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postgresql/src/bin/pg_resetwal/pg_resetwal.c

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/*-------------------------------------------------------------------------
*
* pg_resetwal.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) 1996-2019, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* src/bin/pg_resetwal/pg_resetwal.c
*
*-------------------------------------------------------------------------
*/
/*
* We have to use postgres.h not postgres_fe.h here, because there's so much
* backend-only stuff in the XLOG include files we need. But we need a
* frontend-ish environment otherwise. Hence this ugly hack.
*/
#define FRONTEND 1
#include "postgres.h"
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include "access/heaptoast.h"
#include "access/multixact.h"
#include "access/transam.h"
#include "access/xlog.h"
#include "access/xlog_internal.h"
#include "common/controldata_utils.h"
#include "common/fe_memutils.h"
#include "common/file_perm.h"
#include "common/logging.h"
#include "common/restricted_token.h"
#include "common/string.h"
#include "getopt_long.h"
#include "pg_getopt.h"
#include "storage/large_object.h"
static ControlFileData ControlFile; /* pg_control values */
static XLogSegNo newXlogSegNo; /* new XLOG segment # */
static bool guessed = false; /* T if we had to guess at any values */
static const char *progname;
static uint32 set_xid_epoch = (uint32) -1;
static TransactionId set_xid = 0;
static TransactionId set_oldest_commit_ts_xid = 0;
static TransactionId set_newest_commit_ts_xid = 0;
static Oid set_oid = 0;
static MultiXactId set_mxid = 0;
static MultiXactOffset set_mxoff = (MultiXactOffset) -1;
static uint32 minXlogTli = 0;
static XLogSegNo minXlogSegNo = 0;
static int WalSegSz;
static int set_wal_segsize;
static void CheckDataVersion(void);
static bool ReadControlFile(void);
static void GuessControlValues(void);
static void PrintControlValues(bool guessed);
static void PrintNewControlValues(void);
static void RewriteControlFile(void);
static void FindEndOfXLOG(void);
static void KillExistingXLOG(void);
static void KillExistingArchiveStatus(void);
static void WriteEmptyXLOG(void);
static void usage(void);
int
main(int argc, char *argv[])
{
static struct option long_options[] = {
{"commit-timestamp-ids", required_argument, NULL, 'c'},
{"pgdata", required_argument, NULL, 'D'},
{"epoch", required_argument, NULL, 'e'},
{"force", no_argument, NULL, 'f'},
{"next-wal-file", required_argument, NULL, 'l'},
{"multixact-ids", required_argument, NULL, 'm'},
{"dry-run", no_argument, NULL, 'n'},
{"next-oid", required_argument, NULL, 'o'},
{"multixact-offset", required_argument, NULL, 'O'},
{"next-transaction-id", required_argument, NULL, 'x'},
{"wal-segsize", required_argument, NULL, 1},
{NULL, 0, NULL, 0}
};
int c;
bool force = false;
bool noupdate = false;
MultiXactId set_oldestmxid = 0;
char *endptr;
char *endptr2;
char *DataDir = NULL;
char *log_fname = NULL;
int fd;
pg_logging_init(argv[0]);
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_resetwal"));
progname = get_progname(argv[0]);
if (argc > 1)
{
if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
{
usage();
exit(0);
}
if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
{
puts("pg_resetwal (PostgreSQL) " PG_VERSION);
exit(0);
}
}
while ((c = getopt_long(argc, argv, "c:D:e:fl:m:no:O:x:", long_options, NULL)) != -1)
{
switch (c)
{
case 'D':
DataDir = optarg;
break;
case 'f':
force = true;
break;
case 'n':
noupdate = true;
break;
case 'e':
set_xid_epoch = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
/*------
translator: the second %s is a command line argument (-e, etc) */
pg_log_error("invalid argument for option %s", "-e");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_xid_epoch == -1)
{
pg_log_error("transaction ID epoch (-e) must not be -1");
exit(1);
}
break;
case 'x':
set_xid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
pg_log_error("invalid argument for option %s", "-x");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_xid == 0)
{
