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) 1996-2004, 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 1.22 2004/08/29 04:13:01 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
  40 #include "access/xlog.h"
  41 #include "access/xlog_internal.h"
  42 #include "catalog/catversion.h"
  43 #include "catalog/pg_control.h"
  44
  45 extern int      optind;
  46 extern char *optarg;
  47
  48 #define _(x) gettext((x))
  49
  50
  51 char XLogDir[MAXPGPATH];                /* not static, see xlog_internal.h */
  52 static char ControlFilePath[MAXPGPATH];
  53
  54 static ControlFileData ControlFile;             /* pg_control values */
  55 static uint32 newXlogId,
  56                         newXlogSeg;                     /* ID/Segment of new XLOG segment */
  57 static bool guessed = false;    /* T if we had to guess at any values */
  58 static const char *progname;
  59
  60 static bool ReadControlFile(void);
  61 static void GuessControlValues(void);
  62 static void PrintControlValues(bool guessed);
  63 static void RewriteControlFile(void);
  64 static void KillExistingXLOG(void);
  65 static void WriteEmptyXLOG(void);
  66 static void usage(void);
  67
  68
  69 int
  70 main(int argc, char *argv[])
  71 {
  72         int                     c;
  73         bool            force = false;
  74         bool            noupdate = false;
  75         TransactionId set_xid = 0;
  76         Oid                     set_oid = 0;
  77         uint32          minXlogId = 0,
  78                                 minXlogSeg = 0;
  79         char       *endptr;
  80         char       *endptr2;
  81         char       *DataDir;
  82         int                     fd;
  83         char            path[MAXPGPATH];
  84
  85         set_pglocale_pgservice(argv[0], "pg_resetxlog");
  86
  87         progname = get_progname(argv[0]);
  88
  89         if (argc > 1)
  90         {
  91                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
  92                 {
  93                         usage();
  94                         exit(0);
  95                 }
  96                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
  97                 {
  98                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
  99                         exit(0);
 100                 }
 101         }
 102
 103
 104         while ((c = getopt(argc, argv, "fl:no:x:")) != -1)
 105         {
 106                 switch (c)
 107                 {
 108                         case 'f':
 109                                 force = true;
 110                                 break;
 111
 112                         case 'n':
 113                                 noupdate = true;
 114                                 break;
 115
 116                         case 'x':
 117                                 set_xid = strtoul(optarg, &endptr, 0);
 118                                 if (endptr == optarg || *endptr != '\0')
 119                                 {
 120                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 121                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 122                                         exit(1);
 123                                 }
 124                                 if (set_xid == 0)
 125                                 {
 126                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 127                                         exit(1);
 128                                 }
 129                                 break;
 130
 131                         case 'o':
 132                                 set_oid = strtoul(optarg, &endptr, 0);
 133                                 if (endptr == optarg || *endptr != '\0')
 134                                 {
 135                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 136                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 137                                         exit(1);
 138                                 }
 139                                 if (set_oid == 0)
 140                                 {
 141                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 142                                         exit(1);
 143                                 }
 144                                 break;
 145
 146                         case 'l':
 147                                 minXlogId = strtoul(optarg, &endptr, 0);
 148                                 if (endptr == optarg || *endptr != ',')
 149                                 {
 150                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 151                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 152                                         exit(1);
 153                                 }
 154                                 minXlogSeg = strtoul(endptr + 1, &endptr2, 0);
 155                                 if (endptr2 == endptr + 1 || *endptr2 != '\0')
 156                                 {
 157                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 158                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 159                                         exit(1);
 160                                 }
 161                                 break;
 162
 163                         default:
 164                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 165                                 exit(1);
 166                 }
 167         }
 168
 169         if (optind == argc)
 170         {
 171                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 172                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 173                 exit(1);
 174         }
 175
 176         DataDir = argv[optind];
 177         snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
 178         snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
 179
 180         /*
 181          * Check for a postmaster lock file --- if there is one, refuse to
 182          * proceed, on grounds we might be interfering with a live
 183          * installation.
