61b220ee012a76930d3149be0eba07ba2fef919b
[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-stream.h>
41 #include <common/consumer-timer.h>
42 #include <common/utils.h>
43
44 #include "ust-consumer.h"
45
46 extern struct lttng_consumer_global_data consumer_data;
47 extern int consumer_poll_timeout;
48 extern volatile int consumer_quit;
49
50 /*
51 * Free channel object and all streams associated with it. This MUST be used
52 * only and only if the channel has _NEVER_ been added to the global channel
53 * hash table.
54 */
55 static void destroy_channel(struct lttng_consumer_channel *channel)
56 {
57 struct lttng_consumer_stream *stream, *stmp;
58
59 assert(channel);
60
61 DBG("UST consumer cleaning stream list");
62
63 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
64 send_node) {
65 cds_list_del(&stream->send_node);
66 ustctl_destroy_stream(stream->ustream);
67 free(stream);
68 }
69
70 /*
71 * If a channel is available meaning that was created before the streams
72 * were, delete it.
73 */
74 if (channel->uchan) {
75 lttng_ustconsumer_del_channel(channel);
76 }
77 free(channel);
78 }
79
80 /*
81 * Add channel to internal consumer state.
82 *
83 * Returns 0 on success or else a negative value.
84 */
85 static int add_channel(struct lttng_consumer_channel *channel,
86 struct lttng_consumer_local_data *ctx)
87 {
88 int ret = 0;
89
90 assert(channel);
91 assert(ctx);
92
93 if (ctx->on_recv_channel != NULL) {
94 ret = ctx->on_recv_channel(channel);
95 if (ret == 0) {
96 ret = consumer_add_channel(channel, ctx);
97 } else if (ret < 0) {
98 /* Most likely an ENOMEM. */
99 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
100 goto error;
101 }
102 } else {
103 ret = consumer_add_channel(channel, ctx);
104 }
105
106 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
107
108 error:
109 return ret;
110 }
111
112 /*
113 * Allocate and return a consumer channel object.
114 */
115 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
116 const char *pathname, const char *name, uid_t uid, gid_t gid,
117 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
118 uint64_t tracefile_size, uint64_t tracefile_count,
119 uint64_t session_id_per_pid, unsigned int monitor)
120 {
121 assert(pathname);
122 assert(name);
123
124 return consumer_allocate_channel(key, session_id, pathname, name, uid,
125 gid, relayd_id, output, tracefile_size,
126 tracefile_count, session_id_per_pid, monitor);
127 }
128
129 /*
130 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
131 * error value if applicable is set in it else it is kept untouched.
132 *
133 * Return NULL on error else the newly allocated stream object.
134 */
135 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
136 struct lttng_consumer_channel *channel,
137 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
138 {
139 int alloc_ret;
140 struct lttng_consumer_stream *stream = NULL;
141
142 assert(channel);
143 assert(ctx);
144
145 stream = consumer_allocate_stream(channel->key,
146 key,
147 LTTNG_CONSUMER_ACTIVE_STREAM,
148 channel->name,
149 channel->uid,
150 channel->gid,
151 channel->relayd_id,
152 channel->session_id,
153 cpu,
154 &alloc_ret,
155 channel->type,
156 channel->monitor);
157 if (stream == NULL) {
158 switch (alloc_ret) {
159 case -ENOENT:
160 /*
161 * We could not find the channel. Can happen if cpu hotplug
162 * happens while tearing down.
163 */
164 DBG3("Could not find channel");
165 break;
166 case -ENOMEM:
167 case -EINVAL:
168 default:
169 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
170 break;
171 }
172 goto error;
173 }
174
175 stream->chan = channel;
176
177 error:
178 if (_alloc_ret) {
179 *_alloc_ret = alloc_ret;
180 }
181 return stream;
182 }
183
184 /*
185 * Send the given stream pointer to the corresponding thread.
186 *
187 * Returns 0 on success else a negative value.
188 */
189 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
190 struct lttng_consumer_local_data *ctx)
191 {
192 int ret;
193 struct lttng_pipe *stream_pipe;
194
195 /* Get the right pipe where the stream will be sent. */
196 if (stream->metadata_flag) {
197 stream_pipe = ctx->consumer_metadata_pipe;
198 } else {
199 stream_pipe = ctx->consumer_data_pipe;
200 }
201
202 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
203 if (ret < 0) {
204 ERR("Consumer write %s stream to pipe %d",
205 stream->metadata_flag ? "metadata" : "data",
206 lttng_pipe_get_writefd(stream_pipe));
207 }
208
209 return ret;
210 }
211
212 /*
213 * Create streams for the given channel using liblttng-ust-ctl.
214 *
215 * Return 0 on success else a negative value.
216 */
217 static int create_ust_streams(struct lttng_consumer_channel *channel,
218 struct lttng_consumer_local_data *ctx)
219 {
220 int ret, cpu = 0;
221 struct ustctl_consumer_stream *ustream;
222 struct lttng_consumer_stream *stream;
223
224 assert(channel);
225 assert(ctx);
226
227 /*
228 * While a stream is available from ustctl. When NULL is returned, we've
229 * reached the end of the possible stream for the channel.
230 */
231 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
232 int wait_fd;
233 int ust_metadata_pipe[2];
234
235 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
236 ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
237 if (ret < 0) {
238 ERR("Create ust metadata poll pipe");
239 goto error;
240 }
241 wait_fd = ust_metadata_pipe[0];
242 } else {
243 wait_fd = ustctl_stream_get_wait_fd(ustream);
244 }
245
246 /* Allocate consumer stream object. */
247 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
248 if (!stream) {
249 goto error_alloc;
250 }
251 stream->ustream = ustream;
252 /*
253 * Store it so we can save multiple function calls afterwards since
254 * this value is used heavily in the stream threads. This is UST
255 * specific so this is why it's done after allocation.
256 */
257 stream->wait_fd = wait_fd;
258
259 /*
260 * Increment channel refcount since the channel reference has now been
261 * assigned in the allocation process above.
262 */
263 if (stream->chan->monitor) {
264 uatomic_inc(&stream->chan->refcount);
265 }
266
267 /*
268 * Order is important this is why a list is used. On error, the caller
269 * should clean this list.
