Consumer: implement LTTNG_CONSUMER_CLEAR_CHANNEL
[lttng-tools.git] / src / common / consumer / consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 * 2012 - David Goulet <dgoulet@efficios.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License, version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <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/types.h>
29 #include <unistd.h>
30 #include <inttypes.h>
31 #include <signal.h>
32
33 #include <bin/lttng-consumerd/health-consumerd.h>
34 #include <common/common.h>
35 #include <common/utils.h>
36 #include <common/compat/poll.h>
37 #include <common/compat/endian.h>
38 #include <common/index/index.h>
39 #include <common/kernel-ctl/kernel-ctl.h>
40 #include <common/sessiond-comm/relayd.h>
41 #include <common/sessiond-comm/sessiond-comm.h>
42 #include <common/kernel-consumer/kernel-consumer.h>
43 #include <common/relayd/relayd.h>
44 #include <common/ust-consumer/ust-consumer.h>
45 #include <common/consumer/consumer-timer.h>
46 #include <common/consumer/consumer.h>
47 #include <common/consumer/consumer-stream.h>
48 #include <common/consumer/consumer-testpoint.h>
49 #include <common/align.h>
50 #include <common/consumer/consumer-metadata-cache.h>
51
52 struct lttng_consumer_global_data consumer_data = {
53 .stream_count = 0,
54 .need_update = 1,
55 .type = LTTNG_CONSUMER_UNKNOWN,
56 };
57
58 enum consumer_channel_action {
59 CONSUMER_CHANNEL_ADD,
60 CONSUMER_CHANNEL_DEL,
61 CONSUMER_CHANNEL_QUIT,
62 };
63
64 struct consumer_channel_msg {
65 enum consumer_channel_action action;
66 struct lttng_consumer_channel *chan; /* add */
67 uint64_t key; /* del */
68 };
69
70 /* Flag used to temporarily pause data consumption from testpoints. */
71 int data_consumption_paused;
72
73 /*
74 * Flag to inform the polling thread to quit when all fd hung up. Updated by
75 * the consumer_thread_receive_fds when it notices that all fds has hung up.
76 * Also updated by the signal handler (consumer_should_exit()). Read by the
77 * polling threads.
78 */
79 int consumer_quit;
80
81 /*
82 * Global hash table containing respectively metadata and data streams. The
83 * stream element in this ht should only be updated by the metadata poll thread
84 * for the metadata and the data poll thread for the data.
85 */
86 static struct lttng_ht *metadata_ht;
87 static struct lttng_ht *data_ht;
88
89 /*
90 * Notify a thread lttng pipe to poll back again. This usually means that some
91 * global state has changed so we just send back the thread in a poll wait
92 * call.
93 */
94 static void notify_thread_lttng_pipe(struct lttng_pipe *pipe)
95 {
96 struct lttng_consumer_stream *null_stream = NULL;
97
98 assert(pipe);
99
100 (void) lttng_pipe_write(pipe, &null_stream, sizeof(null_stream));
101 }
102
103 static void notify_health_quit_pipe(int *pipe)
104 {
105 ssize_t ret;
106
107 ret = lttng_write(pipe[1], "4", 1);
108 if (ret < 1) {
109 PERROR("write consumer health quit");
110 }
111 }
112
113 static void notify_channel_pipe(struct lttng_consumer_local_data *ctx,
114 struct lttng_consumer_channel *chan,
115 uint64_t key,
116 enum consumer_channel_action action)
117 {
118 struct consumer_channel_msg msg;
119 ssize_t ret;
120
121 memset(&msg, 0, sizeof(msg));
122
123 msg.action = action;
124 msg.chan = chan;
125 msg.key = key;
126 ret = lttng_write(ctx->consumer_channel_pipe[1], &msg, sizeof(msg));
127 if (ret < sizeof(msg)) {
128 PERROR("notify_channel_pipe write error");
129 }
130 }
131
132 void notify_thread_del_channel(struct lttng_consumer_local_data *ctx,
133 uint64_t key)
134 {
135 notify_channel_pipe(ctx, NULL, key, CONSUMER_CHANNEL_DEL);
136 }
137
138 static int read_channel_pipe(struct lttng_consumer_local_data *ctx,
139 struct lttng_consumer_channel **chan,
140 uint64_t *key,
141 enum consumer_channel_action *action)
142 {
143 struct consumer_channel_msg msg;
144 ssize_t ret;
145
146 ret = lttng_read(ctx->consumer_channel_pipe[0], &msg, sizeof(msg));
147 if (ret < sizeof(msg)) {
148 ret = -1;
149 goto error;
150 }
151 *action = msg.action;
152 *chan = msg.chan;
153 *key = msg.key;
154 error:
155 return (int) ret;
156 }
157
158 /*
159 * Cleanup the stream list of a channel. Those streams are not yet globally
160 * visible
161 */
162 static void clean_channel_stream_list(struct lttng_consumer_channel *channel)
163 {
164 struct lttng_consumer_stream *stream, *stmp;
165
166 assert(channel);
167
168 /* Delete streams that might have been left in the stream list. */
169 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
170 send_node) {
171 cds_list_del(&stream->send_node);
172 /*
173 * Once a stream is added to this list, the buffers were created so we
174 * have a guarantee that this call will succeed. Setting the monitor
175 * mode to 0 so we don't lock nor try to delete the stream from the
176 * global hash table.
177 */
178 stream->monitor = 0;
179 consumer_stream_destroy(stream, NULL);
180 }
181 }
182
183 /*
184 * Find a stream. The consumer_data.lock must be locked during this
185 * call.
186 */
187 static struct lttng_consumer_stream *find_stream(uint64_t key,
188 struct lttng_ht *ht)
189 {
190 struct lttng_ht_iter iter;
191 struct lttng_ht_node_u64 *node;
192 struct lttng_consumer_stream *stream = NULL;
193
194 assert(ht);
195
196 /* -1ULL keys are lookup failures */
197 if (key == (uint64_t) -1ULL) {
198 return NULL;
199 }
200
201 rcu_read_lock();
202
203 lttng_ht_lookup(ht, &key, &iter);
204 node = lttng_ht_iter_get_node_u64(&iter);
205 if (node != NULL) {
206 stream = caa_container_of(node, struct lttng_consumer_stream, node);
207 }
208
209 rcu_read_unlock();
210
211 return stream;
212 }
213
214 static void steal_stream_key(uint64_t key, struct lttng_ht *ht)
215 {
216 struct lttng_consumer_stream *stream;
217
218 rcu_read_lock();
219 stream = find_stream(key, ht);
220 if (stream) {
221 stream->key = (uint64_t) -1ULL;
222 /*
223 * We don't want the lookup to match, but we still need
224 * to iterate on this stream when iterating over the hash table. Just
225 * change the node key.
226 */
227 stream->node.key = (uint64_t) -1ULL;
228 }
229 rcu_read_unlock();
230 }
231
232 /*
233 * Return a channel object for the given key.
234 *
235 * RCU read side lock MUST be acquired before calling this function and
236 * protects the channel ptr.
237 */
238 struct lttng_consumer_channel *consumer_find_channel(uint64_t key)
239 {
240 struct lttng_ht_iter iter;
241 struct lttng_ht_node_u64 *node;
242 struct lttng_consumer_channel *channel = NULL;
243
244 /* -1ULL keys are lookup failures */
245 if (key == (uint64_t) -1ULL) {
246 return NULL;
247 }
248
249 lttng_ht_lookup(consumer_data.channel_ht, &key, &iter);
250 node = lttng_ht_iter_get_node_u64(&iter);
251 if (node != NULL) {
252 channel = caa_container_of(node, struct lttng_consumer_channel, node);
253 }
254
255 return channel;
256 }
257
258 /*
259 * There is a possibility that the consumer does not have enough time between
260 * the close of the channel on the session daemon and the cleanup in here thus
261 * once we have a channel add with an existing key, we know for sure that this
262 * channel will eventually get cleaned up by all streams being closed.
263 *
264 * This function just nullifies the already existing channel key.
265 */
266 static void steal_channel_key(uint64_t key)
267 {
268 struct lttng_consumer_channel *channel;
269
270 rcu_read_lock();
271 channel = consumer_find_channel(key);
272 if (channel) {
273 channel->key = (uint64_t) -1ULL;
274 /*
275 * We don't want the lookup to match, but we still need to iterate on
276 * this channel when iterating over the hash table. Just change the
277 * node key.
278 */
279 channel->node.key = (uint64_t) -1ULL;
280 }
281 rcu_read_unlock();
282 }
283
284 static void free_channel_rcu(struct rcu_head *head)
285 {
286 struct lttng_ht_node_u64 *node =
287 caa_container_of(head, struct lttng_ht_node_u64, head);
288 struct lttng_consumer_channel *channel =
289 caa_container_of(node, struct lttng_consumer_channel, node);
290
291 switch (consumer_data.type) {
292 case LTTNG_CONSUMER_KERNEL:
293 break;
294 case LTTNG_CONSUMER32_UST:
295 case LTTNG_CONSUMER64_UST:
296 lttng_ustconsumer_free_channel(channel);
297 break;
298 default:
299 ERR("Unknown consumer_data type");
300 abort();
301 }
302 free(channel);
303 }
304
305 /*
306 * RCU protected relayd socket pair free.
307 */
308 static void free_relayd_rcu(struct rcu_head *head)
309 {
310 struct lttng_ht_node_u64 *node =
311 caa_container_of(head, struct lttng_ht_node_u64, head);
312 struct consumer_relayd_sock_pair *relayd =
313 caa_container_of(node, struct consumer_relayd_sock_pair, node);
314
315 /*
316 * Close all sockets. This is done in the call RCU since we don't want the
317 * socket fds to be reassigned thus potentially creating bad state of the
318 * relayd object.
319 *
320 * We do not have to lock the control socket mutex here since at this stage
321 * there is no one referencing to this relayd object.
322 */
323 (void) relayd_close(&relayd->control_sock);
324 (void) relayd_close(&relayd->data_sock);
325
326 pthread_mutex_destroy(&relayd->ctrl_sock_mutex);
327 free(relayd);
328 }
329
330 /*
331 * Destroy and free relayd socket pair object.
332 */
333 void consumer_destroy_relayd(struct consumer_relayd_sock_pair *relayd)
334 {
335 int ret;
336 struct lttng_ht_iter iter;
337
338 if (relayd == NULL) {
339 return;
340 }
341
342 DBG("Consumer destroy and close relayd socket pair");
343
344 iter.iter.node = &relayd->node.node;
345 ret = lttng_ht_del(consumer_data.relayd_ht, &iter);
346 if (ret != 0) {
347 /* We assume the relayd is being or is destroyed */
348 return;
349 }
350
351 /* RCU free() call */
352 call_rcu(&relayd->node.head, free_relayd_rcu);
353 }
354
355 /*
356 * Remove a channel from the global list protected by a mutex. This function is
357 * also responsible for freeing its data structures.
358 */
359 void consumer_del_channel(struct lttng_consumer_channel *channel)
360 {
361 int ret;
362 struct lttng_ht_iter iter;
363
364 DBG("Consumer delete channel key %" PRIu64, channel->key);
365
366 pthread_mutex_lock(&consumer_data.lock);
367 pthread_mutex_lock(&channel->lock);
368
369 /* Destroy streams that might have been left in the stream list. */
370 clean_channel_stream_list(channel);
371
372 if (channel->live_timer_enabled == 1) {
373 consumer_timer_live_stop(channel);
374 }
375 if (channel->monitor_timer_enabled == 1) {
376 consumer_timer_monitor_stop(channel);
377 }
378
379 switch (consumer_data.type) {
380 case LTTNG_CONSUMER_KERNEL:
381 break;
382 case LTTNG_CONSUMER32_UST:
383 case LTTNG_CONSUMER64_UST:
384 lttng_ustconsumer_del_channel(channel);
385 break;
386 default:
387 ERR("Unknown consumer_data type");
388 assert(0);
389 goto end;
390 }
391
392 rcu_read_lock();
393 iter.iter.node = &channel->node.node;
394 ret = lttng_ht_del(consumer_data.channel_ht, &iter);
395 assert(!ret);
396 rcu_read_unlock();
397
398 call_rcu(&channel->node.head, free_channel_rcu);
399 end:
400 pthread_mutex_unlock(&channel->lock);
401 pthread_mutex_unlock(&consumer_data.lock);
402 }
403
404 /*
405 * Iterate over the relayd hash table and destroy each element. Finally,
406 * destroy the whole hash table.
407 */
408 static void cleanup_relayd_ht(void)
409 {
410 struct lttng_ht_iter iter;
411 struct consumer_relayd_sock_pair *relayd;
412
413 rcu_read_lock();
414
415 cds_lfht_for_each_entry(consumer_data.relayd_ht->ht, &iter.iter, relayd,
416 node.node) {
417 consumer_destroy_relayd(relayd);
418 }
419
420 rcu_read_unlock();
421
422 lttng_ht_destroy(consumer_data.relayd_ht);
423 }
424
425 /*
426 * Update the end point status of all streams having the given network sequence
427 * index (relayd index).
428 *
429 * It's atomically set without having the stream mutex locked which is fine
430 * because we handle the write/read race with a pipe wakeup for each thread.
431 */
432 static void update_endpoint_status_by_netidx(uint64_t net_seq_idx,
433 enum consumer_endpoint_status status)
434 {
435 struct lttng_ht_iter iter;
436 struct lttng_consumer_stream *stream;
437
438 DBG("Consumer set delete flag on stream by idx %" PRIu64, net_seq_idx);
439
440 rcu_read_lock();
441
442 /* Let's begin with metadata */
443 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) {
444 if (stream->net_seq_idx == net_seq_idx) {
445 uatomic_set(&stream->endpoint_status, status);
446 DBG("Delete flag set to metadata stream %d", stream->wait_fd);
447 }
448 }
449
450 /* Follow up by the data streams */
451 cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) {
452 if (stream->net_seq_idx == net_seq_idx) {
453 uatomic_set(&stream->endpoint_status, status);
454 DBG("Delete flag set to data stream %d", stream->wait_fd);
455 }
456 }
457 rcu_read_unlock();
458 }
459
460 /*
461 * Cleanup a relayd object by flagging every associated streams for deletion,
462 * destroying the object meaning removing it from the relayd hash table,
463 * closing the sockets and freeing the memory in a RCU call.
464 *
465 * If a local data context is available, notify the threads that the streams'
466 * state have changed.
467 */
468 void lttng_consumer_cleanup_relayd(struct consumer_relayd_sock_pair *relayd)
469 {
470 uint64_t netidx;
471
472 assert(relayd);
473
474 DBG("Cleaning up relayd object ID %"PRIu64, relayd->net_seq_idx);
475
476 /* Save the net sequence index before destroying the object */
477 netidx = relayd->net_seq_idx;
478
479 /*
480 * Delete the relayd from the relayd hash table, close the sockets and free
481 * the object in a RCU call.
482 */
483 consumer_destroy_relayd(relayd);
484
485 /* Set inactive endpoint to all streams */
486 update_endpoint_status_by_netidx(netidx, CONSUMER_ENDPOINT_INACTIVE);
487
488 /*
489 * With a local data context, notify the threads that the streams' state
490 * have changed. The write() action on the pipe acts as an "implicit"
491 * memory barrier ordering the updates of the end point status from the
492 * read of this status which happens AFTER receiving this notify.
493 */
494 notify_thread_lttng_pipe(relayd->ctx->consumer_data_pipe);
495 notify_thread_lttng_pipe(relayd->ctx->consumer_metadata_pipe);
496 }
497
498 /*
499 * Flag a relayd socket pair for destruction. Destroy it if the refcount
500 * reaches zero.
501 *
502 * RCU read side lock MUST be aquired before calling this function.
503 */
504 void consumer_flag_relayd_for_destroy(struct consumer_relayd_sock_pair *relayd)
505 {
506 assert(relayd);
507
508 /* Set destroy flag for this object */
509 uatomic_set(&relayd->destroy_flag, 1);
510
511 /* Destroy the relayd if refcount is 0 */
512 if (uatomic_read(&relayd->refcount) == 0) {
513 consumer_destroy_relayd(relayd);
514 }
515 }
516
517 /*
518 * Completly destroy stream from every visiable data structure and the given
519 * hash table if one.
520 *
521 * One this call returns, the stream object is not longer usable nor visible.
522 */
523 void consumer_del_stream(struct lttng_consumer_stream *stream,
524 struct lttng_ht *ht)
525 {
526 consumer_stream_destroy(stream, ht);
527 }
528
529 /*
530 * XXX naming of del vs destroy is all mixed up.
531 */
532 void consumer_del_stream_for_data(struct lttng_consumer_stream *stream)
533 {
534 consumer_stream_destroy(stream, data_ht);
535 }
536
537 void consumer_del_stream_for_metadata(struct lttng_consumer_stream *stream)
538 {
539 consumer_stream_destroy(stream, metadata_ht);
540 }
541
542 void consumer_stream_update_channel_attributes(
543 struct lttng_consumer_stream *stream,
544 struct lttng_consumer_channel *channel)
545 {
546 stream->channel_read_only_attributes.tracefile_size =
547 channel->tracefile_size;
548 memcpy(stream->channel_read_only_attributes.path, channel->pathname,
549 sizeof(stream->channel_read_only_attributes.path));
550 }
551
552 struct lttng_consumer_stream *consumer_allocate_stream(uint64_t channel_key,
553 uint64_t stream_key,
554 enum lttng_consumer_stream_state state,
555 const char *channel_name,
556 uid_t uid,
557 gid_t gid,
558 uint64_t relayd_id,
559 uint64_t session_id,
560 int cpu,
561 int *alloc_ret,
562 enum consumer_channel_type type,
563 unsigned int monitor,
564 uint64_t trace_archive_id)
565 {
566 int ret;
567 struct lttng_consumer_stream *stream;
568
569 stream = zmalloc(sizeof(*stream));
570 if (stream == NULL) {
571 PERROR("malloc struct lttng_consumer_stream");
572 ret = -ENOMEM;
573 goto end;
574 }
575
576 rcu_read_lock();
577
578 stream->key = stream_key;
579 stream->out_fd = -1;
580 stream->out_fd_offset = 0;
581 stream->output_written = 0;
582 stream->state = state;
583 stream->uid = uid;
584 stream->gid = gid;
585 stream->net_seq_idx = relayd_id;
586 stream->session_id = session_id;
587 stream->monitor = monitor;
588 stream->endpoint_status = CONSUMER_ENDPOINT_ACTIVE;
589 stream->index_file = NULL;
590 stream->last_sequence_number = -1ULL;
591 stream->trace_archive_id = trace_archive_id;
592 pthread_mutex_init(&stream->lock, NULL);
593 pthread_mutex_init(&stream->metadata_timer_lock, NULL);
594
595 /* If channel is the metadata, flag this stream as metadata. */
596 if (type == CONSUMER_CHANNEL_TYPE_METADATA) {
597 stream->metadata_flag = 1;
598 /* Metadata is flat out. */
599 strncpy(stream->name, DEFAULT_METADATA_NAME, sizeof(stream->name));
600 /* Live rendez-vous point. */
601 pthread_cond_init(&stream->metadata_rdv, NULL);
602 pthread_mutex_init(&stream->metadata_rdv_lock, NULL);
603 } else {
604 /* Format stream name to <channel_name>_<cpu_number> */
605 ret = snprintf(stream->name, sizeof(stream->name), "%s_%d",
606 channel_name, cpu);
607 if (ret < 0) {
608 PERROR("snprintf stream name");
609 goto error;
610 }
611 }
612
613 /* Key is always the wait_fd for streams. */
614 lttng_ht_node_init_u64(&stream->node, stream->key);
615
616 /* Init node per channel id key */
617 lttng_ht_node_init_u64(&stream->node_channel_id, channel_key);
618
619 /* Init session id node with the stream session id */
620 lttng_ht_node_init_u64(&stream->node_session_id, stream->session_id);
621
622 DBG3("Allocated stream %s (key %" PRIu64 ", chan_key %" PRIu64
623 " relayd_id %" PRIu64 ", session_id %" PRIu64,
624 stream->name, stream->key, channel_key,
625 stream->net_seq_idx, stream->session_id);
626
627 rcu_read_unlock();
628 return stream;
629
630 error:
631 rcu_read_unlock();
632 free(stream);
633 end:
634 if (alloc_ret) {
635 *alloc_ret = ret;
636 }
637 return NULL;
638 }
639
640 /*
641 * Add a stream to the global list protected by a mutex.
