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1ce86c9a JD |
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; either version 2 | |
8 | * of the License, or (at your option) any later version. | |
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 <fcntl.h> | |
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> | |
28 | #include <sys/types.h> | |
29 | #include <unistd.h> | |
30 | #include <urcu/list.h> | |
31 | ||
32 | #include "libkernelctl.h" | |
33 | #include "liblttkconsumerd.h" | |
34 | #include "lttngerr.h" | |
35 | ||
36 | /* Init the list of FDs */ | |
37 | static struct kconsumerd_fd_list kconsumerd_fd_list = { | |
38 | .head = CDS_LIST_HEAD_INIT(kconsumerd_fd_list.head), | |
39 | }; | |
40 | ||
41 | /* Number of element for the list below. */ | |
42 | static unsigned int kconsumerd_fds_count; | |
43 | ||
44 | /* If the local array of FDs needs update in the poll function */ | |
45 | static unsigned int kconsumerd_update_fd_array = 1; | |
46 | ||
47 | /* lock the fd array and structures */ | |
48 | static pthread_mutex_t kconsumerd_lock_fds; | |
49 | ||
50 | /* communication with splice */ | |
51 | static int kconsumerd_thread_pipe[2]; | |
52 | ||
53 | /* pipe to wake the poll thread when necessary */ | |
54 | static int kconsumerd_poll_pipe[2]; | |
55 | ||
56 | /* timeout parameter, to control the polling thread grace period */ | |
57 | static int kconsumerd_poll_timeout = -1; | |
58 | ||
59 | /* socket to communicate errors with sessiond */ | |
60 | static int kconsumerd_error_socket; | |
61 | ||
62 | /* socket to exchange commands with sessiond */ | |
63 | static char *kconsumerd_command_sock_path; | |
64 | ||
65 | /* flag to inform the polling thread to kconsumerd_quit when all fd hung up */ | |
66 | static int kconsumerd_quit = 0; | |
67 | ||
68 | /* | |
69 | * kconsumerd_set_error_socket | |
70 | * | |
71 | * Set the error socket | |
72 | */ | |
73 | void kconsumerd_set_error_socket(int sock) | |
74 | { | |
75 | kconsumerd_error_socket = sock; | |
76 | } | |
77 | ||
78 | /* | |
79 | * kconsumerd_set_command_socket_path | |
80 | * | |
81 | * Set the command socket path | |
82 | */ | |
83 | void kconsumerd_set_command_socket_path(char *sock) | |
84 | { | |
85 | kconsumerd_command_sock_path = sock; | |
86 | } | |
87 | ||
38079a1b DG |
88 | /* |
89 | * kconsumerd_find_session_fd | |
90 | * | |
91 | * Find a session fd in the global list. | |
92 | * | |
93 | * Return 1 if found else 0 | |
94 | */ | |
95 | static int kconsumerd_find_session_fd(int fd) | |
96 | { | |
97 | struct kconsumerd_fd *iter; | |
98 | ||
99 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
100 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
101 | if (iter->sessiond_fd == fd) { | |
102 | DBG("Duplicate session fd %d", fd); | |
103 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
104 | return 1; | |
105 | } | |
106 | } | |
107 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
108 | ||
109 | return 0; | |
110 | } | |
111 | ||
1ce86c9a JD |
112 | /* |
113 | * kconsumerd_del_fd | |
114 | * | |
115 | * Remove a fd from the global list protected by a mutex | |
116 | */ | |
117 | static void kconsumerd_del_fd(struct kconsumerd_fd *lcf) | |
118 | { | |
119 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
120 | cds_list_del(&lcf->list); | |
121 | if (kconsumerd_fds_count > 0) { | |
122 | kconsumerd_fds_count--; | |
123 | if (lcf != NULL) { | |
124 | close(lcf->out_fd); | |
125 | close(lcf->consumerd_fd); | |
126 | free(lcf); | |
127 | lcf = NULL; | |
128 | } | |
129 | } | |
130 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
131 | } | |
132 | ||
133 | /* | |
134 | * kconsumerd_add_fd | |
135 | * | |
