dss.c

   1 #include <string.h>
   2 #include <stdlib.h>
   3 #include <stdarg.h>
   4 #include <assert.h>
   5 #include <errno.h>
   6 #include <sys/types.h>
   7 #include <signal.h>
   8 #include <ctype.h>
   9 #include <sys/stat.h>
  10 #include <unistd.h>
  11 #include <inttypes.h>
  12 #include <sys/time.h>
  13 #include <time.h>
  14 #include <sys/wait.h>
  15 #include <fnmatch.h>
  16 #include <limits.h>
  17
  18
  19 #include "gcc-compat.h"
  20 #include "cmdline.h"
  21 #include "log.h"
  22 #include "string.h"
  23 #include "error.h"
  24 #include "fd.h"
  25 #include "exec.h"
  26 #include "daemon.h"
  27 #include "signal.h"
  28 #include "df.h"
  29 #include "time.h"
  30
  31
  32 struct gengetopt_args_info conf;
  33 char *dss_error_txt = NULL;
  34 static FILE *logfile;
  35 static int signal_pipe;
  36
  37 /** Process id of current rsync process. */
  38 static pid_t rsync_pid;
  39 /** Whether the rsync process is currently stopped */
  40 static int rsync_stopped;
  41 /** Process id of current rm process. */
  42 static pid_t rm_pid;
  43 /** When the next snapshot is due. */
  44 struct timeval next_snapshot_time;
  45 /* Creation time of the snapshot currently being created. */
  46 int64_t current_snapshot_creation_time;
  47
  48
  49 DEFINE_DSS_ERRLIST;
  50
  51
  52 /* a litte cpp magic helps to DRY */
  53 #define COMMANDS \
  54         COMMAND(ls) \
  55         COMMAND(create) \
  56         COMMAND(prune) \
  57         COMMAND(run)
  58 #define COMMAND(x) int com_ ##x(void);
  59 COMMANDS
  60 #undef COMMAND
  61 #define COMMAND(x) if (conf.x ##_given) return com_ ##x();
  62 int call_command_handler(void)
  63 {
  64         COMMANDS
  65         DSS_EMERG_LOG("BUG: did not find command handler\n");
  66         exit(EXIT_FAILURE);
  67 }
  68 #undef COMMAND
  69 #undef COMMANDS
  70
  71 /*
  72  * complete, not being deleted: 1204565370-1204565371.Sun_Mar_02_2008_14_33-Sun_Mar_02_2008_14_43
  73  * complete, being deleted: 1204565370-1204565371.being_deleted
  74  * incomplete, not being deleted: 1204565370-incomplete
  75  * incomplete, being deleted: 1204565370-incomplete.being_deleted
  76  */
  77 enum snapshot_status_flags {
  78         /** The rsync process terminated successfully. */
  79         SS_COMPLETE = 1,
  80         /** The rm process is running to remove this snapshot. */
  81         SS_BEING_DELETED = 2,
  82 };
  83
  84 struct snapshot {
  85         char *name;
  86         int64_t creation_time;
  87         int64_t completion_time;
  88         enum snapshot_status_flags flags;
  89         unsigned interval;
  90 };
  91
  92 /*
  93  * An edge snapshot is either the oldest one or the newest one.
  94  *
  95  * We need to find either of them occasionally: The create code
  96  * needs to know the newest snapshot because that is the one
  97  * used as the link destination dir. The pruning code needs to
  98  * find the oldest one in case disk space becomes low.
  99  */
 100 struct edge_snapshot_data {
 101         int64_t now;
 102         struct snapshot snap;
 103 };
 104
 105 __printf_2_3 void dss_log(int ll, const char* fmt,...)
 106 {
 107         va_list argp;
 108         FILE *outfd;
 109         struct tm *tm;
 110         time_t t1;
 111         char str[255] = "";
 112
 113         if (ll < conf.loglevel_arg)
 114                 return;
 115         outfd = logfile? logfile : stderr;
 116         time(&t1);
 117         tm = localtime(&t1);
 118         strftime(str, sizeof(str), "%b %d %H:%M:%S", tm);
 119         fprintf(outfd, "%s ", str);
 120         if (conf.loglevel_arg <= INFO)
 121                 fprintf(outfd, "%i: ", ll);
 122         va_start(argp, fmt);
 123         vfprintf(outfd, fmt, argp);
 124         va_end(argp);
 125 }
 126
 127 /**
 128  * Print a message either to stdout or to the log file.
 129  */
 130 __printf_1_2 void dss_msg(const char* fmt,...)
 131 {
 132         FILE *outfd = conf.daemon_given? logfile : stdout;
 133         va_list argp;
 134         va_start(argp, fmt);
 135         vfprintf(outfd, fmt, argp);
 136         va_end(argp);
 137 }
 138
 139 /**
 140  * Return the desired number of snapshots of an interval.