pg_log_error("transaction ID (-x) must not be 0");
exit(1);
}
break;
case 'c':
set_oldest_commit_ts_xid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != ',')
{
pg_log_error("invalid argument for option %s", "-c");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_newest_commit_ts_xid = strtoul(endptr + 1, &endptr2, 0);
if (endptr2 == endptr + 1 || *endptr2 != '\0')
{
pg_log_error("invalid argument for option %s", "-c");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_oldest_commit_ts_xid < 2 &&
set_oldest_commit_ts_xid != 0)
{
pg_log_error("transaction ID (-c) must be either 0 or greater than or equal to 2");
exit(1);
}
if (set_newest_commit_ts_xid < 2 &&
set_newest_commit_ts_xid != 0)
{
pg_log_error("transaction ID (-c) must be either 0 or greater than or equal to 2");
exit(1);
}
break;
case 'o':
set_oid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
pg_log_error("invalid argument for option %s", "-o");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_oid == 0)
{
pg_log_error("OID (-o) must not be 0");
exit(1);
}
break;
case 'm':
set_mxid = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != ',')
{
pg_log_error("invalid argument for option %s", "-m");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
if (endptr2 == endptr + 1 || *endptr2 != '\0')
{
pg_log_error("invalid argument for option %s", "-m");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_mxid == 0)
{
pg_log_error("multitransaction ID (-m) must not be 0");
exit(1);
}
/*
* XXX It'd be nice to have more sanity checks here, e.g. so
* that oldest is not wrapped around w.r.t. nextMulti.
*/
if (set_oldestmxid == 0)
{
pg_log_error("oldest multitransaction ID (-m) must not be 0");
exit(1);
}
break;
case 'O':
set_mxoff = strtoul(optarg, &endptr, 0);
if (endptr == optarg || *endptr != '\0')
{
pg_log_error("invalid argument for option %s", "-O");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
if (set_mxoff == -1)
{
pg_log_error("multitransaction offset (-O) must not be -1");
exit(1);
}
break;
case 'l':
if (strspn(optarg, "01234567890ABCDEFabcdef") != XLOG_FNAME_LEN)
{
pg_log_error("invalid argument for option %s", "-l");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
/*
* XLogFromFileName requires wal segment size which is not yet
* set. Hence wal details are set later on.
*/
log_fname = pg_strdup(optarg);
break;
case 1:
set_wal_segsize = strtol(optarg, &endptr, 10) * 1024 * 1024;
if (endptr == optarg || *endptr != '\0')
{
pg_log_error("argument of --wal-segsize must be a number");
exit(1);
}
if (!IsValidWalSegSize(set_wal_segsize))
{
pg_log_error("argument of --wal-segsize must be a power of 2 between 1 and 1024");
exit(1);
}
break;
default:
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
}
if (DataDir == NULL && optind < argc)
DataDir = argv[optind++];
/* Complain if any arguments remain */
if (optind < argc)
{
pg_log_error("too many command-line arguments (first is \"%s\")",
argv[optind]);
fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
progname);
exit(1);
}
if (DataDir == NULL)
{
pg_log_error("no data directory specified");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(1);
}
/*
* Don't allow pg_resetwal to be run as root, to avoid overwriting the
* ownership of files in the data directory. We need only check for root
* -- any other user won't have sufficient permissions to modify files in
* the data directory.
*/
#ifndef WIN32
if (geteuid() == 0)
{
pg_log_error("cannot be executed by \"root\"");
pg_log_info("You must run %s as the PostgreSQL superuser.",
progname);
exit(1);
}
#endif
get_restricted_token();
/* Set mask based on PGDATA permissions */
if (!GetDataDirectoryCreatePerm(DataDir))
{
pg_log_error("could not read permissions of directory \"%s\": %m",
DataDir);
exit(1);
}
umask(pg_mode_mask);
if (chdir(DataDir) < 0)
{
pg_log_error("could not change directory to \"%s\": %m",
DataDir);
exit(1);
}
/* Check that data directory matches our server version */
CheckDataVersion();
/*
* Check for a postmaster lock file --- if there is one, refuse to
* proceed, on grounds we might be interfering with a live installation.