136 | * Add a fd to the global list protected by a mutex | |
137 | */ | |
138 | static int kconsumerd_add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd) | |
139 | { | |
1ce86c9a | 140 | int ret; |
38079a1b DG |
141 | struct kconsumerd_fd *tmp_fd; |
142 | ||
143 | /* Check if already exist */ | |
144 | ret = kconsumerd_find_session_fd(buf->fd); | |
145 | if (ret == 1) { | |
146 | goto end; | |
147 | } | |
1ce86c9a JD |
148 | |
149 | tmp_fd = malloc(sizeof(struct kconsumerd_fd)); | |
150 | tmp_fd->sessiond_fd = buf->fd; | |
151 | tmp_fd->consumerd_fd = consumerd_fd; | |
152 | tmp_fd->state = buf->state; | |
153 | tmp_fd->max_sb_size = buf->max_sb_size; | |
154 | strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX); | |
155 | ||
156 | /* Opening the tracefile in write mode */ | |
157 | ret = open(tmp_fd->path_name, | |
158 | O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO); | |
159 | if (ret < 0) { | |
160 | ERR("Opening %s", tmp_fd->path_name); | |
161 | perror("open"); | |
162 | goto end; | |
163 | } | |
164 | tmp_fd->out_fd = ret; | |
165 | tmp_fd->out_fd_offset = 0; | |
166 | ||
167 | DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name, | |
168 | tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd); | |
169 | ||
170 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
171 | cds_list_add(&tmp_fd->list, &kconsumerd_fd_list.head); | |
172 | kconsumerd_fds_count++; | |
173 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
174 | ||
175 | end: | |
176 | return ret; | |
177 | } | |
178 | ||
179 | /* | |
180 | * kconsumerd_change_fd_state | |
181 | * | |
182 | * Update a fd according to what we just received | |
183 | */ | |
184 | static void kconsumerd_change_fd_state(int sessiond_fd, | |
185 | enum kconsumerd_fd_state state) | |
186 | { | |
187 | struct kconsumerd_fd *iter; | |
0237248c DG |
188 | |
189 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
1ce86c9a JD |
190 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { |
191 | if (iter->sessiond_fd == sessiond_fd) { | |
192 | iter->state = state; | |
193 | break; | |
194 | } | |
195 | } | |
0237248c | 196 | pthread_mutex_unlock(&kconsumerd_lock_fds); |
1ce86c9a JD |
197 | } |
198 | ||
199 | /* | |
200 | * kconsumerd_update_poll_array | |
201 | * | |
202 | * Allocate the pollfd structure and the local view of the out fds | |
203 | * to avoid doing a lookup in the linked list and concurrency issues | |
204 | * when writing is needed. | |
205 | * Returns the number of fds in the structures | |
206 | */ | |
207 | static int kconsumerd_update_poll_array(struct pollfd **pollfd, | |
208 | struct kconsumerd_fd **local_kconsumerd_fd) | |
209 | { | |
210 | struct kconsumerd_fd *iter; | |
211 | int i = 0; | |
212 | ||
213 | DBG("Updating poll fd array"); | |
1ce86c9a JD |
214 | |
215 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
216 | DBG("Inside for each"); | |
217 | if (iter->state == ACTIVE_FD) { | |
218 | DBG("Active FD %d", iter->consumerd_fd); | |
219 | (*pollfd)[i].fd = iter->consumerd_fd; | |
220 | (*pollfd)[i].events = POLLIN | POLLPRI; | |
221 | local_kconsumerd_fd[i] = iter; | |
222 | i++; | |
223 | } | |
224 | } | |
225 | ||
226 | /* | |
227 | * insert the kconsumerd_poll_pipe at the end of the array and don't | |
228 | * increment i so nb_fd is the number of real FD | |
229 | */ | |
230 | (*pollfd)[i].fd = kconsumerd_poll_pipe[0]; | |
231 | (*pollfd)[i].events = POLLIN; | |
232 | ||
233 | kconsumerd_update_fd_array = 0; | |
1ce86c9a JD |
234 | return i; |
235 | } | |
236 | ||
237 | ||
238 | /* | |
239 | * kconsumerd_on_read_subbuffer_mmap | |
240 | * | |
241 | * mmap the ring buffer, read it and write the data to the tracefile. | |
242 | * Returns the number of bytes written | |
