2 * Copyright (C) 2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
11 #include <sys/types.h>
24 #include "gcc-compat.h"
37 /** Command line and config file options. */
38 static struct gengetopt_args_info conf;
39 /** Non-NULL if we log to a file. */
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. */
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;
66 /* a litte cpp magic helps to DRY */
72 #define COMMAND(x) static int com_ ##x(void);
75 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
76 static int call_command_handler(void)
79 DSS_EMERG_LOG("BUG: did not find command handler\n");
86 * The log function of dss.
89 * \param fml Usual format string.
91 * All DSS_XXX_LOG() macros use this function.
93 __printf_2_3 void dss_log(int ll, const char* fmt,...)
101 if (ll < conf.loglevel_arg)
103 outfd = logfile? logfile : stderr;
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);
111 vfprintf(outfd, fmt, argp);
116 * Print a message either to stdout or to the log file.
118 static __printf_1_2 void dss_msg(const char* fmt,...)
120 FILE *outfd = conf.daemon_given? logfile : stdout;
123 vfprintf(outfd, fmt, argp);
127 static int disk_space_low(void)
129 struct disk_space ds;
130 int ret = get_disk_space(".", &ds);
134 if (conf.min_free_mb_arg)
135 if (ds.free_mb < conf.min_free_mb_arg)
137 if (conf.min_free_percent_arg)
138 if (ds.percent_free < conf.min_free_percent_arg)
140 if (conf.min_free_percent_inodes_arg)
141 if (ds.percent_free_inodes < conf.min_free_percent_inodes_arg)
146 static void dss_get_snapshot_list(struct snapshot_list *sl)
148 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
151 static void compute_next_snapshot_time(void)
153 struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
156 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
157 num_complete_snapshots = 0;
159 struct snapshot *s = NULL;
160 struct snapshot_list sl;
162 assert(snapshot_creation_status == SCS_READY);
163 current_snapshot_creation_time = 0;
164 dss_get_snapshot_list(&sl);
165 FOR_EACH_SNAPSHOT(s, i, &sl) {
166 if (!(s->flags & SS_COMPLETE))
168 num_complete_snapshots++;
169 x += s->completion_time - s->creation_time;
172 if (num_complete_snapshots)
173 x /= num_complete_snapshots; /* avg time to create one snapshot */
174 x *= wanted; /* time to create all snapshots in interval 0 */
177 ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */
178 if (ret < 0 || !s) /* unit_interval < tmp or no snapshot */
180 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
181 diff.tv_sec = s->completion_time; /* completion time of the the latest snaphot */
183 tv_add(&diff, &tmp, &next_snapshot_time);
184 gettimeofday(&now, NULL);
185 if (tv_diff(&now, &next_snapshot_time, NULL) < 0)
188 next_snapshot_time = now;
189 next_snapshot_time.tv_sec += 60;
191 free_snapshot_list(&sl);
195 static int remove_snapshot(struct snapshot *s, char *why)
197 int fds[3] = {0, 0, 0};
199 char *new_name = being_deleted_name(s);
200 int ret = dss_rename(s->name, new_name);
201 char *argv[] = {"rm", "-rf", new_name, NULL};
205 DSS_NOTICE_LOG("removing %s snapshot %s (interval = %i)\n",
206 why, s->name, s->interval);
207 ret = dss_exec(&rm_pid, argv[0], argv, fds);
213 static int snapshot_is_being_created(struct snapshot *s)
215 return s->creation_time == current_snapshot_creation_time;
219 * return: 0: no redundant snapshots, 1: rm process started, negative: error
221 static int remove_redundant_snapshot(struct snapshot_list *sl)
223 int ret, i, interval;
225 unsigned missing = 0;
227 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
228 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
229 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
230 unsigned num = sl->interval_count[interval];
231 struct snapshot *victim = NULL, *prev = NULL;
232 int64_t score = LONG_MAX;
235 missing += keep - num;
236 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
237 // interval, keep, num, missing);
238 if (keep + missing >= num)
240 /* redundant snapshot in this interval, pick snapshot with lowest score */
241 FOR_EACH_SNAPSHOT(s, i, sl) {
244 if (snapshot_is_being_created(s))
246 //DSS_DEBUG_LOG("checking %s\n", s->name);
247 if (s->interval > interval) {
251 if (s->interval < interval)
259 /* check if s is a better victim */
260 this_score = s->creation_time - prev->creation_time;
