a077faafba12de1533e5015cc58f71c4ca5d530d
[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
413 assert(channel);
414 assert(ctx);
415 assert(sock >= 0);
416
417 DBG("UST consumer sending channel %s to sessiond", channel->name);
418
419 if (channel->relayd_id != (uint64_t) -1ULL) {
420 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
421
422 health_code_update();
423
424 /* Try to send the stream to the relayd if one is available. */
425 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
426 if (ret < 0) {
427 /*
428 * Flag that the relayd was the problem here probably due to a
429 * communicaton error on the socket.
430 */
431 if (relayd_error) {
432 *relayd_error = 1;
433 }
434 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
435 }
436 }
437 }
438
439 /* Inform sessiond that we are about to send channel and streams. */
440 ret = consumer_send_status_msg(sock, ret_code);
441 if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
442 /*
443 * Either the session daemon is not responding or the relayd died so we
444 * stop now.
445 */
446 goto error;
447 }
448
449 /* Send channel to sessiond. */
450 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
451 if (ret < 0) {
452 goto error;
453 }
454
455 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
456 if (ret < 0) {
457 goto error;
458 }
459
460 /* The channel was sent successfully to the sessiond at this point. */
461 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
462
463 health_code_update();
464
465 /* Send stream to session daemon. */
466 ret = send_sessiond_stream(sock, stream);
467 if (ret < 0) {
468 goto error;
469 }
470 }
471
472 /* Tell sessiond there is no more stream. */
473 ret = ustctl_send_stream_to_sessiond(sock, NULL);
474 if (ret < 0) {
475 goto error;
476 }
477
478 DBG("UST consumer NULL stream sent to sessiond");
479
480 return 0;
481
482 error:
483 if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
484 ret = -1;
485 }
486 return ret;
487 }
488
489 /*
490 * Creates a channel and streams and add the channel it to the channel internal
491 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
492 * received.
493 *
494 * Return 0 on success or else, a negative value is returned and the channel
495 * MUST be destroyed by consumer_del_channel().
496 */
497 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
498 struct lttng_consumer_channel *channel,
499 struct ustctl_consumer_channel_attr *attr)
500 {
501 int ret;
502
503 assert(ctx);
504 assert(channel);
505 assert(attr);
506
507 /*
508 * This value is still used by the kernel consumer since for the kernel,
509 * the stream ownership is not IN the consumer so we need to have the
510 * number of left stream that needs to be initialized so we can know when
511 * to delete the channel (see consumer.c).
512 *
513 * As for the user space tracer now, the consumer creates and sends the
514 * stream to the session daemon which only sends them to the application
515 * once every stream of a channel is received making this value useless
516 * because we they will be added to the poll thread before the application
517 * receives them. This ensures that a stream can not hang up during
518 * initilization of a channel.
519 */
520 channel->nb_init_stream_left = 0;
521
522 /* The reply msg status is handled in the following call. */
523 ret = create_ust_channel(attr, &channel->uchan);
524 if (ret < 0) {
525 goto end;
526 }
527
528 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
529
530 /*
531 * For the snapshots (no monitor), we create the metadata streams
532 * on demand, not during the channel creation.
533 */
534 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
535 ret = 0;
536 goto end;
537 }
538
539 /* Open all streams for this channel. */
540 ret = create_ust_streams(channel, ctx);
541 if (ret < 0) {
542 goto end;
543 }
544
545 end:
546 return ret;
547 }
548
549 /*
550 * Send all stream of a channel to the right thread handling it.
551 *
552 * On error, return a negative value else 0 on success.
553 */
554 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
555 struct lttng_consumer_local_data *ctx)
556 {
557 int ret = 0;
558 struct lttng_consumer_stream *stream, *stmp;
559
560 assert(channel);
561 assert(ctx);
562
563 /* Send streams to the corresponding thread. */
564 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
565 send_node) {
566
567 health_code_update();
568
569 /* Sending the stream to the thread. */
570 ret = send_stream_to_thread(stream, ctx);
571 if (ret < 0) {
572 /*
573 * If we are unable to send the stream to the thread, there is
574 * a big problem so just stop everything.
575 */
576 /* Remove node from the channel stream list. */
577 cds_list_del(&stream->send_node);
578 goto error;
579 }
580
581 /* Remove node from the channel stream list. */
582 cds_list_del(&stream->send_node);
583
584 }
585
586 error:
587 return ret;
588 }
589
590 /*
591 * Flush channel's streams using the given key to retrieve the channel.
592 *
593 * Return 0 on success else an LTTng error code.
594 */
595 static int flush_channel(uint64_t chan_key)
596 {
597 int ret = 0;
598 struct lttng_consumer_channel *channel;
599 struct lttng_consumer_stream *stream;
600 struct lttng_ht *ht;
601 struct lttng_ht_iter iter;
602
603 DBG("UST consumer flush channel key %" PRIu64, chan_key);
604
605 rcu_read_lock();
606 channel = consumer_find_channel(chan_key);
607 if (!channel) {
608 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
609 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
610 goto error;
611 }
612
613 ht = consumer_data.stream_per_chan_id_ht;
614
615 /* For each stream of the channel id, flush it. */
616 cds_lfht_for_each_entry_duplicate(ht->ht,
617 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
618 &channel->key, &iter.iter, stream, node_channel_id.node) {
619
620 health_code_update();
621
622 ustctl_flush_buffer(stream->ustream, 1);
623 }
624 error:
625 rcu_read_unlock();
626 return ret;
627 }
628 /*
629 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
630 * RCU read side lock MUST be acquired before calling this function.
631 *
632 * NOTE: This function does NOT take any channel nor stream lock.
633 *
634 * Return 0 on success else LTTng error code.
635 */
636 static int _close_metadata(struct lttng_consumer_channel *channel)
637 {
638 int ret = LTTCOMM_CONSUMERD_SUCCESS;
639
640 assert(channel);
641 assert(channel->type == CONSUMER_CHANNEL_TYPE_METADATA);
642
643 if (channel->switch_timer_enabled == 1) {
644 DBG("Deleting timer on metadata channel");
645 consumer_timer_switch_stop(channel);
646 }
647
648 if (channel->metadata_stream) {
649 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
650 if (ret < 0) {
651 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
652 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
653 }
654
655 if (channel->monitor) {
656 /* Close the read-side in consumer_del_metadata_stream */
657 ret = close(channel->metadata_stream->ust_metadata_poll_pipe[1]);
658 if (ret < 0) {
659 PERROR("Close UST metadata write-side poll pipe");
660 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
661 }
662 }
663 }
664
665 return ret;
666 }
667
668 /*
669 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
670 * RCU read side lock MUST be acquired before calling this function.
671 *
672 * Return 0 on success else an LTTng error code.