270 */
271 cds_list_add_tail(&stream->send_node, &channel->streams.head);
272
273 ret = ustctl_get_max_subbuf_size(stream->ustream,
274 &stream->max_sb_size);
275 if (ret < 0) {
276 ERR("ustctl_get_max_subbuf_size failed for stream %s",
277 stream->name);
278 goto error;
279 }
280
281 /* Do actions once stream has been received. */
282 if (ctx->on_recv_stream) {
283 ret = ctx->on_recv_stream(stream);
284 if (ret < 0) {
285 goto error;
286 }
287 }
288
289 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
290 stream->name, stream->key, stream->relayd_stream_id);
291
292 /* Set next CPU stream. */
293 channel->streams.count = ++cpu;
294
295 /* Keep stream reference when creating metadata. */
296 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
297 channel->metadata_stream = stream;
298 stream->ust_metadata_poll_pipe[0] = ust_metadata_pipe[0];
299 stream->ust_metadata_poll_pipe[1] = ust_metadata_pipe[1];
300 }
301 }
302
303 return 0;
304
305 error:
306 error_alloc:
307 return ret;
308 }
309
310 /*
311 * Create an UST channel with the given attributes and send it to the session
312 * daemon using the ust ctl API.
313 *
314 * Return 0 on success or else a negative value.
315 */
316 static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
317 struct ustctl_consumer_channel **chanp)
318 {
319 int ret;
320 struct ustctl_consumer_channel *channel;
321
322 assert(attr);
323 assert(chanp);
324
325 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
326 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
327 "switch_timer_interval: %u, read_timer_interval: %u, "
328 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
329 attr->num_subbuf, attr->switch_timer_interval,
330 attr->read_timer_interval, attr->output, attr->type);
331
332 channel = ustctl_create_channel(attr);
333 if (!channel) {
334 ret = -1;
335 goto error_create;
336 }
337
338 *chanp = channel;
339
340 return 0;
341
342 error_create:
343 return ret;
344 }
345
346 /*
347 * Send a single given stream to the session daemon using the sock.
348 *
349 * Return 0 on success else a negative value.
350 */
351 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
352 {
353 int ret;
354
355 assert(stream);
356 assert(sock >= 0);
357
358 DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
359
360 /* Send stream to session daemon. */
361 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
362 if (ret < 0) {
363 goto error;
364 }
365
366 error:
367 return ret;
368 }
369
370 /*
371 * Send channel to sessiond.
372 *
373 * Return 0 on success or else a negative value.
374 */
375 static int send_sessiond_channel(int sock,
376 struct lttng_consumer_channel *channel,
377 struct lttng_consumer_local_data *ctx, int *relayd_error)
378 {
379 int ret, ret_code = LTTNG_OK;
380 struct lttng_consumer_stream *stream;
381
382 assert(channel);
383 assert(ctx);
384 assert(sock >= 0);
385
386 DBG("UST consumer sending channel %s to sessiond", channel->name);
387
388 if (channel->relayd_id != (uint64_t) -1ULL) {
389 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
390 /* Try to send the stream to the relayd if one is available. */
391 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
392 if (ret < 0) {
393 /*
394 * Flag that the relayd was the problem here probably due to a
395 * communicaton error on the socket.
396 */
397 if (relayd_error) {
398 *relayd_error = 1;
399 }
400 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
401 }
402 }
403 }
404
405 /* Inform sessiond that we are about to send channel and streams. */
406 ret = consumer_send_status_msg(sock, ret_code);
407 if (ret < 0 || ret_code != LTTNG_OK) {
408 /*
409 * Either the session daemon is not responding or the relayd died so we
410 * stop now.
411 */
412 goto error;
413 }
414
415 /* Send channel to sessiond. */
416 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
417 if (ret < 0) {
418 goto error;
419 }
420
421 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
422 if (ret < 0) {
423 goto error;
424 }
425
426 /* The channel was sent successfully to the sessiond at this point. */
427 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
428 /* Send stream to session daemon. */
429 ret = send_sessiond_stream(sock, stream);
430 if (ret < 0) {
431 goto error;
432 }
433 }
434
435 /* Tell sessiond there is no more stream. */
436 ret = ustctl_send_stream_to_sessiond(sock, NULL);
437 if (ret < 0) {
438 goto error;
439 }
440
441 DBG("UST consumer NULL stream sent to sessiond");
442
443 return 0;
444
445 error:
446 if (ret_code != LTTNG_OK) {
447 ret = -1;
448 }
449 return ret;
450 }
451
452 /*
453 * Creates a channel and streams and add the channel it to the channel internal
454 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
455 * received.
456 *
457 * Return 0 on success or else, a negative value is returned and the channel
458 * MUST be destroyed by consumer_del_channel().
459 */
460 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
461 struct lttng_consumer_channel *channel,
462 struct ustctl_consumer_channel_attr *attr)
463 {
464 int ret;
465
466 assert(ctx);
467 assert(channel);
468 assert(attr);
469
470 /*
471 * This value is still used by the kernel consumer since for the kernel,
472 * the stream ownership is not IN the consumer so we need to have the
473 * number of left stream that needs to be initialized so we can know when
474 * to delete the channel (see consumer.c).
475 *
476 * As for the user space tracer now, the consumer creates and sends the
477 * stream to the session daemon which only sends them to the application
478 * once every stream of a channel is received making this value useless
479 * because we they will be added to the poll thread before the application
480 * receives them. This ensures that a stream can not hang up during
481 * initilization of a channel.
482 */
483 channel->nb_init_stream_left = 0;
484
485 /* The reply msg status is handled in the following call. */
486 ret = create_ust_channel(attr, &channel->uchan);
487 if (ret < 0) {
488 goto end;
489 }
490
491 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
492
493 /*
494 * For the snapshots (no monitor), we create the metadata streams
495 * on demand, not during the channel creation.
496 */
497 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
498 ret = 0;
499 goto end;
500 }
501
502 /* Open all streams for this channel. */
503 ret = create_ust_streams(channel, ctx);
504 if (ret < 0) {
505 goto end;
506 }
507
508 end:
509 return ret;
510 }
511
512 /*
513 * Send all stream of a channel to the right thread handling it.
514 *
515 * On error, return a negative value else 0 on success.
516 */
517 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
518 struct lttng_consumer_local_data *ctx)
519 {
520 int ret = 0;
521 struct lttng_consumer_stream *stream, *stmp;
522
523 assert(channel);
524 assert(ctx);
525
526 /* Send streams to the corresponding thread. */
527 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
528 send_node) {
529 /* Sending the stream to the thread. */
530 ret = send_stream_to_thread(stream, ctx);
531 if (ret < 0) {
532 /*
533 * If we are unable to send the stream to the thread, there is
534 * a big problem so just stop everything.
535 */
536 goto error;
537 }
538
539 /* Remove node from the channel stream list. */
540 cds_list_del(&stream->send_node);
541
542 /*
543 * From this point on, the stream's ownership has been moved away from
544 * the channel and becomes globally visible.
545 */
546 stream->globally_visible = 1;
547 }
548
549 error:
550 return ret;
551 }
552
553 /*
554 * Flush channel's streams using the given key to retrieve the channel.
555 *
556 * Return 0 on success else an LTTng error code.
