Introduce the snapshot removal status.
[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 /** \sa \ref snap.h for details. */
58 static unsigned snapshot_removal_status;
59
60
61 DEFINE_DSS_ERRLIST;
62
63
64 /* a litte cpp magic helps to DRY */
65 #define COMMANDS \
66 COMMAND(ls) \
67 COMMAND(create) \
68 COMMAND(prune) \
69 COMMAND(run)
70 #define COMMAND(x) static int com_ ##x(void);
71 COMMANDS
72 #undef COMMAND
73 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
74 static int call_command_handler(void)
75 {
76 COMMANDS
77 DSS_EMERG_LOG("BUG: did not find command handler\n");
78 return -E_BUG;
79 }
80 #undef COMMAND
81 #undef COMMANDS
82
83 /**
84 * The log function of dss.
85 *
86 * \param ll Loglevel.
87 * \param fml Usual format string.
88 *
89 * All DSS_XXX_LOG() macros use this function.
90 */
91 __printf_2_3 void dss_log(int ll, const char* fmt,...)
92 {
93 va_list argp;
94 FILE *outfd;
95 struct tm *tm;
96 time_t t1;
97 char str[255] = "";
98
99 if (ll < conf.loglevel_arg)
100 return;
101 outfd = logfile? logfile : stderr;
102 time(&t1);
103 tm = localtime(&t1);
104 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
105 fprintf(outfd, "%s ", str);
106 if (conf.loglevel_arg <= INFO)
107 fprintf(outfd, "%i: ", ll);
108 va_start(argp, fmt);
109 vfprintf(outfd, fmt, argp);
110 va_end(argp);
111 }
112
113 /**
114 * Print a message either to stdout or to the log file.
115 */
116 static __printf_1_2 void dss_msg(const char* fmt,...)
117 {
118 FILE *outfd = conf.daemon_given? logfile : stdout;
119 va_list argp;
120 va_start(argp, fmt);
121 vfprintf(outfd, fmt, argp);
122 va_end(argp);
123 }
124
125 static int disk_space_low(void)
126 {
127 struct disk_space ds;
128 int ret = get_disk_space(".", &ds);
129
130 if (ret < 0)
131 return ret;
132 if (conf.min_free_mb_arg)
133 if (ds.free_mb < conf.min_free_mb_arg)
134 return 1;
135 if (conf.min_free_percent_arg)
136 if (ds.percent_free < conf.min_free_percent_arg)
137 return 1;
138 if (conf.min_free_percent_inodes_arg)
139 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
140 return 1;
141 return 0;
142 }
143
144 static void dss_get_snapshot_list(struct snapshot_list *sl)
145 {
146 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
147 }
148
149 static void compute_next_snapshot_time(void)
150 {
151 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
152 tmp, diff;
153 int64_t x = 0;
154 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
155 num_complete_snapshots = 0;
156 int i, ret;
157 struct snapshot *s = NULL;
158 struct snapshot_list sl;
159
160 assert(snapshot_creation_status == SCS_READY);
161 current_snapshot_creation_time = 0;
162 dss_get_snapshot_list(&sl);
163 FOR_EACH_SNAPSHOT(s, i, &sl) {
164 if (!(s->flags & SS_COMPLETE))
165 continue;
166 num_complete_snapshots++;
167 x += s->completion_time - s->creation_time;
168 }
169 assert(x >= 0);
170 if (num_complete_snapshots)
171 x /= num_complete_snapshots; /* avg time to create one snapshot */
172 x *= wanted; /* time to create all snapshots in interval 0 */
173 tmp.tv_sec = x;
174 tmp.tv_usec = 0;
175 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
176 if (ret < 0 || !s) /* unit_interval < tmp or no snapshot */
177 goto min_sleep;
178 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
179 diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
180 diff.tv_usec = 0;
181 tv_add(&diff, &tmp, &next_snapshot_time);
182 gettimeofday(&now, NULL);
183 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
184 goto out;
185 min_sleep:
186 next_snapshot_time = now;
187 next_snapshot_time.tv_sec += 60;
188 out:
189 free_snapshot_list(&sl);
190 }
191
