Implement the run command.
[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 void compute_next_snapshot_time(struct snapshot_list *sl)
592 {
593 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
594 tmp, diff;
595 int64_t x = 0;
596 unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
597 int i, ret;
598 struct snapshot *s;
599
600 gettimeofday(&now, NULL);
601 FOR_EACH_SNAPSHOT(s, i, sl) {
602 if (!(s->flags & SS_COMPLETE))
603 continue;
604 num_complete_snapshots++;
605 x += s->completion_time - s->creation_time;
606 }
607 assert(x >= 0);
608 if (num_complete_snapshots)
609 x /= num_complete_snapshots; /* avg time to create one snapshot */
610 x *= wanted; /* time to create all snapshots in interval 0 */
611 tmp.tv_sec = x;
612 tmp.tv_usec = 0;
613 ret = tv_diff(&unit_interval, &tmp, &diff); /* time between creation */
614 if (ret < 0) {
615 next_snapshot_time = now;
616 return;
617 }
618 tv_divide(wanted, &diff, &tmp);
619 tv_add(&now, &tmp, &next_snapshot_time);
620 }
621
622 void handle_signal(struct snapshot_list *sl)
623 {
624 int sig, ret = next_signal();
625
626 if (ret <= 0)
627 goto out;
628 sig = ret;
629 switch (sig) {
630 int status;
631 pid_t pid;
632 case SIGINT:
633 case SIGTERM:
634 restart_rsync_process();
635 kill_process(rsync_pid);
636 kill_process(rm_pid);
637 exit(EXIT_FAILURE);
638 case SIGHUP:
639 handle_sighup();
640 break;
641 case SIGCHLD:
642 ret = reap_child(&pid, &status);
643 if (ret <= 0)
644 break;
645 assert(pid == rsync_pid || pid == rm_pid);
646 if (pid == rsync_pid)
647 ret = handle_rsync_exit(status);
648 else
649 ret = handle_rm_exit(status);
650 free_snapshot_list(sl);
651 get_snapshot_list(sl);
652 compute_next_snapshot_time(sl);
653 }
654 out:
655 if (ret < 0)
656 log_err_msg(ERROR, -ret);
657 }
658
659 int get_oldest(const char *dirname, void *private)
660 {
661 struct edge_snapshot_data *esd = private;
662 struct snapshot s;
663 int ret = is_snapshot(dirname, esd->now, &s);
664
665 if (ret <= 0)
666 return 1;
667 if (s.creation_time > esd->snap.creation_time)
668 return 1;
669 free(esd->snap.name);
670 esd->snap = s;
671 return 1;
672 }
673
674 int remove_oldest_snapshot()
675 {
676 int ret;
677 struct edge_snapshot_data esd = {
678 .now = get_current_time(),
679 .snap = {.creation_time = LLONG_MAX}
680 };
681 for_each_subdir(get_oldest, &esd);
682 if (!esd.snap.name) /* no snapshot found */
683 return 0;
684 DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
685 ret = 0;
686 if (esd.snap.creation_time == current_snapshot_creation_time)
687 goto out; /* do not remove the snapshot currently being created */
688 ret = remove_snapshot(&esd.snap);
689 out:
690 free(esd.snap.name);
691 return ret;
692 }
693
694 /* TODO: Also consider number of inodes. */
695 int disk_space_low(void)
696 {
697 struct disk_space ds;
698 int ret = get_disk_space(".", &ds);
699
700 if (ret < 0)
701 return ret;
702 if (conf.min_free_mb_arg)
703 if (ds.free_mb < conf.min_free_mb_arg)
704 return 1;
705 if (conf.min_free_percent_arg)
706 if (ds.percent_free < conf.min_free_percent_arg)
707 return 1;
708 return 0;
709 }
710
711 int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
712 {
713 int ret;
714
715 ret = remove_outdated_snapshot(sl);
716 if (ret) /* error, or we are removing something */
717 return ret;
718 /* no outdated snapshot */
719 ret = remove_redundant_snapshot(sl);
720 if (ret)
721 return ret;
722 if (!low_disk_space)
723 return 0;
724 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
725 ret = remove_oldest_snapshot();
726 if (ret)
727 return ret;
728 make_err_msg("uhuhu: not enough disk space for a single snapshot");
729 return -ENOSPC;
730 }
731
732 int select_loop(void)
733 {
734 int ret;
735 struct timeval tv = {.tv_sec = 60, .tv_usec = 0};
736 struct snapshot_list sl = {.num_snapshots = 0};
737
738 get_snapshot_list(&sl);
739 compute_next_snapshot_time(&sl);
740 for (;;) {
741 struct timeval now;
742 fd_set rfds;
743 int low_disk_space;
744
745 FD_ZERO(&rfds);
746 ret = dss_select(signal_pipe + 1, &rfds, NULL, &tv);
