b48a3c821d386fbf3cbfaceb8b01d9bbcc4f724d
[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 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _GNU_SOURCE
20 #include <assert.h>
21 #include <lttng/ust-ctl.h>
22 #include <poll.h>
23 #include <pthread.h>
24 #include <stdlib.h>
25 #include <string.h>
26 #include <sys/mman.h>
27 #include <sys/socket.h>
28 #include <sys/stat.h>
29 #include <sys/types.h>
30 #include <inttypes.h>
31 #include <unistd.h>
32 #include <urcu/list.h>
33 #include <signal.h>
34
35 #include <bin/lttng-consumerd/health-consumerd.h>
36 #include <common/common.h>
37 #include <common/sessiond-comm/sessiond-comm.h>
38 #include <common/relayd/relayd.h>
39 #include <common/compat/fcntl.h>
40 #include <common/consumer-metadata-cache.h>
41 #include <common/consumer-stream.h>
42 #include <common/consumer-timer.h>
43 #include <common/utils.h>
44 #include <common/index/index.h>
45
46 #include "ust-consumer.h"
47
48 extern struct lttng_consumer_global_data consumer_data;
49 extern int consumer_poll_timeout;
50 extern volatile int consumer_quit;
51
52 /*
53 * Free channel object and all streams associated with it. This MUST be used
54 * only and only if the channel has _NEVER_ been added to the global channel
55 * hash table.
56 */
57 static void destroy_channel(struct lttng_consumer_channel *channel)
58 {
59 struct lttng_consumer_stream *stream, *stmp;
60
61 assert(channel);
62
63 DBG("UST consumer cleaning stream list");
64
65 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
66 send_node) {
67
68 health_code_update();
69
70 cds_list_del(&stream->send_node);
71 ustctl_destroy_stream(stream->ustream);
72 free(stream);
73 }
74
75 /*
76 * If a channel is available meaning that was created before the streams
77 * were, delete it.
78 */
79 if (channel->uchan) {
80 lttng_ustconsumer_del_channel(channel);
81 }
82 free(channel);
83 }
84
85 /*
86 * Add channel to internal consumer state.
87 *
88 * Returns 0 on success or else a negative value.
89 */
90 static int add_channel(struct lttng_consumer_channel *channel,
91 struct lttng_consumer_local_data *ctx)
92 {
93 int ret = 0;
94
95 assert(channel);
96 assert(ctx);
97
98 if (ctx->on_recv_channel != NULL) {
99 ret = ctx->on_recv_channel(channel);
100 if (ret == 0) {
101 ret = consumer_add_channel(channel, ctx);
102 } else if (ret < 0) {
103 /* Most likely an ENOMEM. */
104 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
105 goto error;
106 }
107 } else {
108 ret = consumer_add_channel(channel, ctx);
109 }
110
111 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
112
113 error:
114 return ret;
115 }
116
117 /*
118 * Allocate and return a consumer channel object.
119 */
120 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
121 const char *pathname, const char *name, uid_t uid, gid_t gid,
122 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
123 uint64_t tracefile_size, uint64_t tracefile_count,
124 uint64_t session_id_per_pid, unsigned int monitor,
125 unsigned int live_timer_interval)
126 {
127 assert(pathname);
128 assert(name);
129
130 return consumer_allocate_channel(key, session_id, pathname, name, uid,
131 gid, relayd_id, output, tracefile_size,
132 tracefile_count, session_id_per_pid, monitor, live_timer_interval);
133 }
134
135 /*
136 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
137 * error value if applicable is set in it else it is kept untouched.
138 *
139 * Return NULL on error else the newly allocated stream object.
140 */
141 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
142 struct lttng_consumer_channel *channel,
143 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
144 {
145 int alloc_ret;
146 struct lttng_consumer_stream *stream = NULL;
147
148 assert(channel);
149 assert(ctx);
150
151 stream = consumer_allocate_stream(channel->key,
152 key,
153 LTTNG_CONSUMER_ACTIVE_STREAM,
154 channel->name,
155 channel->uid,
156 channel->gid,
157 channel->relayd_id,
158 channel->session_id,
159 cpu,
160 &alloc_ret,
161 channel->type,
162 channel->monitor);
163 if (stream == NULL) {
164 switch (alloc_ret) {
165 case -ENOENT:
166 /*
167 * We could not find the channel. Can happen if cpu hotplug
168 * happens while tearing down.
169 */
170 DBG3("Could not find channel");
171 break;
172 case -ENOMEM:
173 case -EINVAL:
174 default:
175 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
176 break;
177 }
178 goto error;
179 }
180
181 stream->chan = channel;
182
183 error:
184 if (_alloc_ret) {
185 *_alloc_ret = alloc_ret;
186 }
187 return stream;
188 }
189
190 /*
191 * Send the given stream pointer to the corresponding thread.
192 *
193 * Returns 0 on success else a negative value.
194 */
195 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
196 struct lttng_consumer_local_data *ctx)
197 {
198 int ret;
199 struct lttng_pipe *stream_pipe;
200
201 /* Get the right pipe where the stream will be sent. */
202 if (stream->metadata_flag) {
203 ret = consumer_add_metadata_stream(stream);
204 if (ret) {
205 ERR("Consumer add metadata stream %" PRIu64 " failed.",
206 stream->key);
207 goto error;
208 }
209 stream_pipe = ctx->consumer_metadata_pipe;
210 } else {
211 ret = consumer_add_data_stream(stream);
212 if (ret) {
213 ERR("Consumer add stream %" PRIu64 " failed.",
214 stream->key);
215 goto error;
216 }
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 becomes globally visible.
223 */
224 stream->globally_visible = 1;
225
226 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
227 if (ret < 0) {
228 ERR("Consumer write %s stream to pipe %d",
229 stream->metadata_flag ? "metadata" : "data",
230 lttng_pipe_get_writefd(stream_pipe));
231 if (stream->metadata_flag) {
232 consumer_del_stream_for_metadata(stream);
233 } else {
234 consumer_del_stream_for_data(stream);
235 }
236 }
237 error:
238 return ret;
239 }
240
241 /*
242 * Create streams for the given channel using liblttng-ust-ctl.
243 *
244 * Return 0 on success else a negative value.
245 */
246 static int create_ust_streams(struct lttng_consumer_channel *channel,
247 struct lttng_consumer_local_data *ctx)
248 {
249 int ret, cpu = 0;
250 struct ustctl_consumer_stream *ustream;
251 struct lttng_consumer_stream *stream;
252
253 assert(channel);
254 assert(ctx);
255
256 /*
257 * While a stream is available from ustctl. When NULL is returned, we've
258 * reached the end of the possible stream for the channel.
259 */
260 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
261 int wait_fd;
262 int ust_metadata_pipe[2];
263
264 health_code_update();
265
266 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
267 ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
268 if (ret < 0) {
269 ERR("Create ust metadata poll pipe");
270 goto error;
271 }
272 wait_fd = ust_metadata_pipe[0];
273 } else {
274 wait_fd = ustctl_stream_get_wait_fd(ustream);
275 }
276
277 /* Allocate consumer stream object. */
278 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
279 if (!stream) {
280 goto error_alloc;
281 }
282 stream->ustream = ustream;
283 /*
284 * Store it so we can save multiple function calls afterwards since
285 * this value is used heavily in the stream threads. This is UST
286 * specific so this is why it's done after allocation.
287 */
288 stream->wait_fd = wait_fd;
289
290 /*
291 * Increment channel refcount since the channel reference has now been
292 * assigned in the allocation process above.
293 */
294 if (stream->chan->monitor) {
295 uatomic_inc(&stream->chan->refcount);
296 }
297
298 /*
299 * Order is important this is why a list is used. On error, the caller
300 * should clean this list.
