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 gettimeofday(&now, NULL);
181 tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */
182 diff.tv_sec = s->completion_time;
184 tv_add(&diff, &tmp, &next_snapshot_time);
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)
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 (interval = %i)\n", s->name, s->interval);
206 ret = dss_exec(&rm_pid, argv[0], argv, fds);
213 * return: 0: no redundant snapshots, 1: rm process started, negative: error
215 static int remove_redundant_snapshot(struct snapshot_list *sl)
217 int ret, i, interval;
219 unsigned missing = 0;
221 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
222 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
223 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
224 unsigned num = sl->interval_count[interval];
225 struct snapshot *victim = NULL, *prev = NULL;
226 int64_t score = LONG_MAX;
229 missing += keep - num;
230 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
231 // interval, keep, num, missing);
232 if (keep + missing >= num)
234 /* redundant snapshot in this interval, pick snapshot with lowest score */
235 FOR_EACH_SNAPSHOT(s, i, sl) {
238 //DSS_DEBUG_LOG("checking %s\n", s->name);
239 if (s->interval > interval) {
243 if (s->interval < interval)
251 /* check if s is a better victim */
252 this_score = s->creation_time - prev->creation_time;
253 assert(this_score >= 0);
254 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
255 if (this_score < score) {
262 if (conf.dry_run_given) {
263 dss_msg("%s would be removed (interval = %i)\n",
264 victim->name, victim->interval);
267 ret = remove_snapshot(victim);
268 return ret < 0? ret : 1;
273 static int remove_outdated_snapshot(struct snapshot_list *sl)
278 DSS_DEBUG_LOG("looking for snapshots belonging to intervals greater than %d\n",
279 conf.num_intervals_arg);
280 FOR_EACH_SNAPSHOT(s, i, sl) {
281 if (s->interval <= conf.num_intervals_arg)
283 if (conf.dry_run_given) {
284 dss_msg("%s would be removed (interval = %i)\n",
285 s->name, s->interval);
288 ret = remove_snapshot(s);
296 static int remove_oldest_snapshot(struct snapshot_list *sl)
298 struct snapshot *s = get_oldest_snapshot(sl);
300 if (!s) /* no snapshot found */
302 DSS_INFO_LOG("oldest snapshot: %s\n", s->name);
303 if (s->creation_time == current_snapshot_creation_time)
304 return 0; /* do not remove the snapshot currently being created */
305 return remove_snapshot(s);
308 static int rename_incomplete_snapshot(int64_t start)
313 free(path_to_last_complete_snapshot);
314 ret = complete_name(start, get_current_time(),
315 &path_to_last_complete_snapshot);
318 old_name = incomplete_name(start);
319 ret = dss_rename(old_name, path_to_last_complete_snapshot);
321 DSS_NOTICE_LOG("%s -> %s\n", old_name,
322 path_to_last_complete_snapshot);
327 static int try_to_free_disk_space(int low_disk_space)
330 struct snapshot_list sl;
332 if (!low_disk_space && conf.keep_redundant_given)
334 dss_get_snapshot_list(&sl);
335 ret = remove_outdated_snapshot(&sl);
336 if (ret) /* error, or we are removing something */
338 /* no outdated snapshot */
339 ret = remove_redundant_snapshot(&sl);
345 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
346 ret = remove_oldest_snapshot(&sl);
349 DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n");
350 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
352 free_snapshot_list(&sl);
356 static int pre_create_hook(void)
358 int ret, fds[3] = {0, 0, 0};
360 if (!conf.pre_create_hook_given) {
361 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
364 DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg);
365 ret = dss_exec_cmdline_pid(&pre_create_hook_pid,
366 conf.pre_create_hook_arg, fds);
369 snapshot_creation_status = SCS_PRE_HOOK_RUNNING;
373 static int post_create_hook(void)
375 int ret, fds[3] = {0, 0, 0};
378 if (!conf.post_create_hook_given) {
379 snapshot_creation_status = SCS_READY;
380 compute_next_snapshot_time();
383 cmd = make_message("%s %s", conf.post_create_hook_arg,
384 path_to_last_complete_snapshot);
385 DSS_NOTICE_LOG("executing %s\n", cmd);
386 ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds);
390 snapshot_creation_status = SCS_POST_HOOK_RUNNING;
394 static void kill_process(pid_t pid)
398 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
402 static void stop_rsync_process(void)
404 if (!rsync_pid || rsync_stopped)
406 kill(SIGSTOP, rsync_pid);
410 static void restart_rsync_process(void)
412 if (!rsync_pid || !rsync_stopped)
414 kill (SIGCONT, rsync_pid);
420 * Print a log message about the exit status of a child.
