Get rid of make_err_msg() and log_err_msg().
[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 /** The pid of the pre-create hook. */
46 pid_t pre_create_hook_pid;
47 /** The pid of the post-create hook. */
48 pid_t post_create_hook_pid;
49
50 /* Creation time of the snapshot currently being created. */
51 int64_t current_snapshot_creation_time;
52
53 static char *path_to_last_complete_snapshot;
54
55 enum {
56 /** We are ready to take the next snapshot. */
57 SCS_READY,
58 /** The pre-creation hook has been started. */
59 SCS_PRE_HOOK_RUNNING,
60 /** The pre-creation hook exited successfully. */
61 SCS_PRE_HOOK_SUCCESS,
62 /** The rsync process is running. */
63 SCS_RSYNC_RUNNING,
64 /** The rsync process exited successfully. */
65 SCS_RSYNC_SUCCESS,
66 /** The post-create hook has been started- */
67 SCS_POST_HOOK_RUNNING,
68 };
69
70 static unsigned snapshot_creation_status;
71
72
73 DEFINE_DSS_ERRLIST;
74
75
76 /* a litte cpp magic helps to DRY */
77 #define COMMANDS \
78 COMMAND(ls) \
79 COMMAND(create) \
80 COMMAND(prune) \
81 COMMAND(run)
82 #define COMMAND(x) int com_ ##x(void);
83 COMMANDS
84 #undef COMMAND
85 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
86 int call_command_handler(void)
87 {
88 COMMANDS
89 DSS_EMERG_LOG("BUG: did not find command handler\n");
90 exit(EXIT_FAILURE);
91 }
92 #undef COMMAND
93 #undef COMMANDS
94
95 /*
96 * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
97 * complete, being deleted: 1204565370-1204565371.being_deleted
98 * incomplete, not being deleted: 1204565370-incomplete
99 * incomplete, being deleted: 1204565370-incomplete.being_deleted
100 */
101 enum snapshot_status_flags {
102 /** The rsync process terminated successfully. */
103 SS_COMPLETE = 1,
104 /** The rm process is running to remove this snapshot. */
105 SS_BEING_DELETED = 2,
106 };
107
108 struct snapshot {
109 char *name;
110 int64_t creation_time;
111 int64_t completion_time;
112 enum snapshot_status_flags flags;
113 unsigned interval;
114 };
115
116 /*
117 * An edge snapshot is either the oldest one or the newest one.
118 *
119 * We need to find either of them occasionally: The create code
120 * needs to know the newest snapshot because that is the one
121 * used as the link destination dir. The pruning code needs to
122 * find the oldest one in case disk space becomes low.
123 */
124 struct edge_snapshot_data {
125 int64_t now;
126 struct snapshot snap;
127 };
128
129 __printf_2_3 void dss_log(int ll, const char* fmt,...)
130 {
131 va_list argp;
132 FILE *outfd;
133 struct tm *tm;
134 time_t t1;
135 char str[255] = "";
136
137 if (ll < conf.loglevel_arg)
138 return;
139 outfd = logfile? logfile : stderr;
140 time(&t1);
141 tm = localtime(&t1);
142 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
143 fprintf(outfd, "%s ", str);
144 if (conf.loglevel_arg <= INFO)
145 fprintf(outfd, "%i: ", ll);
146 va_start(argp, fmt);
147 vfprintf(outfd, fmt, argp);
148 va_end(argp);
149 }
150
151 /**
152 * Print a message either to stdout or to the log file.
153 */
154 __printf_1_2 void dss_msg(const char* fmt,...)
155 {
156 FILE *outfd = conf.daemon_given? logfile : stdout;
157 va_list argp;
158 va_start(argp, fmt);
159 vfprintf(outfd, fmt, argp);
160 va_end(argp);
161 }
162
163 /**
164 * Return the desired number of snapshots of an interval.
