08e6ee0d8f895591c995023ffe1292dc5040b773
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
1 /*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License, version 2 only,
7 * as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
17 */
18
19 #define _GNU_SOURCE
20 #define _LGPL_SOURCE
21 #include <assert.h>
22 #include <lttng/ust-ctl.h>
23 #include <poll.h>
24 #include <pthread.h>
25 #include <stdlib.h>
26 #include <string.h>
27 #include <sys/mman.h>
28 #include <sys/socket.h>
29 #include <sys/stat.h>
30 #include <sys/types.h>
31 #include <inttypes.h>
32 #include <unistd.h>
33 #include <urcu/list.h>
34 #include <signal.h>
35
36 #include <bin/lttng-consumerd/health-consumerd.h>
37 #include <common/common.h>
38 #include <common/sessiond-comm/sessiond-comm.h>
39 #include <common/relayd/relayd.h>
40 #include <common/compat/fcntl.h>
41 #include <common/compat/endian.h>
42 #include <common/consumer-metadata-cache.h>
43 #include <common/consumer-stream.h>
44 #include <common/consumer-timer.h>
45 #include <common/utils.h>
46 #include <common/index/index.h>
47
48 #include "ust-consumer.h"
49
50 #define UINT_MAX_STR_LEN 11 /* includes \0 */
51
52 extern struct lttng_consumer_global_data consumer_data;
53 extern int consumer_poll_timeout;
54 extern volatile int consumer_quit;
55
56 /*
57 * Free channel object and all streams associated with it. This MUST be used
58 * only and only if the channel has _NEVER_ been added to the global channel
59 * hash table.
60 */
61 static void destroy_channel(struct lttng_consumer_channel *channel)
62 {
63 struct lttng_consumer_stream *stream, *stmp;
64
65 assert(channel);
66
67 DBG("UST consumer cleaning stream list");
68
69 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
70 send_node) {
71
72 health_code_update();
73
74 cds_list_del(&stream->send_node);
75 ustctl_destroy_stream(stream->ustream);
76 free(stream);
77 }
78
79 /*
80 * If a channel is available meaning that was created before the streams
81 * were, delete it.
82 */
83 if (channel->uchan) {
84 lttng_ustconsumer_del_channel(channel);
85 lttng_ustconsumer_free_channel(channel);
86 }
87 free(channel);
88 }
89
90 /*
91 * Add channel to internal consumer state.
92 *
93 * Returns 0 on success or else a negative value.
94 */
95 static int add_channel(struct lttng_consumer_channel *channel,
96 struct lttng_consumer_local_data *ctx)
97 {
98 int ret = 0;
99
100 assert(channel);
101 assert(ctx);
102
103 if (ctx->on_recv_channel != NULL) {
104 ret = ctx->on_recv_channel(channel);
105 if (ret == 0) {
106 ret = consumer_add_channel(channel, ctx);
107 } else if (ret < 0) {
108 /* Most likely an ENOMEM. */
109 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
110 goto error;
111 }
112 } else {
113 ret = consumer_add_channel(channel, ctx);
114 }
115
116 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
117
118 error:
119 return ret;
120 }
121
122 /*
123 * Allocate and return a consumer channel object.
124 */
125 static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
126 const char *pathname, const char *name, uid_t uid, gid_t gid,
127 uint64_t relayd_id, uint64_t key, enum lttng_event_output output,
128 uint64_t tracefile_size, uint64_t tracefile_count,
129 uint64_t session_id_per_pid, unsigned int monitor,
130 unsigned int live_timer_interval,
131 const char *root_shm_path, const char *shm_path)
132 {
133 assert(pathname);
134 assert(name);
135
136 return consumer_allocate_channel(key, session_id, pathname, name, uid,
137 gid, relayd_id, output, tracefile_size,
138 tracefile_count, session_id_per_pid, monitor,
139 live_timer_interval, root_shm_path, shm_path);
140 }
141
142 /*
143 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
144 * error value if applicable is set in it else it is kept untouched.
145 *
146 * Return NULL on error else the newly allocated stream object.
147 */
148 static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
149 struct lttng_consumer_channel *channel,
150 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
151 {
152 int alloc_ret;
153 struct lttng_consumer_stream *stream = NULL;
154
155 assert(channel);
156 assert(ctx);
157
158 stream = consumer_allocate_stream(channel->key,
159 key,
160 LTTNG_CONSUMER_ACTIVE_STREAM,
161 channel->name,
162 channel->uid,
163 channel->gid,
164 channel->relayd_id,
165 channel->session_id,
166 cpu,
167 &alloc_ret,
168 channel->type,
169 channel->monitor);
170 if (stream == NULL) {
171 switch (alloc_ret) {
172 case -ENOENT:
173 /*
174 * We could not find the channel. Can happen if cpu hotplug
175 * happens while tearing down.
176 */
177 DBG3("Could not find channel");
178 break;
179 case -ENOMEM:
180 case -EINVAL:
181 default:
182 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
183 break;
184 }
185 goto error;
186 }
187
188 stream->chan = channel;
189
190 error:
191 if (_alloc_ret) {
192 *_alloc_ret = alloc_ret;
193 }
194 return stream;
195 }
196
197 /*
198 * Send the given stream pointer to the corresponding thread.
199 *
200 * Returns 0 on success else a negative value.
201 */
202 static int send_stream_to_thread(struct lttng_consumer_stream *stream,
203 struct lttng_consumer_local_data *ctx)
204 {
205 int ret;
206 struct lttng_pipe *stream_pipe;
207
208 /* Get the right pipe where the stream will be sent. */
209 if (stream->metadata_flag) {
210 ret = consumer_add_metadata_stream(stream);
211 if (ret) {
212 ERR("Consumer add metadata stream %" PRIu64 " failed.",
213 stream->key);
214 goto error;
215 }
216 stream_pipe = ctx->consumer_metadata_pipe;
217 } else {
218 ret = consumer_add_data_stream(stream);
219 if (ret) {
220 ERR("Consumer add stream %" PRIu64 " failed.",
221 stream->key);
222 goto error;
223 }
224 stream_pipe = ctx->consumer_data_pipe;
225 }
226
227 /*
228 * From this point on, the stream's ownership has been moved away from
229 * the channel and becomes globally visible.
230 */
231 stream->globally_visible = 1;
232
233 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
234 if (ret < 0) {
235 ERR("Consumer write %s stream to pipe %d",
236 stream->metadata_flag ? "metadata" : "data",
237 lttng_pipe_get_writefd(stream_pipe));
238 if (stream->metadata_flag) {
239 consumer_del_stream_for_metadata(stream);
240 } else {
241 consumer_del_stream_for_data(stream);
242 }
243 }
244 error:
245 return ret;
246 }
247
248 static
249 int get_stream_shm_path(char *stream_shm_path, const char *shm_path, int cpu)
250 {
251 char cpu_nr[UINT_MAX_STR_LEN]; /* unsigned int max len */
252 int ret;
253
254 strncpy(stream_shm_path, shm_path, PATH_MAX);
255 stream_shm_path[PATH_MAX - 1] = '\0';
256 ret = snprintf(cpu_nr, UINT_MAX_STR_LEN, "%u", cpu);
257 if (ret < 0) {
258 PERROR("snprintf");
259 goto end;
260 }
261 strncat(stream_shm_path, cpu_nr,
262 PATH_MAX - strlen(stream_shm_path) - 1);
263 ret = 0;
264 end:
265 return ret;
266 }
267
268 /*
269 * Create streams for the given channel using liblttng-ust-ctl.
270 *
271 * Return 0 on success else a negative value.
272 */
273 static int create_ust_streams(struct lttng_consumer_channel *channel,
274 struct lttng_consumer_local_data *ctx)
275 {
276 int ret, cpu = 0;
277 struct ustctl_consumer_stream *ustream;
278 struct lttng_consumer_stream *stream;
279
280 assert(channel);
281 assert(ctx);
282
283 /*
284 * While a stream is available from ustctl. When NULL is returned, we've
285 * reached the end of the possible stream for the channel.
286 */
287 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
288 int wait_fd;
289 int ust_metadata_pipe[2];
290
291 health_code_update();
292
293 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && channel->monitor) {
294 ret = utils_create_pipe_cloexec_nonblock(ust_metadata_pipe);
295 if (ret < 0) {
296 ERR("Create ust metadata poll pipe");
297 goto error;
298 }
299 wait_fd = ust_metadata_pipe[0];
300 } else {
301 wait_fd = ustctl_stream_get_wait_fd(ustream);
302 }
303
304 /* Allocate consumer stream object. */
305 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
306 if (!stream) {
307 goto error_alloc;
308 }
309 stream->ustream = ustream;
310 /*
311 * Store it so we can save multiple function calls afterwards since
312 * this value is used heavily in the stream threads. This is UST
313 * specific so this is why it's done after allocation.
314 */
315 stream->wait_fd = wait_fd;
316
317 /*
318 * Increment channel refcount since the channel reference has now been
319 * assigned in the allocation process above.
320 */
321 if (stream->chan->monitor) {
322 uatomic_inc(&stream->chan->refcount);
323 }
324
325 /*
326 * Order is important this is why a list is used. On error, the caller
327 * should clean this list.
328 */
329 cds_list_add_tail(&stream->send_node, &channel->streams.head);
330
331 ret = ustctl_get_max_subbuf_size(stream->ustream,
332 &stream->max_sb_size);
333 if (ret < 0) {
334 ERR("ustctl_get_max_subbuf_size failed for stream %s",
335 stream->name);
336 goto error;
337 }
338
339 /* Do actions once stream has been received. */
340 if (ctx->on_recv_stream) {
341 ret = ctx->on_recv_stream(stream);
342 if (ret < 0) {
343 goto error;
344 }
345 }
346
347 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
348 stream->name, stream->key, stream->relayd_stream_id);
349
350 /* Set next CPU stream. */
351 channel->streams.count = ++cpu;
352
353 /* Keep stream reference when creating metadata. */
354 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
355 channel->metadata_stream = stream;
356 if (channel->monitor) {
357 /* Set metadata poll pipe if we created one */
358 memcpy(stream->ust_metadata_poll_pipe,
359 ust_metadata_pipe,
360 sizeof(ust_metadata_pipe));
361 }
362 }
363 }
364
365 return 0;
366
367 error:
368 error_alloc:
369 return ret;
370 }
371
372 /*
373 * create_posix_shm is never called concurrently within a process.
