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) 1996-2013, PostgreSQL Global Development Group
  24  * Portions Copyright (c) 1994, Regents of the University of California
  25  *
  26  * src/bin/pg_resetxlog/pg_resetxlog.c
  27  *
  28  *-------------------------------------------------------------------------
  29  */
  30
  31 /*
  32  * We have to use postgres.h not postgres_fe.h here, because there's so much
  33  * backend-only stuff in the XLOG include files we need.  But we need a
  34  * frontend-ish environment otherwise.  Hence this ugly hack.
  35  */
  36 #define FRONTEND 1
  37
  38 #include "postgres.h"
  39
  40 #include <dirent.h>
  41 #include <fcntl.h>
  42 #include <locale.h>
  43 #include <sys/stat.h>
  44 #include <sys/time.h>
  45 #include <time.h>
  46 #include <unistd.h>
  47 #ifdef HAVE_GETOPT_H
  48 #include <getopt.h>
  49 #endif
  50
  51 #include "access/transam.h"
  52 #include "access/tuptoaster.h"
  53 #include "access/multixact.h"
  54 #include "access/xlog_internal.h"
  55 #include "catalog/catversion.h"
  56 #include "catalog/pg_control.h"
  57 #include "common/fe_memutils.h"
  58
  59 extern int      optind;
  60 extern char *optarg;
  61
  62
  63 static ControlFileData ControlFile;             /* pg_control values */
  64 static XLogSegNo newXlogSegNo;  /* new XLOG segment # */
  65 static bool guessed = false;    /* T if we had to guess at any values */
  66 static const char *progname;
  67
  68 static bool ReadControlFile(void);
  69 static void GuessControlValues(void);
  70 static void PrintControlValues(bool guessed);
  71 static void RewriteControlFile(void);
  72 static void FindEndOfXLOG(void);
  73 static void KillExistingXLOG(void);
  74 static void KillExistingArchiveStatus(void);
  75 static void WriteEmptyXLOG(void);
  76 static void usage(void);
  77
  78
  79 int
  80 main(int argc, char *argv[])
  81 {
  82         int                     c;
  83         bool            force = false;
  84         bool            noupdate = false;
  85         uint32          set_xid_epoch = (uint32) -1;
  86         TransactionId set_xid = 0;
  87         Oid                     set_oid = 0;
  88         MultiXactId set_mxid = 0;
  89         MultiXactId set_oldestmxid = 0;
  90         MultiXactOffset set_mxoff = (MultiXactOffset) -1;
  91         uint32          minXlogTli = 0;
  92         XLogSegNo       minXlogSegNo = 0;
  93         char       *endptr;
  94         char       *endptr2;
  95         char       *DataDir;
  96         int                     fd;
  97
  98         set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));
  99
 100         progname = get_progname(argv[0]);
 101
 102         if (argc > 1)
 103         {
 104                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
 105                 {
 106                         usage();
 107                         exit(0);
 108                 }
 109                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 110                 {
 111                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
 112                         exit(0);
 113                 }
 114         }
 115
 116
 117         while ((c = getopt(argc, argv, "fl:m:no:O:x:e:")) != -1)
 118         {
 119                 switch (c)
 120                 {
 121                         case 'f':
 122                                 force = true;
 123                                 break;
 124
 125                         case 'n':
 126                                 noupdate = true;
 127                                 break;
 128
 129                         case 'e':
 130                                 set_xid_epoch = strtoul(optarg, &endptr, 0);
 131                                 if (endptr == optarg || *endptr != '\0')
 132                                 {
 133                                         fprintf(stderr, _("%s: invalid argument for option -e\n"), progname);
 134                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 135                                         exit(1);
 136                                 }
 137                                 if (set_xid_epoch == -1)
 138                                 {
 139                                         fprintf(stderr, _("%s: transaction ID epoch (-e) must not be -1\n"), progname);
 140                                         exit(1);
 141                                 }
 142                                 break;
 143
 144                         case 'x':
 145                                 set_xid = strtoul(optarg, &endptr, 0);
 146                                 if (endptr == optarg || *endptr != '\0')
 147                                 {
 148                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 149                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 150                                         exit(1);
 151                                 }
 152                                 if (set_xid == 0)
 153                                 {
 154                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 155                                         exit(1);
 156                                 }
 157                                 break;
 158
 159                         case 'o':
 160                                 set_oid = strtoul(optarg, &endptr, 0);
 161                                 if (endptr == optarg || *endptr != '\0')
 162                                 {
 163                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 164                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 165                                         exit(1);
 166                                 }
 167                                 if (set_oid == 0)
 168                                 {
 169                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 170                                         exit(1);
 171                                 }
 172                                 break;
 173
 174                         case 'm':
