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                 pause();
 387                 ret = next_signal();
 388                 if (ret < 0)
 389                         break;
 390                 if (!ret)
 391                         continue;
 392                 if (ret == SIGCHLD) {
 393                         ret = waitpid(pid, status, 0);
 394                         if (ret >= 0)
 395                                 break;
 396                         if (errno != EINTR) { /* error */
 397                                 ret = -ERRNO_TO_DSS_ERROR(errno);
 398                                 break;
 399                         }
 400                 }
 401                 /* SIGINT or SIGTERM */
 402                 DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
 403                 kill(pid, SIGTERM);
 404         }
 405         if (ret < 0)
 406                 make_err_msg("failed to wait for process %d", (int)pid);
 407         else
 408                 log_termination_msg(pid, *status);
 409         return ret;
 410 }
 411
 412 int remove_snapshot(struct snapshot *s)
 413 {
 414         int fds[3] = {0, 0, 0};
 415         assert(!rm_pid);
 416         char *new_name = being_deleted_name(s);
 417         int ret = dss_rename(s->name, new_name);
 418         char *argv[] = {"rm", "-rf", new_name, NULL};
 419
 420         if (ret < 0)
 421                 goto out;
 422         DSS_NOTICE_LOG("removing %s (interval = %i)\n", s->name, s->interval);
 423         stop_rsync_process();
 424         ret = dss_exec(&rm_pid, argv[0], argv, fds);
 425 out:
 426         free(new_name);
 427         return ret;
 428 }
 429
 430 /*
 431  * return: 0: no redundant snapshots, 1: rm process started, negative: error
 432  */
 433 int remove_redundant_snapshot(struct snapshot_list *sl)
 434 {
 435         int ret, i, interval;
 436         struct snapshot *s;
 437         unsigned missing = 0;
 438
 439         DSS_INFO_LOG("looking for intervals containing too many snapshots\n");
 440         for (interval = conf.num_intervals_arg - 1; interval >= 0; interval--) {
 441                 unsigned keep = num_snapshots(interval);
 442                 unsigned num = sl->interval_count[interval];
 443                 struct snapshot *victim = NULL, *prev = NULL;
 444                 int64_t score = LONG_MAX;
 445
 446                 if (keep >= num)
 447                         missing += keep - num;
 448                 DSS_DEBUG_LOG("interval %i: keep: %u, have: %u, missing: %u\n",
 449                         interval, keep, num, missing);
 450                 if (keep + missing >= num)
 451                         continue;
 452                 /* redundant snapshot in this interval, pick snapshot with lowest score */
 453                 FOR_EACH_SNAPSHOT(s, i, sl) {
 454                         int64_t this_score;
 455
 456                         //DSS_DEBUG_LOG("checking %s\n", s->name);
 457                         if (s->interval > interval) {
 458                                 prev = s;
 459                                 continue;
 460                         }
 461                         if (s->interval < interval)
 462                                 break;
 463                         if (!victim) {
 464                                 victim = s;
 465                                 prev = s;
 466                                 continue;
 467                         }
 468                         assert(prev);
 469                         /* check if s is a better victim */
 470                         this_score = s->creation_time - prev->creation_time;
 471                         assert(this_score >= 0);
 472                         //DSS_DEBUG_LOG("%s: score %lli\n", s->name, (long long)score);
 473                         if (this_score < score) {
 474                                 score = this_score;
 475                                 victim = s;
 476                         }
 477                         prev = s;
 478                 }
 479                 assert(victim);
 480                 if (conf.dry_run_given) {
 481                         dss_msg("%s would be removed (interval = %i)\n",
 482                                 victim->name, victim->interval);
 483                         continue;
 484                 }
 485                 ret = remove_snapshot(victim);
 486                 return ret < 0? ret : 1;
 487         }
 488         return 0;
 489 }
 490