374 */
375 static
376 int create_posix_shm(void)
377 {
378 char tmp_name[NAME_MAX];
379 int shmfd, ret;
380
381 ret = snprintf(tmp_name, NAME_MAX, "/ust-shm-consumer-%d", getpid());
382 if (ret < 0) {
383 PERROR("snprintf");
384 return -1;
385 }
386 /*
387 * Allocate shm, and immediately unlink its shm oject, keeping
388 * only the file descriptor as a reference to the object.
389 * We specifically do _not_ use the / at the beginning of the
390 * pathname so that some OS implementations can keep it local to
391 * the process (POSIX leaves this implementation-defined).
392 */
393 shmfd = shm_open(tmp_name, O_CREAT | O_EXCL | O_RDWR, 0700);
394 if (shmfd < 0) {
395 PERROR("shm_open");
396 goto error_shm_open;
397 }
398 ret = shm_unlink(tmp_name);
399 if (ret < 0 && errno != ENOENT) {
400 PERROR("shm_unlink");
401 goto error_shm_release;
402 }
403 return shmfd;
404
405 error_shm_release:
406 ret = close(shmfd);
407 if (ret) {
408 PERROR("close");
409 }
410 error_shm_open:
411 return -1;
412 }
413
414 static int open_ust_stream_fd(struct lttng_consumer_channel *channel,
415 struct ustctl_consumer_channel_attr *attr,
416 int cpu)
417 {
418 char shm_path[PATH_MAX];
419 int ret;
420
421 if (!channel->shm_path[0]) {
422 return create_posix_shm();
423 }
424 ret = get_stream_shm_path(shm_path, channel->shm_path, cpu);
425 if (ret) {
426 goto error_shm_path;
427 }
428 return run_as_open(shm_path,
429 O_RDWR | O_CREAT | O_EXCL, S_IRUSR | S_IWUSR,
430 channel->uid, channel->gid);
431
432 error_shm_path:
433 return -1;
434 }
435
436 /*
437 * Create an UST channel with the given attributes and send it to the session
438 * daemon using the ust ctl API.
439 *
440 * Return 0 on success or else a negative value.
441 */
442 static int create_ust_channel(struct lttng_consumer_channel *channel,
443 struct ustctl_consumer_channel_attr *attr,
444 struct ustctl_consumer_channel **ust_chanp)
445 {
446 int ret, nr_stream_fds, i, j;
447 int *stream_fds;
448 struct ustctl_consumer_channel *ust_channel;
449
450 assert(channel);
451 assert(attr);
452 assert(ust_chanp);
453
454 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
455 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
456 "switch_timer_interval: %u, read_timer_interval: %u, "
457 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
458 attr->num_subbuf, attr->switch_timer_interval,
459 attr->read_timer_interval, attr->output, attr->type);
460
461 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA)
462 nr_stream_fds = 1;
463 else
464 nr_stream_fds = ustctl_get_nr_stream_per_channel();
465 stream_fds = zmalloc(nr_stream_fds * sizeof(*stream_fds));
466 if (!stream_fds) {
467 ret = -1;
468 goto error_alloc;
469 }
470 for (i = 0; i < nr_stream_fds; i++) {
471 stream_fds[i] = open_ust_stream_fd(channel, attr, i);
472 if (stream_fds[i] < 0) {
473 ret = -1;
474 goto error_open;
475 }
476 }
477 ust_channel = ustctl_create_channel(attr, stream_fds, nr_stream_fds);
478 if (!ust_channel) {
479 ret = -1;
480 goto error_create;
481 }
482 channel->nr_stream_fds = nr_stream_fds;
483 channel->stream_fds = stream_fds;
484 *ust_chanp = ust_channel;
485
486 return 0;
487
488 error_create:
489 error_open:
490 for (j = i - 1; j >= 0; j--) {
491 int closeret;
492
493 closeret = close(stream_fds[j]);
494 if (closeret) {
495 PERROR("close");
496 }
497 if (channel->shm_path[0]) {
498 char shm_path[PATH_MAX];
499
500 closeret = get_stream_shm_path(shm_path,
501 channel->shm_path, j);
502 if (closeret) {
503 ERR("Cannot get stream shm path");
504 }
505 closeret = run_as_unlink(shm_path,
506 channel->uid, channel->gid);
507 if (closeret) {
508 PERROR("unlink %s", shm_path);
509 }
510 }
511 }
512 /* Try to rmdir all directories under shm_path root. */
513 if (channel->root_shm_path[0]) {
514 (void) run_as_recursive_rmdir(channel->root_shm_path,
515 channel->uid, channel->gid);
516 }
517 free(stream_fds);
518 error_alloc:
519 return ret;
520 }
521
522 /*
523 * Send a single given stream to the session daemon using the sock.
524 *
525 * Return 0 on success else a negative value.
526 */
527 static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
528 {
529 int ret;
530
531 assert(stream);
532 assert(sock >= 0);
533
534 DBG("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
535
536 /* Send stream to session daemon. */
537 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
538 if (ret < 0) {
539 goto error;
540 }
541
542 error:
543 return ret;
544 }
545
546 /*
547 * Send channel to sessiond.
548 *
549 * Return 0 on success or else a negative value.
550 */
551 static int send_sessiond_channel(int sock,
552 struct lttng_consumer_channel *channel,
553 struct lttng_consumer_local_data *ctx, int *relayd_error)
554 {
555 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
556 struct lttng_consumer_stream *stream;
557 uint64_t net_seq_idx = -1ULL;
558
559 assert(channel);
560 assert(ctx);
561 assert(sock >= 0);
562
563 DBG("UST consumer sending channel %s to sessiond", channel->name);
564
565 if (channel->relayd_id != (uint64_t) -1ULL) {
566 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
567
568 health_code_update();
569
570 /* Try to send the stream to the relayd if one is available. */
571 ret = consumer_send_relayd_stream(stream, stream->chan->pathname);
572 if (ret < 0) {
573 /*
574 * Flag that the relayd was the problem here probably due to a
575 * communicaton error on the socket.
576 */
577 if (relayd_error) {
578 *relayd_error = 1;
579 }
580 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
581 }
582 if (net_seq_idx == -1ULL) {
583 net_seq_idx = stream->net_seq_idx;
584 }
585 }
586 }
587
588 /* Inform sessiond that we are about to send channel and streams. */
589 ret = consumer_send_status_msg(sock, ret_code);
590 if (ret < 0 || ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
591 /*
592 * Either the session daemon is not responding or the relayd died so we
593 * stop now.
594 */
595 goto error;
596 }
597
598 /* Send channel to sessiond. */
599 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
600 if (ret < 0) {
601 goto error;
602 }
603
604 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
605 if (ret < 0) {
606 goto error;
607 }
608
609 /* The channel was sent successfully to the sessiond at this point. */
610 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
611
612 health_code_update();
613
614 /* Send stream to session daemon. */
615 ret = send_sessiond_stream(sock, stream);
616 if (ret < 0) {
617 goto error;
618 }
619 }
620
621 /* Tell sessiond there is no more stream. */
622 ret = ustctl_send_stream_to_sessiond(sock, NULL);
623 if (ret < 0) {
624 goto error;
625 }
626
627 DBG("UST consumer NULL stream sent to sessiond");
628
629 return 0;
630
631 error:
632 if (ret_code != LTTCOMM_CONSUMERD_SUCCESS) {
633 ret = -1;
634 }
635 return ret;
636 }
637
638 /*
639 * Creates a channel and streams and add the channel it to the channel internal
640 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
641 * received.
642 *
643 * Return 0 on success or else, a negative value is returned and the channel
644 * MUST be destroyed by consumer_del_channel().
645 */
646 static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
647 struct lttng_consumer_channel *channel,
648 struct ustctl_consumer_channel_attr *attr)
649 {
650 int ret;
651
652 assert(ctx);
653 assert(channel);
654 assert(attr);
655
656 /*
657 * This value is still used by the kernel consumer since for the kernel,
658 * the stream ownership is not IN the consumer so we need to have the
659 * number of left stream that needs to be initialized so we can know when
660 * to delete the channel (see consumer.c).
661 *
662 * As for the user space tracer now, the consumer creates and sends the
663 * stream to the session daemon which only sends them to the application
664 * once every stream of a channel is received making this value useless
665 * because we they will be added to the poll thread before the application
666 * receives them. This ensures that a stream can not hang up during
667 * initilization of a channel.
668 */
669 channel->nb_init_stream_left = 0;
670
671 /* The reply msg status is handled in the following call. */
672 ret = create_ust_channel(channel, attr, &channel->uchan);
673 if (ret < 0) {
674 goto end;
675 }
676
677 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
678
679 /*
680 * For the snapshots (no monitor), we create the metadata streams
681 * on demand, not during the channel creation.
682 */
683 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA && !channel->monitor) {
684 ret = 0;
685 goto end;
686 }
687
688 /* Open all streams for this channel. */
689 ret = create_ust_streams(channel, ctx);
690 if (ret < 0) {
691 goto end;
692 }
693
694 end:
695 return ret;
696 }
697
698 /*
699 * Send all stream of a channel to the right thread handling it.
700 *
701 * On error, return a negative value else 0 on success.
702 */
703 static int send_streams_to_thread(struct lttng_consumer_channel *channel,
704 struct lttng_consumer_local_data *ctx)
705 {
706 int ret = 0;
707 struct lttng_consumer_stream *stream, *stmp;
708
709 assert(channel);
710 assert(ctx);
711
712 /* Send streams to the corresponding thread. */
713 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
714 send_node) {
715
716 health_code_update();
717
718 /* Sending the stream to the thread. */
719 ret = send_stream_to_thread(stream, ctx);
720 if (ret < 0) {
721 /*
722 * If we are unable to send the stream to the thread, there is
723 * a big problem so just stop everything.
