Fix: consumer double-close on error
[lttng-tools.git] / src / common / ust-consumer / ust-consumer.c
CommitLineData
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1/*
2 * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca>
3 * Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
4 *
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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.
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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 *
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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.
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17 */
18
19#define _GNU_SOURCE
20#include <assert.h>
f02e1e8a 21#include <lttng/ust-ctl.h>
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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>
dbb5dfe6 28#include <sys/stat.h>
3bd1e081 29#include <sys/types.h>
77c7c900 30#include <inttypes.h>
3bd1e081 31#include <unistd.h>
ffe60014 32#include <urcu/list.h>
331744e3 33#include <signal.h>
0857097f 34
990570ed 35#include <common/common.h>
10a8a223 36#include <common/sessiond-comm/sessiond-comm.h>
00e2e675 37#include <common/relayd/relayd.h>
dbb5dfe6 38#include <common/compat/fcntl.h>
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39#include <common/consumer-metadata-cache.h>
40#include <common/consumer-timer.h>
fe4477ee 41#include <common/utils.h>
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42
43#include "ust-consumer.h"
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44
45extern struct lttng_consumer_global_data consumer_data;
46extern int consumer_poll_timeout;
47extern volatile int consumer_quit;
48
49/*
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50 * Free channel object and all streams associated with it. This MUST be used
51 * only and only if the channel has _NEVER_ been added to the global channel
52 * hash table.
3bd1e081 53 */
ffe60014 54static void destroy_channel(struct lttng_consumer_channel *channel)
3bd1e081 55{
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56 struct lttng_consumer_stream *stream, *stmp;
57
58 assert(channel);
59
60 DBG("UST consumer cleaning stream list");
61
62 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
63 send_node) {
64 cds_list_del(&stream->send_node);
65 ustctl_destroy_stream(stream->ustream);
66 free(stream);
67 }
68
69 /*
70 * If a channel is available meaning that was created before the streams
71 * were, delete it.
72 */
73 if (channel->uchan) {
74 lttng_ustconsumer_del_channel(channel);
75 }
76 free(channel);
77}
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78
79/*
ffe60014 80 * Add channel to internal consumer state.
3bd1e081 81 *
ffe60014 82 * Returns 0 on success or else a negative value.
3bd1e081 83 */
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84static int add_channel(struct lttng_consumer_channel *channel,
85 struct lttng_consumer_local_data *ctx)
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86{
87 int ret = 0;
88
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89 assert(channel);
90 assert(ctx);
91
92 if (ctx->on_recv_channel != NULL) {
93 ret = ctx->on_recv_channel(channel);
94 if (ret == 0) {
d8ef542d 95 ret = consumer_add_channel(channel, ctx);
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96 } else if (ret < 0) {
97 /* Most likely an ENOMEM. */
98 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
99 goto error;
100 }
101 } else {
d8ef542d 102 ret = consumer_add_channel(channel, ctx);
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103 }
104
d88aee68 105 DBG("UST consumer channel added (key: %" PRIu64 ")", channel->key);
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106
107error:
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108 return ret;
109}
110
111/*
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112 * Allocate and return a consumer channel object.
113 */
114static struct lttng_consumer_channel *allocate_channel(uint64_t session_id,
115 const char *pathname, const char *name, uid_t uid, gid_t gid,
1624d5b7 116 int relayd_id, uint64_t key, enum lttng_event_output output,
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117 uint64_t tracefile_size, uint64_t tracefile_count,
118 unsigned int monitor)
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119{
120 assert(pathname);
121 assert(name);
122
123 return consumer_allocate_channel(key, session_id, pathname, name, uid, gid,
2bba9e53 124 relayd_id, output, tracefile_size, tracefile_count, monitor);
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125}
126
127/*
128 * Allocate and return a consumer stream object. If _alloc_ret is not NULL, the
129 * error value if applicable is set in it else it is kept untouched.
3bd1e081 130 *
ffe60014 131 * Return NULL on error else the newly allocated stream object.
3bd1e081 132 */
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133static struct lttng_consumer_stream *allocate_stream(int cpu, int key,
134 struct lttng_consumer_channel *channel,
135 struct lttng_consumer_local_data *ctx, int *_alloc_ret)
136{
137 int alloc_ret;
138 struct lttng_consumer_stream *stream = NULL;
139
140 assert(channel);
141 assert(ctx);
142
143 stream = consumer_allocate_stream(channel->key,
144 key,
145 LTTNG_CONSUMER_ACTIVE_STREAM,
146 channel->name,
147 channel->uid,
148 channel->gid,
149 channel->relayd_id,
150 channel->session_id,
151 cpu,
152 &alloc_ret,
153 channel->type);
154 if (stream == NULL) {
155 switch (alloc_ret) {
156 case -ENOENT:
157 /*
158 * We could not find the channel. Can happen if cpu hotplug
159 * happens while tearing down.
160 */
161 DBG3("Could not find channel");
162 break;
163 case -ENOMEM:
164 case -EINVAL:
165 default:
166 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_OUTFD_ERROR);
167 break;
168 }
169 goto error;
170 }
171
172 stream->chan = channel;
173
174error:
175 if (_alloc_ret) {
176 *_alloc_ret = alloc_ret;
177 }
178 return stream;
179}
180
181/*
182 * Send the given stream pointer to the corresponding thread.
183 *
184 * Returns 0 on success else a negative value.
185 */
186static int send_stream_to_thread(struct lttng_consumer_stream *stream,
187 struct lttng_consumer_local_data *ctx)
188{
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189 int ret;
190 struct lttng_pipe *stream_pipe;
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191
192 /* Get the right pipe where the stream will be sent. */
193 if (stream->metadata_flag) {
dae10966 194 stream_pipe = ctx->consumer_metadata_pipe;
ffe60014 195 } else {
dae10966 196 stream_pipe = ctx->consumer_data_pipe;
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197 }
198
dae10966 199 ret = lttng_pipe_write(stream_pipe, &stream, sizeof(stream));
ffe60014 200 if (ret < 0) {
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201 ERR("Consumer write %s stream to pipe %d",
202 stream->metadata_flag ? "metadata" : "data",
203 lttng_pipe_get_writefd(stream_pipe));
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204 }
205
206 return ret;
207}
208
209/*
210 * Search for a relayd object related to the stream. If found, send the stream
211 * to the relayd.
212 *
213 * On success, returns 0 else a negative value.
214 */
215static int send_stream_to_relayd(struct lttng_consumer_stream *stream)
216{
217 int ret = 0;
218 struct consumer_relayd_sock_pair *relayd;
219
220 assert(stream);
221
222 relayd = consumer_find_relayd(stream->net_seq_idx);
223 if (relayd != NULL) {
224 pthread_mutex_lock(&relayd->ctrl_sock_mutex);
225 /* Add stream on the relayd */
226 ret = relayd_add_stream(&relayd->control_sock, stream->name,
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227 stream->chan->pathname, &stream->relayd_stream_id,
228 stream->chan->tracefile_size,
229 stream->chan->tracefile_count);
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230 pthread_mutex_unlock(&relayd->ctrl_sock_mutex);
231 if (ret < 0) {
232 goto error;
233 }
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234 } else if (stream->net_seq_idx != (uint64_t) -1ULL) {
235 ERR("Network sequence index %" PRIu64 " unknown. Not adding stream.",
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236 stream->net_seq_idx);
237 ret = -1;
238 goto error;
239 }
240
241error:
242 return ret;
243}
244
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245/*
246 * Create streams for the given channel using liblttng-ust-ctl.
