Fix: rotation thread does not unregister from RCU on init error
[lttng-tools.git] / src / bin / lttng-sessiond / rotation-thread.c
1 /*
2 * Copyright (C) 2017 - Julien Desfossez <jdesfossez@efficios.com>
3 * Copyright (C) 2018 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License, version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 51
16 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _LGPL_SOURCE
20 #include <lttng/trigger/trigger.h>
21 #include <common/error.h>
22 #include <common/config/session-config.h>
23 #include <common/defaults.h>
24 #include <common/utils.h>
25 #include <common/futex.h>
26 #include <common/align.h>
27 #include <common/time.h>
28 #include <common/hashtable/utils.h>
29 #include <sys/eventfd.h>
30 #include <sys/stat.h>
31 #include <time.h>
32 #include <signal.h>
33 #include <inttypes.h>
34
35 #include <common/kernel-ctl/kernel-ctl.h>
36 #include <lttng/notification/channel-internal.h>
37 #include <lttng/rotate-internal.h>
38
39 #include "rotation-thread.h"
40 #include "lttng-sessiond.h"
41 #include "health-sessiond.h"
42 #include "rotate.h"
43 #include "cmd.h"
44 #include "session.h"
45 #include "timer.h"
46 #include "notification-thread-commands.h"
47
48 #include <urcu.h>
49 #include <urcu/list.h>
50
51 struct lttng_notification_channel *rotate_notification_channel = NULL;
52
53 struct rotation_thread {
54 struct lttng_poll_event events;
55 };
56
57 struct rotation_thread_job {
58 enum rotation_thread_job_type type;
59 uint64_t session_id;
60 /* List member in struct rotation_thread_timer_queue. */
61 struct cds_list_head head;
62 };
63
64 /*
65 * The timer thread enqueues jobs and wakes up the rotation thread.
66 * When the rotation thread wakes up, it empties the queue.
67 */
68 struct rotation_thread_timer_queue {
69 struct lttng_pipe *event_pipe;
70 struct cds_list_head list;
71 pthread_mutex_t lock;
72 };
73
74 struct rotation_thread_handle {
75 int quit_pipe;
76 struct rotation_thread_timer_queue *rotation_timer_queue;
77 /* Access to the notification thread cmd_queue */
78 struct notification_thread_handle *notification_thread_handle;
79 sem_t *notification_thread_ready;
80 };
81
82 static
83 const char *get_job_type_str(enum rotation_thread_job_type job_type)
84 {
85 switch (job_type) {
86 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
87 return "CHECK_PENDING_ROTATION";
88 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
89 return "SCHEDULED_ROTATION";
90 default:
91 abort();
92 }
93 }
94
95 struct rotation_thread_timer_queue *rotation_thread_timer_queue_create(void)
96 {
97 struct rotation_thread_timer_queue *queue = NULL;
98
99 queue = zmalloc(sizeof(*queue));
100 if (!queue) {
101 PERROR("Failed to allocate timer rotate queue");
102 goto end;
103 }
104
105 queue->event_pipe = lttng_pipe_open(FD_CLOEXEC | O_NONBLOCK);
106 CDS_INIT_LIST_HEAD(&queue->list);
107 pthread_mutex_init(&queue->lock, NULL);
108 end:
109 return queue;
110 }
111
112 void log_job_destruction(const struct rotation_thread_job *job)
113 {
114 enum lttng_error_level log_level;
115 const char *job_type_str = get_job_type_str(job->type);
116
117 switch (job->type) {
118 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
119 /*
120 * Not a problem, the scheduled rotation is racing with the teardown
121 * of the daemon. In this case, the rotation will not happen, which
122 * is not a problem (or at least, not important enough to delay
123 * the shutdown of the session daemon).
