Merge commit 'remotes/meins/master'
[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 static 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 /** The rsync process terminated successfully. */
79 SS_COMPLETE = 1,
80 /** The rm process is running to remove this snapshot. */
81 SS_BEING_DELETED = 2,
82 };
83
84 struct snapshot {
85 char *name;
86 int64_t creation_time;
87 int64_t completion_time;
88 enum snapshot_status_flags flags;
89 unsigned interval;
90 };
91
92 /*
93 * An edge snapshot is either the oldest one or the newest one.
94 *
95 * We need to find either of them occasionally: The create code
96 * needs to know the newest snapshot because that is the one
97 * used as the link destination dir. The pruning code needs to
98 * find the oldest one in case disk space becomes low.
99 */
100 struct edge_snapshot_data {
101 int64_t now;
102 struct snapshot snap;
103 };
104
105 __printf_2_3 void dss_log(int ll, const char* fmt,...)
106 {
107 va_list argp;
108 FILE *outfd;
109 struct tm *tm;
110 time_t t1;
111 char str[255] = "";
112
113 if (ll < conf.loglevel_arg)
114 return;
115 outfd = logfile? logfile : stderr;
116 time(&t1);
117 tm = localtime(&t1);
118 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
119 fprintf(outfd, "%s ", str);
120 if (conf.loglevel_arg <= INFO)
121 fprintf(outfd, "%i: ", ll);
122 va_start(argp, fmt);
123 vfprintf(outfd, fmt, argp);
124 va_end(argp);
125 }
126
127 /**
128 * Print a message either to stdout or to the log file.
129 */
130 __printf_1_2 void dss_msg(const char* fmt,...)
131 {
132 FILE *outfd = conf.daemon_given? logfile : stdout;
133 va_list argp;
134 va_start(argp, fmt);
135 vfprintf(outfd, fmt, argp);
136 va_end(argp);
137 }
138
139 /**
140 * Return the desired number of snapshots of an interval.
141 */
142 unsigned num_snapshots(int interval)
143 {
144 unsigned n;
145
146 assert(interval >= 0);
147
148 if (interval >= conf.num_intervals_arg)
149 return 0;
150 n = conf.num_intervals_arg - interval - 1;
151 return 1 << n;
152 }
153
154 /* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
155 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
156 {
157 int i, ret;
158 char *dash, *dot, *tmp;
159 int64_t num;
160
161 assert(dirname);
162 dash = strchr(dirname, '-');
163 if (!dash || !dash[1] || dash == dirname)
164 return 0;
165 for (i = 0; dirname[i] != '-'; i++)
166 if (!isdigit(dirname[i]))
167 return 0;
168 tmp = dss_strdup(dirname);
169 tmp[i] = '\0';
170 ret = dss_atoi64(tmp, &num);
171 free(tmp);
172 if (ret < 0) {
173 free(dss_error_txt);
174 return 0;
175 }
176 assert(num >= 0);
177 if (num > now)
178 return 0;
179 s->creation_time = num;
180 //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
181 s->interval = (long long) ((now - s->creation_time)
182 / conf.unit_interval_arg / 24 / 3600);
183 if (!strcmp(dash + 1, "incomplete")) {
184 s->completion_time = -1;
185 s->flags = 0; /* neither complete, nor being deleted */
186 goto success;
187 }
188 if (!strcmp(dash + 1, "incomplete.being_deleted")) {
189 s->completion_time = -1;
190 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
191 goto success;
192 }
193 tmp = dash + 1;
194 dot = strchr(tmp, '.');
195 if (!dot || !dot[1] || dot == tmp)
196 return 0;
197 for (i = 0; tmp[i] != '.'; i++)
198 if (!isdigit(tmp[i]))
199 return 0;
200 tmp = dss_strdup(dash + 1);
201 tmp[i] = '\0';
202 ret = dss_atoi64(tmp, &num);
203 free(tmp);
204 if (ret < 0) {
205 free(dss_error_txt);
206 return 0;
207 }
208 if (num > now)
209 return 0;
210 s->completion_time = num;
211 s->flags = SS_COMPLETE;
212 if (!strcmp(dot + 1, "being_deleted"))
213 s->flags |= SS_BEING_DELETED;
214 success:
215 s->name = dss_strdup(dirname);
216 return 1;
217 }
218
219 int64_t get_current_time(void)
220 {
221 time_t now;
222 time(&now);
223 DSS_DEBUG_LOG("now: %lli\n", (long long) now);
224 return (int64_t)now;
225 }
226
227 char *incomplete_name(int64_t start)