 184          */
 185         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 186
 187         if ((fd = open(path, O_RDONLY)) < 0)
 188         {
 189                 if (errno != ENOENT)
 190                 {
 191                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 192                         exit(1);
 193                 }
 194         }
 195         else
 196         {
 197                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 198                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 199                                 progname, path);
 200                 exit(1);
 201         }
 202
 203         /*
 204          * Attempt to read the existing pg_control file
 205          */
 206         if (!ReadControlFile())
 207                 GuessControlValues();
 208
 209         /*
 210          * Adjust fields if required by switches.  (Do this now so that
 211          * printout, if any, includes these values.)
 212          */
 213         if (set_xid != 0)
 214                 ControlFile.checkPointCopy.nextXid = set_xid;
 215
 216         if (set_oid != 0)
 217                 ControlFile.checkPointCopy.nextOid = set_oid;
 218
 219         if (minXlogId > ControlFile.logId ||
 220                 (minXlogId == ControlFile.logId &&
 221                  minXlogSeg > ControlFile.logSeg))
 222         {
 223                 ControlFile.logId = minXlogId;
 224                 ControlFile.logSeg = minXlogSeg;
 225         }
 226
 227         /*
 228          * If we had to guess anything, and -f was not given, just print the
 229          * guessed values and exit.  Also print if -n is given.
 230          */
 231         if ((guessed && !force) || noupdate)
 232         {
 233                 PrintControlValues(guessed);
 234                 if (!noupdate)
 235                 {
 236                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 237                         exit(1);
 238                 }
 239                 else
 240                         exit(0);
 241         }
 242
 243         /*
 244          * Don't reset from a dirty pg_control without -f, either.
 245          */
 246         if (ControlFile.state != DB_SHUTDOWNED && !force)
 247         {
 248                 printf(_("The database server was not shut down cleanly.\n"
 249                          "Resetting the transaction log may cause data to be lost.\n"
 250                          "If you want to proceed anyway, use -f to force reset.\n"));
 251                 exit(1);
 252         }
 253
 254         /*
 255          * Else, do the dirty deed.
 256          */
 257         RewriteControlFile();
 258         KillExistingXLOG();
 259         WriteEmptyXLOG();
 260
 261         printf(_("Transaction log reset\n"));
 262         return 0;
 263 }
 264
 265
 266 /*
 267  * Try to read the existing pg_control file.
 268  *
 269  * This routine is also responsible for updating old pg_control versions
 270  * to the current format.  (Currently we don't do anything of the sort.)
 271  */
 272 static bool
 273 ReadControlFile(void)
 274 {
 275         int                     fd;
 276         int                     len;
 277         char       *buffer;
 278         crc64           crc;
 279
 280         if ((fd = open(ControlFilePath, O_RDONLY)) < 0)
 281         {
 282                 /*
 283                  * If pg_control is not there at all, or we can't read it, the
 284                  * odds are we've been handed a bad DataDir path, so give up. User
 285                  * can do "touch pg_control" to force us to proceed.
 286                  */
 287                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 288                                 progname, ControlFilePath, strerror(errno));
 289                 if (errno == ENOENT)
 290                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 291                                                           "  touch %s\n"
 292                                                           "and try again.\n"),
 293                                         ControlFilePath);
 294                 exit(1);
 295         }
 296
 297         /* Use malloc to ensure we have a maxaligned buffer */
 298         buffer = (char *) malloc(BLCKSZ);
 299
 300         len = read(fd, buffer, BLCKSZ);
 301         if (len < 0)
 302         {
 303                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 304                                 progname, ControlFilePath, strerror(errno));
 305                 exit(1);
 306         }
 307         close(fd);
 308
 309         if (len >= sizeof(ControlFileData) &&
 310                 ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 311         {
 312                 /* Check the CRC. */
 313                 INIT_CRC64(crc);
 314                 COMP_CRC64(crc,
 315                                    buffer + sizeof(crc64),
 316                                    sizeof(ControlFileData) - sizeof(crc64));
 317                 FIN_CRC64(crc);
 318
 319                 if (EQ_CRC64(crc, ((ControlFileData *) buffer)->crc))
 320                 {
 321                         /* Valid data... */
 322                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 323                         return true;
 324                 }
 325
 326                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 327                                 progname);
 328                 /* We will use the data anyway, but treat it as guessed. */
 329                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 330                 guessed = true;
 331                 return true;
 332         }
 333
 334         /* Looks like it's a mess. */
 335         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 336                         progname);
 337         return false;
 338 }
 339
 340
 341 /*
 342  * Guess at pg_control values when we can't read the old ones.
