Commit | Line | Data |
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3bd1e081 MD |
1 | /* |
2 | * Copyright (C) 2011 - Julien Desfossez <julien.desfossez@polymtl.ca> | |
3 | * Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
4 | * | |
d14d33bf AM |
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. | |
3bd1e081 MD |
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 | * | |
d14d33bf AM |
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. | |
3bd1e081 MD |
17 | */ |
18 | ||
19 | #define _GNU_SOURCE | |
20 | #include <assert.h> | |
3bd1e081 MD |
21 | #include <poll.h> |
22 | #include <pthread.h> | |
23 | #include <stdlib.h> | |
24 | #include <string.h> | |
25 | #include <sys/mman.h> | |
26 | #include <sys/socket.h> | |
27 | #include <sys/types.h> | |
28 | #include <unistd.h> | |
dbb5dfe6 | 29 | #include <sys/stat.h> |
3bd1e081 | 30 | |
990570ed | 31 | #include <common/common.h> |
10a8a223 | 32 | #include <common/kernel-ctl/kernel-ctl.h> |
10a8a223 | 33 | #include <common/sessiond-comm/sessiond-comm.h> |
00e2e675 | 34 | #include <common/sessiond-comm/relayd.h> |
dbb5dfe6 | 35 | #include <common/compat/fcntl.h> |
00e2e675 | 36 | #include <common/relayd/relayd.h> |
0857097f | 37 | |
10a8a223 | 38 | #include "kernel-consumer.h" |
3bd1e081 MD |
39 | |
40 | extern struct lttng_consumer_global_data consumer_data; | |
41 | extern int consumer_poll_timeout; | |
42 | extern volatile int consumer_quit; | |
43 | ||
44 | /* | |
45 | * Mmap the ring buffer, read it and write the data to the tracefile. | |
46 | * | |
47 | * Returns the number of bytes written | |
48 | */ | |
4078b776 | 49 | ssize_t lttng_kconsumer_on_read_subbuffer_mmap( |
3bd1e081 MD |
50 | struct lttng_consumer_local_data *ctx, |
51 | struct lttng_consumer_stream *stream, unsigned long len) | |
52 | { | |
53 | unsigned long mmap_offset; | |
47e81c02 | 54 | ssize_t ret = 0, written = 0; |
3bd1e081 MD |
55 | off_t orig_offset = stream->out_fd_offset; |
56 | int fd = stream->wait_fd; | |
00e2e675 | 57 | /* Default is on the disk */ |
3bd1e081 | 58 | int outfd = stream->out_fd; |
00e2e675 DG |
59 | uint64_t metadata_id; |
60 | struct consumer_relayd_sock_pair *relayd = NULL; | |
61 | ||
62 | /* Flag that the current stream if set for network streaming. */ | |
63 | if (stream->net_seq_idx != -1) { | |
64 | relayd = consumer_find_relayd(stream->net_seq_idx); | |
65 | if (relayd == NULL) { | |
66 | goto end; | |
67 | } | |
68 | } | |
3bd1e081 MD |
69 | |
70 | /* get the offset inside the fd to mmap */ | |
71 | ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); | |
72 | if (ret != 0) { | |
87dc6a9c | 73 | errno = -ret; |
3bd1e081 | 74 | perror("kernctl_get_mmap_read_offset"); |
47e81c02 | 75 | written = ret; |
3bd1e081 MD |
76 | goto end; |
77 | } | |
78 | ||
00e2e675 DG |
79 | /* RCU lock for the relayd pointer */ |
80 | rcu_read_lock(); | |
81 | ||
82 | /* Handle stream on the relayd if the output is on the network */ | |
83 | if (relayd) { | |
84 | /* | |
85 | * Lock the control socket for the complete duration of the function | |
86 | * since from this point on we will use the socket. | |
87 | */ | |
88 | if (stream->metadata_flag) { | |
89 | /* Metadata requires the control socket. */ | |
90 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
91 | } | |
92 | ||
93 | ret = consumer_handle_stream_before_relayd(stream, len); | |
94 | if (ret >= 0) { | |
95 | /* Use the returned socket. */ | |
96 | outfd = ret; | |
97 | ||
98 | /* Write metadata stream id before payload */ | |
99 | if (stream->metadata_flag) { | |
100 | metadata_id = htobe64(stream->relayd_stream_id); | |
