Fix a couple of bugs and start creating snapshots in the select loop.
[dss.git] / dss.c
1 #include <string.h>
2 #include <stdlib.h>
3 #include <stdarg.h>
4 #include <assert.h>
5 #include <errno.h>
6 #include <sys/types.h>
7 #include <signal.h>
8 #include <ctype.h>
9 #include <sys/stat.h>
10 #include <unistd.h>
11 #include <inttypes.h>
12 #include <sys/time.h>
13 #include <time.h>
14 #include <sys/wait.h>
15 #include <fnmatch.h>
16 #include <limits.h>
17
18
19 #include "gcc-compat.h"
20 #include "cmdline.h"
21 #include "log.h"
22 #include "string.h"
23 #include "error.h"
24 #include "fd.h"
25 #include "exec.h"
26 #include "daemon.h"
27 #include "signal.h"
28 #include "df.h"
29 #include "time.h"
30
31
32 struct gengetopt_args_info conf;
33 char *dss_error_txt = NULL;
34 static FILE *logfile;
35 int signal_pipe;
36
37 /** Process id of current rsync process. */
38 static pid_t rsync_pid;
39 /** Whether the rsync process is currently stopped */
40 static int rsync_stopped;
41 /** Process id of current rm process. */
42 static pid_t rm_pid;
43 /** When the next snapshot is due. */
44 struct timeval next_snapshot_time;
45 /* Creation time of the snapshot currently being created. */
46 int64_t current_snapshot_creation_time;
47
48
49 DEFINE_DSS_ERRLIST;
50
51
52 /* a litte cpp magic helps to DRY */
53 #define COMMANDS \
54 COMMAND(ls) \
55 COMMAND(create) \
56 COMMAND(prune) \
57 COMMAND(run)
58 #define COMMAND(x) int com_ ##x(void);
59 COMMANDS
60 #undef COMMAND
61 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
62 int call_command_handler(void)
63 {
64 COMMANDS
65 DSS_EMERG_LOG("BUG: did not find command handler\n");
66 exit(EXIT_FAILURE);
67 }
68 #undef COMMAND
69 #undef COMMANDS
70
71 /*
72 * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
73 * complete, being deleted: 1204565370-1204565371.being_deleted
74 * incomplete, not being deleted: 1204565370-incomplete
75 * incomplete, being deleted: 1204565370-incomplete.being_deleted
76 */
77 enum snapshot_status_flags {
78 SS_COMPLETE = 1,
79 SS_BEING_DELETED = 2,
80 };
81
82 struct snapshot {
83 char *name;
84 int64_t creation_time;
85 int64_t completion_time;
86 enum snapshot_status_flags flags;
87 unsigned interval;
88 };
89
90 /*
91 * An edge snapshot is either the oldest one or the newest one.
92 *
93 * We need to find either of them occasionally: The create code
94 * needs to know the newest snapshot because that is the one
95 * used as the link destination dir. The pruning code needs to
96 * find the oldest one in case disk space becomes low.
97 */
98 struct edge_snapshot_data {
99 int64_t now;
100 struct snapshot snap;
101 };
102
103 __printf_2_3 void dss_log(int ll, const char* fmt,...)
104 {
105 va_list argp;
106 FILE *outfd;
107 struct tm *tm;
108 time_t t1;
109 char str[255] = "";
110
111 if (ll < conf.loglevel_arg)
112 return;
113 outfd = logfile? logfile : stderr;
114 time(&t1);
115 tm = localtime(&t1);
116 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
117 fprintf(outfd, "%s ", str);
118 if (conf.loglevel_arg <= INFO)
119 fprintf(outfd, "%i: ", ll);
120 va_start(argp, fmt);
121 vfprintf(outfd, fmt, argp);
122 va_end(argp);
123 }
124
125 /**
126 * Print a message either to stdout or to the log file.
127 */
128 __printf_1_2 void dss_msg(const char* fmt,...)
