X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=53850f74aae784b97a668f30c429c92cca8858be;hp=a17cc678ecab2363a95166b82f1c794a15c8ff96;hb=dbfee52cc949c9ac51976ef4680f2e145aa1f1a9;hpb=3285a971b225891df3dc7c2796176ce1f94665fe

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index a17cc678e..53850f74a 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -998,6 +998,8 @@ static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
 
 	/* Create socket for control stream. */
 	if (uri->stype == LTTNG_STREAM_CONTROL) {
+		uint64_t result_flags;
+
 		DBG3("Creating relayd stream socket from URI");
 
 		/* Check relayd version */
@@ -1012,6 +1014,16 @@ static enum lttng_error_code create_connect_relayd(struct lttng_uri *uri,
 		}
 		consumer->relay_major_version = rsock->major;
 		consumer->relay_minor_version = rsock->minor;
+		ret = relayd_get_configuration(rsock, 0,
+				&result_flags);
+		if (ret < 0) {
+			ERR("Unable to get relayd configuration");
+			status = LTTNG_ERR_RELAYD_CONNECT_FAIL;
+			goto close_sock;
+		}
+		if (result_flags & LTTCOMM_RELAYD_CONFIGURATION_FLAG_CLEAR_ALLOWED) {
+			consumer->relay_allows_clear = true;
+		}
 	} else if (uri->stype == LTTNG_STREAM_DATA) {
 		DBG3("Creating relayd data socket from URI");
 	} else {
@@ -1185,6 +1197,7 @@ int cmd_setup_relayd(struct ltt_session *session)
 
 	DBG("Setting relayd for session %s", session->name);
 
+	rcu_read_lock();
 	if (session->current_trace_chunk) {
 		enum lttng_trace_chunk_status status = lttng_trace_chunk_get_id(
 				session->current_trace_chunk, &current_chunk_id.value);
@@ -1198,8 +1211,6 @@ int cmd_setup_relayd(struct ltt_session *session)
 		}
 	}
 
-	rcu_read_lock();
-
 	if (usess && usess->consumer && usess->consumer->type == CONSUMER_DST_NET
 			&& usess->consumer->enabled) {
 		/* For each consumer socket, send relayd sockets */
@@ -1225,6 +1236,8 @@ int cmd_setup_relayd(struct ltt_session *session)
 			usess->consumer->relay_major_version;
 		session->consumer->relay_minor_version =
 			usess->consumer->relay_minor_version;
+		session->consumer->relay_allows_clear =
+			usess->consumer->relay_allows_clear;
 	}
 
 	if (ksess && ksess->consumer && ksess->consumer->type == CONSUMER_DST_NET
@@ -1251,6 +1264,8 @@ int cmd_setup_relayd(struct ltt_session *session)
 			ksess->consumer->relay_major_version;
 		session->consumer->relay_minor_version =
 			ksess->consumer->relay_minor_version;
+		session->consumer->relay_allows_clear =
+			ksess->consumer->relay_allows_clear;
 	}
 
 error:
@@ -1261,7 +1276,7 @@ error:
 /*
  * Start a kernel session by opening all necessary streams.
  */
-static int start_kernel_session(struct ltt_kernel_session *ksess)
+int start_kernel_session(struct ltt_kernel_session *ksess)
 {
 	int ret;
 	struct ltt_kernel_channel *kchan;
@@ -1323,6 +1338,53 @@ error:
 	return ret;
 }
 