 491 int remove_outdated_snapshot(struct snapshot_list *sl)
 492 {
 493         int i, ret;
 494         struct snapshot *s;
 495
 496         DSS_INFO_LOG("looking for snapshots belonging to intervals greater than %d\n",
 497                 conf.num_intervals_arg);
 498         FOR_EACH_SNAPSHOT(s, i, sl) {
 499                 if (s->interval <= conf.num_intervals_arg)
 500                         continue;
 501                 if (conf.dry_run_given) {
 502                         dss_msg("%s would be removed (interval = %i)\n",
 503                                 s->name, s->interval);
 504                         continue;
 505                 }
 506                 ret = remove_snapshot(s);
 507                 if (ret < 0)
 508                         return ret;
 509                 return 1;
 510         }
 511         return 0;
 512 }
 513
 514 int handle_rm_exit(int status)
 515 {
 516         int es, ret;
 517
 518         if (!WIFEXITED(status)) {
 519                 make_err_msg("rm process %d died involuntary", (int)rm_pid);
 520                 ret = -E_INVOLUNTARY_EXIT;
 521                 goto out;
 522         }
 523         es = WEXITSTATUS(status);
 524         if (es) {
 525                 make_err_msg("rm process %d returned %d", (int)rm_pid, es);
 526                 ret = -E_BAD_EXIT_CODE;
 527                 goto out;
 528         }
 529         ret = 1;
 530         rm_pid = 0;
 531 out:
 532         return ret;
 533 }
 534
 535 int wait_for_rm_process(void)
 536 {
 537         int status, ret = wait_for_process(rm_pid, &status);
 538
 539         if (ret < 0)
 540                 return ret;
 541         return handle_rm_exit(status);
 542 }
 543
 544 void kill_process(pid_t pid)
 545 {
 546         if (!pid)
 547                 return;
 548         DSS_WARNING_LOG("sending SIGTERM to pid %d\n", (int)pid);
 549         kill(pid, SIGTERM);
 550 }
 551
 552 int check_config(void)
 553 {
 554         if (conf.unit_interval_arg <= 0) {
 555                 make_err_msg("bad unit interval: %i", conf.unit_interval_arg);
 556                 return -E_INVALID_NUMBER;
 557         }
 558         DSS_DEBUG_LOG("unit interval: %i day(s)\n", conf.unit_interval_arg);
 559         if (conf.num_intervals_arg <= 0) {
 560                 make_err_msg("bad number of intervals  %i", conf.num_intervals_arg);
 561                 return -E_INVALID_NUMBER;
 562         }
 563         DSS_DEBUG_LOG("number of intervals: %i\n", conf.num_intervals_arg);
 564         return 1;
 565 }
 566
 567 /* exits on errors */
 568 void parse_config_file(int override)
 569 {
 570         int ret;
 571         char *config_file;
 572         struct stat statbuf;
 573         char *old_logfile_arg = NULL;
 574         int old_daemon_given = 0;
 575
 576         if (conf.config_file_given)
 577                 config_file = dss_strdup(conf.config_file_arg);
 578         else {
 579                 char *home = get_homedir();
 580                 config_file = make_message("%s/.dssrc", home);
 581                 free(home);
 582         }
 583         if (override) { /* SIGHUP */
 584                 if (conf.logfile_given)
 585                         old_logfile_arg = dss_strdup(conf.logfile_arg);
 586                 old_daemon_given = conf.daemon_given;
 587         }
 588
 589         ret = stat(config_file, &statbuf);
 590         if (ret && conf.config_file_given) {
 591                 ret = -ERRNO_TO_DSS_ERROR(errno);
 592                 make_err_msg("failed to stat config file %s", config_file);
 593                 goto out;
 594         }
 595         if (!ret) {
 596                 struct cmdline_parser_params params = {
 597                         .override = override,
 598                         .initialize = 0,
 599                         .check_required = 0,
 600                         .check_ambiguity = 0
 601                 };
 602                 cmdline_parser_config_file(config_file, &conf, &params);
 603         }
 604         if (!conf.source_dir_given || !conf.dest_dir_given) {
 605                 ret = -E_SYNTAX;
 606                 make_err_msg("you need to specify both source_dir and dest_dir");
 607                 goto out;
 608         }
 609         ret = check_config();
 610         if (ret < 0)
 611                 goto out;
 612         if (override) {
 613                 /* don't change daemon mode on SIGHUP */
 614                 conf.daemon_given = old_daemon_given;
 615                 close_log(logfile);