129 {
130 FILE *outfd = conf.daemon_given? logfile : stdout;
131 va_list argp;
132 va_start(argp, fmt);
133 vfprintf(outfd, fmt, argp);
134 va_end(argp);
135 }
136
137 /**
138 * Return the desired number of snapshots of an interval.
139 */
140 unsigned num_snapshots(int interval)
141 {
142 unsigned n;
143
144 assert(interval >= 0);
145
146 if (interval >= conf.num_intervals_arg)
147 return 0;
148 n = conf.num_intervals_arg - interval - 1;
149 return 1 << n;
150 }
151
152 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
153 {
154 int i, ret;
155 char *dash, *dot, *tmp;
156 int64_t num;
157
158 assert(dirname);
159 dash = strchr(dirname, '-');
160 if (!dash || !dash[1] || dash == dirname)
161 return 0;
162 for (i = 0; dirname[i] != '-'; i++)
163 if (!isdigit(dirname[i]))
164 return 0;
165 tmp = dss_strdup(dirname);
166 tmp[i] = '\0';
167 ret = dss_atoi64(tmp, &num);
168 free(tmp);
169 if (ret < 0) {
170 free(dss_error_txt);
171 return 0;
172 }
173 assert(num >= 0);
174 if (num > now)
175 return 0;
176 s->creation_time = num;
177 //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
178 s->interval = (long long) ((now - s->creation_time)
179 / conf.unit_interval_arg / 24 / 3600);
180 if (!strcmp(dash + 1, "incomplete")) {
181 s->completion_time = -1;
182 s->flags = 0; /* neither complete, nor being deleted */
183 goto success;
184 }
185 if (!strcmp(dash + 1, "incomplete.being_deleted")) {
186 s->completion_time = -1;
187 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
188 goto success;
189 }
190 tmp = dash + 1;
191 dot = strchr(tmp, '.');
192 if (!dot || !dot[1] || dot == tmp)
193 return 0;
194 for (i = 0; tmp[i] != '.'; i++)
195 if (!isdigit(tmp[i]))
196 return 0;
197 tmp = dss_strdup(dash + 1);
198 tmp[i] = '\0';
199 ret = dss_atoi64(tmp, &num);
200 free(tmp);
201 if (ret < 0) {
202 free(dss_error_txt);
203 return 0;
204 }
205 if (num > now)
206 return 0;
207 s->completion_time = num;
208 s->flags = SS_COMPLETE;
209 if (!strcmp(dot + 1, "being_deleted"))
210 s->flags |= SS_BEING_DELETED;
211 success:
212 s->name = dss_strdup(dirname);
213 return 1;
214 }
215
216 int64_t get_current_time(void)
217 {
218 time_t now;
219 time(&now);
220 DSS_DEBUG_LOG("now: %lli\n", (long long) now);
221 return (int64_t)now;
222 }
223
224 char *incomplete_name(int64_t start)
225 {
226 return make_message("%lli-incomplete", (long long)start);
227 }
228
229 char *being_deleted_name(struct snapshot *s)
230 {
231 if (s->flags & SS_COMPLETE)
232 return make_message("%lli-%lli.being_deleted",
233 (long long)s->creation_time,
234 (long long)s->completion_time);
235 return make_message("%lli-incomplete.being_deleted",
236 (long long)s->creation_time);
237 }
238
239 int complete_name(int64_t start, int64_t end, char **result)
240 {
241 struct tm start_tm, end_tm;
242 time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
243 time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
244 char start_str[200], end_str[200];
245
246 if (!localtime_r(start_seconds, &start_tm)) {
247 make_err_msg("%lli", (long long)start);
248 return -E_LOCALTIME;
249 }
250 if (!localtime_r(end_seconds, &end_tm)) {
251 make_err_msg("%lli", (long long)end);
252 return -E_LOCALTIME;
253 }
254 if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) {
255 make_err_msg("%lli", (long long)start);
256 return -E_STRFTIME;
257 }
258 if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) {
259 make_err_msg("%lli", (long long)end);
260 return -E_STRFTIME;
261 }
262 *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
263 start_str, end_str);
264 return 1;
265 }
266
267 struct snapshot_list {
268 int64_t now;
269 unsigned num_snapshots;
270 unsigned array_size;
271 struct snapshot **snapshots;
272 /**
273 * Array of size num_intervals + 1
274 *
275 * It contains the number of snapshots in each interval. interval_count[num_intervals]
276 * is the number of snapshots which belong to any interval greater than num_intervals.