192
193 static int remove_snapshot(struct snapshot *s, char *why)
194 {
195 int fds[3] = {0, 0, 0};
196 assert(!rm_pid);
197 char *new_name = being_deleted_name(s);
198 int ret = dss_rename(s->name, new_name);
199 char *argv[] = {"rm", "-rf", new_name, NULL};
200
201 if (ret < 0)
202 goto out;
203 DSS_NOTICE_LOG("removing %s snapshot %s (interval = %i)\n",
204 why, s->name, s->interval);
205 ret = dss_exec(&rm_pid, argv[0], argv, fds);
206 out:
207 free(new_name);
208 return ret;
209 }
210
211 static int snapshot_is_being_created(struct snapshot *s)
212 {
213 return s->creation_time == current_snapshot_creation_time;
214 }
215
216 /*
217 * return: 0: no redundant snapshots, 1: rm process started, negative: error
218 */
219 static int remove_redundant_snapshot(struct snapshot_list *sl)
220 {
221 int ret, i, interval;
222 struct snapshot *s;
223 unsigned missing = 0;
224
225 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
226 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
227 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
228 unsigned num = sl->interval_count[interval];
229 struct snapshot *victim = NULL, *prev = NULL;
230 int64_t score = LONG_MAX;
231
232 if (keep >= num)
233 missing += keep - num;
234 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
235 // interval, keep, num, missing);
236 if (keep + missing >= num)
237 continue;
238 /* redundant snapshot in this interval, pick snapshot with lowest score */
239 FOR_EACH_SNAPSHOT(s, i, sl) {
240 int64_t this_score;
241
242 if (snapshot_is_being_created(s))
243 continue;
244 //DSS_DEBUG_LOG("checking %s\n", s->name);
245 if (s->interval > interval) {
246 prev = s;
247 continue;
248 }
249 if (s->interval < interval)
250 break;
251 if (!victim) {
252 victim = s;
253 prev = s;
254 continue;
255 }
256 assert(prev);
257 /* check if s is a better victim */
258 this_score = s->creation_time - prev->creation_time;
259 assert(this_score >= 0);
260 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
261 if (this_score < score) {
262 score = this_score;
263 victim = s;
264 }
265 prev = s;
266 }
267 assert(victim);
268 if (conf.dry_run_given) {
269 dss_msg("%s would be removed (interval = %i)\n",
270 victim->name, victim->interval);
271 continue;
272 }
273 ret = remove_snapshot(victim, "redundant");
274 return ret < 0? ret : 1;
275 }
276 return 0;
277 }
278
279 static int remove_outdated_snapshot(struct snapshot_list *sl)
280 {
281 int i, ret;
282 struct snapshot *s;
283
284 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
285 conf.num_intervals_arg);
286 FOR_EACH_SNAPSHOT(s, i, sl) {
287 if (snapshot_is_being_created(s))
288 continue;
289 if (s->interval <= conf.num_intervals_arg)
290 continue;
291 if (conf.dry_run_given) {
292 dss_msg("%s would be removed (interval = %i)\n",
293 s->name, s->interval);
294 continue;
295 }
296 ret = remove_snapshot(s, "outdated");
297 if (ret < 0)
298 return ret;
299 return 1;
300 }
301 return 0;
302 }
303
304 static int remove_oldest_snapshot(struct snapshot_list *sl)
305 {
306 struct snapshot *s = get_oldest_snapshot(sl);
307
308 if (!s) /* no snapshot found */
309 return 0;
310 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
311 if (snapshot_is_being_created(s))
312 return 0;
313 return remove_snapshot(s, "oldest");
314 }
315
316 static int rename_incomplete_snapshot(int64_t start)
317 {
318 char *old_name;
319 int ret;
320
321 free(path_to_last_complete_snapshot);
322 ret = complete_name(start, get_current_time(),
323 &path_to_last_complete_snapshot);
324 if (ret < 0)
325 return ret;
326 old_name = incomplete_name(start);
327 ret = dss_rename(old_name, path_to_last_complete_snapshot);
