X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fbin%2Flttng-sessiond%2Fcmd.c;h=507274f35568bc421887ebfb88674d476297af1d;hp=0f76ac71581935ab39c3c8fd57d1c29983aca2a2;hb=124473a3e6a82e10bbb23727fdff6e1f0c0415cb;hpb=9a6545985844978f34f88b82bf1bcd649968c0a3

diff --git a/src/bin/lttng-sessiond/cmd.c b/src/bin/lttng-sessiond/cmd.c
index 0f76ac715..507274f35 100644
--- a/src/bin/lttng-sessiond/cmd.c
+++ b/src/bin/lttng-sessiond/cmd.c
@@ -2732,7 +2732,7 @@ int cmd_stop_trace(struct ltt_session *session)
 	struct ltt_kernel_channel *kchan;
 	struct ltt_kernel_session *ksession;
 	struct ltt_ust_session *usess;
-	bool error_occured = false;
+	bool error_occurred = false;
 
 	assert(session);
 
@@ -2747,32 +2747,6 @@ int cmd_stop_trace(struct ltt_session *session)
 		goto error;
 	}
 
-	if (session->rotation_schedule_timer_enabled) {
-		if (timer_session_rotation_schedule_timer_stop(
-				session)) {
-			ERR("Failed to stop the \"rotation schedule\" timer of session %s",
-					session->name);
-		}
-	}
-
-	/*
-	 * A rotation is still ongoing. The check timer will continue to wait
-	 * for the rotation to complete. When the rotation finally completes,
-	 * a check will be performed to rename the "active" chunk to the
-	 * expected "timestamp_begin-timestamp_end" format.
-	 */
-	if (session->current_archive_id > 0 &&
-			session->rotation_state != LTTNG_ROTATION_STATE_ONGOING) {
-		ret = rename_active_chunk(session);
-		if (ret) {
-			/*
-			 * This error should not prevent the user from stopping
-			 * the session. However, it will be reported at the end.
-			 */
-			error_occured = true;
-		}
-	}
-
 	/* Kernel tracer */
 	if (ksession && ksession->active) {
 		DBG("Stop kernel tracing");
@@ -2822,7 +2796,7 @@ int cmd_stop_trace(struct ltt_session *session)
 
 	/* Flag inactive after a successful stop. */
 	session->active = 0;
-	ret = !error_occured ? LTTNG_OK : LTTNG_ERR_UNK;
+	ret = !error_occurred ? LTTNG_OK : LTTNG_ERR_UNK;
 
 error:
 	return ret;
@@ -2910,39 +2884,31 @@ int cmd_create_session_uri(char *name, struct lttng_uri *uris,
 		size_t nb_uri, lttng_sock_cred *creds, unsigned int live_timer)
 {
 	int ret;
-	struct ltt_session *session;
+	struct ltt_session *session = NULL;
 
 	assert(name);
 	assert(creds);
 
-	/*
-	 * Verify if the session already exist
-	 *
-	 * XXX: There is no need for the session lock list here since the caller
-	 * (process_client_msg) is holding it. We might want to change that so a
-	 * single command does not lock the entire session list.
-	 */
+	/* Check if the session already exists. */
+	session_lock_list();
 	session = session_find_by_name(name);
+	session_unlock_list();
 	if (session != NULL) {
 		ret = LTTNG_ERR_EXIST_SESS;
-		goto find_error;
+		goto end;
 	}
 
 	/* Create tracing session in the registry */
 	ret = session_create(name, LTTNG_SOCK_GET_UID_CRED(creds),
 			LTTNG_SOCK_GET_GID_CRED(creds));
 	if (ret != LTTNG_OK) {
-		goto session_error;
+		goto end;
 	}
 
