Prevent busy loops on rsync exit code 13.
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6 #include <string.h>
7 #include <stdlib.h>
8 #include <stdarg.h>
9 #include <assert.h>
10 #include <errno.h>
11 #include <sys/types.h>
12 #include <signal.h>
13 #include <ctype.h>
14 #include <sys/stat.h>
15 #include <unistd.h>
16 #include <inttypes.h>
17 #include <sys/time.h>
18 #include <time.h>
19 #include <sys/wait.h>
20 #include <fnmatch.h>
21 #include <limits.h>
22
23
24 #include "gcc-compat.h"
25 #include "cmdline.h"
26 #include "log.h"
27 #include "string.h"
28 #include "error.h"
29 #include "fd.h"
30 #include "exec.h"
31 #include "daemon.h"
32 #include "signal.h"
33 #include "df.h"
34 #include "time.h"
35 #include "snap.h"
36
37 /** Command line and config file options. */
38 static struct gengetopt_args_info conf;
39 /** Non-NULL if we log to a file. */
40 static FILE *logfile;
41 /** The read end of the signal pipe */
42 static int signal_pipe;
43 /** Process id of current rsync process. */
44 static pid_t rsync_pid;
45 /** Whether the rsync process is currently stopped */
46 static int rsync_stopped;
47 /** Process id of current rm process. */
48 static pid_t rm_pid;
49 /** When the next snapshot is due. */
50 static struct timeval next_snapshot_time;
51 /** The pid of the pre-create hook. */
52 static pid_t pre_create_hook_pid;
53 /** The pid of the post-create hook. */
54 static pid_t post_create_hook_pid;
55 /** Creation time of the snapshot currently being created. */
56 static int64_t current_snapshot_creation_time;
57 /** Needed by the post-create hook. */
58 static char *path_to_last_complete_snapshot;
59 /** \sa \ref snap.h for details. */
60 static unsigned snapshot_creation_status;
61
62
63 DEFINE_DSS_ERRLIST;
64
65
66 /* a litte cpp magic helps to DRY */
67 #define COMMANDS \
68 COMMAND(ls) \
69 COMMAND(create) \
70 COMMAND(prune) \
71 COMMAND(run)
72 #define COMMAND(x) static int com_ ##x(void);
73 COMMANDS
74 #undef COMMAND
75 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
76 static int call_command_handler(void)
77 {
78 COMMANDS
79 DSS_EMERG_LOG("BUG: did not find command handler\n");
80 return -E_BUG;
81 }
82 #undef COMMAND
83 #undef COMMANDS
84
85 /**
86 * The log function of dss.
87 *
88 * \param ll Loglevel.
89 * \param fml Usual format string.
90 *
91 * All DSS_XXX_LOG() macros use this function.
92 */
93 __printf_2_3 void dss_log(int ll, const char* fmt,...)
94 {
95 va_list argp;
96 FILE *outfd;
97 struct tm *tm;
98 time_t t1;
99 char str[255] = "";
100
101 if (ll < conf.loglevel_arg)
102 return;
103 outfd = logfile? logfile : stderr;
104 time(&t1);
105 tm = localtime(&t1);
106 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
107 fprintf(outfd, "%s ", str);
108 if (conf.loglevel_arg <= INFO)
109 fprintf(outfd, "%i: ", ll);
110 va_start(argp, fmt);
111 vfprintf(outfd, fmt, argp);
112 va_end(argp);
113 }
114
115 /**
116 * Print a message either to stdout or to the log file.
117 */
118 static __printf_1_2 void dss_msg(const char* fmt,...)