228 {
229 return make_message("%lli-incomplete", (long long)start);
230 }
231
232 char *being_deleted_name(struct snapshot *s)
233 {
234 if (s->flags & SS_COMPLETE)
235 return make_message("%lli-%lli.being_deleted",
236 (long long)s->creation_time,
237 (long long)s->completion_time);
238 return make_message("%lli-incomplete.being_deleted",
239 (long long)s->creation_time);
240 }
241
242 int complete_name(int64_t start, int64_t end, char **result)
243 {
244 struct tm start_tm, end_tm;
245 time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
246 time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
247 char start_str[200], end_str[200];
248
249 if (!localtime_r(start_seconds, &start_tm)) {
250 make_err_msg("%lli", (long long)start);
251 return -E_LOCALTIME;
252 }
253 if (!localtime_r(end_seconds, &end_tm)) {
254 make_err_msg("%lli", (long long)end);
255 return -E_LOCALTIME;
256 }
257 if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) {
258 make_err_msg("%lli", (long long)start);
259 return -E_STRFTIME;
260 }
261 if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) {
262 make_err_msg("%lli", (long long)end);
263 return -E_STRFTIME;
264 }
265 *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
266 start_str, end_str);
267 return 1;
268 }
269
270 struct snapshot_list {
271 int64_t now;
272 unsigned num_snapshots;
273 unsigned array_size;
274 struct snapshot **snapshots;
275 /**
276 * Array of size num_intervals + 1
277 *
278 * It contains the number of snapshots in each interval. interval_count[num_intervals]
279 * is the number of snapshots which belong to any interval greater than num_intervals.
280 */
281 unsigned *interval_count;
282 };
283
284 #define FOR_EACH_SNAPSHOT(s, i, sl) \
285 for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
286
287
288
289 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
290
291 static int compare_snapshots(const void *a, const void *b)
292 {
293 struct snapshot *s1 = *(struct snapshot **)a;
294 struct snapshot *s2 = *(struct snapshot **)b;
295 return NUM_COMPARE(s2->creation_time, s1->creation_time);
296 }
297
298 /** Compute the minimum of \a a and \a b. */
299 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
300
301 int add_snapshot(const char *dirname, void *private)
302 {
303 struct snapshot_list *sl = private;
304 struct snapshot s;
305 int ret = is_snapshot(dirname, sl->now, &s);
306
307 if (!ret)
308 return 1;
309 if (sl->num_snapshots >= sl->array_size) {
310 sl->array_size = 2 * sl->array_size + 1;
311 sl->snapshots = dss_realloc(sl->snapshots,
312 sl->array_size * sizeof(struct snapshot *));
313 }
314 sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
315 *(sl->snapshots[sl->num_snapshots]) = s;
316 sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
317 sl->num_snapshots++;
318 return 1;
319 }
320
321 void get_snapshot_list(struct snapshot_list *sl)
322 {
323 sl->now = get_current_time();
324 sl->num_snapshots = 0;
325 sl->array_size = 0;
326 sl->snapshots = NULL;
327 sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
328 for_each_subdir(add_snapshot, sl);
329 qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
330 compare_snapshots);
331 }
332
333 void free_snapshot_list(struct snapshot_list *sl)
334 {
335 int i;
336 struct snapshot *s;
337
338 FOR_EACH_SNAPSHOT(s, i, sl) {
339 free(s->name);
340 free(s);
341 }
342 free(sl->interval_count);
343 sl->interval_count = NULL;
344 free(sl->snapshots);
345 sl->snapshots = NULL;
346 sl->num_snapshots = 0;
347 }
348
349 void stop_rsync_process(void)
350 {
351 if (!rsync_pid || rsync_stopped)
352 return;
353 kill(SIGSTOP, rsync_pid);
354 rsync_stopped = 1;
355 }
356
357 void restart_rsync_process(void)
358 {
359 if (!rsync_pid || !rsync_stopped)
360 return;
361 kill (SIGCONT, rsync_pid);
362 rsync_stopped = 0;
363 }
364
365 /**
366 * Print a log message about the exit status of a child.
