dss-0.1.3.
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008-2009 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 pre-remove/rm/post-remove process. */
48 static pid_t remove_pid;
49 /** When the next snapshot is due. */
50 static struct timeval next_snapshot_time;
51 /** When to try to remove something. */
52 static struct timeval next_removal_check;
53 /** Creation time of the snapshot currently being created. */
54 static int64_t current_snapshot_creation_time;
55 /** The snapshot currently being removed. */
56 struct snapshot *snapshot_currently_being_removed;
57 /** Needed by the post-create hook. */
58 static char *path_to_last_complete_snapshot;
59 static char *name_of_reference_snapshot;
60 /** \sa \ref snap.h for details. */
61 enum hook_status snapshot_creation_status;
62 /** \sa \ref snap.h for details. */
63 enum hook_status snapshot_removal_status;
64
65
66 DEFINE_DSS_ERRLIST;
67
68
69 /* a litte cpp magic helps to DRY */
70 #define COMMANDS \
71 COMMAND(ls) \
72 COMMAND(create) \
73 COMMAND(prune) \
74 COMMAND(run)
75 #define COMMAND(x) static int com_ ##x(void);
76 COMMANDS
77 #undef COMMAND
78 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
79 static int call_command_handler(void)
80 {
81 COMMANDS
82 DSS_EMERG_LOG("BUG: did not find command handler\n");
83 return -E_BUG;
84 }
85 #undef COMMAND
86 #undef COMMANDS
87
88 /**
89 * The log function of dss.
90 *
91 * \param ll Loglevel.
92 * \param fml Usual format string.
93 *
94 * All DSS_XXX_LOG() macros use this function.
95 */
96 __printf_2_3 void dss_log(int ll, const char* fmt,...)
97 {
98 va_list argp;
99 FILE *outfd;
100 struct tm *tm;
101 time_t t1;
102 char str[255] = "";
103
104 if (ll < conf.loglevel_arg)
105 return;
106 outfd = logfile? logfile : stderr;
107 time(&t1);
108 tm = localtime(&t1);
109 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
110 fprintf(outfd, "%s ", str);
111 if (conf.loglevel_arg <= INFO)
112 fprintf(outfd, "%i: ", ll);
113 va_start(argp, fmt);
114 vfprintf(outfd, fmt, argp);
115 va_end(argp);
116 }
117
118 /**
119 * Print a message either to stdout or to the log file.
120 */
121 static __printf_1_2 void dss_msg(const char* fmt,...)
122 {
123 FILE *outfd = conf.daemon_given? logfile : stdout;
124 va_list argp;
125 va_start(argp, fmt);
126 vfprintf(outfd, fmt, argp);
127 va_end(argp);
128 }
129
130 static int disk_space_low(void)
131 {
132 struct disk_space ds;
133 int ret = get_disk_space(".", &ds);
134
135 if (ret < 0)
136 return ret;
137 if (conf.min_free_mb_arg)
138 if (ds.free_mb < conf.min_free_mb_arg)
139 return 1;
140 if (conf.min_free_percent_arg)
141 if (ds.percent_free < conf.min_free_percent_arg)
142 return 1;
143 if (conf.min_free_percent_inodes_arg)
144 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
145 return 1;
146 return 0;
147 }
148
149 static void dss_get_snapshot_list(struct snapshot_list *sl)
150 {
151 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
152 }
153
154 static int next_snapshot_is_due(void)
155 {
156 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
157 tmp, diff;
158 int64_t x = 0;
159 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
160 num_complete_snapshots = 0;
161 int i, ret;
162 struct snapshot *s = NULL;
163 struct snapshot_list sl;
164
165 gettimeofday(&now, NULL);
166 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
167 return 0;
168 assert(snapshot_creation_status == HS_READY);
169 current_snapshot_creation_time = 0;
170 dss_get_snapshot_list(&sl);
171 FOR_EACH_SNAPSHOT(s, i, &sl) {
172 if (!(s->flags & SS_COMPLETE))
173 continue;
174 num_complete_snapshots++;
175 x += s->completion_time - s->creation_time;
176 }
177 assert(x >= 0);
178 if (num_complete_snapshots)
179 x /= num_complete_snapshots; /* avg time to create one snapshot */