+int stop_kernel_session(struct ltt_kernel_session *ksess)
+{
+	struct ltt_kernel_channel *kchan;
+	bool error_occurred = false;
+	int ret;
+
+	if (!ksess || !ksess->active) {
+		return LTTNG_OK;
+	}
+	DBG("Stopping kernel tracing");
+
+	ret = kernel_stop_session(ksess);
+	if (ret < 0) {
+		ret = LTTNG_ERR_KERN_STOP_FAIL;
+		goto error;
+	}
+
+	kernel_wait_quiescent();
+
+	/* Flush metadata after stopping (if exists) */
+	if (ksess->metadata_stream_fd >= 0) {
+		ret = kernel_metadata_flush_buffer(ksess->metadata_stream_fd);
+		if (ret < 0) {
+			ERR("Kernel metadata flush failed");
+			error_occurred = true;
+		}
+	}
+
+	/* Flush all buffers after stopping */
+	cds_list_for_each_entry(kchan, &ksess->channel_list.head, list) {
+		ret = kernel_flush_buffer(kchan);
+		if (ret < 0) {
+			ERR("Kernel flush buffer error");
+			error_occurred = true;
+		}
+	}
+
+	ksess->active = 0;
+	if (error_occurred) {
+		ret = LTTNG_ERR_UNK;
+	} else {
+		ret = LTTNG_OK;
+	}
+error:
+	return ret;
+}
+
 /*
  * Command LTTNG_DISABLE_CHANNEL processed by the client thread.
  */
@@ -2572,6 +2634,10 @@ int cmd_start_trace(struct ltt_session *session)
 	unsigned long nb_chan = 0;
 	struct ltt_kernel_session *ksession;
 	struct ltt_ust_session *usess;
+	const bool session_rotated_after_last_stop =
+			session->rotated_after_last_stop;
+	const bool session_cleared_after_last_stop =
+			session->cleared_after_last_stop;
 
 	assert(session);
 
@@ -2585,6 +2651,22 @@ int cmd_start_trace(struct ltt_session *session)
 		goto error;
 	}
 
+	if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING &&
+			!session->current_trace_chunk) {
+		/*
+		 * A rotation was launched while the session was stopped and
+		 * it has not been completed yet. It is not possible to start
+		 * the session since starting the session here would require a
+		 * rotation from "NULL" to a new trace chunk. That rotation
+		 * would overlap with the ongoing rotation, which is not
+		 * supported.
+		 */
+		WARN("Refusing to start session \"%s\" as a rotation launched after the last \"stop\" is still ongoing",
+				session->name);
+		ret = LTTNG_ERR_ROTATION_PENDING;
+		goto error;
+	}
+
 	/*
 	 * Starting a session without channel is useless since after that it's not
 	 * possible to enable channel thus inform the client.
@@ -2600,21 +2682,47 @@ int cmd_start_trace(struct ltt_session *session)
 		goto error;
 	}
 
+	session->active = 1;
+	session->rotated_after_last_stop = false;
+	session->cleared_after_last_stop = false;
 	if (session->output_traces && !session->current_trace_chunk) {
-		struct lttng_trace_chunk *trace_chunk;
+		if (!session->has_been_started) {
+			struct lttng_trace_chunk *trace_chunk;
 
-		trace_chunk = session_create_new_trace_chunk(
-				session, NULL, NULL, NULL);
-		if (!trace_chunk) {
-			ret = LTTNG_ERR_CREATE_DIR_FAIL;
-			goto error;
-		}
-		assert(!session->current_trace_chunk);
-		ret = session_set_trace_chunk(session, trace_chunk, NULL);
-		lttng_trace_chunk_put(trace_chunk);
-		if (ret) {
-			ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
-			goto error;
+			DBG("Creating initial trace chunk of session \"%s\"",
+					session->name);
+			trace_chunk = session_create_new_trace_chunk(
+					session, NULL, NULL, NULL);
+			if (!trace_chunk) {
+				ret = LTTNG_ERR_CREATE_DIR_FAIL;
+				goto error;
+			}
+			assert(!session->current_trace_chunk);
+			ret = session_set_trace_chunk(session, trace_chunk,
+					NULL);
+			lttng_trace_chunk_put(trace_chunk);
+			if (ret) {
+				ret = LTTNG_ERR_CREATE_TRACE_CHUNK_FAIL_CONSUMER;
+				goto error;
+			}
+		} else {
+			DBG("Rotating session \"%s\" from its current \"NULL\" trace chunk to a new chunk",
+					session->name);
+			/*
+			 * Rotate existing streams into the new chunk.
+			 * This is a "quiet" rotation has no client has
+			 * explicitly requested this operation.
+			 *
+			 * There is also no need to wait for the rotation
+			 * to complete as it will happen immediately. No data
+			 * was produced as the session was stopped, so the
+			 * rotation should happen on reception of the command.
+			 */
+			ret = cmd_rotate_session(session, NULL, true,
+					LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
+			if (ret != LTTNG_OK) {
+				goto error;
+			}
 		}
 	}
 
