = create_connect_relayd(consumer, session->name, relayd_uri, &sock);
-	if (ret != LTTNG_OK) {
-		goto close_sock;
-	}
-
-	/* If the control socket is connected, network session is ready */
-	if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
-		session->net_handle = 1;
-	}
-
 	/* Send relayd socket to consumer. */
-	ret = consumer_send_relayd_socket(consumer_fd, sock,
-			consumer, relayd_uri->stype);
+	ret = consumer_send_relayd_socket(consumer_sock, sock,
+			consumer, relayd_uri->stype, session->id);
 	if (ret < 0) {
 		ret = LTTNG_ERR_ENABLE_CONSUMER_FAIL;
 		goto close_sock;
@@ -555,9 +579,9 @@ static int send_consumer_relayd_socket(int domain, struct ltt_session *session,
 
 	/* Flag that the corresponding socket was sent. */
 	if (relayd_uri->stype == LTTNG_STREAM_CONTROL) {
-		consumer->dst.net.control_sock_sent = 1;
+		consumer_sock->control_sock_sent = 1;
 	} else if (relayd_uri->stype == LTTNG_STREAM_DATA) {
-		consumer->dst.net.data_sock_sent = 1;
+		consumer_sock->data_sock_sent = 1;
 	}
 
 	ret = LTTNG_OK;
@@ -573,6 +597,14 @@ close_sock:
 		lttcomm_destroy_sock(sock);
 	}
 
+	if (ret != LTTNG_OK) {
+		/*
+		 * On error, nullify the consumer sequence index so streams are not
+		 * associated with it once sent to the consumer.
+		 */
+		uatomic_set(&consumer->net_seq_index, -1);
+	}
+
 	return ret;
 }
 
@@ -582,7 +614,8 @@ close_sock:
  * session.
  */
 static int send_consumer_relayd_sockets(int domain,
-		struct ltt_session *session, struct consumer_output *consumer, int fd)
+		struct ltt_session *session, struct consumer_output *consumer,
+		struct consumer_socket *sock)
 {
 	int ret = LTTNG_OK;
 
@@ -590,18 +623,18 @@ static int send_consumer_relayd_sockets(int domain,
 	assert(consumer);
 
 	/* Sending control relayd socket. */
-	if (!consumer->dst.net.control_sock_sent) {
+	if (!sock->control_sock_sent) {
 		ret = send_consumer_relayd_socket(domain, session,
-				&consumer->dst.net.control, consumer, fd);
+				&consumer->dst.net.control, consumer, sock);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
 	}
 
 	/* Sending data relayd socket. */
-	if (!consumer->dst.net.data_sock_sent) {
+	if (!sock->data_sock_sent) {
 		ret = send_consumer_relayd_socket(domain, session,
-				&consumer->dst.net.data, consumer, fd);
+				&consumer->dst.net.data, consumer, sock);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -616,7 +649,7 @@ error:
  * the relayd and send them to the right domain consumer. Consumer type MUST be
  * network.
  */
-static int setup_relayd(struct ltt_session *session)
+int cmd_setup_relayd(struct ltt_session *session)
 {
 	int ret = LTTNG_OK;
 	struct ltt_ust_session *usess;
@@ -631,6 +664,8 @@ static int setup_relayd(struct ltt_session *session)
 
 	DBG2("Setting relayd for session %s", session->name);
 
+	rcu_read_lock();
+
 	if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 			&& usess->consumer->enabled) {
 		/* For each consumer socket, send relayd sockets */
@@ -641,7 +676,7 @@ static int setup_relayd(struct ltt_session *session)
 
 			pthread_mutex_lock(socket->lock);
 			ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_UST, session,
-					usess->consumer, socket->fd);
+					usess->consumer, socket);
 			pthread_mutex_unlock(socket->lock);
 			if (ret != LTTNG_OK) {
 				goto error;
@@ -658,7 +693,7 @@ static int setup_relayd(struct ltt_session *session)
 
 			pthread_mutex_lock(socket->lock);
 			ret = send_consumer_relayd_sockets(LTTNG_DOMAIN_KERNEL, session,
-					ksess->consumer, socket->fd);
+					ksess->consumer, socket);
 			pthread_mutex_unlock(socket->lock);
 			if (ret != LTTNG_OK) {
 				goto error;
@@ -666,6 +701,72 @@ static int setup_relayd(struct ltt_session *session)
 		}
 	}
 
