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) 1996-2009, PostgreSQL Global Development Group
  24  * Portions Copyright (c) 1994, Regents of the University of California
  25  *
  26  * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.75 2009/08/31 02:23:23 tgl Exp $
  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
  58 extern int      optind;
  59 extern char *optarg;
  60
  61
  62 static ControlFileData ControlFile;             /* pg_control values */
  63 static uint32 newXlogId,
  64                         newXlogSeg;                     /* ID/Segment of 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         MultiXactOffset set_mxoff = (MultiXactOffset) -1;
  90         uint32          minXlogTli = 0,
  91                                 minXlogId = 0,
  92                                 minXlogSeg = 0;
  93         char       *endptr;
  94         char       *endptr2;
  95         char       *endptr3;
  96         char       *DataDir;
  97         int                     fd;
  98         char            path[MAXPGPATH];
  99
 100         set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetxlog"));
 101
 102         progname = get_progname(argv[0]);
 103
 104         if (argc > 1)
 105         {
 106                 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
 107                 {
 108                         usage();
 109                         exit(0);
 110                 }
 111                 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
 112                 {
 113                         puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
 114                         exit(0);
 115                 }
 116         }
 117
 118
 119         while ((c = getopt(argc, argv, "fl:m:no:O:x:e:")) != -1)
 120         {
 121                 switch (c)
 122                 {
 123                         case 'f':
 124                                 force = true;
 125                                 break;
 126
 127                         case 'n':
 128                                 noupdate = true;
 129                                 break;
 130
 131                         case 'e':
 132                                 set_xid_epoch = strtoul(optarg, &endptr, 0);
 133                                 if (endptr == optarg || *endptr != '\0')
 134                                 {
 135                                         fprintf(stderr, _("%s: invalid argument for option -e\n"), progname);
 136                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 137                                         exit(1);
 138                                 }
 139                                 if (set_xid_epoch == -1)
 140                                 {
 141                                         fprintf(stderr, _("%s: transaction ID epoch (-e) must not be -1\n"), progname);
 142                                         exit(1);
 143                                 }
 144                                 break;
 145
 146                         case 'x':
 147                                 set_xid = strtoul(optarg, &endptr, 0);
 148                                 if (endptr == optarg || *endptr != '\0')
 149                                 {
 150                                         fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
 151                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 152                                         exit(1);
 153                                 }
 154                                 if (set_xid == 0)
 155                                 {
 156                                         fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
 157                                         exit(1);
 158                                 }
 159                                 break;
 160
 161                         case 'o':
 162                                 set_oid = strtoul(optarg, &endptr, 0);
 163                                 if (endptr == optarg || *endptr != '\0')
 164                                 {
 165                                         fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
 166                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 167                                         exit(1);
 168                                 }
 169                                 if (set_oid == 0)
 170                                 {
 171                                         fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
 172                                         exit(1);
 173                                 }
 174                                 break;
 175
 176                         case 'm':
 177                                 set_mxid = strtoul(optarg, &endptr, 0);
 178                                 if (endptr == optarg || *endptr != '\0')
 179                                 {
 180                                         fprintf(stderr, _("%s: invalid argument for option -m\n"), progname);
 181                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 182                                         exit(1);
 183                                 }
 184                                 if (set_mxid == 0)
 185                                 {
 186                                         fprintf(stderr, _("%s: multitransaction ID (-m) must not be 0\n"), progname);
 187                                         exit(1);
 188                                 }
 189                                 break;
 190
 191                         case 'O':
 192                                 set_mxoff = strtoul(optarg, &endptr, 0);
 193                                 if (endptr == optarg || *endptr != '\0')
