Fix the pre-create hook.
[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 pre-create-hook/rsync/post-create-hook process. */
44 static pid_t create_pid;
45 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
46 static int create_process_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 /** Creation time of the snapshot currently being created. */
52 static int64_t current_snapshot_creation_time;
53 /** Needed by the post-create hook. */
54 static char *path_to_last_complete_snapshot;
55 /** \sa \ref snap.h for details. */
56 static unsigned snapshot_creation_status;
57
58
59 DEFINE_DSS_ERRLIST;
60
61
62 /* a litte cpp magic helps to DRY */
63 #define COMMANDS \
64 COMMAND(ls) \
65 COMMAND(create) \
66 COMMAND(prune) \
67 COMMAND(run)
68 #define COMMAND(x) static int com_ ##x(void);
69 COMMANDS
70 #undef COMMAND
71 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
72 static int call_command_handler(void)
73 {
74 COMMANDS
75 DSS_EMERG_LOG("BUG: did not find command handler\n");
76 return -E_BUG;
77 }
78 #undef COMMAND
79 #undef COMMANDS
80
81 /**
82 * The log function of dss.
83 *
84 * \param ll Loglevel.
85 * \param fml Usual format string.
86 *
87 * All DSS_XXX_LOG() macros use this function.
88 */
89 __printf_2_3 void dss_log(int ll, const char* fmt,...)
90 {
91 va_list argp;
92 FILE *outfd;
93 struct tm *tm;
94 time_t t1;
95 char str[255] = "";
96
97 if (ll < conf.loglevel_arg)
98 return;
99 outfd = logfile? logfile : stderr;
100 time(&t1);
101 tm = localtime(&t1);
102 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
103 fprintf(outfd, "%s ", str);
104 if (conf.loglevel_arg <= INFO)
105 fprintf(outfd, "%i: ", ll);
106 va_start(argp, fmt);
107 vfprintf(outfd, fmt, argp);
108 va_end(argp);
109 }
110
111 /**
112 * Print a message either to stdout or to the log file.
113 */
114 static __printf_1_2 void dss_msg(const char* fmt,...)
115 {
116 FILE *outfd = conf.daemon_given? logfile : stdout;
117 va_list argp;
118 va_start(argp, fmt);
119 vfprintf(outfd, fmt, argp);
120 va_end(argp);
121 }
122
123 static int disk_space_low(void)
124 {
125 struct disk_space ds;
126 int ret = get_disk_space(".", &ds);
127
128 if (ret < 0)
129 return ret;
130 if (conf.min_free_mb_arg)
131 if (ds.free_mb < conf.min_free_mb_arg)
132 return 1;
133 if (conf.min_free_percent_arg)
134 if (ds.percent_free < conf.min_free_percent_arg)
135 return 1;
136 if (conf.min_free_percent_inodes_arg)
137 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
138 return 1;
139 return 0;
140 }
141
142 static void dss_get_snapshot_list(struct snapshot_list *sl)
143 {
144 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
145 }
146
147 static void compute_next_snapshot_time(void)
148 {
149 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
150 tmp, diff;
151 int64_t x = 0;
152 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
153 num_complete_snapshots = 0;
154 int i, ret;
155 struct snapshot *s = NULL;
156 struct snapshot_list sl;
157
158 assert(snapshot_creation_status == SCS_READY);
159 current_snapshot_creation_time = 0;
160 dss_get_snapshot_list(&sl);
161 FOR_EACH_SNAPSHOT(s, i, &sl) {
162 if (!(s->flags & SS_COMPLETE))
163 continue;
164 num_complete_snapshots++;
165 x += s->completion_time - s->creation_time;
166 }
167 assert(x >= 0);
168 if (num_complete_snapshots)
169 x /= num_complete_snapshots; /* avg time to create one snapshot */
170 x *= wanted; /* time to create all snapshots in interval 0 */