557 */
558 static int flush_channel(uint64_t chan_key)
559 {
560 int ret = 0;
561 struct lttng_consumer_channel *channel;
562 struct lttng_consumer_stream *stream;
563 struct lttng_ht *ht;
564 struct lttng_ht_iter iter;
565
566 DBG("UST consumer flush channel key %" PRIu64, chan_key);
567
568 rcu_read_lock();
569 channel = consumer_find_channel(chan_key);
570 if (!channel) {
571 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
572 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
573 goto error;
574 }
575
576 ht = consumer_data.stream_per_chan_id_ht;
577
578 /* For each stream of the channel id, flush it. */
579 cds_lfht_for_each_entry_duplicate(ht->ht,
580 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
581 &channel->key, &iter.iter, stream, node_channel_id.node) {
582 ustctl_flush_buffer(stream->ustream, 1);
583 }
584 error:
585 rcu_read_unlock();
586 return ret;
587 }
588
589 /*
590 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
591 * RCU read side lock MUST be acquired before calling this function.
592 *
593 * Return 0 on success else an LTTng error code.
594 */
595 static int close_metadata(uint64_t chan_key)
596 {
597 int ret = 0;
598 struct lttng_consumer_channel *channel;
599
600 DBG("UST consumer close metadata key %" PRIu64, chan_key);
601
602 channel = consumer_find_channel(chan_key);
603 if (!channel) {
604 /*
605 * This is possible if the metadata thread has issue a delete because
606 * the endpoint point of the stream hung up. There is no way the
607 * session daemon can know about it thus use a DBG instead of an actual
608 * error.
609 */
610 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
611 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
612 goto error;
613 }
614
615 pthread_mutex_lock(&consumer_data.lock);
616 pthread_mutex_lock(&channel->lock);
617 pthread_mutex_lock(&channel->timer_lock);
618
619 if (cds_lfht_is_node_deleted(&channel->node.node)) {
620 goto error_unlock;
621 }
622
623 if (channel->switch_timer_enabled == 1) {
624 DBG("Deleting timer on metadata channel");
625 consumer_timer_switch_stop(channel);
626 }
627
628 if (channel->metadata_stream) {
629 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
630 if (ret < 0) {
631 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
632 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
633 goto error_unlock;
634 }
635 if (channel->monitor) {
636 /* close the read-side in consumer_del_metadata_stream */
637 ret = close(channel->metadata_stream->ust_metadata_poll_pipe[1]);
638 if (ret < 0) {
639 PERROR("Close UST metadata write-side poll pipe");
640 }
641 }
642 }
643
644 error_unlock:
645 pthread_mutex_unlock(&channel->timer_lock);
646 pthread_mutex_unlock(&channel->lock);
647 pthread_mutex_unlock(&consumer_data.lock);
648 error:
649 return ret;
650 }
651
652 /*
653 * RCU read side lock MUST be acquired before calling this function.
654 *
655 * Return 0 on success else an LTTng error code.
656 */
657 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
658 {
659 int ret;
660 struct lttng_consumer_channel *metadata;
661
662 DBG("UST consumer setup metadata key %" PRIu64, key);
663
664 metadata = consumer_find_channel(key);
665 if (!metadata) {
666 ERR("UST consumer push metadata %" PRIu64 " not found", key);
667 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
668 goto end;
669 }
670
671 /*
672 * In no monitor mode, the metadata channel has no stream(s) so skip the
673 * ownership transfer to the metadata thread.
674 */
675 if (!metadata->monitor) {
676 DBG("Metadata channel in no monitor");
677 ret = 0;
678 goto end;
679 }
680
681 /*
682 * Send metadata stream to relayd if one available. Availability is
683 * known if the stream is still in the list of the channel.
684 */
685 if (cds_list_empty(&metadata->streams.head)) {
686 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
687 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
688 goto error_no_stream;
689 }
690
691 /* Send metadata stream to relayd if needed. */
692 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
693 ret = consumer_send_relayd_stream(metadata->metadata_stream,
694 metadata->pathname);
695 if (ret < 0) {
696 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
697 goto error;
698 }
699 }
700
701 ret = send_streams_to_thread(metadata, ctx);
702 if (ret < 0) {
703 /*
704 * If we are unable to send the stream to the thread, there is
705 * a big problem so just stop everything.
706 */
707 ret = LTTCOMM_CONSUMERD_FATAL;
708 goto error;
709 }
710 /* List MUST be empty after or else it could be reused. */
711 assert(cds_list_empty(&metadata->streams.head));
712
713 ret = 0;
714 goto end;
715
716 error:
717 /*
718 * Delete metadata channel on error. At this point, the metadata stream can
719 * NOT be monitored by the metadata thread thus having the guarantee that
720 * the stream is still in the local stream list of the channel. This call
721 * will make sure to clean that list.
722 */
723 cds_list_del(&metadata->metadata_stream->send_node);
724 consumer_stream_destroy(metadata->metadata_stream, NULL);
725 error_no_stream:
726 end:
727 return ret;
728 }
729
730 /*
731 * Snapshot the whole metadata.
732 *
733 * Returns 0 on success, < 0 on error
734 */
735 static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
736 struct lttng_consumer_local_data *ctx)
737 {
738 int ret = 0;
739 struct lttng_consumer_channel *metadata_channel;
740 struct lttng_consumer_stream *metadata_stream;
741
742 assert(path);
743 assert(ctx);
744
745 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
746 key, path);
747
748 rcu_read_lock();
749
750 metadata_channel = consumer_find_channel(key);
751 if (!metadata_channel) {
752 ERR("UST snapshot metadata channel not found for key %lu", key);
753 ret = -1;
754 goto error;
755 }
756 assert(!metadata_channel->monitor);
757
758 /*
759 * Ask the sessiond if we have new metadata waiting and update the
760 * consumer metadata cache.
761 */
762 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel);
763 if (ret < 0) {
764 goto error;
765 }
766
767 /*
768 * The metadata stream is NOT created in no monitor mode when the channel
769 * is created on a sessiond ask channel command.
770 */
771 ret = create_ust_streams(metadata_channel, ctx);
772 if (ret < 0) {
773 goto error;
774 }
775
776 metadata_stream = metadata_channel->metadata_stream;
777 assert(metadata_stream);
778
779 if (relayd_id != (uint64_t) -1ULL) {
780 metadata_stream->net_seq_idx = relayd_id;
781 ret = consumer_send_relayd_stream(metadata_stream, path);
782 if (ret < 0) {
783 goto error_stream;
784 }
785 } else {
786 ret = utils_create_stream_file(path, metadata_stream->name,
787 metadata_stream->chan->tracefile_size,
788 metadata_stream->tracefile_count_current,
789 metadata_stream->uid, metadata_stream->gid);
790 if (ret < 0) {
791 goto error_stream;
792 }
793 metadata_stream->out_fd = ret;
794 metadata_stream->tracefile_size_current = 0;
795 }
796
797 pthread_mutex_lock(&metadata_channel->metadata_cache->lock);
798
799 do {
800 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
801 if (ret < 0) {
802 goto error_unlock;
803 }
804 } while (ret > 0);
805
806 error_unlock:
807 pthread_mutex_unlock(&metadata_channel->metadata_cache->lock);
808
809 error_stream:
810 /*
811 * Clean up the stream completly because the next snapshot will use a new
812 * metadata stream.