724 */
725 /* Remove node from the channel stream list. */
726 cds_list_del(&stream->send_node);
727 goto error;
728 }
729
730 /* Remove node from the channel stream list. */
731 cds_list_del(&stream->send_node);
732
733 }
734
735 error:
736 return ret;
737 }
738
739 /*
740 * Flush channel's streams using the given key to retrieve the channel.
741 *
742 * Return 0 on success else an LTTng error code.
743 */
744 static int flush_channel(uint64_t chan_key)
745 {
746 int ret = 0;
747 struct lttng_consumer_channel *channel;
748 struct lttng_consumer_stream *stream;
749 struct lttng_ht *ht;
750 struct lttng_ht_iter iter;
751
752 DBG("UST consumer flush channel key %" PRIu64, chan_key);
753
754 rcu_read_lock();
755 channel = consumer_find_channel(chan_key);
756 if (!channel) {
757 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
758 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
759 goto error;
760 }
761
762 ht = consumer_data.stream_per_chan_id_ht;
763
764 /* For each stream of the channel id, flush it. */
765 cds_lfht_for_each_entry_duplicate(ht->ht,
766 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
767 &channel->key, &iter.iter, stream, node_channel_id.node) {
768
769 health_code_update();
770
771 ustctl_flush_buffer(stream->ustream, 1);
772 }
773 error:
774 rcu_read_unlock();
775 return ret;
776 }
777
778 /*
779 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
780 * RCU read side lock MUST be acquired before calling this function.
781 *
782 * Return 0 on success else an LTTng error code.
783 */
784 static int close_metadata(uint64_t chan_key)
785 {
786 int ret = 0;
787 struct lttng_consumer_channel *channel;
788
789 DBG("UST consumer close metadata key %" PRIu64, chan_key);
790
791 channel = consumer_find_channel(chan_key);
792 if (!channel) {
793 /*
794 * This is possible if the metadata thread has issue a delete because
795 * the endpoint point of the stream hung up. There is no way the
796 * session daemon can know about it thus use a DBG instead of an actual
797 * error.
798 */
799 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
800 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
801 goto error;
802 }
803
804 pthread_mutex_lock(&consumer_data.lock);
805 pthread_mutex_lock(&channel->lock);
806
807 if (cds_lfht_is_node_deleted(&channel->node.node)) {
808 goto error_unlock;
809 }
810
811 lttng_ustconsumer_close_metadata(channel);
812
813 error_unlock:
814 pthread_mutex_unlock(&channel->lock);
815 pthread_mutex_unlock(&consumer_data.lock);
816 error:
817 return ret;
818 }
819
820 /*
821 * RCU read side lock MUST be acquired before calling this function.
822 *
823 * Return 0 on success else an LTTng error code.
824 */
825 static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
826 {
827 int ret;
828 struct lttng_consumer_channel *metadata;
829
830 DBG("UST consumer setup metadata key %" PRIu64, key);
831
832 metadata = consumer_find_channel(key);
833 if (!metadata) {
834 ERR("UST consumer push metadata %" PRIu64 " not found", key);
835 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
836 goto end;
837 }
838
839 /*
840 * In no monitor mode, the metadata channel has no stream(s) so skip the
841 * ownership transfer to the metadata thread.
842 */
843 if (!metadata->monitor) {
844 DBG("Metadata channel in no monitor");
845 ret = 0;
846 goto end;
847 }
848
849 /*
850 * Send metadata stream to relayd if one available. Availability is
851 * known if the stream is still in the list of the channel.
852 */
853 if (cds_list_empty(&metadata->streams.head)) {
854 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
855 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
856 goto error_no_stream;
857 }
858
859 /* Send metadata stream to relayd if needed. */
860 if (metadata->metadata_stream->net_seq_idx != (uint64_t) -1ULL) {
861 ret = consumer_send_relayd_stream(metadata->metadata_stream,
862 metadata->pathname);
863 if (ret < 0) {
864 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
865 goto error;
866 }
867 ret = consumer_send_relayd_streams_sent(
868 metadata->metadata_stream->net_seq_idx);
869 if (ret < 0) {
870 ret = LTTCOMM_CONSUMERD_RELAYD_FAIL;
871 goto error;
872 }
873 }
874
875 ret = send_streams_to_thread(metadata, ctx);
876 if (ret < 0) {
877 /*
878 * If we are unable to send the stream to the thread, there is
879 * a big problem so just stop everything.
880 */
881 ret = LTTCOMM_CONSUMERD_FATAL;
882 goto error;
883 }
884 /* List MUST be empty after or else it could be reused. */
885 assert(cds_list_empty(&metadata->streams.head));
886
887 ret = 0;
888 goto end;
889
890 error:
891 /*
892 * Delete metadata channel on error. At this point, the metadata stream can
893 * NOT be monitored by the metadata thread thus having the guarantee that
894 * the stream is still in the local stream list of the channel. This call
895 * will make sure to clean that list.
896 */
897 consumer_stream_destroy(metadata->metadata_stream, NULL);
898 cds_list_del(&metadata->metadata_stream->send_node);
899 metadata->metadata_stream = NULL;
900 error_no_stream:
901 end:
902 return ret;
903 }
904
905 /*
906 * Snapshot the whole metadata.
907 *
908 * Returns 0 on success, < 0 on error
909 */
910 static int snapshot_metadata(uint64_t key, char *path, uint64_t relayd_id,
911 struct lttng_consumer_local_data *ctx)
912 {
913 int ret = 0;
914 struct lttng_consumer_channel *metadata_channel;
915 struct lttng_consumer_stream *metadata_stream;
916
917 assert(path);
918 assert(ctx);
919
920 DBG("UST consumer snapshot metadata with key %" PRIu64 " at path %s",
921 key, path);
922
923 rcu_read_lock();
924
925 metadata_channel = consumer_find_channel(key);
926 if (!metadata_channel) {
927 ERR("UST snapshot metadata channel not found for key %" PRIu64,
928 key);
929 ret = -1;
930 goto error;
931 }
932 assert(!metadata_channel->monitor);
933
934 health_code_update();
935
936 /*
937 * Ask the sessiond if we have new metadata waiting and update the
938 * consumer metadata cache.
939 */
940 ret = lttng_ustconsumer_request_metadata(ctx, metadata_channel, 0, 1);
941 if (ret < 0) {
942 goto error;
943 }
944
945 health_code_update();
946
947 /*
948 * The metadata stream is NOT created in no monitor mode when the channel
949 * is created on a sessiond ask channel command.
950 */
951 ret = create_ust_streams(metadata_channel, ctx);
952 if (ret < 0) {
953 goto error;
954 }
955
956 metadata_stream = metadata_channel->metadata_stream;
957 assert(metadata_stream);
958
959 if (relayd_id != (uint64_t) -1ULL) {
960 metadata_stream->net_seq_idx = relayd_id;
961 ret = consumer_send_relayd_stream(metadata_stream, path);
962 if (ret < 0) {
963 goto error_stream;
964 }
965 } else {
966 ret = utils_create_stream_file(path, metadata_stream->name,
967 metadata_stream->chan->tracefile_size,
968 metadata_stream->tracefile_count_current,
969 metadata_stream->uid, metadata_stream->gid, NULL);
970 if (ret < 0) {
971 goto error_stream;
972 }
973 metadata_stream->out_fd = ret;
974 metadata_stream->tracefile_size_current = 0;
975 }
976
977 do {
978 health_code_update();
979
980 ret = lttng_consumer_read_subbuffer(metadata_stream, ctx);
981 if (ret < 0) {
982 goto error_stream;
983 }
984 } while (ret > 0);
985
986 error_stream:
987 /*
988 * Clean up the stream completly because the next snapshot will use a new
989 * metadata stream.
990 */
991 consumer_stream_destroy(metadata_stream, NULL);
992 cds_list_del(&metadata_stream->send_node);
993 metadata_channel->metadata_stream = NULL;
994
995 error:
996 rcu_read_unlock();
997 return ret;
998 }
999
1000 /*
1001 * Take a snapshot of all the stream of a channel.
1002 *
1003 * Returns 0 on success, < 0 on error
1004 */
1005 static int snapshot_channel(uint64_t key, char *path, uint64_t relayd_id,
1006 uint64_t nb_packets_per_stream, struct lttng_consumer_local_data *ctx)
1007 {
1008 int ret;
1009 unsigned use_relayd = 0;
1010 unsigned long consumed_pos, produced_pos;
1011 struct lttng_consumer_channel *channel;
1012 struct lttng_consumer_stream *stream;
1013
1014 assert(path);
1015 assert(ctx);
1016
1017 rcu_read_lock();
1018
1019 if (relayd_id != (uint64_t) -1ULL) {
1020 use_relayd = 1;
1021 }
1022
1023 channel = consumer_find_channel(key);
1024 if (!channel) {
1025 ERR("UST snapshot channel not found for key %" PRIu64, key);
1026 ret = -1;
1027 goto error;
1028 }
1029 assert(!channel->monitor);
1030 DBG("UST consumer snapshot channel %" PRIu64, key);
1031
1032 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
1033
1034 health_code_update();
1035
1036 /* Lock stream because we are about to change its state. */
1037 pthread_mutex_lock(&stream->lock);
1038 stream->net_seq_idx = relayd_id;
1039
1040 if (use_relayd) {
1041 ret = consumer_send_relayd_stream(stream, path);
1042 if (ret < 0) {
1043 goto error_unlock;
1044 }
1045 } else {
1046 ret = utils_create_stream_file(path, stream->name,
1047 stream->chan->tracefile_size,
1048 stream->tracefile_count_current,
1049 stream->uid, stream->gid, NULL);
1050 if (ret < 0) {
1051 goto error_unlock;
1052 }
1053 stream->out_fd = ret;
1054 stream->tracefile_size_current = 0;
1055
1056 DBG("UST consumer snapshot stream %s/%s (%" PRIu64 ")", path,
1057 stream->name, stream->key);
1058 }
1059 if (relayd_id != -1ULL) {
1060 ret = consumer_send_relayd_streams_sent(relayd_id);
1061 if (ret < 0) {
1062 goto error_unlock;
1063 }
1064 }
1065
1066 ustctl_flush_buffer(stream->ustream, 1);
1067
1068 ret = lttng_ustconsumer_take_snapshot(stream);
1069 if (ret < 0) {
1070 ERR("Taking UST snapshot");
1071 goto error_unlock;
1072 }
1073
1074 ret = lttng_ustconsumer_get_produced_snapshot(stream, &produced_pos);
1075 if (ret < 0) {
1076 ERR("Produced UST snapshot position");
1077 goto error_unlock;
1078 }
1079
1080 ret = lttng_ustconsumer_get_consumed_snapshot(stream, &consumed_pos);
1081 if (ret < 0) {
1082 ERR("Consumerd UST snapshot position");
1083 goto error_unlock;
1084 }
1085
1086 /*
1087 * The original value is sent back if max stream size is larger than
1088 * the possible size of the snapshot. Also, we assume that the session
1089 * daemon should never send a maximum stream size that is lower than
1090 * subbuffer size.
