dss.c

   1 /*
   2  * Copyright (C) 2008-2011 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 #include <string.h>
   7 #include <stdlib.h>
   8 #include <stdarg.h>
   9 #include <assert.h>
  10 #include <errno.h>
  11 #include <sys/types.h>
  12 #include <signal.h>
  13 #include <ctype.h>
  14 #include <sys/stat.h>
  15 #include <unistd.h>
  16 #include <inttypes.h>
  17 #include <sys/time.h>
  18 #include <time.h>
  19 #include <sys/wait.h>
  20 #include <fnmatch.h>
  21 #include <limits.h>
  22
  23
  24 #include "gcc-compat.h"
  25 #include "cmdline.h"
  26 #include "log.h"
  27 #include "string.h"
  28 #include "error.h"
  29 #include "fd.h"
  30 #include "exec.h"
  31 #include "daemon.h"
  32 #include "signal.h"
  33 #include "df.h"
  34 #include "time.h"
  35 #include "snap.h"
  36 #include "ipc.h"
  37
  38 /** Command line and config file options. */
  39 static struct gengetopt_args_info conf;
  40 /** Non-NULL if we log to a file. */
  41 static FILE *logfile;
  42 /** The read end of the signal pipe */
  43 static int signal_pipe;
  44 /** Process id of current pre-create-hook/rsync/post-create-hook process. */
  45 static pid_t create_pid;
  46 /** Whether the pre-create-hook/rsync/post-create-hook is currently stopped. */
  47 static int create_process_stopped;
  48 /** Process id of current pre-remove/rm/post-remove process. */
  49 static pid_t remove_pid;
  50 /** When the next snapshot is due. */
  51 static int64_t next_snapshot_time;
  52 /** When to try to remove something. */
  53 static struct timeval next_removal_check;
  54 /** Creation time of the snapshot currently being created. */
  55 static int64_t current_snapshot_creation_time;
  56 /** The snapshot currently being removed. */
  57 struct snapshot *snapshot_currently_being_removed;
  58 /** Needed by the post-create hook. */
  59 static char *path_to_last_complete_snapshot;
  60 static char *name_of_reference_snapshot;
  61 /** \sa \ref snap.h for details. */
  62 enum hook_status snapshot_creation_status;
  63 /** \sa \ref snap.h for details. */
  64 enum hook_status snapshot_removal_status;
  65
  66
  67 DEFINE_DSS_ERRLIST;
  68 static const char const *hook_status_description[] = {HOOK_STATUS_ARRAY};
  69
  70 /* may be called with ds == NULL. */
  71 static int disk_space_low(struct disk_space *ds)
  72 {
  73         struct disk_space ds_struct;
  74
  75         if (!ds) {
  76                 int ret = get_disk_space(".", &ds_struct);
  77                 if (ret < 0)
  78                         return ret;
  79                 ds = &ds_struct;
  80         }
  81         if (conf.min_free_mb_arg)
  82                 if (ds->free_mb < conf.min_free_mb_arg)
  83                         return 1;
  84         if (conf.min_free_percent_arg)
  85                 if (ds->percent_free < conf.min_free_percent_arg)
  86                         return 1;
  87         if (conf.min_free_percent_inodes_arg)
  88                 if (ds->percent_free_inodes < conf.min_free_percent_inodes_arg)
  89                         return 1;
  90         return 0;
  91 }
  92
  93 static void dump_dss_config(const char *msg)
  94 {
  95         const char dash[] = "-----------------------------";
  96         int ret;
  97         FILE *log = logfile? logfile : stderr;
  98         struct disk_space ds;
  99         int64_t now = get_current_time();
 100
 101         if (conf.loglevel_arg > INFO)
 102                 return;
 103
 104         fprintf(log, "%s <%s config> %s\n", dash, msg, dash);
 105         fprintf(log, "\n*** disk space ***\n\n");
 106         ret = get_disk_space(".", &ds);
 107         if (ret >= 0) {
 108                 DSS_INFO_LOG("disk space low: %s\n", disk_space_low(&ds)?
 109                         "yes" : "no");
 110                 log_disk_space(&ds);
 111         } else
 112                 DSS_ERROR_LOG("can not get free disk space: %s\n",
 113                         dss_strerror(-ret));
 114
 115         /* we continue on errors from get_disk_space */
 116
 117         fprintf(log, "\n*** command line and config file options ***\n\n");
 118         cmdline_parser_dump(log, &conf);
 119         fprintf(log, "\n*** internal state ***\n\n");
 120         fprintf(log,
 121                 "pid: %d\n"
 122                 "logile: %s\n"
 123                 "snapshot_currently_being_removed: %s\n"
 124                 "path_to_last_complete_snapshot: %s\n"
 125                 "reference_snapshot: %s\n"
 126                 "snapshot_creation_status: %s\n"
 127                 "snapshot_removal_status: %s\n"
 128                 ,
 129                 (int) getpid(),
 130                 logfile? conf.logfile_arg : "stderr",
 131                 snapshot_currently_being_removed?
 132                         snapshot_currently_being_removed->name : "(none)",
 133                 path_to_last_complete_snapshot?
 134                         path_to_last_complete_snapshot : "(none)",
 135                 name_of_reference_snapshot?
 136                         name_of_reference_snapshot : "(none)",
 137                 hook_status_description[snapshot_creation_status],
 138                 hook_status_description[snapshot_removal_status]
 139         );
 140         if (create_pid != 0)
 141                 fprintf(log,
 142                         "create_pid: %" PRId32 "\n"
 143                         "create process is %sstopped\n"
 144                         ,
 145                         create_pid,
 146                         create_process_stopped? "" : "not "
 147                 );
 148         if (remove_pid != 0)
 149                 fprintf(log, "remove_pid: %" PRId32 "\n", remove_pid);
 150         if (next_snapshot_time != 0)
 151                 fprintf(log, "next snapshot due in %" PRId64 " seconds\n",
 152                         next_snapshot_time - now);
 153         if (current_snapshot_creation_time != 0)
 154                 fprintf(log, "current_snapshot_creation_time: %"
 155                         PRId64 " (%" PRId64 " seconds ago)\n",
 156                         current_snapshot_creation_time,
 157                         now - current_snapshot_creation_time
 158                 );
 159         if (next_removal_check.tv_sec != 0) {
 160                 fprintf(log, "next removal check: %llu (%llu seconds ago)\n",
 161                         (long long unsigned)next_removal_check.tv_sec,
 162                         now - (long long unsigned)next_removal_check.tv_sec
 163                 );
 164
 165         }
 166         fprintf(log, "%s </%s config> %s\n", dash, msg, dash);
 167 }
 168
 169 /* a litte cpp magic helps to DRY */
 170 #define COMMANDS \
 171         COMMAND(ls) \
 172         COMMAND(create) \
 173         COMMAND(prune) \
 174         COMMAND(run) \
 175         COMMAND(kill) \
 176         COMMAND(reload) \
 177
 178 #define COMMAND(x) static int com_ ##x(void);
 179 COMMANDS
 180 #undef COMMAND
 181 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
 182 static int call_command_handler(void)
 183 {
 184         COMMANDS
 185         DSS_EMERG_LOG("BUG: did not find command handler\n");
 186         return -E_BUG;
 187 }
 188 #undef COMMAND
 189 #undef COMMANDS
 190
 191 /**
 192  * The log function of dss.
