Fix return value of remove_oldest_snapshot().
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 #include <string.h>
7 #include <stdlib.h>
8 #include <stdarg.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <sys/types.h>
12 #include <signal.h>
13 #include <ctype.h>
14 #include <sys/stat.h>
15 #include <unistd.h>
16 #include <inttypes.h>
17 #include <sys/time.h>
18 #include <time.h>
19 #include <sys/wait.h>
20 #include <fnmatch.h>
21 #include <limits.h>
22
23
24 #include "gcc-compat.h"
25 #include "cmdline.h"
26 #include "log.h"
27 #include "string.h"
28 #include "error.h"
29 #include "fd.h"
30 #include "exec.h"
31 #include "daemon.h"
32 #include "signal.h"
33 #include "df.h"
34 #include "time.h"
35 #include "snap.h"
36
37 /** Command line and config file options. */
38 static struct gengetopt_args_info conf;
39 /** Non-NULL if we log to a file. */
40 static FILE *logfile;
41 /** The read end of the signal pipe */
42 static int signal_pipe;
43 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
44 static pid_t create_pid;
45 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
46 static int create_process_stopped;
47 /** Process id of current pre-remove/rm/post-remove process. */
48 static pid_t remove_pid;
49 /** When the next snapshot is due. */
50 static struct timeval next_snapshot_time;
51 /** When to try to remove something. */
52 static struct timeval next_removal_check;
53 /** Creation time of the snapshot currently being created. */
54 static int64_t current_snapshot_creation_time;
55 /* The snapshot currently being removed. */
56 struct snapshot *snapshot_currently_being_removed;
57 /** Needed by the post-create hook. */
58 static char *path_to_last_complete_snapshot;
59 /** \sa \ref snap.h for details. */
60 enum hook_status snapshot_creation_status;
61 /** \sa \ref snap.h for details. */
62 enum hook_status snapshot_removal_status;
63
64
65 DEFINE_DSS_ERRLIST;
66
67
68 /* a litte cpp magic helps to DRY */
69 #define COMMANDS \
70 COMMAND(ls) \
71 COMMAND(create) \
72 COMMAND(prune) \
73 COMMAND(run)
74 #define COMMAND(x) static int com_ ##x(void);
75 COMMANDS
76 #undef COMMAND
77 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
78 static int call_command_handler(void)
79 {
80 COMMANDS
81 DSS_EMERG_LOG("BUG: did not find command handler\n");
82 return -E_BUG;
83 }
84 #undef COMMAND
85 #undef COMMANDS
86
87 /**
88 * The log function of dss.
89 *
90 * \param ll Loglevel.
91 * \param fml Usual format string.
92 *
93 * All DSS_XXX_LOG() macros use this function.
94 */
95 __printf_2_3 void dss_log(int ll, const char* fmt,...)
96 {
97 va_list argp;
98 FILE *outfd;
99 struct tm *tm;
100 time_t t1;
101 char str[255] = "";
102
103 if (ll < conf.loglevel_arg)
104 return;
105 outfd = logfile? logfile : stderr;
106 time(&t1);
107 tm = localtime(&t1);
108 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
109 fprintf(outfd, "%s ", str);
110 if (conf.loglevel_arg <= INFO)
111 fprintf(outfd, "%i: ", ll);
112 va_start(argp, fmt);
113 vfprintf(outfd, fmt, argp);
114 va_end(argp);
115 }
116
117 /**
118 * Print a message either to stdout or to the log file.
119 */
120 static __printf_1_2 void dss_msg(const char* fmt,...)
