mirror of
https://git.postgresql.org/git/postgresql.git
synced 2024-08-22 10:13:24 +02:00
612 lines
15 KiB
C
612 lines
15 KiB
C
/*-------------------------------------------------------------------------
|
|
*
|
|
* 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) 1996-2001, 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 1.17 2002/01/11 21:27:13 tgl 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)
|
|
{
|
|
sprintf(path, "%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;
|
|
}
|