180 x *= wanted; /* time to create all snapshots in interval 0 */
181 tmp.tv_sec = x;
182 tmp.tv_usec = 0;
183 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
184 if (ret < 0 || !s) { /* unit_interval < tmp or no snapshot */
185 ret = 1;
186 goto out;
187 }
188
189 tv_divide(wanted, &diff, &tmp); /* sleep time between two snapshots */
190 diff.tv_sec = s->completion_time; /* completion time of the latest snapshot */
191 diff.tv_usec = 0;
192 tv_add(&diff, &tmp, &next_snapshot_time);
193 ret = (tv_diff(&now, &next_snapshot_time, &diff) < 0)? 0 : 1;
194 out:
195 free_snapshot_list(&sl);
196 if (ret == 0)
197 DSS_DEBUG_LOG("next snapshot due in %lu seconds\n",
198 tv2ms(&diff) / 1000);
199 else
200 DSS_DEBUG_LOG("next snapshot: now\n");
201 return ret;
202 }
203
204 static int pre_create_hook(void)
205 {
206 int ret, fds[3] = {0, 0, 0};
207
208 assert(snapshot_creation_status == HS_READY);
209 if (!conf.pre_create_hook_given) {
210 snapshot_creation_status = HS_PRE_SUCCESS;
211 return 0;
212 }
213 DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
214 ret = dss_exec_cmdline_pid(&create_pid,
215 conf.pre_create_hook_arg, fds);
216 if (ret < 0)
217 return ret;
218 snapshot_creation_status = HS_PRE_RUNNING;
219 return ret;
220 }
221
222 static int pre_remove_hook(struct snapshot *s, const char *why)
223 {
224 int ret, fds[3] = {0, 0, 0};
225 char *cmd;
226
227 if (!s)
228 return 0;
229 DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
230 assert(snapshot_removal_status == HS_READY);
231 assert(remove_pid == 0);
232 assert(!snapshot_currently_being_removed);
233
234 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
235 *snapshot_currently_being_removed = *s;
236 snapshot_currently_being_removed->name = dss_strdup(s->name);
237
238 if (!conf.pre_remove_hook_given) {
239 snapshot_removal_status = HS_PRE_SUCCESS;
240 return 0;
241 }
242 cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
243 conf.dest_dir_arg, s->name);
244 DSS_DEBUG_LOG("executing %s\n", cmd);
245 ret = dss_exec_cmdline_pid(&remove_pid,
246 conf.pre_remove_hook_arg, fds);
247 free(cmd);
248 if (ret < 0)
249 return ret;
250 snapshot_removal_status = HS_PRE_RUNNING;
251 return ret;
252 }
253
254 static int exec_rm(void)
255 {
256 struct snapshot *s = snapshot_currently_being_removed;
257 int fds[3] = {0, 0, 0};
258 char *new_name = being_deleted_name(s);
259 char *argv[] = {"rm", "-rf", new_name, NULL};
260 int ret;
261
262 assert(snapshot_removal_status == HS_PRE_SUCCESS);
263 assert(remove_pid == 0);
264
265 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
266 ret = dss_rename(s->name, new_name);
267 if (ret < 0)
268 goto out;
269 ret = dss_exec(&remove_pid, argv[0], argv, fds);
270 if (ret < 0)
271 goto out;
272 snapshot_removal_status = HS_RUNNING;
273 out:
274 free(new_name);
275 return ret;
276 }
277
278 static int snapshot_is_being_created(struct snapshot *s)
279 {
280 return s->creation_time == current_snapshot_creation_time;
281 }
282
283 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
284 {
285 struct snapshot *s;
286 int i;
287
288 DSS_DEBUG_LOG("looking for orphaned snapshots\n");
289 FOR_EACH_SNAPSHOT(s, i, sl) {
290 if (snapshot_is_being_created(s))
291 continue;
292 /*
293 * We know that no rm is currently running, so if s is marked
294 * as being deleted, a previously started rm must have failed.
295 */
296 if (s->flags & SS_BEING_DELETED)
297 return s;
298
299 if (s->flags & SS_COMPLETE) /* good snapshot */
300 continue;
301 /*
302 * This snapshot is incomplete and it is not the snapshot
303 * currently being created. However, we must not remove it if
304 * rsync is about to be restarted. As only the newest snapshot
305 * can be restarted, this snapshot is orphaned if it is not the
306 * newest snapshot or if we are not about to restart rsync.