813 */
814 cds_list_del(&metadata_stream->send_node);
815 consumer_stream_destroy(metadata_stream, NULL);
816 metadata_channel->metadata_stream = NULL;
817
818 error:
819 rcu_read_unlock();
820 return ret;
821 }
822
823 /*
824 * Take a snapshot of all the stream of a channel.
825 *
826 * Returns 0 on success, < 0 on error
827 */
828 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
829 uint64_t max_stream_size, struct lttng_consumer_local_data *ctx)
830 {
831 int ret;
832 unsigned use_relayd = 0;
833 unsigned long consumed_pos, produced_pos;
834 struct lttng_consumer_channel *channel;
835 struct lttng_consumer_stream *stream;
836
837 assert(path);
838 assert(ctx);
839
840 rcu_read_lock();
841
842 if (relayd_id != (uint64_t) -1ULL) {
843 use_relayd = 1;
844 }
845
846 channel = consumer_find_channel(key);
847 if (!channel) {
848 ERR("UST snapshot channel not found for key %lu", key);
849 ret = -1;
850 goto error;
851 }
852 assert(!channel->monitor);
853 DBG("UST consumer snapshot channel %lu", key);
854
855 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
856 /* Lock stream because we are about to change its state. */
857 pthread_mutex_lock(&stream->lock);
858 stream->net_seq_idx = relayd_id;
859
860 if (use_relayd) {
861 ret = consumer_send_relayd_stream(stream, path);
862 if (ret < 0) {
863 goto error_unlock;
864 }
865 } else {
866 ret = utils_create_stream_file(path, stream->name,
867 stream->chan->tracefile_size,
868 stream->tracefile_count_current,
869 stream->uid, stream->gid);
870 if (ret < 0) {
871 goto error_unlock;
872 }
873 stream->out_fd = ret;
874 stream->tracefile_size_current = 0;
875
876 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
877 stream->name, stream->key);
878 }
879
880 ustctl_flush_buffer(stream->ustream, 1);
881
882 ret = lttng_ustconsumer_take_snapshot(stream);
883 if (ret < 0) {
884 ERR("Taking UST snapshot");
885 goto error_unlock;
886 }
887
888 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
889 if (ret < 0) {
890 ERR("Produced UST snapshot position");
891 goto error_unlock;
892 }
893
894 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
895 if (ret < 0) {
896 ERR("Consumerd UST snapshot position");
897 goto error_unlock;
898 }
899
900 /*
901 * The original value is sent back if max stream size is larger than
902 * the possible size of the snapshot. Also, we asume that the session
903 * daemon should never send a maximum stream size that is lower than
904 * subbuffer size.
905 */
906 consumed_pos = consumer_get_consumed_maxsize(consumed_pos,
907 produced_pos, max_stream_size);
908
909 while (consumed_pos < produced_pos) {
910 ssize_t read_len;
911 unsigned long len, padded_len;
912
913 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
914
915 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
916 if (ret < 0) {
917 if (ret != -EAGAIN) {
918 PERROR("ustctl_get_subbuf snapshot");
919 goto error_close_stream;
920 }
921 DBG("UST consumer get subbuf failed. Skipping it.");
922 consumed_pos += stream->max_sb_size;
923 continue;
924 }
925
926 ret = ustctl_get_subbuf_size(stream->ustream, &len);
927 if (ret < 0) {
928 ERR("Snapshot ustctl_get_subbuf_size");
929 goto error_put_subbuf;
930 }
931
932 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
933 if (ret < 0) {
934 ERR("Snapshot ustctl_get_padded_subbuf_size");
935 goto error_put_subbuf;
936 }
937
938 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
939 padded_len - len);
940 if (use_relayd) {
941 if (read_len != len) {
942 ret = -1;
943 goto error_put_subbuf;
944 }
945 } else {
946 if (read_len != padded_len) {
947 ret = -1;
948 goto error_put_subbuf;
949 }
950 }
951
952 ret = ustctl_put_subbuf(stream->ustream);
953 if (ret < 0) {
954 ERR("Snapshot ustctl_put_subbuf");
955 goto error_close_stream;
956 }
957 consumed_pos += stream->max_sb_size;
958 }
959
960 /* Simply close the stream so we can use it on the next snapshot. */
961 consumer_stream_close(stream);
962 pthread_mutex_unlock(&stream->lock);
963 }
964
965 rcu_read_unlock();
966 return 0;
967
968 error_put_subbuf:
969 if (ustctl_put_subbuf(stream->ustream) < 0) {
970 ERR("Snapshot ustctl_put_subbuf");
971 }
972 error_close_stream:
973 consumer_stream_close(stream);
974 error_unlock:
975 pthread_mutex_unlock(&stream->lock);
976 error:
977 rcu_read_unlock();
978 return ret;
979 }
980
981 /*
982 * Receive the metadata updates from the sessiond.
983 */
984 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
985 uint64_t len, struct lttng_consumer_channel *channel)
986 {
987 int ret, ret_code = LTTNG_OK;
988 char *metadata_str;
989
990 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
991
992 metadata_str = zmalloc(len * sizeof(char));
993 if (!metadata_str) {
994 PERROR("zmalloc metadata string");
995 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
996 goto end;
997 }
998
999 /* Receive metadata string. */
1000 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1001 if (ret < 0) {
1002 /* Session daemon is dead so return gracefully. */
1003 ret_code = ret;
1004 goto end_free;
1005 }
1006
1007 pthread_mutex_lock(&channel->metadata_cache->lock);
1008 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
1009 if (ret < 0) {
1010 /* Unable to handle metadata. Notify session daemon. */
1011 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1012 /*
1013 * Skip metadata flush on write error since the offset and len might
1014 * not have been updated which could create an infinite loop below when
1015 * waiting for the metadata cache to be flushed.
1016 */
1017 pthread_mutex_unlock(&channel->metadata_cache->lock);
1018 goto end_free;
1019 }
1020 pthread_mutex_unlock(&channel->metadata_cache->lock);
1021
1022 while (consumer_metadata_cache_flushed(channel, offset + len)) {
1023 DBG("Waiting for metadata to be flushed");
1024 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1025 }
1026
1027 end_free:
1028 free(metadata_str);
1029 end:
1030 return ret_code;
1031 }
1032
1033 /*
1034 * Receive command from session daemon and process it.