101 | do { | |
102 | ret = write(outfd, (void *) &metadata_id, | |
103 | sizeof(stream->relayd_stream_id)); | |
104 | if (ret < 0) { | |
105 | PERROR("write metadata stream id"); | |
106 | written = ret; | |
107 | goto end; | |
108 | } | |
109 | } while (errno == EINTR); | |
110 | DBG("Metadata stream id %zu written before data", | |
111 | stream->relayd_stream_id); | |
112 | /* | |
113 | * We do this so the return value can match the len passed as | |
114 | * argument to this function. | |
115 | */ | |
116 | written -= sizeof(stream->relayd_stream_id); | |
117 | } | |
118 | } | |
119 | /* Else, use the default set before which is the filesystem. */ | |
120 | } | |
121 | ||
3bd1e081 MD |
122 | while (len > 0) { |
123 | ret = write(outfd, stream->mmap_base + mmap_offset, len); | |
47e81c02 MD |
124 | if (ret < 0) { |
125 | if (errno == EINTR) { | |
126 | /* restart the interrupted system call */ | |
127 | continue; | |
128 | } else { | |
129 | perror("Error in file write"); | |
130 | if (written == 0) { | |
131 | written = ret; | |
132 | } | |
133 | goto end; | |
134 | } | |
135 | } else if (ret > len) { | |
3bd1e081 | 136 | perror("Error in file write"); |
47e81c02 | 137 | written += ret; |
3bd1e081 | 138 | goto end; |
47e81c02 MD |
139 | } else { |
140 | len -= ret; | |
141 | mmap_offset += ret; | |
3bd1e081 | 142 | } |
00e2e675 DG |
143 | |
144 | /* This call is useless on a socket so better save a syscall. */ | |
145 | if (!relayd) { | |
146 | /* This won't block, but will start writeout asynchronously */ | |
147 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret, | |
148 | SYNC_FILE_RANGE_WRITE); | |
149 | stream->out_fd_offset += ret; | |
150 | } | |
47e81c02 | 151 | written += ret; |
3bd1e081 | 152 | } |
3bd1e081 | 153 | lttng_consumer_sync_trace_file(stream, orig_offset); |
00e2e675 | 154 | |
3bd1e081 | 155 | end: |
00e2e675 DG |
156 | /* Unlock only if ctrl socket used */ |
157 | if (relayd && stream->metadata_flag) { | |
158 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
159 | } | |
160 | ||
161 | rcu_read_unlock(); | |
162 | ||
47e81c02 | 163 | return written; |
3bd1e081 MD |
164 | } |
165 | ||
166 | /* | |
167 | * Splice the data from the ring buffer to the tracefile. | |
168 | * | |
169 | * Returns the number of bytes spliced. | |
170 | */ | |
4078b776 | 171 | ssize_t lttng_kconsumer_on_read_subbuffer_splice( |
3bd1e081 MD |
172 | struct lttng_consumer_local_data *ctx, |
173 | struct lttng_consumer_stream *stream, unsigned long len) | |
174 | { | |
00e2e675 | 175 | ssize_t ret = 0, written = 0, ret_splice = 0; |
3bd1e081 MD |
176 | loff_t offset = 0; |
177 | off_t orig_offset = stream->out_fd_offset; | |
178 | int fd = stream->wait_fd; | |
00e2e675 | 179 | /* Default is on the disk */ |
3bd1e081 | 180 | int outfd = stream->out_fd; |
00e2e675 DG |
181 | uint64_t metadata_id; |
182 | struct consumer_relayd_sock_pair *relayd = NULL; | |
183 | ||
184 | /* Flag that the current stream if set for network streaming. */ | |
185 | if (stream->net_seq_idx != -1) { | |
186 | relayd = consumer_find_relayd(stream->net_seq_idx); | |
187 | if (relayd == NULL) { | |
188 | goto end; | |
189 | } | |
190 | } | |
191 | ||
192 | /* RCU lock for the relayd pointer */ | |
193 | rcu_read_lock(); | |
194 | ||
195 | /* Write metadata stream id before payload */ | |
196 | if (stream->metadata_flag && relayd) { | |
197 | /* | |
198 | * Lock the control socket for the complete duration of the function | |
199 | * since from this point on we will use the socket. | |
200 | */ | |
201 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
202 | ||