-	/*
-	 * Get the newly created session pointer back
-	 *
-	 * XXX: There is no need for the session lock list here since the caller
-	 * (process_client_msg) is holding it. We might want to change that so a
-	 * single command does not lock the entire session list.
-	 */
+	/* Get the newly created session pointer back. */
+	session_lock_list();
 	session = session_find_by_name(name);
+	session_unlock_list();
 	assert(session);
 
 	session->live_timer = live_timer;
@@ -2950,13 +2916,13 @@ int cmd_create_session_uri(char *name, struct lttng_uri *uris,
 	session->consumer = consumer_create_output(CONSUMER_DST_LOCAL);
 	if (session->consumer == NULL) {
 		ret = LTTNG_ERR_FATAL;
-		goto consumer_error;
+		goto end;
 	}
 
 	if (uris) {
 		ret = cmd_set_consumer_uri(session, nb_uri, uris);
 		if (ret != LTTNG_OK) {
-			goto consumer_error;
+			goto end;
 		}
 		session->output_traces = 1;
 	} else {
@@ -2966,12 +2932,13 @@ int cmd_create_session_uri(char *name, struct lttng_uri *uris,
 
 	session->consumer->enabled = 1;
 
-	return LTTNG_OK;
-
-consumer_error:
-	session_destroy(session);
-session_error:
-find_error:
+	ret = LTTNG_OK;
+end:
+	if (session) {
+		session_lock_list();
+		session_put(session);
+		session_unlock_list();
+	}
 	return ret;
 }
 
@@ -2982,7 +2949,7 @@ int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
 		size_t nb_uri, lttng_sock_cred *creds)
 {
 	int ret;
-	struct ltt_session *session;
+	struct ltt_session *session = NULL;
 	struct snapshot_output *new_output = NULL;
 
 	assert(name);
@@ -2994,11 +2961,13 @@ int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
 	 */
 	ret = cmd_create_session_uri(name, NULL, 0, creds, 0);
 	if (ret != LTTNG_OK) {
-		goto error;
+		goto end;
 	}
 
 	/* Get the newly created session pointer back. This should NEVER fail. */
+	session_lock_list();
 	session = session_find_by_name(name);
+	session_unlock_list();
 	assert(session);
 
 	/* Flag session for snapshot mode. */
@@ -3006,6 +2975,7 @@ int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
 
 	/* Skip snapshot output creation if no URI is given. */
 	if (nb_uri == 0) {
+		/* Not an error. */
 		goto end;
 	}
 
@@ -3030,14 +3000,18 @@ int cmd_create_session_snapshot(char *name, struct lttng_uri *uris,
 	snapshot_add_output(&session->snapshot, new_output);
 	rcu_read_unlock();
 
-end:
-	return LTTNG_OK;
+	ret = LTTNG_OK;
+	goto end;
 
 error_snapshot:
 	snapshot_output_destroy(new_output);
 error_snapshot_alloc:
-	session_destroy(session);
-error:
+end:
+	if (session) {
+		session_lock_list();
+		session_put(session);
+		session_unlock_list();
+	}
 	return ret;
 }
 
@@ -3046,28 +3020,16 @@ error:
  *
  * Called with session lock held.
  */
-int cmd_destroy_session(struct ltt_session *session, int wpipe,
+int cmd_destroy_session(struct ltt_session *session,
 		struct notification_thread_handle *notification_thread_handle)
 {
 	int ret;
-	struct ltt_ust_session *usess;
-	struct ltt_kernel_session *ksess;
 
 	/* Safety net */
 	assert(session);
 
-	usess = session->ust_session;
-	ksess = session->kernel_session;
-
 	DBG("Begin destroy session %s (id %" PRIu64 ")", session->name, session->id);
 
-	if (session->rotation_pending_check_timer_enabled) {
-		if (timer_session_rotation_pending_check_stop(session)) {
-			ERR("Failed to stop the \"rotation pending check\" timer of session %s",
-					session->name);
-		}
-	}
-
 	if (session->rotation_schedule_timer_enabled) {
 		if (timer_session_rotation_schedule_timer_stop(
 				session)) {
@@ -3081,40 +3043,27 @@ int cmd_destroy_session(struct ltt_session *session, int wpipe,
 		session->rotate_size = 0;
 	}
 