1091 */
1092 consumed_pos = consumer_get_consume_start_pos(consumed_pos,
1093 produced_pos, nb_packets_per_stream,
1094 stream->max_sb_size);
1095
1096 while (consumed_pos < produced_pos) {
1097 ssize_t read_len;
1098 unsigned long len, padded_len;
1099
1100 health_code_update();
1101
1102 DBG("UST consumer taking snapshot at pos %lu", consumed_pos);
1103
1104 ret = ustctl_get_subbuf(stream->ustream, &consumed_pos);
1105 if (ret < 0) {
1106 if (ret != -EAGAIN) {
1107 PERROR("ustctl_get_subbuf snapshot");
1108 goto error_close_stream;
1109 }
1110 DBG("UST consumer get subbuf failed. Skipping it.");
1111 consumed_pos += stream->max_sb_size;
1112 continue;
1113 }
1114
1115 ret = ustctl_get_subbuf_size(stream->ustream, &len);
1116 if (ret < 0) {
1117 ERR("Snapshot ustctl_get_subbuf_size");
1118 goto error_put_subbuf;
1119 }
1120
1121 ret = ustctl_get_padded_subbuf_size(stream->ustream, &padded_len);
1122 if (ret < 0) {
1123 ERR("Snapshot ustctl_get_padded_subbuf_size");
1124 goto error_put_subbuf;
1125 }
1126
1127 read_len = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len,
1128 padded_len - len, NULL);
1129 if (use_relayd) {
1130 if (read_len != len) {
1131 ret = -EPERM;
1132 goto error_put_subbuf;
1133 }
1134 } else {
1135 if (read_len != padded_len) {
1136 ret = -EPERM;
1137 goto error_put_subbuf;
1138 }
1139 }
1140
1141 ret = ustctl_put_subbuf(stream->ustream);
1142 if (ret < 0) {
1143 ERR("Snapshot ustctl_put_subbuf");
1144 goto error_close_stream;
1145 }
1146 consumed_pos += stream->max_sb_size;
1147 }
1148
1149 /* Simply close the stream so we can use it on the next snapshot. */
1150 consumer_stream_close(stream);
1151 pthread_mutex_unlock(&stream->lock);
1152 }
1153
1154 rcu_read_unlock();
1155 return 0;
1156
1157 error_put_subbuf:
1158 if (ustctl_put_subbuf(stream->ustream) < 0) {
1159 ERR("Snapshot ustctl_put_subbuf");
1160 }
1161 error_close_stream:
1162 consumer_stream_close(stream);
1163 error_unlock:
1164 pthread_mutex_unlock(&stream->lock);
1165 error:
1166 rcu_read_unlock();
1167 return ret;
1168 }
1169
1170 /*
1171 * Receive the metadata updates from the sessiond. Supports receiving
1172 * overlapping metadata, but is needs to always belong to a contiguous
1173 * range starting from 0.
1174 * Be careful about the locks held when calling this function: it needs
1175 * the metadata cache flush to concurrently progress in order to
1176 * complete.
1177 */
1178 int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
1179 uint64_t len, struct lttng_consumer_channel *channel,
1180 int timer, int wait)
1181 {
1182 int ret, ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1183 char *metadata_str;
1184
1185 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
1186
1187 metadata_str = zmalloc(len * sizeof(char));
1188 if (!metadata_str) {
1189 PERROR("zmalloc metadata string");
1190 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
1191 goto end;
1192 }
1193
1194 health_code_update();
1195
1196 /* Receive metadata string. */
1197 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
1198 if (ret < 0) {
1199 /* Session daemon is dead so return gracefully. */
1200 ret_code = ret;
1201 goto end_free;
1202 }
1203
1204 health_code_update();
1205
1206 pthread_mutex_lock(&channel->metadata_cache->lock);
1207 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
1208 if (ret < 0) {
1209 /* Unable to handle metadata. Notify session daemon. */
1210 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1211 /*
1212 * Skip metadata flush on write error since the offset and len might
1213 * not have been updated which could create an infinite loop below when
1214 * waiting for the metadata cache to be flushed.
1215 */
1216 pthread_mutex_unlock(&channel->metadata_cache->lock);
1217 goto end_free;
1218 }
1219 pthread_mutex_unlock(&channel->metadata_cache->lock);
1220
1221 if (!wait) {
1222 goto end_free;
1223 }
1224 while (consumer_metadata_cache_flushed(channel, offset + len, timer)) {
1225 DBG("Waiting for metadata to be flushed");
1226
1227 health_code_update();
1228
1229 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
1230 }
1231
1232 end_free:
1233 free(metadata_str);
1234 end:
1235 return ret_code;
1236 }
1237
1238 /*
1239 * Receive command from session daemon and process it.
1240 *
1241 * Return 1 on success else a negative value or 0.
1242 */
1243 int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
1244 int sock, struct pollfd *consumer_sockpoll)
1245 {
1246 ssize_t ret;
1247 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1248 struct lttcomm_consumer_msg msg;
1249 struct lttng_consumer_channel *channel = NULL;
1250
1251 health_code_update();
1252
1253 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
1254 if (ret != sizeof(msg)) {
1255 DBG("Consumer received unexpected message size %zd (expects %zu)",
1256 ret, sizeof(msg));
1257 /*
1258 * The ret value might 0 meaning an orderly shutdown but this is ok
1259 * since the caller handles this.
1260 */
1261 if (ret > 0) {
1262 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1263 ret = -1;
1264 }
1265 return ret;
1266 }
1267
1268 health_code_update();
1269
1270 /* deprecated */
1271 assert(msg.cmd_type != LTTNG_CONSUMER_STOP);
1272
1273 health_code_update();
1274
1275 /* relayd needs RCU read-side lock */
1276 rcu_read_lock();
1277
1278 switch (msg.cmd_type) {
1279 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
1280 {
1281 /* Session daemon status message are handled in the following call. */
1282 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
1283 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
1284 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id,
1285 msg.u.relayd_sock.relayd_session_id);
1286 goto end_nosignal;
1287 }
1288 case LTTNG_CONSUMER_DESTROY_RELAYD:
1289 {
1290 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
1291 struct consumer_relayd_sock_pair *relayd;
1292
1293 DBG("UST consumer destroying relayd %" PRIu64, index);
1294
1295 /* Get relayd reference if exists. */
1296 relayd = consumer_find_relayd(index);
1297 if (relayd == NULL) {
1298 DBG("Unable to find relayd %" PRIu64, index);
1299 ret_code = LTTCOMM_CONSUMERD_RELAYD_FAIL;
1300 }
1301
1302 /*
1303 * Each relayd socket pair has a refcount of stream attached to it
1304 * which tells if the relayd is still active or not depending on the
1305 * refcount value.
1306 *
1307 * This will set the destroy flag of the relayd object and destroy it
1308 * if the refcount reaches zero when called.
1309 *
1310 * The destroy can happen either here or when a stream fd hangs up.
1311 */
1312 if (relayd) {
1313 consumer_flag_relayd_for_destroy(relayd);
1314 }
1315
1316 goto end_msg_sessiond;
1317 }
1318 case LTTNG_CONSUMER_UPDATE_STREAM:
1319 {
1320 rcu_read_unlock();
1321 return -ENOSYS;
1322 }
1323 case LTTNG_CONSUMER_DATA_PENDING:
1324 {
1325 int ret, is_data_pending;
1326 uint64_t id = msg.u.data_pending.session_id;
1327
1328 DBG("UST consumer data pending command for id %" PRIu64, id);
1329
1330 is_data_pending = consumer_data_pending(id);
1331
1332 /* Send back returned value to session daemon */
1333 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
1334 sizeof(is_data_pending));
1335 if (ret < 0) {
1336 DBG("Error when sending the data pending ret code: %d", ret);
1337 goto error_fatal;
1338 }
1339
1340 /*
1341 * No need to send back a status message since the data pending
1342 * returned value is the response.
1343 */
1344 break;
1345 }
1346 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
1347 {
1348 int ret;
1349 struct ustctl_consumer_channel_attr attr;
1350
1351 /* Create a plain object and reserve a channel key. */
1352 channel = allocate_channel(msg.u.ask_channel.session_id,
1353 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
1354 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
1355 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1356 (enum lttng_event_output) msg.u.ask_channel.output,
1357 msg.u.ask_channel.tracefile_size,
1358 msg.u.ask_channel.tracefile_count,
1359 msg.u.ask_channel.session_id_per_pid,
1360 msg.u.ask_channel.monitor,
1361 msg.u.ask_channel.live_timer_interval,
1362 msg.u.ask_channel.root_shm_path,
1363 msg.u.ask_channel.shm_path);
1364 if (!channel) {
1365 goto end_channel_error;
1366 }
1367
1368 /*
1369 * Assign UST application UID to the channel. This value is ignored for
1370 * per PID buffers. This is specific to UST thus setting this after the
1371 * allocation.