 616                 logfile = NULL;
 617                 if (conf.logfile_given)
 618                         free(old_logfile_arg);
 619                 else if (conf.daemon_given) { /* re-use old logfile */
 620                         conf.logfile_arg = old_logfile_arg;
 621                         conf.logfile_given = 1;
 622                 }
 623         }
 624         if (conf.logfile_given) {
 625                 logfile = open_log(conf.logfile_arg);
 626                 log_welcome(conf.loglevel_arg);
 627         }
 628         ret = dss_chdir(conf.dest_dir_arg);
 629 out:
 630         free(config_file);
 631         if (ret >= 0)
 632                 return;
 633         log_err_msg(EMERG, -ret);
 634         exit(EXIT_FAILURE);
 635 }
 636
 637 void handle_sighup(void)
 638 {
 639         DSS_NOTICE_LOG("SIGHUP\n");
 640         parse_config_file(1);
 641 }
 642
 643 int rename_incomplete_snapshot(int64_t start)
 644 {
 645         char *old_name, *new_name;
 646         int ret;
 647
 648         ret = complete_name(start, get_current_time(), &new_name);
 649         if (ret < 0)
 650                 return ret;
 651         old_name = incomplete_name(start);
 652         ret = dss_rename(old_name, new_name);
 653         if (ret >= 0)
 654                 DSS_NOTICE_LOG("%s -> %s\n", old_name, new_name);
 655         free(old_name);
 656         free(new_name);
 657         return ret;
 658 }
 659
 660 int handle_rsync_exit(int status)
 661 {
 662         int es, ret;
 663
 664         if (!WIFEXITED(status)) {
 665                 make_err_msg("rsync process %d died involuntary", (int)rsync_pid);
 666                 ret = -E_INVOLUNTARY_EXIT;
 667                 goto out;
 668         }
 669         es = WEXITSTATUS(status);
 670         if (es != 0 && es != 23 && es != 24) {
 671                 make_err_msg("rsync process %d returned %d", (int)rsync_pid, es);
 672                 ret = -E_BAD_EXIT_CODE;
 673                 goto out;
 674         }
 675         ret = rename_incomplete_snapshot(current_snapshot_creation_time);
 676 out:
 677         rsync_pid = 0;
 678         current_snapshot_creation_time = 0;
 679         rsync_stopped = 0;
 680         return ret;
 681 }
 682
 683 int get_newest_complete(const char *dirname, void *private)
 684 {
 685         struct edge_snapshot_data *esd = private;
 686         struct snapshot s;
 687         int ret = is_snapshot(dirname, esd->now, &s);
 688
 689         if (ret <= 0)
 690                 return 1;
 691         if (s.flags != SS_COMPLETE) /* incomplete or being deleted */
 692                 return 1;
 693         if (s.creation_time < esd->snap.creation_time)
 694                 return 1;
 695         free(esd->snap.name);
 696         esd->snap = s;
 697         return 1;
 698 }
 699
 700 __malloc char *name_of_newest_complete_snapshot(void)
 701 {
 702         struct edge_snapshot_data esd = {
 703                 .now = get_current_time(),
 704                 .snap = {.creation_time = -1}
 705         };
 706         for_each_subdir(get_newest_complete, &esd);
 707         return esd.snap.name;
 708 }
 709
 710 void create_rsync_argv(char ***argv, int64_t *num)
 711 {
 712         char *logname, *newest = name_of_newest_complete_snapshot();
 713         int i = 0, j;
 714
 715         *argv = dss_malloc((15 + conf.rsync_option_given) * sizeof(char *));
 716         (*argv)[i++] = dss_strdup("rsync");
 717         (*argv)[i++] = dss_strdup("-aq");
 718         (*argv)[i++] = dss_strdup("--delete");
 719         for (j = 0; j < conf.rsync_option_given; j++)
 720                 (*argv)[i++] = dss_strdup(conf.rsync_option_arg[j]);
 721         if (newest) {
 722                 DSS_INFO_LOG("using %s as reference snapshot\n", newest);
 723                 (*argv)[i++] = make_message("--link-dest=../%s", newest);
 724                 free(newest);
 725         } else
 726                 DSS_INFO_LOG("no previous snapshot found\n");
 727         if (conf.exclude_patterns_given) {
 728                 (*argv)[i++] = dss_strdup("--exclude-from");
 729                 (*argv)[i++] = dss_strdup(conf.exclude_patterns_arg);
 730
 731         }
 732         logname = dss_logname();
 733         if (conf.remote_user_given && !strcmp(conf.remote_user_arg, logname))
 734                 (*argv)[i++] = dss_strdup(conf.source_dir_arg);
 735         else
 736                 (*argv)[i++] = make_message("%s@%s:%s/", conf.remote_user_given?