 194                                 {
 195                                         fprintf(stderr, _("%s: invalid argument for option -O\n"), progname);
 196                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 197                                         exit(1);
 198                                 }
 199                                 if (set_mxoff == -1)
 200                                 {
 201                                         fprintf(stderr, _("%s: multitransaction offset (-O) must not be -1\n"), progname);
 202                                         exit(1);
 203                                 }
 204                                 break;
 205
 206                         case 'l':
 207                                 minXlogTli = strtoul(optarg, &endptr, 0);
 208                                 if (endptr == optarg || *endptr != ',')
 209                                 {
 210                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 211                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 212                                         exit(1);
 213                                 }
 214                                 minXlogId = strtoul(endptr + 1, &endptr2, 0);
 215                                 if (endptr2 == endptr + 1 || *endptr2 != ',')
 216                                 {
 217                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 218                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 219                                         exit(1);
 220                                 }
 221                                 minXlogSeg = strtoul(endptr2 + 1, &endptr3, 0);
 222                                 if (endptr3 == endptr2 + 1 || *endptr3 != '\0')
 223                                 {
 224                                         fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
 225                                         fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 226                                         exit(1);
 227                                 }
 228                                 break;
 229
 230                         default:
 231                                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 232                                 exit(1);
 233                 }
 234         }
 235
 236         if (optind == argc)
 237         {
 238                 fprintf(stderr, _("%s: no data directory specified\n"), progname);
 239                 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 240                 exit(1);
 241         }
 242
 243         /*
 244          * Don't allow pg_resetxlog to be run as root, to avoid overwriting the
 245          * ownership of files in the data directory. We need only check for root
 246          * -- any other user won't have sufficient permissions to modify files in
 247          * the data directory.
 248          */
 249 #ifndef WIN32
 250         if (geteuid() == 0)
 251         {
 252                 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
 253                                 progname);
 254                 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
 255                                 progname);
 256                 exit(1);
 257         }
 258 #endif
 259
 260         DataDir = argv[optind];
 261
 262         if (chdir(DataDir) < 0)
 263         {
 264                 fprintf(stderr, _("%s: could not change directory to \"%s\": %s\n"),
 265                                 progname, DataDir, strerror(errno));
 266                 exit(1);
 267         }
 268
 269         /*
 270          * Check for a postmaster lock file --- if there is one, refuse to
 271          * proceed, on grounds we might be interfering with a live installation.
 272          */
 273         snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
 274
 275         if ((fd = open(path, O_RDONLY, 0)) < 0)
 276         {
 277                 if (errno != ENOENT)
 278                 {
 279                         fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
 280                         exit(1);
 281                 }
 282         }
 283         else
 284         {
 285                 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
 286                                                   "Is a server running?  If not, delete the lock file and try again.\n"),
 287                                 progname, path);
 288                 exit(1);
 289         }
 290
 291         /*
 292          * Attempt to read the existing pg_control file
 293          */
 294         if (!ReadControlFile())
 295                 GuessControlValues();
 296
 297         /*
 298          * Also look at existing segment files to set up newXlogId/newXlogSeg
 299          */
 300         FindEndOfXLOG();
 301
 302         /*
 303          * Adjust fields if required by switches.  (Do this now so that printout,
 304          * if any, includes these values.)
 305          */
 306         if (set_xid_epoch != -1)
 307                 ControlFile.checkPointCopy.nextXidEpoch = set_xid_epoch;
 308
 309         if (set_xid != 0)
 310         {
 311                 ControlFile.checkPointCopy.nextXid = set_xid;
 312
 313                 /*
 314                  * For the moment, just set oldestXid to a value that will force
 315                  * immediate autovacuum-for-wraparound.  It's not clear whether
 316                  * adding user control of this is useful, so let's just do something
 317                  * that's reasonably safe.  The magic constant here corresponds to
 318                  * the maximum allowed value of autovacuum_freeze_max_age.