 141  */
 142 unsigned num_snapshots(int interval)
 143 {
 144         unsigned n;
 145
 146         assert(interval >= 0);
 147
 148         if (interval >= conf.num_intervals_arg)
 149                 return 0;
 150         n = conf.num_intervals_arg - interval - 1;
 151         return 1 << n;
 152 }
 153
 154 /* return: Whether dirname is a snapshot directory (0: no, 1: yes) */
 155 int is_snapshot(const char *dirname, int64_t now, struct snapshot *s)
 156 {
 157         int i, ret;
 158         char *dash, *dot, *tmp;
 159         int64_t num;
 160
 161         assert(dirname);
 162         dash = strchr(dirname, '-');
 163         if (!dash || !dash[1] || dash == dirname)
 164                 return 0;
 165         for (i = 0; dirname[i] != '-'; i++)
 166                 if (!isdigit(dirname[i]))
 167                         return 0;
 168         tmp = dss_strdup(dirname);
 169         tmp[i] = '\0';
 170         ret = dss_atoi64(tmp, &num);
 171         free(tmp);
 172         if (ret < 0) {
 173                 free(dss_error_txt);
 174                 return 0;
 175         }
 176         assert(num >= 0);
 177         if (num > now)
 178                 return 0;
 179         s->creation_time = num;
 180         //DSS_DEBUG_LOG("%s start time: %lli\n", dirname, (long long)s->creation_time);
 181         s->interval = (long long) ((now - s->creation_time)
 182                 / conf.unit_interval_arg / 24 / 3600);
 183         if (!strcmp(dash + 1, "incomplete")) {
 184                 s->completion_time = -1;
 185                 s->flags = 0; /* neither complete, nor being deleted */
 186                 goto success;
 187         }
 188         if (!strcmp(dash + 1, "incomplete.being_deleted")) {
 189                 s->completion_time = -1;
 190                 s->flags = SS_BEING_DELETED; /* mot cpmplete, being deleted */
 191                 goto success;
 192         }
 193         tmp = dash + 1;
 194         dot = strchr(tmp, '.');
 195         if (!dot || !dot[1] || dot == tmp)
 196                 return 0;
 197         for (i = 0; tmp[i] != '.'; i++)
 198                 if (!isdigit(tmp[i]))
 199                         return 0;
 200         tmp = dss_strdup(dash + 1);
 201         tmp[i] = '\0';
 202         ret = dss_atoi64(tmp, &num);
 203         free(tmp);
 204         if (ret < 0) {
 205                 free(dss_error_txt);
 206                 return 0;
 207         }
 208         if (num > now)
 209                 return 0;
 210         s->completion_time = num;
 211         s->flags = SS_COMPLETE;
 212         if (!strcmp(dot + 1, "being_deleted"))
 213                 s->flags |= SS_BEING_DELETED;
 214 success:
 215         s->name = dss_strdup(dirname);
 216         return 1;
 217 }
 218
 219 int64_t get_current_time(void)
 220 {
 221         time_t now;
 222         time(&now);
 223         DSS_DEBUG_LOG("now: %lli\n", (long long) now);
 224         return (int64_t)now;
 225 }
 226
 227 char *incomplete_name(int64_t start)
 228 {
 229         return make_message("%lli-incomplete", (long long)start);
 230 }
 231
 232 char *being_deleted_name(struct snapshot *s)
 233 {
 234         if (s->flags & SS_COMPLETE)
 235                 return make_message("%lli-%lli.being_deleted",
 236                         (long long)s->creation_time,
 237                         (long long)s->completion_time);
 238         return make_message("%lli-incomplete.being_deleted",
 239                 (long long)s->creation_time);
 240 }
 241
 242 int complete_name(int64_t start, int64_t end, char **result)
 243 {
 244         struct tm start_tm, end_tm;
 245         time_t *start_seconds = (time_t *) (uint64_t *)&start; /* STFU, gcc */
 246         time_t *end_seconds = (time_t *) (uint64_t *)&end; /* STFU, gcc */
 247         char start_str[200], end_str[200];
 248
 249         if (!localtime_r(start_seconds, &start_tm)) {
 250                 make_err_msg("%lli", (long long)start);
 251                 return -E_LOCALTIME;
 252         }
 253         if (!localtime_r(end_seconds, &end_tm)) {
 254                 make_err_msg("%lli", (long long)end);
 255                 return -E_LOCALTIME;
 256         }
 257         if (!strftime(start_str, sizeof(start_str), "%a_%b_%d_%Y_%H_%M_%S", &start_tm)) {
 258                 make_err_msg("%lli", (long long)start);
 259                 return -E_STRFTIME;
 260         }
 261         if (!strftime(end_str, sizeof(end_str), "%a_%b_%d_%Y_%H_%M_%S", &end_tm)) {
 262                 make_err_msg("%lli", (long long)end);
 263                 return -E_STRFTIME;
 264         }
 265         *result = make_message("%lli-%lli.%s-%s", (long long) start, (long long) end,
 266                 start_str, end_str);
 267         return 1;
 268 }
 269
 270 struct snapshot_list {
 271         int64_t now;
 272         unsigned num_snapshots;
 273         unsigned array_size;
 274         struct snapshot **snapshots;
 275         /**
 276          * Array of size num_intervals + 1
 277          *
 278          * It contains the number of snapshots in each interval. interval_count[num_intervals]
 279          * is the number of snapshots which belong to any interval greater than num_intervals.