642 */
643 void consumer_add_data_stream(struct lttng_consumer_stream *stream)
644 {
645 struct lttng_ht *ht = data_ht;
646
647 assert(stream);
648 assert(ht);
649
650 DBG3("Adding consumer stream %" PRIu64, stream->key);
651
652 pthread_mutex_lock(&consumer_data.lock);
653 pthread_mutex_lock(&stream->chan->lock);
654 pthread_mutex_lock(&stream->chan->timer_lock);
655 pthread_mutex_lock(&stream->lock);
656 rcu_read_lock();
657
658 /* Steal stream identifier to avoid having streams with the same key */
659 steal_stream_key(stream->key, ht);
660
661 lttng_ht_add_unique_u64(ht, &stream->node);
662
663 lttng_ht_add_u64(consumer_data.stream_per_chan_id_ht,
664 &stream->node_channel_id);
665
666 /*
667 * Add stream to the stream_list_ht of the consumer data. No need to steal
668 * the key since the HT does not use it and we allow to add redundant keys
669 * into this table.
670 */
671 lttng_ht_add_u64(consumer_data.stream_list_ht, &stream->node_session_id);
672
673 /*
674 * When nb_init_stream_left reaches 0, we don't need to trigger any action
675 * in terms of destroying the associated channel, because the action that
676 * causes the count to become 0 also causes a stream to be added. The
677 * channel deletion will thus be triggered by the following removal of this
678 * stream.
679 */
680 if (uatomic_read(&stream->chan->nb_init_stream_left) > 0) {
681 /* Increment refcount before decrementing nb_init_stream_left */
682 cmm_smp_wmb();
683 uatomic_dec(&stream->chan->nb_init_stream_left);
684 }
685
686 /* Update consumer data once the node is inserted. */
687 consumer_data.stream_count++;
688 consumer_data.need_update = 1;
689
690 rcu_read_unlock();
691 pthread_mutex_unlock(&stream->lock);
692 pthread_mutex_unlock(&stream->chan->timer_lock);
693 pthread_mutex_unlock(&stream->chan->lock);
694 pthread_mutex_unlock(&consumer_data.lock);
695 }
696
697 void consumer_del_data_stream(struct lttng_consumer_stream *stream)
698 {
699 consumer_del_stream(stream, data_ht);
700 }
701
702 /*
703 * Add relayd socket to global consumer data hashtable. RCU read side lock MUST
704 * be acquired before calling this.
705 */
706 static int add_relayd(struct consumer_relayd_sock_pair *relayd)
707 {
708 int ret = 0;
709 struct lttng_ht_node_u64 *node;
710 struct lttng_ht_iter iter;
711
712 assert(relayd);
713
714 lttng_ht_lookup(consumer_data.relayd_ht,
715 &relayd->net_seq_idx, &iter);
716 node = lttng_ht_iter_get_node_u64(&iter);
717 if (node != NULL) {
718 goto end;
719 }
720 lttng_ht_add_unique_u64(consumer_data.relayd_ht, &relayd->node);
721
722 end:
723 return ret;
724 }
725
726 /*
727 * Allocate and return a consumer relayd socket.
728 */
729 static struct consumer_relayd_sock_pair *consumer_allocate_relayd_sock_pair(
730 uint64_t net_seq_idx)
731 {
732 struct consumer_relayd_sock_pair *obj = NULL;
733
734 /* net sequence index of -1 is a failure */
735 if (net_seq_idx == (uint64_t) -1ULL) {
736 goto error;
737 }
738
739 obj = zmalloc(sizeof(struct consumer_relayd_sock_pair));
740 if (obj == NULL) {
741 PERROR("zmalloc relayd sock");
742 goto error;
743 }
744
745 obj->net_seq_idx = net_seq_idx;
746 obj->refcount = 0;
747 obj->destroy_flag = 0;
748 obj->control_sock.sock.fd = -1;
749 obj->data_sock.sock.fd = -1;
750 lttng_ht_node_init_u64(&obj->node, obj->net_seq_idx);
751 pthread_mutex_init(&obj->ctrl_sock_mutex, NULL);
752
753 error:
754 return obj;
755 }
756
757 /*
758 * Find a relayd socket pair in the global consumer data.
759 *
760 * Return the object if found else NULL.
761 * RCU read-side lock must be held across this call and while using the
762 * returned object.
763 */
764 struct consumer_relayd_sock_pair *consumer_find_relayd(uint64_t key)
765 {
766 struct lttng_ht_iter iter;
767 struct lttng_ht_node_u64 *node;
768 struct consumer_relayd_sock_pair *relayd = NULL;
769
770 /* Negative keys are lookup failures */
771 if (key == (uint64_t) -1ULL) {
772 goto error;
773 }
774
775 lttng_ht_lookup(consumer_data.relayd_ht, &key,
776 &iter);
777 node = lttng_ht_iter_get_node_u64(&iter);
778 if (node != NULL) {
779 relayd = caa_container_of(node, struct consumer_relayd_sock_pair, node);
780 }
781
782 error:
783 return relayd;
784 }
785
786 /*
787 * Find a relayd and send the stream
788 *
789 * Returns 0 on success, < 0 on error
790 */
791 int consumer_send_relayd_stream(struct lttng_consumer_stream *stream,
792 char *path)
793 {
794 int ret = 0;
795 struct consumer_relayd_sock_pair *relayd;
796
797 assert(stream);
798 assert(stream->net_seq_idx != -1ULL);
799 assert(path);
800
801 /* The stream is not metadata. Get relayd reference if exists. */
802 rcu_read_lock();
803 relayd = consumer_find_relayd(stream->net_seq_idx);
804 if (relayd != NULL) {
805 /* Add stream on the relayd */
806 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
807 ret = relayd_add_stream(&relayd->control_sock, stream->name,
808 path, &stream->relayd_stream_id,
809 stream->chan->tracefile_size, stream->chan->tracefile_count,
810 stream->trace_archive_id);
811 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
812 if (ret < 0) {
813 ERR("Relayd add stream failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
814 lttng_consumer_cleanup_relayd(relayd);
815 goto end;
816 }
817
818 uatomic_inc(&relayd->refcount);
819 stream->sent_to_relayd = 1;
820 } else {
821 ERR("Stream %" PRIu64 " relayd ID %" PRIu64 " unknown. Can't send it.",
822 stream->key, stream->net_seq_idx);
823 ret = -1;
824 goto end;
825 }
826
827 DBG("Stream %s with key %" PRIu64 " sent to relayd id %" PRIu64,
828 stream->name, stream->key, stream->net_seq_idx);
829
830 end:
831 rcu_read_unlock();
832 return ret;
833 }
834
835 /*
836 * Find a relayd and send the streams sent message
837 *
838 * Returns 0 on success, < 0 on error
839 */
840 int consumer_send_relayd_streams_sent(uint64_t net_seq_idx)
841 {
842 int ret = 0;
843 struct consumer_relayd_sock_pair *relayd;
844
845 assert(net_seq_idx != -1ULL);
846
847 /* The stream is not metadata. Get relayd reference if exists. */
848 rcu_read_lock();
849 relayd = consumer_find_relayd(net_seq_idx);
850 if (relayd != NULL) {
851 /* Add stream on the relayd */
852 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
853 ret = relayd_streams_sent(&relayd->control_sock);
854 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
855 if (ret < 0) {
856 ERR("Relayd streams sent failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
857 lttng_consumer_cleanup_relayd(relayd);
858 goto end;
859 }
860 } else {
861 ERR("Relayd ID %" PRIu64 " unknown. Can't send streams_sent.",
862 net_seq_idx);
863 ret = -1;
864 goto end;
865 }
866
867 ret = 0;
868 DBG("All streams sent relayd id %" PRIu64, net_seq_idx);
869
870 end:
871 rcu_read_unlock();
872 return ret;
873 }
874
875 /*
876 * Find a relayd and close the stream
877 */
878 void close_relayd_stream(struct lttng_consumer_stream *stream)
879 {
880 struct consumer_relayd_sock_pair *relayd;
881
882 /* The stream is not metadata. Get relayd reference if exists. */
883 rcu_read_lock();
884 relayd = consumer_find_relayd(stream->net_seq_idx);
885 if (relayd) {
886 consumer_stream_relayd_close(stream, relayd);
887 }
888 rcu_read_unlock();
889 }
890
891 /*
892 * Handle stream for relayd transmission if the stream applies for network
893 * streaming where the net sequence index is set.
894 *
895 * Return destination file descriptor or negative value on error.
896 */
897 static int write_relayd_stream_header(struct lttng_consumer_stream *stream,
898 size_t data_size, unsigned long padding,
899 struct consumer_relayd_sock_pair *relayd)
900 {
901 int outfd = -1, ret;
902 struct lttcomm_relayd_data_hdr data_hdr;
903
904 /* Safety net */
905 assert(stream);
906 assert(relayd);
907
908 /* Reset data header */
909 memset(&data_hdr, 0, sizeof(data_hdr));
910
911 if (stream->metadata_flag) {
912 /* Caller MUST acquire the relayd control socket lock */
913 ret = relayd_send_metadata(&relayd->control_sock, data_size);
914 if (ret < 0) {
915 goto error;
916 }
917
918 /* Metadata are always sent on the control socket. */
919 outfd = relayd->control_sock.sock.fd;
920 } else {
921 /* Set header with stream information */
922 data_hdr.stream_id = htobe64(stream->relayd_stream_id);
923 data_hdr.data_size = htobe32(data_size);
924 data_hdr.padding_size = htobe32(padding);
925 /*
926 * Note that net_seq_num below is assigned with the *current* value of
927 * next_net_seq_num and only after that the next_net_seq_num will be
928 * increment. This is why when issuing a command on the relayd using
929 * this next value, 1 should always be substracted in order to compare
930 * the last seen sequence number on the relayd side to the last sent.
931 */
932 data_hdr.net_seq_num = htobe64(stream->next_net_seq_num);
933 /* Other fields are zeroed previously */
934
935 ret = relayd_send_data_hdr(&relayd->data_sock, &data_hdr,
936 sizeof(data_hdr));
937 if (ret < 0) {
938 goto error;
939 }
940
941 ++stream->next_net_seq_num;
942
943 /* Set to go on data socket */
944 outfd = relayd->data_sock.sock.fd;
945 }
946
947 error:
948 return outfd;
949 }
950
951 /*
952 * Allocate and return a new lttng_consumer_channel object using the given key
953 * to initialize the hash table node.
954 *
955 * On error, return NULL.
956 */
957 struct lttng_consumer_channel *consumer_allocate_channel(uint64_t key,
958 uint64_t session_id,
959 const char *pathname,
960 const char *name,
961 uid_t uid,
962 gid_t gid,
963 uint64_t relayd_id,
964 enum lttng_event_output output,
965 uint64_t tracefile_size,
966 uint64_t tracefile_count,
967 uint64_t session_id_per_pid,
968 unsigned int monitor,
969 unsigned int live_timer_interval,
970 const char *root_shm_path,
971 const char *shm_path)
972 {
973 struct lttng_consumer_channel *channel;
974
975 channel = zmalloc(sizeof(*channel));
976 if (channel == NULL) {
977 PERROR("malloc struct lttng_consumer_channel");
978 goto end;
979 }
980
981 channel->key = key;
982 channel->refcount = 0;
983 channel->session_id = session_id;
984 channel->session_id_per_pid = session_id_per_pid;
985 channel->uid = uid;
986 channel->gid = gid;
987 channel->relayd_id = relayd_id;
988 channel->tracefile_size = tracefile_size;
989 channel->tracefile_count = tracefile_count;
990 channel->monitor = monitor;
991 channel->live_timer_interval = live_timer_interval;
992 pthread_mutex_init(&channel->lock, NULL);
993 pthread_mutex_init(&channel->timer_lock, NULL);
994
995 switch (output) {
996 case LTTNG_EVENT_SPLICE:
997 channel->output = CONSUMER_CHANNEL_SPLICE;
998 break;
999 case LTTNG_EVENT_MMAP:
1000 channel->output = CONSUMER_CHANNEL_MMAP;
1001 break;
1002 default:
1003 assert(0);
1004 free(channel);
1005 channel = NULL;
1006 goto end;
1007 }
1008
1009 /*
1010 * In monitor mode, the streams associated with the channel will be put in
1011 * a special list ONLY owned by this channel. So, the refcount is set to 1
1012 * here meaning that the channel itself has streams that are referenced.
1013 *
1014 * On a channel deletion, once the channel is no longer visible, the
1015 * refcount is decremented and checked for a zero value to delete it. With
1016 * streams in no monitor mode, it will now be safe to destroy the channel.
1017 */
1018 if (!channel->monitor) {
1019 channel->refcount = 1;
1020 }
1021
1022 strncpy(channel->pathname, pathname, sizeof(channel->pathname));
1023 channel->pathname[sizeof(channel->pathname) - 1] = '\0';
1024
1025 strncpy(channel->name, name, sizeof(channel->name));
1026 channel->name[sizeof(channel->name) - 1] = '\0';
1027
1028 if (root_shm_path) {
1029 strncpy(channel->root_shm_path, root_shm_path, sizeof(channel->root_shm_path));
1030 channel->root_shm_path[sizeof(channel->root_shm_path) - 1] = '\0';
1031 }
1032 if (shm_path) {
1033 strncpy(channel->shm_path, shm_path, sizeof(channel->shm_path));
1034 channel->shm_path[sizeof(channel->shm_path) - 1] = '\0';
1035 }
1036
1037 lttng_ht_node_init_u64(&channel->node, channel->key);
1038
1039 channel->wait_fd = -1;
1040
1041 CDS_INIT_LIST_HEAD(&channel->streams.head);
1042
1043 DBG("Allocated channel (key %" PRIu64 ")", channel->key);
1044
1045 end:
1046 return channel;
1047 }
1048
1049 /*
1050 * Add a channel to the global list protected by a mutex.
1051 *
1052 * Always return 0 indicating success.
1053 */
1054 int consumer_add_channel(struct lttng_consumer_channel *channel,
1055 struct lttng_consumer_local_data *ctx)
1056 {
1057 pthread_mutex_lock(&consumer_data.lock);
1058 pthread_mutex_lock(&channel->lock);
1059 pthread_mutex_lock(&channel->timer_lock);
1060
1061 /*
1062 * This gives us a guarantee that the channel we are about to add to the
1063 * channel hash table will be unique. See this function comment on the why
1064 * we need to steel the channel key at this stage.
1065 */
1066 steal_channel_key(channel->key);
1067
1068 rcu_read_lock();
1069 lttng_ht_add_unique_u64(consumer_data.channel_ht, &channel->node);
1070 rcu_read_unlock();
1071
1072 pthread_mutex_unlock(&channel->timer_lock);
1073 pthread_mutex_unlock(&channel->lock);
1074 pthread_mutex_unlock(&consumer_data.lock);
1075
1076 if (channel->wait_fd != -1 && channel->type == CONSUMER_CHANNEL_TYPE_DATA) {
1077 notify_channel_pipe(ctx, channel, -1, CONSUMER_CHANNEL_ADD);
1078 }
1079
1080 return 0;
1081 }
1082
1083 /*
1084 * Allocate the pollfd structure and the local view of the out fds to avoid
1085 * doing a lookup in the linked list and concurrency issues when writing is
1086 * needed. Called with consumer_data.lock held.
1087 *
1088 * Returns the number of fds in the structures.
1089 */
1090 static int update_poll_array(struct lttng_consumer_local_data *ctx,
1091 struct pollfd **pollfd, struct lttng_consumer_stream **local_stream,
1092 struct lttng_ht *ht, int *nb_inactive_fd)
1093 {
1094 int i = 0;
1095 struct lttng_ht_iter iter;
1096 struct lttng_consumer_stream *stream;
1097
1098 assert(ctx);
1099 assert(ht);
1100 assert(pollfd);
1101 assert(local_stream);
1102
1103 DBG("Updating poll fd array");
1104 *nb_inactive_fd = 0;
1105 rcu_read_lock();
1106 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1107 /*
1108 * Only active streams with an active end point can be added to the
1109 * poll set and local stream storage of the thread.
1110 *
1111 * There is a potential race here for endpoint_status to be updated
1112 * just after the check. However, this is OK since the stream(s) will
1113 * be deleted once the thread is notified that the end point state has
1114 * changed where this function will be called back again.
1115 *
1116 * We track the number of inactive FDs because they still need to be
1117 * closed by the polling thread after a wakeup on the data_pipe or
1118 * metadata_pipe.
1119 */
1120 if (stream->state != LTTNG_CONSUMER_ACTIVE_STREAM ||
1121 stream->endpoint_status == CONSUMER_ENDPOINT_INACTIVE) {
1122 (*nb_inactive_fd)++;
1123 continue;
1124 }
1125 /*
1126 * This clobbers way too much the debug output. Uncomment that if you
1127 * need it for debugging purposes.
1128 *
1129 * DBG("Active FD %d", stream->wait_fd);
1130 */
1131 (*pollfd)[i].fd = stream->wait_fd;
1132 (*pollfd)[i].events = POLLIN | POLLPRI;
1133 local_stream[i] = stream;
1134 i++;
1135 }
1136 rcu_read_unlock();
1137
1138 /*
1139 * Insert the consumer_data_pipe at the end of the array and don't
1140 * increment i so nb_fd is the number of real FD.
1141 */
1142 (*pollfd)[i].fd = lttng_pipe_get_readfd(ctx->consumer_data_pipe);
1143 (*pollfd)[i].events = POLLIN | POLLPRI;
1144
1145 (*pollfd)[i + 1].fd = lttng_pipe_get_readfd(ctx->consumer_wakeup_pipe);
1146 (*pollfd)[i + 1].events = POLLIN | POLLPRI;
1147 return i;
1148 }
1149
1150 /*
1151 * Poll on the should_quit pipe and the command socket return -1 on
1152 * error, 1 if should exit, 0 if data is available on the command socket
1153 */
1154 int lttng_consumer_poll_socket(struct pollfd *consumer_sockpoll)
1155 {
1156 int num_rdy;
1157
1158 restart:
1159 num_rdy = poll(consumer_sockpoll, 2, -1);
1160 if (num_rdy == -1) {
1161 /*
1162 * Restart interrupted system call.
