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) 1996-2006, 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 1.42 2006/04/04 22:39:59 tgl Exp $
  27  *
  28  *-------------------------------------------------------------------------
  29  */
  30 #include "postgres.h"
  31
  32 #include <dirent.h>
  33 #include <fcntl.h>
  34 #include <locale.h>
  35 #include <sys/stat.h>
  36 #include <sys/time.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39 #ifdef HAVE_GETOPT_H
  40 #include <getopt.h>
  41 #endif
  42
  43 #include "access/multixact.h"
  44 #include "access/xlog.h"
  45 #include "access/xlog_internal.h"
  46 #include "catalog/catversion.h"
  47 #include "catalog/pg_control.h"
  48
  49 extern int      optind;
  50 extern char *optarg;
  51
  52
  53 static ControlFileData ControlFile;             /* pg_control values */
  54 static uint32 newXlogId,
  55                         newXlogSeg;                     /* ID/Segment of new XLOG segment */
  56 static bool guessed = false;    /* T if we had to guess at any values */
  57 static const char *progname;
  58
  59 static bool ReadControlFile(void);
  60 static void GuessControlValues(void);
  61 static void PrintControlValues(bool guessed);
  62 static void RewriteControlFile(void);
  63 static void KillExistingXLOG(void);
  64 static void WriteEmptyXLOG(void);
  65 static void usage(void);
  66
  67
  68 int
  69 main(int argc, char *argv[])
  70 {
  71         int                     c;
  72         bool            force = false;
  73         bool            noupdate = false;
  74         TransactionId set_xid = 0;
  75         Oid                     set_oid = 0;
  76         MultiXactId set_mxid = 0;
  77         MultiXactOffset set_mxoff = -1;
  78         uint32          minXlogTli = 0,
  79                                 minXlogId = 0,
  80                                 minXlogSeg = 0;
  81         char       *endptr;
  82         char       *endptr2;
  83         char       *endptr3;
  84         char       *DataDir;
  85         int                     fd;
  86         char            path[MAXPGPATH];
  87
  88         set_pglocale_pgservice(argv[0], "pg_resetxlog");
  89
  90         progname = get_progname(argv[0]);
  91
  92         if (argc > 1)
  93         {
  94                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
  95                 {
  96                         usage();
  97                         exit(0);
  98                 }
  99                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 100                 {
 101                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
 102                         exit(0);
 103                 }
 104         }
 105
 106
 107         while ((c = getopt(argc, argv, "fl:m:no:O:x:")) != -1)
 108         {
 109                 switch (c)
 110                 {
 111                         case 'f':
 112                                 force = true;
 113                                 break;
 114
 115                         case 'n':
 116                                 noupdate = true;
 117                                 break;
 118
 119                         case 'x':
 120                                 set_xid = strtoul(optarg, &endptr, 0);
 121                                 if (endptr == optarg || *endptr != '\0')
 122                                 {
 123                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 124                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 125                                         exit(1);
 126                                 }
 127                                 if (set_xid == 0)
 128                                 {
 129                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 130                                         exit(1);
 131                                 }
 132                                 break;
 133
 134                         case 'o':
 135                                 set_oid = strtoul(optarg, &endptr, 0);
 136                                 if (endptr == optarg || *endptr != '\0')
 137                                 {
 138                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 139                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 140                                         exit(1);
 141                                 }
 142                                 if (set_oid == 0)
 143                                 {
 144                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 145                                         exit(1);
 146                                 }
 147                                 break;
 148
 149                         case 'm':
 150                                 set_mxid = strtoul(optarg, &endptr, 0);
 151                                 if (endptr == optarg || *endptr != '\0')
 152                                 {
 153                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 154                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 155                                         exit(1);
 156                                 }
 157                                 if (set_mxid == 0)
 158                                 {
 159                                         fprintf(stderr, _("%s: 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         if (geteuid() == 0)
 224         {
 225                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 226                                 progname);
 227                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 228                                 progname);
 229                 exit(1);
 230         }
 231 #endif
 232
 233         DataDir = argv[optind];
 234
 235         if (chdir(DataDir) < 0)
 236         {
 237                 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
 238                                 progname, DataDir, strerror(errno));
 239                 exit(1);
 240         }
 241
 242         /*
 243          * Check for a postmaster lock file --- if there is one, refuse to
 244          * proceed, on grounds we might be interfering with a live installation.