301 */
302 cds_list_add_tail(&stream->send_node, &channel->streams.head);
303
304 ret = ustctl_get_max_subbuf_size(stream->ustream,
305 &stream->max_sb_size);
306 if (ret < 0) {
307 ERR("ustctl_get_max_subbuf_size failed for stream %s",
308 stream->name);
309 goto error;
310 }
311
312 /* Do actions once stream has been received. */
313 if (ctx->on_recv_stream) {
314 ret = ctx->on_recv_stream(stream);
315 if (ret < 0) {
316 goto error;
317 }
318 }
319
320 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
321 stream->name, stream->key, stream->relayd_stream_id);
322
323 /* Set next CPU stream. */
324 channel->streams.count = ++cpu;
325
326 /* Keep stream reference when creating metadata. */
327 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
328 channel->metadata_stream = stream;
329 stream->ust_metadata_poll_pipe[0] = ust_metadata_pipe[0];
330 stream->ust_metadata_poll_pipe[1] = ust_metadata_pipe[1];
331 }
332 }
333
334 return 0;
335
336 error:
337 error_alloc:
338 return ret;
339 }
340
341 /*
342 * Create an UST channel with the given attributes and send it to the session
343 * daemon using the ust ctl API.
344 *
345 * Return 0 on success or else a negative value.
346 */
347 static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
348 struct ustctl_consumer_channel **chanp)
349 {
350 int ret;
351 struct ustctl_consumer_channel *channel;
352
353 assert(attr);
354 assert(chanp);
355
356 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
357 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
358 "switch_timer_interval: %u, read_timer_interval: %u, "
359 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
360 attr->num_subbuf, attr->switch_timer_interval,
361 attr->read_timer_interval, attr->output, attr->type);
362
363 channel = ustctl_create_channel(attr);
364 if (!channel) {
365 ret = -1;
366 goto error_create;
367 }
368
369 *chanp = channel;
370
371 return 0;
372
373 error_create:
374 return ret;
375 }
376
377 /*
378 * Send a single given stream to the session daemon using the sock.
379 *
380 * Return 0 on success else a negative value.
381 */
382 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
383 {
384 int ret;
385
386 assert(stream);
387 assert(sock >= 0);
388
389 DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
390
391 /* Send stream to session daemon. */
392 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
393 if (ret < 0) {
394 goto error;
395 }
396
397 error:
398 return ret;
399 }
400
401 /*
402 * Send channel to sessiond.
403 *
404 * Return 0 on success or else a negative value.
405 */
406 static int send_sessiond_channel(int sock,
407 struct lttng_consumer_channel *channel,
408 struct lttng_consumer_local_data *ctx, int *relayd_error)
409 {
410 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
411 struct lttng_consumer_stream *stream;
412 uint64_t net_seq_idx = -1ULL;
413
414 assert(channel);
415 assert(ctx);
416 assert(sock >= 0);
417
418 DBG("UST consumer sending channel %s to sessiond", channel->name);
419
420 if (channel->relayd_id != (uint64_t) -1ULL) {
421 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
422
423 health_code_update();
424
425 /* Try to send the stream to the relayd if one is available. */
426 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
427 if (ret < 0) {
428 /*
429 * Flag that the relayd was the problem here probably due to a
430 * communicaton error on the socket.
431 */
432 if (relayd_error) {
433 *relayd_error = 1;
434 }
435 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
436 }
437 if (net_seq_idx == -1ULL) {
438 net_seq_idx = stream->net_seq_idx;
439 }
440 }
441 }
442
443 /* Inform sessiond that we are about to send channel and streams. */
444 ret = consumer_send_status_msg(sock, ret_code);
445 if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
446 /*
447 * Either the session daemon is not responding or the relayd died so we
448 * stop now.
449 */
450 goto error;
451 }
452
453 /* Send channel to sessiond. */
454 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
455 if (ret < 0) {
456 goto error;
457 }
458
459 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
460 if (ret < 0) {
461 goto error;
462 }
463
464 /* The channel was sent successfully to the sessiond at this point. */
465 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
466
467 health_code_update();
468
469 /* Send stream to session daemon. */
470 ret = send_sessiond_stream(sock, stream);
471 if (ret < 0) {
472 goto error;
473 }
474 }
475
476 /* Tell sessiond there is no more stream. */
477 ret = ustctl_send_stream_to_sessiond(sock, NULL);
478 if (ret < 0) {
479 goto error;
480 }
481
482 DBG("UST consumer NULL stream sent to sessiond");
483
484 return 0;
485
486 error:
487 if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
488 ret = -1;
489 }
490 return ret;
491 }
492
493 /*
494 * Creates a channel and streams and add the channel it to the channel internal
495 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
496 * received.
497 *
498 * Return 0 on success or else, a negative value is returned and the channel
499 * MUST be destroyed by consumer_del_channel().
500 */
501 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
502 struct lttng_consumer_channel *channel,
503 struct ustctl_consumer_channel_attr *attr)
504 {
505 int ret;
506
507 assert(ctx);
508 assert(channel);
509 assert(attr);
510
511 /*
512 * This value is still used by the kernel consumer since for the kernel,
513 * the stream ownership is not IN the consumer so we need to have the
514 * number of left stream that needs to be initialized so we can know when
515 * to delete the channel (see consumer.c).
516 *
517 * As for the user space tracer now, the consumer creates and sends the
518 * stream to the session daemon which only sends them to the application
519 * once every stream of a channel is received making this value useless
520 * because we they will be added to the poll thread before the application
521 * receives them. This ensures that a stream can not hang up during
522 * initilization of a channel.
523 */
524 channel->nb_init_stream_left = 0;
525
526 /* The reply msg status is handled in the following call. */
527 ret = create_ust_channel(attr, &channel->uchan);
528 if (ret < 0) {
529 goto end;
530 }
531
532 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
533
534 /*
535 * For the snapshots (no monitor), we create the metadata streams
536 * on demand, not during the channel creation.
537 */
538 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
539 ret = 0;
540 goto end;
541 }
542
543 /* Open all streams for this channel. */
544 ret = create_ust_streams(channel, ctx);
545 if (ret < 0) {
546 goto end;
547 }
548
549 end:
550 return ret;
551 }
552
553 /*
554 * Send all stream of a channel to the right thread handling it.
555 *
556 * On error, return a negative value else 0 on success.
557 */
558 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
559 struct lttng_consumer_local_data *ctx)
560 {
561 int ret = 0;
562 struct lttng_consumer_stream *stream, *stmp;
563
564 assert(channel);
565 assert(ctx);
566
567 /* Send streams to the corresponding thread. */
568 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
569 send_node) {
570
571 health_code_update();
572
573 /* Sending the stream to the thread. */
574 ret = send_stream_to_thread(stream, ctx);
575 if (ret < 0) {
576 /*
577 * If we are unable to send the stream to the thread, there is
578 * a big problem so just stop everything.
579 */
580 /* Remove node from the channel stream list. */
581 cds_list_del(&stream->send_node);
582 goto error;
583 }
584
585 /* Remove node from the channel stream list. */
586 cds_list_del(&stream->send_node);
587
588 }
589
590 error:
591 return ret;
592 }
593
594 /*
595 * Flush channel's streams using the given key to retrieve the channel.
596 *
597 * Return 0 on success else an LTTng error code.
598 */
599 static int flush_channel(uint64_t chan_key)
600 {
601 int ret = 0;
602 struct lttng_consumer_channel *channel;
603 struct lttng_consumer_stream *stream;
604 struct lttng_ht *ht;
605 struct lttng_ht_iter iter;
606
607 DBG("UST consumer flush channel key %" PRIu64, chan_key);
608
609 rcu_read_lock();
610 channel = consumer_find_channel(chan_key);
611 if (!channel) {
612 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
613 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
614 goto error;
615 }
616
617 ht = consumer_data.stream_per_chan_id_ht;
618
619 /* For each stream of the channel id, flush it. */
620 cds_lfht_for_each_entry_duplicate(ht->ht,
621 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
622 &channel->key, &iter.iter, stream, node_channel_id.node) {
623
624 health_code_update();
625
626 ustctl_flush_buffer(stream->ustream, 1);
627 }
628 error:
629 rcu_read_unlock();
630 return ret;
631 }
632
633 /*
634 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
635 * RCU read side lock MUST be acquired before calling this function.
636 *
637 * Return 0 on success else an LTTng error code.