121 {
122 FILE *outfd = conf.daemon_given? logfile : stdout;
123 va_list argp;
124 va_start(argp, fmt);
125 vfprintf(outfd, fmt, argp);
126 va_end(argp);
127 }
128
129 static int disk_space_low(void)
130 {
131 struct disk_space ds;
132 int ret = get_disk_space(".", &ds);
133
134 if (ret < 0)
135 return ret;
136 if (conf.min_free_mb_arg)
137 if (ds.free_mb < conf.min_free_mb_arg)
138 return 1;
139 if (conf.min_free_percent_arg)
140 if (ds.percent_free < conf.min_free_percent_arg)
141 return 1;
142 if (conf.min_free_percent_inodes_arg)
143 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
144 return 1;
145 return 0;
146 }
147
148 static void dss_get_snapshot_list(struct snapshot_list *sl)
149 {
150 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
151 }
152
153 static int next_snapshot_is_due(void)
154 {
155 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
156 tmp, diff;
157 int64_t x = 0;
158 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
159 num_complete_snapshots = 0;
160 int i, ret;
161 struct snapshot *s = NULL;
162 struct snapshot_list sl;
163
164 gettimeofday(&now, NULL);
165 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
166 return 0;
167 assert(snapshot_creation_status == HS_READY);
168 current_snapshot_creation_time = 0;
169 dss_get_snapshot_list(&sl);
170 FOR_EACH_SNAPSHOT(s, i, &sl) {
171 if (!(s->flags & SS_COMPLETE))
172 continue;
173 num_complete_snapshots++;
174 x += s->completion_time - s->creation_time;
175 }
176 assert(x >= 0);
177 if (num_complete_snapshots)
178 x /= num_complete_snapshots; /* avg time to create one snapshot */
179 x *= wanted; /* time to create all snapshots in interval 0 */
180 tmp.tv_sec = x;
181 tmp.tv_usec = 0;
182 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
183 if (ret < 0 || !s) { /* unit_interval < tmp or no snapshot */
184 ret = 1;
185 goto out;
186 }
187
188 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
189 diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
190 diff.tv_usec = 0;
191 tv_add(&diff, &tmp, &next_snapshot_time);
192 ret = (tv_diff(&now, &next_snapshot_time, &diff) < 0)? 0 : 1;
193 out:
194 free_snapshot_list(&sl);
195 if (ret == 0)
196 DSS_DEBUG_LOG("next snapshot due in %lu seconds\n",
197 tv2ms(&diff) / 1000);
198 else
199 DSS_DEBUG_LOG("next snapshot: now\n");
200 return ret;
201 }
202
203 static int pre_create_hook(void)
204 {
205 int ret, fds[3] = {0, 0, 0};
206
207 assert(snapshot_creation_status == HS_READY);
208 if (!conf.pre_create_hook_given) {
209 snapshot_creation_status = HS_PRE_SUCCESS;
210 return 0;
211 }
212 DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
213 ret = dss_exec_cmdline_pid(&create_pid,
214 conf.pre_create_hook_arg, fds);
215 if (ret < 0)
216 return ret;
217 snapshot_creation_status = HS_PRE_RUNNING;
218 return ret;
219 }
220
221 static int pre_remove_hook(struct snapshot *s, char *why)
222 {
223 int ret, fds[3] = {0, 0, 0};
224 char *cmd;
225
226 DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
227 assert(snapshot_removal_status == HS_READY);
228 assert(remove_pid == 0);
229 assert(!snapshot_currently_being_removed);
230
231 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
232 *snapshot_currently_being_removed = *s;
233 snapshot_currently_being_removed->name = dss_strdup(s->name);
234
235 if (!conf.pre_remove_hook_given) {
236 snapshot_removal_status = HS_PRE_SUCCESS;
237 return 0;
238 }
239 cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
240 conf.dest_dir_arg, s->name);
241 DSS_DEBUG_LOG("executing %s\n", cmd);
242 ret = dss_exec_cmdline_pid(&remove_pid,
243 conf.pre_remove_hook_arg, fds);
244 free(cmd);
245 if (ret < 0)
246 return ret;
247 snapshot_removal_status = HS_PRE_RUNNING;
248 return ret;
249 }
250
251 static int exec_rm(void)
252 {
253 struct snapshot *s = snapshot_currently_being_removed;
254 int fds[3] = {0, 0, 0};
255 char *new_name = being_deleted_name(s);
256 char *argv[] = {"rm", "-rf", new_name, NULL};
257 int ret;
258
259 assert(snapshot_removal_status == HS_PRE_SUCCESS);
