Remove some debug messages.
[dss.git] / dss.c
1 /*
2 * Copyright (C) 2008-2011 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 int64_t 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 static const char *hook_status_description[] = {HOOK_STATUS_ARRAY};
68
69 /* may be called with ds == NULL. */
70 static int disk_space_low(struct disk_space *ds)
71 {
72 struct disk_space ds_struct;
73
74 if (!ds) {
75 int ret = get_disk_space(".", &ds_struct);
76 if (ret < 0)
77 return ret;
78 ds = &ds_struct;
79 }
80 if (conf.min_free_mb_arg)
81 if (ds->free_mb < conf.min_free_mb_arg)
82 return 1;
83 if (conf.min_free_percent_arg)
84 if (ds->percent_free < conf.min_free_percent_arg)
85 return 1;
86 if (conf.min_free_percent_inodes_arg)
87 if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
88 return 1;
89 return 0;
90 }
91
92 static void dump_dss_config(const char *msg)
93 {
94 const char dash[] = "-----------------------------";
95 int ret;
96 FILE *log = logfile? logfile : stderr;
97 struct disk_space ds;
98 int64_t now = get_current_time();
99
100 if (conf.loglevel_arg > INFO)
101 return;
102
103 fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
104 fprintf(log, "\n*** disk space ***\n\n");
105 ret = get_disk_space(".", &ds);
106 if (ret >= 0) {
107 DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
108 "yes" : "no");
109 log_disk_space(&ds);
110 } else
111 DSS_ERROR_LOG("can not get free disk space: %s\n",
112 dss_strerror(-ret));
113
114 /* we continue on errors from get_disk_space */
115
116 fprintf(log, "\n*** command line and config file options ***\n\n");
117 cmdline_parser_dump(log, &conf);
118 fprintf(log, "\n*** internal state ***\n\n");
119 fprintf(log,
120 "pid: %d\n"
121 "logile: %s\n"
122 "snapshot_currently_being_removed: %s\n"
123 "path_to_last_complete_snapshot: %s\n"
124 "reference_snapshot: %s\n"
125 "snapshot_creation_status: %s\n"
126 "snapshot_removal_status: %s\n"
127 ,
128 (int) getpid(),
129 logfile? conf.logfile_arg : "stderr",
130 snapshot_currently_being_removed?
131 snapshot_currently_being_removed->name : "(none)",
132 path_to_last_complete_snapshot?
133 path_to_last_complete_snapshot : "(none)",
134 name_of_reference_snapshot?
135 name_of_reference_snapshot : "(none)",
136 hook_status_description[snapshot_creation_status],
137 hook_status_description[snapshot_removal_status]
138 );
139 if (create_pid != 0)
140 fprintf(log,
141 "create_pid: %" PRId32 "\n"
142 "create process is %sstopped\n"
143 ,
144 create_pid,
145 create_process_stopped? "" : "not "
146 );
147 if (remove_pid != 0)
148 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
149 if (next_snapshot_time != 0)
150 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
151 next_snapshot_time - now);
152 if (current_snapshot_creation_time != 0)
153 fprintf(log, "current_snapshot_creation_time: %"
154 PRId64 " (%" PRId64 " seconds ago)\n",
155 current_snapshot_creation_time,
156 now - current_snapshot_creation_time
157 );
158 if (next_removal_check.tv_sec != 0) {
159 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
160 (long long unsigned)next_removal_check.tv_sec,
161 now - (long long unsigned)next_removal_check.tv_sec
162 );
163
164 }
165 fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
166 }
167
168 /* a litte cpp magic helps to DRY */
169 #define COMMANDS \
170 COMMAND(ls) \
171 COMMAND(create) \
172 COMMAND(prune) \
173 COMMAND(run)
174 #define COMMAND(x) static int com_ ##x(void);
175 COMMANDS
176 #undef COMMAND
177 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
178 static int call_command_handler(void)
179 {
180 COMMANDS
181 DSS_EMERG_LOG("BUG: did not find command handler\n");
182 return -E_BUG;
183 }
184 #undef COMMAND
185 #undef COMMANDS
186
187 /**
188 * The log function of dss.
189 *
190 * \param ll Loglevel.
191 * \param fml Usual format string.
192 *
193 * All DSS_XXX_LOG() macros use this function.
194 */
195 __printf_2_3 void dss_log(int ll, const char* fmt,...)
196 {
197 va_list argp;
198 FILE *outfd;
199 struct tm *tm;
200 time_t t1;
201 char str[255] = "";
202
203 if (ll < conf.loglevel_arg)
204 return;
205 outfd = logfile? logfile : stderr;
206 time(&t1);
207 tm = localtime(&t1);
208 strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
209 fprintf(outfd, "%s ", str);
210 if (conf.loglevel_arg <= INFO)
211 fprintf(outfd, "%i: ", ll);
212 va_start(argp, fmt);
213 vfprintf(outfd, fmt, argp);
214 va_end(argp);
215 }
216
217 /**
218 * Print a message either to stdout or to the log file.