673 */
674 static int close_metadata(uint64_t chan_key)
675 {
676 int ret = 0;
677 struct lttng_consumer_channel *channel;
678
679 DBG("UST consumer close metadata key %" PRIu64, chan_key);
680
681 channel = consumer_find_channel(chan_key);
682 if (!channel) {
683 /*
684 * This is possible if the metadata thread has issue a delete because
685 * the endpoint point of the stream hung up. There is no way the
686 * session daemon can know about it thus use a DBG instead of an actual
687 * error.
688 */
689 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
690 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
691 goto error;
692 }
693
694 pthread_mutex_lock(&consumer_data.lock);
695 pthread_mutex_lock(&channel->lock);
696
697 if (cds_lfht_is_node_deleted(&channel->node.node)) {
698 goto error_unlock;
699 }
700
701 ret = _close_metadata(channel);
702
703 error_unlock:
704 pthread_mutex_unlock(&channel->lock);
705 pthread_mutex_unlock(&consumer_data.lock);
706 error:
707 return ret;
708 }
709
710 /*
711 * RCU read side lock MUST be acquired before calling this function.
712 *
713 * Return 0 on success else an LTTng error code.
714 */
715 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
716 {
717 int ret;
718 struct lttng_consumer_channel *metadata;
719
720 DBG("UST consumer setup metadata key %" PRIu64, key);
721
722 metadata = consumer_find_channel(key);
723 if (!metadata) {
724 ERR("UST consumer push metadata %" PRIu64 " not found", key);
725 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
726 goto end;
727 }
728
729 /*
730 * In no monitor mode, the metadata channel has no stream(s) so skip the
731 * ownership transfer to the metadata thread.
732 */
733 if (!metadata->monitor) {
734 DBG("Metadata channel in no monitor");
735 ret = 0;
736 goto end;
737 }
738
739 /*
740 * Send metadata stream to relayd if one available. Availability is
741 * known if the stream is still in the list of the channel.
742 */
743 if (cds_list_empty(&metadata->streams.head)) {
744 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
745 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
746 goto error_no_stream;
747 }
748
749 /* Send metadata stream to relayd if needed. */
750 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
751 ret = consumer_send_relayd_stream(metadata->metadata_stream,
752 metadata->pathname);
753 if (ret < 0) {
754 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
755 goto error;
756 }
757 }
758
759 ret = send_streams_to_thread(metadata, ctx);
760 if (ret < 0) {
761 /*
762 * If we are unable to send the stream to the thread, there is
763 * a big problem so just stop everything.
764 */
765 ret = LTTCOMM_CONSUMERD_FATAL;
766 goto error;
767 }
768 /* List MUST be empty after or else it could be reused. */
769 assert(cds_list_empty(&metadata->streams.head));
770
771 ret = 0;
772 goto end;
773
774 error:
775 /*
776 * Delete metadata channel on error. At this point, the metadata stream can
777 * NOT be monitored by the metadata thread thus having the guarantee that
778 * the stream is still in the local stream list of the channel. This call
779 * will make sure to clean that list.
780 */
781 cds_list_del(&metadata->metadata_stream->send_node);
782 consumer_stream_destroy(metadata->metadata_stream, NULL);
783 error_no_stream:
784 end:
785 return ret;
786 }
787
788 /*
789 * Snapshot the whole metadata.
790 *
791 * Returns 0 on success, < 0 on error
792 */
793 static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
794 struct lttng_consumer_local_data *ctx)
795 {
796 int ret = 0;
797 struct lttng_consumer_channel *metadata_channel;
798 struct lttng_consumer_stream *metadata_stream;
799
800 assert(path);
801 assert(ctx);
802
803 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
804 key, path);
805
806 rcu_read_lock();
807
808 metadata_channel = consumer_find_channel(key);
809 if (!metadata_channel) {
810 ERR("UST snapshot metadata channel not found for key %" PRIu64,
811 key);
812 ret = -1;
813 goto error;
814 }
815 assert(!metadata_channel->monitor);
816
817 health_code_update();
818
819 /*
820 * Ask the sessiond if we have new metadata waiting and update the
821 * consumer metadata cache.
822 */
823 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
824 if (ret < 0) {
825 goto error;
826 }
827
828 health_code_update();
829
830 /*
831 * The metadata stream is NOT created in no monitor mode when the channel
832 * is created on a sessiond ask channel command.
833 */
834 ret = create_ust_streams(metadata_channel, ctx);
835 if (ret < 0) {
836 goto error;
837 }
838
839 metadata_stream = metadata_channel->metadata_stream;
840 assert(metadata_stream);
841
842 if (relayd_id != (uint64_t) -1ULL) {
843 metadata_stream->net_seq_idx = relayd_id;
844 ret = consumer_send_relayd_stream(metadata_stream, path);
845 if (ret < 0) {
846 goto error_stream;
847 }
848 } else {
849 ret = utils_create_stream_file(path, metadata_stream->name,
850 metadata_stream->chan->tracefile_size,
851 metadata_stream->tracefile_count_current,
852 metadata_stream->uid, metadata_stream->gid, NULL);
853 if (ret < 0) {
854 goto error_stream;
855 }
856 metadata_stream->out_fd = ret;
857 metadata_stream->tracefile_size_current = 0;
858 }
859
860 do {
861 health_code_update();
862
863 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
864 if (ret < 0) {
865 goto error_stream;
866 }
867 } while (ret > 0);
868
869 error_stream:
870 /*
871 * Clean up the stream completly because the next snapshot will use a new
872 * metadata stream.
873 */
874 cds_list_del(&metadata_stream->send_node);
875 consumer_stream_destroy(metadata_stream, NULL);
876 metadata_channel->metadata_stream = NULL;
877
878 error:
879 rcu_read_unlock();
880 return ret;
881 }
882
883 /*
884 * Take a snapshot of all the stream of a channel.