277 */
278 unsigned *interval_count;
279 };
280
281 #define FOR_EACH_SNAPSHOT(s, i, sl) \
282 for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
283
284
285
286 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
287
288 static int compare_snapshots(const void *a, const void *b)
289 {
290 struct snapshot *s1 = *(struct snapshot **)a;
291 struct snapshot *s2 = *(struct snapshot **)b;
292 return NUM_COMPARE(s2->creation_time, s1->creation_time);
293 }
294
295 /** Compute the minimum of \a a and \a b. */
296 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
297
298 int add_snapshot(const char *dirname, void *private)
299 {
300 struct snapshot_list *sl = private;
301 struct snapshot s;
302 int ret = is_snapshot(dirname, sl->now, &s);
303
304 if (!ret)
305 return 1;
306 if (sl->num_snapshots >= sl->array_size) {
307 sl->array_size = 2 * sl->array_size + 1;
308 sl->snapshots = dss_realloc(sl->snapshots,
309 sl->array_size * sizeof(struct snapshot *));
310 }
311 sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
312 *(sl->snapshots[sl->num_snapshots]) = s;
313 sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
314 sl->num_snapshots++;
315 return 1;
316 }
317
318 void get_snapshot_list(struct snapshot_list *sl)
319 {
320 sl->now = get_current_time();
321 sl->num_snapshots = 0;
322 sl->array_size = 0;
323 sl->snapshots = NULL;
324 sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
325 for_each_subdir(add_snapshot, sl);
326 qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
327 compare_snapshots);
328 }
329
330 void stop_rsync_process(void)
331 {
332 if (!rsync_pid || rsync_stopped)
333 return;
334 kill(SIGSTOP, rsync_pid);
335 rsync_stopped = 1;
336 }
337
338 void restart_rsync_process(void)
339 {
340 if (!rsync_pid || !rsync_stopped)
341 return;
342 kill (SIGCONT, rsync_pid);
343 rsync_stopped = 0;
344 }
345
346 void free_snapshot_list(struct snapshot_list *sl)
347 {
348 int i;
349 struct snapshot *s;
350
351 FOR_EACH_SNAPSHOT(s, i, sl) {
352 free(s->name);
353 free(s);
354 }
355 free(sl->interval_count);
356 free(sl->snapshots);
357 }
358
359 /**
360 * Print a log message about the exit status of a child.