 193  *
 194  * \param ll Loglevel.
 195  * \param fml Usual format string.
 196  *
 197  * All DSS_XXX_LOG() macros use this function.
 198  */
 199 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 200 {
 201         va_list argp;
 202         FILE *outfd;
 203         struct tm *tm;
 204         time_t t1;
 205         char str[255] = "";
 206
 207         if (ll < conf.loglevel_arg)
 208                 return;
 209         outfd = logfile? logfile : stderr;
 210         time(&t1);
 211         tm = localtime(&t1);
 212         strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
 213         fprintf(outfd, "%s ", str);
 214         if (conf.loglevel_arg <= INFO)
 215                 fprintf(outfd, "%i: ", ll);
 216         va_start(argp, fmt);
 217         vfprintf(outfd, fmt, argp);
 218         va_end(argp);
 219 }
 220
 221 /**
 222  * Print a message either to stdout or to the log file.
 223  */
 224 static __printf_1_2 void dss_msg(const char* fmt,...)
 225 {
 226         FILE *outfd = conf.daemon_given? logfile : stdout;
 227         va_list argp;
 228         va_start(argp, fmt);
 229         vfprintf(outfd, fmt, argp);
 230         va_end(argp);
 231 }
 232
 233 static char *get_config_file_name(void)
 234 {
 235         char *home, *config_file;
 236
 237         if (conf.config_file_given)
 238                 return dss_strdup(conf.config_file_arg);
 239         home = get_homedir();
 240         config_file = make_message("%s/.dssrc", home);
 241         free(home);
 242         return config_file;
 243 }
 244
 245 static int send_signal(int sig)
 246 {
 247         pid_t pid;
 248         char *config_file = get_config_file_name();
 249         int ret = get_dss_pid(config_file, &pid);
 250
 251         free(config_file);
 252         if (ret < 0)
 253                 return ret;
 254         if (conf.dry_run_given) {
 255                 dss_msg("%d\n", (int)pid);
 256                 return 0;
 257         }
 258         ret = kill(pid, sig);
 259         if (ret < 0)
 260                 return -ERRNO_TO_DSS_ERROR(errno);
 261         return 1;
 262 }
 263
 264 static int com_kill(void)
 265 {
 266         return send_signal(SIGTERM);
 267 }
 268
 269 static int com_reload(void)
 270 {
 271         return send_signal(SIGHUP);
 272 }
 273
 274 static void dss_get_snapshot_list(struct snapshot_list *sl)
 275 {
 276         get_snapshot_list(sl, conf.unit_interval_arg, conf.num_intervals_arg);
 277 }
 278
 279 static int64_t compute_next_snapshot_time(void)
 280 {
 281         int64_t x = 0, now = get_current_time(), unit_interval
 282                 = 24 * 3600 * conf.unit_interval_arg, ret;
 283         unsigned wanted = desired_number_of_snapshots(0, conf.num_intervals_arg),
 284                 num_complete_snapshots = 0;
 285         int i;
 286         struct snapshot *s = NULL;
 287         struct snapshot_list sl;
 288
 289         dss_get_snapshot_list(&sl);
 290         FOR_EACH_SNAPSHOT(s, i, &sl) {
 291                 if (!(s->flags & SS_COMPLETE))
 292                         continue;
 293                 num_complete_snapshots++;
 294                 x += s->completion_time - s->creation_time;
 295         }
 296         assert(x >= 0);
 297
 298         ret = now;
 299         if (num_complete_snapshots == 0)
 300                 goto out;
 301         x /= num_complete_snapshots; /* avg time to create one snapshot */
 302         if (unit_interval < x * wanted) /* oops, no sleep at all */
 303                 goto out;
 304         ret = s->completion_time + unit_interval / wanted - x;
 305 out:
 306         free_snapshot_list(&sl);
 307         return ret;
 308 }
 309
 310 static inline void invalidate_next_snapshot_time(void)
 311 {
 312         next_snapshot_time = 0;
 313 }
 314
 315 static inline int next_snapshot_time_is_valid(void)
 316 {
 317         return next_snapshot_time != 0;
 318 }
 319
 320 static int next_snapshot_is_due(void)
 321 {
 322         int64_t now = get_current_time();
 323
 324         if (!next_snapshot_time_is_valid())
 325                 next_snapshot_time = compute_next_snapshot_time();
 326         if (next_snapshot_time <= now) {
 327                 DSS_DEBUG_LOG("next snapshot: now\n");
 328                 return 1;
 329         }
 330         DSS_DEBUG_LOG("next snapshot due in %" PRId64 " seconds\n",
 331                 next_snapshot_time - now);
 332         return 0;
 333 }
 334
 335 static void pre_create_hook(void)
 336 {
 337         assert(snapshot_creation_status == HS_READY);
 338         /* make sure that the next snapshot time will be recomputed */
 339         invalidate_next_snapshot_time();
 340         DSS_DEBUG_LOG("executing %s\n", conf.pre_create_hook_arg);
 341         dss_exec_cmdline_pid(&create_pid, conf.pre_create_hook_arg);
 342         snapshot_creation_status = HS_PRE_RUNNING;
 343 }
 344
 345 static void pre_remove_hook(struct snapshot *s, const char *why)
 346 {
 347         char *cmd;
 348
 349         if (!s)
 350                 return;
 351         DSS_DEBUG_LOG("%s snapshot %s\n", why, s->name);
 352         assert(snapshot_removal_status == HS_READY);
 353         assert(remove_pid == 0);
 354         assert(!snapshot_currently_being_removed);
 355
 356         snapshot_currently_being_removed = dss_malloc(sizeof(struct snapshot));
 357         *snapshot_currently_being_removed = *s;
 358         snapshot_currently_being_removed->name = dss_strdup(s->name);
 359
 360         cmd = make_message("%s %s/%s", conf.pre_remove_hook_arg,
 361                 conf.dest_dir_arg, s->name);
 362         DSS_DEBUG_LOG("executing %s\n", cmd);
 363         dss_exec_cmdline_pid(&remove_pid, cmd);
 364         free(cmd);
 365         snapshot_removal_status = HS_PRE_RUNNING;
 366 }
 367
 368 static int exec_rm(void)
 369 {