 175                                 set_mxid = strtoul(optarg, &endptr, 0);
 176                                 if (endptr == optarg || *endptr != ',')
 177                                 {
 178                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 179                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 180                                         exit(1);
 181                                 }
 182
 183                                 set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
 184                                 if (endptr2 == endptr + 1 || *endptr2 != '\0')
 185                                 {
 186                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 187                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 188                                         exit(1);
 189                                 }
 190                                 if (set_mxid == 0)
 191                                 {
 192                                         fprintf(stderr, _("%s: multitransaction ID (-m) must not be 0\n"), progname);
 193                                         exit(1);
 194                                 }
 195                                 /*
 196                                  * XXX It'd be nice to have more sanity checks here, e.g. so
 197                                  * that oldest is not wrapped around w.r.t. nextMulti.
 198                                  */
 199                                 if (set_oldestmxid == 0)
 200                                 {
 201                                         fprintf(stderr, _("%s: oldest multitransaction ID (-m) must not be 0\n"),
 202                                                         progname);
 203                                         exit(1);
 204                                 }
 205                                 break;
 206
 207                         case 'O':
 208                                 set_mxoff = strtoul(optarg, &endptr, 0);
 209                                 if (endptr == optarg || *endptr != '\0')
 210                                 {
 211                                         fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
 212                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 213                                         exit(1);
 214                                 }
 215                                 if (set_mxoff == -1)
 216                                 {
 217                                         fprintf(stderr, _("%s: multitransaction offset (-O) must not be -1\n"), progname);
 218                                         exit(1);
 219                                 }
 220                                 break;
 221
 222                         case 'l':
 223                                 if (strspn(optarg, "01234567890ABCDEFabcdef") != 24)
 224                                 {
 225                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 226                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 227                                         exit(1);
 228                                 }
 229                                 XLogFromFileName(optarg, &minXlogTli, &minXlogSegNo);
 230                                 break;
 231
 232                         default:
 233                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 234                                 exit(1);
 235                 }
 236         }
 237
 238         if (optind == argc)
 239         {
 240                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 241                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 242                 exit(1);
 243         }
 244
 245         /*
 246          * Don't allow pg_resetxlog to be run as root, to avoid overwriting the
 247          * ownership of files in the data directory. We need only check for root
 248          * -- any other user won't have sufficient permissions to modify files in
 249          * the data directory.
 250          */
 251 #ifndef WIN32
 252         if (geteuid() == 0)
 253         {
 254                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 255                                 progname);
 256                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 257                                 progname);
 258                 exit(1);
 259         }
 260 #endif
 261
 262         DataDir = argv[optind];
 263
 264         if (chdir(DataDir) < 0)
 265         {
 266                 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
 267                                 progname, DataDir, strerror(errno));
 268                 exit(1);
 269         }
 270
 271         /*
 272          * Check for a postmaster lock file --- if there is one, refuse to
 273          * proceed, on grounds we might be interfering with a live installation.
 274          */
 275         if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
 276         {
 277                 if (errno != ENOENT)
 278                 {
 279                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 280                                         progname, "postmaster.pid", strerror(errno));
 281                         exit(1);
 282                 }
 283         }
 284         else
 285         {
 286                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 287                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 288                                 progname, "postmaster.pid");
 289                 exit(1);
 290         }
 291
 292         /*
 293          * Attempt to read the existing pg_control file
 294          */
 295         if (!ReadControlFile())
 296                 GuessControlValues();
 297
 298         /*
 299          * Also look at existing segment files to set up newXlogSegNo
 300          */
 301         FindEndOfXLOG();
 302
 303         /*
 304          * Adjust fields if required by switches.  (Do this now so that printout,
 305          * if any, includes these values.)