171 tmp.tv_sec = x;
172 tmp.tv_usec = 0;
173 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
174 if (ret < 0 || !s) /* unit_interval < tmp or no snapshot */
175 goto min_sleep;
176 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
177 diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
178 diff.tv_usec = 0;
179 tv_add(&diff, &tmp, &next_snapshot_time);
180 gettimeofday(&now, NULL);
181 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
182 goto out;
183 min_sleep:
184 next_snapshot_time = now;
185 next_snapshot_time.tv_sec += 60;
186 out:
187 free_snapshot_list(&sl);
188 }
189
190
191 static int remove_snapshot(struct snapshot *s, char *why)
192 {
193 int fds[3] = {0, 0, 0};
194 assert(!rm_pid);
195 char *new_name = being_deleted_name(s);
196 int ret = dss_rename(s->name, new_name);
197 char *argv[] = {"rm", "-rf", new_name, NULL};
198
199 if (ret < 0)
200 goto out;
201 DSS_NOTICE_LOG("removing %s snapshot %s (interval = %i)\n",
202 why, s->name, s->interval);
203 ret = dss_exec(&rm_pid, argv[0], argv, fds);
204 out:
205 free(new_name);
206 return ret;
207 }
208
209 static int snapshot_is_being_created(struct snapshot *s)
210 {
211 return s->creation_time == current_snapshot_creation_time;
212 }
213
214 /*
215 * return: 0: no redundant snapshots, 1: rm process started, negative: error
216 */
217 static int remove_redundant_snapshot(struct snapshot_list *sl)
218 {
219 int ret, i, interval;
220 struct snapshot *s;
221 unsigned missing = 0;
222
223 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
224 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
225 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
226 unsigned num = sl->interval_count[interval];
227 struct snapshot *victim = NULL, *prev = NULL;
228 int64_t score = LONG_MAX;
229
230 if (keep >= num)
231 missing += keep - num;
232 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
233 // interval, keep, num, missing);
234 if (keep + missing >= num)
235 continue;
236 /* redundant snapshot in this interval, pick snapshot with lowest score */
237 FOR_EACH_SNAPSHOT(s, i, sl) {
238 int64_t this_score;
239
240 if (snapshot_is_being_created(s))
241 continue;
242 //DSS_DEBUG_LOG("checking %s\n", s->name);
243 if (s->interval > interval) {
244 prev = s;
245 continue;
246 }
247 if (s->interval < interval)
248 break;
249 if (!victim) {
250 victim = s;
251 prev = s;
252 continue;
253 }
254 assert(prev);
255 /* check if s is a better victim */
256 this_score = s->creation_time - prev->creation_time;
257 assert(this_score >= 0);
258 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
259 if (this_score < score) {
260 score = this_score;
261 victim = s;
262 }
263 prev = s;
264 }
265 assert(victim);
266 if (conf.dry_run_given) {
267 dss_msg("%s would be removed (interval = %i)\n",
268 victim->name, victim->interval);
269 continue;
270 }
271 ret = remove_snapshot(victim, "redundant");
272 return ret < 0? ret : 1;
273 }
274 return 0;
275 }
276
277 static int remove_outdated_snapshot(struct snapshot_list *sl)
278 {
279 int i, ret;
280 struct snapshot *s;
281
282 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
283 conf.num_intervals_arg);
284 FOR_EACH_SNAPSHOT(s, i, sl) {
285 if (snapshot_is_being_created(s))
286 continue;
287 if (s->interval <= conf.num_intervals_arg)
288 continue;
289 if (conf.dry_run_given) {
290 dss_msg("%s would be removed (interval = %i)\n",