367 */
368 void log_termination_msg(pid_t pid, int status)
369 {
370 if (WIFEXITED(status))
371 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
372 WEXITSTATUS(status));
373 else if (WIFSIGNALED(status))
374 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
375 WTERMSIG(status));
376 else
377 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
378 }
379
380 int wait_for_process(pid_t pid, int *status)
381 {
382 int ret;
383
384 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
385 for (;;) {
386 pause();
387 ret = next_signal();
388 if (ret < 0)
389 break;
390 if (!ret)
391 continue;
392 if (ret == SIGCHLD) {
393 ret = waitpid(pid, status, 0);
394 if (ret >= 0)
395 break;
396 if (errno != EINTR) { /* error */
397 ret = -ERRNO_TO_DSS_ERROR(errno);
398 break;
399 }
400 }
401 /* SIGINT or SIGTERM */
402 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
403 kill(pid, SIGTERM);
404 }
405 if (ret < 0)
406 make_err_msg("failed to wait for process %d", (int)pid);
407 else
408 log_termination_msg(pid, *status);
409 return ret;
410 }
411
412 int remove_snapshot(struct snapshot *s)
413 {
414 int fds[3] = {0, 0, 0};
415 assert(!rm_pid);
416 char *new_name = being_deleted_name(s);
417 int ret = dss_rename(s->name, new_name);
418 char *argv[] = {"rm", "-rf", new_name, NULL};
419
420 if (ret < 0)
421 goto out;
422 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
423 stop_rsync_process();
424 ret = dss_exec(&rm_pid, argv[0], argv, fds);
425 out:
426 free(new_name);
427 return ret;
428 }
429
430 /*
431 * return: 0: no redundant snapshots, 1: rm process started, negative: error
432 */
433 int remove_redundant_snapshot(struct snapshot_list *sl)
434 {
435 int ret, i, interval;
436 struct snapshot *s;
437 unsigned missing = 0;
438
439 DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
440 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
441 unsigned keep = num_snapshots(interval);
442 unsigned num = sl->interval_count[interval];
443 struct snapshot *victim = NULL, *prev = NULL;
444 int64_t score = LONG_MAX;
445
446 if (keep >= num)
447 missing += keep - num;
448 DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
449 interval, keep, num, missing);
450 if (keep + missing >= num)
451 continue;
452 /* redundant snapshot in this interval, pick snapshot with lowest score */
453 FOR_EACH_SNAPSHOT(s, i, sl) {
454 int64_t this_score;
455
456 //DSS_DEBUG_LOG("checking %s\n", s->name);
457 if (s->interval > interval) {
458 prev = s;
459 continue;
460 }
461 if (s->interval < interval)
462 break;
463 if (!victim) {
464 victim = s;
465 prev = s;
466 continue;
467 }
468 assert(prev);
469 /* check if s is a better victim */
470 this_score = s->creation_time - prev->creation_time;
471 assert(this_score >= 0);
472 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
473 if (this_score < score) {
474 score = this_score;
475 victim = s;
476 }
477 prev = s;
478 }
479 assert(victim);
480 if (conf.dry_run_given) {
481 dss_msg("%s would be removed (interval = %i)\n",
482 victim->name, victim->interval);
483 continue;
484 }
485 ret = remove_snapshot(victim);
486 return ret < 0? ret : 1;
487 }
488 return 0;
489 }
490
491 int remove_outdated_snapshot(struct snapshot_list *sl)
492 {
493 int i, ret;
494 struct snapshot *s;
495
496 DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
497 conf.num_intervals_arg);
498 FOR_EACH_SNAPSHOT(s, i, sl) {
499 if (s->interval <= conf.num_intervals_arg)
500 continue;
501 if (conf.dry_run_given) {
502 dss_msg("%s would be removed (interval = %i)\n",
503 s->name, s->interval);
504 continue;
505 }
506 ret = remove_snapshot(s);
507 if (ret < 0)
508 return ret;
509 return 1;
510 }
