Kill unused dss_error_txt.
[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 static FILE *logfile;
34 static int signal_pipe;
35
36 /** Process id of current rsync process. */
37 static pid_t rsync_pid;
38 /** Whether the rsync process is currently stopped */
39 static int rsync_stopped;
40 /** Process id of current rm process. */
41 static pid_t rm_pid;
42 /** When the next snapshot is due. */
43 struct timeval next_snapshot_time;
44 /** The pid of the pre-create hook. */
45 pid_t pre_create_hook_pid;
46 /** The pid of the post-create hook. */
47 pid_t post_create_hook_pid;
48
49 /* Creation time of the snapshot currently being created. */
50 int64_t current_snapshot_creation_time;
51
52 static char *path_to_last_complete_snapshot;
53
54 enum {
55 /** We are ready to take the next snapshot. */
56 SCS_READY,
57 /** The pre-creation hook has been started. */
58 SCS_PRE_HOOK_RUNNING,
59 /** The pre-creation hook exited successfully. */
60 SCS_PRE_HOOK_SUCCESS,
61 /** The rsync process is running. */
62 SCS_RSYNC_RUNNING,
63 /** The rsync process exited successfully. */
64 SCS_RSYNC_SUCCESS,
65 /** The post-create hook has been started- */
66 SCS_POST_HOOK_RUNNING,
67 };
68
69 static unsigned snapshot_creation_status;
70
71
72 DEFINE_DSS_ERRLIST;
73
74
75 /* a litte cpp magic helps to DRY */
76 #define COMMANDS \
77 COMMAND(ls) \
78 COMMAND(create) \
79 COMMAND(prune) \
80 COMMAND(run)
81 #define COMMAND(x) int com_ ##x(void);
82 COMMANDS
83 #undef COMMAND
84 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
85 int call_command_handler(void)
86 {
87 COMMANDS
88 DSS_EMERG_LOG("BUG: did not find command handler\n");
89 exit(EXIT_FAILURE);
90 }
91 #undef COMMAND
92 #undef COMMANDS
93
94 /*
95 * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
96 * complete, being deleted: 1204565370-1204565371.being_deleted
97 * incomplete, not being deleted: 1204565370-incomplete
98 * incomplete, being deleted: 1204565370-incomplete.being_deleted
99 */
100 enum snapshot_status_flags {
101 /** The rsync process terminated successfully. */
102 SS_COMPLETE = 1,
103 /** The rm process is running to remove this snapshot. */
104 SS_BEING_DELETED = 2,
105 };
106
107 struct snapshot {
108 char *name;
109 int64_t creation_time;
110 int64_t completion_time;
111 enum snapshot_status_flags flags;
112 unsigned interval;
113 };
114
115 __printf_2_3 void dss_log(int ll, const char* fmt,...)
116 {
117 va_list argp;
118 FILE *outfd;
119 struct tm *tm;
120 time_t t1;
121 char str[255] = "";
122
123 if (ll < conf.loglevel_arg)
124 return;
125 outfd = logfile? logfile : stderr;
126 time(&t1);
127 tm = localtime(&t1);
128 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
129 fprintf(outfd, "%s ", str);
130 if (conf.loglevel_arg <= INFO)
131 fprintf(outfd, "%i: ", ll);
132 va_start(argp, fmt);
133 vfprintf(outfd, fmt, argp);
134 va_end(argp);
135 }
136
137 /**
138 * Print a message either to stdout or to the log file.
139 */
140 __printf_1_2 void dss_msg(const char* fmt,...)
141 {
142 FILE *outfd = conf.daemon_given? logfile : stdout;
143 va_list argp;
144 va_start(argp, fmt);
145 vfprintf(outfd, fmt, argp);
146 va_end(argp);
147 }
148
149 /**
150 * Return the desired number of snapshots of an interval.