243 | */ | |
244 | static int kconsumerd_on_read_subbuffer_mmap( | |
245 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
246 | { | |
247 | unsigned long mmap_len, mmap_offset, padded_len, padding_len; | |
248 | char *mmap_base; | |
249 | char *padding = NULL; | |
250 | long ret = 0; | |
251 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
252 | int fd = kconsumerd_fd->consumerd_fd; | |
253 | int outfd = kconsumerd_fd->out_fd; | |
254 | ||
255 | /* get the padded subbuffer size to know the padding required */ | |
256 | ret = kernctl_get_padded_subbuf_size(fd, &padded_len); | |
257 | if (ret != 0) { | |
258 | ret = errno; | |
259 | perror("kernctl_get_padded_subbuf_size"); | |
260 | goto end; | |
261 | } | |
262 | padding_len = padded_len - len; | |
263 | padding = malloc(padding_len * sizeof(char)); | |
264 | memset(padding, '\0', padding_len); | |
265 | ||
266 | /* get the len of the mmap region */ | |
267 | ret = kernctl_get_mmap_len(fd, &mmap_len); | |
268 | if (ret != 0) { | |
269 | ret = errno; | |
270 | perror("kernctl_get_mmap_len"); | |
271 | goto end; | |
272 | } | |
273 | ||
274 | /* get the offset inside the fd to mmap */ | |
275 | ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); | |
276 | if (ret != 0) { | |
277 | ret = errno; | |
278 | perror("kernctl_get_mmap_read_offset"); | |
279 | goto end; | |
280 | } | |
281 | ||
282 | mmap_base = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, mmap_offset); | |
283 | if (mmap_base == MAP_FAILED) { | |
284 | perror("Error mmaping"); | |
285 | ret = -1; | |
286 | goto end; | |
287 | } | |
288 | ||
289 | while (len > 0) { | |
290 | ret = write(outfd, mmap_base, len); | |
291 | if (ret >= len) { | |
292 | len = 0; | |
293 | } else if (ret < 0) { | |
294 | ret = errno; | |
295 | perror("Error in file write"); | |
296 | goto end; | |
297 | } | |
298 | /* This won't block, but will start writeout asynchronously */ | |
299 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
300 | SYNC_FILE_RANGE_WRITE); | |
301 | kconsumerd_fd->out_fd_offset += ret; | |
302 | } | |
303 | ||
304 | /* once all the data is written, write the padding to disk */ | |
305 | ret = write(outfd, padding, padding_len); | |
306 | if (ret < 0) { | |
307 | ret = errno; | |
308 | perror("Error writing padding to file"); | |
309 | goto end; | |
310 | } | |
311 | ||
312 | /* | |
313 | * This does a blocking write-and-wait on any page that belongs to the | |
314 | * subbuffer prior to the one we just wrote. | |
315 | * Don't care about error values, as these are just hints and ways to | |
316 | * limit the amount of page cache used. | |
317 | */ | |
318 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
319 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
320 | kconsumerd_fd->max_sb_size, | |
321 | SYNC_FILE_RANGE_WAIT_BEFORE | |
322 | | SYNC_FILE_RANGE_WRITE | |
323 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
324 | ||
325 | /* | |
326 | * Give hints to the kernel about how we access the file: | |
327 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
328 | * we write it. | |
329 | * | |
330 | * We need to call fadvise again after the file grows because the | |
331 | * kernel does not seem to apply fadvise to non-existing parts of the | |
332 | * file. | |
333 | * | |
334 | * Call fadvise _after_ having waited for the page writeback to | |
335 | * complete because the dirty page writeback semantic is not well | |
336 | * defined. So it can be expected to lead to lower throughput in | |
337 | * streaming. | |
338 | */ | |
339 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
340 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
341 | } | |
342 | goto end; | |
343 | ||
344 | end: | |