1372 */
1373 channel->ust_app_uid = msg.u.ask_channel.ust_app_uid;
1374
1375 /* Build channel attributes from received message. */
1376 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
1377 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
1378 attr.overwrite = msg.u.ask_channel.overwrite;
1379 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
1380 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
1381 attr.chan_id = msg.u.ask_channel.chan_id;
1382 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
1383
1384 /* Match channel buffer type to the UST abi. */
1385 switch (msg.u.ask_channel.output) {
1386 case LTTNG_EVENT_MMAP:
1387 default:
1388 attr.output = LTTNG_UST_MMAP;
1389 break;
1390 }
1391
1392 /* Translate and save channel type. */
1393 switch (msg.u.ask_channel.type) {
1394 case LTTNG_UST_CHAN_PER_CPU:
1395 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
1396 attr.type = LTTNG_UST_CHAN_PER_CPU;
1397 /*
1398 * Set refcount to 1 for owner. Below, we will
1399 * pass ownership to the
1400 * consumer_thread_channel_poll() thread.
1401 */
1402 channel->refcount = 1;
1403 break;
1404 case LTTNG_UST_CHAN_METADATA:
1405 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
1406 attr.type = LTTNG_UST_CHAN_METADATA;
1407 break;
1408 default:
1409 assert(0);
1410 goto error_fatal;
1411 };
1412
1413 health_code_update();
1414
1415 ret = ask_channel(ctx, sock, channel, &attr);
1416 if (ret < 0) {
1417 goto end_channel_error;
1418 }
1419
1420 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1421 ret = consumer_metadata_cache_allocate(channel);
1422 if (ret < 0) {
1423 ERR("Allocating metadata cache");
1424 goto end_channel_error;
1425 }
1426 consumer_timer_switch_start(channel, attr.switch_timer_interval);
1427 attr.switch_timer_interval = 0;
1428 } else {
1429 consumer_timer_live_start(channel,
1430 msg.u.ask_channel.live_timer_interval);
1431 }
1432
1433 health_code_update();
1434
1435 /*
1436 * Add the channel to the internal state AFTER all streams were created
1437 * and successfully sent to session daemon. This way, all streams must
1438 * be ready before this channel is visible to the threads.
1439 * If add_channel succeeds, ownership of the channel is
1440 * passed to consumer_thread_channel_poll().
1441 */
1442 ret = add_channel(channel, ctx);
1443 if (ret < 0) {
1444 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
1445 if (channel->switch_timer_enabled == 1) {
1446 consumer_timer_switch_stop(channel);
1447 }
1448 consumer_metadata_cache_destroy(channel);
1449 }
1450 if (channel->live_timer_enabled == 1) {
1451 consumer_timer_live_stop(channel);
1452 }
1453 goto end_channel_error;
1454 }
1455
1456 health_code_update();
1457
1458 /*
1459 * Channel and streams are now created. Inform the session daemon that
1460 * everything went well and should wait to receive the channel and
1461 * streams with ustctl API.
1462 */
1463 ret = consumer_send_status_channel(sock, channel);
1464 if (ret < 0) {
1465 /*
1466 * There is probably a problem on the socket.
1467 */
1468 goto error_fatal;
1469 }
1470
1471 break;
1472 }
1473 case LTTNG_CONSUMER_GET_CHANNEL:
1474 {
1475 int ret, relayd_err = 0;
1476 uint64_t key = msg.u.get_channel.key;
1477 struct lttng_consumer_channel *channel;
1478
1479 channel = consumer_find_channel(key);
1480 if (!channel) {
1481 ERR("UST consumer get channel key %" PRIu64 " not found", key);
1482 ret_code = LTTCOMM_CONSUMERD_CHAN_NOT_FOUND;
1483 goto end_msg_sessiond;
1484 }
1485
1486 health_code_update();
1487
1488 /* Send everything to sessiond. */
1489 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1490 if (ret < 0) {
1491 if (relayd_err) {
1492 /*
1493 * We were unable to send to the relayd the stream so avoid
1494 * sending back a fatal error to the thread since this is OK
1495 * and the consumer can continue its work. The above call
1496 * has sent the error status message to the sessiond.
1497 */
1498 goto end_nosignal;
1499 }
1500 /*
1501 * The communicaton was broken hence there is a bad state between
1502 * the consumer and sessiond so stop everything.
1503 */
1504 goto error_fatal;
1505 }
1506
1507 health_code_update();
1508
1509 /*
1510 * In no monitor mode, the streams ownership is kept inside the channel
1511 * so don't send them to the data thread.
1512 */
1513 if (!channel->monitor) {
1514 goto end_msg_sessiond;
1515 }
1516
1517 ret = send_streams_to_thread(channel, ctx);
1518 if (ret < 0) {
1519 /*
1520 * If we are unable to send the stream to the thread, there is
1521 * a big problem so just stop everything.
1522 */
1523 goto error_fatal;
1524 }
1525 /* List MUST be empty after or else it could be reused. */
1526 assert(cds_list_empty(&channel->streams.head));
1527 goto end_msg_sessiond;
1528 }
1529 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1530 {
1531 uint64_t key = msg.u.destroy_channel.key;
1532
1533 /*
1534 * Only called if streams have not been sent to stream
1535 * manager thread. However, channel has been sent to
1536 * channel manager thread.
1537 */
1538 notify_thread_del_channel(ctx, key);
1539 goto end_msg_sessiond;
1540 }
1541 case LTTNG_CONSUMER_CLOSE_METADATA:
1542 {
1543 int ret;
1544
1545 ret = close_metadata(msg.u.close_metadata.key);
1546 if (ret != 0) {
1547 ret_code = ret;
1548 }
1549
1550 goto end_msg_sessiond;
1551 }
1552 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1553 {
1554 int ret;
1555
1556 ret = flush_channel(msg.u.flush_channel.key);
1557 if (ret != 0) {
1558 ret_code = ret;
1559 }
1560
1561 goto end_msg_sessiond;
1562 }
1563 case LTTNG_CONSUMER_PUSH_METADATA:
1564 {
1565 int ret;
1566 uint64_t len = msg.u.push_metadata.len;
1567 uint64_t key = msg.u.push_metadata.key;
1568 uint64_t offset = msg.u.push_metadata.target_offset;
1569 struct lttng_consumer_channel *channel;
1570
1571 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1572 len);
1573
1574 channel = consumer_find_channel(key);
1575 if (!channel) {
1576 /*
1577 * This is possible if the metadata creation on the consumer side
1578 * is in flight vis-a-vis a concurrent push metadata from the
1579 * session daemon. Simply return that the channel failed and the
1580 * session daemon will handle that message correctly considering
1581 * that this race is acceptable thus the DBG() statement here.
1582 */
1583 DBG("UST consumer push metadata %" PRIu64 " not found", key);
1584 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1585 goto end_msg_sessiond;
1586 }
1587
1588 health_code_update();
1589
1590 if (!len) {
1591 /*
1592 * There is nothing to receive. We have simply
1593 * checked whether the channel can be found.
1594 */
1595 ret_code = LTTCOMM_CONSUMERD_SUCCESS;
1596 goto end_msg_sessiond;
1597 }
1598
1599 /* Tell session daemon we are ready to receive the metadata. */
1600 ret = consumer_send_status_msg(sock, LTTCOMM_CONSUMERD_SUCCESS);
1601 if (ret < 0) {
1602 /* Somehow, the session daemon is not responding anymore. */
1603 goto error_fatal;
1604 }
1605
1606 health_code_update();
1607
1608 /* Wait for more data. */
1609 health_poll_entry();
1610 ret = lttng_consumer_poll_socket(consumer_sockpoll);
1611 health_poll_exit();
1612 if (ret) {
1613 goto error_fatal;
1614 }
1615
1616 health_code_update();
1617
1618 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1619 len, channel, 0, 1);
1620 if (ret < 0) {
1621 /* error receiving from sessiond */
1622 goto error_fatal;
1623 } else {
1624 ret_code = ret;
1625 goto end_msg_sessiond;
1626 }
1627 }
1628 case LTTNG_CONSUMER_SETUP_METADATA:
1629 {
1630 int ret;
1631
1632 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1633 if (ret) {
1634 ret_code = ret;
1635 }
1636 goto end_msg_sessiond;
1637 }
1638 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1639 {
1640 if (msg.u.snapshot_channel.metadata) {
1641 ret = snapshot_metadata(msg.u.snapshot_channel.key,
1642 msg.u.snapshot_channel.pathname,
1643 msg.u.snapshot_channel.relayd_id,
1644 ctx);
1645 if (ret < 0) {
1646 ERR("Snapshot metadata failed");
1647 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
1648 }
1649 } else {
1650 ret = snapshot_channel(msg.u.snapshot_channel.key,
1651 msg.u.snapshot_channel.pathname,
1652 msg.u.snapshot_channel.relayd_id,
1653 msg.u.snapshot_channel.nb_packets_per_stream,
1654 ctx);
1655 if (ret < 0) {
1656 ERR("Snapshot channel failed");
1657 ret_code = LTTCOMM_CONSUMERD_CHANNEL_FAIL;
1658 }
1659 }
1660
1661 health_code_update();
1662 ret = consumer_send_status_msg(sock, ret_code);
1663 if (ret < 0) {
1664 /* Somehow, the session daemon is not responding anymore. */
1665 goto end_nosignal;
1666 }
1667 health_code_update();
1668 break;
1669 }
1670 default:
1671 break;
1672 }
1673
1674 end_nosignal:
1675 rcu_read_unlock();
1676
1677 health_code_update();
1678
1679 /*
1680 * Return 1 to indicate success since the 0 value can be a socket
1681 * shutdown during the recv() or send() call.