 370         struct snapshot *s = snapshot_currently_being_removed;
 371         char *new_name = being_deleted_name(s);
 372         char *argv[] = {"rm", "-rf", new_name, NULL};
 373         int ret;
 374
 375         assert(snapshot_removal_status == HS_PRE_SUCCESS);
 376         assert(remove_pid == 0);
 377
 378         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 379         ret = dss_rename(s->name, new_name);
 380         if (ret < 0)
 381                 goto out;
 382         dss_exec(&remove_pid, argv[0], argv);
 383         snapshot_removal_status = HS_RUNNING;
 384 out:
 385         free(new_name);
 386         return ret;
 387 }
 388
 389 static int snapshot_is_being_created(struct snapshot *s)
 390 {
 391         return s->creation_time == current_snapshot_creation_time;
 392 }
 393
 394 static struct snapshot *find_orphaned_snapshot(struct snapshot_list *sl)
 395 {
 396         struct snapshot *s;
 397         int i;
 398
 399         DSS_DEBUG_LOG("looking for orphaned snapshots\n");
 400         FOR_EACH_SNAPSHOT(s, i, sl) {
 401                 if (snapshot_is_being_created(s))
 402                         continue;
 403                 /*
 404                  * We know that no rm is currently running, so if s is marked
 405                  * as being deleted, a previously started rm must have failed.
 406                  */
 407                 if (s->flags & SS_BEING_DELETED)
 408                         return s;
 409
 410                 if (s->flags & SS_COMPLETE) /* good snapshot */
 411                         continue;
 412                 /*
 413                  * This snapshot is incomplete and it is not the snapshot
 414                  * currently being created. However, we must not remove it if
 415                  * rsync is about to be restarted. As only the newest snapshot
 416                  * can be restarted, this snapshot is orphaned if it is not the
 417                  * newest snapshot or if we are not about to restart rsync.
 418                  */
 419                 if (get_newest_snapshot(sl) != s)
 420                         return s;
 421                 if (snapshot_creation_status != HS_NEEDS_RESTART)
 422                         return s;
 423         }
 424         /* no orphaned snapshots */
 425         return NULL;
 426 }
 427
 428 static int is_reference_snapshot(struct snapshot *s)
 429 {
 430         if (!name_of_reference_snapshot)
 431                 return 0;
 432         return strcmp(s->name, name_of_reference_snapshot)? 0 : 1;
 433 }
 434
 435 /*
 436  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 437  */
 438 static struct snapshot *find_redundant_snapshot(struct snapshot_list *sl)
 439 {
 440         int i, interval;
 441         struct snapshot *s;
 442         unsigned missing = 0;
 443
 444         DSS_DEBUG_LOG("looking for intervals containing too many snapshots\n");
 445         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 446                 unsigned keep = desired_number_of_snapshots(interval, conf.num_intervals_arg);
 447                 unsigned num = sl->interval_count[interval];
 448                 struct snapshot *victim = NULL, *prev = NULL;
 449                 int64_t score = LONG_MAX;
 450
 451                 if (keep >= num)
 452                         missing += keep - num;
 453 //              DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 454 //                      interval, keep, num, missing);
 455                 if (keep + missing >= num)
 456                         continue;
 457                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 458                 FOR_EACH_SNAPSHOT(s, i, sl) {
 459                         int64_t this_score;
 460
 461                         if (snapshot_is_being_created(s))
 462                                 continue;
 463                         if (is_reference_snapshot(s))
 464                                 continue;
 465                         //DSS_DEBUG_LOG("checking %s\n", s->name);
 466                         if (s->interval > interval) {
 467                                 prev = s;
 468                                 continue;
 469                         }
 470                         if (s->interval < interval)
 471                                 break;
 472                         if (!victim) {
 473                                 victim = s;
 474                                 prev = s;
 475                                 continue;
 476                         }
 477                         assert(prev);
 478                         /* check if s is a better victim */
 479                         this_score = s->creation_time - prev->creation_time;
 480                         assert(this_score >= 0);
 481                         //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 482                         if (this_score < score) {
 483                                 score = this_score;
 484                                 victim = s;
 485                         }
 486                         prev = s;
 487                 }
 488                 assert(victim);
 489                 return victim;
 490         }
 491         return NULL;
 492 }
 493
 494 static struct snapshot *find_outdated_snapshot(struct snapshot_list *sl)
 495 {
 496         int i;
 497         struct snapshot *s;
 498
 499         DSS_DEBUG_LOG("looking for snapshots belonging to intervals >= %d\n",
 500                 conf.num_intervals_arg);
 501         FOR_EACH_SNAPSHOT(s, i, sl) {
 502                 if (snapshot_is_being_created(s))
 503                         continue;
 504                 if (is_reference_snapshot(s))
 505                         continue;
 506                 if (s->interval < conf.num_intervals_arg)
 507                         continue;
