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 1.30 2005/03/29 03:01:32 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/xlog.h"
  44 #include "access/xlog_internal.h"
  45 #include "catalog/catversion.h"
  46 #include "catalog/pg_control.h"
  47
  48 extern int      optind;
  49 extern char *optarg;
  50
  51
  52 char            XLogDir[MAXPGPATH]; /* not static, see xlog_internal.h */
  53 static char ControlFilePath[MAXPGPATH];
  54
  55 static ControlFileData ControlFile;             /* pg_control values */
  56 static uint32 newXlogId,
  57                         newXlogSeg;                     /* ID/Segment of new XLOG segment */
  58 static bool guessed = false;    /* T if we had to guess at any values */
  59 static const char *progname;
  60
  61 static bool ReadControlFile(void);
  62 static void GuessControlValues(void);
  63 static void PrintControlValues(bool guessed);
  64 static void RewriteControlFile(void);
  65 static void KillExistingXLOG(void);
  66 static void WriteEmptyXLOG(void);
  67 static void usage(void);
  68
  69
  70 int
  71 main(int argc, char *argv[])
  72 {
  73         int                     c;
  74         bool            force = false;
  75         bool            noupdate = false;
  76         TransactionId set_xid = 0;
  77         Oid                     set_oid = 0;
  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:no: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 'l':
 150                                 minXlogTli = strtoul(optarg, &endptr, 0);
 151                                 if (endptr == optarg || *endptr != ',')
 152                                 {
 153                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 154                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 155                                         exit(1);
 156                                 }
 157                                 minXlogId = strtoul(endptr + 1, &endptr2, 0);
 158                                 if (endptr2 == endptr + 1 || *endptr2 != ',')
 159                                 {
 160                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 161                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 162                                         exit(1);
 163                                 }
 164                                 minXlogSeg = strtoul(endptr2 + 1, &endptr3, 0);
 165                                 if (endptr3 == endptr2 + 1 || *endptr3 != '\0')
 166                                 {
 167                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 168                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 169                                         exit(1);
 170                                 }
 171                                 break;
 172
 173                         default:
 174                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 175                                 exit(1);
 176                 }
 177         }
 178
 179         if (optind == argc)
 180         {
 181                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 182                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 183                 exit(1);
 184         }
 185
 186         /*
 187          * Don't allow pg_resetxlog to be run as root, to avoid
 188          * overwriting the ownership of files in the data directory. We
 189          * need only check for root -- any other user won't have
 190          * sufficient permissions to modify files in the data directory.
 191          */
 192 #ifndef WIN32
 193 #ifndef __BEOS__                                /* no root check on BeOS */
 194         if (geteuid() == 0)
 195         {
 196                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 197                                 progname);
 198                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 199                                 progname);
 200                 exit(1);
 201         }
 202 #endif
 203 #endif
 204
 205         DataDir = argv[optind];
 206         snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
 207         snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
 208
 209         /*
 210          * Check for a postmaster lock file --- if there is one, refuse to
 211          * proceed, on grounds we might be interfering with a live
 212          * installation.
 213          */
 214         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 215
 216         if ((fd = open(path, O_RDONLY)) < 0)
 217         {
 218                 if (errno != ENOENT)
 219                 {
 220                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 221                         exit(1);
 222                 }
 223         }
 224         else
 225         {
 226                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 227                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 228                                 progname, path);
 229                 exit(1);
 230         }
 231
 232         /*
 233          * Attempt to read the existing pg_control file
 234          */
 235         if (!ReadControlFile())
 236                 GuessControlValues();
 237
 238         /*
 239          * Adjust fields if required by switches.  (Do this now so that
 240          * printout, if any, includes these values.)
