Include the reason why a snapshot gets removed in the log message.
[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 if (ret < 0 || !s) /* unit_interval < tmp or no snapshot */
179 goto min_sleep;
180 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
181 diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
182 diff.tv_usec = 0;
183 tv_add(&diff, &tmp, &next_snapshot_time);
184 gettimeofday(&now, NULL);
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, char *why)
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 snapshot %s (interval = %i)\n",
206 why, s->name, s->interval);
207 ret = dss_exec(&rm_pid, argv[0], argv, fds);
208 out:
209 free(new_name);
210 return ret;
211 }
212
213 static int snapshot_is_being_created(struct snapshot *s)
214 {
215 return s->creation_time == current_snapshot_creation_time;
216 }
217
218 /*
219 * return: 0: no redundant snapshots, 1: rm process started, negative: error
220 */
221 static int remove_redundant_snapshot(struct snapshot_list *sl)
222 {
223 int ret, i, interval;
224 struct snapshot *s;
225 unsigned missing = 0;
226
227 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
228 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
229 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
230 unsigned num = sl->interval_count[interval];
231 struct snapshot *victim = NULL, *prev = NULL;
232 int64_t score = LONG_MAX;
233
234 if (keep >= num)
235 missing += keep - num;
236 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
237 // interval, keep, num, missing);
238 if (keep + missing >= num)
239 continue;
240 /* redundant snapshot in this interval, pick snapshot with lowest score */
241 FOR_EACH_SNAPSHOT(s, i, sl) {
242 int64_t this_score;
243
244 if (snapshot_is_being_created(s))
245 continue;
246 //DSS_DEBUG_LOG("checking %s\n", s->name);
247 if (s->interval > interval) {
248 prev = s;
249 continue;
250 }
251 if (s->interval < interval)
252 break;
253 if (!victim) {
254 victim = s;
255 prev = s;
256 continue;
257 }
258 assert(prev);
259 /* check if s is a better victim */
260 this_score = s->creation_time - prev->creation_time;
261 assert(this_score >= 0);
262 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
263 if (this_score < score) {
264 score = this_score;
265 victim = s;
266 }
267 prev = s;
268 }
269 assert(victim);
270 if (conf.dry_run_given) {
271 dss_msg("%s would be removed (interval = %i)\n",
272 victim->name, victim->interval);
273 continue;
274 }
275 ret = remove_snapshot(victim, "redundant");
276 return ret < 0? ret : 1;
277 }
278 return 0;
279 }
280
281 static int remove_outdated_snapshot(struct snapshot_list *sl)
282 {
283 int i, ret;
284 struct snapshot *s;
285
286 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
287 conf.num_intervals_arg);
288 FOR_EACH_SNAPSHOT(s, i, sl) {
289 if (snapshot_is_being_created(s))
290 continue;
291 if (s->interval <= conf.num_intervals_arg)
292 continue;
293 if (conf.dry_run_given) {
294 dss_msg("%s would be removed (interval = %i)\n",
295 s->name, s->interval);
296 continue;
297 }
298 ret = remove_snapshot(s, "outdated");
299 if (ret < 0)
300 return ret;
301 return 1;
302 }
303 return 0;
304 }
305
306 static int remove_oldest_snapshot(struct snapshot_list *sl)
307 {
308 struct snapshot *s = get_oldest_snapshot(sl);
309
310 if (!s) /* no snapshot found */
311 return 0;
312 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
313 if (snapshot_is_being_created(s))
314 return 0;
315 return remove_snapshot(s, "oldest");
316 }
317
318 static int rename_incomplete_snapshot(int64_t start)
319 {
320 char *old_name;
321 int ret;
322
323 free(path_to_last_complete_snapshot);