638 */
639 static int close_metadata(uint64_t chan_key)
640 {
641 int ret = 0;
642 struct lttng_consumer_channel *channel;
643
644 DBG("UST consumer close metadata key %" PRIu64, chan_key);
645
646 channel = consumer_find_channel(chan_key);
647 if (!channel) {
648 /*
649 * This is possible if the metadata thread has issue a delete because
650 * the endpoint point of the stream hung up. There is no way the
651 * session daemon can know about it thus use a DBG instead of an actual
652 * error.
653 */
654 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
655 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
656 goto error;
657 }
658
659 pthread_mutex_lock(&consumer_data.lock);
660 pthread_mutex_lock(&channel->lock);
661
662 if (cds_lfht_is_node_deleted(&channel->node.node)) {
663 goto error_unlock;
664 }
665
666 lttng_ustconsumer_close_metadata(channel);
667
668 error_unlock:
669 pthread_mutex_unlock(&channel->lock);
670 pthread_mutex_unlock(&consumer_data.lock);
671 error:
672 return ret;
673 }
674
675 /*
676 * RCU read side lock MUST be acquired before calling this function.
677 *
678 * Return 0 on success else an LTTng error code.
679 */
680 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
681 {
682 int ret;
683 struct lttng_consumer_channel *metadata;
684
685 DBG("UST consumer setup metadata key %" PRIu64, key);
686
687 metadata = consumer_find_channel(key);
688 if (!metadata) {
689 ERR("UST consumer push metadata %" PRIu64 " not found", key);
690 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
691 goto end;
692 }
693
694 /*
695 * In no monitor mode, the metadata channel has no stream(s) so skip the
696 * ownership transfer to the metadata thread.
697 */
698 if (!metadata->monitor) {
699 DBG("Metadata channel in no monitor");
700 ret = 0;
701 goto end;
702 }
703
704 /*
705 * Send metadata stream to relayd if one available. Availability is
706 * known if the stream is still in the list of the channel.
707 */
708 if (cds_list_empty(&metadata->streams.head)) {
709 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
710 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
711 goto error_no_stream;
712 }
713
714 /* Send metadata stream to relayd if needed. */
715 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
716 ret = consumer_send_relayd_stream(metadata->metadata_stream,
717 metadata->pathname);
718 if (ret < 0) {
719 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
720 goto error;
721 }
722 ret = consumer_send_relayd_streams_sent(
723 metadata->metadata_stream->net_seq_idx);
724 if (ret < 0) {
725 ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
726 goto error;
727 }
728 }
729
730 ret = send_streams_to_thread(metadata, ctx);
731 if (ret < 0) {
732 /*
733 * If we are unable to send the stream to the thread, there is
734 * a big problem so just stop everything.
735 */
736 ret = LTTCOMM_CONSUMERD_FATAL;
737 goto error;
738 }
739 /* List MUST be empty after or else it could be reused. */
740 assert(cds_list_empty(&metadata->streams.head));
741
742 ret = 0;
743 goto end;
744
745 error:
746 /*
747 * Delete metadata channel on error. At this point, the metadata stream can
748 * NOT be monitored by the metadata thread thus having the guarantee that
749 * the stream is still in the local stream list of the channel. This call
750 * will make sure to clean that list.
751 */
752 consumer_stream_destroy(metadata->metadata_stream, NULL);
753 cds_list_del(&metadata->metadata_stream->send_node);
754 metadata->metadata_stream = NULL;
755 error_no_stream:
756 end:
757 return ret;
758 }
759
760 /*
761 * Snapshot the whole metadata.
762 *
763 * Returns 0 on success, < 0 on error
764 */
765 static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
766 struct lttng_consumer_local_data *ctx)
767 {
768 int ret = 0;
769 struct lttng_consumer_channel *metadata_channel;
770 struct lttng_consumer_stream *metadata_stream;
771
772 assert(path);
773 assert(ctx);
774
775 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
776 key, path);
777
778 rcu_read_lock();
779
780 metadata_channel = consumer_find_channel(key);
781 if (!metadata_channel) {
782 ERR("UST snapshot metadata channel not found for key %" PRIu64,
783 key);
784 ret = -1;
785 goto error;
786 }
787 assert(!metadata_channel->monitor);
788
789 health_code_update();
790
791 /*
792 * Ask the sessiond if we have new metadata waiting and update the
793 * consumer metadata cache.
794 */
795 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
796 if (ret < 0) {
797 goto error;
798 }
799
800 health_code_update();
801
802 /*
803 * The metadata stream is NOT created in no monitor mode when the channel
804 * is created on a sessiond ask channel command.
805 */
806 ret = create_ust_streams(metadata_channel, ctx);
807 if (ret < 0) {
808 goto error;
809 }
810
811 metadata_stream = metadata_channel->metadata_stream;
812 assert(metadata_stream);
813
814 if (relayd_id != (uint64_t) -1ULL) {
815 metadata_stream->net_seq_idx = relayd_id;
816 ret = consumer_send_relayd_stream(metadata_stream, path);
817 if (ret < 0) {
818 goto error_stream;
819 }
820 } else {
821 ret = utils_create_stream_file(path, metadata_stream->name,
822 metadata_stream->chan->tracefile_size,
823 metadata_stream->tracefile_count_current,
824 metadata_stream->uid, metadata_stream->gid, NULL);
825 if (ret < 0) {
826 goto error_stream;
827 }
828 metadata_stream->out_fd = ret;
829 metadata_stream->tracefile_size_current = 0;
830 }
831
832 do {
833 health_code_update();
834
835 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
836 if (ret < 0) {
837 goto error_stream;
838 }
839 } while (ret > 0);
840
841 error_stream:
842 /*
843 * Clean up the stream completly because the next snapshot will use a new
844 * metadata stream.
845 */
846 consumer_stream_destroy(metadata_stream, NULL);
847 cds_list_del(&metadata_stream->send_node);
848 metadata_channel->metadata_stream = NULL;
849
850 error:
851 rcu_read_unlock();
852 return ret;
853 }
854
855 /*
856 * Take a snapshot of all the stream of a channel.
857 *
858 * Returns 0 on success, < 0 on error
859 */
860 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
861 uint64_t max_stream_size, struct lttng_consumer_local_data *ctx)
862 {
863 int ret;
864 unsigned use_relayd = 0;
865 unsigned long consumed_pos, produced_pos;
866 struct lttng_consumer_channel *channel;
867 struct lttng_consumer_stream *stream;
868
869 assert(path);
870 assert(ctx);
871
872 rcu_read_lock();
873
874 if (relayd_id != (uint64_t) -1ULL) {
875 use_relayd = 1;
876 }
877
878 channel = consumer_find_channel(key);
879 if (!channel) {
880 ERR("UST snapshot channel not found for key %" PRIu64, key);
881 ret = -1;
882 goto error;
883 }
884 assert(!channel->monitor);
885 DBG("UST consumer snapshot channel %" PRIu64, key);
886
887 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
888
889 health_code_update();
890
891 /* Lock stream because we are about to change its state. */
892 pthread_mutex_lock(&stream->lock);
893 stream->net_seq_idx = relayd_id;
894
895 if (use_relayd) {
896 ret = consumer_send_relayd_stream(stream, path);
897 if (ret < 0) {
898 goto error_unlock;
899 }
900 } else {
901 ret = utils_create_stream_file(path, stream->name,
902 stream->chan->tracefile_size,
903 stream->tracefile_count_current,
904 stream->uid, stream->gid, NULL);
905 if (ret < 0) {
906 goto error_unlock;
907 }
908 stream->out_fd = ret;
909 stream->tracefile_size_current = 0;
910
911 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
912 stream->name, stream->key);
913 }
914 if (relayd_id != -1ULL) {
915 ret = consumer_send_relayd_streams_sent(relayd_id);
916 if (ret < 0) {
917 goto error_unlock;
918 }
919 }
920
921 ustctl_flush_buffer(stream->ustream, 1);
922
923 ret = lttng_ustconsumer_take_snapshot(stream);
924 if (ret < 0) {
925 ERR("Taking UST snapshot");
926 goto error_unlock;
927 }
928
929 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
930 if (ret < 0) {
931 ERR("Produced UST snapshot position");
932 goto error_unlock;
933 }
934
935 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
936 if (ret < 0) {
937 ERR("Consumerd UST snapshot position");
938 goto error_unlock;
939 }
940
941 /*
942 * The original value is sent back if max stream size is larger than
943 * the possible size of the snapshot. Also, we asume that the session
944 * daemon should never send a maximum stream size that is lower than
945 * subbuffer size.
