+++ /dev/null
-/*-------------------------------------------------------------------------
- *
- * pg_resetxlog.c
- * A utility to "zero out" the xlog when it's corrupt beyond recovery.
- * Can also rebuild pg_control if needed.
- *
- * The theory of operation is fairly simple:
- * 1. Read the existing pg_control (which will include the last
- * checkpoint record). If it is an old format then update to
- * current format.
- * 2. If pg_control is corrupt, attempt to intuit reasonable values,
- * by scanning the old xlog if necessary.
- * 3. Modify pg_control to reflect a "shutdown" state with a checkpoint
- * record at the start of xlog.
- * 4. Flush the existing xlog files and write a new segment with
- * just a checkpoint record in it. The new segment is positioned
- * just past the end of the old xlog, so that existing LSNs in
- * data pages will appear to be "in the past".
- * This is all pretty straightforward except for the intuition part of
- * step 2 ...
- *
- *
- * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- * $Header: /cvsroot/pgsql/contrib/pg_resetxlog/Attic/pg_resetxlog.c,v 1.19 2002/08/15 02:58:29 momjian Exp $
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include <errno.h>
-#include <unistd.h>
-#include <time.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <dirent.h>
-#ifdef USE_LOCALE
-#include <locale.h>
-#endif
-
-#include "access/xlog.h"
-#include "catalog/catversion.h"
-#include "catalog/pg_control.h"
-
-
-/******************** stuff copied from xlog.c ********************/
-
-/* Increment an xlogid/segment pair */
-#define NextLogSeg(logId, logSeg) \
- do { \
- if ((logSeg) >= XLogSegsPerFile-1) \
- { \
- (logId)++; \
- (logSeg) = 0; \
- } \
- else \
- (logSeg)++; \
- } while (0)
-
-#define XLogFileName(path, log, seg) \
- snprintf(path, MAXPGPATH, "%s/%08X%08X", \
- XLogDir, log, seg)
-
-/******************** end of stuff copied from xlog.c ********************/
-
-
-static char *DataDir; /* locations of important stuff */
-static char XLogDir[MAXPGPATH];
-static char ControlFilePath[MAXPGPATH];
-
-static ControlFileData ControlFile; /* pg_control values */
-static uint32 newXlogId,
- newXlogSeg; /* ID/Segment of new XLOG segment */
-static bool guessed = false; /* T if we had to guess at any values */
-
-
-/*
- * Try to read the existing pg_control file.
- *
- * This routine is also responsible for updating old pg_control versions
- * to the current format.
- */
-static bool
-ReadControlFile(void)
-{
- int fd;
- int len;
- char *buffer;
- crc64 crc;
-
- if ((fd = open(ControlFilePath, O_RDONLY)) < 0)
- {
- /*
- * If pg_control is not there at all, or we can't read it, the
- * odds are we've been handed a bad DataDir path, so give up. User
- * can do "touch pg_control" to force us to proceed.
- */
- perror("Failed to open $PGDATA/global/pg_control for reading");
- if (errno == ENOENT)
- fprintf(stderr, "If you're sure the PGDATA path is correct, do\n"
- " touch %s\n"
- "and try again.\n", ControlFilePath);
- exit(1);
- }
-
- /* Use malloc to ensure we have a maxaligned buffer */
- buffer = (char *) malloc(BLCKSZ);
-
- len = read(fd, buffer, BLCKSZ);
- if (len < 0)
- {
- perror("Failed to read $PGDATA/global/pg_control");
- exit(1);
- }
- close(fd);
-
- if (len >= sizeof(ControlFileData) &&
- ((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
- {
- /* Check the CRC. */
- INIT_CRC64(crc);
- COMP_CRC64(crc,
- buffer + sizeof(crc64),
- sizeof(ControlFileData) - sizeof(crc64));
- FIN_CRC64(crc);
-
- if (EQ_CRC64(crc, ((ControlFileData *) buffer)->crc))
- {
- /* Valid data... */
- memcpy(&ControlFile, buffer, sizeof(ControlFile));
- return true;
- }
-
- fprintf(stderr, "pg_control exists but has invalid CRC; proceed with caution.\n");
- /* We will use the data anyway, but treat it as guessed. */
- memcpy(&ControlFile, buffer, sizeof(ControlFile));
- guessed = true;
- return true;
- }
-
- /* Looks like it's a mess. */
- fprintf(stderr, "pg_control exists but is broken or unknown version; ignoring it.\n");
- return false;
-}
-
-
-/*
- * Guess at pg_control values when we can't read the old ones.
- */
-static void
-GuessControlValues(void)
-{
-#ifdef USE_LOCALE
- char *localeptr;
-#endif
-
- /*
- * Set up a completely default set of pg_control values.