1163 */
1164 if (errno == EINTR) {
1165 goto restart;
1166 }
1167 PERROR("Poll error");
1168 return -1;
1169 }
1170 if (consumer_sockpoll[0].revents & (POLLIN | POLLPRI)) {
1171 DBG("consumer_should_quit wake up");
1172 return 1;
1173 }
1174 return 0;
1175 }
1176
1177 /*
1178 * Set the error socket.
1179 */
1180 void lttng_consumer_set_error_sock(struct lttng_consumer_local_data *ctx,
1181 int sock)
1182 {
1183 ctx->consumer_error_socket = sock;
1184 }
1185
1186 /*
1187 * Set the command socket path.
1188 */
1189 void lttng_consumer_set_command_sock_path(
1190 struct lttng_consumer_local_data *ctx, char *sock)
1191 {
1192 ctx->consumer_command_sock_path = sock;
1193 }
1194
1195 /*
1196 * Send return code to the session daemon.
1197 * If the socket is not defined, we return 0, it is not a fatal error
1198 */
1199 int lttng_consumer_send_error(struct lttng_consumer_local_data *ctx, int cmd)
1200 {
1201 if (ctx->consumer_error_socket > 0) {
1202 return lttcomm_send_unix_sock(ctx->consumer_error_socket, &cmd,
1203 sizeof(enum lttcomm_sessiond_command));
1204 }
1205
1206 return 0;
1207 }
1208
1209 /*
1210 * Close all the tracefiles and stream fds and MUST be called when all
1211 * instances are destroyed i.e. when all threads were joined and are ended.
1212 */
1213 void lttng_consumer_cleanup(void)
1214 {
1215 struct lttng_ht_iter iter;
1216 struct lttng_consumer_channel *channel;
1217
1218 rcu_read_lock();
1219
1220 cds_lfht_for_each_entry(consumer_data.channel_ht->ht, &iter.iter, channel,
1221 node.node) {
1222 consumer_del_channel(channel);
1223 }
1224
1225 rcu_read_unlock();
1226
1227 lttng_ht_destroy(consumer_data.channel_ht);
1228
1229 cleanup_relayd_ht();
1230
1231 lttng_ht_destroy(consumer_data.stream_per_chan_id_ht);
1232
1233 /*
1234 * This HT contains streams that are freed by either the metadata thread or
1235 * the data thread so we do *nothing* on the hash table and simply destroy
1236 * it.
1237 */
1238 lttng_ht_destroy(consumer_data.stream_list_ht);
1239 }
1240
1241 /*
1242 * Called from signal handler.
1243 */
1244 void lttng_consumer_should_exit(struct lttng_consumer_local_data *ctx)
1245 {
1246 ssize_t ret;
1247
1248 CMM_STORE_SHARED(consumer_quit, 1);
1249 ret = lttng_write(ctx->consumer_should_quit[1], "4", 1);
1250 if (ret < 1) {
1251 PERROR("write consumer quit");
1252 }
1253
1254 DBG("Consumer flag that it should quit");
1255 }
1256
1257
1258 /*
1259 * Flush pending writes to trace output disk file.
1260 */
1261 static
1262 void lttng_consumer_sync_trace_file(struct lttng_consumer_stream *stream,
1263 off_t orig_offset)
1264 {
1265 int ret;
1266 int outfd = stream->out_fd;
1267
1268 /*
1269 * This does a blocking write-and-wait on any page that belongs to the
1270 * subbuffer prior to the one we just wrote.
1271 * Don't care about error values, as these are just hints and ways to
1272 * limit the amount of page cache used.
1273 */
1274 if (orig_offset < stream->max_sb_size) {
1275 return;
1276 }
1277 lttng_sync_file_range(outfd, orig_offset - stream->max_sb_size,
1278 stream->max_sb_size,
1279 SYNC_FILE_RANGE_WAIT_BEFORE
1280 | SYNC_FILE_RANGE_WRITE
1281 | SYNC_FILE_RANGE_WAIT_AFTER);
1282 /*
1283 * Give hints to the kernel about how we access the file:
1284 * POSIX_FADV_DONTNEED : we won't re-access data in a near future after
1285 * we write it.
1286 *
1287 * We need to call fadvise again after the file grows because the
1288 * kernel does not seem to apply fadvise to non-existing parts of the
1289 * file.
1290 *
1291 * Call fadvise _after_ having waited for the page writeback to
1292 * complete because the dirty page writeback semantic is not well
1293 * defined. So it can be expected to lead to lower throughput in
1294 * streaming.
1295 */
1296 ret = posix_fadvise(outfd, orig_offset - stream->max_sb_size,
1297 stream->max_sb_size, POSIX_FADV_DONTNEED);
1298 if (ret && ret != -ENOSYS) {
1299 errno = ret;
1300 PERROR("posix_fadvise on fd %i", outfd);
1301 }
1302 }
1303
1304 /*
1305 * Initialise the necessary environnement :
1306 * - create a new context
1307 * - create the poll_pipe
1308 * - create the should_quit pipe (for signal handler)
1309 * - create the thread pipe (for splice)
1310 *
1311 * Takes a function pointer as argument, this function is called when data is
1312 * available on a buffer. This function is responsible to do the
1313 * kernctl_get_next_subbuf, read the data with mmap or splice depending on the
1314 * buffer configuration and then kernctl_put_next_subbuf at the end.
1315 *
1316 * Returns a pointer to the new context or NULL on error.
1317 */
1318 struct lttng_consumer_local_data *lttng_consumer_create(
1319 enum lttng_consumer_type type,
1320 ssize_t (*buffer_ready)(struct lttng_consumer_stream *stream,
1321 struct lttng_consumer_local_data *ctx),
1322 int (*recv_channel)(struct lttng_consumer_channel *channel),
1323 int (*recv_stream)(struct lttng_consumer_stream *stream),
1324 int (*update_stream)(uint64_t stream_key, uint32_t state))
1325 {
1326 int ret;
1327 struct lttng_consumer_local_data *ctx;
1328
1329 assert(consumer_data.type == LTTNG_CONSUMER_UNKNOWN ||
1330 consumer_data.type == type);
1331 consumer_data.type = type;
1332
1333 ctx = zmalloc(sizeof(struct lttng_consumer_local_data));
1334 if (ctx == NULL) {
1335 PERROR("allocating context");
1336 goto error;
1337 }
1338
1339 ctx->consumer_error_socket = -1;
1340 ctx->consumer_metadata_socket = -1;
1341 pthread_mutex_init(&ctx->metadata_socket_lock, NULL);
1342 /* assign the callbacks */
1343 ctx->on_buffer_ready = buffer_ready;
1344 ctx->on_recv_channel = recv_channel;
1345 ctx->on_recv_stream = recv_stream;
1346 ctx->on_update_stream = update_stream;
1347
1348 ctx->consumer_data_pipe = lttng_pipe_open(0);
1349 if (!ctx->consumer_data_pipe) {
1350 goto error_poll_pipe;
1351 }
1352
1353 ctx->consumer_wakeup_pipe = lttng_pipe_open(0);
1354 if (!ctx->consumer_wakeup_pipe) {
1355 goto error_wakeup_pipe;
1356 }
1357
1358 ret = pipe(ctx->consumer_should_quit);
1359 if (ret < 0) {
1360 PERROR("Error creating recv pipe");
1361 goto error_quit_pipe;
1362 }
1363
1364 ret = pipe(ctx->consumer_channel_pipe);
1365 if (ret < 0) {
1366 PERROR("Error creating channel pipe");
1367 goto error_channel_pipe;
1368 }
1369
1370 ctx->consumer_metadata_pipe = lttng_pipe_open(0);
1371 if (!ctx->consumer_metadata_pipe) {
1372 goto error_metadata_pipe;
1373 }
1374
1375 ctx->channel_monitor_pipe = -1;
1376
1377 return ctx;
1378
1379 error_metadata_pipe:
1380 utils_close_pipe(ctx->consumer_channel_pipe);
1381 error_channel_pipe:
1382 utils_close_pipe(ctx->consumer_should_quit);
1383 error_quit_pipe:
1384 lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
1385 error_wakeup_pipe:
1386 lttng_pipe_destroy(ctx->consumer_data_pipe);
1387 error_poll_pipe:
1388 free(ctx);
1389 error:
1390 return NULL;
1391 }
1392
1393 /*
1394 * Iterate over all streams of the hashtable and free them properly.
1395 */
1396 static void destroy_data_stream_ht(struct lttng_ht *ht)
1397 {
1398 struct lttng_ht_iter iter;
1399 struct lttng_consumer_stream *stream;
1400
1401 if (ht == NULL) {
1402 return;
1403 }
1404
1405 rcu_read_lock();
1406 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1407 /*
1408 * Ignore return value since we are currently cleaning up so any error
1409 * can't be handled.
1410 */
1411 (void) consumer_del_stream(stream, ht);
1412 }
1413 rcu_read_unlock();
1414
1415 lttng_ht_destroy(ht);
1416 }
1417
1418 /*
1419 * Iterate over all streams of the metadata hashtable and free them
1420 * properly.
1421 */
1422 static void destroy_metadata_stream_ht(struct lttng_ht *ht)
1423 {
1424 struct lttng_ht_iter iter;
1425 struct lttng_consumer_stream *stream;
1426
1427 if (ht == NULL) {
1428 return;
1429 }
1430
1431 rcu_read_lock();
1432 cds_lfht_for_each_entry(ht->ht, &iter.iter, stream, node.node) {
1433 /*
1434 * Ignore return value since we are currently cleaning up so any error
1435 * can't be handled.
1436 */
1437 (void) consumer_del_metadata_stream(stream, ht);
1438 }
1439 rcu_read_unlock();
1440
1441 lttng_ht_destroy(ht);
1442 }
1443
1444 /*
1445 * Close all fds associated with the instance and free the context.
1446 */
1447 void lttng_consumer_destroy(struct lttng_consumer_local_data *ctx)
1448 {
1449 int ret;
1450
1451 DBG("Consumer destroying it. Closing everything.");
1452
1453 if (!ctx) {
1454 return;
1455 }
1456
1457 destroy_data_stream_ht(data_ht);
1458 destroy_metadata_stream_ht(metadata_ht);
1459
1460 ret = close(ctx->consumer_error_socket);
1461 if (ret) {
1462 PERROR("close");
1463 }
1464 ret = close(ctx->consumer_metadata_socket);
1465 if (ret) {
1466 PERROR("close");
1467 }
1468 utils_close_pipe(ctx->consumer_channel_pipe);
1469 lttng_pipe_destroy(ctx->consumer_data_pipe);
1470 lttng_pipe_destroy(ctx->consumer_metadata_pipe);
1471 lttng_pipe_destroy(ctx->consumer_wakeup_pipe);
1472 utils_close_pipe(ctx->consumer_should_quit);
1473
1474 unlink(ctx->consumer_command_sock_path);
1475 free(ctx);
1476 }
1477
1478 /*
1479 * Write the metadata stream id on the specified file descriptor.
1480 */
1481 static int write_relayd_metadata_id(int fd,
1482 struct lttng_consumer_stream *stream,
1483 unsigned long padding)
1484 {
1485 ssize_t ret;
1486 struct lttcomm_relayd_metadata_payload hdr;
1487
1488 hdr.stream_id = htobe64(stream->relayd_stream_id);
1489 hdr.padding_size = htobe32(padding);
1490 ret = lttng_write(fd, (void *) &hdr, sizeof(hdr));
1491 if (ret < sizeof(hdr)) {
1492 /*
1493 * This error means that the fd's end is closed so ignore the PERROR
1494 * not to clubber the error output since this can happen in a normal
1495 * code path.
1496 */
1497 if (errno != EPIPE) {
1498 PERROR("write metadata stream id");
1499 }
1500 DBG3("Consumer failed to write relayd metadata id (errno: %d)", errno);
1501 /*
1502 * Set ret to a negative value because if ret != sizeof(hdr), we don't
1503 * handle writting the missing part so report that as an error and
1504 * don't lie to the caller.
1505 */
1506 ret = -1;
1507 goto end;
1508 }
1509 DBG("Metadata stream id %" PRIu64 " with padding %lu written before data",
1510 stream->relayd_stream_id, padding);
1511
1512 end:
1513 return (int) ret;
1514 }
1515
1516 /*
1517 * Mmap the ring buffer, read it and write the data to the tracefile. This is a
1518 * core function for writing trace buffers to either the local filesystem or
1519 * the network.
1520 *
1521 * It must be called with the stream lock held.
1522 *
1523 * Careful review MUST be put if any changes occur!
1524 *
1525 * Returns the number of bytes written
1526 */
1527 ssize_t lttng_consumer_on_read_subbuffer_mmap(
1528 struct lttng_consumer_local_data *ctx,
1529 struct lttng_consumer_stream *stream, unsigned long len,
1530 unsigned long padding,
1531 struct ctf_packet_index *index)
1532 {
1533 unsigned long mmap_offset;
1534 void *mmap_base;
1535 ssize_t ret = 0;
1536 off_t orig_offset = stream->out_fd_offset;
1537 /* Default is on the disk */
1538 int outfd = stream->out_fd;
1539 struct consumer_relayd_sock_pair *relayd = NULL;
1540 unsigned int relayd_hang_up = 0;
1541
1542 /* RCU lock for the relayd pointer */
1543 rcu_read_lock();
1544
1545 /* Flag that the current stream if set for network streaming. */
1546 if (stream->net_seq_idx != (uint64_t) -1ULL) {
1547 relayd = consumer_find_relayd(stream->net_seq_idx);
1548 if (relayd == NULL) {
1549 ret = -EPIPE;
1550 goto end;
1551 }
1552 }
1553
1554 /* get the offset inside the fd to mmap */
1555 switch (consumer_data.type) {
1556 case LTTNG_CONSUMER_KERNEL:
1557 mmap_base = stream->mmap_base;
1558 ret = kernctl_get_mmap_read_offset(stream->wait_fd, &mmap_offset);
1559 if (ret < 0) {
1560 PERROR("tracer ctl get_mmap_read_offset");
1561 goto end;
1562 }
1563 break;
1564 case LTTNG_CONSUMER32_UST:
1565 case LTTNG_CONSUMER64_UST:
1566 mmap_base = lttng_ustctl_get_mmap_base(stream);
1567 if (!mmap_base) {
1568 ERR("read mmap get mmap base for stream %s", stream->name);
1569 ret = -EPERM;
1570 goto end;
1571 }
1572 ret = lttng_ustctl_get_mmap_read_offset(stream, &mmap_offset);
1573 if (ret != 0) {
1574 PERROR("tracer ctl get_mmap_read_offset");
1575 ret = -EINVAL;
1576 goto end;
1577 }
1578 break;
1579 default:
1580 ERR("Unknown consumer_data type");
1581 assert(0);
1582 }
1583
1584 /* Handle stream on the relayd if the output is on the network */
1585 if (relayd) {
1586 unsigned long netlen = len;
1587
1588 /*
1589 * Lock the control socket for the complete duration of the function
1590 * since from this point on we will use the socket.
1591 */
1592 if (stream->metadata_flag) {
1593 /* Metadata requires the control socket. */
1594 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
1595 if (stream->reset_metadata_flag) {
1596 ret = relayd_reset_metadata(&relayd->control_sock,
1597 stream->relayd_stream_id,
1598 stream->metadata_version);
1599 if (ret < 0) {
1600 relayd_hang_up = 1;
1601 goto write_error;
1602 }
1603 stream->reset_metadata_flag = 0;
1604 }
1605 netlen += sizeof(struct lttcomm_relayd_metadata_payload);
1606 }
1607
1608 ret = write_relayd_stream_header(stream, netlen, padding, relayd);
1609 if (ret < 0) {
1610 relayd_hang_up = 1;
1611 goto write_error;
1612 }
1613 /* Use the returned socket. */
1614 outfd = ret;
1615
1616 /* Write metadata stream id before payload */
1617 if (stream->metadata_flag) {
1618 ret = write_relayd_metadata_id(outfd, stream, padding);
1619 if (ret < 0) {
1620 relayd_hang_up = 1;
1621 goto write_error;
1622 }
1623 }
1624 } else {
1625 /* No streaming, we have to set the len with the full padding */
1626 len += padding;
1627
1628 if (stream->metadata_flag && stream->reset_metadata_flag) {
1629 ret = utils_truncate_stream_file(stream->out_fd, 0);
1630 if (ret < 0) {
1631 ERR("Reset metadata file");
1632 goto end;
1633 }
1634 stream->reset_metadata_flag = 0;
1635 }
1636
1637 /*
1638 * Check if we need to change the tracefile before writing the packet.
1639 */
1640 if (stream->chan->tracefile_size > 0 &&
1641 (stream->tracefile_size_current + len) >
1642 stream->chan->tracefile_size) {
1643 ret = utils_rotate_stream_file(stream->chan->pathname,
1644 stream->name, stream->chan->tracefile_size,
1645 stream->chan->tracefile_count, stream->uid, stream->gid,
1646 stream->out_fd, &(stream->tracefile_count_current),
1647 &stream->out_fd);
1648 if (ret < 0) {
1649 ERR("Rotating output file");
1650 goto end;
1651 }
1652 outfd = stream->out_fd;
1653
1654 if (stream->index_file) {
1655 lttng_index_file_put(stream->index_file);
1656 stream->index_file = lttng_index_file_create(stream->chan->pathname,
1657 stream->name, stream->uid, stream->gid,
1658 stream->chan->tracefile_size,
1659 stream->tracefile_count_current,
1660 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
1661 if (!stream->index_file) {
1662 goto end;
1663 }
1664 }
1665
1666 /* Reset current size because we just perform a rotation. */
1667 stream->tracefile_size_current = 0;
1668 stream->out_fd_offset = 0;
1669 orig_offset = 0;
1670 }
1671 stream->tracefile_size_current += len;
1672 if (index) {
1673 index->offset = htobe64(stream->out_fd_offset);
1674 }
1675 }
1676
1677 /*
1678 * This call guarantee that len or less is returned. It's impossible to
1679 * receive a ret value that is bigger than len.
1680 */
1681 ret = lttng_write(outfd, mmap_base + mmap_offset, len);
1682 DBG("Consumer mmap write() ret %zd (len %lu)", ret, len);
1683 if (ret < 0 || ((size_t) ret != len)) {
1684 /*
1685 * Report error to caller if nothing was written else at least send the
1686 * amount written.
1687 */
1688 if (ret < 0) {
1689 ret = -errno;
1690 }
1691 relayd_hang_up = 1;
1692
1693 /* Socket operation failed. We consider the relayd dead */
1694 if (errno == EPIPE || errno == EINVAL || errno == EBADF) {
1695 /*
1696 * This is possible if the fd is closed on the other side
1697 * (outfd) or any write problem. It can be verbose a bit for a
1698 * normal execution if for instance the relayd is stopped
1699 * abruptly. This can happen so set this to a DBG statement.