324 ret = complete_name(start, get_current_time(),
325 &path_to_last_complete_snapshot);
326 if (ret < 0)
327 return ret;
328 old_name = incomplete_name(start);
329 ret = dss_rename(old_name, path_to_last_complete_snapshot);
330 if (ret >= 0)
331 DSS_NOTICE_LOG("%s -> %s\n", old_name,
332 path_to_last_complete_snapshot);
333 free(old_name);
334 return ret;
335 }
336
337 static int try_to_free_disk_space(int low_disk_space)
338 {
339 int ret;
340 struct snapshot_list sl;
341
342 if (!low_disk_space && conf.keep_redundant_given)
343 return 0;
344 dss_get_snapshot_list(&sl);
345 ret = remove_outdated_snapshot(&sl);
346 if (ret) /* error, or we are removing something */
347 goto out;
348 /* no outdated snapshot */
349 ret = remove_redundant_snapshot(&sl);
350 if (ret)
351 goto out;
352 ret = 0;
353 if (!low_disk_space)
354 goto out;
355 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
356 ret = remove_oldest_snapshot(&sl);
357 if (ret)
358 goto out;
359 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
360 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
361 out:
362 free_snapshot_list(&sl);
363 return ret;
364 }
365
366 static int pre_create_hook(void)
367 {
368 int ret, fds[3] = {0, 0, 0};
369
370 if (!conf.pre_create_hook_given) {
371 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
372 return 0;
373 }
374 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
375 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
376 conf.pre_create_hook_arg, fds);
377 if (ret < 0)
378 return ret;
379 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
380 return ret;
381 }
382
383 static int post_create_hook(void)
384 {
385 int ret, fds[3] = {0, 0, 0};
386 char *cmd;
387
388 if (!conf.post_create_hook_given) {
389 snapshot_creation_status = SCS_READY;
390 compute_next_snapshot_time();
391 return 0;
392 }
393 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
394 conf.dest_dir_arg, path_to_last_complete_snapshot);
395 DSS_NOTICE_LOG("executing %s\n", cmd);
396 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
397 free(cmd);
398 if (ret < 0)
399 return ret;
400 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
401 return ret;
402 }
403
404 static void kill_process(pid_t pid)
405 {
406 if (!pid)
407 return;
408 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
409 kill(pid, SIGTERM);
410 }
411
412 static void stop_rsync_process(void)
413 {
414 if (!rsync_pid || rsync_stopped)
415 return;
416 kill(SIGSTOP, rsync_pid);
417 rsync_stopped = 1;
418 }
419
420 static void restart_rsync_process(void)
421 {
422 if (!rsync_pid || !rsync_stopped)
423 return;
424 kill (SIGCONT, rsync_pid);
425 rsync_stopped = 0;
426 }
427
428
429 /**
430 * Print a log message about the exit status of a child.
431 */
432 static void log_termination_msg(pid_t pid, int status)
433 {
434 if (WIFEXITED(status))
435 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
436 WEXITSTATUS(status));
437 else if (WIFSIGNALED(status))
438 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
439 WTERMSIG(status));
440 else
441 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
442 }
443
444 static int wait_for_process(pid_t pid, int *status)
445 {
446 int ret;
447
448 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
449 for (;;) {
450 fd_set rfds;
451
452 FD_ZERO(&rfds);
453 FD_SET(signal_pipe, &rfds);
454 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
455 if (ret < 0)
456 break;
457 ret = next_signal();
458 if (!ret)
459 continue;
460 if (ret == SIGCHLD) {
461 ret = waitpid(pid, status, 0);
462 if (ret >= 0)
463 break;
464 if (errno != EINTR) { /* error */
465 ret = -ERRNO_TO_DSS_ERROR(errno);