291 s->name, s->interval);
292 continue;
293 }
294 ret = remove_snapshot(s, "outdated");
295 if (ret < 0)
296 return ret;
297 return 1;
298 }
299 return 0;
300 }
301
302 static int remove_oldest_snapshot(struct snapshot_list *sl)
303 {
304 struct snapshot *s = get_oldest_snapshot(sl);
305
306 if (!s) /* no snapshot found */
307 return 0;
308 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
309 if (snapshot_is_being_created(s))
310 return 0;
311 return remove_snapshot(s, "oldest");
312 }
313
314 static int rename_incomplete_snapshot(int64_t start)
315 {
316 char *old_name;
317 int ret;
318
319 free(path_to_last_complete_snapshot);
320 ret = complete_name(start, get_current_time(),
321 &path_to_last_complete_snapshot);
322 if (ret < 0)
323 return ret;
324 old_name = incomplete_name(start);
325 ret = dss_rename(old_name, path_to_last_complete_snapshot);
326 if (ret >= 0)
327 DSS_NOTICE_LOG("%s -> %s\n", old_name,
328 path_to_last_complete_snapshot);
329 free(old_name);
330 return ret;
331 }
332
333 static int try_to_free_disk_space(int low_disk_space)
334 {
335 int ret;
336 struct snapshot_list sl;
337
338 if (!low_disk_space && conf.keep_redundant_given)
339 return 0;
340 dss_get_snapshot_list(&sl);
341 ret = remove_outdated_snapshot(&sl);
342 if (ret) /* error, or we are removing something */
343 goto out;
344 /* no outdated snapshot */
345 ret = remove_redundant_snapshot(&sl);
346 if (ret)
347 goto out;
348 ret = 0;
349 if (!low_disk_space)
350 goto out;
351 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
352 ret = remove_oldest_snapshot(&sl);
353 if (ret)
354 goto out;
355 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
356 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
357 out:
358 free_snapshot_list(&sl);
359 return ret;
360 }
361
362 static int pre_create_hook(void)
363 {
364 int ret, fds[3] = {0, 0, 0};
365
366 if (!conf.pre_create_hook_given) {
367 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
368 return 0;
369 }
370 DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
371 ret = dss_exec_cmdline_pid(&create_pid,
372 conf.pre_create_hook_arg, fds);
373 if (ret < 0)
374 return ret;
375 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
376 return ret;
377 }
378
379 static int post_create_hook(void)
380 {
381 int ret, fds[3] = {0, 0, 0};
382 char *cmd;
383
384 if (!conf.post_create_hook_given) {
385 snapshot_creation_status = SCS_READY;
386 compute_next_snapshot_time();
387 return 0;
388 }
389 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
390 conf.dest_dir_arg, path_to_last_complete_snapshot);
391 DSS_NOTICE_LOG("executing %s\n", cmd);
392 ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
393 free(cmd);
394 if (ret < 0)
395 return ret;
396 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
397 return ret;
398 }
399
400 static void kill_process(pid_t pid)
401 {
402 if (!pid)
403 return;
404 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
405 kill(pid, SIGTERM);
406 }
407
408 static void stop_create_process(void)
409 {
410 if (!create_pid || create_process_stopped)
411 return;
412 kill(SIGSTOP, create_pid);
413 create_process_stopped = 1;
414 }
415
416 static void restart_create_process(void)
417 {
418 if (!create_pid || !create_process_stopped)
419 return;
420 kill (SIGCONT, create_pid);
421 create_process_stopped = 0;
422 }
423
424 /**
425 * Print a log message about the exit status of a child.
