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