511 return 0;
512 }
513
514 int handle_rm_exit(int status)
515 {
516 int es, ret;
517
518 if (!WIFEXITED(status)) {
519 make_err_msg("rm process %d died involuntary", (int)rm_pid);
520 ret = -E_INVOLUNTARY_EXIT;
521 goto out;
522 }
523 es = WEXITSTATUS(status);
524 if (es) {
525 make_err_msg("rm process %d returned %d", (int)rm_pid, es);
526 ret = -E_BAD_EXIT_CODE;
527 goto out;
528 }
529 ret = 1;
530 rm_pid = 0;
531 out:
532 return ret;
533 }
534
535 int wait_for_rm_process(void)
536 {
537 int status, ret = wait_for_process(rm_pid, &status);
538
539 if (ret < 0)
540 return ret;
541 return handle_rm_exit(status);
542 }
543
544 void kill_process(pid_t pid)
545 {
546 if (!pid)
547 return;
548 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
549 kill(pid, SIGTERM);
550 }
551
552 int check_config(void)
553 {
554 if (conf.unit_interval_arg <= 0) {
555 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
556 return -E_INVALID_NUMBER;
557 }
558 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
559 if (conf.num_intervals_arg <= 0) {
560 make_err_msg("bad number of intervals %i", conf.num_intervals_arg);
561 return -E_INVALID_NUMBER;
562 }
563 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
564 return 1;
565 }
566
567 /* exits on errors */
568 void parse_config_file(int override)
569 {
570 int ret;
571 char *config_file;
572 struct stat statbuf;
573 char *old_logfile_arg = NULL;
574 int old_daemon_given = 0;
575
576 if (conf.config_file_given)
577 config_file = dss_strdup(conf.config_file_arg);
578 else {
579 char *home = get_homedir();
580 config_file = make_message("%s/.dssrc", home);
581 free(home);
582 }
583 if (override) { /* SIGHUP */
584 if (conf.logfile_given)
585 old_logfile_arg = dss_strdup(conf.logfile_arg);
586 old_daemon_given = conf.daemon_given;
587 }
588
589 ret = stat(config_file, &statbuf);
590 if (ret && conf.config_file_given) {
591 ret = -ERRNO_TO_DSS_ERROR(errno);
592 make_err_msg("failed to stat config file %s", config_file);
593 goto out;
594 }
595 if (!ret) {
596 struct cmdline_parser_params params = {
597 .override = override,
598 .initialize = 0,
599 .check_required = 0,
600 .check_ambiguity = 0
601 };
602 cmdline_parser_config_file(config_file, &conf, &params);
603 }
604 if (!conf.source_dir_given || !conf.dest_dir_given) {
605 ret = -E_SYNTAX;
606 make_err_msg("you need to specify both source_dir and dest_dir");
607 goto out;
608 }
609 ret = check_config();
610 if (ret < 0)
611 goto out;
612 if (override) {
613 /* don't change daemon mode on SIGHUP */
614 conf.daemon_given = old_daemon_given;
615 close_log(logfile);
616 logfile = NULL;
617 if (conf.logfile_given)
618 free(old_logfile_arg);
619 else if (conf.daemon_given) { /* re-use old logfile */
620 conf.logfile_arg = old_logfile_arg;
621 conf.logfile_given = 1;
622 }
623 }
624 if (conf.logfile_given) {
625 logfile = open_log(conf.logfile_arg);
626 log_welcome(conf.loglevel_arg);
627 }
628 ret = dss_chdir(conf.dest_dir_arg);
629 out:
630 free(config_file);
631 if (ret >= 0)
632 return;
633 log_err_msg(EMERG, -ret);
634 exit(EXIT_FAILURE);
635 }
636
637 void handle_sighup(void)
638 {
639 DSS_NOTICE_LOG("SIGHUP\n");
640 parse_config_file(1);
641 }
642
643 int rename_incomplete_snapshot(int64_t start)
644 {
645 char *old_name, *new_name;
646 int ret;
647
648 ret = complete_name(start, get_current_time(), &new_name);
649 if (ret < 0)
650 return ret;
651 old_name = incomplete_name(start);
652 ret = dss_rename(old_name, new_name);
653 if (ret >= 0)
654 DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
655 free(old_name);
656 free(new_name);
657 return ret;
658 }
659
660 int handle_rsync_exit(int status)
661 {
662 int es, ret;