260 assert(remove_pid == 0);
261
262 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
263 ret = dss_rename(s->name, new_name);
264 if (ret < 0)
265 goto out;
266 ret = dss_exec(&remove_pid, argv[0], argv, fds);
267 if (ret < 0)
268 goto out;
269 snapshot_removal_status = HS_RUNNING;
270 out:
271 free(new_name);
272 return ret;
273 }
274
275 static int snapshot_is_being_created(struct snapshot *s)
276 {
277 return s->creation_time == current_snapshot_creation_time;
278 }
279
280 /*
281 * return: 0: no redundant snapshots, 1: rm process started, negative: error
282 */
283 static int remove_redundant_snapshot(struct snapshot_list *sl)
284 {
285 int ret, i, interval;
286 struct snapshot *s;
287 unsigned missing = 0;
288
289 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
290 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
291 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
292 unsigned num = sl->interval_count[interval];
293 struct snapshot *victim = NULL, *prev = NULL;
294 int64_t score = LONG_MAX;
295
296 if (keep >= num)
297 missing += keep - num;
298 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
299 // interval, keep, num, missing);
300 if (keep + missing >= num)
301 continue;
302 /* redundant snapshot in this interval, pick snapshot with lowest score */
303 FOR_EACH_SNAPSHOT(s, i, sl) {
304 int64_t this_score;
305
306 if (snapshot_is_being_created(s))
307 continue;
308 //DSS_DEBUG_LOG("checking %s\n", s->name);
309 if (s->interval > interval) {
310 prev = s;
311 continue;
312 }
313 if (s->interval < interval)
314 break;
315 if (!victim) {
316 victim = s;
317 prev = s;
318 continue;
319 }
320 assert(prev);
321 /* check if s is a better victim */
322 this_score = s->creation_time - prev->creation_time;
323 assert(this_score >= 0);
324 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
325 if (this_score < score) {
326 score = this_score;
327 victim = s;
328 }
329 prev = s;
330 }
331 assert(victim);
332 if (conf.dry_run_given) {
333 dss_msg("%s would be removed (interval = %i)\n",
334 victim->name, victim->interval);
335 continue;
336 }
337 ret = pre_remove_hook(victim, "redundant");
338 return ret < 0? ret : 1;
339 }
340 return 0;
341 }
342
343 static int remove_outdated_snapshot(struct snapshot_list *sl)
344 {
345 int i, ret;
346 struct snapshot *s;
347
348 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
349 conf.num_intervals_arg);
350 FOR_EACH_SNAPSHOT(s, i, sl) {
351 if (snapshot_is_being_created(s))
352 continue;
353 if (s->interval <= conf.num_intervals_arg)
354 continue;
355 if (conf.dry_run_given) {
356 dss_msg("%s would be removed (interval = %i)\n",
357 s->name, s->interval);
358 continue;
359 }
360 ret = pre_remove_hook(s, "outdated");
361 if (ret < 0)
362 return ret;
363 return 1;
364 }
365 return 0;
366 }
367
368 static int remove_oldest_snapshot(struct snapshot_list *sl)
369 {
370 int ret;
371 struct snapshot *s = get_oldest_snapshot(sl);
372
373 if (!s) /* no snapshot found */
374 return 0;
375 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
376 if (snapshot_is_being_created(s))
377 return 0;
378 ret = pre_remove_hook(s, "oldest");
379 if (ret < 0)
380 return ret;
381 return 1;
382 }
383
384 static int rename_incomplete_snapshot(int64_t start)
385 {
386 char *old_name;
387 int ret;
388
389 free(path_to_last_complete_snapshot);
390 ret = complete_name(start, get_current_time(),
391 &path_to_last_complete_snapshot);
392 if (ret < 0)
393 return ret;
394 old_name = incomplete_name(start);
395 ret = dss_rename(old_name, path_to_last_complete_snapshot);
396 if (ret >= 0)
397 DSS_NOTICE_LOG("%s -> %s\n", old_name,
398 path_to_last_complete_snapshot);
399 free(old_name);
400 return ret;
401 }
402
403 static int try_to_free_disk_space(int low_disk_space)
404 {
405 int ret;
406 struct snapshot_list sl;
407 struct timeval now;
408
409 gettimeofday(&now, NULL);
410 if (tv_diff(&next_removal_check, &now, NULL) > 0)
411 return 0;
412 if (!low_disk_space && conf.keep_redundant_given)
413 return 0;
414 dss_get_snapshot_list(&sl);