466 break;
467 }
468 }
469 /* SIGINT or SIGTERM */
470 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
471 kill(pid, SIGTERM);
472 }
473 if (ret < 0)
474 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
475 else
476 log_termination_msg(pid, *status);
477 return ret;
478 }
479
480 static int handle_rm_exit(int status)
481 {
482 rm_pid = 0;
483 if (!WIFEXITED(status))
484 return -E_INVOLUNTARY_EXIT;
485 if (WEXITSTATUS(status))
486 return -E_BAD_EXIT_CODE;
487 return 1;
488 }
489
490 static int wait_for_rm_process(void)
491 {
492 int status, ret = wait_for_process(rm_pid, &status);
493
494 if (ret < 0)
495 return ret;
496 return handle_rm_exit(status);
497 }
498
499 static int handle_rsync_exit(int status)
500 {
501 int es, ret;
502
503 if (!WIFEXITED(status)) {
504 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
505 ret = -E_INVOLUNTARY_EXIT;
506 snapshot_creation_status = SCS_READY;
507 compute_next_snapshot_time();
508 goto out;
509 }
510 es = WEXITSTATUS(status);
511 if (es == 13) { /* Errors with program diagnostics */
512 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
513 (int)rsync_pid, es);
514 snapshot_creation_status = SCS_RSYNC_NEEDS_RESTART;
515 gettimeofday(&next_snapshot_time, NULL);
516 next_snapshot_time.tv_sec += 60;
517 ret = 1;
518 goto out;
519 }
520 if (es != 0 && es != 23 && es != 24) {
521 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
522 ret = -E_BAD_EXIT_CODE;
523 snapshot_creation_status = SCS_READY;
524 compute_next_snapshot_time();
525 goto out;
526 }
527 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
528 if (ret < 0)
529 goto out;
530 snapshot_creation_status = SCS_RSYNC_SUCCESS;
531 out:
532 rsync_pid = 0;
533 rsync_stopped = 0;
534 return ret;
535 }
536
537 static int handle_pre_create_hook_exit(int status)
538 {
539 int es, ret;
540
541 if (!WIFEXITED(status)) {
542 snapshot_creation_status = SCS_READY;
543 compute_next_snapshot_time();
544 ret = -E_INVOLUNTARY_EXIT;
545 goto out;
546 }
547 es = WEXITSTATUS(status);
548 if (es) {
549 snapshot_creation_status = SCS_READY;
550 compute_next_snapshot_time();
551 ret = -E_BAD_EXIT_CODE;
552 goto out;
553 }
554 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
555 ret = 1;
556 out:
557 pre_create_hook_pid = 0;
558 return ret;
559 }
560
561 static int handle_sigchld(void)
562 {
563 pid_t pid;
564 int status, ret = reap_child(&pid, &status);
565
566 if (ret <= 0)
567 return ret;
568 if (pid == rsync_pid)
569 return handle_rsync_exit(status);
570 if (pid == rm_pid)
571 return handle_rm_exit(status);
572 if (pid == pre_create_hook_pid)
573 return handle_pre_create_hook_exit(status);
574 if (pid == post_create_hook_pid) {
575 snapshot_creation_status = SCS_READY;
576 compute_next_snapshot_time();
577 return 1;
578 }
579 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
580 return -E_BUG;
581 }
582
583 static int check_config(void)
584 {
585 if (conf.unit_interval_arg <= 0) {
586 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
587 return -E_INVALID_NUMBER;
588 }
589 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
590 if (conf.num_intervals_arg <= 0) {
591 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
592 return -E_INVALID_NUMBER;
593 }
594 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
595 return 1;
596 }
597
598 static int parse_config_file(int override)
599 {
600 int ret;
601 char *config_file;
602 struct stat statbuf;
603 char *old_logfile_arg = NULL;
604 int old_daemon_given = 0;
605
606 if (conf.config_file_given)
607 config_file = dss_strdup(conf.config_file_arg);
608 else {
609 char *home = get_homedir();
