1 /*-------------------------------------------------------------------------
4 * A utility to "zero out" the xlog when it's corrupt beyond recovery.
5 * Can also rebuild pg_control if needed.
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
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
23 * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group
24 * Portions Copyright (c) 1994, Regents of the University of California
26 * $PostgreSQL: pgsql/src/bin/pg_resetxlog/pg_resetxlog.c,v 1.30 2005/03/29 03:01:32 tgl Exp $
28 *-------------------------------------------------------------------------
43 #include "access/xlog.h"
44 #include "access/xlog_internal.h"
45 #include "catalog/catversion.h"
46 #include "catalog/pg_control.h"
52 char XLogDir[MAXPGPATH]; /* not static, see xlog_internal.h */
53 static char ControlFilePath[MAXPGPATH];
55 static ControlFileData ControlFile; /* pg_control values */
56 static uint32 newXlogId,
57 newXlogSeg; /* ID/Segment of new XLOG segment */
58 static bool guessed = false; /* T if we had to guess at any values */
59 static const char *progname;
61 static bool ReadControlFile(void);
62 static void GuessControlValues(void);
63 static void PrintControlValues(bool guessed);
64 static void RewriteControlFile(void);
65 static void KillExistingXLOG(void);
66 static void WriteEmptyXLOG(void);
67 static void usage(void);
71 main(int argc, char *argv[])
75 bool noupdate = false;
76 TransactionId set_xid = 0;
78 uint32 minXlogTli = 0,
88 set_pglocale_pgservice(argv[0], "pg_resetxlog");
90 progname = get_progname(argv[0]);
94 if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
99 if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
101 puts("pg_resetxlog (PostgreSQL) " PG_VERSION);
107 while ((c = getopt(argc, argv, "fl:no:x:")) != -1)
120 set_xid = strtoul(optarg, &endptr, 0);
121 if (endptr == optarg || *endptr != '\0')
123 fprintf(stderr, _("%s: invalid argument for option -x\n"), progname);
124 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
129 fprintf(stderr, _("%s: transaction ID (-x) must not be 0\n"), progname);
135 set_oid = strtoul(optarg, &endptr, 0);
136 if (endptr == optarg || *endptr != '\0')
138 fprintf(stderr, _("%s: invalid argument for option -o\n"), progname);
139 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
144 fprintf(stderr, _("%s: OID (-o) must not be 0\n"), progname);
150 minXlogTli = strtoul(optarg, &endptr, 0);
151 if (endptr == optarg || *endptr != ',')
153 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
154 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
157 minXlogId = strtoul(endptr + 1, &endptr2, 0);
158 if (endptr2 == endptr + 1 || *endptr2 != ',')
160 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
161 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
164 minXlogSeg = strtoul(endptr2 + 1, &endptr3, 0);
165 if (endptr3 == endptr2 + 1 || *endptr3 != '\0')
167 fprintf(stderr, _("%s: invalid argument for option -l\n"), progname);
168 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
174 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
181 fprintf(stderr, _("%s: no data directory specified\n"), progname);
182 fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
187 * Don't allow pg_resetxlog to be run as root, to avoid
188 * overwriting the ownership of files in the data directory. We
189 * need only check for root -- any other user won't have
190 * sufficient permissions to modify files in the data directory.
193 #ifndef __BEOS__ /* no root check on BeOS */
196 fprintf(stderr, _("%s: cannot be executed by \"root\"\n"),
198 fprintf(stderr, _("You must run %s as the PostgreSQL superuser.\n"),
205 DataDir = argv[optind];
206 snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
207 snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
210 * Check for a postmaster lock file --- if there is one, refuse to
211 * proceed, on grounds we might be interfering with a live
214 snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
216 if ((fd = open(path, O_RDONLY)) < 0)
220 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"), progname, path, strerror(errno));
226 fprintf(stderr, _("%s: lock file \"%s\" exists\n"
227 "Is a server running? If not, delete the lock file and try again.\n"),
233 * Attempt to read the existing pg_control file
235 if (!ReadControlFile())
236 GuessControlValues();
239 * Adjust fields if required by switches. (Do this now so that
240 * printout, if any, includes these values.)
243 ControlFile.checkPointCopy.nextXid = set_xid;
246 ControlFile.checkPointCopy.nextOid = set_oid;
248 if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
249 ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
251 if (minXlogId > ControlFile.logId ||
252 (minXlogId == ControlFile.logId &&
253 minXlogSeg > ControlFile.logSeg))
255 ControlFile.logId = minXlogId;
256 ControlFile.logSeg = minXlogSeg;
260 * If we had to guess anything, and -f was not given, just print the
261 * guessed values and exit. Also print if -n is given.