426 */
427 static void log_termination_msg(pid_t pid, int status)
428 {
429 if (WIFEXITED(status))
430 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
431 WEXITSTATUS(status));
432 else if (WIFSIGNALED(status))
433 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
434 WTERMSIG(status));
435 else
436 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
437 }
438
439 static int wait_for_process(pid_t pid, int *status)
440 {
441 int ret;
442
443 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
444 for (;;) {
445 fd_set rfds;
446
447 FD_ZERO(&rfds);
448 FD_SET(signal_pipe, &rfds);
449 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
450 if (ret < 0)
451 break;
452 ret = next_signal();
453 if (!ret)
454 continue;
455 if (ret == SIGCHLD) {
456 ret = waitpid(pid, status, 0);
457 if (ret >= 0)
458 break;
459 if (errno != EINTR) { /* error */
460 ret = -ERRNO_TO_DSS_ERROR(errno);
461 break;
462 }
463 }
464 /* SIGINT or SIGTERM */
465 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
466 kill(pid, SIGTERM);
467 }
468 if (ret < 0)
469 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
470 else
471 log_termination_msg(pid, *status);
472 return ret;
473 }
474
475 static int handle_rm_exit(int status)
476 {
477 rm_pid = 0;
478 if (!WIFEXITED(status))
479 return -E_INVOLUNTARY_EXIT;
480 if (WEXITSTATUS(status))
481 return -E_BAD_EXIT_CODE;
482 return 1;
483 }
484
485 static int wait_for_rm_process(void)
486 {
487 int status, ret = wait_for_process(rm_pid, &status);
488
489 if (ret < 0)
490 return ret;
491 return handle_rm_exit(status);
492 }
493
494 static int handle_rsync_exit(int status)
495 {
496 int es, ret;
497
498 if (!WIFEXITED(status)) {
499 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
500 ret = -E_INVOLUNTARY_EXIT;
501 snapshot_creation_status = SCS_READY;
502 compute_next_snapshot_time();
503 goto out;
504 }
505 es = WEXITSTATUS(status);
506 if (es == 13) { /* Errors with program diagnostics */
507 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
508 (int)create_pid, es);
509 snapshot_creation_status = SCS_RSYNC_NEEDS_RESTART;
510 gettimeofday(&next_snapshot_time, NULL);
511 next_snapshot_time.tv_sec += 60;
512 ret = 1;
513 goto out;
514 }
515 if (es != 0 && es != 23 && es != 24) {
516 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
517 ret = -E_BAD_EXIT_CODE;
518 snapshot_creation_status = SCS_READY;
519 compute_next_snapshot_time();
520 goto out;
521 }
522 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
523 if (ret < 0)
524 goto out;
525 snapshot_creation_status = SCS_RSYNC_SUCCESS;
526 out:
527 create_pid = 0;
528 create_process_stopped = 0;
529 return ret;
530 }
531
532 static int handle_pre_create_hook_exit(int status)
533 {
534 int es, ret;
535 static int warn_count;
536
537 if (!WIFEXITED(status)) {
538 snapshot_creation_status = SCS_READY;
539 compute_next_snapshot_time();
540 ret = -E_INVOLUNTARY_EXIT;
541 goto out;
542 }
543 es = WEXITSTATUS(status);
544 if (es) {
545 if (!warn_count--) {
546 DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
547 conf.pre_create_hook_arg, es);
548 DSS_NOTICE_LOG("deferring snapshot creation...\n");
549 warn_count = 60; /* warn only once per hour */
550 }
551 snapshot_creation_status = SCS_READY;
552 compute_next_snapshot_time();
553 ret = 0;
554 goto out;
555 }
556 warn_count = 0;
557 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
558 ret = 1;
559 out:
560 create_pid = 0;
561 return ret;
562 }
563
564 static int handle_sigchld(void)
565 {
566 pid_t pid;
567 int status, ret = reap_child(&pid, &status);
568
569 if (ret <= 0)
570 return ret;
571
572 if (pid == create_pid) {
573 switch (snapshot_creation_status) {
574 case SCS_PRE_HOOK_RUNNING:
575 return handle_pre_create_hook_exit(status);
576 case SCS_RSYNC_RUNNING:
577 return handle_rsync_exit(status);
578 case SCS_POST_HOOK_RUNNING:
579 snapshot_creation_status = SCS_READY;
580 compute_next_snapshot_time();
581 return 1;
582 default:
583 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
584 snapshot_creation_status);
585 return -E_BUG;
586 }
587 }
588 if (pid == rm_pid)
589 return handle_rm_exit(status);
590 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
591 return -E_BUG;
592 }
593
594 static int check_config(void)
595 {
596 if (conf.unit_interval_arg <= 0) {
597 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
598 return -E_INVALID_NUMBER;
599 }
600 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
601 if (conf.num_intervals_arg <= 0) {
602 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
603 return -E_INVALID_NUMBER;
604 }
605 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
606 return 1;
607 }
608
609 static int parse_config_file(int override)
610 {
611 int ret;
612 char *config_file;
613 struct stat statbuf;
614 char *old_logfile_arg = NULL;
615 int old_daemon_given = 0;
616
617 if (conf.config_file_given)
618 config_file = dss_strdup(conf.config_file_arg);
619 else {
620 char *home = get_homedir();
621 config_file = make_message("%s/.dssrc", home);
622 free(home);
623 }
624 if (override) { /* SIGHUP */
625 if (conf.logfile_given)
626 old_logfile_arg = dss_strdup(conf.logfile_arg);
627 old_daemon_given = conf.daemon_given;
628 }
629
630 ret = stat(config_file, &statbuf);
631 if (ret && conf.config_file_given) {
632 ret = -ERRNO_TO_DSS_ERROR(errno);
633 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
634 goto out;
635 }
636 if (!ret) {
637 struct cmdline_parser_params params = {
638 .override = override,
639 .initialize = 0,
640 .check_required = 1,
641 .check_ambiguity = 0,
642 .print_errors = 1
643 };
644 if (override) { /* invalidate all rsync options */
645 int i;
646
647 for (i = 0; i < conf.rsync_option_given; i++) {
648 free(conf.rsync_option_arg[i]);
649 conf.rsync_option_arg[i] = NULL;
650 }
651 conf.rsync_option_given = 0;
652 }
653 cmdline_parser_config_file(config_file, &conf, &params);
654 }
655 ret = check_config();
656 if (ret < 0)
657 goto out;
658 if (override) {
659 /* don't change daemon mode on SIGHUP */
660 conf.daemon_given = old_daemon_given;
661 close_log(logfile);
662 logfile = NULL;
663 if (conf.logfile_given)
664 free(old_logfile_arg);
665 else if (conf.daemon_given) { /* re-use old logfile */
666 conf.logfile_arg = old_logfile_arg;
667 conf.logfile_given = 1;
668 }
669 }
670 if (conf.logfile_given) {
671 logfile = open_log(conf.logfile_arg);
672 log_welcome(conf.loglevel_arg);
673 }
674 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
675 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
676 out:
677 free(config_file);
678 if (ret < 0)
679 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
680 return ret;
681 }
682
683 static int change_to_dest_dir(void)
684 {
685 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
686 return dss_chdir(conf.dest_dir_arg);
687 }
688
689 static int handle_sighup(void)
690 {
691 int ret;
692
693 DSS_NOTICE_LOG("SIGHUP\n");
694 ret = parse_config_file(1);
695 if (ret < 0)
696 return ret;
697 return change_to_dest_dir();
698 }
699
700 static int handle_signal(void)
701 {
702 int sig, ret = next_signal();
703
704 if (ret <= 0)
705 goto out;
706 sig = ret;
707 switch (sig) {
708 case SIGINT:
709 case SIGTERM:
710 restart_create_process();
711 kill_process(create_pid);
712 kill_process(rm_pid);
713 ret = -E_SIGNAL;
714 break;
715 case SIGHUP:
716 ret = handle_sighup();
717 break;
718 case SIGCHLD:
719 ret = handle_sigchld();
720 break;
721 }
722 out:
723 if (ret < 0)
724 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
725 return ret;
726 }
727
728 /*
729 * We can not use rsync locally if the local user is different from the remote
730 * user or if the src dir is not on the local host (or both).
