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 1.38 2005/10/15 02:49:40 momjian 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: multitransaction 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: multitransaction 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 overwriting the
 218          * ownership of files in the data directory. We need only check for root
 219          * -- any other user won't have sufficient permissions to modify files in
 220          * 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 installation.
 247          */
 248         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 249
 250         if ((fd = open(path, O_RDONLY)) < 0)
 251         {
 252                 if (errno != ENOENT)
 253                 {
 254                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 255                         exit(1);
 256                 }
 257         }
 258         else
 259         {
 260                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 261                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 262                                 progname, path);
 263                 exit(1);
 264         }
 265
 266         /*
 267          * Attempt to read the existing pg_control file
 268          */
 269         if (!ReadControlFile())
 270                 GuessControlValues();
 271
 272         /*
 273          * Adjust fields if required by switches.  (Do this now so that printout,
 274          * if any, includes these values.)
 275          */
 276         if (set_xid != 0)
 277                 ControlFile.checkPointCopy.nextXid = set_xid;
 278
 279         if (set_oid != 0)
 280                 ControlFile.checkPointCopy.nextOid = set_oid;
 281
 282         if (set_mxid != 0)
 283                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 284
 285         if (set_mxoff != -1)
 286                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 287
 288         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 289                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 290
 291         if (minXlogId > ControlFile.logId ||
 292                 (minXlogId == ControlFile.logId &&
 293                  minXlogSeg > ControlFile.logSeg))
 294         {
 295                 ControlFile.logId = minXlogId;
 296                 ControlFile.logSeg = minXlogSeg;
 297         }
 298
 299         /*
 300          * If we had to guess anything, and -f was not given, just print the
 301          * guessed values and exit.  Also print if -n is given.
 302          */
 303         if ((guessed && !force) || noupdate)
 304         {
 305                 PrintControlValues(guessed);
 306                 if (!noupdate)
 307                 {
 308                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 309                         exit(1);
 310                 }
 311                 else
 312                         exit(0);
 313         }
 314
 315         /*
 316          * Don't reset from a dirty pg_control without -f, either.
 317          */
 318         if (ControlFile.state != DB_SHUTDOWNED && !force)
 319         {
 320                 printf(_("The database server was not shut down cleanly.\n"
 321                                  "Resetting the transaction log may cause data to be lost.\n"
 322                                  "If you want to proceed anyway, use -f to force reset.\n"));
 323                 exit(1);
 324         }
 325
 326         /*
 327          * Else, do the dirty deed.
 328          */
 329         RewriteControlFile();
 330         KillExistingXLOG();
 331         WriteEmptyXLOG();
 332
 333         printf(_("Transaction log reset\n"));
 334         return 0;
 335 }
 336
 337
 338 /*
 339  * Try to read the existing pg_control file.
 340  *
 341  * This routine is also responsible for updating old pg_control versions
 342  * to the current format.  (Currently we don't do anything of the sort.)
 343  */
 344 static bool
 345 ReadControlFile(void)
 346 {
 347         int                     fd;
 348         int                     len;
 349         char       *buffer;
 350         pg_crc32        crc;
 351
 352         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY)) < 0)
 353         {
 354                 /*
 355                  * If pg_control is not there at all, or we can't read it, the odds
 356                  * are we've been handed a bad DataDir path, so give up. User can do
 357                  * "touch pg_control" to force us to proceed.
 358                  */
 359                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 360                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 361                 if (errno == ENOENT)
 362                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 363                                                           "  touch %s\n"
 364                                                           "and try again.\n"),
 365                                         XLOG_CONTROL_FILE);
 366                 exit(1);
 367         }
 368
 369         /* Use malloc to ensure we have a maxaligned buffer */
 370         buffer = (char *) malloc(BLCKSZ);
 371
 372         len = read(fd, buffer, BLCKSZ);
 373         if (len < 0)
 374         {
 375                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 376                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 377                 exit(1);
 378         }
 379         close(fd);
 380
 381         if (len >= sizeof(ControlFileData) &&
 382           ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 383         {
 384                 /* Check the CRC. */
 385                 INIT_CRC32(crc);
 386                 COMP_CRC32(crc,
 387                                    buffer,
 388                                    offsetof(ControlFileData, crc));
 389                 FIN_CRC32(crc);
 390
 391                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 392                 {
 393                         /* Valid data... */
 394                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 395                         return true;
 396                 }
 397
 398                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 399                                 progname);
 400                 /* We will use the data anyway, but treat it as guessed. */
 401                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 402                 guessed = true;
 403                 return true;
 404         }
 405
 406         /* Looks like it's a mess. */
 407         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 408                         progname);
 409         return false;
 410 }
 411
 412
 413 /*
 414  * Guess at pg_control values when we can't read the old ones.