 306          */
 307         if (set_xid_epoch != -1)
 308                 ControlFile.checkPointCopy.nextXidEpoch = set_xid_epoch;
 309
 310         if (set_xid != 0)
 311         {
 312                 ControlFile.checkPointCopy.nextXid = set_xid;
 313
 314                 /*
 315                  * For the moment, just set oldestXid to a value that will force
 316                  * immediate autovacuum-for-wraparound.  It's not clear whether adding
 317                  * user control of this is useful, so let's just do something that's
 318                  * reasonably safe.  The magic constant here corresponds to the
 319                  * maximum allowed value of autovacuum_freeze_max_age.
 320                  */
 321                 ControlFile.checkPointCopy.oldestXid = set_xid - 2000000000;
 322                 if (ControlFile.checkPointCopy.oldestXid < FirstNormalTransactionId)
 323                         ControlFile.checkPointCopy.oldestXid += FirstNormalTransactionId;
 324                 ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 325         }
 326
 327         if (set_oid != 0)
 328                 ControlFile.checkPointCopy.nextOid = set_oid;
 329
 330         if (set_mxid != 0)
 331         {
 332                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 333
 334                 ControlFile.checkPointCopy.oldestMulti = set_oldestmxid;
 335                 if (ControlFile.checkPointCopy.oldestMulti < FirstMultiXactId)
 336                         ControlFile.checkPointCopy.oldestMulti += FirstMultiXactId;
 337                 ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
 338         }
 339
 340         if (set_mxoff != -1)
 341                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 342
 343         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 344         {
 345                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 346                 ControlFile.checkPointCopy.PrevTimeLineID = minXlogTli;
 347         }
 348
 349         if (minXlogSegNo > newXlogSegNo)
 350                 newXlogSegNo = minXlogSegNo;
 351
 352         /*
 353          * If we had to guess anything, and -f was not given, just print the
 354          * guessed values and exit.  Also print if -n is given.
 355          */
 356         if ((guessed && !force) || noupdate)
 357         {
 358                 PrintControlValues(guessed);
 359                 if (!noupdate)
 360                 {
 361                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 362                         exit(1);
 363                 }
 364                 else
 365                         exit(0);
 366         }
 367
 368         /*
 369          * Don't reset from a dirty pg_control without -f, either.
 370          */
 371         if (ControlFile.state != DB_SHUTDOWNED && !force)
 372         {
 373                 printf(_("The database server was not shut down cleanly.\n"
 374                            "Resetting the transaction log might cause data to be lost.\n"
 375                                  "If you want to proceed anyway, use -f to force reset.\n"));
 376                 exit(1);
 377         }
 378
 379         /*
 380          * Else, do the dirty deed.
 381          */
 382         RewriteControlFile();
 383         KillExistingXLOG();
 384         KillExistingArchiveStatus();
 385         WriteEmptyXLOG();
 386
 387         printf(_("Transaction log reset\n"));
 388         return 0;
 389 }
 390
 391
 392 /*
 393  * Try to read the existing pg_control file.
 394  *
 395  * This routine is also responsible for updating old pg_control versions
 396  * to the current format.  (Currently we don't do anything of the sort.)
 397  */
 398 static bool
 399 ReadControlFile(void)
 400 {
 401         int                     fd;
 402         int                     len;
 403         char       *buffer;
 404         pg_crc32        crc;
 405
 406         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
 407         {
 408                 /*
 409                  * If pg_control is not there at all, or we can't read it, the odds
 410                  * are we've been handed a bad DataDir path, so give up. User can do
 411                  * "touch pg_control" to force us to proceed.