119 {
120 FILE *outfd = conf.daemon_given? logfile : stdout;
121 va_list argp;
122 va_start(argp, fmt);
123 vfprintf(outfd, fmt, argp);
124 va_end(argp);
125 }
126
127 static int disk_space_low(void)
128 {
129 struct disk_space ds;
130 int ret = get_disk_space(".", &ds);
131
132 if (ret < 0)
133 return ret;
134 if (conf.min_free_mb_arg)
135 if (ds.free_mb < conf.min_free_mb_arg)
136 return 1;
137 if (conf.min_free_percent_arg)
138 if (ds.percent_free < conf.min_free_percent_arg)
139 return 1;
140 if (conf.min_free_percent_inodes_arg)
141 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
142 return 1;
143 return 0;
144 }
145
146 static void dss_get_snapshot_list(struct snapshot_list *sl)
147 {
148 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
149 }
150
151 static void compute_next_snapshot_time(void)
152 {
153 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
154 tmp, diff;
155 int64_t x = 0;
156 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
157 num_complete_snapshots = 0;
158 int i, ret;
159 struct snapshot *s = NULL;
160 struct snapshot_list sl;
161
162 assert(snapshot_creation_status == SCS_READY);
163 current_snapshot_creation_time = 0;
164 dss_get_snapshot_list(&sl);
165 FOR_EACH_SNAPSHOT(s, i, &sl) {
166 if (!(s->flags & SS_COMPLETE))
167 continue;
168 num_complete_snapshots++;
169 x += s->completion_time - s->creation_time;
170 }
171 assert(x >= 0);
172 if (num_complete_snapshots)
173 x /= num_complete_snapshots; /* avg time to create one snapshot */
174 x *= wanted; /* time to create all snapshots in interval 0 */
175 tmp.tv_sec = x;
176 tmp.tv_usec = 0;
177 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
178 gettimeofday(&now, NULL);
179 if (ret < 0 || !s)
180 goto min_sleep;
181 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
182 diff.tv_sec = s->completion_time;
183 diff.tv_usec = 0;
184 tv_add(&diff, &tmp, &next_snapshot_time);
185 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
186 goto out;
187 min_sleep:
188 next_snapshot_time = now;
189 next_snapshot_time.tv_sec += 60;
190 out:
191 free_snapshot_list(&sl);
192 }
193
194
195 static int remove_snapshot(struct snapshot *s)
196 {
197 int fds[3] = {0, 0, 0};
198 assert(!rm_pid);
199 char *new_name = being_deleted_name(s);
200 int ret = dss_rename(s->name, new_name);
201 char *argv[] = {"rm", "-rf", new_name, NULL};
202
203 if (ret < 0)
204 goto out;
205 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
206 ret = dss_exec(&rm_pid, argv[0], argv, fds);
207 out:
208 free(new_name);
209 return ret;
210 }
211
212 /*
213 * return: 0: no redundant snapshots, 1: rm process started, negative: error
214 */
215 static int remove_redundant_snapshot(struct snapshot_list *sl)
216 {
217 int ret, i, interval;
218 struct snapshot *s;
219 unsigned missing = 0;
220
221 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
222 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
223 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
224 unsigned num = sl->interval_count[interval];
225 struct snapshot *victim = NULL, *prev = NULL;
226 int64_t score = LONG_MAX;
227
228 if (keep >= num)
229 missing += keep - num;
230 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
231 // interval, keep, num, missing);
232 if (keep + missing >= num)
233 continue;
234 /* redundant snapshot in this interval, pick snapshot with lowest score */
235 FOR_EACH_SNAPSHOT(s, i, sl) {
236 int64_t this_score;
237
238 //DSS_DEBUG_LOG("checking %s\n", s->name);
239 if (s->interval > interval) {
240 prev = s;
241 continue;
242 }
243 if (s->interval < interval)
244 break;
245 if (!victim) {
246 victim = s;
247 prev = s;
248 continue;
249 }
250 assert(prev);
251 /* check if s is a better victim */
252 this_score = s->creation_time - prev->creation_time;
253 assert(this_score >= 0);
254 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
255 if (this_score < score) {
256 score = this_score;
257 victim = s;
258 }
259 prev = s;
260 }
261 assert(victim);
262 if (conf.dry_run_given) {