 280          */
 281         unsigned *interval_count;
 282 };
 283
 284 #define FOR_EACH_SNAPSHOT(s, i, sl) \
 285         for ((i) = 0; (i) < (sl)->num_snapshots && ((s) = (sl)->snapshots[(i)]); (i)++)
 286
 287
 288
 289 #define NUM_COMPARE(x, y) ((int)((x) < (y)) - (int)((x) > (y)))
 290
 291 static int compare_snapshots(const void *a, const void *b)
 292 {
 293         struct snapshot *s1 = *(struct snapshot **)a;
 294         struct snapshot *s2 = *(struct snapshot **)b;
 295         return NUM_COMPARE(s2->creation_time, s1->creation_time);
 296 }
 297
 298 /** Compute the minimum of \a a and \a b. */
 299 #define DSS_MIN(a,b) ((a) < (b) ? (a) : (b))
 300
 301 int add_snapshot(const char *dirname, void *private)
 302 {
 303         struct snapshot_list *sl = private;
 304         struct snapshot s;
 305         int ret = is_snapshot(dirname, sl->now, &s);
 306
 307         if (!ret)
 308                 return 1;
 309         if (sl->num_snapshots >= sl->array_size) {
 310                 sl->array_size = 2 * sl->array_size + 1;
 311                 sl->snapshots = dss_realloc(sl->snapshots,
 312                         sl->array_size * sizeof(struct snapshot *));
 313         }
 314         sl->snapshots[sl->num_snapshots] = dss_malloc(sizeof(struct snapshot));
 315         *(sl->snapshots[sl->num_snapshots]) = s;
 316         sl->interval_count[DSS_MIN(s.interval, conf.num_intervals_arg)]++;
 317         sl->num_snapshots++;
 318         return 1;
 319 }
 320
 321 void get_snapshot_list(struct snapshot_list *sl)
 322 {
 323         sl->now = get_current_time();
 324         sl->num_snapshots = 0;
 325         sl->array_size = 0;
 326         sl->snapshots = NULL;
 327         sl->interval_count = dss_calloc((conf.num_intervals_arg + 1) * sizeof(unsigned));
 328         for_each_subdir(add_snapshot, sl);
 329         qsort(sl->snapshots, sl->num_snapshots, sizeof(struct snapshot *),
 330                 compare_snapshots);
 331 }
 332
 333 void free_snapshot_list(struct snapshot_list *sl)
 334 {
 335         int i;
 336         struct snapshot *s;
 337
 338         FOR_EACH_SNAPSHOT(s, i, sl) {
 339                 free(s->name);
 340                 free(s);
 341         }
 342         free(sl->interval_count);
 343         sl->interval_count = NULL;
 344         free(sl->snapshots);
 345         sl->snapshots = NULL;
 346         sl->num_snapshots = 0;
 347 }
 348
 349 void stop_rsync_process(void)
 350 {
 351         if (!rsync_pid || rsync_stopped)
 352                 return;
 353         kill(SIGSTOP, rsync_pid);
 354         rsync_stopped = 1;
 355 }
 356
 357 void restart_rsync_process(void)
 358 {
 359         if (!rsync_pid || !rsync_stopped)
 360                 return;
 361         kill (SIGCONT, rsync_pid);
 362         rsync_stopped = 0;
 363 }
 364
 365 /**
 366  * Print a log message about the exit status of a child.