 412                  */
 413                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 414                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 415                 if (errno == ENOENT)
 416                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 417                                                           "  touch %s\n"
 418                                                           "and try again.\n"),
 419                                         XLOG_CONTROL_FILE);
 420                 exit(1);
 421         }
 422
 423         /* Use malloc to ensure we have a maxaligned buffer */
 424         buffer = (char *) pg_malloc(PG_CONTROL_SIZE);
 425
 426         len = read(fd, buffer, PG_CONTROL_SIZE);
 427         if (len < 0)
 428         {
 429                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 430                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 431                 exit(1);
 432         }
 433         close(fd);
 434
 435         if (len >= sizeof(ControlFileData) &&
 436           ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 437         {
 438                 /* Check the CRC. */
 439                 INIT_CRC32(crc);
 440                 COMP_CRC32(crc,
 441                                    buffer,
 442                                    offsetof(ControlFileData, crc));
 443                 FIN_CRC32(crc);
 444
 445                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 446                 {
 447                         /* Valid data... */
 448                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 449                         return true;
 450                 }
 451
 452                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 453                                 progname);
 454                 /* We will use the data anyway, but treat it as guessed. */
 455                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 456                 guessed = true;
 457                 return true;
 458         }
 459
 460         /* Looks like it's a mess. */
 461         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 462                         progname);
 463         return false;
 464 }
 465
 466
 467 /*
 468  * Guess at pg_control values when we can't read the old ones.
 469  */
 470 static void
 471 GuessControlValues(void)
 472 {
 473         uint64          sysidentifier;
 474         struct timeval tv;
 475
 476         /*
 477          * Set up a completely default set of pg_control values.
 478          */
 479         guessed = true;
 480         memset(&ControlFile, 0, sizeof(ControlFile));
 481
 482         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 483         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 484
 485         /*
 486          * Create a new unique installation identifier, since we can no longer use
 487          * any old XLOG records.  See notes in xlog.c about the algorithm.
 488          */
 489         gettimeofday(&tv, NULL);
 490         sysidentifier = ((uint64) tv.tv_sec) << 32;
 491         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 492
 493         ControlFile.system_identifier = sysidentifier;
 494
 495         ControlFile.checkPointCopy.redo = SizeOfXLogLongPHD;
 496         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 497         ControlFile.checkPointCopy.PrevTimeLineID = 1;
 498         ControlFile.checkPointCopy.fullPageWrites = false;
 499         ControlFile.checkPointCopy.nextXidEpoch = 0;
 500         ControlFile.checkPointCopy.nextXid = FirstNormalTransactionId;
 501         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 502         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 503         ControlFile.checkPointCopy.nextMultiOffset = 0;
 504         ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
 505         ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 506         ControlFile.checkPointCopy.oldestMulti = FirstMultiXactId;
 507         ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
 508         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 509         ControlFile.checkPointCopy.oldestActiveXid = InvalidTransactionId;
 510
 511         ControlFile.state = DB_SHUTDOWNED;
 512         ControlFile.time = (pg_time_t) time(NULL);
 513         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 514         ControlFile.unloggedLSN = 1;
 515
 516         /* minRecoveryPoint, backupStartPoint and backupEndPoint can be left zero */
 517
 518         ControlFile.wal_level = WAL_LEVEL_MINIMAL;
 519         ControlFile.MaxConnections = 100;
 520         ControlFile.max_prepared_xacts = 0;
 521         ControlFile.max_locks_per_xact = 64;
 522
 523         ControlFile.maxAlign = MAXIMUM_ALIGNOF;
 524         ControlFile.floatFormat = FLOATFORMAT_VALUE;
 525         ControlFile.blcksz = BLCKSZ;
 526         ControlFile.relseg_size = RELSEG_SIZE;
 527         ControlFile.xlog_blcksz = XLOG_BLCKSZ;
 528         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 529         ControlFile.nameDataLen = NAMEDATALEN;
 530         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 531         ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
 532 #ifdef HAVE_INT64_TIMESTAMP
 533         ControlFile.enableIntTimes = true;
 534 #else
 535         ControlFile.enableIntTimes = false;
 536 #endif
 537         ControlFile.float4ByVal = FLOAT4PASSBYVAL;
 538         ControlFile.float8ByVal = FLOAT8PASSBYVAL;
 539
 540         /*
 541          * XXX eventually, should try to grovel through old XLOG to develop more
 542          * accurate values for TimeLineID, nextXID, etc.
 543          */
 544 }
 545
 546
 547 /*
 548  * Print the guessed pg_control values when we had to guess.
 549  *
 550  * NB: this display should be just those fields that will not be
 551  * reset by RewriteControlFile().