+error:
+	rcu_read_unlock();
+	return ret;
+}
+
+/*
+ * Start a kernel session by opening all necessary streams.
+ */
+static int start_kernel_session(struct ltt_kernel_session *ksess, int wpipe)
+{
+	int ret;
+	struct ltt_kernel_channel *kchan;
+
+	/* Open kernel metadata */
+	if (ksess->metadata == NULL) {
+		ret = kernel_open_metadata(ksess);
+		if (ret < 0) {
+			ret = LTTNG_ERR_KERN_META_FAIL;
+			goto error;
+		}
+	}
+
+	/* Open kernel metadata stream */
+	if (ksess->metadata_stream_fd < 0) {
+		ret = kernel_open_metadata_stream(ksess);
+		if (ret < 0) {
+			ERR("Kernel create metadata stream failed");
+			ret = LTTNG_ERR_KERN_STREAM_FAIL;
+			goto error;
+		}
+	}
+
+	/* For each channel */
+	cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
+		if (kchan->stream_count == 0) {
+			ret = kernel_open_channel_stream(kchan);
+			if (ret < 0) {
+				ret = LTTNG_ERR_KERN_STREAM_FAIL;
+				goto error;
+			}
+			/* Update the stream global counter */
+			ksess->stream_count_global += ret;
+		}
+	}
+
+	/* Setup kernel consumer socket and send fds to it */
+	ret = init_kernel_tracing(ksess);
+	if (ret < 0) {
+		ret = LTTNG_ERR_KERN_START_FAIL;
+		goto error;
+	}
+
+	/* This start the kernel tracing */
+	ret = kernel_start_session(ksess);
+	if (ret < 0) {
+		ret = LTTNG_ERR_KERN_START_FAIL;
+		goto error;
+	}
+
+	/* Quiescent wait after starting trace */
+	kernel_wait_quiescent(kernel_tracer_fd);
+
+	ksess->started = 1;
+
+	ret = LTTNG_OK;
+
 error:
 	return ret;
 }
@@ -681,6 +782,8 @@ int cmd_disable_channel(struct ltt_session *session, int domain,
 
 	usess = session->ust_session;
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -725,6 +828,7 @@ int cmd_disable_channel(struct ltt_session *session, int domain,
 	ret = LTTNG_OK;
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -745,14 +849,13 @@ int cmd_enable_channel(struct ltt_session *session,
 
 	DBG("Enabling channel %s for session %s", attr->name, session->name);
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
 		struct ltt_kernel_channel *kchan;
 
-		/* Mandatory for a kernel channel. */
-		assert(wpipe > 0);
-
 		kchan = trace_kernel_get_channel_by_name(attr->name,
 				session->kernel_session);
 		if (kchan == NULL) {
@@ -766,6 +869,18 @@ int cmd_enable_channel(struct ltt_session *session,
 		}
 
 		kernel_wait_quiescent(kernel_tracer_fd);
+
+		/*
+		 * If the session was previously started, start as well this newly
+		 * created kernel session so the events/channels enabled *after* the
+		 * start actually work.
+		 */
+		if (session->started && !session->kernel_session->started) {
+			ret = start_kernel_session(session->kernel_session, wpipe);
+			if (ret != LTTNG_OK) {
+				goto error;
+			}
+		}
 		break;
 	}
 	case LTTNG_DOMAIN_UST:
@@ -780,6 +895,17 @@ int cmd_enable_channel(struct ltt_session *session,
 		} else {
 			ret = channel_ust_enable(usess, domain, uchan);
 		}
+
+		/* Start the UST session if the session was already started. */
+		if (session->started && !usess->start_trace) {
+			ret = ust_app_start_trace_all(usess);
+			if (ret < 0) {
+				ret = LTTNG_ERR_UST_START_FAIL;
+				goto error;
+			}
+			ret = LTTNG_OK;
+			usess->start_trace = 1;
+		}
 		break;
 	}
 #if 0
@@ -793,6 +919,7 @@ int cmd_enable_channel(struct ltt_session *session,
 	}
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -805,6 +932,8 @@ int cmd_disable_event(struct ltt_session *session, int domain,
 {
 	int ret;
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -819,7 +948,7 @@ int cmd_disable_event(struct ltt_session *session, int domain,
 			goto error;
 		}
 