1700 */
1701 DBG("Consumer mmap write detected relayd hang up");
1702 } else {
1703 /* Unhandled error, print it and stop function right now. */
1704 PERROR("Error in write mmap (ret %zd != len %lu)", ret, len);
1705 }
1706 goto write_error;
1707 }
1708 stream->output_written += ret;
1709
1710 /* This call is useless on a socket so better save a syscall. */
1711 if (!relayd) {
1712 /* This won't block, but will start writeout asynchronously */
1713 lttng_sync_file_range(outfd, stream->out_fd_offset, len,
1714 SYNC_FILE_RANGE_WRITE);
1715 stream->out_fd_offset += len;
1716 lttng_consumer_sync_trace_file(stream, orig_offset);
1717 }
1718
1719 write_error:
1720 /*
1721 * This is a special case that the relayd has closed its socket. Let's
1722 * cleanup the relayd object and all associated streams.
1723 */
1724 if (relayd && relayd_hang_up) {
1725 ERR("Relayd hangup. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
1726 lttng_consumer_cleanup_relayd(relayd);
1727 }
1728
1729 end:
1730 /* Unlock only if ctrl socket used */
1731 if (relayd && stream->metadata_flag) {
1732 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
1733 }
1734
1735 rcu_read_unlock();
1736 return ret;
1737 }
1738
1739 /*
1740 * Splice the data from the ring buffer to the tracefile.
1741 *
1742 * It must be called with the stream lock held.
1743 *
1744 * Returns the number of bytes spliced.
1745 */
1746 ssize_t lttng_consumer_on_read_subbuffer_splice(
1747 struct lttng_consumer_local_data *ctx,
1748 struct lttng_consumer_stream *stream, unsigned long len,
1749 unsigned long padding,
1750 struct ctf_packet_index *index)
1751 {
1752 ssize_t ret = 0, written = 0, ret_splice = 0;
1753 loff_t offset = 0;
1754 off_t orig_offset = stream->out_fd_offset;
1755 int fd = stream->wait_fd;
1756 /* Default is on the disk */
1757 int outfd = stream->out_fd;
1758 struct consumer_relayd_sock_pair *relayd = NULL;
1759 int *splice_pipe;
1760 unsigned int relayd_hang_up = 0;
1761
1762 switch (consumer_data.type) {
1763 case LTTNG_CONSUMER_KERNEL:
1764 break;
1765 case LTTNG_CONSUMER32_UST:
1766 case LTTNG_CONSUMER64_UST:
1767 /* Not supported for user space tracing */
1768 return -ENOSYS;
1769 default:
1770 ERR("Unknown consumer_data type");
1771 assert(0);
1772 }
1773
1774 /* RCU lock for the relayd pointer */
1775 rcu_read_lock();
1776
1777 /* Flag that the current stream if set for network streaming. */
1778 if (stream->net_seq_idx != (uint64_t) -1ULL) {
1779 relayd = consumer_find_relayd(stream->net_seq_idx);
1780 if (relayd == NULL) {
1781 written = -ret;
1782 goto end;
1783 }
1784 }
1785 splice_pipe = stream->splice_pipe;
1786
1787 /* Write metadata stream id before payload */
1788 if (relayd) {
1789 unsigned long total_len = len;
1790
1791 if (stream->metadata_flag) {
1792 /*
1793 * Lock the control socket for the complete duration of the function
1794 * since from this point on we will use the socket.
1795 */
1796 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
1797
1798 if (stream->reset_metadata_flag) {
1799 ret = relayd_reset_metadata(&relayd->control_sock,
1800 stream->relayd_stream_id,
1801 stream->metadata_version);
1802 if (ret < 0) {
1803 relayd_hang_up = 1;
1804 goto write_error;
1805 }
1806 stream->reset_metadata_flag = 0;
1807 }
1808 ret = write_relayd_metadata_id(splice_pipe[1], stream,
1809 padding);
1810 if (ret < 0) {
1811 written = ret;
1812 relayd_hang_up = 1;
1813 goto write_error;
1814 }
1815
1816 total_len += sizeof(struct lttcomm_relayd_metadata_payload);
1817 }
1818
1819 ret = write_relayd_stream_header(stream, total_len, padding, relayd);
1820 if (ret < 0) {
1821 written = ret;
1822 relayd_hang_up = 1;
1823 goto write_error;
1824 }
1825 /* Use the returned socket. */
1826 outfd = ret;
1827 } else {
1828 /* No streaming, we have to set the len with the full padding */
1829 len += padding;
1830
1831 if (stream->metadata_flag && stream->reset_metadata_flag) {
1832 ret = utils_truncate_stream_file(stream->out_fd, 0);
1833 if (ret < 0) {
1834 ERR("Reset metadata file");
1835 goto end;
1836 }
1837 stream->reset_metadata_flag = 0;
1838 }
1839 /*
1840 * Check if we need to change the tracefile before writing the packet.
1841 */
1842 if (stream->chan->tracefile_size > 0 &&
1843 (stream->tracefile_size_current + len) >
1844 stream->chan->tracefile_size) {
1845 ret = utils_rotate_stream_file(stream->chan->pathname,
1846 stream->name, stream->chan->tracefile_size,
1847 stream->chan->tracefile_count, stream->uid, stream->gid,
1848 stream->out_fd, &(stream->tracefile_count_current),
1849 &stream->out_fd);
1850 if (ret < 0) {
1851 written = ret;
1852 ERR("Rotating output file");
1853 goto end;
1854 }
1855 outfd = stream->out_fd;
1856
1857 if (stream->index_file) {
1858 lttng_index_file_put(stream->index_file);
1859 stream->index_file = lttng_index_file_create(stream->chan->pathname,
1860 stream->name, stream->uid, stream->gid,
1861 stream->chan->tracefile_size,
1862 stream->tracefile_count_current,
1863 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
1864 if (!stream->index_file) {
1865 goto end;
1866 }
1867 }
1868
1869 /* Reset current size because we just perform a rotation. */
1870 stream->tracefile_size_current = 0;
1871 stream->out_fd_offset = 0;
1872 orig_offset = 0;
1873 }
1874 stream->tracefile_size_current += len;
1875 index->offset = htobe64(stream->out_fd_offset);
1876 }
1877
1878 while (len > 0) {
1879 DBG("splice chan to pipe offset %lu of len %lu (fd : %d, pipe: %d)",
1880 (unsigned long)offset, len, fd, splice_pipe[1]);
1881 ret_splice = splice(fd, &offset, splice_pipe[1], NULL, len,
1882 SPLICE_F_MOVE | SPLICE_F_MORE);
1883 DBG("splice chan to pipe, ret %zd", ret_splice);
1884 if (ret_splice < 0) {
1885 ret = errno;
1886 written = -ret;
1887 PERROR("Error in relay splice");
1888 goto splice_error;
1889 }
1890
1891 /* Handle stream on the relayd if the output is on the network */
1892 if (relayd && stream->metadata_flag) {
1893 size_t metadata_payload_size =
1894 sizeof(struct lttcomm_relayd_metadata_payload);
1895
1896 /* Update counter to fit the spliced data */
1897 ret_splice += metadata_payload_size;
1898 len += metadata_payload_size;
1899 /*
1900 * We do this so the return value can match the len passed as
1901 * argument to this function.
1902 */
1903 written -= metadata_payload_size;
1904 }
1905
1906 /* Splice data out */
1907 ret_splice = splice(splice_pipe[0], NULL, outfd, NULL,
1908 ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE);
1909 DBG("Consumer splice pipe to file (out_fd: %d), ret %zd",
1910 outfd, ret_splice);
1911 if (ret_splice < 0) {
1912 ret = errno;
1913 written = -ret;
1914 relayd_hang_up = 1;
1915 goto write_error;
1916 } else if (ret_splice > len) {
1917 /*
1918 * We don't expect this code path to be executed but you never know
1919 * so this is an extra protection agains a buggy splice().
1920 */
1921 ret = errno;
1922 written += ret_splice;
1923 PERROR("Wrote more data than requested %zd (len: %lu)", ret_splice,
1924 len);
1925 goto splice_error;
1926 } else {
1927 /* All good, update current len and continue. */
1928 len -= ret_splice;
1929 }
1930
1931 /* This call is useless on a socket so better save a syscall. */
1932 if (!relayd) {
1933 /* This won't block, but will start writeout asynchronously */
1934 lttng_sync_file_range(outfd, stream->out_fd_offset, ret_splice,
1935 SYNC_FILE_RANGE_WRITE);
1936 stream->out_fd_offset += ret_splice;
1937 }
1938 stream->output_written += ret_splice;
1939 written += ret_splice;
1940 }
1941 if (!relayd) {
1942 lttng_consumer_sync_trace_file(stream, orig_offset);
1943 }
1944 goto end;
1945
1946 write_error:
1947 /*
1948 * This is a special case that the relayd has closed its socket. Let's
1949 * cleanup the relayd object and all associated streams.
1950 */
1951 if (relayd && relayd_hang_up) {
1952 ERR("Relayd hangup. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
1953 lttng_consumer_cleanup_relayd(relayd);
1954 /* Skip splice error so the consumer does not fail */
1955 goto end;
1956 }
1957
1958 splice_error:
1959 /* send the appropriate error description to sessiond */
1960 switch (ret) {
1961 case EINVAL:
1962 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_EINVAL);
1963 break;
1964 case ENOMEM:
1965 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ENOMEM);
1966 break;
1967 case ESPIPE:
1968 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_SPLICE_ESPIPE);
1969 break;
1970 }
1971
1972 end:
1973 if (relayd && stream->metadata_flag) {
1974 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
1975 }
1976
1977 rcu_read_unlock();
1978 return written;
1979 }
1980
1981 /*
1982 * Sample the snapshot positions for a specific fd
1983 *
1984 * Returns 0 on success, < 0 on error
1985 */
1986 int lttng_consumer_sample_snapshot_positions(struct lttng_consumer_stream *stream)
1987 {
1988 switch (consumer_data.type) {
1989 case LTTNG_CONSUMER_KERNEL:
1990 return lttng_kconsumer_sample_snapshot_positions(stream);
1991 case LTTNG_CONSUMER32_UST:
1992 case LTTNG_CONSUMER64_UST:
1993 return lttng_ustconsumer_sample_snapshot_positions(stream);
1994 default:
1995 ERR("Unknown consumer_data type");
1996 assert(0);
1997 return -ENOSYS;
1998 }
1999 }
2000 /*
2001 * Take a snapshot for a specific fd
2002 *
2003 * Returns 0 on success, < 0 on error
2004 */
2005 int lttng_consumer_take_snapshot(struct lttng_consumer_stream *stream)
2006 {
2007 switch (consumer_data.type) {
2008 case LTTNG_CONSUMER_KERNEL:
2009 return lttng_kconsumer_take_snapshot(stream);
2010 case LTTNG_CONSUMER32_UST:
2011 case LTTNG_CONSUMER64_UST:
2012 return lttng_ustconsumer_take_snapshot(stream);
2013 default:
2014 ERR("Unknown consumer_data type");
2015 assert(0);
2016 return -ENOSYS;
2017 }
2018 }
2019
2020 /*
2021 * Get the produced position
2022 *
2023 * Returns 0 on success, < 0 on error
2024 */
2025 int lttng_consumer_get_produced_snapshot(struct lttng_consumer_stream *stream,
2026 unsigned long *pos)
2027 {
2028 switch (consumer_data.type) {
2029 case LTTNG_CONSUMER_KERNEL:
2030 return lttng_kconsumer_get_produced_snapshot(stream, pos);
2031 case LTTNG_CONSUMER32_UST:
2032 case LTTNG_CONSUMER64_UST:
2033 return lttng_ustconsumer_get_produced_snapshot(stream, pos);
2034 default:
2035 ERR("Unknown consumer_data type");
2036 assert(0);
2037 return -ENOSYS;
2038 }
2039 }
2040
2041 /*
2042 * Get the consumed position (free-running counter position in bytes).
2043 *
2044 * Returns 0 on success, < 0 on error
2045 */
2046 int lttng_consumer_get_consumed_snapshot(struct lttng_consumer_stream *stream,
2047 unsigned long *pos)
2048 {
2049 switch (consumer_data.type) {
2050 case LTTNG_CONSUMER_KERNEL:
2051 return lttng_kconsumer_get_consumed_snapshot(stream, pos);
2052 case LTTNG_CONSUMER32_UST:
2053 case LTTNG_CONSUMER64_UST:
2054 return lttng_ustconsumer_get_consumed_snapshot(stream, pos);
2055 default:
2056 ERR("Unknown consumer_data type");
2057 assert(0);
2058 return -ENOSYS;
2059 }
2060 }
2061
2062 int lttng_consumer_recv_cmd(struct lttng_consumer_local_data *ctx,
2063 int sock, struct pollfd *consumer_sockpoll)
2064 {
2065 switch (consumer_data.type) {
2066 case LTTNG_CONSUMER_KERNEL:
2067 return lttng_kconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
2068 case LTTNG_CONSUMER32_UST:
2069 case LTTNG_CONSUMER64_UST:
2070 return lttng_ustconsumer_recv_cmd(ctx, sock, consumer_sockpoll);
2071 default:
2072 ERR("Unknown consumer_data type");
2073 assert(0);
2074 return -ENOSYS;
2075 }
2076 }
2077
2078 void lttng_consumer_close_all_metadata(void)
2079 {
2080 switch (consumer_data.type) {
2081 case LTTNG_CONSUMER_KERNEL:
2082 /*
2083 * The Kernel consumer has a different metadata scheme so we don't
2084 * close anything because the stream will be closed by the session
2085 * daemon.
2086 */
2087 break;
2088 case LTTNG_CONSUMER32_UST:
2089 case LTTNG_CONSUMER64_UST:
2090 /*
2091 * Close all metadata streams. The metadata hash table is passed and
2092 * this call iterates over it by closing all wakeup fd. This is safe
2093 * because at this point we are sure that the metadata producer is
2094 * either dead or blocked.
2095 */
2096 lttng_ustconsumer_close_all_metadata(metadata_ht);
2097 break;
2098 default:
2099 ERR("Unknown consumer_data type");
2100 assert(0);
2101 }
2102 }
2103
2104 /*
2105 * Clean up a metadata stream and free its memory.
2106 */
2107 void consumer_del_metadata_stream(struct lttng_consumer_stream *stream,
2108 struct lttng_ht *ht)
2109 {
2110 struct lttng_consumer_channel *free_chan = NULL;
2111
2112 assert(stream);
2113 /*
2114 * This call should NEVER receive regular stream. It must always be
2115 * metadata stream and this is crucial for data structure synchronization.
2116 */
2117 assert(stream->metadata_flag);
2118
2119 DBG3("Consumer delete metadata stream %d", stream->wait_fd);
2120
2121 pthread_mutex_lock(&consumer_data.lock);
2122 pthread_mutex_lock(&stream->chan->lock);
2123 pthread_mutex_lock(&stream->lock);
2124 if (stream->chan->metadata_cache) {
2125 /* Only applicable to userspace consumers. */
2126 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
2127 }
2128
2129 /* Remove any reference to that stream. */
2130 consumer_stream_delete(stream, ht);
2131
2132 /* Close down everything including the relayd if one. */
2133 consumer_stream_close(stream);
2134 /* Destroy tracer buffers of the stream. */
2135 consumer_stream_destroy_buffers(stream);
2136
2137 /* Atomically decrement channel refcount since other threads can use it. */
2138 if (!uatomic_sub_return(&stream->chan->refcount, 1)
2139 && !uatomic_read(&stream->chan->nb_init_stream_left)) {
2140 /* Go for channel deletion! */
2141 free_chan = stream->chan;
2142 }
2143
2144 /*
2145 * Nullify the stream reference so it is not used after deletion. The
2146 * channel lock MUST be acquired before being able to check for a NULL
2147 * pointer value.
2148 */
2149 stream->chan->metadata_stream = NULL;
2150
2151 if (stream->chan->metadata_cache) {
2152 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
2153 }
2154 pthread_mutex_unlock(&stream->lock);
2155 pthread_mutex_unlock(&stream->chan->lock);
2156 pthread_mutex_unlock(&consumer_data.lock);
2157
2158 if (free_chan) {
2159 consumer_del_channel(free_chan);
2160 }
2161
2162 consumer_stream_free(stream);
2163 }
2164
2165 /*
2166 * Action done with the metadata stream when adding it to the consumer internal
2167 * data structures to handle it.
2168 */
2169 void consumer_add_metadata_stream(struct lttng_consumer_stream *stream)
2170 {
2171 struct lttng_ht *ht = metadata_ht;
2172 struct lttng_ht_iter iter;
2173 struct lttng_ht_node_u64 *node;
2174
2175 assert(stream);
2176 assert(ht);
2177
2178 DBG3("Adding metadata stream %" PRIu64 " to hash table", stream->key);
2179
2180 pthread_mutex_lock(&consumer_data.lock);
2181 pthread_mutex_lock(&stream->chan->lock);
2182 pthread_mutex_lock(&stream->chan->timer_lock);
2183 pthread_mutex_lock(&stream->lock);
2184
2185 /*
2186 * From here, refcounts are updated so be _careful_ when returning an error
2187 * after this point.
2188 */
2189
2190 rcu_read_lock();
2191
2192 /*
2193 * Lookup the stream just to make sure it does not exist in our internal
2194 * state. This should NEVER happen.
2195 */
2196 lttng_ht_lookup(ht, &stream->key, &iter);
2197 node = lttng_ht_iter_get_node_u64(&iter);
2198 assert(!node);
2199
2200 /*
2201 * When nb_init_stream_left reaches 0, we don't need to trigger any action
2202 * in terms of destroying the associated channel, because the action that
2203 * causes the count to become 0 also causes a stream to be added. The
2204 * channel deletion will thus be triggered by the following removal of this
2205 * stream.
2206 */
2207 if (uatomic_read(&stream->chan->nb_init_stream_left) > 0) {
2208 /* Increment refcount before decrementing nb_init_stream_left */
2209 cmm_smp_wmb();
2210 uatomic_dec(&stream->chan->nb_init_stream_left);
2211 }
2212
2213 lttng_ht_add_unique_u64(ht, &stream->node);
2214
2215 lttng_ht_add_u64(consumer_data.stream_per_chan_id_ht,
2216 &stream->node_channel_id);
2217
2218 /*
2219 * Add stream to the stream_list_ht of the consumer data. No need to steal
2220 * the key since the HT does not use it and we allow to add redundant keys
2221 * into this table.
2222 */
2223 lttng_ht_add_u64(consumer_data.stream_list_ht, &stream->node_session_id);
2224
2225 rcu_read_unlock();
2226
2227 pthread_mutex_unlock(&stream->lock);
2228 pthread_mutex_unlock(&stream->chan->lock);
2229 pthread_mutex_unlock(&stream->chan->timer_lock);
2230 pthread_mutex_unlock(&consumer_data.lock);
2231 }
2232
2233 /*
2234 * Delete data stream that are flagged for deletion (endpoint_status).
2235 */
2236 static void validate_endpoint_status_data_stream(void)
2237 {
2238 struct lttng_ht_iter iter;
2239 struct lttng_consumer_stream *stream;
2240
2241 DBG("Consumer delete flagged data stream");
2242
2243 rcu_read_lock();
2244 cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) {
2245 /* Validate delete flag of the stream */
2246 if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) {
2247 continue;
2248 }
2249 /* Delete it right now */
2250 consumer_del_stream(stream, data_ht);
2251 }
2252 rcu_read_unlock();
2253 }
2254
2255 /*
2256 * Delete metadata stream that are flagged for deletion (endpoint_status).