 737                         conf.remote_user_arg : logname,
 738                         conf.remote_host_arg, conf.source_dir_arg);
 739         free(logname);
 740         *num = get_current_time();
 741         (*argv)[i++] = incomplete_name(*num);
 742         (*argv)[i++] = NULL;
 743         for (j = 0; j < i; j++)
 744                 DSS_DEBUG_LOG("argv[%d] = %s\n", j, (*argv)[j]);
 745 }
 746
 747 void free_rsync_argv(char **argv)
 748 {
 749         int i;
 750         for (i = 0; argv[i]; i++)
 751                 free(argv[i]);
 752         free(argv);
 753 }
 754
 755 int create_snapshot(char **argv)
 756 {
 757         int fds[3] = {0, 0, 0};
 758         char *name = incomplete_name(current_snapshot_creation_time);
 759
 760         DSS_NOTICE_LOG("creating new snapshot %s\n", name);
 761         free(name);
 762         return dss_exec(&rsync_pid, argv[0], argv, fds);
 763 }
 764
 765 void compute_next_snapshot_time(struct snapshot_list *sl)
 766 {
 767         struct timeval now, unit_interval = {.tv_sec = 24 * 3600 * conf.unit_interval_arg},
 768                 tmp, diff;
 769         int64_t x = 0;
 770         unsigned wanted = num_snapshots(0), num_complete_snapshots = 0;
 771         int i, ret;
 772         struct snapshot *s;
 773
 774         gettimeofday(&now, NULL);
 775         FOR_EACH_SNAPSHOT(s, i, sl) {
 776                 if (!(s->flags & SS_COMPLETE))
 777                         continue;
 778                 num_complete_snapshots++;
 779                 x += s->completion_time - s->creation_time;
 780         }
 781         assert(x >= 0);
 782         if (num_complete_snapshots)
 783                 x /= num_complete_snapshots; /* avg time to create one snapshot */
 784         x *= wanted; /* time to create all snapshots in interval 0 */
 785         tmp.tv_sec = x;
 786         tmp.tv_usec = 0;
 787         ret = tv_diff(&unit_interval, &tmp, &diff); /* time between creation */
 788         if (ret < 0) {
 789                 next_snapshot_time = now;
 790                 return;
 791         }
 792         tv_divide(wanted, &diff, &tmp);
 793         tv_add(&now, &tmp, &next_snapshot_time);
 794 }
 795
 796 void handle_signal(void)
 797 {
 798         int sig, ret = next_signal();
 799
 800         if (ret <= 0)
 801                 goto out;
 802         sig = ret;
 803         switch (sig) {
 804                 int status;
 805                 pid_t pid;
 806         case SIGINT:
 807         case SIGTERM:
 808                 restart_rsync_process();
 809                 kill_process(rsync_pid);
 810                 kill_process(rm_pid);
 811                 exit(EXIT_FAILURE);
 812         case SIGHUP:
 813                 handle_sighup();
 814                 ret = 1;
 815                 break;
 816         case SIGCHLD:
 817                 ret = reap_child(&pid, &status);
 818                 if (ret <= 0)
 819                         break;
 820                 assert(pid == rsync_pid || pid == rm_pid);
 821                 if (pid == rsync_pid)
 822                         ret = handle_rsync_exit(status);
 823                 else
 824                         ret = handle_rm_exit(status);
 825         }
 826 out:
 827         if (ret < 0)
 828                 log_err_msg(ERROR, -ret);
 829 }
 830
 831 int get_oldest(const char *dirname, void *private)
 832 {
 833         struct edge_snapshot_data *esd = private;
 834         struct snapshot s;
 835         int ret = is_snapshot(dirname, esd->now, &s);
 836
 837         if (ret <= 0)
 838                 return 1;
 839         if (s.creation_time > esd->snap.creation_time)
 840                 return 1;
 841         free(esd->snap.name);
 842         esd->snap = s;
 843         return 1;
 844 }
 845
 846 int remove_oldest_snapshot()
 847 {
 848         int ret;
 849         struct edge_snapshot_data esd = {
 850                 .now = get_current_time(),
 851                 .snap = {.creation_time = LLONG_MAX}
 852         };
 853         for_each_subdir(get_oldest, &esd);
 854         if (!esd.snap.name) /* no snapshot found */
 855                 return 0;
 856         DSS_INFO_LOG("oldest snapshot: %s\n", esd.snap.name);
 857         ret = 0;
