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> |
dbb5dfe6 | 34 | #include <common/compat/fcntl.h> |
0857097f | 35 | |
10a8a223 | 36 | #include "kernel-consumer.h" |
3bd1e081 MD |
37 | |
38 | extern struct lttng_consumer_global_data consumer_data; | |
39 | extern int consumer_poll_timeout; | |
40 | extern volatile int consumer_quit; | |
41 | ||
42 | /* | |
43 | * Mmap the ring buffer, read it and write the data to the tracefile. | |
44 | * | |
45 | * Returns the number of bytes written | |
46 | */ | |
4078b776 | 47 | ssize_t lttng_kconsumer_on_read_subbuffer_mmap( |
3bd1e081 MD |
48 | struct lttng_consumer_local_data *ctx, |
49 | struct lttng_consumer_stream *stream, unsigned long len) | |
50 | { | |
51 | unsigned long mmap_offset; | |
4078b776 | 52 | ssize_t ret = 0; |
3bd1e081 MD |
53 | off_t orig_offset = stream->out_fd_offset; |
54 | int fd = stream->wait_fd; | |
55 | int outfd = stream->out_fd; | |
56 | ||
57 | /* get the offset inside the fd to mmap */ | |
58 | ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); | |
59 | if (ret != 0) { | |
87dc6a9c | 60 | errno = -ret; |
3bd1e081 MD |
61 | perror("kernctl_get_mmap_read_offset"); |
62 | goto end; | |
63 | } | |
64 | ||
65 | while (len > 0) { | |
66 | ret = write(outfd, stream->mmap_base + mmap_offset, len); | |
67 | if (ret >= len) { | |
68 | len = 0; | |
69 | } else if (ret < 0) { | |
87dc6a9c | 70 | errno = -ret; |
3bd1e081 MD |
71 | perror("Error in file write"); |
72 | goto end; | |
73 | } | |
74 | /* This won't block, but will start writeout asynchronously */ | |
dbb5dfe6 | 75 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret, |
3bd1e081 MD |
76 | SYNC_FILE_RANGE_WRITE); |
77 | stream->out_fd_offset += ret; | |
78 | } | |
79 | ||
80 | lttng_consumer_sync_trace_file(stream, orig_offset); | |
81 | ||
82 | goto end; | |
83 | ||
84 | end: | |
85 | return ret; | |
86 | } | |
87 | ||
88 | /* | |
89 | * Splice the data from the ring buffer to the tracefile. | |
90 | * | |
91 | * Returns the number of bytes spliced. | |
92 | */ | |
4078b776 | 93 | ssize_t lttng_kconsumer_on_read_subbuffer_splice( |
3bd1e081 MD |
94 | struct lttng_consumer_local_data *ctx, |
95 | struct lttng_consumer_stream *stream, unsigned long len) | |
96 | { | |
4078b776 | 97 | ssize_t ret = 0; |
3bd1e081 MD |
98 | loff_t offset = 0; |
99 | off_t orig_offset = stream->out_fd_offset; | |
100 | int fd = stream->wait_fd; | |
101 | int outfd = stream->out_fd; | |
102 | ||
103 | while (len > 0) { | |
104 | DBG("splice chan to pipe offset %lu (fd : %d)", | |
105 | (unsigned long)offset, fd); | |
106 | ret = splice(fd, &offset, ctx->consumer_thread_pipe[1], NULL, len, | |
107 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
630543f2 | 108 | DBG("splice chan to pipe ret %zd", ret); |
3bd1e081 | 109 | if (ret < 0) { |
87dc6a9c | 110 | errno = -ret; |
3bd1e081 MD |
111 | perror("Error in relay splice"); |
112 | goto splice_error; | |
113 | } | |
114 | ||
115 | ret = splice(ctx->consumer_thread_pipe[0], NULL, outfd, NULL, ret, | |
116 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
630543f2 | 117 | DBG("splice pipe to file %zd", ret); |
3bd1e081 | 118 | if (ret < 0) { |
87dc6a9c | 119 | errno = -ret; |
3bd1e081 MD |
120 | perror("Error in file splice"); |
121 | goto splice_error; | |
122 | } | |
123 | len -= ret; | |
124 | /* This won't block, but will start writeout asynchronously */ | |
dbb5dfe6 | 125 | lttng_sync_file_range(outfd, stream->out_fd_offset, ret, |
3bd1e081 MD |
126 | SYNC_FILE_RANGE_WRITE); |
127 | stream->out_fd_offset += ret; | |
