46644a907a9b7bd5e659def07bcae21c2295ed7d
[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 <common/common.h>
36 #include <common/sessiond-comm/sessiond-comm.h>
37 #include <common/relayd/relayd.h>
38 #include <common/compat/fcntl.h>
39 #include <common/consumer-metadata-cache.h>
40 #include <common/consumer-timer.h>
41 #include <common/utils.h>
42
43 #include "ust-consumer.h"
44
45 extern struct lttng_consumer_global_data consumer_data;
46 extern int consumer_poll_timeout;
47 extern volatile int consumer_quit;
48
49 /*
50 * Free channel object and all streams associated with it. This MUST be used
51 * only and only if the channel has _NEVER_ been added to the global channel
52 * hash table.
53 */
54 static void destroy_channel(struct lttng_consumer_channel *channel)
55 {
56 struct lttng_consumer_stream *stream, *stmp;
57
58 assert(channel);
59
60 DBG("UST consumer cleaning stream list");
61
62 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
63 send_node) {
64 cds_list_del(&stream->send_node);
65 ustctl_destroy_stream(stream->ustream);
66 free(stream);
67 }
68
69 /*
70 * If a channel is available meaning that was created before the streams
71 * were, delete it.
72 */
73 if (channel->uchan) {
74 lttng_ustconsumer_del_channel(channel);
75 }
76 free(channel);
77 }
78
79 /*
80 * Add channel to internal consumer state.
81 *
82 * Returns 0 on success or else a negative value.
83 */
84 static int add_channel(struct lttng_consumer_channel *channel,
85 struct lttng_consumer_local_data *ctx)
86 {
87 int ret = 0;
88
89 assert(channel);
90 assert(ctx);
91
92 if (ctx->on_recv_channel != NULL) {
93 ret = ctx->on_recv_channel(channel);
94 if (ret == 0) {
95 ret = consumer_add_channel(channel, ctx);
96 } else if (ret < 0) {
97 /* Most likely an ENOMEM. */
98 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
99 goto error;
100 }
101 } else {
102 ret = consumer_add_channel(channel, ctx);
103 }
104
105 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
106
107 error:
108 return ret;
109 }
110
111 /*
112 * Allocate and return a consumer channel object.
113 */
114 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
115 const char *pathname, const char *name, uid_t uid, gid_t gid,
116 int relayd_id, uint64_t key, enum lttng_event_output output,
117 uint64_t tracefile_size, uint64_t tracefile_count,
118 uint64_t session_id_per_pid, unsigned int monitor)
119 {
120 assert(pathname);
121 assert(name);
122
123 return consumer_allocate_channel(key, session_id, pathname, name, uid,
124 gid, relayd_id, output, tracefile_size,
125 tracefile_count, session_id_per_pid, monitor);
126 }
127
128 /*
129 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
130 * error value if applicable is set in it else it is kept untouched.
131 *
132 * Return NULL on error else the newly allocated stream object.
133 */
134 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
135 struct lttng_consumer_channel *channel,
136 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
137 {
138 int alloc_ret;
139 struct lttng_consumer_stream *stream = NULL;
140
141 assert(channel);
142 assert(ctx);
143
144 stream = consumer_allocate_stream(channel->key,
145 key,
146 LTTNG_CONSUMER_ACTIVE_STREAM,
147 channel->name,
148 channel->uid,
149 channel->gid,
150 channel->relayd_id,
151 channel->session_id,
152 cpu,
153 &alloc_ret,
154 channel->type);
155 if (stream == NULL) {
156 switch (alloc_ret) {
157 case -ENOENT:
158 /*
159 * We could not find the channel. Can happen if cpu hotplug
160 * happens while tearing down.
161 */
162 DBG3("Could not find channel");
163 break;
164 case -ENOMEM:
165 case -EINVAL:
166 default:
167 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
168 break;
169 }
170 goto error;
171 }
172
173 stream->chan = channel;
174
175 error:
176 if (_alloc_ret) {
177 *_alloc_ret = alloc_ret;
178 }
179 return stream;
180 }
181
182 /*
183 * Send the given stream pointer to the corresponding thread.
184 *
185 * Returns 0 on success else a negative value.
186 */
187 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
188 struct lttng_consumer_local_data *ctx)
189 {
190 int ret;
191 struct lttng_pipe *stream_pipe;
192
193 /* Get the right pipe where the stream will be sent. */
194 if (stream->metadata_flag) {
195 stream_pipe = ctx->consumer_metadata_pipe;
196 } else {
197 stream_pipe = ctx->consumer_data_pipe;
198 }
199
200 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
201 if (ret < 0) {
202 ERR("Consumer write %s stream to pipe %d",
203 stream->metadata_flag ? "metadata" : "data",
204 lttng_pipe_get_writefd(stream_pipe));
205 }
206
207 return ret;
208 }
209
210 /*
211 * Search for a relayd object related to the stream. If found, send the stream
212 * to the relayd.
213 *
214 * On success, returns 0 else a negative value.
215 */
216 static int send_stream_to_relayd(struct lttng_consumer_stream *stream)
217 {
218 int ret = 0;
219 struct consumer_relayd_sock_pair *relayd;
220
221 assert(stream);
222
223 relayd = consumer_find_relayd(stream->net_seq_idx);
224 if (relayd != NULL) {
225 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
226 /* Add stream on the relayd */
227 ret = relayd_add_stream(&relayd->control_sock, stream->name,
228 stream->chan->pathname, &stream->relayd_stream_id,
229 stream->chan->tracefile_size,
230 stream->chan->tracefile_count);
231 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
232 if (ret < 0) {
233 goto error;
234 }
235 } else if (stream->net_seq_idx != (uint64_t) -1ULL) {
236 ERR("Network sequence index %" PRIu64 " unknown. Not adding stream.",
237 stream->net_seq_idx);
238 ret = -1;
239 goto error;
240 }
241
242 error:
243 return ret;
244 }
245
246 /*
247 * Create streams for the given channel using liblttng-ust-ctl.