361 */
362 void log_termination_msg(pid_t pid, int status)
363 {
364 if (WIFEXITED(status))
365 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
366 WEXITSTATUS(status));
367 else if (WIFSIGNALED(status))
368 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
369 WTERMSIG(status));
370 else
371 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
372 }
373
374 int wait_for_process(pid_t pid, int *status)
375 {
376 int ret;
377
378 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
379 for (;;) {
380 pause();
381 ret = next_signal();
382 if (ret < 0)
383 break;
384 if (!ret)
385 continue;
386 if (ret == SIGCHLD) {
387 ret = waitpid(pid, status, 0);
388 if (ret >= 0)
389 break;
390 if (errno != EINTR) /* error */
391 break;
392 }
393 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
394 kill(pid, SIGTERM);
395 }
396 if (ret < 0) {
397 ret = -ERRNO_TO_DSS_ERROR(errno);
398 make_err_msg("failed to wait for process %d", (int)pid);
399 } else
400 log_termination_msg(pid, *status);
401 return ret;
402 }
403
404 int remove_snapshot(struct snapshot *s)
405 {
406 int fds[3] = {0, 0, 0};
407 assert(!rm_pid);
408 char *new_name = being_deleted_name(s);
409 int ret = dss_rename(s->name, new_name);
410 char *argv[] = {"rm", "-rf", new_name, NULL};
411
412 if (ret < 0)
413 goto out;
414 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
415 stop_rsync_process();
416 ret = dss_exec(&rm_pid, argv[0], argv, fds);
417 out:
418 free(new_name);
419 return ret;
420 }
421 /*
422 * return: 0: no redundant snapshots, 1: rm process started, negative: error
423 */
424 int remove_redundant_snapshot(struct snapshot_list *sl)
425 {
426 int ret, i, interval;
427 struct snapshot *s;
428 unsigned missing = 0;
429
430 DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
431 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
432 unsigned keep = num_snapshots(interval);
433 unsigned num = sl->interval_count[interval];
434 struct snapshot *victim = NULL, *prev = NULL;
435 int64_t score = LONG_MAX;
436
437 if (keep >= num)
438 missing += keep - num;
439 DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
440 interval, keep, num, missing);
441 if (keep + missing >= num)
442 continue;
443 /* redundant snapshot in this interval, pick snapshot with lowest score */
444 FOR_EACH_SNAPSHOT(s, i, sl) {
445 int64_t this_score;
446
447 //DSS_DEBUG_LOG("checking %s\n", s->name);
448 if (s->interval > interval) {
449 prev = s;
450 continue;
451 }
452 if (s->interval < interval)
453 break;
454 if (!victim) {
455 victim = s;
456 prev = s;
457 continue;
458 }
459 assert(prev);
460 /* check if s is a better victim */
461 this_score = s->creation_time - prev->creation_time;
462 assert(this_score >= 0);
463 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
464 if (this_score < score) {
465 score = this_score;
466 victim = s;
467 }
468 prev = s;
469 }
470 assert(victim);
471 if (conf.dry_run_given) {
472 dss_msg("%s would be removed (interval = %i)\n",
473 victim->name, victim->interval);
474 continue;
475 }
476 ret = remove_snapshot(victim);
477 return ret < 0? ret : 1;
478 }
479 return 0;
480 }
481
482 int remove_outdated_snapshot(struct snapshot_list *sl)
483 {
484 int i, ret;
485 struct snapshot *s;
486
487 DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
488 conf.num_intervals_arg);
489 FOR_EACH_SNAPSHOT(s, i, sl) {
490 if (s->interval <= conf.num_intervals_arg)
491 continue;
492 if (conf.dry_run_given) {
493 dss_msg("%s would be removed (interval = %i)\n",
494 s->name, s->interval);
495 continue;
496 }
497 ret = remove_snapshot(s);