247 *
248 * Return 0 on success else a negative value.
249 */
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250static int create_ust_streams(struct lttng_consumer_channel *channel,
251 struct lttng_consumer_local_data *ctx)
252{
253 int ret, cpu = 0;
254 struct ustctl_consumer_stream *ustream;
255 struct lttng_consumer_stream *stream;
256
257 assert(channel);
258 assert(ctx);
259
260 /*
261 * While a stream is available from ustctl. When NULL is returned, we've
262 * reached the end of the possible stream for the channel.
263 */
264 while ((ustream = ustctl_create_stream(channel->uchan, cpu))) {
265 int wait_fd;
266
749d339a 267 wait_fd = ustctl_stream_get_wait_fd(ustream);
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268
269 /* Allocate consumer stream object. */
270 stream = allocate_stream(cpu, wait_fd, channel, ctx, &ret);
271 if (!stream) {
272 goto error_alloc;
273 }
274 stream->ustream = ustream;
275 /*
276 * Store it so we can save multiple function calls afterwards since
277 * this value is used heavily in the stream threads. This is UST
278 * specific so this is why it's done after allocation.
279 */
280 stream->wait_fd = wait_fd;
281
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282 /*
283 * Increment channel refcount since the channel reference has now been
284 * assigned in the allocation process above.
285 */
286 uatomic_inc(&stream->chan->refcount);
287
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288 /*
289 * Order is important this is why a list is used. On error, the caller
290 * should clean this list.
291 */
292 cds_list_add_tail(&stream->send_node, &channel->streams.head);
293
294 ret = ustctl_get_max_subbuf_size(stream->ustream,
295 &stream->max_sb_size);
296 if (ret < 0) {
297 ERR("ustctl_get_max_subbuf_size failed for stream %s",
298 stream->name);
299 goto error;
300 }
301
302 /* Do actions once stream has been received. */
303 if (ctx->on_recv_stream) {
304 ret = ctx->on_recv_stream(stream);
305 if (ret < 0) {
306 goto error;
307 }
308 }
309
d88aee68 310 DBG("UST consumer add stream %s (key: %" PRIu64 ") with relayd id %" PRIu64,
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311 stream->name, stream->key, stream->relayd_stream_id);
312
313 /* Set next CPU stream. */
314 channel->streams.count = ++cpu;
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315
316 /* Keep stream reference when creating metadata. */
317 if (channel->type == CONSUMER_CHANNEL_TYPE_METADATA) {
318 channel->metadata_stream = stream;
319 }
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320 }
321
322 return 0;
323
324error:
325error_alloc:
326 return ret;
327}
328
329/*
330 * Create an UST channel with the given attributes and send it to the session
331 * daemon using the ust ctl API.
332 *
333 * Return 0 on success or else a negative value.
334 */
335static int create_ust_channel(struct ustctl_consumer_channel_attr *attr,
336 struct ustctl_consumer_channel **chanp)
337{
338 int ret;
339 struct ustctl_consumer_channel *channel;
340
341 assert(attr);
342 assert(chanp);
343
344 DBG3("Creating channel to ustctl with attr: [overwrite: %d, "
345 "subbuf_size: %" PRIu64 ", num_subbuf: %" PRIu64 ", "
346 "switch_timer_interval: %u, read_timer_interval: %u, "
347 "output: %d, type: %d", attr->overwrite, attr->subbuf_size,
348 attr->num_subbuf, attr->switch_timer_interval,
349 attr->read_timer_interval, attr->output, attr->type);
350
351 channel = ustctl_create_channel(attr);
352 if (!channel) {
353 ret = -1;
354 goto error_create;
355 }
356
357 *chanp = channel;
358
359 return 0;
360
361error_create:
362 return ret;
363}
364
d88aee68
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365/*
366 * Send a single given stream to the session daemon using the sock.
367 *
368 * Return 0 on success else a negative value.
369 */
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370static int send_sessiond_stream(int sock, struct lttng_consumer_stream *stream)
371{
372 int ret;
373
374 assert(stream);
375 assert(sock >= 0);
376
d88aee68 377 DBG2("UST consumer sending stream %" PRIu64 " to sessiond", stream->key);
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378
379 /* Send stream to session daemon. */
380 ret = ustctl_send_stream_to_sessiond(sock, stream->ustream);
381 if (ret < 0) {
382 goto error;
383 }
384
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385error:
386 return ret;
387}
388
389/*
390 * Send channel to sessiond.
391 *
d88aee68 392 * Return 0 on success or else a negative value.
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393 */
394static int send_sessiond_channel(int sock,
395 struct lttng_consumer_channel *channel,
396 struct lttng_consumer_local_data *ctx, int *relayd_error)
397{
f2a444f1 398 int ret, ret_code = LTTNG_OK;
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399 struct lttng_consumer_stream *stream;
400
401 assert(channel);
402 assert(ctx);
403 assert(sock >= 0);
404
405 DBG("UST consumer sending channel %s to sessiond", channel->name);
406
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407 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
408 /* Try to send the stream to the relayd if one is available. */
409 ret = send_stream_to_relayd(stream);
410 if (ret < 0) {
411 /*
412 * Flag that the relayd was the problem here probably due to a
413 * communicaton error on the socket.
414 */
415 if (relayd_error) {
416 *relayd_error = 1;
417 }
f2a444f1 418 ret_code = LTTNG_ERR_RELAYD_CONNECT_FAIL;
ffe60014 419 }
f2a444f1 420 }
ffe60014 421
f2a444f1
DG
422 /* Inform sessiond that we are about to send channel and streams. */
423 ret = consumer_send_status_msg(sock, ret_code);
424 if (ret < 0 || ret_code != LTTNG_OK) {
425 /*
426 * Either the session daemon is not responding or the relayd died so we
427 * stop now.
428 */
429 goto error;
430 }
431
432 /* Send channel to sessiond. */
433 ret = ustctl_send_channel_to_sessiond(sock, channel->uchan);
434 if (ret < 0) {
435 goto error;
436 }
437
438 ret = ustctl_channel_close_wakeup_fd(channel->uchan);
439 if (ret < 0) {
440 goto error;
441 }
442
443 /* The channel was sent successfully to the sessiond at this point. */
444 cds_list_for_each_entry(stream, &channel->streams.head, send_node) {
ffe60014
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445 /* Send stream to session daemon. */
446 ret = send_sessiond_stream(sock, stream);
447 if (ret < 0) {
448 goto error;
449 }
450 }
451
452 /* Tell sessiond there is no more stream. */
453 ret = ustctl_send_stream_to_sessiond(sock, NULL);
454 if (ret < 0) {
455 goto error;
456 }
457
458 DBG("UST consumer NULL stream sent to sessiond");
459
460 return 0;
461
462error:
f2a444f1
DG
463 if (ret_code != LTTNG_OK) {
464 ret = -1;
465 }
ffe60014
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466 return ret;
467}
468
469/*
470 * Creates a channel and streams and add the channel it to the channel internal
471 * state. The created stream must ONLY be sent once the GET_CHANNEL command is
472 * received.