885 *
886 * Returns 0 on success, < 0 on error
887 */
888 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
889 uint64_t max_stream_size, struct lttng_consumer_local_data *ctx)
890 {
891 int ret;
892 unsigned use_relayd = 0;
893 unsigned long consumed_pos, produced_pos;
894 struct lttng_consumer_channel *channel;
895 struct lttng_consumer_stream *stream;
896
897 assert(path);
898 assert(ctx);
899
900 rcu_read_lock();
901
902 if (relayd_id != (uint64_t) -1ULL) {
903 use_relayd = 1;
904 }
905
906 channel = consumer_find_channel(key);
907 if (!channel) {
908 ERR("UST snapshot channel not found for key %" PRIu64, key);
909 ret = -1;
910 goto error;
911 }
912 assert(!channel->monitor);
913 DBG("UST consumer snapshot channel %" PRIu64, key);
914
915 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
916
917 health_code_update();
918
919 /* Lock stream because we are about to change its state. */
920 pthread_mutex_lock(&stream->lock);
921 stream->net_seq_idx = relayd_id;
922
923 if (use_relayd) {
924 ret = consumer_send_relayd_stream(stream, path);
925 if (ret < 0) {
926 goto error_unlock;
927 }
928 } else {
929 ret = utils_create_stream_file(path, stream->name,
930 stream->chan->tracefile_size,
931 stream->tracefile_count_current,
932 stream->uid, stream->gid, NULL);
933 if (ret < 0) {
934 goto error_unlock;
935 }
936 stream->out_fd = ret;
937 stream->tracefile_size_current = 0;
938
939 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
940 stream->name, stream->key);
941 }
942
943 ustctl_flush_buffer(stream->ustream, 1);
944
945 ret = lttng_ustconsumer_take_snapshot(stream);
946 if (ret < 0) {
947 ERR("Taking UST snapshot");
948 goto error_unlock;
949 }
950
951 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
952 if (ret < 0) {
953 ERR("Produced UST snapshot position");
954 goto error_unlock;
955 }
956
957 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
958 if (ret < 0) {
959 ERR("Consumerd UST snapshot position");
960 goto error_unlock;
961 }
962
963 /*
964 * The original value is sent back if max stream size is larger than
965 * the possible size of the snapshot. Also, we asume that the session
966 * daemon should never send a maximum stream size that is lower than
967 * subbuffer size.
968 */
969 consumed_pos = consumer_get_consumed_maxsize(consumed_pos,
970 produced_pos, max_stream_size);
971
972 while (consumed_pos < produced_pos) {
973 ssize_t read_len;
974 unsigned long len, padded_len;
975
976 health_code_update();
977
978 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
979
980 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
981 if (ret < 0) {
982 if (ret != -EAGAIN) {
983 PERROR("ustctl_get_subbuf snapshot");
984 goto error_close_stream;
985 }
986 DBG("UST consumer get subbuf failed. Skipping it.");
987 consumed_pos += stream->max_sb_size;
988 continue;
989 }
990
991 ret = ustctl_get_subbuf_size(stream->ustream, &len);
992 if (ret < 0) {
993 ERR("Snapshot ustctl_get_subbuf_size");
994 goto error_put_subbuf;
995 }
996
997 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
998 if (ret < 0) {
999 ERR("Snapshot ustctl_get_padded_subbuf_size");
1000 goto error_put_subbuf;
1001 }
1002
1003 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
1004 padded_len - len, NULL);
1005 if (use_relayd) {
1006 if (read_len != len) {
1007 ret = -EPERM;
1008 goto error_put_subbuf;
1009 }
1010 } else {
1011 if (read_len != padded_len) {
1012 ret = -EPERM;
1013 goto error_put_subbuf;
1014 }
1015 }
1016
1017 ret = ustctl_put_subbuf(stream->ustream);
1018 if (ret < 0) {
1019 ERR("Snapshot ustctl_put_subbuf");
1020 goto error_close_stream;
1021 }
1022 consumed_pos += stream->max_sb_size;
1023 }
1024
1025 /* Simply close the stream so we can use it on the next snapshot. */
1026 consumer_stream_close(stream);
1027 pthread_mutex_unlock(&stream->lock);
1028 }
1029
1030 rcu_read_unlock();
1031 return 0;
1032
1033 error_put_subbuf:
1034 if (ustctl_put_subbuf(stream->ustream) < 0) {
1035 ERR("Snapshot ustctl_put_subbuf");
1036 }
1037 error_close_stream:
1038 consumer_stream_close(stream);
1039 error_unlock:
1040 pthread_mutex_unlock(&stream->lock);
1041 error:
1042 rcu_read_unlock();
1043 return ret;
1044 }
1045
1046 /*
1047 * Receive the metadata updates from the sessiond.
1048 */
1049 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1050 uint64_t len, struct lttng_consumer_channel *channel,
1051 int timer, int wait)
1052 {
1053 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1054 char *metadata_str;
1055
1056 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
1057
1058 metadata_str = zmalloc(len * sizeof(char));
1059 if (!metadata_str) {
1060 PERROR("zmalloc metadata string");
1061 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1062 goto end;
1063 }
1064
1065 health_code_update();
1066
1067 /* Receive metadata string. */
1068 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1069 if (ret < 0) {
1070 /* Session daemon is dead so return gracefully. */
1071 ret_code = ret;
1072 goto end_free;
1073 }
1074
1075 health_code_update();
1076
1077 pthread_mutex_lock(&channel->metadata_cache->lock);
1078 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
1079 if (ret < 0) {
1080 /* Unable to handle metadata. Notify session daemon. */
1081 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1082 /*
1083 * Skip metadata flush on write error since the offset and len might
1084 * not have been updated which could create an infinite loop below when
1085 * waiting for the metadata cache to be flushed.
1086 */
1087 pthread_mutex_unlock(&channel->metadata_cache->lock);
1088 goto end_free;
1089 }
1090 pthread_mutex_unlock(&channel->metadata_cache->lock);
1091
1092 if (!wait) {
1093 goto end_free;
1094 }
1095 while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
1096 DBG("Waiting for metadata to be flushed");
1097
1098 health_code_update();
1099
1100 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1101 }
1102
1103 end_free:
1104 free(metadata_str);
1105 end:
1106 return ret_code;
1107 }
1108
1109 /*
1110 * Receive command from session daemon and process it.
1111 *
1112 * Return 1 on success else a negative value or 0.
1113 */
1114 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1115 int sock, struct pollfd *consumer_sockpoll)
1116 {
1117 ssize_t ret;
1118 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1119 struct lttcomm_consumer_msg msg;
1120 struct lttng_consumer_channel *channel = NULL;
1121
1122 health_code_update();
1123
1124 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1125 if (ret != sizeof(msg)) {
1126 DBG("Consumer received unexpected message size %zd (expects %zu)",
1127 ret, sizeof(msg));
1128 /*
1129 * The ret value might 0 meaning an orderly shutdown but this is ok
1130 * since the caller handles this.
1131 */
1132 if (ret > 0) {
1133 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1134 ret = -1;
1135 }
1136 return ret;
1137 }
1138
1139 health_code_update();
1140
1141 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
1142 /*
1143 * Notify the session daemon that the command is completed.
1144 *
1145 * On transport layer error, the function call will print an error
1146 * message so handling the returned code is a bit useless since we
1147 * return an error code anyway.