307 */
308 if (get_newest_snapshot(sl) != s)
309 return s;
310 if (snapshot_creation_status != HS_NEEDS_RESTART)
311 return s;
312 }
313 /* no orphaned snapshots */
314 return NULL;
315 }
316
317 static int is_reference_snapshot(struct snapshot *s)
318 {
319 if (!name_of_reference_snapshot)
320 return 0;
321 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
322 }
323
324 /*
325 * return: 0: no redundant snapshots, 1: rm process started, negative: error
326 */
327 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
328 {
329 int i, interval;
330 struct snapshot *s;
331 unsigned missing = 0;
332
333 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
334 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
335 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
336 unsigned num = sl->interval_count[interval];
337 struct snapshot *victim = NULL, *prev = NULL;
338 int64_t score = LONG_MAX;
339
340 if (keep >= num)
341 missing += keep - num;
342 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
343 // interval, keep, num, missing);
344 if (keep + missing >= num)
345 continue;
346 /* redundant snapshot in this interval, pick snapshot with lowest score */
347 FOR_EACH_SNAPSHOT(s, i, sl) {
348 int64_t this_score;
349
350 if (snapshot_is_being_created(s))
351 continue;
352 if (is_reference_snapshot(s))
353 continue;
354 //DSS_DEBUG_LOG("checking %s\n", s->name);
355 if (s->interval > interval) {
356 prev = s;
357 continue;
358 }
359 if (s->interval < interval)
360 break;
361 if (!victim) {
362 victim = s;
363 prev = s;
364 continue;
365 }
366 assert(prev);
367 /* check if s is a better victim */
368 this_score = s->creation_time - prev->creation_time;
369 assert(this_score >= 0);
370 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
371 if (this_score < score) {
372 score = this_score;
373 victim = s;
374 }
375 prev = s;
376 }
377 assert(victim);
378 return victim;
379 }
380 return NULL;
381 }
382
383 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
384 {
385 int i;
386 struct snapshot *s;
387
388 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
389 conf.num_intervals_arg);
390 FOR_EACH_SNAPSHOT(s, i, sl) {
391 if (snapshot_is_being_created(s))
392 continue;
393 if (is_reference_snapshot(s))
394 continue;
395 if (s->interval <= conf.num_intervals_arg)
396 continue;
397 return s;
398 }
399 return NULL;
400 }
401
402 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
403 {
404 int i;
405 struct snapshot *s;
406 FOR_EACH_SNAPSHOT(s, i, sl) {
407 if (snapshot_is_being_created(s))
408 continue;
409 if (is_reference_snapshot(s))
410 continue;
411 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
412 return s;
413 }
414 return NULL;
415 }
416
417 static int rename_incomplete_snapshot(int64_t start)
418 {
419 char *old_name;
420 int ret;
421
422 free(path_to_last_complete_snapshot);
423 ret = complete_name(start, get_current_time(),
424 &path_to_last_complete_snapshot);
425 if (ret < 0)
426 return ret;
427 old_name = incomplete_name(start);
428 ret = dss_rename(old_name, path_to_last_complete_snapshot);
429 if (ret >= 0)
430 DSS_NOTICE_LOG("%s -> %s\n", old_name,
431 path_to_last_complete_snapshot);
432 free(old_name);
433 return ret;
434 }
435
436 static int try_to_free_disk_space(int low_disk_space)
437 {
438 int ret;
439 struct snapshot_list sl;
440 struct snapshot *victim;
441 struct timeval now;
442 const char *why;
443
444 gettimeofday(&now, NULL);
445 if (tv_diff(&next_removal_check, &now, NULL) > 0)
446 return 0;
447 if (!low_disk_space && conf.keep_redundant_given)
448 return 0;
449 dss_get_snapshot_list(&sl);
450 ret = 0;
451 if (!low_disk_space && sl.num_snapshots <= 1)
452 goto out;
453 why = "outdated";
454 victim = find_outdated_snapshot(&sl);
455 if (victim)
456 goto remove;
457 why = "redundant";
458 victim = find_redundant_snapshot(&sl);
459 if (victim)
460 goto remove;
461 /* try harder only if disk space is low */
462 if (!low_disk_space)
463 goto out;
464 why = "orphaned";
465 victim = find_orphaned_snapshot(&sl);
466 if (victim)
467 goto remove;
468 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