219 */
220 static __printf_1_2 void dss_msg(const char* fmt,...)
221 {
222 FILE *outfd = conf.daemon_given? logfile : stdout;
223 va_list argp;
224 va_start(argp, fmt);
225 vfprintf(outfd, fmt, argp);
226 va_end(argp);
227 }
228
229 static void dss_get_snapshot_list(struct snapshot_list *sl)
230 {
231 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
232 }
233
234 static int64_t compute_next_snapshot_time(void)
235 {
236 int64_t x = 0, now = get_current_time(), unit_interval
237 = 24 * 3600 * conf.unit_interval_arg, ret;
238 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
239 num_complete_snapshots = 0;
240 int i;
241 struct snapshot *s = NULL;
242 struct snapshot_list sl;
243
244 dss_get_snapshot_list(&sl);
245 FOR_EACH_SNAPSHOT(s, i, &sl) {
246 if (!(s->flags & SS_COMPLETE))
247 continue;
248 num_complete_snapshots++;
249 x += s->completion_time - s->creation_time;
250 }
251 assert(x >= 0);
252
253 ret = now;
254 if (num_complete_snapshots == 0)
255 goto out;
256 x /= num_complete_snapshots; /* avg time to create one snapshot */
257 if (unit_interval < x * wanted) /* oops, no sleep at all */
258 goto out;
259 ret = s->completion_time + unit_interval / wanted - x;
260 out:
261 free_snapshot_list(&sl);
262 return ret;
263 }
264
265 static inline void invalidate_next_snapshot_time(void)
266 {
267 next_snapshot_time = 0;
268 }
269
270 static inline int next_snapshot_time_is_valid(void)
271 {
272 return next_snapshot_time != 0;
273 }
274
275 static int next_snapshot_is_due(void)
276 {
277 int64_t now = get_current_time();
278
279 if (!next_snapshot_time_is_valid())
280 next_snapshot_time = compute_next_snapshot_time();
281 if (next_snapshot_time <= now) {
282 DSS_DEBUG_LOG("next snapshot: now\n");
283 return 1;
284 }
285 DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
286 next_snapshot_time - now);
287 return 0;
288 }
289
290 static void pre_create_hook(void)
291 {
292 assert(snapshot_creation_status == HS_READY);
293 /* make sure that the next snapshot time will be recomputed */
294 invalidate_next_snapshot_time();
295 DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
296 dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
297 snapshot_creation_status = HS_PRE_RUNNING;
298 }
299
300 static void pre_remove_hook(struct snapshot *s, const char *why)
301 {
302 char *cmd;
303
304 if (!s)
305 return;
306 DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
307 assert(snapshot_removal_status == HS_READY);
308 assert(remove_pid == 0);
309 assert(!snapshot_currently_being_removed);
310
311 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
312 *snapshot_currently_being_removed = *s;
313 snapshot_currently_being_removed->name = dss_strdup(s->name);
314
315 cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
316 conf.dest_dir_arg, s->name);
317 DSS_DEBUG_LOG("executing %s\n", cmd);
318 dss_exec_cmdline_pid(&remove_pid, cmd);
319 free(cmd);
320 snapshot_removal_status = HS_PRE_RUNNING;
321 }
322
323 static int exec_rm(void)
324 {
325 struct snapshot *s = snapshot_currently_being_removed;
326 char *new_name = being_deleted_name(s);
327 char *argv[4];
328 int ret;
329
330 argv[0] = "rm";
331 argv[1] = "-rf";
332 argv[2] = new_name;
333 argv[3] = NULL;
334
335 assert(snapshot_removal_status == HS_PRE_SUCCESS);
336 assert(remove_pid == 0);
337
338 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
339 ret = dss_rename(s->name, new_name);
340 if (ret < 0)
341 goto out;
342 dss_exec(&remove_pid, argv[0], argv);
343 snapshot_removal_status = HS_RUNNING;
344 out:
345 free(new_name);
346 return ret;
347 }
348
349 static int snapshot_is_being_created(struct snapshot *s)
350 {
351 return s->creation_time == current_snapshot_creation_time;
352 }
353
354 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
355 {
356 struct snapshot *s;
357 int i;
358
359 DSS_DEBUG_LOG("looking for orphaned snapshots\n");
360 FOR_EACH_SNAPSHOT(s, i, sl) {
361 if (snapshot_is_being_created(s))
362 continue;
363 /*
364 * We know that no rm is currently running, so if s is marked
365 * as being deleted, a previously started rm must have failed.
366 */
367 if (s->flags & SS_BEING_DELETED)
368 return s;
369
370 if (s->flags & SS_COMPLETE) /* good snapshot */
371 continue;
372 /*
373 * This snapshot is incomplete and it is not the snapshot
374 * currently being created. However, we must not remove it if
375 * rsync is about to be restarted. As only the newest snapshot
376 * can be restarted, this snapshot is orphaned if it is not the
377 * newest snapshot or if we are not about to restart rsync.
