X-Git-Url: http://git.tuebingen.mpg.de/?p=dss.git;a=blobdiff_plain;f=dss.c;h=3d00b0b38be37b50878375257d90f9871412c957;hp=665185f6f02e2e85b96c315cb9f274fab0aa0709;hb=27edbe5dcf615a3c445f719b5833af4d392c5874;hpb=354729ae9ab2f166f03fde817ee3ab280de65b7d diff --git a/dss.c b/dss.c index 665185f..3d00b0b 100644 --- a/dss.c +++ b/dss.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -22,10 +23,51 @@ #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; +/** The pid of the pre-create hook. */ +pid_t pre_create_hook_pid; +/** The pid of the post-create hook. */ +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 { + /** We are ready to take the next snapshot. */ + SCS_READY, + /** The pre-creation hook has been started. */ + SCS_PRE_HOOK_RUNNING, + /** The pre-creation hook exited successfully. */ + SCS_PRE_HOOK_SUCCESS, + /** The rsync process is running. */ + SCS_RSYNC_RUNNING, + /** The rsync process exited successfully. */ + SCS_RSYNC_SUCCESS, + /** The post-create hook has been started- */ + SCS_POST_HOOK_RUNNING, +}; + +static unsigned snapshot_creation_status; + DEFINE_DSS_ERRLIST; @@ -36,11 +78,11 @@ 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 DSS_EMERG_LOG("BUG: did not find command handler\n"); @@ -56,7 +98,9 @@ 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, }; @@ -68,6 +112,56 @@ struct snapshot { unsigned interval; }; +__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; @@ -85,10 +179,8 @@ int is_snapshot(const char *dirname, int64_t now, struct snapshot *s) tmp[i] = '\0'; ret = dss_atoi64(tmp, &num); free(tmp); - if (ret < 0) { - free(dss_error_txt); + if (ret < 0) return 0; - } assert(num >= 0); if (num > now) return 0; @@ -117,15 +209,13 @@ int is_snapshot(const char *dirname, int64_t now, struct snapshot *s) tmp[i] = '\0'; ret = dss_atoi64(tmp, &num); free(tmp); - if (ret < 0) { - free(dss_error_txt); + if (ret < 0) return 0; - } if (num > now) 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); @@ -162,22 +252,14 @@ int complete_name(int64_t start, int64_t end, char **result) time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */ char start_str[200], end_str[200]; - if (!localtime_r(start_seconds, &start_tm)) { - make_err_msg("%lli", (long long)start); + if (!localtime_r(start_seconds, &start_tm)) return -E_LOCALTIME; - } - if (!localtime_r(end_seconds, &end_tm)) { - make_err_msg("%lli", (long long)end); + if (!localtime_r(end_seconds, &end_tm)) return -E_LOCALTIME; - } - if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) { - make_err_msg("%lli", (long long)start); + if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) return -E_STRFTIME; - } - if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) { - make_err_msg("%lli", (long long)end); + if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) return -E_STRFTIME; - } *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end, start_str, end_str); return 1; @@ -200,7 +282,15 @@ struct snapshot_list { #define FOR_EACH_SNAPSHOT(s, i, sl) \ for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++) +#define FOR_EACH_SNAPSHOT_REVERSE(s, i, sl) \ + for ((i) = (sl)->num_snapshots; (i) > 0 && ((s) = (sl)->snapshots[(i - 1)]); (i)--) +static inline struct snapshot *oldest_snapshot(struct snapshot_list *sl) +{ + if (!sl->num_snapshots) + return NULL; + return sl->snapshots[0]; +} #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y))) @@ -256,7 +346,26 @@ 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; } /** @@ -280,21 +389,40 @@ 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); - make_err_msg("failed to wait for process %d", (int)pid); - } else + if (ret < 0) + DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid); + 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}; @@ -302,14 +430,17 @@ 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; @@ -317,22 +448,22 @@ 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; @@ -348,7 +479,7 @@ 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; @@ -356,18 +487,18 @@ 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; @@ -377,12 +508,12 @@ 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; @@ -390,106 +521,228 @@ 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); + rm_pid = 0; + if (!WIFEXITED(status)) + return -E_INVOLUNTARY_EXIT; + if (WEXITSTATUS(status)) + return -E_BAD_EXIT_CODE; + return 1; +} + +int wait_for_rm_process(void) +{ + int status, ret = wait_for_process(rm_pid, &status); + if (ret < 0) return ret; - if (!WIFEXITED(status)) { - ret = E_INVOLUNTARY_EXIT; - make_err_msg("rm process %d died involuntary", (int)pid); - 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) { + DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg); + return -E_INVALID_NUMBER; } - es = WEXITSTATUS(status); - if (es) { - ret = -E_BAD_EXIT_CODE; - make_err_msg("rm process %d returned %d", (int)pid, es); - return ret; + DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg); + if (conf.num_intervals_arg <= 0) { + DSS_ERROR_LOG("bad number of intervals %i\n", 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) { - return 