1035 *
1036 * Return 1 on success else a negative value or 0.
1037 */
1038 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1039 int sock, struct pollfd *consumer_sockpoll)
1040 {
1041 ssize_t ret;
1042 enum lttng_error_code ret_code = LTTNG_OK;
1043 struct lttcomm_consumer_msg msg;
1044 struct lttng_consumer_channel *channel = NULL;
1045
1046 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1047 if (ret != sizeof(msg)) {
1048 DBG("Consumer received unexpected message size %zd (expects %zu)",
1049 ret, sizeof(msg));
1050 /*
1051 * The ret value might 0 meaning an orderly shutdown but this is ok
1052 * since the caller handles this.
1053 */
1054 if (ret > 0) {
1055 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1056 ret = -1;
1057 }
1058 return ret;
1059 }
1060 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
1061 /*
1062 * Notify the session daemon that the command is completed.
1063 *
1064 * On transport layer error, the function call will print an error
1065 * message so handling the returned code is a bit useless since we
1066 * return an error code anyway.
1067 */
1068 (void) consumer_send_status_msg(sock, ret_code);
1069 return -ENOENT;
1070 }
1071
1072 /* relayd needs RCU read-side lock */
1073 rcu_read_lock();
1074
1075 switch (msg.cmd_type) {
1076 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1077 {
1078 /* Session daemon status message are handled in the following call. */
1079 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1080 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1081 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
1082 goto end_nosignal;
1083 }
1084 case LTTNG_CONSUMER_DESTROY_RELAYD:
1085 {
1086 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1087 struct consumer_relayd_sock_pair *relayd;
1088
1089 DBG("UST consumer destroying relayd %" PRIu64, index);
1090
1091 /* Get relayd reference if exists. */
1092 relayd = consumer_find_relayd(index);
1093 if (relayd == NULL) {
1094 DBG("Unable to find relayd %" PRIu64, index);
1095 ret_code = LTTNG_ERR_NO_CONSUMER;
1096 }
1097
1098 /*
1099 * Each relayd socket pair has a refcount of stream attached to it
1100 * which tells if the relayd is still active or not depending on the
1101 * refcount value.
1102 *
1103 * This will set the destroy flag of the relayd object and destroy it
1104 * if the refcount reaches zero when called.
1105 *
1106 * The destroy can happen either here or when a stream fd hangs up.
1107 */
1108 if (relayd) {
1109 consumer_flag_relayd_for_destroy(relayd);
1110 }
1111
1112 goto end_msg_sessiond;
1113 }
1114 case LTTNG_CONSUMER_UPDATE_STREAM:
1115 {
1116 rcu_read_unlock();
1117 return -ENOSYS;
1118 }
1119 case LTTNG_CONSUMER_DATA_PENDING:
1120 {
1121 int ret, is_data_pending;
1122 uint64_t id = msg.u.data_pending.session_id;
1123
1124 DBG("UST consumer data pending command for id %" PRIu64, id);
1125
1126 is_data_pending = consumer_data_pending(id);
1127
1128 /* Send back returned value to session daemon */
1129 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1130 sizeof(is_data_pending));
1131 if (ret < 0) {
1132 DBG("Error when sending the data pending ret code: %d", ret);
1133 goto error_fatal;
1134 }
1135
1136 /*
1137 * No need to send back a status message since the data pending
1138 * returned value is the response.
1139 */
1140 break;
1141 }
1142 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1143 {
1144 int ret;
1145 struct ustctl_consumer_channel_attr attr;
1146
1147 /* Create a plain object and reserve a channel key. */
1148 channel = allocate_channel(msg.u.ask_channel.session_id,
1149 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1150 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1151 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1152 (enum lttng_event_output) msg.u.ask_channel.output,
1153 msg.u.ask_channel.tracefile_size,
1154 msg.u.ask_channel.tracefile_count,
1155 msg.u.ask_channel.session_id_per_pid,
1156 msg.u.ask_channel.monitor);
1157 if (!channel) {
1158 goto end_channel_error;
1159 }
1160
1161 /* Build channel attributes from received message. */
1162 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1163 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1164 attr.overwrite = msg.u.ask_channel.overwrite;
1165 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1166 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1167 attr.chan_id = msg.u.ask_channel.chan_id;
1168 attr.output = msg.u.ask_channel.output;
1169 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1170
1171 /* Translate and save channel type. */
1172 switch (msg.u.ask_channel.type) {
1173 case LTTNG_UST_CHAN_PER_CPU:
1174 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1175 attr.type = LTTNG_UST_CHAN_PER_CPU;
1176 /*
1177 * Set refcount to 1 for owner. Below, we will
1178 * pass ownership to the
1179 * consumer_thread_channel_poll() thread.
1180 */
1181 channel->refcount = 1;
1182 break;
1183 case LTTNG_UST_CHAN_METADATA:
1184 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1185 attr.type = LTTNG_UST_CHAN_METADATA;
1186 break;
1187 default:
1188 assert(0);
1189 goto error_fatal;
1190 };
1191
1192 ret = ask_channel(ctx, sock, channel, &attr);
1193 if (ret < 0) {
1194 goto end_channel_error;
1195 }
1196
1197 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1198 ret = consumer_metadata_cache_allocate(channel);
1199 if (ret < 0) {
1200 ERR("Allocating metadata cache");
1201 goto end_channel_error;
1202 }
1203 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1204 attr.switch_timer_interval = 0;
1205 }
1206
1207 /*
1208 * Add the channel to the internal state AFTER all streams were created
1209 * and successfully sent to session daemon. This way, all streams must
1210 * be ready before this channel is visible to the threads.
1211 * If add_channel succeeds, ownership of the channel is
1212 * passed to consumer_thread_channel_poll().
1213 */
1214 ret = add_channel(channel, ctx);
1215 if (ret < 0) {
1216 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1217 if (channel->switch_timer_enabled == 1) {
1218 consumer_timer_switch_stop(channel);
1219 }
1220 consumer_metadata_cache_destroy(channel);
1221 }
1222 goto end_channel_error;
1223 }
1224
1225 /*
1226 * Channel and streams are now created. Inform the session daemon that
1227 * everything went well and should wait to receive the channel and
1228 * streams with ustctl API.
1229 */
1230 ret = consumer_send_status_channel(sock, channel);
1231 if (ret < 0) {
1232 /*
1233 * There is probably a problem on the socket.