 319                  */
 320                 ControlFile.checkPointCopy.oldestXid = set_xid - 2000000000;
 321                 if (ControlFile.checkPointCopy.oldestXid < FirstNormalTransactionId)
 322                         ControlFile.checkPointCopy.oldestXid += FirstNormalTransactionId;
 323                 ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 324         }
 325
 326         if (set_oid != 0)
 327                 ControlFile.checkPointCopy.nextOid = set_oid;
 328
 329         if (set_mxid != 0)
 330                 ControlFile.checkPointCopy.nextMulti = set_mxid;
 331
 332         if (set_mxoff != -1)
 333                 ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
 334
 335         if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
 336                 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
 337
 338         if (minXlogId > newXlogId ||
 339                 (minXlogId == newXlogId &&
 340                  minXlogSeg > newXlogSeg))
 341         {
 342                 newXlogId = minXlogId;
 343                 newXlogSeg = minXlogSeg;
 344         }
 345
 346         /*
 347          * If we had to guess anything, and -f was not given, just print the
 348          * guessed values and exit.  Also print if -n is given.
 349          */
 350         if ((guessed && !force) || noupdate)
 351         {
 352                 PrintControlValues(guessed);
 353                 if (!noupdate)
 354                 {
 355                         printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
 356                         exit(1);
 357                 }
 358                 else
 359                         exit(0);
 360         }
 361
 362         /*
 363          * Don't reset from a dirty pg_control without -f, either.
 364          */
 365         if (ControlFile.state != DB_SHUTDOWNED && !force)
 366         {
 367                 printf(_("The database server was not shut down cleanly.\n"
 368                            "Resetting the transaction log might cause data to be lost.\n"
 369                                  "If you want to proceed anyway, use -f to force reset.\n"));
 370                 exit(1);
 371         }
 372
 373         /*
 374          * Else, do the dirty deed.
 375          */
 376         RewriteControlFile();
 377         KillExistingXLOG();
 378         KillExistingArchiveStatus();
 379         WriteEmptyXLOG();
 380
 381         printf(_("Transaction log reset\n"));
 382         return 0;
 383 }
 384
 385
 386 /*
 387  * Try to read the existing pg_control file.
 388  *
 389  * This routine is also responsible for updating old pg_control versions
 390  * to the current format.  (Currently we don't do anything of the sort.)
 391  */
 392 static bool
 393 ReadControlFile(void)
 394 {
 395         int                     fd;
 396         int                     len;
 397         char       *buffer;
 398         pg_crc32        crc;
 399
 400         if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 0)
 401         {
 402                 /*
 403                  * If pg_control is not there at all, or we can't read it, the odds
 404                  * are we've been handed a bad DataDir path, so give up. User can do
 405                  * "touch pg_control" to force us to proceed.
 406                  */
 407                 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
 408                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 409                 if (errno == ENOENT)
 410                         fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
 411                                                           "  touch %s\n"
 412                                                           "and try again.\n"),
 413                                         XLOG_CONTROL_FILE);
 414                 exit(1);
 415         }
 416
 417         /* Use malloc to ensure we have a maxaligned buffer */
 418         buffer = (char *) malloc(PG_CONTROL_SIZE);
 419
 420         len = read(fd, buffer, PG_CONTROL_SIZE);
 421         if (len < 0)
 422         {
 423                 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
 424                                 progname, XLOG_CONTROL_FILE, strerror(errno));
 425                 exit(1);
 426         }
 427         close(fd);
 428
 429         if (len >= sizeof(ControlFileData) &&
 430           ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
 431         {
 432                 /* Check the CRC. */
 433                 INIT_CRC32(crc);
 434                 COMP_CRC32(crc,
 435                                    buffer,
 436                                    offsetof(ControlFileData, crc));
 437                 FIN_CRC32(crc);
 438
 439                 if (EQ_CRC32(crc, ((ControlFileData *) buffer)->crc))
 440                 {
 441                         /* Valid data... */
 442                         memcpy(&ControlFile, buffer, sizeof(ControlFile));
 443                         return true;
 444                 }
 445
 446                 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
 447                                 progname);
 448                 /* We will use the data anyway, but treat it as guessed. */
 449                 memcpy(&ControlFile, buffer, sizeof(ControlFile));
 450                 guessed = true;
 451                 return true;
 452         }
 453
 454         /* Looks like it's a mess. */
 455         fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
 456                         progname);
 457         return false;
 458 }
 459
 460
 461 /*
 462  * Guess at pg_control values when we can't read the old ones.