*/
if ((fd = open("postmaster.pid", O_RDONLY, 0)) < 0)
{
if (errno != ENOENT)
{
pg_log_error("could not open file \"%s\" for reading: %m",
"postmaster.pid");
exit(1);
}
}
else
{
pg_log_error("lock file \"%s\" exists", "postmaster.pid");
pg_log_info("Is a server running? If not, delete the lock file and try again.");
exit(1);
}
/*
* Attempt to read the existing pg_control file
*/
if (!ReadControlFile())
GuessControlValues();
/*
* If no new WAL segment size was specified, use the control file value.
*/
if (set_wal_segsize != 0)
WalSegSz = set_wal_segsize;
else
WalSegSz = ControlFile.xlog_seg_size;
if (log_fname != NULL)
XLogFromFileName(log_fname, &minXlogTli, &minXlogSegNo, WalSegSz);
/*
* Also look at existing segment files to set up newXlogSegNo
*/
FindEndOfXLOG();
/*
* If we're not going to proceed with the reset, print the current control
* file parameters.
*/
if ((guessed && !force) || noupdate)
PrintControlValues(guessed);
/*
* Adjust fields if required by switches. (Do this now so that printout,
* if any, includes these values.)
*/
if (set_xid_epoch != -1)
ControlFile.checkPointCopy.nextFullXid =
FullTransactionIdFromEpochAndXid(set_xid_epoch,
XidFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid));
if (set_xid != 0)
{
ControlFile.checkPointCopy.nextFullXid =
FullTransactionIdFromEpochAndXid(EpochFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid),
set_xid);
/*
* For the moment, just set oldestXid to a value that will force
* immediate autovacuum-for-wraparound. It's not clear whether adding
* user control of this is useful, so let's just do something that's
* reasonably safe. The magic constant here corresponds to the
* maximum allowed value of autovacuum_freeze_max_age.
*/
ControlFile.checkPointCopy.oldestXid = set_xid - 2000000000;
if (ControlFile.checkPointCopy.oldestXid < FirstNormalTransactionId)
ControlFile.checkPointCopy.oldestXid += FirstNormalTransactionId;
ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
}
if (set_oldest_commit_ts_xid != 0)
ControlFile.checkPointCopy.oldestCommitTsXid = set_oldest_commit_ts_xid;
if (set_newest_commit_ts_xid != 0)
ControlFile.checkPointCopy.newestCommitTsXid = set_newest_commit_ts_xid;
if (set_oid != 0)
ControlFile.checkPointCopy.nextOid = set_oid;
if (set_mxid != 0)
{
ControlFile.checkPointCopy.nextMulti = set_mxid;
ControlFile.checkPointCopy.oldestMulti = set_oldestmxid;
if (ControlFile.checkPointCopy.oldestMulti < FirstMultiXactId)
ControlFile.checkPointCopy.oldestMulti += FirstMultiXactId;
ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
}
if (set_mxoff != -1)
ControlFile.checkPointCopy.nextMultiOffset = set_mxoff;
if (minXlogTli > ControlFile.checkPointCopy.ThisTimeLineID)
{
ControlFile.checkPointCopy.ThisTimeLineID = minXlogTli;
ControlFile.checkPointCopy.PrevTimeLineID = minXlogTli;
}
if (set_wal_segsize != 0)
ControlFile.xlog_seg_size = WalSegSz;
if (minXlogSegNo > newXlogSegNo)
newXlogSegNo = minXlogSegNo;
/*
* 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)
{
PrintNewControlValues();
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 server was not shut down cleanly.\n"
"Resetting the write-ahead log might 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.
*/
RewriteControlFile();
KillExistingXLOG();
KillExistingArchiveStatus();
WriteEmptyXLOG();
printf(_("Write-ahead log reset\n"));
return 0;
}
/*
* Look at the version string stored in PG_VERSION and decide if this utility
* can be run safely or not.
*
* We don't want to inject pg_control and WAL files that are for a different
* major version; that can't do anything good. Note that we don't treat
* mismatching version info in pg_control as a reason to bail out, because
* recovering from a corrupted pg_control is one of the main reasons for this
* program to exist at all. However, PG_VERSION is unlikely to get corrupted,
* and if it were it would be easy to fix by hand. So let's make this check
* to prevent simple user errors.