946 */
947 consumed_pos = consumer_get_consumed_maxsize(consumed_pos,
948 produced_pos, max_stream_size);
949
950 while (consumed_pos < produced_pos) {
951 ssize_t read_len;
952 unsigned long len, padded_len;
953
954 health_code_update();
955
956 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
957
958 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
959 if (ret < 0) {
960 if (ret != -EAGAIN) {
961 PERROR("ustctl_get_subbuf snapshot");
962 goto error_close_stream;
963 }
964 DBG("UST consumer get subbuf failed. Skipping it.");
965 consumed_pos += stream->max_sb_size;
966 continue;
967 }
968
969 ret = ustctl_get_subbuf_size(stream->ustream, &len);
970 if (ret < 0) {
971 ERR("Snapshot ustctl_get_subbuf_size");
972 goto error_put_subbuf;
973 }
974
975 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
976 if (ret < 0) {
977 ERR("Snapshot ustctl_get_padded_subbuf_size");
978 goto error_put_subbuf;
979 }
980
981 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
982 padded_len - len, NULL);
983 if (use_relayd) {
984 if (read_len != len) {
985 ret = -EPERM;
986 goto error_put_subbuf;
987 }
988 } else {
989 if (read_len != padded_len) {
990 ret = -EPERM;
991 goto error_put_subbuf;
992 }
993 }
994
995 ret = ustctl_put_subbuf(stream->ustream);
996 if (ret < 0) {
997 ERR("Snapshot ustctl_put_subbuf");
998 goto error_close_stream;
999 }
1000 consumed_pos += stream->max_sb_size;
1001 }
1002
1003 /* Simply close the stream so we can use it on the next snapshot. */
1004 consumer_stream_close(stream);
1005 pthread_mutex_unlock(&stream->lock);
1006 }
1007
1008 rcu_read_unlock();
1009 return 0;
1010
1011 error_put_subbuf:
1012 if (ustctl_put_subbuf(stream->ustream) < 0) {
1013 ERR("Snapshot ustctl_put_subbuf");
1014 }
1015 error_close_stream:
1016 consumer_stream_close(stream);
1017 error_unlock:
1018 pthread_mutex_unlock(&stream->lock);
1019 error:
1020 rcu_read_unlock();
1021 return ret;
1022 }
1023
1024 /*
1025 * Receive the metadata updates from the sessiond.
1026 */
1027 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1028 uint64_t len, struct lttng_consumer_channel *channel,
1029 int timer, int wait)
1030 {
1031 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1032 char *metadata_str;
1033
1034 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
1035
1036 metadata_str = zmalloc(len * sizeof(char));
1037 if (!metadata_str) {
1038 PERROR("zmalloc metadata string");
1039 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1040 goto end;
1041 }
1042
1043 health_code_update();
1044
1045 /* Receive metadata string. */
1046 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1047 if (ret < 0) {
1048 /* Session daemon is dead so return gracefully. */
1049 ret_code = ret;
1050 goto end_free;
1051 }
1052
1053 health_code_update();
1054
1055 pthread_mutex_lock(&channel->metadata_cache->lock);
1056 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
1057 if (ret < 0) {
1058 /* Unable to handle metadata. Notify session daemon. */
1059 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1060 /*
1061 * Skip metadata flush on write error since the offset and len might
1062 * not have been updated which could create an infinite loop below when
1063 * waiting for the metadata cache to be flushed.
1064 */
1065 pthread_mutex_unlock(&channel->metadata_cache->lock);
1066 goto end_free;
1067 }
1068 pthread_mutex_unlock(&channel->metadata_cache->lock);
1069
1070 if (!wait) {
1071 goto end_free;
1072 }
1073 while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
1074 DBG("Waiting for metadata to be flushed");
1075
1076 health_code_update();
1077
1078 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1079 }
1080
1081 end_free:
1082 free(metadata_str);
1083 end:
1084 return ret_code;
1085 }
1086
1087 /*
1088 * Receive command from session daemon and process it.
1089 *
1090 * Return 1 on success else a negative value or 0.
1091 */
1092 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1093 int sock, struct pollfd *consumer_sockpoll)
1094 {
1095 ssize_t ret;
1096 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1097 struct lttcomm_consumer_msg msg;
1098 struct lttng_consumer_channel *channel = NULL;
1099
1100 health_code_update();
1101
1102 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1103 if (ret != sizeof(msg)) {
1104 DBG("Consumer received unexpected message size %zd (expects %zu)",
1105 ret, sizeof(msg));
1106 /*
1107 * The ret value might 0 meaning an orderly shutdown but this is ok
1108 * since the caller handles this.
1109 */
1110 if (ret > 0) {
1111 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1112 ret = -1;
1113 }
1114 return ret;
1115 }
1116
1117 health_code_update();
1118
1119 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
1120 /*
1121 * Notify the session daemon that the command is completed.
1122 *
1123 * On transport layer error, the function call will print an error
1124 * message so handling the returned code is a bit useless since we
1125 * return an error code anyway.
1126 */
1127 (void) consumer_send_status_msg(sock, ret_code);
1128 return -ENOENT;
1129 }
1130
1131 health_code_update();
1132
1133 /* relayd needs RCU read-side lock */
1134 rcu_read_lock();
1135
1136 switch (msg.cmd_type) {
1137 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1138 {
1139 /* Session daemon status message are handled in the following call. */
1140 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1141 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1142 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
1143 msg.u.relayd_sock.relayd_session_id);
1144 goto end_nosignal;
1145 }
1146 case LTTNG_CONSUMER_DESTROY_RELAYD:
1147 {
1148 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1149 struct consumer_relayd_sock_pair *relayd;
1150
1151 DBG("UST consumer destroying relayd %" PRIu64, index);
1152
1153 /* Get relayd reference if exists. */
1154 relayd = consumer_find_relayd(index);
1155 if (relayd == NULL) {
1156 DBG("Unable to find relayd %" PRIu64, index);
1157 ret_code = LTTNG_ERR_NO_CONSUMER;
1158 }
1159
1160 /*
1161 * Each relayd socket pair has a refcount of stream attached to it
1162 * which tells if the relayd is still active or not depending on the
1163 * refcount value.
1164 *
1165 * This will set the destroy flag of the relayd object and destroy it
1166 * if the refcount reaches zero when called.
1167 *
1168 * The destroy can happen either here or when a stream fd hangs up.
1169 */
1170 if (relayd) {
1171 consumer_flag_relayd_for_destroy(relayd);
1172 }
1173
1174 goto end_msg_sessiond;
1175 }
1176 case LTTNG_CONSUMER_UPDATE_STREAM:
1177 {
1178 rcu_read_unlock();
1179 return -ENOSYS;
1180 }
1181 case LTTNG_CONSUMER_DATA_PENDING:
1182 {
1183 int ret, is_data_pending;
1184 uint64_t id = msg.u.data_pending.session_id;
1185
1186 DBG("UST consumer data pending command for id %" PRIu64, id);
1187
1188 is_data_pending = consumer_data_pending(id);
1189
1190 /* Send back returned value to session daemon */
1191 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1192 sizeof(is_data_pending));
1193 if (ret < 0) {
1194 DBG("Error when sending the data pending ret code: %d", ret);
1195 goto error_fatal;
1196 }
1197
1198 /*
1199 * No need to send back a status message since the data pending
1200 * returned value is the response.