1148 */
1149 (void) consumer_send_status_msg(sock, ret_code);
1150 return -ENOENT;
1151 }
1152
1153 health_code_update();
1154
1155 /* relayd needs RCU read-side lock */
1156 rcu_read_lock();
1157
1158 switch (msg.cmd_type) {
1159 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1160 {
1161 /* Session daemon status message are handled in the following call. */
1162 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1163 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1164 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
1165 msg.u.relayd_sock.relayd_session_id);
1166 goto end_nosignal;
1167 }
1168 case LTTNG_CONSUMER_DESTROY_RELAYD:
1169 {
1170 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1171 struct consumer_relayd_sock_pair *relayd;
1172
1173 DBG("UST consumer destroying relayd %" PRIu64, index);
1174
1175 /* Get relayd reference if exists. */
1176 relayd = consumer_find_relayd(index);
1177 if (relayd == NULL) {
1178 DBG("Unable to find relayd %" PRIu64, index);
1179 ret_code = LTTNG_ERR_NO_CONSUMER;
1180 }
1181
1182 /*
1183 * Each relayd socket pair has a refcount of stream attached to it
1184 * which tells if the relayd is still active or not depending on the
1185 * refcount value.
1186 *
1187 * This will set the destroy flag of the relayd object and destroy it
1188 * if the refcount reaches zero when called.
1189 *
1190 * The destroy can happen either here or when a stream fd hangs up.
1191 */
1192 if (relayd) {
1193 consumer_flag_relayd_for_destroy(relayd);
1194 }
1195
1196 goto end_msg_sessiond;
1197 }
1198 case LTTNG_CONSUMER_UPDATE_STREAM:
1199 {
1200 rcu_read_unlock();
1201 return -ENOSYS;
1202 }
1203 case LTTNG_CONSUMER_DATA_PENDING:
1204 {
1205 int ret, is_data_pending;
1206 uint64_t id = msg.u.data_pending.session_id;
1207
1208 DBG("UST consumer data pending command for id %" PRIu64, id);
1209
1210 is_data_pending = consumer_data_pending(id);
1211
1212 /* Send back returned value to session daemon */
1213 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1214 sizeof(is_data_pending));
1215 if (ret < 0) {
1216 DBG("Error when sending the data pending ret code: %d", ret);
1217 goto error_fatal;
1218 }
1219
1220 /*
1221 * No need to send back a status message since the data pending
1222 * returned value is the response.
1223 */
1224 break;
1225 }
1226 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1227 {
1228 int ret;
1229 struct ustctl_consumer_channel_attr attr;
1230
1231 /* Create a plain object and reserve a channel key. */
1232 channel = allocate_channel(msg.u.ask_channel.session_id,
1233 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1234 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1235 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1236 (enum lttng_event_output) msg.u.ask_channel.output,
1237 msg.u.ask_channel.tracefile_size,
1238 msg.u.ask_channel.tracefile_count,
1239 msg.u.ask_channel.session_id_per_pid,
1240 msg.u.ask_channel.monitor,
1241 msg.u.ask_channel.live_timer_interval);
1242 if (!channel) {
1243 goto end_channel_error;
1244 }
1245
1246 /*
1247 * Assign UST application UID to the channel. This value is ignored for
1248 * per PID buffers. This is specific to UST thus setting this after the
1249 * allocation.
1250 */
1251 channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
1252
1253 /* Build channel attributes from received message. */
1254 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1255 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1256 attr.overwrite = msg.u.ask_channel.overwrite;
1257 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1258 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1259 attr.chan_id = msg.u.ask_channel.chan_id;
1260 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1261
1262 /* Match channel buffer type to the UST abi. */
1263 switch (msg.u.ask_channel.output) {
1264 case LTTNG_EVENT_MMAP:
1265 default:
1266 attr.output = LTTNG_UST_MMAP;
1267 break;
1268 }
1269
1270 /* Translate and save channel type. */
1271 switch (msg.u.ask_channel.type) {
1272 case LTTNG_UST_CHAN_PER_CPU:
1273 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1274 attr.type = LTTNG_UST_CHAN_PER_CPU;
1275 /*
1276 * Set refcount to 1 for owner. Below, we will
1277 * pass ownership to the
1278 * consumer_thread_channel_poll() thread.
1279 */
1280 channel->refcount = 1;
1281 break;
1282 case LTTNG_UST_CHAN_METADATA:
1283 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1284 attr.type = LTTNG_UST_CHAN_METADATA;
1285 break;
1286 default:
1287 assert(0);
1288 goto error_fatal;
1289 };
1290
1291 health_code_update();
1292
1293 ret = ask_channel(ctx, sock, channel, &attr);
1294 if (ret < 0) {
1295 goto end_channel_error;
1296 }
1297
1298 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1299 ret = consumer_metadata_cache_allocate(channel);
1300 if (ret < 0) {
1301 ERR("Allocating metadata cache");
1302 goto end_channel_error;
1303 }
1304 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1305 attr.switch_timer_interval = 0;
1306 } else {
1307 consumer_timer_live_start(channel,
1308 msg.u.ask_channel.live_timer_interval);
1309 }
1310
1311 health_code_update();
1312
1313 /*
1314 * Add the channel to the internal state AFTER all streams were created
1315 * and successfully sent to session daemon. This way, all streams must
1316 * be ready before this channel is visible to the threads.
1317 * If add_channel succeeds, ownership of the channel is
1318 * passed to consumer_thread_channel_poll().
1319 */
1320 ret = add_channel(channel, ctx);
1321 if (ret < 0) {
1322 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1323 if (channel->switch_timer_enabled == 1) {
1324 consumer_timer_switch_stop(channel);
1325 }
1326 consumer_metadata_cache_destroy(channel);
1327 }
1328 if (channel->live_timer_enabled == 1) {
1329 consumer_timer_live_stop(channel);
1330 }
1331 goto end_channel_error;
1332 }
1333
1334 health_code_update();
1335
1336 /*
1337 * Channel and streams are now created. Inform the session daemon that
1338 * everything went well and should wait to receive the channel and
1339 * streams with ustctl API.
1340 */
1341 ret = consumer_send_status_channel(sock, channel);
1342 if (ret < 0) {
1343 /*
1344 * There is probably a problem on the socket.
1345 */
1346 goto error_fatal;
1347 }
1348
1349 break;
1350 }
1351 case LTTNG_CONSUMER_GET_CHANNEL:
1352 {
1353 int ret, relayd_err = 0;
1354 uint64_t key = msg.u.get_channel.key;
1355 struct lttng_consumer_channel *channel;
1356
1357 channel = consumer_find_channel(key);
1358 if (!channel) {
1359 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1360 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1361 goto end_msg_sessiond;
1362 }
1363
1364 health_code_update();
1365
1366 /* Send everything to sessiond. */
1367 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1368 if (ret < 0) {
1369 if (relayd_err) {
1370 /*
1371 * We were unable to send to the relayd the stream so avoid
1372 * sending back a fatal error to the thread since this is OK
1373 * and the consumer can continue its work. The above call
1374 * has sent the error status message to the sessiond.