731 */
732 static int use_rsync_locally(char *logname)
733 {
734 char *h = conf.remote_host_arg;
735
736 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
737 return 0;
738 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
739 return 0;
740 return 1;
741 }
742
743 static void create_rsync_argv(char ***argv, int64_t *num)
744 {
745 char *logname, *newest;
746 int i = 0, j;
747 struct snapshot_list sl;
748
749 dss_get_snapshot_list(&sl);
750 newest = name_of_newest_complete_snapshot(&sl);
751 free_snapshot_list(&sl);
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 logname = dss_logname();
766 if (use_rsync_locally(logname))
767 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
768 else
769 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
770 conf.remote_user_arg : logname,
771 conf.remote_host_arg, conf.source_dir_arg);
772 free(logname);
773 *num = get_current_time();
774 (*argv)[i++] = incomplete_name(*num);
775 (*argv)[i++] = NULL;
776 for (j = 0; j < i; j++)
777 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
778 }
779
780 static void free_rsync_argv(char **argv)
781 {
782 int i;
783
784 if (!argv)
785 return;
786 for (i = 0; argv[i]; i++)
787 free(argv[i]);
788 free(argv);
789 }
790
791 static int create_snapshot(char **argv)
792 {
793 int ret, fds[3] = {0, 0, 0};
794 char *name;
795
796 name = incomplete_name(current_snapshot_creation_time);
797 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
798 free(name);
799 ret = dss_exec(&create_pid, argv[0], argv, fds);
800 if (ret < 0)
801 return ret;
802 snapshot_creation_status = SCS_RSYNC_RUNNING;
803 return ret;
804 }
805
806 static int select_loop(void)
807 {
808 int ret;
809 /* check every 60 seconds for free disk space */
810 struct timeval tv;
811 char **rsync_argv = NULL;
812
813 for (;;) {
814 fd_set rfds;
815 int low_disk_space;
816 struct timeval now, *tvp;
817
818 if (rm_pid)
819 tvp = NULL; /* sleep until rm process dies */
820 else { /* sleep one minute */
821 tv.tv_sec = 60;
822 tv.tv_usec = 0;
823 tvp = &tv;
824 }
825 FD_ZERO(&rfds);
826 FD_SET(signal_pipe, &rfds);
827 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
828 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
829 if (ret < 0)
830 goto out;
831 if (FD_ISSET(signal_pipe, &rfds)) {
832 ret = handle_signal();
833 if (ret < 0)
834 goto out;
835 }
836 if (rm_pid)
837 continue;
838 ret = disk_space_low();
839 if (ret < 0)
840 goto out;
841 low_disk_space = ret;
842 ret = try_to_free_disk_space(low_disk_space);
843 if (ret < 0)
844 goto out;
845 if (rm_pid) {
846 stop_create_process();
847 continue;
848 }
849 restart_create_process();
850 gettimeofday(&now, NULL);
851 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
852 continue;
853 switch (snapshot_creation_status) {
854 case SCS_READY:
855 ret = pre_create_hook();
856 if (ret < 0)
857 goto out;
858 continue;
859 case SCS_PRE_HOOK_RUNNING:
860 continue;
861 case SCS_RSYNC_NEEDS_RESTART:
862 ret = create_snapshot(rsync_argv);
863 if (ret < 0)
864 goto out;
865 continue;
866 case SCS_PRE_HOOK_SUCCESS:
867 free_rsync_argv(rsync_argv);
868 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
869 ret = create_snapshot(rsync_argv);
870 if (ret < 0)
871 goto out;
872 continue;
873 case SCS_RSYNC_RUNNING:
874 continue;
875 case SCS_RSYNC_SUCCESS:
876 ret = post_create_hook();
877 if (ret < 0)
878 goto out;
879 continue;
880 case SCS_POST_HOOK_RUNNING:
881 continue;
882 }
883 }
884 out:
885 return ret;
886 }
887
888 static void exit_hook(int exit_code)
889 {
890 int fds[3] = {0, 0, 0};
891 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
892 pid_t pid;
893
894 if (!conf.exit_hook_given)
895 return;
896 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
897 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
898 }
899
900 static int com_run(void)
901 {
902 int ret;
903
904 if (conf.dry_run_given) {
