X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.c;h=1bab9aef5f2dce9c92c5416e0d266a1bd1df35cc;hp=121cee4c8846269a084c0a7f99bac6c0cd8c04d2;hb=6bb663afeea85733b2037ce8a027efa0a15c5aad;hpb=52917042ff1fca9f83c68ed1c38a92526e1afcb0 diff --git a/dss.c b/dss.c index 121cee4..1bab9ae 100644 --- a/dss.c +++ b/dss.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -22,10 +23,45 @@ #include "error.h" #include "fd.h" #include "exec.h" +#include "daemon.h" +#include "signal.h" +#include "df.h" +#include "time.h" struct gengetopt_args_info conf; char *dss_error_txt = NULL; +static FILE *logfile; +static int signal_pipe; + +/** Process id of current rsync process. */ +static pid_t rsync_pid; +/** Whether the rsync process is currently stopped */ +static int rsync_stopped; +/** Process id of current rm process. */ +static pid_t rm_pid; +/** When the next snapshot is due. */ +struct timeval next_snapshot_time; + +pid_t pre_create_hook_pid; +pid_t post_create_hook_pid; + +/* Creation time of the snapshot currently being created. */ +int64_t current_snapshot_creation_time; + +static char *path_to_last_complete_snapshot; + +enum { + SCS_READY, + SCS_PRE_HOOK_RUNNING, + SCS_PRE_HOOK_SUCCESS, + SCS_RSYNC_RUNNING, + SCS_RSYNC_SUCCESS, + SCS_POST_HOOK_RUNNING, +}; + +static unsigned snapshot_creation_status; + DEFINE_DSS_ERRLIST; @@ -36,14 +72,15 @@ DEFINE_DSS_ERRLIST; COMMAND(create) \ COMMAND(prune) \ COMMAND(run) -#define COMMAND(x) int com_ ##x(int, char * const * const); +#define COMMAND(x) int com_ ##x(void); COMMANDS #undef COMMAND -#define COMMAND(x) if (conf.x ##_given) return com_ ##x(argc, argv); -int call_command_handler(int argc, char * const * const argv) +#define COMMAND(x) if (conf.x ##_given) return com_ ##x(); +int call_command_handler(void) { COMMANDS - return -E_INVALID_COMMAND; + DSS_EMERG_LOG("BUG: did not find command handler\n"); + exit(EXIT_FAILURE); } #undef COMMAND #undef COMMANDS @@ -55,7 +92,9 @@ int call_command_handler(int argc, char * const * const argv) * incomplete, being deleted: 1204565370-incomplete.being_deleted */ enum snapshot_status_flags { + /** The rsync process terminated successfully. */ SS_COMPLETE = 1, + /** The rm process is running to remove this snapshot. */ SS_BEING_DELETED = 2, }; @@ -67,6 +106,69 @@ struct snapshot { unsigned interval; }; +/* + * An edge snapshot is either the oldest one or the newest one. + * + * We need to find either of them occasionally: The create code + * needs to know the newest snapshot because that is the one + * used as the link destination dir. The pruning code needs to + * find the oldest one in case disk space becomes low. + */ +struct edge_snapshot_data { + int64_t now; + struct snapshot snap; +}; + +__printf_2_3 void dss_log(int ll, const char* fmt,...) +{ + va_list argp; + FILE *outfd; + struct tm *tm; + time_t t1; + char str[255] = ""; + + if (ll < conf.loglevel_arg) + return; + outfd = logfile? logfile : stderr; + time(&t1); + tm = localtime(&t1); + strftime(str, sizeof(str), "%b %d %H:%M:%S", tm); + fprintf(outfd, "%s ", str); + if (conf.loglevel_arg <= INFO) + fprintf(outfd, "%i: ", ll); + va_start(argp, fmt); + vfprintf(outfd, fmt, argp); + va_end(argp); +} + +/** + * Print a message either to stdout or to the log file. + */ +__printf_1_2 void dss_msg(const char* fmt,...) +{ + FILE *outfd = conf.daemon_given? logfile : stdout; + va_list argp; + va_start(argp, fmt); + vfprintf(outfd, fmt, argp); + va_end(argp); +} + +/** + * Return the desired number of snapshots of an interval. + */ +unsigned num_snapshots(int interval) +{ + unsigned n; + + assert(interval >= 0); + + if (interval >= conf.num_intervals_arg) + return 0; + n = conf.num_intervals_arg - interval - 1; + return 1 << n; +} + +/* return: Whether dirname is a snapshot directory (0: no, 1: yes) */ int is_snapshot(const char *dirname, int64_t now, struct snapshot *s) { int i, ret; @@ -124,7 +226,7 @@ int is_snapshot(const char *dirname, int64_t now, struct snapshot *s) return 0; s->completion_time = num; s->flags = SS_COMPLETE; - if (strcmp(dot + 1, "being_deleted")) + if (!strcmp(dot + 1, "being_deleted")) s->flags |= SS_BEING_DELETED; success: s->name = dss_strdup(dirname); @@ -255,7 +357,26 @@ void free_snapshot_list(struct snapshot_list *sl) free(s); } free(sl->interval_count); + sl->interval_count = NULL; free(sl->snapshots); + sl->snapshots = NULL; + sl->num_snapshots = 0; +} + +void stop_rsync_process(void) +{ + if (!rsync_pid || rsync_stopped) + return; + kill(SIGSTOP, rsync_pid); + rsync_stopped = 1; +} + +void restart_rsync_process(void) +{ + if (!rsync_pid || !rsync_stopped) + return; + kill (SIGCONT, rsync_pid); + rsync_stopped = 0; } /** @@ -279,21 +400,40 @@ int wait_for_process(pid_t pid, int *status) DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid); for (;;) { - ret = waitpid(pid, status, 0); - if (ret >= 0 || errno != EINTR) + fd_set rfds; + + FD_ZERO(&rfds); + FD_SET(signal_pipe, &rfds); + ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL); + if (ret < 0) break; + ret = next_signal(); + if (!ret) + continue; + if (ret == SIGCHLD) { + ret = waitpid(pid, status, 0); + if (ret >= 0) + break; + if (errno != EINTR) { /* error */ + ret = -ERRNO_TO_DSS_ERROR(errno); + break; + } + } + /* SIGINT or SIGTERM */ + DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid); + kill(pid, SIGTERM); } - if (ret < 0) { - ret = -ERRNO_TO_DSS_ERROR(errno); + if (ret < 0) make_err_msg("failed to wait for process %d", (int)pid); - } else + else log_termination_msg(pid, *status); return ret; } -int remove_snapshot(struct snapshot *s, pid_t *pid) +int remove_snapshot(struct snapshot *s) { int fds[3] = {0, 0, 0}; + assert(!rm_pid); char *new_name = being_deleted_name(s); int ret = dss_rename(s->name, new_name); char *argv[] = {"rm", "-rf", new_name, NULL}; @@ -301,14 +441,17 @@ int remove_snapshot(struct snapshot *s, pid_t *pid) if (ret < 0) goto out; DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval); - ret = dss_exec(pid, argv[0], argv, fds); + stop_rsync_process(); + ret = dss_exec(&rm_pid, argv[0], argv, fds); out: free(new_name); return ret; } -int remove_redundant_snapshot(struct snapshot_list *sl, - int dry_run, pid_t *pid) +/* + * return: 0: no redundant snapshots, 1: rm process started, negative: error + */ +int remove_redundant_snapshot(struct snapshot_list *sl) { int ret, i, interval; struct snapshot *s; @@ -316,22 +459,22 @@ int remove_redundant_snapshot(struct snapshot_list *sl, DSS_INFO_LOG("looking for intervals containing too many snapshots\n"); for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) { - unsigned keep = 1<<(conf.num_intervals_arg - interval - 1); + unsigned keep = num_snapshots(interval); unsigned num = sl->interval_count[interval]; struct snapshot *victim = NULL, *prev = NULL; int64_t score = LONG_MAX; if (keep >= num) missing += keep - num; - DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n", - interval, keep, num, missing); +// DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n", +// interval, keep, num, missing); if (keep + missing >= num) continue; /* redundant snapshot in this interval, pick snapshot with lowest score */ FOR_EACH_SNAPSHOT(s, i, sl) { int64_t this_score; - DSS_DEBUG_LOG("checking %s\n", s->name); + //DSS_DEBUG_LOG("checking %s\n", s->name); if (s->interval > interval) { prev = s; continue; @@ -347,7 +490,7 @@ int remove_redundant_snapshot(struct snapshot_list *sl, /* check if s is a better