165 */
166 unsigned num_snapshots(int interval)
167 {
168 unsigned n;
169
170 assert(interval >= 0);
171
172 if (interval >= conf.num_intervals_arg)
173 return 0;
174 n = conf.num_intervals_arg - interval - 1;
175 return 1 << n;
176 }
177
178 /* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
179 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
180 {
181 int i, ret;
182 char *dash, *dot, *tmp;
183 int64_t num;
184
185 assert(dirname);
186 dash = strchr(dirname, '-');
187 if (!dash || !dash[1] || dash == dirname)
188 return 0;
189 for (i = 0; dirname[i] != '-'; i++)
190 if (!isdigit(dirname[i]))
191 return 0;
192 tmp = dss_strdup(dirname);
193 tmp[i] = '\0';
194 ret = dss_atoi64(tmp, &num);
195 free(tmp);
196 if (ret < 0) {
197 free(dss_error_txt);
198 return 0;
199 }
200 assert(num >= 0);
201 if (num > now)
202 return 0;
203 s->creation_time = num;
204 //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
205 s->interval = (long long) ((now - s->creation_time)
206 / conf.unit_interval_arg / 24 / 3600);
207 if (!strcmp(dash + 1, "incomplete")) {
208 s->completion_time = -1;
209 s->flags = 0; /* neither complete, nor being deleted */
210 goto success;
211 }
212 if (!strcmp(dash + 1, "incomplete.being_deleted")) {
213 s->completion_time = -1;
214 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
215 goto success;
216 }
217 tmp = dash + 1;
218 dot = strchr(tmp, '.');
219 if (!dot || !dot[1] || dot == tmp)
220 return 0;
221 for (i = 0; tmp[i] != '.'; i++)
222 if (!isdigit(tmp[i]))
223 return 0;
224 tmp = dss_strdup(dash + 1);
225 tmp[i] = '\0';
226 ret = dss_atoi64(tmp, &num);
227 free(tmp);
228 if (ret < 0) {
229 free(dss_error_txt);
230 return 0;
231 }
232 if (num > now)
233 return 0;
234 s->completion_time = num;
235 s->flags = SS_COMPLETE;
236 if (!strcmp(dot + 1, "being_deleted"))
237 s->flags |= SS_BEING_DELETED;
238 success:
239 s->name = dss_strdup(dirname);
240 return 1;
241 }
242
243 int64_t get_current_time(void)
244 {
245 time_t now;
246 time(&now);
247 DSS_DEBUG_LOG("now: %lli\n", (long long) now);
248 return (int64_t)now;
249 }
250
251 char *incomplete_name(int64_t start)
252 {
253 return make_message("%lli-incomplete", (long long)start);
254 }
255
256 char *being_deleted_name(struct snapshot *s)
257 {
258 if (s->flags & SS_COMPLETE)
259 return make_message("%lli-%lli.being_deleted",
260 (long long)s->creation_time,
261 (long long)s->completion_time);
262 return make_message("%lli-incomplete.being_deleted",
263 (long long)s->creation_time);
264 }
265
266 int complete_name(int64_t start, int64_t end, char **result)
267 {
268 struct tm start_tm, end_tm;
269 time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
270 time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
271 char start_str[200], end_str[200];
272
273 if (!localtime_r(start_seconds, &start_tm))
274 return -E_LOCALTIME;
275 if (!localtime_r(end_seconds, &end_tm))
276 return -E_LOCALTIME;
277 if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm))
278 return -E_STRFTIME;
279 if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm))
280 return -E_STRFTIME;
281 *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
282 start_str, end_str);
283 return 1;
284 }
285
286 struct snapshot_list {
287 int64_t now;
288 unsigned num_snapshots;
289 unsigned array_size;
290 struct snapshot **snapshots;
291 /**
292 * Array of size num_intervals + 1
293 *
294 * It contains the number of snapshots in each interval. interval_count[num_intervals]
295 * is the number of snapshots which belong to any interval greater than num_intervals.