 367  */
 368 void log_termination_msg(pid_t pid, int status)
 369 {
 370         if (WIFEXITED(status))
 371                 DSS_INFO_LOG("child %i exited. Exit status: %i\n", (int)pid,
 372                         WEXITSTATUS(status));
 373         else if (WIFSIGNALED(status))
 374                 DSS_NOTICE_LOG("child %i was killed by signal %i\n", (int)pid,
 375                         WTERMSIG(status));
 376         else
 377                 DSS_WARNING_LOG("child %i terminated abormally\n", (int)pid);
 378 }
 379
 380 int wait_for_process(pid_t pid, int *status)
 381 {
 382         int ret;
 383
 384         DSS_DEBUG_LOG("Waiting for process %d to terminate\n", (int)pid);
 385         for (;;) {
 386                 fd_set rfds;
 387
 388                 FD_ZERO(&rfds);
 389                 FD_SET(signal_pipe, &rfds);
 390                 ret = dss_select(signal_pipe + 1, &rfds, NULL, NULL);
 391                 if (ret < 0)
 392                         break;
 393                 ret = next_signal();
 394                 if (!ret)
 395                         continue;
 396                 if (ret == SIGCHLD) {
 397                         ret = waitpid(pid, status, 0);
 398                         if (ret >= 0)
 399                                 break;
 400                         if (errno != EINTR) { /* error */
 401                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 402                                 break;
 403                         }
 404                 }
 405                 /* SIGINT or SIGTERM */
 406                 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
 407                 kill(pid, SIGTERM);
 408         }
 409         if (ret < 0)
 410                 make_err_msg("failed to wait for process %d", (int)pid);
 411         else
 412                 log_termination_msg(pid, *status);
 413         return ret;
 414 }
 415
 416 int remove_snapshot(struct snapshot *s)
 417 {
 418         int fds[3] = {0, 0, 0};
 419         assert(!rm_pid);
 420         char *new_name = being_deleted_name(s);
 421         int ret = dss_rename(s->name, new_name);
 422         char *argv[] = {"rm", "-rf", new_name, NULL};
 423
 424         if (ret < 0)
 425                 goto out;
 426         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 427         stop_rsync_process();
 428         ret = dss_exec(&rm_pid, argv[0], argv, fds);
 429 out:
 430         free(new_name);
 431         return ret;
 432 }
 433
 434 /*
 435  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 436  */
 437 int remove_redundant_snapshot(struct snapshot_list *sl)
 438 {
 439         int ret, i, interval;
 440         struct snapshot *s;
 441         unsigned missing = 0;
 442
 443         DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
 444         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 445                 unsigned keep = num_snapshots(interval);
 446                 unsigned num = sl->interval_count[interval];
 447                 struct snapshot *victim = NULL, *prev = NULL;
 448                 int64_t score = LONG_MAX;
 449
 450                 if (keep >= num)
 451                         missing += keep - num;
 452                 DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 453                         interval, keep, num, missing);
 454                 if (keep + missing >= num)
 455                         continue;
 456                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 457                 FOR_EACH_SNAPSHOT(s, i, sl) {
 458                         int64_t this_score;
 459
 460                         //DSS_DEBUG_LOG("checking %s\n", s->name);
 461                         if (s->interval > interval) {
 462                                 prev = s;
 463                                 continue;
 464                         }
 465                         if (s->interval < interval)
 466                                 break;
 467                         if (!victim) {
 468                                 victim = s;
 469                                 prev = s;
 470                                 continue;
 471                         }
 472                         assert(prev);
 473                         /* check if s is a better victim */
 474                         this_score = s->creation_time - prev->creation_time;
 475                         assert(this_score >= 0);
 476                         //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 477                         if (this_score < score) {
 478                                 score = this_score;
 479                                 victim = s;
 480                         }
 481                         prev = s;
 482                 }
 483                 assert(victim);
 484                 if (conf.dry_run_given) {
 485                         dss_msg("%s would be removed (interval = %i)\n",
 486                                 victim->name, victim->interval);
 487                         continue;
 488                 }
 489                 ret = remove_snapshot(victim);
 490                 return ret < 0? ret : 1;
 491         }
 492         return 0;
 493 }
 494
 495 int remove_outdated_snapshot(struct snapshot_list *sl)
 496 {
 497         int i, ret;
 498         struct snapshot *s;
 499