498 if (ret < 0)
499 return ret;
500 return 1;
501 }
502 return 0;
503 }
504
505 int handle_rm_exit(int status)
506 {
507 int es, ret;
508
509 if (!WIFEXITED(status)) {
510 make_err_msg("rm process %d died involuntary", (int)rm_pid);
511 ret = -E_INVOLUNTARY_EXIT;
512 goto out;
513 }
514 es = WEXITSTATUS(status);
515 if (es) {
516 make_err_msg("rm process %d returned %d", (int)rm_pid, es);
517 ret = -E_BAD_EXIT_CODE;
518 goto out;
519 }
520 ret = 1;
521 rm_pid = 0;
522 out:
523 return ret;
524 }
525
526
527 int wait_for_rm_process(void)
528 {
529 int status, ret = wait_for_process(rm_pid, &status);
530
531 if (ret < 0)
532 return ret;
533 return handle_rm_exit(status);
534 }
535
536 void kill_process(pid_t pid)
537 {
538 if (!pid)
539 return;
540 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
541 kill(pid, SIGTERM);
542 }
543
544 void handle_sighup()
545 {
546 DSS_INFO_LOG("FIXME: no sighup handling yet\n");
547 }
548
549 int rename_incomplete_snapshot(int64_t start)
550 {
551 char *old_name, *new_name;
552 int ret;
553
554 ret = complete_name(start, get_current_time(), &new_name);
555 if (ret < 0)
556 return ret;
557 old_name = incomplete_name(start);
558 ret = dss_rename(old_name, new_name);
559 if (ret >= 0)
560 DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
561 free(old_name);
562 free(new_name);
563 return ret;
564 }
565
566
567 int handle_rsync_exit(int status)
568 {
569 int es, ret;
570
571 if (!WIFEXITED(status)) {
572 make_err_msg("rsync process %d died involuntary", (int)rsync_pid);
573 ret = -E_INVOLUNTARY_EXIT;
574 goto out;
575 }
576 es = WEXITSTATUS(status);
577 if (es != 0 && es != 23 && es != 24) {
578 make_err_msg("rsync process %d returned %d", (int)rsync_pid, es);
579 ret = -E_BAD_EXIT_CODE;
580 goto out;
581 }
582 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
583 out:
584 rsync_pid = 0;
585 current_snapshot_creation_time = 0;
586 rsync_stopped = 0;
587 return ret;
588 }
589
590
591 int get_newest_complete(const char *dirname, void *private)
592 {
593 struct edge_snapshot_data *esd = private;
594 struct snapshot s;
595 int ret = is_snapshot(dirname, esd->now, &s);
596
597 if (ret <= 0)
598 return 1;
599 if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
600 return 1;
601 if (s.creation_time < esd->snap.creation_time)
602 return 1;
603 free(esd->snap.name);
604 esd->snap = s;
605 return 1;
606 }
607
608 __malloc char *name_of_newest_complete_snapshot(void)
609 {
610 struct edge_snapshot_data esd = {
611 .now = get_current_time(),
612 .snap = {.creation_time = -1}
613 };
614 for_each_subdir(get_newest_complete, &esd);
615 return esd.snap.name;
616 }
617
618 void create_rsync_argv(char ***argv, int64_t *num)
619 {
620 char *logname, *newest = name_of_newest_complete_snapshot();
621 int i = 0, j;
622
623 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
624 (*argv)[i++] = dss_strdup("rsync");
625 (*argv)[i++] = dss_strdup("-aq");
626 (*argv)[i++] = dss_strdup("--delete");
627 for (j = 0; j < conf.rsync_option_given; j++)
628 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
629 if (newest) {
630 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
631 (*argv)[i++] = make_message("--link-dest=../%s", newest);
632 free(newest);
633 } else
634 DSS_INFO_LOG("no previous snapshot found\n");
635 if (conf.exclude_patterns_given) {
636 (*argv)[i++] = dss_strdup("--exclude-from");
637 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
638
639 }
640 logname = dss_logname();
641 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