1201 */
1202 break;
1203 }
1204 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1205 {
1206 int ret;
1207 struct ustctl_consumer_channel_attr attr;
1208
1209 /* Create a plain object and reserve a channel key. */
1210 channel = allocate_channel(msg.u.ask_channel.session_id,
1211 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1212 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1213 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1214 (enum lttng_event_output) msg.u.ask_channel.output,
1215 msg.u.ask_channel.tracefile_size,
1216 msg.u.ask_channel.tracefile_count,
1217 msg.u.ask_channel.session_id_per_pid,
1218 msg.u.ask_channel.monitor,
1219 msg.u.ask_channel.live_timer_interval);
1220 if (!channel) {
1221 goto end_channel_error;
1222 }
1223
1224 /*
1225 * Assign UST application UID to the channel. This value is ignored for
1226 * per PID buffers. This is specific to UST thus setting this after the
1227 * allocation.
1228 */
1229 channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
1230
1231 /* Build channel attributes from received message. */
1232 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1233 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1234 attr.overwrite = msg.u.ask_channel.overwrite;
1235 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1236 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1237 attr.chan_id = msg.u.ask_channel.chan_id;
1238 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1239
1240 /* Match channel buffer type to the UST abi. */
1241 switch (msg.u.ask_channel.output) {
1242 case LTTNG_EVENT_MMAP:
1243 default:
1244 attr.output = LTTNG_UST_MMAP;
1245 break;
1246 }
1247
1248 /* Translate and save channel type. */
1249 switch (msg.u.ask_channel.type) {
1250 case LTTNG_UST_CHAN_PER_CPU:
1251 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1252 attr.type = LTTNG_UST_CHAN_PER_CPU;
1253 /*
1254 * Set refcount to 1 for owner. Below, we will
1255 * pass ownership to the
1256 * consumer_thread_channel_poll() thread.
1257 */
1258 channel->refcount = 1;
1259 break;
1260 case LTTNG_UST_CHAN_METADATA:
1261 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1262 attr.type = LTTNG_UST_CHAN_METADATA;
1263 break;
1264 default:
1265 assert(0);
1266 goto error_fatal;
1267 };
1268
1269 health_code_update();
1270
1271 ret = ask_channel(ctx, sock, channel, &attr);
1272 if (ret < 0) {
1273 goto end_channel_error;
1274 }
1275
1276 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1277 ret = consumer_metadata_cache_allocate(channel);
1278 if (ret < 0) {
1279 ERR("Allocating metadata cache");
1280 goto end_channel_error;
1281 }
1282 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1283 attr.switch_timer_interval = 0;
1284 } else {
1285 consumer_timer_live_start(channel,
1286 msg.u.ask_channel.live_timer_interval);
1287 }
1288
1289 health_code_update();
1290
1291 /*
1292 * Add the channel to the internal state AFTER all streams were created
1293 * and successfully sent to session daemon. This way, all streams must
1294 * be ready before this channel is visible to the threads.
1295 * If add_channel succeeds, ownership of the channel is
1296 * passed to consumer_thread_channel_poll().
1297 */
1298 ret = add_channel(channel, ctx);
1299 if (ret < 0) {
1300 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1301 if (channel->switch_timer_enabled == 1) {
1302 consumer_timer_switch_stop(channel);
1303 }
1304 consumer_metadata_cache_destroy(channel);
1305 }
1306 if (channel->live_timer_enabled == 1) {
1307 consumer_timer_live_stop(channel);
1308 }
1309 goto end_channel_error;
1310 }
1311
1312 health_code_update();
1313
1314 /*
1315 * Channel and streams are now created. Inform the session daemon that
1316 * everything went well and should wait to receive the channel and
1317 * streams with ustctl API.
1318 */
1319 ret = consumer_send_status_channel(sock, channel);
1320 if (ret < 0) {
1321 /*
1322 * There is probably a problem on the socket.
1323 */
1324 goto error_fatal;
1325 }
1326
1327 break;
1328 }
1329 case LTTNG_CONSUMER_GET_CHANNEL:
1330 {
1331 int ret, relayd_err = 0;
1332 uint64_t key = msg.u.get_channel.key;
1333 struct lttng_consumer_channel *channel;
1334
1335 channel = consumer_find_channel(key);
1336 if (!channel) {
1337 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1338 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1339 goto end_msg_sessiond;
1340 }
1341
1342 health_code_update();
1343
1344 /* Send everything to sessiond. */
1345 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1346 if (ret < 0) {
1347 if (relayd_err) {
1348 /*
1349 * We were unable to send to the relayd the stream so avoid
1350 * sending back a fatal error to the thread since this is OK
1351 * and the consumer can continue its work. The above call
1352 * has sent the error status message to the sessiond.
1353 */
1354 goto end_nosignal;
1355 }
1356 /*
1357 * The communicaton was broken hence there is a bad state between
1358 * the consumer and sessiond so stop everything.
1359 */
1360 goto error_fatal;
1361 }
1362
1363 health_code_update();
1364
1365 /*
1366 * In no monitor mode, the streams ownership is kept inside the channel
1367 * so don't send them to the data thread.
1368 */
1369 if (!channel->monitor) {
1370 goto end_msg_sessiond;
1371 }
1372
1373 ret = send_streams_to_thread(channel, ctx);
1374 if (ret < 0) {
1375 /*
1376 * If we are unable to send the stream to the thread, there is
1377 * a big problem so just stop everything.
1378 */
1379 goto error_fatal;
1380 }
1381 /* List MUST be empty after or else it could be reused. */
1382 assert(cds_list_empty(&channel->streams.head));
1383 goto end_msg_sessiond;
1384 }
1385 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1386 {
1387 uint64_t key = msg.u.destroy_channel.key;
1388
1389 /*
1390 * Only called if streams have not been sent to stream
1391 * manager thread. However, channel has been sent to
1392 * channel manager thread.
1393 */
1394 notify_thread_del_channel(ctx, key);
1395 goto end_msg_sessiond;
1396 }
1397 case LTTNG_CONSUMER_CLOSE_METADATA:
1398 {
1399 int ret;
1400
1401 ret = close_metadata(msg.u.close_metadata.key);
1402 if (ret != 0) {
1403 ret_code = ret;
1404 }
1405
1406 goto end_msg_sessiond;
1407 }
1408 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1409 {
1410 int ret;
1411
1412 ret = flush_channel(msg.u.flush_channel.key);
1413 if (ret != 0) {
1414 ret_code = ret;
1415 }
1416
1417 goto end_msg_sessiond;
1418 }
1419 case LTTNG_CONSUMER_PUSH_METADATA:
1420 {
1421 int ret;
1422 uint64_t len = msg.u.push_metadata.len;
1423 uint64_t key = msg.u.push_metadata.key;
1424 uint64_t offset = msg.u.push_metadata.target_offset;
1425 struct lttng_consumer_channel *channel;
1426
1427 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1428 len);
1429
1430 channel = consumer_find_channel(key);
1431 if (!channel) {
1432 /*
1433 * This is possible if the metadata creation on the consumer side
1434 * is in flight vis-a-vis a concurrent push metadata from the
1435 * session daemon. Simply return that the channel failed and the
1436 * session daemon will handle that message correctly considering
1437 * that this race is acceptable thus the DBG() statement here.