- */
- guessed = true;
- memset(&ControlFile, 0, sizeof(ControlFile));
-
- ControlFile.pg_control_version = PG_CONTROL_VERSION;
- ControlFile.catalog_version_no = CATALOG_VERSION_NO;
-
- ControlFile.checkPointCopy.redo.xlogid = 0;
- ControlFile.checkPointCopy.redo.xrecoff = SizeOfXLogPHD;
- ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
- ControlFile.checkPointCopy.ThisStartUpID = 0;
- ControlFile.checkPointCopy.nextXid = (TransactionId) 514; /* XXX */
- ControlFile.checkPointCopy.nextOid = BootstrapObjectIdData;
- ControlFile.checkPointCopy.time = time(NULL);
-
- ControlFile.state = DB_SHUTDOWNED;
- ControlFile.time = time(NULL);
- ControlFile.logId = 0;
- ControlFile.logSeg = 1;
- ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
-
- ControlFile.blcksz = BLCKSZ;
- ControlFile.relseg_size = RELSEG_SIZE;
-#ifdef USE_LOCALE
- localeptr = setlocale(LC_COLLATE, "");
- if (!localeptr)
- {
- fprintf(stderr, "Invalid LC_COLLATE setting\n");
- exit(1);
- }
- StrNCpy(ControlFile.lc_collate, localeptr, LOCALE_NAME_BUFLEN);
- localeptr = setlocale(LC_CTYPE, "");
- if (!localeptr)
- {
- fprintf(stderr, "Invalid LC_CTYPE setting\n");
- exit(1);
- }
- StrNCpy(ControlFile.lc_ctype, localeptr, LOCALE_NAME_BUFLEN);
-#else
- strcpy(ControlFile.lc_collate, "C");
- strcpy(ControlFile.lc_ctype, "C");
-#endif
-
- /*
- * XXX eventually, should try to grovel through old XLOG to develop
- * more accurate values for startupid, nextXID, and nextOID.
- */
-}
-
-
-/*
- * Print the guessed pg_control values when we had to guess.
- *
- * NB: this display should be just those fields that will not be
- * reset by RewriteControlFile().
- */
-static void
-PrintControlValues(bool guessed)
-{
- printf("%spg_control values:\n\n"
- "pg_control version number: %u\n"
- "Catalog version number: %u\n"
- "Current log file id: %u\n"
- "Next log file segment: %u\n"
- "Latest checkpoint's StartUpID: %u\n"
- "Latest checkpoint's NextXID: %u\n"
- "Latest checkpoint's NextOID: %u\n"
- "Database block size: %u\n"
- "Blocks per segment of large relation: %u\n"
- "LC_COLLATE: %s\n"
- "LC_CTYPE: %s\n",
-
- (guessed ? "Guessed-at " : ""),
- ControlFile.pg_control_version,
- ControlFile.catalog_version_no,
- ControlFile.logId,
- ControlFile.logSeg,
- ControlFile.checkPointCopy.ThisStartUpID,
- ControlFile.checkPointCopy.nextXid,
- ControlFile.checkPointCopy.nextOid,
- ControlFile.blcksz,
- ControlFile.relseg_size,
- ControlFile.lc_collate,
- ControlFile.lc_ctype);
-}
-
-
-/*
- * Write out the new pg_control file.
- */
-static void
-RewriteControlFile(void)
-{
- int fd;
- char buffer[BLCKSZ]; /* need not be aligned */
-
- /*
- * Adjust fields as needed to force an empty XLOG starting at the next
- * available segment.
- */
- newXlogId = ControlFile.logId;
- newXlogSeg = ControlFile.logSeg;
- /* be sure we wrap around correctly at end of a logfile */
- NextLogSeg(newXlogId, newXlogSeg);
-
- ControlFile.checkPointCopy.redo.xlogid = newXlogId;
- ControlFile.checkPointCopy.redo.xrecoff =
- newXlogSeg * XLogSegSize + SizeOfXLogPHD;
- ControlFile.checkPointCopy.undo = ControlFile.checkPointCopy.redo;
- ControlFile.checkPointCopy.time = time(NULL);
-
- ControlFile.state = DB_SHUTDOWNED;
- ControlFile.time = time(NULL);
- ControlFile.logId = newXlogId;
- ControlFile.logSeg = newXlogSeg + 1;
- ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
- ControlFile.prevCheckPoint.xlogid = 0;
- ControlFile.prevCheckPoint.xrecoff = 0;
-
- /* Contents are protected with a CRC */
- INIT_CRC64(ControlFile.crc);
- COMP_CRC64(ControlFile.crc,
- (char *) &ControlFile + sizeof(crc64),
- sizeof(ControlFileData) - sizeof(crc64));
- FIN_CRC64(ControlFile.crc);
-
- /*
- * We write out BLCKSZ bytes into pg_control, zero-padding the excess
- * over sizeof(ControlFileData). This reduces the odds of
- * premature-EOF errors when reading pg_control. We'll still fail
- * when we check the contents of the file, but hopefully with a more
- * specific error than "couldn't read pg_control".