642 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
643 else
644 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
645 conf.remote_user_arg : logname,
646 conf.remote_host_arg, conf.source_dir_arg);
647 free(logname);
648 *num = get_current_time();
649 (*argv)[i++] = incomplete_name(*num);
650 (*argv)[i++] = NULL;
651 for (j = 0; j < i; j++)
652 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
653 }
654
655 void free_rsync_argv(char **argv)
656 {
657 int i;
658 for (i = 0; argv[i]; i++)
659 free(argv[i]);
660 free(argv);
661 }
662
663 int create_snapshot(char **argv)
664 {
665 int fds[3] = {0, 0, 0};
666 char *name = incomplete_name(current_snapshot_creation_time);
667
668 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
669 free(name);
670 return dss_exec(&rsync_pid, argv[0], argv, fds);
671 }
672
673 void compute_next_snapshot_time(struct snapshot_list *sl)
674 {
675 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
676 tmp, diff;
677 int64_t x = 0;
678 unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
679 int i, ret;
680 struct snapshot *s;
681
682 gettimeofday(&now, NULL);
683 FOR_EACH_SNAPSHOT(s, i, sl) {
684 if (!(s->flags & SS_COMPLETE))
685 continue;
686 num_complete_snapshots++;
687 x += s->completion_time - s->creation_time;
688 }
689 assert(x >= 0);
690 if (num_complete_snapshots)
691 x /= num_complete_snapshots; /* avg time to create one snapshot */
692 x *= wanted; /* time to create all snapshots in interval 0 */
693 tmp.tv_sec = x;
694 tmp.tv_usec = 0;
695 ret = tv_diff(&unit_interval, &tmp, &diff); /* time between creation */
696 if (ret < 0) {
697 next_snapshot_time = now;
698 return;
699 }
700 tv_divide(wanted, &diff, &tmp);
701 tv_add(&now, &tmp, &next_snapshot_time);
702 }
703
704 void handle_signal(struct snapshot_list *sl)
705 {
706 int sig, ret = next_signal();
707
708 if (ret <= 0)
709 goto out;
710 sig = ret;
711 switch (sig) {
712 int status;
713 pid_t pid;
714 case SIGINT:
715 case SIGTERM:
716 restart_rsync_process();
717 kill_process(rsync_pid);
718 kill_process(rm_pid);
719 exit(EXIT_FAILURE);
720 case SIGHUP:
721 handle_sighup();
722 break;
723 case SIGCHLD:
724 ret = reap_child(&pid, &status);
725 if (ret <= 0)
726 break;
727 assert(pid == rsync_pid || pid == rm_pid);
728 if (pid == rsync_pid)
729 ret = handle_rsync_exit(status);
730 else
731 ret = handle_rm_exit(status);
732 free_snapshot_list(sl);
733 get_snapshot_list(sl);
734 compute_next_snapshot_time(sl);
735 }
736 out:
737 if (ret < 0)
738 log_err_msg(ERROR, -ret);
739 }
740
741 int get_oldest(const char *dirname, void *private)
742 {
743 struct edge_snapshot_data *esd = private;
744 struct snapshot s;
745 int ret = is_snapshot(dirname, esd->now, &s);
746
747 if (ret <= 0)
748 return 1;
749 if (s.creation_time > esd->snap.creation_time)
750 return 1;
751 free(esd->snap.name);
752 esd->snap = s;
753 return 1;
754 }
755
756 int remove_oldest_snapshot()
757 {
758 int ret;
759 struct edge_snapshot_data esd = {
760 .now = get_current_time(),
761 .snap = {.creation_time = LLONG_MAX}
762 };
763 for_each_subdir(get_oldest, &esd);
764 if (!esd.snap.name) /* no snapshot found */
765 return 0;
766 DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
767 ret = 0;
768 if (esd.snap.creation_time == current_snapshot_creation_time)
769 goto out; /* do not remove the snapshot currently being created */
770 ret = remove_snapshot(&esd.snap);
771 out:
772 free(esd.snap.name);
773 return ret;
774 }
775
776 /* TODO: Also consider number of inodes. */
777 int disk_space_low(void)
778 {
779 struct disk_space ds;