 343  */
 344 static void
 345 GuessControlValues(void)
 346 {
 347         uint64          sysidentifier;
 348         struct timeval tv;
 349         char       *localeptr;
 350
 351         /*
 352          * Set up a completely default set of pg_control values.
 353          */
 354         guessed = true;
 355         memset(&ControlFile, 0, sizeof(ControlFile));
 356
 357         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 358         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 359
 360         /*
 361          * Create a new unique installation identifier, since we can no longer
 362          * use any old XLOG records.  See notes in xlog.c about the algorithm.
 363          */
 364         gettimeofday(&tv, NULL);
 365         sysidentifier = ((uint64) tv.tv_sec) << 32;
 366         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 367
 368         ControlFile.system_identifier = sysidentifier;
 369
 370         ControlFile.checkPointCopy.redo.xlogid = 0;
 371         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 372         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 373         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 374         ControlFile.checkPointCopy.nextXid = (TransactionId) 514;       /* XXX */
 375         ControlFile.checkPointCopy.nextOid = BootstrapObjectIdData;
 376         ControlFile.checkPointCopy.time = time(NULL);
 377
 378         ControlFile.state = DB_SHUTDOWNED;
 379         ControlFile.time = time(NULL);
 380         ControlFile.logId = 0;
 381         ControlFile.logSeg = 1;
 382         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 383
 384         ControlFile.blcksz = BLCKSZ;
 385         ControlFile.relseg_size = RELSEG_SIZE;
 386         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 387         ControlFile.nameDataLen = NAMEDATALEN;
 388         ControlFile.funcMaxArgs = FUNC_MAX_ARGS;
 389 #ifdef HAVE_INT64_TIMESTAMP
 390         ControlFile.enableIntTimes = TRUE;
 391 #else
 392         ControlFile.enableIntTimes = FALSE;
 393 #endif
 394         ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
 395
 396         localeptr = setlocale(LC_COLLATE, "");
 397         if (!localeptr)
 398         {
 399                 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
 400                 exit(1);
 401         }
 402         StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
 403         localeptr = setlocale(LC_CTYPE, "");
 404         if (!localeptr)
 405         {
 406                 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
 407                 exit(1);
 408         }
 409         StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
 410
 411         /*
 412          * XXX eventually, should try to grovel through old XLOG to develop
 413          * more accurate values for TimeLineID, nextXID, and nextOID.
 414          */
 415 }
 416
 417
 418 /*
 419  * Print the guessed pg_control values when we had to guess.
 420  *
 421  * NB: this display should be just those fields that will not be
 422  * reset by RewriteControlFile().
 423  */
 424 static void
 425 PrintControlValues(bool guessed)
 426 {
 427         char            sysident_str[32];
 428
 429         if (guessed)
 430                 printf(_("Guessed pg_control values:\n\n"));
 431         else
 432                 printf(_("pg_control values:\n\n"));
 433
 434         /*
 435          * Format system_identifier separately to keep platform-dependent format
 436          * code out of the translatable message string.
 437          */
 438         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 439                          ControlFile.system_identifier);
 440
 441         printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 442         printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
 443         printf(_("Database system identifier:           %s\n"), sysident_str);
 444         printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 445         printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 446         printf(_("Latest checkpoint's TimeLineID:       %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
 447         printf(_("Latest checkpoint's NextXID:          %u\n"), ControlFile.checkPointCopy.nextXid);
 448         printf(_("Latest checkpoint's NextOID:          %u\n"), ControlFile.checkPointCopy.nextOid);
 449         printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
 450         printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
 451         printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
 452         printf(_("Maximum number of function arguments: %u\n"), ControlFile.funcMaxArgs);
 453         printf(_("Date/time type storage:               %s\n"),
 454                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 455         printf(_("Maximum length of locale name:        %u\n"), ControlFile.localeBuflen);
 456         printf(_("LC_COLLATE:                           %s\n"), ControlFile.lc_collate);
 457         printf(_("LC_CTYPE:                             %s\n"), ControlFile.lc_ctype);
 458 }
 459
 460
 461 /*
 462  * Write out the new pg_control file.
