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 | * | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; only version 2 | |
8 | * of the License. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, | |
11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | * GNU General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | */ | |
19 | ||
20 | #define _GNU_SOURCE | |
21 | #include <assert.h> | |
ca4537d3 | 22 | #include <fcntl.h> |
3bd1e081 MD |
23 | #include <poll.h> |
24 | #include <pthread.h> | |
25 | #include <stdlib.h> | |
26 | #include <string.h> | |
27 | #include <sys/mman.h> | |
28 | #include <sys/socket.h> | |
29 | #include <sys/types.h> | |
30 | #include <unistd.h> | |
31 | ||
990570ed | 32 | #include <common/common.h> |
10a8a223 | 33 | #include <common/kernel-ctl/kernel-ctl.h> |
10a8a223 | 34 | #include <common/sessiond-comm/sessiond-comm.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 | */ | |
47 | int lttng_kconsumer_on_read_subbuffer_mmap( | |
48 | struct lttng_consumer_local_data *ctx, | |
49 | struct lttng_consumer_stream *stream, unsigned long len) | |
50 | { | |
51 | unsigned long mmap_offset; | |
52 | long ret = 0; | |
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) { | |
6bf73bf5 | 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) { | |
6bf73bf5 | 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 */ | |
ca4537d3 | 75 | 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 | */ | |
93 | int lttng_kconsumer_on_read_subbuffer_splice( | |
94 | struct lttng_consumer_local_data *ctx, | |
95 | struct lttng_consumer_stream *stream, unsigned long len) | |
96 | { | |
97 | long ret = 0; | |
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); | |
108 | DBG("splice chan to pipe ret %ld", ret); | |
109 | if (ret < 0) { | |
6bf73bf5 | 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); | |
117 | DBG("splice pipe to file %ld", ret); | |
118 | if (ret < 0) { | |
6bf73bf5 | 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 */ | |
ca4537d3 | 125 | 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) { | |
6bf73bf5 | 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) { | |
6bf73bf5 | 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: | |
298 | /* signal the poll thread */ | |
299 | ret = write(ctx->consumer_poll_pipe[1], "4", 1); | |
300 | if (ret < 0) { | |
301 | perror("write consumer poll"); | |
302 | } | |
303 | end_nosignal: | |
304 | return 0; | |
305 | } | |
d41f73b7 MD |
306 | |
307 | /* | |
308 | * Consume data on a file descriptor and write it on a trace file. | |
309 | */ | |
310 | int lttng_kconsumer_read_subbuffer(struct lttng_consumer_stream *stream, | |
311 | struct lttng_consumer_local_data *ctx) | |
312 | { | |
313 | unsigned long len; | |
314 | int err; | |
315 | long ret = 0; | |
316 | int infd = stream->wait_fd; | |
317 | ||
318 | DBG("In read_subbuffer (infd : %d)", infd); | |
319 | /* Get the next subbuffer */ | |
320 | err = kernctl_get_next_subbuf(infd); | |
321 | if (err != 0) { | |
d41f73b7 MD |
322 | /* |
323 | * This is a debug message even for single-threaded consumer, | |
324 | * because poll() have more relaxed criterions than get subbuf, | |
325 | * so get_subbuf may fail for short race windows where poll() | |
326 | * would issue wakeups. | |
327 | */ | |
328 | DBG("Reserving sub buffer failed (everything is normal, " | |
329 | "it is due to concurrency)"); | |
330 | goto end; | |
331 | } | |
332 | ||
333 | switch (stream->output) { | |