422 static void log_termination_msg(pid_t pid, int status)
424 if (WIFEXITED(status))
425 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
426 WEXITSTATUS(status));
427 else if (WIFSIGNALED(status))
428 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
431 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
434 static int wait_for_process(pid_t pid, int *status)
438 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
443 FD_SET(signal_pipe, &rfds);
444 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
450 if (ret == SIGCHLD) {
451 ret = waitpid(pid, status, 0);
454 if (errno != EINTR) { /* error */
455 ret = -ERRNO_TO_DSS_ERROR(errno);
459 /* SIGINT or SIGTERM */
460 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
464 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
466 log_termination_msg(pid, *status);
470 static int handle_rm_exit(int status)
473 if (!WIFEXITED(status))
474 return -E_INVOLUNTARY_EXIT;
475 if (WEXITSTATUS(status))
476 return -E_BAD_EXIT_CODE;
480 static int wait_for_rm_process(void)
482 int status, ret = wait_for_process(rm_pid, &status);
486 return handle_rm_exit(status);
489 static int handle_rsync_exit(int status)
493 if (!WIFEXITED(status)) {
494 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid);
495 ret = -E_INVOLUNTARY_EXIT;
496 snapshot_creation_status = SCS_READY;
497 compute_next_snapshot_time();
500 es = WEXITSTATUS(status);
501 if (es != 0 && es != 23 && es != 24) {
502 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es);
503 ret = -E_BAD_EXIT_CODE;
504 snapshot_creation_status = SCS_READY;
505 compute_next_snapshot_time();
508 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
511 snapshot_creation_status = SCS_RSYNC_SUCCESS;
518 static int handle_pre_create_hook_exit(int status)
522 if (!WIFEXITED(status)) {
523 snapshot_creation_status = SCS_READY;
524 compute_next_snapshot_time();
525 ret = -E_INVOLUNTARY_EXIT;
528 es = WEXITSTATUS(status);
530 snapshot_creation_status = SCS_READY;
531 compute_next_snapshot_time();
532 ret = -E_BAD_EXIT_CODE;
535 snapshot_creation_status = SCS_PRE_HOOK_SUCCESS;
538 pre_create_hook_pid = 0;
542 static int handle_sigchld(void)
545 int status, ret = reap_child(&pid, &status);
549 if (pid == rsync_pid)
550 return handle_rsync_exit(status);
552 return handle_rm_exit(status);
553 if (pid == pre_create_hook_pid)
554 return handle_pre_create_hook_exit(status);
555 if (pid == post_create_hook_pid) {
556 snapshot_creation_status = SCS_READY;
557 compute_next_snapshot_time();
560 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
564 static int check_config(void)
566 if (conf.unit_interval_arg <= 0) {
567 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
568 return -E_INVALID_NUMBER;
570 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
571 if (conf.num_intervals_arg <= 0) {
572 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
573 return -E_INVALID_NUMBER;
575 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
579 static int parse_config_file(int override)
584 char *old_logfile_arg = NULL;
585 int old_daemon_given = 0;
587 if (conf.config_file_given)
588 config_file = dss_strdup(conf.config_file_arg);
590 char *home = get_homedir();
591 config_file = make_message("%s/.dssrc", home);
594 if (override) { /* SIGHUP */
595 if (conf.logfile_given)
596 old_logfile_arg = dss_strdup(conf.logfile_arg);