610 config_file = make_message("%s/.dssrc", home);
611 free(home);
612 }
613 if (override) { /* SIGHUP */
614 if (conf.logfile_given)
615 old_logfile_arg = dss_strdup(conf.logfile_arg);
616 old_daemon_given = conf.daemon_given;
617 }
618
619 ret = stat(config_file, &statbuf);
620 if (ret && conf.config_file_given) {
621 ret = -ERRNO_TO_DSS_ERROR(errno);
622 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
623 goto out;
624 }
625 if (!ret) {
626 struct cmdline_parser_params params = {
627 .override = override,
628 .initialize = 0,
629 .check_required = 1,
630 .check_ambiguity = 0,
631 .print_errors = 1
632 };
633 if (override) { /* invalidate all rsync options */
634 int i;
635
636 for (i = 0; i < conf.rsync_option_given; i++) {
637 free(conf.rsync_option_arg[i]);
638 conf.rsync_option_arg[i] = NULL;
639 }
640 conf.rsync_option_given = 0;
641 }
642 cmdline_parser_config_file(config_file, &conf, &params);
643 }
644 ret = check_config();
645 if (ret < 0)
646 goto out;
647 if (override) {
648 /* don't change daemon mode on SIGHUP */
649 conf.daemon_given = old_daemon_given;
650 close_log(logfile);
651 logfile = NULL;
652 if (conf.logfile_given)
653 free(old_logfile_arg);
654 else if (conf.daemon_given) { /* re-use old logfile */
655 conf.logfile_arg = old_logfile_arg;
656 conf.logfile_given = 1;
657 }
658 }
659 if (conf.logfile_given) {
660 logfile = open_log(conf.logfile_arg);
661 log_welcome(conf.loglevel_arg);
662 }
663 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
664 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
665 out:
666 free(config_file);
667 if (ret < 0)
668 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
669 return ret;
670 }
671
672 static int change_to_dest_dir(void)
673 {
674 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
675 return dss_chdir(conf.dest_dir_arg);
676 }
677
678 static int handle_sighup(void)
679 {
680 int ret;
681
682 DSS_NOTICE_LOG("SIGHUP\n");
683 ret = parse_config_file(1);
684 if (ret < 0)
685 return ret;
686 return change_to_dest_dir();
687 }
688
689 static int handle_signal(void)
690 {
691 int sig, ret = next_signal();
692
693 if (ret <= 0)
694 goto out;
695 sig = ret;
696 switch (sig) {
697 case SIGINT:
698 case SIGTERM:
699 restart_rsync_process();
700 kill_process(rsync_pid);
701 kill_process(rm_pid);
702 ret = -E_SIGNAL;
703 break;
704 case SIGHUP:
705 ret = handle_sighup();
706 break;
707 case SIGCHLD:
708 ret = handle_sigchld();
709 break;
710 }
711 out:
712 if (ret < 0)
713 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
714 return ret;
715 }
716
717 /*
718 * We can not use rsync locally if the local user is different from the remote
719 * user or if the src dir is not on the local host (or both).
720 */
721 static int use_rsync_locally(char *logname)
722 {
723 char *h = conf.remote_host_arg;
724
725 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
726 return 0;
727 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
728 return 0;
729 return 1;
730 }
731
732 static void create_rsync_argv(char ***argv, int64_t *num)
733 {
734 char *logname, *newest;
735 int i = 0, j;
736 struct snapshot_list sl;
737
738 dss_get_snapshot_list(&sl);
739 newest = name_of_newest_complete_snapshot(&sl);
740 free_snapshot_list(&sl);
741
742 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
743 (*argv)[i++] = dss_strdup("rsync");
744 (*argv)[i++] = dss_strdup("-aq");
745 (*argv)[i++] = dss_strdup("--delete");
746 for (j = 0; j < conf.rsync_option_given; j++)
747 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
748 if (newest) {
749 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
750 (*argv)[i++] = make_message("--link-dest=../%s", newest);
