Ust-consumer: Add channel key to error msg on channel clear
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * Copyright (C) 2017 - Jérémie Galarneau <jeremie.galarneau@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <lttng/ust-ctl.h>
23 #include <poll.h>
24 #include <pthread.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/mman.h>
28 #include <sys/socket.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31 #include <inttypes.h>
32 #include <unistd.h>
33 #include <urcu/list.h>
34 #include <signal.h>
35 #include <stdbool.h>
36
37 #include <bin/lttng-consumerd/health-consumerd.h>
38 #include <common/common.h>
39 #include <common/sessiond-comm/sessiond-comm.h>
40 #include <common/relayd/relayd.h>
41 #include <common/compat/fcntl.h>
42 #include <common/compat/endian.h>
43 #include <common/consumer/consumer-metadata-cache.h>
44 #include <common/consumer/consumer-stream.h>
45 #include <common/consumer/consumer-timer.h>
46 #include <common/utils.h>
47 #include <common/index/index.h>
48
49 #include "ust-consumer.h"
50
51 #define INT_MAX_STR_LEN 12 /* includes \0 */
52
53 extern struct lttng_consumer_global_data consumer_data;
54 extern int consumer_poll_timeout;
55
56 /*
57 * Free channel object and all streams associated with it. This MUST be used
58 * only and only if the channel has _NEVER_ been added to the global channel
59 * hash table.
60 */
61 static void destroy_channel(struct lttng_consumer_channel *channel)
62 {
63 struct lttng_consumer_stream *stream, *stmp;
64
65 assert(channel);
66
67 DBG("UST consumer cleaning stream list");
68
69 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
70 send_node) {
71
72 health_code_update();
73
74 cds_list_del(&stream->send_node);
75 ustctl_destroy_stream(stream->ustream);
76 free(stream);
77 }
78
79 /*
80 * If a channel is available meaning that was created before the streams
81 * were, delete it.
82 */
83 if (channel->uchan) {
84 lttng_ustconsumer_del_channel(channel);
85 lttng_ustconsumer_free_channel(channel);
86 }
87 free(channel);
88 }
89
90 /*
91 * Add channel to internal consumer state.
92 *
93 * Returns 0 on success or else a negative value.
94 */
95 static int add_channel(struct lttng_consumer_channel *channel,
96 struct lttng_consumer_local_data *ctx)
97 {
98 int ret = 0;
99
100 assert(channel);
101 assert(ctx);
102
103 if (ctx->on_recv_channel != NULL) {
104 ret = ctx->on_recv_channel(channel);
105 if (ret == 0) {
106 ret = consumer_add_channel(channel, ctx);
107 } else if (ret < 0) {
108 /* Most likely an ENOMEM. */
109 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
110 goto error;
111 }
112 } else {
113 ret = consumer_add_channel(channel, ctx);
114 }
115
116 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
117
118 error:
119 return ret;
120 }
121
122 /*
123 * Allocate and return a consumer channel object.
124 */
125 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
126 const char *pathname, const char *name, uid_t uid, gid_t gid,
127 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
128 uint64_t tracefile_size, uint64_t tracefile_count,
129 uint64_t session_id_per_pid, unsigned int monitor,
130 unsigned int live_timer_interval,
131 const char *root_shm_path, const char *shm_path)
132 {
133 assert(pathname);
134 assert(name);
135
136 return consumer_allocate_channel(key, session_id, pathname, name, uid,
137 gid, relayd_id, output, tracefile_size,
138 tracefile_count, session_id_per_pid, monitor,
139 live_timer_interval, root_shm_path, shm_path);
140 }
141
142 /*
143 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
144 * error value if applicable is set in it else it is kept untouched.
145 *
146 * Return NULL on error else the newly allocated stream object.
147 */
148 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
149 struct lttng_consumer_channel *channel,
150 struct lttng_consumer_local_data *ctx, int *_alloc_ret,
151 uint64_t trace_archive_id)
152 {
153 int alloc_ret;
154 struct lttng_consumer_stream *stream = NULL;
155
156 assert(channel);
157 assert(ctx);
158
159 stream = consumer_allocate_stream(channel->key,
160 key,
161 LTTNG_CONSUMER_ACTIVE_STREAM,
162 channel->name,
163 channel->uid,
164 channel->gid,
165 channel->relayd_id,
166 channel->session_id,
167 cpu,
168 &alloc_ret,
169 channel->type,
170 channel->monitor,
171 trace_archive_id);
172 if (stream == NULL) {
173 switch (alloc_ret) {
174 case -ENOENT:
175 /*
176 * We could not find the channel. Can happen if cpu hotplug
177 * happens while tearing down.
178 */
179 DBG3("Could not find channel");
180 break;
181 case -ENOMEM:
182 case -EINVAL:
183 default:
184 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
185 break;
186 }
187 goto error;
188 }
189
190 consumer_stream_update_channel_attributes(stream, channel);
191 stream->chan = channel;
192
193 error:
194 if (_alloc_ret) {
195 *_alloc_ret = alloc_ret;
196 }
197 return stream;
198 }
199
200 /*
201 * Send the given stream pointer to the corresponding thread.
202 *
203 * Returns 0 on success else a negative value.
204 */
205 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
206 struct lttng_consumer_local_data *ctx)
207 {
208 int ret;
209 struct lttng_pipe *stream_pipe;
210
211 /* Get the right pipe where the stream will be sent. */
212 if (stream->metadata_flag) {
213 consumer_add_metadata_stream(stream);
214 stream_pipe = ctx->consumer_metadata_pipe;
215 } else {
216 consumer_add_data_stream(stream);
217 stream_pipe = ctx->consumer_data_pipe;
218 }
219
220 /*
221 * From this point on, the stream's ownership has been moved away from
222 * the channel and it becomes globally visible. Hence, remove it from
223 * the local stream list to prevent the stream from being both local and
224 * global.
225 */
226 stream->globally_visible = 1;
227 cds_list_del(&stream->send_node);
228
229 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
230 if (ret < 0) {
231 ERR("Consumer write %s stream to pipe %d",
232 stream->metadata_flag ? "metadata" : "data",
233 lttng_pipe_get_writefd(stream_pipe));
234 if (stream->metadata_flag) {
235 consumer_del_stream_for_metadata(stream);
236 } else {
237 consumer_del_stream_for_data(stream);
238 }
239 goto error;
240 }
241
242 error:
243 return ret;
244 }
245
246 static
247 int get_stream_shm_path(char *stream_shm_path, const char *shm_path, int cpu)
248 {
249 char cpu_nr[INT_MAX_STR_LEN]; /* int max len */
250 int ret;
251
252 strncpy(stream_shm_path, shm_path, PATH_MAX);
253 stream_shm_path[PATH_MAX - 1] = '\0';
254 ret = snprintf(cpu_nr, INT_MAX_STR_LEN, "%i", cpu);
255 if (ret < 0) {
256 PERROR("snprintf");
257 goto end;
258 }
259 strncat(stream_shm_path, cpu_nr,
260 PATH_MAX - strlen(stream_shm_path) - 1);
261 ret = 0;
262 end:
263 return ret;
264 }
265
266 /*
267 * Create streams for the given channel using liblttng-ust-ctl.
268 *
269 * Return 0 on success else a negative value.
270 */
271 static int create_ust_streams(struct lttng_consumer_channel *channel,
272 struct lttng_consumer_local_data *ctx,
273 uint64_t trace_archive_id)
274 {
275 int ret, cpu = 0;
276 struct ustctl_consumer_stream *ustream;
277 struct lttng_consumer_stream *stream;
278
279 assert(channel);
280 assert(ctx);
281
282 /*
283 * While a stream is available from ustctl. When NULL is returned, we've
284 * reached the end of the possible stream for the channel.
285 */
286 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
287 int wait_fd;
288 int ust_metadata_pipe[2];
289
290 health_code_update();
291
292 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
293 ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
294 if (ret < 0) {
295 ERR("Create ust metadata poll pipe");
296 goto error;
297 }
298 wait_fd = ust_metadata_pipe[0];
299 } else {
300 wait_fd = ustctl_stream_get_wait_fd(ustream);
301 }
302
303 /* Allocate consumer stream object. */
304 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret,
305 trace_archive_id);
306 if (!stream) {
307 goto error_alloc;
308 }
309 stream->ustream = ustream;
310 /*
311 * Store it so we can save multiple function calls afterwards since
312 * this value is used heavily in the stream threads. This is UST
313 * specific so this is why it's done after allocation.
314 */
315 stream->wait_fd = wait_fd;
316
317 /*
318 * Increment channel refcount since the channel reference has now been
319 * assigned in the allocation process above.
320 */
321 if (stream->chan->monitor) {
322 uatomic_inc(&stream->chan->refcount);
323 }
324
325 /*
326 * Order is important this is why a list is used. On error, the caller
327 * should clean this list.
328 */
329 cds_list_add_tail(&stream->send_node, &channel->streams.head);
330
331 ret = ustctl_get_max_subbuf_size(stream->ustream,
332 &stream->max_sb_size);
333 if (ret < 0) {
334 ERR("ustctl_get_max_subbuf_size failed for stream %s",
335 stream->name);
336 goto error;
337 }
338
339 /* Do actions once stream has been received. */
340 if (ctx->on_recv_stream) {
341 ret = ctx->on_recv_stream(stream);
342 if (ret < 0) {
343 goto error;
344 }
345 }
346
347 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
348 stream->name, stream->key, stream->relayd_stream_id);
349
350 /* Set next CPU stream. */
351 channel->streams.count = ++cpu;
352
353 /* Keep stream reference when creating metadata. */
354 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
355 channel->metadata_stream = stream;
356 if (channel->monitor) {
357 /* Set metadata poll pipe if we created one */
358 memcpy(stream->ust_metadata_poll_pipe,
359 ust_metadata_pipe,
360 sizeof(ust_metadata_pipe));
361 }
362 }
363 }
364
365 return 0;
366
367 error:
368 error_alloc:
369 return ret;
370 }
371
372 /*
373 * create_posix_shm is never called concurrently within a process.
374 */
375 static
376 int create_posix_shm(void)
377 {
378 char tmp_name[NAME_MAX];
379 int shmfd, ret;
380
381 ret = snprintf(tmp_name, NAME_MAX, "/ust-shm-consumer-%d", getpid());
382 if (ret < 0) {
383 PERROR("snprintf");
384 return -1;
385 }
386 /*
387 * Allocate shm, and immediately unlink its shm oject, keeping
388 * only the file descriptor as a reference to the object.
389 * We specifically do _not_ use the / at the beginning of the
390 * pathname so that some OS implementations can keep it local to
391 * the process (POSIX leaves this implementation-defined).
392 */
393 shmfd = shm_open(tmp_name, O_CREAT | O_EXCL | O_RDWR, 0700);
394 if (shmfd < 0) {
395 PERROR("shm_open");
396 goto error_shm_open;
397 }
398 ret = shm_unlink(tmp_name);
399 if (ret < 0 && errno != ENOENT) {
400 PERROR("shm_unlink");
401 goto error_shm_release;
402 }
403 return shmfd;
404
405 error_shm_release:
406 ret = close(shmfd);
407 if (ret) {
408 PERROR("close");
409 }
410 error_shm_open:
411 return -1;
412 }
413
414 static int open_ust_stream_fd(struct lttng_consumer_channel *channel, int cpu)
415 {
416 char shm_path[PATH_MAX];
417 int ret;
418
419 if (!channel->shm_path[0]) {
420 return create_posix_shm();
421 }
422 ret = get_stream_shm_path(shm_path, channel->shm_path, cpu);
423 if (ret) {
424 goto error_shm_path;
425 }
426 return run_as_open(shm_path,
427 O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR,
428 channel->uid, channel->gid);
429
430 error_shm_path:
431 return -1;
432 }
433
434 /*
435 * Create an UST channel with the given attributes and send it to the session
436 * daemon using the ust ctl API.
437 *
438 * Return 0 on success or else a negative value.