296 */
297 unsigned *interval_count;
298 };
299
300 #define FOR_EACH_SNAPSHOT(s, i, sl) \
301 for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
302
303 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
304
305 static int compare_snapshots(const void *a, const void *b)
306 {
307 struct snapshot *s1 = *(struct snapshot **)a;
308 struct snapshot *s2 = *(struct snapshot **)b;
309 return NUM_COMPARE(s2->creation_time, s1->creation_time);
310 }
311
312 /** Compute the minimum of \a a and \a b. */
313 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
314
315 int add_snapshot(const char *dirname, void *private)
316 {
317 struct snapshot_list *sl = private;
318 struct snapshot s;
319 int ret = is_snapshot(dirname, sl->now, &s);
320
321 if (!ret)
322 return 1;
323 if (sl->num_snapshots >= sl->array_size) {
324 sl->array_size = 2 * sl->array_size + 1;
325 sl->snapshots = dss_realloc(sl->snapshots,
326 sl->array_size * sizeof(struct snapshot *));
327 }
328 sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
329 *(sl->snapshots[sl->num_snapshots]) = s;
330 sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
331 sl->num_snapshots++;
332 return 1;
333 }
334
335 void get_snapshot_list(struct snapshot_list *sl)
336 {
337 sl->now = get_current_time();
338 sl->num_snapshots = 0;
339 sl->array_size = 0;
340 sl->snapshots = NULL;
341 sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
342 for_each_subdir(add_snapshot, sl);
343 qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
344 compare_snapshots);
345 }
346
347 void free_snapshot_list(struct snapshot_list *sl)
348 {
349 int i;
350 struct snapshot *s;
351
352 FOR_EACH_SNAPSHOT(s, i, sl) {
353 free(s->name);
354 free(s);
355 }
356 free(sl->interval_count);
357 sl->interval_count = NULL;
358 free(sl->snapshots);
359 sl->snapshots = NULL;
360 sl->num_snapshots = 0;
361 }
362
363 void stop_rsync_process(void)
364 {
365 if (!rsync_pid || rsync_stopped)
366 return;
367 kill(SIGSTOP, rsync_pid);
368 rsync_stopped = 1;
369 }
370
371 void restart_rsync_process(void)
372 {
373 if (!rsync_pid || !rsync_stopped)
374 return;
375 kill (SIGCONT, rsync_pid);
376 rsync_stopped = 0;
377 }
378
379 /**
380 * Print a log message about the exit status of a child.
381 */
382 void log_termination_msg(pid_t pid, int status)
383 {
384 if (WIFEXITED(status))
385 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
386 WEXITSTATUS(status));
387 else if (WIFSIGNALED(status))
388 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
389 WTERMSIG(status));
390 else
391 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
392 }
393
394 int wait_for_process(pid_t pid, int *status)
395 {
396 int ret;
397
398 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
399 for (;;) {
400 fd_set rfds;
401
402 FD_ZERO(&rfds);
403 FD_SET(signal_pipe, &rfds);
404 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
405 if (ret < 0)
406 break;
407 ret = next_signal();
408 if (!ret)
409 continue;
410 if (ret == SIGCHLD) {
411 ret = waitpid(pid, status, 0);
412 if (ret >= 0)
413 break;
414 if (errno != EINTR) { /* error */
415 ret = -ERRNO_TO_DSS_ERROR(errno);
416 break;
417 }
418 }
419 /* SIGINT or SIGTERM */
420 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
421 kill(pid, SIGTERM);
422 }
423 if (ret < 0)
424 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
425 else
426 log_termination_msg(pid, *status);
427 return ret;
428 }
429
430 int remove_snapshot(struct snapshot *s)
431 {
432 int fds[3] = {0, 0, 0};
433 assert(!rm_pid);
434 char *new_name = being_deleted_name(s);
435 int ret = dss_rename(s->name, new_name);
436 char *argv[] = {"rm", "-rf", new_name, NULL};
437
438 if (ret < 0)
439 goto out;
440 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
441 stop_rsync_process();
442 ret = dss_exec(&rm_pid, argv[0], argv, fds);
443 out:
444 free(new_name);
445 return ret;
446 }
447
448 /*
449 * return: 0: no redundant snapshots, 1: rm process started, negative: error
450 */
451 int remove_redundant_snapshot(struct snapshot_list *sl)
452 {