1438 */
1439 DBG("UST consumer push metadata %" PRIu64 " not found", key);
1440 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1441 goto end_msg_sessiond;
1442 }
1443
1444 health_code_update();
1445
1446 /* Tell session daemon we are ready to receive the metadata. */
1447 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
1448 if (ret < 0) {
1449 /* Somehow, the session daemon is not responding anymore. */
1450 goto error_fatal;
1451 }
1452
1453 health_code_update();
1454
1455 /* Wait for more data. */
1456 health_poll_entry();
1457 ret = lttng_consumer_poll_socket(consumer_sockpoll);
1458 health_poll_exit();
1459 if (ret < 0) {
1460 goto error_fatal;
1461 }
1462
1463 health_code_update();
1464
1465 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1466 len, channel, 0, 1);
1467 if (ret < 0) {
1468 /* error receiving from sessiond */
1469 goto error_fatal;
1470 } else {
1471 ret_code = ret;
1472 goto end_msg_sessiond;
1473 }
1474 }
1475 case LTTNG_CONSUMER_SETUP_METADATA:
1476 {
1477 int ret;
1478
1479 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1480 if (ret) {
1481 ret_code = ret;
1482 }
1483 goto end_msg_sessiond;
1484 }
1485 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1486 {
1487 if (msg.u.snapshot_channel.metadata) {
1488 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1489 msg.u.snapshot_channel.pathname,
1490 msg.u.snapshot_channel.relayd_id,
1491 ctx);
1492 if (ret < 0) {
1493 ERR("Snapshot metadata failed");
1494 ret_code = LTTNG_ERR_UST_META_FAIL;
1495 }
1496 } else {
1497 ret = snapshot_channel(msg.u.snapshot_channel.key,
1498 msg.u.snapshot_channel.pathname,
1499 msg.u.snapshot_channel.relayd_id,
1500 msg.u.snapshot_channel.max_stream_size,
1501 ctx);
1502 if (ret < 0) {
1503 ERR("Snapshot channel failed");
1504 ret_code = LTTNG_ERR_UST_CHAN_FAIL;
1505 }
1506 }
1507
1508 health_code_update();
1509 ret = consumer_send_status_msg(sock, ret_code);
1510 if (ret < 0) {
1511 /* Somehow, the session daemon is not responding anymore. */
1512 goto end_nosignal;
1513 }
1514 health_code_update();
1515 break;
1516 }
1517 default:
1518 break;
1519 }
1520
1521 end_nosignal:
1522 rcu_read_unlock();
1523
1524 health_code_update();
1525
1526 /*
1527 * Return 1 to indicate success since the 0 value can be a socket
1528 * shutdown during the recv() or send() call.
1529 */
1530 return 1;
1531
1532 end_msg_sessiond:
1533 /*
1534 * The returned value here is not useful since either way we'll return 1 to
1535 * the caller because the session daemon socket management is done
1536 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1537 */
1538 ret = consumer_send_status_msg(sock, ret_code);
1539 if (ret < 0) {
1540 goto error_fatal;
1541 }
1542 rcu_read_unlock();
1543
1544 health_code_update();
1545
1546 return 1;
1547 end_channel_error:
1548 if (channel) {
1549 /*
1550 * Free channel here since no one has a reference to it. We don't
1551 * free after that because a stream can store this pointer.
1552 */
1553 destroy_channel(channel);
1554 }
1555 /* We have to send a status channel message indicating an error. */
1556 ret = consumer_send_status_channel(sock, NULL);
1557 if (ret < 0) {
1558 /* Stop everything if session daemon can not be notified. */
1559 goto error_fatal;
1560 }
1561 rcu_read_unlock();
1562
1563 health_code_update();
1564
1565 return 1;
1566 error_fatal:
1567 rcu_read_unlock();
1568 /* This will issue a consumer stop. */
1569 return -1;
1570 }
1571
1572 /*
1573 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1574 * compiled out, we isolate it in this library.
1575 */
1576 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1577 unsigned long *off)
1578 {
1579 assert(stream);
1580 assert(stream->ustream);
1581
1582 return ustctl_get_mmap_read_offset(stream->ustream, off);
1583 }
1584
1585 /*
1586 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1587 * compiled out, we isolate it in this library.
1588 */
1589 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1590 {
1591 assert(stream);
1592 assert(stream->ustream);
1593
1594 return ustctl_get_mmap_base(stream->ustream);
1595 }
1596
1597 /*
1598 * Take a snapshot for a specific fd
1599 *
1600 * Returns 0 on success, < 0 on error
1601 */
1602 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1603 {
1604 assert(stream);
1605 assert(stream->ustream);
1606
1607 return ustctl_snapshot(stream->ustream);
1608 }
1609
1610 /*
1611 * Get the produced position
1612 *
1613 * Returns 0 on success, < 0 on error
1614 */
1615 int lttng_ustconsumer_get_produced_snapshot(
1616 struct lttng_consumer_stream *stream, unsigned long *pos)
1617 {
1618 assert(stream);
1619 assert(stream->ustream);
1620 assert(pos);
1621
1622 return ustctl_snapshot_get_produced(stream->ustream, pos);
1623 }
1624
1625 /*
1626 * Get the consumed position
1627 *
1628 * Returns 0 on success, < 0 on error
1629 */
1630 int lttng_ustconsumer_get_consumed_snapshot(
1631 struct lttng_consumer_stream *stream, unsigned long *pos)
1632 {
1633 assert(stream);
1634 assert(stream->ustream);
1635 assert(pos);
1636
1637 return ustctl_snapshot_get_consumed(stream->ustream, pos);
1638 }
1639
1640 void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
1641 int producer)
1642 {
1643 assert(stream);
1644 assert(stream->ustream);
1645
1646 ustctl_flush_buffer(stream->ustream, producer);
1647 }
1648
1649 int lttng_ustconsumer_get_current_timestamp(
1650 struct lttng_consumer_stream *stream, uint64_t *ts)
1651 {
1652 assert(stream);
1653 assert(stream->ustream);
1654 assert(ts);
1655
1656 return ustctl_get_current_timestamp(stream->ustream, ts);
1657 }
1658
1659 /*
1660 * Called when the stream signal the consumer that it has hang up.
1661 */
1662 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1663 {
1664 assert(stream);
1665 assert(stream->ustream);
1666
1667 ustctl_flush_buffer(stream->ustream, 0);
1668 stream->hangup_flush_done = 1;
1669 }
1670
1671 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1672 {
1673 assert(chan);
1674 assert(chan->uchan);
1675
1676 if (chan->switch_timer_enabled == 1) {
1677 consumer_timer_switch_stop(chan);
1678 }
1679 consumer_metadata_cache_destroy(chan);
1680 ustctl_destroy_channel(chan->uchan);
1681 }
1682
1683 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1684 {
1685 assert(stream);
1686 assert(stream->ustream);
1687
1688 if (stream->chan->switch_timer_enabled == 1) {
1689 consumer_timer_switch_stop(stream->chan);
1690 }
1691 ustctl_destroy_stream(stream->ustream);
1692 }
1693
1694 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
1695 {
1696 assert(stream);
1697 assert(stream->ustream);
1698
1699 return ustctl_stream_get_wakeup_fd(stream->ustream);
1700 }
1701
1702 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
1703 {
1704 assert(stream);
1705 assert(stream->ustream);
1706
1707 return ustctl_stream_close_wakeup_fd(stream->ustream);
1708 }
1709
1710 /*
1711 * Populate index values of a UST stream. Values are set in big endian order.
1712 *
1713 * Return 0 on success or else a negative value.
1714 */
1715 static int get_index_values(struct ctf_packet_index *index,
1716 struct ustctl_consumer_stream *ustream)
1717 {
1718 int ret;
1719
1720 ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
1721 if (ret < 0) {
1722 PERROR("ustctl_get_timestamp_begin");
1723 goto error;
1724 }
1725 index->timestamp_begin = htobe64(index->timestamp_begin);
1726
1727 ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
1728 if (ret < 0) {
1729 PERROR("ustctl_get_timestamp_end");
1730 goto error;
1731 }
1732 index->timestamp_end = htobe64(index->timestamp_end);
1733
1734 ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
1735 if (ret < 0) {
1736 PERROR("ustctl_get_events_discarded");
1737 goto error;
1738 }
1739 index->events_discarded = htobe64(index->events_discarded);
1740
1741 ret = ustctl_get_content_size(ustream, &index->content_size);
1742 if (ret < 0) {
1743 PERROR("ustctl_get_content_size");
1744 goto error;
1745 }
1746 index->content_size = htobe64(index->content_size);
1747
1748 ret = ustctl_get_packet_size(ustream, &index->packet_size);
1749 if (ret < 0) {
1750 PERROR("ustctl_get_packet_size");
1751 goto error;
1752 }
1753 index->packet_size = htobe64(index->packet_size);
1754
1755 ret = ustctl_get_stream_id(ustream, &index->stream_id);
1756 if (ret < 0) {
1757 PERROR("ustctl_get_stream_id");
1758 goto error;
1759 }
1760 index->stream_id = htobe64(index->stream_id);
1761
1762 error:
1763 return ret;
1764 }
1765
1766 /*
1767 * Write up to one packet from the metadata cache to the channel.