 463  */
 464 static void
 465 RewriteControlFile(void)
 466 {
 467         int                     fd;
 468         char            buffer[BLCKSZ]; /* need not be aligned */
 469
 470         /*
 471          * Adjust fields as needed to force an empty XLOG starting at the next
 472          * available segment.
 473          */
 474         newXlogId = ControlFile.logId;
 475         newXlogSeg = ControlFile.logSeg;
 476
 477         /* adjust in case we are changing segment size */
 478         newXlogSeg *= ControlFile.xlog_seg_size;
 479         newXlogSeg = (newXlogSeg + XLogSegSize-1) / XLogSegSize;
 480
 481         /* be sure we wrap around correctly at end of a logfile */
 482         NextLogSeg(newXlogId, newXlogSeg);
 483
 484         /* Now we can force the recorded xlog seg size to the right thing. */
 485         ControlFile.xlog_seg_size = XLogSegSize;
 486
 487         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 488         ControlFile.checkPointCopy.redo.xrecoff =
 489                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 490         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 491         ControlFile.checkPointCopy.time = time(NULL);
 492
 493         ControlFile.state = DB_SHUTDOWNED;
 494         ControlFile.time = time(NULL);
 495         ControlFile.logId = newXlogId;
 496         ControlFile.logSeg = newXlogSeg + 1;
 497         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 498         ControlFile.prevCheckPoint.xlogid = 0;
 499         ControlFile.prevCheckPoint.xrecoff = 0;
 500
 501         /* Contents are protected with a CRC */
 502         INIT_CRC64(ControlFile.crc);
 503         COMP_CRC64(ControlFile.crc,
 504                            (char *) &ControlFile + sizeof(crc64),
 505                            sizeof(ControlFileData) - sizeof(crc64));
 506         FIN_CRC64(ControlFile.crc);
 507
 508         /*
 509          * We write out BLCKSZ bytes into pg_control, zero-padding the excess
 510          * over sizeof(ControlFileData).  This reduces the odds of
 511          * premature-EOF errors when reading pg_control.  We'll still fail
 512          * when we check the contents of the file, but hopefully with a more
 513          * specific error than "couldn't read pg_control".
 514          */
 515         if (sizeof(ControlFileData) > BLCKSZ)
 516         {
 517                 fprintf(stderr,
 518                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"),
 519                                 progname);
 520                 exit(1);
 521         }
 522
 523         memset(buffer, 0, BLCKSZ);
 524         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 525
 526         unlink(ControlFilePath);
 527
 528         fd = open(ControlFilePath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
 529         if (fd < 0)
 530         {
 531                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 532                                 progname, strerror(errno));
 533                 exit(1);
 534         }
 535
 536         errno = 0;
 537         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 538         {
 539                 /* if write didn't set errno, assume problem is no disk space */
 540                 if (errno == 0)
 541                         errno = ENOSPC;
 542                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 543                                 progname, strerror(errno));
 544                 exit(1);
 545         }
 546
 547         if (fsync(fd) != 0)
 548         {
 549                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 550                 exit(1);
 551         }
 552
 553         close(fd);
 554 }
 555
 556
 557 /*
 558  * Remove existing XLOG files
 559  */
 560 static void
 561 KillExistingXLOG(void)
 562 {
 563         DIR                *xldir;
 564         struct dirent *xlde;
 565         char            path[MAXPGPATH];
 566
 567         xldir = opendir(XLogDir);
 568         if (xldir == NULL)
 569         {
 570                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 571                                 progname, XLogDir, strerror(errno));
 572                 exit(1);
 573         }
 574
 575         errno = 0;
 576         while ((xlde = readdir(xldir)) != NULL)
 577         {
 578                 if (strlen(xlde->d_name) == 16 &&
 579                         strspn(xlde->d_name, "0123456789ABCDEF") == 16)
 580                 {
 581                         snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
 582                         if (unlink(path) < 0)
 583                         {
 584                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 585                                                 progname, path, strerror(errno));
 586                                 exit(1);
 587                         }
 588                 }
 589                 errno = 0;
 590         }
 591 #ifdef WIN32
 592         /* This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
 593            not in released version */
 594         if (GetLastError() == ERROR_NO_MORE_FILES)
 595                 errno = 0;
 596 #endif
 597
 598         if (errno)
 599         {
 600                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 601                                 progname, XLogDir, strerror(errno));
 602                 exit(1);
 603         }
 604         closedir(xldir);
 605 }
 606
 607
 608 /*
 609  * Write an empty XLOG file, containing only the checkpoint record
 610  * already set up in ControlFile.