 552  */
 553 static void
 554 PrintControlValues(bool guessed)
 555 {
 556         char            sysident_str[32];
 557         char            fname[MAXFNAMELEN];
 558
 559         if (guessed)
 560                 printf(_("Guessed pg_control values:\n\n"));
 561         else
 562                 printf(_("pg_control values:\n\n"));
 563
 564         /*
 565          * Format system_identifier separately to keep platform-dependent format
 566          * code out of the translatable message string.
 567          */
 568         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 569                          ControlFile.system_identifier);
 570
 571         XLogFileName(fname, ControlFile.checkPointCopy.ThisTimeLineID, newXlogSegNo);
 572
 573         printf(_("First log segment after reset:        %s\n"),
 574                    fname);
 575         printf(_("pg_control version number:            %u\n"),
 576                    ControlFile.pg_control_version);
 577         printf(_("Catalog version number:               %u\n"),
 578                    ControlFile.catalog_version_no);
 579         printf(_("Database system identifier:           %s\n"),
 580                    sysident_str);
 581         printf(_("Latest checkpoint's TimeLineID:       %u\n"),
 582                    ControlFile.checkPointCopy.ThisTimeLineID);
 583         printf(_("Latest checkpoint's full_page_writes: %s\n"),
 584                    ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
 585         printf(_("Latest checkpoint's NextXID:          %u/%u\n"),
 586                    ControlFile.checkPointCopy.nextXidEpoch,
 587                    ControlFile.checkPointCopy.nextXid);
 588         printf(_("Latest checkpoint's NextOID:          %u\n"),
 589                    ControlFile.checkPointCopy.nextOid);
 590         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
 591                    ControlFile.checkPointCopy.nextMulti);
 592         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"),
 593                    ControlFile.checkPointCopy.nextMultiOffset);
 594         printf(_("Latest checkpoint's oldestXID:        %u\n"),
 595                    ControlFile.checkPointCopy.oldestXid);
 596         printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
 597                    ControlFile.checkPointCopy.oldestXidDB);
 598         printf(_("Latest checkpoint's oldestActiveXID:  %u\n"),
 599                    ControlFile.checkPointCopy.oldestActiveXid);
 600         printf(_("Latest checkpoint's oldestMultiXid:   %u\n"),
 601                    ControlFile.checkPointCopy.oldestMulti);
 602         printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
 603                    ControlFile.checkPointCopy.oldestMultiDB);
 604         printf(_("Maximum data alignment:               %u\n"),
 605                    ControlFile.maxAlign);
 606         /* we don't print floatFormat since can't say much useful about it */
 607         printf(_("Database block size:                  %u\n"),
 608                    ControlFile.blcksz);
 609         printf(_("Blocks per segment of large relation: %u\n"),
 610                    ControlFile.relseg_size);
 611         printf(_("WAL block size:                       %u\n"),
 612                    ControlFile.xlog_blcksz);
 613         printf(_("Bytes per WAL segment:                %u\n"),
 614                    ControlFile.xlog_seg_size);
 615         printf(_("Maximum length of identifiers:        %u\n"),
 616                    ControlFile.nameDataLen);
 617         printf(_("Maximum columns in an index:          %u\n"),
 618                    ControlFile.indexMaxKeys);
 619         printf(_("Maximum size of a TOAST chunk:        %u\n"),
 620                    ControlFile.toast_max_chunk_size);
 621         printf(_("Date/time type storage:               %s\n"),
 622                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 623         printf(_("Float4 argument passing:              %s\n"),
 624                    (ControlFile.float4ByVal ? _("by value") : _("by reference")));
 625         printf(_("Float8 argument passing:              %s\n"),
 626                    (ControlFile.float8ByVal ? _("by value") : _("by reference")));
 627 }
 628
 629
 630 /*
 631  * Write out the new pg_control file.
 632  */
 633 static void
 634 RewriteControlFile(void)
 635 {
 636         int                     fd;
 637         char            buffer[PG_CONTROL_SIZE];                /* need not be aligned */
 638
 639         /*
 640          * Adjust fields as needed to force an empty XLOG starting at
 641          * newXlogSegNo.