469 victim = find_oldest_removable_snapshot(&sl);
470 if (victim)
471 goto remove;
472 DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
473 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
474 goto out;
475 remove:
476 ret = pre_remove_hook(victim, why);
477 out:
478 free_snapshot_list(&sl);
479 return ret;
480 }
481
482 static int post_create_hook(void)
483 {
484 int ret, fds[3] = {0, 0, 0};
485 char *cmd;
486
487 if (!conf.post_create_hook_given) {
488 snapshot_creation_status = HS_READY;
489 return 0;
490 }
491 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
492 conf.dest_dir_arg, path_to_last_complete_snapshot);
493 DSS_NOTICE_LOG("executing %s\n", cmd);
494 ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
495 free(cmd);
496 if (ret < 0)
497 return ret;
498 snapshot_creation_status = HS_POST_RUNNING;
499 return ret;
500 }
501
502 static int post_remove_hook(void)
503 {
504 int ret, fds[3] = {0, 0, 0};
505 char *cmd;
506 struct snapshot *s = snapshot_currently_being_removed;
507
508 assert(s);
509
510 if (!conf.post_remove_hook_given) {
511 snapshot_removal_status = HS_READY;
512 return 0;
513 }
514 cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
515 conf.dest_dir_arg, s->name);
516 DSS_NOTICE_LOG("executing %s\n", cmd);
517 ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
518 free(cmd);
519 if (ret < 0)
520 return ret;
521 snapshot_removal_status = HS_POST_RUNNING;
522 return ret;
523 }
524
525 static void kill_process(pid_t pid)
526 {
527 if (!pid)
528 return;
529 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
530 kill(pid, SIGTERM);
531 }
532
533 static void stop_create_process(void)
534 {
535 if (!create_pid || create_process_stopped)
536 return;
537 kill(SIGSTOP, create_pid);
538 create_process_stopped = 1;
539 }
540
541 static void restart_create_process(void)
542 {
543 if (!create_pid || !create_process_stopped)
544 return;
545 kill (SIGCONT, create_pid);
546 create_process_stopped = 0;
547 }
548
549 /**
550 * Print a log message about the exit status of a child.
551 */
552 static void log_termination_msg(pid_t pid, int status)
553 {
554 if (WIFEXITED(status))
555 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
556 WEXITSTATUS(status));
557 else if (WIFSIGNALED(status))
558 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
559 WTERMSIG(status));
560 else
561 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
562 }
563
564 static int wait_for_process(pid_t pid, int *status)
565 {
566 int ret;
567
568 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
569 for (;;) {
570 fd_set rfds;
571
572 FD_ZERO(&rfds);
573 FD_SET(signal_pipe, &rfds);
574 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
575 if (ret < 0)
576 break;
577 ret = next_signal();
578 if (!ret)
579 continue;
580 if (ret == SIGCHLD) {
581 ret = waitpid(pid, status, 0);
582 if (ret >= 0)
583 break;
584 if (errno != EINTR) { /* error */
585 ret = -ERRNO_TO_DSS_ERROR(errno);
586 break;
587 }
588 }
589 /* SIGINT or SIGTERM */
590 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
591 kill(pid, SIGTERM);
592 }
593 if (ret < 0)
594 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
595 else
596 log_termination_msg(pid, *status);
597 return ret;
598 }
599
600 static void handle_pre_remove_exit(int status)
601 {
602 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
603 snapshot_removal_status = HS_READY;
604 gettimeofday(&next_removal_check, NULL);
605 next_removal_check.tv_sec += 60;
606 return;
607 }
608 snapshot_removal_status = HS_PRE_SUCCESS;
609 }
610
611 static int handle_rm_exit(int status)
612 {
613 if (!WIFEXITED(status)) {
614 snapshot_removal_status = HS_READY;
615 return -E_INVOLUNTARY_EXIT;
616 }
617 if (WEXITSTATUS(status)) {
618 snapshot_removal_status = HS_READY;
619 return -E_BAD_EXIT_CODE;
620 }
621 if (conf.post_remove_hook_given)
622 snapshot_removal_status = HS_SUCCESS;
623 else
624 snapshot_removal_status = HS_READY;
625 return 1;
626 }
627
628 static void handle_post_remove_exit(void)
629 {
630 snapshot_removal_status = HS_READY;
631 }
632
633 static int handle_remove_exit(int status)