 500         DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
 501                 conf.num_intervals_arg);
 502         FOR_EACH_SNAPSHOT(s, i, sl) {
 503                 if (s->interval <= conf.num_intervals_arg)
 504                         continue;
 505                 if (conf.dry_run_given) {
 506                         dss_msg("%s would be removed (interval = %i)\n",
 507                                 s->name, s->interval);
 508                         continue;
 509                 }
 510                 ret = remove_snapshot(s);
 511                 if (ret < 0)
 512                         return ret;
 513                 return 1;
 514         }
 515         return 0;
 516 }
 517
 518 int handle_rm_exit(int status)
 519 {
 520         int es, ret;
 521
 522         if (!WIFEXITED(status)) {
 523                 make_err_msg("rm process %d died involuntary", (int)rm_pid);
 524                 ret = -E_INVOLUNTARY_EXIT;
 525                 goto out;
 526         }
 527         es = WEXITSTATUS(status);
 528         if (es) {
 529                 make_err_msg("rm process %d returned %d", (int)rm_pid, es);
 530                 ret = -E_BAD_EXIT_CODE;
 531                 goto out;
 532         }
 533         ret = 1;
 534         rm_pid = 0;
 535 out:
 536         return ret;
 537 }
 538
 539 int wait_for_rm_process(void)
 540 {
 541         int status, ret = wait_for_process(rm_pid, &status);
 542
 543         if (ret < 0)
 544                 return ret;
 545         return handle_rm_exit(status);
 546 }
 547
 548 void kill_process(pid_t pid)
 549 {
 550         if (!pid)
 551                 return;
 552         DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
 553         kill(pid, SIGTERM);
 554 }
 555
 556 int check_config(void)
 557 {
 558         if (conf.unit_interval_arg <= 0) {
 559                 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
 560                 return -E_INVALID_NUMBER;
 561         }
 562         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 563         if (conf.num_intervals_arg <= 0) {
 564                 make_err_msg("bad number of intervals  %i", conf.num_intervals_arg);
 565                 return -E_INVALID_NUMBER;
 566         }
 567         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 568         return 1;
 569 }
 570
 571 /* exits on errors */
 572 void parse_config_file(int override)
 573 {
 574         int ret;
 575         char *config_file;
 576         struct stat statbuf;
 577         char *old_logfile_arg = NULL;
 578         int old_daemon_given = 0;
 579
 580         if (conf.config_file_given)
 581                 config_file = dss_strdup(conf.config_file_arg);
 582         else {
 583                 char *home = get_homedir();
 584                 config_file = make_message("%s/.dssrc", home);
 585                 free(home);
 586         }
 587         if (override) { /* SIGHUP */
 588                 if (conf.logfile_given)
 589                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 590                 old_daemon_given = conf.daemon_given;
 591         }
 592
 593         ret = stat(config_file, &statbuf);
 594         if (ret && conf.config_file_given) {
 595                 ret = -ERRNO_TO_DSS_ERROR(errno);
 596                 make_err_msg("failed to stat config file %s", config_file);
 597                 goto out;
 598         }
 599         if (!ret) {
 600                 struct cmdline_parser_params params = {
 601                         .override = override,
 602                         .initialize = 0,
 603                         .check_required = 1,
 604                         .check_ambiguity = 0
 605                 };
 606                 cmdline_parser_config_file(config_file, &conf, &params);
 607         }
 608         ret = check_config();
 609         if (ret < 0)
 610                 goto out;
 611         if (override) {
 612                 /* don't change daemon mode on SIGHUP */
 613                 conf.daemon_given = old_daemon_given;
 614                 close_log(logfile);
 615                 logfile = NULL;
 616                 if (conf.logfile_given)
 617                         free(old_logfile_arg);
 618                 else if (conf.daemon_given) { /* re-use old logfile */
 619                         conf.logfile_arg = old_logfile_arg;
 620                         conf.logfile_given = 1;
 621                 }
 622         }
 623         if (conf.logfile_given) {
 624                 logfile = open_log(conf.logfile_arg);
 625                 log_welcome(conf.loglevel_arg);
 626         }
 627         ret = dss_chdir(conf.dest_dir_arg);
 628 out:
 629         free(config_file);
 630         if (ret >= 0)
 631                 return;
 632         log_err_msg(EMERG, -ret);
 633         exit(EXIT_FAILURE);
 634 }
 635
 636 void handle_sighup(void)
 637 {
 638         DSS_NOTICE_LOG("SIGHUP\n");
 639         parse_config_file(1);
 640 }
 641
 642 int rename_incomplete_snapshot(int64_t start)
 643 {
 644         char *old_name, *new_name;
 645         int ret;
 646
 647         ret = complete_name(start, get_current_time(), &new_name);
 648         if (ret < 0)
 649                 return ret;
 650         old_name = incomplete_name(start);
 651         ret = dss_rename(old_name, new_name);
 652         if (ret >= 0)