780 int ret = get_disk_space(".", &ds);
781
782 if (ret < 0)
783 return ret;
784 if (conf.min_free_mb_arg)
785 if (ds.free_mb < conf.min_free_mb_arg)
786 return 1;
787 if (conf.min_free_percent_arg)
788 if (ds.percent_free < conf.min_free_percent_arg)
789 return 1;
790 return 0;
791 }
792
793 int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
794 {
795 int ret;
796
797 ret = remove_outdated_snapshot(sl);
798 if (ret) /* error, or we are removing something */
799 return ret;
800 /* no outdated snapshot */
801 ret = remove_redundant_snapshot(sl);
802 if (ret)
803 return ret;
804 if (!low_disk_space)
805 return 0;
806 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
807 ret = remove_oldest_snapshot();
808 if (ret)
809 return ret;
810 make_err_msg("uhuhu: not enough disk space for a single snapshot");
811 return -ENOSPC;
812 }
813
814 int select_loop(void)
815 {
816 int ret;
817 struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
818 struct snapshot_list sl = {.num_snapshots = 0};
819
820 get_snapshot_list(&sl);
821 compute_next_snapshot_time(&sl);
822 for (;;) {
823 struct timeval now, *tvp = &tv;
824 fd_set rfds;
825 int low_disk_space;
826 char **rsync_argv;
827
828 FD_ZERO(&rfds);
829 FD_SET(signal_pipe, &rfds);
830 if (rsync_pid)
831 tv.tv_sec = 60;
832 else if (rm_pid)
833 tvp = NULL;
834 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
835 if (ret < 0)
836 return ret;
837 if (FD_ISSET(signal_pipe, &rfds))
838 handle_signal(&sl);
839 if (rm_pid)
840 continue;
841 ret = disk_space_low();
842 if (ret < 0)
843 break;
844 low_disk_space = ret;
845 if (low_disk_space)
846 stop_rsync_process();
847 ret = try_to_free_disk_space(low_disk_space, &sl);
848 if (ret < 0)
849 break;
850 if (rm_pid)
851 continue;
852 if (rsync_pid) {
853 restart_rsync_process();
854 continue;
855 }
856 /* neither rsync nor rm are running. Start rsync? */
857 gettimeofday(&now, NULL);
858 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
859 continue;
860 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
861 ret = create_snapshot(rsync_argv);
862 free_rsync_argv(rsync_argv);
863 if (ret < 0)
864 break;
865 }
866 free_snapshot_list(&sl);
867 return ret;
868 }
869
870 int com_run(void)
871 {
872 int ret;
873
874 if (conf.dry_run_given) {
875 make_err_msg("dry_run not supported by this command");
876 return -E_SYNTAX;
877 }
878 ret = install_sighandler(SIGHUP);
879 if (ret < 0)
880 return ret;
881 return select_loop();
882 }
883
884 void log_disk_space(struct disk_space *ds)
885 {
886 DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
887 ds->free_mb, ds->total_mb, ds->percent_free,
888 ds->percent_free_inodes);
889 }
890
891 int com_prune(void)
892 {
893 int ret;
894 struct snapshot_list sl;
895 struct disk_space ds;
896
897 ret = get_disk_space(".", &ds);
898 if (ret < 0)
899 return ret;
900 log_disk_space(&ds);
901 for (;;) {
902 get_snapshot_list(&sl);
903 ret = remove_outdated_snapshot(&sl);
904 free_snapshot_list(&sl);
905 if (ret < 0)
906 return ret;
907 if (!ret)
908 break;
909 ret = wait_for_rm_process();
910 if (ret < 0)
911 goto out;
912 }
913 for (;;) {
914 get_snapshot_list(&sl);
915 ret = remove_redundant_snapshot(&sl);
916 free_snapshot_list(&sl);
917 if (ret < 0)
918 return ret;
919 if (!ret)
920 break;
921 ret = wait_for_rm_process();
922 if (ret < 0)
923 goto out;
924 }
925 return 1;
926 out:
927 return ret;
928 }
929
930 int com_create(void)
931 {
932 int ret, status;
933 char **rsync_argv;
934
935 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
936 if (conf.dry_run_given) {
937 int i;