- */
- if (sizeof(ControlFileData) > BLCKSZ)
- {
- fprintf(stderr, "sizeof(ControlFileData) is too large ... fix xlog.c\n");
- exit(1);
- }
-
- memset(buffer, 0, BLCKSZ);
- memcpy(buffer, &ControlFile, sizeof(ControlFileData));
-
- unlink(ControlFilePath);
-
- fd = open(ControlFilePath, O_RDWR | O_CREAT | O_EXCL | PG_BINARY, S_IRUSR | S_IWUSR);
- if (fd < 0)
- {
- perror("RewriteControlFile failed to create pg_control file");
- exit(1);
- }
-
- errno = 0;
- if (write(fd, buffer, BLCKSZ) != BLCKSZ)
- {
- /* if write didn't set errno, assume problem is no disk space */
- if (errno == 0)
- errno = ENOSPC;
- perror("RewriteControlFile failed to write pg_control file");
- exit(1);
- }
-
- if (fsync(fd) != 0)
- {
- perror("fsync");
- exit(1);
- }
-
- close(fd);
-}
-
-
-/*
- * Remove existing XLOG files
- */
-static void
-KillExistingXLOG(void)
-{
- DIR *xldir;
- struct dirent *xlde;
- char path[MAXPGPATH];
-
- xldir = opendir(XLogDir);
- if (xldir == NULL)
- {
- perror("KillExistingXLOG: cannot open $PGDATA/pg_xlog directory");
- exit(1);
- }
-
- errno = 0;
- while ((xlde = readdir(xldir)) != NULL)
- {
- if (strlen(xlde->d_name) == 16 &&
- strspn(xlde->d_name, "0123456789ABCDEF") == 16)
- {
- snprintf(path, MAXPGPATH, "%s/%s", XLogDir, xlde->d_name);
- if (unlink(path) < 0)
- {
- perror(path);
- exit(1);
- }
- }
- errno = 0;
- }
- if (errno)
- {
- perror("KillExistingXLOG: cannot read $PGDATA/pg_xlog directory");
- exit(1);
- }
- closedir(xldir);
-}
-
-
-/*
- * Write an empty XLOG file, containing only the checkpoint record
- * already set up in ControlFile.
- */
-static void
-WriteEmptyXLOG(void)
-{
- char *buffer;
- XLogPageHeader page;
- XLogRecord *record;
- crc64 crc;
- char path[MAXPGPATH];
- int fd;
- int nbytes;
-
- /* Use malloc() to ensure buffer is MAXALIGNED */
- buffer = (char *) malloc(BLCKSZ);
- page = (XLogPageHeader) buffer;
-
- /* Set up the first page with initial record */
- memset(buffer, 0, BLCKSZ);
- page->xlp_magic = XLOG_PAGE_MAGIC;
- page->xlp_info = 0;
- page->xlp_sui = ControlFile.checkPointCopy.ThisStartUpID;
- page->xlp_pageaddr.xlogid =
- ControlFile.checkPointCopy.redo.xlogid;
- page->xlp_pageaddr.xrecoff =
- ControlFile.checkPointCopy.redo.xrecoff - SizeOfXLogPHD;
- record = (XLogRecord *) ((char *) page + SizeOfXLogPHD);
- record->xl_prev.xlogid = 0;
- record->xl_prev.xrecoff = 0;
- record->xl_xact_prev = record->xl_prev;
- record->xl_xid = InvalidTransactionId;
- record->xl_len = sizeof(CheckPoint);
- record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
- record->xl_rmid = RM_XLOG_ID;
- memcpy(XLogRecGetData(record), &ControlFile.checkPointCopy,
- sizeof(CheckPoint));
-
- INIT_CRC64(crc);
- COMP_CRC64(crc, &ControlFile.checkPointCopy, sizeof(CheckPoint));
- COMP_CRC64(crc, (char *) record + sizeof(crc64),
- SizeOfXLogRecord - sizeof(crc64));
- FIN_CRC64(crc);
- record->xl_crc = crc;
-
- /* Write the first page */
- XLogFileName(path, newXlogId, newXlogSeg);
-
- unlink(path);
-
- fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
- S_IRUSR | S_IWUSR);
- if (fd < 0)
- {
- perror(path);
- exit(1);
- }
-
- errno = 0;
- if (write(fd, buffer, BLCKSZ) != BLCKSZ)
- {
- /* if write didn't set errno, assume problem is no disk space */
- if (errno == 0)
- errno = ENOSPC;
- perror("WriteEmptyXLOG: failed to write xlog file");
- exit(1);
- }
-
- /* Fill the rest of the file with zeroes */
- memset(buffer, 0, BLCKSZ);
- for (nbytes = BLCKSZ; nbytes < XLogSegSize; nbytes += BLCKSZ)
- {
- errno = 0;
