2 * Copyright (C) 2008-2010 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 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;
67 static const char const *hook_status_description[] = {HOOK_STATUS_ARRAY};
69 /* may be called with ds == NULL. */
70 static int disk_space_low(struct disk_space *ds)
72 struct disk_space ds_struct;
75 int ret = get_disk_space(".", &ds_struct);
80 if (conf.min_free_mb_arg)
81 if (ds->free_mb < conf.min_free_mb_arg)
83 if (conf.min_free_percent_arg)
84 if (ds->percent_free < conf.min_free_percent_arg)
86 if (conf.min_free_percent_inodes_arg)
87 if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
92 static void dump_dss_config(const char *msg)
94 const char dash[] = "-----------------------------";
96 FILE *log = logfile? logfile : stderr;
98 int64_t now = get_current_time();
100 if (conf.loglevel_arg > INFO)
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);
107 DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
111 DSS_ERROR_LOG("can not get free disk space: %s\n",
114 /* we continue on errors from get_disk_space */
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");
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"
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]
141 "create_pid: %" PRId32 "\n"
142 "create process is %sstopped\n"
145 create_process_stopped? "" : "not "
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
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
165 fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
168 /* a litte cpp magic helps to DRY */
174 #define COMMAND(x) static int com_ ##x(void);
177 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
178 static int call_command_handler(void)
181 DSS_EMERG_LOG("BUG: did not find command handler\n");
188 * The log function of dss.
190 * \param ll Loglevel.
191 * \param fml Usual format string.
193 * All DSS_XXX_LOG() macros use this function.
195 __printf_2_3 void dss_log(int ll, const char* fmt,...)
203 if (ll < conf.loglevel_arg)
205 outfd = logfile? logfile : stderr;
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);
213 vfprintf(outfd, fmt, argp);
218 * Print a message either to stdout or to the log file.
220 static __printf_1_2 void dss_msg(const char* fmt,...)
222 FILE *outfd = conf.daemon_given? logfile : stdout;
225 vfprintf(outfd, fmt, argp);
229 static char *get_config_file_name(void)
231 char *home, *config_file;
233 if (conf.config_file_given)
234 return dss_strdup(conf.config_file_arg);
235 home = get_homedir();
236 config_file = make_message("%s/.dssrc", home);
241 static void dss_get_snapshot_list(struct snapshot_list *sl)
243 get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
246 static int64_t compute_next_snapshot_time(void)
248 int64_t x = 0, now = get_current_time(), unit_interval
249 = 24 * 3600 * conf.unit_interval_arg, ret;
250 unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
251 num_complete_snapshots = 0;
253 struct snapshot *s = NULL;
254 struct snapshot_list sl;
256 dss_get_snapshot_list(&sl);
257 FOR_EACH_SNAPSHOT(s, i, &sl) {
258 if (!(s->flags & SS_COMPLETE))
260 num_complete_snapshots++;
261 x += s->completion_time - s->creation_time;
266 if (num_complete_snapshots == 0)
268 x /= num_complete_snapshots; /* avg time to create one snapshot */
269 if (unit_interval < x * wanted) /* oops, no sleep at all */
271 ret = s->completion_time + unit_interval / wanted - x;
273 free_snapshot_list(&sl);
277 static inline void invalidate_next_snapshot_time(void)
279 next_snapshot_time = 0;
282 static inline int next_snapshot_time_is_valid(void)
284 return next_snapshot_time != 0;
287 static int next_snapshot_is_due(void)
289 int64_t now = get_current_time();
291 if (!next_snapshot_time_is_valid())
292 next_snapshot_time = compute_next_snapshot_time();
293 if (next_snapshot_time <= now) {
294 DSS_DEBUG_LOG("next snapshot: now\n");
297 DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
298 next_snapshot_time - now);
302 static int pre_create_hook(void)
304 int ret, fds[3] = {0, 0, 0};
306 assert(snapshot_creation_status == HS_READY);
307 /* make sure that the next snapshot time will be recomputed */
308 invalidate_next_snapshot_time();
309 DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
310 ret = dss_exec_cmdline_pid(&create_pid,
311 conf.pre_create_hook_arg, fds);
314 snapshot_creation_status = HS_PRE_RUNNING;
318 static int pre_remove_hook(struct snapshot *s, const char *why)
320 int ret, fds[3] = {0, 0, 0};
325 DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
326 assert(snapshot_removal_status == HS_READY);
327 assert(remove_pid == 0);