124 */
125 log_level = PRINT_DBG;
126 break;
127 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
128 /* This is not expected to happen; warn the user. */
129 log_level = PRINT_WARN;
130 break;
131 default:
132 abort();
133 }
134
135 LOG(log_level, "Rotation thread timer queue still contains job of type %s targeting session %" PRIu64 " on destruction",
136 job_type_str, job->session_id);
137 }
138
139 void rotation_thread_timer_queue_destroy(
140 struct rotation_thread_timer_queue *queue)
141 {
142 struct rotation_thread_job *job, *tmp_job;
143
144 if (!queue) {
145 return;
146 }
147
148 lttng_pipe_destroy(queue->event_pipe);
149
150 pthread_mutex_lock(&queue->lock);
151 /* Empty wait queue. */
152 cds_list_for_each_entry_safe(job, tmp_job, &queue->list, head) {
153 log_job_destruction(job);
154 cds_list_del(&job->head);
155 free(job);
156 }
157 pthread_mutex_unlock(&queue->lock);
158 pthread_mutex_destroy(&queue->lock);
159 free(queue);
160 }
161
162 /*
163 * Destroy the thread data previously created by the init function.
164 */
165 void rotation_thread_handle_destroy(
166 struct rotation_thread_handle *handle)
167 {
168 free(handle);
169 }
170
171 struct rotation_thread_handle *rotation_thread_handle_create(
172 int quit_pipe,
173 struct rotation_thread_timer_queue *rotation_timer_queue,
174 struct notification_thread_handle *notification_thread_handle,
175 sem_t *notification_thread_ready)
176 {
177 struct rotation_thread_handle *handle;
178
179 handle = zmalloc(sizeof(*handle));
180 if (!handle) {
181 goto end;
182 }
183
184 handle->quit_pipe = quit_pipe;
185 handle->rotation_timer_queue = rotation_timer_queue;
186 handle->notification_thread_handle = notification_thread_handle;
187 handle->notification_thread_ready = notification_thread_ready;
188
189 end:
190 return handle;
191 }
192
193 /*
194 * Called with the rotation_thread_timer_queue lock held.
195 * Return true if the same timer job already exists in the queue, false if not.
196 */
197 static
198 bool timer_job_exists(const struct rotation_thread_timer_queue *queue,
199 enum rotation_thread_job_type job_type, uint64_t session_id)
200 {
201 bool exists = false;
202 struct rotation_thread_job *job;
203
204 cds_list_for_each_entry(job, &queue->list, head) {
205 if (job->session_id == session_id && job->type == job_type) {
206 exists = true;
207 goto end;
208 }
209 }
210 end:
211 return exists;
212 }
213
214 void rotation_thread_enqueue_job(struct rotation_thread_timer_queue *queue,
215 enum rotation_thread_job_type job_type, uint64_t session_id)
216 {
217 int ret;
218 const char * const dummy = "!";
219 struct rotation_thread_job *job = NULL;
220 const char *job_type_str = get_job_type_str(job_type);
221
222 pthread_mutex_lock(&queue->lock);
223 if (timer_job_exists(queue, session_id, job_type)) {
224 /*
225 * This timer job is already pending, we don't need to add
226 * it.
227 */
228 goto end;
229 }
230
231 job = zmalloc(sizeof(struct rotation_thread_job));
232 if (!job) {
233 PERROR("Failed to allocate rotation thread job of type \"%s\" for session id %" PRIu64,
234 job_type_str, session_id);
235 goto end;
236 }
237 job->type = job_type;
238 job->session_id = session_id;
239 cds_list_add_tail(&job->head, &queue->list);
240
241 ret = lttng_write(lttng_pipe_get_writefd(queue->event_pipe), dummy,
242 1);
243 if (ret < 0) {
244 /*
245 * We do not want to block in the timer handler, the job has
246 * been enqueued in the list, the wakeup pipe is probably full,
247 * the job will be processed when the rotation_thread catches
248 * up.
249 */
250 if (errno == EAGAIN || errno == EWOULDBLOCK) {
251 /*
252 * Not an error, but would be surprising and indicate
253 * that the rotation thread can't keep up with the
254 * current load.