1234 */
1235 goto error_fatal;
1236 }
1237
1238 break;
1239 }
1240 case LTTNG_CONSUMER_GET_CHANNEL:
1241 {
1242 int ret, relayd_err = 0;
1243 uint64_t key = msg.u.get_channel.key;
1244 struct lttng_consumer_channel *channel;
1245
1246 channel = consumer_find_channel(key);
1247 if (!channel) {
1248 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1249 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1250 goto end_msg_sessiond;
1251 }
1252
1253 /* Send everything to sessiond. */
1254 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1255 if (ret < 0) {
1256 if (relayd_err) {
1257 /*
1258 * We were unable to send to the relayd the stream so avoid
1259 * sending back a fatal error to the thread since this is OK
1260 * and the consumer can continue its work. The above call
1261 * has sent the error status message to the sessiond.
1262 */
1263 goto end_nosignal;
1264 }
1265 /*
1266 * The communicaton was broken hence there is a bad state between
1267 * the consumer and sessiond so stop everything.
1268 */
1269 goto error_fatal;
1270 }
1271
1272 /*
1273 * In no monitor mode, the streams ownership is kept inside the channel
1274 * so don't send them to the data thread.
1275 */
1276 if (!channel->monitor) {
1277 goto end_msg_sessiond;
1278 }
1279
1280 ret = send_streams_to_thread(channel, ctx);
1281 if (ret < 0) {
1282 /*
1283 * If we are unable to send the stream to the thread, there is
1284 * a big problem so just stop everything.
1285 */
1286 goto error_fatal;
1287 }
1288 /* List MUST be empty after or else it could be reused. */
1289 assert(cds_list_empty(&channel->streams.head));
1290 goto end_msg_sessiond;
1291 }
1292 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1293 {
1294 uint64_t key = msg.u.destroy_channel.key;
1295
1296 /*
1297 * Only called if streams have not been sent to stream
1298 * manager thread. However, channel has been sent to
1299 * channel manager thread.
1300 */
1301 notify_thread_del_channel(ctx, key);
1302 goto end_msg_sessiond;
1303 }
1304 case LTTNG_CONSUMER_CLOSE_METADATA:
1305 {
1306 int ret;
1307
1308 ret = close_metadata(msg.u.close_metadata.key);
1309 if (ret != 0) {
1310 ret_code = ret;
1311 }
1312
1313 goto end_msg_sessiond;
1314 }
1315 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1316 {
1317 int ret;
1318
1319 ret = flush_channel(msg.u.flush_channel.key);
1320 if (ret != 0) {
1321 ret_code = ret;
1322 }
1323
1324 goto end_msg_sessiond;
1325 }
1326 case LTTNG_CONSUMER_PUSH_METADATA:
1327 {
1328 int ret;
1329 uint64_t len = msg.u.push_metadata.len;
1330 uint64_t key = msg.u.push_metadata.key;
1331 uint64_t offset = msg.u.push_metadata.target_offset;
1332 struct lttng_consumer_channel *channel;
1333
1334 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1335 len);
1336
1337 channel = consumer_find_channel(key);
1338 if (!channel) {
1339 ERR("UST consumer push metadata %" PRIu64 " not found", key);
1340 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1341 goto end_msg_sessiond;
1342 }
1343
1344 /* Tell session daemon we are ready to receive the metadata. */
1345 ret = consumer_send_status_msg(sock, LTTNG_OK);
1346 if (ret < 0) {
1347 /* Somehow, the session daemon is not responding anymore. */
1348 goto error_fatal;
1349 }
1350
1351 /* Wait for more data. */
1352 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
1353 goto error_fatal;
1354 }
1355
1356 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1357 len, channel);
1358 if (ret < 0) {
1359 /* error receiving from sessiond */
1360 goto error_fatal;
1361 } else {
1362 ret_code = ret;
1363 goto end_msg_sessiond;
1364 }
1365 }
1366 case LTTNG_CONSUMER_SETUP_METADATA:
1367 {
1368 int ret;
1369
1370 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1371 if (ret) {
1372 ret_code = ret;
1373 }
1374 goto end_msg_sessiond;
1375 }
1376 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1377 {
1378 if (msg.u.snapshot_channel.metadata) {
1379 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1380 msg.u.snapshot_channel.pathname,
1381 msg.u.snapshot_channel.relayd_id,
1382 ctx);
1383 if (ret < 0) {
1384 ERR("Snapshot metadata failed");
1385 ret_code = LTTNG_ERR_UST_META_FAIL;
1386 }
1387 } else {
1388 ret = snapshot_channel(msg.u.snapshot_channel.key,
1389 msg.u.snapshot_channel.pathname,
1390 msg.u.snapshot_channel.relayd_id,
1391 msg.u.snapshot_channel.max_stream_size,
1392 ctx);
1393 if (ret < 0) {
1394 ERR("Snapshot channel failed");
1395 ret_code = LTTNG_ERR_UST_CHAN_FAIL;
1396 }
1397 }
1398
1399 ret = consumer_send_status_msg(sock, ret_code);
1400 if (ret < 0) {
1401 /* Somehow, the session daemon is not responding anymore. */
1402 goto end_nosignal;
1403 }
1404 break;
1405 }
1406 default:
1407 break;
1408 }
1409
1410 end_nosignal:
1411 rcu_read_unlock();
1412
1413 /*
1414 * Return 1 to indicate success since the 0 value can be a socket
1415 * shutdown during the recv() or send() call.
1416 */
1417 return 1;
1418
1419 end_msg_sessiond:
1420 /*
1421 * The returned value here is not useful since either way we'll return 1 to
1422 * the caller because the session daemon socket management is done
1423 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1424 */
1425 ret = consumer_send_status_msg(sock, ret_code);
1426 if (ret < 0) {
1427 goto error_fatal;
1428 }
1429 rcu_read_unlock();
1430 return 1;
1431 end_channel_error:
1432 if (channel) {
1433 /*
1434 * Free channel here since no one has a reference to it. We don't
1435 * free after that because a stream can store this pointer.
1436 */
1437 destroy_channel(channel);
1438 }
1439 /* We have to send a status channel message indicating an error. */
1440 ret = consumer_send_status_channel(sock, NULL);
1441 if (ret < 0) {
1442 /* Stop everything if session daemon can not be notified. */
1443 goto error_fatal;
1444 }
1445 rcu_read_unlock();
1446 return 1;
1447 error_fatal:
1448 rcu_read_unlock();
1449 /* This will issue a consumer stop. */
1450 return -1;
1451 }
1452
1453 /*
1454 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1455 * compiled out, we isolate it in this library.
1456 */
1457 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1458 unsigned long *off)
1459 {
1460 assert(stream);
1461 assert(stream->ustream);
1462
1463 return ustctl_get_mmap_read_offset(stream->ustream, off);
1464 }
1465
1466 /*
1467 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1468 * compiled out, we isolate it in this library.
