granicus.if.org Git - postgresql/blob - src/bin/pg_resetxlog/pg_resetxlog.c

   1 /*-------------------------------------------------------------------------
   2  *
   3  * pg_resetxlog.c
   4  *        A utility to "zero out" the xlog when it's corrupt beyond recovery.
   5  *        Can also rebuild pg_control if needed.
   6  *
   7  * The theory of operation is fairly simple:
   8  *        1. Read the existing pg_control (which will include the last
   9  *               checkpoint record).  If it is an old format then update to
  10  *               current format.
  11  *        2. If pg_control is corrupt, attempt to intuit reasonable values,
  12  *               by scanning the old xlog if necessary.
  13  *        3. Modify pg_control to reflect a "shutdown" state with a checkpoint
  14  *               record at the start of xlog.
  15  *        4. Flush the existing xlog files and write a new segment with
  16  *               just a checkpoint record in it.  The new segment is positioned
  17  *               just past the end of the old xlog, so that existing LSNs in
  18  *               data pages will appear to be "in the past".
  19  * This is all pretty straightforward except for the intuition part of
  20  * step 2 ...
  21  *
  22  *
  23  * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
  24  * Portions Copyright (c) 1994, Regents of the University of California
  25  *
  26  * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.35 2005/07/04 04:51:51 tgl Exp $
  27  *
  28  *-------------------------------------------------------------------------
  29  */
  30 #include "postgres.h"
  31
  32 #include <dirent.h>
  33 #include <fcntl.h>
  34 #include <locale.h>
  35 #include <sys/stat.h>
  36 #include <sys/time.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39 #ifdef HAVE_GETOPT_H
  40 #include <getopt.h>
  41 #endif
  42
  43 #include "access/multixact.h"
  44 #include "access/xlog.h"
  45 #include "access/xlog_internal.h"
  46 #include "catalog/catversion.h"
  47 #include "catalog/pg_control.h"
  48
  49 extern int      optind;
  50 extern char *optarg;
  51
  52
  53 static ControlFileData ControlFile;             /* pg_control values */
  54 static uint32 newXlogId,
  55                         newXlogSeg;                     /* ID/Segment of new XLOG segment */
  56 static bool guessed = false;    /* T if we had to guess at any values */
  57 static const char *progname;
  58
  59 static bool ReadControlFile(void);
  60 static void GuessControlValues(void);
  61 static void PrintControlValues(bool guessed);
  62 static void RewriteControlFile(void);
  63 static void KillExistingXLOG(void);
  64 static void WriteEmptyXLOG(void);
  65 static void usage(void);
  66
  67
  68 int
  69 main(int argc, char *argv[])
  70 {
  71         int                     c;
  72         bool            force = false;
  73         bool            noupdate = false;
  74         TransactionId set_xid = 0;
  75         Oid                     set_oid = 0;
  76         MultiXactId     set_mxid = 0;
  77         MultiXactOffset set_mxoff = -1;
  78         uint32          minXlogTli = 0,
  79                                 minXlogId = 0,
  80                                 minXlogSeg = 0;
  81         char       *endptr;
  82         char       *endptr2;
  83         char       *endptr3;
  84         char       *DataDir;
  85         int                     fd;
  86         char            path[MAXPGPATH];
  87
  88         set_pglocale_pgservice(argv[0], "pg_resetxlog");
  89
  90         progname = get_progname(argv[0]);
  91
  92         if (argc > 1)
  93         {
  94                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
  95                 {
  96                         usage();
  97                         exit(0);
  98                 }
  99                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 100                 {
 101                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
 102                         exit(0);
 103                 }
 104         }
 105
 106
 107         while ((c = getopt(argc, argv, "fl:m:no:O:x:")) != -1)
 108         {
 109                 switch (c)
 110                 {
 111                         case 'f':
 112                                 force = true;
 113                                 break;
 114
 115                         case 'n':
 116                                 noupdate = true;
 117                                 break;
 118
 119                         case 'x':
 120                                 set_xid = strtoul(optarg, &endptr, 0);
 121                                 if (endptr == optarg || *endptr != '\0')
 122                                 {
 123                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 124                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 125                                         exit(1);
 126                                 }
 127                                 if (set_xid == 0)
 128                                 {
 129                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 130                                         exit(1);
 131                                 }
 132                                 break;
 133
 134                         case 'o':
 135                                 set_oid = strtoul(optarg, &endptr, 0);
 136                                 if (endptr == optarg || *endptr != '\0')
 137                                 {
 138                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 139                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 140                                         exit(1);
 141                                 }
 142                                 if (set_oid == 0)
 143                                 {
 144                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 145                                         exit(1);