 463  */
 464 static void
 465 GuessControlValues(void)
 466 {
 467         uint64          sysidentifier;
 468         struct timeval tv;
 469
 470         /*
 471          * Set up a completely default set of pg_control values.
 472          */
 473         guessed = true;
 474         memset(&ControlFile, 0, sizeof(ControlFile));
 475
 476         ControlFile.pg_control_version = PG_CONTROL_VERSION;
 477         ControlFile.catalog_version_no = CATALOG_VERSION_NO;
 478
 479         /*
 480          * Create a new unique installation identifier, since we can no longer use
 481          * any old XLOG records.  See notes in xlog.c about the algorithm.
 482          */
 483         gettimeofday(&tv, NULL);
 484         sysidentifier = ((uint64) tv.tv_sec) << 32;
 485         sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
 486
 487         ControlFile.system_identifier = sysidentifier;
 488
 489         ControlFile.checkPointCopy.redo.xlogid = 0;
 490         ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
 491         ControlFile.checkPointCopy.ThisTimeLineID = 1;
 492         ControlFile.checkPointCopy.nextXidEpoch = 0;
 493         ControlFile.checkPointCopy.nextXid = FirstNormalTransactionId;
 494         ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
 495         ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
 496         ControlFile.checkPointCopy.nextMultiOffset = 0;
 497         ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
 498         ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
 499         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 500
 501         ControlFile.state = DB_SHUTDOWNED;
 502         ControlFile.time = (pg_time_t) time(NULL);
 503         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 504
 505         ControlFile.maxAlign = MAXIMUM_ALIGNOF;
 506         ControlFile.floatFormat = FLOATFORMAT_VALUE;
 507         ControlFile.blcksz = BLCKSZ;
 508         ControlFile.relseg_size = RELSEG_SIZE;
 509         ControlFile.xlog_blcksz = XLOG_BLCKSZ;
 510         ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
 511         ControlFile.nameDataLen = NAMEDATALEN;
 512         ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
 513         ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
 514 #ifdef HAVE_INT64_TIMESTAMP
 515         ControlFile.enableIntTimes = true;
 516 #else
 517         ControlFile.enableIntTimes = false;
 518 #endif
 519         ControlFile.float4ByVal = FLOAT4PASSBYVAL;
 520         ControlFile.float8ByVal = FLOAT8PASSBYVAL;
 521
 522         /*
 523          * XXX eventually, should try to grovel through old XLOG to develop more
 524          * accurate values for TimeLineID, nextXID, etc.
 525          */
 526 }
 527
 528
 529 /*
 530  * Print the guessed pg_control values when we had to guess.
 531  *
 532  * NB: this display should be just those fields that will not be
 533  * reset by RewriteControlFile().
 534  */
 535 static void
 536 PrintControlValues(bool guessed)
 537 {
 538         char            sysident_str[32];
 539
 540         if (guessed)
 541                 printf(_("Guessed pg_control values:\n\n"));
 542         else
 543                 printf(_("pg_control values:\n\n"));
 544
 545         /*
 546          * Format system_identifier separately to keep platform-dependent format
 547          * code out of the translatable message string.