751 free(newest);
752 } else
753 DSS_INFO_LOG("no previous snapshot found\n");
754 logname = dss_logname();
755 if (use_rsync_locally(logname))
756 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
757 else
758 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
759 conf.remote_user_arg : logname,
760 conf.remote_host_arg, conf.source_dir_arg);
761 free(logname);
762 *num = get_current_time();
763 (*argv)[i++] = incomplete_name(*num);
764 (*argv)[i++] = NULL;
765 for (j = 0; j < i; j++)
766 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
767 }
768
769 static void free_rsync_argv(char **argv)
770 {
771 int i;
772
773 if (!argv)
774 return;
775 for (i = 0; argv[i]; i++)
776 free(argv[i]);
777 free(argv);
778 }
779
780 static int create_snapshot(char **argv)
781 {
782 int ret, fds[3] = {0, 0, 0};
783 char *name;
784
785 name = incomplete_name(current_snapshot_creation_time);
786 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
787 free(name);
788 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
789 if (ret < 0)
790 return ret;
791 snapshot_creation_status = SCS_RSYNC_RUNNING;
792 return ret;
793 }
794
795 static int select_loop(void)
796 {
797 int ret;
798 /* check every 60 seconds for free disk space */
799 struct timeval tv;
800 char **rsync_argv = NULL;
801
802 for (;;) {
803 fd_set rfds;
804 int low_disk_space;
805 struct timeval now, *tvp;
806
807 if (rm_pid)
808 tvp = NULL; /* sleep until rm process dies */
809 else { /* sleep one minute */
810 tv.tv_sec = 60;
811 tv.tv_usec = 0;
812 tvp = &tv;
813 }
814 FD_ZERO(&rfds);
815 FD_SET(signal_pipe, &rfds);
816 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
817 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
818 if (ret < 0)
819 goto out;
820 if (FD_ISSET(signal_pipe, &rfds)) {
821 ret = handle_signal();
822 if (ret < 0)
823 goto out;
824 }
825 if (rm_pid)
826 continue;
827 ret = disk_space_low();
828 if (ret < 0)
829 goto out;
830 low_disk_space = ret;
831 ret = try_to_free_disk_space(low_disk_space);
832 if (ret < 0)
833 goto out;
834 if (rm_pid) {
835 stop_rsync_process();
836 continue;
837 }
838 restart_rsync_process();
839 gettimeofday(&now, NULL);
840 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
841 continue;
842 switch (snapshot_creation_status) {
843 case SCS_READY:
844 ret = pre_create_hook();
845 if (ret < 0)
846 goto out;
847 continue;
848 case SCS_PRE_HOOK_RUNNING:
849 continue;
850 case SCS_RSYNC_NEEDS_RESTART:
851 ret = create_snapshot(rsync_argv);
852 if (ret < 0)
853 goto out;
854 continue;
855 case SCS_PRE_HOOK_SUCCESS:
856 free_rsync_argv(rsync_argv);
857 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
858 ret = create_snapshot(rsync_argv);
859 if (ret < 0)
860 goto out;
861 continue;
862 case SCS_RSYNC_RUNNING:
863 continue;
864 case SCS_RSYNC_SUCCESS:
865 ret = post_create_hook();
866 if (ret < 0)
867 goto out;
868 continue;
869 case SCS_POST_HOOK_RUNNING:
870 continue;
871 }
872 }
873 out:
874 return ret;
875 }
876
877 static void exit_hook(int exit_code)
878 {
879 int fds[3] = {0, 0, 0};
880 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
881 pid_t pid;
882
883 if (!conf.exit_hook_given)
884 return;
885 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
886 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
887 }
888
889 static int com_run(void)
890 {
891 int ret;
892
893 if (conf.dry_run_given) {
894 DSS_ERROR_LOG("dry_run not supported by this command\n");
895 return -E_SYNTAX;
896 }
897 ret = install_sighandler(SIGHUP);
898 if (ret < 0)
899 return ret;
900 compute_next_snapshot_time();
901 ret = select_loop();
902 if (ret >= 0) /* impossible */