663
664 if (!WIFEXITED(status)) {
665 make_err_msg("rsync process %d died involuntary", (int)rsync_pid);
666 ret = -E_INVOLUNTARY_EXIT;
667 goto out;
668 }
669 es = WEXITSTATUS(status);
670 if (es != 0 && es != 23 && es != 24) {
671 make_err_msg("rsync process %d returned %d", (int)rsync_pid, es);
672 ret = -E_BAD_EXIT_CODE;
673 goto out;
674 }
675 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
676 out:
677 rsync_pid = 0;
678 current_snapshot_creation_time = 0;
679 rsync_stopped = 0;
680 return ret;
681 }
682
683 int get_newest_complete(const char *dirname, void *private)
684 {
685 struct edge_snapshot_data *esd = private;
686 struct snapshot s;
687 int ret = is_snapshot(dirname, esd->now, &s);
688
689 if (ret <= 0)
690 return 1;
691 if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
692 return 1;
693 if (s.creation_time < esd->snap.creation_time)
694 return 1;
695 free(esd->snap.name);
696 esd->snap = s;
697 return 1;
698 }
699
700 __malloc char *name_of_newest_complete_snapshot(void)
701 {
702 struct edge_snapshot_data esd = {
703 .now = get_current_time(),
704 .snap = {.creation_time = -1}
705 };
706 for_each_subdir(get_newest_complete, &esd);
707 return esd.snap.name;
708 }
709
710 void create_rsync_argv(char ***argv, int64_t *num)
711 {
712 char *logname, *newest = name_of_newest_complete_snapshot();
713 int i = 0, j;
714
715 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
716 (*argv)[i++] = dss_strdup("rsync");
717 (*argv)[i++] = dss_strdup("-aq");
718 (*argv)[i++] = dss_strdup("--delete");
719 for (j = 0; j < conf.rsync_option_given; j++)
720 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
721 if (newest) {
722 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
723 (*argv)[i++] = make_message("--link-dest=../%s", newest);
724 free(newest);
725 } else
726 DSS_INFO_LOG("no previous snapshot found\n");
727 if (conf.exclude_patterns_given) {
728 (*argv)[i++] = dss_strdup("--exclude-from");
729 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
730
731 }
732 logname = dss_logname();
733 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
734 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
735 else
736 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
737 conf.remote_user_arg : logname,
738 conf.remote_host_arg, conf.source_dir_arg);
739 free(logname);
740 *num = get_current_time();
741 (*argv)[i++] = incomplete_name(*num);
742 (*argv)[i++] = NULL;
743 for (j = 0; j < i; j++)
744 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
745 }
746
747 void free_rsync_argv(char **argv)
748 {
749 int i;
750 for (i = 0; argv[i]; i++)
751 free(argv[i]);
752 free(argv);
753 }
754
755 int create_snapshot(char **argv)
756 {
757 int fds[3] = {0, 0, 0};
758 char *name = incomplete_name(current_snapshot_creation_time);
759
760 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
761 free(name);
762 return dss_exec(&rsync_pid, argv[0], argv, fds);
763 }
764
765 void compute_next_snapshot_time(struct snapshot_list *sl)
766 {
767 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
768 tmp, diff;
769 int64_t x = 0;
770 unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
771 int i, ret;
772 struct snapshot *s;
773
774 gettimeofday(&now, NULL);
775 FOR_EACH_SNAPSHOT(s, i, sl) {
776 if (!(s->flags & SS_COMPLETE))
777 continue;
778 num_complete_snapshots++;
779 x += s->completion_time - s->creation_time;
780 }
781 assert(x >= 0);
782 if (num_complete_snapshots)
783 x /= num_complete_snapshots; /* avg time to create one snapshot */
784 x *= wanted; /* time to create all snapshots in interval 0 */
785 tmp.tv_sec = x;
786 tmp.tv_usec = 0;
787 ret = tv_diff(&unit_interval, &tmp, &diff); /* time between creation */