 642          */
 643         XLogSegNoOffsetToRecPtr(newXlogSegNo, SizeOfXLogLongPHD,
 644                                                         ControlFile.checkPointCopy.redo);
 645         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 646
 647         ControlFile.state = DB_SHUTDOWNED;
 648         ControlFile.time = (pg_time_t) time(NULL);
 649         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 650         ControlFile.prevCheckPoint = 0;
 651         ControlFile.minRecoveryPoint = 0;
 652         ControlFile.minRecoveryPointTLI = 0;
 653         ControlFile.backupStartPoint = 0;
 654         ControlFile.backupEndPoint = 0;
 655         ControlFile.backupEndRequired = false;
 656
 657         /*
 658          * Force the defaults for max_* settings. The values don't really matter
 659          * as long as wal_level='minimal'; the postmaster will reset these fields
 660          * anyway at startup.
 661          */
 662         ControlFile.wal_level = WAL_LEVEL_MINIMAL;
 663         ControlFile.MaxConnections = 100;
 664         ControlFile.max_prepared_xacts = 0;
 665         ControlFile.max_locks_per_xact = 64;
 666
 667         /* Now we can force the recorded xlog seg size to the right thing. */
 668         ControlFile.xlog_seg_size = XLogSegSize;
 669
 670         /* Contents are protected with a CRC */
 671         INIT_CRC32(ControlFile.crc);
 672         COMP_CRC32(ControlFile.crc,
 673                            (char *) &ControlFile,
 674                            offsetof(ControlFileData, crc));
 675         FIN_CRC32(ControlFile.crc);
 676
 677         /*
 678          * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
 679          * excess over sizeof(ControlFileData).  This reduces the odds of
 680          * premature-EOF errors when reading pg_control.  We'll still fail when we
 681          * check the contents of the file, but hopefully with a more specific
 682          * error than "couldn't read pg_control".
 683          */
 684         if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
 685         {
 686                 fprintf(stderr,
 687                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
 688                                 progname);
 689                 exit(1);
 690         }
 691
 692         memset(buffer, 0, PG_CONTROL_SIZE);
 693         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 694
 695         unlink(XLOG_CONTROL_FILE);
 696
 697         fd = open(XLOG_CONTROL_FILE,
 698                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 699                           S_IRUSR | S_IWUSR);
 700         if (fd < 0)
 701         {
 702                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 703                                 progname, strerror(errno));
 704                 exit(1);
 705         }
 706
 707         errno = 0;
 708         if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
 709         {
 710                 /* if write didn't set errno, assume problem is no disk space */
 711                 if (errno == 0)
 712                         errno = ENOSPC;
 713                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 714                                 progname, strerror(errno));
 715                 exit(1);
 716         }
 717
 718         if (fsync(fd) != 0)
 719         {
 720                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 721                 exit(1);
 722         }
 723
 724         close(fd);
 725 }
 726
 727
 728 /*
 729  * Scan existing XLOG files and determine the highest existing WAL address
 730  *
 731  * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
 732  * are assumed valid (note that we allow the old xlog seg size to differ
 733  * from what we're using).  On exit, newXlogId and newXlogSeg are set to
 734  * suitable values for the beginning of replacement WAL (in our seg size).
 735  */
 736 static void
 737 FindEndOfXLOG(void)
 738 {
 739         DIR                *xldir;
 740         struct dirent *xlde;
 741         uint64          segs_per_xlogid;
 742         uint64          xlogbytepos;
 743
 744         /*
 745          * Initialize the max() computation using the last checkpoint address from
 746          * old pg_control.      Note that for the moment we are working with segment
 747          * numbering according to the old xlog seg size.
 748          */
 749         segs_per_xlogid = (UINT64CONST(0x0000000100000000) / ControlFile.xlog_seg_size);
 750         newXlogSegNo = ControlFile.checkPointCopy.redo / ControlFile.xlog_seg_size;
 751
 752         /*
 753          * Scan the pg_xlog directory to find existing WAL segment files. We
 754          * assume any present have been used; in most scenarios this should be
 755          * conservative, because of xlog.c's attempts to pre-create files.