 245          */
 246         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 247
 248         if ((fd = open(path, O_RDONLY)) < 0)
 249         {
 250                 if (errno != ENOENT)
 251                 {
 252                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 253                         exit(1);
 254                 }
 255         }
 256         else
 257         {
 258                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 259                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 260                                 progname, path);
 261                 exit(1);
 262         }
 263
 264         /*
 265          * Attempt to read the existing pg_control file
 266          */
 267         if (!ReadControlFile())
 268                 GuessControlValues();
 269
 270         /*
 271          * Adjust fields if required by switches.  (Do this now so that printout,
 272          * if any, includes these values.)
 273          */
 274         if (set_xid != 0)
 275                 ControlFile.checkPointCopy.nextXid = set_xid;
 276
 277         if (set_oid != 0)
 278                 ControlFile.checkPointCopy.nextOid = set_oid;
 279
 280         if (set_mxid != 0)
 281                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 282
 283         if (set_mxoff != -1)
 284                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 285
 286         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 287                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 288
 289         if (minXlogId > ControlFile.logId ||
 290                 (minXlogId == ControlFile.logId &&
 291                  minXlogSeg > ControlFile.logSeg))
 292         {
 293                 ControlFile.logId = minXlogId;
 294                 ControlFile.logSeg = minXlogSeg;
 295         }
 296
 297         /*
 298          * If we had to guess anything, and -f was not given, just print the
 299          * guessed values and exit.  Also print if -n is given.
 300          */
 301         if ((guessed && !force) || noupdate)
 302         {
 303                 PrintControlValues(guessed);
 304                 if (!noupdate)
 305                 {
 306                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 307                         exit(1);
 308                 }
 309                 else
 310                         exit(0);
 311         }
 312
 313         /*
 314          * Don't reset from a dirty pg_control without -f, either.
 315          */
 316         if (ControlFile.state != DB_SHUTDOWNED && !force)
 317         {
 318                 printf(_("The database server was not shut down cleanly.\n"
 319                                  "Resetting the transaction log may cause data to be lost.\n"
 320                                  "If you want to proceed anyway, use -f to force reset.\n"));
 321                 exit(1);
 322         }
 323
 324         /*
 325          * Else, do the dirty deed.
 326          */
 327         RewriteControlFile();
 328         KillExistingXLOG();
 329         WriteEmptyXLOG();
 330
 331         printf(_("Transaction log reset\n"));
 332         return 0;
 333 }
 334
 335
 336 /*
 337  * Try to read the existing pg_control file.
 338  *
 339  * This routine is also responsible for updating old pg_control versions
 340  * to the current format.  (Currently we don't do anything of the sort.)
 341  */
 342 static bool
 343 ReadControlFile(void)
 344 {
 345         int                     fd;
 346         int                     len;
 347         char       *buffer;
 348         pg_crc32        crc;
 349
 350         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY)) < 0)
 351         {
 352                 /*
 353                  * If pg_control is not there at all, or we can't read it, the odds
 354                  * are we've been handed a bad DataDir path, so give up. User can do
 355                  * "touch pg_control" to force us to proceed.
 356                  */
 357                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 358                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 359                 if (errno == ENOENT)
 360                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 361                                                           "  touch %s\n"
 362                                                           "and try again.\n"),
 363                                         XLOG_CONTROL_FILE);
 364                 exit(1);
 365         }
 366
 367         /* Use malloc to ensure we have a maxaligned buffer */
 368         buffer = (char *) malloc(PG_CONTROL_SIZE);
 369
 370         len = read(fd, buffer, PG_CONTROL_SIZE);
 371         if (len < 0)
 372         {
 373                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 374                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 375                 exit(1);
 376         }
 377         close(fd);
 378
 379         if (len >= sizeof(ControlFileData) &&
 380           ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 381         {
 382                 /* Check the CRC. */
 383                 INIT_CRC32(crc);
 384                 COMP_CRC32(crc,
 385                                    buffer,
 386                                    offsetof(ControlFileData, crc));
 387                 FIN_CRC32(crc);
 388
 389                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 390                 {
 391                         /* Valid data... */
 392                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 393                         return true;
 394                 }
 395
 396                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 397                                 progname);
 398                 /* We will use the data anyway, but treat it as guessed. */
 399                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 400                 guessed = true;
 401                 return true;
 402         }
 403
 404         /* Looks like it's a mess. */
 405         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 406                         progname);
 407         return false;
 408 }
 409
 410
 411 /*
 412  * Guess at pg_control values when we can't read the old ones.