263 if ((guessed && !force) || noupdate)
265 PrintControlValues(guessed);
268 printf(_("\nIf these values seem acceptable, use -f to force reset.\n"));
276 * Don't reset from a dirty pg_control without -f, either.
278 if (ControlFile.state != DB_SHUTDOWNED && !force)
280 printf(_("The database server was not shut down cleanly.\n"
281 "Resetting the transaction log may cause data to be lost.\n"
282 "If you want to proceed anyway, use -f to force reset.\n"));
287 * Else, do the dirty deed.
289 RewriteControlFile();
293 printf(_("Transaction log reset\n"));
299 * Try to read the existing pg_control file.
301 * This routine is also responsible for updating old pg_control versions
302 * to the current format. (Currently we don't do anything of the sort.)
305 ReadControlFile(void)
312 if ((fd = open(ControlFilePath, O_RDONLY)) < 0)
315 * If pg_control is not there at all, or we can't read it, the
316 * odds are we've been handed a bad DataDir path, so give up. User
317 * can do "touch pg_control" to force us to proceed.
319 fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
320 progname, ControlFilePath, strerror(errno));
322 fprintf(stderr, _("If you are sure the data directory path is correct, execute\n"
329 /* Use malloc to ensure we have a maxaligned buffer */
330 buffer = (char *) malloc(BLCKSZ);
332 len = read(fd, buffer, BLCKSZ);
335 fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
336 progname, ControlFilePath, strerror(errno));
341 if (len >= sizeof(ControlFileData) &&
342 ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
347 buffer + sizeof(crc64),
348 sizeof(ControlFileData) - sizeof(crc64));
351 if (EQ_CRC64(crc, ((ControlFileData *) buffer)->crc))
354 memcpy(&ControlFile, buffer, sizeof(ControlFile));
358 fprintf(stderr, _("%s: pg_control exists but has invalid CRC; proceed with caution\n"),
360 /* We will use the data anyway, but treat it as guessed. */
361 memcpy(&ControlFile, buffer, sizeof(ControlFile));
366 /* Looks like it's a mess. */
367 fprintf(stderr, _("%s: pg_control exists but is broken or unknown version; ignoring it\n"),
374 * Guess at pg_control values when we can't read the old ones.
377 GuessControlValues(void)
379 uint64 sysidentifier;
384 * Set up a completely default set of pg_control values.
387 memset(&ControlFile, 0, sizeof(ControlFile));
389 ControlFile.pg_control_version = PG_CONTROL_VERSION;
390 ControlFile.catalog_version_no = CATALOG_VERSION_NO;
393 * Create a new unique installation identifier, since we can no longer
394 * use any old XLOG records. See notes in xlog.c about the algorithm.
396 gettimeofday(&tv, NULL);
397 sysidentifier = ((uint64) tv.tv_sec) << 32;
398 sysidentifier |= (uint32) (tv.tv_sec | tv.tv_usec);
400 ControlFile.system_identifier = sysidentifier;
402 ControlFile.checkPointCopy.redo.xlogid = 0;
403 ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogLongPHD;
404 ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
405 ControlFile.checkPointCopy.ThisTimeLineID = 1;
406 ControlFile.checkPointCopy.nextXid = (TransactionId) 514; /* XXX */
407 ControlFile.checkPointCopy.nextOid = BootstrapObjectIdData;
408 ControlFile.checkPointCopy.time = time(NULL);
410 ControlFile.state = DB_SHUTDOWNED;
411 ControlFile.time = time(NULL);
412 ControlFile.logId = 0;
413 ControlFile.logSeg = 1;
414 ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
416 ControlFile.blcksz = BLCKSZ;
417 ControlFile.relseg_size = RELSEG_SIZE;
418 ControlFile.xlog_seg_size = XLOG_SEG_SIZE;
419 ControlFile.nameDataLen = NAMEDATALEN;
420 ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
421 #ifdef HAVE_INT64_TIMESTAMP
422 ControlFile.enableIntTimes = TRUE;
424 ControlFile.enableIntTimes = FALSE;
426 ControlFile.localeBuflen = LOCALE_NAME_BUFLEN;
428 localeptr = setlocale(LC_COLLATE, "");
431 fprintf(stderr, _("%s: invalid LC_COLLATE setting\n"), progname);
434 StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
435 localeptr = setlocale(LC_CTYPE, "");
438 fprintf(stderr, _("%s: invalid LC_CTYPE setting\n"), progname);
441 StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
444 * XXX eventually, should try to grovel through old XLOG to develop
445 * more accurate values for TimeLineID, nextXID, and nextOID.