2257 */
2258 static void validate_endpoint_status_metadata_stream(
2259 struct lttng_poll_event *pollset)
2260 {
2261 struct lttng_ht_iter iter;
2262 struct lttng_consumer_stream *stream;
2263
2264 DBG("Consumer delete flagged metadata stream");
2265
2266 assert(pollset);
2267
2268 rcu_read_lock();
2269 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) {
2270 /* Validate delete flag of the stream */
2271 if (stream->endpoint_status == CONSUMER_ENDPOINT_ACTIVE) {
2272 continue;
2273 }
2274 /*
2275 * Remove from pollset so the metadata thread can continue without
2276 * blocking on a deleted stream.
2277 */
2278 lttng_poll_del(pollset, stream->wait_fd);
2279
2280 /* Delete it right now */
2281 consumer_del_metadata_stream(stream, metadata_ht);
2282 }
2283 rcu_read_unlock();
2284 }
2285
2286 /*
2287 * Perform operations that need to be done after a stream has
2288 * rotated and released the stream lock.
2289 *
2290 * Multiple rotations cannot occur simultaneously, so we know the state of the
2291 * "rotated" stream flag cannot change.
2292 *
2293 * This MUST be called WITHOUT the stream lock held.
2294 */
2295 static
2296 int consumer_post_rotation(struct lttng_consumer_stream *stream,
2297 struct lttng_consumer_local_data *ctx)
2298 {
2299 int ret = 0;
2300
2301 pthread_mutex_lock(&stream->chan->lock);
2302
2303 switch (consumer_data.type) {
2304 case LTTNG_CONSUMER_KERNEL:
2305 break;
2306 case LTTNG_CONSUMER32_UST:
2307 case LTTNG_CONSUMER64_UST:
2308 /*
2309 * The ust_metadata_pushed counter has been reset to 0, so now
2310 * we can wakeup the metadata thread so it dumps the metadata
2311 * cache to the new file.
2312 */
2313 if (stream->metadata_flag) {
2314 consumer_metadata_wakeup_pipe(stream->chan);
2315 }
2316 break;
2317 default:
2318 ERR("Unknown consumer_data type");
2319 abort();
2320 }
2321
2322 pthread_mutex_unlock(&stream->chan->lock);
2323 return ret;
2324 }
2325
2326 /*
2327 * Thread polls on metadata file descriptor and write them on disk or on the
2328 * network.
2329 */
2330 void *consumer_thread_metadata_poll(void *data)
2331 {
2332 int ret, i, pollfd, err = -1;
2333 uint32_t revents, nb_fd;
2334 struct lttng_consumer_stream *stream = NULL;
2335 struct lttng_ht_iter iter;
2336 struct lttng_ht_node_u64 *node;
2337 struct lttng_poll_event events;
2338 struct lttng_consumer_local_data *ctx = data;
2339 ssize_t len;
2340
2341 rcu_register_thread();
2342
2343 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_METADATA);
2344
2345 if (testpoint(consumerd_thread_metadata)) {
2346 goto error_testpoint;
2347 }
2348
2349 health_code_update();
2350
2351 DBG("Thread metadata poll started");
2352
2353 /* Size is set to 1 for the consumer_metadata pipe */
2354 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2355 if (ret < 0) {
2356 ERR("Poll set creation failed");
2357 goto end_poll;
2358 }
2359
2360 ret = lttng_poll_add(&events,
2361 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe), LPOLLIN);
2362 if (ret < 0) {
2363 goto end;
2364 }
2365
2366 /* Main loop */
2367 DBG("Metadata main loop started");
2368
2369 while (1) {
2370 restart:
2371 health_code_update();
2372 health_poll_entry();
2373 DBG("Metadata poll wait");
2374 ret = lttng_poll_wait(&events, -1);
2375 DBG("Metadata poll return from wait with %d fd(s)",
2376 LTTNG_POLL_GETNB(&events));
2377 health_poll_exit();
2378 DBG("Metadata event caught in thread");
2379 if (ret < 0) {
2380 if (errno == EINTR) {
2381 ERR("Poll EINTR caught");
2382 goto restart;
2383 }
2384 if (LTTNG_POLL_GETNB(&events) == 0) {
2385 err = 0; /* All is OK */
2386 }
2387 goto end;
2388 }
2389
2390 nb_fd = ret;
2391
2392 /* From here, the event is a metadata wait fd */
2393 for (i = 0; i < nb_fd; i++) {
2394 health_code_update();
2395
2396 revents = LTTNG_POLL_GETEV(&events, i);
2397 pollfd = LTTNG_POLL_GETFD(&events, i);
2398
2399 if (!revents) {
2400 /* No activity for this FD (poll implementation). */
2401 continue;
2402 }
2403
2404 if (pollfd == lttng_pipe_get_readfd(ctx->consumer_metadata_pipe)) {
2405 if (revents & LPOLLIN) {
2406 ssize_t pipe_len;
2407
2408 pipe_len = lttng_pipe_read(ctx->consumer_metadata_pipe,
2409 &stream, sizeof(stream));
2410 if (pipe_len < sizeof(stream)) {
2411 if (pipe_len < 0) {
2412 PERROR("read metadata stream");
2413 }
2414 /*
2415 * Remove the pipe from the poll set and continue the loop
2416 * since their might be data to consume.
2417 */
2418 lttng_poll_del(&events,
2419 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe));
2420 lttng_pipe_read_close(ctx->consumer_metadata_pipe);
2421 continue;
2422 }
2423
2424 /* A NULL stream means that the state has changed. */
2425 if (stream == NULL) {
2426 /* Check for deleted streams. */
2427 validate_endpoint_status_metadata_stream(&events);
2428 goto restart;
2429 }
2430
2431 DBG("Adding metadata stream %d to poll set",
2432 stream->wait_fd);
2433
2434 /* Add metadata stream to the global poll events list */
2435 lttng_poll_add(&events, stream->wait_fd,
2436 LPOLLIN | LPOLLPRI | LPOLLHUP);
2437 } else if (revents & (LPOLLERR | LPOLLHUP)) {
2438 DBG("Metadata thread pipe hung up");
2439 /*
2440 * Remove the pipe from the poll set and continue the loop
2441 * since their might be data to consume.
2442 */
2443 lttng_poll_del(&events,
2444 lttng_pipe_get_readfd(ctx->consumer_metadata_pipe));
2445 lttng_pipe_read_close(ctx->consumer_metadata_pipe);
2446 continue;
2447 } else {
2448 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2449 goto end;
2450 }
2451
2452 /* Handle other stream */
2453 continue;
2454 }
2455
2456 rcu_read_lock();
2457 {
2458 uint64_t tmp_id = (uint64_t) pollfd;
2459
2460 lttng_ht_lookup(metadata_ht, &tmp_id, &iter);
2461 }
2462 node = lttng_ht_iter_get_node_u64(&iter);
2463 assert(node);
2464
2465 stream = caa_container_of(node, struct lttng_consumer_stream,
2466 node);
2467
2468 if (revents & (LPOLLIN | LPOLLPRI)) {
2469 /* Get the data out of the metadata file descriptor */
2470 DBG("Metadata available on fd %d", pollfd);
2471 assert(stream->wait_fd == pollfd);
2472
2473 do {
2474 health_code_update();
2475
2476 len = ctx->on_buffer_ready(stream, ctx);
2477 /*
2478 * We don't check the return value here since if we get
2479 * a negative len, it means an error occurred thus we
2480 * simply remove it from the poll set and free the
2481 * stream.
2482 */
2483 } while (len > 0);
2484
2485 /* It's ok to have an unavailable sub-buffer */
2486 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2487 /* Clean up stream from consumer and free it. */
2488 lttng_poll_del(&events, stream->wait_fd);
2489 consumer_del_metadata_stream(stream, metadata_ht);
2490 }
2491 } else if (revents & (LPOLLERR | LPOLLHUP)) {
2492 DBG("Metadata fd %d is hup|err.", pollfd);
2493 if (!stream->hangup_flush_done
2494 && (consumer_data.type == LTTNG_CONSUMER32_UST
2495 || consumer_data.type == LTTNG_CONSUMER64_UST)) {
2496 DBG("Attempting to flush and consume the UST buffers");
2497 lttng_ustconsumer_on_stream_hangup(stream);
2498
2499 /* We just flushed the stream now read it. */
2500 do {
2501 health_code_update();
2502
2503 len = ctx->on_buffer_ready(stream, ctx);
2504 /*
2505 * We don't check the return value here since if we get
2506 * a negative len, it means an error occurred thus we
2507 * simply remove it from the poll set and free the
2508 * stream.
2509 */
2510 } while (len > 0);
2511 }
2512
2513 lttng_poll_del(&events, stream->wait_fd);
2514 /*
2515 * This call update the channel states, closes file descriptors
2516 * and securely free the stream.
2517 */
2518 consumer_del_metadata_stream(stream, metadata_ht);
2519 } else {
2520 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
2521 rcu_read_unlock();
2522 goto end;
2523 }
2524 /* Release RCU lock for the stream looked up */
2525 rcu_read_unlock();
2526 }
2527 }
2528
2529 /* All is OK */
2530 err = 0;
2531 end:
2532 DBG("Metadata poll thread exiting");
2533
2534 lttng_poll_clean(&events);
2535 end_poll:
2536 error_testpoint:
2537 if (err) {
2538 health_error();
2539 ERR("Health error occurred in %s", __func__);
2540 }
2541 health_unregister(health_consumerd);
2542 rcu_unregister_thread();
2543 return NULL;
2544 }
2545
2546 /*
2547 * This thread polls the fds in the set to consume the data and write
2548 * it to tracefile if necessary.
2549 */
2550 void *consumer_thread_data_poll(void *data)
2551 {
2552 int num_rdy, num_hup, high_prio, ret, i, err = -1;
2553 struct pollfd *pollfd = NULL;
2554 /* local view of the streams */
2555 struct lttng_consumer_stream **local_stream = NULL, *new_stream = NULL;
2556 /* local view of consumer_data.fds_count */
2557 int nb_fd = 0;
2558 /* 2 for the consumer_data_pipe and wake up pipe */
2559 const int nb_pipes_fd = 2;
2560 /* Number of FDs with CONSUMER_ENDPOINT_INACTIVE but still open. */
2561 int nb_inactive_fd = 0;
2562 struct lttng_consumer_local_data *ctx = data;
2563 ssize_t len;
2564
2565 rcu_register_thread();
2566
2567 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_DATA);
2568
2569 if (testpoint(consumerd_thread_data)) {
2570 goto error_testpoint;
2571 }
2572
2573 health_code_update();
2574
2575 local_stream = zmalloc(sizeof(struct lttng_consumer_stream *));
2576 if (local_stream == NULL) {
2577 PERROR("local_stream malloc");
2578 goto end;
2579 }
2580
2581 while (1) {
2582 health_code_update();
2583
2584 high_prio = 0;
2585 num_hup = 0;
2586
2587 /*
2588 * the fds set has been updated, we need to update our
2589 * local array as well
2590 */
2591 pthread_mutex_lock(&consumer_data.lock);
2592 if (consumer_data.need_update) {
2593 free(pollfd);
2594 pollfd = NULL;
2595
2596 free(local_stream);
2597 local_stream = NULL;
2598
2599 /* Allocate for all fds */
2600 pollfd = zmalloc((consumer_data.stream_count + nb_pipes_fd) * sizeof(struct pollfd));
2601 if (pollfd == NULL) {
2602 PERROR("pollfd malloc");
2603 pthread_mutex_unlock(&consumer_data.lock);
2604 goto end;
2605 }
2606
2607 local_stream = zmalloc((consumer_data.stream_count + nb_pipes_fd) *
2608 sizeof(struct lttng_consumer_stream *));
2609 if (local_stream == NULL) {
2610 PERROR("local_stream malloc");
2611 pthread_mutex_unlock(&consumer_data.lock);
2612 goto end;
2613 }
2614 ret = update_poll_array(ctx, &pollfd, local_stream,
2615 data_ht, &nb_inactive_fd);
2616 if (ret < 0) {
2617 ERR("Error in allocating pollfd or local_outfds");
2618 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
2619 pthread_mutex_unlock(&consumer_data.lock);
2620 goto end;
2621 }
2622 nb_fd = ret;
2623 consumer_data.need_update = 0;
2624 }
2625 pthread_mutex_unlock(&consumer_data.lock);
2626
2627 /* No FDs and consumer_quit, consumer_cleanup the thread */
2628 if (nb_fd == 0 && nb_inactive_fd == 0 &&
2629 CMM_LOAD_SHARED(consumer_quit) == 1) {
2630 err = 0; /* All is OK */
2631 goto end;
2632 }
2633 /* poll on the array of fds */
2634 restart:
2635 DBG("polling on %d fd", nb_fd + nb_pipes_fd);
2636 if (testpoint(consumerd_thread_data_poll)) {
2637 goto end;
2638 }
2639 health_poll_entry();
2640 num_rdy = poll(pollfd, nb_fd + nb_pipes_fd, -1);
2641 health_poll_exit();
2642 DBG("poll num_rdy : %d", num_rdy);
2643 if (num_rdy == -1) {
2644 /*
2645 * Restart interrupted system call.
2646 */
2647 if (errno == EINTR) {
2648 goto restart;
2649 }
2650 PERROR("Poll error");
2651 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
2652 goto end;
2653 } else if (num_rdy == 0) {
2654 DBG("Polling thread timed out");
2655 goto end;
2656 }
2657
2658 if (caa_unlikely(data_consumption_paused)) {
2659 DBG("Data consumption paused, sleeping...");
2660 sleep(1);
2661 goto restart;
2662 }
2663
2664 /*
2665 * If the consumer_data_pipe triggered poll go directly to the
2666 * beginning of the loop to update the array. We want to prioritize
2667 * array update over low-priority reads.
2668 */
2669 if (pollfd[nb_fd].revents & (POLLIN | POLLPRI)) {
2670 ssize_t pipe_readlen;
2671
2672 DBG("consumer_data_pipe wake up");
2673 pipe_readlen = lttng_pipe_read(ctx->consumer_data_pipe,
2674 &new_stream, sizeof(new_stream));
2675 if (pipe_readlen < sizeof(new_stream)) {
2676 PERROR("Consumer data pipe");
2677 /* Continue so we can at least handle the current stream(s). */
2678 continue;
2679 }
2680
2681 /*
2682 * If the stream is NULL, just ignore it. It's also possible that
2683 * the sessiond poll thread changed the consumer_quit state and is
2684 * waking us up to test it.
2685 */
2686 if (new_stream == NULL) {
2687 validate_endpoint_status_data_stream();
2688 continue;
2689 }
2690
2691 /* Continue to update the local streams and handle prio ones */
2692 continue;
2693 }
2694
2695 /* Handle wakeup pipe. */
2696 if (pollfd[nb_fd + 1].revents & (POLLIN | POLLPRI)) {
2697 char dummy;
2698 ssize_t pipe_readlen;
2699
2700 pipe_readlen = lttng_pipe_read(ctx->consumer_wakeup_pipe, &dummy,
2701 sizeof(dummy));
2702 if (pipe_readlen < 0) {
2703 PERROR("Consumer data wakeup pipe");
2704 }
2705 /* We've been awakened to handle stream(s). */
2706 ctx->has_wakeup = 0;
2707 }
2708
2709 /* Take care of high priority channels first. */
2710 for (i = 0; i < nb_fd; i++) {
2711 health_code_update();
2712
2713 if (local_stream[i] == NULL) {
2714 continue;
2715 }
2716 if (pollfd[i].revents & POLLPRI) {
2717 DBG("Urgent read on fd %d", pollfd[i].fd);
2718 high_prio = 1;
2719 len = ctx->on_buffer_ready(local_stream[i], ctx);
2720 /* it's ok to have an unavailable sub-buffer */
2721 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2722 /* Clean the stream and free it. */
2723 consumer_del_stream(local_stream[i], data_ht);
2724 local_stream[i] = NULL;
2725 } else if (len > 0) {
2726 local_stream[i]->data_read = 1;
2727 }
2728 }
2729 }
2730
2731 /*
2732 * If we read high prio channel in this loop, try again
2733 * for more high prio data.
2734 */
2735 if (high_prio) {
2736 continue;
2737 }
2738
2739 /* Take care of low priority channels. */
2740 for (i = 0; i < nb_fd; i++) {
2741 health_code_update();
2742
2743 if (local_stream[i] == NULL) {
2744 continue;
2745 }
2746 if ((pollfd[i].revents & POLLIN) ||
2747 local_stream[i]->hangup_flush_done ||
2748 local_stream[i]->has_data) {
2749 DBG("Normal read on fd %d", pollfd[i].fd);
2750 len = ctx->on_buffer_ready(local_stream[i], ctx);
2751 /* it's ok to have an unavailable sub-buffer */
2752 if (len < 0 && len != -EAGAIN && len != -ENODATA) {
2753 /* Clean the stream and free it. */
2754 consumer_del_stream(local_stream[i], data_ht);
2755 local_stream[i] = NULL;
2756 } else if (len > 0) {
2757 local_stream[i]->data_read = 1;
2758 }
2759 }
2760 }
2761
2762 /* Handle hangup and errors */
2763 for (i = 0; i < nb_fd; i++) {
2764 health_code_update();
2765
2766 if (local_stream[i] == NULL) {
2767 continue;
2768 }
2769 if (!local_stream[i]->hangup_flush_done
2770 && (pollfd[i].revents & (POLLHUP | POLLERR | POLLNVAL))
2771 && (consumer_data.type == LTTNG_CONSUMER32_UST
2772 || consumer_data.type == LTTNG_CONSUMER64_UST)) {
2773 DBG("fd %d is hup|err|nval. Attempting flush and read.",
2774 pollfd[i].fd);
2775 lttng_ustconsumer_on_stream_hangup(local_stream[i]);
2776 /* Attempt read again, for the data we just flushed. */
2777 local_stream[i]->data_read = 1;
2778 }
2779 /*
2780 * If the poll flag is HUP/ERR/NVAL and we have
2781 * read no data in this pass, we can remove the
2782 * stream from its hash table.
2783 */
2784 if ((pollfd[i].revents & POLLHUP)) {
2785 DBG("Polling fd %d tells it has hung up.", pollfd[i].fd);
2786 if (!local_stream[i]->data_read) {
2787 consumer_del_stream(local_stream[i], data_ht);
2788 local_stream[i] = NULL;
2789 num_hup++;
2790 }
2791 } else if (pollfd[i].revents & POLLERR) {
2792 ERR("Error returned in polling fd %d.", pollfd[i].fd);
2793 if (!local_stream[i]->data_read) {
2794 consumer_del_stream(local_stream[i], data_ht);
2795 local_stream[i] = NULL;
2796 num_hup++;
2797 }
2798 } else if (pollfd[i].revents & POLLNVAL) {
2799 ERR("Polling fd %d tells fd is not open.", pollfd[i].fd);
2800 if (!local_stream[i]->data_read) {
2801 consumer_del_stream(local_stream[i], data_ht);
2802 local_stream[i] = NULL;
2803 num_hup++;
2804 }
2805 }
2806 if (local_stream[i] != NULL) {
2807 local_stream[i]->data_read = 0;
2808 }
2809 }
2810 }
2811 /* All is OK */
2812 err = 0;
2813 end:
2814 DBG("polling thread exiting");
2815 free(pollfd);
2816 free(local_stream);
2817
2818 /*
2819 * Close the write side of the pipe so epoll_wait() in
2820 * consumer_thread_metadata_poll can catch it. The thread is monitoring the
2821 * read side of the pipe. If we close them both, epoll_wait strangely does
2822 * not return and could create a endless wait period if the pipe is the
2823 * only tracked fd in the poll set. The thread will take care of closing
2824 * the read side.