128 | } | |
129 | lttng_consumer_sync_trace_file(stream, orig_offset); | |
130 | ||
131 | goto end; | |
132 | ||
133 | splice_error: | |
134 | /* send the appropriate error description to sessiond */ | |
135 | switch(ret) { | |
136 | case EBADF: | |
137 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EBADF); | |
138 | break; | |
139 | case EINVAL: | |
140 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_EINVAL); | |
141 | break; | |
142 | case ENOMEM: | |
143 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ENOMEM); | |
144 | break; | |
145 | case ESPIPE: | |
146 | lttng_consumer_send_error(ctx, CONSUMERD_SPLICE_ESPIPE); | |
147 | break; | |
148 | } | |
149 | ||
150 | end: | |
151 | return ret; | |
152 | } | |
153 | ||
154 | /* | |
155 | * Take a snapshot for a specific fd | |
156 | * | |
157 | * Returns 0 on success, < 0 on error | |
158 | */ | |
159 | int lttng_kconsumer_take_snapshot(struct lttng_consumer_local_data *ctx, | |
160 | struct lttng_consumer_stream *stream) | |
161 | { | |
162 | int ret = 0; | |
163 | int infd = stream->wait_fd; | |
164 | ||
165 | ret = kernctl_snapshot(infd); | |
166 | if (ret != 0) { | |
87dc6a9c | 167 | errno = -ret; |
3bd1e081 MD |
168 | perror("Getting sub-buffer snapshot."); |
169 | } | |
170 | ||
171 | return ret; | |
172 | } | |
173 | ||
174 | /* | |
175 | * Get the produced position | |
176 | * | |
177 | * Returns 0 on success, < 0 on error | |
178 | */ | |
179 | int lttng_kconsumer_get_produced_snapshot( | |
180 | struct lttng_consumer_local_data *ctx, | |
181 | struct lttng_consumer_stream *stream, | |
182 | unsigned long *pos) | |
183 | { | |
184 | int ret; | |
185 | int infd = stream->wait_fd; | |
186 | ||
187 | ret = kernctl_snapshot_get_produced(infd, pos); | |
188 | if (ret != 0) { | |
87dc6a9c | 189 | errno = -ret; |
3bd1e081 MD |
190 | perror("kernctl_snapshot_get_produced"); |
191 | } | |
192 | ||
193 | return ret; | |
194 | } | |
195 | ||
196 | int lttng_kconsumer_recv_cmd(struct lttng_consumer_local_data *ctx, | |
197 | int sock, struct pollfd *consumer_sockpoll) | |
198 | { | |
199 | ssize_t ret; | |
200 | struct lttcomm_consumer_msg msg; | |
201 | ||
202 | ret = lttcomm_recv_unix_sock(sock, &msg, sizeof(msg)); | |
203 | if (ret != sizeof(msg)) { | |
f2fc6720 | 204 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_CMD); |
3bd1e081 MD |
205 | return ret; |
206 | } | |
207 | if (msg.cmd_type == LTTNG_CONSUMER_STOP) { | |
208 | return -ENOENT; | |
209 | } | |
210 | ||
211 | switch (msg.cmd_type) { | |
212 | case LTTNG_CONSUMER_ADD_CHANNEL: | |
213 | { | |
214 | struct lttng_consumer_channel *new_channel; | |
215 | ||
216 | DBG("consumer_add_channel %d", msg.u.channel.channel_key); | |
217 | new_channel = consumer_allocate_channel(msg.u.channel.channel_key, | |
218 | -1, -1, | |
219 | msg.u.channel.mmap_len, | |
220 | msg.u.channel.max_sb_size); | |
221 | if (new_channel == NULL) { | |
222 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
223 | goto end_nosignal; | |
224 | } | |
225 | if (ctx->on_recv_channel != NULL) { | |
226 | ret = ctx->on_recv_channel(new_channel); | |
227 | if (ret == 0) { | |
228 | consumer_add_channel(new_channel); | |
229 | } else if (ret < 0) { | |
230 | goto end_nosignal; | |
231 | } | |
232 | } else { | |
233 | consumer_add_channel(new_channel); | |
234 | } | |
235 | goto end_nosignal; | |
236 | } | |
237 | case LTTNG_CONSUMER_ADD_STREAM: | |
238 | { | |
239 | struct lttng_consumer_stream *new_stream; | |
f2fc6720 | 240 | int fd; |
3bd1e081 MD |
241 | |
242 | /* block */ | |