451 * Print the guessed pg_control values when we had to guess.
453 * NB: this display should be just those fields that will not be
454 * reset by RewriteControlFile().
457 PrintControlValues(bool guessed)
459 char sysident_str[32];
462 printf(_("Guessed pg_control values:\n\n"));
464 printf(_("pg_control values:\n\n"));
467 * Format system_identifier separately to keep platform-dependent
468 * format code out of the translatable message string.
470 snprintf(sysident_str, sizeof(sysident_str), UINT64_FORMAT,
471 ControlFile.system_identifier);
473 printf(_("pg_control version number: %u\n"), ControlFile.pg_control_version);
474 printf(_("Catalog version number: %u\n"), ControlFile.catalog_version_no);
475 printf(_("Database system identifier: %s\n"), sysident_str);
476 printf(_("Current log file ID: %u\n"), ControlFile.logId);
477 printf(_("Next log file segment: %u\n"), ControlFile.logSeg);
478 printf(_("Latest checkpoint's TimeLineID: %u\n"), ControlFile.checkPointCopy.ThisTimeLineID);
479 printf(_("Latest checkpoint's NextXID: %u\n"), ControlFile.checkPointCopy.nextXid);
480 printf(_("Latest checkpoint's NextOID: %u\n"), ControlFile.checkPointCopy.nextOid);
481 printf(_("Database block size: %u\n"), ControlFile.blcksz);
482 printf(_("Blocks per segment of large relation: %u\n"), ControlFile.relseg_size);
483 printf(_("Maximum length of identifiers: %u\n"), ControlFile.nameDataLen);
484 printf(_("Maximum columns in an index: %u\n"), ControlFile.indexMaxKeys);
485 printf(_("Date/time type storage: %s\n"),
486 (ControlFile.enableIntTimes ? _("64-bit integers") : _("floating-point numbers")));
487 printf(_("Maximum length of locale name: %u\n"), ControlFile.localeBuflen);
488 printf(_("LC_COLLATE: %s\n"), ControlFile.lc_collate);
489 printf(_("LC_CTYPE: %s\n"), ControlFile.lc_ctype);
494 * Write out the new pg_control file.
497 RewriteControlFile(void)
500 char buffer[BLCKSZ]; /* need not be aligned */
503 * Adjust fields as needed to force an empty XLOG starting at the next
506 newXlogId = ControlFile.logId;
507 newXlogSeg = ControlFile.logSeg;
509 /* adjust in case we are changing segment size */
510 newXlogSeg *= ControlFile.xlog_seg_size;
511 newXlogSeg = (newXlogSeg + XLogSegSize - 1) / XLogSegSize;
513 /* be sure we wrap around correctly at end of a logfile */
514 NextLogSeg(newXlogId, newXlogSeg);
516 /* Now we can force the recorded xlog seg size to the right thing. */
517 ControlFile.xlog_seg_size = XLogSegSize;
519 ControlFile.checkPointCopy.redo.xlogid = newXlogId;
520 ControlFile.checkPointCopy.redo.xrecoff =
521 newXlogSeg * XLogSegSize + SizeOfXLogLongPHD;
522 ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
523 ControlFile.checkPointCopy.time = time(NULL);
525 ControlFile.state = DB_SHUTDOWNED;
526 ControlFile.time = time(NULL);
527 ControlFile.logId = newXlogId;
528 ControlFile.logSeg = newXlogSeg + 1;
529 ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
530 ControlFile.prevCheckPoint.xlogid = 0;
531 ControlFile.prevCheckPoint.xrecoff = 0;
533 /* Contents are protected with a CRC */
534 INIT_CRC64(ControlFile.crc);
535 COMP_CRC64(ControlFile.crc,
536 (char *) &ControlFile + sizeof(crc64),
537 sizeof(ControlFileData) - sizeof(crc64));
538 FIN_CRC64(ControlFile.crc);
541 * We write out BLCKSZ bytes into pg_control, zero-padding the excess
542 * over sizeof(ControlFileData). This reduces the odds of
543 * premature-EOF errors when reading pg_control. We'll still fail
544 * when we check the contents of the file, but hopefully with a more
545 * specific error than "couldn't read pg_control".