473 *
474 * Return 0 on success or else, a negative value is returned and the channel
475 * MUST be destroyed by consumer_del_channel().
476 */
477static int ask_channel(struct lttng_consumer_local_data *ctx, int sock,
478 struct lttng_consumer_channel *channel,
479 struct ustctl_consumer_channel_attr *attr)
3bd1e081
MD
480{
481 int ret;
482
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483 assert(ctx);
484 assert(channel);
485 assert(attr);
486
487 /*
488 * This value is still used by the kernel consumer since for the kernel,
489 * the stream ownership is not IN the consumer so we need to have the
490 * number of left stream that needs to be initialized so we can know when
491 * to delete the channel (see consumer.c).
492 *
493 * As for the user space tracer now, the consumer creates and sends the
494 * stream to the session daemon which only sends them to the application
495 * once every stream of a channel is received making this value useless
496 * because we they will be added to the poll thread before the application
497 * receives them. This ensures that a stream can not hang up during
498 * initilization of a channel.
499 */
500 channel->nb_init_stream_left = 0;
501
502 /* The reply msg status is handled in the following call. */
503 ret = create_ust_channel(attr, &channel->uchan);
504 if (ret < 0) {
505 goto error;
3bd1e081
MD
506 }
507
d8ef542d
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508 channel->wait_fd = ustctl_channel_get_wait_fd(channel->uchan);
509
ffe60014
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510 /* Open all streams for this channel. */
511 ret = create_ust_streams(channel, ctx);
512 if (ret < 0) {
513 goto error;
514 }
515
516error:
3bd1e081
MD
517 return ret;
518}
519
d88aee68
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520/*
521 * Send all stream of a channel to the right thread handling it.
522 *
523 * On error, return a negative value else 0 on success.
524 */
525static int send_streams_to_thread(struct lttng_consumer_channel *channel,
526 struct lttng_consumer_local_data *ctx)
527{
528 int ret = 0;
529 struct lttng_consumer_stream *stream, *stmp;
530
531 assert(channel);
532 assert(ctx);
533
534 /* Send streams to the corresponding thread. */
535 cds_list_for_each_entry_safe(stream, stmp, &channel->streams.head,
536 send_node) {
537 /* Sending the stream to the thread. */
538 ret = send_stream_to_thread(stream, ctx);
539 if (ret < 0) {
540 /*
541 * If we are unable to send the stream to the thread, there is
542 * a big problem so just stop everything.
543 */
544 goto error;
545 }
546
547 /* Remove node from the channel stream list. */
548 cds_list_del(&stream->send_node);
549 }
550
551error:
552 return ret;
553}
554
555/*
556 * Write metadata to the given channel using ustctl to convert the string to
557 * the ringbuffer.
331744e3
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558 * Called only from consumer_metadata_cache_write.
559 * The metadata cache lock MUST be acquired to write in the cache.
d88aee68
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560 *
561 * Return 0 on success else a negative value.
562 */
331744e3 563int lttng_ustconsumer_push_metadata(struct lttng_consumer_channel *metadata,
d88aee68
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564 const char *metadata_str, uint64_t target_offset, uint64_t len)
565{
566 int ret;
567
568 assert(metadata);
569 assert(metadata_str);
570
571 DBG("UST consumer writing metadata to channel %s", metadata->name);
572
73811ecc
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573 if (!metadata->metadata_stream) {
574 ret = 0;
575 goto error;
576 }
577
331744e3
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578 assert(target_offset <= metadata->metadata_cache->max_offset);
579 ret = ustctl_write_metadata_to_channel(metadata->uchan,
580 metadata_str + target_offset, len);
d88aee68 581 if (ret < 0) {
8fd623e0 582 ERR("ustctl write metadata fail with ret %d, len %" PRIu64, ret, len);
d88aee68
DG
583 goto error;
584 }
d88aee68
DG
585
586 ustctl_flush_buffer(metadata->metadata_stream->ustream, 1);
587
588error:
589 return ret;
590}
591
7972aab2
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592/*
593 * Flush channel's streams using the given key to retrieve the channel.
594 *
595 * Return 0 on success else an LTTng error code.
596 */
597static int flush_channel(uint64_t chan_key)
598{
599 int ret = 0;
600 struct lttng_consumer_channel *channel;
601 struct lttng_consumer_stream *stream;
602 struct lttng_ht *ht;
603 struct lttng_ht_iter iter;
604
8fd623e0 605 DBG("UST consumer flush channel key %" PRIu64, chan_key);
7972aab2 606
a500c257 607 rcu_read_lock();
7972aab2
DG
608 channel = consumer_find_channel(chan_key);
609 if (!channel) {
8fd623e0 610 ERR("UST consumer flush channel %" PRIu64 " not found", chan_key);
7972aab2
DG
611 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
612 goto error;
613 }
614
615 ht = consumer_data.stream_per_chan_id_ht;
616
617 /* For each stream of the channel id, flush it. */
7972aab2
DG
618 cds_lfht_for_each_entry_duplicate(ht->ht,
619 ht->hash_fct(&channel->key, lttng_ht_seed), ht->match_fct,
620 &channel->key, &iter.iter, stream, node_channel_id.node) {
621 ustctl_flush_buffer(stream->ustream, 1);
622 }
7972aab2 623error:
a500c257 624 rcu_read_unlock();
7972aab2
DG
625 return ret;
626}
627
d88aee68
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628/*
629 * Close metadata stream wakeup_fd using the given key to retrieve the channel.
a500c257 630 * RCU read side lock MUST be acquired before calling this function.
d88aee68
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631 *
632 * Return 0 on success else an LTTng error code.
633 */
634static int close_metadata(uint64_t chan_key)
635{
ea88ca2a 636 int ret = 0;
d88aee68
DG
637 struct lttng_consumer_channel *channel;
638
8fd623e0 639 DBG("UST consumer close metadata key %" PRIu64, chan_key);
d88aee68
DG
640
641 channel = consumer_find_channel(chan_key);
642 if (!channel) {
84cc9aa0
DG
643 /*
644 * This is possible if the metadata thread has issue a delete because
645 * the endpoint point of the stream hung up. There is no way the
646 * session daemon can know about it thus use a DBG instead of an actual
647 * error.
648 */
649 DBG("UST consumer close metadata %" PRIu64 " not found", chan_key);
d88aee68
DG
650 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
651 goto error;
652 }
653
ea88ca2a 654 pthread_mutex_lock(&consumer_data.lock);
73811ecc
DG
655
656 if (cds_lfht_is_node_deleted(&channel->node.node)) {
657 goto error_unlock;
658 }
659
660 if (channel->switch_timer_enabled == 1) {
661 DBG("Deleting timer on metadata channel");
662 consumer_timer_switch_stop(channel);
663 }
664
665 if (channel->metadata_stream) {
ea88ca2a
MD
666 ret = ustctl_stream_close_wakeup_fd(channel->metadata_stream->ustream);
667 if (ret < 0) {
668 ERR("UST consumer unable to close fd of metadata (ret: %d)", ret);
669 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
670 goto error_unlock;
671 }
331744e3 672 }
d88aee68 673
ea88ca2a
MD
674error_unlock:
675 pthread_mutex_unlock(&consumer_data.lock);
d88aee68
DG
676error:
677 return ret;
678}
679
680/*
681 * RCU read side lock MUST be acquired before calling this function.