453 int ret, i, interval;
454 struct snapshot *s;
455 unsigned missing = 0;
456
457 DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
458 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
459 unsigned keep = num_snapshots(interval);
460 unsigned num = sl->interval_count[interval];
461 struct snapshot *victim = NULL, *prev = NULL;
462 int64_t score = LONG_MAX;
463
464 if (keep >= num)
465 missing += keep - num;
466 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
467 // interval, keep, num, missing);
468 if (keep + missing >= num)
469 continue;
470 /* redundant snapshot in this interval, pick snapshot with lowest score */
471 FOR_EACH_SNAPSHOT(s, i, sl) {
472 int64_t this_score;
473
474 //DSS_DEBUG_LOG("checking %s\n", s->name);
475 if (s->interval > interval) {
476 prev = s;
477 continue;
478 }
479 if (s->interval < interval)
480 break;
481 if (!victim) {
482 victim = s;
483 prev = s;
484 continue;
485 }
486 assert(prev);
487 /* check if s is a better victim */
488 this_score = s->creation_time - prev->creation_time;
489 assert(this_score >= 0);
490 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
491 if (this_score < score) {
492 score = this_score;
493 victim = s;
494 }
495 prev = s;
496 }
497 assert(victim);
498 if (conf.dry_run_given) {
499 dss_msg("%s would be removed (interval = %i)\n",
500 victim->name, victim->interval);
501 continue;
502 }
503 ret = remove_snapshot(victim);
504 return ret < 0? ret : 1;
505 }
506 return 0;
507 }
508
509 int remove_outdated_snapshot(struct snapshot_list *sl)
510 {
511 int i, ret;
512 struct snapshot *s;
513
514 DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
515 conf.num_intervals_arg);
516 FOR_EACH_SNAPSHOT(s, i, sl) {
517 if (s->interval <= conf.num_intervals_arg)
518 continue;
519 if (conf.dry_run_given) {
520 dss_msg("%s would be removed (interval = %i)\n",
521 s->name, s->interval);
522 continue;
523 }
524 ret = remove_snapshot(s);
525 if (ret < 0)
526 return ret;
527 return 1;
528 }
529 return 0;
530 }
531
532 int handle_rm_exit(int status)
533 {
534 rm_pid = 0;
535 if (!WIFEXITED(status))
536 return -E_INVOLUNTARY_EXIT;
537 if (WEXITSTATUS(status))
538 return -E_BAD_EXIT_CODE;
539 return 1;
540 }
541
542 int wait_for_rm_process(void)
543 {
544 int status, ret = wait_for_process(rm_pid, &status);
545
546 if (ret < 0)
547 return ret;
548 return handle_rm_exit(status);
549 }
550
551 void kill_process(pid_t pid)
552 {
553 if (!pid)
554 return;
555 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
556 kill(pid, SIGTERM);
557 }
558
559 int check_config(void)
560 {
561 if (conf.unit_interval_arg <= 0) {
562 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
563 return -E_INVALID_NUMBER;
564 }
565 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
566 if (conf.num_intervals_arg <= 0) {
567 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
568 return -E_INVALID_NUMBER;
569 }
570 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
571 return 1;
572 }
573
574 /* exits on errors */
575 void parse_config_file(int override)
576 {
577 int ret;
578 char *config_file;
579 struct stat statbuf;
580 char *old_logfile_arg = NULL;
581 int old_daemon_given = 0;
582
583 if (conf.config_file_given)
584 config_file = dss_strdup(conf.config_file_arg);
585 else {
586 char *home = get_homedir();
587 config_file = make_message("%s/.dssrc", home);
588 free(home);
589 }
590 if (override) { /* SIGHUP */
591 if (conf.logfile_given)
592 old_logfile_arg = dss_strdup(conf.logfile_arg);
593 old_daemon_given = conf.daemon_given;
594 }
595
596 ret = stat(config_file, &statbuf);
597 if (ret && conf.config_file_given) {
598 ret = -ERRNO_TO_DSS_ERROR(errno);
599 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
600 goto out;
601 }
602 if (!ret) {
603 struct cmdline_parser_params params = {
604 .override = override,
605 .initialize = 0,
606 .check_required = 1,
607 .check_ambiguity = 0
608 };
609 cmdline_parser_config_file(config_file, &conf, &params);
610 }
611 ret = check_config();
612 if (ret < 0)
613 goto out;
614 if (override) {