328 if (ret >= 0)
329 DSS_NOTICE_LOG("%s -> %s\n", old_name,
330 path_to_last_complete_snapshot);
331 free(old_name);
332 return ret;
333 }
334
335 static int try_to_free_disk_space(int low_disk_space)
336 {
337 int ret;
338 struct snapshot_list sl;
339
340 if (!low_disk_space && conf.keep_redundant_given)
341 return 0;
342 dss_get_snapshot_list(&sl);
343 ret = remove_outdated_snapshot(&sl);
344 if (ret) /* error, or we are removing something */
345 goto out;
346 /* no outdated snapshot */
347 ret = remove_redundant_snapshot(&sl);
348 if (ret)
349 goto out;
350 ret = 0;
351 if (!low_disk_space)
352 goto out;
353 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
354 ret = remove_oldest_snapshot(&sl);
355 if (ret)
356 goto out;
357 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
358 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
359 out:
360 free_snapshot_list(&sl);
361 return ret;
362 }
363
364 static int pre_create_hook(void)
365 {
366 int ret, fds[3] = {0, 0, 0};
367
368 if (!conf.pre_create_hook_given) {
369 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
370 return 0;
371 }
372 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
373 ret = dss_exec_cmdline_pid(&create_pid,
374 conf.pre_create_hook_arg, fds);
375 if (ret < 0)
376 return ret;
377 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
378 return ret;
379 }
380
381 static int post_create_hook(void)
382 {
383 int ret, fds[3] = {0, 0, 0};
384 char *cmd;
385
386 if (!conf.post_create_hook_given) {
387 snapshot_creation_status = SCS_READY;
388 compute_next_snapshot_time();
389 return 0;
390 }
391 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
392 conf.dest_dir_arg, path_to_last_complete_snapshot);
393 DSS_NOTICE_LOG("executing %s\n", cmd);
394 ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
395 free(cmd);
396 if (ret < 0)
397 return ret;
398 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
399 return ret;
400 }
401
402 static void kill_process(pid_t pid)
403 {
404 if (!pid)
405 return;
406 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
407 kill(pid, SIGTERM);
408 }
409
410 static void stop_create_process(void)
411 {
412 if (!create_pid || create_process_stopped)
413 return;
414 kill(SIGSTOP, create_pid);
415 create_process_stopped = 1;
416 }
417
418 static void restart_create_process(void)
419 {
420 if (!create_pid || !create_process_stopped)
421 return;
422 kill (SIGCONT, create_pid);
423 create_process_stopped = 0;
424 }
425
426 /**
427 * Print a log message about the exit status of a child.
428 */
429 static void log_termination_msg(pid_t pid, int status)
430 {
431 if (WIFEXITED(status))
432 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
433 WEXITSTATUS(status));
434 else if (WIFSIGNALED(status))
435 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
436 WTERMSIG(status));
437 else
438 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
439 }
440
441 static int wait_for_process(pid_t pid, int *status)
442 {
443 int ret;
444
445 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
446 for (;;) {
447 fd_set rfds;
448
449 FD_ZERO(&rfds);
450 FD_SET(signal_pipe, &rfds);
451 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
452 if (ret < 0)
453 break;
454 ret = next_signal();
455 if (!ret)
456 continue;
457 if (ret == SIGCHLD) {
458 ret = waitpid(pid, status, 0);
459 if (ret >= 0)
460 break;
461 if (errno != EINTR) { /* error */
462 ret = -ERRNO_TO_DSS_ERROR(errno);
463 break;
464 }
465 }
466 /* SIGINT or SIGTERM */
467 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
468 kill(pid, SIGTERM);
469 }
470 if (ret < 0)