2825 */
2826 (void) lttng_pipe_write_close(ctx->consumer_metadata_pipe);
2827
2828 error_testpoint:
2829 if (err) {
2830 health_error();
2831 ERR("Health error occurred in %s", __func__);
2832 }
2833 health_unregister(health_consumerd);
2834
2835 rcu_unregister_thread();
2836 return NULL;
2837 }
2838
2839 /*
2840 * Close wake-up end of each stream belonging to the channel. This will
2841 * allow the poll() on the stream read-side to detect when the
2842 * write-side (application) finally closes them.
2843 */
2844 static
2845 void consumer_close_channel_streams(struct lttng_consumer_channel *channel)
2846 {
2847 struct lttng_ht *ht;
2848 struct lttng_consumer_stream *stream;
2849 struct lttng_ht_iter iter;
2850
2851 ht = consumer_data.stream_per_chan_id_ht;
2852
2853 rcu_read_lock();
2854 cds_lfht_for_each_entry_duplicate(ht->ht,
2855 ht->hash_fct(&channel->key, lttng_ht_seed),
2856 ht->match_fct, &channel->key,
2857 &iter.iter, stream, node_channel_id.node) {
2858 /*
2859 * Protect against teardown with mutex.
2860 */
2861 pthread_mutex_lock(&stream->lock);
2862 if (cds_lfht_is_node_deleted(&stream->node.node)) {
2863 goto next;
2864 }
2865 switch (consumer_data.type) {
2866 case LTTNG_CONSUMER_KERNEL:
2867 break;
2868 case LTTNG_CONSUMER32_UST:
2869 case LTTNG_CONSUMER64_UST:
2870 if (stream->metadata_flag) {
2871 /* Safe and protected by the stream lock. */
2872 lttng_ustconsumer_close_metadata(stream->chan);
2873 } else {
2874 /*
2875 * Note: a mutex is taken internally within
2876 * liblttng-ust-ctl to protect timer wakeup_fd
2877 * use from concurrent close.
2878 */
2879 lttng_ustconsumer_close_stream_wakeup(stream);
2880 }
2881 break;
2882 default:
2883 ERR("Unknown consumer_data type");
2884 assert(0);
2885 }
2886 next:
2887 pthread_mutex_unlock(&stream->lock);
2888 }
2889 rcu_read_unlock();
2890 }
2891
2892 static void destroy_channel_ht(struct lttng_ht *ht)
2893 {
2894 struct lttng_ht_iter iter;
2895 struct lttng_consumer_channel *channel;
2896 int ret;
2897
2898 if (ht == NULL) {
2899 return;
2900 }
2901
2902 rcu_read_lock();
2903 cds_lfht_for_each_entry(ht->ht, &iter.iter, channel, wait_fd_node.node) {
2904 ret = lttng_ht_del(ht, &iter);
2905 assert(ret != 0);
2906 }
2907 rcu_read_unlock();
2908
2909 lttng_ht_destroy(ht);
2910 }
2911
2912 /*
2913 * This thread polls the channel fds to detect when they are being
2914 * closed. It closes all related streams if the channel is detected as
2915 * closed. It is currently only used as a shim layer for UST because the
2916 * consumerd needs to keep the per-stream wakeup end of pipes open for
2917 * periodical flush.
2918 */
2919 void *consumer_thread_channel_poll(void *data)
2920 {
2921 int ret, i, pollfd, err = -1;
2922 uint32_t revents, nb_fd;
2923 struct lttng_consumer_channel *chan = NULL;
2924 struct lttng_ht_iter iter;
2925 struct lttng_ht_node_u64 *node;
2926 struct lttng_poll_event events;
2927 struct lttng_consumer_local_data *ctx = data;
2928 struct lttng_ht *channel_ht;
2929
2930 rcu_register_thread();
2931
2932 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_CHANNEL);
2933
2934 if (testpoint(consumerd_thread_channel)) {
2935 goto error_testpoint;
2936 }
2937
2938 health_code_update();
2939
2940 channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
2941 if (!channel_ht) {
2942 /* ENOMEM at this point. Better to bail out. */
2943 goto end_ht;
2944 }
2945
2946 DBG("Thread channel poll started");
2947
2948 /* Size is set to 1 for the consumer_channel pipe */
2949 ret = lttng_poll_create(&events, 2, LTTNG_CLOEXEC);
2950 if (ret < 0) {
2951 ERR("Poll set creation failed");
2952 goto end_poll;
2953 }
2954
2955 ret = lttng_poll_add(&events, ctx->consumer_channel_pipe[0], LPOLLIN);
2956 if (ret < 0) {
2957 goto end;
2958 }
2959
2960 /* Main loop */
2961 DBG("Channel main loop started");
2962
2963 while (1) {
2964 restart:
2965 health_code_update();
2966 DBG("Channel poll wait");
2967 health_poll_entry();
2968 ret = lttng_poll_wait(&events, -1);
2969 DBG("Channel poll return from wait with %d fd(s)",
2970 LTTNG_POLL_GETNB(&events));
2971 health_poll_exit();
2972 DBG("Channel event caught in thread");
2973 if (ret < 0) {
2974 if (errno == EINTR) {
2975 ERR("Poll EINTR caught");
2976 goto restart;
2977 }
2978 if (LTTNG_POLL_GETNB(&events) == 0) {
2979 err = 0; /* All is OK */
2980 }
2981 goto end;
2982 }
2983
2984 nb_fd = ret;
2985
2986 /* From here, the event is a channel wait fd */
2987 for (i = 0; i < nb_fd; i++) {
2988 health_code_update();
2989
2990 revents = LTTNG_POLL_GETEV(&events, i);
2991 pollfd = LTTNG_POLL_GETFD(&events, i);
2992
2993 if (!revents) {
2994 /* No activity for this FD (poll implementation). */
2995 continue;
2996 }
2997
2998 if (pollfd == ctx->consumer_channel_pipe[0]) {
2999 if (revents & LPOLLIN) {
3000 enum consumer_channel_action action;
3001 uint64_t key;
3002
3003 ret = read_channel_pipe(ctx, &chan, &key, &action);
3004 if (ret <= 0) {
3005 if (ret < 0) {
3006 ERR("Error reading channel pipe");
3007 }
3008 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3009 continue;
3010 }
3011
3012 switch (action) {
3013 case CONSUMER_CHANNEL_ADD:
3014 DBG("Adding channel %d to poll set",
3015 chan->wait_fd);
3016
3017 lttng_ht_node_init_u64(&chan->wait_fd_node,
3018 chan->wait_fd);
3019 rcu_read_lock();
3020 lttng_ht_add_unique_u64(channel_ht,
3021 &chan->wait_fd_node);
3022 rcu_read_unlock();
3023 /* Add channel to the global poll events list */
3024 lttng_poll_add(&events, chan->wait_fd,
3025 LPOLLERR | LPOLLHUP);
3026 break;
3027 case CONSUMER_CHANNEL_DEL:
3028 {
3029 /*
3030 * This command should never be called if the channel
3031 * has streams monitored by either the data or metadata
3032 * thread. The consumer only notify this thread with a
3033 * channel del. command if it receives a destroy
3034 * channel command from the session daemon that send it
3035 * if a command prior to the GET_CHANNEL failed.
3036 */
3037
3038 rcu_read_lock();
3039 chan = consumer_find_channel(key);
3040 if (!chan) {
3041 rcu_read_unlock();
3042 ERR("UST consumer get channel key %" PRIu64 " not found for del channel", key);
3043 break;
3044 }
3045 lttng_poll_del(&events, chan->wait_fd);
3046 iter.iter.node = &chan->wait_fd_node.node;
3047 ret = lttng_ht_del(channel_ht, &iter);
3048 assert(ret == 0);
3049
3050 switch (consumer_data.type) {
3051 case LTTNG_CONSUMER_KERNEL:
3052 break;
3053 case LTTNG_CONSUMER32_UST:
3054 case LTTNG_CONSUMER64_UST:
3055 health_code_update();
3056 /* Destroy streams that might have been left in the stream list. */
3057 clean_channel_stream_list(chan);
3058 break;
3059 default:
3060 ERR("Unknown consumer_data type");
3061 assert(0);
3062 }
3063
3064 /*
3065 * Release our own refcount. Force channel deletion even if
3066 * streams were not initialized.
3067 */
3068 if (!uatomic_sub_return(&chan->refcount, 1)) {
3069 consumer_del_channel(chan);
3070 }
3071 rcu_read_unlock();
3072 goto restart;
3073 }
3074 case CONSUMER_CHANNEL_QUIT:
3075 /*
3076 * Remove the pipe from the poll set and continue the loop
3077 * since their might be data to consume.
3078 */
3079 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3080 continue;
3081 default:
3082 ERR("Unknown action");
3083 break;
3084 }
3085 } else if (revents & (LPOLLERR | LPOLLHUP)) {
3086 DBG("Channel thread pipe hung up");
3087 /*
3088 * Remove the pipe from the poll set and continue the loop
3089 * since their might be data to consume.
3090 */
3091 lttng_poll_del(&events, ctx->consumer_channel_pipe[0]);
3092 continue;
3093 } else {
3094 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3095 goto end;
3096 }
3097
3098 /* Handle other stream */
3099 continue;
3100 }
3101
3102 rcu_read_lock();
3103 {
3104 uint64_t tmp_id = (uint64_t) pollfd;
3105
3106 lttng_ht_lookup(channel_ht, &tmp_id, &iter);
3107 }
3108 node = lttng_ht_iter_get_node_u64(&iter);
3109 assert(node);
3110
3111 chan = caa_container_of(node, struct lttng_consumer_channel,
3112 wait_fd_node);
3113
3114 /* Check for error event */
3115 if (revents & (LPOLLERR | LPOLLHUP)) {
3116 DBG("Channel fd %d is hup|err.", pollfd);
3117
3118 lttng_poll_del(&events, chan->wait_fd);
3119 ret = lttng_ht_del(channel_ht, &iter);
3120 assert(ret == 0);
3121
3122 /*
3123 * This will close the wait fd for each stream associated to
3124 * this channel AND monitored by the data/metadata thread thus
3125 * will be clean by the right thread.
3126 */
3127 consumer_close_channel_streams(chan);
3128
3129 /* Release our own refcount */
3130 if (!uatomic_sub_return(&chan->refcount, 1)
3131 && !uatomic_read(&chan->nb_init_stream_left)) {
3132 consumer_del_channel(chan);
3133 }
3134 } else {
3135 ERR("Unexpected poll events %u for sock %d", revents, pollfd);
3136 rcu_read_unlock();
3137 goto end;
3138 }
3139
3140 /* Release RCU lock for the channel looked up */
3141 rcu_read_unlock();
3142 }
3143 }
3144
3145 /* All is OK */
3146 err = 0;
3147 end:
3148 lttng_poll_clean(&events);
3149 end_poll:
3150 destroy_channel_ht(channel_ht);
3151 end_ht:
3152 error_testpoint:
3153 DBG("Channel poll thread exiting");
3154 if (err) {
3155 health_error();
3156 ERR("Health error occurred in %s", __func__);
3157 }
3158 health_unregister(health_consumerd);
3159 rcu_unregister_thread();
3160 return NULL;
3161 }
3162
3163 static int set_metadata_socket(struct lttng_consumer_local_data *ctx,
3164 struct pollfd *sockpoll, int client_socket)
3165 {
3166 int ret;
3167
3168 assert(ctx);
3169 assert(sockpoll);
3170
3171 ret = lttng_consumer_poll_socket(sockpoll);
3172 if (ret) {
3173 goto error;
3174 }
3175 DBG("Metadata connection on client_socket");
3176
3177 /* Blocking call, waiting for transmission */
3178 ctx->consumer_metadata_socket = lttcomm_accept_unix_sock(client_socket);
3179 if (ctx->consumer_metadata_socket < 0) {
3180 WARN("On accept metadata");
3181 ret = -1;
3182 goto error;
3183 }
3184 ret = 0;
3185
3186 error:
3187 return ret;
3188 }
3189
3190 /*
3191 * This thread listens on the consumerd socket and receives the file
3192 * descriptors from the session daemon.
3193 */
3194 void *consumer_thread_sessiond_poll(void *data)
3195 {
3196 int sock = -1, client_socket, ret, err = -1;
3197 /*
3198 * structure to poll for incoming data on communication socket avoids
3199 * making blocking sockets.
3200 */
3201 struct pollfd consumer_sockpoll[2];
3202 struct lttng_consumer_local_data *ctx = data;
3203
3204 rcu_register_thread();
3205
3206 health_register(health_consumerd, HEALTH_CONSUMERD_TYPE_SESSIOND);
3207
3208 if (testpoint(consumerd_thread_sessiond)) {
3209 goto error_testpoint;
3210 }
3211
3212 health_code_update();
3213
3214 DBG("Creating command socket %s", ctx->consumer_command_sock_path);
3215 unlink(ctx->consumer_command_sock_path);
3216 client_socket = lttcomm_create_unix_sock(ctx->consumer_command_sock_path);
3217 if (client_socket < 0) {
3218 ERR("Cannot create command socket");
3219 goto end;
3220 }
3221
3222 ret = lttcomm_listen_unix_sock(client_socket);
3223 if (ret < 0) {
3224 goto end;
3225 }
3226
3227 DBG("Sending ready command to lttng-sessiond");
3228 ret = lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_COMMAND_SOCK_READY);
3229 /* return < 0 on error, but == 0 is not fatal */
3230 if (ret < 0) {
3231 ERR("Error sending ready command to lttng-sessiond");
3232 goto end;
3233 }
3234
3235 /* prepare the FDs to poll : to client socket and the should_quit pipe */
3236 consumer_sockpoll[0].fd = ctx->consumer_should_quit[0];
3237 consumer_sockpoll[0].events = POLLIN | POLLPRI;
3238 consumer_sockpoll[1].fd = client_socket;
3239 consumer_sockpoll[1].events = POLLIN | POLLPRI;
3240
3241 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3242 if (ret) {
3243 if (ret > 0) {
3244 /* should exit */
3245 err = 0;
3246 }
3247 goto end;
3248 }
3249 DBG("Connection on client_socket");
3250
3251 /* Blocking call, waiting for transmission */
3252 sock = lttcomm_accept_unix_sock(client_socket);
3253 if (sock < 0) {
3254 WARN("On accept");
3255 goto end;
3256 }
3257
3258 /*
3259 * Setup metadata socket which is the second socket connection on the
3260 * command unix socket.
3261 */
3262 ret = set_metadata_socket(ctx, consumer_sockpoll, client_socket);
3263 if (ret) {
3264 if (ret > 0) {
3265 /* should exit */
3266 err = 0;
3267 }
3268 goto end;
3269 }
3270
3271 /* This socket is not useful anymore. */
3272 ret = close(client_socket);
3273 if (ret < 0) {
3274 PERROR("close client_socket");
3275 }
3276 client_socket = -1;
3277
3278 /* update the polling structure to poll on the established socket */
3279 consumer_sockpoll[1].fd = sock;
3280 consumer_sockpoll[1].events = POLLIN | POLLPRI;
3281
3282 while (1) {
3283 health_code_update();
3284
3285 health_poll_entry();
3286 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3287 health_poll_exit();
3288 if (ret) {
3289 if (ret > 0) {
3290 /* should exit */
3291 err = 0;
3292 }
3293 goto end;
3294 }
3295 DBG("Incoming command on sock");
3296 ret = lttng_consumer_recv_cmd(ctx, sock, consumer_sockpoll);
3297 if (ret <= 0) {
3298 /*
3299 * This could simply be a session daemon quitting. Don't output
3300 * ERR() here.
3301 */
3302 DBG("Communication interrupted on command socket");
3303 err = 0;
3304 goto end;
3305 }
3306 if (CMM_LOAD_SHARED(consumer_quit)) {
3307 DBG("consumer_thread_receive_fds received quit from signal");
3308 err = 0; /* All is OK */
3309 goto end;
3310 }
3311 DBG("received command on sock");
3312 }
3313 /* All is OK */
3314 err = 0;
3315
3316 end:
3317 DBG("Consumer thread sessiond poll exiting");
3318
3319 /*
3320 * Close metadata streams since the producer is the session daemon which
3321 * just died.
3322 *
3323 * NOTE: for now, this only applies to the UST tracer.
3324 */
3325 lttng_consumer_close_all_metadata();
3326
3327 /*
3328 * when all fds have hung up, the polling thread
3329 * can exit cleanly
3330 */
3331 CMM_STORE_SHARED(consumer_quit, 1);
3332
3333 /*
3334 * Notify the data poll thread to poll back again and test the
3335 * consumer_quit state that we just set so to quit gracefully.
3336 */
3337 notify_thread_lttng_pipe(ctx->consumer_data_pipe);
3338
3339 notify_channel_pipe(ctx, NULL, -1, CONSUMER_CHANNEL_QUIT);
3340
3341 notify_health_quit_pipe(health_quit_pipe);
3342
3343 /* Cleaning up possibly open sockets. */
3344 if (sock >= 0) {
3345 ret = close(sock);
3346 if (ret < 0) {
3347 PERROR("close sock sessiond poll");
3348 }
3349 }
3350 if (client_socket >= 0) {
3351 ret = close(client_socket);
3352 if (ret < 0) {
3353 PERROR("close client_socket sessiond poll");
3354 }
3355 }
3356
3357 error_testpoint:
3358 if (err) {
3359 health_error();
3360 ERR("Health error occurred in %s", __func__);
3361 }
3362 health_unregister(health_consumerd);
3363
3364 rcu_unregister_thread();
3365 return NULL;
3366 }
3367
3368 ssize_t lttng_consumer_read_subbuffer(struct lttng_consumer_stream *stream,
3369 struct lttng_consumer_local_data *ctx)
3370 {
3371 ssize_t ret;
3372 int rotate_ret;
3373 bool rotated = false;
3374
3375 pthread_mutex_lock(&stream->lock);
3376 if (stream->metadata_flag) {
3377 pthread_mutex_lock(&stream->metadata_rdv_lock);
3378 }
3379
3380 switch (consumer_data.type) {
3381 case LTTNG_CONSUMER_KERNEL:
3382 ret = lttng_kconsumer_read_subbuffer(stream, ctx, &rotated);
3383 break;
3384 case LTTNG_CONSUMER32_UST:
3385 case LTTNG_CONSUMER64_UST:
3386 ret = lttng_ustconsumer_read_subbuffer(stream, ctx, &rotated);
3387 break;
3388 default:
3389 ERR("Unknown consumer_data type");
3390 assert(0);
3391 ret = -ENOSYS;
3392 break;
3393 }
3394
3395 if (stream->metadata_flag) {
3396 pthread_cond_broadcast(&stream->metadata_rdv);
3397 pthread_mutex_unlock(&stream->metadata_rdv_lock);
3398 }
3399 pthread_mutex_unlock(&stream->lock);
3400 if (rotated) {
3401 rotate_ret = consumer_post_rotation(stream, ctx);
3402 if (rotate_ret < 0) {
3403 ERR("Failed after a rotation");
3404 ret = -1;
3405 }
3406 }
3407
3408 return ret;
3409 }
3410
3411 int lttng_consumer_on_recv_stream(struct lttng_consumer_stream *stream)
3412 {
3413 switch (consumer_data.type) {
3414 case LTTNG_CONSUMER_KERNEL:
3415 return lttng_kconsumer_on_recv_stream(stream);
3416 case LTTNG_CONSUMER32_UST:
3417 case LTTNG_CONSUMER64_UST:
3418 return lttng_ustconsumer_on_recv_stream(stream);
3419 default:
3420 ERR("Unknown consumer_data type");
3421 assert(0);
3422 return -ENOSYS;
3423 }
3424 }
3425
3426 /*
3427 * Allocate and set consumer data hash tables.