597 old_daemon_given = conf.daemon_given;
600 ret = stat(config_file, &statbuf);
601 if (ret && conf.config_file_given) {
602 ret = -ERRNO_TO_DSS_ERROR(errno);
603 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
607 struct cmdline_parser_params params = {
608 .override = override,
611 .check_ambiguity = 0,
614 cmdline_parser_config_file(config_file, &conf, ¶ms);
616 ret = check_config();
620 /* don't change daemon mode on SIGHUP */
621 conf.daemon_given = old_daemon_given;
624 if (conf.logfile_given)
625 free(old_logfile_arg);
626 else if (conf.daemon_given) { /* re-use old logfile */
627 conf.logfile_arg = old_logfile_arg;
628 conf.logfile_given = 1;
631 if (conf.logfile_given) {
632 logfile = open_log(conf.logfile_arg);
633 log_welcome(conf.loglevel_arg);
635 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
636 // cmdline_parser_dump(logfile? logfile : stdout, &conf);
640 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
644 static int change_to_dest_dir(void)
646 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
647 return dss_chdir(conf.dest_dir_arg);
650 static int handle_sighup(void)
654 DSS_NOTICE_LOG("SIGHUP\n");
655 ret = parse_config_file(1);
658 return change_to_dest_dir();
661 static int handle_signal(void)
663 int sig, ret = next_signal();
671 restart_rsync_process();
672 kill_process(rsync_pid);
673 kill_process(rm_pid);
677 ret = handle_sighup();
680 ret = handle_sigchld();
685 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
689 static void create_rsync_argv(char ***argv, int64_t *num)
691 char *logname, *newest;
693 struct snapshot_list sl;
695 dss_get_snapshot_list(&sl);
696 newest = name_of_newest_complete_snapshot(&sl);
697 free_snapshot_list(&sl);
699 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
700 (*argv)[i++] = dss_strdup("rsync");
701 (*argv)[i++] = dss_strdup("-aq");
702 (*argv)[i++] = dss_strdup("--delete");
703 for (j = 0; j < conf.rsync_option_given; j++)
704 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
706 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
707 (*argv)[i++] = make_message("--link-dest=../%s", newest);
710 DSS_INFO_LOG("no previous snapshot found\n");
711 logname = dss_logname();
712 if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
713 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
715 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
716 conf.remote_user_arg : logname,
717 conf.remote_host_arg, conf.source_dir_arg);
719 *num = get_current_time();
720 (*argv)[i++] = incomplete_name(*num);
722 for (j = 0; j < i; j++)
723 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
726 static void free_rsync_argv(char **argv)
729 for (i = 0; argv[i]; i++)
734 static int create_snapshot(char **argv)
736 int ret, fds[3] = {0, 0, 0};
739 name = incomplete_name(current_snapshot_creation_time);
740 DSS_NOTICE_LOG("creating new snapshot %s\n", name);
742 ret = dss_exec(&rsync_pid, argv[0], argv, fds);
745 snapshot_creation_status = SCS_RSYNC_RUNNING;
749 static int select_loop(void)
752 /* check every 60 seconds for free disk space */
759 struct timeval now, *tvp;
762 tvp = NULL; /* sleep until rm process dies */
763 else { /* sleep one minute */
769 FD_SET(signal_pipe, &rfds);
770 DSS_DEBUG_LOG("tvp: %p, tv_sec : %lu\n", tvp, (long unsigned) tv.tv_sec);
771 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
