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) 1996-2014, 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
  48 #include "access/transam.h"
  49 #include "access/tuptoaster.h"
  50 #include "access/multixact.h"
  51 #include "access/xlog_internal.h"
  52 #include "catalog/catversion.h"
  53 #include "catalog/pg_control.h"
  54 #include "common/fe_memutils.h"
  55 #include "pg_getopt.h"
  56
  57
  58 static ControlFileData ControlFile;             /* pg_control values */
  59 static XLogSegNo newXlogSegNo;  /* new XLOG segment # */
  60 static bool guessed = false;    /* T if we had to guess at any values */
  61 static const char *progname;
  62 static uint32 set_xid_epoch = (uint32) -1;
  63 static TransactionId set_xid = 0;
  64 static Oid      set_oid = 0;
  65 static MultiXactId set_mxid = 0;
  66 static MultiXactOffset set_mxoff = (MultiXactOffset) -1;
  67 static uint32 minXlogTli = 0;
  68 static XLogSegNo minXlogSegNo = 0;
  69
  70 static bool ReadControlFile(void);
  71 static void GuessControlValues(void);
  72 static void PrintControlValues(bool guessed);
  73 static void PrintNewControlValues(void);
  74 static void RewriteControlFile(void);
  75 static void FindEndOfXLOG(void);
  76 static void KillExistingXLOG(void);
  77 static void KillExistingArchiveStatus(void);
  78 static void WriteEmptyXLOG(void);
  79 static void usage(void);
  80
  81
  82 int
  83 main(int argc, char *argv[])
  84 {
  85         int                     c;
  86         bool            force = false;
  87         bool            noupdate = false;
  88         MultiXactId set_oldestmxid = 0;
  89         char       *endptr;
  90         char       *endptr2;
  91         char       *DataDir;
  92         int                     fd;
  93
  94         set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));
  95
  96         progname = get_progname(argv[0]);
  97
  98         if (argc > 1)
  99         {
 100                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
 101                 {
 102                         usage();
 103                         exit(0);
 104                 }
 105                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 106                 {
 107                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
 108                         exit(0);
 109                 }
 110         }
 111
 112
 113         while ((c = getopt(argc, argv, "fl:m:no:O:x:e:")) != -1)
 114         {
 115                 switch (c)
 116                 {
 117                         case 'f':
 118                                 force = true;
 119                                 break;
 120
 121                         case 'n':
 122                                 noupdate = true;
 123                                 break;
 124
 125                         case 'e':
 126                                 set_xid_epoch = strtoul(optarg, &endptr, 0);
 127                                 if (endptr == optarg || *endptr != '\0')
 128                                 {
 129                                         fprintf(stderr, _("%s: invalid argument for option -e\n"), progname);
 130                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 131                                         exit(1);
 132                                 }
 133                                 if (set_xid_epoch == -1)
 134                                 {
 135                                         fprintf(stderr, _("%s: transaction ID epoch (-e) must not be -1\n"), progname);
 136                                         exit(1);
 137                                 }
 138                                 break;
 139
 140                         case 'x':
 141                                 set_xid = strtoul(optarg, &endptr, 0);
 142                                 if (endptr == optarg || *endptr != '\0')
 143                                 {
 144                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 145                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 146                                         exit(1);
 147                                 }
 148                                 if (set_xid == 0)
 149                                 {
 150                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 151                                         exit(1);
 152                                 }
 153                                 break;
 154
 155                         case 'o':
 156                                 set_oid = strtoul(optarg, &endptr, 0);
 157                                 if (endptr == optarg || *endptr != '\0')
 158                                 {
 159                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 160                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 161                                         exit(1);
 162                                 }
 163                                 if (set_oid == 0)
 164                                 {
 165                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 166                                         exit(1);
 167                                 }
 168                                 break;
 169
 170                         case 'm':
 171                                 set_mxid = strtoul(optarg, &endptr, 0);
 172                                 if (endptr == optarg || *endptr != ',')
 173                                 {
 174                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 175                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 176                                         exit(1);
 177                                 }
 178
 179                                 set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
 180                                 if (endptr2 == endptr + 1 || *endptr2 != '\0')
 181                                 {
 182                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 183                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 184                                         exit(1);
 185                                 }
 186                                 if (set_mxid == 0)
 187                                 {
 188                                         fprintf(stderr, _("%s: multitransaction ID (-m) must not be 0\n"), progname);
 189                                         exit(1);
 190                                 }
 191
 192                                 /*
 193                                  * XXX It'd be nice to have more sanity checks here, e.g. so
 194                                  * that oldest is not wrapped around w.r.t. nextMulti.