 415  */
 416 static void
 417 GuessControlValues(void)
 418 {
 419         uint64          sysidentifier;
 420         struct timeval tv;
 421         char       *localeptr;
 422
 423         /*
 424          * Set up a completely default set of pg_control values.
 425          */
 426         guessed = true;
 427         memset(&ControlFile, 0, sizeof(ControlFile));
 428
 429         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 430         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 431
 432         /*
 433          * Create a new unique installation identifier, since we can no longer use
 434          * any old XLOG records.  See notes in xlog.c about the algorithm.
 435          */
 436         gettimeofday(&tv, NULL);
 437         sysidentifier = ((uint64) tv.tv_sec) << 32;
 438         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 439
 440         ControlFile.system_identifier = sysidentifier;
 441
 442         ControlFile.checkPointCopy.redo.xlogid = 0;
 443         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 444         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 445         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 446         ControlFile.checkPointCopy.nextXid = (TransactionId) 514;       /* XXX */
 447         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 448         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 449         ControlFile.checkPointCopy.nextMultiOffset = 0;
 450         ControlFile.checkPointCopy.time = time(NULL);
 451
 452         ControlFile.state = DB_SHUTDOWNED;
 453         ControlFile.time = time(NULL);
 454         ControlFile.logId = 0;
 455         ControlFile.logSeg = 1;
 456         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 457
 458         ControlFile.maxAlign = MAXIMUM_ALIGNOF;
 459         ControlFile.floatFormat = FLOATFORMAT_VALUE;
 460         ControlFile.blcksz = BLCKSZ;
 461         ControlFile.relseg_size = RELSEG_SIZE;
 462         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 463         ControlFile.nameDataLen = NAMEDATALEN;
 464         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 465 #ifdef HAVE_INT64_TIMESTAMP
 466         ControlFile.enableIntTimes = TRUE;
 467 #else
 468         ControlFile.enableIntTimes = FALSE;
 469 #endif
 470         ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
 471
 472         localeptr = setlocale(LC_COLLATE, "");
 473         if (!localeptr)
 474         {
 475                 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
 476                 exit(1);
 477         }
 478         StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
 479         localeptr = setlocale(LC_CTYPE, "");
 480         if (!localeptr)
 481         {
 482                 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
 483                 exit(1);
 484         }
 485         StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
 486
 487         /*
 488          * XXX eventually, should try to grovel through old XLOG to develop more
 489          * accurate values for TimeLineID, nextXID, etc.
 490          */
 491 }
 492
 493
 494 /*
 495  * Print the guessed pg_control values when we had to guess.
 496  *
 497  * NB: this display should be just those fields that will not be
 498  * reset by RewriteControlFile().
 499  */
 500 static void
 501 PrintControlValues(bool guessed)
 502 {
 503         char            sysident_str[32];
 504
 505         if (guessed)
 506                 printf(_("Guessed pg_control values:\n\n"));
 507         else
 508                 printf(_("pg_control values:\n\n"));
 509
 510         /*
 511          * Format system_identifier separately to keep platform-dependent format
 512          * code out of the translatable message string.
 513          */
 514         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 515                          ControlFile.system_identifier);
 516
 517         printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 518         printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
 519         printf(_("Database system identifier:           %s\n"), sysident_str);
 520         printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 521         printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 522         printf(_("Latest checkpoint's TimeLineID:       %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
 523         printf(_("Latest checkpoint's NextXID:          %u\n"), ControlFile.checkPointCopy.nextXid);
 524         printf(_("Latest checkpoint's NextOID:          %u\n"), ControlFile.checkPointCopy.nextOid);
 525         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"), ControlFile.checkPointCopy.nextMulti);
 526         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"), ControlFile.checkPointCopy.nextMultiOffset);
 527         printf(_("Maximum data alignment:               %u\n"), ControlFile.maxAlign);
 528         /* we don't print floatFormat since can't say much useful about it */
 529         printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
 530         printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
 531         printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
 532         printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);
 533         printf(_("Date/time type storage:               %s\n"),
 534                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 535         printf(_("Maximum length of locale name:        %u\n"), ControlFile.localeBuflen);
 536         printf(_("LC_COLLATE:                           %s\n"), ControlFile.lc_collate);
 537         printf(_("LC_CTYPE:                             %s\n"), ControlFile.lc_ctype);
 538 }
 539
 540
 541 /*
 542  * Write out the new pg_control file.