415 ret = remove_outdated_snapshot(&sl);
416 if (ret) /* error, or we are removing something */
417 goto out;
418 /* no outdated snapshot */
419 ret = remove_redundant_snapshot(&sl);
420 if (ret)
421 goto out;
422 ret = 0;
423 if (!low_disk_space)
424 goto out;
425 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
426 ret = remove_oldest_snapshot(&sl);
427 if (ret)
428 goto out;
429 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
430 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
431 out:
432 free_snapshot_list(&sl);
433 return ret;
434 }
435
436 static int post_create_hook(void)
437 {
438 int ret, fds[3] = {0, 0, 0};
439 char *cmd;
440
441 if (!conf.post_create_hook_given) {
442 snapshot_creation_status = HS_READY;
443 return 0;
444 }
445 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
446 conf.dest_dir_arg, path_to_last_complete_snapshot);
447 DSS_NOTICE_LOG("executing %s\n", cmd);
448 ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
449 free(cmd);
450 if (ret < 0)
451 return ret;
452 snapshot_creation_status = HS_POST_RUNNING;
453 return ret;
454 }
455
456 static int post_remove_hook(void)
457 {
458 int ret, fds[3] = {0, 0, 0};
459 char *cmd;
460 struct snapshot *s = snapshot_currently_being_removed;
461
462 assert(s);
463
464 if (!conf.post_remove_hook_given) {
465 snapshot_removal_status = HS_READY;
466 return 0;
467 }
468 cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
469 conf.dest_dir_arg, s->name);
470 DSS_NOTICE_LOG("executing %s\n", cmd);
471 ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
472 free(cmd);
473 if (ret < 0)
474 return ret;
475 snapshot_removal_status = HS_POST_RUNNING;
476 return ret;
477 }
478
479 static void kill_process(pid_t pid)
480 {
481 if (!pid)
482 return;
483 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
484 kill(pid, SIGTERM);
485 }
486
487 static void stop_create_process(void)
488 {
489 if (!create_pid || create_process_stopped)
490 return;
491 kill(SIGSTOP, create_pid);
492 create_process_stopped = 1;
493 }
494
495 static void restart_create_process(void)
496 {
497 if (!create_pid || !create_process_stopped)
498 return;
499 kill (SIGCONT, create_pid);
500 create_process_stopped = 0;
501 }
502
503 /**
504 * Print a log message about the exit status of a child.
505 */
506 static void log_termination_msg(pid_t pid, int status)
507 {
508 if (WIFEXITED(status))
509 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
510 WEXITSTATUS(status));
511 else if (WIFSIGNALED(status))
512 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
513 WTERMSIG(status));
514 else
515 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
516 }
517
518 static int wait_for_process(pid_t pid, int *status)
519 {
520 int ret;
521
522 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
523 for (;;) {
524 fd_set rfds;
525
526 FD_ZERO(&rfds);
527 FD_SET(signal_pipe, &rfds);
528 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
529 if (ret < 0)
530 break;
531 ret = next_signal();
532 if (!ret)
533 continue;
534 if (ret == SIGCHLD) {
535 ret = waitpid(pid, status, 0);
536 if (ret >= 0)
537 break;
538 if (errno != EINTR) { /* error */
539 ret = -ERRNO_TO_DSS_ERROR(errno);
540 break;
541 }
542 }
543 /* SIGINT or SIGTERM */
544 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
545 kill(pid, SIGTERM);
546 }
547 if (ret < 0)
548 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
549 else
550 log_termination_msg(pid, *status);
551 return ret;
552 }
553
554 static void handle_pre_remove_exit(int status)
555 {
556 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
557 snapshot_removal_status = HS_READY;
558 gettimeofday(&next_removal_check, NULL);
559 next_removal_check.tv_sec += 60;
560 return;
561 }
562 snapshot_removal_status = HS_PRE_SUCCESS;
563 }
564
565 static int handle_rm_exit(int status)
566 {
567 if (!WIFEXITED(status)) {
568 snapshot_removal_status = HS_READY;
569 return -E_INVOLUNTARY_EXIT;
570 }
571 if (WEXITSTATUS(status)) {
572 snapshot_removal_status = HS_READY;