1375 */
1376 goto end_nosignal;
1377 }
1378 /*
1379 * The communicaton was broken hence there is a bad state between
1380 * the consumer and sessiond so stop everything.
1381 */
1382 goto error_fatal;
1383 }
1384
1385 health_code_update();
1386
1387 /*
1388 * In no monitor mode, the streams ownership is kept inside the channel
1389 * so don't send them to the data thread.
1390 */
1391 if (!channel->monitor) {
1392 goto end_msg_sessiond;
1393 }
1394
1395 ret = send_streams_to_thread(channel, ctx);
1396 if (ret < 0) {
1397 /*
1398 * If we are unable to send the stream to the thread, there is
1399 * a big problem so just stop everything.
1400 */
1401 goto error_fatal;
1402 }
1403 /* List MUST be empty after or else it could be reused. */
1404 assert(cds_list_empty(&channel->streams.head));
1405 goto end_msg_sessiond;
1406 }
1407 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1408 {
1409 uint64_t key = msg.u.destroy_channel.key;
1410
1411 /*
1412 * Only called if streams have not been sent to stream
1413 * manager thread. However, channel has been sent to
1414 * channel manager thread.
1415 */
1416 notify_thread_del_channel(ctx, key);
1417 goto end_msg_sessiond;
1418 }
1419 case LTTNG_CONSUMER_CLOSE_METADATA:
1420 {
1421 int ret;
1422
1423 ret = close_metadata(msg.u.close_metadata.key);
1424 if (ret != 0) {
1425 ret_code = ret;
1426 }
1427
1428 goto end_msg_sessiond;
1429 }
1430 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1431 {
1432 int ret;
1433
1434 ret = flush_channel(msg.u.flush_channel.key);
1435 if (ret != 0) {
1436 ret_code = ret;
1437 }
1438
1439 goto end_msg_sessiond;
1440 }
1441 case LTTNG_CONSUMER_PUSH_METADATA:
1442 {
1443 int ret;
1444 uint64_t len = msg.u.push_metadata.len;
1445 uint64_t key = msg.u.push_metadata.key;
1446 uint64_t offset = msg.u.push_metadata.target_offset;
1447 struct lttng_consumer_channel *channel;
1448
1449 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1450 len);
1451
1452 channel = consumer_find_channel(key);
1453 if (!channel) {
1454 /*
1455 * This is possible if the metadata creation on the consumer side
1456 * is in flight vis-a-vis a concurrent push metadata from the
1457 * session daemon. Simply return that the channel failed and the
1458 * session daemon will handle that message correctly considering
1459 * that this race is acceptable thus the DBG() statement here.
1460 */
1461 DBG("UST consumer push metadata %" PRIu64 " not found", key);
1462 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1463 goto end_msg_sessiond;
1464 }
1465
1466 health_code_update();
1467
1468 /* Tell session daemon we are ready to receive the metadata. */
1469 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
1470 if (ret < 0) {
1471 /* Somehow, the session daemon is not responding anymore. */
1472 goto error_fatal;
1473 }
1474
1475 health_code_update();
1476
1477 /* Wait for more data. */
1478 health_poll_entry();
1479 ret = lttng_consumer_poll_socket(consumer_sockpoll);
1480 health_poll_exit();
1481 if (ret < 0) {
1482 goto error_fatal;
1483 }
1484
1485 health_code_update();
1486
1487 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1488 len, channel, 0, 1);
1489 if (ret < 0) {
1490 /* error receiving from sessiond */
1491 goto error_fatal;
1492 } else {
1493 ret_code = ret;
1494 goto end_msg_sessiond;
1495 }
1496 }
1497 case LTTNG_CONSUMER_SETUP_METADATA:
1498 {
1499 int ret;
1500
1501 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1502 if (ret) {
1503 ret_code = ret;
1504 }
1505 goto end_msg_sessiond;
1506 }
1507 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1508 {
1509 if (msg.u.snapshot_channel.metadata) {
1510 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1511 msg.u.snapshot_channel.pathname,
1512 msg.u.snapshot_channel.relayd_id,
1513 ctx);
1514 if (ret < 0) {
1515 ERR("Snapshot metadata failed");
1516 ret_code = LTTNG_ERR_UST_META_FAIL;
1517 }
1518 } else {
1519 ret = snapshot_channel(msg.u.snapshot_channel.key,
1520 msg.u.snapshot_channel.pathname,
1521 msg.u.snapshot_channel.relayd_id,
1522 msg.u.snapshot_channel.max_stream_size,
1523 ctx);
1524 if (ret < 0) {
1525 ERR("Snapshot channel failed");
1526 ret_code = LTTNG_ERR_UST_CHAN_FAIL;
1527 }
1528 }
1529
1530 health_code_update();
1531 ret = consumer_send_status_msg(sock, ret_code);
1532 if (ret < 0) {
1533 /* Somehow, the session daemon is not responding anymore. */
1534 goto end_nosignal;
1535 }
1536 health_code_update();
1537 break;
1538 }
1539 default:
1540 break;
1541 }
1542
1543 end_nosignal:
1544 rcu_read_unlock();
1545
1546 health_code_update();
1547
1548 /*
1549 * Return 1 to indicate success since the 0 value can be a socket
1550 * shutdown during the recv() or send() call.
1551 */
1552 return 1;
1553
1554 end_msg_sessiond:
1555 /*
1556 * The returned value here is not useful since either way we'll return 1 to
1557 * the caller because the session daemon socket management is done
1558 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1559 */
1560 ret = consumer_send_status_msg(sock, ret_code);
1561 if (ret < 0) {
1562 goto error_fatal;
1563 }
1564 rcu_read_unlock();
1565
1566 health_code_update();
1567
1568 return 1;
1569 end_channel_error:
1570 if (channel) {
1571 /*
1572 * Free channel here since no one has a reference to it. We don't
1573 * free after that because a stream can store this pointer.
1574 */
1575 destroy_channel(channel);
1576 }
1577 /* We have to send a status channel message indicating an error. */
1578 ret = consumer_send_status_channel(sock, NULL);
1579 if (ret < 0) {
1580 /* Stop everything if session daemon can not be notified. */
1581 goto error_fatal;
1582 }
1583 rcu_read_unlock();
1584
1585 health_code_update();
1586
1587 return 1;
1588 error_fatal:
1589 rcu_read_unlock();
1590 /* This will issue a consumer stop. */
1591 return -1;
1592 }
1593
1594 /*
1595 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1596 * compiled out, we isolate it in this library.
1597 */
1598 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1599 unsigned long *off)
1600 {
1601 assert(stream);
1602 assert(stream->ustream);
1603
1604 return ustctl_get_mmap_read_offset(stream->ustream, off);
1605 }
1606
1607 /*
1608 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1609 * compiled out, we isolate it in this library.