261 assert(this_score >= 0);
262 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
263 if (this_score < score) {
270 if (conf.dry_run_given) {
271 dss_msg("%s would be removed (interval = %i)\n",
272 victim->name, victim->interval);
275 ret = remove_snapshot(victim, "redundant");
276 return ret < 0? ret : 1;
281 static int remove_outdated_snapshot(struct snapshot_list *sl)
286 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
287 conf.num_intervals_arg);
288 FOR_EACH_SNAPSHOT(s, i, sl) {
289 if (snapshot_is_being_created(s))
291 if (s->interval <= conf.num_intervals_arg)
293 if (conf.dry_run_given) {
294 dss_msg("%s would be removed (interval = %i)\n",
295 s->name, s->interval);
298 ret = remove_snapshot(s, "outdated");
306 static int remove_oldest_snapshot(struct snapshot_list *sl)
308 struct snapshot *s = get_oldest_snapshot(sl);
310 if (!s) /* no snapshot found */
312 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
313 if (snapshot_is_being_created(s))
315 return remove_snapshot(s, "oldest");
318 static int rename_incomplete_snapshot(int64_t start)
323 free(path_to_last_complete_snapshot);
324 ret = complete_name(start, get_current_time(),
325 &path_to_last_complete_snapshot);
328 old_name = incomplete_name(start);
329 ret = dss_rename(old_name, path_to_last_complete_snapshot);
331 DSS_NOTICE_LOG("%s -> %s\n", old_name,
332 path_to_last_complete_snapshot);
337 static int try_to_free_disk_space(int low_disk_space)
340 struct snapshot_list sl;
342 if (!low_disk_space && conf.keep_redundant_given)
344 dss_get_snapshot_list(&sl);
345 ret = remove_outdated_snapshot(&sl);
346 if (ret) /* error, or we are removing something */
348 /* no outdated snapshot */
349 ret = remove_redundant_snapshot(&sl);
355 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
356 ret = remove_oldest_snapshot(&sl);
359 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
360 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
362 free_snapshot_list(&sl);
366 static int pre_create_hook(void)
368 int ret, fds[3] = {0, 0, 0};
370 if (!conf.pre_create_hook_given) {
371 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
374 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
375 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
376 conf.pre_create_hook_arg, fds);
379 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
383 static int post_create_hook(void)
385 int ret, fds[3] = {0, 0, 0};
388 if (!conf.post_create_hook_given) {
389 snapshot_creation_status = SCS_READY;
390 compute_next_snapshot_time();
393 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
394 conf.dest_dir_arg, path_to_last_complete_snapshot);
395 DSS_NOTICE_LOG("executing %s\n", cmd);
396 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
400 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
404 static void kill_process(pid_t pid)
408 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
412 static void stop_rsync_process(void)
414 if (!rsync_pid || rsync_stopped)
416 kill(SIGSTOP, rsync_pid);
420 static void restart_rsync_process(void)
422 if (!rsync_pid || !rsync_stopped)
424 kill (SIGCONT, rsync_pid);
430 * Print a log message about the exit status of a child.
432 static void log_termination_msg(pid_t pid, int status)
434 if (WIFEXITED(status))
435 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
436 WEXITSTATUS(status));
437 else if (WIFSIGNALED(status))
438 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
441 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
444 static int wait_for_process(pid_t pid, int *status)
448 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
453 FD_SET(signal_pipe, &rfds);
454 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
460 if (ret == SIGCHLD) {
461 ret = waitpid(pid, status, 0);
464 if (errno != EINTR) { /* error */
465 ret = -ERRNO_TO_DSS_ERROR(errno);
469 /* SIGINT or SIGTERM */
470 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
474 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
476 log_termination_msg(pid, *status);
480 static int handle_rm_exit(int status)
483 if (!WIFEXITED(status))
484 return -E_INVOLUNTARY_EXIT;
485 if (WEXITSTATUS(status))
486 return -E_BAD_EXIT_CODE;
490 static int wait_for_rm_process(void)
492 int status, ret = wait_for_process(rm_pid, &status);
496 return handle_rm_exit(status);