151 */
152 unsigned num_snapshots(int interval)
153 {
154 unsigned n;
155
156 assert(interval >= 0);
157
158 if (interval >= conf.num_intervals_arg)
159 return 0;
160 n = conf.num_intervals_arg - interval - 1;
161 return 1 << n;
162 }
163
164 /* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
165 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
166 {
167 int i, ret;
168 char *dash, *dot, *tmp;
169 int64_t num;
170
171 assert(dirname);
172 dash = strchr(dirname, '-');
173 if (!dash || !dash[1] || dash == dirname)
174 return 0;
175 for (i = 0; dirname[i] != '-'; i++)
176 if (!isdigit(dirname[i]))
177 return 0;
178 tmp = dss_strdup(dirname);
179 tmp[i] = '\0';
180 ret = dss_atoi64(tmp, &num);
181 free(tmp);
182 if (ret < 0)
183 return 0;
184 assert(num >= 0);
185 if (num > now)
186 return 0;
187 s->creation_time = num;
188 //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
189 s->interval = (long long) ((now - s->creation_time)
190 / conf.unit_interval_arg / 24 / 3600);
191 if (!strcmp(dash + 1, "incomplete")) {
192 s->completion_time = -1;
193 s->flags = 0; /* neither complete, nor being deleted */
194 goto success;
195 }
196 if (!strcmp(dash + 1, "incomplete.being_deleted")) {
197 s->completion_time = -1;
198 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
199 goto success;
200 }
201 tmp = dash + 1;
202 dot = strchr(tmp, '.');
203 if (!dot || !dot[1] || dot == tmp)
204 return 0;
205 for (i = 0; tmp[i] != '.'; i++)
206 if (!isdigit(tmp[i]))
207 return 0;
208 tmp = dss_strdup(dash + 1);
209 tmp[i] = '\0';
210 ret = dss_atoi64(tmp, &num);
211 free(tmp);
212 if (ret < 0)
213 return 0;
214 if (num > now)
215 return 0;
216 s->completion_time = num;
217 s->flags = SS_COMPLETE;
218 if (!strcmp(dot + 1, "being_deleted"))
219 s->flags |= SS_BEING_DELETED;
220 success:
221 s->name = dss_strdup(dirname);
222 return 1;
223 }
224
225 int64_t get_current_time(void)
226 {
227 time_t now;
228 time(&now);
229 DSS_DEBUG_LOG("now: %lli\n", (long long) now);
230 return (int64_t)now;
231 }
232
233 char *incomplete_name(int64_t start)
234 {
235 return make_message("%lli-incomplete", (long long)start);
236 }
237
238 char *being_deleted_name(struct snapshot *s)
239 {
240 if (s->flags & SS_COMPLETE)
241 return make_message("%lli-%lli.being_deleted",
242 (long long)s->creation_time,
243 (long long)s->completion_time);
244 return make_message("%lli-incomplete.being_deleted",
245 (long long)s->creation_time);
246 }
247
248 int complete_name(int64_t start, int64_t end, char **result)
249 {
250 struct tm start_tm, end_tm;
251 time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
252 time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
253 char start_str[200], end_str[200];
254
255 if (!localtime_r(start_seconds, &start_tm))
256 return -E_LOCALTIME;
257 if (!localtime_r(end_seconds, &end_tm))
258 return -E_LOCALTIME;
259 if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm))
260 return -E_STRFTIME;
261 if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm))
262 return -E_STRFTIME;
263 *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
264 start_str, end_str);
265 return 1;
266 }
267
268 struct snapshot_list {
269 int64_t now;
270 unsigned num_snapshots;
271 unsigned array_size;
272 struct snapshot **snapshots;
273 /**
274 * Array of size num_intervals + 1
275 *
276 * It contains the number of snapshots in each interval. interval_count[num_intervals]
277 * is the number of snapshots which belong to any interval greater than num_intervals.