203 | do { | |
204 | metadata_id = htobe64(stream->relayd_stream_id); | |
205 | ret = write(ctx->consumer_thread_pipe[1], | |
206 | (void *) &metadata_id, | |
207 | sizeof(stream->relayd_stream_id)); | |
208 | if (ret < 0) { | |
209 | PERROR("write metadata stream id"); | |
210 | written = ret; | |
211 | goto end; | |
212 | } | |
213 | } while (errno == EINTR); | |
214 | DBG("Metadata stream id %zu written before data", | |
215 | stream->relayd_stream_id); | |
216 | } | |
3bd1e081 MD |
217 | |
218 | while (len > 0) { | |
00e2e675 DG |
219 | DBG("splice chan to pipe offset %lu of len %lu (fd : %d)", |
220 | (unsigned long)offset, len, fd); | |
221 | ret_splice = splice(fd, &offset, ctx->consumer_thread_pipe[1], NULL, len, | |
3bd1e081 | 222 | SPLICE_F_MOVE | SPLICE_F_MORE); |
00e2e675 DG |
223 | DBG("splice chan to pipe, ret %zd", ret_splice); |
224 | if (ret_splice < 0) { | |
3bd1e081 | 225 | perror("Error in relay splice"); |
47e81c02 | 226 | if (written == 0) { |
00e2e675 | 227 | written = ret_splice; |
47e81c02 MD |
228 | } |
229 | ret = errno; | |
3bd1e081 MD |
230 | goto splice_error; |
231 | } | |
232 | ||
00e2e675 DG |
233 | /* Handle stream on the relayd if the output is on the network */ |
234 | if (relayd) { | |
235 | if (stream->metadata_flag) { | |
236 | /* Update counter to fit the spliced data */ | |
237 | ret_splice += sizeof(stream->relayd_stream_id); | |
238 | len += sizeof(stream->relayd_stream_id); | |
239 | /* | |
240 | * We do this so the return value can match the len passed as | |
241 | * argument to this function. | |
242 | */ | |
243 | written -= sizeof(stream->relayd_stream_id); | |
244 | } | |
245 | ||
246 | ret = consumer_handle_stream_before_relayd(stream, ret_splice); | |
247 | if (ret >= 0) { | |
248 | /* Use the returned socket. */ | |
249 | outfd = ret; | |
250 | } else { | |
251 | if (outfd == -1) { | |
252 | ERR("Remote relayd disconnected. Stopping"); | |
253 | goto end; | |
254 | } | |
255 | } | |
256 | } | |
257 | ||
258 | DBG3("Kernel consumer splice data in %d to out %d", | |
259 | ctx->consumer_thread_pipe[0], outfd); | |
260 | ret_splice = splice(ctx->consumer_thread_pipe[0], NULL, outfd, NULL, | |
261 | ret_splice, SPLICE_F_MOVE | SPLICE_F_MORE); | |
262 | DBG("splice pipe to file, ret %zd", ret_splice); | |
263 | if (ret_splice < 0) { | |
3bd1e081 | 264 | perror("Error in file splice"); |
47e81c02 | 265 | if (written == 0) { |
00e2e675 | 266 | written = ret_splice; |
47e81c02 MD |
267 | } |
268 | ret = errno; | |
269 | goto splice_error; | |
270 | } | |
00e2e675 | 271 | if (ret_splice > len) { |
47e81c02 | 272 | errno = EINVAL; |
00e2e675 DG |
273 | PERROR("Wrote more data than requested %zd (len: %lu)", |
274 | ret_splice, len); | |
275 | written += ret_splice; | |
47e81c02 | 276 | ret = errno; |
3bd1e081 MD |
277 | goto splice_error; |
278 | } | |
00e2e675 DG |
279 | len -= ret_splice; |
280 | ||
281 | /* This call is useless on a socket so better save a syscall. */ | |
282 | if (!relayd) { | |
283 | /* This won't block, but will start writeout asynchronously */ | |
284 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret_splice, | |
285 | SYNC_FILE_RANGE_WRITE); | |
286 | stream->out_fd_offset += ret_splice; | |
287 | } | |
288 | written += ret_splice; | |
3bd1e081 MD |
289 | } |
290 | lttng_consumer_sync_trace_file(stream, orig_offset); | |
291 | ||
00e2e675 DG |
292 | ret = ret_splice; |
293 | ||
3bd1e081 MD |
294 | goto end; |
295 | ||
296 | splice_error: | |
297 | /* send the appropriate error description to sessiond */ | |
47e81c02 | 298 | switch (ret) { |
3bd1e081 MD |
299 | case EBADF: |