 756          */
 757         xldir = opendir(XLOGDIR);
 758         if (xldir == NULL)
 759         {
 760                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 761                                 progname, XLOGDIR, strerror(errno));
 762                 exit(1);
 763         }
 764
 765         errno = 0;
 766         while ((xlde = readdir(xldir)) != NULL)
 767         {
 768                 if (strlen(xlde->d_name) == 24 &&
 769                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 770                 {
 771                         unsigned int tli,
 772                                                 log,
 773                                                 seg;
 774                         XLogSegNo       segno;
 775
 776                         sscanf(xlde->d_name, "%08X%08X%08X", &tli, &log, &seg);
 777                         segno = ((uint64) log) * segs_per_xlogid + seg;
 778
 779                         /*
 780                          * Note: we take the max of all files found, regardless of their
 781                          * timelines.  Another possibility would be to ignore files of
 782                          * timelines other than the target TLI, but this seems safer.
 783                          * Better too large a result than too small...
 784                          */
 785                         if (segno > newXlogSegNo)
 786                                 newXlogSegNo = segno;
 787                 }
 788                 errno = 0;
 789         }
 790 #ifdef WIN32
 791
 792         /*
 793          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 794          * released version
 795          */
 796         if (GetLastError() == ERROR_NO_MORE_FILES)
 797                 errno = 0;
 798 #endif
 799
 800         if (errno)
 801         {
 802                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 803                                 progname, XLOGDIR, strerror(errno));
 804                 exit(1);
 805         }
 806         closedir(xldir);
 807
 808         /*
 809          * Finally, convert to new xlog seg size, and advance by one to ensure we
 810          * are in virgin territory.
 811          */
 812         xlogbytepos = newXlogSegNo * ControlFile.xlog_seg_size;
 813         newXlogSegNo = (xlogbytepos + XLogSegSize - 1) / XLogSegSize;
 814         newXlogSegNo++;
 815 }
 816
 817
 818 /*
 819  * Remove existing XLOG files
 820  */
 821 static void
 822 KillExistingXLOG(void)
 823 {
 824         DIR                *xldir;
 825         struct dirent *xlde;
 826         char            path[MAXPGPATH];
 827
 828         xldir = opendir(XLOGDIR);
 829         if (xldir == NULL)
 830         {
 831                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 832                                 progname, XLOGDIR, strerror(errno));
 833                 exit(1);
 834         }
 835
 836         errno = 0;
 837         while ((xlde = readdir(xldir)) != NULL)
 838         {
 839                 if (strlen(xlde->d_name) == 24 &&
 840                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 841                 {
 842                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 843                         if (unlink(path) < 0)
 844                         {
 845                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 846                                                 progname, path, strerror(errno));
 847                                 exit(1);
 848                         }
 849                 }
 850                 errno = 0;
 851         }
 852 #ifdef WIN32
 853
 854         /*
 855          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 856          * released version
 857          */
 858         if (GetLastError() == ERROR_NO_MORE_FILES)
 859                 errno = 0;
 860 #endif
 861
 862         if (errno)
 863         {
 864                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 865                                 progname, XLOGDIR, strerror(errno));
 866                 exit(1);
 867         }
 868         closedir(xldir);
 869 }
 870
 871
 872 /*
 873  * Remove existing archive status files
 874  */
 875 static void
 876 KillExistingArchiveStatus(void)
 877 {
 878         DIR                *xldir;
 879         struct dirent *xlde;
 880         char            path[MAXPGPATH];
 881
 882 #define ARCHSTATDIR XLOGDIR "/archive_status"
 883
 884         xldir = opendir(ARCHSTATDIR);
 885         if (xldir == NULL)
 886         {
 887                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 888                                 progname, ARCHSTATDIR, strerror(errno));
 889                 exit(1);
 890         }
 891
 892         errno = 0;
 893         while ((xlde = readdir(xldir)) != NULL)
 894         {
 895                 if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
 896                         (strcmp(xlde->d_name + 24, ".ready") == 0 ||
 897                          strcmp(xlde->d_name + 24, ".done") == 0))
 898                 {
 899                         snprintf(path, MAXPGPATH, "%s/%s", ARCHSTATDIR, xlde->d_name);
 900                         if (unlink(path) < 0)
 901                         {
 902                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 903                                                 progname, path, strerror(errno));
 904                                 exit(1);
 905                         }
 906                 }
 907                 errno = 0;
 908         }
 909 #ifdef WIN32
 910
 911         /*
 912          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 913          * released version
 914          */
 915         if (GetLastError() == ERROR_NO_MORE_FILES)
 916                 errno = 0;
 917 #endif
 918
 919         if (errno)
 920         {
 921                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 922                                 progname, ARCHSTATDIR, strerror(errno));
 923                 exit(1);
 924         }
 925         closedir(xldir);
 926 }
 927
 928
 929 /*
 930  * Write an empty XLOG file, containing only the checkpoint record
 931  * already set up in ControlFile.