 548          */
 549         snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
 550                          ControlFile.system_identifier);
 551
 552         printf(_("First log file ID after reset:        %u\n"),
 553                    newXlogId);
 554         printf(_("First log file segment after reset:   %u\n"),
 555                    newXlogSeg);
 556         printf(_("pg_control version number:            %u\n"),
 557                    ControlFile.pg_control_version);
 558         printf(_("Catalog version number:               %u\n"),
 559                    ControlFile.catalog_version_no);
 560         printf(_("Database system identifier:           %s\n"),
 561                    sysident_str);
 562         printf(_("Latest checkpoint's TimeLineID:       %u\n"),
 563                    ControlFile.checkPointCopy.ThisTimeLineID);
 564         printf(_("Latest checkpoint's NextXID:          %u/%u\n"),
 565                    ControlFile.checkPointCopy.nextXidEpoch,
 566                    ControlFile.checkPointCopy.nextXid);
 567         printf(_("Latest checkpoint's NextOID:          %u\n"),
 568                    ControlFile.checkPointCopy.nextOid);
 569         printf(_("Latest checkpoint's NextMultiXactId:  %u\n"),
 570                    ControlFile.checkPointCopy.nextMulti);
 571         printf(_("Latest checkpoint's NextMultiOffset:  %u\n"),
 572                    ControlFile.checkPointCopy.nextMultiOffset);
 573         printf(_("Latest checkpoint's oldestXID:        %u\n"),
 574                    ControlFile.checkPointCopy.oldestXid);
 575         printf(_("Latest checkpoint's oldestXID's DB:   %u\n"),
 576                    ControlFile.checkPointCopy.oldestXidDB);
 577         printf(_("Maximum data alignment:               %u\n"),
 578                    ControlFile.maxAlign);
 579         /* we don't print floatFormat since can't say much useful about it */
 580         printf(_("Database block size:                  %u\n"),
 581                    ControlFile.blcksz);
 582         printf(_("Blocks per segment of large relation: %u\n"),
 583                    ControlFile.relseg_size);
 584         printf(_("WAL block size:                       %u\n"),
 585                    ControlFile.xlog_blcksz);
 586         printf(_("Bytes per WAL segment:                %u\n"),
 587                    ControlFile.xlog_seg_size);
 588         printf(_("Maximum length of identifiers:        %u\n"),
 589                    ControlFile.nameDataLen);
 590         printf(_("Maximum columns in an index:          %u\n"),
 591                    ControlFile.indexMaxKeys);
 592         printf(_("Maximum size of a TOAST chunk:        %u\n"),
 593                    ControlFile.toast_max_chunk_size);
 594         printf(_("Date/time type storage:               %s\n"),
 595                    (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
 596         printf(_("Float4 argument passing:              %s\n"),
 597                    (ControlFile.float4ByVal ? _("by value") : _("by reference")));
 598         printf(_("Float8 argument passing:              %s\n"),
 599                    (ControlFile.float8ByVal ? _("by value") : _("by reference")));
 600 }
 601
 602
 603 /*
 604  * Write out the new pg_control file.
 605  */
 606 static void
 607 RewriteControlFile(void)
 608 {
 609         int                     fd;
 610         char            buffer[PG_CONTROL_SIZE];                /* need not be aligned */
 611
 612         /*
 613          * Adjust fields as needed to force an empty XLOG starting at
 614          * newXlogId/newXlogSeg.
 615          */
 616         ControlFile.checkPointCopy.redo.xlogid = newXlogId;
 617         ControlFile.checkPointCopy.redo.xrecoff =
 618                 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
 619         ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
 620
 621         ControlFile.state = DB_SHUTDOWNED;
 622         ControlFile.time = (pg_time_t) time(NULL);
 623         ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
 624         ControlFile.prevCheckPoint.xlogid = 0;
 625         ControlFile.prevCheckPoint.xrecoff = 0;
 626         ControlFile.minRecoveryPoint.xlogid = 0;
 627         ControlFile.minRecoveryPoint.xrecoff = 0;
 628
 629         /* Now we can force the recorded xlog seg size to the right thing. */
 630         ControlFile.xlog_seg_size = XLogSegSize;
 631
 632         /* Contents are protected with a CRC */
 633         INIT_CRC32(ControlFile.crc);
 634         COMP_CRC32(ControlFile.crc,
 635                            (char *) &ControlFile,
 636                            offsetof(ControlFileData, crc));
 637         FIN_CRC32(ControlFile.crc);
 638
 639         /*
 640          * We write out PG_CONTROL_SIZE bytes into pg_control, zero-padding the
 641          * excess over sizeof(ControlFileData).  This reduces the odds of
 642          * premature-EOF errors when reading pg_control.  We'll still fail when we
 643          * check the contents of the file, but hopefully with a more specific
 644          * error than "couldn't read pg_control".