248 *
249 * Return 0 on success else a negative value.
250 */
251 static int create_ust_streams(struct lttng_consumer_channel *channel,
252 struct lttng_consumer_local_data *ctx)
253 {
254 int ret, cpu = 0;
255 struct ustctl_consumer_stream *ustream;
256 struct lttng_consumer_stream *stream;
257
258 assert(channel);
259 assert(ctx);
260
261 /*
262 * While a stream is available from ustctl. When NULL is returned, we've
263 * reached the end of the possible stream for the channel.
264 */
265 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
266 int wait_fd;
267
268 wait_fd = ustctl_stream_get_wait_fd(ustream);
269
270 /* Allocate consumer stream object. */
271 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
272 if (!stream) {
273 goto error_alloc;
274 }
275 stream->ustream = ustream;
276 /*
277 * Store it so we can save multiple function calls afterwards since
278 * this value is used heavily in the stream threads. This is UST
279 * specific so this is why it's done after allocation.
280 */
281 stream->wait_fd = wait_fd;
282
283 /*
284 * Increment channel refcount since the channel reference has now been
285 * assigned in the allocation process above.
286 */
287 uatomic_inc(&stream->chan->refcount);
288
289 /*
290 * Order is important this is why a list is used. On error, the caller
291 * should clean this list.
292 */
293 cds_list_add_tail(&stream->send_node, &channel->streams.head);
294
295 ret = ustctl_get_max_subbuf_size(stream->ustream,
296 &stream->max_sb_size);
297 if (ret < 0) {
298 ERR("ustctl_get_max_subbuf_size failed for stream %s",
299 stream->name);
300 goto error;
301 }
302
303 /* Do actions once stream has been received. */
304 if (ctx->on_recv_stream) {
305 ret = ctx->on_recv_stream(stream);
306 if (ret < 0) {
307 goto error;
308 }
309 }
310
311 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
312 stream->name, stream->key, stream->relayd_stream_id);
313
314 /* Set next CPU stream. */
315 channel->streams.count = ++cpu;
316
317 /* Keep stream reference when creating metadata. */
318 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
319 channel->metadata_stream = stream;
320 }
321 }
322
323 return 0;
324
325 error:
326 error_alloc:
327 return ret;
328 }
329
330 /*
331 * Create an UST channel with the given attributes and send it to the session
332 * daemon using the ust ctl API.
333 *
334 * Return 0 on success or else a negative value.
335 */
336 static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
337 struct ustctl_consumer_channel **chanp)
338 {
339 int ret;
340 struct ustctl_consumer_channel *channel;
341
342 assert(attr);
343 assert(chanp);
344
345 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
346 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
347 "switch_timer_interval: %u, read_timer_interval: %u, "
348 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
349 attr->num_subbuf, attr->switch_timer_interval,
350 attr->read_timer_interval, attr->output, attr->type);
351
352 channel = ustctl_create_channel(attr);
353 if (!channel) {
354 ret = -1;
355 goto error_create;
356 }
357
358 *chanp = channel;
359
360 return 0;
361
362 error_create:
363 return ret;
364 }
365
366 /*
367 * Send a single given stream to the session daemon using the sock.
368 *
369 * Return 0 on success else a negative value.
370 */
371 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
372 {
373 int ret;
374
375 assert(stream);
376 assert(sock >= 0);
377
378 DBG2("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
379
380 /* Send stream to session daemon. */
381 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
382 if (ret < 0) {
383 goto error;
384 }
385
386 error:
387 return ret;
388 }
389
390 /*
391 * Send channel to sessiond.
392 *
393 * Return 0 on success or else a negative value.
394 */
395 static int send_sessiond_channel(int sock,
396 struct lttng_consumer_channel *channel,
397 struct lttng_consumer_local_data *ctx, int *relayd_error)
398 {
399 int ret, ret_code = LTTNG_OK;
400 struct lttng_consumer_stream *stream;
401
402 assert(channel);
403 assert(ctx);
404 assert(sock >= 0);
405
406 DBG("UST consumer sending channel %s to sessiond", channel->name);
407
408 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
409 /* Try to send the stream to the relayd if one is available. */
410 ret = send_stream_to_relayd(stream);
411 if (ret < 0) {
412 /*
413 * Flag that the relayd was the problem here probably due to a
414 * communicaton error on the socket.
415 */
416 if (relayd_error) {
417 *relayd_error = 1;
418 }
419 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
420 }
421 }
422
423 /* Inform sessiond that we are about to send channel and streams. */
424 ret = consumer_send_status_msg(sock, ret_code);
425 if (ret < 0 || ret_code != LTTNG_OK) {
426 /*
427 * Either the session daemon is not responding or the relayd died so we
428 * stop now.