 146                                 }
 147                                 break;
 148
 149                         case 'm':
 150                                 set_mxid = strtoul(optarg, &endptr, 0);
 151                                 if (endptr == optarg || *endptr != '\0')
 152                                 {
 153                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 154                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 155                                         exit(1);
 156                                 }
 157                                 if (set_mxid == 0)
 158                                 {
 159                                         fprintf(stderr, _("%s: multi transaction ID (-m) must not be 0\n"), progname);
 160                                         exit(1);
 161                                 }
 162                                 break;
 163
 164                         case 'O':
 165                                 set_mxoff = strtoul(optarg, &endptr, 0);
 166                                 if (endptr == optarg || *endptr != '\0')
 167                                 {
 168                                         fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
 169                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 170                                         exit(1);
 171                                 }
 172                                 if (set_mxoff == -1)
 173                                 {
 174                                         fprintf(stderr, _("%s: multi transaction offset (-O) must not be -1\n"), progname);
 175                                         exit(1);
 176                                 }
 177                                 break;
 178
 179                         case 'l':
 180                                 minXlogTli = strtoul(optarg, &endptr, 0);
 181                                 if (endptr == optarg || *endptr != ',')
 182                                 {
 183                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 184                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 185                                         exit(1);
 186                                 }
 187                                 minXlogId = strtoul(endptr + 1, &endptr2, 0);
 188                                 if (endptr2 == endptr + 1 || *endptr2 != ',')
 189                                 {
 190                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 191                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 192                                         exit(1);
 193                                 }
 194                                 minXlogSeg = strtoul(endptr2 + 1, &endptr3, 0);
 195                                 if (endptr3 == endptr2 + 1 || *endptr3 != '\0')
 196                                 {
 197                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 198                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 199                                         exit(1);
 200                                 }
 201                                 break;
 202
 203                         default:
 204                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 205                                 exit(1);
 206                 }
 207         }
 208
 209         if (optind == argc)
 210         {
 211                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 212                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 213                 exit(1);
 214         }
 215
 216         /*
 217          * Don't allow pg_resetxlog to be run as root, to avoid
 218          * overwriting the ownership of files in the data directory. We
 219          * need only check for root -- any other user won't have
 220          * sufficient permissions to modify files in the data directory.
 221          */
 222 #ifndef WIN32
 223 #ifndef __BEOS__                                /* no root check on BeOS */
 224         if (geteuid() == 0)
 225         {
 226                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 227                                 progname);
 228                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 229                                 progname);
 230                 exit(1);
 231         }
 232 #endif
 233 #endif
 234
 235         DataDir = argv[optind];
 236
 237         if (chdir(DataDir) < 0)
 238         {
 239                 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
 240                                 progname, DataDir, strerror(errno));
 241                 exit(1);
 242         }
 243
 244         /*
 245          * Check for a postmaster lock file --- if there is one, refuse to
 246          * proceed, on grounds we might be interfering with a live
 247          * installation.
 248          */
 249         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 250
 251         if ((fd = open(path, O_RDONLY)) < 0)
 252         {
 253                 if (errno != ENOENT)
 254                 {
 255                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 256                         exit(1);
 257                 }
 258         }
 259         else
 260         {
 261                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 262                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 263                                 progname, path);
 264                 exit(1);
 265         }
 266
 267         /*
 268          * Attempt to read the existing pg_control file
 269          */
 270         if (!ReadControlFile())
 271                 GuessControlValues();
 272
 273         /*
 274          * Adjust fields if required by switches.  (Do this now so that
 275          * printout, if any, includes these values.)