 241          */
 242         if (set_xid != 0)
 243                 ControlFile.checkPointCopy.nextXid = set_xid;
 244
 245         if (set_oid != 0)
 246                 ControlFile.checkPointCopy.nextOid = set_oid;
 247
 248         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 249                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 250
 251         if (minXlogId > ControlFile.logId ||
 252                 (minXlogId == ControlFile.logId &&
 253                  minXlogSeg > ControlFile.logSeg))
 254         {
 255                 ControlFile.logId = minXlogId;
 256                 ControlFile.logSeg = minXlogSeg;
 257         }
 258
 259         /*
 260          * If we had to guess anything, and -f was not given, just print the
 261          * guessed values and exit.  Also print if -n is given.
 262          */
 263         if ((guessed && !force) || noupdate)
 264         {
 265                 PrintControlValues(guessed);
 266                 if (!noupdate)
 267                 {
 268                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 269                         exit(1);
 270                 }
 271                 else
 272                         exit(0);
 273         }
 274
 275         /*
 276          * Don't reset from a dirty pg_control without -f, either.
 277          */
 278         if (ControlFile.state != DB_SHUTDOWNED && !force)
 279         {
 280                 printf(_("The database server was not shut down cleanly.\n"
 281                          "Resetting the transaction log may cause data to be lost.\n"
 282                          "If you want to proceed anyway, use -f to force reset.\n"));
 283                 exit(1);
 284         }
 285
 286         /*
 287          * Else, do the dirty deed.
 288          */
 289         RewriteControlFile();
 290         KillExistingXLOG();
 291         WriteEmptyXLOG();
 292
 293         printf(_("Transaction log reset\n"));
 294         return 0;
 295 }
 296
 297
 298 /*
 299  * Try to read the existing pg_control file.
 300  *
 301  * This routine is also responsible for updating old pg_control versions
 302  * to the current format.  (Currently we don't do anything of the sort.)
 303  */
 304 static bool
 305 ReadControlFile(void)
 306 {
 307         int                     fd;
 308         int                     len;
 309         char       *buffer;
 310         crc64           crc;
 311
 312         if ((fd = open(ControlFilePath, O_RDONLY)) < 0)
 313         {
 314                 /*
 315                  * If pg_control is not there at all, or we can't read it, the
 316                  * odds are we've been handed a bad DataDir path, so give up. User
 317                  * can do "touch pg_control" to force us to proceed.
 318                  */
 319                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 320                                 progname, ControlFilePath, strerror(errno));
 321                 if (errno == ENOENT)
 322                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 323                                                           "  touch %s\n"
 324                                                           "and try again.\n"),
 325                                         ControlFilePath);
 326                 exit(1);
 327         }
 328
 329         /* Use malloc to ensure we have a maxaligned buffer */
 330         buffer = (char *) malloc(BLCKSZ);
 331
 332         len = read(fd, buffer, BLCKSZ);
 333         if (len < 0)
 334         {
 335                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 336                                 progname, ControlFilePath, strerror(errno));
 337                 exit(1);
 338         }
 339         close(fd);
 340
 341         if (len >= sizeof(ControlFileData) &&
 342                 ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 343         {
 344                 /* Check the CRC. */
 345                 INIT_CRC64(crc);
 346                 COMP_CRC64(crc,
 347                                    buffer + sizeof(crc64),
 348                                    sizeof(ControlFileData) - sizeof(crc64));
 349                 FIN_CRC64(crc);
 350
 351                 if (EQ_CRC64(crc, ((ControlFileData *) buffer)->crc))
 352                 {
 353                         /* Valid data... */
 354                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 355                         return true;
 356                 }
 357
 358                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 359                                 progname);
 360                 /* We will use the data anyway, but treat it as guessed. */
 361                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 362                 guessed = true;
 363                 return true;
 364         }
 365
 366         /* Looks like it's a mess. */
 367         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 368                         progname);
 369         return false;
 370 }
 371
 372
 373 /*
 374  * Guess at pg_control values when we can't read the old ones.
 375  */
 376 static void
 377 GuessControlValues(void)
 378 {
 379         uint64          sysidentifier;
 380         struct timeval tv;
 381         char       *localeptr;
 382
 383         /*
 384          * Set up a completely default set of pg_control values.