3428 */
3429 int lttng_consumer_init(void)
3430 {
3431 consumer_data.channel_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3432 if (!consumer_data.channel_ht) {
3433 goto error;
3434 }
3435
3436 consumer_data.relayd_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3437 if (!consumer_data.relayd_ht) {
3438 goto error;
3439 }
3440
3441 consumer_data.stream_list_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3442 if (!consumer_data.stream_list_ht) {
3443 goto error;
3444 }
3445
3446 consumer_data.stream_per_chan_id_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3447 if (!consumer_data.stream_per_chan_id_ht) {
3448 goto error;
3449 }
3450
3451 data_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3452 if (!data_ht) {
3453 goto error;
3454 }
3455
3456 metadata_ht = lttng_ht_new(0, LTTNG_HT_TYPE_U64);
3457 if (!metadata_ht) {
3458 goto error;
3459 }
3460
3461 return 0;
3462
3463 error:
3464 return -1;
3465 }
3466
3467 /*
3468 * Process the ADD_RELAYD command receive by a consumer.
3469 *
3470 * This will create a relayd socket pair and add it to the relayd hash table.
3471 * The caller MUST acquire a RCU read side lock before calling it.
3472 */
3473 void consumer_add_relayd_socket(uint64_t net_seq_idx, int sock_type,
3474 struct lttng_consumer_local_data *ctx, int sock,
3475 struct pollfd *consumer_sockpoll,
3476 struct lttcomm_relayd_sock *relayd_sock, uint64_t sessiond_id,
3477 uint64_t relayd_session_id)
3478 {
3479 int fd = -1, ret = -1, relayd_created = 0;
3480 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
3481 struct consumer_relayd_sock_pair *relayd = NULL;
3482
3483 assert(ctx);
3484 assert(relayd_sock);
3485
3486 DBG("Consumer adding relayd socket (idx: %" PRIu64 ")", net_seq_idx);
3487
3488 /* Get relayd reference if exists. */
3489 relayd = consumer_find_relayd(net_seq_idx);
3490 if (relayd == NULL) {
3491 assert(sock_type == LTTNG_STREAM_CONTROL);
3492 /* Not found. Allocate one. */
3493 relayd = consumer_allocate_relayd_sock_pair(net_seq_idx);
3494 if (relayd == NULL) {
3495 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3496 goto error;
3497 } else {
3498 relayd->sessiond_session_id = sessiond_id;
3499 relayd_created = 1;
3500 }
3501
3502 /*
3503 * This code path MUST continue to the consumer send status message to
3504 * we can notify the session daemon and continue our work without
3505 * killing everything.
3506 */
3507 } else {
3508 /*
3509 * relayd key should never be found for control socket.
3510 */
3511 assert(sock_type != LTTNG_STREAM_CONTROL);
3512 }
3513
3514 /* First send a status message before receiving the fds. */
3515 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
3516 if (ret < 0) {
3517 /* Somehow, the session daemon is not responding anymore. */
3518 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3519 goto error_nosignal;
3520 }
3521
3522 /* Poll on consumer socket. */
3523 ret = lttng_consumer_poll_socket(consumer_sockpoll);
3524 if (ret) {
3525 /* Needing to exit in the middle of a command: error. */
3526 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_POLL_ERROR);
3527 goto error_nosignal;
3528 }
3529
3530 /* Get relayd socket from session daemon */
3531 ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1);
3532 if (ret != sizeof(fd)) {
3533 fd = -1; /* Just in case it gets set with an invalid value. */
3534
3535 /*
3536 * Failing to receive FDs might indicate a major problem such as
3537 * reaching a fd limit during the receive where the kernel returns a
3538 * MSG_CTRUNC and fails to cleanup the fd in the queue. Any case, we
3539 * don't take any chances and stop everything.
3540 *
3541 * XXX: Feature request #558 will fix that and avoid this possible
3542 * issue when reaching the fd limit.
3543 */
3544 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_FD);
3545 ret_code = LTTCOMM_CONSUMERD_ERROR_RECV_FD;
3546 goto error;
3547 }
3548
3549 /* Copy socket information and received FD */
3550 switch (sock_type) {
3551 case LTTNG_STREAM_CONTROL:
3552 /* Copy received lttcomm socket */
3553 lttcomm_copy_sock(&relayd->control_sock.sock, &relayd_sock->sock);
3554 ret = lttcomm_create_sock(&relayd->control_sock.sock);
3555 /* Handle create_sock error. */
3556 if (ret < 0) {
3557 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3558 goto error;
3559 }
3560 /*
3561 * Close the socket created internally by
3562 * lttcomm_create_sock, so we can replace it by the one
3563 * received from sessiond.
3564 */
3565 if (close(relayd->control_sock.sock.fd)) {
3566 PERROR("close");
3567 }
3568
3569 /* Assign new file descriptor */
3570 relayd->control_sock.sock.fd = fd;
3571 /* Assign version values. */
3572 relayd->control_sock.major = relayd_sock->major;
3573 relayd->control_sock.minor = relayd_sock->minor;
3574
3575 relayd->relayd_session_id = relayd_session_id;
3576
3577 break;
3578 case LTTNG_STREAM_DATA:
3579 /* Copy received lttcomm socket */
3580 lttcomm_copy_sock(&relayd->data_sock.sock, &relayd_sock->sock);
3581 ret = lttcomm_create_sock(&relayd->data_sock.sock);
3582 /* Handle create_sock error. */
3583 if (ret < 0) {
3584 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
3585 goto error;
3586 }
3587 /*
3588 * Close the socket created internally by
3589 * lttcomm_create_sock, so we can replace it by the one
3590 * received from sessiond.
3591 */
3592 if (close(relayd->data_sock.sock.fd)) {
3593 PERROR("close");
3594 }
3595
3596 /* Assign new file descriptor */
3597 relayd->data_sock.sock.fd = fd;
3598 /* Assign version values. */
3599 relayd->data_sock.major = relayd_sock->major;
3600 relayd->data_sock.minor = relayd_sock->minor;
3601 break;
3602 default:
3603 ERR("Unknown relayd socket type (%d)", sock_type);
3604 ret_code = LTTCOMM_CONSUMERD_FATAL;
3605 goto error;
3606 }
3607
3608 DBG("Consumer %s socket created successfully with net idx %" PRIu64 " (fd: %d)",
3609 sock_type == LTTNG_STREAM_CONTROL ? "control" : "data",
3610 relayd->net_seq_idx, fd);
3611 /*
3612 * We gave the ownership of the fd to the relayd structure. Set the
3613 * fd to -1 so we don't call close() on it in the error path below.
3614 */
3615 fd = -1;
3616
3617 /* We successfully added the socket. Send status back. */
3618 ret = consumer_send_status_msg(sock, ret_code);
3619 if (ret < 0) {
3620 /* Somehow, the session daemon is not responding anymore. */
3621 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3622 goto error_nosignal;
3623 }
3624
3625 /*
3626 * Add relayd socket pair to consumer data hashtable. If object already
3627 * exists or on error, the function gracefully returns.
3628 */
3629 relayd->ctx = ctx;
3630 add_relayd(relayd);
3631
3632 /* All good! */
3633 return;
3634
3635 error:
3636 if (consumer_send_status_msg(sock, ret_code) < 0) {
3637 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_FATAL);
3638 }
3639
3640 error_nosignal:
3641 /* Close received socket if valid. */
3642 if (fd >= 0) {
3643 if (close(fd)) {
3644 PERROR("close received socket");
3645 }
3646 }
3647
3648 if (relayd_created) {
3649 free(relayd);
3650 }
3651 }
3652
3653 /*
3654 * Search for a relayd associated to the session id and return the reference.
3655 *
3656 * A rcu read side lock MUST be acquire before calling this function and locked
3657 * until the relayd object is no longer necessary.
3658 */
3659 static struct consumer_relayd_sock_pair *find_relayd_by_session_id(uint64_t id)
3660 {
3661 struct lttng_ht_iter iter;
3662 struct consumer_relayd_sock_pair *relayd = NULL;
3663
3664 /* Iterate over all relayd since they are indexed by net_seq_idx. */
3665 cds_lfht_for_each_entry(consumer_data.relayd_ht->ht, &iter.iter, relayd,
3666 node.node) {
3667 /*
3668 * Check by sessiond id which is unique here where the relayd session
3669 * id might not be when having multiple relayd.
3670 */
3671 if (relayd->sessiond_session_id == id) {
3672 /* Found the relayd. There can be only one per id. */
3673 goto found;
3674 }
3675 }
3676
3677 return NULL;
3678
3679 found:
3680 return relayd;
3681 }
3682
3683 /*
3684 * Check if for a given session id there is still data needed to be extract
3685 * from the buffers.
3686 *
3687 * Return 1 if data is pending or else 0 meaning ready to be read.
3688 */
3689 int consumer_data_pending(uint64_t id)
3690 {
3691 int ret;
3692 struct lttng_ht_iter iter;
3693 struct lttng_ht *ht;
3694 struct lttng_consumer_stream *stream;
3695 struct consumer_relayd_sock_pair *relayd = NULL;
3696 int (*data_pending)(struct lttng_consumer_stream *);
3697
3698 DBG("Consumer data pending command on session id %" PRIu64, id);
3699
3700 rcu_read_lock();
3701 pthread_mutex_lock(&consumer_data.lock);
3702
3703 switch (consumer_data.type) {
3704 case LTTNG_CONSUMER_KERNEL:
3705 data_pending = lttng_kconsumer_data_pending;
3706 break;
3707 case LTTNG_CONSUMER32_UST:
3708 case LTTNG_CONSUMER64_UST:
3709 data_pending = lttng_ustconsumer_data_pending;
3710 break;
3711 default:
3712 ERR("Unknown consumer data type");
3713 assert(0);
3714 }
3715
3716 /* Ease our life a bit */
3717 ht = consumer_data.stream_list_ht;
3718
3719 cds_lfht_for_each_entry_duplicate(ht->ht,
3720 ht->hash_fct(&id, lttng_ht_seed),
3721 ht->match_fct, &id,
3722 &iter.iter, stream, node_session_id.node) {
3723 pthread_mutex_lock(&stream->lock);
3724
3725 /*
3726 * A removed node from the hash table indicates that the stream has
3727 * been deleted thus having a guarantee that the buffers are closed
3728 * on the consumer side. However, data can still be transmitted
3729 * over the network so don't skip the relayd check.
3730 */
3731 ret = cds_lfht_is_node_deleted(&stream->node.node);
3732 if (!ret) {
3733 /* Check the stream if there is data in the buffers. */
3734 ret = data_pending(stream);
3735 if (ret == 1) {
3736 pthread_mutex_unlock(&stream->lock);
3737 goto data_pending;
3738 }
3739 }
3740
3741 pthread_mutex_unlock(&stream->lock);
3742 }
3743
3744 relayd = find_relayd_by_session_id(id);
3745 if (relayd) {
3746 unsigned int is_data_inflight = 0;
3747
3748 /* Send init command for data pending. */
3749 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
3750 ret = relayd_begin_data_pending(&relayd->control_sock,
3751 relayd->relayd_session_id);
3752 if (ret < 0) {
3753 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
3754 /* Communication error thus the relayd so no data pending. */
3755 goto data_not_pending;
3756 }
3757
3758 cds_lfht_for_each_entry_duplicate(ht->ht,
3759 ht->hash_fct(&id, lttng_ht_seed),
3760 ht->match_fct, &id,
3761 &iter.iter, stream, node_session_id.node) {
3762 if (stream->metadata_flag) {
3763 ret = relayd_quiescent_control(&relayd->control_sock,
3764 stream->relayd_stream_id);
3765 } else {
3766 ret = relayd_data_pending(&relayd->control_sock,
3767 stream->relayd_stream_id,
3768 stream->next_net_seq_num - 1);
3769 }
3770
3771 if (ret == 1) {
3772 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
3773 goto data_pending;
3774 } else if (ret < 0) {
3775 ERR("Relayd data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
3776 lttng_consumer_cleanup_relayd(relayd);
3777 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
3778 goto data_not_pending;
3779 }
3780 }
3781
3782 /* Send end command for data pending. */
3783 ret = relayd_end_data_pending(&relayd->control_sock,
3784 relayd->relayd_session_id, &is_data_inflight);
3785 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
3786 if (ret < 0) {
3787 ERR("Relayd end data pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
3788 lttng_consumer_cleanup_relayd(relayd);
3789 goto data_not_pending;
3790 }
3791 if (is_data_inflight) {
3792 goto data_pending;
3793 }
3794 }
3795
3796 /*
3797 * Finding _no_ node in the hash table and no inflight data means that the
3798 * stream(s) have been removed thus data is guaranteed to be available for
3799 * analysis from the trace files.
3800 */
3801
3802 data_not_pending:
3803 /* Data is available to be read by a viewer. */
3804 pthread_mutex_unlock(&consumer_data.lock);
3805 rcu_read_unlock();
3806 return 0;
3807
3808 data_pending:
3809 /* Data is still being extracted from buffers. */
3810 pthread_mutex_unlock(&consumer_data.lock);
3811 rcu_read_unlock();
3812 return 1;
3813 }
3814
3815 /*
3816 * Send a ret code status message to the sessiond daemon.
3817 *
3818 * Return the sendmsg() return value.
3819 */
3820 int consumer_send_status_msg(int sock, int ret_code)
3821 {
3822 struct lttcomm_consumer_status_msg msg;
3823
3824 memset(&msg, 0, sizeof(msg));
3825 msg.ret_code = ret_code;
3826
3827 return lttcomm_send_unix_sock(sock, &msg, sizeof(msg));
3828 }
3829
3830 /*
3831 * Send a channel status message to the sessiond daemon.
3832 *
3833 * Return the sendmsg() return value.
3834 */
3835 int consumer_send_status_channel(int sock,
3836 struct lttng_consumer_channel *channel)
3837 {
3838 struct lttcomm_consumer_status_channel msg;
3839
3840 assert(sock >= 0);
3841
3842 memset(&msg, 0, sizeof(msg));
3843 if (!channel) {
3844 msg.ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
3845 } else {
3846 msg.ret_code = LTTCOMM_CONSUMERD_SUCCESS;
3847 msg.key = channel->key;
3848 msg.stream_count = channel->streams.count;
3849 }
3850
3851 return lttcomm_send_unix_sock(sock, &msg, sizeof(msg));
3852 }
3853
3854 unsigned long consumer_get_consume_start_pos(unsigned long consumed_pos,
3855 unsigned long produced_pos, uint64_t nb_packets_per_stream,
3856 uint64_t max_sb_size)
3857 {
3858 unsigned long start_pos;
3859
3860 if (!nb_packets_per_stream) {
3861 return consumed_pos; /* Grab everything */
3862 }
3863 start_pos = produced_pos - offset_align_floor(produced_pos, max_sb_size);
3864 start_pos -= max_sb_size * nb_packets_per_stream;
3865 if ((long) (start_pos - consumed_pos) < 0) {
3866 return consumed_pos; /* Grab everything */
3867 }
3868 return start_pos;
3869 }
3870
3871 static
3872 int consumer_flush_buffer(struct lttng_consumer_stream *stream, int producer_active)
3873 {
3874 int ret = 0;
3875
3876 switch (consumer_data.type) {
3877 case LTTNG_CONSUMER_KERNEL:
3878 ret = kernctl_buffer_flush(stream->wait_fd);
3879 if (ret < 0) {
3880 ERR("Failed to flush kernel stream");
3881 goto end;
3882 }
3883 break;
3884 case LTTNG_CONSUMER32_UST:
3885 case LTTNG_CONSUMER64_UST:
3886 lttng_ustconsumer_flush_buffer(stream, producer_active);
3887 break;
3888 default:
3889 ERR("Unknown consumer_data type");
3890 abort();
3891 }
3892
3893 end:
3894 return ret;
3895 }
3896
3897 static
3898 int consumer_clear_buffer(struct lttng_consumer_stream *stream)
3899 {
3900 int ret = 0;
3901
3902 switch (consumer_data.type) {
3903 case LTTNG_CONSUMER_KERNEL:
3904 ret = kernctl_buffer_clear(stream->wait_fd);
3905 if (ret < 0) {
3906 ERR("Failed to flush kernel stream");
3907 goto end;
3908 }
3909 break;
3910 case LTTNG_CONSUMER32_UST:
3911 case LTTNG_CONSUMER64_UST:
3912 lttng_ustconsumer_clear_buffer(stream);
3913 break;
3914 default:
3915 ERR("Unknown consumer_data type");
3916 abort();
3917 }
3918
3919 end:
3920 return ret;
3921 }
3922 /*
3923 * Sample the rotate position for all the streams of a channel. If a stream
3924 * is already at the rotate position (produced == consumed), we flag it as
3925 * ready for rotation. The rotation of ready streams occurs after we have
3926 * replied to the session daemon that we have finished sampling the positions.
3927 * Must be called with RCU read-side lock held to ensure existence of channel.
3928 *
3929 * Returns 0 on success, < 0 on error
3930 */
3931 int lttng_consumer_rotate_sample_channel(struct lttng_consumer_channel *channel,
3932 uint64_t key, const char *path, uint64_t relayd_id,
3933 uint32_t metadata, uint64_t new_chunk_id,
3934 struct lttng_consumer_local_data *ctx)
3935 {
3936 int ret;
3937 struct lttng_consumer_stream *stream;
3938 struct lttng_ht_iter iter;
3939 struct lttng_ht *ht = consumer_data.stream_per_chan_id_ht;
3940
3941 DBG("Consumer sample rotate position for channel %" PRIu64, key);
3942
3943 rcu_read_lock();
3944
3945 pthread_mutex_lock(&channel->lock);
3946 channel->current_chunk_id = new_chunk_id;
3947
3948 ret = lttng_strncpy(channel->pathname, path, sizeof(channel->pathname));
3949 if (ret) {
3950 ERR("Failed to copy new path to channel during channel rotation");
3951 ret = -1;
3952 goto end_unlock_channel;
3953 }
3954
3955 if (relayd_id == -1ULL) {
3956 /*
3957 * The domain path (/ust or /kernel) has been created before, we
3958 * now need to create the last part of the path: the application/user
3959 * specific section (uid/1000/64-bit).
3960 */
3961 ret = utils_mkdir_recursive(channel->pathname, S_IRWXU | S_IRWXG,
3962 channel->uid, channel->gid);
3963 if (ret < 0) {
3964 ERR("Failed to create trace directory at %s during rotation",
3965 channel->pathname);
3966 ret = -1;
3967 goto end_unlock_channel;
3968 }
3969 }
3970
3971 cds_lfht_for_each_entry_duplicate(ht->ht,
3972 ht->hash_fct(&channel->key, lttng_ht_seed),
3973 ht->match_fct, &channel->key, &iter.iter,
3974 stream, node_channel_id.node) {
3975 unsigned long consumed_pos;
3976
3977 health_code_update();
3978
3979 /*
3980 * Lock stream because we are about to change its state.