 276          */
 277         if (set_xid != 0)
 278                 ControlFile.checkPointCopy.nextXid = set_xid;
 279
 280         if (set_oid != 0)
 281                 ControlFile.checkPointCopy.nextOid = set_oid;
 282
 283         if (set_mxid != 0)
 284                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 285
 286         if (set_mxoff != -1)
 287                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 288
 289         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 290                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 291
 292         if (minXlogId > ControlFile.logId ||
 293                 (minXlogId == ControlFile.logId &&
 294                  minXlogSeg > ControlFile.logSeg))
 295         {
 296                 ControlFile.logId = minXlogId;
 297                 ControlFile.logSeg = minXlogSeg;
 298         }
 299
 300         /*
 301          * If we had to guess anything, and -f was not given, just print the
 302          * guessed values and exit.  Also print if -n is given.
 303          */
 304         if ((guessed && !force) || noupdate)
 305         {
 306                 PrintControlValues(guessed);
 307                 if (!noupdate)
 308                 {
 309                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 310                         exit(1);
 311                 }
 312                 else
 313                         exit(0);
 314         }
 315
 316         /*
 317          * Don't reset from a dirty pg_control without -f, either.
 318          */
 319         if (ControlFile.state != DB_SHUTDOWNED && !force)
 320         {
 321                 printf(_("The database server was not shut down cleanly.\n"
 322                          "Resetting the transaction log may cause data to be lost.\n"
 323                          "If you want to proceed anyway, use -f to force reset.\n"));
 324                 exit(1);
 325         }
 326
 327         /*
 328          * Else, do the dirty deed.
 329          */
 330         RewriteControlFile();
 331         KillExistingXLOG();
 332         WriteEmptyXLOG();
 333
 334         printf(_("Transaction log reset\n"));
 335         return 0;
 336 }
 337
 338
 339 /*
 340  * Try to read the existing pg_control file.
 341  *
 342  * This routine is also responsible for updating old pg_control versions
 343  * to the current format.  (Currently we don't do anything of the sort.)
 344  */
 345 static bool
 346 ReadControlFile(void)
 347 {
 348         int                     fd;
 349         int                     len;
 350         char       *buffer;
 351         pg_crc32        crc;
 352
 353         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY)) < 0)
 354         {
 355                 /*
 356                  * If pg_control is not there at all, or we can't read it, the
 357                  * odds are we've been handed a bad DataDir path, so give up. User
 358                  * can do "touch pg_control" to force us to proceed.
 359                  */
 360                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 361                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 362                 if (errno == ENOENT)
 363                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 364                                                           "  touch %s\n"
 365                                                           "and try again.\n"),
 366                                         XLOG_CONTROL_FILE);
 367                 exit(1);
 368         }
 369
 370         /* Use malloc to ensure we have a maxaligned buffer */
 371         buffer = (char *) malloc(BLCKSZ);
 372
 373         len = read(fd, buffer, BLCKSZ);
 374         if (len < 0)
 375         {
 376                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 377                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 378                 exit(1);
 379         }
 380         close(fd);
 381
 382         if (len >= sizeof(ControlFileData) &&
 383                 ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 384         {
 385                 /* Check the CRC. */
 386                 INIT_CRC32(crc);
 387                 COMP_CRC32(crc,
 388                                    buffer,
 389                                    offsetof(ControlFileData, crc));
 390                 FIN_CRC32(crc);
 391
 392                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 393                 {
 394                         /* Valid data... */
 395                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 396                         return true;
 397                 }
 398
 399                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 400                                 progname);
 401                 /* We will use the data anyway, but treat it as guessed. */
 402                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 403                 guessed = true;
 404                 return true;
 405         }
 406
 407         /* Looks like it's a mess. */
 408         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 409                         progname);
 410         return false;
 411 }
 412
 413
 414 /*
 415  * Guess at pg_control values when we can't read the old ones.