573 return -E_BAD_EXIT_CODE;
574 }
575 if (conf.post_remove_hook_given)
576 snapshot_removal_status = HS_SUCCESS;
577 else
578 snapshot_removal_status = HS_READY;
579 return 1;
580 }
581
582 static void handle_post_remove_exit(void)
583 {
584 snapshot_removal_status = HS_READY;
585 }
586
587 static int handle_remove_exit(int status)
588 {
589 int ret;
590 struct snapshot *s = snapshot_currently_being_removed;
591
592 assert(s);
593 switch (snapshot_removal_status) {
594 case HS_PRE_RUNNING:
595 handle_pre_remove_exit(status);
596 ret = 1;
597 break;
598 case HS_RUNNING:
599 ret = handle_rm_exit(status);
600 break;
601 case HS_POST_RUNNING:
602 handle_post_remove_exit();
603 ret = 1;
604 break;
605 default:
606 ret = -E_BUG;
607 }
608 if (snapshot_removal_status == HS_READY) {
609 free(s->name);
610 free(s);
611 snapshot_currently_being_removed = NULL;
612 }
613 remove_pid = 0;
614 return ret;
615 }
616
617 static int wait_for_remove_process(void)
618 {
619 int status, ret;
620
621 assert(remove_pid);
622 assert(
623 snapshot_removal_status == HS_PRE_RUNNING ||
624 snapshot_removal_status == HS_RUNNING ||
625 snapshot_removal_status == HS_POST_RUNNING
626 );
627 ret = wait_for_process(remove_pid, &status);
628 if (ret < 0)
629 return ret;
630 return handle_remove_exit(status);
631 }
632
633 static int handle_rsync_exit(int status)
634 {
635 int es, ret;
636
637 if (!WIFEXITED(status)) {
638 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
639 ret = -E_INVOLUNTARY_EXIT;
640 snapshot_creation_status = HS_READY;
641 goto out;
642 }
643 es = WEXITSTATUS(status);
644 if (es == 13) { /* Errors with program diagnostics */
645 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
646 (int)create_pid, es);
647 snapshot_creation_status = HS_NEEDS_RESTART;
648 gettimeofday(&next_snapshot_time, NULL);
649 next_snapshot_time.tv_sec += 60;
650 ret = 1;
651 goto out;
652 }
653 if (es != 0 && es != 23 && es != 24) {
654 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
655 ret = -E_BAD_EXIT_CODE;
656 snapshot_creation_status = HS_READY;
657 goto out;
658 }
659 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
660 if (ret < 0)
661 goto out;
662 snapshot_creation_status = HS_SUCCESS;
663 out:
664 create_pid = 0;
665 create_process_stopped = 0;
666 return ret;
667 }
668
669 static int handle_pre_create_hook_exit(int status)
670 {
671 int es, ret;
672 static int warn_count;
673
674 if (!WIFEXITED(status)) {
675 snapshot_creation_status = HS_READY;
676 ret = -E_INVOLUNTARY_EXIT;
677 goto out;
678 }
679 es = WEXITSTATUS(status);
680 if (es) {
681 if (!warn_count--) {
682 DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
683 conf.pre_create_hook_arg, es);
684 DSS_NOTICE_LOG("deferring snapshot creation...\n");
685 warn_count = 60; /* warn only once per hour */
686 }
687 snapshot_creation_status = HS_READY;
688 ret = 0;
689 goto out;
690 }
691 warn_count = 0;
692 snapshot_creation_status = HS_PRE_SUCCESS;
693 ret = 1;
694 out:
695 create_pid = 0;
696 return ret;
697 }
698
699 static int handle_sigchld(void)
700 {
701 pid_t pid;
702 int status, ret = reap_child(&pid, &status);
703
704 if (ret <= 0)
705 return ret;
706
707 if (pid == create_pid) {
708 switch (snapshot_creation_status) {
709 case HS_PRE_RUNNING:
710 return handle_pre_create_hook_exit(status);
711 case HS_RUNNING:
712 return handle_rsync_exit(status);
713 case HS_POST_RUNNING:
714 snapshot_creation_status = HS_READY;
715 return 1;
716 default:
717 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
718 snapshot_creation_status);
719 return -E_BUG;
720 }
721 }
722 if (pid == remove_pid) {
723 ret = handle_remove_exit(status);
724 if (ret < 0)
725 return ret;
726 return ret;
727 }
728 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
729 return -E_BUG;
730 }
731
732 static int check_config(void)
733 {
734 if (conf.unit_interval_arg <= 0) {
735 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
736 return -E_INVALID_NUMBER;
737 }
738 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