634 {
635 int ret;
636 struct snapshot *s = snapshot_currently_being_removed;
637
638 assert(s);
639 switch (snapshot_removal_status) {
640 case HS_PRE_RUNNING:
641 handle_pre_remove_exit(status);
642 ret = 1;
643 break;
644 case HS_RUNNING:
645 ret = handle_rm_exit(status);
646 break;
647 case HS_POST_RUNNING:
648 handle_post_remove_exit();
649 ret = 1;
650 break;
651 default:
652 ret = -E_BUG;
653 }
654 if (snapshot_removal_status == HS_READY) {
655 free(s->name);
656 free(s);
657 snapshot_currently_being_removed = NULL;
658 }
659 remove_pid = 0;
660 return ret;
661 }
662
663 static int wait_for_remove_process(void)
664 {
665 int status, ret;
666
667 assert(remove_pid);
668 assert(
669 snapshot_removal_status == HS_PRE_RUNNING ||
670 snapshot_removal_status == HS_RUNNING ||
671 snapshot_removal_status == HS_POST_RUNNING
672 );
673 ret = wait_for_process(remove_pid, &status);
674 if (ret < 0)
675 return ret;
676 return handle_remove_exit(status);
677 }
678
679 static int handle_rsync_exit(int status)
680 {
681 int es, ret;
682
683 if (!WIFEXITED(status)) {
684 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
685 ret = -E_INVOLUNTARY_EXIT;
686 snapshot_creation_status = HS_READY;
687 goto out;
688 }
689 es = WEXITSTATUS(status);
690 /*
691 * Restart rsync on non-fatal errors:
692 * 12: Error in rsync protocol data stream
693 * 13: Errors with program diagnostics
694 */
695 if (es == 12 || es == 13) {
696 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
697 (int)create_pid, es);
698 snapshot_creation_status = HS_NEEDS_RESTART;
699 gettimeofday(&next_snapshot_time, NULL);
700 next_snapshot_time.tv_sec += 60;
701 ret = 1;
702 goto out;
703 }
704 if (es != 0 && es != 23 && es != 24) {
705 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
706 ret = -E_BAD_EXIT_CODE;
707 snapshot_creation_status = HS_READY;
708 goto out;
709 }
710 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
711 if (ret < 0)
712 goto out;
713 snapshot_creation_status = HS_SUCCESS;
714 free(name_of_reference_snapshot);
715 name_of_reference_snapshot = NULL;
716 out:
717 create_pid = 0;
718 create_process_stopped = 0;
719 return ret;
720 }
721
722 static int handle_pre_create_hook_exit(int status)
723 {
724 int es, ret;
725 static int warn_count;
726
727 if (!WIFEXITED(status)) {
728 snapshot_creation_status = HS_READY;
729 ret = -E_INVOLUNTARY_EXIT;
730 goto out;
731 }
732 es = WEXITSTATUS(status);
733 if (es) {
734 if (!warn_count--) {
735 DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
736 conf.pre_create_hook_arg, es);
737 DSS_NOTICE_LOG("deferring snapshot creation...\n");
738 warn_count = 60; /* warn only once per hour */
739 }
740 gettimeofday(&next_snapshot_time, NULL);
741 next_snapshot_time.tv_sec += 60;
742 snapshot_creation_status = HS_READY;
743 ret = 0;
744 goto out;
745 }
746 warn_count = 0;
747 snapshot_creation_status = HS_PRE_SUCCESS;
748 ret = 1;
749 out:
750 create_pid = 0;
751 return ret;
752 }
753
754 static int handle_sigchld(void)
755 {
756 pid_t pid;
757 int status, ret = reap_child(&pid, &status);
758
759 if (ret <= 0)
760 return ret;
761
762 if (pid == create_pid) {
763 switch (snapshot_creation_status) {
764 case HS_PRE_RUNNING:
765 return handle_pre_create_hook_exit(status);
766 case HS_RUNNING:
767 return handle_rsync_exit(status);
768 case HS_POST_RUNNING:
769 snapshot_creation_status = HS_READY;
770 return 1;
771 default:
772 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
773 snapshot_creation_status);
774 return -E_BUG;
775 }
776 }
777 if (pid == remove_pid) {
778 ret = handle_remove_exit(status);
779 if (ret < 0)
780 return ret;
781 return ret;
782 }
783 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
784 return -E_BUG;
785 }
786
787 static int check_config(void)
788 {
789 if (conf.unit_interval_arg <= 0) {
790 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
791 return -E_INVALID_NUMBER;
792 }
793 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
794 if (conf.num_intervals_arg <= 0) {
795 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
796 return -E_INVALID_NUMBER;
797 }