747 if (ret < 0)
748 return ret;
749 if (FD_ISSET(signal_pipe, &rfds))
750 handle_signal(&sl);
751 if (rm_pid)
752 continue;
753 ret = disk_space_low();
754 if (ret < 0)
755 break;
756 low_disk_space = ret;
757 if (low_disk_space)
758 stop_rsync_process();
759 ret = try_to_free_disk_space(low_disk_space, &sl);
760 if (ret < 0)
761 break;
762 if (rm_pid)
763 continue;
764 if (rsync_pid) {
765 restart_rsync_process();
766 continue;
767 }
768 /* neither rsync nor rm are running. Start rsync? */
769 gettimeofday(&now, NULL);
770 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
771 continue;
772 }
773 free_snapshot_list(&sl);
774 return ret;
775 }
776
777 int com_run(void)
778 {
779 int ret;
780
781 if (conf.dry_run_given) {
782 make_err_msg("dry_run not supported by this command");
783 return -E_SYNTAX;
784 }
785 ret = install_sighandler(SIGHUP);
786 if (ret < 0)
787 return ret;
788 return select_loop();
789 }
790
791 void log_disk_space(struct disk_space *ds)
792 {
793 DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
794 ds->free_mb, ds->total_mb, ds->percent_free,
795 ds->percent_free_inodes);
796 }
797
798 int com_prune(void)
799 {
800 int ret;
801 struct snapshot_list sl;
802 struct disk_space ds;
803
804 ret = get_disk_space(".", &ds);
805 if (ret < 0)
806 return ret;
807 log_disk_space(&ds);
808 for (;;) {
809 get_snapshot_list(&sl);
810 ret = remove_outdated_snapshot(&sl);
811 free_snapshot_list(&sl);
812 if (ret < 0)
813 return ret;
814 if (!ret)
815 break;
816 ret = wait_for_rm_process();
817 if (ret < 0)
818 goto out;
819 }
820 for (;;) {
821 get_snapshot_list(&sl);
822 ret = remove_redundant_snapshot(&sl);
823 free_snapshot_list(&sl);
824 if (ret < 0)
825 return ret;
826 if (!ret)
827 break;
828 ret = wait_for_rm_process();
829 if (ret < 0)
830 goto out;
831 }
832 return 1;
833 out:
834 return ret;
835 }
836
837 int get_newest_complete(const char *dirname, void *private)
838 {
839 struct edge_snapshot_data *esd = private;
840 struct snapshot s;
841 int ret = is_snapshot(dirname, esd->now, &s);
842
843 if (ret <= 0)
844 return 1;
845 if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
846 return 1;
847 if (s.creation_time < esd->snap.creation_time)
848 return 1;
849 free(esd->snap.name);
850 esd->snap = s;
851 return 1;
852 }
853
854 __malloc char *name_of_newest_complete_snapshot(void)
855 {
856 struct edge_snapshot_data esd = {
857 .now = get_current_time(),
858 .snap = {.creation_time = -1}
859 };
860 for_each_subdir(get_newest_complete, &esd);
861 return esd.snap.name;
862 }
863
864 void create_rsync_argv(char ***argv, int64_t *num)
865 {
866 char *logname, *newest = name_of_newest_complete_snapshot();
867 int i = 0, j;
868
869 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
870 (*argv)[i++] = dss_strdup("rsync");
871 (*argv)[i++] = dss_strdup("-aq");
872 (*argv)[i++] = dss_strdup("--delete");
873 for (j = 0; j < conf.rsync_option_given; j++)
874 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
875 if (newest) {
876 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
877 (*argv)[i++] = make_message("--link-dest=../%s", newest);
878 free(newest);
879 } else
880 DSS_INFO_LOG("no previous snapshot found");
881 if (conf.exclude_patterns_given) {
882 (*argv)[i++] = dss_strdup("--exclude-from");
883 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
884
885 }
886 logname = dss_logname();
887 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
888 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
889 else
890 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
891 conf.remote_user_arg : logname,
892 conf.remote_host_arg, conf.source_dir_arg);
893 free(logname);
894 *num = get_current_time();
895 (*argv)[i++] = incomplete_name(*num);
896 (*argv)[i++] = NULL;
897 for (j = 0; j < i; j++)
898 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
899 }
900
901 void free_rsync_argv(char **argv)
902 {
903 int i;
904 for (i = 0; argv[i]; i++)
905 free(argv[i]);
906 free(argv);
907 }
908
909 int create_snapshot(char **argv)
910 {