 195                                  */
 196                                 if (set_oldestmxid == 0)
 197                                 {
 198                                         fprintf(stderr, _("%s: oldest multitransaction ID (-m) must not be 0\n"),
 199                                                         progname);
 200                                         exit(1);
 201                                 }
 202                                 break;
 203
 204                         case 'O':
 205                                 set_mxoff = strtoul(optarg, &endptr, 0);
 206                                 if (endptr == optarg || *endptr != '\0')
 207                                 {
 208                                         fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
 209                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 210                                         exit(1);
 211                                 }
 212                                 if (set_mxoff == -1)
 213                                 {
 214                                         fprintf(stderr, _("%s: multitransaction offset (-O) must not be -1\n"), progname);
 215                                         exit(1);
 216                                 }
 217                                 break;
 218
 219                         case 'l':
 220                                 if (strspn(optarg, "01234567890ABCDEFabcdef") != 24)
 221                                 {
 222                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 223                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 224                                         exit(1);
 225                                 }
 226                                 XLogFromFileName(optarg, &minXlogTli, &minXlogSegNo);
 227                                 break;
 228
 229                         default:
 230                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 231                                 exit(1);
 232                 }
 233         }
 234
 235         if (optind == argc)
 236         {
 237                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 238                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 239                 exit(1);
 240         }
 241
 242         /*
 243          * Don't allow pg_resetxlog to be run as root, to avoid overwriting the
 244          * ownership of files in the data directory. We need only check for root
 245          * -- any other user won't have sufficient permissions to modify files in
 246          * the data directory.
 247          */
 248 #ifndef WIN32
 249         if (geteuid() == 0)
 250         {
 251                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 252                                 progname);
 253                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 254                                 progname);
 255                 exit(1);
 256         }
 257 #endif
 258
 259         DataDir = argv[optind];
 260
 261         if (chdir(DataDir) < 0)
 262         {
 263                 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
 264                                 progname, DataDir, strerror(errno));
 265                 exit(1);
 266         }
 267
 268         /*
 269          * Check for a postmaster lock file --- if there is one, refuse to
 270          * proceed, on grounds we might be interfering with a live installation.
 271          */
 272         if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
 273         {
 274                 if (errno != ENOENT)
 275                 {
 276                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 277                                         progname, "postmaster.pid", strerror(errno));
 278                         exit(1);
 279                 }
 280         }
 281         else
 282         {
 283                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 284                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 285                                 progname, "postmaster.pid");
 286                 exit(1);
 287         }
 288
 289         /*
 290          * Attempt to read the existing pg_control file
 291          */
 292         if (!ReadControlFile())
 293                 GuessControlValues();
 294
 295         /*
 296          * Also look at existing segment files to set up newXlogSegNo
 297          */
 298         FindEndOfXLOG();
 299
 300         /*
 301          * If we're not going to proceed with the reset, print the current control
 302          * file parameters.
 303          */
 304         if ((guessed && !force) || noupdate)
 305                 PrintControlValues(guessed);
 306
 307         /*
 308          * Adjust fields if required by switches.  (Do this now so that printout,
 309          * if any, includes these values.)
 310          */
 311         if (set_xid_epoch != -1)
 312                 ControlFile.checkPointCopy.nextXidEpoch = set_xid_epoch;
 313
 314         if (set_xid != 0)
 315         {
 316                 ControlFile.checkPointCopy.nextXid = set_xid;
 317
 318                 /*
 319                  * For the moment, just set oldestXid to a value that will force
 320                  * immediate autovacuum-for-wraparound.  It's not clear whether adding
 321                  * user control of this is useful, so let's just do something that's
 322                  * reasonably safe.  The magic constant here corresponds to the
 323                  * maximum allowed value of autovacuum_freeze_max_age.