938 char *msg = NULL;
939 for (i = 0; rsync_argv[i]; i++) {
940 char *tmp = msg;
941 msg = make_message("%s%s%s", tmp? tmp : "",
942 tmp? " " : "", rsync_argv[i]);
943 free(tmp);
944 }
945 dss_msg("%s\n", msg);
946 free(msg);
947 return 1;
948 }
949 ret = create_snapshot(rsync_argv);
950 if (ret < 0)
951 goto out;
952 ret = wait_for_process(rsync_pid, &status);
953 if (ret < 0)
954 goto out;
955 ret = handle_rsync_exit(status);
956 out:
957 free_rsync_argv(rsync_argv);
958 return ret;
959 }
960
961 int com_ls(void)
962 {
963 int i;
964 struct snapshot_list sl;
965 struct snapshot *s;
966 get_snapshot_list(&sl);
967 FOR_EACH_SNAPSHOT(s, i, &sl)
968 dss_msg("%u\t%s\n", s->interval, s->name);
969 free_snapshot_list(&sl);
970 return 1;
971 }
972
973 /* TODO: Unlink pid file */
974 __noreturn void clean_exit(int status)
975 {
976 //kill(0, SIGTERM);
977 free(dss_error_txt);
978 exit(status);
979 }
980
981 int read_config_file(void)
982 {
983 int ret;
984 char *config_file;
985 struct stat statbuf;
986
987 if (conf.config_file_given)
988 config_file = dss_strdup(conf.config_file_arg);
989 else {
990 char *home = get_homedir();
991 config_file = make_message("%s/.dssrc", home);
992 free(home);
993 }
994 ret = stat(config_file, &statbuf);
995 if (ret && conf.config_file_given) {
996 ret = -ERRNO_TO_DSS_ERROR(errno);
997 make_err_msg("failed to stat config file %s", config_file);
998 goto out;
999 }
1000 if (!ret) {
1001 struct cmdline_parser_params params = {
1002 .override = 0,
1003 .initialize = 0,
1004 .check_required = 0,
1005 .check_ambiguity = 0
1006 };
1007 cmdline_parser_config_file(config_file, &conf, &params);
1008 }
1009 if (!conf.source_dir_given || !conf.dest_dir_given) {
1010 ret = -E_SYNTAX;
1011 make_err_msg("you need to specify both source_dir and dest_dir");
1012 goto out;
1013 }
1014 ret = 1;
1015 out:
1016 free(config_file);
1017 return ret;
1018 }
1019
1020 int check_config(void)
1021 {
1022 if (conf.unit_interval_arg <= 0) {
1023 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
1024 return -E_INVALID_NUMBER;
1025 }
1026 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
1027 if (conf.num_intervals_arg <= 0) {
1028 make_err_msg("bad number of intervals %i", conf.num_intervals_arg);
1029 return -E_INVALID_NUMBER;
1030 }
1031 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
1032 return 1;
1033 }
1034
1035 static void setup_signal_handling(void)
1036 {
1037 int ret;
1038
1039 DSS_INFO_LOG("setting up signal handlers\n");
1040 signal_pipe = signal_init(); /* always successful */
1041 ret = install_sighandler(SIGINT);
1042 if (ret < 0)
1043 goto err;
1044 ret = install_sighandler(SIGTERM);
1045 if (ret < 0)
1046 goto err;
1047 ret = install_sighandler(SIGCHLD);
1048 if (ret < 0)
1049 goto err;
1050 return;
1051 err:
1052 DSS_EMERG_LOG("could not install signal handlers\n");
1053 exit(EXIT_FAILURE);
1054 }
1055
1056
1057 int main(int argc, char **argv)
1058 {
1059 int ret;
1060
1061 cmdline_parser(argc, argv, &conf); /* aborts on errors */
1062 ret = read_config_file();
1063 if (ret < 0)
1064 goto out;
1065 ret = check_config();
1066 if (ret < 0)
1067 goto out;
1068 if (conf.logfile_given) {
1069 logfile = open_log(conf.logfile_arg);
1070 log_welcome(conf.loglevel_arg);
1071 }
1072 ret = dss_chdir(conf.dest_dir_arg);
1073 if (ret < 0)
1074 goto out;
1075 if (conf.daemon_given)
1076 daemon_init();
1077 setup_signal_handling();
1078 ret = call_command_handler();
1079 out:
1080 if (ret < 0)
1081 log_err_msg(EMERG, -ret);
1082 clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1083 }