1469 */
1470 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1471 {
1472 assert(stream);
1473 assert(stream->ustream);
1474
1475 return ustctl_get_mmap_base(stream->ustream);
1476 }
1477
1478 /*
1479 * Take a snapshot for a specific fd
1480 *
1481 * Returns 0 on success, < 0 on error
1482 */
1483 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1484 {
1485 assert(stream);
1486 assert(stream->ustream);
1487
1488 return ustctl_snapshot(stream->ustream);
1489 }
1490
1491 /*
1492 * Get the produced position
1493 *
1494 * Returns 0 on success, < 0 on error
1495 */
1496 int lttng_ustconsumer_get_produced_snapshot(
1497 struct lttng_consumer_stream *stream, unsigned long *pos)
1498 {
1499 assert(stream);
1500 assert(stream->ustream);
1501 assert(pos);
1502
1503 return ustctl_snapshot_get_produced(stream->ustream, pos);
1504 }
1505
1506 /*
1507 * Get the consumed position
1508 *
1509 * Returns 0 on success, < 0 on error
1510 */
1511 int lttng_ustconsumer_get_consumed_snapshot(
1512 struct lttng_consumer_stream *stream, unsigned long *pos)
1513 {
1514 assert(stream);
1515 assert(stream->ustream);
1516 assert(pos);
1517
1518 return ustctl_snapshot_get_consumed(stream->ustream, pos);
1519 }
1520
1521 /*
1522 * Called when the stream signal the consumer that it has hang up.
1523 */
1524 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1525 {
1526 assert(stream);
1527 assert(stream->ustream);
1528
1529 ustctl_flush_buffer(stream->ustream, 0);
1530 stream->hangup_flush_done = 1;
1531 }
1532
1533 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1534 {
1535 assert(chan);
1536 assert(chan->uchan);
1537
1538 if (chan->switch_timer_enabled == 1) {
1539 consumer_timer_switch_stop(chan);
1540 }
1541 consumer_metadata_cache_destroy(chan);
1542 ustctl_destroy_channel(chan->uchan);
1543 }
1544
1545 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1546 {
1547 assert(stream);
1548 assert(stream->ustream);
1549
1550 if (stream->chan->switch_timer_enabled == 1) {
1551 consumer_timer_switch_stop(stream->chan);
1552 }
1553 ustctl_destroy_stream(stream->ustream);
1554 }
1555
1556 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1557 struct lttng_consumer_local_data *ctx)
1558 {
1559 unsigned long len, subbuf_size, padding;
1560 int err;
1561 long ret = 0;
1562 char dummy;
1563 struct ustctl_consumer_stream *ustream;
1564
1565 assert(stream);
1566 assert(stream->ustream);
1567 assert(ctx);
1568
1569 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1570 stream->name);
1571
1572 /* Ease our life for what's next. */
1573 ustream = stream->ustream;
1574
1575 /* We can consume the 1 byte written into the wait_fd by UST */
1576 if (stream->monitor && !stream->hangup_flush_done) {
1577 ssize_t readlen;
1578
1579 do {
1580 readlen = read(stream->wait_fd, &dummy, 1);
1581 } while (readlen == -1 && errno == EINTR);
1582 if (readlen == -1 && errno != EAGAIN && errno != EWOULDBLOCK) {
1583 ret = readlen;
1584 goto end;
1585 }
1586 }
1587
1588 retry:
1589 /* Get the next subbuffer */
1590 err = ustctl_get_next_subbuf(ustream);
1591 if (err != 0) {
1592 /*
1593 * Populate metadata info if the existing info has
1594 * already been read.
1595 */
1596 if (stream->metadata_flag) {
1597 ssize_t write_len;
1598
1599 if (stream->chan->metadata_cache->contiguous
1600 == stream->ust_metadata_pushed) {
1601 ret = 0;
1602 goto end;
1603 }
1604
1605 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
1606 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
1607 stream->chan->metadata_cache->contiguous
1608 - stream->ust_metadata_pushed);
1609 assert(write_len != 0);
1610 if (write_len < 0) {
1611 ERR("Writing one metadata packet");
1612 ret = -1;
1613 goto end;
1614 }
1615 stream->ust_metadata_pushed += write_len;
1616 ustctl_flush_buffer(stream->ustream, 1);
1617 goto retry;
1618 }
1619
1620 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
1621 /*
1622 * This is a debug message even for single-threaded consumer,
1623 * because poll() have more relaxed criterions than get subbuf,
1624 * so get_subbuf may fail for short race windows where poll()
1625 * would issue wakeups.
1626 */
1627 DBG("Reserving sub buffer failed (everything is normal, "
1628 "it is due to concurrency) [ret: %d]", err);
1629 goto end;
1630 }
1631 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1632 /* Get the full padded subbuffer size */
1633 err = ustctl_get_padded_subbuf_size(ustream, &len);
1634 assert(err == 0);
1635
1636 /* Get subbuffer data size (without padding) */
1637 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
1638 assert(err == 0);
1639
1640 /* Make sure we don't get a subbuffer size bigger than the padded */
1641 assert(len >= subbuf_size);
1642
1643 padding = len - subbuf_size;
1644 /* write the subbuffer to the tracefile */
1645 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
1646 /*
1647 * The mmap operation should write subbuf_size amount of data when network
1648 * streaming or the full padding (len) size when we are _not_ streaming.
1649 */
1650 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1651 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
1652 /*
1653 * Display the error but continue processing to try to release the
1654 * subbuffer. This is a DBG statement since any unexpected kill or
1655 * signal, the application gets unregistered, relayd gets closed or
1656 * anything that affects the buffer lifetime will trigger this error.
1657 * So, for the sake of the user, don't print this error since it can
1658 * happen and it is OK with the code flow.
1659 */
1660 DBG("Error writing to tracefile "
1661 "(ret: %ld != len: %lu != subbuf_size: %lu)",
1662 ret, len, subbuf_size);
1663 }
1664 err = ustctl_put_next_subbuf(ustream);
1665 assert(err == 0);
1666
1667 end:
1668 return ret;
1669 }
1670
1671 /*
1672 * Called when a stream is created.
1673 *
1674 * Return 0 on success or else a negative value.
1675 */
1676 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
1677 {
1678 int ret;
1679
1680 assert(stream);
1681
1682 /* Don't create anything if this is set for streaming. */
1683 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
1684 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
1685 stream->chan->tracefile_size, stream->tracefile_count_current,
1686 stream->uid, stream->gid);
1687 if (ret < 0) {
1688 goto error;
1689 }
1690 stream->out_fd = ret;
1691 stream->tracefile_size_current = 0;
1692 }
1693 ret = 0;
1694
1695 error:
1696 return ret;
1697 }
1698
1699 /*
1700 * Check if data is still being extracted from the buffers for a specific
1701 * stream. Consumer data lock MUST be acquired before calling this function
1702 * and the stream lock.