 324                  */
 325                 ControlFile.checkPointCopy.oldestXid = set_xid - 2000000000;
 326                 if (ControlFile.checkPointCopy.oldestXid < FirstNormalTransactionId)
 327                         ControlFile.checkPointCopy.oldestXid += FirstNormalTransactionId;
 328                 ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 329         }
 330
 331         if (set_oid != 0)
 332                 ControlFile.checkPointCopy.nextOid = set_oid;
 333
 334         if (set_mxid != 0)
 335         {
 336                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 337
 338                 ControlFile.checkPointCopy.oldestMulti = set_oldestmxid;
 339                 if (ControlFile.checkPointCopy.oldestMulti < FirstMultiXactId)
 340                         ControlFile.checkPointCopy.oldestMulti += FirstMultiXactId;
 341                 ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
 342         }
 343
 344         if (set_mxoff != -1)
 345                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 346
 347         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 348         {
 349                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 350                 ControlFile.checkPointCopy.PrevTimeLineID = minXlogTli;
 351         }
 352
 353         if (minXlogSegNo > newXlogSegNo)
 354                 newXlogSegNo = minXlogSegNo;
 355
 356         /*
 357          * If we had to guess anything, and -f was not given, just print the
 358          * guessed values and exit.  Also print if -n is given.
 359          */
 360         if ((guessed && !force) || noupdate)
 361         {
 362                 PrintNewControlValues();
 363                 if (!noupdate)
 364                 {
 365                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 366                         exit(1);
 367                 }
 368                 else
 369                         exit(0);
 370         }
 371
 372         /*
 373          * Don't reset from a dirty pg_control without -f, either.
 374          */
 375         if (ControlFile.state != DB_SHUTDOWNED && !force)
 376         {
 377                 printf(_("The database server was not shut down cleanly.\n"
 378                            "Resetting the transaction log might cause data to be lost.\n"
 379                                  "If you want to proceed anyway, use -f to force reset.\n"));
 380                 exit(1);
 381         }
 382
 383         /*
 384          * Else, do the dirty deed.
 385          */
 386         RewriteControlFile();
 387         KillExistingXLOG();
 388         KillExistingArchiveStatus();
 389         WriteEmptyXLOG();
 390
 391         printf(_("Transaction log reset\n"));
 392         return 0;
 393 }
 394
 395
 396 /*
 397  * Try to read the existing pg_control file.
 398  *
 399  * This routine is also responsible for updating old pg_control versions
 400  * to the current format.  (Currently we don't do anything of the sort.)
 401  */
 402 static bool
 403 ReadControlFile(void)
 404 {
 405         int                     fd;
 406         int                     len;
 407         char       *buffer;
 408         pg_crc32        crc;
 409
 410         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
 411         {
 412                 /*
 413                  * If pg_control is not there at all, or we can't read it, the odds
 414                  * are we've been handed a bad DataDir path, so give up. User can do
 415                  * "touch pg_control" to force us to proceed.
 416                  */
 417                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 418                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 419                 if (errno == ENOENT)
 420                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 421                                                           "  touch %s\n"
 422                                                           "and try again.\n"),
 423                                         XLOG_CONTROL_FILE);
 424                 exit(1);
 425         }
 426
 427         /* Use malloc to ensure we have a maxaligned buffer */
 428         buffer = (char *) pg_malloc(PG_CONTROL_SIZE);
 429
 430         len = read(fd, buffer, PG_CONTROL_SIZE);
 431         if (len < 0)
 432         {
 433                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 434                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 435                 exit(1);
 436         }
 437         close(fd);
 438
 439         if (len >= sizeof(ControlFileData) &&
 440           ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 441         {
 442                 /* Check the CRC. */
 443                 INIT_CRC32(crc);
 444                 COMP_CRC32(crc,
 445                                    buffer,
 446                                    offsetof(ControlFileData, crc));
 447                 FIN_CRC32(crc);
 448
 449                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 450                 {
 451                         /* Valid data... */
 452                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 453                         return true;
 454                 }
 455
 456                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 457                                 progname);
 458                 /* We will use the data anyway, but treat it as guessed. */
 459                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 460                 guessed = true;
 461                 return true;
 462         }
 463
 464         /* Looks like it's a mess. */
 465         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 466                         progname);
 467         return false;
 468 }
 469
 470
 471 /*
 472  * Guess at pg_control values when we can't read the old ones.
 473  */
 474 static void
 475 GuessControlValues(void)
 476 {
 477         uint64          sysidentifier;
 478         struct timeval tv;
 479
 480         /*
 481          * Set up a completely default set of pg_control values.
 482          */
 483         guessed = true;
 484         memset(&ControlFile, 0, sizeof(ControlFile));
 485
 486         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 487         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 488
 489         /*
 490          * Create a new unique installation identifier, since we can no longer use
 491          * any old XLOG records.  See notes in xlog.c about the algorithm.