429 */
430 goto error;
431 }
432
433 /* Send channel to sessiond. */
434 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
435 if (ret < 0) {
436 goto error;
437 }
438
439 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
440 if (ret < 0) {
441 goto error;
442 }
443
444 /* The channel was sent successfully to the sessiond at this point. */
445 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
446 /* Send stream to session daemon. */
447 ret = send_sessiond_stream(sock, stream);
448 if (ret < 0) {
449 goto error;
450 }
451 }
452
453 /* Tell sessiond there is no more stream. */
454 ret = ustctl_send_stream_to_sessiond(sock, NULL);
455 if (ret < 0) {
456 goto error;
457 }
458
459 DBG("UST consumer NULL stream sent to sessiond");
460
461 return 0;
462
463 error:
464 if (ret_code != LTTNG_OK) {
465 ret = -1;
466 }
467 return ret;
468 }
469
470 /*
471 * Creates a channel and streams and add the channel it to the channel internal
472 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
473 * received.
474 *
475 * Return 0 on success or else, a negative value is returned and the channel
476 * MUST be destroyed by consumer_del_channel().
477 */
478 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
479 struct lttng_consumer_channel *channel,
480 struct ustctl_consumer_channel_attr *attr)
481 {
482 int ret;
483
484 assert(ctx);
485 assert(channel);
486 assert(attr);
487
488 /*
489 * This value is still used by the kernel consumer since for the kernel,
490 * the stream ownership is not IN the consumer so we need to have the
491 * number of left stream that needs to be initialized so we can know when
492 * to delete the channel (see consumer.c).
493 *
494 * As for the user space tracer now, the consumer creates and sends the
495 * stream to the session daemon which only sends them to the application
496 * once every stream of a channel is received making this value useless
497 * because we they will be added to the poll thread before the application
498 * receives them. This ensures that a stream can not hang up during
499 * initilization of a channel.
500 */
501 channel->nb_init_stream_left = 0;
502
503 /* The reply msg status is handled in the following call. */
504 ret = create_ust_channel(attr, &channel->uchan);
505 if (ret < 0) {
506 goto error;
507 }
508
509 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
510
511 /* Open all streams for this channel. */
512 ret = create_ust_streams(channel, ctx);
513 if (ret < 0) {
514 goto error;
515 }
516
517 error:
518 return ret;
519 }
520
521 /*
522 * Send all stream of a channel to the right thread handling it.
523 *
524 * On error, return a negative value else 0 on success.
525 */
526 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
527 struct lttng_consumer_local_data *ctx)
528 {
529 int ret = 0;
530 struct lttng_consumer_stream *stream, *stmp;
531
532 assert(channel);
533 assert(ctx);
534
535 /* Send streams to the corresponding thread. */
536 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
537 send_node) {
538 /* Sending the stream to the thread. */
539 ret = send_stream_to_thread(stream, ctx);
540 if (ret < 0) {
541 /*
542 * If we are unable to send the stream to the thread, there is
543 * a big problem so just stop everything.
544 */
545 goto error;
546 }
547
548 /* Remove node from the channel stream list. */
549 cds_list_del(&stream->send_node);
550 }
551
552 error:
553 return ret;
554 }
555
556 /*
557 * Write metadata to the given channel using ustctl to convert the string to
558 * the ringbuffer.
559 * Called only from consumer_metadata_cache_write.
560 * The metadata cache lock MUST be acquired to write in the cache.
561 *
562 * Return 0 on success else a negative value.
563 */
564 int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel *metadata,
565 const char *metadata_str, uint64_t target_offset, uint64_t len)
566 {
567 int ret;
568
569 assert(metadata);
570 assert(metadata_str);
571
572 DBG("UST consumer writing metadata to channel %s", metadata->name);
573
574 if (!metadata->metadata_stream) {
575 ret = 0;
576 goto error;
577 }
578
579 assert(target_offset <= metadata->metadata_cache->max_offset);
580 ret = ustctl_write_metadata_to_channel(metadata->uchan,
581 metadata_str + target_offset, len);
582 if (ret < 0) {
583 ERR("ustctl write metadata fail with ret %d, len %" PRIu64, ret, len);
584 goto error;
585 }
586
587 ustctl_flush_buffer(metadata->metadata_stream->ustream, 1);
588
589 error:
590 return ret;
591 }
592
593 /*
594 * Flush channel's streams using the given key to retrieve the channel.
595 *
596 * Return 0 on success else an LTTng error code.
597 */
598 static int flush_channel(uint64_t chan_key)
599 {
600 int ret = 0;
601 struct lttng_consumer_channel *channel;
602 struct lttng_consumer_stream *stream;
603 struct lttng_ht *ht;
604 struct lttng_ht_iter iter;
605
606 DBG("UST consumer flush channel key %" PRIu64, chan_key);
607
608 rcu_read_lock();
609 channel = consumer_find_channel(chan_key);
610 if (!channel) {
611 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
612 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
613 goto error;
614 }
615
616 ht = consumer_data.stream_per_chan_id_ht;
617
618 /* For each stream of the channel id, flush it. */
619 cds_lfht_for_each_entry_duplicate(ht->ht,
620 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
621 &channel->key, &iter.iter, stream, node_channel_id.node) {
622 ustctl_flush_buffer(stream->ustream, 1);
623 }
624 error:
625 rcu_read_unlock();
626 return ret;
627 }
628
629 /*
630 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
631 * RCU read side lock MUST be acquired before calling this function.
632 *
633 * Return 0 on success else an LTTng error code.
634 */
635 static int close_metadata(uint64_t chan_key)
636 {
637 int ret = 0;
638 struct lttng_consumer_channel *channel;
639
640 DBG("UST consumer close metadata key %" PRIu64, chan_key);
641
642 channel = consumer_find_channel(chan_key);
643 if (!channel) {
644 /*
645 * This is possible if the metadata thread has issue a delete because
646 * the endpoint point of the stream hung up. There is no way the
647 * session daemon can know about it thus use a DBG instead of an actual
648 * error.