255 */
256 DBG("Wake-up pipe of rotation thread job queue is full");
257 goto end;
258 }
259 PERROR("Failed to wake-up the rotation thread after pushing a job of type \"%s\" for session id %" PRIu64,
260 job_type_str, session_id);
261 goto end;
262 }
263
264 end:
265 pthread_mutex_unlock(&queue->lock);
266 }
267
268 static
269 int init_poll_set(struct lttng_poll_event *poll_set,
270 struct rotation_thread_handle *handle)
271 {
272 int ret;
273
274 /*
275 * Create pollset with size 2:
276 * - quit pipe,
277 * - rotation thread timer queue pipe,
278 */
279 ret = lttng_poll_create(poll_set, 2, LTTNG_CLOEXEC);
280 if (ret < 0) {
281 goto end;
282 }
283
284 ret = lttng_poll_add(poll_set, handle->quit_pipe,
285 LPOLLIN | LPOLLERR);
286 if (ret < 0) {
287 ERR("[rotation-thread] Failed to add quit_pipe fd to pollset");
288 goto error;
289 }
290 ret = lttng_poll_add(poll_set,
291 lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe),
292 LPOLLIN | LPOLLERR);
293 if (ret < 0) {
294 ERR("[rotation-thread] Failed to add rotate_pending fd to pollset");
295 goto error;
296 }
297
298 end:
299 return ret;
300 error:
301 lttng_poll_clean(poll_set);
302 return ret;
303 }
304
305 static
306 void fini_thread_state(struct rotation_thread *state)
307 {
308 lttng_poll_clean(&state->events);
309 if (rotate_notification_channel) {
310 lttng_notification_channel_destroy(rotate_notification_channel);
311 }
312 }
313
314 static
315 int init_thread_state(struct rotation_thread_handle *handle,
316 struct rotation_thread *state)
317 {
318 int ret;
319
320 memset(state, 0, sizeof(*state));
321 lttng_poll_init(&state->events);
322
323 ret = init_poll_set(&state->events, handle);
324 if (ret) {
325 ERR("[rotation-thread] Failed to initialize rotation thread poll set");
326 goto end;
327 }
328
329 /*
330 * We wait until the notification thread is ready to create the
331 * notification channel and add it to the poll_set.
332 */
333 sem_wait(handle->notification_thread_ready);
334 rotate_notification_channel = lttng_notification_channel_create(
335 lttng_session_daemon_notification_endpoint);
336 if (!rotate_notification_channel) {
337 ERR("[rotation-thread] Could not create notification channel");
338 ret = -1;
339 goto end;
340 }
341 ret = lttng_poll_add(&state->events, rotate_notification_channel->socket,
342 LPOLLIN | LPOLLERR);
343 if (ret < 0) {
344 ERR("[rotation-thread] Failed to add notification fd to pollset");
345 goto end;
346 }
347
348 end:
349 return ret;
350 }
351
352 static
353 int check_session_rotation_pending_local_on_consumer(
354 const struct ltt_session *session,
355 struct consumer_socket *socket, bool *rotation_completed)
356 {
357 int ret;
358
359 pthread_mutex_lock(socket->lock);
360 DBG("[rotation-thread] Checking for locally pending rotation on the %s consumer for session %s",
361 lttng_consumer_type_str(socket->type),
362 session->name);
363 ret = consumer_check_rotation_pending_local(socket,
364 session->id,
365 session->current_archive_id - 1);
366 pthread_mutex_unlock(socket->lock);
367
368 if (ret == 0) {
369 /* Rotation was completed on this consumer. */
370 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" was completed on the %s consumer",
371 session->current_archive_id - 1,
372 session->name,
373 lttng_consumer_type_str(socket->type));
374 *rotation_completed = true;
375 } else if (ret == 1) {
376 /* Rotation pending on this consumer. */
377 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
378 session->current_archive_id - 1,
379 session->name,
380 lttng_consumer_type_str(socket->type));
381 *rotation_completed = false;
382 ret = 0;
383 } else {
384 /* Not a fatal error. */
385 ERR("[rotation-thread] Encountered an error when checking if local rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the %s consumer",
386 session->current_archive_id - 1,
387 session->name,
388 lttng_consumer_type_str(socket->type));
389 *rotation_completed = false;
390 }
391 return ret;
392 }
393
394 static
395 int check_session_rotation_pending_local(struct ltt_session *session)
396 {
397 int ret = 0;
398 struct consumer_socket *socket;
399 struct cds_lfht_iter iter;
400 bool rotation_completed = true;
401
402 /*
403 * Check for a local pending rotation on all consumers (32-bit
404 * user space, 64-bit user space, and kernel).