1768 *
1769 * Returns the number of bytes pushed in the cache, or a negative value
1770 * on error.
1771 */
1772 static
1773 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
1774 {
1775 ssize_t write_len;
1776 int ret;
1777
1778 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
1779 if (stream->chan->metadata_cache->contiguous
1780 == stream->ust_metadata_pushed) {
1781 ret = 0;
1782 goto end;
1783 }
1784
1785 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
1786 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
1787 stream->chan->metadata_cache->contiguous
1788 - stream->ust_metadata_pushed);
1789 assert(write_len != 0);
1790 if (write_len < 0) {
1791 ERR("Writing one metadata packet");
1792 ret = -1;
1793 goto end;
1794 }
1795 stream->ust_metadata_pushed += write_len;
1796
1797 assert(stream->chan->metadata_cache->contiguous >=
1798 stream->ust_metadata_pushed);
1799 ret = write_len;
1800
1801 end:
1802 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
1803 return ret;
1804 }
1805
1806
1807 /*
1808 * Sync metadata meaning request them to the session daemon and snapshot to the
1809 * metadata thread can consumer them.
1810 *
1811 * Metadata stream lock MUST be acquired.
1812 *
1813 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
1814 * is empty or a negative value on error.
1815 */
1816 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
1817 struct lttng_consumer_stream *metadata)
1818 {
1819 int ret;
1820 int retry = 0;
1821
1822 assert(ctx);
1823 assert(metadata);
1824
1825 /*
1826 * Request metadata from the sessiond, but don't wait for the flush
1827 * because we locked the metadata thread.
1828 */
1829 ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
1830 if (ret < 0) {
1831 goto end;
1832 }
1833
1834 ret = commit_one_metadata_packet(metadata);
1835 if (ret <= 0) {
1836 goto end;
1837 } else if (ret > 0) {
1838 retry = 1;
1839 }
1840
1841 ustctl_flush_buffer(metadata->ustream, 1);
1842 ret = ustctl_snapshot(metadata->ustream);
1843 if (ret < 0) {
1844 if (errno != EAGAIN) {
1845 ERR("Sync metadata, taking UST snapshot");
1846 goto end;
1847 }
1848 DBG("No new metadata when syncing them.");
1849 /* No new metadata, exit. */
1850 ret = ENODATA;
1851 goto end;
1852 }
1853
1854 /*
1855 * After this flush, we still need to extract metadata.
1856 */
1857 if (retry) {
1858 ret = EAGAIN;
1859 }
1860
1861 end:
1862 return ret;
1863 }
1864
1865 /*
1866 * Read subbuffer from the given stream.
1867 *
1868 * Stream lock MUST be acquired.
1869 *
1870 * Return 0 on success else a negative value.
1871 */
1872 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1873 struct lttng_consumer_local_data *ctx)
1874 {
1875 unsigned long len, subbuf_size, padding;
1876 int err, write_index = 1;
1877 long ret = 0;
1878 char dummy;
1879 struct ustctl_consumer_stream *ustream;
1880 struct ctf_packet_index index;
1881
1882 assert(stream);
1883 assert(stream->ustream);
1884 assert(ctx);
1885
1886 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1887 stream->name);
1888
1889 /* Ease our life for what's next. */
1890 ustream = stream->ustream;
1891
1892 /*
1893 * We can consume the 1 byte written into the wait_fd by UST.
1894 * Don't trigger error if we cannot read this one byte (read
1895 * returns 0), or if the error is EAGAIN or EWOULDBLOCK.
1896 */
1897 if (stream->monitor && !stream->hangup_flush_done) {
1898 ssize_t readlen;
1899
1900 readlen = lttng_read(stream->wait_fd, &dummy, 1);
1901 if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
1902 ret = readlen;
1903 goto end;
1904 }
1905 }
1906
1907 retry:
1908 /* Get the next subbuffer */
1909 err = ustctl_get_next_subbuf(ustream);
1910 if (err != 0) {
1911 /*
1912 * Populate metadata info if the existing info has
1913 * already been read.
1914 */
1915 if (stream->metadata_flag) {
1916 ret = commit_one_metadata_packet(stream);
1917 if (ret <= 0) {
1918 goto end;
1919 }
1920 ustctl_flush_buffer(stream->ustream, 1);
1921 goto retry;
1922 }
1923
1924 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1925 /*
1926 * This is a debug message even for single-threaded consumer,
1927 * because poll() have more relaxed criterions than get subbuf,
1928 * so get_subbuf may fail for short race windows where poll()
1929 * would issue wakeups.
1930 */
1931 DBG("Reserving sub buffer failed (everything is normal, "
1932 "it is due to concurrency) [ret: %d]", err);
1933 goto end;
1934 }
1935 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1936
1937 if (!stream->metadata_flag) {
1938 index.offset = htobe64(stream->out_fd_offset);
1939 ret = get_index_values(&index, ustream);
1940 if (ret < 0) {
1941 goto end;
1942 }
1943 } else {
1944 write_index = 0;
1945 }
1946
1947 /* Get the full padded subbuffer size */
1948 err = ustctl_get_padded_subbuf_size(ustream, &len);
1949 assert(err == 0);
1950
1951 /* Get subbuffer data size (without padding) */
1952 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1953 assert(err == 0);
1954
1955 /* Make sure we don't get a subbuffer size bigger than the padded */
1956 assert(len >= subbuf_size);
1957
1958 padding = len - subbuf_size;
1959 /* write the subbuffer to the tracefile */
1960 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
1961 /*
1962 * The mmap operation should write subbuf_size amount of data when network
1963 * streaming or the full padding (len) size when we are _not_ streaming.
1964 */
1965 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1966 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
1967 /*
1968 * Display the error but continue processing to try to release the
1969 * subbuffer. This is a DBG statement since any unexpected kill or
1970 * signal, the application gets unregistered, relayd gets closed or
1971 * anything that affects the buffer lifetime will trigger this error.
1972 * So, for the sake of the user, don't print this error since it can
1973 * happen and it is OK with the code flow.
1974 */
1975 DBG("Error writing to tracefile "
1976 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1977 ret, len, subbuf_size);
1978 write_index = 0;
1979 }
1980 err = ustctl_put_next_subbuf(ustream);
1981 assert(err == 0);
1982
1983 /* Write index if needed. */
1984 if (!write_index) {
1985 goto end;
1986 }
1987
1988 if (stream->chan->live_timer_interval && !stream->metadata_flag) {
1989 /*
1990 * In live, block until all the metadata is sent.
1991 */
1992 err = consumer_stream_sync_metadata(ctx, stream->session_id);
1993 if (err < 0) {
1994 goto end;
1995 }
1996 }
1997
1998 assert(!stream->metadata_flag);
1999 err = consumer_stream_write_index(stream, &index);
2000 if (err < 0) {
2001 goto end;
2002 }
2003
2004 end:
2005 return ret;
2006 }
2007
2008 /*
2009 * Called when a stream is created.
2010 *
2011 * Return 0 on success or else a negative value.
2012 */
2013 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
2014 {
2015 int ret;
2016
2017 assert(stream);
2018
2019 /* Don't create anything if this is set for streaming. */
2020 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
2021 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
2022 stream->chan->tracefile_size, stream->tracefile_count_current,
2023 stream->uid, stream->gid, NULL);
2024 if (ret < 0) {
2025 goto error;
2026 }
2027 stream->out_fd = ret;
2028 stream->tracefile_size_current = 0;
2029
2030 if (!stream->metadata_flag) {
2031 ret = index_create_file(stream->chan->pathname,
2032 stream->name, stream->uid, stream->gid,
2033 stream->chan->tracefile_size,
2034 stream->tracefile_count_current);
2035 if (ret < 0) {
2036 goto error;
2037 }
2038 stream->index_fd = ret;
2039 }
2040 }
2041 ret = 0;
2042
2043 error:
2044 return ret;
2045 }
2046
2047 /*
2048 * Check if data is still being extracted from the buffers for a specific
2049 * stream. Consumer data lock MUST be acquired before calling this function
2050 * and the stream lock.