682 *
683 * Return 0 on success else an LTTng error code.
684 */
685static int setup_metadata(struct lttng_consumer_local_data *ctx, uint64_t key)
686{
687 int ret;
688 struct lttng_consumer_channel *metadata;
689
8fd623e0 690 DBG("UST consumer setup metadata key %" PRIu64, key);
d88aee68
DG
691
692 metadata = consumer_find_channel(key);
693 if (!metadata) {
694 ERR("UST consumer push metadata %" PRIu64 " not found", key);
695 ret = LTTNG_ERR_UST_CHAN_NOT_FOUND;
f2a444f1 696 goto error_find;
d88aee68
DG
697 }
698
699 /*
700 * Send metadata stream to relayd if one available. Availability is
701 * known if the stream is still in the list of the channel.
702 */
703 if (cds_list_empty(&metadata->streams.head)) {
704 ERR("Metadata channel key %" PRIu64 ", no stream available.", key);
705 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
706 goto error;
707 }
708
709 /* Send metadata stream to relayd if needed. */
710 ret = send_stream_to_relayd(metadata->metadata_stream);
711 if (ret < 0) {
712 ret = LTTCOMM_CONSUMERD_ERROR_METADATA;
713 goto error;
714 }
715
716 ret = send_streams_to_thread(metadata, ctx);
717 if (ret < 0) {
718 /*
719 * If we are unable to send the stream to the thread, there is
720 * a big problem so just stop everything.
721 */
722 ret = LTTCOMM_CONSUMERD_FATAL;
723 goto error;
724 }
725 /* List MUST be empty after or else it could be reused. */
726 assert(cds_list_empty(&metadata->streams.head));
727
f2a444f1 728 return 0;
d88aee68
DG
729
730error:
f2a444f1
DG
731 /*
732 * Delete metadata channel on error. At this point, the metadata stream can
733 * NOT be monitored by the metadata thread thus having the guarantee that
734 * the stream is still in the local stream list of the channel. This call
735 * will make sure to clean that list.
736 */
737 consumer_del_channel(metadata);
738error_find:
d88aee68
DG
739 return ret;
740}
741
331744e3
JD
742/*
743 * Receive the metadata updates from the sessiond.
744 */
745int lttng_ustconsumer_recv_metadata(int sock, uint64_t key, uint64_t offset,
746 uint64_t len, struct lttng_consumer_channel *channel)
747{
748 int ret, ret_code = LTTNG_OK;
749 char *metadata_str;
750
8fd623e0 751 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key, len);
331744e3
JD
752
753 metadata_str = zmalloc(len * sizeof(char));
754 if (!metadata_str) {
755 PERROR("zmalloc metadata string");
756 ret_code = LTTCOMM_CONSUMERD_ENOMEM;
757 goto end;
758 }
759
760 /* Receive metadata string. */
761 ret = lttcomm_recv_unix_sock(sock, metadata_str, len);
762 if (ret < 0) {
763 /* Session daemon is dead so return gracefully. */
764 ret_code = ret;
765 goto end_free;
766 }
767
73811ecc
DG
768 /*
769 * XXX: The consumer data lock is acquired before calling metadata cache
770 * write which calls push metadata that MUST be protected by the consumer
771 * lock in order to be able to check the validity of the metadata stream of
772 * the channel.
773 *
774 * Note that this will be subject to change to better fine grained locking
775 * and ultimately try to get rid of this global consumer data lock.
776 */
777 pthread_mutex_lock(&consumer_data.lock);
778
331744e3
JD
779 pthread_mutex_lock(&channel->metadata_cache->lock);
780 ret = consumer_metadata_cache_write(channel, offset, len, metadata_str);
781 if (ret < 0) {
782 /* Unable to handle metadata. Notify session daemon. */
783 ret_code = LTTCOMM_CONSUMERD_ERROR_METADATA;
a32bd775
DG
784 /*
785 * Skip metadata flush on write error since the offset and len might
786 * not have been updated which could create an infinite loop below when
787 * waiting for the metadata cache to be flushed.
788 */
789 pthread_mutex_unlock(&channel->metadata_cache->lock);
790 pthread_mutex_unlock(&consumer_data.lock);
791 goto end_free;
331744e3
JD
792 }
793 pthread_mutex_unlock(&channel->metadata_cache->lock);
73811ecc 794 pthread_mutex_unlock(&consumer_data.lock);
331744e3
JD
795
796 while (consumer_metadata_cache_flushed(channel, offset + len)) {
797 DBG("Waiting for metadata to be flushed");
798 usleep(DEFAULT_METADATA_AVAILABILITY_WAIT_TIME);
799 }
800
801end_free:
802 free(metadata_str);
803end:
804 return ret_code;
805}
806
4cbc1a04
DG
807/*
808 * Receive command from session daemon and process it.
809 *
810 * Return 1 on success else a negative value or 0.
811 */
3bd1e081
MD
812int lttng_ustconsumer_recv_cmd(struct lttng_consumer_local_data *ctx,
813 int sock, struct pollfd *consumer_sockpoll)
814{
815 ssize_t ret;
f50f23d9 816 enum lttng_error_code ret_code = LTTNG_OK;
3bd1e081 817 struct lttcomm_consumer_msg msg;
ffe60014 818 struct lttng_consumer_channel *channel = NULL;
3bd1e081
MD
819
820 ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg));
821 if (ret != sizeof(msg)) {
173af62f
DG
822 DBG("Consumer received unexpected message size %zd (expects %zu)",
823 ret, sizeof(msg));
ffe60014 824 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
3be74084
DG
825 /*
826 * The ret value might 0 meaning an orderly shutdown but this is ok
827 * since the caller handles this.
828 */
489f70e9
MD
829 if (ret > 0) {
830 ret = -1;
831 }
3bd1e081
MD
832 return ret;
833 }
834 if (msg.cmd_type == LTTNG_CONSUMER_STOP) {
f50f23d9
DG
835 /*
836 * Notify the session daemon that the command is completed.
837 *
838 * On transport layer error, the function call will print an error
839 * message so handling the returned code is a bit useless since we
840 * return an error code anyway.
841 */
842 (void) consumer_send_status_msg(sock, ret_code);
3bd1e081
MD
843 return -ENOENT;
844 }
845
3f8e211f 846 /* relayd needs RCU read-side lock */
b0b335c8
MD
847 rcu_read_lock();
848
3bd1e081 849 switch (msg.cmd_type) {
00e2e675
DG
850 case LTTNG_CONSUMER_ADD_RELAYD_SOCKET:
851 {
f50f23d9 852 /* Session daemon status message are handled in the following call. */
7735ef9e
DG
853 ret = consumer_add_relayd_socket(msg.u.relayd_sock.net_index,
854 msg.u.relayd_sock.type, ctx, sock, consumer_sockpoll,
46e6455f 855 &msg.u.relayd_sock.sock, msg.u.relayd_sock.session_id);
00e2e675
DG
856 goto end_nosignal;
857 }
173af62f
DG
858 case LTTNG_CONSUMER_DESTROY_RELAYD:
859 {
a6ba4fe1 860 uint64_t index = msg.u.destroy_relayd.net_seq_idx;
173af62f
DG
861 struct consumer_relayd_sock_pair *relayd;
862
a6ba4fe1 863 DBG("UST consumer destroying relayd %" PRIu64, index);
173af62f
DG
864
865 /* Get relayd reference if exists. */
a6ba4fe1 866 relayd = consumer_find_relayd(index);
173af62f 867 if (relayd == NULL) {
3448e266 868 DBG("Unable to find relayd %" PRIu64, index);
f50f23d9 869 ret_code = LTTNG_ERR_NO_CONSUMER;
173af62f
DG
870 }
871
a6ba4fe1
DG
872 /*
873 * Each relayd socket pair has a refcount of stream attached to it
874 * which tells if the relayd is still active or not depending on the
875 * refcount value.