*/
static void
CheckDataVersion(void)
{
const char *ver_file = "PG_VERSION";
FILE *ver_fd;
char rawline[64];
if ((ver_fd = fopen(ver_file, "r")) == NULL)
{
pg_log_error("could not open file \"%s\" for reading: %m",
ver_file);
exit(1);
}
/* version number has to be the first line read */
if (!fgets(rawline, sizeof(rawline), ver_fd))
{
if (!ferror(ver_fd))
pg_log_error("unexpected empty file \"%s\"", ver_file);
else
pg_log_error("could not read file \"%s\": %m", ver_file);
exit(1);
}
/* strip trailing newline and carriage return */
(void) pg_strip_crlf(rawline);
if (strcmp(rawline, PG_MAJORVERSION) != 0)
{
pg_log_error("data directory is of wrong version");
pg_log_info("File \"%s\" contains \"%s\", which is not compatible with this program's version \"%s\".",
ver_file, rawline, PG_MAJORVERSION);
exit(1);
}
fclose(ver_fd);
}
/*
* Try to read the existing pg_control file.
*
* This routine is also responsible for updating old pg_control versions
* to the current format. (Currently we don't do anything of the sort.)
*/
static bool
ReadControlFile(void)
{
int fd;
int len;
char *buffer;
pg_crc32c crc;
if ((fd = open(XLOG_CONTROL_FILE, O_RDONLY | PG_BINARY, 0)) < 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.
*/
pg_log_error("could not open file \"%s\" for reading: %m",
XLOG_CONTROL_FILE);
if (errno == ENOENT)
pg_log_info("If you are sure the data directory path is correct, execute\n"
" touch %s\n"
"and try again.",
XLOG_CONTROL_FILE);
exit(1);
}
/* Use malloc to ensure we have a maxaligned buffer */
buffer = (char *) pg_malloc(PG_CONTROL_FILE_SIZE);
len = read(fd, buffer, PG_CONTROL_FILE_SIZE);
if (len < 0)
{
pg_log_error("could not read file \"%s\": %m", XLOG_CONTROL_FILE);
exit(1);
}
close(fd);
if (len >= sizeof(ControlFileData) &&
((ControlFileData *) buffer)->pg_control_version == PG_CONTROL_VERSION)
{
/* Check the CRC. */
INIT_CRC32C(crc);
COMP_CRC32C(crc,
buffer,
offsetof(ControlFileData, crc));
FIN_CRC32C(crc);
if (!EQ_CRC32C(crc, ((ControlFileData *) buffer)->crc))
{
/* We will use the data but treat it as guessed. */
pg_log_warning("pg_control exists but has invalid CRC; proceed with caution");
guessed = true;
}
memcpy(&ControlFile, buffer, sizeof(ControlFile));
/* return false if WAL segment size is not valid */
if (!IsValidWalSegSize(ControlFile.xlog_seg_size))
{
pg_log_warning(ngettext("pg_control specifies invalid WAL segment size (%d byte); proceed with caution",
"pg_control specifies invalid WAL segment size (%d bytes); proceed with caution",
ControlFile.xlog_seg_size),
ControlFile.xlog_seg_size);
return false;
}
return true;
}
/* Looks like it's a mess. */
pg_log_warning("pg_control exists but is broken or wrong version; ignoring it");
return false;
}
/*
* Guess at pg_control values when we can't read the old ones.
*/
static void
GuessControlValues(void)
{
uint64 sysidentifier;
struct timeval tv;
/*
* 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;
/*
* Create a new unique installation identifier, since we can no longer use
* any old XLOG records. See notes in xlog.c about the algorithm.