615 /* don't change daemon mode on SIGHUP */
616 conf.daemon_given = old_daemon_given;
617 close_log(logfile);
618 logfile = NULL;
619 if (conf.logfile_given)
620 free(old_logfile_arg);
621 else if (conf.daemon_given) { /* re-use old logfile */
622 conf.logfile_arg = old_logfile_arg;
623 conf.logfile_given = 1;
624 }
625 }
626 if (conf.logfile_given) {
627 logfile = open_log(conf.logfile_arg);
628 log_welcome(conf.loglevel_arg);
629 }
630 DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg);
631 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
632 ret = dss_chdir(conf.dest_dir_arg);
633 out:
634 free(config_file);
635 if (ret >= 0)
636 return;
637 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
638 exit(EXIT_FAILURE);
639 }
640
641 void handle_sighup(void)
642 {
643 DSS_NOTICE_LOG("SIGHUP\n");
644 parse_config_file(1);
645 }
646
647 int rename_incomplete_snapshot(int64_t start)
648 {
649 char *old_name;
650 int ret;
651
652 free(path_to_last_complete_snapshot);
653 ret = complete_name(start, get_current_time(),
654 &path_to_last_complete_snapshot);
655 if (ret < 0)
656 return ret;
657 old_name = incomplete_name(start);
658 ret = dss_rename(old_name, path_to_last_complete_snapshot);
659 if (ret >= 0)
660 DSS_NOTICE_LOG("%s -> %s\n", old_name,
661 path_to_last_complete_snapshot);
662 free(old_name);
663 return ret;
664 }
665
666 void compute_next_snapshot_time(void)
667 {
668 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
669 tmp, diff;
670 int64_t x = 0;
671 unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
672 int i, ret;
673 struct snapshot *s = NULL;
674 struct snapshot_list sl;
675
676 assert(snapshot_creation_status == SCS_READY);
677 current_snapshot_creation_time = 0;
678 get_snapshot_list(&sl);
679 FOR_EACH_SNAPSHOT(s, i, &sl) {
680 if (!(s->flags & SS_COMPLETE))
681 continue;
682 num_complete_snapshots++;
683 x += s->completion_time - s->creation_time;
684 }
685 assert(x >= 0);
686 if (num_complete_snapshots)
687 x /= num_complete_snapshots; /* avg time to create one snapshot */
688 x *= wanted; /* time to create all snapshots in interval 0 */
689 tmp.tv_sec = x;
690 tmp.tv_usec = 0;
691 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
692 gettimeofday(&now, NULL);
693 if (ret < 0 || !s)
694 goto min_sleep;
695 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
696 diff.tv_sec = s->completion_time;
697 diff.tv_usec = 0;
698 tv_add(&diff, &tmp, &next_snapshot_time);
699 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
700 goto out;
701 min_sleep:
702 next_snapshot_time = now;
703 next_snapshot_time.tv_sec += 60;
704 out:
705 free_snapshot_list(&sl);
706 }
707
708 int handle_rsync_exit(int status)
709 {
710 int es, ret;
711
712 if (!WIFEXITED(status)) {
713 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
714 ret = -E_INVOLUNTARY_EXIT;
715 snapshot_creation_status = SCS_READY;
716 compute_next_snapshot_time();
717 goto out;
718 }
719 es = WEXITSTATUS(status);
720 if (es != 0 && es != 23 && es != 24) {
721 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
722 ret = -E_BAD_EXIT_CODE;
723 snapshot_creation_status = SCS_READY;
724 compute_next_snapshot_time();
725 goto out;
726 }
727 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
728 if (ret < 0)
729 goto out;
730 snapshot_creation_status = SCS_RSYNC_SUCCESS;
731 out:
732 rsync_pid = 0;
733 rsync_stopped = 0;
734 return ret;
735 }
736
737 int get_newest_complete(const char *dirname, void *private)
738 {
739 struct edge_snapshot_data *esd = private;
740 struct snapshot s;
741 int ret = is_snapshot(dirname, esd->now, &s);
742
743 if (ret <= 0)
744 return 1;
745 if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
746 return 1;
747 if (s.creation_time < esd->snap.creation_time)
748 return 1;
749 free(esd->snap.name);
750 esd->snap = s;
751 return 1;
752 }
753
754 __malloc char *name_of_newest_complete_snapshot(void)
755 {
756 struct edge_snapshot_data esd = {
757 .now = get_current_time(),
758 .snap = {.creation_time = -1}
759 };