 385          */
 386         guessed = true;
 387         memset(&ControlFile, 0, sizeof(ControlFile));
 388
 389         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 390         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 391
 392         /*
 393          * Create a new unique installation identifier, since we can no longer
 394          * use any old XLOG records.  See notes in xlog.c about the algorithm.
 395          */
 396         gettimeofday(&tv, NULL);
 397         sysidentifier = ((uint64) tv.tv_sec) << 32;
 398         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 399
 400         ControlFile.system_identifier = sysidentifier;
 401
 402         ControlFile.checkPointCopy.redo.xlogid = 0;
 403         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 404         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 405         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 406         ControlFile.checkPointCopy.nextXid = (TransactionId) 514;       /* XXX */
 407         ControlFile.checkPointCopy.nextOid = BootstrapObjectIdData;
 408         ControlFile.checkPointCopy.time = time(NULL);
 409
 410         ControlFile.state = DB_SHUTDOWNED;
 411         ControlFile.time = time(NULL);
 412         ControlFile.logId = 0;
 413         ControlFile.logSeg = 1;
 414         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 415
 416         ControlFile.blcksz = BLCKSZ;
 417         ControlFile.relseg_size = RELSEG_SIZE;
 418         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 419         ControlFile.nameDataLen = NAMEDATALEN;
 420         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 421 #ifdef HAVE_INT64_TIMESTAMP
 422         ControlFile.enableIntTimes = TRUE;
 423 #else
 424         ControlFile.enableIntTimes = FALSE;
 425 #endif
 426         ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
 427
 428         localeptr = setlocale(LC_COLLATE, "");
 429         if (!localeptr)
 430         {
 431                 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
 432                 exit(1);
 433         }
 434         StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
 435         localeptr = setlocale(LC_CTYPE, "");
 436         if (!localeptr)
 437         {
 438                 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
 439                 exit(1);
 440         }
 441         StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
 442
 443         /*
 444          * XXX eventually, should try to grovel through old XLOG to develop
 445          * more accurate values for TimeLineID, nextXID, and nextOID.
 446          */
 447 }
 448
 449
 450 /*
 451  * Print the guessed pg_control values when we had to guess.
 452  *
 453  * NB: this display should be just those fields that will not be
 454  * reset by RewriteControlFile().
 455  */
 456 static void
 457 PrintControlValues(bool guessed)
 458 {
 459         char            sysident_str[32];
 460
 461         if (guessed)
 462                 printf(_("Guessed pg_control values:\n\n"));
 463         else
 464                 printf(_("pg_control values:\n\n"));
 465
 466         /*
 467          * Format system_identifier separately to keep platform-dependent
 468          * format code out of the translatable message string.
 469          */
 470         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 471                          ControlFile.system_identifier);
 472
 473         printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 474         printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
 475         printf(_("Database system identifier:           %s\n"), sysident_str);
 476         printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 477         printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 478         printf(_("Latest checkpoint's TimeLineID:       %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
 479         printf(_("Latest checkpoint's NextXID:          %u\n"), ControlFile.checkPointCopy.nextXid);
 480         printf(_("Latest checkpoint's NextOID:          %u\n"), ControlFile.checkPointCopy.nextOid);
 481         printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
 482         printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
 483         printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
 484         printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);
 485         printf(_("Date/time type storage:               %s\n"),
 486                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 487         printf(_("Maximum length of locale name:        %u\n"), ControlFile.localeBuflen);
 488         printf(_("LC_COLLATE:                           %s\n"), ControlFile.lc_collate);
 489         printf(_("LC_CTYPE:                             %s\n"), ControlFile.lc_ctype);
 490 }
 491
 492
 493 /*
 494  * Write out the new pg_control file.