3981 */
3982 pthread_mutex_lock(&stream->lock);
3983
3984 ret = lttng_strncpy(stream->channel_read_only_attributes.path,
3985 channel->pathname,
3986 sizeof(stream->channel_read_only_attributes.path));
3987 if (ret) {
3988 ERR("Failed to sample channel path name during channel rotation");
3989 goto end_unlock_stream;
3990 }
3991 ret = lttng_consumer_sample_snapshot_positions(stream);
3992 if (ret < 0) {
3993 ERR("Failed to sample snapshot position during channel rotation");
3994 goto end_unlock_stream;
3995 }
3996
3997 ret = lttng_consumer_get_produced_snapshot(stream,
3998 &stream->rotate_position);
3999 if (ret < 0) {
4000 ERR("Failed to sample produced position during channel rotation");
4001 goto end_unlock_stream;
4002 }
4003
4004 lttng_consumer_get_consumed_snapshot(stream,
4005 &consumed_pos);
4006 if (consumed_pos == stream->rotate_position) {
4007 stream->rotate_ready = true;
4008 }
4009
4010 ret = consumer_flush_buffer(stream, 1);
4011 if (ret < 0) {
4012 ERR("Failed to flush stream %" PRIu64 " during channel rotation",
4013 stream->key);
4014 goto end_unlock_stream;
4015 }
4016
4017 pthread_mutex_unlock(&stream->lock);
4018 }
4019 pthread_mutex_unlock(&channel->lock);
4020
4021 ret = 0;
4022 goto end;
4023
4024 end_unlock_stream:
4025 pthread_mutex_unlock(&stream->lock);
4026 end_unlock_channel:
4027 pthread_mutex_unlock(&channel->lock);
4028 end:
4029 rcu_read_unlock();
4030 return ret;
4031 }
4032
4033 /*
4034 * Check if a stream is ready to be rotated after extracting it.
4035 *
4036 * Return 1 if it is ready for rotation, 0 if it is not, a negative value on
4037 * error. Stream lock must be held.
4038 */
4039 int lttng_consumer_stream_is_rotate_ready(struct lttng_consumer_stream *stream)
4040 {
4041 int ret;
4042 unsigned long consumed_pos;
4043
4044 if (!stream->rotate_position && !stream->rotate_ready) {
4045 ret = 0;
4046 goto end;
4047 }
4048
4049 if (stream->rotate_ready) {
4050 ret = 1;
4051 goto end;
4052 }
4053
4054 /*
4055 * If we don't have the rotate_ready flag, check the consumed position
4056 * to determine if we need to rotate.
4057 */
4058 ret = lttng_consumer_sample_snapshot_positions(stream);
4059 if (ret < 0) {
4060 ERR("Taking snapshot positions");
4061 goto end;
4062 }
4063
4064 ret = lttng_consumer_get_consumed_snapshot(stream, &consumed_pos);
4065 if (ret < 0) {
4066 ERR("Consumed snapshot position");
4067 goto end;
4068 }
4069
4070 /* Rotate position not reached yet (with check for overflow). */
4071 if ((long) (consumed_pos - stream->rotate_position) < 0) {
4072 ret = 0;
4073 goto end;
4074 }
4075 ret = 1;
4076
4077 end:
4078 return ret;
4079 }
4080
4081 /*
4082 * Reset the state for a stream after a rotation occurred.
4083 */
4084 void lttng_consumer_reset_stream_rotate_state(struct lttng_consumer_stream *stream)
4085 {
4086 stream->rotate_position = 0;
4087 stream->rotate_ready = false;
4088 }
4089
4090 /*
4091 * Perform the rotation a local stream file.
4092 */
4093 int rotate_local_stream(struct lttng_consumer_local_data *ctx,
4094 struct lttng_consumer_stream *stream)
4095 {
4096 int ret;
4097
4098 DBG("Rotate local stream: stream key %" PRIu64 ", channel key %" PRIu64 " at path %s",
4099 stream->key,
4100 stream->chan->key,
4101 stream->channel_read_only_attributes.path);
4102
4103 ret = close(stream->out_fd);
4104 if (ret < 0) {
4105 PERROR("Closing trace file (fd %d), stream %" PRIu64,
4106 stream->out_fd, stream->key);
4107 assert(0);
4108 goto error;
4109 }
4110
4111 ret = utils_create_stream_file(
4112 stream->channel_read_only_attributes.path,
4113 stream->name,
4114 stream->channel_read_only_attributes.tracefile_size,
4115 stream->tracefile_count_current,
4116 stream->uid, stream->gid, NULL);
4117 if (ret < 0) {
4118 ERR("Rotate create stream file");
4119 goto error;
4120 }
4121 stream->out_fd = ret;
4122 stream->tracefile_size_current = 0;
4123
4124 if (!stream->metadata_flag) {
4125 struct lttng_index_file *index_file;
4126
4127 lttng_index_file_put(stream->index_file);
4128
4129 index_file = lttng_index_file_create(
4130 stream->channel_read_only_attributes.path,
4131 stream->name, stream->uid, stream->gid,
4132 stream->channel_read_only_attributes.tracefile_size,
4133 stream->tracefile_count_current,
4134 CTF_INDEX_MAJOR, CTF_INDEX_MINOR);
4135 if (!index_file) {
4136 ERR("Create index file during rotation");
4137 goto error;
4138 }
4139 stream->index_file = index_file;
4140 stream->out_fd_offset = 0;
4141 }
4142
4143 ret = 0;
4144 goto end;
4145
4146 error:
4147 ret = -1;
4148 end:
4149 return ret;
4150
4151 }
4152
4153 /*
4154 * Perform the rotation a stream file on the relay.
4155 */
4156 int rotate_relay_stream(struct lttng_consumer_local_data *ctx,
4157 struct lttng_consumer_stream *stream)
4158 {
4159 int ret;
4160 struct consumer_relayd_sock_pair *relayd;
4161
4162 DBG("Rotate relay stream");
4163 relayd = consumer_find_relayd(stream->net_seq_idx);
4164 if (!relayd) {
4165 ERR("Failed to find relayd");
4166 ret = -1;
4167 goto end;
4168 }
4169
4170 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
4171 ret = relayd_rotate_stream(&relayd->control_sock,
4172 stream->relayd_stream_id,
4173 stream->channel_read_only_attributes.path,
4174 stream->chan->current_chunk_id,
4175 stream->last_sequence_number);
4176 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
4177 if (ret < 0) {
4178 ERR("Relayd rotate stream failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
4179 lttng_consumer_cleanup_relayd(relayd);
4180 }
4181 if (ret) {
4182 ERR("Rotate relay stream");
4183 }
4184
4185 end:
4186 return ret;
4187 }
4188
4189 /*
4190 * Performs the stream rotation for the rotate session feature if needed.
4191 * It must be called with the stream lock held.
4192 *
4193 * Return 0 on success, a negative number of error.
4194 */
4195 int lttng_consumer_rotate_stream(struct lttng_consumer_local_data *ctx,
4196 struct lttng_consumer_stream *stream, bool *rotated)
4197 {
4198 int ret;
4199
4200 DBG("Consumer rotate stream %" PRIu64, stream->key);
4201
4202 if (stream->net_seq_idx != (uint64_t) -1ULL) {
4203 ret = rotate_relay_stream(ctx, stream);
4204 } else {
4205 ret = rotate_local_stream(ctx, stream);
4206 }
4207 stream->trace_archive_id++;
4208 if (ret < 0) {
4209 ERR("Failed to rotate stream, ret = %i", ret);
4210 goto error;
4211 }
4212
4213 if (stream->metadata_flag) {
4214 switch (consumer_data.type) {
4215 case LTTNG_CONSUMER_KERNEL:
4216 /*
4217 * Reset the position of what has been read from the metadata
4218 * cache to 0 so we can dump it again.
4219 */
4220 ret = kernctl_metadata_cache_dump(stream->wait_fd);
4221 if (ret < 0) {
4222 ERR("Failed to dump the kernel metadata cache after rotation");
4223 goto error;
4224 }
4225 break;
4226 case LTTNG_CONSUMER32_UST:
4227 case LTTNG_CONSUMER64_UST:
4228 /*
4229 * Reset the position pushed from the metadata cache so it
4230 * will write from the beginning on the next push.
4231 */
4232 stream->ust_metadata_pushed = 0;
4233 break;
4234 default:
4235 ERR("Unknown consumer_data type");
4236 abort();
4237 }
4238 }
4239 lttng_consumer_reset_stream_rotate_state(stream);
4240
4241 if (rotated) {
4242 *rotated = true;
4243 }
4244
4245 ret = 0;
4246
4247 error:
4248 return ret;
4249 }
4250
4251 /*
4252 * Rotate all the ready streams now.
4253 *
4254 * This is especially important for low throughput streams that have already
4255 * been consumed, we cannot wait for their next packet to perform the
4256 * rotation.
4257 * Need to be called with RCU read-side lock held to ensure existence of
4258 * channel.
4259 *
4260 * Returns 0 on success, < 0 on error
4261 */
4262 int lttng_consumer_rotate_ready_streams(struct lttng_consumer_channel *channel,
4263 uint64_t key, struct lttng_consumer_local_data *ctx)
4264 {
4265 int ret;
4266 struct lttng_consumer_stream *stream;
4267 struct lttng_ht_iter iter;
4268 struct lttng_ht *ht = consumer_data.stream_per_chan_id_ht;
4269
4270 rcu_read_lock();
4271
4272 DBG("Consumer rotate ready streams in channel %" PRIu64, key);
4273
4274 cds_lfht_for_each_entry_duplicate(ht->ht,
4275 ht->hash_fct(&channel->key, lttng_ht_seed),
4276 ht->match_fct, &channel->key, &iter.iter,
4277 stream, node_channel_id.node) {
4278 health_code_update();
4279
4280 pthread_mutex_lock(&stream->lock);
4281
4282 if (!stream->rotate_ready) {
4283 pthread_mutex_unlock(&stream->lock);
4284 continue;
4285 }
4286 DBG("Consumer rotate ready stream %" PRIu64, stream->key);
4287
4288 ret = lttng_consumer_rotate_stream(ctx, stream, NULL);
4289 pthread_mutex_unlock(&stream->lock);
4290 if (ret) {
4291 goto end;
4292 }
4293
4294 ret = consumer_post_rotation(stream, ctx);
4295 if (ret) {
4296 goto end;
4297 }
4298 }
4299
4300 ret = 0;
4301
4302 end:
4303 rcu_read_unlock();
4304 return ret;
4305 }
4306
4307 static
4308 int rotate_rename_local(const char *old_path, const char *new_path,
4309 uid_t uid, gid_t gid)
4310 {
4311 int ret;
4312
4313 assert(old_path);
4314 assert(new_path);
4315
4316 ret = utils_mkdir_recursive(new_path, S_IRWXU | S_IRWXG, uid, gid);
4317 if (ret < 0) {
4318 ERR("Create directory on rotate");
4319 goto end;
4320 }
4321
4322 ret = rename(old_path, new_path);
4323 if (ret < 0 && errno != ENOENT) {
4324 PERROR("Rename completed rotation chunk");
4325 goto end;
4326 }
4327
4328 ret = 0;
4329 end:
4330 return ret;
4331 }
4332
4333 static
4334 int rotate_rename_relay(const char *old_path, const char *new_path,
4335 uint64_t relayd_id)
4336 {
4337 int ret;
4338 struct consumer_relayd_sock_pair *relayd;
4339
4340 relayd = consumer_find_relayd(relayd_id);
4341 if (!relayd) {
4342 ERR("Failed to find relayd while running rotate_rename_relay command");
4343 ret = -1;
4344 goto end;
4345 }
4346
4347 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
4348 ret = relayd_rotate_rename(&relayd->control_sock, old_path, new_path);
4349 if (ret < 0) {
4350 ERR("Relayd rotate rename failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
4351 lttng_consumer_cleanup_relayd(relayd);
4352 }
4353 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
4354 end:
4355 return ret;
4356 }
4357
4358 int lttng_consumer_rotate_rename(const char *old_path, const char *new_path,
4359 uid_t uid, gid_t gid, uint64_t relayd_id)
4360 {
4361 if (relayd_id != -1ULL) {
4362 return rotate_rename_relay(old_path, new_path, relayd_id);
4363 } else {
4364 return rotate_rename_local(old_path, new_path, uid, gid);
4365 }
4366 }
4367
4368 /* Stream lock must be acquired by the caller. */
4369 static
4370 bool check_stream_rotation_pending(const struct lttng_consumer_stream *stream,
4371 uint64_t session_id, uint64_t chunk_id)
4372 {
4373 bool pending = false;
4374
4375 if (stream->session_id != session_id) {
4376 /* Skip. */
4377 goto end;
4378 }
4379
4380 /*
4381 * If the stream's archive_id belongs to the chunk being rotated (or an
4382 * even older one), it means that the consumer has not consumed all the
4383 * buffers that belong to the chunk being rotated. Therefore, the
4384 * rotation is considered as ongoing/pending.
4385 */
4386 pending = stream->trace_archive_id <= chunk_id;
4387 end:
4388 return pending;
4389 }
4390
4391 /* RCU read lock must be acquired by the caller. */
4392 int lttng_consumer_check_rotation_pending_local(uint64_t session_id,
4393 uint64_t chunk_id)
4394 {
4395 struct lttng_ht_iter iter;
4396 struct lttng_consumer_stream *stream;
4397 bool rotation_pending = false;
4398
4399 /* Start with the metadata streams... */
4400 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream, node.node) {
4401 pthread_mutex_lock(&stream->lock);
4402 rotation_pending = check_stream_rotation_pending(stream,
4403 session_id, chunk_id);
4404 pthread_mutex_unlock(&stream->lock);
4405 if (rotation_pending) {
4406 goto end;
4407 }
4408 }
4409
4410 /* ... followed by the data streams. */
4411 cds_lfht_for_each_entry(data_ht->ht, &iter.iter, stream, node.node) {
4412 pthread_mutex_lock(&stream->lock);
4413 rotation_pending = check_stream_rotation_pending(stream,
4414 session_id, chunk_id);
4415 pthread_mutex_unlock(&stream->lock);
4416 if (rotation_pending) {
4417 goto end;
4418 }
4419 }
4420
4421 end:
4422 return !!rotation_pending;
4423 }
4424
4425 int lttng_consumer_check_rotation_pending_relay(uint64_t session_id,
4426 uint64_t relayd_id, uint64_t chunk_id)
4427 {
4428 int ret;
4429 struct consumer_relayd_sock_pair *relayd;
4430
4431 relayd = consumer_find_relayd(relayd_id);
4432 if (!relayd) {
4433 ERR("Failed to find relayd id %" PRIu64, relayd_id);
4434 ret = -1;
4435 goto end;
4436 }
4437
4438 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
4439 ret = relayd_rotate_pending(&relayd->control_sock, chunk_id);
4440 if (ret < 0) {
4441 ERR("Relayd rotate pending failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
4442 lttng_consumer_cleanup_relayd(relayd);
4443 }
4444 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
4445
4446 end:
4447 return ret;
4448 }
4449
4450 static
4451 int mkdir_local(const char *path, uid_t uid, gid_t gid)
4452 {
4453 int ret;
4454
4455 ret = utils_mkdir_recursive(path, S_IRWXU | S_IRWXG, uid, gid);
4456 if (ret < 0) {
4457 /* utils_mkdir_recursive logs an error. */
4458 goto end;
4459 }
4460
4461 ret = 0;
4462 end:
4463 return ret;
4464 }
4465
4466 static
4467 int mkdir_relay(const char *path, uint64_t relayd_id)
4468 {
4469 int ret;
4470 struct consumer_relayd_sock_pair *relayd;
4471
4472 relayd = consumer_find_relayd(relayd_id);
4473 if (!relayd) {
4474 ERR("Failed to find relayd");
4475 ret = -1;
4476 goto end;
4477 }
4478
4479 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
4480 ret = relayd_mkdir(&relayd->control_sock, path);
4481 if (ret < 0) {
4482 ERR("Relayd mkdir failed. Cleaning up relayd %" PRIu64".", relayd->net_seq_idx);
4483 lttng_consumer_cleanup_relayd(relayd);
4484 }
4485 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
4486
4487 end:
4488 return ret;
4489
4490 }
4491
4492 int lttng_consumer_mkdir(const char *path, uid_t uid, gid_t gid,
4493 uint64_t relayd_id)
4494 {
4495 if (relayd_id != -1ULL) {
4496 return mkdir_relay(path, relayd_id);
4497 } else {
4498 return mkdir_local(path, uid, gid);
4499 }
4500 }
4501
4502 static
4503 int clear_unmonitored_channel(struct lttng_consumer_channel *channel)
4504 {
4505
4506 int ret;
4507 struct lttng_consumer_stream *stream;
4508
4509 assert(!channel->monitor);
4510 assert(channel->type != CONSUMER_CHANNEL_TYPE_METADATA);
4511
4512 rcu_read_lock();
4513 pthread_mutex_lock(&channel->lock);
4514 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
4515 health_code_update();
4516 pthread_mutex_lock(&stream->lock);
4517
4518 ret = consumer_flush_buffer(stream, 1);
4519 if (ret < 0) {
4520 ERR("Failed to flush stream %" PRIu64 " during channel clear",
4521 stream->key);
4522 ret = LTTCOMM_CONSUMERD_FATAL;
4523 goto error_unlock;
4524 }
4525
4526 ret = consumer_clear_buffer(stream);
4527 if (ret < 0) {
4528 ERR("Failed to clear stream %" PRIu64 " during channel clear",
4529 stream->key);
4530 ret = LTTCOMM_CONSUMERD_FATAL;
4531 goto error_unlock;
4532 }
4533 pthread_mutex_unlock(&stream->lock);
4534 }
4535 pthread_mutex_unlock(&channel->lock);
4536 rcu_read_unlock();
4537 return 0;
4538
4539 error_unlock:
4540 pthread_mutex_unlock(&stream->lock);
4541 pthread_mutex_unlock(&channel->lock);
4542 rcu_read_unlock();
4543 return ret;
4544 }
4545
4546 int lttng_consumer_clear_channel(struct lttng_consumer_channel *channel)
4547 {
4548 int ret;
4549
4550 DBG("Consumer clear channel %" PRIu64, channel->key);
4551
4552 if (!channel->monitor) {
4553 /* Snapshot mode */
4554 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
4555 /*
4556 * Nothing to do for the metadata channel/stream.
4557 * Snapshot mechanism already take care of the metadata
4558 * handling/generation.
4559 */
4560 goto end;
4561 }
4562 ret = clear_unmonitored_channel(channel);
4563 if (ret) {
4564 goto error;
4565 }
4566 } else {
4567 /* TODO:
4568 * Normal channel and relayd bound clear operation not supported
4569 * for now
4570 */
4571 ret = LTTCOMM_CONSUMERD_FATAL;
4572 goto error;
4573 }
4574
4575 end:
4576 ret = LTTCOMM_CONSUMERD_SUCCESS;
4577 error:
4578 return ret;
4579 }
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