263 dss_msg("%s would be removed (interval = %i)\n",
264 victim->name, victim->interval);
265 continue;
266 }
267 ret = remove_snapshot(victim);
268 return ret < 0? ret : 1;
269 }
270 return 0;
271 }
272
273 static int remove_outdated_snapshot(struct snapshot_list *sl)
274 {
275 int i, ret;
276 struct snapshot *s;
277
278 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
279 conf.num_intervals_arg);
280 FOR_EACH_SNAPSHOT(s, i, sl) {
281 if (s->interval <= conf.num_intervals_arg)
282 continue;
283 if (conf.dry_run_given) {
284 dss_msg("%s would be removed (interval = %i)\n",
285 s->name, s->interval);
286 continue;
287 }
288 ret = remove_snapshot(s);
289 if (ret < 0)
290 return ret;
291 return 1;
292 }
293 return 0;
294 }
295
296 static int remove_oldest_snapshot(struct snapshot_list *sl)
297 {
298 struct snapshot *s = get_oldest_snapshot(sl);
299
300 if (!s) /* no snapshot found */
301 return 0;
302 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
303 if (s->creation_time == current_snapshot_creation_time)
304 return 0; /* do not remove the snapshot currently being created */
305 return remove_snapshot(s);
306 }
307
308 static int rename_incomplete_snapshot(int64_t start)
309 {
310 char *old_name;
311 int ret;
312
313 free(path_to_last_complete_snapshot);
314 ret = complete_name(start, get_current_time(),
315 &path_to_last_complete_snapshot);
316 if (ret < 0)
317 return ret;
318 old_name = incomplete_name(start);
319 ret = dss_rename(old_name, path_to_last_complete_snapshot);
320 if (ret >= 0)
321 DSS_NOTICE_LOG("%s -> %s\n", old_name,
322 path_to_last_complete_snapshot);
323 free(old_name);
324 return ret;
325 }
326
327 static int try_to_free_disk_space(int low_disk_space)
328 {
329 int ret;
330 struct snapshot_list sl;
331
332 if (!low_disk_space && conf.keep_redundant_given)
333 return 0;
334 dss_get_snapshot_list(&sl);
335 ret = remove_outdated_snapshot(&sl);
336 if (ret) /* error, or we are removing something */
337 goto out;
338 /* no outdated snapshot */
339 ret = remove_redundant_snapshot(&sl);
340 if (ret)
341 goto out;
342 ret = 0;
343 if (!low_disk_space)
344 goto out;
345 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
346 ret = remove_oldest_snapshot(&sl);
347 if (ret)
348 goto out;
349 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
350 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
351 out:
352 free_snapshot_list(&sl);
353 return ret;
354 }
355
356 static int pre_create_hook(void)
357 {
358 int ret, fds[3] = {0, 0, 0};
359
360 if (!conf.pre_create_hook_given) {
361 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
362 return 0;
363 }
364 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
365 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
366 conf.pre_create_hook_arg, fds);
367 if (ret < 0)
368 return ret;
369 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
370 return ret;
371 }
372
373 static int post_create_hook(void)
374 {
375 int ret, fds[3] = {0, 0, 0};
376 char *cmd;
377
378 if (!conf.post_create_hook_given) {
379 snapshot_creation_status = SCS_READY;
380 compute_next_snapshot_time();
381 return 0;
382 }
383 cmd = make_message("%s %s", conf.post_create_hook_arg,
384 path_to_last_complete_snapshot);
385 DSS_NOTICE_LOG("executing %s\n", cmd);
386 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
387 free(cmd);
388 if (ret < 0)
389 return ret;
390 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
391 return ret;
392 }
393
394 static void kill_process(pid_t pid)
395 {
396 if (!pid)
397 return;
398 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
399 kill(pid, SIGTERM);
400 }
401
402 static void stop_rsync_process(void)
403 {
404 if (!rsync_pid || rsync_stopped)
405 return;
406 kill(SIGSTOP, rsync_pid);
407 rsync_stopped = 1;
408 }
409
410 static void restart_rsync_process(void)
411 {
412 if (!rsync_pid || !rsync_stopped)
413 return;
414 kill (SIGCONT, rsync_pid);
415 rsync_stopped = 0;
416 }
417
418
419 /**
420 * Print a log message about the exit status of a child.