499 static int handle_rsync_exit(int status)
503 if (!WIFEXITED(status)) {
504 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
505 ret = -E_INVOLUNTARY_EXIT;
506 snapshot_creation_status = SCS_READY;
507 compute_next_snapshot_time();
510 es = WEXITSTATUS(status);
511 if (es == 13) { /* Errors with program diagnostics */
512 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
514 snapshot_creation_status = SCS_RSYNC_NEEDS_RESTART;
515 gettimeofday(&next_snapshot_time, NULL);
516 next_snapshot_time.tv_sec += 60;
520 if (es != 0 && es != 23 && es != 24) {
521 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
522 ret = -E_BAD_EXIT_CODE;
523 snapshot_creation_status = SCS_READY;
524 compute_next_snapshot_time();
527 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
530 snapshot_creation_status = SCS_RSYNC_SUCCESS;
537 static int handle_pre_create_hook_exit(int status)
541 if (!WIFEXITED(status)) {
542 snapshot_creation_status = SCS_READY;
543 compute_next_snapshot_time();
544 ret = -E_INVOLUNTARY_EXIT;
547 es = WEXITSTATUS(status);
549 snapshot_creation_status = SCS_READY;
550 compute_next_snapshot_time();
551 ret = -E_BAD_EXIT_CODE;
554 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
557 pre_create_hook_pid = 0;
561 static int handle_sigchld(void)
564 int status, ret = reap_child(&pid, &status);
568 if (pid == rsync_pid)
569 return handle_rsync_exit(status);
571 return handle_rm_exit(status);
572 if (pid == pre_create_hook_pid)
573 return handle_pre_create_hook_exit(status);
574 if (pid == post_create_hook_pid) {
575 snapshot_creation_status = SCS_READY;
576 compute_next_snapshot_time();
579 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
583 static int check_config(void)
585 if (conf.unit_interval_arg <= 0) {
586 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
587 return -E_INVALID_NUMBER;
589 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
590 if (conf.num_intervals_arg <= 0) {
591 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
592 return -E_INVALID_NUMBER;
594 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
598 static int parse_config_file(int override)
603 char *old_logfile_arg = NULL;
604 int old_daemon_given = 0;
606 if (conf.config_file_given)
607 config_file = dss_strdup(conf.config_file_arg);
609 char *home = get_homedir();
610 config_file = make_message("%s/.dssrc", home);
613 if (override) { /* SIGHUP */
614 if (conf.logfile_given)
615 old_logfile_arg = dss_strdup(conf.logfile_arg);
616 old_daemon_given = conf.daemon_given;
619 ret = stat(config_file, &statbuf);
620 if (ret && conf.config_file_given) {
621 ret = -ERRNO_TO_DSS_ERROR(errno);
622 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
626 struct cmdline_parser_params params = {
627 .override = override,
630 .check_ambiguity = 0,
633 if (override) { /* invalidate all rsync options */
636 for (i = 0; i < conf.rsync_option_given; i++) {
637 free(conf.rsync_option_arg[i]);
638 conf.rsync_option_arg[i] = NULL;
640 conf.rsync_option_given = 0;
642 cmdline_parser_config_file(config_file, &conf, ¶ms);
644 ret = check_config();
648 /* don't change daemon mode on SIGHUP */
649 conf.daemon_given = old_daemon_given;
652 if (conf.logfile_given)
653 free(old_logfile_arg);
654 else if (conf.daemon_given) { /* re-use old logfile */
655 conf.logfile_arg = old_logfile_arg;
656 conf.logfile_given = 1;
659 if (conf.logfile_given) {
660 logfile = open_log(conf.logfile_arg);
661 log_welcome(conf.loglevel_arg);
663 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
664 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
668 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
672 static int change_to_dest_dir(void)
674 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
675 return dss_chdir(conf.dest_dir_arg);
678 static int handle_sighup(void)
682 DSS_NOTICE_LOG("SIGHUP\n");
683 ret = parse_config_file(1);
686 return change_to_dest_dir();
689 static int handle_signal(void)
691 int sig, ret = next_signal();
699 restart_rsync_process();
700 kill_process(rsync_pid);
701 kill_process(rm_pid);
705 ret = handle_sighup();
708 ret = handle_sigchld();
713 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
718 * We can not use rsync locally if the local user is different from the remote
719 * user or if the src dir is not on the local host (or both).