1703 *
1704 * Return 1 if the traced data are still getting read else 0 meaning that the
1705 * data is available for trace viewer reading.
1706 */
1707 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
1708 {
1709 int ret;
1710
1711 assert(stream);
1712 assert(stream->ustream);
1713
1714 DBG("UST consumer checking data pending");
1715
1716 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
1717 ret = 0;
1718 goto end;
1719 }
1720
1721 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
1722 /*
1723 * We can simply check whether all contiguously available data
1724 * has been pushed to the ring buffer, since the push operation
1725 * is performed within get_next_subbuf(), and because both
1726 * get_next_subbuf() and put_next_subbuf() are issued atomically
1727 * thanks to the stream lock within
1728 * lttng_ustconsumer_read_subbuffer(). This basically means that
1729 * whetnever ust_metadata_pushed is incremented, the associated
1730 * metadata has been consumed from the metadata stream.
1731 */
1732 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
1733 stream->chan->metadata_cache->contiguous,
1734 stream->ust_metadata_pushed);
1735 if (stream->chan->metadata_cache->contiguous
1736 != stream->ust_metadata_pushed) {
1737 ret = 1; /* Data is pending */
1738 goto end;
1739 }
1740 } else {
1741 ret = ustctl_get_next_subbuf(stream->ustream);
1742 if (ret == 0) {
1743 /*
1744 * There is still data so let's put back this
1745 * subbuffer.
1746 */
1747 ret = ustctl_put_subbuf(stream->ustream);
1748 assert(ret == 0);
1749 ret = 1; /* Data is pending */
1750 goto end;
1751 }
1752 }
1753
1754 /* Data is NOT pending so ready to be read. */
1755 ret = 0;
1756
1757 end:
1758 return ret;
1759 }
1760
1761 /*
1762 * Close every metadata stream wait fd of the metadata hash table. This
1763 * function MUST be used very carefully so not to run into a race between the
1764 * metadata thread handling streams and this function closing their wait fd.
1765 *
1766 * For UST, this is used when the session daemon hangs up. Its the metadata
1767 * producer so calling this is safe because we are assured that no state change
1768 * can occur in the metadata thread for the streams in the hash table.
1769 */
1770 void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
1771 {
1772 int ret;
1773 struct lttng_ht_iter iter;
1774 struct lttng_consumer_stream *stream;
1775
1776 assert(metadata_ht);
1777 assert(metadata_ht->ht);
1778
1779 DBG("UST consumer closing all metadata streams");
1780
1781 rcu_read_lock();
1782 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
1783 node.node) {
1784 int fd = stream->wait_fd;
1785
1786 /*
1787 * Whatever happens here we have to continue to try to close every
1788 * streams. Let's report at least the error on failure.
1789 */
1790 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1791 if (ret) {
1792 ERR("Unable to close metadata stream fd %d ret %d", fd, ret);
1793 }
1794 DBG("Metadata wait fd %d closed", fd);
1795 }
1796 rcu_read_unlock();
1797 }
1798
1799 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
1800 {
1801 int ret;
1802
1803 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1804 if (ret < 0) {
1805 ERR("Unable to close wakeup fd");
1806 }
1807 }
1808
1809 /*
1810 * Please refer to consumer-timer.c before adding any lock within this
1811 * function or any of its callees. Timers have a very strict locking
1812 * semantic with respect to teardown. Failure to respect this semantic
1813 * introduces deadlocks.
1814 */
1815 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
1816 struct lttng_consumer_channel *channel)
1817 {
1818 struct lttcomm_metadata_request_msg request;
1819 struct lttcomm_consumer_msg msg;
1820 enum lttng_error_code ret_code = LTTNG_OK;
1821 uint64_t len, key, offset;
1822 int ret;
1823
1824 assert(channel);
1825 assert(channel->metadata_cache);
1826
1827 /* send the metadata request to sessiond */
1828 switch (consumer_data.type) {
1829 case LTTNG_CONSUMER64_UST:
1830 request.bits_per_long = 64;
1831 break;
1832 case LTTNG_CONSUMER32_UST:
1833 request.bits_per_long = 32;
1834 break;
1835 default:
1836 request.bits_per_long = 0;
1837 break;
1838 }
1839
1840 request.session_id = channel->session_id;
1841 request.session_id_per_pid = channel->session_id_per_pid;
1842 request.uid = channel->uid;
1843 request.key = channel->key;
1844 DBG("Sending metadata request to sessiond, session id %" PRIu64
1845 ", per-pid %" PRIu64,
1846 channel->session_id,
1847 channel->session_id_per_pid);
1848
1849 pthread_mutex_lock(&ctx->metadata_socket_lock);
1850 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
1851 sizeof(request));
1852 if (ret < 0) {
1853 ERR("Asking metadata to sessiond");
1854 goto end;
1855 }
1856
1857 /* Receive the metadata from sessiond */
1858 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
1859 sizeof(msg));
1860 if (ret != sizeof(msg)) {
1861 DBG("Consumer received unexpected message size %d (expects %zu)",
1862 ret, sizeof(msg));
1863 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1864 /*
1865 * The ret value might 0 meaning an orderly shutdown but this is ok
1866 * since the caller handles this.
1867 */
1868 goto end;
1869 }
1870
1871 if (msg.cmd_type == LTTNG_ERR_UND) {
1872 /* No registry found */
1873 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
1874 ret_code);
1875 ret = 0;
1876 goto end;
1877 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
1878 ERR("Unexpected cmd_type received %d", msg.cmd_type);
1879 ret = -1;
1880 goto end;
1881 }
1882
1883 len = msg.u.push_metadata.len;
1884 key = msg.u.push_metadata.key;
1885 offset = msg.u.push_metadata.target_offset;
1886
1887 assert(key == channel->key);
1888 if (len == 0) {
1889 DBG("No new metadata to receive for key %" PRIu64, key);
1890 }
1891
1892 /* Tell session daemon we are ready to receive the metadata. */
1893 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
1894 LTTNG_OK);
1895 if (ret < 0 || len == 0) {
1896 /*
1897 * Somehow, the session daemon is not responding anymore or there is
1898 * nothing to receive.
1899 */
1900 goto end;
1901 }
1902
1903 ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
1904 key, offset, len, channel);
1905 if (ret_code >= 0) {
1906 /*
1907 * Only send the status msg if the sessiond is alive meaning a positive
1908 * ret code.
1909 */
1910 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
1911 }
1912 ret = 0;
1913
1914 end:
1915 pthread_mutex_unlock(&ctx->metadata_socket_lock);
1916 return ret;
1917 }
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