 495  */
 496 static void
 497 RewriteControlFile(void)
 498 {
 499         int                     fd;
 500         char            buffer[BLCKSZ]; /* need not be aligned */
 501
 502         /*
 503          * Adjust fields as needed to force an empty XLOG starting at the next
 504          * available segment.
 505          */
 506         newXlogId = ControlFile.logId;
 507         newXlogSeg = ControlFile.logSeg;
 508
 509         /* adjust in case we are changing segment size */
 510         newXlogSeg *= ControlFile.xlog_seg_size;
 511         newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
 512
 513         /* be sure we wrap around correctly at end of a logfile */
 514         NextLogSeg(newXlogId, newXlogSeg);
 515
 516         /* Now we can force the recorded xlog seg size to the right thing. */
 517         ControlFile.xlog_seg_size = XLogSegSize;
 518
 519         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 520         ControlFile.checkPointCopy.redo.xrecoff =
 521                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 522         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 523         ControlFile.checkPointCopy.time = time(NULL);
 524
 525         ControlFile.state = DB_SHUTDOWNED;
 526         ControlFile.time = time(NULL);
 527         ControlFile.logId = newXlogId;
 528         ControlFile.logSeg = newXlogSeg + 1;
 529         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 530         ControlFile.prevCheckPoint.xlogid = 0;
 531         ControlFile.prevCheckPoint.xrecoff = 0;
 532
 533         /* Contents are protected with a CRC */
 534         INIT_CRC64(ControlFile.crc);
 535         COMP_CRC64(ControlFile.crc,
 536                            (char *) &ControlFile + sizeof(crc64),
 537                            sizeof(ControlFileData) - sizeof(crc64));
 538         FIN_CRC64(ControlFile.crc);
 539
 540         /*
 541          * We write out BLCKSZ bytes into pg_control, zero-padding the excess
 542          * over sizeof(ControlFileData).  This reduces the odds of
 543          * premature-EOF errors when reading pg_control.  We'll still fail
 544          * when we check the contents of the file, but hopefully with a more
 545          * specific error than "couldn't read pg_control".
 546          */
 547         if (sizeof(ControlFileData) > BLCKSZ)
 548         {
 549                 fprintf(stderr,
 550                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"),
 551                                 progname);
 552                 exit(1);
 553         }
 554
 555         memset(buffer, 0, BLCKSZ);
 556         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 557
 558         unlink(ControlFilePath);
 559
 560         fd = open(ControlFilePath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
 561         if (fd < 0)
 562         {
 563                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 564                                 progname, strerror(errno));
 565                 exit(1);
 566         }
 567
 568         errno = 0;
 569         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 570         {
 571                 /* if write didn't set errno, assume problem is no disk space */
 572                 if (errno == 0)
 573                         errno = ENOSPC;
 574                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 575                                 progname, strerror(errno));
 576                 exit(1);
 577         }
 578
 579         if (fsync(fd) != 0)
 580         {
 581                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 582                 exit(1);
 583         }
 584
 585         close(fd);
 586 }
 587
 588
 589 /*
 590  * Remove existing XLOG files
 591  */
 592 static void
 593 KillExistingXLOG(void)
 594 {
 595         DIR                *xldir;
 596         struct dirent *xlde;
 597         char            path[MAXPGPATH];
 598
 599         xldir = opendir(XLogDir);
 600         if (xldir == NULL)
 601         {
 602                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 603                                 progname, XLogDir, strerror(errno));
 604                 exit(1);
 605         }
 606
 607         errno = 0;
 608         while ((xlde = readdir(xldir)) != NULL)
 609         {
 610                 if (strlen(xlde->d_name) == 24 &&
 611                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 612                 {
 613                         snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
 614                         if (unlink(path) < 0)
 615                         {
 616                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 617                                                 progname, path, strerror(errno));
 618                                 exit(1);
 619                         }
 620                 }
 621                 errno = 0;
 622         }
 623 #ifdef WIN32
 624
 625         /*
 626          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
 627          * not in released version
 628          */
 629         if (GetLastError() == ERROR_NO_MORE_FILES)
 630                 errno = 0;
 631 #endif
 632
 633         if (errno)
 634         {
 635                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 636                                 progname, XLogDir, strerror(errno));
 637                 exit(1);
 638         }
 639         closedir(xldir);
 640 }
 641
 642
 643 /*
 644  * Write an empty XLOG file, containing only the checkpoint record
 645  * already set up in ControlFile.