victim */ this_score = s->creation_time - prev->creation_time; assert(this_score >= 0); - DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score); + //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score); if (this_score < score) { score = this_score; victim = s; @@ -355,18 +498,18 @@ int remove_redundant_snapshot(struct snapshot_list *sl, prev = s; } assert(victim); - if (dry_run) { - printf("%s would be removed (interval = %i)\n", + if (conf.dry_run_given) { + dss_msg("%s would be removed (interval = %i)\n", victim->name, victim->interval); continue; } - ret = remove_snapshot(victim, pid); + ret = remove_snapshot(victim); return ret < 0? ret : 1; } return 0; } -int remove_old_snapshot(struct snapshot_list *sl, int dry_run, pid_t *pid) +int remove_outdated_snapshot(struct snapshot_list *sl) { int i, ret; struct snapshot *s; @@ -376,12 +519,12 @@ int remove_old_snapshot(struct snapshot_list *sl, int dry_run, pid_t *pid) FOR_EACH_SNAPSHOT(s, i, sl) { if (s->interval <= conf.num_intervals_arg) continue; - if (dry_run) { - printf("%s would be removed (interval = %i)\n", + if (conf.dry_run_given) { + dss_msg("%s would be removed (interval = %i)\n", s->name, s->interval); continue; } - ret = remove_snapshot(s, pid); + ret = remove_snapshot(s); if (ret < 0) return ret; return 1; @@ -389,106 +532,247 @@ int remove_old_snapshot(struct snapshot_list *sl, int dry_run, pid_t *pid) return 0; } -int wait_for_rm_process(pid_t pid) +int handle_rm_exit(int status) { - int status, es, ret = wait_for_process(pid, &status); - if (ret < 0) - return ret; + int es, ret; + if (!WIFEXITED(status)) { - ret = E_INVOLUNTARY_EXIT; - make_err_msg("rm process %d died involuntary", (int)pid); - return ret; + make_err_msg("rm process %d died involuntary", (int)rm_pid); + ret = -E_INVOLUNTARY_EXIT; + goto out; } es = WEXITSTATUS(status); if (es) { + make_err_msg("rm process %d returned %d", (int)rm_pid, es); ret = -E_BAD_EXIT_CODE; - make_err_msg("rm process %d returned %d", (int)pid, es); + goto out; + } + ret = 1; + rm_pid = 0; +out: + return ret; +} + +int wait_for_rm_process(void) +{ + int status, ret = wait_for_process(rm_pid, &status); + + if (ret < 0) return ret; + return handle_rm_exit(status); +} + +void kill_process(pid_t pid) +{ + if (!pid) + return; + DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid); + kill(pid, SIGTERM); +} + +int check_config(void) +{ + if (conf.unit_interval_arg <= 0) { + make_err_msg("bad unit interval: %i", conf.unit_interval_arg); + return -E_INVALID_NUMBER; } + DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg); + if (conf.num_intervals_arg <= 0) { + make_err_msg("bad number of intervals %i", conf.num_intervals_arg); + return -E_INVALID_NUMBER; + } + DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg); return 1; } -int com_run(int argc, char * const * argv) +/* exits on errors */ +void parse_config_file(int override) +{ + int ret; + char *config_file; + struct stat statbuf; + char *old_logfile_arg = NULL; + int old_daemon_given = 0; + + if (conf.config_file_given) + config_file = dss_strdup(conf.config_file_arg); + else { + char *home = get_homedir(); + config_file = make_message("%s/.dssrc", home); + free(home); + } + if (override) { /* SIGHUP */ + if (conf.logfile_given) + old_logfile_arg = dss_strdup(conf.logfile_arg); + old_daemon_given = conf.daemon_given; + } + + ret = stat(config_file, &statbuf); + if (ret && conf.config_file_given) { + ret = -ERRNO_TO_DSS_ERROR(errno); + make_err_msg("failed to stat config file %s", config_file); + goto out; + } + if (!ret) { + struct cmdline_parser_params params = { + .override = override, + .initialize = 0, + .check_required = 1, + .check_ambiguity = 0 + }; + cmdline_parser_config_file(config_file, &conf, ¶ms); + } + ret = check_config(); + if (ret < 0) + goto out; + if (override) { + /* don't change daemon mode on SIGHUP */ + conf.daemon_given = old_daemon_given; + close_log(logfile); + logfile = NULL; + if (conf.logfile_given) + free(old_logfile_arg); + else if (conf.daemon_given) { /* re-use old logfile */ + conf.logfile_arg = old_logfile_arg; + conf.logfile_given = 1; + } + } + if (conf.logfile_given) { + logfile = open_log(conf.logfile_arg); + log_welcome(conf.loglevel_arg); + } + DSS_EMERG_LOG("loglevel: %d\n", conf.loglevel_arg); +// cmdline_parser_dump(logfile? logfile : stdout, &conf); + ret = dss_chdir(conf.dest_dir_arg); +out: + free(config_file); + if (ret >= 0) + return; + log_err_msg(EMERG, -ret); + exit(EXIT_FAILURE); +} + +void handle_sighup(void) { - return 42; + DSS_NOTICE_LOG("SIGHUP\n"); + parse_config_file(1); +} + +int rename_incomplete_snapshot(int64_t start) +{ + char *old_name; + int ret; + + free(path_to_last_complete_snapshot); + ret = complete_name(start, get_current_time(), + &path_to_last_complete_snapshot); + if (ret < 0) + return ret; + old_name = incomplete_name(start); + ret = dss_rename(old_name, path_to_last_complete_snapshot); + if (ret >= 0) + DSS_NOTICE_LOG("%s -> %s\n", old_name, + path_to_last_complete_snapshot); + free(old_name); + return ret; } -int com_prune(int argc, char * const * argv) +void compute_next_snapshot_time(void) { - int ret, dry_run = 0; + struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg}, + tmp, diff; + int64_t x = 0; + unsigned wanted = num_snapshots(0), num_complete_snapshots = 0; + int i, ret; + struct snapshot *s = NULL; struct snapshot_list sl; - pid_t pid; - if (argc > 2) { - make_err_msg("too many arguments"); - return -E_SYNTAX; - } - if (argc == 2) { - if (strcmp(argv[1], "-d")) { - make_err_msg("%s", argv[1]); - return -E_SYNTAX; - } - dry_run = 1; + assert(snapshot_creation_status == SCS_READY); + current_snapshot_creation_time = 0; + get_snapshot_list(&sl); + FOR_EACH_SNAPSHOT(s, i, &sl) { + if (!(s->flags & SS_COMPLETE)) + continue; + num_complete_snapshots++; + x += s->completion_time - s->creation_time; } - for (;;) { - get_snapshot_list(&sl); - ret = remove_old_snapshot(&sl, dry_run, &pid); - free_snapshot_list(&sl); - if (ret < 0) - return ret; - if (!ret) - break; - ret = wait_for_rm_process(pid); - if (ret < 0) - goto out; + assert(x >= 0); + if (num_complete_snapshots) + x /= num_complete_snapshots; /* avg time to create one snapshot */ + x *= wanted; /* time to create all snapshots in interval 0 */ + tmp.tv_sec = x; + tmp.tv_usec = 0; + ret = tv_diff(&unit_interval, &tmp, &diff); /* total sleep time per unit interval */ + gettimeofday(&now, NULL); + if (ret < 0 || !s) + goto min_sleep; + tv_divide(wanted, &diff, &tmp); /* sleep time betweeen two snapshots */ + diff.tv_sec = s->completion_time; + diff.tv_usec = 0; + tv_add(&diff, &tmp, &next_snapshot_time); + if (tv_diff(&now, &next_snapshot_time, NULL) < 0) + goto out; +min_sleep: + next_snapshot_time = now; + next_snapshot_time.tv_sec += 60; +out: + free_snapshot_list(&sl); +} + +int handle_rsync_exit(int status) +{ + int es, ret; + + if (!WIFEXITED(status)) { + make_err_msg("rsync process %d died involuntary", (int)rsync_pid); + ret = -E_INVOLUNTARY_EXIT; + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + goto out; } - for (;;) { - get_snapshot_list(&sl); - ret = remove_redundant_snapshot(&sl, dry_run, &pid); - free_snapshot_list(&sl); - if (ret < 0) - return ret; - if (!ret) - break; - ret = wait_for_rm_process(pid); - if (ret < 0) - goto out; + es = WEXITSTATUS(status); + if (es != 0 && es != 23 && es != 24) { + make_err_msg("rsync process %d returned %d", (int)rsync_pid, es); + ret = -E_BAD_EXIT_CODE; + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + goto out; } - return 1; + ret = rename_incomplete_snapshot(current_snapshot_creation_time); + if (ret < 0) + goto out; + snapshot_creation_status = SCS_RSYNC_SUCCESS; out: + rsync_pid = 0; + rsync_stopped = 0; return ret; } -struct newest_snapshot_data { - char * newest_name; - int64_t newest_creation_time; - int64_t now; -}; - int get_newest_complete(const char *dirname, void *private) { - struct newest_snapshot_data *nsd = private; + struct edge_snapshot_data *esd = private; struct snapshot s; - int ret = is_snapshot(dirname, nsd->now, &s); + int ret = is_snapshot(dirname, esd->now, &s); if (ret <= 0) return 1; - if (s.creation_time < nsd->newest_creation_time) + if (s.flags != SS_COMPLETE) /* incomplete or being deleted */ + return 1; + if (s.creation_time < esd->snap.creation_time) return 1; - nsd->newest_creation_time = s.creation_time; - free(nsd->newest_name); - nsd->newest_name = s.name; + free(esd->snap.name); + esd->snap = s; return 1; } __malloc char *name_of_newest_complete_snapshot(void) { - struct newest_snapshot_data nsd = { + struct edge_snapshot_data esd = { .now = get_current_time(), - .newest_creation_time = -1 + .snap = {.creation_time = -1} }; - for_each_subdir(get_newest_complete, &nsd); - return nsd.newest_name; + for_each_subdir(get_newest_complete, &esd); + return esd.snap.name; } void create_rsync_argv(char ***argv, int64_t *num) @@ -507,7 +791,7 @@ void create_rsync_argv(char ***argv, int64_t *num) (*argv)[i++] = make_message("--link-dest=../%s", newest); free(newest); } else - DSS_INFO_LOG("no previous snapshot found"); + DSS_INFO_LOG("no previous snapshot found\n"); if (conf.exclude_patterns_given) { (*argv)[i++] = dss_strdup("--exclude-from"); (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg); @@ -536,177 +820,450 @@ void free_rsync_argv(char **argv) free(argv); } -int create_snapshot(char **argv, pid_t *pid) +int pre_create_hook(void) { - int fds[3] = {0, 0, 0}; + int ret, fds[3] = {0, 0, 0}; - return dss_exec(pid, argv[0], argv, fds); + if (!conf.pre_create_hook_given) { + snapshot_creation_status = SCS_PRE_HOOK_SUCCESS; + return 0; + } + DSS_NOTICE_LOG("executing %s\n", conf.pre_create_hook_arg); + ret = dss_exec_cmdline_pid(&pre_create_hook_pid, + conf.pre_create_hook_arg, fds); + if (ret < 0) + return ret; + snapshot_creation_status = SCS_PRE_HOOK_RUNNING; + return ret; } -int rename_incomplete_snapshot(int64_t start) +int post_create_hook(void) { - char *old_name, *new_name; - int ret; + int ret, fds[3] = {0, 0, 0}; + char *cmd; - ret = complete_name(start, get_current_time(), &new_name); + if (!conf.post_create_hook_given) { + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + return 0; + } + cmd = make_message("%s %s", conf.post_create_hook_arg, + path_to_last_complete_snapshot); + DSS_NOTICE_LOG("executing %s\n", cmd); + ret = dss_exec_cmdline_pid(&post_create_hook_pid, cmd, fds); + free(cmd); if (ret < 0) return ret; - old_name = incomplete_name(start); - ret = dss_rename(old_name, new_name); - if (ret >= 0) - DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name); - free(old_name); - free(new_name); + snapshot_creation_status = SCS_POST_HOOK_RUNNING; return ret; } -int com_create(int argc, __a_unused char * const * argv) +int create_snapshot(char **argv) { - int ret, status, es; - char **rsync_argv; - int64_t snapshot_num; - pid_t pid; + int ret, fds[3] = {0, 0, 0}; + char *name; - if (argc != 1) { - ret = -E_SYNTAX; - make_err_msg("create: no args expected, %d given", argc - 1); - return ret; - } - create_rsync_argv(&rsync_argv, &snapshot_num); - DSS_NOTICE_LOG("creating snapshot %lli\n", (long long)snapshot_num); - ret = create_snapshot(rsync_argv, &pid); - if (ret < 0) - goto out; - ret = wait_for_process(pid, &status); + name = incomplete_name(current_snapshot_creation_time); + DSS_NOTICE_LOG("creating new snapshot %s\n", name); + free(name); + ret = dss_exec(&rsync_pid, argv[0], argv, fds); if (ret < 0) - goto out; + return ret; + snapshot_creation_status = SCS_RSYNC_RUNNING; + return ret; +} + +int handle_pre_create_hook_exit(int status) +{ + int es, ret; + if (!WIFEXITED(status)) { - ret = E_INVOLUNTARY_EXIT; - make_err_msg("rsync process %d died involuntary", (int)pid); + make_err_msg("pre-create-hook %d died involuntary", + (int)pre_create_hook_pid); + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + ret = -E_INVOLUNTARY_EXIT; goto out; } es = WEXITSTATUS(status); - if (es != 0 && es != 23 && es != 24) { + if (es) { + make_err_msg("pre-create-hook %d returned %d", + (int)pre_create_hook_pid, es); + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); ret = -E_BAD_EXIT_CODE; - make_err_msg("rsync process %d returned %d", (int)pid, es); goto out; } - ret = rename_incomplete_snapshot(snapshot_num); + snapshot_creation_status = SCS_PRE_HOOK_SUCCESS; + ret = 1; out: - free_rsync_argv(rsync_argv); + pre_create_hook_pid = 0; return ret; } -int com_ls(int argc, __a_unused char * const * argv) +int handle_sigchld() { - int i, ret; - struct snapshot_list sl; - struct snapshot *s; - if (argc != 1) { - ret = -E_SYNTAX; - make_err_msg("ls: no args expected, %d given", argc - 1); + pid_t pid; + int status, ret = reap_child(&pid, &status); + + if (ret <= 0) return ret; + if (pid == rsync_pid) + return handle_rsync_exit(status); + if (pid == rm_pid) + return handle_rm_exit(status); + if (pid == pre_create_hook_pid) + return handle_pre_create_hook_exit(status); + if (pid == post_create_hook_pid) { + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + return 1; } - get_snapshot_list(&sl); - FOR_EACH_SNAPSHOT(s, i, &sl) - printf("%u\t%s\n", s->interval, s->name); - free_snapshot_list(&sl); + DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid); + exit(EXIT_FAILURE); +} + +void handle_signal(void) +{ + int sig, ret = next_signal(); + + if (ret <= 0) + goto out; + sig = ret; + switch (sig) { + case SIGINT: + case SIGTERM: + restart_rsync_process(); + kill_process(rsync_pid); + kill_process(rm_pid); + exit(EXIT_FAILURE); + case SIGHUP: + handle_sighup(); + ret = 1; + break; + case SIGCHLD: + ret = handle_sigchld(); + break; + } +out: + if (ret < 0) + log_err_msg(ERROR, -ret); +} + +int get_oldest(const char *dirname, void *private) +{ + struct edge_snapshot_data *esd = private; + struct snapshot s; + int ret = is_snapshot(dirname, esd->now, &s); + + if (ret <= 0) + return 1; + if (s.creation_time > esd->snap.creation_time) + return 1; + free(esd->snap.name); + esd->snap = s; return 1; } -/* TODO: Unlink pid file */ -__noreturn void clean_exit(int status) +int remove_oldest_snapshot() { - //kill(0, SIGTERM); - free(dss_error_txt); - exit(status); + int ret; + struct edge_snapshot_data esd = { + .now = get_current_time(), + .snap = {.creation_time = LLONG_MAX} + }; + for_each_subdir(get_oldest, &esd); + if (!esd.snap.name) /* no snapshot found */ + return 0; + DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name); + ret = 0; + if (esd.snap.creation_time == current_snapshot_creation_time) + goto out; /* do not remove the snapshot currently being created */ + ret = remove_snapshot(&esd.snap); +out: + free(esd.snap.name); + return ret; } -__printf_2_3 void dss_log(int ll, const char* fmt,...) +/* TODO: Also consider number of inodes. */ +int disk_space_low(void) { - va_list argp; - if (ll < conf.loglevel_arg) - return; - va_start(argp, fmt); - vfprintf(stderr, fmt, argp); - va_end(argp); + struct