 508                 return s;
 509         }
 510         return NULL;
 511 }
 512
 513 struct snapshot *find_oldest_removable_snapshot(struct snapshot_list *sl)
 514 {
 515         int i;
 516         struct snapshot *s;
 517         FOR_EACH_SNAPSHOT(s, i, sl) {
 518                 if (snapshot_is_being_created(s))
 519                         continue;
 520                 if (is_reference_snapshot(s))
 521                         continue;
 522                 DSS_INFO_LOG("oldest removable snapshot: %s\n", s->name);
 523                 return s;
 524         }
 525         return NULL;
 526 }
 527
 528 static int rename_incomplete_snapshot(int64_t start)
 529 {
 530         char *old_name;
 531         int ret;
 532
 533         free(path_to_last_complete_snapshot);
 534         ret = complete_name(start, get_current_time(),
 535                 &path_to_last_complete_snapshot);
 536         if (ret < 0)
 537                 return ret;
 538         old_name = incomplete_name(start);
 539         ret = dss_rename(old_name, path_to_last_complete_snapshot);
 540         if (ret >= 0)
 541                 DSS_NOTICE_LOG("%s -> %s\n", old_name,
 542                         path_to_last_complete_snapshot);
 543         free(old_name);
 544         return ret;
 545 }
 546
 547 static int try_to_free_disk_space(void)
 548 {
 549         int ret;
 550         struct snapshot_list sl;
 551         struct snapshot *victim;
 552         struct timeval now;
 553         const char *why;
 554         int low_disk_space;
 555
 556         ret = disk_space_low(NULL);
 557         if (ret < 0)
 558                 return ret;
 559         low_disk_space = ret;
 560         gettimeofday(&now, NULL);
 561         if (tv_diff(&next_removal_check, &now, NULL) > 0)
 562                 return 0;
 563         if (!low_disk_space) {
 564                 if (conf.keep_redundant_given)
 565                         return 0;
 566                 if (snapshot_creation_status != HS_READY)
 567                         return 0;
 568                 if (next_snapshot_is_due())
 569                         return 0;
 570         }
 571         dss_get_snapshot_list(&sl);
 572         ret = 0;
 573         if (!low_disk_space && sl.num_snapshots <= 1)
 574                 goto out;
 575         why = "outdated";
 576         victim = find_outdated_snapshot(&sl);
 577         if (victim)
 578                 goto remove;
 579         why = "redundant";
 580         victim = find_redundant_snapshot(&sl);
 581         if (victim)
 582                 goto remove;
 583         /* try harder only if disk space is low */
 584         if (!low_disk_space)
 585                 goto out;
 586         why = "orphaned";
 587         victim = find_orphaned_snapshot(&sl);
 588         if (victim)
 589                 goto remove;
 590         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 591         victim = find_oldest_removable_snapshot(&sl);
 592         if (victim)
 593                 goto remove;
 594         DSS_CRIT_LOG("uhuhu: disk space low and nothing to remove\n");
 595         ret = -ERRNO_TO_DSS_ERROR(ENOSPC);
 596         goto out;
 597 remove:
 598         pre_remove_hook(victim, why);
 599 out:
 600         free_snapshot_list(&sl);
 601         return ret;
 602 }
 603
 604 static void post_create_hook(void)
 605 {
 606         char *cmd = make_message("%s %s/%s", conf.post_create_hook_arg,
 607                 conf.dest_dir_arg, path_to_last_complete_snapshot);
 608         DSS_NOTICE_LOG("executing %s\n", cmd);
 609         dss_exec_cmdline_pid(&create_pid, cmd);
 610         free(cmd);
 611         snapshot_creation_status = HS_POST_RUNNING;
 612 }
 613
 614 static void post_remove_hook(void)
 615 {
 616         char *cmd;
 617         struct snapshot *s = snapshot_currently_being_removed;
 618
 619         assert(s);
 620
 621         cmd = make_message("%s %s/%s", conf.post_remove_hook_arg,
 622                 conf.dest_dir_arg, s->name);
 623         DSS_NOTICE_LOG("executing %s\n", cmd);
 624         dss_exec_cmdline_pid(&remove_pid, cmd);
 625         free(cmd);
 626         snapshot_removal_status = HS_POST_RUNNING;
 627 }
 628
 629 static void dss_kill(pid_t pid, int sig, const char *msg)
 630 {
 631         const char *signame, *process_name;
 632
 633         if (pid == 0)
 634                 return;
 635         switch (sig) {
 636         case SIGTERM: signame = "TERM"; break;
 637         case SIGSTOP: signame = "STOP"; break;
 638         case SIGCONT: signame = "CONT"; break;
 639         default: signame = "????";
 640         }
 641
 642         if (pid == create_pid)
 643                 process_name = "create";
 644         else if (pid == remove_pid)
 645                 process_name = "remove";
 646         else process_name = "??????";
 647
 648         if (msg)
 649                 DSS_INFO_LOG("%s\n", msg);
 650         DSS_DEBUG_LOG("sending signal %d (%s) to pid %d (%s process)\n",
 651                 sig, signame, (int)pid, process_name);
 652         if (kill(pid, sig) >= 0)
 653                 return;
 654         DSS_INFO_LOG("failed to send signal %d (%s) to pid %d (%s process)\n",
 655                 sig, signame, (int)pid, process_name);
 656 }
 657
 658 static void stop_create_process(void)
 659 {
 660         if (create_process_stopped)
 661                 return;
 662         dss_kill(create_pid, SIGSTOP, "suspending create process");
 663         create_process_stopped = 1;
 664 }
 665
 666 static void restart_create_process(void)
 667 {
 668         if (!create_process_stopped)
 669                 return;
 670         dss_kill(create_pid, SIGCONT, "resuming create process");
 671         create_process_stopped = 0;
 672 }
 673
 674 /**
 675  * Print a log message about the exit status of a child.