649 */
650 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
651 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
652 goto error;
653 }
654
655 pthread_mutex_lock(&consumer_data.lock);
656
657 if (cds_lfht_is_node_deleted(&channel->node.node)) {
658 goto error_unlock;
659 }
660
661 if (channel->switch_timer_enabled == 1) {
662 DBG("Deleting timer on metadata channel");
663 consumer_timer_switch_stop(channel);
664 }
665
666 if (channel->metadata_stream) {
667 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
668 if (ret < 0) {
669 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
670 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
671 goto error_unlock;
672 }
673 }
674
675 error_unlock:
676 pthread_mutex_unlock(&consumer_data.lock);
677 error:
678 return ret;
679 }
680
681 /*
682 * RCU read side lock MUST be acquired before calling this function.
683 *
684 * Return 0 on success else an LTTng error code.
685 */
686 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
687 {
688 int ret;
689 struct lttng_consumer_channel *metadata;
690
691 DBG("UST consumer setup metadata key %" PRIu64, key);
692
693 metadata = consumer_find_channel(key);
694 if (!metadata) {
695 ERR("UST consumer push metadata %" PRIu64 " not found", key);
696 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
697 goto error_find;
698 }
699
700 /*
701 * Send metadata stream to relayd if one available. Availability is
702 * known if the stream is still in the list of the channel.
703 */
704 if (cds_list_empty(&metadata->streams.head)) {
705 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
706 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
707 goto error;
708 }
709
710 /* Send metadata stream to relayd if needed. */
711 ret = send_stream_to_relayd(metadata->metadata_stream);
712 if (ret < 0) {
713 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
714 goto error;
715 }
716
717 ret = send_streams_to_thread(metadata, ctx);
718 if (ret < 0) {
719 /*
720 * If we are unable to send the stream to the thread, there is
721 * a big problem so just stop everything.
722 */
723 ret = LTTCOMM_CONSUMERD_FATAL;
724 goto error;
725 }
726 /* List MUST be empty after or else it could be reused. */
727 assert(cds_list_empty(&metadata->streams.head));
728
729 return 0;
730
731 error:
732 /*
733 * Delete metadata channel on error. At this point, the metadata stream can
734 * NOT be monitored by the metadata thread thus having the guarantee that
735 * the stream is still in the local stream list of the channel. This call
736 * will make sure to clean that list.
737 */
738 consumer_del_channel(metadata);
739 error_find:
740 return ret;
741 }
742
743 /*
744 * Receive the metadata updates from the sessiond.
745 */
746 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
747 uint64_t len, struct lttng_consumer_channel *channel)
748 {
749 int ret, ret_code = LTTNG_OK;
750 char *metadata_str;
751
752 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
753
754 metadata_str = zmalloc(len * sizeof(char));
755 if (!metadata_str) {
756 PERROR("zmalloc metadata string");
757 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
758 goto end;
759 }
760
761 /* Receive metadata string. */
762 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
763 if (ret < 0) {
764 /* Session daemon is dead so return gracefully. */
765 ret_code = ret;
766 goto end_free;
767 }
768
769 /*
770 * XXX: The consumer data lock is acquired before calling metadata cache
771 * write which calls push metadata that MUST be protected by the consumer
772 * lock in order to be able to check the validity of the metadata stream of
773 * the channel.
774 *
775 * Note that this will be subject to change to better fine grained locking
776 * and ultimately try to get rid of this global consumer data lock.
777 */
778 pthread_mutex_lock(&consumer_data.lock);
779
780 pthread_mutex_lock(&channel->metadata_cache->lock);
781 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
782 if (ret < 0) {
783 /* Unable to handle metadata. Notify session daemon. */
784 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
785 /*
786 * Skip metadata flush on write error since the offset and len might
787 * not have been updated which could create an infinite loop below when
788 * waiting for the metadata cache to be flushed.
789 */
790 pthread_mutex_unlock(&channel->metadata_cache->lock);
791 pthread_mutex_unlock(&consumer_data.lock);
792 goto end_free;
793 }
794 pthread_mutex_unlock(&channel->metadata_cache->lock);
795 pthread_mutex_unlock(&consumer_data.lock);
796
797 while (consumer_metadata_cache_flushed(channel, offset + len)) {
798 DBG("Waiting for metadata to be flushed");
799 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
800 }
801
802 end_free:
803 free(metadata_str);
804 end:
805 return ret_code;
806 }
807
808 /*
809 * Receive command from session daemon and process it.
810 *
811 * Return 1 on success else a negative value or 0.
812 */
813 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
814 int sock, struct pollfd *consumer_sockpoll)
815 {
816 ssize_t ret;
817 enum lttng_error_code ret_code = LTTNG_OK;
818 struct lttcomm_consumer_msg msg;
819 struct lttng_consumer_channel *channel = NULL;
820
821 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
822 if (ret != sizeof(msg)) {
823 DBG("Consumer received unexpected message size %zd (expects %zu)",
824 ret, sizeof(msg));
825 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
826 /*
827 * The ret value might 0 meaning an orderly shutdown but this is ok
828 * since the caller handles this.
829 */
830 if (ret > 0) {
831 ret = -1;
832 }
833 return ret;
834 }
835 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
836 /*
837 * Notify the session daemon that the command is completed.
838 *
839 * On transport layer error, the function call will print an error
840 * message so handling the returned code is a bit useless since we
841 * return an error code anyway.