*/
gettimeofday(&tv, NULL);
sysidentifier = ((uint64) tv.tv_sec) << 32;
sysidentifier |= ((uint64) tv.tv_usec) << 12;
sysidentifier |= getpid() & 0xFFF;
ControlFile.system_identifier = sysidentifier;
ControlFile.checkPointCopy.redo = SizeOfXLogLongPHD;
ControlFile.checkPointCopy.ThisTimeLineID = 1;
ControlFile.checkPointCopy.PrevTimeLineID = 1;
ControlFile.checkPointCopy.fullPageWrites = false;
ControlFile.checkPointCopy.nextFullXid =
FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
ControlFile.checkPointCopy.nextOid = FirstBootstrapObjectId;
ControlFile.checkPointCopy.nextMulti = FirstMultiXactId;
ControlFile.checkPointCopy.nextMultiOffset = 0;
ControlFile.checkPointCopy.oldestXid = FirstNormalTransactionId;
ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
ControlFile.checkPointCopy.oldestMulti = FirstMultiXactId;
ControlFile.checkPointCopy.oldestMultiDB = InvalidOid;
ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
ControlFile.checkPointCopy.oldestActiveXid = InvalidTransactionId;
ControlFile.state = DB_SHUTDOWNED;
ControlFile.time = (pg_time_t) time(NULL);
ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
ControlFile.unloggedLSN = 1;
/* minRecoveryPoint, backupStartPoint and backupEndPoint can be left zero */
ControlFile.wal_level = WAL_LEVEL_MINIMAL;
ControlFile.wal_log_hints = false;
ControlFile.track_commit_timestamp = false;
ControlFile.MaxConnections = 100;
ControlFile.max_wal_senders = 10;
ControlFile.max_worker_processes = 8;
ControlFile.max_prepared_xacts = 0;
ControlFile.max_locks_per_xact = 64;
ControlFile.maxAlign = MAXIMUM_ALIGNOF;
ControlFile.floatFormat = FLOATFORMAT_VALUE;
ControlFile.blcksz = BLCKSZ;
ControlFile.relseg_size = RELSEG_SIZE;
ControlFile.xlog_blcksz = XLOG_BLCKSZ;
ControlFile.xlog_seg_size = DEFAULT_XLOG_SEG_SIZE;
ControlFile.nameDataLen = NAMEDATALEN;
ControlFile.indexMaxKeys = INDEX_MAX_KEYS;
ControlFile.toast_max_chunk_size = TOAST_MAX_CHUNK_SIZE;
ControlFile.loblksize = LOBLKSIZE;
ControlFile.float4ByVal = FLOAT4PASSBYVAL;
ControlFile.float8ByVal = FLOAT8PASSBYVAL;
/*
* XXX eventually, should try to grovel through old XLOG to develop more
* accurate values for TimeLineID, nextXID, etc.
*/
}
/*
* 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)
{
if (guessed)
printf(_("Guessed pg_control values:\n\n"));
else
printf(_("Current pg_control values:\n\n"));
printf(_("pg_control version number: %u\n"),
ControlFile.pg_control_version);
printf(_("Catalog version number: %u\n"),
ControlFile.catalog_version_no);
printf(_("Database system identifier: %llu\n"),
(unsigned long long) ControlFile.system_identifier);
printf(_("Latest checkpoint's TimeLineID: %u\n"),
ControlFile.checkPointCopy.ThisTimeLineID);
printf(_("Latest checkpoint's full_page_writes: %s\n"),
ControlFile.checkPointCopy.fullPageWrites ? _("on") : _("off"));
printf(_("Latest checkpoint's NextXID: %u:%u\n"),
EpochFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid),
XidFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid));
printf(_("Latest checkpoint's NextOID: %u\n"),
ControlFile.checkPointCopy.nextOid);
printf(_("Latest checkpoint's NextMultiXactId: %u\n"),
ControlFile.checkPointCopy.nextMulti);
printf(_("Latest checkpoint's NextMultiOffset: %u\n"),
ControlFile.checkPointCopy.nextMultiOffset);
printf(_("Latest checkpoint's oldestXID: %u\n"),
ControlFile.checkPointCopy.oldestXid);
printf(_("Latest checkpoint's oldestXID's DB: %u\n"),
ControlFile.checkPointCopy.oldestXidDB);
printf(_("Latest checkpoint's oldestActiveXID: %u\n"),
ControlFile.checkPointCopy.oldestActiveXid);
printf(_("Latest checkpoint's oldestMultiXid: %u\n"),
ControlFile.checkPointCopy.oldestMulti);
printf(_("Latest checkpoint's oldestMulti's DB: %u\n"),
ControlFile.checkPointCopy.oldestMultiDB);
printf(_("Latest checkpoint's oldestCommitTsXid:%u\n"),
ControlFile.checkPointCopy.oldestCommitTsXid);
printf(_("Latest checkpoint's newestCommitTsXid:%u\n"),
ControlFile.checkPointCopy.newestCommitTsXid);
printf(_("Maximum data alignment: %u\n"),
ControlFile.maxAlign);
/* we don't print floatFormat since can't say much useful about it */
printf(_("Database block size: %u\n"),
ControlFile.blcksz);
printf(_("Blocks per segment of large relation: %u\n"),
ControlFile.relseg_size);
printf(_("WAL block size: %u\n"),
ControlFile.xlog_blcksz);
printf(_("Bytes per WAL segment: %u\n"),
ControlFile.xlog_seg_size);
printf(_("Maximum length of identifiers: %u\n"),
ControlFile.nameDataLen);
printf(_("Maximum columns in an index: %u\n"),
ControlFile.indexMaxKeys);
printf(_("Maximum size of a TOAST chunk: %u\n"),
ControlFile.toast_max_chunk_size);
printf(_("Size of a large-object chunk: %u\n"),
ControlFile.loblksize);
/* This is no longer configurable, but users may still expect to see it: */
printf(_("Date/time type storage: %s\n"),
_("64-bit integers"));
printf(_("Float4 argument passing: %s\n"),
(ControlFile.float4ByVal ? _("by value") : _("by reference")));
printf(_("Float8 argument passing: %s\n"),
(ControlFile.float8ByVal ? _("by value") : _("by reference")));
printf(_("Data page checksum version: %u\n"),
ControlFile.data_checksum_version);
}
/*
* Print the values to be changed.