 543  */
 544 static void
 545 RewriteControlFile(void)
 546 {
 547         int                     fd;
 548         char            buffer[BLCKSZ]; /* need not be aligned */
 549
 550         /*
 551          * Adjust fields as needed to force an empty XLOG starting at the next
 552          * available segment.
 553          */
 554         newXlogId = ControlFile.logId;
 555         newXlogSeg = ControlFile.logSeg;
 556
 557         /* adjust in case we are changing segment size */
 558         newXlogSeg *= ControlFile.xlog_seg_size;
 559         newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
 560
 561         /* be sure we wrap around correctly at end of a logfile */
 562         NextLogSeg(newXlogId, newXlogSeg);
 563
 564         /* Now we can force the recorded xlog seg size to the right thing. */
 565         ControlFile.xlog_seg_size = XLogSegSize;
 566
 567         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 568         ControlFile.checkPointCopy.redo.xrecoff =
 569                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 570         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 571         ControlFile.checkPointCopy.time = time(NULL);
 572
 573         ControlFile.state = DB_SHUTDOWNED;
 574         ControlFile.time = time(NULL);
 575         ControlFile.logId = newXlogId;
 576         ControlFile.logSeg = newXlogSeg + 1;
 577         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 578         ControlFile.prevCheckPoint.xlogid = 0;
 579         ControlFile.prevCheckPoint.xrecoff = 0;
 580
 581         /* Contents are protected with a CRC */
 582         INIT_CRC32(ControlFile.crc);
 583         COMP_CRC32(ControlFile.crc,
 584                            (char *) &ControlFile,
 585                            offsetof(ControlFileData, crc));
 586         FIN_CRC32(ControlFile.crc);
 587
 588         /*
 589          * We write out BLCKSZ bytes into pg_control, zero-padding the excess over
 590          * sizeof(ControlFileData).  This reduces the odds of premature-EOF errors
 591          * when reading pg_control.  We'll still fail when we check the contents
 592          * of the file, but hopefully with a more specific error than "couldn't
 593          * read pg_control".
 594          */
 595         if (sizeof(ControlFileData) > BLCKSZ)
 596         {
 597                 fprintf(stderr,
 598                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"),
 599                                 progname);
 600                 exit(1);
 601         }
 602
 603         memset(buffer, 0, BLCKSZ);
 604         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 605
 606         unlink(XLOG_CONTROL_FILE);
 607
 608         fd = open(XLOG_CONTROL_FILE,
 609                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 610                           S_IRUSR | S_IWUSR);
 611         if (fd < 0)
 612         {
 613                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 614                                 progname, strerror(errno));
 615                 exit(1);
 616         }
 617
 618         errno = 0;
 619         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 620         {
 621                 /* if write didn't set errno, assume problem is no disk space */
 622                 if (errno == 0)
 623                         errno = ENOSPC;
 624                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 625                                 progname, strerror(errno));
 626                 exit(1);
 627         }
 628
 629         if (fsync(fd) != 0)
 630         {
 631                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 632                 exit(1);
 633         }
 634
 635         close(fd);
 636 }
 637
 638
 639 /*
 640  * Remove existing XLOG files
 641  */
 642 static void
 643 KillExistingXLOG(void)
 644 {
 645         DIR                *xldir;
 646         struct dirent *xlde;
 647         char            path[MAXPGPATH];
 648
 649         xldir = opendir(XLOGDIR);
 650         if (xldir == NULL)
 651         {
 652                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 653                                 progname, XLOGDIR, strerror(errno));
 654                 exit(1);
 655         }
 656
 657         errno = 0;
 658         while ((xlde = readdir(xldir)) != NULL)
 659         {
 660                 if (strlen(xlde->d_name) == 24 &&
 661                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 662                 {
 663                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 664                         if (unlink(path) < 0)
 665                         {
 666                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 667                                                 progname, path, strerror(errno));
 668                                 exit(1);
 669                         }
 670                 }
 671                 errno = 0;
 672         }
 673 #ifdef WIN32
 674
 675         /*
 676          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 677          * released version
 678          */
 679         if (GetLastError() == ERROR_NO_MORE_FILES)
 680                 errno = 0;
 681 #endif
 682
 683         if (errno)
 684         {
 685                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 686                                 progname, XLOGDIR, strerror(errno));
 687                 exit(1);
 688         }
 689         closedir(xldir);
 690 }
 691
 692
 693 /*
 694  * Write an empty XLOG file, containing only the checkpoint record
 695  * already set up in ControlFile.