774 if (FD_ISSET(signal_pipe, &rfds)) {
775 ret = handle_signal();
781 ret = disk_space_low();
784 low_disk_space = ret;
785 ret = try_to_free_disk_space(low_disk_space);
789 stop_rsync_process();
792 restart_rsync_process();
793 gettimeofday(&now, NULL);
794 if (tv_diff(&next_snapshot_time, &now, NULL) > 0)
796 switch (snapshot_creation_status) {
798 ret = pre_create_hook();
802 case SCS_PRE_HOOK_RUNNING:
804 case SCS_PRE_HOOK_SUCCESS:
805 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
806 ret = create_snapshot(rsync_argv);
807 free_rsync_argv(rsync_argv);
811 case SCS_RSYNC_RUNNING:
813 case SCS_RSYNC_SUCCESS:
814 ret = post_create_hook();
818 case SCS_POST_HOOK_RUNNING:
826 static void exit_hook(int exit_code)
828 int fds[3] = {0, 0, 0};
832 if (!conf.exit_hook_given)
834 cmd = make_message("%s %s", conf.exit_hook_arg,
835 dss_strerror(-exit_code));
836 DSS_NOTICE_LOG("executing %s\n", cmd);
837 dss_exec_cmdline_pid(&pid, cmd, fds);
841 static int com_run(void)
845 if (conf.dry_run_given) {
846 DSS_ERROR_LOG("dry_run not supported by this command\n");
849 ret = install_sighandler(SIGHUP);
852 compute_next_snapshot_time();
854 if (ret >= 0) /* impossible */
860 static int com_prune(void)
863 struct snapshot_list sl;
864 struct disk_space ds;
866 ret = get_disk_space(".", &ds);
871 dss_get_snapshot_list(&sl);
872 ret = remove_outdated_snapshot(&sl);
873 free_snapshot_list(&sl);
878 ret = wait_for_rm_process();
883 dss_get_snapshot_list(&sl);
884 ret = remove_redundant_snapshot(&sl);
885 free_snapshot_list(&sl);
890 ret = wait_for_rm_process();
899 static int com_create(void)
904 if (conf.dry_run_given) {
907 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
908 for (i = 0; rsync_argv[i]; i++) {
910 msg = make_message("%s%s%s", tmp? tmp : "",
911 tmp? " " : "", rsync_argv[i]);
914 free_rsync_argv(rsync_argv);
915 dss_msg("%s\n", msg);
919 ret = pre_create_hook();
922 if (pre_create_hook_pid) {
923 ret = wait_for_process(pre_create_hook_pid, &status);
926 ret = handle_pre_create_hook_exit(status);
930 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
931 ret = create_snapshot(rsync_argv);
934 ret = wait_for_process(rsync_pid, &status);
937 ret = handle_rsync_exit(status);
941 if (post_create_hook_pid)
942 ret = wait_for_process(post_create_hook_pid, &status);
944 free_rsync_argv(rsync_argv);
948 static int com_ls(void)
951 struct snapshot_list sl;
954 dss_get_snapshot_list(&sl);
955 FOR_EACH_SNAPSHOT(s, i, &sl)
956 dss_msg("%u\t%s\n", s->interval, s->name);
957 free_snapshot_list(&sl);
961 static int setup_signal_handling(void)
965 DSS_INFO_LOG("setting up signal handlers\n");
966 signal_pipe = signal_init(); /* always successful */
967 ret = install_sighandler(SIGINT);
970 ret = install_sighandler(SIGTERM);
973 return install_sighandler(SIGCHLD);
977 * The main function of dss.
979 * \param argc Usual argument count.
980 * \param argv Usual argument vector.
982 int main(int argc, char **argv)
985 struct cmdline_parser_params params = {
989 .check_ambiguity = 0,
993 cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */
994 ret = parse_config_file(0);
997 if (conf.daemon_given)
999 ret = change_to_dest_dir();
1002 ret = setup_signal_handling();
1005 ret = call_command_handler();
1008 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1009 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);