 492          */
 493         gettimeofday(&tv, NULL);
 494         sysidentifier = ((uint64) tv.tv_sec) << 32;
 495         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 496
 497         ControlFile.system_identifier = sysidentifier;
 498
 499         ControlFile.checkPointCopy.redo = SizeOfXLogLongPHD;
 500         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 501         ControlFile.checkPointCopy.PrevTimeLineID = 1;
 502         ControlFile.checkPointCopy.fullPageWrites = false;
 503         ControlFile.checkPointCopy.nextXidEpoch = 0;
 504         ControlFile.checkPointCopy.nextXid = FirstNormalTransactionId;
 505         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 506         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 507         ControlFile.checkPointCopy.nextMultiOffset = 0;
 508         ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
 509         ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 510         ControlFile.checkPointCopy.oldestMulti = FirstMultiXactId;
 511         ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
 512         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 513         ControlFile.checkPointCopy.oldestActiveXid = InvalidTransactionId;
 514
 515         ControlFile.state = DB_SHUTDOWNED;
 516         ControlFile.time = (pg_time_t) time(NULL);
 517         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 518         ControlFile.unloggedLSN = 1;
 519
 520         /* minRecoveryPoint, backupStartPoint and backupEndPoint can be left zero */
 521
 522         ControlFile.wal_level = WAL_LEVEL_MINIMAL;
 523         ControlFile.wal_log_hints = false;
 524         ControlFile.MaxConnections = 100;
 525         ControlFile.max_worker_processes = 8;
 526         ControlFile.max_prepared_xacts = 0;
 527         ControlFile.max_locks_per_xact = 64;
 528
 529         ControlFile.maxAlign = MAXIMUM_ALIGNOF;
 530         ControlFile.floatFormat = FLOATFORMAT_VALUE;
 531         ControlFile.blcksz = BLCKSZ;
 532         ControlFile.relseg_size = RELSEG_SIZE;
 533         ControlFile.xlog_blcksz = XLOG_BLCKSZ;
 534         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 535         ControlFile.nameDataLen = NAMEDATALEN;
 536         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 537         ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
 538 #ifdef HAVE_INT64_TIMESTAMP
 539         ControlFile.enableIntTimes = true;
 540 #else
 541         ControlFile.enableIntTimes = false;
 542 #endif
 543         ControlFile.float4ByVal = FLOAT4PASSBYVAL;
 544         ControlFile.float8ByVal = FLOAT8PASSBYVAL;
 545
 546         /*
 547          * XXX eventually, should try to grovel through old XLOG to develop more
 548          * accurate values for TimeLineID, nextXID, etc.
 549          */
 550 }
 551
 552
 553 /*
 554  * Print the guessed pg_control values when we had to guess.
 555  *
 556  * NB: this display should be just those fields that will not be
 557  * reset by RewriteControlFile().
 558  */
 559 static void
 560 PrintControlValues(bool guessed)
 561 {
 562         char            sysident_str[32];
 563
 564         if (guessed)
 565                 printf(_("Guessed pg_control values:\n\n"));
 566         else
 567                 printf(_("Current pg_control values:\n\n"));
 568
 569         /*
 570          * Format system_identifier separately to keep platform-dependent format
 571          * code out of the translatable message string.