1610 */
1611 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1612 {
1613 assert(stream);
1614 assert(stream->ustream);
1615
1616 return ustctl_get_mmap_base(stream->ustream);
1617 }
1618
1619 /*
1620 * Take a snapshot for a specific fd
1621 *
1622 * Returns 0 on success, < 0 on error
1623 */
1624 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1625 {
1626 assert(stream);
1627 assert(stream->ustream);
1628
1629 return ustctl_snapshot(stream->ustream);
1630 }
1631
1632 /*
1633 * Get the produced position
1634 *
1635 * Returns 0 on success, < 0 on error
1636 */
1637 int lttng_ustconsumer_get_produced_snapshot(
1638 struct lttng_consumer_stream *stream, unsigned long *pos)
1639 {
1640 assert(stream);
1641 assert(stream->ustream);
1642 assert(pos);
1643
1644 return ustctl_snapshot_get_produced(stream->ustream, pos);
1645 }
1646
1647 /*
1648 * Get the consumed position
1649 *
1650 * Returns 0 on success, < 0 on error
1651 */
1652 int lttng_ustconsumer_get_consumed_snapshot(
1653 struct lttng_consumer_stream *stream, unsigned long *pos)
1654 {
1655 assert(stream);
1656 assert(stream->ustream);
1657 assert(pos);
1658
1659 return ustctl_snapshot_get_consumed(stream->ustream, pos);
1660 }
1661
1662 void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
1663 int producer)
1664 {
1665 assert(stream);
1666 assert(stream->ustream);
1667
1668 ustctl_flush_buffer(stream->ustream, producer);
1669 }
1670
1671 int lttng_ustconsumer_get_current_timestamp(
1672 struct lttng_consumer_stream *stream, uint64_t *ts)
1673 {
1674 assert(stream);
1675 assert(stream->ustream);
1676 assert(ts);
1677
1678 return ustctl_get_current_timestamp(stream->ustream, ts);
1679 }
1680
1681 /*
1682 * Called when the stream signal the consumer that it has hang up.
1683 */
1684 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1685 {
1686 assert(stream);
1687 assert(stream->ustream);
1688
1689 ustctl_flush_buffer(stream->ustream, 0);
1690 stream->hangup_flush_done = 1;
1691 }
1692
1693 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1694 {
1695 assert(chan);
1696 assert(chan->uchan);
1697
1698 if (chan->switch_timer_enabled == 1) {
1699 consumer_timer_switch_stop(chan);
1700 }
1701 consumer_metadata_cache_destroy(chan);
1702 ustctl_destroy_channel(chan->uchan);
1703 }
1704
1705 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1706 {
1707 assert(stream);
1708 assert(stream->ustream);
1709
1710 if (stream->chan->switch_timer_enabled == 1) {
1711 consumer_timer_switch_stop(stream->chan);
1712 }
1713 ustctl_destroy_stream(stream->ustream);
1714 }
1715
1716 /*
1717 * Populate index values of a UST stream. Values are set in big endian order.
1718 *
1719 * Return 0 on success or else a negative value.
1720 */
1721 static int get_index_values(struct ctf_packet_index *index,
1722 struct ustctl_consumer_stream *ustream)
1723 {
1724 int ret;
1725
1726 ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
1727 if (ret < 0) {
1728 PERROR("ustctl_get_timestamp_begin");
1729 goto error;
1730 }
1731 index->timestamp_begin = htobe64(index->timestamp_begin);
1732
1733 ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
1734 if (ret < 0) {
1735 PERROR("ustctl_get_timestamp_end");
1736 goto error;
1737 }
1738 index->timestamp_end = htobe64(index->timestamp_end);
1739
1740 ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
1741 if (ret < 0) {
1742 PERROR("ustctl_get_events_discarded");
1743 goto error;
1744 }
1745 index->events_discarded = htobe64(index->events_discarded);
1746
1747 ret = ustctl_get_content_size(ustream, &index->content_size);
1748 if (ret < 0) {
1749 PERROR("ustctl_get_content_size");
1750 goto error;
1751 }
1752 index->content_size = htobe64(index->content_size);
1753
1754 ret = ustctl_get_packet_size(ustream, &index->packet_size);
1755 if (ret < 0) {
1756 PERROR("ustctl_get_packet_size");
1757 goto error;
1758 }
1759 index->packet_size = htobe64(index->packet_size);
1760
1761 ret = ustctl_get_stream_id(ustream, &index->stream_id);
1762 if (ret < 0) {
1763 PERROR("ustctl_get_stream_id");
1764 goto error;
1765 }
1766 index->stream_id = htobe64(index->stream_id);
1767
1768 error:
1769 return ret;
1770 }
1771
1772 /*
1773 * Write up to one packet from the metadata cache to the channel.
1774 *
1775 * Returns the number of bytes pushed in the cache, or a negative value
1776 * on error.
1777 */
1778 static
1779 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
1780 {
1781 ssize_t write_len;
1782 int ret;
1783
1784 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
1785 if (stream->chan->metadata_cache->contiguous
1786 == stream->ust_metadata_pushed) {
1787 ret = 0;
1788 goto end;
1789 }
1790
1791 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
1792 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
1793 stream->chan->metadata_cache->contiguous
1794 - stream->ust_metadata_pushed);
1795 assert(write_len != 0);
1796 if (write_len < 0) {
1797 ERR("Writing one metadata packet");
1798 ret = -1;
1799 goto end;
1800 }
1801 stream->ust_metadata_pushed += write_len;
1802
1803 assert(stream->chan->metadata_cache->contiguous >=
1804 stream->ust_metadata_pushed);
1805 ret = write_len;
1806
1807 end:
1808 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
1809 return ret;
1810 }
1811
1812
1813 /*
1814 * Sync metadata meaning request them to the session daemon and snapshot to the
1815 * metadata thread can consumer them.
1816 *
1817 * Metadata stream lock MUST be acquired.
1818 *
1819 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
1820 * is empty or a negative value on error.
1821 */
1822 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
1823 struct lttng_consumer_stream *metadata)
1824 {
1825 int ret;
1826 int retry = 0;
1827
1828 assert(ctx);
1829 assert(metadata);
1830
1831 /*
1832 * Request metadata from the sessiond, but don't wait for the flush
1833 * because we locked the metadata thread.