876 *
877 * This will set the destroy flag of the relayd object and destroy it
878 * if the refcount reaches zero when called.
879 *
880 * The destroy can happen either here or when a stream fd hangs up.
881 */
f50f23d9
DG
882 if (relayd) {
883 consumer_flag_relayd_for_destroy(relayd);
884 }
885
d88aee68 886 goto end_msg_sessiond;
173af62f 887 }
3bd1e081
MD
888 case LTTNG_CONSUMER_UPDATE_STREAM:
889 {
3f8e211f 890 rcu_read_unlock();
7ad0a0cb 891 return -ENOSYS;
3bd1e081 892 }
6d805429 893 case LTTNG_CONSUMER_DATA_PENDING:
53632229 894 {
3be74084 895 int ret, is_data_pending;
6d805429 896 uint64_t id = msg.u.data_pending.session_id;
ca22feea 897
6d805429 898 DBG("UST consumer data pending command for id %" PRIu64, id);
ca22feea 899
3be74084 900 is_data_pending = consumer_data_pending(id);
ca22feea
DG
901
902 /* Send back returned value to session daemon */
3be74084
DG
903 ret = lttcomm_send_unix_sock(sock, &is_data_pending,
904 sizeof(is_data_pending));
ca22feea 905 if (ret < 0) {
3be74084 906 DBG("Error when sending the data pending ret code: %d", ret);
489f70e9 907 goto error_fatal;
ca22feea 908 }
f50f23d9
DG
909
910 /*
911 * No need to send back a status message since the data pending
912 * returned value is the response.
913 */
ca22feea 914 break;
53632229 915 }
ffe60014
DG
916 case LTTNG_CONSUMER_ASK_CHANNEL_CREATION:
917 {
918 int ret;
919 struct ustctl_consumer_channel_attr attr;
920
921 /* Create a plain object and reserve a channel key. */
922 channel = allocate_channel(msg.u.ask_channel.session_id,
923 msg.u.ask_channel.pathname, msg.u.ask_channel.name,
924 msg.u.ask_channel.uid, msg.u.ask_channel.gid,
925 msg.u.ask_channel.relayd_id, msg.u.ask_channel.key,
1624d5b7
JD
926 (enum lttng_event_output) msg.u.ask_channel.output,
927 msg.u.ask_channel.tracefile_size,
2bba9e53
DG
928 msg.u.ask_channel.tracefile_count,
929 msg.u.ask_channel.monitor);
ffe60014
DG
930 if (!channel) {
931 goto end_channel_error;
932 }
933
934 /* Build channel attributes from received message. */
935 attr.subbuf_size = msg.u.ask_channel.subbuf_size;
936 attr.num_subbuf = msg.u.ask_channel.num_subbuf;
937 attr.overwrite = msg.u.ask_channel.overwrite;
938 attr.switch_timer_interval = msg.u.ask_channel.switch_timer_interval;
939 attr.read_timer_interval = msg.u.ask_channel.read_timer_interval;
7972aab2 940 attr.chan_id = msg.u.ask_channel.chan_id;
ffe60014
DG
941 memcpy(attr.uuid, msg.u.ask_channel.uuid, sizeof(attr.uuid));
942
943 /* Translate the event output type to UST. */
944 switch (channel->output) {
945 case LTTNG_EVENT_SPLICE:
946 /* Splice not supported so fallback on mmap(). */
947 case LTTNG_EVENT_MMAP:
948 default:
949 attr.output = CONSUMER_CHANNEL_MMAP;
950 break;
951 };
952
953 /* Translate and save channel type. */
954 switch (msg.u.ask_channel.type) {
955 case LTTNG_UST_CHAN_PER_CPU:
956 channel->type = CONSUMER_CHANNEL_TYPE_DATA;
957 attr.type = LTTNG_UST_CHAN_PER_CPU;
8633d6e3
MD
958 /*
959 * Set refcount to 1 for owner. Below, we will
960 * pass ownership to the
961 * consumer_thread_channel_poll() thread.
962 */
963 channel->refcount = 1;
ffe60014
DG
964 break;
965 case LTTNG_UST_CHAN_METADATA:
966 channel->type = CONSUMER_CHANNEL_TYPE_METADATA;
967 attr.type = LTTNG_UST_CHAN_METADATA;
968 break;
969 default:
970 assert(0);
971 goto error_fatal;
972 };
973
974 ret = ask_channel(ctx, sock, channel, &attr);
975 if (ret < 0) {
976 goto end_channel_error;
977 }
978
fc643247
MD
979 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
980 ret = consumer_metadata_cache_allocate(channel);
981 if (ret < 0) {
982 ERR("Allocating metadata cache");
983 goto end_channel_error;
984 }
985 consumer_timer_switch_start(channel, attr.switch_timer_interval);
986 attr.switch_timer_interval = 0;
987 }
988
ffe60014
DG
989 /*
990 * Add the channel to the internal state AFTER all streams were created
991 * and successfully sent to session daemon. This way, all streams must
992 * be ready before this channel is visible to the threads.
fc643247
MD
993 * If add_channel succeeds, ownership of the channel is
994 * passed to consumer_thread_channel_poll().
ffe60014
DG
995 */
996 ret = add_channel(channel, ctx);
997 if (ret < 0) {
ea88ca2a
MD
998 if (msg.u.ask_channel.type == LTTNG_UST_CHAN_METADATA) {
999 if (channel->switch_timer_enabled == 1) {
1000 consumer_timer_switch_stop(channel);
1001 }
1002 consumer_metadata_cache_destroy(channel);
1003 }
ffe60014
DG
1004 goto end_channel_error;
1005 }
1006
1007 /*
1008 * Channel and streams are now created. Inform the session daemon that
1009 * everything went well and should wait to receive the channel and
1010 * streams with ustctl API.
1011 */
1012 ret = consumer_send_status_channel(sock, channel);
1013 if (ret < 0) {
1014 /*
489f70e9 1015 * There is probably a problem on the socket.
ffe60014 1016 */
489f70e9 1017 goto error_fatal;
ffe60014
DG
1018 }
1019
1020 break;
1021 }
1022 case LTTNG_CONSUMER_GET_CHANNEL:
1023 {
1024 int ret, relayd_err = 0;
d88aee68 1025 uint64_t key = msg.u.get_channel.key;
ffe60014 1026 struct lttng_consumer_channel *channel;
ffe60014
DG
1027
1028 channel = consumer_find_channel(key);
1029 if (!channel) {
8fd623e0 1030 ERR("UST consumer get channel key %" PRIu64 " not found", key);
ffe60014
DG
1031 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
1032 goto end_msg_sessiond;
1033 }
1034
ffe60014
DG
1035 /* Send everything to sessiond. */
1036 ret = send_sessiond_channel(sock, channel, ctx, &relayd_err);
1037 if (ret < 0) {
1038 if (relayd_err) {
1039 /*
1040 * We were unable to send to the relayd the stream so avoid
1041 * sending back a fatal error to the thread since this is OK
f2a444f1
DG
1042 * and the consumer can continue its work. The above call
1043 * has sent the error status message to the sessiond.
ffe60014 1044 */
f2a444f1 1045 goto end_nosignal;
ffe60014
DG
1046 }
1047 /*
1048 * The communicaton was broken hence there is a bad state between
1049 * the consumer and sessiond so stop everything.