 413  */
 414 static void
 415 GuessControlValues(void)
 416 {
 417         uint64          sysidentifier;
 418         struct timeval tv;
 419         char       *localeptr;
 420
 421         /*
 422          * Set up a completely default set of pg_control values.
 423          */
 424         guessed = true;
 425         memset(&ControlFile, 0, sizeof(ControlFile));
 426
 427         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 428         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 429
 430         /*
 431          * Create a new unique installation identifier, since we can no longer use
 432          * any old XLOG records.  See notes in xlog.c about the algorithm.
 433          */
 434         gettimeofday(&tv, NULL);
 435         sysidentifier = ((uint64) tv.tv_sec) << 32;
 436         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 437
 438         ControlFile.system_identifier = sysidentifier;
 439
 440         ControlFile.checkPointCopy.redo.xlogid = 0;
 441         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 442         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 443         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 444         ControlFile.checkPointCopy.nextXid = (TransactionId) 514;       /* XXX */
 445         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 446         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 447         ControlFile.checkPointCopy.nextMultiOffset = 0;
 448         ControlFile.checkPointCopy.time = time(NULL);
 449
 450         ControlFile.state = DB_SHUTDOWNED;
 451         ControlFile.time = time(NULL);
 452         ControlFile.logId = 0;
 453         ControlFile.logSeg = 1;
 454         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 455
 456         ControlFile.maxAlign = MAXIMUM_ALIGNOF;
 457         ControlFile.floatFormat = FLOATFORMAT_VALUE;
 458         ControlFile.blcksz = BLCKSZ;
 459         ControlFile.relseg_size = RELSEG_SIZE;
 460         ControlFile.xlog_blcksz = XLOG_BLCKSZ;
 461         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 462         ControlFile.nameDataLen = NAMEDATALEN;
 463         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 464 #ifdef HAVE_INT64_TIMESTAMP
 465         ControlFile.enableIntTimes = TRUE;
 466 #else
 467         ControlFile.enableIntTimes = FALSE;
 468 #endif
 469         ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
 470
 471         localeptr = setlocale(LC_COLLATE, "");
 472         if (!localeptr)
 473         {
 474                 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
 475                 exit(1);
 476         }
 477         StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
 478         localeptr = setlocale(LC_CTYPE, "");
 479         if (!localeptr)
 480         {
 481                 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
 482                 exit(1);
 483         }
 484         StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
 485
 486         /*
 487          * XXX eventually, should try to grovel through old XLOG to develop more
 488          * accurate values for TimeLineID, nextXID, etc.
 489          */
 490 }
 491
 492
 493 /*
 494  * Print the guessed pg_control values when we had to guess.
 495  *
 496  * NB: this display should be just those fields that will not be
 497  * reset by RewriteControlFile().
 498  */
 499 static void
 500 PrintControlValues(bool guessed)
 501 {
 502         char            sysident_str[32];
 503
 504         if (guessed)
 505                 printf(_("Guessed pg_control values:\n\n"));
 506         else
 507                 printf(_("pg_control values:\n\n"));
 508
 509         /*
 510          * Format system_identifier separately to keep platform-dependent format
 511          * code out of the translatable message string.
 512          */
 513         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 514                          ControlFile.system_identifier);
 515
 516         printf(_("pg_control version number:            %u\n"), ControlFile.pg_control_version);
 517         printf(_("Catalog version number:               %u\n"), ControlFile.catalog_version_no);
 518         printf(_("Database system identifier:           %s\n"), sysident_str);
 519         printf(_("Current log file ID:                  %u\n"), ControlFile.logId);
 520         printf(_("Next log file segment:                %u\n"), ControlFile.logSeg);
 521         printf(_("Latest checkpoint's TimeLineID:       %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
 522         printf(_("Latest checkpoint's NextXID:          %u\n"), ControlFile.checkPointCopy.nextXid);
 523         printf(_("Latest checkpoint's NextOID:          %u\n"), ControlFile.checkPointCopy.nextOid);
 524         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"), ControlFile.checkPointCopy.nextMulti);
 525         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"), ControlFile.checkPointCopy.nextMultiOffset);
 526         printf(_("Maximum data alignment:               %u\n"), ControlFile.maxAlign);
 527         /* we don't print floatFormat since can't say much useful about it */
 528         printf(_("Database block size:                  %u\n"), ControlFile.blcksz);
 529         printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
 530         printf(_("WAL block size:                       %u\n"), ControlFile.xlog_blcksz);
 531         printf(_("Bytes per WAL segment:                %u\n"), ControlFile.xlog_seg_size);
 532         printf(_("Maximum length of identifiers:        %u\n"), ControlFile.nameDataLen);
 533         printf(_("Maximum columns in an index:          %u\n"), ControlFile.indexMaxKeys);
 534         printf(_("Date/time type storage:               %s\n"),
 535                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 536         printf(_("Maximum length of locale name:        %u\n"), ControlFile.localeBuflen);
 537         printf(_("LC_COLLATE:                           %s\n"), ControlFile.lc_collate);
 538         printf(_("LC_CTYPE:                             %s\n"), ControlFile.lc_ctype);
 539 }
 540
 541
 542 /*
 543  * Write out the new pg_control file.