@@ -2637,10 +2745,6 @@ int cmd_start_trace(struct ltt_session *session)
 		}
 	}
 
-	/* Flag this after a successful start. */
-	session->has_been_started = 1;
-	session->active = 1;
-
 	/*
 	 * Clear the flag that indicates that a rotation was done while the
 	 * session was stopped.
@@ -2661,6 +2765,17 @@ int cmd_start_trace(struct ltt_session *session)
 	ret = LTTNG_OK;
 
 error:
+	if (ret == LTTNG_OK) {
+		/* Flag this after a successful start. */
+		session->has_been_started |= 1;
+	} else {
+		session->active = 0;
+		/* Restore initial state on error. */
+		session->rotated_after_last_stop =
+				session_rotated_after_last_stop;
+		session->cleared_after_last_stop =
+				session_cleared_after_last_stop;
+	}
 	return ret;
 }
 
@@ -2670,14 +2785,12 @@ error:
 int cmd_stop_trace(struct ltt_session *session)
 {
 	int ret;
-	struct ltt_kernel_channel *kchan;
 	struct ltt_kernel_session *ksession;
 	struct ltt_ust_session *usess;
-	bool error_occurred = false;
 
 	assert(session);
 
-	DBG("Begin stop session %s (id %" PRIu64 ")", session->name, session->id);
+	DBG("Begin stop session \"%s\" (id %" PRIu64 ")", session->name, session->id);
 	/* Short cut */
 	ksession = session->kernel_session;
 	usess = session->ust_session;
@@ -2688,39 +2801,9 @@ int cmd_stop_trace(struct ltt_session *session)
 		goto error;
 	}
 
-	/* Kernel tracer */
-	if (ksession && ksession->active) {
-		DBG("Stop kernel tracing");
-
-		ret = kernel_stop_session(ksession);
-		if (ret < 0) {
-			ret = LTTNG_ERR_KERN_STOP_FAIL;
-			goto error;
-		}
-
-		kernel_wait_quiescent();
-
-		/* Flush metadata after stopping (if exists) */
-		if (ksession->metadata_stream_fd >= 0) {
-			ret = kernel_metadata_flush_buffer(ksession->metadata_stream_fd);
-			if (ret < 0) {
-				ERR("Kernel metadata flush failed");
-				error_occurred = true;
-			}
-		}
-
-		/* Flush all buffers after stopping */
-		cds_list_for_each_entry(kchan, &ksession->channel_list.head, list) {
-			ret = kernel_flush_buffer(kchan);
-			if (ret < 0) {
-				ERR("Kernel flush buffer error");
-				error_occurred = true;
-			}
-		}
-
-		ksession->active = 0;
-		DBG("Kernel session stopped %s (id %" PRIu64 ")", session->name,
-				session->id);
+	ret = stop_kernel_session(ksession);
+	if (ret != LTTNG_OK) {
+		goto error;
 	}
 
 	if (usess && usess->active) {
@@ -2731,14 +2814,55 @@ int cmd_stop_trace(struct ltt_session *session)
 		}
 	}
 