 416  */
 417 static void
 418 GuessControlValues(void)
 419 {
 420         uint64          sysidentifier;
 421         struct timeval tv;
 422         char       *localeptr;
 423
 424         /*
 425          * Set up a completely default set of pg_control values.
 426          */
 427         guessed = true;
 428         memset(&ControlFile, 0, sizeof(ControlFile));
 429
 430         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 431         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 432
 433         /*
 434          * Create a new unique installation identifier, since we can no longer
 435          * use any old XLOG records.  See notes in xlog.c about the algorithm.
 436          */
 437         gettimeofday(&tv, NULL);
 438         sysidentifier = ((uint64) tv.tv_sec) << 32;
 439         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 440
 441         ControlFile.system_identifier = sysidentifier;
 442
 443         ControlFile.checkPointCopy.redo.xlogid = 0;
 444         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 445         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 446         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 447         ControlFile.checkPointCopy.nextXid = (TransactionId) 514;       /* XXX */
 448         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 449         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 450         ControlFile.checkPointCopy.nextMultiOffset = 0;
 451         ControlFile.checkPointCopy.time = time(NULL);
 452
 453         ControlFile.state = DB_SHUTDOWNED;
 454         ControlFile.time = time(NULL);
 455         ControlFile.logId = 0;
 456         ControlFile.logSeg = 1;
 457         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 458
 459         ControlFile.blcksz = BLCKSZ;
 460         ControlFile.relseg_size = RELSEG_SIZE;
 461         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 462         ControlFile.nameDataLen = NAMEDATALEN;
 463         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 464 #ifdef HAVE_INT64_TIMESTAMP
 465         ControlFile.enableIntTimes = TRUE;
 466 #else
 467         ControlFile.enableIntTimes = FALSE;
 468 #endif
 469         ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
 470
 471         localeptr = setlocale(LC_COLLATE, "");
 472         if (!localeptr)
 473         {
 474                 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
 475                 exit(1);
 476         }
 477         StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
 478         localeptr = setlocale(LC_CTYPE, "");
 479         if (!localeptr)
 480         {
 481                 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
 482                 exit(1);
 483         }
 484         StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
 485
 486         /*
 487          * XXX eventually, should try to grovel through old XLOG to develop
 488          * more accurate values for TimeLineID, nextXID, etc.
 489          */
 490 }
 491
 492
 493 /*
 494  * Print the guessed pg_control values when we had to guess.
 495  *
 496  * NB: this display should be just those fields that will not be
 497  * reset by RewriteControlFile().
 498  */
 499 static void
 500 PrintControlValues(bool guessed)
 501 {
 502         char            sysident_str[32];
 503
 504         if (guessed)
 505                 printf(_("Guessed pg_control values:\n\n"));
 506         else
 507                 printf(_("pg_control values:\n\n"));
 508
 509         /*
 510          * Format system_identifier separately to keep platform-dependent
 511          * format code out of the translatable message string.
 512          */
 513         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 514                          ControlFile.system_identifier);
 515
 516         printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 517         printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
 518         printf(_("Database system identifier:           %s\n"), sysident_str);
 519         printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 520         printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 521         printf(_("Latest checkpoint's TimeLineID:       %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
 522         printf(_("Latest checkpoint's NextXID:          %u\n"), ControlFile.checkPointCopy.nextXid);
 523         printf(_("Latest checkpoint's NextOID:          %u\n"), ControlFile.checkPointCopy.nextOid);
 524         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"), ControlFile.checkPointCopy.nextMulti);
 525         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"), ControlFile.checkPointCopy.nextMultiOffset);
 526         printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
 527         printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
 528         printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
 529         printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);
 530         printf(_("Date/time type storage:               %s\n"),
 531                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 532         printf(_("Maximum length of locale name:        %u\n"), ControlFile.localeBuflen);
 533         printf(_("LC_COLLATE:                           %s\n"), ControlFile.lc_collate);
 534         printf(_("LC_CTYPE:                             %s\n"), ControlFile.lc_ctype);
 535 }
 536
 537
 538 /*
 539  * Write out the new pg_control file.