 544  */
 545 static void
 546 RewriteControlFile(void)
 547 {
 548         int                     fd;
 549         char            buffer[PG_CONTROL_SIZE]; /* need not be aligned */
 550
 551         /*
 552          * Adjust fields as needed to force an empty XLOG starting at the next
 553          * available segment.
 554          */
 555         newXlogId = ControlFile.logId;
 556         newXlogSeg = ControlFile.logSeg;
 557
 558         /* adjust in case we are changing segment size */
 559         newXlogSeg *= ControlFile.xlog_seg_size;
 560         newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
 561
 562         /* be sure we wrap around correctly at end of a logfile */
 563         NextLogSeg(newXlogId, newXlogSeg);
 564
 565         /* Now we can force the recorded xlog seg size to the right thing. */
 566         ControlFile.xlog_seg_size = XLogSegSize;
 567
 568         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 569         ControlFile.checkPointCopy.redo.xrecoff =
 570                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 571         ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
 572         ControlFile.checkPointCopy.time = time(NULL);
 573
 574         ControlFile.state = DB_SHUTDOWNED;
 575         ControlFile.time = time(NULL);
 576         ControlFile.logId = newXlogId;
 577         ControlFile.logSeg = newXlogSeg + 1;
 578         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 579         ControlFile.prevCheckPoint.xlogid = 0;
 580         ControlFile.prevCheckPoint.xrecoff = 0;
 581
 582         /* Contents are protected with a CRC */
 583         INIT_CRC32(ControlFile.crc);
 584         COMP_CRC32(ControlFile.crc,
 585                            (char *) &ControlFile,
 586                            offsetof(ControlFileData, crc));
 587         FIN_CRC32(ControlFile.crc);
 588
 589         /*
 590          * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
 591          * excess over sizeof(ControlFileData).  This reduces the odds of
 592          * premature-EOF errors when reading pg_control.  We'll still fail when we
 593          * check the contents of the file, but hopefully with a more specific
 594          * error than "couldn't read pg_control".
 595          */
 596         if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
 597         {
 598                 fprintf(stderr,
 599                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
 600                                 progname);
 601                 exit(1);
 602         }
 603
 604         memset(buffer, 0, PG_CONTROL_SIZE);
 605         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 606
 607         unlink(XLOG_CONTROL_FILE);
 608
 609         fd = open(XLOG_CONTROL_FILE,
 610                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 611                           S_IRUSR | S_IWUSR);
 612         if (fd < 0)
 613         {
 614                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 615                                 progname, strerror(errno));
 616                 exit(1);
 617         }
 618
 619         errno = 0;
 620         if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
 621         {
 622                 /* if write didn't set errno, assume problem is no disk space */
 623                 if (errno == 0)
 624                         errno = ENOSPC;
 625                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 626                                 progname, strerror(errno));
 627                 exit(1);
 628         }
 629
 630         if (fsync(fd) != 0)
 631         {
 632                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 633                 exit(1);
 634         }
 635
 636         close(fd);
 637 }
 638
 639
 640 /*
 641  * Remove existing XLOG files
 642  */
 643 static void
 644 KillExistingXLOG(void)
 645 {
 646         DIR                *xldir;
 647         struct dirent *xlde;
 648         char            path[MAXPGPATH];
 649
 650         xldir = opendir(XLOGDIR);
 651         if (xldir == NULL)
 652         {
 653                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 654                                 progname, XLOGDIR, strerror(errno));
 655                 exit(1);
 656         }
 657
 658         errno = 0;
 659         while ((xlde = readdir(xldir)) != NULL)
 660         {
 661                 if (strlen(xlde->d_name) == 24 &&
 662                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 663                 {
 664                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 665                         if (unlink(path) < 0)
 666                         {
 667                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 668                                                 progname, path, strerror(errno));
 669                                 exit(1);
 670                         }
 671                 }
 672                 errno = 0;
 673         }
 674 #ifdef WIN32
 675
 676         /*
 677          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 678          * released version
 679          */
 680         if (GetLastError() == ERROR_NO_MORE_FILES)
 681                 errno = 0;
 682 #endif
 683
 684         if (errno)
 685         {
 686                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 687                                 progname, XLOGDIR, strerror(errno));
 688                 exit(1);
 689         }
 690         closedir(xldir);
 691 }
 692
 693
 694 /*
 695  * Write an empty XLOG file, containing only the checkpoint record
 696  * already set up in ControlFile.