721 static int use_rsync_locally(char *logname)
723 char *h = conf.remote_host_arg;
725 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
727 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
732 static void create_rsync_argv(char ***argv, int64_t *num)
734 char *logname, *newest;
736 struct snapshot_list sl;
738 dss_get_snapshot_list(&sl);
739 newest = name_of_newest_complete_snapshot(&sl);
740 free_snapshot_list(&sl);
742 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
743 (*argv)[i++] = dss_strdup("rsync");
744 (*argv)[i++] = dss_strdup("-aq");
745 (*argv)[i++] = dss_strdup("--delete");
746 for (j = 0; j < conf.rsync_option_given; j++)
747 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
749 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
750 (*argv)[i++] = make_message("--link-dest=../%s", newest);
753 DSS_INFO_LOG("no previous snapshot found\n");
754 logname = dss_logname();
755 if (use_rsync_locally(logname))
756 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
758 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
759 conf.remote_user_arg : logname,
760 conf.remote_host_arg, conf.source_dir_arg);
762 *num = get_current_time();
763 (*argv)[i++] = incomplete_name(*num);
765 for (j = 0; j < i; j++)
766 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
769 static void free_rsync_argv(char **argv)
775 for (i = 0; argv[i]; i++)
780 static int create_snapshot(char **argv)
782 int ret, fds[3] = {0, 0, 0};
785 name = incomplete_name(current_snapshot_creation_time);
786 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
788 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
791 snapshot_creation_status = SCS_RSYNC_RUNNING;
795 static int select_loop(void)
798 /* check every 60 seconds for free disk space */
800 char **rsync_argv = NULL;
805 struct timeval now, *tvp;
808 tvp = NULL; /* sleep until rm process dies */
809 else { /* sleep one minute */
815 FD_SET(signal_pipe, &rfds);
816 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
817 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
820 if (FD_ISSET(signal_pipe, &rfds)) {
821 ret = handle_signal();
827 ret = disk_space_low();
830 low_disk_space = ret;
831 ret = try_to_free_disk_space(low_disk_space);
835 stop_rsync_process();
838 restart_rsync_process();
839 gettimeofday(&now, NULL);
840 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
842 switch (snapshot_creation_status) {
844 ret = pre_create_hook();
848 case SCS_PRE_HOOK_RUNNING:
850 case SCS_RSYNC_NEEDS_RESTART:
851 ret = create_snapshot(rsync_argv);
855 case SCS_PRE_HOOK_SUCCESS:
856 free_rsync_argv(rsync_argv);
857 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
858 ret = create_snapshot(rsync_argv);
862 case SCS_RSYNC_RUNNING:
864 case SCS_RSYNC_SUCCESS:
865 ret = post_create_hook();
869 case SCS_POST_HOOK_RUNNING:
877 static void exit_hook(int exit_code)
879 int fds[3] = {0, 0, 0};
880 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
883 if (!conf.exit_hook_given)
885 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
886 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
889 static int com_run(void)
893 if (conf.dry_run_given) {
894 DSS_ERROR_LOG("dry_run not supported by this command\n");
897 ret = install_sighandler(SIGHUP);
900 compute_next_snapshot_time();
902 if (ret >= 0) /* impossible */
908 static int com_prune(void)
911 struct snapshot_list sl;
912 struct disk_space ds;
914 ret = get_disk_space(".", &ds);
919 dss_get_snapshot_list(&sl);
920 ret = remove_outdated_snapshot(&sl);
921 free_snapshot_list(&sl);
926 ret = wait_for_rm_process();
931 dss_get_snapshot_list(&sl);
932 ret = remove_redundant_snapshot(&sl);
933 free_snapshot_list(&sl);
938 ret = wait_for_rm_process();
947 static int com_create(void)
952 if (conf.dry_run_given) {
955 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
956 for (i = 0; rsync_argv[i]; i++) {
958 msg = make_message("%s%s%s", tmp? tmp : "",
959 tmp? " " : "", rsync_argv[i]);
962 free_rsync_argv(rsync_argv);
963 dss_msg("%s\n", msg);
967 ret = pre_create_hook();
970 if (pre_create_hook_pid) {
971 ret = wait_for_process(pre_create_hook_pid, &status);
974 ret = handle_pre_create_hook_exit(status);
978 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
979 ret = create_snapshot(rsync_argv);
982 ret = wait_for_process(rsync_pid, &status);
985 ret = handle_rsync_exit(status);
989 if (post_create_hook_pid)
990 ret = wait_for_process(post_create_hook_pid, &status);
992 free_rsync_argv(rsync_argv);
996 static int com_ls(void)
999 struct snapshot_list sl;
1002 dss_get_snapshot_list(&sl);
1003 FOR_EACH_SNAPSHOT(s, i, &sl) {
1005 if (s->flags & SS_COMPLETE)
1006 d = (s->completion_time - s->creation_time) / 60;
1007 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1009 free_snapshot_list(&sl);
1013 static int setup_signal_handling(void)
1017 DSS_INFO_LOG("setting up signal handlers\n");
1018 signal_pipe = signal_init(); /* always successful */
1019 ret = install_sighandler(SIGINT);
1022 ret = install_sighandler(SIGTERM);
1025 return install_sighandler(SIGCHLD);
1029 * The main function of dss.
1031 * \param argc Usual argument count.
1032 * \param argv Usual argument vector.
1034 int main(int argc, char **argv)
1037 struct cmdline_parser_params params = {
1040 .check_required = 0,
1041 .check_ambiguity = 0,
1045 cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */
1046 ret = parse_config_file(0);
1049 if (conf.daemon_given)
1051 ret = change_to_dest_dir();
1054 ret = setup_signal_handling();
1057 ret = call_command_handler();
1060 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1061 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);