 676  */
 677 static void log_termination_msg(pid_t pid, int status)
 678 {
 679         if (WIFEXITED(status))
 680                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 681                         WEXITSTATUS(status));
 682         else if (WIFSIGNALED(status))
 683                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 684                         WTERMSIG(status));
 685         else
 686                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 687 }
 688
 689 static int wait_for_process(pid_t pid, int *status)
 690 {
 691         int ret;
 692
 693         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 694         for (;;) {
 695                 fd_set rfds;
 696
 697                 FD_ZERO(&rfds);
 698                 FD_SET(signal_pipe, &rfds);
 699                 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
 700                 if (ret < 0)
 701                         break;
 702                 ret = next_signal();
 703                 if (!ret)
 704                         continue;
 705                 if (ret == SIGCHLD) {
 706                         ret = waitpid(pid, status, 0);
 707                         if (ret >= 0)
 708                                 break;
 709                         if (errno != EINTR) { /* error */
 710                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 711                                 break;
 712                         }
 713                 }
 714                 /* SIGINT or SIGTERM */
 715                 dss_kill(pid, SIGTERM, "killing child process");
 716         }
 717         if (ret < 0)
 718                 DSS_ERROR_LOG("failed to wait for process %d\n", (int)pid);
 719         else
 720                 log_termination_msg(pid, *status);
 721         return ret;
 722 }
 723
 724 static void handle_pre_remove_exit(int status)
 725 {
 726         if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
 727                 snapshot_removal_status = HS_READY;
 728                 gettimeofday(&next_removal_check, NULL);
 729                 next_removal_check.tv_sec += 60;
 730                 return;
 731         }
 732         snapshot_removal_status = HS_PRE_SUCCESS;
 733 }
 734
 735 static int handle_rm_exit(int status)
 736 {
 737         if (!WIFEXITED(status)) {
 738                 snapshot_removal_status = HS_READY;
 739                 return -E_INVOLUNTARY_EXIT;
 740         }
 741         if (WEXITSTATUS(status)) {
 742                 snapshot_removal_status = HS_READY;
 743                 return -E_BAD_EXIT_CODE;
 744         }
 745         snapshot_removal_status = HS_SUCCESS;
 746         return 1;
 747 }
 748
 749 static void handle_post_remove_exit(void)
 750 {
 751         snapshot_removal_status = HS_READY;
 752 }
 753
 754 static int handle_remove_exit(int status)
 755 {
 756         int ret;
 757         struct snapshot *s = snapshot_currently_being_removed;
 758
 759         assert(s);
 760         switch (snapshot_removal_status) {
 761         case HS_PRE_RUNNING:
 762                 handle_pre_remove_exit(status);
 763                 ret = 1;
 764                 break;
 765         case HS_RUNNING:
 766                 ret = handle_rm_exit(status);
 767                 break;
 768         case HS_POST_RUNNING:
 769                 handle_post_remove_exit();
 770                 ret = 1;
 771                 break;
 772         default:
 773                 ret = -E_BUG;
 774         }
 775         if (snapshot_removal_status == HS_READY) {
 776                 free(s->name);
 777                 free(s);
 778                 snapshot_currently_being_removed = NULL;
 779         }
 780         remove_pid = 0;
 781         return ret;
 782 }
 783
 784 static int wait_for_remove_process(void)
 785 {
 786         int status, ret;
 787
 788         assert(remove_pid);
 789         assert(
 790                 snapshot_removal_status == HS_PRE_RUNNING ||
 791                 snapshot_removal_status == HS_RUNNING ||
 792                 snapshot_removal_status == HS_POST_RUNNING
 793         );
 794         ret = wait_for_process(remove_pid, &status);
 795         if (ret < 0)
 796                 return ret;
 797         return handle_remove_exit(status);
 798 }
 799
 800 static int handle_rsync_exit(int status)
 801 {
 802         int es, ret;
 803
 804         if (!WIFEXITED(status)) {
 805                 DSS_ERROR_LOG("rsync process %d died involuntary\n", (int)create_pid);
 806                 ret = -E_INVOLUNTARY_EXIT;
 807                 snapshot_creation_status = HS_READY;
 808                 goto out;
 809         }
 810         es = WEXITSTATUS(status);
 811         /*
 812          * Restart rsync on non-fatal errors:
 813          * 12: Error in rsync protocol data stream
 814          * 13: Errors with program diagnostics
 815          */
 816         if (es == 12 || es == 13) {
 817                 DSS_WARNING_LOG("rsync process %d returned %d -- restarting\n",
 818                         (int)create_pid, es);
 819                 snapshot_creation_status = HS_NEEDS_RESTART;
 820                 next_snapshot_time = get_current_time() + 60;
 821                 ret = 1;
 822                 goto out;
 823         }
 824         if (es != 0 && es != 23 && es != 24) {
 825                 DSS_ERROR_LOG("rsync process %d returned %d\n", (int)create_pid, es);
 826                 ret = -E_BAD_EXIT_CODE;
 827                 snapshot_creation_status = HS_READY;
 828                 goto out;
 829         }
 830         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 831         if (ret < 0)
 832                 goto out;
 833         snapshot_creation_status = HS_SUCCESS;
 834         free(name_of_reference_snapshot);
 835         name_of_reference_snapshot = NULL;
 836 out:
 837         create_process_stopped = 0;
 838         return ret;
 839 }
 840
 841 static int handle_pre_create_hook_exit(int status)
 842 {
 843         int es, ret;
 844         static int warn_count;
 845
 846         if (!WIFEXITED(status)) {
 847                 snapshot_creation_status = HS_READY;
 848                 ret = -E_INVOLUNTARY_EXIT;
 849                 goto out;
 850         }
 851         es = WEXITSTATUS(status);
 852         if (es) {
 853                 if (!warn_count--) {
 854                         DSS_NOTICE_LOG("pre_create_hook %s returned %d\n",
 855                                 conf.pre_create_hook_arg, es);
 856                         DSS_NOTICE_LOG("deferring snapshot creation...\n");
 857                         warn_count = 60; /* warn only once per hour */
 858                 }
 859                 next_snapshot_time = get_current_time() + 60;
 860                 snapshot_creation_status = HS_READY;
 861                 ret = 0;
 862                 goto out;
 863         }
 864         warn_count = 0;
 865         snapshot_creation_status = HS_PRE_SUCCESS;
 866         ret = 1;
 867 out:
 868         return ret;
 869 }
 870
 871 static int handle_sigchld(void)
 872 {
 873         pid_t pid;
 874         int status, ret = reap_child(&pid, &status);
 875
 876         if (ret <= 0)
 877                 return ret;
 878
 879         if (pid == create_pid) {
 880                 switch (snapshot_creation_status) {
 881                 case HS_PRE_RUNNING:
 882                         ret = handle_pre_create_hook_exit(status);
 883                         break;
 884                 case HS_RUNNING:
 885                         ret = handle_rsync_exit(status);
 886                         break;
 887                 case HS_POST_RUNNING:
 888                         snapshot_creation_status = HS_READY;
 889                         ret = 1;
 890                         break;
 891                 default:
 892                         DSS_EMERG_LOG("BUG: create can't die in status %d\n",
 893                                 snapshot_creation_status);
 894                         return -E_BUG;
 895                 }
 896                 create_pid = 0;
 897                 return ret;
 898         }
 899         if (pid == remove_pid) {
 900                 ret = handle_remove_exit(status);
 901                 if (ret < 0)
 902                         return ret;
 903                 return ret;
 904         }
 905         DSS_EMERG_LOG("BUG: unknown process %d died\n", (int)pid);
 906         return -E_BUG;
 907 }
 908
 909 static int check_config(void)
 910 {
 911         if (conf.unit_interval_arg <= 0) {
 912                 DSS_ERROR_LOG("bad unit interval: %i\n", conf.unit_interval_arg);
 913                 return -E_INVALID_NUMBER;
 914         }
 915         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 916         if (conf.num_intervals_arg <= 0) {
 917                 DSS_ERROR_LOG("bad number of intervals  %i\n", conf.num_intervals_arg);
 918                 return -E_INVALID_NUMBER;
 919         }
 920         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 921         return 1;
 922 }
 923
 924 /*
 925  * Returns < 0 on errors, 0 if no config file is given and > 0 if the config
 926  * file was read successfully.