421 */
422 static void log_termination_msg(pid_t pid, int status)
423 {
424 if (WIFEXITED(status))
425 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
426 WEXITSTATUS(status));
427 else if (WIFSIGNALED(status))
428 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
429 WTERMSIG(status));
430 else
431 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
432 }
433
434 static int wait_for_process(pid_t pid, int *status)
435 {
436 int ret;
437
438 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
439 for (;;) {
440 fd_set rfds;
441
442 FD_ZERO(&rfds);
443 FD_SET(signal_pipe, &rfds);
444 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
445 if (ret < 0)
446 break;
447 ret = next_signal();
448 if (!ret)
449 continue;
450 if (ret == SIGCHLD) {
451 ret = waitpid(pid, status, 0);
452 if (ret >= 0)
453 break;
454 if (errno != EINTR) { /* error */
455 ret = -ERRNO_TO_DSS_ERROR(errno);
456 break;
457 }
458 }
459 /* SIGINT or SIGTERM */
460 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
461 kill(pid, SIGTERM);
462 }
463 if (ret < 0)
464 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
465 else
466 log_termination_msg(pid, *status);
467 return ret;
468 }
469
470 static int handle_rm_exit(int status)
471 {
472 rm_pid = 0;
473 if (!WIFEXITED(status))
474 return -E_INVOLUNTARY_EXIT;
475 if (WEXITSTATUS(status))
476 return -E_BAD_EXIT_CODE;
477 return 1;
478 }
479
480 static int wait_for_rm_process(void)
481 {
482 int status, ret = wait_for_process(rm_pid, &status);
483
484 if (ret < 0)
485 return ret;
486 return handle_rm_exit(status);
487 }
488
489 static int handle_rsync_exit(int status)
490 {
491 int es, ret;
492
493 if (!WIFEXITED(status)) {
494 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
495 ret = -E_INVOLUNTARY_EXIT;
496 snapshot_creation_status = SCS_READY;
497 compute_next_snapshot_time();
498 goto out;
499 }
500 es = WEXITSTATUS(status);
501 if (es == 13) { /* Errors with program diagnostics */
502 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
503 (int)rsync_pid, es);
504 snapshot_creation_status = SCS_RSYNC_NEEDS_RESTART;
505 gettimeofday(&next_snapshot_time, NULL);
506 next_snapshot_time.tv_sec += 60;
507 ret = 1;
508 goto out;
509 }
510 if (es != 0 && es != 23 && es != 24) {
511 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
512 ret = -E_BAD_EXIT_CODE;
513 snapshot_creation_status = SCS_READY;
514 compute_next_snapshot_time();
515 goto out;
516 }
517 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
518 if (ret < 0)
519 goto out;
520 snapshot_creation_status = SCS_RSYNC_SUCCESS;
521 out:
522 rsync_pid = 0;
523 rsync_stopped = 0;
524 return ret;
525 }
526
527 static int handle_pre_create_hook_exit(int status)
528 {
529 int es, ret;
530
531 if (!WIFEXITED(status)) {
532 snapshot_creation_status = SCS_READY;
533 compute_next_snapshot_time();
534 ret = -E_INVOLUNTARY_EXIT;
535 goto out;
536 }
537 es = WEXITSTATUS(status);
538 if (es) {
539 snapshot_creation_status = SCS_READY;
540 compute_next_snapshot_time();
541 ret = -E_BAD_EXIT_CODE;
542 goto out;
543 }
544 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
545 ret = 1;
546 out:
547 pre_create_hook_pid = 0;
548 return ret;
549 }
550
551 static int handle_sigchld(void)
552 {
553 pid_t pid;
554 int status, ret = reap_child(&pid, &status);
555
556 if (ret <= 0)
557 return ret;
558 if (pid == rsync_pid)
559 return handle_rsync_exit(status);
560 if (pid == rm_pid)
561 return handle_rm_exit(status);
562 if (pid == pre_create_hook_pid)
563 return handle_pre_create_hook_exit(status);
564 if (pid == post_create_hook_pid) {
565 snapshot_creation_status = SCS_READY;
566 compute_next_snapshot_time();
567 return 1;
568 }