471 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
472 else
473 log_termination_msg(pid, *status);
474 return ret;
475 }
476
477 static int handle_rm_exit(int status)
478 {
479 rm_pid = 0;
480 if (!WIFEXITED(status))
481 return -E_INVOLUNTARY_EXIT;
482 if (WEXITSTATUS(status))
483 return -E_BAD_EXIT_CODE;
484 return 1;
485 }
486
487 static int wait_for_rm_process(void)
488 {
489 int status, ret = wait_for_process(rm_pid, &status);
490
491 if (ret < 0)
492 return ret;
493 return handle_rm_exit(status);
494 }
495
496 static int handle_rsync_exit(int status)
497 {
498 int es, ret;
499
500 if (!WIFEXITED(status)) {
501 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
502 ret = -E_INVOLUNTARY_EXIT;
503 snapshot_creation_status = SCS_READY;
504 compute_next_snapshot_time();
505 goto out;
506 }
507 es = WEXITSTATUS(status);
508 if (es == 13) { /* Errors with program diagnostics */
509 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
510 (int)create_pid, es);
511 snapshot_creation_status = SCS_RSYNC_NEEDS_RESTART;
512 gettimeofday(&next_snapshot_time, NULL);
513 next_snapshot_time.tv_sec += 60;
514 ret = 1;
515 goto out;
516 }
517 if (es != 0 && es != 23 && es != 24) {
518 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
519 ret = -E_BAD_EXIT_CODE;
520 snapshot_creation_status = SCS_READY;
521 compute_next_snapshot_time();
522 goto out;
523 }
524 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
525 if (ret < 0)
526 goto out;
527 snapshot_creation_status = SCS_RSYNC_SUCCESS;
528 out:
529 create_pid = 0;
530 create_process_stopped = 0;
531 return ret;
532 }
533
534 static int handle_pre_create_hook_exit(int status)
535 {
536 int es, ret;
537
538 if (!WIFEXITED(status)) {
539 snapshot_creation_status = SCS_READY;
540 compute_next_snapshot_time();
541 ret = -E_INVOLUNTARY_EXIT;
542 goto out;
543 }
544 es = WEXITSTATUS(status);
545 if (es) {
546 snapshot_creation_status = SCS_READY;
547 compute_next_snapshot_time();
548 ret = -E_BAD_EXIT_CODE;
549 goto out;
550 }
551 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
552 ret = 1;
553 out:
554 create_pid = 0;
555 return ret;
556 }
557
558 static int handle_sigchld(void)
559 {
560 pid_t pid;
561 int status, ret = reap_child(&pid, &status);
562
563 if (ret <= 0)
564 return ret;
565
566 if (pid == create_pid) {
567 switch (snapshot_creation_status) {
568 case SCS_PRE_HOOK_RUNNING:
569 return handle_pre_create_hook_exit(status);
570 case SCS_RSYNC_RUNNING:
571 return handle_rsync_exit(status);
572 case SCS_POST_HOOK_RUNNING:
573 snapshot_creation_status = SCS_READY;
574 compute_next_snapshot_time();
575 return 1;
576 default:
577 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
578 snapshot_creation_status);
579 return -E_BUG;
580 }
581 }
582 if (pid == rm_pid)
583 return handle_rm_exit(status);
584 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
585 return -E_BUG;
586 }
587
588 static int check_config(void)
589 {
590 if (conf.unit_interval_arg <= 0) {
591 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
592 return -E_INVALID_NUMBER;
593 }
594 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
595 if (conf.num_intervals_arg <= 0) {
596 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
597 return -E_INVALID_NUMBER;
598 }
599 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
600 return 1;
601 }
602
603 static int parse_config_file(int override)
604 {
605 int ret;
606 char *config_file;
607 struct stat statbuf;
608 char *old_logfile_arg = NULL;
609 int old_daemon_given = 0;
610
611 if (conf.config_file_given)
612 config_file = dss_strdup(conf.config_file_arg);
613 else {
614 char *home = get_homedir();