842 */
843 (void) consumer_send_status_msg(sock, ret_code);
844 return -ENOENT;
845 }
846
847 /* relayd needs RCU read-side lock */
848 rcu_read_lock();
849
850 switch (msg.cmd_type) {
851 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
852 {
853 /* Session daemon status message are handled in the following call. */
854 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
855 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
856 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
857 goto end_nosignal;
858 }
859 case LTTNG_CONSUMER_DESTROY_RELAYD:
860 {
861 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
862 struct consumer_relayd_sock_pair *relayd;
863
864 DBG("UST consumer destroying relayd %" PRIu64, index);
865
866 /* Get relayd reference if exists. */
867 relayd = consumer_find_relayd(index);
868 if (relayd == NULL) {
869 DBG("Unable to find relayd %" PRIu64, index);
870 ret_code = LTTNG_ERR_NO_CONSUMER;
871 }
872
873 /*
874 * Each relayd socket pair has a refcount of stream attached to it
875 * which tells if the relayd is still active or not depending on the
876 * refcount value.
877 *
878 * This will set the destroy flag of the relayd object and destroy it
879 * if the refcount reaches zero when called.
880 *
881 * The destroy can happen either here or when a stream fd hangs up.
882 */
883 if (relayd) {
884 consumer_flag_relayd_for_destroy(relayd);
885 }
886
887 goto end_msg_sessiond;
888 }
889 case LTTNG_CONSUMER_UPDATE_STREAM:
890 {
891 rcu_read_unlock();
892 return -ENOSYS;
893 }
894 case LTTNG_CONSUMER_DATA_PENDING:
895 {
896 int ret, is_data_pending;
897 uint64_t id = msg.u.data_pending.session_id;
898
899 DBG("UST consumer data pending command for id %" PRIu64, id);
900
901 is_data_pending = consumer_data_pending(id);
902
903 /* Send back returned value to session daemon */
904 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
905 sizeof(is_data_pending));
906 if (ret < 0) {
907 DBG("Error when sending the data pending ret code: %d", ret);
908 goto error_fatal;
909 }
910
911 /*
912 * No need to send back a status message since the data pending
913 * returned value is the response.
914 */
915 break;
916 }
917 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
918 {
919 int ret;
920 struct ustctl_consumer_channel_attr attr;
921
922 /* Create a plain object and reserve a channel key. */
923 channel = allocate_channel(msg.u.ask_channel.session_id,
924 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
925 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
926 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
927 (enum lttng_event_output) msg.u.ask_channel.output,
928 msg.u.ask_channel.tracefile_size,
929 msg.u.ask_channel.tracefile_count,
930 msg.u.ask_channel.session_id_per_pid,
931 msg.u.ask_channel.monitor);
932 if (!channel) {
933 goto end_channel_error;
934 }
935
936 /* Build channel attributes from received message. */
937 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
938 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
939 attr.overwrite = msg.u.ask_channel.overwrite;
940 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
941 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
942 attr.chan_id = msg.u.ask_channel.chan_id;
943 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
944
945 /* Translate the event output type to UST. */
946 switch (channel->output) {
947 case LTTNG_EVENT_SPLICE:
948 /* Splice not supported so fallback on mmap(). */
949 case LTTNG_EVENT_MMAP:
950 default:
951 attr.output = CONSUMER_CHANNEL_MMAP;
952 break;
953 };
954
955 /* Translate and save channel type. */
956 switch (msg.u.ask_channel.type) {
957 case LTTNG_UST_CHAN_PER_CPU:
958 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
959 attr.type = LTTNG_UST_CHAN_PER_CPU;
960 /*
961 * Set refcount to 1 for owner. Below, we will
962 * pass ownership to the
963 * consumer_thread_channel_poll() thread.
964 */
965 channel->refcount = 1;
966 break;
967 case LTTNG_UST_CHAN_METADATA:
968 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
969 attr.type = LTTNG_UST_CHAN_METADATA;
970 break;
971 default:
972 assert(0);
973 goto error_fatal;
974 };
975
976 ret = ask_channel(ctx, sock, channel, &attr);
977 if (ret < 0) {
978 goto end_channel_error;
979 }
980
981 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
982 ret = consumer_metadata_cache_allocate(channel);
983 if (ret < 0) {
984 ERR("Allocating metadata cache");
985 goto end_channel_error;
986 }
987 consumer_timer_switch_start(channel, attr.switch_timer_interval);
988 attr.switch_timer_interval = 0;
989 }
990
991 /*
992 * Add the channel to the internal state AFTER all streams were created
993 * and successfully sent to session daemon. This way, all streams must
994 * be ready before this channel is visible to the threads.
995 * If add_channel succeeds, ownership of the channel is
996 * passed to consumer_thread_channel_poll().
997 */
998 ret = add_channel(channel, ctx);
999 if (ret < 0) {
1000 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1001 if (channel->switch_timer_enabled == 1) {
1002 consumer_timer_switch_stop(channel);
1003 }
1004 consumer_metadata_cache_destroy(channel);
1005 }
1006 goto end_channel_error;
1007 }
1008
1009 /*
1010 * Channel and streams are now created. Inform the session daemon that
1011 * everything went well and should wait to receive the channel and
1012 * streams with ustctl API.
1013 */
1014 ret = consumer_send_status_channel(sock, channel);
1015 if (ret < 0) {
1016 /*
1017 * There is probably a problem on the socket.