439 */
440 static int create_ust_channel(struct lttng_consumer_channel *channel,
441 struct ustctl_consumer_channel_attr *attr,
442 struct ustctl_consumer_channel **ust_chanp)
443 {
444 int ret, nr_stream_fds, i, j;
445 int *stream_fds;
446 struct ustctl_consumer_channel *ust_channel;
447
448 assert(channel);
449 assert(attr);
450 assert(ust_chanp);
451
452 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
453 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
454 "switch_timer_interval: %u, read_timer_interval: %u, "
455 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
456 attr->num_subbuf, attr->switch_timer_interval,
457 attr->read_timer_interval, attr->output, attr->type);
458
459 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA)
460 nr_stream_fds = 1;
461 else
462 nr_stream_fds = ustctl_get_nr_stream_per_channel();
463 stream_fds = zmalloc(nr_stream_fds * sizeof(*stream_fds));
464 if (!stream_fds) {
465 ret = -1;
466 goto error_alloc;
467 }
468 for (i = 0; i < nr_stream_fds; i++) {
469 stream_fds[i] = open_ust_stream_fd(channel, i);
470 if (stream_fds[i] < 0) {
471 ret = -1;
472 goto error_open;
473 }
474 }
475 ust_channel = ustctl_create_channel(attr, stream_fds, nr_stream_fds);
476 if (!ust_channel) {
477 ret = -1;
478 goto error_create;
479 }
480 channel->nr_stream_fds = nr_stream_fds;
481 channel->stream_fds = stream_fds;
482 *ust_chanp = ust_channel;
483
484 return 0;
485
486 error_create:
487 error_open:
488 for (j = i - 1; j >= 0; j--) {
489 int closeret;
490
491 closeret = close(stream_fds[j]);
492 if (closeret) {
493 PERROR("close");
494 }
495 if (channel->shm_path[0]) {
496 char shm_path[PATH_MAX];
497
498 closeret = get_stream_shm_path(shm_path,
499 channel->shm_path, j);
500 if (closeret) {
501 ERR("Cannot get stream shm path");
502 }
503 closeret = run_as_unlink(shm_path,
504 channel->uid, channel->gid);
505 if (closeret) {
506 PERROR("unlink %s", shm_path);
507 }
508 }
509 }
510 /* Try to rmdir all directories under shm_path root. */
511 if (channel->root_shm_path[0]) {
512 (void) run_as_rmdir_recursive(channel->root_shm_path,
513 channel->uid, channel->gid);
514 }
515 free(stream_fds);
516 error_alloc:
517 return ret;
518 }
519
520 /*
521 * Send a single given stream to the session daemon using the sock.
522 *
523 * Return 0 on success else a negative value.
524 */
525 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
526 {
527 int ret;
528
529 assert(stream);
530 assert(sock >= 0);
531
532 DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
533
534 /* Send stream to session daemon. */
535 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
536 if (ret < 0) {
537 goto error;
538 }
539
540 error:
541 return ret;
542 }
543
544 /*
545 * Send channel to sessiond and relayd if applicable.
546 *
547 * Return 0 on success or else a negative value.
548 */
549 static int send_channel_to_sessiond_and_relayd(int sock,
550 struct lttng_consumer_channel *channel,
551 struct lttng_consumer_local_data *ctx, int *relayd_error)
552 {
553 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
554 struct lttng_consumer_stream *stream;
555 uint64_t net_seq_idx = -1ULL;
556
557 assert(channel);
558 assert(ctx);
559 assert(sock >= 0);
560
561 DBG("UST consumer sending channel %s to sessiond", channel->name);
562
563 if (channel->relayd_id != (uint64_t) -1ULL) {
564 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
565
566 health_code_update();
567
568 /* Try to send the stream to the relayd if one is available. */
569 DBG("Sending stream %" PRIu64 " of channel \"%s\" to relayd",
570 stream->key, channel->name);
571 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
572 if (ret < 0) {
573 /*
574 * Flag that the relayd was the problem here probably due to a
575 * communicaton error on the socket.
576 */
577 if (relayd_error) {
578 *relayd_error = 1;
579 }
580 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
581 }
582 if (net_seq_idx == -1ULL) {
583 net_seq_idx = stream->net_seq_idx;
584 }
585 }
586 }
587
588 /* Inform sessiond that we are about to send channel and streams. */
589 ret = consumer_send_status_msg(sock, ret_code);
590 if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
591 /*
592 * Either the session daemon is not responding or the relayd died so we
593 * stop now.
594 */
595 goto error;
596 }
597
598 /* Send channel to sessiond. */
599 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
600 if (ret < 0) {
601 goto error;
602 }
603
604 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
605 if (ret < 0) {
606 goto error;
607 }
608
609 /* The channel was sent successfully to the sessiond at this point. */
610 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
611
612 health_code_update();
613
614 /* Send stream to session daemon. */
615 ret = send_sessiond_stream(sock, stream);
616 if (ret < 0) {
617 goto error;
618 }
619 }
620
621 /* Tell sessiond there is no more stream. */
622 ret = ustctl_send_stream_to_sessiond(sock, NULL);
623 if (ret < 0) {
624 goto error;
625 }
626
627 DBG("UST consumer NULL stream sent to sessiond");
628
629 return 0;
630
631 error:
632 if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
633 ret = -1;
634 }
635 return ret;
636 }
637
638 /*
639 * Creates a channel and streams and add the channel it to the channel internal
640 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
641 * received.
642 *
643 * Return 0 on success or else, a negative value is returned and the channel
644 * MUST be destroyed by consumer_del_channel().
645 */
646 static int ask_channel(struct lttng_consumer_local_data *ctx,
647 struct lttng_consumer_channel *channel,
648 struct ustctl_consumer_channel_attr *attr,
649 uint64_t trace_archive_id)
650 {
651 int ret;
652
653 assert(ctx);
654 assert(channel);
655 assert(attr);
656
657 /*
658 * This value is still used by the kernel consumer since for the kernel,
659 * the stream ownership is not IN the consumer so we need to have the
660 * number of left stream that needs to be initialized so we can know when
661 * to delete the channel (see consumer.c).
662 *
663 * As for the user space tracer now, the consumer creates and sends the
664 * stream to the session daemon which only sends them to the application
665 * once every stream of a channel is received making this value useless
666 * because we they will be added to the poll thread before the application
667 * receives them. This ensures that a stream can not hang up during
668 * initilization of a channel.
669 */
670 channel->nb_init_stream_left = 0;
671
672 /* The reply msg status is handled in the following call. */
673 ret = create_ust_channel(channel, attr, &channel->uchan);
674 if (ret < 0) {
675 goto end;
676 }
677
678 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
679
680 /*
681 * For the snapshots (no monitor), we create the metadata streams
682 * on demand, not during the channel creation.
683 */
684 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
685 ret = 0;
686 goto end;
687 }
688
689 /* Open all streams for this channel. */
690 ret = create_ust_streams(channel, ctx, trace_archive_id);
691 if (ret < 0) {
692 goto end;
693 }
694
695 end:
696 return ret;
697 }
698
699 /*
700 * Send all stream of a channel to the right thread handling it.
701 *
702 * On error, return a negative value else 0 on success.
703 */
704 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
705 struct lttng_consumer_local_data *ctx)
706 {
707 int ret = 0;
708 struct lttng_consumer_stream *stream, *stmp;
709
710 assert(channel);
711 assert(ctx);
712
713 /* Send streams to the corresponding thread. */
714 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
715 send_node) {
716
717 health_code_update();
718
719 /* Sending the stream to the thread. */
720 ret = send_stream_to_thread(stream, ctx);
721 if (ret < 0) {
722 /*
723 * If we are unable to send the stream to the thread, there is
724 * a big problem so just stop everything.
725 */
726 goto error;
727 }
728 }
729
730 error:
731 return ret;
732 }
733
734 /*
735 * Flush channel's streams using the given key to retrieve the channel.
736 *
737 * Return 0 on success else an LTTng error code.
738 */
739 static int flush_channel(uint64_t chan_key)
740 {
741 int ret = 0;
742 struct lttng_consumer_channel *channel;
743 struct lttng_consumer_stream *stream;
744 struct lttng_ht *ht;
745 struct lttng_ht_iter iter;
746
747 DBG("UST consumer flush channel key %" PRIu64, chan_key);
748
749 rcu_read_lock();
750 channel = consumer_find_channel(chan_key);
751 if (!channel) {
752 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
753 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
754 goto error;
755 }
756
757 ht = consumer_data.stream_per_chan_id_ht;
758
759 /* For each stream of the channel id, flush it. */
760 cds_lfht_for_each_entry_duplicate(ht->ht,
761 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
762 &channel->key, &iter.iter, stream, node_channel_id.node) {
763
764 health_code_update();
765
766 pthread_mutex_lock(&stream->lock);
767 if (!stream->quiescent) {
768 lttng_ustconsumer_flush_buffer(stream, 0);
769 stream->quiescent = true;
770 }
771 pthread_mutex_unlock(&stream->lock);
772 }
773 error:
774 rcu_read_unlock();
775 return ret;
776 }
777
778 /*
779 * Clear quiescent state from channel's streams using the given key to
780 * retrieve the channel.
781 *
782 * Return 0 on success else an LTTng error code.
783 */
784 static int clear_quiescent_channel(uint64_t chan_key)
785 {
786 int ret = 0;
787 struct lttng_consumer_channel *channel;
788 struct lttng_consumer_stream *stream;
789 struct lttng_ht *ht;
790 struct lttng_ht_iter iter;
791
792 DBG("UST consumer clear quiescent channel key %" PRIu64, chan_key);
793
794 rcu_read_lock();
795 channel = consumer_find_channel(chan_key);
796 if (!channel) {
797 ERR("UST consumer clear quiescent channel %" PRIu64 " not found", chan_key);
798 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
799 goto error;
800 }
801
802 ht = consumer_data.stream_per_chan_id_ht;
803
804 /* For each stream of the channel id, clear quiescent state. */
805 cds_lfht_for_each_entry_duplicate(ht->ht,
806 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
807 &channel->key, &iter.iter, stream, node_channel_id.node) {
808
809 health_code_update();
810
811 pthread_mutex_lock(&stream->lock);
812 stream->quiescent = false;
813 pthread_mutex_unlock(&stream->lock);
814 }
815 error:
816 rcu_read_unlock();
817 return ret;
818 }
819
820 /*
821 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
822 * RCU read side lock MUST be acquired before calling this function.
823 *
824 * Return 0 on success else an LTTng error code.
825 */
826 static int close_metadata(uint64_t chan_key)
827 {
828 int ret = 0;
829 struct lttng_consumer_channel *channel;
830 unsigned int channel_monitor;
831
832 DBG("UST consumer close metadata key %" PRIu64, chan_key);
833
834 channel = consumer_find_channel(chan_key);
835 if (!channel) {
836 /*
837 * This is possible if the metadata thread has issue a delete because
838 * the endpoint point of the stream hung up. There is no way the
839 * session daemon can know about it thus use a DBG instead of an actual
840 * error.
841 */
842 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
843 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
844 goto error;
845 }
846
847 pthread_mutex_lock(&consumer_data.lock);
848 pthread_mutex_lock(&channel->lock);
849 channel_monitor = channel->monitor;
850 if (cds_lfht_is_node_deleted(&channel->node.node)) {
851 goto error_unlock;
852 }
853
854 lttng_ustconsumer_close_metadata(channel);
855 pthread_mutex_unlock(&channel->lock);
856 pthread_mutex_unlock(&consumer_data.lock);
857
858 /*
859 * The ownership of a metadata channel depends on the type of
860 * session to which it belongs. In effect, the monitor flag is checked
861 * to determine if this metadata channel is in "snapshot" mode or not.
862 *
863 * In the non-snapshot case, the metadata channel is created along with
864 * a single stream which will remain present until the metadata channel
865 * is destroyed (on the destruction of its session). In this case, the
866 * metadata stream in "monitored" by the metadata poll thread and holds
867 * the ownership of its channel.