 653                 DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
 654         free(old_name);
 655         free(new_name);
 656         return ret;
 657 }
 658
 659 int handle_rsync_exit(int status)
 660 {
 661         int es, ret;
 662
 663         if (!WIFEXITED(status)) {
 664                 make_err_msg("rsync process %d died involuntary", (int)rsync_pid);
 665                 ret = -E_INVOLUNTARY_EXIT;
 666                 goto out;
 667         }
 668         es = WEXITSTATUS(status);
 669         if (es != 0 && es != 23 && es != 24) {
 670                 make_err_msg("rsync process %d returned %d", (int)rsync_pid, es);
 671                 ret = -E_BAD_EXIT_CODE;
 672                 goto out;
 673         }
 674         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 675 out:
 676         rsync_pid = 0;
 677         current_snapshot_creation_time = 0;
 678         rsync_stopped = 0;
 679         return ret;
 680 }
 681
 682 int get_newest_complete(const char *dirname, void *private)
 683 {
 684         struct edge_snapshot_data *esd = private;
 685         struct snapshot s;
 686         int ret = is_snapshot(dirname, esd->now, &s);
 687
 688         if (ret <= 0)
 689                 return 1;
 690         if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
 691                 return 1;
 692         if (s.creation_time < esd->snap.creation_time)
 693                 return 1;
 694         free(esd->snap.name);
 695         esd->snap = s;
 696         return 1;
 697 }
 698
 699 __malloc char *name_of_newest_complete_snapshot(void)
 700 {
 701         struct edge_snapshot_data esd = {
 702                 .now = get_current_time(),
 703                 .snap = {.creation_time = -1}
 704         };
 705         for_each_subdir(get_newest_complete, &esd);
 706         return esd.snap.name;
 707 }
 708
 709 void create_rsync_argv(char ***argv, int64_t *num)
 710 {
 711         char *logname, *newest = name_of_newest_complete_snapshot();
 712         int i = 0, j;
 713
 714         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
 715         (*argv)[i++] = dss_strdup("rsync");
 716         (*argv)[i++] = dss_strdup("-aq");
 717         (*argv)[i++] = dss_strdup("--delete");
 718         for (j = 0; j < conf.rsync_option_given; j++)
 719                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
 720         if (newest) {
 721                 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
 722                 (*argv)[i++] = make_message("--link-dest=../%s", newest);
 723                 free(newest);
 724         } else
 725                 DSS_INFO_LOG("no previous snapshot found\n");
 726         if (conf.exclude_patterns_given) {
 727                 (*argv)[i++] = dss_strdup("--exclude-from");
 728                 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
 729
 730         }
 731         logname = dss_logname();
 732         if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
 733                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
 734         else
 735                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
 736                         conf.remote_user_arg : logname,
 737                         conf.remote_host_arg, conf.source_dir_arg);
 738         free(logname);
 739         *num = get_current_time();
 740         (*argv)[i++] = incomplete_name(*num);
 741         (*argv)[i++] = NULL;
 742         for (j = 0; j < i; j++)
 743                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
 744 }
 745
 746 void free_rsync_argv(char **argv)
 747 {
 748         int i;
 749         for (i = 0; argv[i]; i++)
 750                 free(argv[i]);
 751         free(argv);
 752 }
 753
 754 int create_snapshot(char **argv)
 755 {
 756         int fds[3] = {0, 0, 0};
 757         char *name = incomplete_name(current_snapshot_creation_time);
 758
 759         DSS_NOTICE_LOG("creating new snapshot %s\n", name);
 760         free(name);
 761         return dss_exec(&rsync_pid, argv[0], argv, fds);
 762 }
 763
 764 void compute_next_snapshot_time(struct snapshot_list *sl)
 765 {
 766         struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
 767                 tmp, diff;
 768         int64_t x = 0;
 769         unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
 770         int i, ret;
 771         struct snapshot *s;
 772
 773         gettimeofday(&now, NULL);
 774         FOR_EACH_SNAPSHOT(s, i, sl) {
 775                 if (!(s->flags & SS_COMPLETE))
 776                         continue;
 777                 num_complete_snapshots++;
 778                 x += s->completion_time - s->creation_time;
 779         }
 780         assert(x >= 0);
 781         if (num_complete_snapshots)
 782                 x /= num_complete_snapshots; /* avg time to create one snapshot */
 783         x *= wanted; /* time to create all snapshots in interval 0 */
 784         tmp.tv_sec = x;
 785         tmp.tv_usec = 0;
 786         ret = tv_diff(&unit_interval, &tmp, &diff); /* time between creation */
 787         if (ret < 0) {
 788                 next_snapshot_time = now;
 789                 return;
 790         }
 791         tv_divide(wanted, &diff, &tmp);
 792         tv_add(&now, &tmp, &next_snapshot_time);
 793 }
 794
 795 void handle_signal(void)
 796 {