405 */
406 DBG("[rotation-thread] Checking for pending local rotation on session \"%s\", trace archive %" PRIu64,
407 session->name, session->current_archive_id - 1);
408
409 rcu_read_lock();
410 if (!session->ust_session) {
411 goto skip_ust;
412 }
413 cds_lfht_for_each_entry(session->ust_session->consumer->socks->ht,
414 &iter, socket, node.node) {
415 ret = check_session_rotation_pending_local_on_consumer(session,
416 socket, &rotation_completed);
417 if (ret || !rotation_completed) {
418 goto end;
419 }
420 }
421
422 skip_ust:
423 if (!session->kernel_session) {
424 goto skip_kernel;
425 }
426 cds_lfht_for_each_entry(session->kernel_session->consumer->socks->ht,
427 &iter, socket, node.node) {
428 ret = check_session_rotation_pending_local_on_consumer(session,
429 socket, &rotation_completed);
430 if (ret || !rotation_completed) {
431 goto end;
432 }
433 }
434 skip_kernel:
435 end:
436 rcu_read_unlock();
437
438 if (rotation_completed) {
439 DBG("[rotation-thread] Local rotation of trace archive %" PRIu64 " of session \"%s\" is complete on all consumers",
440 session->current_archive_id - 1,
441 session->name);
442 session->rotation_pending_local = false;
443 }
444 if (ret) {
445 session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
446 }
447 return 0;
448 }
449
450 static
451 int check_session_rotation_pending_relay(struct ltt_session *session)
452 {
453 int ret;
454 struct consumer_socket *socket;
455 struct cds_lfht_iter iter;
456 bool rotation_completed = true;
457 const struct consumer_output *output;
458
459 /*
460 * Check for a pending rotation on any consumer as we only use
461 * it as a "tunnel" to the relayd.
462 */
463
464 rcu_read_lock();
465 if (session->ust_session) {
466 cds_lfht_first(session->ust_session->consumer->socks->ht,
467 &iter);
468 output = session->ust_session->consumer;
469 } else {
470 cds_lfht_first(session->kernel_session->consumer->socks->ht,
471 &iter);
472 output = session->kernel_session->consumer;
473 }
474 assert(cds_lfht_iter_get_node(&iter));
475
476 socket = caa_container_of(cds_lfht_iter_get_node(&iter),
477 typeof(*socket), node.node);
478
479 pthread_mutex_lock(socket->lock);
480 DBG("[rotation-thread] Checking for pending relay rotation on session \"%s\", trace archive %" PRIu64 " through the %s consumer",
481 session->name, session->current_archive_id - 1,
482 lttng_consumer_type_str(socket->type));
483 ret = consumer_check_rotation_pending_relay(socket,
484 output,
485 session->id,
486 session->current_archive_id - 1);
487 pthread_mutex_unlock(socket->lock);
488
489 if (ret == 0) {
490 /* Rotation was completed on the relay. */
491 DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" was completed",
492 session->current_archive_id - 1,
493 session->name);
494 } else if (ret == 1) {
495 /* Rotation pending on relay. */
496 DBG("[rotation-thread] Relay rotation of trace archive %" PRIu64 " of session \"%s\" is pending",
497 session->current_archive_id - 1,
498 session->name);
499 rotation_completed = false;
500 } else {
501 /* Not a fatal error. */
502 ERR("[rotation-thread] Encountered an error when checking if rotation of trace archive %" PRIu64 " of session \"%s\" is pending on the relay",
503 session->current_archive_id - 1,
504 session->name);
505 session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
506 rotation_completed = false;
507 }
508
509 rcu_read_unlock();
510
511 if (rotation_completed) {
512 DBG("[rotation-thread] Totation of trace archive %" PRIu64 " of session \"%s\" is complete on the relay",
513 session->current_archive_id - 1,
514 session->name);
515 session->rotation_pending_relay = false;
516 }
517 return 0;
518 }
519
520 /*
521 * Check if the last rotation was completed, called with session lock held.