1018 */
1019 goto error_fatal;
1020 }
1021
1022 break;
1023 }
1024 case LTTNG_CONSUMER_GET_CHANNEL:
1025 {
1026 int ret, relayd_err = 0;
1027 uint64_t key = msg.u.get_channel.key;
1028 struct lttng_consumer_channel *channel;
1029
1030 channel = consumer_find_channel(key);
1031 if (!channel) {
1032 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1033 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1034 goto end_msg_sessiond;
1035 }
1036
1037 /* Send everything to sessiond. */
1038 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1039 if (ret < 0) {
1040 if (relayd_err) {
1041 /*
1042 * We were unable to send to the relayd the stream so avoid
1043 * sending back a fatal error to the thread since this is OK
1044 * and the consumer can continue its work. The above call
1045 * has sent the error status message to the sessiond.
1046 */
1047 goto end_nosignal;
1048 }
1049 /*
1050 * The communicaton was broken hence there is a bad state between
1051 * the consumer and sessiond so stop everything.
1052 */
1053 goto error_fatal;
1054 }
1055
1056 ret = send_streams_to_thread(channel, ctx);
1057 if (ret < 0) {
1058 /*
1059 * If we are unable to send the stream to the thread, there is
1060 * a big problem so just stop everything.
1061 */
1062 goto error_fatal;
1063 }
1064 /* List MUST be empty after or else it could be reused. */
1065 assert(cds_list_empty(&channel->streams.head));
1066
1067 goto end_msg_sessiond;
1068 }
1069 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1070 {
1071 uint64_t key = msg.u.destroy_channel.key;
1072
1073 /*
1074 * Only called if streams have not been sent to stream
1075 * manager thread. However, channel has been sent to
1076 * channel manager thread.
1077 */
1078 notify_thread_del_channel(ctx, key);
1079 goto end_msg_sessiond;
1080 }
1081 case LTTNG_CONSUMER_CLOSE_METADATA:
1082 {
1083 int ret;
1084
1085 ret = close_metadata(msg.u.close_metadata.key);
1086 if (ret != 0) {
1087 ret_code = ret;
1088 }
1089
1090 goto end_msg_sessiond;
1091 }
1092 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1093 {
1094 int ret;
1095
1096 ret = flush_channel(msg.u.flush_channel.key);
1097 if (ret != 0) {
1098 ret_code = ret;
1099 }
1100
1101 goto end_msg_sessiond;
1102 }
1103 case LTTNG_CONSUMER_PUSH_METADATA:
1104 {
1105 int ret;
1106 uint64_t len = msg.u.push_metadata.len;
1107 uint64_t key = msg.u.push_metadata.key;
1108 uint64_t offset = msg.u.push_metadata.target_offset;
1109 struct lttng_consumer_channel *channel;
1110
1111 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1112 len);
1113
1114 channel = consumer_find_channel(key);
1115 if (!channel) {
1116 ERR("UST consumer push metadata %" PRIu64 " not found", key);
1117 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1118 goto end_msg_sessiond;
1119 }
1120
1121 /* Tell session daemon we are ready to receive the metadata. */
1122 ret = consumer_send_status_msg(sock, LTTNG_OK);
1123 if (ret < 0) {
1124 /* Somehow, the session daemon is not responding anymore. */
1125 goto error_fatal;
1126 }
1127
1128 /* Wait for more data. */
1129 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
1130 goto error_fatal;
1131 }
1132
1133 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1134 len, channel);
1135 if (ret < 0) {
1136 /* error receiving from sessiond */
1137 goto error_fatal;
1138 } else {
1139 ret_code = ret;
1140 goto end_msg_sessiond;
1141 }
1142 }
1143 case LTTNG_CONSUMER_SETUP_METADATA:
1144 {
1145 int ret;
1146
1147 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1148 if (ret) {
1149 ret_code = ret;
1150 }
1151 goto end_msg_sessiond;
1152 }
1153 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1154 {
1155 ret = consumer_send_status_msg(sock, ret_code);
1156 if (ret < 0) {
1157 /* Somehow, the session daemon is not responding anymore. */
1158 goto end_nosignal;
1159 }
1160 break;
1161 }
1162 default:
1163 break;
1164 }
1165
1166 end_nosignal:
1167 rcu_read_unlock();
1168
1169 /*
1170 * Return 1 to indicate success since the 0 value can be a socket
1171 * shutdown during the recv() or send() call.
1172 */
1173 return 1;
1174
1175 end_msg_sessiond:
1176 /*
1177 * The returned value here is not useful since either way we'll return 1 to
1178 * the caller because the session daemon socket management is done
1179 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1180 */
1181 ret = consumer_send_status_msg(sock, ret_code);
1182 if (ret < 0) {
1183 goto error_fatal;
1184 }
1185 rcu_read_unlock();
1186 return 1;
1187 end_channel_error:
1188 if (channel) {
1189 /*
1190 * Free channel here since no one has a reference to it. We don't
1191 * free after that because a stream can store this pointer.
1192 */
1193 destroy_channel(channel);
1194 }
1195 /* We have to send a status channel message indicating an error. */
1196 ret = consumer_send_status_channel(sock, NULL);
1197 if (ret < 0) {
1198 /* Stop everything if session daemon can not be notified. */
1199 goto error_fatal;
1200 }
1201 rcu_read_unlock();
1202 return 1;
1203 error_fatal:
1204 rcu_read_unlock();
1205 /* This will issue a consumer stop. */
1206 return -1;
1207 }
1208
1209 /*
1210 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1211 * compiled out, we isolate it in this library.