 540  */
 541 static void
 542 RewriteControlFile(void)
 543 {
 544         int                     fd;
 545         char            buffer[BLCKSZ]; /* need not be aligned */
 546
 547         /*
 548          * Adjust fields as needed to force an empty XLOG starting at the next
 549          * available segment.
 550          */
 551         newXlogId = ControlFile.logId;
 552         newXlogSeg = ControlFile.logSeg;
 553
 554         /* adjust in case we are changing segment size */
 555         newXlogSeg *= ControlFile.xlog_seg_size;
 556         newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
 557
 558         /* be sure we wrap around correctly at end of a logfile */
 559         NextLogSeg(newXlogId, newXlogSeg);
 560
 561         /* Now we can force the recorded xlog seg size to the right thing. */
 562         ControlFile.xlog_seg_size = XLogSegSize;
 563
 564         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 565         ControlFile.checkPointCopy.redo.xrecoff =
 566                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 567         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 568         ControlFile.checkPointCopy.time = time(NULL);
 569
 570         ControlFile.state = DB_SHUTDOWNED;
 571         ControlFile.time = time(NULL);
 572         ControlFile.logId = newXlogId;
 573         ControlFile.logSeg = newXlogSeg + 1;
 574         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 575         ControlFile.prevCheckPoint.xlogid = 0;
 576         ControlFile.prevCheckPoint.xrecoff = 0;
 577
 578         /* Contents are protected with a CRC */
 579         INIT_CRC32(ControlFile.crc);
 580         COMP_CRC32(ControlFile.crc,
 581                            (char *) &ControlFile,
 582                            offsetof(ControlFileData, crc));
 583         FIN_CRC32(ControlFile.crc);
 584
 585         /*
 586          * We write out BLCKSZ bytes into pg_control, zero-padding the excess
 587          * over sizeof(ControlFileData).  This reduces the odds of
 588          * premature-EOF errors when reading pg_control.  We'll still fail
 589          * when we check the contents of the file, but hopefully with a more
 590          * specific error than "couldn't read pg_control".
 591          */
 592         if (sizeof(ControlFileData) > BLCKSZ)
 593         {
 594                 fprintf(stderr,
 595                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"),
 596                                 progname);
 597                 exit(1);
 598         }
 599
 600         memset(buffer, 0, BLCKSZ);
 601         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 602
 603         unlink(XLOG_CONTROL_FILE);
 604
 605         fd = open(XLOG_CONTROL_FILE,
 606                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 607                           S_IRUSR | S_IWUSR);
 608         if (fd < 0)
 609         {
 610                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 611                                 progname, strerror(errno));
 612                 exit(1);
 613         }
 614
 615         errno = 0;
 616         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 617         {
 618                 /* if write didn't set errno, assume problem is no disk space */
 619                 if (errno == 0)
 620                         errno = ENOSPC;
 621                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 622                                 progname, strerror(errno));
 623                 exit(1);
 624         }
 625
 626         if (fsync(fd) != 0)
 627         {
 628                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 629                 exit(1);
 630         }
 631
 632         close(fd);
 633 }
 634
 635
 636 /*
 637  * Remove existing XLOG files
 638  */
 639 static void
 640 KillExistingXLOG(void)
 641 {
 642         DIR                *xldir;
 643         struct dirent *xlde;
 644         char            path[MAXPGPATH];
 645
 646         xldir = opendir(XLOGDIR);
 647         if (xldir == NULL)
 648         {
 649                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 650                                 progname, XLOGDIR, strerror(errno));
 651                 exit(1);
 652         }
 653
 654         errno = 0;
 655         while ((xlde = readdir(xldir)) != NULL)
 656         {
 657                 if (strlen(xlde->d_name) == 24 &&
 658                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 659                 {
 660                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 661                         if (unlink(path) < 0)
 662                         {
 663                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 664                                                 progname, path, strerror(errno));
 665                                 exit(1);
 666                         }
 667                 }
 668                 errno = 0;
 669         }
 670 #ifdef WIN32
 671
 672         /*
 673          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
 674          * not in released version
 675          */
 676         if (GetLastError() == ERROR_NO_MORE_FILES)
 677                 errno = 0;
 678 #endif
 679
 680         if (errno)
 681         {
 682                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 683                                 progname, XLOGDIR, strerror(errno));
 684                 exit(1);
 685         }
 686         closedir(xldir);
 687 }
 688
 689
 690 /*
 691  * Write an empty XLOG file, containing only the checkpoint record
 692  * already set up in ControlFile.