-		ret = event_kernel_disable_tracepoint(ksess, kchan, event_name);
+		ret = event_kernel_disable_tracepoint(kchan, event_name);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -863,6 +992,7 @@ int cmd_disable_event(struct ltt_session *session, int domain,
 	ret = LTTNG_OK;
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -874,6 +1004,8 @@ int cmd_disable_event_all(struct ltt_session *session, int domain,
 {
 	int ret;
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -888,7 +1020,7 @@ int cmd_disable_event_all(struct ltt_session *session, int domain,
 			goto error;
 		}
 
-		ret = event_kernel_disable_all(ksess, kchan);
+		ret = event_kernel_disable_all(kchan);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -932,6 +1064,7 @@ int cmd_disable_event_all(struct ltt_session *session, int domain,
 	ret = LTTNG_OK;
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -939,15 +1072,24 @@ error:
  * Command LTTNG_ADD_CONTEXT processed by the client thread.
  */
 int cmd_add_context(struct ltt_session *session, int domain,
-		char *channel_name, char *event_name, struct lttng_event_context *ctx)
+		char *channel_name, struct lttng_event_context *ctx, int kwpipe)
 {
 	int ret;
 
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
+		assert(session->kernel_session);
+
+		if (session->kernel_session->channel_count == 0) {
+			/* Create default channel */
+			ret = channel_kernel_create(session->kernel_session, NULL, kwpipe);
+			if (ret != LTTNG_OK) {
+				goto error;
+			}
+		}
+
 		/* Add kernel context to kernel tracer */
-		ret = context_kernel_add(session->kernel_session, ctx,
-				event_name, channel_name);
+		ret = context_kernel_add(session->kernel_session, ctx, channel_name);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -955,49 +1097,28 @@ int cmd_add_context(struct ltt_session *session, int domain,
 	case LTTNG_DOMAIN_UST:
 	{
 		struct ltt_ust_session *usess = session->ust_session;
-
 		assert(usess);
 
-		ret = context_ust_add(usess, domain, ctx, event_name, channel_name);
-		if (ret != LTTNG_OK) {
-			goto error;
-		}
-		break;
-	}
-#if 0
-	case LTTNG_DOMAIN_UST_EXEC_NAME:
-	case LTTNG_DOMAIN_UST_PID:
-	case LTTNG_DOMAIN_UST_PID_FOLLOW_CHILDREN:
-#endif
-	default:
-		ret = LTTNG_ERR_UND;
-		goto error;
-	}
-
-	ret = LTTNG_OK;
-
-error:
-	return ret;
-}
-
-/*
- * Command LTTNG_SET_FILTER processed by the client thread.
- */
-int cmd_set_filter(struct ltt_session *session, int domain,
-		char *channel_name, char *event_name,
-		struct lttng_filter_bytecode *bytecode)
-{
-	int ret;
+		unsigned int chan_count =
+			lttng_ht_get_count(usess->domain_global.channels);
+		if (chan_count == 0) {
+			struct lttng_channel *attr;
+			/* Create default channel */
+			attr = channel_new_default_attr(domain);
+			if (attr == NULL) {
+				ret = LTTNG_ERR_FATAL;
+				goto error;
+			}
 