615 config_file = make_message("%s/.dssrc", home);
616 free(home);
617 }
618 if (override) { /* SIGHUP */
619 if (conf.logfile_given)
620 old_logfile_arg = dss_strdup(conf.logfile_arg);
621 old_daemon_given = conf.daemon_given;
622 }
623
624 ret = stat(config_file, &statbuf);
625 if (ret && conf.config_file_given) {
626 ret = -ERRNO_TO_DSS_ERROR(errno);
627 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
628 goto out;
629 }
630 if (!ret) {
631 struct cmdline_parser_params params = {
632 .override = override,
633 .initialize = 0,
634 .check_required = 1,
635 .check_ambiguity = 0,
636 .print_errors = 1
637 };
638 if (override) { /* invalidate all rsync options */
639 int i;
640
641 for (i = 0; i < conf.rsync_option_given; i++) {
642 free(conf.rsync_option_arg[i]);
643 conf.rsync_option_arg[i] = NULL;
644 }
645 conf.rsync_option_given = 0;
646 }
647 cmdline_parser_config_file(config_file, &conf, &params);
648 }
649 ret = check_config();
650 if (ret < 0)
651 goto out;
652 if (override) {
653 /* don't change daemon mode on SIGHUP */
654 conf.daemon_given = old_daemon_given;
655 close_log(logfile);
656 logfile = NULL;
657 if (conf.logfile_given)
658 free(old_logfile_arg);
659 else if (conf.daemon_given) { /* re-use old logfile */
660 conf.logfile_arg = old_logfile_arg;
661 conf.logfile_given = 1;
662 }
663 }
664 if (conf.logfile_given) {
665 logfile = open_log(conf.logfile_arg);
666 log_welcome(conf.loglevel_arg);
667 }
668 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
669 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
670 out:
671 free(config_file);
672 if (ret < 0)
673 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
674 return ret;
675 }
676
677 static int change_to_dest_dir(void)
678 {
679 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
680 return dss_chdir(conf.dest_dir_arg);
681 }
682
683 static int handle_sighup(void)
684 {
685 int ret;
686
687 DSS_NOTICE_LOG("SIGHUP\n");
688 ret = parse_config_file(1);
689 if (ret < 0)
690 return ret;
691 return change_to_dest_dir();
692 }
693
694 static int handle_signal(void)
695 {
696 int sig, ret = next_signal();
697
698 if (ret <= 0)
699 goto out;
700 sig = ret;
701 switch (sig) {
702 case SIGINT:
703 case SIGTERM:
704 restart_create_process();
705 kill_process(create_pid);
706 kill_process(rm_pid);
707 ret = -E_SIGNAL;
708 break;
709 case SIGHUP:
710 ret = handle_sighup();
711 break;
712 case SIGCHLD:
713 ret = handle_sigchld();
714 break;
715 }
716 out:
717 if (ret < 0)
718 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
719 return ret;
720 }
721
722 /*
723 * We can not use rsync locally if the local user is different from the remote
724 * user or if the src dir is not on the local host (or both).
725 */
726 static int use_rsync_locally(char *logname)
727 {
728 char *h = conf.remote_host_arg;
729
730 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
731 return 0;
732 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
733 return 0;
734 return 1;
735 }
736
737 static void create_rsync_argv(char ***argv, int64_t *num)
738 {
739 char *logname, *newest;
740 int i = 0, j;
741 struct snapshot_list sl;
742
743 dss_get_snapshot_list(&sl);
744 newest = name_of_newest_complete_snapshot(&sl);
745 free_snapshot_list(&sl);
746
747 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
748 (*argv)[i++] = dss_strdup("rsync");
749 (*argv)[i++] = dss_strdup("-aq");
750 (*argv)[i++] = dss_strdup("--delete");
751 for (j = 0; j < conf.rsync_option_given; j++)
752 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
753 if (newest) {
754 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