 797         int sig, ret = next_signal();
 798
 799         if (ret <= 0)
 800                 goto out;
 801         sig = ret;
 802         switch (sig) {
 803                 int status;
 804                 pid_t pid;
 805         case SIGINT:
 806         case SIGTERM:
 807                 restart_rsync_process();
 808                 kill_process(rsync_pid);
 809                 kill_process(rm_pid);
 810                 exit(EXIT_FAILURE);
 811         case SIGHUP:
 812                 handle_sighup();
 813                 ret = 1;
 814                 break;
 815         case SIGCHLD:
 816                 ret = reap_child(&pid, &status);
 817                 if (ret <= 0)
 818                         break;
 819                 assert(pid == rsync_pid || pid == rm_pid);
 820                 if (pid == rsync_pid)
 821                         ret = handle_rsync_exit(status);
 822                 else
 823                         ret = handle_rm_exit(status);
 824         }
 825 out:
 826         if (ret < 0)
 827                 log_err_msg(ERROR, -ret);
 828 }
 829
 830 int get_oldest(const char *dirname, void *private)
 831 {
 832         struct edge_snapshot_data *esd = private;
 833         struct snapshot s;
 834         int ret = is_snapshot(dirname, esd->now, &s);
 835
 836         if (ret <= 0)
 837                 return 1;
 838         if (s.creation_time > esd->snap.creation_time)
 839                 return 1;
 840         free(esd->snap.name);
 841         esd->snap = s;
 842         return 1;
 843 }
 844
 845 int remove_oldest_snapshot()
 846 {
 847         int ret;
 848         struct edge_snapshot_data esd = {
 849                 .now = get_current_time(),
 850                 .snap = {.creation_time = LLONG_MAX}
 851         };
 852         for_each_subdir(get_oldest, &esd);
 853         if (!esd.snap.name) /* no snapshot found */
 854                 return 0;
 855         DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
 856         ret = 0;
 857         if (esd.snap.creation_time == current_snapshot_creation_time)
 858                 goto out; /* do not remove the snapshot currently being created */
 859         ret = remove_snapshot(&esd.snap);
 860 out:
 861         free(esd.snap.name);
 862         return ret;
 863 }
 864
 865 /* TODO: Also consider number of inodes. */
 866 int disk_space_low(void)
 867 {
 868         struct disk_space ds;
 869         int ret = get_disk_space(".", &ds);
 870
 871         if (ret < 0)
 872                 return ret;
 873         if (conf.min_free_mb_arg)
 874                 if (ds.free_mb < conf.min_free_mb_arg)
 875                         return 1;
 876         if (conf.min_free_percent_arg)
 877                 if (ds.percent_free < conf.min_free_percent_arg)
 878                         return 1;
 879         return 0;
 880 }
 881
 882 int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
 883 {
 884         int ret;
 885
 886         ret = remove_outdated_snapshot(sl);
 887         if (ret) /* error, or we are removing something */
 888                 return ret;
 889         /* no outdated snapshot */
 890         ret = remove_redundant_snapshot(sl);
 891         if (ret)
 892                 return ret;
 893         if (!low_disk_space)
 894                 return 0;
 895         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 896         ret = remove_oldest_snapshot();
 897         if (ret)
 898                 return ret;
 899         make_err_msg("uhuhu: not enough disk space for a single snapshot");
 900         return  -ENOSPC;
 901 }
 902
 903 int select_loop(void)
 904 {
 905         int ret;
 906         struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
 907         struct snapshot_list sl = {.num_snapshots = 0};
 908
 909         for (;;) {
 910                 struct timeval now, *tvp = &tv;
 911                 fd_set rfds;
 912                 int low_disk_space;
 913                 char **rsync_argv;
 914
 915                 free_snapshot_list(&sl);
 916                 get_snapshot_list(&sl);
 917                 compute_next_snapshot_time(&sl);
 918                 FD_ZERO(&rfds);
 919                 FD_SET(signal_pipe, &rfds);
 920                 if (rsync_pid)
 921                         tv.tv_sec = 60;
 922                 else if (rm_pid)
 923                         tvp = NULL;
 924                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
 925                 if (ret < 0)
 926                         return ret;
 927                 if (FD_ISSET(signal_pipe, &rfds)) {
 928                         handle_signal();
 929                         continue;
 930                 }
 931                 if (rm_pid)
 932                         continue;
 933                 ret = disk_space_low();
 934                 if (ret < 0)
 935                         break;
 936                 low_disk_space = ret;
 937                 if (low_disk_space)
 938                         stop_rsync_process();
 939                 ret = try_to_free_disk_space(low_disk_space, &sl);
 940                 if (ret < 0)
 941                         break;
 942                 if (rm_pid)
 943                         continue;
 944                 if (rsync_pid) {
 945                         restart_rsync_process();
 946                         continue;