868 *
869 * Closing the metadata will cause the metadata stream's "metadata poll
870 * pipe" to be closed. Closing this pipe will wake-up the metadata poll
871 * thread which will teardown the metadata stream which, in return,
872 * deletes the metadata channel.
873 *
874 * In the snapshot case, the metadata stream is created and destroyed
875 * on every snapshot record. Since the channel doesn't have an owner
876 * other than the session daemon, it is safe to destroy it immediately
877 * on reception of the CLOSE_METADATA command.
878 */
879 if (!channel_monitor) {
880 /*
881 * The channel and consumer_data locks must be
882 * released before this call since consumer_del_channel
883 * re-acquires the channel and consumer_data locks to teardown
884 * the channel and queue its reclamation by the "call_rcu"
885 * worker thread.
886 */
887 consumer_del_channel(channel);
888 }
889
890 return ret;
891 error_unlock:
892 pthread_mutex_unlock(&channel->lock);
893 pthread_mutex_unlock(&consumer_data.lock);
894 error:
895 return ret;
896 }
897
898 /*
899 * RCU read side lock MUST be acquired before calling this function.
900 *
901 * Return 0 on success else an LTTng error code.
902 */
903 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
904 {
905 int ret;
906 struct lttng_consumer_channel *metadata;
907
908 DBG("UST consumer setup metadata key %" PRIu64, key);
909
910 metadata = consumer_find_channel(key);
911 if (!metadata) {
912 ERR("UST consumer push metadata %" PRIu64 " not found", key);
913 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
914 goto end;
915 }
916
917 /*
918 * In no monitor mode, the metadata channel has no stream(s) so skip the
919 * ownership transfer to the metadata thread.
920 */
921 if (!metadata->monitor) {
922 DBG("Metadata channel in no monitor");
923 ret = 0;
924 goto end;
925 }
926
927 /*
928 * Send metadata stream to relayd if one available. Availability is
929 * known if the stream is still in the list of the channel.
930 */
931 if (cds_list_empty(&metadata->streams.head)) {
932 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
933 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
934 goto error_no_stream;
935 }
936
937 /* Send metadata stream to relayd if needed. */
938 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
939 ret = consumer_send_relayd_stream(metadata->metadata_stream,
940 metadata->pathname);
941 if (ret < 0) {
942 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
943 goto error;
944 }
945 ret = consumer_send_relayd_streams_sent(
946 metadata->metadata_stream->net_seq_idx);
947 if (ret < 0) {
948 ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
949 goto error;
950 }
951 }
952
953 /*
954 * Ownership of metadata stream is passed along. Freeing is handled by
955 * the callee.
956 */
957 ret = send_streams_to_thread(metadata, ctx);
958 if (ret < 0) {
959 /*
960 * If we are unable to send the stream to the thread, there is
961 * a big problem so just stop everything.
962 */
963 ret = LTTCOMM_CONSUMERD_FATAL;
964 goto send_streams_error;
965 }
966 /* List MUST be empty after or else it could be reused. */
967 assert(cds_list_empty(&metadata->streams.head));
968
969 ret = 0;
970 goto end;
971
972 error:
973 /*
974 * Delete metadata channel on error. At this point, the metadata stream can
975 * NOT be monitored by the metadata thread thus having the guarantee that
976 * the stream is still in the local stream list of the channel. This call
977 * will make sure to clean that list.
978 */
979 consumer_stream_destroy(metadata->metadata_stream, NULL);
980 cds_list_del(&metadata->metadata_stream->send_node);
981 metadata->metadata_stream = NULL;
982 send_streams_error:
983 error_no_stream:
984 end:
985 return ret;
986 }
987
988 /*
989 * Snapshot the whole metadata.
990 * RCU read-side lock must be held across this function to ensure existence of
991 * metadata_channel.
992 *
993 * Returns 0 on success, < 0 on error
994 */
995 static int snapshot_metadata(struct lttng_consumer_channel *metadata_channel,
996 uint64_t key, char *path, uint64_t relayd_id,
997 struct lttng_consumer_local_data *ctx,
998 uint64_t trace_archive_id)
999 {
1000 int ret = 0;
1001 struct lttng_consumer_stream *metadata_stream;
1002
1003 assert(path);
1004 assert(ctx);
1005
1006 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
1007 key, path);
1008
1009 rcu_read_lock();
1010
1011 assert(!metadata_channel->monitor);
1012
1013 health_code_update();
1014
1015 /*
1016 * Ask the sessiond if we have new metadata waiting and update the
1017 * consumer metadata cache.
1018 */
1019 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
1020 if (ret < 0) {
1021 goto error;
1022 }
1023
1024 health_code_update();
1025
1026 /*
1027 * The metadata stream is NOT created in no monitor mode when the channel
1028 * is created on a sessiond ask channel command.
1029 */
1030 ret = create_ust_streams(metadata_channel, ctx, trace_archive_id);
1031 if (ret < 0) {
1032 goto error;
1033 }
1034
1035 metadata_stream = metadata_channel->metadata_stream;
1036 assert(metadata_stream);
1037
1038 if (relayd_id != (uint64_t) -1ULL) {
1039 metadata_stream->net_seq_idx = relayd_id;
1040 ret = consumer_send_relayd_stream(metadata_stream, path);
1041 if (ret < 0) {
1042 goto error_stream;
1043 }
1044 } else {
1045 ret = utils_create_stream_file(path, metadata_stream->name,
1046 metadata_stream->chan->tracefile_size,
1047 metadata_stream->tracefile_count_current,
1048 metadata_stream->uid, metadata_stream->gid, NULL);
1049 if (ret < 0) {
1050 goto error_stream;
1051 }
1052 metadata_stream->out_fd = ret;
1053 metadata_stream->tracefile_size_current = 0;
1054 }
1055
1056 do {
1057 health_code_update();
1058
1059 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
1060 if (ret < 0) {
1061 goto error_stream;
1062 }
1063 } while (ret > 0);
1064
1065 error_stream:
1066 /*
1067 * Clean up the stream completly because the next snapshot will use a new
1068 * metadata stream.
1069 */
1070 consumer_stream_destroy(metadata_stream, NULL);
1071 cds_list_del(&metadata_stream->send_node);
1072 metadata_channel->metadata_stream = NULL;
1073
1074 error:
1075 rcu_read_unlock();
1076 return ret;
1077 }
1078
1079 /*
1080 * Take a snapshot of all the stream of a channel.
1081 * RCU read-side lock must be held across this function to ensure existence of
1082 * channel.
1083 *
1084 * Returns 0 on success, < 0 on error
1085 */
1086 static int snapshot_channel(struct lttng_consumer_channel *channel,
1087 uint64_t key, char *path, uint64_t relayd_id,
1088 uint64_t nb_packets_per_stream,
1089 struct lttng_consumer_local_data *ctx)
1090 {
1091 int ret;
1092 unsigned use_relayd = 0;
1093 unsigned long consumed_pos, produced_pos;
1094 struct lttng_consumer_stream *stream;
1095
1096 assert(path);
1097 assert(ctx);
1098
1099 rcu_read_lock();
1100
1101 if (relayd_id != (uint64_t) -1ULL) {
1102 use_relayd = 1;
1103 }
1104
1105 assert(!channel->monitor);
1106 DBG("UST consumer snapshot channel %" PRIu64, key);
1107
1108 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
1109 health_code_update();
1110
1111 /* Lock stream because we are about to change its state. */
1112 pthread_mutex_lock(&stream->lock);
1113 stream->net_seq_idx = relayd_id;
1114
1115 if (use_relayd) {
1116 ret = consumer_send_relayd_stream(stream, path);
1117 if (ret < 0) {
1118 goto error_unlock;
1119 }
1120 } else {
1121 ret = utils_create_stream_file(path, stream->name,
1122 stream->chan->tracefile_size,
1123 stream->tracefile_count_current,
1124 stream->uid, stream->gid, NULL);
1125 if (ret < 0) {
1126 goto error_unlock;
1127 }
1128 stream->out_fd = ret;
1129 stream->tracefile_size_current = 0;
1130
1131 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
1132 stream->name, stream->key);
1133 }
1134
1135 /*
1136 * If tracing is active, we want to perform a "full" buffer flush.
1137 * Else, if quiescent, it has already been done by the prior stop.
1138 */
1139 if (!stream->quiescent) {
1140 lttng_ustconsumer_flush_buffer(stream, 0);
1141 }
1142
1143 ret = lttng_ustconsumer_take_snapshot(stream);
1144 if (ret < 0) {
1145 ERR("Taking UST snapshot");
1146 goto error_unlock;
1147 }
1148
1149 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
1150 if (ret < 0) {
1151 ERR("Produced UST snapshot position");
1152 goto error_unlock;
1153 }
1154
1155 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
1156 if (ret < 0) {
1157 ERR("Consumerd UST snapshot position");
1158 goto error_unlock;
1159 }
1160
1161 /*
1162 * The original value is sent back if max stream size is larger than
1163 * the possible size of the snapshot. Also, we assume that the session
1164 * daemon should never send a maximum stream size that is lower than
1165 * subbuffer size.
1166 */
1167 consumed_pos = consumer_get_consume_start_pos(consumed_pos,
1168 produced_pos, nb_packets_per_stream,
1169 stream->max_sb_size);
1170
1171 while (consumed_pos < produced_pos) {
1172 ssize_t read_len;
1173 unsigned long len, padded_len;
1174
1175 health_code_update();
1176
1177 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
1178
1179 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
1180 if (ret < 0) {
1181 if (ret != -EAGAIN) {
1182 PERROR("ustctl_get_subbuf snapshot");
1183 goto error_close_stream;
1184 }
1185 DBG("UST consumer get subbuf failed. Skipping it.");
1186 consumed_pos += stream->max_sb_size;
1187 stream->chan->lost_packets++;
1188 continue;
1189 }
1190
1191 ret = ustctl_get_subbuf_size(stream->ustream, &len);
1192 if (ret < 0) {
1193 ERR("Snapshot ustctl_get_subbuf_size");
1194 goto error_put_subbuf;
1195 }
1196
1197 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
1198 if (ret < 0) {
1199 ERR("Snapshot ustctl_get_padded_subbuf_size");
1200 goto error_put_subbuf;
1201 }
1202
1203 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
1204 padded_len - len, NULL);
1205 if (use_relayd) {
1206 if (read_len != len) {
1207 ret = -EPERM;
1208 goto error_put_subbuf;
1209 }
1210 } else {
1211 if (read_len != padded_len) {
1212 ret = -EPERM;
1213 goto error_put_subbuf;
1214 }
1215 }
1216
1217 ret = ustctl_put_subbuf(stream->ustream);
1218 if (ret < 0) {
1219 ERR("Snapshot ustctl_put_subbuf");
1220 goto error_close_stream;
1221 }
1222 consumed_pos += stream->max_sb_size;
1223 }
1224
1225 /* Simply close the stream so we can use it on the next snapshot. */
1226 consumer_stream_close(stream);
1227 pthread_mutex_unlock(&stream->lock);
1228 }
1229
1230 rcu_read_unlock();
1231 return 0;
1232
1233 error_put_subbuf:
1234 if (ustctl_put_subbuf(stream->ustream) < 0) {
1235 ERR("Snapshot ustctl_put_subbuf");
1236 }
1237 error_close_stream:
1238 consumer_stream_close(stream);
1239 error_unlock:
1240 pthread_mutex_unlock(&stream->lock);
1241 rcu_read_unlock();
1242 return ret;
1243 }
1244
1245 /*
1246 * Receive the metadata updates from the sessiond. Supports receiving
1247 * overlapping metadata, but is needs to always belong to a contiguous
1248 * range starting from 0.
1249 * Be careful about the locks held when calling this function: it needs
1250 * the metadata cache flush to concurrently progress in order to
1251 * complete.