345 | if (padding != NULL) { | |
346 | free(padding); | |
347 | } | |
348 | return ret; | |
349 | } | |
350 | ||
351 | /* | |
352 | * kconsumerd_on_read_subbuffer | |
353 | * | |
354 | * Splice the data from the ring buffer to the tracefile. | |
355 | * Returns the number of bytes spliced | |
356 | */ | |
357 | static int kconsumerd_on_read_subbuffer( | |
358 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
359 | { | |
360 | long ret = 0; | |
361 | loff_t offset = 0; | |
362 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
363 | int fd = kconsumerd_fd->consumerd_fd; | |
364 | int outfd = kconsumerd_fd->out_fd; | |
365 | ||
366 | while (len > 0) { | |
367 | DBG("splice chan to pipe offset %lu (fd : %d)", | |
368 | (unsigned long)offset, fd); | |
369 | ret = splice(fd, &offset, kconsumerd_thread_pipe[1], NULL, len, | |
370 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
371 | DBG("splice chan to pipe ret %ld", ret); | |
372 | if (ret < 0) { | |
373 | ret = errno; | |
374 | perror("Error in relay splice"); | |
375 | goto splice_error; | |
376 | } | |
377 | ||
378 | ret = splice(kconsumerd_thread_pipe[0], NULL, outfd, NULL, ret, | |
379 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
380 | DBG("splice pipe to file %ld", ret); | |
381 | if (ret < 0) { | |
382 | ret = errno; | |
383 | perror("Error in file splice"); | |
384 | goto splice_error; | |
385 | } | |
386 | if (ret >= len) { | |
387 | len = 0; | |
388 | } | |
389 | /* This won't block, but will start writeout asynchronously */ | |
390 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
391 | SYNC_FILE_RANGE_WRITE); | |
392 | kconsumerd_fd->out_fd_offset += ret; | |
393 | } | |
394 | ||
395 | /* | |
396 | * This does a blocking write-and-wait on any page that belongs to the | |
397 | * subbuffer prior to the one we just wrote. | |
398 | * Don't care about error values, as these are just hints and ways to | |
399 | * limit the amount of page cache used. | |
400 | */ | |
401 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
402 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
403 | kconsumerd_fd->max_sb_size, | |
404 | SYNC_FILE_RANGE_WAIT_BEFORE | |
405 | | SYNC_FILE_RANGE_WRITE | |
406 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
407 | /* | |
408 | * Give hints to the kernel about how we access the file: | |
409 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
410 | * we write it. | |
411 | * | |
412 | * We need to call fadvise again after the file grows because the | |
413 | * kernel does not seem to apply fadvise to non-existing parts of the | |
414 | * file. | |
415 | * | |
416 | * Call fadvise _after_ having waited for the page writeback to | |
417 | * complete because the dirty page writeback semantic is not well | |
418 | * defined. So it can be expected to lead to lower throughput in | |
419 | * streaming. | |
420 | */ | |
421 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
422 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
423 | } | |
424 | goto end; | |
425 | ||
426 | splice_error: | |
427 | /* send the appropriate error description to sessiond */ | |
428 | switch(ret) { | |
429 | case EBADF: | |
430 | kconsumerd_send_error(KCONSUMERD_SPLICE_EBADF); | |
431 | break; | |
432 | case EINVAL: | |
433 | kconsumerd_send_error(KCONSUMERD_SPLICE_EINVAL); | |
434 | break; | |
435 | case ENOMEM: | |
436 | kconsumerd_send_error(KCONSUMERD_SPLICE_ENOMEM); | |
437 | break; | |
438 | case ESPIPE: | |
439 | kconsumerd_send_error(KCONSUMERD_SPLICE_ESPIPE); | |
440 | break; | |
441 | } | |
442 | ||
443 | end: | |
444 | return ret; | |
445 | } | |
446 | ||
447 | /* | |
448 | * kconsumerd_read_subbuffer | |
449 | * | |