 693  */
 694 static void
 695 WriteEmptyXLOG(void)
 696 {
 697         char       *buffer;
 698         XLogPageHeader page;
 699         XLogLongPageHeader longpage;
 700         XLogRecord *record;
 701         pg_crc32        crc;
 702         char            path[MAXPGPATH];
 703         int                     fd;
 704         int                     nbytes;
 705
 706         /* Use malloc() to ensure buffer is MAXALIGNED */
 707         buffer = (char *) malloc(BLCKSZ);
 708         page = (XLogPageHeader) buffer;
 709         memset(buffer, 0, BLCKSZ);
 710
 711         /* Set up the XLOG page header */
 712         page->xlp_magic = XLOG_PAGE_MAGIC;
 713         page->xlp_info = XLP_LONG_HEADER;
 714         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 715         page->xlp_pageaddr.xlogid =
 716                 ControlFile.checkPointCopy.redo.xlogid;
 717         page->xlp_pageaddr.xrecoff =
 718                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 719         longpage = (XLogLongPageHeader) page;
 720         longpage->xlp_sysid = ControlFile.system_identifier;
 721         longpage->xlp_seg_size = XLogSegSize;
 722
 723         /* Insert the initial checkpoint record */
 724         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 725         record->xl_prev.xlogid = 0;
 726         record->xl_prev.xrecoff = 0;
 727         record->xl_xid = InvalidTransactionId;
 728         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
 729         record->xl_len = sizeof(CheckPoint);
 730         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 731         record->xl_rmid = RM_XLOG_ID;
 732         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 733                    sizeof(CheckPoint));
 734
 735         INIT_CRC32(crc);
 736         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 737         COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
 738                            SizeOfXLogRecord - sizeof(pg_crc32));
 739         FIN_CRC32(crc);
 740         record->xl_crc = crc;
 741
 742         /* Write the first page */
 743         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 744                                  newXlogId, newXlogSeg);
 745
 746         unlink(path);
 747
 748         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 749                           S_IRUSR | S_IWUSR);
 750         if (fd < 0)
 751         {
 752                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 753                                 progname, path, strerror(errno));
 754                 exit(1);
 755         }
 756
 757         errno = 0;
 758         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 759         {
 760                 /* if write didn't set errno, assume problem is no disk space */
 761                 if (errno == 0)
 762                         errno = ENOSPC;
 763                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 764                                 progname, path, strerror(errno));
 765                 exit(1);
 766         }
 767
 768         /* Fill the rest of the file with zeroes */
 769         memset(buffer, 0, BLCKSZ);
 770         for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
 771         {
 772                 errno = 0;
 773                 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 774                 {
 775                         if (errno == 0)
 776                                 errno = ENOSPC;
 777                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 778                                         progname, path, strerror(errno));
 779                         exit(1);
 780                 }
 781         }
 782
 783         if (fsync(fd) != 0)
 784         {
 785                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 786                 exit(1);
 787         }
 788
 789         close(fd);
 790 }
 791
 792
 793 static void
 794 usage(void)
 795 {
 796         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
 797         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 798         printf(_("Options:\n"));
 799         printf(_("  -f              force update to be done\n"));
 800         printf(_("  -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
 801         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
 802         printf(_("  -o OID          set next OID\n"));
 803         printf(_("  -x XID          set next transaction ID\n"));
 804         printf(_("  -m multiXID     set next multi transaction ID\n"));
 805         printf(_("  -O multiOffset  set next multi transaction offset\n"));
 806         printf(_("  --help          show this help, then exit\n"));
 807         printf(_("  --version       output version information, then exit\n"));
 808         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
 809 }