1252 */
1253 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1254 uint64_t len, uint64_t version,
1255 struct lttng_consumer_channel *channel, int timer, int wait)
1256 {
1257 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1258 char *metadata_str;
1259
1260 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
1261
1262 metadata_str = zmalloc(len * sizeof(char));
1263 if (!metadata_str) {
1264 PERROR("zmalloc metadata string");
1265 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1266 goto end;
1267 }
1268
1269 health_code_update();
1270
1271 /* Receive metadata string. */
1272 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1273 if (ret < 0) {
1274 /* Session daemon is dead so return gracefully. */
1275 ret_code = ret;
1276 goto end_free;
1277 }
1278
1279 health_code_update();
1280
1281 pthread_mutex_lock(&channel->metadata_cache->lock);
1282 ret = consumer_metadata_cache_write(channel, offset, len, version,
1283 metadata_str);
1284 if (ret < 0) {
1285 /* Unable to handle metadata. Notify session daemon. */
1286 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1287 /*
1288 * Skip metadata flush on write error since the offset and len might
1289 * not have been updated which could create an infinite loop below when
1290 * waiting for the metadata cache to be flushed.
1291 */
1292 pthread_mutex_unlock(&channel->metadata_cache->lock);
1293 goto end_free;
1294 }
1295 pthread_mutex_unlock(&channel->metadata_cache->lock);
1296
1297 if (!wait) {
1298 goto end_free;
1299 }
1300 while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
1301 DBG("Waiting for metadata to be flushed");
1302
1303 health_code_update();
1304
1305 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1306 }
1307
1308 end_free:
1309 free(metadata_str);
1310 end:
1311 return ret_code;
1312 }
1313
1314 /*
1315 * Receive command from session daemon and process it.
1316 *
1317 * Return 1 on success else a negative value or 0.
1318 */
1319 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1320 int sock, struct pollfd *consumer_sockpoll)
1321 {
1322 ssize_t ret;
1323 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1324 struct lttcomm_consumer_msg msg;
1325 struct lttng_consumer_channel *channel = NULL;
1326
1327 health_code_update();
1328
1329 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1330 if (ret != sizeof(msg)) {
1331 DBG("Consumer received unexpected message size %zd (expects %zu)",
1332 ret, sizeof(msg));
1333 /*
1334 * The ret value might 0 meaning an orderly shutdown but this is ok
1335 * since the caller handles this.
1336 */
1337 if (ret > 0) {
1338 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1339 ret = -1;
1340 }
1341 return ret;
1342 }
1343
1344 health_code_update();
1345
1346 /* deprecated */
1347 assert(msg.cmd_type != LTTNG_CONSUMER_STOP);
1348
1349 health_code_update();
1350
1351 /* relayd needs RCU read-side lock */
1352 rcu_read_lock();
1353
1354 switch (msg.cmd_type) {
1355 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1356 {
1357 /* Session daemon status message are handled in the following call. */
1358 consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1359 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1360 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
1361 msg.u.relayd_sock.relayd_session_id);
1362 goto end_nosignal;
1363 }
1364 case LTTNG_CONSUMER_DESTROY_RELAYD:
1365 {
1366 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1367 struct consumer_relayd_sock_pair *relayd;
1368
1369 DBG("UST consumer destroying relayd %" PRIu64, index);
1370
1371 /* Get relayd reference if exists. */
1372 relayd = consumer_find_relayd(index);
1373 if (relayd == NULL) {
1374 DBG("Unable to find relayd %" PRIu64, index);
1375 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
1376 }
1377
1378 /*
1379 * Each relayd socket pair has a refcount of stream attached to it
1380 * which tells if the relayd is still active or not depending on the
1381 * refcount value.
1382 *
1383 * This will set the destroy flag of the relayd object and destroy it
1384 * if the refcount reaches zero when called.
1385 *
1386 * The destroy can happen either here or when a stream fd hangs up.
1387 */
1388 if (relayd) {
1389 consumer_flag_relayd_for_destroy(relayd);
1390 }
1391
1392 goto end_msg_sessiond;
1393 }
1394 case LTTNG_CONSUMER_UPDATE_STREAM:
1395 {
1396 rcu_read_unlock();
1397 return -ENOSYS;
1398 }
1399 case LTTNG_CONSUMER_DATA_PENDING:
1400 {
1401 int ret, is_data_pending;
1402 uint64_t id = msg.u.data_pending.session_id;
1403
1404 DBG("UST consumer data pending command for id %" PRIu64, id);
1405
1406 is_data_pending = consumer_data_pending(id);
1407
1408 /* Send back returned value to session daemon */
1409 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1410 sizeof(is_data_pending));
1411 if (ret < 0) {
1412 DBG("Error when sending the data pending ret code: %d", ret);
1413 goto error_fatal;
1414 }
1415
1416 /*
1417 * No need to send back a status message since the data pending
1418 * returned value is the response.
1419 */
1420 break;
1421 }
1422 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1423 {
1424 int ret;
1425 struct ustctl_consumer_channel_attr attr;
1426
1427 /* Create a plain object and reserve a channel key. */
1428 channel = allocate_channel(msg.u.ask_channel.session_id,
1429 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1430 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1431 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1432 (enum lttng_event_output) msg.u.ask_channel.output,
1433 msg.u.ask_channel.tracefile_size,
1434 msg.u.ask_channel.tracefile_count,
1435 msg.u.ask_channel.session_id_per_pid,
1436 msg.u.ask_channel.monitor,
1437 msg.u.ask_channel.live_timer_interval,
1438 msg.u.ask_channel.root_shm_path,
1439 msg.u.ask_channel.shm_path);
1440 if (!channel) {
1441 goto end_channel_error;
1442 }
1443
1444 /*
1445 * Assign UST application UID to the channel. This value is ignored for
1446 * per PID buffers. This is specific to UST thus setting this after the
1447 * allocation.
1448 */
1449 channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
1450
1451 /* Build channel attributes from received message. */
1452 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1453 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1454 attr.overwrite = msg.u.ask_channel.overwrite;
1455 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1456 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1457 attr.chan_id = msg.u.ask_channel.chan_id;
1458 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1459 attr.blocking_timeout= msg.u.ask_channel.blocking_timeout;
1460
1461 /* Match channel buffer type to the UST abi. */
1462 switch (msg.u.ask_channel.output) {
1463 case LTTNG_EVENT_MMAP:
1464 default:
1465 attr.output = LTTNG_UST_MMAP;
1466 break;
1467 }
1468
1469 /* Translate and save channel type. */
1470 switch (msg.u.ask_channel.type) {
1471 case LTTNG_UST_CHAN_PER_CPU:
1472 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1473 attr.type = LTTNG_UST_CHAN_PER_CPU;
1474 /*
1475 * Set refcount to 1 for owner. Below, we will
1476 * pass ownership to the
1477 * consumer_thread_channel_poll() thread.
1478 */
1479 channel->refcount = 1;
1480 break;
1481 case LTTNG_UST_CHAN_METADATA:
1482 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1483 attr.type = LTTNG_UST_CHAN_METADATA;
1484 break;
1485 default:
1486 assert(0);
1487 goto error_fatal;
1488 };
1489
1490 health_code_update();
1491
1492 ret = ask_channel(ctx, channel, &attr,
1493 msg.u.ask_channel.trace_archive_id);
1494 if (ret < 0) {
1495 goto end_channel_error;
1496 }
1497
1498 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1499 ret = consumer_metadata_cache_allocate(channel);
1500 if (ret < 0) {
1501 ERR("Allocating metadata cache");
1502 goto end_channel_error;
1503 }
1504 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1505 attr.switch_timer_interval = 0;
1506 } else {
1507 int monitor_start_ret;
1508
1509 consumer_timer_live_start(channel,
1510 msg.u.ask_channel.live_timer_interval);
1511 monitor_start_ret = consumer_timer_monitor_start(
1512 channel,
1513 msg.u.ask_channel.monitor_timer_interval);
1514 if (monitor_start_ret < 0) {
1515 ERR("Starting channel monitoring timer failed");
1516 goto end_channel_error;
1517 }
1518 }
1519
1520 health_code_update();
1521
1522 /*
1523 * Add the channel to the internal state AFTER all streams were created
1524 * and successfully sent to session daemon. This way, all streams must
1525 * be ready before this channel is visible to the threads.
1526 * If add_channel succeeds, ownership of the channel is
1527 * passed to consumer_thread_channel_poll().
1528 */
1529 ret = add_channel(channel, ctx);
1530 if (ret < 0) {
1531 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1532 if (channel->switch_timer_enabled == 1) {
1533 consumer_timer_switch_stop(channel);
1534 }
1535 consumer_metadata_cache_destroy(channel);
1536 }
1537 if (channel->live_timer_enabled == 1) {
1538 consumer_timer_live_stop(channel);
1539 }
1540 if (channel->monitor_timer_enabled == 1) {
1541 consumer_timer_monitor_stop(channel);
1542 }
1543 goto end_channel_error;
1544 }
1545
1546 health_code_update();
1547
1548 /*
1549 * Channel and streams are now created. Inform the session daemon that
1550 * everything went well and should wait to receive the channel and
1551 * streams with ustctl API.
1552 */
1553 ret = consumer_send_status_channel(sock, channel);
1554 if (ret < 0) {
1555 /*
1556 * There is probably a problem on the socket.
1557 */
1558 goto error_fatal;
1559 }
1560
1561 break;
1562 }
1563 case LTTNG_CONSUMER_GET_CHANNEL:
1564 {
1565 int ret, relayd_err = 0;
1566 uint64_t key = msg.u.get_channel.key;
1567 struct lttng_consumer_channel *channel;
1568
1569 channel = consumer_find_channel(key);
1570 if (!channel) {
1571 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1572 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1573 goto end_msg_sessiond;
1574 }
1575
1576 health_code_update();
1577
1578 /* Send the channel to sessiond (and relayd, if applicable). */
1579 ret = send_channel_to_sessiond_and_relayd(sock, channel, ctx,
1580 &relayd_err);
1581 if (ret < 0) {
1582 if (relayd_err) {
1583 /*
1584 * We were unable to send to the relayd the stream so avoid
1585 * sending back a fatal error to the thread since this is OK
1586 * and the consumer can continue its work. The above call
1587 * has sent the error status message to the sessiond.
1588 */
1589 goto end_nosignal;
1590 }
1591 /*
1592 * The communicaton was broken hence there is a bad state between
1593 * the consumer and sessiond so stop everything.
1594 */
1595 goto error_fatal;
1596 }
1597
1598 health_code_update();
1599
1600 /*
1601 * In no monitor mode, the streams ownership is kept inside the channel
1602 * so don't send them to the data thread.
1603 */
1604 if (!channel->monitor) {
1605 goto end_msg_sessiond;
1606 }
1607
1608 ret = send_streams_to_thread(channel, ctx);
1609 if (ret < 0) {
1610 /*
1611 * If we are unable to send the stream to the thread, there is
1612 * a big problem so just stop everything.
1613 */
1614 goto error_fatal;
1615 }
1616 /* List MUST be empty after or else it could be reused. */
1617 assert(cds_list_empty(&channel->streams.head));
1618 goto end_msg_sessiond;
1619 }
1620 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1621 {
1622 uint64_t key = msg.u.destroy_channel.key;
1623
1624 /*
1625 * Only called if streams have not been sent to stream
1626 * manager thread. However, channel has been sent to
1627 * channel manager thread.