378 */
379 if (get_newest_snapshot(sl) != s)
380 return s;
381 if (snapshot_creation_status != HS_NEEDS_RESTART)
382 return s;
383 }
384 /* no orphaned snapshots */
385 return NULL;
386 }
387
388 static int is_reference_snapshot(struct snapshot *s)
389 {
390 if (!name_of_reference_snapshot)
391 return 0;
392 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
393 }
394
395 /*
396 * return: 0: no redundant snapshots, 1: rm process started, negative: error
397 */
398 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
399 {
400 int i, interval;
401 struct snapshot *s;
402 unsigned missing = 0;
403
404 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
405 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
406 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
407 unsigned num = sl->interval_count[interval];
408 struct snapshot *victim = NULL, *prev = NULL;
409 int64_t score = LONG_MAX;
410
411 if (keep >= num)
412 missing += keep - num;
413 if (keep + missing >= num)
414 continue;
415 /* redundant snapshot in this interval, pick snapshot with lowest score */
416 FOR_EACH_SNAPSHOT(s, i, sl) {
417 int64_t this_score;
418
419 if (snapshot_is_being_created(s))
420 continue;
421 if (is_reference_snapshot(s))
422 continue;
423 if (s->interval > interval) {
424 prev = s;
425 continue;
426 }
427 if (s->interval < interval)
428 break;
429 if (!victim) {
430 victim = s;
431 prev = s;
432 continue;
433 }
434 assert(prev);
435 /* check if s is a better victim */
436 this_score = s->creation_time - prev->creation_time;
437 assert(this_score >= 0);
438 if (this_score < score) {
439 score = this_score;
440 victim = s;
441 }
442 prev = s;
443 }
444 assert(victim);
445 return victim;
446 }
447 return NULL;
448 }
449
450 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
451 {
452 int i;
453 struct snapshot *s;
454
455 DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
456 conf.num_intervals_arg);
457 FOR_EACH_SNAPSHOT(s, i, sl) {
458 if (snapshot_is_being_created(s))
459 continue;
460 if (is_reference_snapshot(s))
461 continue;
462 if (s->interval < conf.num_intervals_arg)
463 continue;
464 return s;
465 }
466 return NULL;
467 }
468
469 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
470 {
471 int i;
472 struct snapshot *s;
473 FOR_EACH_SNAPSHOT(s, i, sl) {
474 if (snapshot_is_being_created(s))
475 continue;
476 if (is_reference_snapshot(s))
477 continue;
478 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
479 return s;
480 }
481 return NULL;
482 }
483
484 static int rename_incomplete_snapshot(int64_t start)
485 {
486 char *old_name;
487 int ret;
488
489 free(path_to_last_complete_snapshot);
490 ret = complete_name(start, get_current_time(),
491 &path_to_last_complete_snapshot);
492 if (ret < 0)
493 return ret;
494 old_name = incomplete_name(start);
495 ret = dss_rename(old_name, path_to_last_complete_snapshot);
496 if (ret >= 0)
497 DSS_NOTICE_LOG("%s -> %s\n", old_name,
498 path_to_last_complete_snapshot);
499 free(old_name);
500 return ret;
501 }
502
503 static int try_to_free_disk_space(void)
504 {
505 int ret;
506 struct snapshot_list sl;
507 struct snapshot *victim;
508 struct timeval now;
509 const char *why;
510 int low_disk_space;
511
512 ret = disk_space_low(NULL);
513 if (ret < 0)
514 return ret;
515 low_disk_space = ret;
516 gettimeofday(&now, NULL);
517 if (tv_diff(&next_removal_check, &now, NULL) > 0)
518 return 0;
519 if (!low_disk_space) {
520 if (conf.keep_redundant_given)
521 return 0;
522 if (snapshot_creation_status != HS_READY)
523 return 0;
524 if (next_snapshot_is_due())
525 return 0;
526 }
527 dss_get_snapshot_list(&sl);
528 ret = 0;
529 if (!low_disk_space && sl.num_snapshots <= 1)
530 goto out;
531 why = "outdated";
532 victim = find_outdated_snapshot(&sl);
533 if (victim)
534 goto remove;
535 why = "redundant";
536 victim = find_redundant_snapshot(&sl);
537 if (victim)
538 goto remove;
539 /* try harder only if disk space is low */
540 if (!low_disk_space)
541 goto out;
542 why = "orphaned";
543 victim = find_orphaned_snapshot(&sl);
544 if (victim)
545 goto remove;
546 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
547 victim = find_oldest_removable_snapshot(&sl);
548 if (victim)
549 goto remove;
550 DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
551 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
552 goto out;
553 remove:
554 pre_remove_hook(victim, why);
555 out:
556 free_snapshot_list(&sl);
557 return ret;
558 }
559
560 static void post_create_hook(void)