328 assert(!snapshot_currently_being_removed);
330 snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
331 *snapshot_currently_being_removed = *s;
332 snapshot_currently_being_removed->name = dss_strdup(s->name);
334 cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
335 conf.dest_dir_arg, s->name);
336 DSS_DEBUG_LOG("executing %s\n", cmd);
337 ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
341 snapshot_removal_status = HS_PRE_RUNNING;
345 static int exec_rm(void)
347 struct snapshot *s = snapshot_currently_being_removed;
348 int fds[3] = {0, 0, 0};
349 char *new_name = being_deleted_name(s);
350 char *argv[] = {"rm", "-rf", new_name, NULL};
353 assert(snapshot_removal_status == HS_PRE_SUCCESS);
354 assert(remove_pid == 0);
356 DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
357 ret = dss_rename(s->name, new_name);
360 ret = dss_exec(&remove_pid, argv[0], argv, fds);
363 snapshot_removal_status = HS_RUNNING;
369 static int snapshot_is_being_created(struct snapshot *s)
371 return s->creation_time == current_snapshot_creation_time;
374 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
379 DSS_DEBUG_LOG("looking for orphaned snapshots\n");
380 FOR_EACH_SNAPSHOT(s, i, sl) {
381 if (snapshot_is_being_created(s))
384 * We know that no rm is currently running, so if s is marked
385 * as being deleted, a previously started rm must have failed.
387 if (s->flags & SS_BEING_DELETED)
390 if (s->flags & SS_COMPLETE) /* good snapshot */
393 * This snapshot is incomplete and it is not the snapshot
394 * currently being created. However, we must not remove it if
395 * rsync is about to be restarted. As only the newest snapshot
396 * can be restarted, this snapshot is orphaned if it is not the
397 * newest snapshot or if we are not about to restart rsync.
399 if (get_newest_snapshot(sl) != s)
401 if (snapshot_creation_status != HS_NEEDS_RESTART)
404 /* no orphaned snapshots */
408 static int is_reference_snapshot(struct snapshot *s)
410 if (!name_of_reference_snapshot)
412 return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
416 * return: 0: no redundant snapshots, 1: rm process started, negative: error
418 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
422 unsigned missing = 0;
424 DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
425 for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
426 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
427 unsigned num = sl->interval_count[interval];
428 struct snapshot *victim = NULL, *prev = NULL;
429 int64_t score = LONG_MAX;
432 missing += keep - num;
433 // DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
434 // interval, keep, num, missing);
435 if (keep + missing >= num)
437 /* redundant snapshot in this interval, pick snapshot with lowest score */
438 FOR_EACH_SNAPSHOT(s, i, sl) {
441 if (snapshot_is_being_created(s))
443 if (is_reference_snapshot(s))
445 //DSS_DEBUG_LOG("checking %s\n", s->name);
446 if (s->interval > interval) {
450 if (s->interval < interval)
458 /* check if s is a better victim */
459 this_score = s->creation_time - prev->creation_time;
460 assert(this_score >= 0);
461 //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
462 if (this_score < score) {
474 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
479 DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
480 conf.num_intervals_arg);
481 FOR_EACH_SNAPSHOT(s, i, sl) {
482 if (snapshot_is_being_created(s))
484 if (is_reference_snapshot(s))
486 if (s->interval < conf.num_intervals_arg)
493 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
497 FOR_EACH_SNAPSHOT(s, i, sl) {
498 if (snapshot_is_being_created(s))
500 if (is_reference_snapshot(s))
502 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
508 static int rename_incomplete_snapshot(int64_t start)
513 free(path_to_last_complete_snapshot);
514 ret = complete_name(start, get_current_time(),
515 &path_to_last_complete_snapshot);
518 old_name = incomplete_name(start);
519 ret = dss_rename(old_name, path_to_last_complete_snapshot);
521 DSS_NOTICE_LOG("%s -> %s\n", old_name,
522 path_to_last_complete_snapshot);
527 static int try_to_free_disk_space(void)
530 struct snapshot_list sl;
531 struct snapshot *victim;
536 ret = disk_space_low(NULL);
539 low_disk_space = ret;
540 gettimeofday(&now, NULL);
541 if (tv_diff(&next_removal_check, &now, NULL) > 0)
543 if (!low_disk_space) {
544 if (conf.keep_redundant_given)
546 if (snapshot_creation_status != HS_READY)
548 if (next_snapshot_is_due())
551 dss_get_snapshot_list(&sl);
553 if (!low_disk_space && sl.num_snapshots <= 1)
556 victim = find_outdated_snapshot(&sl);
560 victim = find_redundant_snapshot(&sl);