522 */
523 static
524 int check_session_rotation_pending(struct ltt_session *session,
525 struct notification_thread_handle *notification_thread_handle)
526 {
527 int ret;
528 struct lttng_trace_archive_location *location;
529 time_t now;
530
531 DBG("[rotation-thread] Checking for pending rotation on session \"%s\", trace archive %" PRIu64,
532 session->name, session->current_archive_id - 1);
533
534 if (session->rotation_pending_local) {
535 /* Updates session->rotation_pending_local as needed. */
536 ret = check_session_rotation_pending_local(session);
537 if (ret) {
538 goto end;
539 }
540
541 /*
542 * No need to check for a pending rotation on the relay
543 * since the rotation is not even completed locally yet.
544 */
545 if (session->rotation_pending_local) {
546 goto end;
547 }
548 }
549
550 if (session->rotation_pending_relay) {
551 /* Updates session->rotation_pending_relay as needed. */
552 ret = check_session_rotation_pending_relay(session);
553 if (ret) {
554 goto end;
555 }
556
557 if (session->rotation_pending_relay) {
558 goto end;
559 }
560 }
561
562 DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " completed for "
563 "session %s", session->current_archive_id - 1,
564 session->name);
565
566 /* Rename the completed trace archive's location. */
567 now = time(NULL);
568 if (now == (time_t) -1) {
569 session->rotation_state = LTTNG_ROTATION_STATE_ERROR;
570 ret = LTTNG_ERR_UNK;
571 goto end;
572 }
573
574 ret = rename_completed_chunk(session, now);
575 if (ret < 0) {
576 ERR("Failed to rename completed rotation chunk");
577 goto end;
578 }
579 session->last_chunk_start_ts = session->current_chunk_start_ts;
580
581 /*
582 * Now we can clear the "ONGOING" state in the session. New
583 * rotations can start now.
584 */
585 session->rotation_state = LTTNG_ROTATION_STATE_COMPLETED;
586
587 /* Ownership of location is transferred. */
588 location = session_get_trace_archive_location(session);
589 ret = notification_thread_command_session_rotation_completed(
590 notification_thread_handle,
591 session->name,
592 session->uid,
593 session->gid,
594 session->current_archive_id,
595 location);
596 if (ret != LTTNG_OK) {
597 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
598 session->name);
599 }
600
601 if (!session->active) {
602 /*
603 * A stop command was issued during the rotation, it is
604 * up to the rotation completion check to perform the
605 * renaming of the last chunk that was produced.