-	switch (domain) {
-	case LTTNG_DOMAIN_KERNEL:
-		ret = LTTNG_ERR_FATAL;
-		break;
-	case LTTNG_DOMAIN_UST:
-	{
-		struct ltt_ust_session *usess = session->ust_session;
+			ret = channel_ust_create(usess, domain, attr);
+			if (ret != LTTNG_OK) {
+				free(attr);
+				goto error;
+			}
+			free(attr);
+		}
 
-		ret = filter_ust_set(usess, domain, bytecode, event_name, channel_name);
+		ret = context_ust_add(usess, domain, ctx, channel_name);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -1017,23 +1138,24 @@ int cmd_set_filter(struct ltt_session *session, int domain,
 
 error:
 	return ret;
-
 }
 
-
 /*
  * Command LTTNG_ENABLE_EVENT processed by the client thread.
  */
 int cmd_enable_event(struct ltt_session *session, int domain,
-		char *channel_name, struct lttng_event *event, int wpipe)
+		char *channel_name, struct lttng_event *event,
+		struct lttng_filter_bytecode *filter, int wpipe)
 {
-	int ret;
+	int ret, channel_created = 0;
 	struct lttng_channel *attr;
 
 	assert(session);
 	assert(event);
 	assert(channel_name);
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -1055,6 +1177,8 @@ int cmd_enable_event(struct ltt_session *session, int domain,
 				goto error;
 			}
 			free(attr);
+
+			channel_created = 1;
 		}
 
 		/* Get the newly created kernel channel pointer */
@@ -1066,9 +1190,12 @@ int cmd_enable_event(struct ltt_session *session, int domain,
 			goto error;
 		}
 
-		ret = event_kernel_enable_tracepoint(session->kernel_session, kchan,
-				event);
+		ret = event_kernel_enable_tracepoint(kchan, event);
 		if (ret != LTTNG_OK) {
+			if (channel_created) {
+				/* Let's not leak a useless channel. */
+				kernel_destroy_channel(kchan);
+			}
 			goto error;
 		}
 
@@ -1108,7 +1235,7 @@ int cmd_enable_event(struct ltt_session *session, int domain,
 		}
 
 		/* At this point, the session and channel exist on the tracer */
-		ret = event_ust_enable_tracepoint(usess, domain, uchan, event);
+		ret = event_ust_enable_tracepoint(usess, domain, uchan, event, filter);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -1127,6 +1254,7 @@ int cmd_enable_event(struct ltt_session *session, int domain,
 	ret = LTTNG_OK;
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -1134,7 +1262,8 @@ error:
  * Command LTTNG_ENABLE_ALL_EVENT processed by the client thread.
  */
 int cmd_enable_event_all(struct ltt_session *session, int domain,
-		char *channel_name, int event_type, int wpipe)
+		char *channel_name, int event_type,
+		struct lttng_filter_bytecode *filter, int wpipe)
 {
 	int ret;
 	struct lttng_channel *attr;
@@ -1142,6 +1271,8 @@ int cmd_enable_event_all(struct ltt_session *session, int domain,
 	assert(session);
 	assert(channel_name);
 
+	rcu_read_lock();
+
 	switch (domain) {
 	case LTTNG_DOMAIN_KERNEL:
 	{
@@ -1175,21 +1306,18 @@ int cmd_enable_event_all(struct ltt_session *session, int domain,
 
 		switch (event_type) {
 		case LTTNG_EVENT_SYSCALL:
-			ret = event_kernel_enable_all_syscalls(session->kernel_session,
-					kchan, kernel_tracer_fd);
+			ret = event_kernel_enable_all_syscalls(kchan, kernel_tracer_fd);
 			break;
 		case LTTNG_EVENT_TRACEPOINT:
 			/*
 			 * This call enables all LTTNG_KERNEL_TRACEPOINTS and
 			 * events already registered to the channel.
 			 */
-			ret = event_kernel_enable_all_tracepoints(session->kernel_session,
-					kchan, kernel_tracer_fd);
+			ret = event_kernel_enable_all_tracepoints(kchan, kernel_tracer_fd);
 			break;
 		case LTTNG_EVENT_ALL:
 			/* Enable syscalls and tracepoints */
-			ret = event_kernel_enable_all(session->kernel_session,
-					kchan, kernel_tracer_fd);
+			ret = event_kernel_enable_all(kchan, kernel_tracer_fd);
 			break;
 		default:
 			ret = LTTNG_ERR_KERN_ENABLE_FAIL;
@@ -1198,6 +1326,10 @@ int cmd_enable_event_all(struct ltt_session *session, int domain,
 