760 for_each_subdir(get_newest_complete, &esd);
761 return esd.snap.name;
762 }
763
764 void create_rsync_argv(char ***argv, int64_t *num)
765 {
766 char *logname, *newest = name_of_newest_complete_snapshot();
767 int i = 0, j;
768
769 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
770 (*argv)[i++] = dss_strdup("rsync");
771 (*argv)[i++] = dss_strdup("-aq");
772 (*argv)[i++] = dss_strdup("--delete");
773 for (j = 0; j < conf.rsync_option_given; j++)
774 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
775 if (newest) {
776 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
777 (*argv)[i++] = make_message("--link-dest=../%s", newest);
778 free(newest);
779 } else
780 DSS_INFO_LOG("no previous snapshot found\n");
781 if (conf.exclude_patterns_given) {
782 (*argv)[i++] = dss_strdup("--exclude-from");
783 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
784
785 }
786 logname = dss_logname();
787 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
788 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
789 else
790 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
791 conf.remote_user_arg : logname,
792 conf.remote_host_arg, conf.source_dir_arg);
793 free(logname);
794 *num = get_current_time();
795 (*argv)[i++] = incomplete_name(*num);
796 (*argv)[i++] = NULL;
797 for (j = 0; j < i; j++)
798 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
799 }
800
801 void free_rsync_argv(char **argv)
802 {
803 int i;
804 for (i = 0; argv[i]; i++)
805 free(argv[i]);
806 free(argv);
807 }
808
809 int pre_create_hook(void)
810 {
811 int ret, fds[3] = {0, 0, 0};
812
813 if (!conf.pre_create_hook_given) {
814 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
815 return 0;
816 }
817 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
818 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
819 conf.pre_create_hook_arg, fds);
820 if (ret < 0)
821 return ret;
822 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
823 return ret;
824 }
825
826 int post_create_hook(void)
827 {
828 int ret, fds[3] = {0, 0, 0};
829 char *cmd;
830
831 if (!conf.post_create_hook_given) {
832 snapshot_creation_status = SCS_READY;
833 compute_next_snapshot_time();
834 return 0;
835 }
836 cmd = make_message("%s %s", conf.post_create_hook_arg,
837 path_to_last_complete_snapshot);
838 DSS_NOTICE_LOG("executing %s\n", cmd);
839 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
840 free(cmd);
841 if (ret < 0)
842 return ret;
843 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
844 return ret;
845 }
846
847 int create_snapshot(char **argv)
848 {
849 int ret, fds[3] = {0, 0, 0};
850 char *name;
851
852 name = incomplete_name(current_snapshot_creation_time);
853 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
854 free(name);
855 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
856 if (ret < 0)
857 return ret;
858 snapshot_creation_status = SCS_RSYNC_RUNNING;
859 return ret;
860 }
861
862 int handle_pre_create_hook_exit(int status)
863 {
864 int es, ret;
865
866 if (!WIFEXITED(status)) {
867 snapshot_creation_status = SCS_READY;
868 compute_next_snapshot_time();
869 ret = -E_INVOLUNTARY_EXIT;
870 goto out;
871 }
872 es = WEXITSTATUS(status);
873 if (es) {
874 snapshot_creation_status = SCS_READY;
875 compute_next_snapshot_time();
876 ret = -E_BAD_EXIT_CODE;
877 goto out;
878 }
879 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
880 ret = 1;
881 out:
882 pre_create_hook_pid = 0;
883 return ret;
884 }
885
886 int handle_sigchld()
887 {
888 pid_t pid;
889 int status, ret = reap_child(&pid, &status);
890
891 if (ret <= 0)
892 return ret;
893 if (pid == rsync_pid)
894 return handle_rsync_exit(status);
895 if (pid == rm_pid)
896 return handle_rm_exit(status);
897 if (pid == pre_create_hook_pid)
898 return handle_pre_create_hook_exit(status);
899 if (pid == post_create_hook_pid) {
900 snapshot_creation_status = SCS_READY;
901 compute_next_snapshot_time();
902 return 1;
903 }
904 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
905 exit(EXIT_FAILURE);
906 }
907
908 void handle_signal(void)