42; -} + int ret; + char *config_file; + struct stat statbuf; + char *old_logfile_arg = NULL; + int old_daemon_given = 0; -int com_prune(int argc, char * const * argv) -{ - int ret, dry_run = 0; - struct snapshot_list sl; - pid_t pid; + 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; + } - if (argc > 2) { - make_err_msg("too many arguments"); - return -E_SYNTAX; + ret = stat(config_file, &statbuf); + if (ret && conf.config_file_given) { + ret = -ERRNO_TO_DSS_ERROR(errno); + DSS_ERROR_LOG("failed to stat config file %s\n", config_file); + goto out; } - if (argc == 2) { - if (strcmp(argv[1], "-d")) { - make_err_msg("%s", argv[1]); - return -E_SYNTAX; - } - dry_run = 1; + 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); } - 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; + 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; + } } - 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; + if (conf.logfile_given) { + logfile = open_log(conf.logfile_arg); + log_welcome(conf.loglevel_arg); } - return 1; + 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; + DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); + exit(EXIT_FAILURE); +} + +void handle_sighup(void) +{ + 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; } -struct newest_snapshot_data { - char * newest_name; - int64_t newest_creation_time; - int64_t now; -}; +void compute_next_snapshot_time(void) +{ + 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; -int get_newest_complete(const char *dirname, void *private) + 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; + } + 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) { - struct newest_snapshot_data *nsd = private; - struct snapshot s; - int ret = is_snapshot(dirname, nsd->now, &s); + int es, ret; - if (ret <= 0) - return 1; - if (s.creation_time < nsd->newest_creation_time) - return 1; - nsd->newest_creation_time = s.creation_time; - free(nsd->newest_name); - nsd->newest_name = s.name; - return 1; + if (!WIFEXITED(status)) { + DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)rsync_pid); + ret = -E_INVOLUNTARY_EXIT; + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + goto out; + } + es = WEXITSTATUS(status); + if (es != 0 && es != 23 && es != 24) { + DSS_ERROR_LOG("rsync process %d returned %d\n", (int)rsync_pid, es); + ret = -E_BAD_EXIT_CODE; + snapshot_creation_status = SCS_READY; + compute_next_snapshot_time(); + goto out; + } + 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; } __malloc char *name_of_newest_complete_snapshot(void) { - struct newest_snapshot_data nsd = { - .now = get_current_time(), - .newest_creation_time = -1 - }; - for_each_subdir(get_newest_complete, &nsd); - return nsd.newest_name; + struct snapshot_list sl; + struct snapshot *s; + int i; + char *name = NULL; + + get_snapshot_list(&sl); + + FOR_EACH_SNAPSHOT_REVERSE(s, i, &sl) { + if (s->flags != SS_COMPLETE) /* incomplete or being deleted */ + continue; + name = dss_strdup(s->name); + break; + } + free_snapshot_list(&sl); + return name; } void create_rsync_argv(char ***argv, int64_t *num) @@ -508,7 +761,7 @@ 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); @@ -537,178 +790,412 @@ 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); + 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) { + 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); - return 1; + DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid); + exit(EXIT_FAILURE); } -/* TODO: Unlink pid file */ -__noreturn void clean_exit(int status) +void handle_signal(void) { - //kill(0, SIGTERM); - free(dss_error_txt); - exit(status); + 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) + DSS_ERROR_LOG("%s\n", dss_strerror(-ret)); } -__printf_2_3 void dss_log(int ll, const char* fmt,...) +int remove_oldest_snapshot(struct snapshot_list *sl) { - va_list argp; - if (ll < conf.loglevel_arg) - return; - va_start(argp, fmt); - vfprintf(stderr, fmt, argp); - va_end(argp); + struct snapshot *s = oldest_snapshot(sl); + + if (!s) /* no snapshot found */ + return 0; + DSS_INFO_LOG("oldest snapshot: %s\n", s->name); + if (s->creation_time == current_snapshot_creation_time) + return 0; /* do not remove the snapshot currently being created */ + return remove_snapshot(s); +} + +/* TODO: Also consider number of inodes. */ +int disk_space_low(void) +{ + 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(&sl); + if (ret) + goto out; + DSS_CRIT_LOG("uhuhu: not enough disk space for a single snapshot\n"); + 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) { + DSS_ERROR_LOG("dry_run not supported by this command\n"); + 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(); +} + +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 = read_config_file(); + 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; + } + 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; +} + +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); + DSS_EMERG_LOG("%s\n", dss_strerror(-ret)); + exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE); }