1682 */
1683 return 1;
1684
1685 end_msg_sessiond:
1686 /*
1687 * The returned value here is not useful since either way we'll return 1 to
1688 * the caller because the session daemon socket management is done
1689 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1690 */
1691 ret = consumer_send_status_msg(sock, ret_code);
1692 if (ret < 0) {
1693 goto error_fatal;
1694 }
1695 rcu_read_unlock();
1696
1697 health_code_update();
1698
1699 return 1;
1700 end_channel_error:
1701 if (channel) {
1702 /*
1703 * Free channel here since no one has a reference to it. We don't
1704 * free after that because a stream can store this pointer.
1705 */
1706 destroy_channel(channel);
1707 }
1708 /* We have to send a status channel message indicating an error. */
1709 ret = consumer_send_status_channel(sock, NULL);
1710 if (ret < 0) {
1711 /* Stop everything if session daemon can not be notified. */
1712 goto error_fatal;
1713 }
1714 rcu_read_unlock();
1715
1716 health_code_update();
1717
1718 return 1;
1719 error_fatal:
1720 rcu_read_unlock();
1721 /* This will issue a consumer stop. */
1722 return -1;
1723 }
1724
1725 /*
1726 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1727 * compiled out, we isolate it in this library.
1728 */
1729 int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1730 unsigned long *off)
1731 {
1732 assert(stream);
1733 assert(stream->ustream);
1734
1735 return ustctl_get_mmap_read_offset(stream->ustream, off);
1736 }
1737
1738 /*
1739 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1740 * compiled out, we isolate it in this library.
1741 */
1742 void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
1743 {
1744 assert(stream);
1745 assert(stream->ustream);
1746
1747 return ustctl_get_mmap_base(stream->ustream);
1748 }
1749
1750 /*
1751 * Take a snapshot for a specific fd
1752 *
1753 * Returns 0 on success, < 0 on error
1754 */
1755 int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
1756 {
1757 assert(stream);
1758 assert(stream->ustream);
1759
1760 return ustctl_snapshot(stream->ustream);
1761 }
1762
1763 /*
1764 * Get the produced position
1765 *
1766 * Returns 0 on success, < 0 on error
1767 */
1768 int lttng_ustconsumer_get_produced_snapshot(
1769 struct lttng_consumer_stream *stream, unsigned long *pos)
1770 {
1771 assert(stream);
1772 assert(stream->ustream);
1773 assert(pos);
1774
1775 return ustctl_snapshot_get_produced(stream->ustream, pos);
1776 }
1777
1778 /*
1779 * Get the consumed position
1780 *
1781 * Returns 0 on success, < 0 on error
1782 */
1783 int lttng_ustconsumer_get_consumed_snapshot(
1784 struct lttng_consumer_stream *stream, unsigned long *pos)
1785 {
1786 assert(stream);
1787 assert(stream->ustream);
1788 assert(pos);
1789
1790 return ustctl_snapshot_get_consumed(stream->ustream, pos);
1791 }
1792
1793 void lttng_ustconsumer_flush_buffer(struct lttng_consumer_stream *stream,
1794 int producer)
1795 {
1796 assert(stream);
1797 assert(stream->ustream);
1798
1799 ustctl_flush_buffer(stream->ustream, producer);
1800 }
1801
1802 int lttng_ustconsumer_get_current_timestamp(
1803 struct lttng_consumer_stream *stream, uint64_t *ts)
1804 {
1805 assert(stream);
1806 assert(stream->ustream);
1807 assert(ts);
1808
1809 return ustctl_get_current_timestamp(stream->ustream, ts);
1810 }
1811
1812 /*
1813 * Called when the stream signal the consumer that it has hang up.
1814 */
1815 void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1816 {
1817 assert(stream);
1818 assert(stream->ustream);
1819
1820 ustctl_flush_buffer(stream->ustream, 0);
1821 stream->hangup_flush_done = 1;
1822 }
1823
1824 void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1825 {
1826 int i;
1827
1828 assert(chan);
1829 assert(chan->uchan);
1830
1831 if (chan->switch_timer_enabled == 1) {
1832 consumer_timer_switch_stop(chan);
1833 }
1834 for (i = 0; i < chan->nr_stream_fds; i++) {
1835 int ret;
1836
1837 ret = close(chan->stream_fds[i]);
1838 if (ret) {
1839 PERROR("close");
1840 }
1841 if (chan->shm_path[0]) {
1842 char shm_path[PATH_MAX];
1843
1844 ret = get_stream_shm_path(shm_path, chan->shm_path, i);
1845 if (ret) {
1846 ERR("Cannot get stream shm path");
1847 }
1848 ret = run_as_unlink(shm_path, chan->uid, chan->gid);
1849 if (ret) {
1850 PERROR("unlink %s", shm_path);
1851 }
1852 }
1853 }
1854 /* Try to rmdir all directories under shm_path root. */
1855 if (chan->root_shm_path[0]) {
1856 (void) run_as_recursive_rmdir(chan->root_shm_path,
1857 chan->uid, chan->gid);
1858 }
1859 }
1860
1861 void lttng_ustconsumer_free_channel(struct lttng_consumer_channel *chan)
1862 {
1863 assert(chan);
1864 assert(chan->uchan);
1865
1866 consumer_metadata_cache_destroy(chan);
1867 ustctl_destroy_channel(chan->uchan);
1868 free(chan->stream_fds);
1869 }
1870
1871 void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1872 {
1873 assert(stream);
1874 assert(stream->ustream);
1875
1876 if (stream->chan->switch_timer_enabled == 1) {
1877 consumer_timer_switch_stop(stream->chan);
1878 }
1879 ustctl_destroy_stream(stream->ustream);
1880 }
1881
1882 int lttng_ustconsumer_get_wakeup_fd(struct lttng_consumer_stream *stream)
1883 {
1884 assert(stream);
1885 assert(stream->ustream);
1886
1887 return ustctl_stream_get_wakeup_fd(stream->ustream);
1888 }
1889
1890 int lttng_ustconsumer_close_wakeup_fd(struct lttng_consumer_stream *stream)
1891 {
1892 assert(stream);
1893 assert(stream->ustream);
1894
1895 return ustctl_stream_close_wakeup_fd(stream->ustream);
1896 }
1897
1898 /*
1899 * Populate index values of a UST stream. Values are set in big endian order.
1900 *
1901 * Return 0 on success or else a negative value.
1902 */
1903 static int get_index_values(struct ctf_packet_index *index,
1904 struct ustctl_consumer_stream *ustream)
1905 {
1906 int ret;
1907
1908 ret = ustctl_get_timestamp_begin(ustream, &index->timestamp_begin);
1909 if (ret < 0) {
1910 PERROR("ustctl_get_timestamp_begin");
1911 goto error;
1912 }
1913 index->timestamp_begin = htobe64(index->timestamp_begin);
1914
1915 ret = ustctl_get_timestamp_end(ustream, &index->timestamp_end);
1916 if (ret < 0) {
1917 PERROR("ustctl_get_timestamp_end");
1918 goto error;
1919 }
1920 index->timestamp_end = htobe64(index->timestamp_end);
1921
1922 ret = ustctl_get_events_discarded(ustream, &index->events_discarded);
1923 if (ret < 0) {
1924 PERROR("ustctl_get_events_discarded");
1925 goto error;
1926 }
1927 index->events_discarded = htobe64(index->events_discarded);
1928
1929 ret = ustctl_get_content_size(ustream, &index->content_size);
1930 if (ret < 0) {
1931 PERROR("ustctl_get_content_size");
1932 goto error;
1933 }
1934 index->content_size = htobe64(index->content_size);
1935
1936 ret = ustctl_get_packet_size(ustream, &index->packet_size);
1937 if (ret < 0) {
1938 PERROR("ustctl_get_packet_size");
1939 goto error;
1940 }
1941 index->packet_size = htobe64(index->packet_size);
1942
1943 ret = ustctl_get_stream_id(ustream, &index->stream_id);
1944 if (ret < 0) {
1945 PERROR("ustctl_get_stream_id");
1946 goto error;
1947 }
1948 index->stream_id = htobe64(index->stream_id);
1949
1950 error:
1951 return ret;
1952 }
1953
1954 /*
1955 * Write up to one packet from the metadata cache to the channel.
1956 *
1957 * Returns the number of bytes pushed in the cache, or a negative value
1958 * on error.
1959 */
1960 static
1961 int commit_one_metadata_packet(struct lttng_consumer_stream *stream)
1962 {
1963 ssize_t write_len;
1964 int ret;
1965
1966 pthread_mutex_lock(&stream->chan->metadata_cache->lock);
1967 if (stream->chan->metadata_cache->max_offset
1968 == stream->ust_metadata_pushed) {
1969 ret = 0;
1970 goto end;
1971 }
1972
1973 write_len = ustctl_write_one_packet_to_channel(stream->chan->uchan,
1974 &stream->chan->metadata_cache->data[stream->ust_metadata_pushed],
1975 stream->chan->metadata_cache->max_offset
1976 - stream->ust_metadata_pushed);
1977 assert(write_len != 0);
1978 if (write_len < 0) {
1979 ERR("Writing one metadata packet");
1980 ret = -1;
1981 goto end;
1982 }
1983 stream->ust_metadata_pushed += write_len;
1984
1985 assert(stream->chan->metadata_cache->max_offset >=
1986 stream->ust_metadata_pushed);
1987 ret = write_len;
1988
1989 end:
1990 pthread_mutex_unlock(&stream->chan->metadata_cache->lock);
1991 return ret;
1992 }
1993
1994
1995 /*
1996 * Sync metadata meaning request them to the session daemon and snapshot to the
1997 * metadata thread can consumer them.
1998 *
1999 * Metadata stream lock is held here, but we need to release it when
2000 * interacting with sessiond, else we cause a deadlock with live
2001 * awaiting on metadata to be pushed out.