300 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF); | |
301 | break; | |
302 | case EINVAL: | |
303 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EINVAL); | |
304 | break; | |
305 | case ENOMEM: | |
306 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ENOMEM); | |
307 | break; | |
308 | case ESPIPE: | |
309 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ESPIPE); | |
310 | break; | |
311 | } | |
312 | ||
313 | end: | |
00e2e675 DG |
314 | if (relayd && stream->metadata_flag) { |
315 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
316 | } | |
317 | ||
318 | rcu_read_unlock(); | |
319 | ||
47e81c02 | 320 | return written; |
3bd1e081 MD |
321 | } |
322 | ||
323 | /* | |
324 | * Take a snapshot for a specific fd | |
325 | * | |
326 | * Returns 0 on success, < 0 on error | |
327 | */ | |
328 | int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, | |
329 | struct lttng_consumer_stream *stream) | |
330 | { | |
331 | int ret = 0; | |
332 | int infd = stream->wait_fd; | |
333 | ||
334 | ret = kernctl_snapshot(infd); | |
335 | if (ret != 0) { | |
87dc6a9c | 336 | errno = -ret; |
3bd1e081 MD |
337 | perror("Getting sub-buffer snapshot."); |
338 | } | |
339 | ||
340 | return ret; | |
341 | } | |
342 | ||
343 | /* | |
344 | * Get the produced position | |
345 | * | |
346 | * Returns 0 on success, < 0 on error | |
347 | */ | |
348 | int lttng_kconsumer_get_produced_snapshot( | |
349 | struct lttng_consumer_local_data *ctx, | |
350 | struct lttng_consumer_stream *stream, | |
351 | unsigned long *pos) | |
352 | { | |
353 | int ret; | |
354 | int infd = stream->wait_fd; | |
355 | ||
356 | ret = kernctl_snapshot_get_produced(infd, pos); | |
357 | if (ret != 0) { | |
87dc6a9c | 358 | errno = -ret; |
3bd1e081 MD |
359 | perror("kernctl_snapshot_get_produced"); |
360 | } | |
361 | ||
362 | return ret; | |
363 | } | |
364 | ||
365 | int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, | |
366 | int sock, struct pollfd *consumer_sockpoll) | |
367 | { | |
368 | ssize_t ret; | |
369 | struct lttcomm_consumer_msg msg; | |
370 | ||
371 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); | |
372 | if (ret != sizeof(msg)) { | |
f2fc6720 | 373 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_CMD); |
3bd1e081 MD |
374 | return ret; |
375 | } | |
376 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { | |
377 | return -ENOENT; | |
378 | } | |
379 | ||
380 | switch (msg.cmd_type) { | |
00e2e675 DG |
381 | case LTTNG_CONSUMER_ADD_RELAYD_SOCKET: |
382 | { | |
383 | int fd; | |
384 | struct consumer_relayd_sock_pair *relayd; | |
385 | ||
386 | DBG("Consumer adding relayd socket"); | |
387 | ||
388 | /* Get relayd reference if exists. */ | |
389 | relayd = consumer_find_relayd(msg.u.relayd_sock.net_index); | |
390 | if (relayd == NULL) { | |
391 | /* Not found. Allocate one. */ | |
392 | relayd = consumer_allocate_relayd_sock_pair( | |
393 | msg.u.relayd_sock.net_index); | |
394 | if (relayd == NULL) { | |
395 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
396 | goto end_nosignal; | |
397 | } | |
398 | } | |
399 | ||
400 | /* Poll on consumer socket. */ | |
401 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
402 | return -EINTR; | |
403 | } | |
404 | ||
405 | /* Get relayd socket from session daemon */ | |
406 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); | |
407 | if (ret != sizeof(fd)) { | |
408 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); | |
409 | goto end_nosignal; | |
410 | } | |
411 | ||
412 | /* Copy socket information and received FD */ | |
413 | switch (msg.u.relayd_sock.type) { | |