 572          */
 573         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 574                          ControlFile.system_identifier);
 575
 576         printf(_("pg_control version number:            %u\n"),
 577                    ControlFile.pg_control_version);
 578         printf(_("Catalog version number:               %u\n"),
 579                    ControlFile.catalog_version_no);
 580         printf(_("Database system identifier:           %s\n"),
 581                    sysident_str);
 582         printf(_("Latest checkpoint's TimeLineID:       %u\n"),
 583                    ControlFile.checkPointCopy.ThisTimeLineID);
 584         printf(_("Latest checkpoint's full_page_writes: %s\n"),
 585                    ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
 586         printf(_("Latest checkpoint's NextXID:          %u/%u\n"),
 587                    ControlFile.checkPointCopy.nextXidEpoch,
 588                    ControlFile.checkPointCopy.nextXid);
 589         printf(_("Latest checkpoint's NextOID:          %u\n"),
 590                    ControlFile.checkPointCopy.nextOid);
 591         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
 592                    ControlFile.checkPointCopy.nextMulti);
 593         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"),
 594                    ControlFile.checkPointCopy.nextMultiOffset);
 595         printf(_("Latest checkpoint's oldestXID:        %u\n"),
 596                    ControlFile.checkPointCopy.oldestXid);
 597         printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
 598                    ControlFile.checkPointCopy.oldestXidDB);
 599         printf(_("Latest checkpoint's oldestActiveXID:  %u\n"),
 600                    ControlFile.checkPointCopy.oldestActiveXid);
 601         printf(_("Latest checkpoint's oldestMultiXid:   %u\n"),
 602                    ControlFile.checkPointCopy.oldestMulti);
 603         printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
 604                    ControlFile.checkPointCopy.oldestMultiDB);
 605         printf(_("Maximum data alignment:               %u\n"),
 606                    ControlFile.maxAlign);
 607         /* we don't print floatFormat since can't say much useful about it */
 608         printf(_("Database block size:                  %u\n"),
 609                    ControlFile.blcksz);
 610         printf(_("Blocks per segment of large relation: %u\n"),
 611                    ControlFile.relseg_size);
 612         printf(_("WAL block size:                       %u\n"),
 613                    ControlFile.xlog_blcksz);
 614         printf(_("Bytes per WAL segment:                %u\n"),
 615                    ControlFile.xlog_seg_size);
 616         printf(_("Maximum length of identifiers:        %u\n"),
 617                    ControlFile.nameDataLen);
 618         printf(_("Maximum columns in an index:          %u\n"),
 619                    ControlFile.indexMaxKeys);
 620         printf(_("Maximum size of a TOAST chunk:        %u\n"),
 621                    ControlFile.toast_max_chunk_size);
 622         printf(_("Date/time type storage:               %s\n"),
 623                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 624         printf(_("Float4 argument passing:              %s\n"),
 625                    (ControlFile.float4ByVal ? _("by value") : _("by reference")));
 626         printf(_("Float8 argument passing:              %s\n"),
 627                    (ControlFile.float8ByVal ? _("by value") : _("by reference")));
 628         printf(_("Data page checksum version:           %u\n"),
 629                    ControlFile.data_checksum_version);
 630 }
 631
 632
 633 /*
 634  * Print the values to be changed.
 635  */
 636 static void
 637 PrintNewControlValues()
 638 {
 639         char            fname[MAXFNAMELEN];
 640
 641         /* This will be always printed in order to keep format same. */
 642         printf(_("\n\nValues to be changed:\n\n"));
 643
 644         XLogFileName(fname, ControlFile.checkPointCopy.ThisTimeLineID, newXlogSegNo);
 645         printf(_("First log segment after reset:        %s\n"), fname);
 646
 647         if (set_mxid != 0)
 648         {
 649                 printf(_("NextMultiXactId:                      %u\n"),
 650                            ControlFile.checkPointCopy.nextMulti);
 651                 printf(_("OldestMultiXid:                       %u\n"),
 652                            ControlFile.checkPointCopy.oldestMulti);
 653                 printf(_("OldestMulti's DB:                     %u\n"),
 654                            ControlFile.checkPointCopy.oldestMultiDB);
 655         }
 656
 657         if (set_mxoff != -1)
 658         {
 659                 printf(_("NextMultiOffset:                      %u\n"),
 660                            ControlFile.checkPointCopy.nextMultiOffset);
 661         }
 662
 663         if (set_oid != 0)
 664         {
 665                 printf(_("NextOID:                              %u\n"),
 666                            ControlFile.checkPointCopy.nextOid);
 667         }
 668
 669         if (set_xid != 0)
 670         {
 671                 printf(_("NextXID:                              %u\n"),
 672                            ControlFile.checkPointCopy.nextXid);
 673                 printf(_("OldestXID:                            %u\n"),
 674                            ControlFile.checkPointCopy.oldestXid);
 675                 printf(_("OldestXID's DB:                       %u\n"),
 676                            ControlFile.checkPointCopy.oldestXidDB);
 677         }
 678
 679         if (set_xid_epoch != -1)
 680         {
 681                 printf(_("NextXID Epoch:                        %u\n"),
 682                            ControlFile.checkPointCopy.nextXidEpoch);
 683         }
 684 }
 685
 686
 687 /*
 688  * Write out the new pg_control file.