278 */
279 unsigned *interval_count;
280 };
281
282 #define FOR_EACH_SNAPSHOT(s, i, sl) \
283 for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
284
285 #define FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) \
286 for ((i) = (sl)->num_snapshots; (i) > 0 && ((s) = (sl)->snapshots[(i - 1)]); (i)--)
287
288 static inline struct snapshot *oldest_snapshot(struct snapshot_list *sl)
289 {
290 if (!sl->num_snapshots)
291 return NULL;
292 return sl->snapshots[0];
293 }
294
295 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
296
297 static int compare_snapshots(const void *a, const void *b)
298 {
299 struct snapshot *s1 = *(struct snapshot **)a;
300 struct snapshot *s2 = *(struct snapshot **)b;
301 return NUM_COMPARE(s2->creation_time, s1->creation_time);
302 }
303
304 /** Compute the minimum of \a a and \a b. */
305 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
306
307 int add_snapshot(const char *dirname, void *private)
308 {
309 struct snapshot_list *sl = private;
310 struct snapshot s;
311 int ret = is_snapshot(dirname, sl->now, &s);
312
313 if (!ret)
314 return 1;
315 if (sl->num_snapshots >= sl->array_size) {
316 sl->array_size = 2 * sl->array_size + 1;
317 sl->snapshots = dss_realloc(sl->snapshots,
318 sl->array_size * sizeof(struct snapshot *));
319 }
320 sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
321 *(sl->snapshots[sl->num_snapshots]) = s;
322 sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
323 sl->num_snapshots++;
324 return 1;
325 }
326
327 void get_snapshot_list(struct snapshot_list *sl)
328 {
329 sl->now = get_current_time();
330 sl->num_snapshots = 0;
331 sl->array_size = 0;
332 sl->snapshots = NULL;
333 sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
334 for_each_subdir(add_snapshot, sl);
335 qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
336 compare_snapshots);
337 }
338
339 void free_snapshot_list(struct snapshot_list *sl)
340 {
341 int i;
342 struct snapshot *s;
343
344 FOR_EACH_SNAPSHOT(s, i, sl) {
345 free(s->name);
346 free(s);
347 }
348 free(sl->interval_count);
349 sl->interval_count = NULL;
350 free(sl->snapshots);
351 sl->snapshots = NULL;
352 sl->num_snapshots = 0;
353 }
354
355 void stop_rsync_process(void)
356 {
357 if (!rsync_pid || rsync_stopped)
358 return;
359 kill(SIGSTOP, rsync_pid);
360 rsync_stopped = 1;
361 }
362
363 void restart_rsync_process(void)
364 {
365 if (!rsync_pid || !rsync_stopped)
366 return;
367 kill (SIGCONT, rsync_pid);
368 rsync_stopped = 0;
369 }
370
371 /**
372 * Print a log message about the exit status of a child.
373 */
374 void log_termination_msg(pid_t pid, int status)
375 {
376 if (WIFEXITED(status))
377 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
378 WEXITSTATUS(status));
379 else if (WIFSIGNALED(status))
380 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
381 WTERMSIG(status));
382 else
383 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
384 }
385
386 int wait_for_process(pid_t pid, int *status)
387 {
388 int ret;
389
390 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
391 for (;;) {
392 fd_set rfds;
393
394 FD_ZERO(&rfds);
395 FD_SET(signal_pipe, &rfds);
396 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
397 if (ret < 0)
398 break;
399 ret = next_signal();
400 if (!ret)
401 continue;
402 if (ret == SIGCHLD) {
403 ret = waitpid(pid, status, 0);
404 if (ret >= 0)
405 break;
406 if (errno != EINTR) { /* error */
407 ret = -ERRNO_TO_DSS_ERROR(errno);
408 break;
409 }
410 }
411 /* SIGINT or SIGTERM */
412 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
413 kill(pid, SIGTERM);
414 }
415 if (ret < 0)
416 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
417 else
418 log_termination_msg(pid, *status);
419 return ret;
420 }
421
422 int remove_snapshot(struct snapshot *s)
423 {
424 int fds[3] = {0, 0, 0};
425 assert(!rm_pid);
426 char *new_name = being_deleted_name(s);
427 int ret = dss_rename(s->name, new_name);