1050 */
1051 goto error_fatal;
1052 }
1053
d88aee68
DG
1054 ret = send_streams_to_thread(channel, ctx);
1055 if (ret < 0) {
1056 /*
1057 * If we are unable to send the stream to the thread, there is
1058 * a big problem so just stop everything.
1059 */
1060 goto error_fatal;
ffe60014 1061 }
ffe60014
DG
1062 /* List MUST be empty after or else it could be reused. */
1063 assert(cds_list_empty(&channel->streams.head));
1064
d88aee68
DG
1065 goto end_msg_sessiond;
1066 }
1067 case LTTNG_CONSUMER_DESTROY_CHANNEL:
1068 {
1069 uint64_t key = msg.u.destroy_channel.key;
d88aee68 1070
a0cbdd2e
MD
1071 /*
1072 * Only called if streams have not been sent to stream
1073 * manager thread. However, channel has been sent to
1074 * channel manager thread.
1075 */
1076 notify_thread_del_channel(ctx, key);
d88aee68 1077 goto end_msg_sessiond;
ffe60014 1078 }
d88aee68
DG
1079 case LTTNG_CONSUMER_CLOSE_METADATA:
1080 {
1081 int ret;
1082
1083 ret = close_metadata(msg.u.close_metadata.key);
1084 if (ret != 0) {
1085 ret_code = ret;
1086 }
1087
1088 goto end_msg_sessiond;
1089 }
7972aab2
DG
1090 case LTTNG_CONSUMER_FLUSH_CHANNEL:
1091 {
1092 int ret;
1093
1094 ret = flush_channel(msg.u.flush_channel.key);
1095 if (ret != 0) {
1096 ret_code = ret;
1097 }
1098
1099 goto end_msg_sessiond;
1100 }
d88aee68 1101 case LTTNG_CONSUMER_PUSH_METADATA:
ffe60014
DG
1102 {
1103 int ret;
d88aee68 1104 uint64_t len = msg.u.push_metadata.len;
d88aee68 1105 uint64_t key = msg.u.push_metadata.key;
331744e3 1106 uint64_t offset = msg.u.push_metadata.target_offset;
ffe60014
DG
1107 struct lttng_consumer_channel *channel;
1108
8fd623e0
DG
1109 DBG("UST consumer push metadata key %" PRIu64 " of len %" PRIu64, key,
1110 len);
ffe60014
DG
1111
1112 channel = consumer_find_channel(key);
1113 if (!channel) {
8fd623e0 1114 ERR("UST consumer push metadata %" PRIu64 " not found", key);
ffe60014 1115 ret_code = LTTNG_ERR_UST_CHAN_NOT_FOUND;
4a2eb0ca 1116 goto end_msg_sessiond;
d88aee68
DG
1117 }
1118
1119 /* Tell session daemon we are ready to receive the metadata. */
ffe60014
DG
1120 ret = consumer_send_status_msg(sock, LTTNG_OK);
1121 if (ret < 0) {
1122 /* Somehow, the session daemon is not responding anymore. */
d88aee68
DG
1123 goto error_fatal;
1124 }
1125
1126 /* Wait for more data. */
1127 if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) {
489f70e9 1128 goto error_fatal;
d88aee68
DG
1129 }
1130
331744e3
JD
1131 ret = lttng_ustconsumer_recv_metadata(sock, key, offset,
1132 len, channel);
d88aee68 1133 if (ret < 0) {
331744e3 1134 /* error receiving from sessiond */
489f70e9 1135 goto error_fatal;
331744e3
JD
1136 } else {
1137 ret_code = ret;
d88aee68
DG
1138 goto end_msg_sessiond;
1139 }
d88aee68
DG
1140 }
1141 case LTTNG_CONSUMER_SETUP_METADATA:
1142 {
1143 int ret;
1144
1145 ret = setup_metadata(ctx, msg.u.setup_metadata.key);
1146 if (ret) {
1147 ret_code = ret;
1148 }
1149 goto end_msg_sessiond;
ffe60014 1150 }
6dc3064a
DG
1151 case LTTNG_CONSUMER_SNAPSHOT_CHANNEL:
1152 {
1153 ret = consumer_send_status_msg(sock, ret_code);
1154 if (ret < 0) {
1155 /* Somehow, the session daemon is not responding anymore. */
1156 goto end_nosignal;
1157 }
1158 break;
1159 }
3bd1e081
MD
1160 default:
1161 break;
1162 }
3f8e211f 1163
3bd1e081 1164end_nosignal:
b0b335c8 1165 rcu_read_unlock();
4cbc1a04
DG
1166
1167 /*
1168 * Return 1 to indicate success since the 0 value can be a socket
1169 * shutdown during the recv() or send() call.
1170 */
1171 return 1;
ffe60014
DG
1172
1173end_msg_sessiond:
1174 /*
1175 * The returned value here is not useful since either way we'll return 1 to
1176 * the caller because the session daemon socket management is done
1177 * elsewhere. Returning a negative code or 0 will shutdown the consumer.
1178 */
489f70e9
MD
1179 ret = consumer_send_status_msg(sock, ret_code);
1180 if (ret < 0) {
1181 goto error_fatal;
1182 }
ffe60014
DG
1183 rcu_read_unlock();
1184 return 1;
1185end_channel_error:
1186 if (channel) {
1187 /*
1188 * Free channel here since no one has a reference to it. We don't
1189 * free after that because a stream can store this pointer.
1190 */
1191 destroy_channel(channel);
1192 }
1193 /* We have to send a status channel message indicating an error. */
1194 ret = consumer_send_status_channel(sock, NULL);
1195 if (ret < 0) {
1196 /* Stop everything if session daemon can not be notified. */
1197 goto error_fatal;
1198 }
1199 rcu_read_unlock();
1200 return 1;
1201error_fatal:
1202 rcu_read_unlock();
1203 /* This will issue a consumer stop. */
1204 return -1;
3bd1e081
MD
1205}
1206
ffe60014
DG
1207/*
1208 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1209 * compiled out, we isolate it in this library.
1210 */
1211int lttng_ustctl_get_mmap_read_offset(struct lttng_consumer_stream *stream,
1212 unsigned long *off)
3bd1e081 1213{
ffe60014
DG
1214 assert(stream);
1215 assert(stream->ustream);
b5c5fc29 1216
ffe60014 1217 return ustctl_get_mmap_read_offset(stream->ustream, off);
3bd1e081
MD
1218}
1219
ffe60014
DG
1220/*
1221 * Wrapper over the mmap() read offset from ust-ctl library. Since this can be
1222 * compiled out, we isolate it in this library.