563 /* try harder only if disk space is low */
567 victim = find_orphaned_snapshot(&sl);
570 DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
571 victim = find_oldest_removable_snapshot(&sl);
574 DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
575 ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
578 ret = pre_remove_hook(victim, why);
580 free_snapshot_list(&sl);
584 static int post_create_hook(void)
586 int ret, fds[3] = {0, 0, 0};
589 cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
590 conf.dest_dir_arg, path_to_last_complete_snapshot);
591 DSS_NOTICE_LOG("executing %s\n", cmd);
592 ret = dss_exec_cmdline_pid(&create_pid, cmd, fds);
596 snapshot_creation_status = HS_POST_RUNNING;
600 static int post_remove_hook(void)
602 int ret, fds[3] = {0, 0, 0};
604 struct snapshot *s = snapshot_currently_being_removed;
608 cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
609 conf.dest_dir_arg, s->name);
610 DSS_NOTICE_LOG("executing %s\n", cmd);
611 ret = dss_exec_cmdline_pid(&remove_pid, cmd, fds);
615 snapshot_removal_status = HS_POST_RUNNING;
619 static void dss_kill(pid_t pid, int sig, const char *msg)
621 const char *signame, *process_name;
626 case SIGTERM: signame = "TERM"; break;
627 case SIGSTOP: signame = "STOP"; break;
628 case SIGCONT: signame = "CONT"; break;
629 default: signame = "????";
632 if (pid == create_pid)
633 process_name = "create";
634 else if (pid == remove_pid)
635 process_name = "remove";
636 else process_name = "??????";
639 DSS_INFO_LOG("%s\n", msg);
640 DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
641 sig, signame, (int)pid, process_name);
642 if (kill(pid, sig) >= 0)
644 DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
645 sig, signame, (int)pid, process_name);
648 static void stop_create_process(void)
650 if (create_process_stopped)
652 dss_kill(create_pid, SIGSTOP, "suspending create process");
653 create_process_stopped = 1;
656 static void restart_create_process(void)
658 if (!create_process_stopped)
660 dss_kill(create_pid, SIGCONT, "resuming create process");
661 create_process_stopped = 0;
665 * Print a log message about the exit status of a child.
667 static void log_termination_msg(pid_t pid, int status)
669 if (WIFEXITED(status))
670 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
671 WEXITSTATUS(status));
672 else if (WIFSIGNALED(status))
673 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
676 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
679 static int wait_for_process(pid_t pid, int *status)
683 DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
688 FD_SET(signal_pipe, &rfds);
689 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
695 if (ret == SIGCHLD) {
696 ret = waitpid(pid, status, 0);
699 if (errno != EINTR) { /* error */
700 ret = -ERRNO_TO_DSS_ERROR(errno);
704 /* SIGINT or SIGTERM */
705 dss_kill(pid, SIGTERM, "killing child process");
708 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
710 log_termination_msg(pid, *status);
714 static void handle_pre_remove_exit(int status)
716 if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
717 snapshot_removal_status = HS_READY;
718 gettimeofday(&next_removal_check, NULL);
719 next_removal_check.tv_sec += 60;
722 snapshot_removal_status = HS_PRE_SUCCESS;
725 static int handle_rm_exit(int status)
727 if (!WIFEXITED(status)) {
728 snapshot_removal_status = HS_READY;
729 return -E_INVOLUNTARY_EXIT;
731 if (WEXITSTATUS(status)) {
732 snapshot_removal_status = HS_READY;
733 return -E_BAD_EXIT_CODE;
735 snapshot_removal_status = HS_SUCCESS;
739 static void handle_post_remove_exit(void)
741 snapshot_removal_status = HS_READY;
744 static int handle_remove_exit(int status)
747 struct snapshot *s = snapshot_currently_being_removed;
750 switch (snapshot_removal_status) {
752 handle_pre_remove_exit(status);
756 ret = handle_rm_exit(status);
758 case HS_POST_RUNNING:
759 handle_post_remove_exit();
765 if (snapshot_removal_status == HS_READY) {
768 snapshot_currently_being_removed = NULL;
774 static int wait_for_remove_process(void)
780 snapshot_removal_status == HS_PRE_RUNNING ||
781 snapshot_removal_status == HS_RUNNING ||
782 snapshot_removal_status == HS_POST_RUNNING
784 ret = wait_for_process(remove_pid, &status);
787 return handle_remove_exit(status);
790 static int handle_rsync_exit(int status)
794 if (!WIFEXITED(status)) {
795 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
796 ret = -E_INVOLUNTARY_EXIT;
797 snapshot_creation_status = HS_READY;
800 es = WEXITSTATUS(status);
802 * Restart rsync on non-fatal errors:
803 * 12: Error in rsync protocol data stream