 927  */
 928 static int parse_config_file(int override)
 929 {
 930         int ret, config_file_exists;
 931         char *config_file = get_config_file_name();
 932         struct stat statbuf;
 933         char *old_logfile_arg = NULL;
 934         int old_daemon_given = 0;
 935
 936         if (override) { /* SIGHUP */
 937                 if (conf.logfile_given)
 938                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 939                 old_daemon_given = conf.daemon_given;
 940         }
 941
 942         config_file_exists = !stat(config_file, &statbuf);
 943         if (!config_file_exists && conf.config_file_given) {
 944                 ret = -ERRNO_TO_DSS_ERROR(errno);
 945                 DSS_ERROR_LOG("failed to stat config file %s\n", config_file);
 946                 goto out;
 947         }
 948         if (config_file_exists) {
 949                 struct cmdline_parser_params params = {
 950                         .override = override,
 951                         .initialize = 0,
 952                         .check_required = 1,
 953                         .check_ambiguity = 0,
 954                         .print_errors = 1
 955                 };
 956                 if (override) { /* invalidate all rsync options */
 957                         int i;
 958
 959                         for (i = 0; i < conf.rsync_option_given; i++) {
 960                                 free(conf.rsync_option_arg[i]);
 961                                 conf.rsync_option_arg[i] = NULL;
 962                         }
 963                         conf.rsync_option_given = 0;
 964                 }
 965                 cmdline_parser_config_file(config_file, &conf, &params);
 966         }
 967         ret = check_config();
 968         if (ret < 0)
 969                 goto out;
 970         if (override) {
 971                 /* don't change daemon mode on SIGHUP */
 972                 conf.daemon_given = old_daemon_given;
 973                 close_log(logfile);
 974                 logfile = NULL;
 975                 if (conf.logfile_given)
 976                         free(old_logfile_arg);
 977                 else if (conf.daemon_given) { /* re-use old logfile */
 978                         conf.logfile_arg = old_logfile_arg;
 979                         conf.logfile_given = 1;
 980                 }
 981         }
 982         if (conf.logfile_given && conf.run_given && conf.daemon_given) {
 983                 logfile = open_log(conf.logfile_arg);
 984                 log_welcome(conf.loglevel_arg);
 985         }
 986         DSS_DEBUG_LOG("loglevel: %d\n", conf.loglevel_arg);
 987         ret = config_file_exists;
 988 out:
 989         free(config_file);
 990         if (ret < 0)
 991                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
 992         return ret;
 993 }
 994
 995 static int change_to_dest_dir(void)
 996 {
 997         DSS_INFO_LOG("changing cwd to %s\n", conf.dest_dir_arg);
 998         return dss_chdir(conf.dest_dir_arg);
 999 }
1000
1001 static int handle_sighup(void)
1002 {
1003         int ret;
1004
1005         DSS_NOTICE_LOG("SIGHUP, re-reading config\n");
1006         dump_dss_config("old");
1007         ret = parse_config_file(1);
1008         if (ret < 0)
1009                 return ret;
1010         dump_dss_config("reloaded");
1011         invalidate_next_snapshot_time();
1012         return change_to_dest_dir();
1013 }
1014
1015 static int handle_signal(void)
1016 {
1017         int sig, ret = next_signal();
1018
1019         if (ret <= 0)
1020                 goto out;
1021         sig = ret;
1022         switch (sig) {
1023         case SIGINT:
1024         case SIGTERM:
1025                 restart_create_process();
1026                 dss_kill(create_pid, SIGTERM, NULL);
1027                 dss_kill(remove_pid, SIGTERM, NULL);
1028                 ret = -E_SIGNAL;
1029                 break;
1030         case SIGHUP:
1031                 ret = handle_sighup();
1032                 break;
1033         case SIGCHLD:
1034                 ret = handle_sigchld();
1035                 break;
1036         }
1037 out:
1038         if (ret < 0)
1039                 DSS_ERROR_LOG("%s\n", dss_strerror(-ret));
1040         return ret;
1041 }
1042
1043 /*
1044  * We can not use rsync locally if the local user is different from the remote
1045  * user or if the src dir is not on the local host (or both).
1046  */
1047 static int use_rsync_locally(char *logname)
1048 {
1049         char *h = conf.remote_host_arg;
1050
1051         if (strcmp(h, "localhost") && strcmp(h, "127.0.0.1"))
1052                 return 0;
1053         if (conf.remote_user_given && strcmp(conf.remote_user_arg, logname))
1054                 return 0;
1055         return 1;
1056 }
1057
1058 static int rename_resume_snap(int64_t creation_time)
1059 {
1060         struct snapshot_list sl = {.num_snapshots = 0};
1061         struct snapshot *s = NULL;
1062         char *new_name = incomplete_name(creation_time);
1063         int ret;
1064         const char *why;
1065
1066         ret = 0;
1067         if (conf.no_resume_given)
1068                 goto out;
1069         dss_get_snapshot_list(&sl);
1070         /*
1071          * Snapshot recycling: We first look at the newest snapshot. If this
1072          * snapshot happens to be incomplete, the last rsync process was
1073          * aborted and we reuse this one. Otherwise we look at snapshots which
1074          * could be removed (outdated and redundant snapshots) as candidates
1075          * for recycling. If no outdated/redundant snapshot exists, we check if
1076          * there is an orphaned snapshot, which likely is useless anyway.
1077          *
1078          * Only if no existing snapshot is suitable for recycling, we bite the
1079          * bullet and create a new one.