1834 */
1835 ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
1836 if (ret < 0) {
1837 goto end;
1838 }
1839
1840 ret = commit_one_metadata_packet(metadata);
1841 if (ret <= 0) {
1842 goto end;
1843 } else if (ret > 0) {
1844 retry = 1;
1845 }
1846
1847 ustctl_flush_buffer(metadata->ustream, 1);
1848 ret = ustctl_snapshot(metadata->ustream);
1849 if (ret < 0) {
1850 if (errno != EAGAIN) {
1851 ERR("Sync metadata, taking UST snapshot");
1852 goto end;
1853 }
1854 DBG("No new metadata when syncing them.");
1855 /* No new metadata, exit. */
1856 ret = ENODATA;
1857 goto end;
1858 }
1859
1860 /*
1861 * After this flush, we still need to extract metadata.
1862 */
1863 if (retry) {
1864 ret = EAGAIN;
1865 }
1866
1867 end:
1868 return ret;
1869 }
1870
1871 /*
1872 * Read subbuffer from the given stream.
1873 *
1874 * Stream lock MUST be acquired.
1875 *
1876 * Return 0 on success else a negative value.
1877 */
1878 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1879 struct lttng_consumer_local_data *ctx)
1880 {
1881 unsigned long len, subbuf_size, padding;
1882 int err, write_index = 1;
1883 long ret = 0;
1884 char dummy;
1885 struct ustctl_consumer_stream *ustream;
1886 struct ctf_packet_index index;
1887
1888 assert(stream);
1889 assert(stream->ustream);
1890 assert(ctx);
1891
1892 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1893 stream->name);
1894
1895 /* Ease our life for what's next. */
1896 ustream = stream->ustream;
1897
1898 /*
1899 * We can consume the 1 byte written into the wait_fd by UST.
1900 * Don't trigger error if we cannot read this one byte (read
1901 * returns 0), or if the error is EAGAIN or EWOULDBLOCK.
1902 */
1903 if (stream->monitor && !stream->hangup_flush_done) {
1904 ssize_t readlen;
1905
1906 readlen = lttng_read(stream->wait_fd, &dummy, 1);
1907 if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
1908 ret = readlen;
1909 goto end;
1910 }
1911 }
1912
1913 retry:
1914 /* Get the next subbuffer */
1915 err = ustctl_get_next_subbuf(ustream);
1916 if (err != 0) {
1917 /*
1918 * Populate metadata info if the existing info has
1919 * already been read.
1920 */
1921 if (stream->metadata_flag) {
1922 ret = commit_one_metadata_packet(stream);
1923 if (ret <= 0) {
1924 goto end;
1925 }
1926 ustctl_flush_buffer(stream->ustream, 1);
1927 goto retry;
1928 }
1929
1930 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1931 /*
1932 * This is a debug message even for single-threaded consumer,
1933 * because poll() have more relaxed criterions than get subbuf,
1934 * so get_subbuf may fail for short race windows where poll()
1935 * would issue wakeups.
1936 */
1937 DBG("Reserving sub buffer failed (everything is normal, "
1938 "it is due to concurrency) [ret: %d]", err);
1939 goto end;
1940 }
1941 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1942
1943 if (!stream->metadata_flag) {
1944 index.offset = htobe64(stream->out_fd_offset);
1945 ret = get_index_values(&index, ustream);
1946 if (ret < 0) {
1947 goto end;
1948 }
1949 } else {
1950 write_index = 0;
1951 }
1952
1953 /* Get the full padded subbuffer size */
1954 err = ustctl_get_padded_subbuf_size(ustream, &len);
1955 assert(err == 0);
1956
1957 /* Get subbuffer data size (without padding) */
1958 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1959 assert(err == 0);
1960
1961 /* Make sure we don't get a subbuffer size bigger than the padded */
1962 assert(len >= subbuf_size);
1963
1964 padding = len - subbuf_size;
1965 /* write the subbuffer to the tracefile */
1966 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
1967 /*
1968 * The mmap operation should write subbuf_size amount of data when network
1969 * streaming or the full padding (len) size when we are _not_ streaming.
1970 */
1971 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1972 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
1973 /*
1974 * Display the error but continue processing to try to release the
1975 * subbuffer. This is a DBG statement since any unexpected kill or
1976 * signal, the application gets unregistered, relayd gets closed or
1977 * anything that affects the buffer lifetime will trigger this error.
1978 * So, for the sake of the user, don't print this error since it can
1979 * happen and it is OK with the code flow.
1980 */
1981 DBG("Error writing to tracefile "
1982 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1983 ret, len, subbuf_size);
1984 write_index = 0;
1985 }
1986 err = ustctl_put_next_subbuf(ustream);
1987 assert(err == 0);
1988
1989 /* Write index if needed. */
1990 if (!write_index) {
1991 goto end;
1992 }
1993
1994 if (stream->chan->live_timer_interval && !stream->metadata_flag) {
1995 /*
1996 * In live, block until all the metadata is sent.
1997 */
1998 err = consumer_stream_sync_metadata(ctx, stream->session_id);
1999 if (err < 0) {
2000 goto end;
2001 }
2002 }
2003
2004 assert(!stream->metadata_flag);
2005 err = consumer_stream_write_index(stream, &index);
2006 if (err < 0) {
2007 goto end;
2008 }
2009
2010 end:
2011 return ret;
2012 }
2013
2014 /*
2015 * Called when a stream is created.
2016 *
2017 * Return 0 on success or else a negative value.
2018 */
2019 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
2020 {
2021 int ret;
2022
2023 assert(stream);
2024
2025 /* Don't create anything if this is set for streaming. */
2026 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
2027 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
2028 stream->chan->tracefile_size, stream->tracefile_count_current,
2029 stream->uid, stream->gid, NULL);
2030 if (ret < 0) {
2031 goto error;
2032 }
2033 stream->out_fd = ret;
2034 stream->tracefile_size_current = 0;
2035
2036 if (!stream->metadata_flag) {
2037 ret = index_create_file(stream->chan->pathname,
2038 stream->name, stream->uid, stream->gid,
2039 stream->chan->tracefile_size,
2040 stream->tracefile_count_current);
2041 if (ret < 0) {
2042 goto error;
2043 }
2044 stream->index_fd = ret;
2045 }
2046 }
2047 ret = 0;
2048
2049 error:
2050 return ret;
2051 }
2052
2053 /*
2054 * Check if data is still being extracted from the buffers for a specific
2055 * stream. Consumer data lock MUST be acquired before calling this function
2056 * and the stream lock.
2057 *
2058 * Return 1 if the traced data are still getting read else 0 meaning that the
2059 * data is available for trace viewer reading.