905 DSS_ERROR_LOG("dry_run not supported by this command\n");
906 return -E_SYNTAX;
907 }
908 ret = install_sighandler(SIGHUP);
909 if (ret < 0)
910 return ret;
911 compute_next_snapshot_time();
912 ret = select_loop();
913 if (ret >= 0) /* impossible */
914 ret = -E_BUG;
915 exit_hook(ret);
916 return ret;
917 }
918
919 static int com_prune(void)
920 {
921 int ret;
922 struct snapshot_list sl;
923 struct disk_space ds;
924
925 ret = get_disk_space(".", &ds);
926 if (ret < 0)
927 return ret;
928 log_disk_space(&ds);
929 for (;;) {
930 dss_get_snapshot_list(&sl);
931 ret = remove_outdated_snapshot(&sl);
932 free_snapshot_list(&sl);
933 if (ret < 0)
934 return ret;
935 if (!ret)
936 break;
937 ret = wait_for_rm_process();
938 if (ret < 0)
939 goto out;
940 }
941 for (;;) {
942 dss_get_snapshot_list(&sl);
943 ret = remove_redundant_snapshot(&sl);
944 free_snapshot_list(&sl);
945 if (ret < 0)
946 return ret;
947 if (!ret)
948 break;
949 ret = wait_for_rm_process();
950 if (ret < 0)
951 goto out;
952 }
953 return 1;
954 out:
955 return ret;
956 }
957
958 static int com_create(void)
959 {
960 int ret, status;
961 char **rsync_argv;
962
963 if (conf.dry_run_given) {
964 int i;
965 char *msg = NULL;
966 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
967 for (i = 0; rsync_argv[i]; i++) {
968 char *tmp = msg;
969 msg = make_message("%s%s%s", tmp? tmp : "",
970 tmp? " " : "", rsync_argv[i]);
971 free(tmp);
972 }
973 free_rsync_argv(rsync_argv);
974 dss_msg("%s\n", msg);
975 free(msg);
976 return 1;
977 }
978 ret = pre_create_hook();
979 if (ret < 0)
980 return ret;
981 if (create_pid) {
982 ret = wait_for_process(create_pid, &status);
983 if (ret < 0)
984 return ret;
985 ret = handle_pre_create_hook_exit(status);
986 if (ret < 0)
987 return ret;
988 }
989 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
990 ret = create_snapshot(rsync_argv);
991 if (ret < 0)
992 goto out;
993 ret = wait_for_process(create_pid, &status);
994 if (ret < 0)
995 goto out;
996 ret = handle_rsync_exit(status);
997 if (ret < 0)
998 goto out;
999 post_create_hook();
1000 if (create_pid)
1001 ret = wait_for_process(create_pid, &status);
1002 out:
1003 free_rsync_argv(rsync_argv);
1004 return ret;
1005 }
1006
1007 static int com_ls(void)
1008 {
1009 int i;
1010 struct snapshot_list sl;
1011 struct snapshot *s;
1012
1013 dss_get_snapshot_list(&sl);
1014 FOR_EACH_SNAPSHOT(s, i, &sl) {
1015 int64_t d = 0;
1016 if (s->flags & SS_COMPLETE)
1017 d = (s->completion_time - s->creation_time) / 60;
1018 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1019 };
1020 free_snapshot_list(&sl);
1021 return 1;
1022 }
1023
1024 static int setup_signal_handling(void)
1025 {
1026 int ret;
1027
1028 DSS_INFO_LOG("setting up signal handlers\n");
1029 signal_pipe = signal_init(); /* always successful */
1030 ret = install_sighandler(SIGINT);
1031 if (ret < 0)
1032 return ret;
1033 ret = install_sighandler(SIGTERM);
1034 if (ret < 0)
1035 return ret;
1036 return install_sighandler(SIGCHLD);
1037 }
1038
1039 /**
1040 * The main function of dss.
1041 *
1042 * \param argc Usual argument count.
1043 * \param argv Usual argument vector.
1044 */
1045 int main(int argc, char **argv)
1046 {
1047 int ret;
1048 struct cmdline_parser_params params = {
1049 .override = 0,
1050 .initialize = 1,
1051 .check_required = 0,
1052 .check_ambiguity = 0,
1053 .print_errors = 1
1054 };
1055
1056 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1057 ret = parse_config_file(0);
1058 if (ret < 0)
1059 goto out;
1060 if (conf.daemon_given)
1061 daemon_init();
1062 ret = change_to_dest_dir();
1063 if (ret < 0)
1064 goto out;
1065 ret = setup_signal_handling();
1066 if (ret < 0)
1067 goto out;
1068 ret = call_command_handler();
1069 out:
1070 if (ret < 0)
1071 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1072 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1073 }