547 if (sizeof(ControlFileData) > BLCKSZ)
550 _("%s: internal error -- sizeof(ControlFileData) is too large ... fix xlog.c\n"),
555 memset(buffer, 0, BLCKSZ);
556 memcpy(buffer, &ControlFile, sizeof(ControlFileData));
558 unlink(ControlFilePath);
560 fd = open(ControlFilePath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
563 fprintf(stderr, _("%s: could not create pg_control file: %s\n"),
564 progname, strerror(errno));
569 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
571 /* if write didn't set errno, assume problem is no disk space */
574 fprintf(stderr, _("%s: could not write pg_control file: %s\n"),
575 progname, strerror(errno));
581 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
590 * Remove existing XLOG files
593 KillExistingXLOG(void)
597 char path[MAXPGPATH];
599 xldir = opendir(XLogDir);
602 fprintf(stderr, _("%s: could not open directory \"%s\": %s\n"),
603 progname, XLogDir, strerror(errno));
608 while ((xlde = readdir(xldir)) != NULL)
610 if (strlen(xlde->d_name) == 24 &&
611 strspn(xlde->d_name, "0123456789ABCDEF") == 24)
613 snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
614 if (unlink(path) < 0)
616 fprintf(stderr, _("%s: could not delete file \"%s\": %s\n"),
617 progname, path, strerror(errno));
626 * This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4), but
627 * not in released version
629 if (GetLastError() == ERROR_NO_MORE_FILES)
635 fprintf(stderr, _("%s: could not read from directory \"%s\": %s\n"),
636 progname, XLogDir, strerror(errno));
644 * Write an empty XLOG file, containing only the checkpoint record
645 * already set up in ControlFile.
652 XLogLongPageHeader longpage;
655 char path[MAXPGPATH];
659 /* Use malloc() to ensure buffer is MAXALIGNED */
660 buffer = (char *) malloc(BLCKSZ);
661 page = (XLogPageHeader) buffer;
662 memset(buffer, 0, BLCKSZ);
664 /* Set up the XLOG page header */
665 page->xlp_magic = XLOG_PAGE_MAGIC;
666 page->xlp_info = XLP_LONG_HEADER;
667 page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
668 page->xlp_pageaddr.xlogid =
669 ControlFile.checkPointCopy.redo.xlogid;
670 page->xlp_pageaddr.xrecoff =
671 ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogLongPHD;
672 longpage = (XLogLongPageHeader) page;
673 longpage->xlp_sysid = ControlFile.system_identifier;
674 longpage->xlp_seg_size = XLogSegSize;
676 /* Insert the initial checkpoint record */
677 record = (XLogRecord *) ((char *) page + SizeOfXLogLongPHD);
678 record->xl_prev.xlogid = 0;
679 record->xl_prev.xrecoff = 0;
680 record->xl_xid = InvalidTransactionId;
681 record->xl_len = sizeof(CheckPoint);
682 record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
683 record->xl_rmid = RM_XLOG_ID;
684 memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
688 COMP_CRC64(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
689 COMP_CRC64(crc, (char *) record + sizeof(crc64),
690 SizeOfXLogRecord - sizeof(crc64));
692 record->xl_crc = crc;
694 /* Write the first page */
695 XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
696 newXlogId, newXlogSeg);
700 fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
704 fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
705 progname, path, strerror(errno));
710 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
712 /* if write didn't set errno, assume problem is no disk space */
715 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
716 progname, path, strerror(errno));
720 /* Fill the rest of the file with zeroes */
721 memset(buffer, 0, BLCKSZ);
722 for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
725 if (write(fd, buffer, BLCKSZ) != BLCKSZ)
729 fprintf(stderr, _("%s: could not write file \"%s\": %s\n"),
730 progname, path, strerror(errno));
737 fprintf(stderr, _("%s: fsync error: %s\n"), progname, strerror(errno));
748 printf(_("%s resets the PostgreSQL transaction log.\n\n"), progname);
749 printf(_("Usage:\n %s [OPTION]... DATADIR\n\n"), progname);
750 printf(_("Options:\n"));
751 printf(_(" -f force update to be done\n"));
752 printf(_(" -l TLI,FILE,SEG force minimum WAL starting location for new transaction log\n"));
753 printf(_(" -n no update, just show extracted control values (for testing)\n"));
754 printf(_(" -o OID set next OID\n"));
755 printf(_(" -x XID set next transaction ID\n"));
756 printf(_(" --help show this help, then exit\n"));
757 printf(_(" --version output version information, then exit\n"));
758 printf(_("\nReport bugs to <pgsql-bugs@postgresql.org>.\n"));