 645          */
 646         if (sizeof(ControlFileData) > PG_CONTROL_SIZE)
 647         {
 648                 fprintf(stderr,
 649                                 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix PG_CONTROL_SIZE\n"),
 650                                 progname);
 651                 exit(1);
 652         }
 653
 654         memset(buffer, 0, PG_CONTROL_SIZE);
 655         memcpy(buffer, &ControlFile, sizeof(ControlFileData));
 656
 657         unlink(XLOG_CONTROL_FILE);
 658
 659         fd = open(XLOG_CONTROL_FILE,
 660                           O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 661                           S_IRUSR | S_IWUSR);
 662         if (fd < 0)
 663         {
 664                 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
 665                                 progname, strerror(errno));
 666                 exit(1);
 667         }
 668
 669         errno = 0;
 670         if (write(fd, buffer, PG_CONTROL_SIZE) != PG_CONTROL_SIZE)
 671         {
 672                 /* if write didn't set errno, assume problem is no disk space */
 673                 if (errno == 0)
 674                         errno = ENOSPC;
 675                 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
 676                                 progname, strerror(errno));
 677                 exit(1);
 678         }
 679
 680         if (fsync(fd) != 0)
 681         {
 682                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 683                 exit(1);
 684         }
 685
 686         close(fd);
 687 }
 688
 689
 690 /*
 691  * Scan existing XLOG files and determine the highest existing WAL address
 692  *
 693  * On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
 694  * are assumed valid (note that we allow the old xlog seg size to differ
 695  * from what we're using).  On exit, newXlogId and newXlogSeg are set to
 696  * suitable values for the beginning of replacement WAL (in our seg size).
 697  */
 698 static void
 699 FindEndOfXLOG(void)
 700 {
 701         DIR                *xldir;
 702         struct dirent *xlde;
 703
 704         /*
 705          * Initialize the max() computation using the last checkpoint address from
 706          * old pg_control.      Note that for the moment we are working with segment
 707          * numbering according to the old xlog seg size.
 708          */
 709         newXlogId = ControlFile.checkPointCopy.redo.xlogid;
 710         newXlogSeg = ControlFile.checkPointCopy.redo.xrecoff / ControlFile.xlog_seg_size;
 711
 712         /*
 713          * Scan the pg_xlog directory to find existing WAL segment files. We
 714          * assume any present have been used; in most scenarios this should be
 715          * conservative, because of xlog.c's attempts to pre-create files.
 716          */
 717         xldir = opendir(XLOGDIR);
 718         if (xldir == NULL)
 719         {
 720                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 721                                 progname, XLOGDIR, strerror(errno));
 722                 exit(1);
 723         }
 724
 725         errno = 0;
 726         while ((xlde = readdir(xldir)) != NULL)
 727         {
 728                 if (strlen(xlde->d_name) == 24 &&
 729                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 730                 {
 731                         unsigned int tli,
 732                                                 log,
 733                                                 seg;
 734
 735                         sscanf(xlde->d_name, "%08X%08X%08X", &tli, &log, &seg);
 736
 737                         /*
 738                          * Note: we take the max of all files found, regardless of their
 739                          * timelines.  Another possibility would be to ignore files of
 740                          * timelines other than the target TLI, but this seems safer.
 741                          * Better too large a result than too small...
 742                          */
 743                         if (log > newXlogId ||
 744                                 (log == newXlogId && seg > newXlogSeg))
 745                         {
 746                                 newXlogId = log;
 747                                 newXlogSeg = seg;
 748                         }
 749                 }
 750                 errno = 0;
 751         }
 752 #ifdef WIN32
 753
 754         /*
 755          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 756          * released version
 757          */
 758         if (GetLastError() == ERROR_NO_MORE_FILES)
 759                 errno = 0;
 760 #endif
 761
 762         if (errno)
 763         {
 764                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 765                                 progname, XLOGDIR, strerror(errno));
 766                 exit(1);
 767         }
 768         closedir(xldir);
 769
 770         /*
 771          * Finally, convert to new xlog seg size, and advance by one to ensure we
 772          * are in virgin territory.