 689  */
 690 static void
 691 RewriteControlFile(void)
 692 {
 693         int                     fd;
 694         char            buffer[PG_CONTROL_SIZE];                /* need not be aligned */
 695
 696         /*
 697          * Adjust fields as needed to force an empty XLOG starting at
 698          * newXlogSegNo.
 699          */
 700         XLogSegNoOffsetToRecPtr(newXlogSegNo, SizeOfXLogLongPHD,
 701                                                         ControlFile.checkPointCopy.redo);
 702         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 703
 704         ControlFile.state = DB_SHUTDOWNED;
 705         ControlFile.time = (pg_time_t) time(NULL);
 706         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 707         ControlFile.prevCheckPoint = 0;
 708         ControlFile.minRecoveryPoint = 0;
 709         ControlFile.minRecoveryPointTLI = 0;
 710         ControlFile.backupStartPoint = 0;
 711         ControlFile.backupEndPoint = 0;
 712         ControlFile.backupEndRequired = false;
 713
 714         /*
 715          * Force the defaults for max_* settings. The values don't really matter
 716          * as long as wal_level='minimal'; the postmaster will reset these fields
 717          * anyway at startup.
 718          */
 719         ControlFile.wal_level = WAL_LEVEL_MINIMAL;
 720         ControlFile.wal_log_hints = false;
 721         ControlFile.MaxConnections = 100;
 722         ControlFile.max_worker_processes = 8;
 723         ControlFile.max_prepared_xacts = 0;
 724         ControlFile.max_locks_per_xact = 64;
 725
 726         /* Now we can force the recorded xlog seg size to the right thing. */
 727         ControlFile.xlog_seg_size = XLogSegSize;
 728
 729         /* Contents are protected with a CRC */
 730         INIT_CRC32(ControlFile.crc);
 731         COMP_CRC32(ControlFile.crc,
 732                            (char *) &ControlFile,
 733                            offsetof(ControlFileData, crc));
 734         FIN_CRC32(ControlFile.crc);
 735
 736         /*
 737          * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
 738          * excess over sizeof(ControlFileData).  This reduces the odds of
 739          * premature-EOF errors when reading pg_control.  We'll still fail when we
 740          * check the contents of the file, but hopefully with a more specific
 741          * error than "couldn't read pg_control".
 742          */
 743         if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
 744         {
 745                 fprintf(stderr,
 746                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
 747                                 progname);
 748                 exit(1);
 749         }
 750
 751         memset(buffer, 0, PG_CONTROL_SIZE);
 752         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 753
 754         unlink(XLOG_CONTROL_FILE);
 755
 756         fd = open(XLOG_CONTROL_FILE,
 757                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 758                           S_IRUSR | S_IWUSR);
 759         if (fd < 0)
 760         {
 761                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 762                                 progname, strerror(errno));
 763                 exit(1);
 764         }
 765
 766         errno = 0;
 767         if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
 768         {
 769                 /* if write didn't set errno, assume problem is no disk space */
 770                 if (errno == 0)
 771                         errno = ENOSPC;
 772                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 773                                 progname, strerror(errno));
 774                 exit(1);
 775         }
 776
 777         if (fsync(fd) != 0)
 778         {
 779                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 780                 exit(1);
 781         }
 782
 783         close(fd);
 784 }
 785
 786
 787 /*
 788  * Scan existing XLOG files and determine the highest existing WAL address
 789  *
 790  * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
 791  * are assumed valid (note that we allow the old xlog seg size to differ
 792  * from what we're using).  On exit, newXlogId and newXlogSeg are set to
 793  * suitable values for the beginning of replacement WAL (in our seg size).
 794  */
 795 static void
 796 FindEndOfXLOG(void)
 797 {
 798         DIR                *xldir;
 799         struct dirent *xlde;
 800         uint64          segs_per_xlogid;
 801         uint64          xlogbytepos;
 802
 803         /*
 804          * Initialize the max() computation using the last checkpoint address from
 805          * old pg_control.      Note that for the moment we are working with segment
 806          * numbering according to the old xlog seg size.
 807          */
 808         segs_per_xlogid = (UINT64CONST(0x0000000100000000) / ControlFile.xlog_seg_size);
 809         newXlogSegNo = ControlFile.checkPointCopy.redo / ControlFile.xlog_seg_size;
 810
 811         /*
 812          * Scan the pg_xlog directory to find existing WAL segment files. We
 813          * assume any present have been used; in most scenarios this should be
 814          * conservative, because of xlog.c's attempts to pre-create files.