*/
static void
PrintNewControlValues(void)
{
char fname[MAXFNAMELEN];
/* This will be always printed in order to keep format same. */
printf(_("\n\nValues to be changed:\n\n"));
XLogFileName(fname, ControlFile.checkPointCopy.ThisTimeLineID,
newXlogSegNo, WalSegSz);
printf(_("First log segment after reset: %s\n"), fname);
if (set_mxid != 0)
{
printf(_("NextMultiXactId: %u\n"),
ControlFile.checkPointCopy.nextMulti);
printf(_("OldestMultiXid: %u\n"),
ControlFile.checkPointCopy.oldestMulti);
printf(_("OldestMulti's DB: %u\n"),
ControlFile.checkPointCopy.oldestMultiDB);
}
if (set_mxoff != -1)
{
printf(_("NextMultiOffset: %u\n"),
ControlFile.checkPointCopy.nextMultiOffset);
}
if (set_oid != 0)
{
printf(_("NextOID: %u\n"),
ControlFile.checkPointCopy.nextOid);
}
if (set_xid != 0)
{
printf(_("NextXID: %u\n"),
XidFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid));
printf(_("OldestXID: %u\n"),
ControlFile.checkPointCopy.oldestXid);
printf(_("OldestXID's DB: %u\n"),
ControlFile.checkPointCopy.oldestXidDB);
}
if (set_xid_epoch != -1)
{
printf(_("NextXID epoch: %u\n"),
EpochFromFullTransactionId(ControlFile.checkPointCopy.nextFullXid));
}
if (set_oldest_commit_ts_xid != 0)
{
printf(_("oldestCommitTsXid: %u\n"),
ControlFile.checkPointCopy.oldestCommitTsXid);
}
if (set_newest_commit_ts_xid != 0)
{
printf(_("newestCommitTsXid: %u\n"),
ControlFile.checkPointCopy.newestCommitTsXid);
}
if (set_wal_segsize != 0)
{
printf(_("Bytes per WAL segment: %u\n"),
ControlFile.xlog_seg_size);
}
}
/*
* Write out the new pg_control file.
*/
static void
RewriteControlFile(void)
{
/*
* Adjust fields as needed to force an empty XLOG starting at
* newXlogSegNo.
*/
XLogSegNoOffsetToRecPtr(newXlogSegNo, SizeOfXLogLongPHD, WalSegSz,
ControlFile.checkPointCopy.redo);
ControlFile.checkPointCopy.time = (pg_time_t) time(NULL);
ControlFile.state = DB_SHUTDOWNED;
ControlFile.time = (pg_time_t) time(NULL);
ControlFile.checkPoint = ControlFile.checkPointCopy.redo;
ControlFile.minRecoveryPoint = 0;
ControlFile.minRecoveryPointTLI = 0;
ControlFile.backupStartPoint = 0;
ControlFile.backupEndPoint = 0;
ControlFile.backupEndRequired = false;
/*
* Force the defaults for max_* settings. The values don't really matter
* as long as wal_level='minimal'; the postmaster will reset these fields
* anyway at startup.