 		/* Manage return value */
 		if (ret != LTTNG_OK) {
+			/*
+			 * On error, cmd_enable_channel call will take care of destroying
+			 * the created channel if it was needed.
+			 */
 			goto error;
 		}
 
@@ -1241,7 +1373,8 @@ int cmd_enable_event_all(struct ltt_session *session, int domain,
 		switch (event_type) {
 		case LTTNG_EVENT_ALL:
 		case LTTNG_EVENT_TRACEPOINT:
-			ret = event_ust_enable_all_tracepoints(usess, domain, uchan);
+			ret = event_ust_enable_all_tracepoints(usess, domain, uchan,
+					filter);
 			if (ret != LTTNG_OK) {
 				goto error;
 			}
@@ -1271,6 +1404,7 @@ int cmd_enable_event_all(struct ltt_session *session, int domain,
 	ret = LTTNG_OK;
 
 error:
+	rcu_read_unlock();
 	return ret;
 }
 
@@ -1348,7 +1482,6 @@ int cmd_start_trace(struct ltt_session *session)
 	int ret;
 	struct ltt_kernel_session *ksession;
 	struct ltt_ust_session *usess;
-	struct ltt_kernel_channel *kchan;
 
 	assert(session);
 
@@ -1364,62 +1497,12 @@ int cmd_start_trace(struct ltt_session *session)
 
 	session->enabled = 1;
 
-	ret = setup_relayd(session);
-	if (ret != LTTNG_OK) {
-		ERR("Error setting up relayd for session %s", session->name);
-		goto error;
-	}
-
 	/* Kernel tracing */
 	if (ksession != NULL) {
-		/* Open kernel metadata */
-		if (ksession->metadata == NULL) {
-			ret = kernel_open_metadata(ksession);
-			if (ret < 0) {
-				ret = LTTNG_ERR_KERN_META_FAIL;
-				goto error;
-			}
-		}
-
-		/* Open kernel metadata stream */
-		if (ksession->metadata_stream_fd < 0) {
-			ret = kernel_open_metadata_stream(ksession);
-			if (ret < 0) {
-				ERR("Kernel create metadata stream failed");
-				ret = LTTNG_ERR_KERN_STREAM_FAIL;
-				goto error;
-			}
-		}
-
-		/* For each channel */
-		cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
-			if (kchan->stream_count == 0) {
-				ret = kernel_open_channel_stream(kchan);
-				if (ret < 0) {
-					ret = LTTNG_ERR_KERN_STREAM_FAIL;
-					goto error;
-				}
-				/* Update the stream global counter */
-				ksession->stream_count_global += ret;
-			}
-		}
-
-		/* Setup kernel consumer socket and send fds to it */
-		ret = init_kernel_tracing(ksession);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_START_FAIL;
-			goto error;
-		}
-
-		/* This start the kernel tracing */
-		ret = kernel_start_session(ksession);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_START_FAIL;
+		ret = start_kernel_session(ksession, kernel_tracer_fd);
+		if (ret != LTTNG_OK) {
 			goto error;
 		}
-
-		/* Quiescent wait after starting trace */
-		kernel_wait_quiescent(kernel_tracer_fd);
 	}
 
 	/* Flag session that trace should start automatically */
@@ -1433,6 +1516,8 @@ int cmd_start_trace(struct ltt_session *session)
 		}
 	}
 