569 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
570 return -E_BUG;
571 }
572
573 static int check_config(void)
574 {
575 if (conf.unit_interval_arg <= 0) {
576 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
577 return -E_INVALID_NUMBER;
578 }
579 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
580 if (conf.num_intervals_arg <= 0) {
581 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
582 return -E_INVALID_NUMBER;
583 }
584 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
585 return 1;
586 }
587
588 static int parse_config_file(int override)
589 {
590 int ret;
591 char *config_file;
592 struct stat statbuf;
593 char *old_logfile_arg = NULL;
594 int old_daemon_given = 0;
595
596 if (conf.config_file_given)
597 config_file = dss_strdup(conf.config_file_arg);
598 else {
599 char *home = get_homedir();
600 config_file = make_message("%s/.dssrc", home);
601 free(home);
602 }
603 if (override) { /* SIGHUP */
604 if (conf.logfile_given)
605 old_logfile_arg = dss_strdup(conf.logfile_arg);
606 old_daemon_given = conf.daemon_given;
607 }
608
609 ret = stat(config_file, &statbuf);
610 if (ret && conf.config_file_given) {
611 ret = -ERRNO_TO_DSS_ERROR(errno);
612 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
613 goto out;
614 }
615 if (!ret) {
616 struct cmdline_parser_params params = {
617 .override = override,
618 .initialize = 0,
619 .check_required = 1,
620 .check_ambiguity = 0,
621 .print_errors = 1
622 };
623 cmdline_parser_config_file(config_file, &conf, &params);
624 }
625 ret = check_config();
626 if (ret < 0)
627 goto out;
628 if (override) {
629 /* don't change daemon mode on SIGHUP */
630 conf.daemon_given = old_daemon_given;
631 close_log(logfile);
632 logfile = NULL;
633 if (conf.logfile_given)
634 free(old_logfile_arg);
635 else if (conf.daemon_given) { /* re-use old logfile */
636 conf.logfile_arg = old_logfile_arg;
637 conf.logfile_given = 1;
638 }
639 }
640 if (conf.logfile_given) {
641 logfile = open_log(conf.logfile_arg);
642 log_welcome(conf.loglevel_arg);
643 }
644 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
645 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
646 out:
647 free(config_file);
648 if (ret < 0)
649 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
650 return ret;
651 }
652
653 static int change_to_dest_dir(void)
654 {
655 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
656 return dss_chdir(conf.dest_dir_arg);
657 }
658
659 static int handle_sighup(void)
660 {
661 int ret;
662
663 DSS_NOTICE_LOG("SIGHUP\n");
664 ret = parse_config_file(1);
665 if (ret < 0)
666 return ret;
667 return change_to_dest_dir();
668 }
669
670 static int handle_signal(void)
671 {
672 int sig, ret = next_signal();
673
674 if (ret <= 0)
675 goto out;
676 sig = ret;
677 switch (sig) {
678 case SIGINT:
679 case SIGTERM:
680 restart_rsync_process();
681 kill_process(rsync_pid);
682 kill_process(rm_pid);
683 ret = -E_SIGNAL;
684 break;
685 case SIGHUP:
686 ret = handle_sighup();
687 break;
688 case SIGCHLD:
689 ret = handle_sigchld();
690 break;
691 }
692 out:
693 if (ret < 0)
694 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
695 return ret;
696 }
697
698 static void create_rsync_argv(char ***argv, int64_t *num)
699 {
700 char *logname, *newest;
701 int i = 0, j;
702 struct snapshot_list sl;
703
704 dss_get_snapshot_list(&sl);
705 newest = name_of_newest_complete_snapshot(&sl);
706 free_snapshot_list(&sl);
707
708 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
709 (*argv)[i++] = dss_strdup("rsync");
710 (*argv)[i++] = dss_strdup("-aq");
711 (*argv)[i++] = dss_strdup("--delete");
712 for (j = 0; j < conf.rsync_option_given; j++)
713 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