450 | * Consume data on a file descriptor and write it on a trace file | |
451 | */ | |
452 | static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) | |
453 | { | |
454 | unsigned long len; | |
455 | int err; | |
456 | long ret = 0; | |
457 | int infd = kconsumerd_fd->consumerd_fd; | |
458 | ||
459 | DBG("In kconsumerd_read_subbuffer (infd : %d)", infd); | |
460 | /* Get the next subbuffer */ | |
461 | err = kernctl_get_next_subbuf(infd); | |
462 | if (err != 0) { | |
463 | ret = errno; | |
464 | perror("Reserving sub buffer failed (everything is normal, " | |
465 | "it is due to concurrency)"); | |
466 | goto end; | |
467 | } | |
468 | ||
469 | switch (DEFAULT_KERNEL_CHANNEL_OUTPUT) { | |
470 | case LTTNG_KERNEL_SPLICE: | |
471 | /* read the whole subbuffer */ | |
472 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
473 | if (err != 0) { | |
474 | ret = errno; | |
475 | perror("Getting sub-buffer len failed."); | |
476 | goto end; | |
477 | } | |
478 | ||
479 | /* splice the subbuffer to the tracefile */ | |
480 | ret = kconsumerd_on_read_subbuffer(kconsumerd_fd, len); | |
481 | if (ret < 0) { | |
482 | /* | |
483 | * display the error but continue processing to try | |
484 | * to release the subbuffer | |
485 | */ | |
486 | ERR("Error splicing to tracefile"); | |
487 | } | |
488 | break; | |
489 | case LTTNG_KERNEL_MMAP: | |
490 | /* read the used subbuffer size */ | |
491 | err = kernctl_get_subbuf_size(infd, &len); | |
492 | if (err != 0) { | |
493 | ret = errno; | |
494 | perror("Getting sub-buffer len failed."); | |
495 | goto end; | |
496 | } | |
497 | /* write the subbuffer to the tracefile */ | |
498 | ret = kconsumerd_on_read_subbuffer_mmap(kconsumerd_fd, len); | |
499 | if (ret < 0) { | |
500 | /* | |
501 | * display the error but continue processing to try | |
502 | * to release the subbuffer | |
503 | */ | |
504 | ERR("Error writing to tracefile"); | |
505 | } | |
506 | break; | |
507 | default: | |
508 | ERR("Unknown output method"); | |
509 | ret = -1; | |
510 | } | |
511 | ||
512 | err = kernctl_put_next_subbuf(infd); | |
513 | if (err != 0) { | |
514 | ret = errno; | |
515 | if (errno == EFAULT) { | |
516 | perror("Error in unreserving sub buffer\n"); | |
517 | } else if (errno == EIO) { | |
518 | /* Should never happen with newer LTTng versions */ | |
519 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
520 | } | |
521 | goto end; | |
522 | } | |
523 | ||
524 | end: | |
525 | return ret; | |
526 | } | |
527 | ||
528 | /* | |
529 | * kconsumerd_consumerd_recv_fd | |
530 | * | |
531 | * Receives an array of file descriptors and the associated | |
532 | * structures describing each fd (path name). | |
533 | * Returns the size of received data | |
534 | */ | |
535 | static int kconsumerd_consumerd_recv_fd(int sfd, int size, | |
536 | enum kconsumerd_command cmd_type) | |
537 | { | |
538 | struct msghdr msg; | |
539 | struct iovec iov[1]; | |
540 | int ret = 0, i, tmp2; | |
541 | struct cmsghdr *cmsg; | |
542 | int nb_fd; | |
543 | char recv_fd[CMSG_SPACE(sizeof(int))]; | |
544 | struct lttcomm_kconsumerd_msg lkm; | |
545 | ||
546 | /* the number of fds we are about to receive */ | |
547 | nb_fd = size / sizeof(struct lttcomm_kconsumerd_msg); | |
548 | ||
549 | for (i = 0; i < nb_fd; i++) { | |
550 | memset(&msg, 0, sizeof(msg)); | |
551 | ||
552 | /* Prepare to receive the structures */ | |
553 | iov[0].iov_base = &lkm; | |
554 | iov[0].iov_len = sizeof(lkm); | |
555 | msg.msg_iov = iov; | |
556 | msg.msg_iovlen = 1; | |
557 | ||
558 | msg.msg_control = recv_fd; | |
559 | msg.msg_controllen = sizeof(recv_fd); | |
560 | ||
561 | DBG("Waiting to receive fd"); | |
562 | if ((ret = recvmsg(sfd, &msg, 0)) < 0) { | |
563 | perror("recvmsg"); | |
564 | continue; | |
565 | } | |
566 | ||
567 | if (ret != (size / nb_fd)) { | |
568 | ERR("Received only %d, expected %d", ret, size); | |
569 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
570 | goto end; | |
571 | } | |
572 | ||
573 | cmsg = CMSG_FIRSTHDR(&msg); | |
574 | if (!cmsg) { | |
575 | ERR("Invalid control message header"); | |
576 | ret = -1; | |
577 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
578 | goto end; | |
579 | } | |
580 | /* if we received fds */ | |
581 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { | |
582 | switch (cmd_type) { | |
583 | case ADD_STREAM: | |
584 | DBG("kconsumerd_add_fd %s (%d)", lkm.path_name, (CMSG_DATA(cmsg)[0])); | |
585 | ret = kconsumerd_add_fd(&lkm, (CMSG_DATA(cmsg)[0])); | |
586 | if (ret < 0) { | |
587 | kconsumerd_send_error(KCONSUMERD_OUTFD_ERROR); | |
588 | goto end; | |
589 | } | |
590 | break; | |
591 | case UPDATE_STREAM: | |
592 | kconsumerd_change_fd_state(lkm.fd, lkm.state); | |
593 | break; | |
594 | default: | |
595 | break; | |
596 | } | |
597 | /* flag to tell the polling thread to update its fd array */ | |
598 | kconsumerd_update_fd_array = 1; | |
599 | /* signal the poll thread */ | |
600 | tmp2 = write(kconsumerd_poll_pipe[1], "4", 1); | |
601 | } else { | |
602 | ERR("Didn't received any fd"); | |
603 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
604 | ret = -1; | |
605 | goto end; | |
606 | } | |
607 | } | |
608 | ||
609 | end: | |
1ce86c9a JD |
610 | return ret; |
611 | } | |
612 | ||
613 | /* | |
614 | * kconsumerd_thread_poll_fds | |
615 | * | |
616 | * This thread polls the fds in the ltt_fd_list to consume the data | |
617 | * and write it to tracefile if necessary. | |
618 | */ | |
619 | void *kconsumerd_thread_poll_fds(void *data) | |
620 | { | |
621 | int num_rdy, num_hup, high_prio, ret, i; | |
622 | struct pollfd *pollfd = NULL; | |
623 | /* local view of the fds */ | |
624 | struct kconsumerd_fd **local_kconsumerd_fd = NULL; | |
625 | /* local view of kconsumerd_fds_count */ | |
626 | int nb_fd = 0; | |
627 | char tmp; | |
628 | int tmp2; | |
629 | ||
630 | ret = pipe(kconsumerd_thread_pipe); | |
631 | if (ret < 0) { | |
632 | perror("Error creating pipe"); | |
633 | goto end; | |
634 | } | |
635 | ||
636 | local_kconsumerd_fd = malloc(sizeof(struct kconsumerd_fd)); | |
637 | ||
638 | while (1) { | |
639 | high_prio = 0; | |
640 | num_hup = 0; | |
641 | ||
642 | /* | |
643 | * the ltt_fd_list has been updated, we need to update our | |
644 | * local array as well | |
645 | */ | |
646 | if (kconsumerd_update_fd_array == 1) { | |
647 | if (pollfd != NULL) { | |
648 | free(pollfd); | |
649 | pollfd = NULL; | |
650 | } | |
651 | if (local_kconsumerd_fd != NULL) { | |
652 | free(local_kconsumerd_fd); | |
653 | local_kconsumerd_fd = NULL; | |
654 | } | |
0237248c DG |
655 | |
656 | /* Lock mutex for fds count */ | |
657 | pthread_mutex_lock(&kconsumerd_lock_fds); | |
1ce86c9a JD |
658 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ |
659 | pollfd = malloc((kconsumerd_fds_count + 1) * sizeof(struct pollfd)); | |
660 | if (pollfd == NULL) { | |
661 | perror("pollfd malloc"); | |
662 | goto end; | |
663 | } | |
0237248c | 664 | |
1ce86c9a JD |
665 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ |
666 | local_kconsumerd_fd = malloc((kconsumerd_fds_count + 1) * | |
667 | sizeof(struct kconsumerd_fd)); | |
668 | if (local_kconsumerd_fd == NULL) { | |
669 | perror("local_kconsumerd_fd malloc"); | |
670 | goto end; | |
671 | } | |
672 | ret = kconsumerd_update_poll_array(&pollfd, local_kconsumerd_fd); | |
673 | if (ret < 0) { | |
674 | ERR("Error in allocating pollfd or local_outfds"); | |
675 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
676 | goto end; | |
677 | } | |
0237248c DG |
678 | /* Unlock mutex for fds count */ |
679 | pthread_mutex_unlock(&kconsumerd_lock_fds); | |
680 | ||
1ce86c9a JD |
681 | nb_fd = ret; |
682 | } | |
683 | ||
684 | /* poll on the array of fds */ | |
685 | DBG("polling on %d fd", nb_fd + 1); | |
686 | num_rdy = poll(pollfd, nb_fd + 1, kconsumerd_poll_timeout); | |
687 | DBG("poll num_rdy : %d", num_rdy); | |
688 | if (num_rdy == -1) { | |
689 | perror("Poll error"); | |
690 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
691 | goto end; | |
692 | } else if (num_rdy == 0) { | |
693 | DBG("Polling thread timed out"); | |
694 | goto end; | |
695 | } | |
696 | ||
697 | /* No FDs and kconsumerd_quit, kconsumerd_cleanup the thread */ | |
698 | if (nb_fd == 0 && kconsumerd_quit == 1) { | |
699 | goto end; | |
700 | } | |
701 | ||
702 | /* | |
703 | * if only the kconsumerd_poll_pipe triggered poll to return just | |
704 | * return to the beginning of the loop to update the array | |
705 | */ | |
706 | if (num_rdy == 1 && pollfd[nb_fd].revents == POLLIN) { | |
707 | DBG("kconsumerd_poll_pipe wake up"); | |
708 | tmp2 = read(kconsumerd_poll_pipe[0], &tmp, 1); | |
709 | continue; | |
710 | } | |
711 | ||
712 | /* Take care of high priority channels first. */ | |
713 | for (i = 0; i < nb_fd; i++) { | |
714 | switch(pollfd[i].revents) { | |
715 | case POLLERR: | |
716 | ERR("Error returned in polling fd %d.", pollfd[i].fd); | |
717 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
718 | kconsumerd_update_fd_array = 1; | |
719 | num_hup++; | |
720 | break; | |
721 | case POLLHUP: | |
722 | DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); | |
723 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
724 | kconsumerd_update_fd_array = 1; | |
725 | num_hup++; | |
726 | break; | |
727 | case POLLNVAL: | |
728 | ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); | |
729 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
730 | kconsumerd_update_fd_array = 1; | |
731 | num_hup++; | |
732 | break; | |
733 | case POLLPRI: | |
734 | DBG("Urgent read on fd %d", pollfd[i].fd); | |
735 | high_prio = 1; | |
736 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
737 | /* it's ok to have an unavailable sub-buffer */ | |
738 | if (ret == EAGAIN) { | |
739 | ret = 0; | |
740 | } | |
741 | break; | |
742 | } | |
743 | } | |
744 | ||
745 | /* If every buffer FD has hung up, we end the read loop here */ | |
746 | if (nb_fd > 0 && num_hup == nb_fd) { | |
747 | DBG("every buffer FD has hung up\n"); | |
748 | if (kconsumerd_quit == 1) { | |
749 | goto end; | |
750 | } | |
751 | continue; | |
752 | } | |
753 | ||
754 | /* Take care of low priority channels. */ | |
755 | if (high_prio == 0) { | |
756 | for (i = 0; i < nb_fd; i++) { | |
757 | if (pollfd[i].revents == POLLIN) { | |
758 | DBG("Normal read on fd %d", pollfd[i].fd); | |
759 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
760 | /* it's ok to have an unavailable subbuffer */ | |
761 | if (ret == EAGAIN) { | |
762 | ret = 0; | |
763 | } | |
764 | } | |
765 | } | |
766 | } | |
767 | } | |
768 | end: | |
0237248c | 769 | pthread_mutex_unlock(&kconsumerd_lock_fds); |
1ce86c9a JD |
770 | DBG("polling thread exiting"); |
771 | if (pollfd != NULL) { | |
772 | free(pollfd); | |
773 | pollfd = NULL; | |
774 | } | |
775 | if (local_kconsumerd_fd != NULL) { | |
776 | free(local_kconsumerd_fd); | |
777 | local_kconsumerd_fd = NULL; | |
778 | } | |
779 | kconsumerd_cleanup(); | |
780 | return NULL; | |
781 | } | |
782 | ||
783 | /* | |
784 | * kconsumerd_create_poll_pipe | |
785 | * | |
786 | * create the pipe to wake to polling thread when needed | |
787 | */ | |
788 | int kconsumerd_create_poll_pipe() | |
789 | { | |
790 | return pipe(kconsumerd_poll_pipe); | |
791 | } | |
792 | ||
793 | /* | |
794 | * kconsumerd_thread_receive_fds | |
795 | * | |
796 | * This thread listens on the consumerd socket and | |
797 | * receives the file descriptors from ltt-sessiond | |
798 | */ | |
799 | void *kconsumerd_thread_receive_fds(void *data) | |
800 | { | |
801 | int sock, client_socket, ret; | |
802 | struct lttcomm_kconsumerd_header tmp; | |
803 | ||
804 | DBG("Creating command socket %s", kconsumerd_command_sock_path); | |
805 | unlink(kconsumerd_command_sock_path); | |
806 | client_socket = lttcomm_create_unix_sock(kconsumerd_command_sock_path); | |
807 | if (client_socket < 0) { | |
808 | ERR("Cannot create command socket"); | |
809 | goto end; | |
810 | } | |
811 | ||
812 | ret = lttcomm_listen_unix_sock(client_socket); | |
813 | if (ret < 0) { | |
814 | goto end; | |
815 | } | |
816 | ||
817 | DBG("Sending ready command to ltt-sessiond"); | |
818 | ret = kconsumerd_send_error(KCONSUMERD_COMMAND_SOCK_READY); | |
819 | if (ret < 0) { | |
820 | ERR("Error sending ready command to ltt-sessiond"); | |
821 | goto end; | |
822 | } | |
823 | ||
824 | /* Blocking call, waiting for transmission */ | |
825 | sock = lttcomm_accept_unix_sock(client_socket); | |
826 | if (sock <= 0) { | |
827 | WARN("On accept"); | |
828 | goto end; | |
829 | } | |
830 | while (1) { | |
831 | /* We first get the number of fd we are about to receive */ | |
832 | ret = lttcomm_recv_unix_sock(sock, &tmp, | |
833 | sizeof(struct lttcomm_kconsumerd_header)); | |
834 | if (ret <= 0) { | |
835 | ERR("Communication interrupted on command socket"); | |
836 | goto end; | |
837 | } | |
838 | if (tmp.cmd_type == STOP) { | |
839 | DBG("Received STOP command"); | |
840 | goto end; | |
841 | } | |
842 | /* we received a command to add or update fds */ | |
843 | ret = kconsumerd_consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type); | |
844 | if (ret <= 0) { | |
845 | ERR("Receiving the FD, exiting"); | |
846 | goto end; | |
847 | } | |
848 | } | |
849 | ||
850 | end: | |
851 | DBG("kconsumerd_thread_receive_fds exiting"); | |
852 | ||
853 | /* | |
854 | * when all fds have hung up, the polling thread | |
855 | * can exit cleanly | |
856 | */ | |
857 | kconsumerd_quit = 1; | |
858 | ||
859 | /* | |
860 | * 2s of grace period, if no polling events occur during | |
861 | * this period, the polling thread will exit even if there | |
862 | * are still open FDs (should not happen, but safety mechanism). | |
863 | */ | |
864 | kconsumerd_poll_timeout = KCONSUMERD_POLL_GRACE_PERIOD; | |
865 | ||
866 | /* wake up the polling thread */ | |
867 | ret = write(kconsumerd_poll_pipe[1], "4", 1); | |
868 | if (ret < 0) { | |
869 | perror("poll pipe write"); | |
870 | } | |
871 | return NULL; | |
872 | } | |
873 | ||
874 | /* | |
875 | * kconsumerd_cleanup | |
876 | * | |
877 | * Cleanup the daemon's socket on exit | |
878 | */ | |
879 | void kconsumerd_cleanup() | |
880 | { | |
881 | struct kconsumerd_fd *iter; | |
882 | ||
883 | /* remove the socket file */ | |
884 | unlink(kconsumerd_command_sock_path); | |
885 | ||
886 | /* close all outfd */ | |
887 | cds_list_for_each_entry(iter, &kconsumerd_fd_list.head, list) { | |
888 | kconsumerd_del_fd(iter); | |
889 | } | |
890 | } | |
891 | ||
892 | /* | |
893 | * kconsumerd_send_error | |
894 | * | |
895 | * send return code to ltt-sessiond | |
896 | */ | |
897 | int kconsumerd_send_error(enum lttcomm_return_code cmd) | |
898 | { | |
899 | if (kconsumerd_error_socket > 0) { | |
900 | return lttcomm_send_unix_sock(kconsumerd_error_socket, &cmd, | |
901 | sizeof(enum lttcomm_sessiond_command)); | |
902 | } | |
903 | ||
904 | return 0; | |
905 | } |