243 | if (lttng_consumer_poll_socket(consumer_sockpoll) < 0) { | |
244 | return -EINTR; | |
245 | } | |
f2fc6720 MD |
246 | ret = lttcomm_recv_fds_unix_sock(sock, &fd, 1); |
247 | if (ret != sizeof(fd)) { | |
3bd1e081 MD |
248 | lttng_consumer_send_error(ctx, CONSUMERD_ERROR_RECV_FD); |
249 | return ret; | |
250 | } | |
3bd1e081 | 251 | |
f2fc6720 MD |
252 | DBG("consumer_add_stream %s (%d)", msg.u.stream.path_name, |
253 | fd); | |
3bd1e081 MD |
254 | new_stream = consumer_allocate_stream(msg.u.stream.channel_key, |
255 | msg.u.stream.stream_key, | |
f2fc6720 | 256 | fd, fd, |
3bd1e081 MD |
257 | msg.u.stream.state, |
258 | msg.u.stream.mmap_len, | |
259 | msg.u.stream.output, | |
6df2e2c9 MD |
260 | msg.u.stream.path_name, |
261 | msg.u.stream.uid, | |
262 | msg.u.stream.gid); | |
3bd1e081 MD |
263 | if (new_stream == NULL) { |
264 | lttng_consumer_send_error(ctx, CONSUMERD_OUTFD_ERROR); | |
265 | goto end; | |
266 | } | |
267 | if (ctx->on_recv_stream != NULL) { | |
268 | ret = ctx->on_recv_stream(new_stream); | |
269 | if (ret == 0) { | |
270 | consumer_add_stream(new_stream); | |
271 | } else if (ret < 0) { | |
272 | goto end; | |
273 | } | |
274 | } else { | |
275 | consumer_add_stream(new_stream); | |
276 | } | |
277 | break; | |
278 | } | |
279 | case LTTNG_CONSUMER_UPDATE_STREAM: | |
280 | { | |
281 | if (ctx->on_update_stream != NULL) { | |
282 | ret = ctx->on_update_stream(msg.u.stream.stream_key, msg.u.stream.state); | |
283 | if (ret == 0) { | |
284 | consumer_change_stream_state(msg.u.stream.stream_key, msg.u.stream.state); | |
285 | } else if (ret < 0) { | |
286 | goto end; | |
287 | } | |
288 | } else { | |
289 | consumer_change_stream_state(msg.u.stream.stream_key, | |
290 | msg.u.stream.state); | |
291 | } | |
292 | break; | |
293 | } | |
294 | default: | |
295 | break; | |
296 | } | |
297 | end: | |
04fdd819 MD |
298 | /* |
299 | * Wake-up the other end by writing a null byte in the pipe | |
300 | * (non-blocking). Important note: Because writing into the | |
301 | * pipe is non-blocking (and therefore we allow dropping wakeup | |
302 | * data, as long as there is wakeup data present in the pipe | |
303 | * buffer to wake up the other end), the other end should | |
304 | * perform the following sequence for waiting: | |
305 | * 1) empty the pipe (reads). | |
306 | * 2) perform update operation. | |
307 | * 3) wait on the pipe (poll). | |
308 | */ | |
309 | do { | |
310 | ret = write(ctx->consumer_poll_pipe[1], "", 1); | |
311 | } while (ret == -1UL && errno == EINTR); | |
3bd1e081 MD |
312 | end_nosignal: |
313 | return 0; | |
314 | } | |
d41f73b7 MD |
315 | |
316 | /* | |
317 | * Consume data on a file descriptor and write it on a trace file. | |
318 | */ | |
4078b776 | 319 | ssize_t lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, |
d41f73b7 MD |
320 | struct lttng_consumer_local_data *ctx) |
321 | { | |
322 | unsigned long len; | |
323 | int err; | |
4078b776 | 324 | ssize_t ret = 0; |
d41f73b7 MD |
325 | int infd = stream->wait_fd; |
326 | ||
327 | DBG("In read_subbuffer (infd : %d)", infd); | |
328 | /* Get the next subbuffer */ | |
329 | err = kernctl_get_next_subbuf(infd); | |
330 | if (err != 0) { | |
d41f73b7 MD |
331 | /* |
332 | * This is a debug message even for single-threaded consumer, | |
333 | * because poll() have more relaxed criterions than get subbuf, | |
334 | * so get_subbuf may fail for short race windows where poll() | |
335 | * would issue wakeups. | |
336 | */ | |
337 | DBG("Reserving sub buffer failed (everything is normal, " | |