 947                 }
 948                 /* neither rsync nor rm are running. Start rsync? */
 949                 gettimeofday(&now, NULL);
 950                 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
 951                         continue;
 952                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
 953                 ret = create_snapshot(rsync_argv);
 954                 free_rsync_argv(rsync_argv);
 955                 if (ret < 0)
 956                         break;
 957         }
 958         free_snapshot_list(&sl);
 959         return ret;
 960 }
 961
 962 int com_run(void)
 963 {
 964         int ret;
 965
 966         if (conf.dry_run_given) {
 967                 make_err_msg("dry_run not supported by this command");
 968                 return -E_SYNTAX;
 969         }
 970         ret = install_sighandler(SIGHUP);
 971         if (ret < 0)
 972                 return ret;
 973         return select_loop();
 974 }
 975
 976 void log_disk_space(struct disk_space *ds)
 977 {
 978         DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
 979                 ds->free_mb, ds->total_mb, ds->percent_free,
 980                 ds->percent_free_inodes);
 981 }
 982
 983 int com_prune(void)
 984 {
 985         int ret;
 986         struct snapshot_list sl;
 987         struct disk_space ds;
 988
 989         ret = get_disk_space(".", &ds);
 990         if (ret < 0)
 991                 return ret;
 992         log_disk_space(&ds);
 993         for (;;) {
 994                 get_snapshot_list(&sl);
 995                 ret = remove_outdated_snapshot(&sl);
 996                 free_snapshot_list(&sl);
 997                 if (ret < 0)
 998                         return ret;
 999                 if (!ret)
1000                         break;
1001                 ret = wait_for_rm_process();
1002                 if (ret < 0)
1003                         goto out;
1004         }
1005         for (;;) {
1006                 get_snapshot_list(&sl);
1007                 ret = remove_redundant_snapshot(&sl);
1008                 free_snapshot_list(&sl);
1009                 if (ret < 0)
1010                         return ret;
1011                 if (!ret)
1012                         break;
1013                 ret = wait_for_rm_process();
1014                 if (ret < 0)
1015                         goto out;
1016         }
1017         return 1;
1018 out:
1019         return ret;
1020 }
1021
1022 int com_create(void)
1023 {
1024         int ret, status;
1025         char **rsync_argv;
1026
1027         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1028         if (conf.dry_run_given) {
1029                 int i;
1030                 char *msg = NULL;
1031                 for (i = 0; rsync_argv[i]; i++) {
1032                         char *tmp = msg;
1033                         msg = make_message("%s%s%s", tmp? tmp : "",
1034                                 tmp? " " : "", rsync_argv[i]);
1035                         free(tmp);
1036                 }
1037                 dss_msg("%s\n", msg);
1038                 free(msg);
1039                 return 1;
1040         }
1041         ret = create_snapshot(rsync_argv);
1042         if (ret < 0)
1043                 goto out;
1044         ret = wait_for_process(rsync_pid, &status);
1045         if (ret < 0)
1046                 goto out;
1047         ret = handle_rsync_exit(status);
1048 out:
1049         free_rsync_argv(rsync_argv);
1050         return ret;
1051 }
1052
1053 int com_ls(void)
1054 {
1055         int i;
1056         struct snapshot_list sl;
1057         struct snapshot *s;
1058         get_snapshot_list(&sl);
1059         FOR_EACH_SNAPSHOT(s, i, &sl)
1060                 dss_msg("%u\t%s\n", s->interval, s->name);
1061         free_snapshot_list(&sl);
1062         return 1;
1063 }
1064
1065 __noreturn void clean_exit(int status)
1066 {
1067         free(dss_error_txt);
1068         exit(status);
1069 }
1070 static void setup_signal_handling(void)
1071 {
1072         int ret;
1073
1074         DSS_INFO_LOG("setting up signal handlers\n");
1075         signal_pipe = signal_init(); /* always successful */
1076         ret = install_sighandler(SIGINT);
1077         if (ret < 0)
1078                 goto err;
1079         ret = install_sighandler(SIGTERM);
1080         if (ret < 0)
1081                 goto err;
1082         ret = install_sighandler(SIGCHLD);
1083         if (ret < 0)
1084                 goto err;
1085         return;
1086 err:
1087         DSS_EMERG_LOG("could not install signal handlers\n");
1088         exit(EXIT_FAILURE);
1089 }
1090
1091 int main(int argc, char **argv)
1092 {
1093         int ret;
1094         struct cmdline_parser_params params = {
1095                 .override = 0,
1096                 .initialize = 1,
1097                 .check_required = 0,
1098                 .check_ambiguity = 0
1099         };
1100
1101         cmdline_parser_ext(argc, argv, &conf, &params); /* aborts on errors */
1102         parse_config_file(0);
1103
1104         if (conf.daemon_given)
1105                 daemon_init();
1106         setup_signal_handling();
1107         ret = call_command_handler();
1108         if (ret < 0)
1109                 log_err_msg(EMERG, -ret);
1110         clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1111 }