428 char *argv[] = {"rm", "-rf", new_name, NULL};
429
430 if (ret < 0)
431 goto out;
432 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
433 stop_rsync_process();
434 ret = dss_exec(&rm_pid, argv[0], argv, fds);
435 out:
436 free(new_name);
437 return ret;
438 }
439
440 /*
441 * return: 0: no redundant snapshots, 1: rm process started, negative: error
442 */
443 int remove_redundant_snapshot(struct snapshot_list *sl)
444 {
445 int ret, i, interval;
446 struct snapshot *s;
447 unsigned missing = 0;
448
449 DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
450 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
451 unsigned keep = num_snapshots(interval);
452 unsigned num = sl->interval_count[interval];
453 struct snapshot *victim = NULL, *prev = NULL;
454 int64_t score = LONG_MAX;
455
456 if (keep >= num)
457 missing += keep - num;
458 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
459 // interval, keep, num, missing);
460 if (keep + missing >= num)
461 continue;
462 /* redundant snapshot in this interval, pick snapshot with lowest score */
463 FOR_EACH_SNAPSHOT(s, i, sl) {
464 int64_t this_score;
465
466 //DSS_DEBUG_LOG("checking %s\n", s->name);
467 if (s->interval > interval) {
468 prev = s;
469 continue;
470 }
471 if (s->interval < interval)
472 break;
473 if (!victim) {
474 victim = s;
475 prev = s;
476 continue;
477 }
478 assert(prev);
479 /* check if s is a better victim */
480 this_score = s->creation_time - prev->creation_time;
481 assert(this_score >= 0);
482 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
483 if (this_score < score) {
484 score = this_score;
485 victim = s;
486 }
487 prev = s;
488 }
489 assert(victim);
490 if (conf.dry_run_given) {
491 dss_msg("%s would be removed (interval = %i)\n",
492 victim->name, victim->interval);
493 continue;
494 }
495 ret = remove_snapshot(victim);
496 return ret < 0? ret : 1;
497 }
498 return 0;
499 }
500
501 int remove_outdated_snapshot(struct snapshot_list *sl)
502 {
503 int i, ret;
504 struct snapshot *s;
505
506 DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
507 conf.num_intervals_arg);
508 FOR_EACH_SNAPSHOT(s, i, sl) {
509 if (s->interval <= conf.num_intervals_arg)
510 continue;
511 if (conf.dry_run_given) {
512 dss_msg("%s would be removed (interval = %i)\n",
513 s->name, s->interval);
514 continue;
515 }
516 ret = remove_snapshot(s);
517 if (ret < 0)
518 return ret;
519 return 1;
520 }
521 return 0;
522 }
523
524 int handle_rm_exit(int status)
525 {
526 rm_pid = 0;
527 if (!WIFEXITED(status))
528 return -E_INVOLUNTARY_EXIT;
529 if (WEXITSTATUS(status))
530 return -E_BAD_EXIT_CODE;
531 return 1;
532 }
533
534 int wait_for_rm_process(void)
535 {
536 int status, ret = wait_for_process(rm_pid, &status);
537
538 if (ret < 0)
539 return ret;
540 return handle_rm_exit(status);
541 }
542
543 void kill_process(pid_t pid)
544 {
545 if (!pid)
546 return;
547 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
548 kill(pid, SIGTERM);
549 }
550
551 int check_config(void)
552 {
553 if (conf.unit_interval_arg <= 0) {
554 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
555 return -E_INVALID_NUMBER;
556 }
557 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
558 if (conf.num_intervals_arg <= 0) {
559 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
560 return -E_INVALID_NUMBER;
561 }
562 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
563 return 1;
564 }
565
566 /* exits on errors */
567 void parse_config_file(int override)
568 {
569 int ret;
570 char *config_file;
571 struct stat statbuf;
572 char *old_logfile_arg = NULL;
573 int old_daemon_given = 0;
574
575 if (conf.config_file_given)
576 config_file = dss_strdup(conf.config_file_arg);
577 else {
578 char *home = get_homedir();
579 config_file = make_message("%s/.dssrc", home);
580 free(home);
581 }
582 if (override) { /* SIGHUP */
583 if (conf.logfile_given)
584 old_logfile_arg = dss_strdup(conf.logfile_arg);