338 | "it is due to concurrency)"); | |
339 | goto end; | |
340 | } | |
341 | ||
342 | switch (stream->output) { | |
343 | case LTTNG_EVENT_SPLICE: | |
344 | /* read the whole subbuffer */ | |
345 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
346 | if (err != 0) { | |
87dc6a9c | 347 | errno = -ret; |
d41f73b7 MD |
348 | perror("Getting sub-buffer len failed."); |
349 | goto end; | |
350 | } | |
351 | ||
352 | /* splice the subbuffer to the tracefile */ | |
353 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len); | |
354 | if (ret < 0) { | |
355 | /* | |
356 | * display the error but continue processing to try | |
357 | * to release the subbuffer | |
358 | */ | |
359 | ERR("Error splicing to tracefile"); | |
360 | } | |
361 | break; | |
362 | case LTTNG_EVENT_MMAP: | |
363 | /* read the used subbuffer size */ | |
364 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
365 | if (err != 0) { | |
87dc6a9c | 366 | errno = -ret; |
d41f73b7 MD |
367 | perror("Getting sub-buffer len failed."); |
368 | goto end; | |
369 | } | |
370 | /* write the subbuffer to the tracefile */ | |
371 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); | |
372 | if (ret < 0) { | |
373 | /* | |
374 | * display the error but continue processing to try | |
375 | * to release the subbuffer | |
376 | */ | |
377 | ERR("Error writing to tracefile"); | |
378 | } | |
379 | break; | |
380 | default: | |
381 | ERR("Unknown output method"); | |
382 | ret = -1; | |
383 | } | |
384 | ||
385 | err = kernctl_put_next_subbuf(infd); | |
386 | if (err != 0) { | |
87dc6a9c | 387 | errno = -ret; |
d41f73b7 MD |
388 | if (errno == EFAULT) { |
389 | perror("Error in unreserving sub buffer\n"); | |
390 | } else if (errno == EIO) { | |
391 | /* Should never happen with newer LTTng versions */ | |
392 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
393 | } | |
394 | goto end; | |
395 | } | |
396 | ||
397 | end: | |
398 | return ret; | |
399 | } | |
400 | ||
401 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
402 | { | |
403 | int ret; | |
404 | ||
405 | /* Opening the tracefile in write mode */ | |
406 | if (stream->path_name != NULL) { | |
e11d277b | 407 | ret = run_as_open(stream->path_name, |
60b6c79c MD |
408 | O_WRONLY|O_CREAT|O_TRUNC, |
409 | S_IRWXU|S_IRWXG|S_IRWXO, | |
410 | stream->uid, stream->gid); | |
d41f73b7 MD |
411 | if (ret < 0) { |
412 | ERR("Opening %s", stream->path_name); | |
413 | perror("open"); | |
414 | goto error; | |
415 | } | |
416 | stream->out_fd = ret; | |
417 | } | |
418 | ||
419 | if (stream->output == LTTNG_EVENT_MMAP) { | |
420 | /* get the len of the mmap region */ | |
421 | unsigned long mmap_len; | |
422 | ||
423 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); | |
424 | if (ret != 0) { | |
87dc6a9c | 425 | errno = -ret; |
d41f73b7 MD |
426 | perror("kernctl_get_mmap_len"); |
427 | goto error_close_fd; | |
428 | } | |
429 | stream->mmap_len = (size_t) mmap_len; | |
430 | ||
431 | stream->mmap_base = mmap(NULL, stream->mmap_len, | |
432 | PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); | |
433 | if (stream->mmap_base == MAP_FAILED) { | |
434 | perror("Error mmaping"); | |
435 | ret = -1; | |
436 | goto error_close_fd; | |
437 | } | |
438 | } | |
439 | ||
440 | /* we return 0 to let the library handle the FD internally */ | |
441 | return 0; | |
442 | ||
443 | error_close_fd: | |
444 | { | |
445 | int err; | |
446 | ||
447 | err = close(stream->out_fd); | |
448 | assert(!err); | |
449 | } | |
450 | error: | |
451 | return ret; | |
452 | } | |
453 |