804 * 13: Errors with program diagnostics
806 if (es == 12 || es == 13) {
807 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
808 (int)create_pid, es);
809 snapshot_creation_status = HS_NEEDS_RESTART;
810 next_snapshot_time = get_current_time() + 60;
814 if (es != 0 && es != 23 && es != 24) {
815 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
816 ret = -E_BAD_EXIT_CODE;
817 snapshot_creation_status = HS_READY;
820 ret = rename_incomplete_snapshot(current_snapshot_creation_time);
823 snapshot_creation_status = HS_SUCCESS;
824 free(name_of_reference_snapshot);
825 name_of_reference_snapshot = NULL;
827 create_process_stopped = 0;
831 static int handle_pre_create_hook_exit(int status)
834 static int warn_count;
836 if (!WIFEXITED(status)) {
837 snapshot_creation_status = HS_READY;
838 ret = -E_INVOLUNTARY_EXIT;
841 es = WEXITSTATUS(status);
844 DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
845 conf.pre_create_hook_arg, es);
846 DSS_NOTICE_LOG("deferring snapshot creation...\n");
847 warn_count = 60; /* warn only once per hour */
849 next_snapshot_time = get_current_time() + 60;
850 snapshot_creation_status = HS_READY;
855 snapshot_creation_status = HS_PRE_SUCCESS;
861 static int handle_sigchld(void)
864 int status, ret = reap_child(&pid, &status);
869 if (pid == create_pid) {
870 switch (snapshot_creation_status) {
872 ret = handle_pre_create_hook_exit(status);
875 ret = handle_rsync_exit(status);
877 case HS_POST_RUNNING:
878 snapshot_creation_status = HS_READY;
882 DSS_EMERG_LOG("BUG: create can't die in status %d\n",
883 snapshot_creation_status);
889 if (pid == remove_pid) {
890 ret = handle_remove_exit(status);
895 DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
899 static int check_config(void)
901 if (conf.unit_interval_arg <= 0) {
902 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
903 return -E_INVALID_NUMBER;
905 DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
906 if (conf.num_intervals_arg <= 0) {
907 DSS_ERROR_LOG("bad number of intervals %i\n", conf.num_intervals_arg);
908 return -E_INVALID_NUMBER;
910 DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
915 * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
916 * file was read successfully.
918 static int parse_config_file(int override)
920 int ret, config_file_exists;
921 char *config_file = get_config_file_name();
923 char *old_logfile_arg = NULL;
924 int old_daemon_given = 0;
926 if (override) { /* SIGHUP */
927 if (conf.logfile_given)
928 old_logfile_arg = dss_strdup(conf.logfile_arg);
929 old_daemon_given = conf.daemon_given;
932 config_file_exists = !stat(config_file, &statbuf);
933 if (!config_file_exists && conf.config_file_given) {
934 ret = -ERRNO_TO_DSS_ERROR(errno);
935 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
938 if (config_file_exists) {
939 struct cmdline_parser_params params = {
940 .override = override,
943 .check_ambiguity = 0,
946 if (override) { /* invalidate all rsync options */
949 for (i = 0; i < conf.rsync_option_given; i++) {
950 free(conf.rsync_option_arg[i]);
951 conf.rsync_option_arg[i] = NULL;
953 conf.rsync_option_given = 0;
955 cmdline_parser_config_file(config_file, &conf, ¶ms);
957 ret = check_config();
961 /* don't change daemon mode on SIGHUP */
962 conf.daemon_given = old_daemon_given;
965 if (conf.logfile_given)
966 free(old_logfile_arg);
967 else if (conf.daemon_given) { /* re-use old logfile */
968 conf.logfile_arg = old_logfile_arg;
969 conf.logfile_given = 1;
972 if (conf.logfile_given && conf.run_given && conf.daemon_given) {
973 logfile = open_log(conf.logfile_arg);
974 log_welcome(conf.loglevel_arg);
976 DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
977 ret = config_file_exists;
981 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
985 static int change_to_dest_dir(void)
987 DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
988 return dss_chdir(conf.dest_dir_arg);
991 static int handle_sighup(void)
995 DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
996 dump_dss_config("old");
997 ret = parse_config_file(1);
1000 dump_dss_config("reloaded");
1001 invalidate_next_snapshot_time();
1002 return change_to_dest_dir();
1005 static int handle_signal(void)
1007 int sig, ret = next_signal();
1015 restart_create_process();
1016 dss_kill(create_pid, SIGTERM, NULL);
1017 dss_kill(remove_pid, SIGTERM, NULL);
1021 ret = handle_sighup();
1024 ret = handle_sigchld();
1029 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1034 * We can not use rsync locally if the local user is different from the remote
1035 * user or if the src dir is not on the local host (or both).