911 int fds[3] = {0, 0, 0};
912
913 return dss_exec(&rsync_pid, argv[0], argv, fds);
914 }
915
916 int com_create(void)
917 {
918 int ret, status;
919 char **rsync_argv;
920
921 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
922 if (conf.dry_run_given) {
923 int i;
924 char *msg = NULL;
925 for (i = 0; rsync_argv[i]; i++) {
926 char *tmp = msg;
927 msg = make_message("%s%s%s", tmp? tmp : "",
928 tmp? " " : "", rsync_argv[i]);
929 free(tmp);
930 }
931 dss_msg("%s\n", msg);
932 free(msg);
933 return 1;
934 }
935 DSS_NOTICE_LOG("creating snapshot %lli\n",
936 (long long)current_snapshot_creation_time);
937 ret = create_snapshot(rsync_argv);
938 if (ret < 0)
939 goto out;
940 ret = wait_for_process(rsync_pid, &status);
941 if (ret < 0)
942 goto out;
943 ret = handle_rsync_exit(status);
944 out:
945 free_rsync_argv(rsync_argv);
946 return ret;
947 }
948
949 int com_ls(void)
950 {
951 int i;
952 struct snapshot_list sl;
953 struct snapshot *s;
954 get_snapshot_list(&sl);
955 FOR_EACH_SNAPSHOT(s, i, &sl)
956 dss_msg("%u\t%s\n", s->interval, s->name);
957 free_snapshot_list(&sl);
958 return 1;
959 }
960
961 /* TODO: Unlink pid file */
962 __noreturn void clean_exit(int status)
963 {
964 //kill(0, SIGTERM);
965 free(dss_error_txt);
966 exit(status);
967 }
968
969 int read_config_file(void)
970 {
971 int ret;
972 char *config_file;
973 struct stat statbuf;
974
975 if (conf.config_file_given)
976 config_file = dss_strdup(conf.config_file_arg);
977 else {
978 char *home = get_homedir();
979 config_file = make_message("%s/.dssrc", home);
980 free(home);
981 }
982 ret = stat(config_file, &statbuf);
983 if (ret && conf.config_file_given) {
984 ret = -ERRNO_TO_DSS_ERROR(errno);
985 make_err_msg("failed to stat config file %s", config_file);
986 goto out;
987 }
988 if (!ret) {
989 struct cmdline_parser_params params = {
990 .override = 0,
991 .initialize = 0,
992 .check_required = 0,
993 .check_ambiguity = 0
994 };
995 cmdline_parser_config_file(config_file, &conf, &params);
996 }
997 if (!conf.source_dir_given || !conf.dest_dir_given) {
998 ret = -E_SYNTAX;
999 make_err_msg("you need to specify both source_dir and dest_dir");
1000 goto out;
1001 }
1002 ret = 1;
1003 out:
1004 free(config_file);
1005 return ret;
1006 }
1007
1008 int check_config(void)
1009 {
1010 if (conf.unit_interval_arg <= 0) {
1011 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
1012 return -E_INVALID_NUMBER;
1013 }
1014 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
1015 if (conf.num_intervals_arg <= 0) {
1016 make_err_msg("bad number of intervals %i", conf.num_intervals_arg);
1017 return -E_INVALID_NUMBER;
1018 }
1019 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
1020 return 1;
1021 }
1022
1023 static void setup_signal_handling(void)
1024 {
1025 int ret;
1026
1027 DSS_NOTICE_LOG("setting up signal handlers\n");
1028 signal_pipe = signal_init(); /* always successful */
1029 ret = install_sighandler(SIGINT);
1030 if (ret < 0)
1031 goto err;
1032 ret = install_sighandler(SIGTERM);
1033 if (ret < 0)
1034 goto err;
1035 ret = install_sighandler(SIGCHLD);
1036 if (ret < 0)
1037 goto err;
1038 return;
1039 err:
1040 DSS_EMERG_LOG("could not install signal handlers\n");
1041 exit(EXIT_FAILURE);
1042 }
1043
1044
1045 int main(int argc, char **argv)
1046 {
1047 int ret;
1048
1049 cmdline_parser(argc, argv, &conf); /* aborts on errors */
1050 if (conf.inputs_num) {
1051 ret = -E_SYNTAX;
1052 make_err_msg("additional non-options given");
1053 goto out;
1054 }
1055 ret = read_config_file();
1056 if (ret < 0)
1057 goto out;
1058 ret = check_config();
1059 if (ret < 0)
1060 goto out;
1061 if (conf.logfile_given) {
1062 logfile = open_log(conf.logfile_arg);
1063 log_welcome(conf.loglevel_arg);
1064 }
1065 ret = dss_chdir(conf.dest_dir_arg);
1066 if (ret < 0)
1067 goto out;
1068 if (conf.daemon_given)
1069 daemon_init();
1070 setup_signal_handling();
1071 ret = call_command_handler();
1072 out:
1073 if (ret < 0)
1074 log_err_msg(EMERG, -ret);
1075 clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1076 }