2002 *
2003 * Return 0 if new metadatda is available, EAGAIN if the metadata stream
2004 * is empty or a negative value on error.
2005 */
2006 int lttng_ustconsumer_sync_metadata(struct lttng_consumer_local_data *ctx,
2007 struct lttng_consumer_stream *metadata)
2008 {
2009 int ret;
2010 int retry = 0;
2011
2012 assert(ctx);
2013 assert(metadata);
2014
2015 pthread_mutex_unlock(&metadata->lock);
2016 /*
2017 * Request metadata from the sessiond, but don't wait for the flush
2018 * because we locked the metadata thread.
2019 */
2020 ret = lttng_ustconsumer_request_metadata(ctx, metadata->chan, 0, 0);
2021 if (ret < 0) {
2022 goto end;
2023 }
2024 pthread_mutex_lock(&metadata->lock);
2025
2026 ret = commit_one_metadata_packet(metadata);
2027 if (ret <= 0) {
2028 goto end;
2029 } else if (ret > 0) {
2030 retry = 1;
2031 }
2032
2033 ustctl_flush_buffer(metadata->ustream, 1);
2034 ret = ustctl_snapshot(metadata->ustream);
2035 if (ret < 0) {
2036 if (errno != EAGAIN) {
2037 ERR("Sync metadata, taking UST snapshot");
2038 goto end;
2039 }
2040 DBG("No new metadata when syncing them.");
2041 /* No new metadata, exit. */
2042 ret = ENODATA;
2043 goto end;
2044 }
2045
2046 /*
2047 * After this flush, we still need to extract metadata.
2048 */
2049 if (retry) {
2050 ret = EAGAIN;
2051 }
2052
2053 end:
2054 return ret;
2055 }
2056
2057 /*
2058 * Return 0 on success else a negative value.
2059 */
2060 static int notify_if_more_data(struct lttng_consumer_stream *stream,
2061 struct lttng_consumer_local_data *ctx)
2062 {
2063 int ret;
2064 struct ustctl_consumer_stream *ustream;
2065
2066 assert(stream);
2067 assert(ctx);
2068
2069 ustream = stream->ustream;
2070
2071 /*
2072 * First, we are going to check if there is a new subbuffer available
2073 * before reading the stream wait_fd.
2074 */
2075 /* Get the next subbuffer */
2076 ret = ustctl_get_next_subbuf(ustream);
2077 if (ret) {
2078 /* No more data found, flag the stream. */
2079 stream->has_data = 0;
2080 ret = 0;
2081 goto end;
2082 }
2083
2084 ret = ustctl_put_subbuf(ustream);
2085 assert(!ret);
2086
2087 /* This stream still has data. Flag it and wake up the data thread. */
2088 stream->has_data = 1;
2089
2090 if (stream->monitor && !stream->hangup_flush_done && !ctx->has_wakeup) {
2091 ssize_t writelen;
2092
2093 writelen = lttng_pipe_write(ctx->consumer_wakeup_pipe, "!", 1);
2094 if (writelen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2095 ret = writelen;
2096 goto end;
2097 }
2098
2099 /* The wake up pipe has been notified. */
2100 ctx->has_wakeup = 1;
2101 }
2102 ret = 0;
2103
2104 end:
2105 return ret;
2106 }
2107
2108 /*
2109 * Read subbuffer from the given stream.
2110 *
2111 * Stream lock MUST be acquired.
2112 *
2113 * Return 0 on success else a negative value.
2114 */
2115 int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
2116 struct lttng_consumer_local_data *ctx)
2117 {
2118 unsigned long len, subbuf_size, padding;
2119 int err, write_index = 1;
2120 long ret = 0;
2121 struct ustctl_consumer_stream *ustream;
2122 struct ctf_packet_index index;
2123
2124 assert(stream);
2125 assert(stream->ustream);
2126 assert(ctx);
2127
2128 DBG("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
2129 stream->name);
2130
2131 /* Ease our life for what's next. */
2132 ustream = stream->ustream;
2133
2134 /*
2135 * We can consume the 1 byte written into the wait_fd by UST. Don't trigger
2136 * error if we cannot read this one byte (read returns 0), or if the error
2137 * is EAGAIN or EWOULDBLOCK.
2138 *
2139 * This is only done when the stream is monitored by a thread, before the
2140 * flush is done after a hangup and if the stream is not flagged with data
2141 * since there might be nothing to consume in the wait fd but still have
2142 * data available flagged by the consumer wake up pipe.
2143 */
2144 if (stream->monitor && !stream->hangup_flush_done && !stream->has_data) {
2145 char dummy;
2146 ssize_t readlen;
2147
2148 readlen = lttng_read(stream->wait_fd, &dummy, 1);
2149 if (readlen < 0 && errno != EAGAIN && errno != EWOULDBLOCK) {
2150 ret = readlen;
2151 goto end;
2152 }
2153 }
2154
2155 retry:
2156 /* Get the next subbuffer */
2157 err = ustctl_get_next_subbuf(ustream);
2158 if (err != 0) {
2159 /*
2160 * Populate metadata info if the existing info has
2161 * already been read.
2162 */
2163 if (stream->metadata_flag) {
2164 ret = commit_one_metadata_packet(stream);
2165 if (ret <= 0) {
2166 goto end;
2167 }
2168 ustctl_flush_buffer(stream->ustream, 1);
2169 goto retry;
2170 }
2171
2172 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
2173 /*
2174 * This is a debug message even for single-threaded consumer,
2175 * because poll() have more relaxed criterions than get subbuf,
2176 * so get_subbuf may fail for short race windows where poll()
2177 * would issue wakeups.
2178 */
2179 DBG("Reserving sub buffer failed (everything is normal, "
2180 "it is due to concurrency) [ret: %d]", err);
2181 goto end;
2182 }
2183 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
2184
2185 if (!stream->metadata_flag) {
2186 index.offset = htobe64(stream->out_fd_offset);
2187 ret = get_index_values(&index, ustream);
2188 if (ret < 0) {
2189 goto end;
2190 }
2191 } else {
2192 write_index = 0;
2193 }
2194
2195 /* Get the full padded subbuffer size */
2196 err = ustctl_get_padded_subbuf_size(ustream, &len);
2197 assert(err == 0);
2198
2199 /* Get subbuffer data size (without padding) */
2200 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
2201 assert(err == 0);
2202
2203 /* Make sure we don't get a subbuffer size bigger than the padded */
2204 assert(len >= subbuf_size);
2205
2206 padding = len - subbuf_size;
2207 /* write the subbuffer to the tracefile */
2208 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding, &index);
2209 /*
2210 * The mmap operation should write subbuf_size amount of data when network
2211 * streaming or the full padding (len) size when we are _not_ streaming.
2212 */
2213 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
2214 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
2215 /*
2216 * Display the error but continue processing to try to release the
2217 * subbuffer. This is a DBG statement since any unexpected kill or
2218 * signal, the application gets unregistered, relayd gets closed or
2219 * anything that affects the buffer lifetime will trigger this error.
2220 * So, for the sake of the user, don't print this error since it can
2221 * happen and it is OK with the code flow.
2222 */
2223 DBG("Error writing to tracefile "
2224 "(ret: %ld != len: %lu != subbuf_size: %lu)",
2225 ret, len, subbuf_size);
2226 write_index = 0;
2227 }
2228 err = ustctl_put_next_subbuf(ustream);
2229 assert(err == 0);
2230
2231 /*
2232 * This will consumer the byte on the wait_fd if and only if there is not
2233 * next subbuffer to be acquired.
2234 */
2235 if (!stream->metadata_flag) {
2236 ret = notify_if_more_data(stream, ctx);
2237 if (ret < 0) {
2238 goto end;
2239 }
2240 }
2241
2242 /* Write index if needed. */
2243 if (!write_index) {
2244 goto end;
2245 }
2246
2247 if (stream->chan->live_timer_interval && !stream->metadata_flag) {
2248 /*
2249 * In live, block until all the metadata is sent.
2250 */
2251 pthread_mutex_lock(&stream->metadata_timer_lock);
2252 assert(!stream->missed_metadata_flush);
2253 stream->waiting_on_metadata = true;
2254 pthread_mutex_unlock(&stream->metadata_timer_lock);
2255
2256 err = consumer_stream_sync_metadata(ctx, stream->session_id);
2257
2258 pthread_mutex_lock(&stream->metadata_timer_lock);
2259 stream->waiting_on_metadata = false;
2260 if (stream->missed_metadata_flush) {
2261 stream->missed_metadata_flush = false;
2262 pthread_mutex_unlock(&stream->metadata_timer_lock);
2263 (void) consumer_flush_ust_index(stream);
2264 } else {
2265 pthread_mutex_unlock(&stream->metadata_timer_lock);
2266 }
2267
2268 if (err < 0) {
2269 goto end;
2270 }
2271 }
2272
2273 assert(!stream->metadata_flag);
2274 err = consumer_stream_write_index(stream, &index);
2275 if (err < 0) {
2276 goto end;
2277 }
2278
2279 end:
2280 return ret;
2281 }
2282
2283 /*
2284 * Called when a stream is created.
2285 *
2286 * Return 0 on success or else a negative value.
2287 */
2288 int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
2289 {
2290 int ret;
2291
2292 assert(stream);
2293
2294 /* Don't create anything if this is set for streaming. */
2295 if (stream->net_seq_idx == (uint64_t) -1ULL && stream->chan->monitor) {
2296 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
2297 stream->chan->tracefile_size, stream->tracefile_count_current,
2298 stream->uid, stream->gid, NULL);
2299 if (ret < 0) {
2300 goto error;
2301 }
2302 stream->out_fd = ret;
2303 stream->tracefile_size_current = 0;
2304
2305 if (!stream->metadata_flag) {
2306 ret = index_create_file(stream->chan->pathname,
2307 stream->name, stream->uid, stream->gid,
2308 stream->chan->tracefile_size,
2309 stream->tracefile_count_current);
2310 if (ret < 0) {
2311 goto error;
2312 }
2313 stream->index_fd = ret;
2314 }
2315 }
2316 ret = 0;
2317
2318 error:
2319 return ret;
2320 }
2321
2322 /*
2323 * Check if data is still being extracted from the buffers for a specific
2324 * stream. Consumer data lock MUST be acquired before calling this function
2325 * and the stream lock.