1080          */
1081         s = get_newest_snapshot(&sl);
1082         if (!s) /* no snapshots at all */
1083                 goto out;
1084         /* re-use last snapshot if it is incomplete */
1085         why = "aborted";
1086         if ((s->flags & SS_COMPLETE) == 0)
1087                 goto out;
1088         why = "outdated";
1089         s = find_outdated_snapshot(&sl);
1090         if (s)
1091                 goto out;
1092         why = "redundant";
1093         s = find_redundant_snapshot(&sl);
1094         if (s)
1095                 goto out;
1096         why = "orphaned";
1097         s = find_orphaned_snapshot(&sl);
1098 out:
1099         if (s) {
1100                 DSS_INFO_LOG("reusing %s snapshot %s\n", why, s->name);
1101                 ret = dss_rename(s->name, new_name);
1102         }
1103         if (ret >= 0)
1104                 DSS_NOTICE_LOG("creating new snapshot %s\n", new_name);
1105         free(new_name);
1106         free_snapshot_list(&sl);
1107         return ret;
1108 }
1109
1110 static void create_rsync_argv(char ***argv, int64_t *num)
1111 {
1112         char *logname;
1113         int i = 0, j;
1114         struct snapshot_list sl;
1115
1116         dss_get_snapshot_list(&sl);
1117         assert(!name_of_reference_snapshot);
1118         name_of_reference_snapshot = name_of_newest_complete_snapshot(&sl);
1119         free_snapshot_list(&sl);
1120
1121         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
1122         (*argv)[i++] = dss_strdup("rsync");
1123         (*argv)[i++] = dss_strdup("-aq");
1124         (*argv)[i++] = dss_strdup("--delete");
1125         for (j = 0; j < conf.rsync_option_given; j++)
1126                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
1127         if (name_of_reference_snapshot) {
1128                 DSS_INFO_LOG("using %s as reference\n", name_of_reference_snapshot);
1129                 (*argv)[i++] = make_message("--link-dest=../%s",
1130                         name_of_reference_snapshot);
1131         } else
1132                 DSS_INFO_LOG("no suitable reference snapshot found\n");
1133         logname = dss_logname();
1134         if (use_rsync_locally(logname))
1135                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
1136         else
1137                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
1138                         conf.remote_user_arg : logname,
1139                         conf.remote_host_arg, conf.source_dir_arg);
1140         free(logname);
1141         *num = get_current_time();
1142         (*argv)[i++] = incomplete_name(*num);
1143         (*argv)[i++] = NULL;
1144         for (j = 0; j < i; j++)
1145                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
1146 }
1147
1148 static void free_rsync_argv(char **argv)
1149 {
1150         int i;
1151
1152         if (!argv)
1153                 return;
1154         for (i = 0; argv[i]; i++)
1155                 free(argv[i]);
1156         free(argv);
1157 }
1158
1159 static int create_snapshot(char **argv)
1160 {
1161         int ret;
1162
1163         ret = rename_resume_snap(current_snapshot_creation_time);
1164         if (ret < 0)
1165                 return ret;
1166         dss_exec(&create_pid, argv[0], argv);
1167         snapshot_creation_status = HS_RUNNING;
1168         return ret;
1169 }
1170
1171 static int select_loop(void)
1172 {
1173         int ret;
1174         /* check every 60 seconds for free disk space */
1175         struct timeval tv;
1176         char **rsync_argv = NULL;
1177
1178         for (;;) {
1179                 fd_set rfds;
1180                 struct timeval *tvp;
1181
1182                 if (remove_pid)
1183                         tvp = NULL; /* sleep until rm hook/process dies */
1184                 else { /* sleep one minute */
1185                         tv.tv_sec = 60;
1186                         tv.tv_usec = 0;
1187                         tvp = &tv;
1188                 }
1189                 FD_ZERO(&rfds);
1190                 FD_SET(signal_pipe, &rfds);
1191                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
1192                 if (ret < 0)
1193                         goto out;
1194                 if (FD_ISSET(signal_pipe, &rfds)) {
1195                         ret = handle_signal();
1196                         if (ret < 0)
1197                                 goto out;
1198                 }
1199                 if (remove_pid)
1200                         continue;
1201                 if (snapshot_removal_status == HS_PRE_SUCCESS) {
1202                         ret = exec_rm();
1203                         if (ret < 0)
1204                                 goto out;
1205                         continue;
1206                 }
1207                 if (snapshot_removal_status == HS_SUCCESS) {
1208                         post_remove_hook();
1209                         continue;
1210                 }
1211                 ret = try_to_free_disk_space();
1212                 if (ret < 0)
1213                         goto out;
1214                 if (snapshot_removal_status != HS_READY) {
1215                         stop_create_process();
1216                         continue;
1217                 }
1218                 restart_create_process();
1219                 switch (snapshot_creation_status) {
1220                 case HS_READY:
1221                         if (!next_snapshot_is_due())
1222                                 continue;
1223                         pre_create_hook();
1224                         continue;
1225                 case HS_PRE_RUNNING:
1226                 case HS_RUNNING:
1227                 case HS_POST_RUNNING:
1228                         continue;
1229                 case HS_PRE_SUCCESS:
1230                         if (!name_of_reference_snapshot) {
1231                                 free_rsync_argv(rsync_argv);
1232                                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1233                         }
1234                         ret = create_snapshot(rsync_argv);
1235                         if (ret < 0)
1236                                 goto out;
1237                         continue;
1238                 case HS_NEEDS_RESTART:
1239                         if (!next_snapshot_is_due())
1240                                 continue;
1241                         ret = create_snapshot(rsync_argv);
1242                         if (ret < 0)
1243                                 goto out;
1244                         continue;
1245                 case HS_SUCCESS:
1246                         post_create_hook();
1247                         continue;
1248                 }
1249         }
1250 out:
1251         return ret;
1252 }
1253
1254 static void exit_hook(int exit_code)
1255 {
1256         char *argv[] = {conf.exit_hook_arg, dss_strerror(-exit_code), NULL};
1257         pid_t pid;
1258
1259         DSS_NOTICE_LOG("executing %s %s\n", argv[0], argv[1]);
1260         dss_exec(&pid, conf.exit_hook_arg, argv);
1261 }
1262
1263 static void lock_dss_or_die(void)
1264 {
1265         char *config_file = get_config_file_name();
1266         int ret = lock_dss(config_file);
1267
1268         free(config_file);
1269         if (ret < 0) {