606 */
607 ret = notification_thread_command_session_rotation_ongoing(
608 notification_thread_handle,
609 session->name,
610 session->uid,
611 session->gid,
612 session->current_archive_id);
613 if (ret != LTTNG_OK) {
614 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
615 session->name);
616 }
617
618 ret = rename_active_chunk(session);
619 if (ret < 0) {
620 ERR("[rotation-thread] Failed to rename active rotation chunk");
621 goto end;
622 }
623
624 /* Ownership of location is transferred. */
625 location = session_get_trace_archive_location(session);
626 ret = notification_thread_command_session_rotation_completed(
627 notification_thread_handle,
628 session->name,
629 session->uid,
630 session->gid,
631 session->current_archive_id,
632 location);
633 if (ret != LTTNG_OK) {
634 ERR("[rotation-thread] Failed to notify notification thread of completed rotation for session %s",
635 session->name);
636 }
637 }
638
639 ret = 0;
640 end:
641 if (session->rotation_state == LTTNG_ROTATION_STATE_ONGOING) {
642 DBG("[rotation-thread] Rotation of trace archive %" PRIu64 " is still pending for session %s",
643 session->current_archive_id - 1, session->name);
644 ret = timer_session_rotation_pending_check_start(session,
645 DEFAULT_ROTATE_PENDING_TIMER);
646 if (ret) {
647 ERR("Re-enabling rotate pending timer");
648 ret = -1;
649 goto end;
650 }
651 }
652
653 return ret;
654 }
655
656 /* Call with the session lock held. */
657 static
658 int launch_session_rotation(struct ltt_session *session)
659 {
660 int ret;
661 struct lttng_rotate_session_return rotation_return;
662
663 DBG("[rotation-thread] Launching scheduled time-based rotation on session \"%s\"",
664 session->name);
665
666 ret = cmd_rotate_session(session, &rotation_return);
667 if (ret == LTTNG_OK) {
668 DBG("[rotation-thread] Scheduled time-based rotation successfully launched on session \"%s\"",
669 session->name);
670 } else {
671 /* Don't consider errors as fatal. */
672 DBG("[rotation-thread] Scheduled time-based rotation aborted for session %s: %s",
673 session->name, lttng_strerror(ret));
674 }
675 return 0;
676 }
677
678 static
679 int run_job(struct rotation_thread_job *job, struct ltt_session *session,
680 struct notification_thread_handle *notification_thread_handle)
681 {
682 int ret;
683
684 switch (job->type) {
685 case ROTATION_THREAD_JOB_TYPE_SCHEDULED_ROTATION:
686 ret = launch_session_rotation(session);
687 break;
688 case ROTATION_THREAD_JOB_TYPE_CHECK_PENDING_ROTATION:
689 ret = check_session_rotation_pending(session,
690 notification_thread_handle);
691 break;
692 default:
693 abort();
694 }
695 return ret;
696 }
697
698 static
699 int handle_job_queue(struct rotation_thread_handle *handle,
700 struct rotation_thread *state,
701 struct rotation_thread_timer_queue *queue)
702 {
703 int ret = 0;
704 int fd = lttng_pipe_get_readfd(queue->event_pipe);
705 struct ltt_session *session;
706 char buf;
707
708 ret = lttng_read(fd, &buf, 1);
709 if (ret != 1) {
710 ERR("[rotation-thread] Failed to read from wakeup pipe (fd = %i)", fd);
711 ret = -1;
712 goto end;
713 }
714
715 for (;;) {
716 struct rotation_thread_job *job;
717
718 /* Take the queue lock only to pop an element from the list. */
719 pthread_mutex_lock(&queue->lock);
720 if (cds_list_empty(&queue->list)) {
721 pthread_mutex_unlock(&queue->lock);
722 break;
723 }
724 job = cds_list_first_entry(&queue->list,
725 typeof(*job), head);
726 cds_list_del(&job->head);
727 pthread_mutex_unlock(&queue->lock);
728
729 session_lock_list();
730 session = session_find_by_id(job->session_id);
731 if (!session) {
732 DBG("[rotation-thread] Session %" PRIu64 " not found",
733 job->session_id);
734 /*
735 * This is a non-fatal error, and we cannot report it to
736 * the user (timer), so just print the error and
737 * continue the processing.
738 *
739 * While the timer thread will purge pending signals for
740 * a session on the session's destruction, it is
741 * possible for a job targeting that session to have
742 * already been queued before it was destroyed.