2051 *
2052 * Return 1 if the traced data are still getting read else 0 meaning that the
2053 * data is available for trace viewer reading.
2054 */
2055 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
2056 {
2057 int ret;
2058
2059 assert(stream);
2060 assert(stream->ustream);
2061
2062 DBG("UST consumer checking data pending");
2063
2064 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
2065 ret = 0;
2066 goto end;
2067 }
2068
2069 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
2070 uint64_t contiguous, pushed;
2071
2072 /* Ease our life a bit. */
2073 contiguous = stream->chan->metadata_cache->contiguous;
2074 pushed = stream->ust_metadata_pushed;
2075
2076 /*
2077 * We can simply check whether all contiguously available data
2078 * has been pushed to the ring buffer, since the push operation
2079 * is performed within get_next_subbuf(), and because both
2080 * get_next_subbuf() and put_next_subbuf() are issued atomically
2081 * thanks to the stream lock within
2082 * lttng_ustconsumer_read_subbuffer(). This basically means that
2083 * whetnever ust_metadata_pushed is incremented, the associated
2084 * metadata has been consumed from the metadata stream.
2085 */
2086 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
2087 contiguous, pushed);
2088 assert(((int64_t) contiguous - pushed) >= 0);
2089 if ((contiguous != pushed) ||
2090 (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
2091 ret = 1; /* Data is pending */
2092 goto end;
2093 }
2094 } else {
2095 ret = ustctl_get_next_subbuf(stream->ustream);
2096 if (ret == 0) {
2097 /*
2098 * There is still data so let's put back this
2099 * subbuffer.
2100 */
2101 ret = ustctl_put_subbuf(stream->ustream);
2102 assert(ret == 0);
2103 ret = 1; /* Data is pending */
2104 goto end;
2105 }
2106 }
2107
2108 /* Data is NOT pending so ready to be read. */
2109 ret = 0;
2110
2111 end:
2112 return ret;
2113 }
2114
2115 /*
2116 * Stop a given metadata channel timer if enabled and close the wait fd which
2117 * is the poll pipe of the metadata stream.
2118 *
2119 * This MUST be called with the metadata channel acquired.
2120 */
2121 void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata)
2122 {
2123 int ret;
2124
2125 assert(metadata);
2126 assert(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA);
2127
2128 DBG("Closing metadata channel key %" PRIu64, metadata->key);
2129
2130 if (metadata->switch_timer_enabled == 1) {
2131 consumer_timer_switch_stop(metadata);
2132 }
2133
2134 if (!metadata->metadata_stream) {
2135 goto end;
2136 }
2137
2138 /*
2139 * Closing write side so the thread monitoring the stream wakes up if any
2140 * and clean the metadata stream.
2141 */
2142 if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) {
2143 ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]);
2144 if (ret < 0) {
2145 PERROR("closing metadata pipe write side");
2146 }
2147 metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1;
2148 }
2149
2150 end:
2151 return;
2152 }
2153
2154 /*
2155 * Close every metadata stream wait fd of the metadata hash table. This
2156 * function MUST be used very carefully so not to run into a race between the
2157 * metadata thread handling streams and this function closing their wait fd.
2158 *
2159 * For UST, this is used when the session daemon hangs up. Its the metadata
2160 * producer so calling this is safe because we are assured that no state change
2161 * can occur in the metadata thread for the streams in the hash table.
2162 */
2163 void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht)
2164 {
2165 struct lttng_ht_iter iter;
2166 struct lttng_consumer_stream *stream;
2167
2168 assert(metadata_ht);
2169 assert(metadata_ht->ht);
2170
2171 DBG("UST consumer closing all metadata streams");
2172
2173 rcu_read_lock();
2174 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
2175 node.node) {
2176
2177 health_code_update();
2178
2179 pthread_mutex_lock(&stream->chan->lock);
2180 lttng_ustconsumer_close_metadata(stream->chan);
2181 pthread_mutex_unlock(&stream->chan->lock);
2182
2183 }
2184 rcu_read_unlock();
2185 }
2186
2187 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
2188 {
2189 int ret;
2190
2191 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
2192 if (ret < 0) {
2193 ERR("Unable to close wakeup fd");
2194 }
2195 }
2196
2197 /*
2198 * Please refer to consumer-timer.c before adding any lock within this
2199 * function or any of its callees. Timers have a very strict locking
2200 * semantic with respect to teardown. Failure to respect this semantic
2201 * introduces deadlocks.
2202 */
2203 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
2204 struct lttng_consumer_channel *channel, int timer, int wait)
2205 {
2206 struct lttcomm_metadata_request_msg request;
2207 struct lttcomm_consumer_msg msg;
2208 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
2209 uint64_t len, key, offset;
2210 int ret;
2211
2212 assert(channel);
2213 assert(channel->metadata_cache);
2214
2215 /* send the metadata request to sessiond */
2216 switch (consumer_data.type) {
2217 case LTTNG_CONSUMER64_UST:
2218 request.bits_per_long = 64;
2219 break;
2220 case LTTNG_CONSUMER32_UST:
2221 request.bits_per_long = 32;
2222 break;
2223 default:
2224 request.bits_per_long = 0;
2225 break;
2226 }
2227
2228 request.session_id = channel->session_id;
2229 request.session_id_per_pid = channel->session_id_per_pid;
2230 /*
2231 * Request the application UID here so the metadata of that application can
2232 * be sent back. The channel UID corresponds to the user UID of the session
2233 * used for the rights on the stream file(s).
2234 */
2235 request.uid = channel->ust_app_uid;
2236 request.key = channel->key;
2237
2238 DBG("Sending metadata request to sessiond, session id %" PRIu64
2239 ", per-pid %" PRIu64 ", app UID %u and channek key %" PRIu64,
2240 request.session_id, request.session_id_per_pid, request.uid,
2241 request.key);
2242
2243 pthread_mutex_lock(&ctx->metadata_socket_lock);
2244
2245 health_code_update();
2246
2247 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
2248 sizeof(request));
2249 if (ret < 0) {
2250 ERR("Asking metadata to sessiond");
2251 goto end;
2252 }
2253
2254 health_code_update();
2255
2256 /* Receive the metadata from sessiond */
2257 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
2258 sizeof(msg));
2259 if (ret != sizeof(msg)) {
2260 DBG("Consumer received unexpected message size %d (expects %zu)",
2261 ret, sizeof(msg));
2262 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
2263 /*
2264 * The ret value might 0 meaning an orderly shutdown but this is ok
2265 * since the caller handles this.
2266 */
2267 goto end;
2268 }
2269
2270 health_code_update();
2271
2272 if (msg.cmd_type == LTTNG_ERR_UND) {
2273 /* No registry found */
2274 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
2275 ret_code);
2276 ret = 0;
2277 goto end;
2278 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
2279 ERR("Unexpected cmd_type received %d", msg.cmd_type);
2280 ret = -1;
2281 goto end;
2282 }
2283
2284 len = msg.u.push_metadata.len;
2285 key = msg.u.push_metadata.key;
2286 offset = msg.u.push_metadata.target_offset;
2287
2288 assert(key == channel->key);
2289 if (len == 0) {
2290 DBG("No new metadata to receive for key %" PRIu64, key);
2291 }
2292
2293 health_code_update();
2294
2295 /* Tell session daemon we are ready to receive the metadata. */
2296 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
2297 LTTCOMM_CONSUMERD_SUCCESS);
2298 if (ret < 0 || len == 0) {
2299 /*
2300 * Somehow, the session daemon is not responding anymore or there is
2301 * nothing to receive.
2302 */
2303 goto end;
2304 }
2305
2306 health_code_update();
2307
2308 ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
2309 key, offset, len, channel, timer, wait);
2310 if (ret >= 0) {
2311 /*
2312 * Only send the status msg if the sessiond is alive meaning a positive
2313 * ret code.
2314 */
2315 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret);
2316 }
2317 ret = 0;
2318
2319 end:
2320 health_code_update();
2321
2322 pthread_mutex_unlock(&ctx->metadata_socket_lock);
2323 return ret;
2324 }
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