 611  */
 612 static void
 613 WriteEmptyXLOG(void)
 614 {
 615         char       *buffer;
 616         XLogPageHeader page;
 617         XLogLongPageHeader longpage;
 618         XLogRecord *record;
 619         crc64           crc;
 620         char            path[MAXPGPATH];
 621         int                     fd;
 622         int                     nbytes;
 623
 624         /* Use malloc() to ensure buffer is MAXALIGNED */
 625         buffer = (char *) malloc(BLCKSZ);
 626         page = (XLogPageHeader) buffer;
 627         memset(buffer, 0, BLCKSZ);
 628
 629         /* Set up the XLOG page header */
 630         page->xlp_magic = XLOG_PAGE_MAGIC;
 631         page->xlp_info = XLP_LONG_HEADER;
 632         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 633         page->xlp_pageaddr.xlogid =
 634                 ControlFile.checkPointCopy.redo.xlogid;
 635         page->xlp_pageaddr.xrecoff =
 636                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 637         longpage = (XLogLongPageHeader) page;
 638         longpage->xlp_sysid = ControlFile.system_identifier;
 639         longpage->xlp_seg_size = XLogSegSize;
 640
 641         /* Insert the initial checkpoint record */
 642         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 643         record->xl_prev.xlogid = 0;
 644         record->xl_prev.xrecoff = 0;
 645         record->xl_xact_prev.xlogid = 0;
 646         record->xl_xact_prev.xrecoff = 0;
 647         record->xl_xid = InvalidTransactionId;
 648         record->xl_len = sizeof(CheckPoint);
 649         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 650         record->xl_rmid = RM_XLOG_ID;
 651         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 652                    sizeof(CheckPoint));
 653
 654         INIT_CRC64(crc);
 655         COMP_CRC64(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 656         COMP_CRC64(crc, (char *) record + sizeof(crc64),
 657                            SizeOfXLogRecord - sizeof(crc64));
 658         FIN_CRC64(crc);
 659         record->xl_crc = crc;
 660
 661         /* Write the first page */
 662         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 663                                  newXlogId, newXlogSeg);
 664
 665         unlink(path);
 666
 667         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 668                           S_IRUSR | S_IWUSR);
 669         if (fd < 0)
 670         {
 671                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 672                                 progname, path, strerror(errno));
 673                 exit(1);
 674         }
 675
 676         errno = 0;
 677         if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 678         {
 679                 /* if write didn't set errno, assume problem is no disk space */
 680                 if (errno == 0)
 681                         errno = ENOSPC;
 682                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 683                                 progname, path, strerror(errno));
 684                 exit(1);
 685         }
 686
 687         /* Fill the rest of the file with zeroes */
 688         memset(buffer, 0, BLCKSZ);
 689         for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
 690         {
 691                 errno = 0;
 692                 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
 693                 {
 694                         if (errno == 0)
 695                                 errno = ENOSPC;
 696                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 697                                         progname, path, strerror(errno));
 698                         exit(1);
 699                 }
 700         }
 701
 702         if (fsync(fd) != 0)
 703         {
 704                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 705                 exit(1);
 706         }
 707
 708         close(fd);
 709 }
 710
 711
 712 static void
 713 usage(void)
 714 {
 715         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
 716         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 717         printf(_("Options:\n"));
 718         printf(_("  -f              force update to be done\n"));
 719         printf(_("  -l FILEID,SEG   force minimum WAL starting location for new transaction log\n"));
 720         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
 721         printf(_("  -o OID          set next OID\n"));
 722         printf(_("  -x XID          set next transaction ID\n"));
 723         printf(_("  --help          show this help, then exit\n"));
 724         printf(_("  --version       output version information, then exit\n"));
 725         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
 726 }