 858         if (esd.snap.creation_time == current_snapshot_creation_time)
 859                 goto out; /* do not remove the snapshot currently being created */
 860         ret = remove_snapshot(&esd.snap);
 861 out:
 862         free(esd.snap.name);
 863         return ret;
 864 }
 865
 866 /* TODO: Also consider number of inodes. */
 867 int disk_space_low(void)
 868 {
 869         struct disk_space ds;
 870         int ret = get_disk_space(".", &ds);
 871
 872         if (ret < 0)
 873                 return ret;
 874         if (conf.min_free_mb_arg)
 875                 if (ds.free_mb < conf.min_free_mb_arg)
 876                         return 1;
 877         if (conf.min_free_percent_arg)
 878                 if (ds.percent_free < conf.min_free_percent_arg)
 879                         return 1;
 880         return 0;
 881 }
 882
 883 int try_to_free_disk_space(int low_disk_space, struct snapshot_list *sl)
 884 {
 885         int ret;
 886
 887         ret = remove_outdated_snapshot(sl);
 888         if (ret) /* error, or we are removing something */
 889                 return ret;
 890         /* no outdated snapshot */
 891         ret = remove_redundant_snapshot(sl);
 892         if (ret)
 893                 return ret;
 894         if (!low_disk_space)
 895                 return 0;
 896         DSS_WARNING_LOG("disk space low and nothing obvious to remove\n");
 897         ret = remove_oldest_snapshot();
 898         if (ret)
 899                 return ret;
 900         make_err_msg("uhuhu: not enough disk space for a single snapshot");
 901         return  -ENOSPC;
 902 }
 903
 904 int select_loop(void)
 905 {
 906         int ret;
 907         struct timeval tv = {.tv_sec = 0, .tv_usec = 0};
 908         struct snapshot_list sl = {.num_snapshots = 0};
 909
 910         for (;;) {
 911                 struct timeval now, *tvp = &tv;
 912                 fd_set rfds;
 913                 int low_disk_space;
 914                 char **rsync_argv;
 915
 916                 free_snapshot_list(&sl);
 917                 get_snapshot_list(&sl);
 918                 compute_next_snapshot_time(&sl);
 919                 FD_ZERO(&rfds);
 920                 FD_SET(signal_pipe, &rfds);
 921                 if (rsync_pid)
 922                         tv.tv_sec = 60;
 923                 else if (rm_pid)
 924                         tvp = NULL;
 925                 ret = dss_select(signal_pipe + 1, &rfds, NULL, tvp);
 926                 if (ret < 0)
 927                         return ret;
 928                 if (FD_ISSET(signal_pipe, &rfds)) {
 929                         handle_signal();
 930                         continue;
 931                 }
 932                 if (rm_pid)
 933                         continue;
 934                 ret = disk_space_low();
 935                 if (ret < 0)
 936                         break;
 937                 low_disk_space = ret;
 938                 if (low_disk_space)
 939                         stop_rsync_process();
 940                 ret = try_to_free_disk_space(low_disk_space, &sl);
 941                 if (ret < 0)
 942                         break;
 943                 if (rm_pid)
 944                         continue;
 945                 if (rsync_pid) {
 946                         restart_rsync_process();
 947                         continue;
 948                 }
 949                 /* neither rsync nor rm are running. Start rsync? */
 950                 gettimeofday(&now, NULL);
 951                 if (tv_diff(&next_snapshot_time, &now, &tv) > 0)
 952                         continue;
 953                 create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
 954                 ret = create_snapshot(rsync_argv);
 955                 free_rsync_argv(rsync_argv);
 956                 if (ret < 0)
 957                         break;
 958         }
 959         free_snapshot_list(&sl);
 960         return ret;
 961 }
 962
 963 int com_run(void)
 964 {
 965         int ret;
 966
 967         if (conf.dry_run_given) {
 968                 make_err_msg("dry_run not supported by this command");
 969                 return -E_SYNTAX;
 970         }
 971         ret = install_sighandler(SIGHUP);