739 if (conf.num_intervals_arg <= 0) {
740 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
741 return -E_INVALID_NUMBER;
742 }
743 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
744 return 1;
745 }
746
747 static int parse_config_file(int override)
748 {
749 int ret;
750 char *config_file;
751 struct stat statbuf;
752 char *old_logfile_arg = NULL;
753 int old_daemon_given = 0;
754
755 if (conf.config_file_given)
756 config_file = dss_strdup(conf.config_file_arg);
757 else {
758 char *home = get_homedir();
759 config_file = make_message("%s/.dssrc", home);
760 free(home);
761 }
762 if (override) { /* SIGHUP */
763 if (conf.logfile_given)
764 old_logfile_arg = dss_strdup(conf.logfile_arg);
765 old_daemon_given = conf.daemon_given;
766 }
767
768 ret = stat(config_file, &statbuf);
769 if (ret && conf.config_file_given) {
770 ret = -ERRNO_TO_DSS_ERROR(errno);
771 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
772 goto out;
773 }
774 if (!ret) {
775 struct cmdline_parser_params params = {
776 .override = override,
777 .initialize = 0,
778 .check_required = 1,
779 .check_ambiguity = 0,
780 .print_errors = 1
781 };
782 if (override) { /* invalidate all rsync options */
783 int i;
784
785 for (i = 0; i < conf.rsync_option_given; i++) {
786 free(conf.rsync_option_arg[i]);
787 conf.rsync_option_arg[i] = NULL;
788 }
789 conf.rsync_option_given = 0;
790 }
791 cmdline_parser_config_file(config_file, &conf, &params);
792 }
793 ret = check_config();
794 if (ret < 0)
795 goto out;
796 if (override) {
797 /* don't change daemon mode on SIGHUP */
798 conf.daemon_given = old_daemon_given;
799 close_log(logfile);
800 logfile = NULL;
801 if (conf.logfile_given)
802 free(old_logfile_arg);
803 else if (conf.daemon_given) { /* re-use old logfile */
804 conf.logfile_arg = old_logfile_arg;
805 conf.logfile_given = 1;
806 }
807 }
808 if (conf.logfile_given) {
809 logfile = open_log(conf.logfile_arg);
810 log_welcome(conf.loglevel_arg);
811 }
812 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
813 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
814 out:
815 free(config_file);
816 if (ret < 0)
817 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
818 return ret;
819 }
820
821 static int change_to_dest_dir(void)
822 {
823 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
824 return dss_chdir(conf.dest_dir_arg);
825 }
826
827 static int handle_sighup(void)
828 {
829 int ret;
830
831 DSS_NOTICE_LOG("SIGHUP\n");
832 ret = parse_config_file(1);
833 if (ret < 0)
834 return ret;
835 return change_to_dest_dir();
836 }
837
838 static int handle_signal(void)
839 {
840 int sig, ret = next_signal();
841
842 if (ret <= 0)
843 goto out;
844 sig = ret;
845 switch (sig) {
846 case SIGINT:
847 case SIGTERM:
848 restart_create_process();
849 kill_process(create_pid);
850 kill_process(remove_pid);
851 ret = -E_SIGNAL;
852 break;
853 case SIGHUP:
854 ret = handle_sighup();
855 break;
856 case SIGCHLD:
857 ret = handle_sigchld();
858 break;
859 }
860 out:
861 if (ret < 0)
862 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
863 return ret;
864 }
865
866 /*
867 * We can not use rsync locally if the local user is different from the remote
868 * user or if the src dir is not on the local host (or both).
869 */
870 static int use_rsync_locally(char *logname)
871 {
872 char *h = conf.remote_host_arg;
873
874 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
875 return 0;
876 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
877 return 0;
878 return 1;
879 }
880
881 static void create_rsync_argv(char ***argv, int64_t *num)
882 {
883 char *logname, *newest;
884 int i = 0, j;
885 struct snapshot_list sl;
886
887 dss_get_snapshot_list(&sl);
888 newest = name_of_newest_complete_snapshot(&sl);
889 free_snapshot_list(&sl);
890
891 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
892 (*argv)[i++] = dss_strdup("rsync");
893 (*argv)[i++] = dss_strdup("-aq");
894 (*argv)[i++] = dss_strdup("--delete");
895 for (j = 0; j < conf.rsync_option_given; j++)