+	DBG("Completed stop session \"%s\" (id %" PRIu64 ")", session->name,
+			session->id);
 	/* Flag inactive after a successful stop. */
 	session->active = 0;
-	ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
+	ret = LTTNG_OK;
 
 error:
 	return ret;
 }
 
+/*
+ * Set the base_path of the session only if subdir of a control uris is set.
+ * Return LTTNG_OK on success, otherwise LTTNG_ERR_*.
+ */
+static int set_session_base_path_from_uris(struct ltt_session *session,
+		size_t nb_uri,
+		struct lttng_uri *uris)
+{
+	int ret;
+	size_t i;
+
+	for (i = 0; i < nb_uri; i++) {
+		if (uris[i].stype != LTTNG_STREAM_CONTROL ||
+				uris[i].subdir[0] == '\0') {
+			/* Not interested in these URIs */
+			continue;
+		}
+
+		if (session->base_path != NULL) {
+			free(session->base_path);
+			session->base_path = NULL;
+		}
+
+		/* Set session base_path */
+		session->base_path = strdup(uris[i].subdir);
+		if (!session->base_path) {
+			PERROR("Failed to copy base path \"%s\" to session \"%s\"",
+					uris[i].subdir, session->name);
+			ret = LTTNG_ERR_NOMEM;
+			goto error;
+		}
+		DBG2("Setting base path \"%s\" for session \"%s\"",
+				session->base_path, session->name);
+	}
+	ret = LTTNG_OK;
+error:
+	return ret;
+}
+
 /*
  * Command LTTNG_SET_CONSUMER_URI processed by the client thread.
  */
@@ -2759,11 +2883,20 @@ int cmd_set_consumer_uri(struct ltt_session *session, size_t nb_uri,
 		goto error;
 	}
 
+	/*
+	 * Set the session base path if any. This is done inside
+	 * cmd_set_consumer_uri to preserve backward compatibility of the
+	 * previous session creation api vs the session descriptor api.
+	 */
+	ret = set_session_base_path_from_uris(session, nb_uri, uris);
+	if (ret != LTTNG_OK) {
+		goto error;
+	}
+
 	/* Set the "global" consumer URIs */
 	for (i = 0; i < nb_uri; i++) {
-		ret = add_uri_to_consumer(session,
-				session->consumer,
-				&uris[i], LTTNG_DOMAIN_NONE);
+		ret = add_uri_to_consumer(session, session->consumer, &uris[i],
+				LTTNG_DOMAIN_NONE);
 		if (ret != LTTNG_OK) {
 			goto error;
 		}
@@ -2894,7 +3027,6 @@ enum lttng_error_code cmd_create_session_from_descriptor(
 	const char *session_name;
 	struct ltt_session *new_session = NULL;
 	enum lttng_session_descriptor_status descriptor_status;
-	const char *base_path;
 
 	session_lock_list();
 	if (home_path) {
@@ -2917,13 +3049,9 @@ enum lttng_error_code cmd_create_session_from_descriptor(
 		ret_code = LTTNG_ERR_INVALID;
 		goto end;
 	}
-	ret = lttng_session_descriptor_get_base_path(descriptor, &base_path);
-	if (ret) {
-		ret_code = LTTNG_ERR_INVALID;
-		goto end;
-	}
+
 	ret_code = session_create(session_name, creds->uid, creds->gid,
-			base_path, &new_session);
+			&new_session);
 	if (ret_code != LTTNG_OK) {
 		goto end;
 	}
@@ -3200,14 +3328,13 @@ int cmd_destroy_session(struct ltt_session *session,
 		session->rotate_size = 0;
 	}
 