561 {
562 char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
563 conf.dest_dir_arg, path_to_last_complete_snapshot);
564 DSS_NOTICE_LOG("executing %s\n", cmd);
565 dss_exec_cmdline_pid(&create_pid, cmd);
566 free(cmd);
567 snapshot_creation_status = HS_POST_RUNNING;
568 }
569
570 static void post_remove_hook(void)
571 {
572 char *cmd;
573 struct snapshot *s = snapshot_currently_being_removed;
574
575 assert(s);
576
577 cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
578 conf.dest_dir_arg, s->name);
579 DSS_NOTICE_LOG("executing %s\n", cmd);
580 dss_exec_cmdline_pid(&remove_pid, cmd);
581 free(cmd);
582 snapshot_removal_status = HS_POST_RUNNING;
583 }
584
585 static void dss_kill(pid_t pid, int sig, const char *msg)
586 {
587 const char *signame, *process_name;
588
589 if (pid == 0)
590 return;
591 switch (sig) {
592 case SIGTERM: signame = "TERM"; break;
593 case SIGSTOP: signame = "STOP"; break;
594 case SIGCONT: signame = "CONT"; break;
595 default: signame = "????";
596 }
597
598 if (pid == create_pid)
599 process_name = "create";
600 else if (pid == remove_pid)
601 process_name = "remove";
602 else process_name = "??????";
603
604 if (msg)
605 DSS_INFO_LOG("%s\n", msg);
606 DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
607 sig, signame, (int)pid, process_name);
608 if (kill(pid, sig) >= 0)
609 return;
610 DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
611 sig, signame, (int)pid, process_name);
612 }
613
614 static void stop_create_process(void)
615 {
616 if (create_process_stopped)
617 return;
618 dss_kill(create_pid, SIGSTOP, "suspending create process");
619 create_process_stopped = 1;
620 }
621
622 static void restart_create_process(void)
623 {
624 if (!create_process_stopped)
625 return;
626 dss_kill(create_pid, SIGCONT, "resuming create process");
627 create_process_stopped = 0;
628 }
629
630 /**
631 * Print a log message about the exit status of a child.
632 */
633 static void log_termination_msg(pid_t pid, int status)
634 {
635 if (WIFEXITED(status))
636 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
637 WEXITSTATUS(status));
638 else if (WIFSIGNALED(status))
639 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
640 WTERMSIG(status));
641 else
642 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
643 }
644
645 static int wait_for_process(pid_t pid, int *status)
646 {
647 int ret;
648
649 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
650 for (;;) {
651 fd_set rfds;
652
653 FD_ZERO(&rfds);
654 FD_SET(signal_pipe, &rfds);
655 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
656 if (ret < 0)
657 break;
658 ret = next_signal();
659 if (!ret)
660 continue;
661 if (ret == SIGCHLD) {
662 ret = waitpid(pid, status, 0);
663 if (ret >= 0)
664 break;
665 if (errno != EINTR) { /* error */
666 ret = -ERRNO_TO_DSS_ERROR(errno);
667 break;
668 }
669 }
670 /* SIGINT or SIGTERM */
671 dss_kill(pid, SIGTERM, "killing child process");
672 }
673 if (ret < 0)
674 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
675 else
676 log_termination_msg(pid, *status);
677 return ret;
678 }
679
680 static void handle_pre_remove_exit(int status)
681 {
682 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
683 snapshot_removal_status = HS_READY;
684 gettimeofday(&next_removal_check, NULL);
685 next_removal_check.tv_sec += 60;
686 return;
687 }
688 snapshot_removal_status = HS_PRE_SUCCESS;
689 }
690
691 static int handle_rm_exit(int status)
692 {
693 if (!WIFEXITED(status)) {
694 snapshot_removal_status = HS_READY;
695 return -E_INVOLUNTARY_EXIT;
696 }
697 if (WEXITSTATUS(status)) {
698 snapshot_removal_status = HS_READY;
699 return -E_BAD_EXIT_CODE;
700 }
701 snapshot_removal_status = HS_SUCCESS;
702 return 1;
703 }
704
705 static void handle_post_remove_exit(void)
706 {
707 snapshot_removal_status = HS_READY;
708 }
709
710 static int handle_remove_exit(int status)
711 {
712 int ret;
713 struct snapshot *s = snapshot_currently_being_removed;
714
715 assert(s);
716 switch (snapshot_removal_status) {
717 case HS_PRE_RUNNING:
718 handle_pre_remove_exit(status);
719 ret = 1;
720 break;
721 case HS_RUNNING:
722 ret = handle_rm_exit(status);
723 break;
724 case HS_POST_RUNNING:
725 handle_post_remove_exit();
726 ret = 1;
727 break;
728 default:
729 ret = -E_BUG;
730 }
731 if (snapshot_removal_status == HS_READY) {
732 free(s->name);
733 free(s);
734 snapshot_currently_being_removed = NULL;
735 }
736 remove_pid = 0;
737 return ret;
738 }
739
740 static int wait_for_remove_process(void)