1223 */
1224void *lttng_ustctl_get_mmap_base(struct lttng_consumer_stream *stream)
d056b477 1225{
ffe60014
DG
1226 assert(stream);
1227 assert(stream->ustream);
1228
1229 return ustctl_get_mmap_base(stream->ustream);
d056b477
MD
1230}
1231
ffe60014
DG
1232/*
1233 * Take a snapshot for a specific fd
1234 *
1235 * Returns 0 on success, < 0 on error
1236 */
1237int lttng_ustconsumer_take_snapshot(struct lttng_consumer_stream *stream)
3bd1e081 1238{
ffe60014
DG
1239 assert(stream);
1240 assert(stream->ustream);
1241
1242 return ustctl_snapshot(stream->ustream);
3bd1e081
MD
1243}
1244
ffe60014
DG
1245/*
1246 * Get the produced position
1247 *
1248 * Returns 0 on success, < 0 on error
1249 */
1250int lttng_ustconsumer_get_produced_snapshot(
1251 struct lttng_consumer_stream *stream, unsigned long *pos)
3bd1e081 1252{
ffe60014
DG
1253 assert(stream);
1254 assert(stream->ustream);
1255 assert(pos);
7a57cf92 1256
ffe60014
DG
1257 return ustctl_snapshot_get_produced(stream->ustream, pos);
1258}
7a57cf92 1259
ffe60014
DG
1260/*
1261 * Called when the stream signal the consumer that it has hang up.
1262 */
1263void lttng_ustconsumer_on_stream_hangup(struct lttng_consumer_stream *stream)
1264{
1265 assert(stream);
1266 assert(stream->ustream);
2c1dd183 1267
ffe60014
DG
1268 ustctl_flush_buffer(stream->ustream, 0);
1269 stream->hangup_flush_done = 1;
1270}
ee77a7b0 1271
ffe60014
DG
1272void lttng_ustconsumer_del_channel(struct lttng_consumer_channel *chan)
1273{
1274 assert(chan);
1275 assert(chan->uchan);
e316aad5 1276
ea88ca2a
MD
1277 if (chan->switch_timer_enabled == 1) {
1278 consumer_timer_switch_stop(chan);
1279 }
1280 consumer_metadata_cache_destroy(chan);
ffe60014 1281 ustctl_destroy_channel(chan->uchan);
3bd1e081
MD
1282}
1283
1284void lttng_ustconsumer_del_stream(struct lttng_consumer_stream *stream)
1285{
ffe60014
DG
1286 assert(stream);
1287 assert(stream->ustream);
d41f73b7 1288
ea88ca2a
MD
1289 if (stream->chan->switch_timer_enabled == 1) {
1290 consumer_timer_switch_stop(stream->chan);
1291 }
ffe60014
DG
1292 ustctl_destroy_stream(stream->ustream);
1293}
d41f73b7
MD
1294
1295int lttng_ustconsumer_read_subbuffer(struct lttng_consumer_stream *stream,
1296 struct lttng_consumer_local_data *ctx)
1297{
1d4dfdef 1298 unsigned long len, subbuf_size, padding;
d41f73b7
MD
1299 int err;
1300 long ret = 0;
d41f73b7 1301 char dummy;
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1302 struct ustctl_consumer_stream *ustream;
1303
1304 assert(stream);
1305 assert(stream->ustream);
1306 assert(ctx);
d41f73b7 1307
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1308 DBG2("In UST read_subbuffer (wait_fd: %d, name: %s)", stream->wait_fd,
1309 stream->name);
1310
1311 /* Ease our life for what's next. */
1312 ustream = stream->ustream;
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MD
1313
1314 /* We can consume the 1 byte written into the wait_fd by UST */
effcf122 1315 if (!stream->hangup_flush_done) {
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MD
1316 ssize_t readlen;
1317
effcf122
MD
1318 do {
1319 readlen = read(stream->wait_fd, &dummy, 1);
87dc6a9c 1320 } while (readlen == -1 && errno == EINTR);
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MD
1321 if (readlen == -1) {
1322 ret = readlen;
1323 goto end;
1324 }
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MD
1325 }
1326
d41f73b7 1327 /* Get the next subbuffer */
ffe60014 1328 err = ustctl_get_next_subbuf(ustream);
d41f73b7 1329 if (err != 0) {
1d4dfdef 1330 ret = err; /* ustctl_get_next_subbuf returns negative, caller expect positive. */
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MD
1331 /*
1332 * This is a debug message even for single-threaded consumer,
1333 * because poll() have more relaxed criterions than get subbuf,
1334 * so get_subbuf may fail for short race windows where poll()
1335 * would issue wakeups.
1336 */
1337 DBG("Reserving sub buffer failed (everything is normal, "
ffe60014 1338 "it is due to concurrency) [ret: %d]", err);
d41f73b7
MD
1339 goto end;
1340 }
ffe60014 1341 assert(stream->chan->output == CONSUMER_CHANNEL_MMAP);
1d4dfdef 1342 /* Get the full padded subbuffer size */
ffe60014 1343 err = ustctl_get_padded_subbuf_size(ustream, &len);
effcf122 1344 assert(err == 0);
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1345
1346 /* Get subbuffer data size (without padding) */
ffe60014 1347 err = ustctl_get_subbuf_size(ustream, &subbuf_size);
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DG
1348 assert(err == 0);
1349
1350 /* Make sure we don't get a subbuffer size bigger than the padded */
1351 assert(len >= subbuf_size);
1352
1353 padding = len - subbuf_size;
d41f73b7 1354 /* write the subbuffer to the tracefile */
1d4dfdef 1355 ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, subbuf_size, padding);
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DG
1356 /*
1357 * The mmap operation should write subbuf_size amount of data when network
1358 * streaming or the full padding (len) size when we are _not_ streaming.
1359 */
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1360 if ((ret != subbuf_size && stream->net_seq_idx != (uint64_t) -1ULL) ||
1361 (ret != len && stream->net_seq_idx == (uint64_t) -1ULL)) {
d41f73b7 1362 /*
91dfef6e 1363 * Display the error but continue processing to try to release the
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DG
1364 * subbuffer. This is a DBG statement since any unexpected kill or
1365 * signal, the application gets unregistered, relayd gets closed or
1366 * anything that affects the buffer lifetime will trigger this error.
1367 * So, for the sake of the user, don't print this error since it can
1368 * happen and it is OK with the code flow.
d41f73b7 1369 */
c5c45efa 1370 DBG("Error writing to tracefile "
8fd623e0 1371 "(ret: %ld != len: %lu != subbuf_size: %lu)",
91dfef6e 1372 ret, len, subbuf_size);
d41f73b7 1373 }
ffe60014 1374 err = ustctl_put_next_subbuf(ustream);
effcf122 1375 assert(err == 0);
331744e3 1376
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MD
1377end:
1378 return ret;
1379}
1380
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1381/*
1382 * Called when a stream is created.