334 | case LTTNG_EVENT_SPLICE: | |
335 | /* read the whole subbuffer */ | |
336 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
337 | if (err != 0) { | |
6bf73bf5 | 338 | errno = -ret; |
d41f73b7 MD |
339 | perror("Getting sub-buffer len failed."); |
340 | goto end; | |
341 | } | |
342 | ||
343 | /* splice the subbuffer to the tracefile */ | |
344 | ret = lttng_consumer_on_read_subbuffer_splice(ctx, stream, len); | |
345 | if (ret < 0) { | |
346 | /* | |
347 | * display the error but continue processing to try | |
348 | * to release the subbuffer | |
349 | */ | |
350 | ERR("Error splicing to tracefile"); | |
351 | } | |
352 | break; | |
353 | case LTTNG_EVENT_MMAP: | |
354 | /* read the used subbuffer size */ | |
355 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
356 | if (err != 0) { | |
6bf73bf5 | 357 | errno = -ret; |
d41f73b7 MD |
358 | perror("Getting sub-buffer len failed."); |
359 | goto end; | |
360 | } | |
361 | /* write the subbuffer to the tracefile */ | |
362 | ret = lttng_consumer_on_read_subbuffer_mmap(ctx, stream, len); | |
363 | if (ret < 0) { | |
364 | /* | |
365 | * display the error but continue processing to try | |
366 | * to release the subbuffer | |
367 | */ | |
368 | ERR("Error writing to tracefile"); | |
369 | } | |
370 | break; | |
371 | default: | |
372 | ERR("Unknown output method"); | |
373 | ret = -1; | |
374 | } | |
375 | ||
376 | err = kernctl_put_next_subbuf(infd); | |
377 | if (err != 0) { | |
6bf73bf5 | 378 | errno = -ret; |
d41f73b7 MD |
379 | if (errno == EFAULT) { |
380 | perror("Error in unreserving sub buffer\n"); | |
381 | } else if (errno == EIO) { | |
382 | /* Should never happen with newer LTTng versions */ | |
383 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
384 | } | |
385 | goto end; | |
386 | } | |
387 | ||
388 | end: | |
389 | return ret; | |
390 | } | |
391 | ||
392 | int lttng_kconsumer_on_recv_stream(struct lttng_consumer_stream *stream) | |
393 | { | |
394 | int ret; | |
395 | ||
396 | /* Opening the tracefile in write mode */ | |
397 | if (stream->path_name != NULL) { | |
e11d277b | 398 | ret = run_as_open(stream->path_name, |
60b6c79c MD |
399 | O_WRONLY|O_CREAT|O_TRUNC, |
400 | S_IRWXU|S_IRWXG|S_IRWXO, | |
401 | stream->uid, stream->gid); | |
d41f73b7 MD |
402 | if (ret < 0) { |
403 | ERR("Opening %s", stream->path_name); | |
404 | perror("open"); | |
405 | goto error; | |
406 | } | |
407 | stream->out_fd = ret; | |
408 | } | |
409 | ||
410 | if (stream->output == LTTNG_EVENT_MMAP) { | |
411 | /* get the len of the mmap region */ | |
412 | unsigned long mmap_len; | |
413 | ||
414 | ret = kernctl_get_mmap_len(stream->wait_fd, &mmap_len); | |
415 | if (ret != 0) { | |
6bf73bf5 | 416 | errno = -ret; |
d41f73b7 MD |
417 | perror("kernctl_get_mmap_len"); |
418 | goto error_close_fd; | |
419 | } | |
420 | stream->mmap_len = (size_t) mmap_len; | |
421 | ||
422 | stream->mmap_base = mmap(NULL, stream->mmap_len, | |
423 | PROT_READ, MAP_PRIVATE, stream->wait_fd, 0); | |
424 | if (stream->mmap_base == MAP_FAILED) { | |
425 | perror("Error mmaping"); | |
426 | ret = -1; | |
427 | goto error_close_fd; | |
428 | } | |
429 | } | |
430 | ||
431 | /* we return 0 to let the library handle the FD internally */ | |
432 | return 0; | |
433 | ||
434 | error_close_fd: | |
435 | { | |
436 | int err; | |
437 | ||
438 | err = close(stream->out_fd); | |
439 | assert(!err); | |
440 | } | |
441 | error: | |
442 | return ret; | |
443 | } | |
444 |