 932  */
 933 static void
 934 WriteEmptyXLOG(void)
 935 {
 936         char       *buffer;
 937         XLogPageHeader page;
 938         XLogLongPageHeader longpage;
 939         XLogRecord *record;
 940         pg_crc32        crc;
 941         char            path[MAXPGPATH];
 942         int                     fd;
 943         int                     nbytes;
 944
 945         /* Use malloc() to ensure buffer is MAXALIGNED */
 946         buffer = (char *) pg_malloc(XLOG_BLCKSZ);
 947         page = (XLogPageHeader) buffer;
 948         memset(buffer, 0, XLOG_BLCKSZ);
 949
 950         /* Set up the XLOG page header */
 951         page->xlp_magic = XLOG_PAGE_MAGIC;
 952         page->xlp_info = XLP_LONG_HEADER;
 953         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 954         page->xlp_pageaddr = ControlFile.checkPointCopy.redo - SizeOfXLogLongPHD;
 955         longpage = (XLogLongPageHeader) page;
 956         longpage->xlp_sysid = ControlFile.system_identifier;
 957         longpage->xlp_seg_size = XLogSegSize;
 958         longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
 959
 960         /* Insert the initial checkpoint record */
 961         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 962         record->xl_prev = 0;
 963         record->xl_xid = InvalidTransactionId;
 964         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
 965         record->xl_len = sizeof(CheckPoint);
 966         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 967         record->xl_rmid = RM_XLOG_ID;
 968         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 969                    sizeof(CheckPoint));
 970
 971         INIT_CRC32(crc);
 972         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 973         COMP_CRC32(crc, (char *) record, offsetof(XLogRecord, xl_crc));
 974         FIN_CRC32(crc);
 975         record->xl_crc = crc;
 976
 977         /* Write the first page */
 978         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID, newXlogSegNo);
 979
 980         unlink(path);
 981
 982         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 983                           S_IRUSR | S_IWUSR);
 984         if (fd < 0)
 985         {
 986                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 987                                 progname, path, strerror(errno));
 988                 exit(1);
 989         }
 990
 991         errno = 0;
 992         if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 993         {
 994                 /* if write didn't set errno, assume problem is no disk space */
 995                 if (errno == 0)
 996                         errno = ENOSPC;
 997                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 998                                 progname, path, strerror(errno));
 999                 exit(1);
1000         }
1001
1002         /* Fill the rest of the file with zeroes */
1003         memset(buffer, 0, XLOG_BLCKSZ);
1004         for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
1005         {
1006                 errno = 0;
1007                 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
1008                 {
1009                         if (errno == 0)
1010                                 errno = ENOSPC;
1011                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
1012                                         progname, path, strerror(errno));
1013                         exit(1);
1014                 }
1015         }
1016
1017         if (fsync(fd) != 0)
1018         {
1019                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
1020                 exit(1);
1021         }
1022
1023         close(fd);
1024 }
1025
1026
1027 static void
1028 usage(void)
1029 {
1030         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
1031         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
1032         printf(_("Options:\n"));
1033         printf(_("  -e XIDEPOCH      set next transaction ID epoch\n"));
1034         printf(_("  -f               force update to be done\n"));
1035         printf(_("  -l xlogfile      force minimum WAL starting location for new transaction log\n"));
1036         printf(_("  -m XID,OLDEST    set next multitransaction ID and oldest value\n"));
1037         printf(_("  -n               no update, just show extracted control values (for testing)\n"));
1038         printf(_("  -o OID           set next OID\n"));
1039         printf(_("  -O OFFSET        set next multitransaction offset\n"));
1040         printf(_("  -V, --version    output version information, then exit\n"));
1041         printf(_("  -x XID           set next transaction ID\n"));
1042         printf(_("  -?, --help       show this help, then exit\n"));
1043         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
1044 }