1037 static int use_rsync_locally(char *logname)
1039 char *h = conf.remote_host_arg;
1041 if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1043 if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1048 static int rename_resume_snap(int64_t creation_time)
1050 struct snapshot_list sl = {.num_snapshots = 0};
1051 struct snapshot *s = NULL;
1052 char *new_name = incomplete_name(creation_time);
1057 if (conf.no_resume_given)
1059 dss_get_snapshot_list(&sl);
1061 * Snapshot recycling: We first look at the newest snapshot. If this
1062 * snapshot happens to be incomplete, the last rsync process was
1063 * aborted and we reuse this one. Otherwise we look at snapshots which
1064 * could be removed (outdated and redundant snapshots) as candidates
1065 * for recycling. If no outdated/redundant snapshot exists, we check if
1066 * there is an orphaned snapshot, which likely is useless anyway.
1068 * Only if no existing snapshot is suitable for recycling, we bite the
1069 * bullet and create a new one.
1071 s = get_newest_snapshot(&sl);
1072 if (!s) /* no snapshots at all */
1074 /* re-use last snapshot if it is incomplete */
1076 if ((s->flags & SS_COMPLETE) == 0)
1079 s = find_outdated_snapshot(&sl);
1083 s = find_redundant_snapshot(&sl);
1087 s = find_orphaned_snapshot(&sl);
1090 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1091 ret = dss_rename(s->name, new_name);
1094 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1096 free_snapshot_list(&sl);
1100 static void create_rsync_argv(char ***argv, int64_t *num)
1104 struct snapshot_list sl;
1106 dss_get_snapshot_list(&sl);
1107 assert(!name_of_reference_snapshot);
1108 name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1109 free_snapshot_list(&sl);
1111 *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1112 (*argv)[i++] = dss_strdup("rsync");
1113 (*argv)[i++] = dss_strdup("-aq");
1114 (*argv)[i++] = dss_strdup("--delete");
1115 for (j = 0; j < conf.rsync_option_given; j++)
1116 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1117 if (name_of_reference_snapshot) {
1118 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1119 (*argv)[i++] = make_message("--link-dest=../%s",
1120 name_of_reference_snapshot);
1122 DSS_INFO_LOG("no suitable reference snapshot found\n");
1123 logname = dss_logname();
1124 if (use_rsync_locally(logname))
1125 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1127 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1128 conf.remote_user_arg : logname,
1129 conf.remote_host_arg, conf.source_dir_arg);
1131 *num = get_current_time();
1132 (*argv)[i++] = incomplete_name(*num);
1133 (*argv)[i++] = NULL;
1134 for (j = 0; j < i; j++)
1135 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1138 static void free_rsync_argv(char **argv)
1144 for (i = 0; argv[i]; i++)
1149 static int create_snapshot(char **argv)
1151 int ret, fds[3] = {0, 0, 0};
1153 ret = rename_resume_snap(current_snapshot_creation_time);
1156 ret = dss_exec(&create_pid, argv[0], argv, fds);
1159 snapshot_creation_status = HS_RUNNING;
1163 static int select_loop(void)
1166 /* check every 60 seconds for free disk space */
1168 char **rsync_argv = NULL;
1172 struct timeval *tvp;
1175 tvp = NULL; /* sleep until rm hook/process dies */
1176 else { /* sleep one minute */
1182 FD_SET(signal_pipe, &rfds);
1183 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1186 if (FD_ISSET(signal_pipe, &rfds)) {
1187 ret = handle_signal();
1193 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1199 if (snapshot_removal_status == HS_SUCCESS) {
1200 ret = post_remove_hook();
1205 ret = try_to_free_disk_space();
1208 if (snapshot_removal_status != HS_READY) {
1209 stop_create_process();
1212 restart_create_process();
1213 switch (snapshot_creation_status) {
1215 if (!next_snapshot_is_due())
1217 ret = pre_create_hook();
1221 case HS_PRE_RUNNING:
1223 case HS_POST_RUNNING:
1225 case HS_PRE_SUCCESS:
1226 if (!name_of_reference_snapshot) {
1227 free_rsync_argv(rsync_argv);
1228 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
1230 ret = create_snapshot(rsync_argv);
1234 case HS_NEEDS_RESTART:
1235 if (!next_snapshot_is_due())
1237 ret = create_snapshot(rsync_argv);
1242 ret = post_create_hook();
1252 static void exit_hook(int exit_code)
1254 int fds[3] = {0, 0, 0};
1255 char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
1258 DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1259 dss_exec(&pid, conf.exit_hook_arg, argv, fds);
1262 static int com_run(void)
1266 if (conf.dry_run_given) {
1267 DSS_ERROR_LOG("dry_run not supported by this command\n");
1270 ret = install_sighandler(SIGHUP);
1273 ret = select_loop();
1274 if (ret >= 0) /* impossible */
1280 static int com_prune(void)
1283 struct snapshot_list sl;
1284 struct snapshot *victim;
1285 struct disk_space ds;
1288 ret = get_disk_space(".", &ds);
1291 log_disk_space(&ds);
1292 dss_get_snapshot_list(&sl);
1294 victim = find_outdated_snapshot(&sl);
1298 victim = find_redundant_snapshot(&sl);
1304 if (conf.dry_run_given) {
1305 dss_msg("%s snapshot %s (interval = %i)\n",
1306 why, victim->name, victim->interval);
1310 ret = pre_remove_hook(victim, why);
1313 if (snapshot_removal_status == HS_PRE_RUNNING) {
1314 ret = wait_for_remove_process();
1317 if (snapshot_removal_status != HS_PRE_SUCCESS)
1323 ret = wait_for_remove_process();
1326 if (snapshot_removal_status != HS_SUCCESS)
1328 ret = post_remove_hook();
1331 if (snapshot_removal_status != HS_POST_RUNNING)
1333 ret = wait_for_remove_process();
1338 free_snapshot_list(&sl);
1342 static int com_create(void)
1347 if (conf.dry_run_given) {
1350 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
1351 for (i = 0; rsync_argv[i]; i++) {
1353 msg = make_message("%s%s%s", tmp? tmp : "",
1354 tmp? " " : "", rsync_argv[i]);
1357 free_rsync_argv(rsync_argv);
1358 dss_msg("%s\n", msg);
1362 ret = pre_create_hook();
1366 ret = wait_for_process(create_pid, &status);
1369 ret = handle_pre_create_hook_exit(status);
1370 if (ret <= 0) /* error, or pre-create failed */
1373 create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time);
1374 ret = create_snapshot(rsync_argv);
1377 ret = wait_for_process(create_pid, &status);
1380 ret = handle_rsync_exit(status);
1385 ret = wait_for_process(create_pid, &status);
1387 free_rsync_argv(rsync_argv);
1391 static int com_ls(void)
1394 struct snapshot_list sl;
1397 dss_get_snapshot_list(&sl);
1398 FOR_EACH_SNAPSHOT(s, i, &sl) {
1400 if (s->flags & SS_COMPLETE)
1401 d = (s->completion_time - s->creation_time) / 60;
1402 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1404 free_snapshot_list(&sl);
1408 static int setup_signal_handling(void)
1412 DSS_INFO_LOG("setting up signal handlers\n");
1413 signal_pipe = signal_init(); /* always successful */
1414 ret = install_sighandler(SIGINT);
1417 ret = install_sighandler(SIGTERM);
1420 return install_sighandler(SIGCHLD);
1424 * The main function of dss.
1426 * \param argc Usual argument count.
1427 * \param argv Usual argument vector.
1429 int main(int argc, char **argv)
1432 struct cmdline_parser_params params = {
1435 .check_required = 0,
1436 .check_ambiguity = 0,
1440 cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */
1441 ret = parse_config_file(0);
1444 if (ret == 0) { /* no config file given */
1446 * Parse the command line options again, but this time check
1447 * that all required options are given.
1449 params = (struct cmdline_parser_params) {
1452 .check_required = 1,
1453 .check_ambiguity = 1,
1456 cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */
1458 if (conf.daemon_given)
1460 ret = change_to_dest_dir();
1463 dump_dss_config("startup");
1464 ret = setup_signal_handling();
1467 ret = call_command_handler();
1470 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1471 exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);