 815          */
 816         xldir = opendir(XLOGDIR);
 817         if (xldir == NULL)
 818         {
 819                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 820                                 progname, XLOGDIR, strerror(errno));
 821                 exit(1);
 822         }
 823
 824         errno = 0;
 825         while ((xlde = readdir(xldir)) != NULL)
 826         {
 827                 if (strlen(xlde->d_name) == 24 &&
 828                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 829                 {
 830                         unsigned int tli,
 831                                                 log,
 832                                                 seg;
 833                         XLogSegNo       segno;
 834
 835                         sscanf(xlde->d_name, "%08X%08X%08X", &tli, &log, &seg);
 836                         segno = ((uint64) log) * segs_per_xlogid + seg;
 837
 838                         /*
 839                          * Note: we take the max of all files found, regardless of their
 840                          * timelines.  Another possibility would be to ignore files of
 841                          * timelines other than the target TLI, but this seems safer.
 842                          * Better too large a result than too small...
 843                          */
 844                         if (segno > newXlogSegNo)
 845                                 newXlogSegNo = segno;
 846                 }
 847                 errno = 0;
 848         }
 849 #ifdef WIN32
 850
 851         /*
 852          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 853          * released version
 854          */
 855         if (GetLastError() == ERROR_NO_MORE_FILES)
 856                 errno = 0;
 857 #endif
 858
 859         if (errno)
 860         {
 861                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 862                                 progname, XLOGDIR, strerror(errno));
 863                 exit(1);
 864         }
 865         closedir(xldir);
 866
 867         /*
 868          * Finally, convert to new xlog seg size, and advance by one to ensure we
 869          * are in virgin territory.
 870          */
 871         xlogbytepos = newXlogSegNo * ControlFile.xlog_seg_size;
 872         newXlogSegNo = (xlogbytepos + XLogSegSize - 1) / XLogSegSize;
 873         newXlogSegNo++;
 874 }
 875
 876
 877 /*
 878  * Remove existing XLOG files
 879  */
 880 static void
 881 KillExistingXLOG(void)
 882 {
 883         DIR                *xldir;
 884         struct dirent *xlde;
 885         char            path[MAXPGPATH];
 886
 887         xldir = opendir(XLOGDIR);
 888         if (xldir == NULL)
 889         {
 890                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 891                                 progname, XLOGDIR, strerror(errno));
 892                 exit(1);
 893         }
 894
 895         errno = 0;
 896         while ((xlde = readdir(xldir)) != NULL)
 897         {
 898                 if (strlen(xlde->d_name) == 24 &&
 899                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 900                 {
 901                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 902                         if (unlink(path) < 0)
 903                         {
 904                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 905                                                 progname, path, strerror(errno));
 906                                 exit(1);
 907                         }
 908                 }
 909                 errno = 0;
 910         }
 911 #ifdef WIN32
 912
 913         /*
 914          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 915          * released version
 916          */
 917         if (GetLastError() == ERROR_NO_MORE_FILES)
 918                 errno = 0;
 919 #endif
 920
 921         if (errno)
 922         {
 923                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 924                                 progname, XLOGDIR, strerror(errno));
 925                 exit(1);
 926         }
 927         closedir(xldir);
 928 }
 929
 930
 931 /*
 932  * Remove existing archive status files
 933  */
 934 static void
 935 KillExistingArchiveStatus(void)
 936 {
 937         DIR                *xldir;
 938         struct dirent *xlde;
 939         char            path[MAXPGPATH];
 940
 941 #define ARCHSTATDIR XLOGDIR "/archive_status"
 942
 943         xldir = opendir(ARCHSTATDIR);
 944         if (xldir == NULL)
 945         {
 946                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 947                                 progname, ARCHSTATDIR, strerror(errno));
 948                 exit(1);
 949         }
 950
 951         errno = 0;
 952         while ((xlde = readdir(xldir)) != NULL)
 953         {
 954                 if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
 955                         (strcmp(xlde->d_name + 24, ".ready") == 0 ||
 956                          strcmp(xlde->d_name + 24, ".done") == 0))
 957                 {
 958                         snprintf(path, MAXPGPATH, "%s/%s", ARCHSTATDIR, xlde->d_name);
 959                         if (unlink(path) < 0)
 960                         {
 961                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 962                                                 progname, path, strerror(errno));
 963                                 exit(1);
 964                         }
 965                 }
 966                 errno = 0;
 967         }
 968 #ifdef WIN32
 969
 970         /*
 971          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 972          * released version
 973          */
 974         if (GetLastError() == ERROR_NO_MORE_FILES)
 975                 errno = 0;
 976 #endif
 977
 978         if (errno)
 979         {
 980                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 981                                 progname, ARCHSTATDIR, strerror(errno));
 982                 exit(1);
 983         }
 984         closedir(xldir);
 985 }
 986
 987
 988 /*
 989  * Write an empty XLOG file, containing only the checkpoint record
 990  * already set up in ControlFile.