1628 */
1629 notify_thread_del_channel(ctx, key);
1630 goto end_msg_sessiond;
1631 }
1632 case LTTNG_CONSUMER_CLOSE_METADATA:
1633 {
1634 int ret;
1635
1636 ret = close_metadata(msg.u.close_metadata.key);
1637 if (ret != 0) {
1638 ret_code = ret;
1639 }
1640
1641 goto end_msg_sessiond;
1642 }
1643 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1644 {
1645 int ret;
1646
1647 ret = flush_channel(msg.u.flush_channel.key);
1648 if (ret != 0) {
1649 ret_code = ret;
1650 }
1651
1652 goto end_msg_sessiond;
1653 }
1654 case LTTNG_CONSUMER_CLEAR_QUIESCENT_CHANNEL:
1655 {
1656 int ret;
1657
1658 ret = clear_quiescent_channel(
1659 msg.u.clear_quiescent_channel.key);
1660 if (ret != 0) {
1661 ret_code = ret;
1662 }
1663
1664 goto end_msg_sessiond;
1665 }
1666 case LTTNG_CONSUMER_PUSH_METADATA:
1667 {
1668 int ret;
1669 uint64_t len = msg.u.push_metadata.len;
1670 uint64_t key = msg.u.push_metadata.key;
1671 uint64_t offset = msg.u.push_metadata.target_offset;
1672 uint64_t version = msg.u.push_metadata.version;
1673 struct lttng_consumer_channel *channel;
1674
1675 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1676 len);
1677
1678 channel = consumer_find_channel(key);
1679 if (!channel) {
1680 /*
1681 * This is possible if the metadata creation on the consumer side
1682 * is in flight vis-a-vis a concurrent push metadata from the
1683 * session daemon. Simply return that the channel failed and the
1684 * session daemon will handle that message correctly considering
1685 * that this race is acceptable thus the DBG() statement here.
1686 */
1687 DBG("UST consumer push metadata %" PRIu64 " not found", key);
1688 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1689 goto end_msg_sessiond;
1690 }
1691
1692 health_code_update();
1693
1694 if (!len) {
1695 /*
1696 * There is nothing to receive. We have simply
1697 * checked whether the channel can be found.
1698 */
1699 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1700 goto end_msg_sessiond;
1701 }
1702
1703 /* Tell session daemon we are ready to receive the metadata. */
1704 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
1705 if (ret < 0) {
1706 /* Somehow, the session daemon is not responding anymore. */
1707 goto error_fatal;
1708 }
1709
1710 health_code_update();
1711
1712 /* Wait for more data. */
1713 health_poll_entry();
1714 ret = lttng_consumer_poll_socket(consumer_sockpoll);
1715 health_poll_exit();
1716 if (ret) {
1717 goto error_fatal;
1718 }
1719
1720 health_code_update();
1721
1722 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1723 len, version, channel, 0, 1);
1724 if (ret < 0) {
1725 /* error receiving from sessiond */
1726 goto error_fatal;
1727 } else {
1728 ret_code = ret;
1729 goto end_msg_sessiond;
1730 }
1731 }
1732 case LTTNG_CONSUMER_SETUP_METADATA:
1733 {
1734 int ret;
1735
1736 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1737 if (ret) {
1738 ret_code = ret;
1739 }
1740 goto end_msg_sessiond;
1741 }
1742 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1743 {
1744 struct lttng_consumer_channel *channel;
1745 uint64_t key = msg.u.snapshot_channel.key;
1746
1747 channel = consumer_find_channel(key);
1748 if (!channel) {
1749 DBG("UST snapshot channel not found for key %" PRIu64, key);
1750 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1751 } else {
1752 if (msg.u.snapshot_channel.metadata) {
1753 ret = snapshot_metadata(channel, key,
1754 msg.u.snapshot_channel.pathname,
1755 msg.u.snapshot_channel.relayd_id,
1756 ctx,
1757 msg.u.snapshot_channel.trace_archive_id);
1758 if (ret < 0) {
1759 ERR("Snapshot metadata failed");
1760 ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED;
1761 }
1762 } else {
1763 ret = snapshot_channel(channel, key,
1764 msg.u.snapshot_channel.pathname,
1765 msg.u.snapshot_channel.relayd_id,
1766 msg.u.snapshot_channel.nb_packets_per_stream,
1767 ctx);
1768 if (ret < 0) {
1769 ERR("Snapshot channel failed");
1770 ret_code = LTTCOMM_CONSUMERD_SNAPSHOT_FAILED;
1771 }
1772 }
1773 }
1774 health_code_update();
1775 ret = consumer_send_status_msg(sock, ret_code);
1776 if (ret < 0) {
1777 /* Somehow, the session daemon is not responding anymore. */
1778 goto end_nosignal;
1779 }
1780 health_code_update();
1781 break;
1782 }
1783 case LTTNG_CONSUMER_DISCARDED_EVENTS:
1784 {
1785 int ret = 0;
1786 uint64_t discarded_events;
1787 struct lttng_ht_iter iter;
1788 struct lttng_ht *ht;
1789 struct lttng_consumer_stream *stream;
1790 uint64_t id = msg.u.discarded_events.session_id;
1791 uint64_t key = msg.u.discarded_events.channel_key;
1792
1793 DBG("UST consumer discarded events command for session id %"
1794 PRIu64, id);
1795 rcu_read_lock();
1796 pthread_mutex_lock(&consumer_data.lock);
1797
1798 ht = consumer_data.stream_list_ht;
1799
1800 /*
1801 * We only need a reference to the channel, but they are not
1802 * directly indexed, so we just use the first matching stream
1803 * to extract the information we need, we default to 0 if not
1804 * found (no events are dropped if the channel is not yet in
1805 * use).
1806 */
1807 discarded_events = 0;
1808 cds_lfht_for_each_entry_duplicate(ht->ht,
1809 ht->hash_fct(&id, lttng_ht_seed),
1810 ht->match_fct, &id,
1811 &iter.iter, stream, node_session_id.node) {
1812 if (stream->chan->key == key) {
1813 discarded_events = stream->chan->discarded_events;
1814 break;
1815 }
1816 }
1817 pthread_mutex_unlock(&consumer_data.lock);
1818 rcu_read_unlock();
1819
1820 DBG("UST consumer discarded events command for session id %"
1821 PRIu64 ", channel key %" PRIu64, id, key);
1822
1823 health_code_update();
1824
1825 /* Send back returned value to session daemon */
1826 ret = lttcomm_send_unix_sock(sock, &discarded_events, sizeof(discarded_events));
1827 if (ret < 0) {
1828 PERROR("send discarded events");
1829 goto error_fatal;
1830 }
1831
1832 break;
1833 }
1834 case LTTNG_CONSUMER_LOST_PACKETS:
1835 {
1836 int ret;
1837 uint64_t lost_packets;
1838 struct lttng_ht_iter iter;
1839 struct lttng_ht *ht;
1840 struct lttng_consumer_stream *stream;
1841 uint64_t id = msg.u.lost_packets.session_id;
1842 uint64_t key = msg.u.lost_packets.channel_key;
1843
1844 DBG("UST consumer lost packets command for session id %"
1845 PRIu64, id);
1846 rcu_read_lock();
1847 pthread_mutex_lock(&consumer_data.lock);
1848
1849 ht = consumer_data.stream_list_ht;
1850
1851 /*
1852 * We only need a reference to the channel, but they are not
1853 * directly indexed, so we just use the first matching stream
1854 * to extract the information we need, we default to 0 if not
1855 * found (no packets lost if the channel is not yet in use).
1856 */
1857 lost_packets = 0;
1858 cds_lfht_for_each_entry_duplicate(ht->ht,
1859 ht->hash_fct(&id, lttng_ht_seed),
1860 ht->match_fct, &id,
1861 &iter.iter, stream, node_session_id.node) {
1862 if (stream->chan->key == key) {
1863 lost_packets = stream->chan->lost_packets;
1864 break;
1865 }
1866 }
1867 pthread_mutex_unlock(&consumer_data.lock);
1868 rcu_read_unlock();
1869
1870 DBG("UST consumer lost packets command for session id %"
1871 PRIu64 ", channel key %" PRIu64, id, key);
1872
1873 health_code_update();
1874
1875 /* Send back returned value to session daemon */
1876 ret = lttcomm_send_unix_sock(sock, &lost_packets,
1877 sizeof(lost_packets));
1878 if (ret < 0) {
1879 PERROR("send lost packets");
1880 goto error_fatal;
1881 }
1882
1883 break;
1884 }
1885 case LTTNG_CONSUMER_SET_CHANNEL_MONITOR_PIPE:
1886 {
1887 int channel_monitor_pipe;
1888
1889 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1890 /* Successfully received the command's type. */
1891 ret = consumer_send_status_msg(sock, ret_code);
1892 if (ret < 0) {
1893 goto error_fatal;
1894 }
1895
1896 ret = lttcomm_recv_fds_unix_sock(sock, &channel_monitor_pipe,
1897 1);
1898 if (ret != sizeof(channel_monitor_pipe)) {
1899 ERR("Failed to receive channel monitor pipe");
1900 goto error_fatal;
1901 }
1902
1903 DBG("Received channel monitor pipe (%d)", channel_monitor_pipe);
1904 ret = consumer_timer_thread_set_channel_monitor_pipe(
1905 channel_monitor_pipe);
1906 if (!ret) {
1907 int flags;
1908
1909 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1910 /* Set the pipe as non-blocking. */
1911 ret = fcntl(channel_monitor_pipe, F_GETFL, 0);
1912 if (ret == -1) {
1913 PERROR("fcntl get flags of the channel monitoring pipe");
1914 goto error_fatal;
1915 }
1916 flags = ret;
1917
1918 ret = fcntl(channel_monitor_pipe, F_SETFL,
1919 flags | O_NONBLOCK);
1920 if (ret == -1) {
1921 PERROR("fcntl set O_NONBLOCK flag of the channel monitoring pipe");
1922 goto error_fatal;
1923 }
1924 DBG("Channel monitor pipe set as non-blocking");
1925 } else {
1926 ret_code = LTTCOMM_CONSUMERD_ALREADY_SET;
1927 }
1928 goto end_msg_sessiond;
1929 }
1930 case LTTNG_CONSUMER_ROTATE_CHANNEL:
1931 {
1932 struct lttng_consumer_channel *channel;
1933 uint64_t key = msg.u.rotate_channel.key;
1934
1935 channel = consumer_find_channel(key);
1936 if (!channel) {
1937 DBG("Channel %" PRIu64 " not found", key);
1938 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1939 } else {
1940 /*
1941 * Sample the rotate position of all the streams in
1942 * this channel.
1943 */
1944 ret = lttng_consumer_rotate_sample_channel(channel, key,
1945 msg.u.rotate_channel.pathname,
1946 msg.u.rotate_channel.relayd_id,
1947 msg.u.rotate_channel.metadata,
1948 msg.u.rotate_channel.new_chunk_id,
1949 ctx);
1950 if (ret < 0) {
1951 ERR("Rotate channel failed");
1952 ret_code = LTTCOMM_CONSUMERD_ROTATION_FAIL;
1953 }
1954
1955 health_code_update();
1956 }
1957 ret = consumer_send_status_msg(sock, ret_code);
1958 if (ret < 0) {
1959 /* Somehow, the session daemon is not responding anymore. */
1960 goto end_nosignal;
1961 }
1962
1963 /*
1964 * Rotate the streams that are ready right now.
1965 * FIXME: this is a second consecutive iteration over the
1966 * streams in a channel, there is probably a better way to
1967 * handle this, but it needs to be after the
1968 * consumer_send_status_msg() call.