909 {
910 int sig, ret = next_signal();
911
912 if (ret <= 0)
913 goto out;
914 sig = ret;
915 switch (sig) {
916 case SIGINT:
917 case SIGTERM:
918 restart_rsync_process();
919 kill_process(rsync_pid);
920 kill_process(rm_pid);
921 exit(EXIT_FAILURE);
922 case SIGHUP:
923 handle_sighup();
924 ret = 1;
925 break;
926 case SIGCHLD:
927 ret = handle_sigchld();
928 break;
929 }
930 out:
931 if (ret < 0)
932 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
933 }
934
935 int get_oldest(const char *dirname, void *private)
936 {
937 struct edge_snapshot_data *esd = private;
938 struct snapshot s;
939 int ret = is_snapshot(dirname, esd->now, &s);
940
941 if (ret <= 0)
942 return 1;
943 if (s.creation_time > esd->snap.creation_time)
944 return 1;
945 free(esd->snap.name);
946 esd->snap = s;
947 return 1;
948 }
949
950 int remove_oldest_snapshot()
951 {
952 int ret;
953 struct edge_snapshot_data esd = {
954 .now = get_current_time(),
955 .snap = {.creation_time = LLONG_MAX}
956 };
957 for_each_subdir(get_oldest, &esd);
958 if (!esd.snap.name) /* no snapshot found */
959 return 0;
960 DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
961 ret = 0;
962 if (esd.snap.creation_time == current_snapshot_creation_time)
963 goto out; /* do not remove the snapshot currently being created */
964 ret = remove_snapshot(&esd.snap);
965 out:
966 free(esd.snap.name);
967 return ret;
968 }
969
970 /* TODO: Also consider number of inodes. */
971 int disk_space_low(void)
972 {
973 struct disk_space ds;
974 int ret = get_disk_space(".", &ds);
975
976 if (ret < 0)
977 return ret;
978 if (conf.min_free_mb_arg)
979 if (ds.free_mb < conf.min_free_mb_arg)
980 return 1;
981 if (conf.min_free_percent_arg)
982 if (ds.percent_free < conf.min_free_percent_arg)
983 return 1;
984 return 0;
985 }
986
987 int try_to_free_disk_space(int low_disk_space)
988 {
989 int ret;
990 struct snapshot_list sl;
991
992 get_snapshot_list(&sl);
993 ret = remove_outdated_snapshot(&sl);
994 if (ret) /* error, or we are removing something */
995 goto out;
996 /* no outdated snapshot */
997 ret = remove_redundant_snapshot(&sl);
998 if (ret)
999 goto out;
1000 ret = 0;
1001 if (!low_disk_space)
1002 goto out;
1003 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
1004 ret = remove_oldest_snapshot();
1005 if (ret)
1006 goto out;
1007 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
1008 ret= -ENOSPC;
1009 out:
1010 free_snapshot_list(&sl);
1011 return ret;
1012 }
1013
1014 int select_loop(void)
1015 {
1016 int ret;
1017 struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
1018
1019 for (;;) {
1020 fd_set rfds;
1021 int low_disk_space;
1022 char **rsync_argv;
1023 struct timeval now, *tvp = &tv;
1024
1025 if (rsync_pid)
1026 tv.tv_sec = 60; /* check every 60 seconds for free disk space */
1027 else if (rm_pid)
1028 tvp = NULL; /* sleep until rm process dies */
1029 FD_ZERO(&rfds);
1030 FD_SET(signal_pipe, &rfds);
1031 DSS_DEBUG_LOG("tvp: %p, tv_sec: %lu\n", tvp, (long unsigned) tv.tv_sec);
1032 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1033 if (ret < 0)
1034 return ret;
1035 if (FD_ISSET(signal_pipe, &rfds))
1036 handle_signal();
1037 if (rm_pid)
1038 continue;
1039 ret = disk_space_low();
1040 if (ret < 0)
1041 break;
1042 low_disk_space = ret;
1043 if (low_disk_space)
1044 stop_rsync_process();
1045 ret = try_to_free_disk_space(low_disk_space);
1046 if (ret < 0)
1047 break;
1048 if (rm_pid)
1049 continue;
1050 restart_rsync_process();
1051 gettimeofday(&now, NULL);
1052 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
1053 continue;
1054 switch (snapshot_creation_status) {
1055 case SCS_READY:
1056 ret = pre_create_hook();
1057 if (ret < 0)
1058 goto out;
1059 continue;
1060 case SCS_PRE_HOOK_RUNNING:
1061 continue;
1062 case SCS_PRE_HOOK_SUCCESS:
1063 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1064 ret = create_snapshot(rsync_argv);
1065 free_rsync_argv(rsync_argv);
1066 if (ret < 0)
1067 goto out;
1068 continue;
1069 case SCS_RSYNC_RUNNING:
1070 continue;
1071 case SCS_RSYNC_SUCCESS:
1072 ret = post_create_hook();
1073 if (ret < 0)
1074 goto out;
1075 continue;
1076 case SCS_POST_HOOK_RUNNING:
1077 continue;
1078 }
1079 }
1080 out:
1081 return ret;
1082 }
1083
1084 int com_run(void)
1085 {
1086 int ret;
1087
1088 if (conf.dry_run_given) {
1089 DSS_ERROR_LOG("dry_run not supported by this command\n");
1090 return -E_SYNTAX;
1091 }
1092 ret = install_sighandler(SIGHUP);
1093 if (ret < 0)
1094 return ret;
1095 compute_next_snapshot_time();
1096 return select_loop();
1097 }
1098
1099 void log_disk_space(struct disk_space *ds)
1100 {
1101 DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
1102 ds->free_mb, ds->total_mb, ds->percent_free,
1103 ds->percent_free_inodes);
1104 }
1105
1106 int com_prune(void)
1107 {
1108 int ret;
1109 struct snapshot_list sl;
1110 struct disk_space ds;
1111
1112 ret = get_disk_space(".", &ds);
1113 if (ret < 0)
1114 return ret;
1115 log_disk_space(&ds);
1116 for (;;) {
1117 get_snapshot_list(&sl);
1118 ret = remove_outdated_snapshot(&sl);
1119 free_snapshot_list(&sl);
1120 if (ret < 0)
1121 return ret;
1122 if (!ret)
1123 break;
1124 ret = wait_for_rm_process();
1125 if (ret < 0)
1126 goto out;
1127 }
1128 for (;;) {
1129 get_snapshot_list(&sl);
1130 ret = remove_redundant_snapshot(&sl);
1131 free_snapshot_list(&sl);
1132 if (ret < 0)
1133 return ret;
1134 if (!ret)
1135 break;
1136 ret = wait_for_rm_process();
1137 if (ret < 0)
1138 goto out;
1139 }
1140 return 1;
1141 out:
1142 return ret;
1143 }
1144
1145 int com_create(void)
1146 {
1147 int ret, status;
1148 char **rsync_argv;
1149
1150 if (conf.dry_run_given) {
1151 int i;
1152 char *msg = NULL;
1153 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1154 for (i = 0; rsync_argv[i]; i++) {
1155 char *tmp = msg;
1156 msg = make_message("%s%s%s", tmp? tmp : "",
1157 tmp? " " : "", rsync_argv[i]);
1158 free(tmp);
1159 }
1160 free_rsync_argv(rsync_argv);
1161 dss_msg("%s\n", msg);
1162 free(msg);
1163 return 1;
1164 }
1165 ret = pre_create_hook();
1166 if (ret < 0)
1167 return ret;
1168 if (pre_create_hook_pid) {
1169 ret = wait_for_process(pre_create_hook_pid, &status);
1170 if (ret < 0)
1171 return ret;
1172 ret = handle_pre_create_hook_exit(status);
1173 if (ret < 0)
1174 return ret;
1175 }
1176 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1177 ret = create_snapshot(rsync_argv);
1178 if (ret < 0)
1179 goto out;
1180 ret = wait_for_process(rsync_pid, &status);
1181 if (ret < 0)
1182 goto out;
1183 ret = handle_rsync_exit(status);
1184 if (ret < 0)
1185 goto out;
1186 post_create_hook();
1187 if (post_create_hook_pid)
1188 ret = wait_for_process(post_create_hook_pid, &status);
1189 out:
1190 free_rsync_argv(rsync_argv);
1191 return ret;
1192 }
1193
1194 int com_ls(void)
1195 {
1196 int i;
1197 struct snapshot_list sl;
1198 struct snapshot *s;
1199 get_snapshot_list(&sl);
1200 FOR_EACH_SNAPSHOT(s, i, &sl)
1201 dss_msg("%u\t%s\n", s->interval, s->name);
1202 free_snapshot_list(&sl);
1203 return 1;
1204 }
1205
1206 static void setup_signal_handling(void)
1207 {
1208 int ret;
1209
1210 DSS_INFO_LOG("setting up signal handlers\n");
1211 signal_pipe = signal_init(); /* always successful */
1212 ret = install_sighandler(SIGINT);
1213 if (ret < 0)
1214 goto err;
1215 ret = install_sighandler(SIGTERM);
1216 if (ret < 0)
1217 goto err;
1218 ret = install_sighandler(SIGCHLD);
1219 if (ret < 0)
1220 goto err;
1221 return;
1222 err:
1223 DSS_EMERG_LOG("could not install signal handlers\n");
1224 exit(EXIT_FAILURE);
1225 }
1226
1227 int main(int argc, char **argv)
1228 {
1229 int ret;
1230 struct cmdline_parser_params params = {
1231 .override = 0,
1232 .initialize = 1,
1233 .check_required = 0,
1234 .check_ambiguity = 0
1235 };
1236
1237 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1238 parse_config_file(0);
1239
1240 if (conf.daemon_given)
1241 daemon_init();
1242 setup_signal_handling();
1243 ret = call_command_handler();
1244 if (ret < 0)
1245 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1246 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1247 }