Use only one global variable for snapshot creation pids.
[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_NOTICE_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
536 if (!WIFEXITED(status)) {
537 snapshot_creation_status = SCS_READY;
538 compute_next_snapshot_time();
539 ret = -E_INVOLUNTARY_EXIT;
540 goto out;
541 }
542 es = WEXITSTATUS(status);
543 if (es) {
544 snapshot_creation_status = SCS_READY;
545 compute_next_snapshot_time();
546 ret = -E_BAD_EXIT_CODE;
547 goto out;
548 }
549 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
550 ret = 1;
551 out:
552 create_pid = 0;
553 return ret;
554 }
555
556 static int handle_sigchld(void)
557 {
558 pid_t pid;
559 int status, ret = reap_child(&pid, &status);
560
561 if (ret <= 0)
562 return ret;
563
564 if (pid == create_pid) {
565 switch (snapshot_creation_status) {
566 case SCS_PRE_HOOK_RUNNING:
567 return handle_pre_create_hook_exit(status);
568 case SCS_RSYNC_RUNNING:
569 return handle_rsync_exit(status);
570 case SCS_POST_HOOK_RUNNING:
571 snapshot_creation_status = SCS_READY;
572 compute_next_snapshot_time();
573 return 1;
574 default:
575 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
576 snapshot_creation_status);
577 return -E_BUG;
578 }
579 }
580 if (pid == rm_pid)
581 return handle_rm_exit(status);
582 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
583 return -E_BUG;
584 }
585
586 static int check_config(void)
587 {
588 if (conf.unit_interval_arg <= 0) {
589 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
590 return -E_INVALID_NUMBER;
591 }
592 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
593 if (conf.num_intervals_arg <= 0) {
594 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
595 return -E_INVALID_NUMBER;
596 }
597 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
598 return 1;
599 }
600
601 static int parse_config_file(int override)
602 {
603 int ret;
604 char *config_file;
605 struct stat statbuf;
606 char *old_logfile_arg = NULL;
607 int old_daemon_given = 0;
608
609 if (conf.config_file_given)
610 config_file = dss_strdup(conf.config_file_arg);
611 else {
612 char *home = get_homedir();
613 config_file = make_message("%s/.dssrc", home);
614 free(home);
615 }
616 if (override) { /* SIGHUP */
617 if (conf.logfile_given)
618 old_logfile_arg = dss_strdup(conf.logfile_arg);
619 old_daemon_given = conf.daemon_given;
620 }
621
622 ret = stat(config_file, &statbuf);
623 if (ret && conf.config_file_given) {
624 ret = -ERRNO_TO_DSS_ERROR(errno);
625 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
626 goto out;
627 }
628 if (!ret) {
629 struct cmdline_parser_params params = {
630 .override = override,
631 .initialize = 0,
632 .check_required = 1,
633 .check_ambiguity = 0,
634 .print_errors = 1
635 };
636 if (override) { /* invalidate all rsync options */
637 int i;
638
639 for (i = 0; i < conf.rsync_option_given; i++) {
640 free(conf.rsync_option_arg[i]);
641 conf.rsync_option_arg[i] = NULL;
642 }
643 conf.rsync_option_given = 0;
644 }
645 cmdline_parser_config_file(config_file, &conf, &params);
646 }
647 ret = check_config();
648 if (ret < 0)
649 goto out;
650 if (override) {
651 /* don't change daemon mode on SIGHUP */
652 conf.daemon_given = old_daemon_given;
653 close_log(logfile);
654 logfile = NULL;
655 if (conf.logfile_given)
656 free(old_logfile_arg);
657 else if (conf.daemon_given) { /* re-use old logfile */
658 conf.logfile_arg = old_logfile_arg;
659 conf.logfile_given = 1;
660 }
661 }
662 if (conf.logfile_given) {
663 logfile = open_log(conf.logfile_arg);
664 log_welcome(conf.loglevel_arg);
665 }
666 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
667 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
668 out:
669 free(config_file);
670 if (ret < 0)
671 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
672 return ret;
673 }
674
675 static int change_to_dest_dir(void)
676 {
677 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
678 return dss_chdir(conf.dest_dir_arg);
679 }
680
681 static int handle_sighup(void)
682 {
683 int ret;
684
685 DSS_NOTICE_LOG("SIGHUP\n");
686 ret = parse_config_file(1);
687 if (ret < 0)
688 return ret;
689 return change_to_dest_dir();
690 }
691
692 static int handle_signal(void)
693 {
694 int sig, ret = next_signal();
695
696 if (ret <= 0)
697 goto out;
698 sig = ret;
699 switch (sig) {
700 case SIGINT:
701 case SIGTERM:
702 restart_create_process();
703 kill_process(create_pid);
704 kill_process(rm_pid);
705 ret = -E_SIGNAL;
706 break;
707 case SIGHUP:
708 ret = handle_sighup();
709 break;
710 case SIGCHLD:
711 ret = handle_sigchld();
712 break;
713 }
714 out:
715 if (ret < 0)
716 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
717 return ret;
718 }
719
720 /*
721 * We can not use rsync locally if the local user is different from the remote
722 * user or if the src dir is not on the local host (or both).