1969 */
1970 if (channel) {
1971 ret = lttng_consumer_rotate_ready_streams(
1972 channel, key, ctx);
1973 if (ret < 0) {
1974 ERR("Rotate channel failed");
1975 }
1976 }
1977 break;
1978 }
1979 case LTTNG_CONSUMER_ROTATE_RENAME:
1980 {
1981 DBG("Consumer rename session %" PRIu64 " after rotation",
1982 msg.u.rotate_rename.session_id);
1983 ret = lttng_consumer_rotate_rename(msg.u.rotate_rename.old_path,
1984 msg.u.rotate_rename.new_path,
1985 msg.u.rotate_rename.uid,
1986 msg.u.rotate_rename.gid,
1987 msg.u.rotate_rename.relayd_id);
1988 if (ret < 0) {
1989 ERR("Rotate rename failed");
1990 ret_code = LTTCOMM_CONSUMERD_ROTATE_RENAME_FAILED;
1991 }
1992
1993 health_code_update();
1994
1995 ret = consumer_send_status_msg(sock, ret_code);
1996 if (ret < 0) {
1997 /* Somehow, the session daemon is not responding anymore. */
1998 goto end_nosignal;
1999 }
2000 break;
2001 }
2002 case LTTNG_CONSUMER_CHECK_ROTATION_PENDING_LOCAL:
2003 {
2004 int pending;
2005 uint32_t pending_reply;
2006
2007 DBG("Perform local check of pending rotation for session id %" PRIu64,
2008 msg.u.check_rotation_pending_local.session_id);
2009 pending = lttng_consumer_check_rotation_pending_local(
2010 msg.u.check_rotation_pending_local.session_id,
2011 msg.u.check_rotation_pending_local.chunk_id);
2012 if (pending < 0) {
2013 ERR("Local rotation pending check failed with code %i", pending);
2014 ret_code = LTTCOMM_CONSUMERD_ROTATION_PENDING_LOCAL_FAILED;
2015 } else {
2016 pending_reply = !!pending;
2017 }
2018
2019 health_code_update();
2020
2021 ret = consumer_send_status_msg(sock, ret_code);
2022 if (ret < 0) {
2023 /* Somehow, the session daemon is not responding anymore. */
2024 goto end_nosignal;
2025 }
2026
2027 if (pending < 0) {
2028 /*
2029 * An error occurred while running the command;
2030 * don't send the 'pending' flag as the sessiond
2031 * will not read it.
2032 */
2033 break;
2034 }
2035
2036 /* Send back returned value to session daemon */
2037 ret = lttcomm_send_unix_sock(sock, &pending_reply,
2038 sizeof(pending_reply));
2039 if (ret < 0) {
2040 PERROR("Failed to send rotation pending return code");
2041 goto error_fatal;
2042 }
2043 break;
2044 }
2045 case LTTNG_CONSUMER_CHECK_ROTATION_PENDING_RELAY:
2046 {
2047 int pending;
2048 uint32_t pending_reply;
2049
2050 DBG("Perform relayd check of pending rotation for session id %" PRIu64,
2051 msg.u.check_rotation_pending_relay.session_id);
2052 pending = lttng_consumer_check_rotation_pending_relay(
2053 msg.u.check_rotation_pending_relay.session_id,
2054 msg.u.check_rotation_pending_relay.relayd_id,
2055 msg.u.check_rotation_pending_relay.chunk_id);
2056 if (pending < 0) {
2057 ERR("Relayd rotation pending check failed with code %i", pending);
2058 ret_code = LTTCOMM_CONSUMERD_ROTATION_PENDING_RELAY_FAILED;
2059 } else {
2060 pending_reply = !!pending;
2061 }
2062
2063 health_code_update();
2064
2065 ret = consumer_send_status_msg(sock, ret_code);
2066 if (ret < 0) {
2067 /* Somehow, the session daemon is not responding anymore. */
2068 goto end_nosignal;
2069 }
2070
2071 if (pending < 0) {
2072 /*
2073 * An error occurred while running the command;
2074 * don't send the 'pending' flag as the sessiond
2075 * will not read it.
2076 */
2077 break;
2078 }
2079
2080 /* Send back returned value to session daemon */
2081 ret = lttcomm_send_unix_sock(sock, &pending_reply,
2082 sizeof(pending_reply));
2083 if (ret < 0) {
2084 PERROR("Failed to send rotation pending return code");
2085 goto error_fatal;
2086 }
2087 break;
2088 }
2089 case LTTNG_CONSUMER_MKDIR:
2090 {
2091 DBG("Consumer mkdir %s in session %" PRIu64,
2092 msg.u.mkdir.path,
2093 msg.u.mkdir.session_id);
2094 ret = lttng_consumer_mkdir(msg.u.mkdir.path,
2095 msg.u.mkdir.uid,
2096 msg.u.mkdir.gid,
2097 msg.u.mkdir.relayd_id);
2098 if (ret < 0) {
2099 ERR("consumer mkdir failed");
2100 ret_code = LTTCOMM_CONSUMERD_MKDIR_FAILED;
2101 }
2102
2103 health_code_update();
2104
2105 ret = consumer_send_status_msg(sock, ret_code);
2106 if (ret < 0) {
2107 /* Somehow, the session daemon is not responding anymore. */
2108 goto end_nosignal;
2109 }
2110 break;
2111 }
2112 case LTTNG_CONSUMER_CLEAR_CHANNEL:
2113 {
2114 struct lttng_consumer_channel *channel;
2115 uint64_t key = msg.u.clear_channel.key;
2116
2117 channel = consumer_find_channel(key);
2118 if (!channel) {
2119 DBG("Channel %" PRIu64 " not found", key);
2120 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
2121 } else {
2122 ret = lttng_consumer_clear_channel(channel);
2123 if (ret) {
2124 ERR("Clear channel failed key %" PRIu64, key);
2125 ret_code = ret;
2126 }
2127
2128 health_code_update();
2129 }
2130 ret = consumer_send_status_msg(sock, ret_code);
2131 if (ret < 0) {
2132 /* Somehow, the session daemon is not responding anymore. */
2133 goto end_nosignal;
2134 }
2135 break;
2136 }
2137 default:
2138 break;
2139 }
2140
2141 end_nosignal:
2142 rcu_read_unlock();
2143
2144 health_code_update();
2145
2146 /*
2147 * Return 1 to indicate success since the 0 value can be a socket
2148 * shutdown during the recv() or send() call.
2149 */
2150 return 1;
2151
2152 end_msg_sessiond:
2153 /*
2154 * The returned value here is not useful since either way we'll return 1 to
2155 * the caller because the session daemon socket management is done
2156 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
2157 */
2158 ret = consumer_send_status_msg(sock, ret_code);
2159 if (ret < 0) {
2160 goto error_fatal;
2161 }
2162 rcu_read_unlock();
2163
2164 health_code_update();
2165
2166 return 1;
2167 end_channel_error:
2168 if (channel) {
2169 /*
2170 * Free channel here since no one has a reference to it. We don't
2171 * free after that because a stream can store this pointer.
2172 */
2173 destroy_channel(channel);
2174 }
2175 /* We have to send a status channel message indicating an error. */
2176 ret = consumer_send_status_channel(sock, NULL);
2177 if (ret < 0) {
2178 /* Stop everything if session daemon can not be notified. */
2179 goto error_fatal;
2180 }
2181 rcu_read_unlock();
2182
2183 health_code_update();
2184
2185 return 1;
2186 error_fatal:
2187 rcu_read_unlock();
2188 /* This will issue a consumer stop. */
2189 return -1;
2190 }
2191
2192 /*
2193 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
2194 * compiled out, we isolate it in this library.
2195 */
2196 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
2197 unsigned long *off)
2198 {
2199 assert(stream);
2200 assert(stream->ustream);
2201
2202 return ustctl_get_mmap_read_offset(stream->ustream, off);
2203 }
2204
2205 /*
2206 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
2207 * compiled out, we isolate it in this library.
2208 */
2209 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
2210 {
2211 assert(stream);
2212 assert(stream->ustream);
2213
2214 return ustctl_get_mmap_base(stream->ustream);
2215 }
2216
2217 /*
2218 * Take a snapshot for a specific stream.
2219 *
2220 * Returns 0 on success, < 0 on error
2221 */
2222 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
2223 {
2224 assert(stream);
2225 assert(stream->ustream);
2226
2227 return ustctl_snapshot(stream->ustream);
2228 }
2229
2230 /*
2231 * Sample consumed and produced positions for a specific stream.
2232 *
2233 * Returns 0 on success, < 0 on error.
2234 */
2235 int lttng_ustconsumer_sample_snapshot_positions(
2236 struct lttng_consumer_stream *stream)
2237 {
2238 assert(stream);
2239 assert(stream->ustream);
2240
2241 return ustctl_snapshot_sample_positions(stream->ustream);
2242 }
2243
2244 /*
2245 * Get the produced position
2246 *
2247 * Returns 0 on success, < 0 on error
2248 */
2249 int lttng_ustconsumer_get_produced_snapshot(
2250 struct lttng_consumer_stream *stream, unsigned long *pos)
2251 {
2252 assert(stream);
2253 assert(stream->ustream);
2254 assert(pos);
2255
2256 return ustctl_snapshot_get_produced(stream->ustream, pos);
2257 }
2258
2259 /*
2260 * Get the consumed position
2261 *
2262 * Returns 0 on success, < 0 on error
2263 */
2264 int lttng_ustconsumer_get_consumed_snapshot(
2265 struct lttng_consumer_stream *stream, unsigned long *pos)
2266 {
2267 assert(stream);
2268 assert(stream->ustream);
2269 assert(pos);
2270
2271 return ustctl_snapshot_get_consumed(stream->ustream, pos);
2272 }
2273
2274 void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
2275 int producer)
2276 {
2277 assert(stream);
2278 assert(stream->ustream);
2279
2280 ustctl_flush_buffer(stream->ustream, producer);
2281 }
2282
2283 void lttng_ustconsumer_clear_buffer(struct lttng_consumer_stream *stream)
2284 {
2285 assert(stream);
2286 assert(stream->ustream);
2287
2288 ustctl_clear_buffer(stream->ustream);
2289 }
2290
2291 int lttng_ustconsumer_get_current_timestamp(
2292 struct lttng_consumer_stream *stream, uint64_t *ts)
2293 {
2294 assert(stream);
2295 assert(stream->ustream);
2296 assert(ts);
2297
2298 return ustctl_get_current_timestamp(stream->ustream, ts);
2299 }
2300
2301 int lttng_ustconsumer_get_sequence_number(
2302 struct lttng_consumer_stream *stream, uint64_t *seq)
2303 {
2304 assert(stream);
2305 assert(stream->ustream);
2306 assert(seq);
2307
2308 return ustctl_get_sequence_number(stream->ustream, seq);
2309 }
2310
2311 /*
2312 * Called when the stream signals the consumer that it has hung up.
2313 */
2314 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
2315 {
2316 assert(stream);
2317 assert(stream->ustream);
2318
2319 pthread_mutex_lock(&stream->lock);
2320 if (!stream->quiescent) {
2321 lttng_ustconsumer_flush_buffer(stream, 0);
2322 stream->quiescent = true;
2323 }
2324 pthread_mutex_unlock(&stream->lock);
2325 stream->hangup_flush_done = 1;
2326 }
2327
2328 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
2329 {
2330 int i;
2331
2332 assert(chan);
2333 assert(chan->uchan);
2334
2335 if (chan->switch_timer_enabled == 1) {
2336 consumer_timer_switch_stop(chan);
2337 }
2338 for (i = 0; i < chan->nr_stream_fds; i++) {
2339 int ret;
2340
2341 ret = close(chan->stream_fds[i]);
2342 if (ret) {
2343 PERROR("close");
2344 }
2345 if (chan->shm_path[0]) {
2346 char shm_path[PATH_MAX];
2347
2348 ret = get_stream_shm_path(shm_path, chan->shm_path, i);
2349 if (ret) {
2350 ERR("Cannot get stream shm path");
2351 }
2352 ret = run_as_unlink(shm_path, chan->uid, chan->gid);
2353 if (ret) {
2354 PERROR("unlink %s", shm_path);
2355 }
2356 }
2357 }
2358 }
2359
2360 void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
2361 {
2362 assert(chan);
2363 assert(chan->uchan);
2364
2365 consumer_metadata_cache_destroy(chan);
2366 ustctl_destroy_channel(chan->uchan);
2367 /* Try to rmdir all directories under shm_path root. */
2368 if (chan->root_shm_path[0]) {
2369 (void) run_as_rmdir_recursive(chan->root_shm_path,
2370 chan->uid, chan->gid);
2371 }
2372 free(chan->stream_fds);
2373 }
2374
2375 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
2376 {
2377 assert(stream);
2378 assert(stream->ustream);
2379
2380 if (stream->chan->switch_timer_enabled == 1) {
2381 consumer_timer_switch_stop(stream->chan);
2382 }
2383 ustctl_destroy_stream(stream->ustream);
2384 }
2385
2386 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
2387 {
2388 assert(stream);
2389 assert(stream->ustream);
2390
2391 return ustctl_stream_get_wakeup_fd(stream->ustream);
2392 }
2393
2394 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
2395 {
2396 assert(stream);
2397 assert(stream->ustream);
2398
2399 return ustctl_stream_close_wakeup_fd(stream->ustream);
2400 }
2401
2402 /*
2403 * Populate index values of a UST stream. Values are set in big endian order.