585 old_daemon_given = conf.daemon_given;
586 }
587
588 ret = stat(config_file, &statbuf);
589 if (ret && conf.config_file_given) {
590 ret = -ERRNO_TO_DSS_ERROR(errno);
591 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
592 goto out;
593 }
594 if (!ret) {
595 struct cmdline_parser_params params = {
596 .override = override,
597 .initialize = 0,
598 .check_required = 1,
599 .check_ambiguity = 0
600 };
601 cmdline_parser_config_file(config_file, &conf, &params);
602 }
603 ret = check_config();
604 if (ret < 0)
605 goto out;
606 if (override) {
607 /* don't change daemon mode on SIGHUP */
608 conf.daemon_given = old_daemon_given;
609 close_log(logfile);
610 logfile = NULL;
611 if (conf.logfile_given)
612 free(old_logfile_arg);
613 else if (conf.daemon_given) { /* re-use old logfile */
614 conf.logfile_arg = old_logfile_arg;
615 conf.logfile_given = 1;
616 }
617 }
618 if (conf.logfile_given) {
619 logfile = open_log(conf.logfile_arg);
620 log_welcome(conf.loglevel_arg);
621 }
622 DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg);
623 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
624 ret = dss_chdir(conf.dest_dir_arg);
625 out:
626 free(config_file);
627 if (ret >= 0)
628 return;
629 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
630 exit(EXIT_FAILURE);
631 }
632
633 void handle_sighup(void)
634 {
635 DSS_NOTICE_LOG("SIGHUP\n");
636 parse_config_file(1);
637 }
638
639 int rename_incomplete_snapshot(int64_t start)
640 {
641 char *old_name;
642 int ret;
643
644 free(path_to_last_complete_snapshot);
645 ret = complete_name(start, get_current_time(),
646 &path_to_last_complete_snapshot);
647 if (ret < 0)
648 return ret;
649 old_name = incomplete_name(start);
650 ret = dss_rename(old_name, path_to_last_complete_snapshot);
651 if (ret >= 0)
652 DSS_NOTICE_LOG("%s -> %s\n", old_name,
653 path_to_last_complete_snapshot);
654 free(old_name);
655 return ret;
656 }
657
658 void compute_next_snapshot_time(void)
659 {
660 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
661 tmp, diff;
662 int64_t x = 0;
663 unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
664 int i, ret;
665 struct snapshot *s = NULL;
666 struct snapshot_list sl;
667
668 assert(snapshot_creation_status == SCS_READY);
669 current_snapshot_creation_time = 0;
670 get_snapshot_list(&sl);
671 FOR_EACH_SNAPSHOT(s, i, &sl) {
672 if (!(s->flags & SS_COMPLETE))
673 continue;
674 num_complete_snapshots++;
675 x += s->completion_time - s->creation_time;
676 }
677 assert(x >= 0);
678 if (num_complete_snapshots)
679 x /= num_complete_snapshots; /* avg time to create one snapshot */
680 x *= wanted; /* time to create all snapshots in interval 0 */
681 tmp.tv_sec = x;
682 tmp.tv_usec = 0;
683 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
684 gettimeofday(&now, NULL);
685 if (ret < 0 || !s)
686 goto min_sleep;
687 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
688 diff.tv_sec = s->completion_time;
689 diff.tv_usec = 0;
690 tv_add(&diff, &tmp, &next_snapshot_time);
691 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
692 goto out;
693 min_sleep:
694 next_snapshot_time = now;
695 next_snapshot_time.tv_sec += 60;
696 out:
697 free_snapshot_list(&sl);
698 }
699
700 int handle_rsync_exit(int status)
701 {
702 int es, ret;
703
704 if (!WIFEXITED(status)) {
705 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
706 ret = -E_INVOLUNTARY_EXIT;
707 snapshot_creation_status = SCS_READY;
708 compute_next_snapshot_time();
709 goto out;
710 }
711 es = WEXITSTATUS(status);
712 if (es != 0 && es != 23 && es != 24) {
713 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
714 ret = -E_BAD_EXIT_CODE;
715 snapshot_creation_status = SCS_READY;
716 compute_next_snapshot_time();
717 goto out;
718 }
719 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
720 if (ret < 0)
721 goto out;
722 snapshot_creation_status = SCS_RSYNC_SUCCESS;
723 out:
724 rsync_pid = 0;
725 rsync_stopped = 0;
726 return ret;
727 }
728
729 __malloc char *name_of_newest_complete_snapshot(void)
730 {
731 struct snapshot_list sl;
732 struct snapshot *s;
733 int i;
734 char *name = NULL;
735
736 get_snapshot_list(&sl);
737
738 FOR_EACH_SNAPSHOT_REVERSE(s, i, &sl) {
739 if (s->flags != SS_COMPLETE) /* incomplete or being deleted */
740 continue;
741 name = dss_strdup(s->name);
742 break;
743 }
744 free_snapshot_list(&sl);
745 return name;
746 }
747
748 void create_rsync_argv(char ***argv, int64_t *num)
749 {
750 char *logname, *newest = name_of_newest_complete_snapshot();
751 int i = 0, j;
752
753 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
754 (*argv)[i++] = dss_strdup("rsync");
755 (*argv)[i++] = dss_strdup("-aq");
756 (*argv)[i++] = dss_strdup("--delete");
757 for (j = 0; j < conf.rsync_option_given; j++)
758 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
759 if (newest) {
760 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
761 (*argv)[i++] = make_message("--link-dest=../%s", newest);
762 free(newest);
763 } else
764 DSS_INFO_LOG("no previous snapshot found\n");
765 if (conf.exclude_patterns_given) {
766 (*argv)[i++] = dss_strdup("--exclude-from");
767 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
768
769 }
770 logname = dss_logname();
771 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
772 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
773 else
774 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
775 conf.remote_user_arg : logname,
776 conf.remote_host_arg, conf.source_dir_arg);
777 free(logname);
778 *num = get_current_time();
779 (*argv)[i++] = incomplete_name(*num);
780 (*argv)[i++] = NULL;
781 for (j = 0; j < i; j++)
782 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
783 }
784
785 void free_rsync_argv(char **argv)
786 {
787 int i;
788 for (i = 0; argv[i]; i++)
789 free(argv[i]);
790 free(argv);
791 }
792
793 int pre_create_hook(void)
794 {
795 int ret, fds[3] = {0, 0, 0};
796
797 if (!conf.pre_create_hook_given) {
798 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
799 return 0;
800 }
801 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
802 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
803 conf.pre_create_hook_arg, fds);
804 if (ret < 0)
805 return ret;
806 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
807 return ret;
808 }
809
810 int post_create_hook(void)
811 {
812 int ret, fds[3] = {0, 0, 0};
813 char *cmd;
814
815 if (!conf.post_create_hook_given) {
816 snapshot_creation_status = SCS_READY;
817 compute_next_snapshot_time();
818 return 0;
819 }
820 cmd = make_message("%s %s", conf.post_create_hook_arg,
821 path_to_last_complete_snapshot);
822 DSS_NOTICE_LOG("executing %s\n", cmd);
823 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
824 free(cmd);
825 if (ret < 0)
826 return ret;
827 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
828 return ret;
829 }
830
831 int create_snapshot(char **argv)
832 {
833 int ret, fds[3] = {0, 0, 0};
834 char *name;
835
836 name = incomplete_name(current_snapshot_creation_time);
837 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
838 free(name);
839 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
840 if (ret < 0)
841 return ret;
842 snapshot_creation_status = SCS_RSYNC_RUNNING;
843 return ret;
844 }
845
846 int handle_pre_create_hook_exit(int status)
847 {
848 int es, ret;
849
850 if (!WIFEXITED(status)) {
851 snapshot_creation_status = SCS_READY;
852 compute_next_snapshot_time();
853 ret = -E_INVOLUNTARY_EXIT;
854 goto out;
855 }
856 es = WEXITSTATUS(status);
857 if (es) {
858 snapshot_creation_status = SCS_READY;
859 compute_next_snapshot_time();
860 ret = -E_BAD_EXIT_CODE;
861 goto out;
862 }
863 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
864 ret = 1;
865 out:
866 pre_create_hook_pid = 0;
867 return ret;
868 }
869
870 int handle_sigchld()
871 {
872 pid_t pid;