896 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
897 if (newest) {
898 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
899 (*argv)[i++] = make_message("--link-dest=../%s", newest);
900 free(newest);
901 } else
902 DSS_INFO_LOG("no previous snapshot found\n");
903 logname = dss_logname();
904 if (use_rsync_locally(logname))
905 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
906 else
907 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
908 conf.remote_user_arg : logname,
909 conf.remote_host_arg, conf.source_dir_arg);
910 free(logname);
911 *num = get_current_time();
912 (*argv)[i++] = incomplete_name(*num);
913 (*argv)[i++] = NULL;
914 for (j = 0; j < i; j++)
915 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
916 }
917
918 static void free_rsync_argv(char **argv)
919 {
920 int i;
921
922 if (!argv)
923 return;
924 for (i = 0; argv[i]; i++)
925 free(argv[i]);
926 free(argv);
927 }
928
929 static int create_snapshot(char **argv)
930 {
931 int ret, fds[3] = {0, 0, 0};
932 char *name;
933
934 name = incomplete_name(current_snapshot_creation_time);
935 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
936 free(name);
937 ret = dss_exec(&create_pid, argv[0], argv, fds);
938 if (ret < 0)
939 return ret;
940 snapshot_creation_status = HS_RUNNING;
941 return ret;
942 }
943
944 static int select_loop(void)
945 {
946 int ret;
947 /* check every 60 seconds for free disk space */
948 struct timeval tv;
949 char **rsync_argv = NULL;
950
951 for (;;) {
952 fd_set rfds;
953 int low_disk_space;
954 struct timeval *tvp;
955
956 if (remove_pid)
957 tvp = NULL; /* sleep until rm hook/process dies */
958 else { /* sleep one minute */
959 tv.tv_sec = 60;
960 tv.tv_usec = 0;
961 tvp = &tv;
962 }
963 FD_ZERO(&rfds);
964 FD_SET(signal_pipe, &rfds);
965 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
966 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
967 if (ret < 0)
968 goto out;
969 if (FD_ISSET(signal_pipe, &rfds)) {
970 ret = handle_signal();
971 if (ret < 0)
972 goto out;
973 }
974 if (remove_pid)
975 continue;
976 if (snapshot_removal_status == HS_PRE_SUCCESS) {
977 ret = exec_rm();
978 if (ret < 0)
979 goto out;
980 continue;
981 }
982 if (snapshot_removal_status == HS_SUCCESS) {
983 ret = post_remove_hook();
984 if (ret < 0)
985 goto out;
986 continue;
987 }
988 ret = disk_space_low();
989 if (ret < 0)
990 goto out;
991 low_disk_space = ret;
992 ret = try_to_free_disk_space(low_disk_space);
993 if (ret < 0)
994 goto out;
995 if (snapshot_removal_status != HS_READY) {
996 stop_create_process();
997 continue;
998 }
999 restart_create_process();
1000 switch (snapshot_creation_status) {
1001 case HS_READY:
1002 if (!next_snapshot_is_due())
1003 continue;
1004 ret = pre_create_hook();
1005 if (ret < 0)
1006 goto out;
1007 continue;
1008 case HS_PRE_RUNNING:
1009 case HS_RUNNING:
1010 case HS_POST_RUNNING:
1011 continue;
1012 case HS_PRE_SUCCESS:
1013 free_rsync_argv(rsync_argv);
1014 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1015 /* fall through */
1016 case HS_NEEDS_RESTART:
1017 ret = create_snapshot(rsync_argv);
1018 if (ret < 0)
1019 goto out;
1020 continue;
1021 case HS_SUCCESS:
1022 ret = post_create_hook();
1023 if (ret < 0)
1024 goto out;
1025 continue;
1026 }
1027 }
1028 out:
1029 return ret;
1030 }
1031
1032 static void exit_hook(int exit_code)
1033 {
1034 int fds[3] = {0, 0, 0};
1035 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
1036 pid_t pid;
1037
1038 if (!conf.exit_hook_given)
1039 return;
1040 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1041 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
1042 }
1043
1044 static int com_run(void)
1045 {
1046 int ret;
1047
1048 if (conf.dry_run_given) {
1049 DSS_ERROR_LOG("dry_run not supported by this command\n");
1050 return -E_SYNTAX;
1051 }
1052 ret = install_sighandler(SIGHUP);
1053 if (ret < 0)
1054 return ret;
1055 ret = select_loop();
1056 if (ret >= 0) /* impossible */
1057 ret = -E_BUG;
1058 exit_hook(ret);
1059 return ret;
1060 }
1061
1062 static int com_prune(void)