1270                 DSS_EMERG_LOG("failed to lock: %s\n", dss_strerror(-ret));
1271                 exit(EXIT_FAILURE);
1272         }
1273 }
1274
1275 static int com_run(void)
1276 {
1277         int ret;
1278
1279         lock_dss_or_die();
1280         if (conf.dry_run_given) {
1281                 DSS_ERROR_LOG("dry_run not supported by this command\n");
1282                 return -E_SYNTAX;
1283         }
1284         ret = install_sighandler(SIGHUP);
1285         if (ret < 0)
1286                 return ret;
1287         ret = select_loop();
1288         if (ret >= 0) /* impossible */
1289                 ret = -E_BUG;
1290         exit_hook(ret);
1291         return ret;
1292 }
1293
1294 static int com_prune(void)
1295 {
1296         int ret;
1297         struct snapshot_list sl;
1298         struct snapshot *victim;
1299         struct disk_space ds;
1300         const char *why;
1301
1302         lock_dss_or_die();
1303         ret = get_disk_space(".", &ds);
1304         if (ret < 0)
1305                 return ret;
1306         log_disk_space(&ds);
1307         dss_get_snapshot_list(&sl);
1308         why = "outdated";
1309         victim = find_outdated_snapshot(&sl);
1310         if (victim)
1311                 goto rm;
1312         why = "redundant";
1313         victim = find_redundant_snapshot(&sl);
1314         if (victim)
1315                 goto rm;
1316         ret = 0;
1317         goto out;
1318 rm:
1319         if (conf.dry_run_given) {
1320                 dss_msg("%s snapshot %s (interval = %i)\n",
1321                         why, victim->name, victim->interval);
1322                 ret = 0;
1323                 goto out;
1324         }
1325         pre_remove_hook(victim, why);
1326         if (snapshot_removal_status == HS_PRE_RUNNING) {
1327                 ret = wait_for_remove_process();
1328                 if (ret < 0)
1329                         goto out;
1330                 if (snapshot_removal_status != HS_PRE_SUCCESS)
1331                         goto out;
1332         }
1333         ret = exec_rm();
1334         if (ret < 0)
1335                 goto out;
1336         ret = wait_for_remove_process();
1337         if (ret < 0)
1338                 goto out;
1339         if (snapshot_removal_status != HS_SUCCESS)
1340                 goto out;
1341         post_remove_hook();
1342         if (snapshot_removal_status != HS_POST_RUNNING)
1343                 goto out;
1344         ret = wait_for_remove_process();
1345         if (ret < 0)
1346                 goto out;
1347         ret = 1;
1348 out:
1349         free_snapshot_list(&sl);
1350         return ret;
1351 }
1352
1353 static int com_create(void)
1354 {
1355         int ret, status;
1356         char **rsync_argv;
1357
1358         lock_dss_or_die();
1359         if (conf.dry_run_given) {
1360                 int i;
1361                 char *msg = NULL;
1362                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1363                 for (i = 0; rsync_argv[i]; i++) {
1364                         char *tmp = msg;
1365                         msg = make_message("%s%s%s", tmp? tmp : "",
1366                                 tmp? " " : "", rsync_argv[i]);
1367                         free(tmp);
1368                 }
1369                 free_rsync_argv(rsync_argv);
1370                 dss_msg("%s\n", msg);
1371                 free(msg);
1372                 return 1;
1373         }
1374         pre_create_hook();
1375         if (create_pid) {
1376                 ret = wait_for_process(create_pid, &status);
1377                 if (ret < 0)
1378                         return ret;
1379                 ret = handle_pre_create_hook_exit(status);
1380                 if (ret <= 0) /* error, or pre-create failed */
1381                         return ret;
1382         }
1383         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1384         ret = create_snapshot(rsync_argv);
1385         if (ret < 0)
1386                 goto out;
1387         ret = wait_for_process(create_pid, &status);
1388         if (ret < 0)
1389                 goto out;
1390         ret = handle_rsync_exit(status);
1391         if (ret < 0)
1392                 goto out;
1393         post_create_hook();
1394         if (create_pid)
1395                 ret = wait_for_process(create_pid, &status);
1396 out:
1397         free_rsync_argv(rsync_argv);
1398         return ret;
1399 }
1400
1401 static int com_ls(void)
1402 {
1403         int i;
1404         struct snapshot_list sl;
1405         struct snapshot *s;
1406
1407         dss_get_snapshot_list(&sl);
1408         FOR_EACH_SNAPSHOT(s, i, &sl) {
1409                 int64_t d = 0;
1410                 if (s->flags & SS_COMPLETE)
1411                         d = (s->completion_time - s->creation_time) / 60;
1412                 dss_msg("%u\t%s\t%3" PRId64 ":%02" PRId64 "\n", s->interval, s->name, d/60, d%60);
1413         };
1414         free_snapshot_list(&sl);
1415         return 1;
1416 }
1417
1418 static int setup_signal_handling(void)
1419 {
1420         int ret;
1421
1422         DSS_INFO_LOG("setting up signal handlers\n");
1423         signal_pipe = signal_init(); /* always successful */
1424         ret = install_sighandler(SIGINT);
1425         if (ret < 0)
1426                 return ret;
1427         ret = install_sighandler(SIGTERM);
1428         if (ret < 0)
1429                 return ret;
1430         return install_sighandler(SIGCHLD);
1431 }
1432
1433 /**
1434  * The main function of dss.
1435  *
1436  * \param argc Usual argument count.
1437  * \param argv Usual argument vector.
1438  */
1439 int main(int argc, char **argv)
1440 {
1441         int ret;
1442         struct cmdline_parser_params params = {
1443                 .override = 0,
1444                 .initialize = 1,
1445                 .check_required = 0,
1446                 .check_ambiguity = 0,
1447                 .print_errors = 1
1448         };
1449
1450         cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1451         ret = parse_config_file(0);
1452         if (ret < 0)
1453                 goto out;
1454         if (ret == 0) { /* no config file given */
1455                 /*
1456                  * Parse the command line options again, but this time check
1457                  * that all required options are given.
1458                  */
1459                 params = (struct cmdline_parser_params) {
1460                         .override = 1,
1461                         .initialize = 1,
1462                         .check_required = 1,
1463                         .check_ambiguity = 1,
1464                         .print_errors = 1
1465                 };
1466                 cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1467         }
1468         if (conf.daemon_given)
1469                 daemon_init();
1470         ret = change_to_dest_dir();
1471         if (ret < 0)
1472                 goto out;
1473         dump_dss_config("startup");
1474         ret = setup_signal_handling();
1475         if (ret < 0)
1476                 goto out;
1477         ret = call_command_handler();
1478 out:
1479         if (ret < 0)
1480                 DSS_EMERG_LOG("%s\n", dss_strerror(-ret));
1481         exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1482 }