714 if (newest) {
715 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
716 (*argv)[i++] = make_message("--link-dest=../%s", newest);
717 free(newest);
718 } else
719 DSS_INFO_LOG("no previous snapshot found\n");
720 logname = dss_logname();
721 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
722 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
723 else
724 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
725 conf.remote_user_arg : logname,
726 conf.remote_host_arg, conf.source_dir_arg);
727 free(logname);
728 *num = get_current_time();
729 (*argv)[i++] = incomplete_name(*num);
730 (*argv)[i++] = NULL;
731 for (j = 0; j < i; j++)
732 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
733 }
734
735 static void free_rsync_argv(char **argv)
736 {
737 int i;
738
739 if (!argv)
740 return;
741 for (i = 0; argv[i]; i++)
742 free(argv[i]);
743 free(argv);
744 }
745
746 static int create_snapshot(char **argv)
747 {
748 int ret, fds[3] = {0, 0, 0};
749 char *name;
750
751 name = incomplete_name(current_snapshot_creation_time);
752 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
753 free(name);
754 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
755 if (ret < 0)
756 return ret;
757 snapshot_creation_status = SCS_RSYNC_RUNNING;
758 return ret;
759 }
760
761 static int select_loop(void)
762 {
763 int ret;
764 /* check every 60 seconds for free disk space */
765 struct timeval tv;
766 char **rsync_argv = NULL;
767
768 for (;;) {
769 fd_set rfds;
770 int low_disk_space;
771 struct timeval now, *tvp;
772
773 if (rm_pid)
774 tvp = NULL; /* sleep until rm process dies */
775 else { /* sleep one minute */
776 tv.tv_sec = 60;
777 tv.tv_usec = 0;
778 tvp = &tv;
779 }
780 FD_ZERO(&rfds);
781 FD_SET(signal_pipe, &rfds);
782 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
783 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
784 if (ret < 0)
785 goto out;
786 if (FD_ISSET(signal_pipe, &rfds)) {
787 ret = handle_signal();
788 if (ret < 0)
789 goto out;
790 }
791 if (rm_pid)
792 continue;
793 ret = disk_space_low();
794 if (ret < 0)
795 goto out;
796 low_disk_space = ret;
797 ret = try_to_free_disk_space(low_disk_space);
798 if (ret < 0)
799 goto out;
800 if (rm_pid) {
801 stop_rsync_process();
802 continue;
803 }
804 restart_rsync_process();
805 gettimeofday(&now, NULL);
806 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
807 continue;
808 switch (snapshot_creation_status) {
809 case SCS_READY:
810 ret = pre_create_hook();
811 if (ret < 0)
812 goto out;
813 continue;
814 case SCS_PRE_HOOK_RUNNING:
815 continue;
816 case SCS_RSYNC_NEEDS_RESTART:
817 ret = create_snapshot(rsync_argv);
818 if (ret < 0)
819 goto out;
820 continue;
821 case SCS_PRE_HOOK_SUCCESS:
822 free_rsync_argv(rsync_argv);
823 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
824 ret = create_snapshot(rsync_argv);
825 if (ret < 0)
826 goto out;
827 continue;
828 case SCS_RSYNC_RUNNING:
829 continue;
830 case SCS_RSYNC_SUCCESS:
831 ret = post_create_hook();
832 if (ret < 0)
833 goto out;
834 continue;
835 case SCS_POST_HOOK_RUNNING:
836 continue;
837 }
838 }
839 out:
840 return ret;
841 }
842
843 static void exit_hook(int exit_code)
844 {
845 int fds[3] = {0, 0, 0};
846 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
847 pid_t pid;
848
849 if (!conf.exit_hook_given)
850 return;
851 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
852 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
853 }
854
855 static int com_run(void)
856 {
857 int ret;
858
859 if (conf.dry_run_given) {
860 DSS_ERROR_LOG("dry_run not supported by this command\n");
861 return -E_SYNTAX;
862 }
863 ret = install_sighandler(SIGHUP);
864 if (ret < 0)
865 return ret;