 972         if (ret < 0)
 973                 return ret;
 974         return select_loop();
 975 }
 976
 977 void log_disk_space(struct disk_space *ds)
 978 {
 979         DSS_INFO_LOG("free: %uM/%uM (%u%%), %u%% inodes unused\n",
 980                 ds->free_mb, ds->total_mb, ds->percent_free,
 981                 ds->percent_free_inodes);
 982 }
 983
 984 int com_prune(void)
 985 {
 986         int ret;
 987         struct snapshot_list sl;
 988         struct disk_space ds;
 989
 990         ret = get_disk_space(".", &ds);
 991         if (ret < 0)
 992                 return ret;
 993         log_disk_space(&ds);
 994         for (;;) {
 995                 get_snapshot_list(&sl);
 996                 ret = remove_outdated_snapshot(&sl);
 997                 free_snapshot_list(&sl);
 998                 if (ret < 0)
 999                         return ret;
1000                 if (!ret)
1001                         break;
1002                 ret = wait_for_rm_process();
1003                 if (ret < 0)
1004                         goto out;
1005         }
1006         for (;;) {
1007                 get_snapshot_list(&sl);
1008                 ret = remove_redundant_snapshot(&sl);
1009                 free_snapshot_list(&sl);
1010                 if (ret < 0)
1011                         return ret;
1012                 if (!ret)
1013                         break;
1014                 ret = wait_for_rm_process();
1015                 if (ret < 0)
1016                         goto out;
1017         }
1018         return 1;
1019 out:
1020         return ret;
1021 }
1022
1023 int com_create(void)
1024 {
1025         int ret, status;
1026         char **rsync_argv;
1027
1028         create_rsync_argv(&rsync_argv, &current_snapshot_creation_time);
1029         if (conf.dry_run_given) {
1030                 int i;
1031                 char *msg = NULL;
1032                 for (i = 0; rsync_argv[i]; i++) {
1033                         char *tmp = msg;
1034                         msg = make_message("%s%s%s", tmp? tmp : "",
1035                                 tmp? " " : "", rsync_argv[i]);
1036                         free(tmp);
1037                 }
1038                 dss_msg("%s\n", msg);
1039                 free(msg);
1040                 return 1;
1041         }
1042         ret = create_snapshot(rsync_argv);
1043         if (ret < 0)
1044                 goto out;
1045         ret = wait_for_process(rsync_pid, &status);
1046         if (ret < 0)
1047                 goto out;
1048         ret = handle_rsync_exit(status);
1049 out:
1050         free_rsync_argv(rsync_argv);
1051         return ret;
1052 }
1053
1054 int com_ls(void)
1055 {
1056         int i;
1057         struct snapshot_list sl;
1058         struct snapshot *s;
1059         get_snapshot_list(&sl);
1060         FOR_EACH_SNAPSHOT(s, i, &sl)
1061                 dss_msg("%u\t%s\n", s->interval, s->name);
1062         free_snapshot_list(&sl);
1063         return 1;
1064 }
1065
1066 __noreturn void clean_exit(int status)
1067 {
1068         free(dss_error_txt);
1069         exit(status);
1070 }
1071 static void setup_signal_handling(void)
1072 {
1073         int ret;
1074
1075         DSS_INFO_LOG("setting up signal handlers\n");
1076         signal_pipe = signal_init(); /* always successful */
1077         ret = install_sighandler(SIGINT);
1078         if (ret < 0)
1079                 goto err;
1080         ret = install_sighandler(SIGTERM);
1081         if (ret < 0)
1082                 goto err;
1083         ret = install_sighandler(SIGCHLD);
1084         if (ret < 0)
1085                 goto err;
1086         return;
1087 err:
1088         DSS_EMERG_LOG("could not install signal handlers\n");
1089         exit(EXIT_FAILURE);
1090 }
1091
1092 int main(int argc, char **argv)
1093 {
1094         int ret;
1095
1096         cmdline_parser(argc, argv, &conf); /* aborts on errors */
1097         parse_config_file(0);
1098         if (conf.daemon_given)
1099                 daemon_init();
1100         setup_signal_handling();
1101         ret = call_command_handler();
1102         if (ret < 0)
1103                 log_err_msg(EMERG, -ret);
1104         clean_exit(ret >= 0? EXIT_SUCCESS : EXIT_FAILURE);
1105 }