798 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
799 return 1;
800 }
801
802 static int parse_config_file(int override)
803 {
804 int ret;
805 char *config_file;
806 struct stat statbuf;
807 char *old_logfile_arg = NULL;
808 int old_daemon_given = 0;
809
810 if (conf.config_file_given)
811 config_file = dss_strdup(conf.config_file_arg);
812 else {
813 char *home = get_homedir();
814 config_file = make_message("%s/.dssrc", home);
815 free(home);
816 }
817 if (override) { /* SIGHUP */
818 if (conf.logfile_given)
819 old_logfile_arg = dss_strdup(conf.logfile_arg);
820 old_daemon_given = conf.daemon_given;
821 }
822
823 ret = stat(config_file, &statbuf);
824 if (ret && conf.config_file_given) {
825 ret = -ERRNO_TO_DSS_ERROR(errno);
826 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
827 goto out;
828 }
829 if (!ret) {
830 struct cmdline_parser_params params = {
831 .override = override,
832 .initialize = 0,
833 .check_required = 1,
834 .check_ambiguity = 0,
835 .print_errors = 1
836 };
837 if (override) { /* invalidate all rsync options */
838 int i;
839
840 for (i = 0; i < conf.rsync_option_given; i++) {
841 free(conf.rsync_option_arg[i]);
842 conf.rsync_option_arg[i] = NULL;
843 }
844 conf.rsync_option_given = 0;
845 }
846 cmdline_parser_config_file(config_file, &conf, &params);
847 }
848 ret = check_config();
849 if (ret < 0)
850 goto out;
851 if (override) {
852 /* don't change daemon mode on SIGHUP */
853 conf.daemon_given = old_daemon_given;
854 close_log(logfile);
855 logfile = NULL;
856 if (conf.logfile_given)
857 free(old_logfile_arg);
858 else if (conf.daemon_given) { /* re-use old logfile */
859 conf.logfile_arg = old_logfile_arg;
860 conf.logfile_given = 1;
861 }
862 }
863 if (conf.logfile_given) {
864 logfile = open_log(conf.logfile_arg);
865 log_welcome(conf.loglevel_arg);
866 }
867 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
868 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
869 out:
870 free(config_file);
871 if (ret < 0)
872 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
873 return ret;
874 }
875
876 static int change_to_dest_dir(void)
877 {
878 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
879 return dss_chdir(conf.dest_dir_arg);
880 }
881
882 static int handle_sighup(void)
883 {
884 int ret;
885
886 DSS_NOTICE_LOG("SIGHUP\n");
887 ret = parse_config_file(1);
888 if (ret < 0)
889 return ret;
890 return change_to_dest_dir();
891 }
892
893 static int handle_signal(void)
894 {
895 int sig, ret = next_signal();
896
897 if (ret <= 0)
898 goto out;
899 sig = ret;
900 switch (sig) {
901 case SIGINT:
902 case SIGTERM:
903 restart_create_process();
904 kill_process(create_pid);
905 kill_process(remove_pid);
906 ret = -E_SIGNAL;
907 break;
908 case SIGHUP:
909 ret = handle_sighup();
910 break;
911 case SIGCHLD:
912 ret = handle_sigchld();
913 break;
914 }
915 out:
916 if (ret < 0)
917 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
918 return ret;
919 }
920
921 /*
922 * We can not use rsync locally if the local user is different from the remote
923 * user or if the src dir is not on the local host (or both).
924 */
925 static int use_rsync_locally(char *logname)
926 {
927 char *h = conf.remote_host_arg;
928
929 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
930 return 0;
931 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
932 return 0;
933 return 1;
934 }
935
936 static void create_rsync_argv(char ***argv, int64_t *num)
937 {
938 char *logname;
939 int i = 0, j;
940 struct snapshot_list sl;
941
942 dss_get_snapshot_list(&sl);
943 assert(!name_of_reference_snapshot);
944 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
945 free_snapshot_list(&sl);
946
947 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
948 (*argv)[i++] = dss_strdup("rsync");
949 (*argv)[i++] = dss_strdup("-aq");
950 (*argv)[i++] = dss_strdup("--delete");
951 for (j = 0; j < conf.rsync_option_given; j++)
952 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
953 if (name_of_reference_snapshot) {
954 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
955 (*argv)[i++] = make_message("--link-dest=../%s",