741 {
742 int status, ret;
743
744 assert(remove_pid);
745 assert(
746 snapshot_removal_status == HS_PRE_RUNNING ||
747 snapshot_removal_status == HS_RUNNING ||
748 snapshot_removal_status == HS_POST_RUNNING
749 );
750 ret = wait_for_process(remove_pid, &status);
751 if (ret < 0)
752 return ret;
753 return handle_remove_exit(status);
754 }
755
756 static int handle_rsync_exit(int status)
757 {
758 int es, ret;
759
760 if (!WIFEXITED(status)) {
761 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
762 ret = -E_INVOLUNTARY_EXIT;
763 snapshot_creation_status = HS_READY;
764 goto out;
765 }
766 es = WEXITSTATUS(status);
767 /*
768 * Restart rsync on non-fatal errors:
769 * 12: Error in rsync protocol data stream
770 * 13: Errors with program diagnostics
771 */
772 if (es == 12 || es == 13) {
773 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
774 (int)create_pid, es);
775 snapshot_creation_status = HS_NEEDS_RESTART;
776 next_snapshot_time = get_current_time() + 60;
777 ret = 1;
778 goto out;
779 }
780 if (es != 0 && es != 23 && es != 24) {
781 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
782 ret = -E_BAD_EXIT_CODE;
783 snapshot_creation_status = HS_READY;
784 goto out;
785 }
786 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
787 if (ret < 0)
788 goto out;
789 snapshot_creation_status = HS_SUCCESS;
790 free(name_of_reference_snapshot);
791 name_of_reference_snapshot = NULL;
792 out:
793 create_process_stopped = 0;
794 return ret;
795 }
796
797 static int handle_pre_create_hook_exit(int status)
798 {
799 int es, ret;
800 static int warn_count;
801
802 if (!WIFEXITED(status)) {
803 snapshot_creation_status = HS_READY;
804 ret = -E_INVOLUNTARY_EXIT;
805 goto out;
806 }
807 es = WEXITSTATUS(status);
808 if (es) {
809 if (!warn_count--) {
810 DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
811 conf.pre_create_hook_arg, es);
812 DSS_NOTICE_LOG("deferring snapshot creation...\n");
813 warn_count = 60; /* warn only once per hour */
814 }
815 next_snapshot_time = get_current_time() + 60;
816 snapshot_creation_status = HS_READY;
817 ret = 0;
818 goto out;
819 }
820 warn_count = 0;
821 snapshot_creation_status = HS_PRE_SUCCESS;
822 ret = 1;
823 out:
824 return ret;
825 }
826
827 static int handle_sigchld(void)
828 {
829 pid_t pid;
830 int status, ret = reap_child(&pid, &status);
831
832 if (ret <= 0)
833 return ret;
834
835 if (pid == create_pid) {
836 switch (snapshot_creation_status) {
837 case HS_PRE_RUNNING:
838 ret = handle_pre_create_hook_exit(status);
839 break;
840 case HS_RUNNING:
841 ret = handle_rsync_exit(status);
842 break;
843 case HS_POST_RUNNING:
844 snapshot_creation_status = HS_READY;
845 ret = 1;
846 break;
847 default:
848 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
849 snapshot_creation_status);
850 return -E_BUG;
851 }
852 create_pid = 0;
853 return ret;
854 }
855 if (pid == remove_pid) {
856 ret = handle_remove_exit(status);
857 if (ret < 0)
858 return ret;
859 return ret;
860 }
861 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
862 return -E_BUG;
863 }
864
865 static int check_config(void)
866 {
867 if (conf.unit_interval_arg <= 0) {
868 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
869 return -E_INVALID_NUMBER;
870 }
871 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
872 if (conf.num_intervals_arg <= 0) {
873 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
874 return -E_INVALID_NUMBER;
875 }
876 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
877 return 1;
878 }
879
880 /*
881 * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
882 * file was read successfully.
883 */
884 static int parse_config_file(int override)
885 {
886 int ret, config_file_exists;
887 char *config_file;
888 struct stat statbuf;
889 char *old_logfile_arg = NULL;
890 int old_daemon_given = 0;
891
892 if (conf.config_file_given)
893 config_file = dss_strdup(conf.config_file_arg);
894 else {
895 char *home = get_homedir();
896 config_file = make_message("%s/.dssrc", home);
897 free(home);
898 }
899 if (override) { /* SIGHUP */
900 if (conf.logfile_given)
901 old_logfile_arg = dss_strdup(conf.logfile_arg);
902 old_daemon_given = conf.daemon_given;
903 }
904
905 config_file_exists = !stat(config_file, &statbuf);
906 if (!config_file_exists && conf.config_file_given) {
907 ret = -ERRNO_TO_DSS_ERROR(errno);
908 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
909 goto out;
910 }
911 if (config_file_exists) {
912 struct cmdline_parser_params params;