1212 */
1213 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1214 unsigned long *off)
1215 {
1216 assert(stream);
1217 assert(stream->ustream);
1218
1219 return ustctl_get_mmap_read_offset(stream->ustream, off);
1220 }
1221
1222 /*
1223 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1224 * compiled out, we isolate it in this library.
1225 */
1226 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1227 {
1228 assert(stream);
1229 assert(stream->ustream);
1230
1231 return ustctl_get_mmap_base(stream->ustream);
1232 }
1233
1234 /*
1235 * Take a snapshot for a specific fd
1236 *
1237 * Returns 0 on success, < 0 on error
1238 */
1239 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1240 {
1241 assert(stream);
1242 assert(stream->ustream);
1243
1244 return ustctl_snapshot(stream->ustream);
1245 }
1246
1247 /*
1248 * Get the produced position
1249 *
1250 * Returns 0 on success, < 0 on error
1251 */
1252 int lttng_ustconsumer_get_produced_snapshot(
1253 struct lttng_consumer_stream *stream, unsigned long *pos)
1254 {
1255 assert(stream);
1256 assert(stream->ustream);
1257 assert(pos);
1258
1259 return ustctl_snapshot_get_produced(stream->ustream, pos);
1260 }
1261
1262 /*
1263 * Called when the stream signal the consumer that it has hang up.
1264 */
1265 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1266 {
1267 assert(stream);
1268 assert(stream->ustream);
1269
1270 ustctl_flush_buffer(stream->ustream, 0);
1271 stream->hangup_flush_done = 1;
1272 }
1273
1274 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1275 {
1276 assert(chan);
1277 assert(chan->uchan);
1278
1279 if (chan->switch_timer_enabled == 1) {
1280 consumer_timer_switch_stop(chan);
1281 }
1282 consumer_metadata_cache_destroy(chan);
1283 ustctl_destroy_channel(chan->uchan);
1284 }
1285
1286 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1287 {
1288 assert(stream);
1289 assert(stream->ustream);
1290
1291 if (stream->chan->switch_timer_enabled == 1) {
1292 consumer_timer_switch_stop(stream->chan);
1293 }
1294 ustctl_destroy_stream(stream->ustream);
1295 }
1296
1297 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1298 struct lttng_consumer_local_data *ctx)
1299 {
1300 unsigned long len, subbuf_size, padding;
1301 int err;
1302 long ret = 0;
1303 char dummy;
1304 struct ustctl_consumer_stream *ustream;
1305
1306 assert(stream);
1307 assert(stream->ustream);
1308 assert(ctx);
1309
1310 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1311 stream->name);
1312
1313 /* Ease our life for what's next. */
1314 ustream = stream->ustream;
1315
1316 /* We can consume the 1 byte written into the wait_fd by UST */
1317 if (!stream->hangup_flush_done) {
1318 ssize_t readlen;
1319
1320 do {
1321 readlen = read(stream->wait_fd, &dummy, 1);
1322 } while (readlen == -1 && errno == EINTR);
1323 if (readlen == -1) {
1324 ret = readlen;
1325 goto end;
1326 }
1327 }
1328
1329 /* Get the next subbuffer */
1330 err = ustctl_get_next_subbuf(ustream);
1331 if (err != 0) {
1332 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1333 /*
1334 * This is a debug message even for single-threaded consumer,
1335 * because poll() have more relaxed criterions than get subbuf,
1336 * so get_subbuf may fail for short race windows where poll()
1337 * would issue wakeups.
1338 */
1339 DBG("Reserving sub buffer failed (everything is normal, "
1340 "it is due to concurrency) [ret: %d]", err);
1341 goto end;
1342 }
1343 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1344 /* Get the full padded subbuffer size */
1345 err = ustctl_get_padded_subbuf_size(ustream, &len);
1346 assert(err == 0);
1347
1348 /* Get subbuffer data size (without padding) */
1349 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1350 assert(err == 0);
1351
1352 /* Make sure we don't get a subbuffer size bigger than the padded */
1353 assert(len >= subbuf_size);
1354
1355 padding = len - subbuf_size;
1356 /* write the subbuffer to the tracefile */
1357 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
1358 /*
1359 * The mmap operation should write subbuf_size amount of data when network
1360 * streaming or the full padding (len) size when we are _not_ streaming.
1361 */
1362 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1363 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
1364 /*
1365 * Display the error but continue processing to try to release the
1366 * subbuffer. This is a DBG statement since any unexpected kill or
1367 * signal, the application gets unregistered, relayd gets closed or
1368 * anything that affects the buffer lifetime will trigger this error.
1369 * So, for the sake of the user, don't print this error since it can
1370 * happen and it is OK with the code flow.
1371 */
1372 DBG("Error writing to tracefile "
1373 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1374 ret, len, subbuf_size);
1375 }
1376 err = ustctl_put_next_subbuf(ustream);
1377 assert(err == 0);
1378
1379 end:
1380 return ret;
1381 }
1382
1383 /*
1384 * Called when a stream is created.
1385 *
1386 * Return 0 on success or else a negative value.
1387 */
1388 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
1389 {
1390 int ret;
1391
1392 /* Don't create anything if this is set for streaming. */
1393 if (stream->net_seq_idx == (uint64_t) -1ULL) {
1394 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
1395 stream->chan->tracefile_size, stream->tracefile_count_current,
1396 stream->uid, stream->gid);
1397 if (ret < 0) {
1398 goto error;
1399 }
1400 stream->out_fd = ret;
1401 stream->tracefile_size_current = 0;
1402 }
1403 ret = 0;
1404
1405 error:
1406 return ret;
1407 }
1408
1409 /*
1410 * Check if data is still being extracted from the buffers for a specific
1411 * stream. Consumer data lock MUST be acquired before calling this function
1412 * and the stream lock.