755 (*argv)[i++] = make_message("--link-dest=../%s", newest);
756 free(newest);
757 } else
758 DSS_INFO_LOG("no previous snapshot found\n");
759 logname = dss_logname();
760 if (use_rsync_locally(logname))
761 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
762 else
763 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
764 conf.remote_user_arg : logname,
765 conf.remote_host_arg, conf.source_dir_arg);
766 free(logname);
767 *num = get_current_time();
768 (*argv)[i++] = incomplete_name(*num);
769 (*argv)[i++] = NULL;
770 for (j = 0; j < i; j++)
771 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
772 }
773
774 static void free_rsync_argv(char **argv)
775 {
776 int i;
777
778 if (!argv)
779 return;
780 for (i = 0; argv[i]; i++)
781 free(argv[i]);
782 free(argv);
783 }
784
785 static int create_snapshot(char **argv)
786 {
787 int ret, fds[3] = {0, 0, 0};
788 char *name;
789
790 name = incomplete_name(current_snapshot_creation_time);
791 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
792 free(name);
793 ret = dss_exec(&create_pid, argv[0], argv, fds);
794 if (ret < 0)
795 return ret;
796 snapshot_creation_status = SCS_RSYNC_RUNNING;
797 return ret;
798 }
799
800 static int select_loop(void)
801 {
802 int ret;
803 /* check every 60 seconds for free disk space */
804 struct timeval tv;
805 char **rsync_argv = NULL;
806
807 for (;;) {
808 fd_set rfds;
809 int low_disk_space;
810 struct timeval now, *tvp;
811
812 if (rm_pid)
813 tvp = NULL; /* sleep until rm process dies */
814 else { /* sleep one minute */
815 tv.tv_sec = 60;
816 tv.tv_usec = 0;
817 tvp = &tv;
818 }
819 FD_ZERO(&rfds);
820 FD_SET(signal_pipe, &rfds);
821 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
822 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
823 if (ret < 0)
824 goto out;
825 if (FD_ISSET(signal_pipe, &rfds)) {
826 ret = handle_signal();
827 if (ret < 0)
828 goto out;
829 }
830 if (rm_pid)
831 continue;
832 ret = disk_space_low();
833 if (ret < 0)
834 goto out;
835 low_disk_space = ret;
836 ret = try_to_free_disk_space(low_disk_space);
837 if (ret < 0)
838 goto out;
839 if (rm_pid) {
840 stop_create_process();
841 continue;
842 }
843 restart_create_process();
844 gettimeofday(&now, NULL);
845 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
846 continue;
847 switch (snapshot_creation_status) {
848 case SCS_READY:
849 ret = pre_create_hook();
850 if (ret < 0)
851 goto out;
852 continue;
853 case SCS_PRE_HOOK_RUNNING:
854 continue;
855 case SCS_RSYNC_NEEDS_RESTART:
856 ret = create_snapshot(rsync_argv);
857 if (ret < 0)
858 goto out;
859 continue;
860 case SCS_PRE_HOOK_SUCCESS:
861 free_rsync_argv(rsync_argv);
862 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
863 ret = create_snapshot(rsync_argv);
864 if (ret < 0)
865 goto out;
866 continue;
867 case SCS_RSYNC_RUNNING:
868 continue;
869 case SCS_RSYNC_SUCCESS:
870 ret = post_create_hook();
871 if (ret < 0)
872 goto out;
873 continue;
874 case SCS_POST_HOOK_RUNNING:
875 continue;
876 }
877 }
878 out:
879 return ret;
880 }
881
882 static void exit_hook(int exit_code)
883 {
884 int fds[3] = {0, 0, 0};
885 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
886 pid_t pid;
887
888 if (!conf.exit_hook_given)
889 return;
890 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
891 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
892 }
893
894 static int com_run(void)
895 {
896 int ret;
897
898 if (conf.dry_run_given) {
899 DSS_ERROR_LOG("dry_run not supported by this command\n");
900 return -E_SYNTAX;
901 }
902 ret = install_sighandler(SIGHUP);
903 if (ret < 0)
904 return ret;
905 compute_next_snapshot_time();
906 ret = select_loop();