414 | case LTTNG_STREAM_CONTROL: | |
415 | /* Copy received lttcomm socket */ | |
416 | lttcomm_copy_sock(&relayd->control_sock, &msg.u.relayd_sock.sock); | |
417 | ||
418 | ret = lttcomm_create_sock(&relayd->control_sock); | |
419 | if (ret < 0) { | |
420 | goto end_nosignal; | |
421 | } | |
422 | ||
423 | /* Close the created socket fd which is useless */ | |
424 | close(relayd->control_sock.fd); | |
425 | ||
426 | /* Assign new file descriptor */ | |
427 | relayd->control_sock.fd = fd; | |
428 | break; | |
429 | case LTTNG_STREAM_DATA: | |
430 | /* Copy received lttcomm socket */ | |
431 | lttcomm_copy_sock(&relayd->data_sock, &msg.u.relayd_sock.sock); | |
432 | ret = lttcomm_create_sock(&relayd->data_sock); | |
433 | if (ret < 0) { | |
434 | goto end_nosignal; | |
435 | } | |
436 | ||
437 | /* Close the created socket fd which is useless */ | |
438 | close(relayd->data_sock.fd); | |
439 | ||
440 | /* Assign new file descriptor */ | |
441 | relayd->data_sock.fd = fd; | |
442 | break; | |
443 | default: | |
444 | ERR("Unknown relayd socket type"); | |
445 | goto end_nosignal; | |
446 | } | |
447 | ||
448 | DBG("Consumer %s socket created successfully with net idx %d (fd: %d)", | |
449 | msg.u.relayd_sock.type == LTTNG_STREAM_CONTROL ? "control" : "data", | |
450 | relayd->net_seq_idx, fd); | |
451 | ||
452 | /* | |
453 | * Add relayd socket pair to consumer data hashtable. If object already | |
454 | * exists or on error, the function gracefully returns. | |
455 | */ | |
456 | consumer_add_relayd(relayd); | |
457 | ||
458 | goto end_nosignal; | |
459 | } | |
3bd1e081 MD |
460 | case LTTNG_CONSUMER_ADD_CHANNEL: |
461 | { | |
462 | struct lttng_consumer_channel *new_channel; | |
463 | ||
464 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); | |
465 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, | |
466 | -1, -1, | |
467 | msg.u.channel.mmap_len, | |
468 | msg.u.channel.max_sb_size); | |
469 | if (new_channel == NULL) { | |
470 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
471 | goto end_nosignal; | |
472 | } | |
473 | if (ctx->on_recv_channel != NULL) { | |
474 | ret = ctx->on_recv_channel(new_channel); | |
475 | if (ret == 0) { | |
476 | consumer_add_channel(new_channel); | |
477 | } else if (ret < 0) { | |
478 | goto end_nosignal; | |
479 | } | |
480 | } else { | |
481 | consumer_add_channel(new_channel); | |
482 | } | |
483 | goto end_nosignal; | |
484 | } | |
485 | case LTTNG_CONSUMER_ADD_STREAM: | |
486 | { | |
f2fc6720 | 487 | int fd; |
00e2e675 DG |
488 | struct consumer_relayd_sock_pair *relayd = NULL; |
489 | struct lttng_consumer_stream *new_stream; | |
3bd1e081 MD |
490 | |
491 | /* block */ | |
492 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
493 | return -EINTR; | |
494 | } | |
00e2e675 DG |
495 | |
496 | /* Get stream file descriptor from socket */ | |
f2fc6720 MD |
497 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
498 | if (ret != sizeof(fd)) { | |
3bd1e081 MD |
499 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
500 | return ret; | |
501 | } | |
3bd1e081 | 502 | |
3bd1e081 MD |
503 | new_stream = consumer_allocate_stream(msg.u.stream.channel_key, |
504 | msg.u.stream.stream_key, | |
f2fc6720 | 505 | fd, fd, |
3bd1e081 MD |
506 | msg.u.stream.state, |
507 | msg.u.stream.mmap_len, | |
508 | msg.u.stream.output, | |
6df2e2c9 MD |
509 | msg.u.stream.path_name, |
510 | msg.u.stream.uid, | |
00e2e675 DG |
511 | msg.u.stream.gid, |
512 | msg.u.stream.net_index, | |
513 | msg.u.stream.metadata_flag); | |
3bd1e081 MD |
514 | if (new_stream == NULL) { |
515 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