913 params.override = override;
914 params.initialize = 0;
915 params.check_required = 1;
916 params.check_ambiguity = 0;
917 params.print_errors = 1;
918 if (override) { /* invalidate all rsync options */
919 int i;
920
921 for (i = 0; i < conf.rsync_option_given; i++) {
922 free(conf.rsync_option_arg[i]);
923 conf.rsync_option_arg[i] = NULL;
924 }
925 conf.rsync_option_given = 0;
926 }
927 cmdline_parser_config_file(config_file, &conf, &params);
928 }
929 ret = check_config();
930 if (ret < 0)
931 goto out;
932 if (override) {
933 /* don't change daemon mode on SIGHUP */
934 conf.daemon_given = old_daemon_given;
935 close_log(logfile);
936 logfile = NULL;
937 if (conf.logfile_given)
938 free(old_logfile_arg);
939 else if (conf.daemon_given) { /* re-use old logfile */
940 conf.logfile_arg = old_logfile_arg;
941 conf.logfile_given = 1;
942 }
943 }
944 if (conf.logfile_given && conf.run_given && conf.daemon_given) {
945 logfile = open_log(conf.logfile_arg);
946 log_welcome(conf.loglevel_arg);
947 }
948 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
949 ret = config_file_exists;
950 out:
951 free(config_file);
952 if (ret < 0)
953 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
954 return ret;
955 }
956
957 static int change_to_dest_dir(void)
958 {
959 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
960 return dss_chdir(conf.dest_dir_arg);
961 }
962
963 static int handle_sighup(void)
964 {
965 int ret;
966
967 DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
968 dump_dss_config("old");
969 ret = parse_config_file(1);
970 if (ret < 0)
971 return ret;
972 dump_dss_config("reloaded");
973 invalidate_next_snapshot_time();
974 return change_to_dest_dir();
975 }
976
977 static int handle_signal(void)
978 {
979 int sig, ret = next_signal();
980
981 if (ret <= 0)
982 goto out;
983 sig = ret;
984 switch (sig) {
985 case SIGINT:
986 case SIGTERM:
987 restart_create_process();
988 dss_kill(create_pid, SIGTERM, NULL);
989 dss_kill(remove_pid, SIGTERM, NULL);
990 ret = -E_SIGNAL;
991 break;
992 case SIGHUP:
993 ret = handle_sighup();
994 break;
995 case SIGCHLD:
996 ret = handle_sigchld();
997 break;
998 }
999 out:
1000 if (ret < 0)
1001 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1002 return ret;
1003 }
1004
1005 /*
1006 * We can not use rsync locally if the local user is different from the remote
1007 * user or if the src dir is not on the local host (or both).
1008 */
1009 static int use_rsync_locally(char *logname)
1010 {
1011 char *h = conf.remote_host_arg;
1012
1013 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1014 return 0;
1015 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1016 return 0;
1017 return 1;
1018 }
1019
1020 static int rename_resume_snap(int64_t creation_time)
1021 {
1022 struct snapshot_list sl;
1023 struct snapshot *s = NULL;
1024 char *new_name = incomplete_name(creation_time);
1025 int ret;
1026 const char *why;
1027
1028 sl.num_snapshots = 0;
1029
1030 ret = 0;
1031 if (conf.no_resume_given)
1032 goto out;
1033 dss_get_snapshot_list(&sl);
1034 /*
1035 * Snapshot recycling: We first look at the newest snapshot. If this
1036 * snapshot happens to be incomplete, the last rsync process was
1037 * aborted and we reuse this one. Otherwise we look at snapshots which
1038 * could be removed (outdated and redundant snapshots) as candidates
1039 * for recycling. If no outdated/redundant snapshot exists, we check if
1040 * there is an orphaned snapshot, which likely is useless anyway.
1041 *
1042 * Only if no existing snapshot is suitable for recycling, we bite the
1043 * bullet and create a new one.
1044 */
1045 s = get_newest_snapshot(&sl);
1046 if (!s) /* no snapshots at all */
1047 goto out;
1048 /* re-use last snapshot if it is incomplete */
1049 why = "aborted";
1050 if ((s->flags & SS_COMPLETE) == 0)
1051 goto out;
1052 why = "outdated";
1053 s = find_outdated_snapshot(&sl);
1054 if (s)
1055 goto out;
1056 why = "redundant";
1057 s = find_redundant_snapshot(&sl);
1058 if (s)
1059 goto out;
1060 why = "orphaned";
1061 s = find_orphaned_snapshot(&sl);
1062 out:
1063 if (s) {
1064 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1065 ret = dss_rename(s->name, new_name);
1066 }
1067 if (ret >= 0)
1068 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1069 free(new_name);
1070 free_snapshot_list(&sl);
1071 return ret;
1072 }
1073
1074 static void create_rsync_argv(char ***argv, int64_t *num)
1075 {
1076 char *logname;
1077 int i = 0, j;
1078 struct snapshot_list sl;