723 */
724 static int use_rsync_locally(char *logname)
725 {
726 char *h = conf.remote_host_arg;
727
728 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
729 return 0;
730 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
731 return 0;
732 return 1;
733 }
734
735 static void create_rsync_argv(char ***argv, int64_t *num)
736 {
737 char *logname, *newest;
738 int i = 0, j;
739 struct snapshot_list sl;
740
741 dss_get_snapshot_list(&sl);
742 newest = name_of_newest_complete_snapshot(&sl);
743 free_snapshot_list(&sl);
744
745 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
746 (*argv)[i++] = dss_strdup("rsync");
747 (*argv)[i++] = dss_strdup("-aq");
748 (*argv)[i++] = dss_strdup("--delete");
749 for (j = 0; j < conf.rsync_option_given; j++)
750 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
751 if (newest) {
752 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
753 (*argv)[i++] = make_message("--link-dest=../%s", newest);
754 free(newest);
755 } else
756 DSS_INFO_LOG("no previous snapshot found\n");
757 logname = dss_logname();
758 if (use_rsync_locally(logname))
759 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
760 else
761 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
762 conf.remote_user_arg : logname,
763 conf.remote_host_arg, conf.source_dir_arg);
764 free(logname);
765 *num = get_current_time();
766 (*argv)[i++] = incomplete_name(*num);
767 (*argv)[i++] = NULL;
768 for (j = 0; j < i; j++)
769 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
770 }
771
772 static void free_rsync_argv(char **argv)
773 {
774 int i;
775
776 if (!argv)
777 return;
778 for (i = 0; argv[i]; i++)
779 free(argv[i]);
780 free(argv);
781 }
782
783 static int create_snapshot(char **argv)
784 {
785 int ret, fds[3] = {0, 0, 0};
786 char *name;
787
788 name = incomplete_name(current_snapshot_creation_time);
789 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
790 free(name);
791 ret = dss_exec(&create_pid, argv[0], argv, fds);
792 if (ret < 0)
793 return ret;
794 snapshot_creation_status = SCS_RSYNC_RUNNING;
795 return ret;
796 }
797
798 static int select_loop(void)
799 {
800 int ret;
801 /* check every 60 seconds for free disk space */
802 struct timeval tv;
803 char **rsync_argv = NULL;
804
805 for (;;) {
806 fd_set rfds;
807 int low_disk_space;
808 struct timeval now, *tvp;
809
810 if (rm_pid)
811 tvp = NULL; /* sleep until rm process dies */
812 else { /* sleep one minute */
813 tv.tv_sec = 60;
814 tv.tv_usec = 0;
815 tvp = &tv;
816 }
817 FD_ZERO(&rfds);
818 FD_SET(signal_pipe, &rfds);
819 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
820 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
821 if (ret < 0)
822 goto out;
823 if (FD_ISSET(signal_pipe, &rfds)) {
824 ret = handle_signal();
825 if (ret < 0)
826 goto out;
827 }
828 if (rm_pid)
829 continue;
830 ret = disk_space_low();
831 if (ret < 0)
832 goto out;
833 low_disk_space = ret;
834 ret = try_to_free_disk_space(low_disk_space);
835 if (ret < 0)
836 goto out;
837 if (rm_pid) {
838 stop_create_process();
839 continue;
840 }
841 restart_create_process();
842 gettimeofday(&now, NULL);
843 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
844 continue;
845 switch (snapshot_creation_status) {
846 case SCS_READY:
847 ret = pre_create_hook();
848 if (ret < 0)
849 goto out;
850 continue;
851 case SCS_PRE_HOOK_RUNNING:
852 continue;
853 case SCS_RSYNC_NEEDS_RESTART:
854 ret = create_snapshot(rsync_argv);
855 if (ret < 0)
856 goto out;
857 continue;
858 case SCS_PRE_HOOK_SUCCESS:
859 free_rsync_argv(rsync_argv);
860 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
861 ret = create_snapshot(rsync_argv);
862 if (ret < 0)
863 goto out;
864 continue;
865 case SCS_RSYNC_RUNNING:
866 continue;
867 case SCS_RSYNC_SUCCESS:
868 ret = post_create_hook();
869 if (ret < 0)
870 goto out;
871 continue;
872 case SCS_POST_HOOK_RUNNING:
873 continue;
874 }
875 }
876 out:
877 return ret;
878 }
879
880 static void exit_hook(int exit_code)
881 {
882 int fds[3] = {0, 0, 0};
883 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
884 pid_t pid;
885