 991  */
 992 static void
 993 WriteEmptyXLOG(void)
 994 {
 995         char       *buffer;
 996         XLogPageHeader page;
 997         XLogLongPageHeader longpage;
 998         XLogRecord *record;
 999         pg_crc32        crc;
1000         char            path[MAXPGPATH];
1001         int                     fd;
1002         int                     nbytes;
1003
1004         /* Use malloc() to ensure buffer is MAXALIGNED */
1005         buffer = (char *) pg_malloc(XLOG_BLCKSZ);
1006         page = (XLogPageHeader) buffer;
1007         memset(buffer, 0, XLOG_BLCKSZ);
1008
1009         /* Set up the XLOG page header */
1010         page->xlp_magic = XLOG_PAGE_MAGIC;
1011         page->xlp_info = XLP_LONG_HEADER;
1012         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
1013         page->xlp_pageaddr = ControlFile.checkPointCopy.redo - SizeOfXLogLongPHD;
1014         longpage = (XLogLongPageHeader) page;
1015         longpage->xlp_sysid = ControlFile.system_identifier;
1016         longpage->xlp_seg_size = XLogSegSize;
1017         longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
1018
1019         /* Insert the initial checkpoint record */
1020         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
1021         record->xl_prev = 0;
1022         record->xl_xid = InvalidTransactionId;
1023         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
1024         record->xl_len = sizeof(CheckPoint);
1025         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
1026         record->xl_rmid = RM_XLOG_ID;
1027         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
1028                    sizeof(CheckPoint));
1029
1030         INIT_CRC32(crc);
1031         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
1032         COMP_CRC32(crc, (char *) record, offsetof(XLogRecord, xl_crc));
1033         FIN_CRC32(crc);
1034         record->xl_crc = crc;
1035
1036         /* Write the first page */
1037         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID, newXlogSegNo);
1038
1039         unlink(path);
1040
1041         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
1042                           S_IRUSR | S_IWUSR);
1043         if (fd < 0)
1044         {
1045                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
1046                                 progname, path, strerror(errno));
1047                 exit(1);
1048         }
1049
1050         errno = 0;
1051         if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
1052         {
1053                 /* if write didn't set errno, assume problem is no disk space */
1054                 if (errno == 0)
1055                         errno = ENOSPC;
1056                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
1057                                 progname, path, strerror(errno));
1058                 exit(1);
1059         }
1060
1061         /* Fill the rest of the file with zeroes */
1062         memset(buffer, 0, XLOG_BLCKSZ);
1063         for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
1064         {
1065                 errno = 0;
1066                 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
1067                 {
1068                         if (errno == 0)
1069                                 errno = ENOSPC;
1070                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
1071                                         progname, path, strerror(errno));
1072                         exit(1);
1073                 }
1074         }
1075
1076         if (fsync(fd) != 0)
1077         {
1078                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
1079                 exit(1);
1080         }
1081
1082         close(fd);
1083 }
1084
1085
1086 static void
1087 usage(void)
1088 {
1089         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
1090         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
1091         printf(_("Options:\n"));
1092         printf(_("  -e XIDEPOCH      set next transaction ID epoch\n"));
1093         printf(_("  -f               force update to be done\n"));
1094         printf(_("  -l XLOGFILE      force minimum WAL starting location for new transaction log\n"));
1095         printf(_("  -m MXID,MXID     set next and oldest multitransaction ID\n"));
1096         printf(_("  -n               no update, just show what would be done (for testing)\n"));
1097         printf(_("  -o OID           set next OID\n"));
1098         printf(_("  -O OFFSET        set next multitransaction offset\n"));
1099         printf(_("  -V, --version    output version information, then exit\n"));
1100         printf(_("  -x XID           set next transaction ID\n"));
1101         printf(_("  -?, --help       show this help, then exit\n"));
1102         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
1103 }