 696  */
 697 static void
 698 WriteEmptyXLOG(void)
 699 {
 700         char       *buffer;
 701         XLogPageHeader page;
 702         XLogLongPageHeader longpage;
 703         XLogRecord *record;
 704         pg_crc32        crc;
 705         char            path[MAXPGPATH];
 706         int                     fd;
 707         int                     nbytes;
 708
 709         /* Use malloc() to ensure buffer is MAXALIGNED */
 710         buffer = (char *) malloc(BLCKSZ);
 711         page = (XLogPageHeader) buffer;
 712         memset(buffer, 0, BLCKSZ);
 713
 714         /* Set up the XLOG page header */
 715         page->xlp_magic = XLOG_PAGE_MAGIC;
 716         page->xlp_info = XLP_LONG_HEADER;
 717         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 718         page->xlp_pageaddr.xlogid =
 719                 ControlFile.checkPointCopy.redo.xlogid;
 720         page->xlp_pageaddr.xrecoff =
 721                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 722         longpage = (XLogLongPageHeader) page;
 723         longpage->xlp_sysid = ControlFile.system_identifier;
 724         longpage->xlp_seg_size = XLogSegSize;
 725
 726         /* Insert the initial checkpoint record */
 727         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 728         record->xl_prev.xlogid = 0;
 729         record->xl_prev.xrecoff = 0;
 730         record->xl_xid = InvalidTransactionId;
 731         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
 732         record->xl_len = sizeof(CheckPoint);
 733         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 734         record->xl_rmid = RM_XLOG_ID;
 735         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 736                    sizeof(CheckPoint));
 737
 738         INIT_CRC32(crc);
 739         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 740         COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
 741                            SizeOfXLogRecord - sizeof(pg_crc32));
 742         FIN_CRC32(crc);
 743         record->xl_crc = crc;
 744
 745         /* Write the first page */
 746         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 747                                  newXlogId, newXlogSeg);
 748
 749         unlink(path);
 750
 751         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 752                           S_IRUSR | S_IWUSR);
 753         if (fd < 0)
 754         {
 755                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 756                                 progname, path, strerror(errno));
 757                 exit(1);
 758         }
 759
 760         errno = 0;
 761         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 762         {
 763                 /* if write didn't set errno, assume problem is no disk space */
 764                 if (errno == 0)
 765                         errno = ENOSPC;
 766                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 767                                 progname, path, strerror(errno));
 768                 exit(1);
 769         }
 770
 771         /* Fill the rest of the file with zeroes */
 772         memset(buffer, 0, BLCKSZ);
 773         for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
 774         {
 775                 errno = 0;
 776                 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 777                 {
 778                         if (errno == 0)
 779                                 errno = ENOSPC;
 780                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 781                                         progname, path, strerror(errno));
 782                         exit(1);
 783                 }
 784         }
 785
 786         if (fsync(fd) != 0)
 787         {
 788                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 789                 exit(1);
 790         }
 791
 792         close(fd);
 793 }
 794
 795
 796 static void
 797 usage(void)
 798 {
 799         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
 800         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 801         printf(_("Options:\n"));
 802         printf(_("  -f              force update to be done\n"));
 803         printf(_("  -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
 804         printf(_("  -m XID          set next multitransaction ID\n"));
 805         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
 806         printf(_("  -o OID          set next OID\n"));
 807         printf(_("  -O OFFSET       set next multitransaction offset\n"));
 808         printf(_("  -x XID          set next transaction ID\n"));
 809         printf(_("  --help          show this help, then exit\n"));
 810         printf(_("  --version       output version information, then exit\n"));
 811         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
 812 }