+	session->started = 1;
+
 	ret = LTTNG_OK;
 
 error:
@@ -1489,6 +1574,8 @@ int cmd_stop_trace(struct ltt_session *session)
 		}
 
 		kernel_wait_quiescent(kernel_tracer_fd);
+
+		ksession->started = 0;
 	}
 
 	if (usess) {
@@ -1501,6 +1588,8 @@ int cmd_stop_trace(struct ltt_session *session)
 		}
 	}
 
+	session->started = 0;
+
 	ret = LTTNG_OK;
 
 error:
@@ -1581,44 +1670,10 @@ int cmd_set_consumer_uri(int domain, struct ltt_session *session,
 	}
 
 	for (i = 0; i < nb_uri; i++) {
-		struct consumer_socket *socket;
-		struct lttng_ht_iter iter;
-
 		ret = add_uri_to_consumer(consumer, &uris[i], domain, session->name);
 		if (ret < 0) {
 			goto error;
 		}
-
-		/*
-		 * Don't send relayd socket if URI is NOT remote or if the relayd
-		 * socket for the session was already sent.
-		 */
-		if (uris[i].dtype == LTTNG_DST_PATH ||
-				(uris[i].stype == LTTNG_STREAM_CONTROL &&
-				consumer->dst.net.control_sock_sent) ||
-				(uris[i].stype == LTTNG_STREAM_DATA &&
-				consumer->dst.net.data_sock_sent)) {
-			continue;
-		}
-
-		/* Try to send relayd URI to the consumer if exist. */
-		rcu_read_lock();
-		cds_lfht_for_each_entry(consumer->socks->ht, &iter.iter,
-				socket, node.node) {
-
-			/* A socket in the HT should never have a negative fd */
-			assert(socket->fd >= 0);
-
-			pthread_mutex_lock(socket->lock);
-			ret = send_consumer_relayd_socket(domain, session, &uris[i],
-					consumer, socket->fd);
-			pthread_mutex_unlock(socket->lock);
-			if (ret != LTTNG_OK) {
-				rcu_read_unlock();
-				goto error;
-			}
-		}
-		rcu_read_unlock();
 	}
 
 	/* All good! */
@@ -1834,8 +1889,11 @@ int cmd_register_consumer(struct ltt_session *session, int domain,
 
 		socket = consumer_allocate_socket(sock);
 		if (socket == NULL) {
+			ret = close(sock);
+			if (ret < 0) {
+				PERROR("close register consumer");
+			}
 			ret = LTTNG_ERR_FATAL;
-			close(sock);
 			goto error;
 		}
 
@@ -2319,10 +2377,10 @@ error:
 }
 
 /*
- * Command LTTNG_DATA_AVAILABLE returning 0 if the data is NOT ready to be read
- * or else 1 if the data is available for trace analysis.
+ * Command LTTNG_DATA_PENDING returning 0 if the data is NOT pending meaning
+ * ready for trace analysis (or anykind of reader) or else 1 for pending data.
  */
-int cmd_data_available(struct ltt_session *session)
+int cmd_data_pending(struct ltt_session *session)
 {
 	int ret;
 	struct ltt_kernel_session *ksess = session->kernel_session;
@@ -2337,23 +2395,23 @@ int cmd_data_available(struct ltt_session *session)
 	}
 
 	if (ksess && ksess->consumer) {
-		ret = consumer_is_data_available(ksess->id, ksess->consumer);
-		if (ret == 0) {
+		ret = consumer_is_data_pending(ksess->id, ksess->consumer);
+		if (ret == 1) {
 			/* Data is still being extracted for the kernel. */
 			goto error;
 		}
 	}
 
 	if (usess && usess->consumer) {
-		ret = consumer_is_data_available(usess->id, usess->consumer);
-		if (ret == 0) {
+		ret = consumer_is_data_pending(usess->id, usess->consumer);
+		if (ret == 1) {
 			/* Data is still being extracted for the kernel. */
 			goto error;
 		}
 	}
 
 	/* Data is ready to be read by a viewer */
-	ret = 1;
+	ret = 0;
 
 error:
 	return ret;