2404 *
2405 * Return 0 on success or else a negative value.
2406 */
2407 static int get_index_values(struct ctf_packet_index *index,
2408 struct ustctl_consumer_stream *ustream)
2409 {
2410 int ret;
2411
2412 ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
2413 if (ret < 0) {
2414 PERROR("ustctl_get_timestamp_begin");
2415 goto error;
2416 }
2417 index->timestamp_begin = htobe64(index->timestamp_begin);
2418
2419 ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
2420 if (ret < 0) {
2421 PERROR("ustctl_get_timestamp_end");
2422 goto error;
2423 }
2424 index->timestamp_end = htobe64(index->timestamp_end);
2425
2426 ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
2427 if (ret < 0) {
2428 PERROR("ustctl_get_events_discarded");
2429 goto error;
2430 }
2431 index->events_discarded = htobe64(index->events_discarded);
2432
2433 ret = ustctl_get_content_size(ustream, &index->content_size);
2434 if (ret < 0) {
2435 PERROR("ustctl_get_content_size");
2436 goto error;
2437 }
2438 index->content_size = htobe64(index->content_size);
2439
2440 ret = ustctl_get_packet_size(ustream, &index->packet_size);
2441 if (ret < 0) {
2442 PERROR("ustctl_get_packet_size");
2443 goto error;
2444 }
2445 index->packet_size = htobe64(index->packet_size);
2446
2447 ret = ustctl_get_stream_id(ustream, &index->stream_id);
2448 if (ret < 0) {
2449 PERROR("ustctl_get_stream_id");
2450 goto error;
2451 }
2452 index->stream_id = htobe64(index->stream_id);
2453
2454 ret = ustctl_get_instance_id(ustream, &index->stream_instance_id);
2455 if (ret < 0) {
2456 PERROR("ustctl_get_instance_id");
2457 goto error;
2458 }
2459 index->stream_instance_id = htobe64(index->stream_instance_id);
2460
2461 ret = ustctl_get_sequence_number(ustream, &index->packet_seq_num);
2462 if (ret < 0) {
2463 PERROR("ustctl_get_sequence_number");
2464 goto error;
2465 }
2466 index->packet_seq_num = htobe64(index->packet_seq_num);
2467
2468 error:
2469 return ret;
2470 }
2471
2472 static
2473 void metadata_stream_reset_cache(struct lttng_consumer_stream *stream,
2474 struct consumer_metadata_cache *cache)
2475 {
2476 DBG("Metadata stream update to version %" PRIu64,
2477 cache->version);
2478 stream->ust_metadata_pushed = 0;
2479 stream->metadata_version = cache->version;
2480 stream->reset_metadata_flag = 1;
2481 }
2482
2483 /*
2484 * Check if the version of the metadata stream and metadata cache match.
2485 * If the cache got updated, reset the metadata stream.
2486 * The stream lock and metadata cache lock MUST be held.
2487 * Return 0 on success, a negative value on error.
2488 */
2489 static
2490 int metadata_stream_check_version(struct lttng_consumer_stream *stream)
2491 {
2492 int ret = 0;
2493 struct consumer_metadata_cache *cache = stream->chan->metadata_cache;
2494
2495 if (cache->version == stream->metadata_version) {
2496 goto end;
2497 }
2498 metadata_stream_reset_cache(stream, cache);
2499
2500 end:
2501 return ret;
2502 }
2503
2504 /*
2505 * Write up to one packet from the metadata cache to the channel.
2506 *
2507 * Returns the number of bytes pushed in the cache, or a negative value
2508 * on error.
2509 */
2510 static
2511 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
2512 {
2513 ssize_t write_len;
2514 int ret;
2515
2516 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
2517 ret = metadata_stream_check_version(stream);
2518 if (ret < 0) {
2519 goto end;
2520 }
2521 if (stream->chan->metadata_cache->max_offset
2522 == stream->ust_metadata_pushed) {
2523 ret = 0;
2524 goto end;
2525 }
2526
2527 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
2528 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
2529 stream->chan->metadata_cache->max_offset
2530 - stream->ust_metadata_pushed);
2531 assert(write_len != 0);
2532 if (write_len < 0) {
2533 ERR("Writing one metadata packet");
2534 ret = -1;
2535 goto end;
2536 }
2537 stream->ust_metadata_pushed += write_len;
2538
2539 assert(stream->chan->metadata_cache->max_offset >=
2540 stream->ust_metadata_pushed);
2541 ret = write_len;
2542
2543 end:
2544 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
2545 return ret;
2546 }
2547
2548
2549 /*
2550 * Sync metadata meaning request them to the session daemon and snapshot to the
2551 * metadata thread can consumer them.
2552 *
2553 * Metadata stream lock is held here, but we need to release it when
2554 * interacting with sessiond, else we cause a deadlock with live
2555 * awaiting on metadata to be pushed out.
2556 *
2557 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
2558 * is empty or a negative value on error.
2559 */
2560 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
2561 struct lttng_consumer_stream *metadata)
2562 {
2563 int ret;
2564 int retry = 0;
2565
2566 assert(ctx);
2567 assert(metadata);
2568
2569 pthread_mutex_unlock(&metadata->lock);
2570 /*
2571 * Request metadata from the sessiond, but don't wait for the flush
2572 * because we locked the metadata thread.
2573 */
2574 ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
2575 pthread_mutex_lock(&metadata->lock);
2576 if (ret < 0) {
2577 goto end;
2578 }
2579
2580 ret = commit_one_metadata_packet(metadata);
2581 if (ret <= 0) {
2582 goto end;
2583 } else if (ret > 0) {
2584 retry = 1;
2585 }
2586
2587 lttng_ustconsumer_flush_buffer(metadata, 1);
2588 ret = ustctl_snapshot(metadata->ustream);
2589 if (ret < 0) {
2590 if (errno != EAGAIN) {
2591 ERR("Sync metadata, taking UST snapshot");
2592 goto end;
2593 }
2594 DBG("No new metadata when syncing them.");
2595 /* No new metadata, exit. */
2596 ret = ENODATA;
2597 goto end;
2598 }
2599
2600 /*
2601 * After this flush, we still need to extract metadata.
2602 */
2603 if (retry) {
2604 ret = EAGAIN;
2605 }
2606
2607 end:
2608 return ret;
2609 }
2610
2611 /*
2612 * Return 0 on success else a negative value.
2613 */
2614 static int notify_if_more_data(struct lttng_consumer_stream *stream,
2615 struct lttng_consumer_local_data *ctx)
2616 {
2617 int ret;
2618 struct ustctl_consumer_stream *ustream;
2619
2620 assert(stream);
2621 assert(ctx);
2622
2623 ustream = stream->ustream;
2624
2625 /*
2626 * First, we are going to check if there is a new subbuffer available
2627 * before reading the stream wait_fd.
2628 */
2629 /* Get the next subbuffer */
2630 ret = ustctl_get_next_subbuf(ustream);
2631 if (ret) {
2632 /* No more data found, flag the stream. */
2633 stream->has_data = 0;
2634 ret = 0;
2635 goto end;
2636 }
2637
2638 ret = ustctl_put_subbuf(ustream);
2639 assert(!ret);
2640
2641 /* This stream still has data. Flag it and wake up the data thread. */
2642 stream->has_data = 1;
2643
2644 if (stream->monitor && !stream->hangup_flush_done && !ctx->has_wakeup) {
2645 ssize_t writelen;
2646
2647 writelen = lttng_pipe_write(ctx->consumer_wakeup_pipe, "!", 1);
2648 if (writelen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2649 ret = writelen;
2650 goto end;
2651 }
2652
2653 /* The wake up pipe has been notified. */
2654 ctx->has_wakeup = 1;
2655 }
2656 ret = 0;
2657
2658 end:
2659 return ret;
2660 }
2661
2662 static
2663 int update_stream_stats(struct lttng_consumer_stream *stream)
2664 {
2665 int ret;
2666 uint64_t seq, discarded;
2667
2668 ret = ustctl_get_sequence_number(stream->ustream, &seq);
2669 if (ret < 0) {
2670 PERROR("ustctl_get_sequence_number");
2671 goto end;
2672 }
2673 /*
2674 * Start the sequence when we extract the first packet in case we don't
2675 * start at 0 (for example if a consumer is not connected to the
2676 * session immediately after the beginning).
2677 */
2678 if (stream->last_sequence_number == -1ULL) {
2679 stream->last_sequence_number = seq;
2680 } else if (seq > stream->last_sequence_number) {
2681 stream->chan->lost_packets += seq -
2682 stream->last_sequence_number - 1;
2683 } else {
2684 /* seq <= last_sequence_number */
2685 ERR("Sequence number inconsistent : prev = %" PRIu64
2686 ", current = %" PRIu64,
2687 stream->last_sequence_number, seq);
2688 ret = -1;
2689 goto end;
2690 }
2691 stream->last_sequence_number = seq;
2692
2693 ret = ustctl_get_events_discarded(stream->ustream, &discarded);
2694 if (ret < 0) {
2695 PERROR("kernctl_get_events_discarded");
2696 goto end;
2697 }
2698 if (discarded < stream->last_discarded_events) {
2699 /*
2700 * Overflow has occurred. We assume only one wrap-around
2701 * has occurred.
2702 */
2703 stream->chan->discarded_events +=
2704 (1ULL << (CAA_BITS_PER_LONG - 1)) -
2705 stream->last_discarded_events + discarded;
2706 } else {
2707 stream->chan->discarded_events += discarded -
2708 stream->last_discarded_events;
2709 }
2710 stream->last_discarded_events = discarded;
2711 ret = 0;
2712
2713 end:
2714 return ret;
2715 }
2716
2717 /*
2718 * Read subbuffer from the given stream.
2719 *
2720 * Stream lock MUST be acquired.
2721 *
2722 * Return 0 on success else a negative value.
2723 */
2724 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
2725 struct lttng_consumer_local_data *ctx, bool *rotated)
2726 {
2727 unsigned long len, subbuf_size, padding;
2728 int err, write_index = 1, rotation_ret;
2729 long ret = 0;
2730 struct ustctl_consumer_stream *ustream;
2731 struct ctf_packet_index index;
2732
2733 assert(stream);
2734 assert(stream->ustream);
2735 assert(ctx);
2736
2737 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
2738 stream->name);
2739
2740 /* Ease our life for what's next. */
2741 ustream = stream->ustream;
2742
2743 /*
2744 * We can consume the 1 byte written into the wait_fd by UST. Don't trigger
2745 * error if we cannot read this one byte (read returns 0), or if the error
2746 * is EAGAIN or EWOULDBLOCK.
2747 *
2748 * This is only done when the stream is monitored by a thread, before the
2749 * flush is done after a hangup and if the stream is not flagged with data
2750 * since there might be nothing to consume in the wait fd but still have
2751 * data available flagged by the consumer wake up pipe.
2752 */
2753 if (stream->monitor && !stream->hangup_flush_done && !stream->has_data) {
2754 char dummy;
2755 ssize_t readlen;
2756
2757 readlen = lttng_read(stream->wait_fd, &dummy, 1);
2758 if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2759 ret = readlen;
2760 goto error;
2761 }
2762 }
2763
2764 /*
2765 * If the stream was flagged to be ready for rotation before we extract the
2766 * next packet, rotate it now.
2767 */
2768 if (stream->rotate_ready) {
2769 DBG("Rotate stream before extracting data");
2770 rotation_ret = lttng_consumer_rotate_stream(ctx, stream, rotated);
2771 if (rotation_ret < 0) {
2772 ERR("Stream rotation error");
2773 ret = -1;
2774 goto error;
2775 }
2776 }
2777
2778 retry:
2779 /* Get the next subbuffer */
2780 err = ustctl_get_next_subbuf(ustream);
2781 if (err != 0) {
2782 /*
2783 * Populate metadata info if the existing info has
2784 * already been read.