516 | goto end; | |
517 | } | |
00e2e675 DG |
518 | |
519 | /* The stream is not metadata. Get relayd reference if exists. */ | |
520 | relayd = consumer_find_relayd(msg.u.stream.net_index); | |
521 | if (relayd != NULL) { | |
522 | /* Add stream on the relayd */ | |
523 | pthread_mutex_lock(&relayd->ctrl_sock_mutex); | |
524 | ret = relayd_add_stream(&relayd->control_sock, | |
525 | msg.u.stream.name, msg.u.stream.path_name, | |
526 | &new_stream->relayd_stream_id); | |
527 | pthread_mutex_unlock(&relayd->ctrl_sock_mutex); | |
528 | if (ret < 0) { | |
529 | goto end; | |
530 | } | |
531 | } else if (msg.u.stream.net_index != -1) { | |
532 | ERR("Network sequence index %d unknown. Not adding stream.", | |
533 | msg.u.stream.net_index); | |
534 | free(new_stream); | |
535 | goto end; | |
536 | } | |
537 | ||
3bd1e081 MD |
538 | if (ctx->on_recv_stream != NULL) { |
539 | ret = ctx->on_recv_stream(new_stream); | |
540 | if (ret == 0) { | |
541 | consumer_add_stream(new_stream); | |
542 | } else if (ret < 0) { | |
543 | goto end; | |
544 | } | |
545 | } else { | |
546 | consumer_add_stream(new_stream); | |
547 | } | |
00e2e675 DG |
548 | |
549 | DBG("Kernel consumer_add_stream (%d)", fd); | |
3bd1e081 MD |
550 | break; |
551 | } | |
552 | case LTTNG_CONSUMER_UPDATE_STREAM: | |
553 | { | |
554 | if (ctx->on_update_stream != NULL) { | |
555 | ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); | |
556 | if (ret == 0) { | |
557 | consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); | |
558 | } else if (ret < 0) { | |
559 | goto end; | |
560 | } | |
561 | } else { | |
562 | consumer_change_stream_state(msg.u.stream.stream_key, | |
563 | msg.u.stream.state); | |
564 | } | |
565 | break; | |
566 | } | |
567 | default: | |
568 | break; | |
569 | } | |
570 | end: | |
04fdd819 MD |
571 | /* |
572 | * Wake-up the other end by writing a null byte in the pipe | |
573 | * (non-blocking). Important note: Because writing into the | |
574 | * pipe is non-blocking (and therefore we allow dropping wakeup | |
575 | * data, as long as there is wakeup data present in the pipe | |
576 | * buffer to wake up the other end), the other end should | |
577 | * perform the following sequence for waiting: | |
578 | * 1) empty the pipe (reads). | |
579 | * 2) perform update operation. | |
580 | * 3) wait on the pipe (poll). | |
581 | */ | |
582 | do { | |
583 | ret = write(ctx->consumer_poll_pipe[1], "", 1); | |
584 | } while (ret == -1UL && errno == EINTR); | |
3bd1e081 MD |
585 | end_nosignal: |
586 | return 0; | |
587 | } | |
d41f73b7 MD |
588 | |
589 | /* | |
590 | * Consume data on a file descriptor and write it on a trace file. | |
591 | */ | |
4078b776 | 592 | ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
d41f73b7 MD |
593 | struct lttng_consumer_local_data *ctx) |
594 | { | |
595 | unsigned long len; | |
596 | int err; | |
4078b776 | 597 | ssize_t ret = 0; |
d41f73b7 MD |
598 | int infd = stream->wait_fd; |
599 | ||
600 | DBG("In read_subbuffer (infd : %d)", infd); | |
601 | /* Get the next subbuffer */ | |
602 | err = kernctl_get_next_subbuf(infd); | |
603 | if (err != 0) { | |
d41f73b7 MD |
604 | /* |
605 | * This is a debug message even for single-threaded consumer, | |
606 | * because poll() have more relaxed criterions than get subbuf, | |
607 | * so get_subbuf may fail for short race windows where poll() | |
608 | * would issue wakeups. | |
609 | */ | |
610 | DBG("Reserving sub buffer failed (everything is normal, " | |
611 | "it is due to concurrency)"); | |
612 | goto end; | |
613 | } | |
614 | ||
615 | switch (stream->output) { | |