886 if (!conf.exit_hook_given)
887 return;
888 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
889 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
890 }
891
892 static int com_run(void)
893 {
894 int ret;
895
896 if (conf.dry_run_given) {
897 DSS_ERROR_LOG("dry_run not supported by this command\n");
898 return -E_SYNTAX;
899 }
900 ret = install_sighandler(SIGHUP);
901 if (ret < 0)
902 return ret;
903 compute_next_snapshot_time();
904 ret = select_loop();
905 if (ret >= 0) /* impossible */
906 ret = -E_BUG;
907 exit_hook(ret);
908 return ret;
909 }
910
911 static int com_prune(void)
912 {
913 int ret;
914 struct snapshot_list sl;
915 struct disk_space ds;
916
917 ret = get_disk_space(".", &ds);
918 if (ret < 0)
919 return ret;
920 log_disk_space(&ds);
921 for (;;) {
922 dss_get_snapshot_list(&sl);
923 ret = remove_outdated_snapshot(&sl);
924 free_snapshot_list(&sl);
925 if (ret < 0)
926 return ret;
927 if (!ret)
928 break;
929 ret = wait_for_rm_process();
930 if (ret < 0)
931 goto out;
932 }
933 for (;;) {
934 dss_get_snapshot_list(&sl);
935 ret = remove_redundant_snapshot(&sl);
936 free_snapshot_list(&sl);
937 if (ret < 0)
938 return ret;
939 if (!ret)
940 break;
941 ret = wait_for_rm_process();
942 if (ret < 0)
943 goto out;
944 }
945 return 1;
946 out:
947 return ret;
948 }
949
950 static int com_create(void)
951 {
952 int ret, status;
953 char **rsync_argv;
954
955 if (conf.dry_run_given) {
956 int i;
957 char *msg = NULL;
958 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
959 for (i = 0; rsync_argv[i]; i++) {
960 char *tmp = msg;
961 msg = make_message("%s%s%s", tmp? tmp : "",
962 tmp? " " : "", rsync_argv[i]);
963 free(tmp);
964 }
965 free_rsync_argv(rsync_argv);
966 dss_msg("%s\n", msg);
967 free(msg);
968 return 1;
969 }
970 ret = pre_create_hook();
971 if (ret < 0)
972 return ret;
973 if (create_pid) {
974 ret = wait_for_process(create_pid, &status);
975 if (ret < 0)
976 return ret;
977 ret = handle_pre_create_hook_exit(status);
978 if (ret < 0)
979 return ret;
980 }
981 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
982 ret = create_snapshot(rsync_argv);
983 if (ret < 0)
984 goto out;
985 ret = wait_for_process(create_pid, &status);
986 if (ret < 0)
987 goto out;
988 ret = handle_rsync_exit(status);
989 if (ret < 0)
990 goto out;
991 post_create_hook();
992 if (create_pid)
993 ret = wait_for_process(create_pid, &status);
994 out:
995 free_rsync_argv(rsync_argv);
996 return ret;
997 }
998
999 static int com_ls(void)
1000 {
1001 int i;
1002 struct snapshot_list sl;
1003 struct snapshot *s;
1004
1005 dss_get_snapshot_list(&sl);
1006 FOR_EACH_SNAPSHOT(s, i, &sl) {
1007 int64_t d = 0;
1008 if (s->flags & SS_COMPLETE)
1009 d = (s->completion_time - s->creation_time) / 60;
1010 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1011 };
1012 free_snapshot_list(&sl);
1013 return 1;
1014 }
1015
1016 static int setup_signal_handling(void)
1017 {
1018 int ret;
1019
1020 DSS_INFO_LOG("setting up signal handlers\n");
1021 signal_pipe = signal_init(); /* always successful */
1022 ret = install_sighandler(SIGINT);
1023 if (ret < 0)
1024 return ret;
1025 ret = install_sighandler(SIGTERM);
1026 if (ret < 0)
1027 return ret;
1028 return install_sighandler(SIGCHLD);
1029 }
1030
1031 /**
1032 * The main function of dss.
1033 *
1034 * \param argc Usual argument count.
1035 * \param argv Usual argument vector.
1036 */
1037 int main(int argc, char **argv)
1038 {
1039 int ret;
1040 struct cmdline_parser_params params = {
1041 .override = 0,
1042 .initialize = 1,
1043 .check_required = 0,
1044 .check_ambiguity = 0,
1045 .print_errors = 1
1046 };
1047
1048 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1049 ret = parse_config_file(0);
1050 if (ret < 0)
1051 goto out;
1052 if (conf.daemon_given)
1053 daemon_init();
1054 ret = change_to_dest_dir();
1055 if (ret < 0)
1056 goto out;
1057 ret = setup_signal_handling();
1058 if (ret < 0)
1059 goto out;
1060 ret = call_command_handler();
1061 out:
1062 if (ret < 0)
1063 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1064 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1065 }