-	if (session->most_recent_chunk_id.is_set &&
-			session->most_recent_chunk_id.value != 0 &&
-			session->current_trace_chunk && session->output_traces) {
+	if (session->rotated && session->current_trace_chunk && session->output_traces) {
 		/*
 		 * Perform a last rotation on destruction if rotations have
 		 * occurred during the session's lifetime.
 		 */
-		ret = cmd_rotate_session(session, NULL, false);
+		ret = cmd_rotate_session(session, NULL, false,
+			LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED);
 		if (ret != LTTNG_OK) {
 			ERR("Failed to perform an implicit rotation as part of the destruction of session \"%s\": %s",
 					session->name, lttng_strerror(-ret));
@@ -3226,7 +3353,8 @@ int cmd_destroy_session(struct ltt_session *session,
 		 * emitted and no renaming of the current trace chunk takes
 		 * place.
 		 */
-		ret = cmd_rotate_session(session, NULL, true);
+		ret = cmd_rotate_session(session, NULL, true,
+			LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION);
 		if (ret != LTTNG_OK) {
 			ERR("Failed to perform a quiet rotation as part of the destruction of session \"%s\": %s",
 					session->name, lttng_strerror(-ret));
@@ -4585,8 +4713,14 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
 		}
 	}
 
-	if (session_close_trace_chunk(
-			    session, session->current_trace_chunk, NULL, NULL)) {
+	if (session_set_trace_chunk(session, NULL, &snapshot_trace_chunk)) {
+		ERR("Failed to release the current trace chunk of session \"%s\"",
+				session->name);
+		ret_code = LTTNG_ERR_UNK;
+	}
+
+	if (session_close_trace_chunk(session, snapshot_trace_chunk,
+			LTTNG_TRACE_CHUNK_COMMAND_TYPE_NO_OPERATION, NULL)) {
 		/*
 		 * Don't goto end; make sure the chunk is closed for the session
 		 * to allow future snapshots.
@@ -4595,11 +4729,6 @@ enum lttng_error_code snapshot_record(struct ltt_session *session,
 				session->name);
 		ret_code = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
 	}
-	if (session_set_trace_chunk(session, NULL, NULL)) {
-		ERR("Failed to release the current trace chunk of session \"%s\"",
-				session->name);
-		ret_code = LTTNG_ERR_UNK;
-	}
 error:
 	if (original_ust_consumer_output) {
 		session->ust_session->consumer = original_ust_consumer_output;
@@ -4780,7 +4909,8 @@ int cmd_set_session_shm_path(struct ltt_session *session,
  */
 int cmd_rotate_session(struct ltt_session *session,
 		struct lttng_rotate_session_return *rotate_return,
-		bool quiet_rotation)
+		bool quiet_rotation,
+		enum lttng_trace_chunk_command_type command)
 {
 	int ret;
 	uint64_t ongoing_rotation_chunk_id;
@@ -4788,6 +4918,8 @@ int cmd_rotate_session(struct ltt_session *session,
 	struct lttng_trace_chunk *chunk_being_archived = NULL;
 	struct lttng_trace_chunk *new_trace_chunk = NULL;
 	enum lttng_trace_chunk_status chunk_status;
+	bool failed_to_rotate = false;
+	enum lttng_error_code rotation_fail_code = LTTNG_OK;
 
 	assert(session);
 
@@ -4816,6 +4948,12 @@ int cmd_rotate_session(struct ltt_session *session,
 		goto end;
 	}
 
+	/* Unsupported feature in lttng-modules before 2.8 (lack of sequence number). */
+	if (session->kernel_session && !kernel_supports_ring_buffer_packet_sequence_number()) {
+		cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE_KERNEL;
+		goto end;
+	}
+
 	if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
 		DBG("Refusing to launch a rotation; a rotation is already in progress for session %s",
 				session->name);
@@ -4834,7 +4972,16 @@ int cmd_rotate_session(struct ltt_session *session,
 		goto end;
 	}
 
-	session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
+	/*
+	 * After a stop followed by a clear, disallow following rotations a they would
+	 * generate empty chunks.
+	 */
+	if (session->cleared_after_last_stop) {
+		DBG("Session \"%s\" was already cleared after stop, refusing rotation",
+				session->name);
+		cmd_ret = LTTNG_ERR_ROTATION_AFTER_STOP_CLEAR;
+		goto end;
+	}
 
 	if (session->active) {
 		new_trace_chunk = session_create_new_trace_chunk(session, NULL,
@@ -4845,7 +4992,13 @@ int cmd_rotate_session(struct ltt_session *session,
 		}
         }
 