788 if (ret < 0) {
789 next_snapshot_time = now;
790 return;
791 }
792 tv_divide(wanted, &diff, &tmp);
793 tv_add(&now, &tmp, &next_snapshot_time);
794 }
795
796 void handle_signal(void)
797 {
798 int sig, ret = next_signal();
799
800 if (ret <= 0)
801 goto out;
802 sig = ret;
803 switch (sig) {
804 int status;
805 pid_t pid;
806 case SIGINT:
807 case SIGTERM:
808 restart_rsync_process();
809 kill_process(rsync_pid);
810 kill_process(rm_pid);
811 exit(EXIT_FAILURE);
812 case SIGHUP:
813 handle_sighup();
814 ret = 1;
815 break;
816 case SIGCHLD:
817 ret = reap_child(&pid, &status);
818 if (ret <= 0)
819 break;
820 assert(pid == rsync_pid || pid == rm_pid);
821 if (pid == rsync_pid)
822 ret = handle_rsync_exit(status);
823 else
824 ret = handle_rm_exit(status);
825 }
826 out:
827 if (ret < 0)
828 log_err_msg(ERROR, -ret);
829 }
830
831 int get_oldest(const char *dirname, void *private)
832 {
833 struct edge_snapshot_data *esd = private;
834 struct snapshot s;
835 int ret = is_snapshot(dirname, esd->now, &s);
836
837 if (ret <= 0)
838 return 1;
839 if (s.creation_time > esd->snap.creation_time)
840 return 1;
841 free(esd->snap.name);
842 esd->snap = s;
843 return 1;
844 }
845
846 int remove_oldest_snapshot()
847 {
848 int ret;
849 struct edge_snapshot_data esd = {
850 .now = get_current_time(),
851 .snap = {.creation_time = LLONG_MAX}
852 };
853 for_each_subdir(get_oldest, &esd);
854 if (!esd.snap.name) /* no snapshot found */
855 return 0;
856 DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
857 ret = 0;
858 if (esd.snap.creation_time == current_snapshot_creation_time)
859 goto out; /* do not remove the snapshot currently being created */
860 ret = remove_snapshot(&esd.snap);
861 out:
862 free(esd.snap.name);
863 return ret;
864 }
865
866 /* TODO: Also consider number of inodes. */
867 int disk_space_low(void)
868 {
869 struct disk_space ds;
870 int ret = get_disk_space(".", &ds);
871
872 if (ret < 0)
873 return ret;
874 if (conf.min_free_mb_arg)
875 if (ds.free_mb < conf.min_free_mb_arg)
876 return 1;
877 if (conf.min_free_percent_arg)
878 if (ds.percent_free < conf.min_free_percent_arg)
879 return 1;
880 return 0;
881 }
882
883 int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
884 {
885 int ret;
886
887 ret = remove_outdated_snapshot(sl);
888 if (ret) /* error, or we are removing something */
889 return ret;
890 /* no outdated snapshot */
891 ret = remove_redundant_snapshot(sl);
892 if (ret)
893 return ret;
894 if (!low_disk_space)
895 return 0;
896 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
897 ret = remove_oldest_snapshot();
898 if (ret)
899 return ret;
900 make_err_msg("uhuhu: not enough disk space for a single snapshot");
901 return -ENOSPC;
902 }
903
904 int select_loop(void)
905 {
906 int ret;
907 struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
908 struct snapshot_list sl = {.num_snapshots = 0};
909
910 for (;;) {
911 struct timeval now, *tvp = &tv;
912 fd_set rfds;
913 int low_disk_space;
914 char **rsync_argv;
915
916 free_snapshot_list(&sl);
917 get_snapshot_list(&sl);
918 compute_next_snapshot_time(&sl);
919 FD_ZERO(&rfds);
920 FD_SET(signal_pipe, &rfds);
921 if (rsync_pid)
922 tv.tv_sec = 60;
923 else if (rm_pid)
924 tvp = NULL;
925 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
926 if (ret < 0)
927 return ret;
928 if (FD_ISSET(signal_pipe, &rfds)) {
929 handle_signal();
930 continue;
931 }
932 if (rm_pid)
933 continue;
934 ret = disk_space_low();
935 if (ret < 0)
936 break;
937 low_disk_space = ret;
938 if (low_disk_space)
939 stop_rsync_process();
940 ret = try_to_free_disk_space(low_disk_space, &sl);
941 if (ret < 0)
942 break;