956 name_of_reference_snapshot);
957 } else
958 DSS_INFO_LOG("no suitable reference snapshot found\n");
959 logname = dss_logname();
960 if (use_rsync_locally(logname))
961 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
962 else
963 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
964 conf.remote_user_arg : logname,
965 conf.remote_host_arg, conf.source_dir_arg);
966 free(logname);
967 *num = get_current_time();
968 (*argv)[i++] = incomplete_name(*num);
969 (*argv)[i++] = NULL;
970 for (j = 0; j < i; j++)
971 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
972 }
973
974 static void free_rsync_argv(char **argv)
975 {
976 int i;
977
978 if (!argv)
979 return;
980 for (i = 0; argv[i]; i++)
981 free(argv[i]);
982 free(argv);
983 }
984
985 static int create_snapshot(char **argv)
986 {
987 int ret, fds[3] = {0, 0, 0};
988 char *name;
989
990 name = incomplete_name(current_snapshot_creation_time);
991 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
992 free(name);
993 ret = dss_exec(&create_pid, argv[0], argv, fds);
994 if (ret < 0)
995 return ret;
996 snapshot_creation_status = HS_RUNNING;
997 return ret;
998 }
999
1000 static int select_loop(void)
1001 {
1002 int ret;
1003 /* check every 60 seconds for free disk space */
1004 struct timeval tv;
1005 char **rsync_argv = NULL;
1006
1007 for (;;) {
1008 fd_set rfds;
1009 int low_disk_space;
1010 struct timeval *tvp;
1011
1012 if (remove_pid)
1013 tvp = NULL; /* sleep until rm hook/process dies */
1014 else { /* sleep one minute */
1015 tv.tv_sec = 60;
1016 tv.tv_usec = 0;
1017 tvp = &tv;
1018 }
1019 FD_ZERO(&rfds);
1020 FD_SET(signal_pipe, &rfds);
1021 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
1022 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1023 if (ret < 0)
1024 goto out;
1025 if (FD_ISSET(signal_pipe, &rfds)) {
1026 ret = handle_signal();
1027 if (ret < 0)
1028 goto out;
1029 }
1030 if (remove_pid)
1031 continue;
1032 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1033 ret = exec_rm();
1034 if (ret < 0)
1035 goto out;
1036 continue;
1037 }
1038 if (snapshot_removal_status == HS_SUCCESS) {
1039 ret = post_remove_hook();
1040 if (ret < 0)
1041 goto out;
1042 continue;
1043 }
1044 ret = disk_space_low();
1045 if (ret < 0)
1046 goto out;
1047 low_disk_space = ret;
1048 ret = try_to_free_disk_space(low_disk_space);
1049 if (ret < 0)
1050 goto out;
1051 if (snapshot_removal_status != HS_READY) {
1052 stop_create_process();
1053 continue;
1054 }
1055 restart_create_process();
1056 switch (snapshot_creation_status) {
1057 case HS_READY:
1058 if (!next_snapshot_is_due())
1059 continue;
1060 ret = pre_create_hook();
1061 if (ret < 0)
1062 goto out;
1063 continue;
1064 case HS_PRE_RUNNING:
1065 case HS_RUNNING:
1066 case HS_POST_RUNNING:
1067 continue;
1068 case HS_PRE_SUCCESS:
1069 free_rsync_argv(rsync_argv);
1070 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1071 /* fall through */
1072 case HS_NEEDS_RESTART:
1073 ret = create_snapshot(rsync_argv);
1074 if (ret < 0)
1075 goto out;
1076 continue;
1077 case HS_SUCCESS:
1078 ret = post_create_hook();
1079 if (ret < 0)
1080 goto out;
1081 continue;
1082 }
1083 }
1084 out:
1085 return ret;
1086 }
1087
1088 static void exit_hook(int exit_code)
1089 {
1090 int fds[3] = {0, 0, 0};
1091 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
1092 pid_t pid;
1093
1094 if (!conf.exit_hook_given)
1095 return;
1096 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1097 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
1098 }
1099
1100 static int com_run(void)
1101 {
1102 int ret;
1103
1104 if (conf.dry_run_given) {
1105 DSS_ERROR_LOG("dry_run not supported by this command\n");
1106 return -E_SYNTAX;
1107 }
1108 ret = install_sighandler(SIGHUP);
1109 if (ret < 0)
1110 return ret;
1111 ret = select_loop();
1112 if (ret >= 0) /* impossible */
1113 ret = -E_BUG;
1114 exit_hook(ret);
1115 return ret;
1116 }
1117
1118 static int com_prune(void)
1119 {
1120 int ret;
1121 struct snapshot_list sl;
1122 struct snapshot *victim;
1123 struct disk_space ds;
1124 const char *why;
1125
1126 ret = get_disk_space(".", &ds);