903 ret = -E_BUG;
904 exit_hook(ret);
905 return ret;
906 }
907
908 static int com_prune(void)
909 {
910 int ret;
911 struct snapshot_list sl;
912 struct disk_space ds;
913
914 ret = get_disk_space(".", &ds);
915 if (ret < 0)
916 return ret;
917 log_disk_space(&ds);
918 for (;;) {
919 dss_get_snapshot_list(&sl);
920 ret = remove_outdated_snapshot(&sl);
921 free_snapshot_list(&sl);
922 if (ret < 0)
923 return ret;
924 if (!ret)
925 break;
926 ret = wait_for_rm_process();
927 if (ret < 0)
928 goto out;
929 }
930 for (;;) {
931 dss_get_snapshot_list(&sl);
932 ret = remove_redundant_snapshot(&sl);
933 free_snapshot_list(&sl);
934 if (ret < 0)
935 return ret;
936 if (!ret)
937 break;
938 ret = wait_for_rm_process();
939 if (ret < 0)
940 goto out;
941 }
942 return 1;
943 out:
944 return ret;
945 }
946
947 static int com_create(void)
948 {
949 int ret, status;
950 char **rsync_argv;
951
952 if (conf.dry_run_given) {
953 int i;
954 char *msg = NULL;
955 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
956 for (i = 0; rsync_argv[i]; i++) {
957 char *tmp = msg;
958 msg = make_message("%s%s%s", tmp? tmp : "",
959 tmp? " " : "", rsync_argv[i]);
960 free(tmp);
961 }
962 free_rsync_argv(rsync_argv);
963 dss_msg("%s\n", msg);
964 free(msg);
965 return 1;
966 }
967 ret = pre_create_hook();
968 if (ret < 0)
969 return ret;
970 if (pre_create_hook_pid) {
971 ret = wait_for_process(pre_create_hook_pid, &status);
972 if (ret < 0)
973 return ret;
974 ret = handle_pre_create_hook_exit(status);
975 if (ret < 0)
976 return ret;
977 }
978 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
979 ret = create_snapshot(rsync_argv);
980 if (ret < 0)
981 goto out;
982 ret = wait_for_process(rsync_pid, &status);
983 if (ret < 0)
984 goto out;
985 ret = handle_rsync_exit(status);
986 if (ret < 0)
987 goto out;
988 post_create_hook();
989 if (post_create_hook_pid)
990 ret = wait_for_process(post_create_hook_pid, &status);
991 out:
992 free_rsync_argv(rsync_argv);
993 return ret;
994 }
995
996 static int com_ls(void)
997 {
998 int i;
999 struct snapshot_list sl;
1000 struct snapshot *s;
1001
1002 dss_get_snapshot_list(&sl);
1003 FOR_EACH_SNAPSHOT(s, i, &sl) {
1004 int64_t d = 0;
1005 if (s->flags & SS_COMPLETE)
1006 d = (s->completion_time - s->creation_time) / 60;
1007 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1008 };
1009 free_snapshot_list(&sl);
1010 return 1;
1011 }
1012
1013 static int setup_signal_handling(void)
1014 {
1015 int ret;
1016
1017 DSS_INFO_LOG("setting up signal handlers\n");
1018 signal_pipe = signal_init(); /* always successful */
1019 ret = install_sighandler(SIGINT);
1020 if (ret < 0)
1021 return ret;
1022 ret = install_sighandler(SIGTERM);
1023 if (ret < 0)
1024 return ret;
1025 return install_sighandler(SIGCHLD);
1026 }
1027
1028 /**
1029 * The main function of dss.
1030 *
1031 * \param argc Usual argument count.
1032 * \param argv Usual argument vector.
1033 */
1034 int main(int argc, char **argv)
1035 {
1036 int ret;
1037 struct cmdline_parser_params params = {
1038 .override = 0,
1039 .initialize = 1,
1040 .check_required = 0,
1041 .check_ambiguity = 0,
1042 .print_errors = 1
1043 };
1044
1045 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1046 ret = parse_config_file(0);
1047 if (ret < 0)
1048 goto out;
1049 if (conf.daemon_given)
1050 daemon_init();
1051 ret = change_to_dest_dir();
1052 if (ret < 0)
1053 goto out;
1054 ret = setup_signal_handling();
1055 if (ret < 0)
1056 goto out;
1057 ret = call_command_handler();
1058 out:
1059 if (ret < 0)
1060 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1061 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1062 }