873 int status, ret = reap_child(&pid, &status);
874
875 if (ret <= 0)
876 return ret;
877 if (pid == rsync_pid)
878 return handle_rsync_exit(status);
879 if (pid == rm_pid)
880 return handle_rm_exit(status);
881 if (pid == pre_create_hook_pid)
882 return handle_pre_create_hook_exit(status);
883 if (pid == post_create_hook_pid) {
884 snapshot_creation_status = SCS_READY;
885 compute_next_snapshot_time();
886 return 1;
887 }
888 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
889 exit(EXIT_FAILURE);
890 }
891
892 void handle_signal(void)
893 {
894 int sig, ret = next_signal();
895
896 if (ret <= 0)
897 goto out;
898 sig = ret;
899 switch (sig) {
900 case SIGINT:
901 case SIGTERM:
902 restart_rsync_process();
903 kill_process(rsync_pid);
904 kill_process(rm_pid);
905 exit(EXIT_FAILURE);
906 case SIGHUP:
907 handle_sighup();
908 ret = 1;
909 break;
910 case SIGCHLD:
911 ret = handle_sigchld();
912 break;
913 }
914 out:
915 if (ret < 0)
916 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
917 }
918
919 int remove_oldest_snapshot(struct snapshot_list *sl)
920 {
921 struct snapshot *s = oldest_snapshot(sl);
922
923 if (!s) /* no snapshot found */
924 return 0;
925 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
926 if (s->creation_time == current_snapshot_creation_time)
927 return 0; /* do not remove the snapshot currently being created */
928 return remove_snapshot(s);
929 }
930
931 /* TODO: Also consider number of inodes. */
932 int disk_space_low(void)
933 {
934 struct disk_space ds;
935 int ret = get_disk_space(".", &ds);
936
937 if (ret < 0)
938 return ret;
939 if (conf.min_free_mb_arg)
940 if (ds.free_mb < conf.min_free_mb_arg)
941 return 1;
942 if (conf.min_free_percent_arg)
943 if (ds.percent_free < conf.min_free_percent_arg)
944 return 1;
945 return 0;
946 }
947
948 int try_to_free_disk_space(int low_disk_space)
949 {
950 int ret;
951 struct snapshot_list sl;
952
953 get_snapshot_list(&sl);
954 ret = remove_outdated_snapshot(&sl);
955 if (ret) /* error, or we are removing something */
956 goto out;
957 /* no outdated snapshot */
958 ret = remove_redundant_snapshot(&sl);
959 if (ret)
960 goto out;
961 ret = 0;
962 if (!low_disk_space)
963 goto out;
964 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
965 ret = remove_oldest_snapshot(&sl);
966 if (ret)
967 goto out;
968 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
969 ret= -ENOSPC;
970 out:
971 free_snapshot_list(&sl);
972 return ret;
973 }
974
975 int select_loop(void)
976 {
977 int ret;
978 struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
979
980 for (;;) {
981 fd_set rfds;
982 int low_disk_space;
983 char **rsync_argv;
984 struct timeval now, *tvp = &tv;
985
986 if (rsync_pid)
987 tv.tv_sec = 60; /* check every 60 seconds for free disk space */
988 else if (rm_pid)
989 tvp = NULL; /* sleep until rm process dies */
990 FD_ZERO(&rfds);
991 FD_SET(signal_pipe, &rfds);
992 DSS_DEBUG_LOG("tvp: %p, tv_sec: %lu\n", tvp, (long unsigned) tv.tv_sec);
993 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
994 if (ret < 0)
995 return ret;
996 if (FD_ISSET(signal_pipe, &rfds))
997 handle_signal();
998 if (rm_pid)
999 continue;
1000 ret = disk_space_low();
1001 if (ret < 0)
1002 break;
1003 low_disk_space = ret;
1004 if (low_disk_space)
1005 stop_rsync_process();
1006 ret = try_to_free_disk_space(low_disk_space);
1007 if (ret < 0)
1008 break;
1009 if (rm_pid)
1010 continue;
1011 restart_rsync_process();
1012 gettimeofday(&now, NULL);
1013 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
1014 continue;
1015 switch (snapshot_creation_status) {
1016 case SCS_READY:
1017 ret = pre_create_hook();
1018 if (ret < 0)
1019 goto out;
1020 continue;
1021 case SCS_PRE_HOOK_RUNNING:
1022 continue;
1023 case SCS_PRE_HOOK_SUCCESS:
1024 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1025 ret = create_snapshot(rsync_argv);
1026 free_rsync_argv(rsync_argv);
1027 if (ret < 0)
1028 goto out;