1127 if (ret < 0)
1128 return ret;
1129 log_disk_space(&ds);
1130 dss_get_snapshot_list(&sl);
1131 why = "outdated";
1132 victim = find_outdated_snapshot(&sl);
1133 if (victim)
1134 goto rm;
1135 why = "redundant";
1136 victim = find_redundant_snapshot(&sl);
1137 if (victim)
1138 goto rm;
1139 ret = 0;
1140 goto out;
1141 rm:
1142 if (conf.dry_run_given) {
1143 dss_msg("%s snapshot %s (interval = %i)\n",
1144 why, victim->name, victim->interval);
1145 ret = 0;
1146 goto out;
1147 }
1148 ret = pre_remove_hook(victim, why);
1149 if (ret < 0)
1150 goto out;
1151 if (snapshot_removal_status == HS_PRE_RUNNING) {
1152 ret = wait_for_remove_process();
1153 if (ret < 0)
1154 goto out;
1155 if (snapshot_removal_status != HS_PRE_SUCCESS)
1156 goto out;
1157 }
1158 ret = exec_rm();
1159 if (ret < 0)
1160 goto out;
1161 ret = wait_for_remove_process();
1162 if (ret < 0)
1163 goto out;
1164 if (snapshot_removal_status != HS_SUCCESS)
1165 goto out;
1166 ret = post_remove_hook();
1167 if (ret < 0)
1168 goto out;
1169 if (snapshot_removal_status != HS_POST_RUNNING)
1170 goto out;
1171 ret = wait_for_remove_process();
1172 if (ret < 0)
1173 goto out;
1174 ret = 1;
1175 out:
1176 free_snapshot_list(&sl);
1177 return ret;
1178 }
1179
1180 static int com_create(void)
1181 {
1182 int ret, status;
1183 char **rsync_argv;
1184
1185 if (conf.dry_run_given) {
1186 int i;
1187 char *msg = NULL;
1188 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1189 for (i = 0; rsync_argv[i]; i++) {
1190 char *tmp = msg;
1191 msg = make_message("%s%s%s", tmp? tmp : "",
1192 tmp? " " : "", rsync_argv[i]);
1193 free(tmp);
1194 }
1195 free_rsync_argv(rsync_argv);
1196 dss_msg("%s\n", msg);
1197 free(msg);
1198 return 1;
1199 }
1200 ret = pre_create_hook();
1201 if (ret < 0)
1202 return ret;
1203 if (create_pid) {
1204 ret = wait_for_process(create_pid, &status);
1205 if (ret < 0)
1206 return ret;
1207 ret = handle_pre_create_hook_exit(status);
1208 if (ret <= 0) /* error, or pre-create failed */
1209 return ret;
1210 }
1211 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1212 ret = create_snapshot(rsync_argv);
1213 if (ret < 0)
1214 goto out;
1215 ret = wait_for_process(create_pid, &status);
1216 if (ret < 0)
1217 goto out;
1218 ret = handle_rsync_exit(status);
1219 if (ret < 0)
1220 goto out;
1221 post_create_hook();
1222 if (create_pid)
1223 ret = wait_for_process(create_pid, &status);
1224 out:
1225 free_rsync_argv(rsync_argv);
1226 return ret;
1227 }
1228
1229 static int com_ls(void)
1230 {
1231 int i;
1232 struct snapshot_list sl;
1233 struct snapshot *s;
1234
1235 dss_get_snapshot_list(&sl);
1236 FOR_EACH_SNAPSHOT(s, i, &sl) {
1237 int64_t d = 0;
1238 if (s->flags & SS_COMPLETE)
1239 d = (s->completion_time - s->creation_time) / 60;
1240 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1241 };
1242 free_snapshot_list(&sl);
1243 return 1;
1244 }
1245
1246 static int setup_signal_handling(void)
1247 {
1248 int ret;
1249
1250 DSS_INFO_LOG("setting up signal handlers\n");
1251 signal_pipe = signal_init(); /* always successful */
1252 ret = install_sighandler(SIGINT);
1253 if (ret < 0)
1254 return ret;
1255 ret = install_sighandler(SIGTERM);
1256 if (ret < 0)
1257 return ret;
1258 return install_sighandler(SIGCHLD);
1259 }
1260
1261 /**
1262 * The main function of dss.
1263 *
1264 * \param argc Usual argument count.
1265 * \param argv Usual argument vector.
1266 */
1267 int main(int argc, char **argv)
1268 {
1269 int ret;
1270 struct cmdline_parser_params params = {
1271 .override = 0,
1272 .initialize = 1,
1273 .check_required = 0,
1274 .check_ambiguity = 0,
1275 .print_errors = 1
1276 };
1277
1278 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1279 ret = parse_config_file(0);
1280 if (ret < 0)
1281 goto out;
1282 if (conf.daemon_given)
1283 daemon_init();
1284 ret = change_to_dest_dir();
1285 if (ret < 0)
1286 goto out;
1287 ret = setup_signal_handling();
1288 if (ret < 0)
1289 goto out;
1290 ret = call_command_handler();
1291 out:
1292 if (ret < 0)
1293 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1294 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1295 }