2326 *
2327 * Return 1 if the traced data are still getting read else 0 meaning that the
2328 * data is available for trace viewer reading.
2329 */
2330 int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
2331 {
2332 int ret;
2333
2334 assert(stream);
2335 assert(stream->ustream);
2336
2337 DBG("UST consumer checking data pending");
2338
2339 if (stream->endpoint_status != CONSUMER_ENDPOINT_ACTIVE) {
2340 ret = 0;
2341 goto end;
2342 }
2343
2344 if (stream->chan->type == CONSUMER_CHANNEL_TYPE_METADATA) {
2345 uint64_t contiguous, pushed;
2346
2347 /* Ease our life a bit. */
2348 contiguous = stream->chan->metadata_cache->max_offset;
2349 pushed = stream->ust_metadata_pushed;
2350
2351 /*
2352 * We can simply check whether all contiguously available data
2353 * has been pushed to the ring buffer, since the push operation
2354 * is performed within get_next_subbuf(), and because both
2355 * get_next_subbuf() and put_next_subbuf() are issued atomically
2356 * thanks to the stream lock within
2357 * lttng_ustconsumer_read_subbuffer(). This basically means that
2358 * whetnever ust_metadata_pushed is incremented, the associated
2359 * metadata has been consumed from the metadata stream.
2360 */
2361 DBG("UST consumer metadata pending check: contiguous %" PRIu64 " vs pushed %" PRIu64,
2362 contiguous, pushed);
2363 assert(((int64_t) (contiguous - pushed)) >= 0);
2364 if ((contiguous != pushed) ||
2365 (((int64_t) contiguous - pushed) > 0 || contiguous == 0)) {
2366 ret = 1; /* Data is pending */
2367 goto end;
2368 }
2369 } else {
2370 ret = ustctl_get_next_subbuf(stream->ustream);
2371 if (ret == 0) {
2372 /*
2373 * There is still data so let's put back this
2374 * subbuffer.
2375 */
2376 ret = ustctl_put_subbuf(stream->ustream);
2377 assert(ret == 0);
2378 ret = 1; /* Data is pending */
2379 goto end;
2380 }
2381 }
2382
2383 /* Data is NOT pending so ready to be read. */
2384 ret = 0;
2385
2386 end:
2387 return ret;
2388 }
2389
2390 /*
2391 * Stop a given metadata channel timer if enabled and close the wait fd which
2392 * is the poll pipe of the metadata stream.
2393 *
2394 * This MUST be called with the metadata channel acquired.
2395 */
2396 void lttng_ustconsumer_close_metadata(struct lttng_consumer_channel *metadata)
2397 {
2398 int ret;
2399
2400 assert(metadata);
2401 assert(metadata->type == CONSUMER_CHANNEL_TYPE_METADATA);
2402
2403 DBG("Closing metadata channel key %" PRIu64, metadata->key);
2404
2405 if (metadata->switch_timer_enabled == 1) {
2406 consumer_timer_switch_stop(metadata);
2407 }
2408
2409 if (!metadata->metadata_stream) {
2410 goto end;
2411 }
2412
2413 /*
2414 * Closing write side so the thread monitoring the stream wakes up if any
2415 * and clean the metadata stream.
2416 */
2417 if (metadata->metadata_stream->ust_metadata_poll_pipe[1] >= 0) {
2418 ret = close(metadata->metadata_stream->ust_metadata_poll_pipe[1]);
2419 if (ret < 0) {
2420 PERROR("closing metadata pipe write side");
2421 }
2422 metadata->metadata_stream->ust_metadata_poll_pipe[1] = -1;
2423 }
2424
2425 end:
2426 return;
2427 }
2428
2429 /*
2430 * Close every metadata stream wait fd of the metadata hash table. This
2431 * function MUST be used very carefully so not to run into a race between the
2432 * metadata thread handling streams and this function closing their wait fd.
2433 *
2434 * For UST, this is used when the session daemon hangs up. Its the metadata
2435 * producer so calling this is safe because we are assured that no state change
2436 * can occur in the metadata thread for the streams in the hash table.
2437 */
2438 void lttng_ustconsumer_close_all_metadata(struct lttng_ht *metadata_ht)
2439 {
2440 struct lttng_ht_iter iter;
2441 struct lttng_consumer_stream *stream;
2442
2443 assert(metadata_ht);
2444 assert(metadata_ht->ht);
2445
2446 DBG("UST consumer closing all metadata streams");
2447
2448 rcu_read_lock();
2449 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
2450 node.node) {
2451
2452 health_code_update();
2453
2454 pthread_mutex_lock(&stream->chan->lock);
2455 lttng_ustconsumer_close_metadata(stream->chan);
2456 pthread_mutex_unlock(&stream->chan->lock);
2457
2458 }
2459 rcu_read_unlock();
2460 }
2461
2462 void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
2463 {
2464 int ret;
2465
2466 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
2467 if (ret < 0) {
2468 ERR("Unable to close wakeup fd");
2469 }
2470 }
2471
2472 /*
2473 * Please refer to consumer-timer.c before adding any lock within this
2474 * function or any of its callees. Timers have a very strict locking
2475 * semantic with respect to teardown. Failure to respect this semantic
2476 * introduces deadlocks.
2477 *
2478 * DON'T hold the metadata lock when calling this function, else this
2479 * can cause deadlock involving consumer awaiting for metadata to be
2480 * pushed out due to concurrent interaction with the session daemon.
2481 */
2482 int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
2483 struct lttng_consumer_channel *channel, int timer, int wait)
2484 {
2485 struct lttcomm_metadata_request_msg request;
2486 struct lttcomm_consumer_msg msg;
2487 enum lttcomm_return_code ret_code = LTTCOMM_CONSUMERD_SUCCESS;
2488 uint64_t len, key, offset;
2489 int ret;
2490
2491 assert(channel);
2492 assert(channel->metadata_cache);
2493
2494 memset(&request, 0, sizeof(request));
2495
2496 /* send the metadata request to sessiond */
2497 switch (consumer_data.type) {
2498 case LTTNG_CONSUMER64_UST:
2499 request.bits_per_long = 64;
2500 break;
2501 case LTTNG_CONSUMER32_UST:
2502 request.bits_per_long = 32;
2503 break;
2504 default:
2505 request.bits_per_long = 0;
2506 break;
2507 }
2508
2509 request.session_id = channel->session_id;
2510 request.session_id_per_pid = channel->session_id_per_pid;
2511 /*
2512 * Request the application UID here so the metadata of that application can
2513 * be sent back. The channel UID corresponds to the user UID of the session
2514 * used for the rights on the stream file(s).
2515 */
2516 request.uid = channel->ust_app_uid;
2517 request.key = channel->key;
2518
2519 DBG("Sending metadata request to sessiond, session id %" PRIu64
2520 ", per-pid %" PRIu64 ", app UID %u and channek key %" PRIu64,
2521 request.session_id, request.session_id_per_pid, request.uid,
2522 request.key);
2523
2524 pthread_mutex_lock(&ctx->metadata_socket_lock);
2525
2526 health_code_update();
2527
2528 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
2529 sizeof(request));
2530 if (ret < 0) {
2531 ERR("Asking metadata to sessiond");
2532 goto end;
2533 }
2534
2535 health_code_update();
2536
2537 /* Receive the metadata from sessiond */
2538 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
2539 sizeof(msg));
2540 if (ret != sizeof(msg)) {
2541 DBG("Consumer received unexpected message size %d (expects %zu)",
2542 ret, sizeof(msg));
2543 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
2544 /*
2545 * The ret value might 0 meaning an orderly shutdown but this is ok
2546 * since the caller handles this.
2547 */
2548 goto end;
2549 }
2550
2551 health_code_update();
2552
2553 if (msg.cmd_type == LTTNG_ERR_UND) {
2554 /* No registry found */
2555 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
2556 ret_code);
2557 ret = 0;
2558 goto end;
2559 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
2560 ERR("Unexpected cmd_type received %d", msg.cmd_type);
2561 ret = -1;
2562 goto end;
2563 }
2564
2565 len = msg.u.push_metadata.len;
2566 key = msg.u.push_metadata.key;
2567 offset = msg.u.push_metadata.target_offset;
2568
2569 assert(key == channel->key);
2570 if (len == 0) {
2571 DBG("No new metadata to receive for key %" PRIu64, key);
2572 }
2573
2574 health_code_update();
2575
2576 /* Tell session daemon we are ready to receive the metadata. */
2577 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
2578 LTTCOMM_CONSUMERD_SUCCESS);
2579 if (ret < 0 || len == 0) {
2580 /*
2581 * Somehow, the session daemon is not responding anymore or there is
2582 * nothing to receive.
2583 */
2584 goto end;
2585 }
2586
2587 health_code_update();
2588
2589 ret = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
2590 key, offset, len, channel, timer, wait);
2591 if (ret >= 0) {
2592 /*
2593 * Only send the status msg if the sessiond is alive meaning a positive
2594 * ret code.
2595 */
2596 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret);
2597 }
2598 ret = 0;
2599
2600 end:
2601 health_code_update();
2602
2603 pthread_mutex_unlock(&ctx->metadata_socket_lock);
2604 return ret;
2605 }
2606
2607 /*
2608 * Return the ustctl call for the get stream id.
2609 */
2610 int lttng_ustconsumer_get_stream_id(struct lttng_consumer_stream *stream,
2611 uint64_t *stream_id)
2612 {
2613 assert(stream);
2614 assert(stream_id);
2615
2616 return ustctl_get_stream_id(stream->ustream, stream_id);
2617 }
This page took 0.15081 seconds and 4 git commands to generate.