 646  */
 647 static void
 648 WriteEmptyXLOG(void)
 649 {
 650         char       *buffer;
 651         XLogPageHeader page;
 652         XLogLongPageHeader longpage;
 653         XLogRecord *record;
 654         crc64           crc;
 655         char            path[MAXPGPATH];
 656         int                     fd;
 657         int                     nbytes;
 658
 659         /* Use malloc() to ensure buffer is MAXALIGNED */
 660         buffer = (char *) malloc(BLCKSZ);
 661         page = (XLogPageHeader) buffer;
 662         memset(buffer, 0, BLCKSZ);
 663
 664         /* Set up the XLOG page header */
 665         page->xlp_magic = XLOG_PAGE_MAGIC;
 666         page->xlp_info = XLP_LONG_HEADER;
 667         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 668         page->xlp_pageaddr.xlogid =
 669                 ControlFile.checkPointCopy.redo.xlogid;
 670         page->xlp_pageaddr.xrecoff =
 671                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 672         longpage = (XLogLongPageHeader) page;
 673         longpage->xlp_sysid = ControlFile.system_identifier;
 674         longpage->xlp_seg_size = XLogSegSize;
 675
 676         /* Insert the initial checkpoint record */
 677         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 678         record->xl_prev.xlogid = 0;
 679         record->xl_prev.xrecoff = 0;
 680         record->xl_xid = InvalidTransactionId;
 681         record->xl_len = sizeof(CheckPoint);
 682         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 683         record->xl_rmid = RM_XLOG_ID;
 684         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 685                    sizeof(CheckPoint));
 686
 687         INIT_CRC64(crc);
 688         COMP_CRC64(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 689         COMP_CRC64(crc, (char *) record + sizeof(crc64),
 690                            SizeOfXLogRecord - sizeof(crc64));
 691         FIN_CRC64(crc);
 692         record->xl_crc = crc;
 693
 694         /* Write the first page */
 695         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 696                                  newXlogId, newXlogSeg);
 697
 698         unlink(path);
 699
 700         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 701                           S_IRUSR | S_IWUSR);
 702         if (fd < 0)
 703         {
 704                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 705                                 progname, path, strerror(errno));
 706                 exit(1);
 707         }
 708
 709         errno = 0;
 710         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 711         {
 712                 /* if write didn't set errno, assume problem is no disk space */
 713                 if (errno == 0)
 714                         errno = ENOSPC;
 715                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 716                                 progname, path, strerror(errno));
 717                 exit(1);
 718         }
 719
 720         /* Fill the rest of the file with zeroes */
 721         memset(buffer, 0, BLCKSZ);
 722         for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
 723         {
 724                 errno = 0;
 725                 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 726                 {
 727                         if (errno == 0)
 728                                 errno = ENOSPC;
 729                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 730                                         progname, path, strerror(errno));
 731                         exit(1);
 732                 }
 733         }
 734
 735         if (fsync(fd) != 0)
 736         {
 737                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 738                 exit(1);
 739         }
 740
 741         close(fd);
 742 }
 743
 744
 745 static void
 746 usage(void)
 747 {
 748         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
 749         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 750         printf(_("Options:\n"));
 751         printf(_("  -f              force update to be done\n"));
 752         printf(_("  -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
 753         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
 754         printf(_("  -o OID          set next OID\n"));
 755         printf(_("  -x XID          set next transaction ID\n"));
 756         printf(_("  --help          show this help, then exit\n"));
 757         printf(_("  --version       output version information, then exit\n"));
 758         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
 759 }