1029 continue;
1030 case SCS_RSYNC_RUNNING:
1031 continue;
1032 case SCS_RSYNC_SUCCESS:
1033 ret = post_create_hook();
1034 if (ret < 0)
1035 goto out;
1036 continue;
1037 case SCS_POST_HOOK_RUNNING:
1038 continue;
1039 }
1040 }
1041 out:
1042 return ret;
1043 }
1044
1045 int com_run(void)
1046 {
1047 int ret;
1048
1049 if (conf.dry_run_given) {
1050 DSS_ERROR_LOG("dry_run not supported by this command\n");
1051 return -E_SYNTAX;
1052 }
1053 ret = install_sighandler(SIGHUP);
1054 if (ret < 0)
1055 return ret;
1056 compute_next_snapshot_time();
1057 return select_loop();
1058 }
1059
1060 int com_prune(void)
1061 {
1062 int ret;
1063 struct snapshot_list sl;
1064 struct disk_space ds;
1065
1066 ret = get_disk_space(".", &ds);
1067 if (ret < 0)
1068 return ret;
1069 log_disk_space(&ds);
1070 for (;;) {
1071 get_snapshot_list(&sl);
1072 ret = remove_outdated_snapshot(&sl);
1073 free_snapshot_list(&sl);
1074 if (ret < 0)
1075 return ret;
1076 if (!ret)
1077 break;
1078 ret = wait_for_rm_process();
1079 if (ret < 0)
1080 goto out;
1081 }
1082 for (;;) {
1083 get_snapshot_list(&sl);
1084 ret = remove_redundant_snapshot(&sl);
1085 free_snapshot_list(&sl);
1086 if (ret < 0)
1087 return ret;
1088 if (!ret)
1089 break;
1090 ret = wait_for_rm_process();
1091 if (ret < 0)
1092 goto out;
1093 }
1094 return 1;
1095 out:
1096 return ret;
1097 }
1098
1099 int com_create(void)
1100 {
1101 int ret, status;
1102 char **rsync_argv;
1103
1104 if (conf.dry_run_given) {
1105 int i;
1106 char *msg = NULL;
1107 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1108 for (i = 0; rsync_argv[i]; i++) {
1109 char *tmp = msg;
1110 msg = make_message("%s%s%s", tmp? tmp : "",
1111 tmp? " " : "", rsync_argv[i]);
1112 free(tmp);
1113 }
1114 free_rsync_argv(rsync_argv);
1115 dss_msg("%s\n", msg);
1116 free(msg);
1117 return 1;
1118 }
1119 ret = pre_create_hook();
1120 if (ret < 0)
1121 return ret;
1122 if (pre_create_hook_pid) {
1123 ret = wait_for_process(pre_create_hook_pid, &status);
1124 if (ret < 0)
1125 return ret;
1126 ret = handle_pre_create_hook_exit(status);
1127 if (ret < 0)
1128 return ret;
1129 }
1130 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1131 ret = create_snapshot(rsync_argv);
1132 if (ret < 0)
1133 goto out;
1134 ret = wait_for_process(rsync_pid, &status);
1135 if (ret < 0)
1136 goto out;
1137 ret = handle_rsync_exit(status);
1138 if (ret < 0)
1139 goto out;
1140 post_create_hook();
1141 if (post_create_hook_pid)
1142 ret = wait_for_process(post_create_hook_pid, &status);
1143 out:
1144 free_rsync_argv(rsync_argv);
1145 return ret;
1146 }
1147
1148 int com_ls(void)
1149 {
1150 int i;
1151 struct snapshot_list sl;
1152 struct snapshot *s;
1153 get_snapshot_list(&sl);
1154 FOR_EACH_SNAPSHOT(s, i, &sl)
1155 dss_msg("%u\t%s\n", s->interval, s->name);
1156 free_snapshot_list(&sl);
1157 return 1;
1158 }
1159
1160 static void setup_signal_handling(void)
1161 {
1162 int ret;
1163
1164 DSS_INFO_LOG("setting up signal handlers\n");
1165 signal_pipe = signal_init(); /* always successful */
1166 ret = install_sighandler(SIGINT);
1167 if (ret < 0)
1168 goto err;
1169 ret = install_sighandler(SIGTERM);
1170 if (ret < 0)
1171 goto err;
1172 ret = install_sighandler(SIGCHLD);
1173 if (ret < 0)
1174 goto err;
1175 return;
1176 err:
1177 DSS_EMERG_LOG("could not install signal handlers\n");
1178 exit(EXIT_FAILURE);
1179 }
1180
1181 int main(int argc, char **argv)
1182 {
1183 int ret;
1184 struct cmdline_parser_params params = {
1185 .override = 0,
1186 .initialize = 1,
1187 .check_required = 0,
1188 .check_ambiguity = 0
1189 };
1190
1191 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1192 parse_config_file(0);
1193
1194 if (conf.daemon_given)
1195 daemon_init();
1196 setup_signal_handling();
1197 ret = call_command_handler();
1198 if (ret < 0)
1199 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1200 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1201 }