 773          */
 774         newXlogSeg *= ControlFile.xlog_seg_size;
 775         newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
 776
 777         /* be sure we wrap around correctly at end of a logfile */
 778         NextLogSeg(newXlogId, newXlogSeg);
 779 }
 780
 781
 782 /*
 783  * Remove existing XLOG files
 784  */
 785 static void
 786 KillExistingXLOG(void)
 787 {
 788         DIR                *xldir;
 789         struct dirent *xlde;
 790         char            path[MAXPGPATH];
 791
 792         xldir = opendir(XLOGDIR);
 793         if (xldir == NULL)
 794         {
 795                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 796                                 progname, XLOGDIR, strerror(errno));
 797                 exit(1);
 798         }
 799
 800         errno = 0;
 801         while ((xlde = readdir(xldir)) != NULL)
 802         {
 803                 if (strlen(xlde->d_name) == 24 &&
 804                         strspn(xlde->d_name, "0123456789ABCDEF") == 24)
 805                 {
 806                         snprintf(path, MAXPGPATH, "%s/%s", XLOGDIR, xlde->d_name);
 807                         if (unlink(path) < 0)
 808                         {
 809                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 810                                                 progname, path, strerror(errno));
 811                                 exit(1);
 812                         }
 813                 }
 814                 errno = 0;
 815         }
 816 #ifdef WIN32
 817
 818         /*
 819          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 820          * released version
 821          */
 822         if (GetLastError() == ERROR_NO_MORE_FILES)
 823                 errno = 0;
 824 #endif
 825
 826         if (errno)
 827         {
 828                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 829                                 progname, XLOGDIR, strerror(errno));
 830                 exit(1);
 831         }
 832         closedir(xldir);
 833 }
 834
 835
 836 /*
 837  * Remove existing archive status files
 838  */
 839 static void
 840 KillExistingArchiveStatus(void)
 841 {
 842         DIR                *xldir;
 843         struct dirent *xlde;
 844         char            path[MAXPGPATH];
 845
 846 #define ARCHSTATDIR XLOGDIR "/archive_status"
 847
 848         xldir = opendir(ARCHSTATDIR);
 849         if (xldir == NULL)
 850         {
 851                 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
 852                                 progname, ARCHSTATDIR, strerror(errno));
 853                 exit(1);
 854         }
 855
 856         errno = 0;
 857         while ((xlde = readdir(xldir)) != NULL)
 858         {
 859                 if (strspn(xlde->d_name, "0123456789ABCDEF") == 24 &&
 860                         (strcmp(xlde->d_name + 24, ".ready") == 0 ||
 861                          strcmp(xlde->d_name + 24, ".done") == 0))
 862                 {
 863                         snprintf(path, MAXPGPATH, "%s/%s", ARCHSTATDIR, xlde->d_name);
 864                         if (unlink(path) < 0)
 865                         {
 866                                 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
 867                                                 progname, path, strerror(errno));
 868                                 exit(1);
 869                         }
 870                 }
 871                 errno = 0;
 872         }
 873 #ifdef WIN32
 874
 875         /*
 876          * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but not in
 877          * released version
 878          */
 879         if (GetLastError() == ERROR_NO_MORE_FILES)
 880                 errno = 0;
 881 #endif
 882
 883         if (errno)
 884         {
 885                 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
 886                                 progname, ARCHSTATDIR, strerror(errno));
 887                 exit(1);
 888         }
 889         closedir(xldir);
 890 }
 891
 892
 893 /*
 894  * Write an empty XLOG file, containing only the checkpoint record
 895  * already set up in ControlFile.