1413 *
1414 * Return 1 if the traced data are still getting read else 0 meaning that the
1415 * data is available for trace viewer reading.
1416 */
1417 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
1418 {
1419 int ret;
1420
1421 assert(stream);
1422 assert(stream->ustream);
1423
1424 DBG("UST consumer checking data pending");
1425
1426 ret = ustctl_get_next_subbuf(stream->ustream);
1427 if (ret == 0) {
1428 /* There is still data so let's put back this subbuffer. */
1429 ret = ustctl_put_subbuf(stream->ustream);
1430 assert(ret == 0);
1431 ret = 1; /* Data is pending */
1432 goto end;
1433 }
1434
1435 /* Data is NOT pending so ready to be read. */
1436 ret = 0;
1437
1438 end:
1439 return ret;
1440 }
1441
1442 /*
1443 * Close every metadata stream wait fd of the metadata hash table. This
1444 * function MUST be used very carefully so not to run into a race between the
1445 * metadata thread handling streams and this function closing their wait fd.
1446 *
1447 * For UST, this is used when the session daemon hangs up. Its the metadata
1448 * producer so calling this is safe because we are assured that no state change
1449 * can occur in the metadata thread for the streams in the hash table.
1450 */
1451 void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
1452 {
1453 int ret;
1454 struct lttng_ht_iter iter;
1455 struct lttng_consumer_stream *stream;
1456
1457 assert(metadata_ht);
1458 assert(metadata_ht->ht);
1459
1460 DBG("UST consumer closing all metadata streams");
1461
1462 rcu_read_lock();
1463 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
1464 node.node) {
1465 int fd = stream->wait_fd;
1466
1467 /*
1468 * Whatever happens here we have to continue to try to close every
1469 * streams. Let's report at least the error on failure.
1470 */
1471 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1472 if (ret) {
1473 ERR("Unable to close metadata stream fd %d ret %d", fd, ret);
1474 }
1475 DBG("Metadata wait fd %d closed", fd);
1476 }
1477 rcu_read_unlock();
1478 }
1479
1480 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
1481 {
1482 int ret;
1483
1484 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1485 if (ret < 0) {
1486 ERR("Unable to close wakeup fd");
1487 }
1488 }
1489
1490 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
1491 struct lttng_consumer_channel *channel)
1492 {
1493 struct lttcomm_metadata_request_msg request;
1494 struct lttcomm_consumer_msg msg;
1495 enum lttng_error_code ret_code = LTTNG_OK;
1496 uint64_t len, key, offset;
1497 int ret;
1498
1499 assert(channel);
1500 assert(channel->metadata_cache);
1501
1502 /* send the metadata request to sessiond */
1503 switch (consumer_data.type) {
1504 case LTTNG_CONSUMER64_UST:
1505 request.bits_per_long = 64;
1506 break;
1507 case LTTNG_CONSUMER32_UST:
1508 request.bits_per_long = 32;
1509 break;
1510 default:
1511 request.bits_per_long = 0;
1512 break;
1513 }
1514
1515 request.session_id = channel->session_id;
1516 request.session_id_per_pid = channel->session_id_per_pid;
1517 request.uid = channel->uid;
1518 request.key = channel->key;
1519 DBG("Sending metadata request to sessiond, session id %" PRIu64
1520 ", per-pid %" PRIu64,
1521 channel->session_id,
1522 channel->session_id_per_pid);
1523
1524 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
1525 sizeof(request));
1526 if (ret < 0) {
1527 ERR("Asking metadata to sessiond");
1528 goto end;
1529 }
1530
1531 /* Receive the metadata from sessiond */
1532 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
1533 sizeof(msg));
1534 if (ret != sizeof(msg)) {
1535 DBG("Consumer received unexpected message size %d (expects %zu)",
1536 ret, sizeof(msg));
1537 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1538 /*
1539 * The ret value might 0 meaning an orderly shutdown but this is ok
1540 * since the caller handles this.
1541 */
1542 goto end;
1543 }
1544
1545 if (msg.cmd_type == LTTNG_ERR_UND) {
1546 /* No registry found */
1547 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
1548 ret_code);
1549 ret = 0;
1550 goto end;
1551 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
1552 ERR("Unexpected cmd_type received %d", msg.cmd_type);
1553 ret = -1;
1554 goto end;
1555 }
1556
1557 len = msg.u.push_metadata.len;
1558 key = msg.u.push_metadata.key;
1559 offset = msg.u.push_metadata.target_offset;
1560
1561 assert(key == channel->key);
1562 if (len == 0) {
1563 DBG("No new metadata to receive for key %" PRIu64, key);
1564 }
1565
1566 /* Tell session daemon we are ready to receive the metadata. */
1567 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
1568 LTTNG_OK);
1569 if (ret < 0 || len == 0) {
1570 /*
1571 * Somehow, the session daemon is not responding anymore or there is
1572 * nothing to receive.
1573 */
1574 goto end;
1575 }
1576
1577 ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
1578 key, offset, len, channel);
1579 if (ret_code >= 0) {
1580 /*
1581 * Only send the status msg if the sessiond is alive meaning a positive
1582 * ret code.
1583 */
1584 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
1585 }
1586 ret = 0;
1587
1588 end:
1589 return ret;
1590 }
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