- if (write(fd, buffer, BLCKSZ) != BLCKSZ)
- {
- if (errno == 0)
- errno = ENOSPC;
- perror("WriteEmptyXLOG: failed to write xlog file");
- exit(1);
- }
- }
-
- if (fsync(fd) != 0)
- {
- perror("fsync");
- exit(1);
- }
-
- close(fd);
-}
-
-
-static void
-usage(void)
-{
- fprintf(stderr, "Usage: pg_resetxlog [-f] [-n] [-x xid] [ -l fileid seg ] PGDataDirectory\n"
- " -f\t\tforce update to be done\n"
- " -n\t\tno update, just show extracted pg_control values (for testing)\n"
- " -x xid\tset next transaction ID\n"
- " -l fileid seg\tforce minimum WAL starting location for new xlog\n");
- exit(1);
-}
-
-
-int
-main(int argc, char **argv)
-{
- int argn;
- bool force = false;
- bool noupdate = false;
- TransactionId set_xid = 0;
- uint32 minXlogId = 0,
- minXlogSeg = 0;
- int fd;
- char path[MAXPGPATH];
-
- for (argn = 1; argn < argc; argn++)
- {
- if (argv[argn][0] != '-')
- break; /* end of switches */
- if (strcmp(argv[argn], "-f") == 0)
- force = true;
- else if (strcmp(argv[argn], "-n") == 0)
- noupdate = true;
- else if (strcmp(argv[argn], "-x") == 0)
- {
- argn++;
- if (argn == argc)
- usage();
- set_xid = strtoul(argv[argn], NULL, 0);
- if (set_xid == 0)
- {
- fprintf(stderr, "XID can not be 0.\n");
- exit(1);
- }
- }
- else if (strcmp(argv[argn], "-l") == 0)
- {
- argn++;
- if (argn == argc)
- usage();
- minXlogId = strtoul(argv[argn], NULL, 0);
- argn++;
- if (argn == argc)
- usage();
- minXlogSeg = strtoul(argv[argn], NULL, 0);
- }
- else
- usage();
- }
-
- if (argn != argc - 1) /* one required non-switch argument */
- usage();
-
- DataDir = argv[argn++];
-
- snprintf(XLogDir, MAXPGPATH, "%s/pg_xlog", DataDir);
-
- snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);
-
- /*
- * Check for a postmaster lock file --- if there is one, refuse to
- * proceed, on grounds we might be interfering with a live
- * installation.
- */
- snprintf(path, MAXPGPATH, "%s/postmaster.pid", DataDir);
-
- if ((fd = open(path, O_RDONLY)) < 0)
- {
- if (errno != ENOENT)
- {
- perror("Failed to open $PGDATA/postmaster.pid for reading");
- exit(1);
- }
- }
- else
- {
- fprintf(stderr, "Lock file '%s' exists --- is a postmaster running?\n"
- "If not, delete the lock file and try again.\n",
- path);
- exit(1);
- }
-
- /*
- * Attempt to read the existing pg_control file
- */
- if (!ReadControlFile())
- GuessControlValues();
-
- /*
- * If we had to guess anything, and -f was not given, just print the
- * guessed values and exit. Also print if -n is given.
- */
- if ((guessed && !force) || noupdate)
- {
- PrintControlValues(guessed);
- if (!noupdate)
- {
- printf("\nIf these values seem acceptable, use -f to force reset.\n");
- exit(1);
- }
- else
- exit(0);
- }
-
- /*
- * Don't reset from a dirty pg_control without -f, either.
- */
- if (ControlFile.state != DB_SHUTDOWNED && !force)
- {
- printf("The database was not shut down cleanly.\n"
- "Resetting the xlog may cause data to be lost!\n"
- "If you want to proceed anyway, use -f to force reset.\n");
- exit(1);
- }
-
- /*
- * Else, do the dirty deed.
- *
- * First adjust fields if required by switches.
- */
- if (set_xid != 0)
- ControlFile.checkPointCopy.nextXid = set_xid;
-
- if (minXlogId > ControlFile.logId ||
- (minXlogId == ControlFile.logId && minXlogSeg > ControlFile.logSeg))
- {
- ControlFile.logId = minXlogId;
- ControlFile.logSeg = minXlogSeg;
- }
-
- RewriteControlFile();
- KillExistingXLOG();
- WriteEmptyXLOG();
-
- printf("XLOG reset.\n");
- return 0;
-}
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