2785 */
2786 if (stream->metadata_flag) {
2787 ret = commit_one_metadata_packet(stream);
2788 if (ret <= 0) {
2789 goto error;
2790 }
2791 lttng_ustconsumer_flush_buffer(stream, 1);
2792 goto retry;
2793 }
2794
2795 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
2796 /*
2797 * This is a debug message even for single-threaded consumer,
2798 * because poll() have more relaxed criterions than get subbuf,
2799 * so get_subbuf may fail for short race windows where poll()
2800 * would issue wakeups.
2801 */
2802 DBG("Reserving sub buffer failed (everything is normal, "
2803 "it is due to concurrency) [ret: %d]", err);
2804 goto error;
2805 }
2806 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
2807
2808 if (!stream->metadata_flag) {
2809 index.offset = htobe64(stream->out_fd_offset);
2810 ret = get_index_values(&index, ustream);
2811 if (ret < 0) {
2812 err = ustctl_put_subbuf(ustream);
2813 assert(err == 0);
2814 goto error;
2815 }
2816
2817 /* Update the stream's sequence and discarded events count. */
2818 ret = update_stream_stats(stream);
2819 if (ret < 0) {
2820 PERROR("kernctl_get_events_discarded");
2821 err = ustctl_put_subbuf(ustream);
2822 assert(err == 0);
2823 goto error;
2824 }
2825 } else {
2826 write_index = 0;
2827 }
2828
2829 /* Get the full padded subbuffer size */
2830 err = ustctl_get_padded_subbuf_size(ustream, &len);
2831 assert(err == 0);
2832
2833 /* Get subbuffer data size (without padding) */
2834 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
2835 assert(err == 0);
2836
2837 /* Make sure we don't get a subbuffer size bigger than the padded */
2838 assert(len >= subbuf_size);
2839
2840 padding = len - subbuf_size;
2841
2842 /* write the subbuffer to the tracefile */
2843 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
2844 /*
2845 * The mmap operation should write subbuf_size amount of data when network
2846 * streaming or the full padding (len) size when we are _not_ streaming.
2847 */
2848 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
2849 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
2850 /*
2851 * Display the error but continue processing to try to release the
2852 * subbuffer. This is a DBG statement since any unexpected kill or
2853 * signal, the application gets unregistered, relayd gets closed or
2854 * anything that affects the buffer lifetime will trigger this error.
2855 * So, for the sake of the user, don't print this error since it can
2856 * happen and it is OK with the code flow.
2857 */
2858 DBG("Error writing to tracefile "
2859 "(ret: %ld != len: %lu != subbuf_size: %lu)",
2860 ret, len, subbuf_size);
2861 write_index = 0;
2862 }
2863 err = ustctl_put_next_subbuf(ustream);
2864 assert(err == 0);
2865
2866 /*
2867 * This will consumer the byte on the wait_fd if and only if there is not
2868 * next subbuffer to be acquired.
2869 */
2870 if (!stream->metadata_flag) {
2871 ret = notify_if_more_data(stream, ctx);
2872 if (ret < 0) {
2873 goto error;
2874 }
2875 }
2876
2877 /* Write index if needed. */
2878 if (!write_index) {
2879 goto rotate;
2880 }
2881
2882 if (stream->chan->live_timer_interval && !stream->metadata_flag) {
2883 /*
2884 * In live, block until all the metadata is sent.
2885 */
2886 pthread_mutex_lock(&stream->metadata_timer_lock);
2887 assert(!stream->missed_metadata_flush);
2888 stream->waiting_on_metadata = true;
2889 pthread_mutex_unlock(&stream->metadata_timer_lock);
2890
2891 err = consumer_stream_sync_metadata(ctx, stream->session_id);
2892
2893 pthread_mutex_lock(&stream->metadata_timer_lock);
2894 stream->waiting_on_metadata = false;
2895 if (stream->missed_metadata_flush) {
2896 stream->missed_metadata_flush = false;
2897 pthread_mutex_unlock(&stream->metadata_timer_lock);
2898 (void) consumer_flush_ust_index(stream);
2899 } else {
2900 pthread_mutex_unlock(&stream->metadata_timer_lock);
2901 }
2902
2903 if (err < 0) {
2904 goto error;
2905 }
2906 }
2907
2908 assert(!stream->metadata_flag);
2909 err = consumer_stream_write_index(stream, &index);
2910 if (err < 0) {
2911 goto error;
2912 }
2913
2914 rotate:
2915 /*
2916 * After extracting the packet, we check if the stream is now ready to be
2917 * rotated and perform the action immediately.
2918 */
2919 rotation_ret = lttng_consumer_stream_is_rotate_ready(stream);
2920 if (rotation_ret == 1) {
2921 rotation_ret = lttng_consumer_rotate_stream(ctx, stream, rotated);
2922 if (rotation_ret < 0) {
2923 ERR("Stream rotation error");
2924 ret = -1;
2925 goto error;
2926 }
2927 } else if (rotation_ret < 0) {
2928 ERR("Checking if stream is ready to rotate");
2929 ret = -1;
2930 goto error;
2931 }
2932 error:
2933 return ret;
2934 }
2935
2936 /*
2937 * Called when a stream is created.
2938 *
2939 * Return 0 on success or else a negative value.
2940 */
2941 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
2942 {
2943 int ret;
2944
2945 assert(stream);
2946
2947 /* Don't create anything if this is set for streaming. */
2948 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
2949 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
2950 stream->chan->tracefile_size, stream->tracefile_count_current,
2951 stream->uid, stream->gid, NULL);
2952 if (ret < 0) {
2953 goto error;
2954 }
2955 stream->out_fd = ret;
2956 stream->tracefile_size_current = 0;
2957
2958 if (!stream->metadata_flag) {
2959 struct lttng_index_file *index_file;
2960
2961 index_file = lttng_index_file_create(stream->chan->pathname,
2962 stream->name, stream->uid, stream->gid,
2963 stream->chan->tracefile_size,
2964 stream->tracefile_count_current,
2965 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
2966 if (!index_file) {
2967 goto error;
2968 }
2969 assert(!stream->index_file);
2970 stream->index_file = index_file;
2971 }
2972 }
2973 ret = 0;
2974
2975 error:
2976 return ret;
2977 }
2978
2979 /*
2980 * Check if data is still being extracted from the buffers for a specific
2981 * stream. Consumer data lock MUST be acquired before calling this function
2982 * and the stream lock.
2983 *
2984 * Return 1 if the traced data are still getting read else 0 meaning that the
2985 * data is available for trace viewer reading.
2986 */
2987 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
2988 {
2989 int ret;
2990
2991 assert(stream);
2992 assert(stream->ustream);
2993
2994 DBG("UST consumer checking data pending");
2995
2996 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
2997 ret = 0;
2998 goto end;
2999 }
3000
3001 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
3002 uint64_t contiguous, pushed;
3003
3004 /* Ease our life a bit. */
3005 contiguous = stream->chan->metadata_cache->max_offset;
3006 pushed = stream->ust_metadata_pushed;
3007
3008 /*
3009 * We can simply check whether all contiguously available data
3010 * has been pushed to the ring buffer, since the push operation
3011 * is performed within get_next_subbuf(), and because both
3012 * get_next_subbuf() and put_next_subbuf() are issued atomically
3013 * thanks to the stream lock within
3014 * lttng_ustconsumer_read_subbuffer(). This basically means that
3015 * whetnever ust_metadata_pushed is incremented, the associated
3016 * metadata has been consumed from the metadata stream.
3017 */
3018 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
3019 contiguous, pushed);
3020 assert(((int64_t) (contiguous - pushed)) >= 0);
3021 if ((contiguous != pushed) ||
3022 (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
3023 ret = 1; /* Data is pending */
3024 goto end;
3025 }
3026 } else {
3027 ret = ustctl_get_next_subbuf(stream->ustream);
3028 if (ret == 0) {
3029 /*
3030 * There is still data so let's put back this
3031 * subbuffer.
3032 */
3033 ret = ustctl_put_subbuf(stream->ustream);
3034 assert(ret == 0);
3035 ret = 1; /* Data is pending */
3036 goto end;
3037 }
3038 }
3039
3040 /* Data is NOT pending so ready to be read. */
3041 ret = 0;
3042
3043 end:
3044 return ret;
3045 }
3046
3047 /*
3048 * Stop a given metadata channel timer if enabled and close the wait fd which
3049 * is the poll pipe of the metadata stream.
3050 *
3051 * This MUST be called with the metadata channel acquired.
3052 */
3053 void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata)
3054 {
3055 int ret;
3056
3057 assert(metadata);
3058 assert(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA);
3059
3060 DBG("Closing metadata channel key %" PRIu64, metadata->key);
3061
3062 if (metadata->switch_timer_enabled == 1) {
3063 consumer_timer_switch_stop(metadata);
3064 }
3065
3066 if (!metadata->metadata_stream) {
3067 goto end;
3068 }
3069
3070 /*
3071 * Closing write side so the thread monitoring the stream wakes up if any
3072 * and clean the metadata stream.
3073 */
3074 if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) {
3075 ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]);
3076 if (ret < 0) {
3077 PERROR("closing metadata pipe write side");
3078 }
3079 metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1;
3080 }
3081
3082 end:
3083 return;
3084 }
3085
3086 /*
3087 * Close every metadata stream wait fd of the metadata hash table. This
3088 * function MUST be used very carefully so not to run into a race between the
3089 * metadata thread handling streams and this function closing their wait fd.
3090 *
3091 * For UST, this is used when the session daemon hangs up. Its the metadata
3092 * producer so calling this is safe because we are assured that no state change
3093 * can occur in the metadata thread for the streams in the hash table.
3094 */
3095 void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht)
3096 {
3097 struct lttng_ht_iter iter;
3098 struct lttng_consumer_stream *stream;
3099
3100 assert(metadata_ht);
3101 assert(metadata_ht->ht);
3102
3103 DBG("UST consumer closing all metadata streams");
3104
3105 rcu_read_lock();
3106 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
3107 node.node) {
3108
3109 health_code_update();
3110
3111 pthread_mutex_lock(&stream->chan->lock);
3112 lttng_ustconsumer_close_metadata(stream->chan);
3113 pthread_mutex_unlock(&stream->chan->lock);
3114
3115 }
3116 rcu_read_unlock();
3117 }
3118
3119 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
3120 {
3121 int ret;
3122
3123 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
3124 if (ret < 0) {
3125 ERR("Unable to close wakeup fd");
3126 }
3127 }
3128
3129 /*
3130 * Please refer to consumer-timer.c before adding any lock within this
3131 * function or any of its callees. Timers have a very strict locking
3132 * semantic with respect to teardown. Failure to respect this semantic
3133 * introduces deadlocks.
3134 *
3135 * DON'T hold the metadata lock when calling this function, else this
3136 * can cause deadlock involving consumer awaiting for metadata to be
3137 * pushed out due to concurrent interaction with the session daemon.
3138 */
3139 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
3140 struct lttng_consumer_channel *channel, int timer, int wait)
3141 {
3142 struct lttcomm_metadata_request_msg request;
3143 struct lttcomm_consumer_msg msg;
3144 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
3145 uint64_t len, key, offset, version;
3146 int ret;
3147
3148 assert(channel);
3149 assert(channel->metadata_cache);
3150
3151 memset(&request, 0, sizeof(request));
3152
3153 /* send the metadata request to sessiond */
3154 switch (consumer_data.type) {
3155 case LTTNG_CONSUMER64_UST:
3156 request.bits_per_long = 64;
3157 break;
3158 case LTTNG_CONSUMER32_UST:
3159 request.bits_per_long = 32;
3160 break;
3161 default:
3162 request.bits_per_long = 0;
3163 break;
3164 }
3165
3166 request.session_id = channel->session_id;
3167 request.session_id_per_pid = channel->session_id_per_pid;