943 if (rm_pid)
944 continue;
945 if (rsync_pid) {
946 restart_rsync_process();
947 continue;
948 }
949 /* neither rsync nor rm are running. Start rsync? */
950 gettimeofday(&now, NULL);
951 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
952 continue;
953 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
954 ret = create_snapshot(rsync_argv);
955 free_rsync_argv(rsync_argv);
956 if (ret < 0)
957 break;
958 }
959 free_snapshot_list(&sl);
960 return ret;
961 }
962
963 int com_run(void)
964 {
965 int ret;
966
967 if (conf.dry_run_given) {
968 make_err_msg("dry_run not supported by this command");
969 return -E_SYNTAX;
970 }
971 ret = install_sighandler(SIGHUP);
972 if (ret < 0)
973 return ret;
974 return select_loop();
975 }
976
977 void log_disk_space(struct disk_space *ds)
978 {
979 DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
980 ds->free_mb, ds->total_mb, ds->percent_free,
981 ds->percent_free_inodes);
982 }
983
984 int com_prune(void)
985 {
986 int ret;
987 struct snapshot_list sl;
988 struct disk_space ds;
989
990 ret = get_disk_space(".", &ds);
991 if (ret < 0)
992 return ret;
993 log_disk_space(&ds);
994 for (;;) {
995 get_snapshot_list(&sl);
996 ret = remove_outdated_snapshot(&sl);
997 free_snapshot_list(&sl);
998 if (ret < 0)
999 return ret;
1000 if (!ret)
1001 break;
1002 ret = wait_for_rm_process();
1003 if (ret < 0)
1004 goto out;
1005 }
1006 for (;;) {
1007 get_snapshot_list(&sl);
1008 ret = remove_redundant_snapshot(&sl);
1009 free_snapshot_list(&sl);
1010 if (ret < 0)
1011 return ret;
1012 if (!ret)
1013 break;
1014 ret = wait_for_rm_process();
1015 if (ret < 0)
1016 goto out;
1017 }
1018 return 1;
1019 out:
1020 return ret;
1021 }
1022
1023 int com_create(void)
1024 {
1025 int ret, status;
1026 char **rsync_argv;
1027
1028 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1029 if (conf.dry_run_given) {
1030 int i;
1031 char *msg = NULL;
1032 for (i = 0; rsync_argv[i]; i++) {
1033 char *tmp = msg;
1034 msg = make_message("%s%s%s", tmp? tmp : "",
1035 tmp? " " : "", rsync_argv[i]);
1036 free(tmp);
1037 }
1038 dss_msg("%s\n", msg);
1039 free(msg);
1040 return 1;
1041 }
1042 ret = create_snapshot(rsync_argv);
1043 if (ret < 0)
1044 goto out;
1045 ret = wait_for_process(rsync_pid, &status);
1046 if (ret < 0)
1047 goto out;
1048 ret = handle_rsync_exit(status);
1049 out:
1050 free_rsync_argv(rsync_argv);
1051 return ret;
1052 }
1053
1054 int com_ls(void)
1055 {
1056 int i;
1057 struct snapshot_list sl;
1058 struct snapshot *s;
1059 get_snapshot_list(&sl);
1060 FOR_EACH_SNAPSHOT(s, i, &sl)
1061 dss_msg("%u\t%s\n", s->interval, s->name);
1062 free_snapshot_list(&sl);
1063 return 1;
1064 }
1065
1066 __noreturn void clean_exit(int status)
1067 {
1068 free(dss_error_txt);
1069 exit(status);
1070 }
1071 static void setup_signal_handling(void)
1072 {
1073 int ret;
1074
1075 DSS_INFO_LOG("setting up signal handlers\n");
1076 signal_pipe = signal_init(); /* always successful */
1077 ret = install_sighandler(SIGINT);
1078 if (ret < 0)
1079 goto err;
1080 ret = install_sighandler(SIGTERM);
1081 if (ret < 0)
1082 goto err;
1083 ret = install_sighandler(SIGCHLD);
1084 if (ret < 0)
1085 goto err;
1086 return;
1087 err:
1088 DSS_EMERG_LOG("could not install signal handlers\n");
1089 exit(EXIT_FAILURE);
1090 }
1091
1092 int main(int argc, char **argv)
1093 {
1094 int ret;
1095
1096 cmdline_parser(argc, argv, &conf); /* aborts on errors */
1097 parse_config_file(0);
1098 if (conf.daemon_given)
1099 daemon_init();
1100 setup_signal_handling();
1101 ret = call_command_handler();
1102 if (ret < 0)
1103 log_err_msg(EMERG, -ret);
1104 clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1105 }