616 | case LTTNG_EVENT_SPLICE: | |
617 | /* read the whole subbuffer */ | |
618 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
619 | if (err != 0) { | |
87dc6a9c | 620 | errno = -ret; |
d41f73b7 MD |
621 | perror("Getting sub-buffer len failed."); |
622 | goto end; | |
623 | } | |
624 | ||
625 | /* splice the subbuffer to the tracefile */ | |
626 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len); | |
47e81c02 | 627 | if (ret != len) { |
d41f73b7 MD |
628 | /* |
629 | * display the error but continue processing to try | |
630 | * to release the subbuffer | |
631 | */ | |
00e2e675 DG |
632 | ERR("Error splicing to tracefile (ret: %ld != len: %ld)", |
633 | ret, len); | |
d41f73b7 | 634 | } |
47e81c02 | 635 | |
d41f73b7 MD |
636 | break; |
637 | case LTTNG_EVENT_MMAP: | |
638 | /* read the used subbuffer size */ | |
639 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
640 | if (err != 0) { | |
87dc6a9c | 641 | errno = -ret; |
d41f73b7 MD |
642 | perror("Getting sub-buffer len failed."); |
643 | goto end; | |
644 | } | |
645 | /* write the subbuffer to the tracefile */ | |
646 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); | |
47e81c02 | 647 | if (ret != len) { |
d41f73b7 MD |
648 | /* |
649 | * display the error but continue processing to try | |
650 | * to release the subbuffer | |
651 | */ | |
652 | ERR("Error writing to tracefile"); | |
653 | } | |
654 | break; | |
655 | default: | |
656 | ERR("Unknown output method"); | |
657 | ret = -1; | |
658 | } | |
659 | ||
660 | err = kernctl_put_next_subbuf(infd); | |
661 | if (err != 0) { | |
87dc6a9c | 662 | errno = -ret; |
d41f73b7 MD |
663 | if (errno == EFAULT) { |
664 | perror("Error in unreserving sub buffer\n"); | |
665 | } else if (errno == EIO) { | |
666 | /* Should never happen with newer LTTng versions */ | |
667 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
668 | } | |
669 | goto end; | |
670 | } | |
671 | ||
672 | end: | |
673 | return ret; | |
674 | } | |
675 | ||
676 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
677 | { | |
678 | int ret; | |
679 | ||
680 | /* Opening the tracefile in write mode */ | |
00e2e675 | 681 | if (strlen(stream->path_name) > 0 && stream->net_seq_idx == -1) { |
e11d277b | 682 | ret = run_as_open(stream->path_name, |
60b6c79c MD |
683 | O_WRONLY|O_CREAT|O_TRUNC, |
684 | S_IRWXU|S_IRWXG|S_IRWXO, | |
685 | stream->uid, stream->gid); | |
d41f73b7 MD |
686 | if (ret < 0) { |
687 | ERR("Opening %s", stream->path_name); | |
688 | perror("open"); | |
689 | goto error; | |
690 | } | |
691 | stream->out_fd = ret; | |
692 | } | |
693 | ||
694 | if (stream->output == LTTNG_EVENT_MMAP) { | |
695 | /* get the len of the mmap region */ | |
696 | unsigned long mmap_len; | |
697 | ||
698 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); | |
699 | if (ret != 0) { | |
87dc6a9c | 700 | errno = -ret; |
d41f73b7 MD |
701 | perror("kernctl_get_mmap_len"); |
702 | goto error_close_fd; | |
703 | } | |
704 | stream->mmap_len = (size_t) mmap_len; | |
705 | ||
706 | stream->mmap_base = mmap(NULL, stream->mmap_len, | |
707 | PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); | |
708 | if (stream->mmap_base == MAP_FAILED) { | |
709 | perror("Error mmaping"); | |
710 | ret = -1; | |
711 | goto error_close_fd; | |
712 | } | |
713 | } | |
714 | ||
715 | /* we return 0 to let the library handle the FD internally */ | |
716 | return 0; | |
717 | ||
718 | error_close_fd: | |
719 | { | |
720 | int err; | |
721 | ||
722 | err = close(stream->out_fd); | |
723 | assert(!err); | |
724 | } | |
725 | error: | |
726 | return ret; | |
727 | } | |
728 |