disk_space ds; + int ret = get_disk_space(".", &ds); + + if (ret < 0) + return ret; + if (conf.min_free_mb_arg) + if (ds.free_mb < conf.min_free_mb_arg) + return 1; + if (conf.min_free_percent_arg) + if (ds.percent_free < conf.min_free_percent_arg) + return 1; + return 0; } -int read_config_file(void) +int try_to_free_disk_space(int low_disk_space) { int ret; - char *config_file; - struct stat statbuf; + struct snapshot_list sl; - if (conf.config_file_given) - config_file = dss_strdup(conf.config_file_arg); - else { - char *home = get_homedir(); - config_file = make_message("%s/.dssrc", home); - free(home); - } - ret = stat(config_file, &statbuf); - if (ret && conf.config_file_given) { - ret = -ERRNO_TO_DSS_ERROR(errno); - make_err_msg("failed to stat config file %s", config_file); + get_snapshot_list(&sl); + ret = remove_outdated_snapshot(&sl); + if (ret) /* error, or we are removing something */ goto out; - } - if (!ret) { - struct cmdline_parser_params params = { - .override = 0, - .initialize = 0, - .check_required = 0, - .check_ambiguity = 0 - }; - cmdline_parser_config_file(config_file, &conf, ¶ms); - } - if (!conf.source_dir_given || !conf.dest_dir_given) { - ret = -E_SYNTAX; - make_err_msg("you need to specify both source_dir and dest_dir"); + /* no outdated snapshot */ + ret = remove_redundant_snapshot(&sl); + if (ret) + goto out; + ret = 0; + if (!low_disk_space) + goto out; + DSS_WARNING_LOG("disk space low and nothing obvious to remove\n"); + ret = remove_oldest_snapshot(); + if (ret) goto out; + make_err_msg("uhuhu: not enough disk space for a single snapshot"); + ret= -ENOSPC; +out: + free_snapshot_list(&sl); + return ret; +} + +int select_loop(void) +{ + int ret; + struct timeval tv = {.tv_sec = 0, .tv_usec = 0}; + + for (;;) { + fd_set rfds; + int low_disk_space; + char **rsync_argv; + struct timeval now, *tvp = &tv; + + if (rsync_pid) + tv.tv_sec = 60; /* check every 60 seconds for free disk space */ + else if (rm_pid) + tvp = NULL; /* sleep until rm process dies */ + FD_ZERO(&rfds); + FD_SET(signal_pipe, &rfds); + DSS_DEBUG_LOG("tvp: %p, tv_sec: %lu\n", tvp, (long unsigned) tv.tv_sec); + ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp); + if (ret < 0) + return ret; + if (FD_ISSET(signal_pipe, &rfds)) + handle_signal(); + if (rm_pid) + continue; + ret = disk_space_low(); + if (ret < 0) + break; + low_disk_space = ret; + if (low_disk_space) + stop_rsync_process(); + ret = try_to_free_disk_space(low_disk_space); + if (ret < 0) + break; + if (rm_pid) + continue; + restart_rsync_process(); + gettimeofday(&now, NULL); + if (tv_diff(&next_snapshot_time, &now, &tv) > 0) + continue; + switch (snapshot_creation_status) { + case SCS_READY: + ret = pre_create_hook(); + if (ret < 0) + goto out; + continue; + case SCS_PRE_HOOK_RUNNING: + continue; + case SCS_PRE_HOOK_SUCCESS: + create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time); + ret = create_snapshot(rsync_argv); + free_rsync_argv(rsync_argv); + if (ret < 0) + goto out; + continue; + case SCS_RSYNC_RUNNING: + continue; + case SCS_RSYNC_SUCCESS: + ret = post_create_hook(); + if (ret < 0) + goto out; + continue; + case SCS_POST_HOOK_RUNNING: + continue; + } } - ret = 1; out: - free(config_file); return ret; } -int check_config(void) +int com_run(void) { - if (conf.unit_interval_arg <= 0) { - make_err_msg("bad unit interval: %i", conf.unit_interval_arg); - return -E_INVALID_NUMBER; + int ret; + + if (conf.dry_run_given) { + make_err_msg("dry_run not supported by this command"); + return -E_SYNTAX; } - DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg); - if (conf.num_intervals_arg <= 0) { - make_err_msg("bad number of intervals %i", conf.num_intervals_arg); - return -E_INVALID_NUMBER; + ret = install_sighandler(SIGHUP); + if (ret < 0) + return ret; + compute_next_snapshot_time(); + return select_loop(); +} + +void log_disk_space(struct disk_space *ds) +{ + DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n", + ds->free_mb, ds->total_mb, ds->percent_free, + ds->percent_free_inodes); +} + +int com_prune(void) +{ + int ret; + struct snapshot_list sl; + struct disk_space ds; + + ret = get_disk_space(".", &ds); + if (ret < 0) + return ret; + log_disk_space(&ds); + for (;;) { + get_snapshot_list(&sl); + ret = remove_outdated_snapshot(&sl); + free_snapshot_list(&sl); + if (ret < 0) + return ret; + if (!ret) + break; + ret = wait_for_rm_process(); + if (ret < 0) + goto out; + } + for (;;) { + get_snapshot_list(&sl); + ret = remove_redundant_snapshot(&sl); + free_snapshot_list(&sl); + if (ret < 0) + return ret; + if (!ret) + break; + ret = wait_for_rm_process(); + if (ret < 0) + goto out; } - DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg); return 1; +out: + return ret; } -int main(int argc, char **argv) +int com_create(void) { - int ret; + int ret, status; + char **rsync_argv; - cmdline_parser(argc, argv, &conf); /* aborts on errors */ - if (conf.inputs_num) { - ret = -E_SYNTAX; - make_err_msg("additional non-options given"); - goto out; + if (conf.dry_run_given) { + int i; + char *msg = NULL; + create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time); + for (i = 0; rsync_argv[i]; i++) { + char *tmp = msg; + msg = make_message("%s%s%s", tmp? tmp : "", + tmp? " " : "", rsync_argv[i]); + free(tmp); + } + free_rsync_argv(rsync_argv); + dss_msg("%s\n", msg); + free(msg); + return 1; + } + ret = pre_create_hook(); + if (ret < 0) + return ret; + if (pre_create_hook_pid) { + ret = wait_for_process(pre_create_hook_pid, &status); + if (ret < 0) + return ret; + ret = handle_pre_create_hook_exit(status); + if (ret < 0) + return ret; } - ret = read_config_file(); + create_rsync_argv(&rsync_argv, ¤t_snapshot_creation_time); + ret = create_snapshot(rsync_argv); if (ret < 0) goto out; - ret = check_config(); + ret = wait_for_process(rsync_pid, &status); if (ret < 0) goto out; - ret = dss_chdir(conf.dest_dir_arg); + ret = handle_rsync_exit(status); if (ret < 0) goto out; - ret = call_command_handler(conf.inputs_num, conf.inputs); + post_create_hook(); + if (post_create_hook_pid) + ret = wait_for_process(post_create_hook_pid, &status); out: + free_rsync_argv(rsync_argv); + return ret; +} + +int com_ls(void) +{ + int i; + struct snapshot_list sl; + struct snapshot *s; + get_snapshot_list(&sl); + FOR_EACH_SNAPSHOT(s, i, &sl) + dss_msg("%u\t%s\n", s->interval, s->name); + free_snapshot_list(&sl); + return 1; +} + +__noreturn void clean_exit(int status) +{ + free(dss_error_txt); + exit(status); +} +static void setup_signal_handling(void) +{ + int ret; + + DSS_INFO_LOG("setting up signal handlers\n"); + signal_pipe = signal_init(); /* always successful */ + ret = install_sighandler(SIGINT); + if (ret < 0) + goto err; + ret = install_sighandler(SIGTERM); + if (ret < 0) + goto err; + ret = install_sighandler(SIGCHLD); + if (ret < 0) + goto err; + return; +err: + DSS_EMERG_LOG("could not install signal handlers\n"); + exit(EXIT_FAILURE); +} + +int main(int argc, char **argv) +{ + int ret; + struct cmdline_parser_params params = { + .override = 0, + .initialize = 1, + .check_required = 0, + .check_ambiguity = 0 + }; + + cmdline_parser_ext(argc, argv, &conf, ¶ms); /* aborts on errors */ + parse_config_file(0); + + if (conf.daemon_given) + daemon_init(); + setup_signal_handling(); + ret = call_command_handler(); if (ret < 0) log_err_msg(EMERG, -ret); clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);