1079
1080 dss_get_snapshot_list(&sl);
1081 assert(!name_of_reference_snapshot);
1082 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1083 free_snapshot_list(&sl);
1084
1085 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1086 (*argv)[i++] = dss_strdup("rsync");
1087 (*argv)[i++] = dss_strdup("-aq");
1088 (*argv)[i++] = dss_strdup("--delete");
1089 for (j = 0; j < conf.rsync_option_given; j++)
1090 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1091 if (name_of_reference_snapshot) {
1092 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1093 (*argv)[i++] = make_message("--link-dest=../%s",
1094 name_of_reference_snapshot);
1095 } else
1096 DSS_INFO_LOG("no suitable reference snapshot found\n");
1097 logname = dss_logname();
1098 if (use_rsync_locally(logname))
1099 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1100 else
1101 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1102 conf.remote_user_arg : logname,
1103 conf.remote_host_arg, conf.source_dir_arg);
1104 free(logname);
1105 *num = get_current_time();
1106 (*argv)[i++] = incomplete_name(*num);
1107 (*argv)[i++] = NULL;
1108 for (j = 0; j < i; j++)
1109 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1110 }
1111
1112 static void free_rsync_argv(char **argv)
1113 {
1114 int i;
1115
1116 if (!argv)
1117 return;
1118 for (i = 0; argv[i]; i++)
1119 free(argv[i]);
1120 free(argv);
1121 }
1122
1123 static int create_snapshot(char **argv)
1124 {
1125 int ret;
1126
1127 ret = rename_resume_snap(current_snapshot_creation_time);
1128 if (ret < 0)
1129 return ret;
1130 dss_exec(&create_pid, argv[0], argv);
1131 snapshot_creation_status = HS_RUNNING;
1132 return ret;
1133 }
1134
1135 static int select_loop(void)
1136 {
1137 int ret;
1138 /* check every 60 seconds for free disk space */
1139 struct timeval tv;
1140 char **rsync_argv = NULL;
1141
1142 for (;;) {
1143 fd_set rfds;
1144 struct timeval *tvp;
1145
1146 if (remove_pid)
1147 tvp = NULL; /* sleep until rm hook/process dies */
1148 else { /* sleep one minute */
1149 tv.tv_sec = 60;
1150 tv.tv_usec = 0;
1151 tvp = &tv;
1152 }
1153 FD_ZERO(&rfds);
1154 FD_SET(signal_pipe, &rfds);
1155 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1156 if (ret < 0)
1157 goto out;
1158 if (FD_ISSET(signal_pipe, &rfds)) {
1159 ret = handle_signal();
1160 if (ret < 0)
1161 goto out;
1162 }
1163 if (remove_pid)
1164 continue;
1165 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1166 ret = exec_rm();
1167 if (ret < 0)
1168 goto out;
1169 continue;
1170 }
1171 if (snapshot_removal_status == HS_SUCCESS) {
1172 post_remove_hook();
1173 continue;
1174 }
1175 ret = try_to_free_disk_space();
1176 if (ret < 0)
1177 goto out;
1178 if (snapshot_removal_status != HS_READY) {
1179 stop_create_process();
1180 continue;
1181 }
1182 restart_create_process();
1183 switch (snapshot_creation_status) {
1184 case HS_READY:
1185 if (!next_snapshot_is_due())
1186 continue;
1187 pre_create_hook();
1188 continue;
1189 case HS_PRE_RUNNING:
1190 case HS_RUNNING:
1191 case HS_POST_RUNNING:
1192 continue;
1193 case HS_PRE_SUCCESS:
1194 if (!name_of_reference_snapshot) {
1195 free_rsync_argv(rsync_argv);
1196 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1197 }
1198 ret = create_snapshot(rsync_argv);
1199 if (ret < 0)
1200 goto out;
1201 continue;
1202 case HS_NEEDS_RESTART:
1203 if (!next_snapshot_is_due())
1204 continue;
1205 ret = create_snapshot(rsync_argv);
1206 if (ret < 0)
1207 goto out;
1208 continue;
1209 case HS_SUCCESS:
1210 post_create_hook();
1211 continue;
1212 }
1213 }
1214 out:
1215 return ret;
1216 }
1217
1218 static void exit_hook(int exit_code)
1219 {
1220 char *argv[3];
1221 pid_t pid;
1222
1223 argv[0] = conf.exit_hook_arg;
1224 argv[1] = dss_strerror(-exit_code);
1225 argv[2] = NULL;
1226
1227 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1228 dss_exec(&pid, conf.exit_hook_arg, argv);
1229 }
1230
1231 static int com_run(void)
1232 {
1233 int ret;
1234
1235 if (conf.dry_run_given) {
1236 DSS_ERROR_LOG("dry_run not supported by this command\n");
1237 return -E_SYNTAX;
1238 }
1239 ret = install_sighandler(SIGHUP);
1240 if (ret < 0)
1241 return ret;
1242 ret = select_loop();
1243 if (ret >= 0) /* impossible */
1244 ret = -E_BUG;
1245 exit_hook(ret);
1246 return ret;
1247 }
1248
1249 static int com_prune(void)
1250 {
1251 int ret;
1252 struct snapshot_list sl;
1253 struct snapshot *victim;
1254 struct disk_space ds;
1255 const char *why;
1256
1257 ret = get_disk_space(".", &ds);