743 */
744 session_unlock_list();
745 free(job);
746 continue;
747 }
748
749 session_lock(session);
750 session_unlock_list();
751
752 ret = run_job(job, session, handle->notification_thread_handle);
753 session_unlock(session);
754 free(job);
755 if (ret) {
756 goto end;
757 }
758 }
759
760 ret = 0;
761
762 end:
763 return ret;
764 }
765
766 static
767 int handle_condition(const struct lttng_condition *condition,
768 const struct lttng_evaluation *evaluation,
769 struct notification_thread_handle *notification_thread_handle)
770 {
771 int ret = 0;
772 const char *condition_session_name = NULL;
773 enum lttng_condition_type condition_type;
774 enum lttng_condition_status condition_status;
775 enum lttng_evaluation_status evaluation_status;
776 uint64_t consumed;
777 struct ltt_session *session;
778
779 condition_type = lttng_condition_get_type(condition);
780
781 if (condition_type != LTTNG_CONDITION_TYPE_SESSION_CONSUMED_SIZE) {
782 ret = -1;
783 ERR("[rotation-thread] Condition type and session usage type are not the same");
784 goto end;
785 }
786
787 /* Fetch info to test */
788 condition_status = lttng_condition_session_consumed_size_get_session_name(
789 condition, &condition_session_name);
790 if (condition_status != LTTNG_CONDITION_STATUS_OK) {
791 ERR("[rotation-thread] Session name could not be fetched");
792 ret = -1;
793 goto end;
794 }
795 evaluation_status = lttng_evaluation_session_consumed_size_get_consumed_size(evaluation,
796 &consumed);
797 if (evaluation_status != LTTNG_EVALUATION_STATUS_OK) {
798 ERR("[rotation-thread] Failed to get evaluation");
799 ret = -1;
800 goto end;
801 }
802
803 session_lock_list();
804 session = session_find_by_name(condition_session_name);
805 if (!session) {
806 ret = -1;
807 session_unlock_list();
808 ERR("[rotation-thread] Session \"%s\" not found",
809 condition_session_name);
810 goto end;
811 }
812 session_lock(session);
813 session_unlock_list();
814
815 ret = unsubscribe_session_consumed_size_rotation(session,
816 notification_thread_handle);
817 if (ret) {
818 goto end;
819 }
820
821 ret = cmd_rotate_session(session, NULL);
822 if (ret == -LTTNG_ERR_ROTATION_PENDING) {
823 DBG("Rotate already pending, subscribe to the next threshold value");
824 } else if (ret != LTTNG_OK) {
825 ERR("[rotation-thread] Failed to rotate on size notification with error: %s",
826 lttng_strerror(ret));
827 ret = -1;
828 goto end_unlock;
829 }
830 ret = subscribe_session_consumed_size_rotation(session,
831 consumed + session->rotate_size,
832 notification_thread_handle);
833 if (ret) {
834 ERR("[rotation-thread] Failed to subscribe to session consumed size condition");
835 goto end_unlock;
836 }
837 ret = 0;
838
839 end_unlock:
840 session_unlock(session);
841 end:
842 return ret;
843 }
844
845 static
846 int handle_notification_channel(int fd,
847 struct rotation_thread_handle *handle,
848 struct rotation_thread *state)
849 {
850 int ret;
851 bool notification_pending;
852 struct lttng_notification *notification = NULL;
853 enum lttng_notification_channel_status status;
854 const struct lttng_evaluation *notification_evaluation;
855 const struct lttng_condition *notification_condition;
856
857 status = lttng_notification_channel_has_pending_notification(
858 rotate_notification_channel, &notification_pending);
859 if (status != LTTNG_NOTIFICATION_CHANNEL_STATUS_OK) {
860 ERR("[rotation-thread ]Error occured while checking for pending notification");
861 ret = -1;
862 goto end;
863 }
864