 697  */
 698 static void
 699 WriteEmptyXLOG(void)
 700 {
 701         char       *buffer;
 702         XLogPageHeader page;
 703         XLogLongPageHeader longpage;
 704         XLogRecord *record;
 705         pg_crc32        crc;
 706         char            path[MAXPGPATH];
 707         int                     fd;
 708         int                     nbytes;
 709
 710         /* Use malloc() to ensure buffer is MAXALIGNED */
 711         buffer = (char *) malloc(XLOG_BLCKSZ);
 712         page = (XLogPageHeader) buffer;
 713         memset(buffer, 0, XLOG_BLCKSZ);
 714
 715         /* Set up the XLOG page header */
 716         page->xlp_magic = XLOG_PAGE_MAGIC;
 717         page->xlp_info = XLP_LONG_HEADER;
 718         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 719         page->xlp_pageaddr.xlogid =
 720                 ControlFile.checkPointCopy.redo.xlogid;
 721         page->xlp_pageaddr.xrecoff =
 722                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 723         longpage = (XLogLongPageHeader) page;
 724         longpage->xlp_sysid = ControlFile.system_identifier;
 725         longpage->xlp_seg_size = XLogSegSize;
 726
 727         /* Insert the initial checkpoint record */
 728         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 729         record->xl_prev.xlogid = 0;
 730         record->xl_prev.xrecoff = 0;
 731         record->xl_xid = InvalidTransactionId;
 732         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
 733         record->xl_len = sizeof(CheckPoint);
 734         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 735         record->xl_rmid = RM_XLOG_ID;
 736         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 737                    sizeof(CheckPoint));
 738
 739         INIT_CRC32(crc);
 740         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 741         COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
 742                            SizeOfXLogRecord - sizeof(pg_crc32));
 743         FIN_CRC32(crc);
 744         record->xl_crc = crc;
 745
 746         /* Write the first page */
 747         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 748                                  newXlogId, newXlogSeg);
 749
 750         unlink(path);
 751
 752         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 753                           S_IRUSR | S_IWUSR);
 754         if (fd < 0)
 755         {
 756                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 757                                 progname, path, strerror(errno));
 758                 exit(1);
 759         }
 760
 761         errno = 0;
 762         if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 763         {
 764                 /* if write didn't set errno, assume problem is no disk space */
 765                 if (errno == 0)
 766                         errno = ENOSPC;
 767                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 768                                 progname, path, strerror(errno));
 769                 exit(1);
 770         }
 771
 772         /* Fill the rest of the file with zeroes */
 773         memset(buffer, 0, XLOG_BLCKSZ);
 774         for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
 775         {
 776                 errno = 0;
 777                 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 778                 {
 779                         if (errno == 0)
 780                                 errno = ENOSPC;
 781                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 782                                         progname, path, strerror(errno));
 783                         exit(1);
 784                 }
 785         }
 786
 787         if (fsync(fd) != 0)
 788         {
 789                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 790                 exit(1);
 791         }
 792
 793         close(fd);
 794 }
 795
 796
 797 static void
 798 usage(void)
 799 {
 800         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
 801         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
 802         printf(_("Options:\n"));
 803         printf(_("  -f              force update to be done\n"));
 804         printf(_("  -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
 805         printf(_("  -m XID          set next multitransaction ID\n"));
 806         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
 807         printf(_("  -o OID          set next OID\n"));
 808         printf(_("  -O OFFSET       set next multitransaction offset\n"));
 809         printf(_("  -x XID          set next transaction ID\n"));
 810         printf(_("  --help          show this help, then exit\n"));
 811         printf(_("  --version       output version information, then exit\n"));
 812         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
 813 }