1258 if (ret < 0)
1259 return ret;
1260 log_disk_space(&ds);
1261 dss_get_snapshot_list(&sl);
1262 why = "outdated";
1263 victim = find_outdated_snapshot(&sl);
1264 if (victim)
1265 goto rm;
1266 why = "redundant";
1267 victim = find_redundant_snapshot(&sl);
1268 if (victim)
1269 goto rm;
1270 ret = 0;
1271 goto out;
1272 rm:
1273 if (conf.dry_run_given) {
1274 dss_msg("%s snapshot %s (interval = %i)\n",
1275 why, victim->name, victim->interval);
1276 ret = 0;
1277 goto out;
1278 }
1279 pre_remove_hook(victim, why);
1280 if (snapshot_removal_status == HS_PRE_RUNNING) {
1281 ret = wait_for_remove_process();
1282 if (ret < 0)
1283 goto out;
1284 if (snapshot_removal_status != HS_PRE_SUCCESS)
1285 goto out;
1286 }
1287 ret = exec_rm();
1288 if (ret < 0)
1289 goto out;
1290 ret = wait_for_remove_process();
1291 if (ret < 0)
1292 goto out;
1293 if (snapshot_removal_status != HS_SUCCESS)
1294 goto out;
1295 post_remove_hook();
1296 if (snapshot_removal_status != HS_POST_RUNNING)
1297 goto out;
1298 ret = wait_for_remove_process();
1299 if (ret < 0)
1300 goto out;
1301 ret = 1;
1302 out:
1303 free_snapshot_list(&sl);
1304 return ret;
1305 }
1306
1307 static int com_create(void)
1308 {
1309 int ret, status;
1310 char **rsync_argv;
1311
1312 if (conf.dry_run_given) {
1313 int i;
1314 char *msg = NULL;
1315 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1316 for (i = 0; rsync_argv[i]; i++) {
1317 char *tmp = msg;
1318 msg = make_message("%s%s%s", tmp? tmp : "",
1319 tmp? " " : "", rsync_argv[i]);
1320 free(tmp);
1321 }
1322 free_rsync_argv(rsync_argv);
1323 dss_msg("%s\n", msg);
1324 free(msg);
1325 return 1;
1326 }
1327 pre_create_hook();
1328 if (create_pid) {
1329 ret = wait_for_process(create_pid, &status);
1330 if (ret < 0)
1331 return ret;
1332 ret = handle_pre_create_hook_exit(status);
1333 if (ret <= 0) /* error, or pre-create failed */
1334 return ret;
1335 }
1336 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1337 ret = create_snapshot(rsync_argv);
1338 if (ret < 0)
1339 goto out;
1340 ret = wait_for_process(create_pid, &status);
1341 if (ret < 0)
1342 goto out;
1343 ret = handle_rsync_exit(status);
1344 if (ret < 0)
1345 goto out;
1346 post_create_hook();
1347 if (create_pid)
1348 ret = wait_for_process(create_pid, &status);
1349 out:
1350 free_rsync_argv(rsync_argv);
1351 return ret;
1352 }
1353
1354 static int com_ls(void)
1355 {
1356 int i;
1357 struct snapshot_list sl;
1358 struct snapshot *s;
1359
1360 dss_get_snapshot_list(&sl);
1361 FOR_EACH_SNAPSHOT(s, i, &sl) {
1362 int64_t d = 0;
1363 if (s->flags & SS_COMPLETE)
1364 d = (s->completion_time - s->creation_time) / 60;
1365 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1366 };
1367 free_snapshot_list(&sl);
1368 return 1;
1369 }
1370
1371 static int setup_signal_handling(void)
1372 {
1373 int ret;
1374
1375 DSS_INFO_LOG("setting up signal handlers\n");
1376 signal_pipe = signal_init(); /* always successful */
1377 ret = install_sighandler(SIGINT);
1378 if (ret < 0)
1379 return ret;
1380 ret = install_sighandler(SIGTERM);
1381 if (ret < 0)
1382 return ret;
1383 return install_sighandler(SIGCHLD);
1384 }
1385
1386 /**
1387 * The main function of dss.
1388 *
1389 * \param argc Usual argument count.
1390 * \param argv Usual argument vector.
1391 */
1392 int main(int argc, char **argv)
1393 {
1394 int ret;
1395 struct cmdline_parser_params params;
1396
1397 params.override = 0;
1398 params.initialize = 1;
1399 params.check_required = 0;
1400 params.check_ambiguity = 0;
1401 params.print_errors = 1;
1402
1403 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1404 ret = parse_config_file(0);
1405 if (ret < 0)
1406 goto out;
1407 if (ret == 0) { /* no config file given */
1408 /*
1409 * Parse the command line options again, but this time check
1410 * that all required options are given.
1411 */
1412 struct cmdline_parser_params params;
1413 params.override = 1;
1414 params.initialize = 1;
1415 params.check_required = 1;
1416 params.check_ambiguity = 1;
1417 params.print_errors = 1;
1418 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1419 }
1420 if (conf.daemon_given)
1421 daemon_init();
1422 ret = change_to_dest_dir();
1423 if (ret < 0)
1424 goto out;
1425 dump_dss_config("startup");
1426 ret = setup_signal_handling();
1427 if (ret < 0)
1428 goto out;
1429 ret = call_command_handler();
1430 out:
1431 if (ret < 0)
1432 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1433 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1434 }