907 if (ret >= 0) /* impossible */
908 ret = -E_BUG;
909 exit_hook(ret);
910 return ret;
911 }
912
913 static int com_prune(void)
914 {
915 int ret;
916 struct snapshot_list sl;
917 struct disk_space ds;
918
919 ret = get_disk_space(".", &ds);
920 if (ret < 0)
921 return ret;
922 log_disk_space(&ds);
923 for (;;) {
924 dss_get_snapshot_list(&sl);
925 ret = remove_outdated_snapshot(&sl);
926 free_snapshot_list(&sl);
927 if (ret < 0)
928 return ret;
929 if (!ret)
930 break;
931 ret = wait_for_rm_process();
932 if (ret < 0)
933 goto out;
934 }
935 for (;;) {
936 dss_get_snapshot_list(&sl);
937 ret = remove_redundant_snapshot(&sl);
938 free_snapshot_list(&sl);
939 if (ret < 0)
940 return ret;
941 if (!ret)
942 break;
943 ret = wait_for_rm_process();
944 if (ret < 0)
945 goto out;
946 }
947 return 1;
948 out:
949 return ret;
950 }
951
952 static int com_create(void)
953 {
954 int ret, status;
955 char **rsync_argv;
956
957 if (conf.dry_run_given) {
958 int i;
959 char *msg = NULL;
960 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
961 for (i = 0; rsync_argv[i]; i++) {
962 char *tmp = msg;
963 msg = make_message("%s%s%s", tmp? tmp : "",
964 tmp? " " : "", rsync_argv[i]);
965 free(tmp);
966 }
967 free_rsync_argv(rsync_argv);
968 dss_msg("%s\n", msg);
969 free(msg);
970 return 1;
971 }
972 ret = pre_create_hook();
973 if (ret < 0)
974 return ret;
975 if (create_pid) {
976 ret = wait_for_process(create_pid, &status);
977 if (ret < 0)
978 return ret;
979 ret = handle_pre_create_hook_exit(status);
980 if (ret < 0)
981 return ret;
982 }
983 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
984 ret = create_snapshot(rsync_argv);
985 if (ret < 0)
986 goto out;
987 ret = wait_for_process(create_pid, &status);
988 if (ret < 0)
989 goto out;
990 ret = handle_rsync_exit(status);
991 if (ret < 0)
992 goto out;
993 post_create_hook();
994 if (create_pid)
995 ret = wait_for_process(create_pid, &status);
996 out:
997 free_rsync_argv(rsync_argv);
998 return ret;
999 }
1000
1001 static int com_ls(void)
1002 {
1003 int i;
1004 struct snapshot_list sl;
1005 struct snapshot *s;
1006
1007 dss_get_snapshot_list(&sl);
1008 FOR_EACH_SNAPSHOT(s, i, &sl) {
1009 int64_t d = 0;
1010 if (s->flags & SS_COMPLETE)
1011 d = (s->completion_time - s->creation_time) / 60;
1012 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1013 };
1014 free_snapshot_list(&sl);
1015 return 1;
1016 }
1017
1018 static int setup_signal_handling(void)
1019 {
1020 int ret;
1021
1022 DSS_INFO_LOG("setting up signal handlers\n");
1023 signal_pipe = signal_init(); /* always successful */
1024 ret = install_sighandler(SIGINT);
1025 if (ret < 0)
1026 return ret;
1027 ret = install_sighandler(SIGTERM);
1028 if (ret < 0)
1029 return ret;
1030 return install_sighandler(SIGCHLD);
1031 }
1032
1033 /**
1034 * The main function of dss.
1035 *
1036 * \param argc Usual argument count.
1037 * \param argv Usual argument vector.
1038 */
1039 int main(int argc, char **argv)
1040 {
1041 int ret;
1042 struct cmdline_parser_params params = {
1043 .override = 0,
1044 .initialize = 1,
1045 .check_required = 0,
1046 .check_ambiguity = 0,
1047 .print_errors = 1
1048 };
1049
1050 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1051 ret = parse_config_file(0);
1052 if (ret < 0)
1053 goto out;
1054 if (conf.daemon_given)
1055 daemon_init();
1056 ret = change_to_dest_dir();
1057 if (ret < 0)
1058 goto out;
1059 ret = setup_signal_handling();
1060 if (ret < 0)
1061 goto out;
1062 ret = call_command_handler();
1063 out:
1064 if (ret < 0)
1065 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1066 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1067 }