866 compute_next_snapshot_time();
867 ret = select_loop();
868 if (ret >= 0) /* impossible */
869 ret = -E_BUG;
870 exit_hook(ret);
871 return ret;
872 }
873
874 static int com_prune(void)
875 {
876 int ret;
877 struct snapshot_list sl;
878 struct disk_space ds;
879
880 ret = get_disk_space(".", &ds);
881 if (ret < 0)
882 return ret;
883 log_disk_space(&ds);
884 for (;;) {
885 dss_get_snapshot_list(&sl);
886 ret = remove_outdated_snapshot(&sl);
887 free_snapshot_list(&sl);
888 if (ret < 0)
889 return ret;
890 if (!ret)
891 break;
892 ret = wait_for_rm_process();
893 if (ret < 0)
894 goto out;
895 }
896 for (;;) {
897 dss_get_snapshot_list(&sl);
898 ret = remove_redundant_snapshot(&sl);
899 free_snapshot_list(&sl);
900 if (ret < 0)
901 return ret;
902 if (!ret)
903 break;
904 ret = wait_for_rm_process();
905 if (ret < 0)
906 goto out;
907 }
908 return 1;
909 out:
910 return ret;
911 }
912
913 static int com_create(void)
914 {
915 int ret, status;
916 char **rsync_argv;
917
918 if (conf.dry_run_given) {
919 int i;
920 char *msg = NULL;
921 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
922 for (i = 0; rsync_argv[i]; i++) {
923 char *tmp = msg;
924 msg = make_message("%s%s%s", tmp? tmp : "",
925 tmp? " " : "", rsync_argv[i]);
926 free(tmp);
927 }
928 free_rsync_argv(rsync_argv);
929 dss_msg("%s\n", msg);
930 free(msg);
931 return 1;
932 }
933 ret = pre_create_hook();
934 if (ret < 0)
935 return ret;
936 if (pre_create_hook_pid) {
937 ret = wait_for_process(pre_create_hook_pid, &status);
938 if (ret < 0)
939 return ret;
940 ret = handle_pre_create_hook_exit(status);
941 if (ret < 0)
942 return ret;
943 }
944 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
945 ret = create_snapshot(rsync_argv);
946 if (ret < 0)
947 goto out;
948 ret = wait_for_process(rsync_pid, &status);
949 if (ret < 0)
950 goto out;
951 ret = handle_rsync_exit(status);
952 if (ret < 0)
953 goto out;
954 post_create_hook();
955 if (post_create_hook_pid)
956 ret = wait_for_process(post_create_hook_pid, &status);
957 out:
958 free_rsync_argv(rsync_argv);
959 return ret;
960 }
961
962 static int com_ls(void)
963 {
964 int i;
965 struct snapshot_list sl;
966 struct snapshot *s;
967
968 dss_get_snapshot_list(&sl);
969 FOR_EACH_SNAPSHOT(s, i, &sl) {
970 int64_t d = 0;
971 if (s->flags & SS_COMPLETE)
972 d = (s->completion_time - s->creation_time) / 60;
973 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
974 };
975 free_snapshot_list(&sl);
976 return 1;
977 }
978
979 static int setup_signal_handling(void)
980 {
981 int ret;
982
983 DSS_INFO_LOG("setting up signal handlers\n");
984 signal_pipe = signal_init(); /* always successful */
985 ret = install_sighandler(SIGINT);
986 if (ret < 0)
987 return ret;
988 ret = install_sighandler(SIGTERM);
989 if (ret < 0)
990 return ret;
991 return install_sighandler(SIGCHLD);
992 }
993
994 /**
995 * The main function of dss.
996 *
997 * \param argc Usual argument count.
998 * \param argv Usual argument vector.
999 */
1000 int main(int argc, char **argv)
1001 {
1002 int ret;
1003 struct cmdline_parser_params params = {
1004 .override = 0,
1005 .initialize = 1,
1006 .check_required = 0,
1007 .check_ambiguity = 0,
1008 .print_errors = 1
1009 };
1010
1011 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1012 ret = parse_config_file(0);
1013 if (ret < 0)
1014 goto out;
1015 if (conf.daemon_given)
1016 daemon_init();
1017 ret = change_to_dest_dir();
1018 if (ret < 0)
1019 goto out;
1020 ret = setup_signal_handling();
1021 if (ret < 0)
1022 goto out;
1023 ret = call_command_handler();
1024 out:
1025 if (ret < 0)
1026 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1027 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1028 }