865 if (!notification_pending) {
866 ret = 0;
867 goto end;
868 }
869
870 /* Receive the next notification. */
871 status = lttng_notification_channel_get_next_notification(
872 rotate_notification_channel,
873 &notification);
874
875 switch (status) {
876 case LTTNG_NOTIFICATION_CHANNEL_STATUS_OK:
877 break;
878 case LTTNG_NOTIFICATION_CHANNEL_STATUS_NOTIFICATIONS_DROPPED:
879 /* Not an error, we will wait for the next one */
880 ret = 0;
881 goto end;;
882 case LTTNG_NOTIFICATION_CHANNEL_STATUS_CLOSED:
883 ERR("Notification channel was closed");
884 ret = -1;
885 goto end;
886 default:
887 /* Unhandled conditions / errors. */
888 ERR("Unknown notification channel status");
889 ret = -1;
890 goto end;
891 }
892
893 notification_condition = lttng_notification_get_condition(notification);
894 notification_evaluation = lttng_notification_get_evaluation(notification);
895
896 ret = handle_condition(notification_condition, notification_evaluation,
897 handle->notification_thread_handle);
898
899 end:
900 lttng_notification_destroy(notification);
901 return ret;
902 }
903
904 void *thread_rotation(void *data)
905 {
906 int ret;
907 struct rotation_thread_handle *handle = data;
908 struct rotation_thread thread;
909
910 DBG("[rotation-thread] Started rotation thread");
911
912 if (!handle) {
913 ERR("[rotation-thread] Invalid thread context provided");
914 goto end;
915 }
916
917 rcu_register_thread();
918 rcu_thread_online();
919
920 health_register(health_sessiond, HEALTH_SESSIOND_TYPE_ROTATION);
921 health_code_update();
922
923 ret = init_thread_state(handle, &thread);
924 if (ret) {
925 goto error;
926 }
927
928 /* Ready to handle client connections. */
929 sessiond_notify_ready();
930
931 while (true) {
932 int fd_count, i;
933
934 health_poll_entry();
935 DBG("[rotation-thread] Entering poll wait");
936 ret = lttng_poll_wait(&thread.events, -1);
937 DBG("[rotation-thread] Poll wait returned (%i)", ret);
938 health_poll_exit();
939 if (ret < 0) {
940 /*
941 * Restart interrupted system call.
942 */
943 if (errno == EINTR) {
944 continue;
945 }
946 ERR("[rotation-thread] Error encountered during lttng_poll_wait (%i)", ret);
947 goto error;
948 }
949
950 fd_count = ret;
951 for (i = 0; i < fd_count; i++) {
952 int fd = LTTNG_POLL_GETFD(&thread.events, i);
953 uint32_t revents = LTTNG_POLL_GETEV(&thread.events, i);
954
955 DBG("[rotation-thread] Handling fd (%i) activity (%u)",
956 fd, revents);
957
958 if (revents & LPOLLERR) {
959 ERR("[rotation-thread] Polling returned an error on fd %i", fd);
960 goto error;
961 }
962
963 if (fd == handle->quit_pipe) {
964 DBG("[rotation-thread] Quit pipe activity");
965 /* TODO flush the queue. */
966 goto exit;
967 } else if (fd == lttng_pipe_get_readfd(handle->rotation_timer_queue->event_pipe)) {
968 ret = handle_job_queue(handle, &thread,
969 handle->rotation_timer_queue);
970 if (ret) {
971 ERR("[rotation-thread] Failed to handle rotation timer pipe event");
972 goto error;
973 }
974 } else if (fd == rotate_notification_channel->socket) {
975 ret = handle_notification_channel(fd, handle,
976 &thread);
977 if (ret) {
978 ERR("[rotation-thread] Error occured while handling activity on notification channel socket");
979 goto error;
980 }
981 }
982 }
983 }
984 exit:
985 error:
986 DBG("[rotation-thread] Exit");
987 fini_thread_state(&thread);
988 health_unregister(health_sessiond);
989 rcu_thread_offline();
990 rcu_unregister_thread();
991 end:
992 return NULL;
993 }
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