 896  */
 897 static void
 898 WriteEmptyXLOG(void)
 899 {
 900         char       *buffer;
 901         XLogPageHeader page;
 902         XLogLongPageHeader longpage;
 903         XLogRecord *record;
 904         pg_crc32        crc;
 905         char            path[MAXPGPATH];
 906         int                     fd;
 907         int                     nbytes;
 908
 909         /* Use malloc() to ensure buffer is MAXALIGNED */
 910         buffer = (char *) malloc(XLOG_BLCKSZ);
 911         page = (XLogPageHeader) buffer;
 912         memset(buffer, 0, XLOG_BLCKSZ);
 913
 914         /* Set up the XLOG page header */
 915         page->xlp_magic = XLOG_PAGE_MAGIC;
 916         page->xlp_info = XLP_LONG_HEADER;
 917         page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
 918         page->xlp_pageaddr.xlogid =
 919                 ControlFile.checkPointCopy.redo.xlogid;
 920         page->xlp_pageaddr.xrecoff =
 921                 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
 922         longpage = (XLogLongPageHeader) page;
 923         longpage->xlp_sysid = ControlFile.system_identifier;
 924         longpage->xlp_seg_size = XLogSegSize;
 925         longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
 926
 927         /* Insert the initial checkpoint record */
 928         record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
 929         record->xl_prev.xlogid = 0;
 930         record->xl_prev.xrecoff = 0;
 931         record->xl_xid = InvalidTransactionId;
 932         record->xl_tot_len = SizeOfXLogRecord + sizeof(CheckPoint);
 933         record->xl_len = sizeof(CheckPoint);
 934         record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
 935         record->xl_rmid = RM_XLOG_ID;
 936         memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
 937                    sizeof(CheckPoint));
 938
 939         INIT_CRC32(crc);
 940         COMP_CRC32(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
 941         COMP_CRC32(crc, (char *) record + sizeof(pg_crc32),
 942                            SizeOfXLogRecord - sizeof(pg_crc32));
 943         FIN_CRC32(crc);
 944         record->xl_crc = crc;
 945
 946         /* Write the first page */
 947         XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
 948                                  newXlogId, newXlogSeg);
 949
 950         unlink(path);
 951
 952         fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
 953                           S_IRUSR | S_IWUSR);
 954         if (fd < 0)
 955         {
 956                 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
 957                                 progname, path, strerror(errno));
 958                 exit(1);
 959         }
 960
 961         errno = 0;
 962         if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 963         {
 964                 /* if write didn't set errno, assume problem is no disk space */
 965                 if (errno == 0)
 966                         errno = ENOSPC;
 967                 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 968                                 progname, path, strerror(errno));
 969                 exit(1);
 970         }
 971
 972         /* Fill the rest of the file with zeroes */
 973         memset(buffer, 0, XLOG_BLCKSZ);
 974         for (nbytes = XLOG_BLCKSZ; nbytes < XLogSegSize; nbytes += XLOG_BLCKSZ)
 975         {
 976                 errno = 0;
 977                 if (write(fd, buffer, XLOG_BLCKSZ) != XLOG_BLCKSZ)
 978                 {
 979                         if (errno == 0)
 980                                 errno = ENOSPC;
 981                         fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
 982                                         progname, path, strerror(errno));
 983                         exit(1);
 984                 }
 985         }
 986
 987         if (fsync(fd) != 0)
 988         {
 989                 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
 990                 exit(1);
 991         }
 992
 993         close(fd);
 994 }
 995
 996
 997 static void
 998 usage(void)
 999 {
1000         printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
1001         printf(_("Usage:\n  %s [OPTION]... DATADIR\n\n"), progname);
1002         printf(_("Options:\n"));
1003         printf(_("  -e XIDEPOCH     set next transaction ID epoch\n"));
1004         printf(_("  -f              force update to be done\n"));
1005         printf(_("  -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
1006         printf(_("  -m XID          set next multitransaction ID\n"));
1007         printf(_("  -n              no update, just show extracted control values (for testing)\n"));
1008         printf(_("  -o OID          set next OID\n"));
1009         printf(_("  -O OFFSET       set next multitransaction offset\n"));
1010         printf(_("  -x XID          set next transaction ID\n"));
1011         printf(_("  --help          show this help, then exit\n"));
1012         printf(_("  --version       output version information, then exit\n"));
1013         printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));
1014 }