-        /* The current trace chunk becomes the chunk being archived. */
+	/*
+	 * The current trace chunk becomes the chunk being archived.
+	 *
+	 * After this point, "chunk_being_archived" must absolutely
+	 * be closed on the consumer(s), otherwise it will never be
+	 * cleaned-up, which will result in a leak.
+	 */
 	ret = session_set_trace_chunk(session, new_trace_chunk,
 			&chunk_being_archived);
 	if (ret) {
@@ -4853,35 +5006,53 @@ int cmd_rotate_session(struct ltt_session *session,
 		goto error;
 	}
 
-	assert(chunk_being_archived);
-	chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
-			&ongoing_rotation_chunk_id);
-	assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
-
 	if (session->kernel_session) {
 		cmd_ret = kernel_rotate_session(session);
 		if (cmd_ret != LTTNG_OK) {
-			goto error;
+			failed_to_rotate = true;
+			rotation_fail_code = cmd_ret;
 		}
 	}
 	if (session->ust_session) {
 		cmd_ret = ust_app_rotate_session(session);
 		if (cmd_ret != LTTNG_OK) {
+			failed_to_rotate = true;
+			rotation_fail_code = cmd_ret;
+		}
+	}
+
+	if (!session->active) {
+		session->rotated_after_last_stop = true;
+	}
+
+	if (!chunk_being_archived) {
+		DBG("Rotating session \"%s\" from a \"NULL\" trace chunk to a new trace chunk, skipping completion check",
+				session->name);
+		if (failed_to_rotate) {
+			cmd_ret = rotation_fail_code;
 			goto error;
 		}
+		cmd_ret = LTTNG_OK;
+		goto end;
 	}
 
+	session->rotation_state = LTTNG_ROTATION_STATE_ONGOING;
+	chunk_status = lttng_trace_chunk_get_id(chunk_being_archived,
+			&ongoing_rotation_chunk_id);
+	assert(chunk_status == LTTNG_TRACE_CHUNK_STATUS_OK);
+
 	ret = session_close_trace_chunk(session, chunk_being_archived,
-			quiet_rotation ?
-					NULL :
-					&((enum lttng_trace_chunk_command_type){
-							LTTNG_TRACE_CHUNK_COMMAND_TYPE_MOVE_TO_COMPLETED}),
-			session->last_chunk_path);
+		command, session->last_chunk_path);
 	if (ret) {
 		cmd_ret = LTTNG_ERR_CLOSE_TRACE_CHUNK_FAIL_CONSUMER;
 		goto error;
 	}
 
+	if (failed_to_rotate) {
+		cmd_ret = rotation_fail_code;
+		goto error;
+	}
+
 	session->quiet_rotation = quiet_rotation;
 	ret = timer_session_rotation_pending_check_start(session,
 			DEFAULT_ROTATE_PENDING_TIMER);
@@ -4890,10 +5061,6 @@ int cmd_rotate_session(struct ltt_session *session,
 		goto error;
 	}
 
-	if (!session->active) {
-		session->rotated_after_last_stop = true;
-	}
-
 	if (rotate_return) {
 		rotate_return->rotation_id = ongoing_rotation_chunk_id;
 	}
@@ -4968,7 +5135,7 @@ int cmd_rotate_get_info(struct ltt_session *session,
 
 	switch (rotation_state) {
 	case LTTNG_ROTATION_STATE_NO_ROTATION:
-		DBG("Reporting that no rotation has occured within the lifetime of session \"%s\"",
+		DBG("Reporting that no rotation has occurred within the lifetime of session \"%s\"",
 				session->name);
 		goto end;
 	case LTTNG_ROTATION_STATE_EXPIRED: