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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 | ||
242cd187 MD |
36 | static |
37 | struct kconsumerd_global_data { | |
38 | /* | |
39 | * kconsumerd_data.lock protects kconsumerd_data.fd_list, | |
40 | * kconsumerd_data.fds_count, and kconsumerd_data.need_update. It | |
41 | * ensures the count matches the number of items in the fd_list. | |
42 | * It ensures the list updates *always* trigger an fd_array | |
43 | * update (therefore need to make list update vs | |
44 | * kconsumerd_data.need_update flag update atomic, and also flag | |
45 | * read, fd array and flag clear atomic). | |
46 | */ | |
47 | pthread_mutex_t lock; | |
48 | /* | |
49 | * Number of element for the list below. Protected by | |
50 | * kconsumerd_data.lock. | |
51 | */ | |
52 | unsigned int fds_count; | |
53 | /* | |
54 | * List of FDs. Protected by kconsumerd_data.lock. | |
55 | */ | |
56 | struct kconsumerd_fd_list fd_list; | |
57 | /* | |
58 | * Flag specifying if the local array of FDs needs update in the | |
59 | * poll function. Protected by kconsumerd_data.lock. | |
60 | */ | |
61 | unsigned int need_update; | |
62 | } kconsumerd_data = { | |
63 | .fd_list.head = CDS_LIST_HEAD_INIT(kconsumerd_data.fd_list.head), | |
1ce86c9a JD |
64 | }; |
65 | ||
1ce86c9a JD |
66 | /* communication with splice */ |
67 | static int kconsumerd_thread_pipe[2]; | |
68 | ||
69 | /* pipe to wake the poll thread when necessary */ | |
70 | static int kconsumerd_poll_pipe[2]; | |
71 | ||
3dcd2721 MD |
72 | /* |
73 | * TODO: create a should_quit pipe to let the signal handler wake up the | |
74 | * fd receiver thread. It should be initialized before any signal can be | |
75 | * received by the library. | |
76 | */ | |
77 | ||
1ce86c9a JD |
78 | /* timeout parameter, to control the polling thread grace period */ |
79 | static int kconsumerd_poll_timeout = -1; | |
80 | ||
81 | /* socket to communicate errors with sessiond */ | |
82 | static int kconsumerd_error_socket; | |
83 | ||
84 | /* socket to exchange commands with sessiond */ | |
85 | static char *kconsumerd_command_sock_path; | |
86 | ||
3dcd2721 MD |
87 | /* |
88 | * flag to inform the polling thread to quit when all fd hung up. | |
89 | * Updated by the kconsumerd_thread_receive_fds when it notices that all | |
90 | * fds has hung up. Also updated by the signal handler | |
91 | * (kconsumerd_should_exit()). Read by the polling threads. | |
92 | */ | |
93 | static volatile int kconsumerd_quit = 0; | |
1ce86c9a JD |
94 | |
95 | /* | |
96 | * kconsumerd_set_error_socket | |
97 | * | |
98 | * Set the error socket | |
99 | */ | |
100 | void kconsumerd_set_error_socket(int sock) | |
101 | { | |
102 | kconsumerd_error_socket = sock; | |
103 | } | |
104 | ||
105 | /* | |
106 | * kconsumerd_set_command_socket_path | |
107 | * | |
108 | * Set the command socket path | |
109 | */ | |
110 | void kconsumerd_set_command_socket_path(char *sock) | |
111 | { | |
112 | kconsumerd_command_sock_path = sock; | |
113 | } | |
114 | ||
38079a1b DG |
115 | /* |
116 | * kconsumerd_find_session_fd | |
117 | * | |
118 | * Find a session fd in the global list. | |
119 | * | |
120 | * Return 1 if found else 0 | |
121 | */ | |
122 | static int kconsumerd_find_session_fd(int fd) | |
123 | { | |
124 | struct kconsumerd_fd *iter; | |
125 | ||
242cd187 MD |
126 | pthread_mutex_lock(&kconsumerd_data.lock); |
127 | cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { | |
38079a1b DG |
128 | if (iter->sessiond_fd == fd) { |
129 | DBG("Duplicate session fd %d", fd); | |
242cd187 | 130 | pthread_mutex_unlock(&kconsumerd_data.lock); |
38079a1b DG |
131 | return 1; |
132 | } | |
133 | } | |
242cd187 | 134 | pthread_mutex_unlock(&kconsumerd_data.lock); |
38079a1b DG |
135 | |
136 | return 0; | |
137 | } | |
138 | ||
1ce86c9a JD |
139 | /* |
140 | * kconsumerd_del_fd | |
141 | * | |
142 | * Remove a fd from the global list protected by a mutex | |
143 | */ | |
144 | static void kconsumerd_del_fd(struct kconsumerd_fd *lcf) | |
145 | { | |
242cd187 | 146 | pthread_mutex_lock(&kconsumerd_data.lock); |
1ce86c9a | 147 | cds_list_del(&lcf->list); |
242cd187 MD |
148 | if (kconsumerd_data.fds_count > 0) { |
149 | kconsumerd_data.fds_count--; | |
1ce86c9a JD |
150 | if (lcf != NULL) { |
151 | close(lcf->out_fd); | |
152 | close(lcf->consumerd_fd); | |
153 | free(lcf); | |
154 | lcf = NULL; | |
155 | } | |
156 | } | |
242cd187 MD |
157 | kconsumerd_data.need_update = 1; |
158 | pthread_mutex_unlock(&kconsumerd_data.lock); | |
1ce86c9a JD |
159 | } |
160 | ||
161 | /* | |
162 | * kconsumerd_add_fd | |
163 | * | |
164 | * Add a fd to the global list protected by a mutex | |
165 | */ | |
166 | static int kconsumerd_add_fd(struct lttcomm_kconsumerd_msg *buf, int consumerd_fd) | |
167 | { | |
1ce86c9a | 168 | int ret; |
38079a1b DG |
169 | struct kconsumerd_fd *tmp_fd; |
170 | ||
242cd187 | 171 | pthread_mutex_lock(&kconsumerd_data.lock); |
38079a1b DG |
172 | /* Check if already exist */ |
173 | ret = kconsumerd_find_session_fd(buf->fd); | |
174 | if (ret == 1) { | |
175 | goto end; | |
176 | } | |
1ce86c9a JD |
177 | |
178 | tmp_fd = malloc(sizeof(struct kconsumerd_fd)); | |
179 | tmp_fd->sessiond_fd = buf->fd; | |
180 | tmp_fd->consumerd_fd = consumerd_fd; | |
181 | tmp_fd->state = buf->state; | |
182 | tmp_fd->max_sb_size = buf->max_sb_size; | |
183 | strncpy(tmp_fd->path_name, buf->path_name, PATH_MAX); | |
184 | ||
185 | /* Opening the tracefile in write mode */ | |
186 | ret = open(tmp_fd->path_name, | |
187 | O_WRONLY|O_CREAT|O_TRUNC, S_IRWXU|S_IRWXG|S_IRWXO); | |
188 | if (ret < 0) { | |
189 | ERR("Opening %s", tmp_fd->path_name); | |
190 | perror("open"); | |
191 | goto end; | |
192 | } | |
193 | tmp_fd->out_fd = ret; | |
194 | tmp_fd->out_fd_offset = 0; | |
195 | ||
196 | DBG("Adding %s (%d, %d, %d)", tmp_fd->path_name, | |
197 | tmp_fd->sessiond_fd, tmp_fd->consumerd_fd, tmp_fd->out_fd); | |
198 | ||
242cd187 MD |
199 | cds_list_add(&tmp_fd->list, &kconsumerd_data.fd_list.head); |
200 | kconsumerd_data.fds_count++; | |
201 | kconsumerd_data.need_update = 1; | |
1ce86c9a | 202 | end: |
242cd187 | 203 | pthread_mutex_unlock(&kconsumerd_data.lock); |
1ce86c9a JD |
204 | return ret; |
205 | } | |
206 | ||
207 | /* | |
208 | * kconsumerd_change_fd_state | |
209 | * | |
210 | * Update a fd according to what we just received | |
211 | */ | |
212 | static void kconsumerd_change_fd_state(int sessiond_fd, | |
213 | enum kconsumerd_fd_state state) | |
214 | { | |
215 | struct kconsumerd_fd *iter; | |
0237248c | 216 | |
242cd187 MD |
217 | pthread_mutex_lock(&kconsumerd_data.lock); |
218 | cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { | |
1ce86c9a JD |
219 | if (iter->sessiond_fd == sessiond_fd) { |
220 | iter->state = state; | |
221 | break; | |
222 | } | |
223 | } | |
242cd187 MD |
224 | kconsumerd_data.need_update = 1; |
225 | pthread_mutex_unlock(&kconsumerd_data.lock); | |
1ce86c9a JD |
226 | } |
227 | ||
228 | /* | |
229 | * kconsumerd_update_poll_array | |
230 | * | |
231 | * Allocate the pollfd structure and the local view of the out fds | |
232 | * to avoid doing a lookup in the linked list and concurrency issues | |
233 | * when writing is needed. | |
234 | * Returns the number of fds in the structures | |
242cd187 | 235 | * Called with kconsumerd_data.lock held. |
1ce86c9a JD |
236 | */ |
237 | static int kconsumerd_update_poll_array(struct pollfd **pollfd, | |
238 | struct kconsumerd_fd **local_kconsumerd_fd) | |
239 | { | |
240 | struct kconsumerd_fd *iter; | |
241 | int i = 0; | |
242 | ||
243 | DBG("Updating poll fd array"); | |
1ce86c9a | 244 | |
242cd187 | 245 | cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { |
1ce86c9a JD |
246 | DBG("Inside for each"); |
247 | if (iter->state == ACTIVE_FD) { | |
248 | DBG("Active FD %d", iter->consumerd_fd); | |
249 | (*pollfd)[i].fd = iter->consumerd_fd; | |
250 | (*pollfd)[i].events = POLLIN | POLLPRI; | |
251 | local_kconsumerd_fd[i] = iter; | |
252 | i++; | |
253 | } | |
254 | } | |
255 | ||
256 | /* | |
257 | * insert the kconsumerd_poll_pipe at the end of the array and don't | |
258 | * increment i so nb_fd is the number of real FD | |
259 | */ | |
260 | (*pollfd)[i].fd = kconsumerd_poll_pipe[0]; | |
261 | (*pollfd)[i].events = POLLIN; | |
1ce86c9a JD |
262 | return i; |
263 | } | |
264 | ||
265 | ||
266 | /* | |
267 | * kconsumerd_on_read_subbuffer_mmap | |
268 | * | |
269 | * mmap the ring buffer, read it and write the data to the tracefile. | |
270 | * Returns the number of bytes written | |
271 | */ | |
272 | static int kconsumerd_on_read_subbuffer_mmap( | |
273 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
274 | { | |
275 | unsigned long mmap_len, mmap_offset, padded_len, padding_len; | |
276 | char *mmap_base; | |
277 | char *padding = NULL; | |
278 | long ret = 0; | |
279 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
280 | int fd = kconsumerd_fd->consumerd_fd; | |
281 | int outfd = kconsumerd_fd->out_fd; | |
282 | ||
283 | /* get the padded subbuffer size to know the padding required */ | |
284 | ret = kernctl_get_padded_subbuf_size(fd, &padded_len); | |
285 | if (ret != 0) { | |
286 | ret = errno; | |
287 | perror("kernctl_get_padded_subbuf_size"); | |
288 | goto end; | |
289 | } | |
290 | padding_len = padded_len - len; | |
291 | padding = malloc(padding_len * sizeof(char)); | |
292 | memset(padding, '\0', padding_len); | |
293 | ||
294 | /* get the len of the mmap region */ | |
295 | ret = kernctl_get_mmap_len(fd, &mmap_len); | |
296 | if (ret != 0) { | |
297 | ret = errno; | |
298 | perror("kernctl_get_mmap_len"); | |
299 | goto end; | |
300 | } | |
301 | ||
302 | /* get the offset inside the fd to mmap */ | |
303 | ret = kernctl_get_mmap_read_offset(fd, &mmap_offset); | |
304 | if (ret != 0) { | |
305 | ret = errno; | |
306 | perror("kernctl_get_mmap_read_offset"); | |
307 | goto end; | |
308 | } | |
309 | ||
310 | mmap_base = mmap(NULL, mmap_len, PROT_READ, MAP_PRIVATE, fd, mmap_offset); | |
311 | if (mmap_base == MAP_FAILED) { | |
312 | perror("Error mmaping"); | |
313 | ret = -1; | |
314 | goto end; | |
315 | } | |
316 | ||
317 | while (len > 0) { | |
318 | ret = write(outfd, mmap_base, len); | |
319 | if (ret >= len) { | |
320 | len = 0; | |
321 | } else if (ret < 0) { | |
322 | ret = errno; | |
323 | perror("Error in file write"); | |
324 | goto end; | |
325 | } | |
326 | /* This won't block, but will start writeout asynchronously */ | |
327 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
328 | SYNC_FILE_RANGE_WRITE); | |
329 | kconsumerd_fd->out_fd_offset += ret; | |
330 | } | |
331 | ||
332 | /* once all the data is written, write the padding to disk */ | |
333 | ret = write(outfd, padding, padding_len); | |
334 | if (ret < 0) { | |
335 | ret = errno; | |
336 | perror("Error writing padding to file"); | |
337 | goto end; | |
338 | } | |
339 | ||
340 | /* | |
341 | * This does a blocking write-and-wait on any page that belongs to the | |
342 | * subbuffer prior to the one we just wrote. | |
343 | * Don't care about error values, as these are just hints and ways to | |
344 | * limit the amount of page cache used. | |
345 | */ | |
346 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
347 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
348 | kconsumerd_fd->max_sb_size, | |
349 | SYNC_FILE_RANGE_WAIT_BEFORE | |
350 | | SYNC_FILE_RANGE_WRITE | |
351 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
352 | ||
353 | /* | |
354 | * Give hints to the kernel about how we access the file: | |
355 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
356 | * we write it. | |
357 | * | |
358 | * We need to call fadvise again after the file grows because the | |
359 | * kernel does not seem to apply fadvise to non-existing parts of the | |
360 | * file. | |
361 | * | |
362 | * Call fadvise _after_ having waited for the page writeback to | |
363 | * complete because the dirty page writeback semantic is not well | |
364 | * defined. So it can be expected to lead to lower throughput in | |
365 | * streaming. | |
366 | */ | |
367 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
368 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
369 | } | |
370 | goto end; | |
371 | ||
372 | end: | |
373 | if (padding != NULL) { | |
374 | free(padding); | |
375 | } | |
376 | return ret; | |
377 | } | |
378 | ||
379 | /* | |
380 | * kconsumerd_on_read_subbuffer | |
381 | * | |
382 | * Splice the data from the ring buffer to the tracefile. | |
383 | * Returns the number of bytes spliced | |
384 | */ | |
385 | static int kconsumerd_on_read_subbuffer( | |
386 | struct kconsumerd_fd *kconsumerd_fd, unsigned long len) | |
387 | { | |
388 | long ret = 0; | |
389 | loff_t offset = 0; | |
390 | off_t orig_offset = kconsumerd_fd->out_fd_offset; | |
391 | int fd = kconsumerd_fd->consumerd_fd; | |
392 | int outfd = kconsumerd_fd->out_fd; | |
393 | ||
394 | while (len > 0) { | |
395 | DBG("splice chan to pipe offset %lu (fd : %d)", | |
396 | (unsigned long)offset, fd); | |
397 | ret = splice(fd, &offset, kconsumerd_thread_pipe[1], NULL, len, | |
398 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
399 | DBG("splice chan to pipe ret %ld", ret); | |
400 | if (ret < 0) { | |
401 | ret = errno; | |
402 | perror("Error in relay splice"); | |
403 | goto splice_error; | |
404 | } | |
405 | ||
406 | ret = splice(kconsumerd_thread_pipe[0], NULL, outfd, NULL, ret, | |
407 | SPLICE_F_MOVE | SPLICE_F_MORE); | |
408 | DBG("splice pipe to file %ld", ret); | |
409 | if (ret < 0) { | |
410 | ret = errno; | |
411 | perror("Error in file splice"); | |
412 | goto splice_error; | |
413 | } | |
414 | if (ret >= len) { | |
415 | len = 0; | |
416 | } | |
417 | /* This won't block, but will start writeout asynchronously */ | |
418 | sync_file_range(outfd, kconsumerd_fd->out_fd_offset, ret, | |
419 | SYNC_FILE_RANGE_WRITE); | |
420 | kconsumerd_fd->out_fd_offset += ret; | |
421 | } | |
422 | ||
423 | /* | |
424 | * This does a blocking write-and-wait on any page that belongs to the | |
425 | * subbuffer prior to the one we just wrote. | |
426 | * Don't care about error values, as these are just hints and ways to | |
427 | * limit the amount of page cache used. | |
428 | */ | |
429 | if (orig_offset >= kconsumerd_fd->max_sb_size) { | |
430 | sync_file_range(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
431 | kconsumerd_fd->max_sb_size, | |
432 | SYNC_FILE_RANGE_WAIT_BEFORE | |
433 | | SYNC_FILE_RANGE_WRITE | |
434 | | SYNC_FILE_RANGE_WAIT_AFTER); | |
435 | /* | |
436 | * Give hints to the kernel about how we access the file: | |
437 | * POSIX_FADV_DONTNEED : we won't re-access data in a near future after | |
438 | * we write it. | |
439 | * | |
440 | * We need to call fadvise again after the file grows because the | |
441 | * kernel does not seem to apply fadvise to non-existing parts of the | |
442 | * file. | |
443 | * | |
444 | * Call fadvise _after_ having waited for the page writeback to | |
445 | * complete because the dirty page writeback semantic is not well | |
446 | * defined. So it can be expected to lead to lower throughput in | |
447 | * streaming. | |
448 | */ | |
449 | posix_fadvise(outfd, orig_offset - kconsumerd_fd->max_sb_size, | |
450 | kconsumerd_fd->max_sb_size, POSIX_FADV_DONTNEED); | |
451 | } | |
452 | goto end; | |
453 | ||
454 | splice_error: | |
455 | /* send the appropriate error description to sessiond */ | |
456 | switch(ret) { | |
457 | case EBADF: | |
458 | kconsumerd_send_error(KCONSUMERD_SPLICE_EBADF); | |
459 | break; | |
460 | case EINVAL: | |
461 | kconsumerd_send_error(KCONSUMERD_SPLICE_EINVAL); | |
462 | break; | |
463 | case ENOMEM: | |
464 | kconsumerd_send_error(KCONSUMERD_SPLICE_ENOMEM); | |
465 | break; | |
466 | case ESPIPE: | |
467 | kconsumerd_send_error(KCONSUMERD_SPLICE_ESPIPE); | |
468 | break; | |
469 | } | |
470 | ||
471 | end: | |
472 | return ret; | |
473 | } | |
474 | ||
475 | /* | |
476 | * kconsumerd_read_subbuffer | |
477 | * | |
478 | * Consume data on a file descriptor and write it on a trace file | |
479 | */ | |
480 | static int kconsumerd_read_subbuffer(struct kconsumerd_fd *kconsumerd_fd) | |
481 | { | |
482 | unsigned long len; | |
483 | int err; | |
484 | long ret = 0; | |
485 | int infd = kconsumerd_fd->consumerd_fd; | |
486 | ||
487 | DBG("In kconsumerd_read_subbuffer (infd : %d)", infd); | |
488 | /* Get the next subbuffer */ | |
489 | err = kernctl_get_next_subbuf(infd); | |
490 | if (err != 0) { | |
491 | ret = errno; | |
492 | perror("Reserving sub buffer failed (everything is normal, " | |
493 | "it is due to concurrency)"); | |
494 | goto end; | |
495 | } | |
496 | ||
497 | switch (DEFAULT_KERNEL_CHANNEL_OUTPUT) { | |
498 | case LTTNG_KERNEL_SPLICE: | |
499 | /* read the whole subbuffer */ | |
500 | err = kernctl_get_padded_subbuf_size(infd, &len); | |
501 | if (err != 0) { | |
502 | ret = errno; | |
503 | perror("Getting sub-buffer len failed."); | |
504 | goto end; | |
505 | } | |
506 | ||
507 | /* splice the subbuffer to the tracefile */ | |
508 | ret = kconsumerd_on_read_subbuffer(kconsumerd_fd, len); | |
509 | if (ret < 0) { | |
510 | /* | |
511 | * display the error but continue processing to try | |
512 | * to release the subbuffer | |
513 | */ | |
514 | ERR("Error splicing to tracefile"); | |
515 | } | |
516 | break; | |
517 | case LTTNG_KERNEL_MMAP: | |
518 | /* read the used subbuffer size */ | |
519 | err = kernctl_get_subbuf_size(infd, &len); | |
520 | if (err != 0) { | |
521 | ret = errno; | |
522 | perror("Getting sub-buffer len failed."); | |
523 | goto end; | |
524 | } | |
525 | /* write the subbuffer to the tracefile */ | |
526 | ret = kconsumerd_on_read_subbuffer_mmap(kconsumerd_fd, len); | |
527 | if (ret < 0) { | |
528 | /* | |
529 | * display the error but continue processing to try | |
530 | * to release the subbuffer | |
531 | */ | |
532 | ERR("Error writing to tracefile"); | |
533 | } | |
534 | break; | |
535 | default: | |
536 | ERR("Unknown output method"); | |
537 | ret = -1; | |
538 | } | |
539 | ||
540 | err = kernctl_put_next_subbuf(infd); | |
541 | if (err != 0) { | |
542 | ret = errno; | |
543 | if (errno == EFAULT) { | |
544 | perror("Error in unreserving sub buffer\n"); | |
545 | } else if (errno == EIO) { | |
546 | /* Should never happen with newer LTTng versions */ | |
547 | perror("Reader has been pushed by the writer, last sub-buffer corrupted."); | |
548 | } | |
549 | goto end; | |
550 | } | |
551 | ||
552 | end: | |
553 | return ret; | |
554 | } | |
555 | ||
556 | /* | |
557 | * kconsumerd_consumerd_recv_fd | |
558 | * | |
559 | * Receives an array of file descriptors and the associated | |
560 | * structures describing each fd (path name). | |
561 | * Returns the size of received data | |
562 | */ | |
563 | static int kconsumerd_consumerd_recv_fd(int sfd, int size, | |
564 | enum kconsumerd_command cmd_type) | |
565 | { | |
566 | struct msghdr msg; | |
567 | struct iovec iov[1]; | |
568 | int ret = 0, i, tmp2; | |
569 | struct cmsghdr *cmsg; | |
570 | int nb_fd; | |
571 | char recv_fd[CMSG_SPACE(sizeof(int))]; | |
572 | struct lttcomm_kconsumerd_msg lkm; | |
573 | ||
574 | /* the number of fds we are about to receive */ | |
575 | nb_fd = size / sizeof(struct lttcomm_kconsumerd_msg); | |
576 | ||
577 | for (i = 0; i < nb_fd; i++) { | |
578 | memset(&msg, 0, sizeof(msg)); | |
579 | ||
580 | /* Prepare to receive the structures */ | |
581 | iov[0].iov_base = &lkm; | |
582 | iov[0].iov_len = sizeof(lkm); | |
583 | msg.msg_iov = iov; | |
584 | msg.msg_iovlen = 1; | |
585 | ||
586 | msg.msg_control = recv_fd; | |
587 | msg.msg_controllen = sizeof(recv_fd); | |
588 | ||
589 | DBG("Waiting to receive fd"); | |
590 | if ((ret = recvmsg(sfd, &msg, 0)) < 0) { | |
591 | perror("recvmsg"); | |
592 | continue; | |
593 | } | |
594 | ||
595 | if (ret != (size / nb_fd)) { | |
596 | ERR("Received only %d, expected %d", ret, size); | |
597 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
598 | goto end; | |
599 | } | |
600 | ||
601 | cmsg = CMSG_FIRSTHDR(&msg); | |
602 | if (!cmsg) { | |
603 | ERR("Invalid control message header"); | |
604 | ret = -1; | |
605 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
606 | goto end; | |
607 | } | |
608 | /* if we received fds */ | |
609 | if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_RIGHTS) { | |
610 | switch (cmd_type) { | |
611 | case ADD_STREAM: | |
612 | DBG("kconsumerd_add_fd %s (%d)", lkm.path_name, (CMSG_DATA(cmsg)[0])); | |
613 | ret = kconsumerd_add_fd(&lkm, (CMSG_DATA(cmsg)[0])); | |
614 | if (ret < 0) { | |
615 | kconsumerd_send_error(KCONSUMERD_OUTFD_ERROR); | |
616 | goto end; | |
617 | } | |
618 | break; | |
619 | case UPDATE_STREAM: | |
620 | kconsumerd_change_fd_state(lkm.fd, lkm.state); | |
621 | break; | |
622 | default: | |
623 | break; | |
624 | } | |
1ce86c9a JD |
625 | /* signal the poll thread */ |
626 | tmp2 = write(kconsumerd_poll_pipe[1], "4", 1); | |
627 | } else { | |
628 | ERR("Didn't received any fd"); | |
629 | kconsumerd_send_error(KCONSUMERD_ERROR_RECV_FD); | |
630 | ret = -1; | |
631 | goto end; | |
632 | } | |
633 | } | |
634 | ||
635 | end: | |
1ce86c9a JD |
636 | return ret; |
637 | } | |
638 | ||
639 | /* | |
640 | * kconsumerd_thread_poll_fds | |
641 | * | |
642 | * This thread polls the fds in the ltt_fd_list to consume the data | |
643 | * and write it to tracefile if necessary. | |
644 | */ | |
645 | void *kconsumerd_thread_poll_fds(void *data) | |
646 | { | |
647 | int num_rdy, num_hup, high_prio, ret, i; | |
648 | struct pollfd *pollfd = NULL; | |
649 | /* local view of the fds */ | |
650 | struct kconsumerd_fd **local_kconsumerd_fd = NULL; | |
242cd187 | 651 | /* local view of kconsumerd_data.fds_count */ |
1ce86c9a JD |
652 | int nb_fd = 0; |
653 | char tmp; | |
654 | int tmp2; | |
655 | ||
656 | ret = pipe(kconsumerd_thread_pipe); | |
657 | if (ret < 0) { | |
658 | perror("Error creating pipe"); | |
659 | goto end; | |
660 | } | |
661 | ||
662 | local_kconsumerd_fd = malloc(sizeof(struct kconsumerd_fd)); | |
663 | ||
664 | while (1) { | |
665 | high_prio = 0; | |
666 | num_hup = 0; | |
667 | ||
668 | /* | |
669 | * the ltt_fd_list has been updated, we need to update our | |
670 | * local array as well | |
671 | */ | |
242cd187 MD |
672 | pthread_mutex_lock(&kconsumerd_data.lock); |
673 | if (kconsumerd_data.need_update) { | |
1ce86c9a JD |
674 | if (pollfd != NULL) { |
675 | free(pollfd); | |
676 | pollfd = NULL; | |
677 | } | |
678 | if (local_kconsumerd_fd != NULL) { | |
679 | free(local_kconsumerd_fd); | |
680 | local_kconsumerd_fd = NULL; | |
681 | } | |
0237248c | 682 | |
1ce86c9a | 683 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ |
242cd187 | 684 | pollfd = malloc((kconsumerd_data.fds_count + 1) * sizeof(struct pollfd)); |
1ce86c9a JD |
685 | if (pollfd == NULL) { |
686 | perror("pollfd malloc"); | |
242cd187 | 687 | pthread_mutex_unlock(&kconsumerd_data.lock); |
1ce86c9a JD |
688 | goto end; |
689 | } | |
0237248c | 690 | |
1ce86c9a | 691 | /* allocate for all fds + 1 for the kconsumerd_poll_pipe */ |
242cd187 | 692 | local_kconsumerd_fd = malloc((kconsumerd_data.fds_count + 1) * |
1ce86c9a JD |
693 | sizeof(struct kconsumerd_fd)); |
694 | if (local_kconsumerd_fd == NULL) { | |
695 | perror("local_kconsumerd_fd malloc"); | |
242cd187 | 696 | pthread_mutex_unlock(&kconsumerd_data.lock); |
1ce86c9a JD |
697 | goto end; |
698 | } | |
699 | ret = kconsumerd_update_poll_array(&pollfd, local_kconsumerd_fd); | |
700 | if (ret < 0) { | |
701 | ERR("Error in allocating pollfd or local_outfds"); | |
702 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
242cd187 | 703 | pthread_mutex_unlock(&kconsumerd_data.lock); |
1ce86c9a JD |
704 | goto end; |
705 | } | |
706 | nb_fd = ret; | |
242cd187 | 707 | kconsumerd_data.need_update = 0; |
1ce86c9a | 708 | } |
242cd187 | 709 | pthread_mutex_unlock(&kconsumerd_data.lock); |
1ce86c9a JD |
710 | |
711 | /* poll on the array of fds */ | |
712 | DBG("polling on %d fd", nb_fd + 1); | |
713 | num_rdy = poll(pollfd, nb_fd + 1, kconsumerd_poll_timeout); | |
714 | DBG("poll num_rdy : %d", num_rdy); | |
715 | if (num_rdy == -1) { | |
716 | perror("Poll error"); | |
717 | kconsumerd_send_error(KCONSUMERD_POLL_ERROR); | |
718 | goto end; | |
719 | } else if (num_rdy == 0) { | |
720 | DBG("Polling thread timed out"); | |
721 | goto end; | |
722 | } | |
723 | ||
724 | /* No FDs and kconsumerd_quit, kconsumerd_cleanup the thread */ | |
725 | if (nb_fd == 0 && kconsumerd_quit == 1) { | |
726 | goto end; | |
727 | } | |
728 | ||
729 | /* | |
242cd187 MD |
730 | * If the kconsumerd_poll_pipe triggered poll go |
731 | * directly to the beginning of the loop to update the | |
732 | * array. We want to prioritize array update over | |
733 | * low-priority reads. | |
1ce86c9a | 734 | */ |
242cd187 | 735 | if (pollfd[nb_fd].revents == POLLIN) { |
1ce86c9a JD |
736 | DBG("kconsumerd_poll_pipe wake up"); |
737 | tmp2 = read(kconsumerd_poll_pipe[0], &tmp, 1); | |
738 | continue; | |
739 | } | |
740 | ||
741 | /* Take care of high priority channels first. */ | |
742 | for (i = 0; i < nb_fd; i++) { | |
743 | switch(pollfd[i].revents) { | |
744 | case POLLERR: | |
745 | ERR("Error returned in polling fd %d.", pollfd[i].fd); | |
746 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
1ce86c9a JD |
747 | num_hup++; |
748 | break; | |
749 | case POLLHUP: | |
750 | DBG("Polling fd %d tells it has hung up.", pollfd[i].fd); | |
751 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
1ce86c9a JD |
752 | num_hup++; |
753 | break; | |
754 | case POLLNVAL: | |
755 | ERR("Polling fd %d tells fd is not open.", pollfd[i].fd); | |
756 | kconsumerd_del_fd(local_kconsumerd_fd[i]); | |
1ce86c9a JD |
757 | num_hup++; |
758 | break; | |
759 | case POLLPRI: | |
760 | DBG("Urgent read on fd %d", pollfd[i].fd); | |
761 | high_prio = 1; | |
762 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
763 | /* it's ok to have an unavailable sub-buffer */ | |
764 | if (ret == EAGAIN) { | |
765 | ret = 0; | |
766 | } | |
767 | break; | |
768 | } | |
769 | } | |
770 | ||
771 | /* If every buffer FD has hung up, we end the read loop here */ | |
772 | if (nb_fd > 0 && num_hup == nb_fd) { | |
773 | DBG("every buffer FD has hung up\n"); | |
774 | if (kconsumerd_quit == 1) { | |
775 | goto end; | |
776 | } | |
777 | continue; | |
778 | } | |
779 | ||
780 | /* Take care of low priority channels. */ | |
781 | if (high_prio == 0) { | |
782 | for (i = 0; i < nb_fd; i++) { | |
783 | if (pollfd[i].revents == POLLIN) { | |
784 | DBG("Normal read on fd %d", pollfd[i].fd); | |
785 | ret = kconsumerd_read_subbuffer(local_kconsumerd_fd[i]); | |
786 | /* it's ok to have an unavailable subbuffer */ | |
787 | if (ret == EAGAIN) { | |
788 | ret = 0; | |
789 | } | |
790 | } | |
791 | } | |
792 | } | |
793 | } | |
794 | end: | |
795 | DBG("polling thread exiting"); | |
796 | if (pollfd != NULL) { | |
797 | free(pollfd); | |
798 | pollfd = NULL; | |
799 | } | |
800 | if (local_kconsumerd_fd != NULL) { | |
801 | free(local_kconsumerd_fd); | |
802 | local_kconsumerd_fd = NULL; | |
803 | } | |
1ce86c9a JD |
804 | return NULL; |
805 | } | |
806 | ||
807 | /* | |
808 | * kconsumerd_create_poll_pipe | |
809 | * | |
810 | * create the pipe to wake to polling thread when needed | |
811 | */ | |
812 | int kconsumerd_create_poll_pipe() | |
813 | { | |
814 | return pipe(kconsumerd_poll_pipe); | |
815 | } | |
816 | ||
817 | /* | |
818 | * kconsumerd_thread_receive_fds | |
819 | * | |
820 | * This thread listens on the consumerd socket and | |
821 | * receives the file descriptors from ltt-sessiond | |
822 | */ | |
823 | void *kconsumerd_thread_receive_fds(void *data) | |
824 | { | |
825 | int sock, client_socket, ret; | |
826 | struct lttcomm_kconsumerd_header tmp; | |
827 | ||
828 | DBG("Creating command socket %s", kconsumerd_command_sock_path); | |
829 | unlink(kconsumerd_command_sock_path); | |
830 | client_socket = lttcomm_create_unix_sock(kconsumerd_command_sock_path); | |
831 | if (client_socket < 0) { | |
832 | ERR("Cannot create command socket"); | |
833 | goto end; | |
834 | } | |
835 | ||
836 | ret = lttcomm_listen_unix_sock(client_socket); | |
837 | if (ret < 0) { | |
838 | goto end; | |
839 | } | |
840 | ||
841 | DBG("Sending ready command to ltt-sessiond"); | |
842 | ret = kconsumerd_send_error(KCONSUMERD_COMMAND_SOCK_READY); | |
843 | if (ret < 0) { | |
844 | ERR("Error sending ready command to ltt-sessiond"); | |
845 | goto end; | |
846 | } | |
847 | ||
3dcd2721 MD |
848 | /* TODO: poll on socket and "should_quit" fd pipe */ |
849 | /* TODO: change blocking call into non-blocking call */ | |
1ce86c9a JD |
850 | /* Blocking call, waiting for transmission */ |
851 | sock = lttcomm_accept_unix_sock(client_socket); | |
852 | if (sock <= 0) { | |
853 | WARN("On accept"); | |
854 | goto end; | |
855 | } | |
856 | while (1) { | |
857 | /* We first get the number of fd we are about to receive */ | |
3dcd2721 MD |
858 | /* TODO: poll on sock and "should_quit" fd pipe */ |
859 | /* TODO: change recv into a non-blocking call */ | |
1ce86c9a JD |
860 | ret = lttcomm_recv_unix_sock(sock, &tmp, |
861 | sizeof(struct lttcomm_kconsumerd_header)); | |
862 | if (ret <= 0) { | |
863 | ERR("Communication interrupted on command socket"); | |
864 | goto end; | |
865 | } | |
866 | if (tmp.cmd_type == STOP) { | |
867 | DBG("Received STOP command"); | |
868 | goto end; | |
869 | } | |
3dcd2721 MD |
870 | if (kconsumerd_quit) { |
871 | DBG("kconsumerd_thread_receive_fds received quit from signal"); | |
872 | goto end; | |
873 | } | |
1ce86c9a JD |
874 | /* we received a command to add or update fds */ |
875 | ret = kconsumerd_consumerd_recv_fd(sock, tmp.payload_size, tmp.cmd_type); | |
876 | if (ret <= 0) { | |
877 | ERR("Receiving the FD, exiting"); | |
878 | goto end; | |
879 | } | |
880 | } | |
881 | ||
882 | end: | |
883 | DBG("kconsumerd_thread_receive_fds exiting"); | |
884 | ||
885 | /* | |
886 | * when all fds have hung up, the polling thread | |
887 | * can exit cleanly | |
888 | */ | |
889 | kconsumerd_quit = 1; | |
890 | ||
891 | /* | |
892 | * 2s of grace period, if no polling events occur during | |
893 | * this period, the polling thread will exit even if there | |
894 | * are still open FDs (should not happen, but safety mechanism). | |
895 | */ | |
896 | kconsumerd_poll_timeout = KCONSUMERD_POLL_GRACE_PERIOD; | |
897 | ||
898 | /* wake up the polling thread */ | |
899 | ret = write(kconsumerd_poll_pipe[1], "4", 1); | |
900 | if (ret < 0) { | |
901 | perror("poll pipe write"); | |
902 | } | |
903 | return NULL; | |
904 | } | |
905 | ||
906 | /* | |
907 | * kconsumerd_cleanup | |
908 | * | |
909 | * Cleanup the daemon's socket on exit | |
910 | */ | |
3dcd2721 | 911 | void kconsumerd_cleanup(void) |
1ce86c9a JD |
912 | { |
913 | struct kconsumerd_fd *iter; | |
914 | ||
915 | /* remove the socket file */ | |
916 | unlink(kconsumerd_command_sock_path); | |
917 | ||
3dcd2721 MD |
918 | /* |
919 | * close all outfd. Called when there are no more threads | |
920 | * running (after joining on the threads), no need to protect | |
921 | * list iteration with mutex. | |
922 | */ | |
242cd187 | 923 | cds_list_for_each_entry(iter, &kconsumerd_data.fd_list.head, list) { |
1ce86c9a JD |
924 | kconsumerd_del_fd(iter); |
925 | } | |
926 | } | |
927 | ||
3dcd2721 MD |
928 | /* |
929 | * Called from signal handler. | |
930 | */ | |
931 | void kconsumerd_should_exit(void) | |
932 | { | |
933 | kconsumerd_quit = 1; | |
934 | /* | |
935 | * TODO: write into a should_quit pipe to wake up the fd | |
936 | * receiver thread. | |
937 | */ | |
938 | } | |
939 | ||
1ce86c9a JD |
940 | /* |
941 | * kconsumerd_send_error | |
942 | * | |
943 | * send return code to ltt-sessiond | |
944 | */ | |
945 | int kconsumerd_send_error(enum lttcomm_return_code cmd) | |
946 | { | |
947 | if (kconsumerd_error_socket > 0) { | |
948 | return lttcomm_send_unix_sock(kconsumerd_error_socket, &cmd, | |
949 | sizeof(enum lttcomm_sessiond_command)); | |
950 | } | |
951 | ||
952 | return 0; | |
953 | } |