-	/*
-	 * The rename of the current chunk is performed at stop, but if we rotated
-	 * the session after the previous stop command, we need to rename the
-	 * new (and empty) chunk that was started in between.
-	 */
-	if (session->rotated_after_last_stop) {
-		rename_active_chunk(session);
-	}
-
-	/* Clean kernel session teardown */
-	kernel_destroy_session(ksess);
-
-	/* UST session teardown */
-	if (usess) {
-		/* Close any relayd session */
-		consumer_output_send_destroy_relayd(usess->consumer);
-
-		/* Destroy every UST application related to this session. */
-		ret = ust_app_destroy_trace_all(usess);
-		if (ret) {
-			ERR("Error in ust_app_destroy_trace_all");
+	if (session->current_archive_id != 0) {
+		if (!session->rotated_after_last_stop) {
+			ret = cmd_rotate_session(session, NULL);
+			if (ret != LTTNG_OK) {
+				ERR("Failed to perform an implicit rotation as part of the rotation: %s", lttng_strerror(-ret));
+			}
+		} else {
+			/*
+			 * Rename the active chunk to ensure it has a name
+			 * of the form ts_begin-ts_end-id.
+			 *
+			 * Note that no trace data has been produced since
+			 * the last rotation; the directory should be
+			 * removed.
+			 */
+			ret = rename_active_chunk(session);
+			if (ret) {
+				ERR("Failed to rename active chunk during the destruction of session \"%s\"",
+						session->name);
+			}
 		}
-
-		/* Clean up the rest. */
-		trace_ust_destroy_session(usess);
-	}
-
-	/*
-	 * Must notify the kernel thread here to update it's poll set in order to
-	 * remove the channel(s)' fd just destroyed.
-	 */
-	ret = notify_thread_pipe(wpipe);
-	if (ret < 0) {
-		PERROR("write kernel poll pipe");
 	}
 
 	if (session->shm_path[0]) {
@@ -3170,7 +3119,14 @@ int cmd_destroy_session(struct ltt_session *session, int wpipe,
 				sizeof(destroy_completion_handler.shm_path));
 		assert(!ret);
 	}
-	ret = session_destroy(session);
+
+	/*
+	 * The session is destroyed. However, note that the command context
+	 * still holds a reference to the session, thus delaying its destruction
+	 * _at least_ up to the point when that reference is released.
+	 */
+	session_destroy(session);
+	ret = LTTNG_OK;
 
 	return ret;
 }
@@ -3475,10 +3431,15 @@ void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
 	 * the buffer.
 	 */
 	cds_list_for_each_entry(session, &list->head, list) {
+		if (!session_get(session)) {
+			continue;
+		}
 		/*
 		 * Only list the sessions the user can control.
 		 */
-		if (!session_access_ok(session, uid, gid)) {
+		if (!session_access_ok(session, uid, gid) ||
+				session->destroyed) {
+			session_put(session);
 			continue;
 		}
 
@@ -3496,6 +3457,7 @@ void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
 		}
 		if (ret < 0) {
 			PERROR("snprintf session path");
+			session_put(session);
 			continue;
 		}
 
@@ -3505,6 +3467,7 @@ void cmd_list_lttng_sessions(struct lttng_session *sessions, uid_t uid,
 		sessions[i].snapshot_mode = session->snapshot_mode;
 		sessions[i].live_timer_interval = session->live_timer;
 		i++;
+		session_put(session);
 	}
 }
 
@@ -4620,7 +4583,7 @@ int cmd_rotate_session(struct ltt_session *session,
 
 	now = time(NULL);
 	if (now == (time_t) -1) {
-		cmd_ret = LTTNG_ERR_ROTATION_NOT_AVAILABLE;
+		cmd_ret = LTTNG_ERR_UNK;
 		goto end;
 	}