1063 {
1064 int ret;
1065 struct snapshot_list sl;
1066 struct disk_space ds;
1067
1068 ret = get_disk_space(".", &ds);
1069 if (ret < 0)
1070 return ret;
1071 log_disk_space(&ds);
1072 dss_get_snapshot_list(&sl);
1073 ret = remove_outdated_snapshot(&sl);
1074 if (ret < 0)
1075 goto out;
1076 if (ret > 0)
1077 goto rm;
1078 ret = remove_redundant_snapshot(&sl);
1079 if (ret < 0)
1080 goto out;
1081 if (ret > 0)
1082 goto rm;
1083 ret = 0;
1084 goto out;
1085 rm:
1086 if (snapshot_removal_status == HS_PRE_RUNNING) {
1087 ret = wait_for_remove_process();
1088 if (ret < 0)
1089 goto out;
1090 if (snapshot_removal_status != HS_PRE_SUCCESS)
1091 goto out;
1092 }
1093 ret = exec_rm();
1094 if (ret < 0)
1095 goto out;
1096 ret = wait_for_remove_process();
1097 if (ret < 0)
1098 goto out;
1099 if (snapshot_removal_status != HS_SUCCESS)
1100 goto out;
1101 ret = post_remove_hook();
1102 if (ret < 0)
1103 goto out;
1104 if (snapshot_removal_status != HS_POST_RUNNING)
1105 goto out;
1106 ret = wait_for_remove_process();
1107 if (ret < 0)
1108 goto out;
1109 ret = 1;
1110 out:
1111 free_snapshot_list(&sl);
1112 return ret;
1113 }
1114
1115 static int com_create(void)
1116 {
1117 int ret, status;
1118 char **rsync_argv;
1119
1120 if (conf.dry_run_given) {
1121 int i;
1122 char *msg = NULL;
1123 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1124 for (i = 0; rsync_argv[i]; i++) {
1125 char *tmp = msg;
1126 msg = make_message("%s%s%s", tmp? tmp : "",
1127 tmp? " " : "", rsync_argv[i]);
1128 free(tmp);
1129 }
1130 free_rsync_argv(rsync_argv);
1131 dss_msg("%s\n", msg);
1132 free(msg);
1133 return 1;
1134 }
1135 ret = pre_create_hook();
1136 if (ret < 0)
1137 return ret;
1138 if (create_pid) {
1139 ret = wait_for_process(create_pid, &status);
1140 if (ret < 0)
1141 return ret;
1142 ret = handle_pre_create_hook_exit(status);
1143 if (ret <= 0) /* error, or pre-create failed */
1144 return ret;
1145 }
1146 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1147 ret = create_snapshot(rsync_argv);
1148 if (ret < 0)
1149 goto out;
1150 ret = wait_for_process(create_pid, &status);
1151 if (ret < 0)
1152 goto out;
1153 ret = handle_rsync_exit(status);
1154 if (ret < 0)
1155 goto out;
1156 post_create_hook();
1157 if (create_pid)
1158 ret = wait_for_process(create_pid, &status);
1159 out:
1160 free_rsync_argv(rsync_argv);
1161 return ret;
1162 }
1163
1164 static int com_ls(void)
1165 {
1166 int i;
1167 struct snapshot_list sl;
1168 struct snapshot *s;
1169
1170 dss_get_snapshot_list(&sl);
1171 FOR_EACH_SNAPSHOT(s, i, &sl) {
1172 int64_t d = 0;
1173 if (s->flags & SS_COMPLETE)
1174 d = (s->completion_time - s->creation_time) / 60;
1175 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1176 };
1177 free_snapshot_list(&sl);
1178 return 1;
1179 }
1180
1181 static int setup_signal_handling(void)
1182 {
1183 int ret;
1184
1185 DSS_INFO_LOG("setting up signal handlers\n");
1186 signal_pipe = signal_init(); /* always successful */
1187 ret = install_sighandler(SIGINT);
1188 if (ret < 0)
1189 return ret;
1190 ret = install_sighandler(SIGTERM);
1191 if (ret < 0)
1192 return ret;
1193 return install_sighandler(SIGCHLD);
1194 }
1195
1196 /**
1197 * The main function of dss.
1198 *
1199 * \param argc Usual argument count.
1200 * \param argv Usual argument vector.
1201 */
1202 int main(int argc, char **argv)
1203 {
1204 int ret;
1205 struct cmdline_parser_params params = {
1206 .override = 0,
1207 .initialize = 1,
1208 .check_required = 0,
1209 .check_ambiguity = 0,
1210 .print_errors = 1
1211 };
1212
1213 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1214 ret = parse_config_file(0);
1215 if (ret < 0)
1216 goto out;
1217 if (conf.daemon_given)
1218 daemon_init();
1219 ret = change_to_dest_dir();
1220 if (ret < 0)
1221 goto out;
1222 ret = setup_signal_handling();
1223 if (ret < 0)
1224 goto out;
1225 ret = call_command_handler();
1226 out:
1227 if (ret < 0)
1228 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1229 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1230 }