2060 */
2061 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
2062 {
2063 int ret;
2064
2065 assert(stream);
2066 assert(stream->ustream);
2067
2068 DBG("UST consumer checking data pending");
2069
2070 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
2071 ret = 0;
2072 goto end;
2073 }
2074
2075 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
2076 uint64_t contiguous, pushed;
2077
2078 /* Ease our life a bit. */
2079 contiguous = stream->chan->metadata_cache->contiguous;
2080 pushed = stream->ust_metadata_pushed;
2081
2082 /*
2083 * We can simply check whether all contiguously available data
2084 * has been pushed to the ring buffer, since the push operation
2085 * is performed within get_next_subbuf(), and because both
2086 * get_next_subbuf() and put_next_subbuf() are issued atomically
2087 * thanks to the stream lock within
2088 * lttng_ustconsumer_read_subbuffer(). This basically means that
2089 * whetnever ust_metadata_pushed is incremented, the associated
2090 * metadata has been consumed from the metadata stream.
2091 */
2092 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
2093 contiguous, pushed);
2094 assert(((int64_t) contiguous - pushed) >= 0);
2095 if ((contiguous != pushed) ||
2096 (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
2097 ret = 1; /* Data is pending */
2098 goto end;
2099 }
2100 } else {
2101 ret = ustctl_get_next_subbuf(stream->ustream);
2102 if (ret == 0) {
2103 /*
2104 * There is still data so let's put back this
2105 * subbuffer.
2106 */
2107 ret = ustctl_put_subbuf(stream->ustream);
2108 assert(ret == 0);
2109 ret = 1; /* Data is pending */
2110 goto end;
2111 }
2112 }
2113
2114 /* Data is NOT pending so ready to be read. */
2115 ret = 0;
2116
2117 end:
2118 return ret;
2119 }
2120
2121 /*
2122 * Close every metadata stream wait fd of the metadata hash table. This
2123 * function MUST be used very carefully so not to run into a race between the
2124 * metadata thread handling streams and this function closing their wait fd.
2125 *
2126 * For UST, this is used when the session daemon hangs up. Its the metadata
2127 * producer so calling this is safe because we are assured that no state change
2128 * can occur in the metadata thread for the streams in the hash table.
2129 */
2130 void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
2131 {
2132 struct lttng_ht_iter iter;
2133 struct lttng_consumer_stream *stream;
2134
2135 assert(metadata_ht);
2136 assert(metadata_ht->ht);
2137
2138 DBG("UST consumer closing all metadata streams");
2139
2140 rcu_read_lock();
2141 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
2142 node.node) {
2143
2144 health_code_update();
2145
2146 pthread_mutex_lock(&stream->chan->lock);
2147 /*
2148 * Whatever returned value, we must continue to try to close everything
2149 * so ignore it.
2150 */
2151 (void) _close_metadata(stream->chan);
2152 DBG("Metadata wait fd %d and poll pipe fd %d closed", stream->wait_fd,
2153 stream->ust_metadata_poll_pipe[1]);
2154 pthread_mutex_unlock(&stream->chan->lock);
2155
2156 }
2157 rcu_read_unlock();
2158 }
2159
2160 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
2161 {
2162 int ret;
2163
2164 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
2165 if (ret < 0) {
2166 ERR("Unable to close wakeup fd");
2167 }
2168 }
2169
2170 /*
2171 * Please refer to consumer-timer.c before adding any lock within this
2172 * function or any of its callees. Timers have a very strict locking
2173 * semantic with respect to teardown. Failure to respect this semantic
2174 * introduces deadlocks.
2175 */
2176 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
2177 struct lttng_consumer_channel *channel, int timer, int wait)
2178 {
2179 struct lttcomm_metadata_request_msg request;
2180 struct lttcomm_consumer_msg msg;
2181 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
2182 uint64_t len, key, offset;
2183 int ret;
2184
2185 assert(channel);
2186 assert(channel->metadata_cache);
2187
2188 /* send the metadata request to sessiond */
2189 switch (consumer_data.type) {
2190 case LTTNG_CONSUMER64_UST:
2191 request.bits_per_long = 64;
2192 break;
2193 case LTTNG_CONSUMER32_UST:
2194 request.bits_per_long = 32;
2195 break;
2196 default:
2197 request.bits_per_long = 0;
2198 break;
2199 }
2200
2201 request.session_id = channel->session_id;
2202 request.session_id_per_pid = channel->session_id_per_pid;
2203 /*
2204 * Request the application UID here so the metadata of that application can
2205 * be sent back. The channel UID corresponds to the user UID of the session
2206 * used for the rights on the stream file(s).
2207 */
2208 request.uid = channel->ust_app_uid;
2209 request.key = channel->key;
2210
2211 DBG("Sending metadata request to sessiond, session id %" PRIu64
2212 ", per-pid %" PRIu64 ", app UID %u and channek key %" PRIu64,
2213 request.session_id, request.session_id_per_pid, request.uid,
2214 request.key);
2215
2216 pthread_mutex_lock(&ctx->metadata_socket_lock);
2217
2218 health_code_update();
2219
2220 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
2221 sizeof(request));
2222 if (ret < 0) {
2223 ERR("Asking metadata to sessiond");
2224 goto end;
2225 }
2226
2227 health_code_update();
2228
2229 /* Receive the metadata from sessiond */
2230 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
2231 sizeof(msg));
2232 if (ret != sizeof(msg)) {
2233 DBG("Consumer received unexpected message size %d (expects %zu)",
2234 ret, sizeof(msg));
2235 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
2236 /*
2237 * The ret value might 0 meaning an orderly shutdown but this is ok
2238 * since the caller handles this.
2239 */
2240 goto end;
2241 }
2242
2243 health_code_update();
2244
2245 if (msg.cmd_type == LTTNG_ERR_UND) {
2246 /* No registry found */
2247 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
2248 ret_code);
2249 ret = 0;
2250 goto end;
2251 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
2252 ERR("Unexpected cmd_type received %d", msg.cmd_type);
2253 ret = -1;
2254 goto end;
2255 }
2256
2257 len = msg.u.push_metadata.len;
2258 key = msg.u.push_metadata.key;
2259 offset = msg.u.push_metadata.target_offset;
2260
2261 assert(key == channel->key);
2262 if (len == 0) {
2263 DBG("No new metadata to receive for key %" PRIu64, key);
2264 }
2265
2266 health_code_update();
2267
2268 /* Tell session daemon we are ready to receive the metadata. */
2269 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
2270 LTTCOMM_CONSUMERD_SUCCESS);
2271 if (ret < 0 || len == 0) {
2272 /*
2273 * Somehow, the session daemon is not responding anymore or there is
2274 * nothing to receive.
2275 */
2276 goto end;
2277 }
2278
2279 health_code_update();
2280
2281 ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
2282 key, offset, len, channel, timer, wait);
2283 if (ret >= 0) {
2284 /*
2285 * Only send the status msg if the sessiond is alive meaning a positive
2286 * ret code.
2287 */
2288 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret);
2289 }
2290 ret = 0;
2291
2292 end:
2293 health_code_update();
2294
2295 pthread_mutex_unlock(&ctx->metadata_socket_lock);
2296 return ret;
2297 }
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