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JD
1383 *
1384 * Return 0 on success or else a negative value.
ffe60014 1385 */
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MD
1386int lttng_ustconsumer_on_recv_stream(struct lttng_consumer_stream *stream)
1387{
fe4477ee
JD
1388 int ret;
1389
1390 /* Don't create anything if this is set for streaming. */
1391 if (stream->net_seq_idx == (uint64_t) -1ULL) {
1392 ret = utils_create_stream_file(stream->chan->pathname, stream->name,
1393 stream->chan->tracefile_size, stream->tracefile_count_current,
1394 stream->uid, stream->gid);
1395 if (ret < 0) {
1396 goto error;
1397 }
1398 stream->out_fd = ret;
1399 stream->tracefile_size_current = 0;
1400 }
1401 ret = 0;
1402
1403error:
1404 return ret;
d41f73b7 1405}
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DG
1406
1407/*
1408 * Check if data is still being extracted from the buffers for a specific
4e9a4686
DG
1409 * stream. Consumer data lock MUST be acquired before calling this function
1410 * and the stream lock.
ca22feea 1411 *
6d805429 1412 * Return 1 if the traced data are still getting read else 0 meaning that the
ca22feea
DG
1413 * data is available for trace viewer reading.
1414 */
6d805429 1415int lttng_ustconsumer_data_pending(struct lttng_consumer_stream *stream)
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DG
1416{
1417 int ret;
1418
1419 assert(stream);
ffe60014 1420 assert(stream->ustream);
ca22feea 1421
6d805429 1422 DBG("UST consumer checking data pending");
c8f59ee5 1423
ffe60014 1424 ret = ustctl_get_next_subbuf(stream->ustream);
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DG
1425 if (ret == 0) {
1426 /* There is still data so let's put back this subbuffer. */
ffe60014 1427 ret = ustctl_put_subbuf(stream->ustream);
ca22feea 1428 assert(ret == 0);
6d805429 1429 ret = 1; /* Data is pending */
4e9a4686 1430 goto end;
ca22feea
DG
1431 }
1432
6d805429
DG
1433 /* Data is NOT pending so ready to be read. */
1434 ret = 0;
ca22feea 1435
6efae65e
DG
1436end:
1437 return ret;
ca22feea 1438}
d88aee68
DG
1439
1440/*
1441 * Close every metadata stream wait fd of the metadata hash table. This
1442 * function MUST be used very carefully so not to run into a race between the
1443 * metadata thread handling streams and this function closing their wait fd.
1444 *
1445 * For UST, this is used when the session daemon hangs up. Its the metadata
1446 * producer so calling this is safe because we are assured that no state change
1447 * can occur in the metadata thread for the streams in the hash table.
1448 */
1449void lttng_ustconsumer_close_metadata(struct lttng_ht *metadata_ht)
1450{
1451 int ret;
1452 struct lttng_ht_iter iter;
1453 struct lttng_consumer_stream *stream;
1454
1455 assert(metadata_ht);
1456 assert(metadata_ht->ht);
1457
1458 DBG("UST consumer closing all metadata streams");
1459
1460 rcu_read_lock();
1461 cds_lfht_for_each_entry(metadata_ht->ht, &iter.iter, stream,
1462 node.node) {
1463 int fd = stream->wait_fd;
1464
1465 /*
1466 * Whatever happens here we have to continue to try to close every
1467 * streams. Let's report at least the error on failure.
1468 */
1469 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1470 if (ret) {
1471 ERR("Unable to close metadata stream fd %d ret %d", fd, ret);
1472 }
1473 DBG("Metadata wait fd %d closed", fd);
1474 }
1475 rcu_read_unlock();
1476}
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1477
1478void lttng_ustconsumer_close_stream_wakeup(struct lttng_consumer_stream *stream)
1479{
1480 int ret;
1481
1482 ret = ustctl_stream_close_wakeup_fd(stream->ustream);
1483 if (ret < 0) {
1484 ERR("Unable to close wakeup fd");
1485 }
1486}
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1487
1488int lttng_ustconsumer_request_metadata(struct lttng_consumer_local_data *ctx,
1489 struct lttng_consumer_channel *channel)
1490{
1491 struct lttcomm_metadata_request_msg request;
1492 struct lttcomm_consumer_msg msg;
1493 enum lttng_error_code ret_code = LTTNG_OK;
1494 uint64_t len, key, offset;
1495 int ret;
1496
1497 assert(channel);
1498 assert(channel->metadata_cache);
1499
1500 /* send the metadata request to sessiond */
1501 switch (consumer_data.type) {
1502 case LTTNG_CONSUMER64_UST:
1503 request.bits_per_long = 64;
1504 break;
1505 case LTTNG_CONSUMER32_UST:
1506 request.bits_per_long = 32;
1507 break;
1508 default:
1509 request.bits_per_long = 0;
1510 break;
1511 }
1512
1513 request.session_id = channel->session_id;
1514 request.uid = channel->uid;
1515 request.key = channel->key;
1516 DBG("Sending metadata request to sessiond, session %" PRIu64,
1517 channel->session_id);
1518
1519 ret = lttcomm_send_unix_sock(ctx->consumer_metadata_socket, &request,
1520 sizeof(request));
1521 if (ret < 0) {
1522 ERR("Asking metadata to sessiond");
1523 goto end;
1524 }
1525
1526 /* Receive the metadata from sessiond */
1527 ret = lttcomm_recv_unix_sock(ctx->consumer_metadata_socket, &msg,
1528 sizeof(msg));
1529 if (ret != sizeof(msg)) {
8fd623e0 1530 DBG("Consumer received unexpected message size %d (expects %zu)",
331744e3
JD
1531 ret, sizeof(msg));
1532 lttng_consumer_send_error(ctx, LTTCOMM_CONSUMERD_ERROR_RECV_CMD);
1533 /*
1534 * The ret value might 0 meaning an orderly shutdown but this is ok
1535 * since the caller handles this.
1536 */
1537 goto end;
1538 }
1539
1540 if (msg.cmd_type == LTTNG_ERR_UND) {
1541 /* No registry found */
1542 (void) consumer_send_status_msg(ctx->consumer_metadata_socket,
1543 ret_code);
1544 ret = 0;
1545 goto end;
1546 } else if (msg.cmd_type != LTTNG_CONSUMER_PUSH_METADATA) {
1547 ERR("Unexpected cmd_type received %d", msg.cmd_type);
1548 ret = -1;
1549 goto end;
1550 }
1551
1552 len = msg.u.push_metadata.len;
1553 key = msg.u.push_metadata.key;
1554 offset = msg.u.push_metadata.target_offset;
1555
1556 assert(key == channel->key);
1557 if (len == 0) {
1558 DBG("No new metadata to receive for key %" PRIu64, key);
1559 }
1560
1561 /* Tell session daemon we are ready to receive the metadata. */
1562 ret = consumer_send_status_msg(ctx->consumer_metadata_socket,
1563 LTTNG_OK);
1564 if (ret < 0 || len == 0) {
1565 /*
1566 * Somehow, the session daemon is not responding anymore or there is
1567 * nothing to receive.
1568 */
1569 goto end;
1570 }
1571
1572 ret_code = lttng_ustconsumer_recv_metadata(ctx->consumer_metadata_socket,
1573 key, offset, len, channel);
f2a444f1
DG
1574 if (ret_code >= 0) {
1575 /*
1576 * Only send the status msg if the sessiond is alive meaning a positive
1577 * ret code.
1578 */
1579 (void) consumer_send_status_msg(ctx->consumer_metadata_socket, ret_code);
1580 }
331744e3
JD
1581 ret = 0;
1582
1583end:
1584 return ret;
1585}
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