*/
ControlFile.wal_level = WAL_LEVEL_MINIMAL;
ControlFile.wal_log_hints = false;
ControlFile.track_commit_timestamp = false;
ControlFile.MaxConnections = 100;
ControlFile.max_wal_senders = 10;
ControlFile.max_worker_processes = 8;
ControlFile.max_prepared_xacts = 0;
ControlFile.max_locks_per_xact = 64;
/* The control file gets flushed here. */
update_controlfile(".", &ControlFile, true);
}
/*
* Scan existing XLOG files and determine the highest existing WAL address
*
* On entry, ControlFile.checkPointCopy.redo and ControlFile.xlog_seg_size
* are assumed valid (note that we allow the old xlog seg size to differ
* from what we're using). On exit, newXlogSegNo is set to suitable
* value for the beginning of replacement WAL (in our seg size).
*/
static void
FindEndOfXLOG(void)
{
DIR *xldir;
struct dirent *xlde;
uint64 segs_per_xlogid;
uint64 xlogbytepos;
/*
* Initialize the max() computation using the last checkpoint address from
* old pg_control. Note that for the moment we are working with segment
* numbering according to the old xlog seg size.
*/
segs_per_xlogid = (UINT64CONST(0x0000000100000000) / ControlFile.xlog_seg_size);
newXlogSegNo = ControlFile.checkPointCopy.redo / ControlFile.xlog_seg_size;
/*
* Scan the pg_wal directory to find existing WAL segment files. We assume
* any present have been used; in most scenarios this should be
* conservative, because of xlog.c's attempts to pre-create files.
*/
xldir = opendir(XLOGDIR);
if (xldir == NULL)
{
pg_log_error("could not open directory \"%s\": %m", XLOGDIR);
exit(1);
}
while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
if (IsXLogFileName(xlde->d_name) ||
IsPartialXLogFileName(xlde->d_name))
{
unsigned int tli,
log,
seg;
XLogSegNo segno;
/*
* Note: We don't use XLogFromFileName here, because we want to
* use the segment size from the control file, not the size the
* pg_resetwal binary was compiled with
*/
sscanf(xlde->d_name, "%08X%08X%08X", &tli, &log, &seg);
segno = ((uint64) log) * segs_per_xlogid + seg;
/*
* Note: we take the max of all files found, regardless of their
* timelines. Another possibility would be to ignore files of
* timelines other than the target TLI, but this seems safer.
* Better too large a result than too small...
*/
if (segno > newXlogSegNo)
newXlogSegNo = segno;
}
}
if (errno)
{
pg_log_error("could not read directory \"%s\": %m", XLOGDIR);
exit(1);
}
if (closedir(xldir))
{
pg_log_error("could not close directory \"%s\": %m", XLOGDIR);
exit(1);
}
/*
* Finally, convert to new xlog seg size, and advance by one to ensure we
* are in virgin territory.
*/
xlogbytepos = newXlogSegNo * ControlFile.xlog_seg_size;
newXlogSegNo = (xlogbytepos + ControlFile.xlog_seg_size - 1) / WalSegSz;
newXlogSegNo++;
}
/*
* Remove existing XLOG files
*/
static void
KillExistingXLOG(void)
{
DIR *xldir;
struct dirent *xlde;
char path[MAXPGPATH + sizeof(XLOGDIR)];
xldir = opendir(XLOGDIR);
if (xldir == NULL)
{
pg_log_error("could not open directory \"%s\": %m", XLOGDIR);
exit(1);
}
while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
if (IsXLogFileName(xlde->d_name) ||
IsPartialXLogFileName(xlde->d_name))
{
snprintf(path, sizeof(path), "%s/%s", XLOGDIR, xlde->d_name);
if (unlink(path) < 0)
{
pg_log_error("could not delete file \"%s\": %m", path);
exit(1);
}
}
}
if (errno)
{
pg_log_error("could not read directory \"%s\": %m", XLOGDIR);
exit(1);
}
if (closedir(xldir))
{
pg_log_error("could not close directory \"%s\": %m", XLOGDIR);
exit(1);
}
}
/*
* Remove existing archive status files
*/
static void
KillExistingArchiveStatus(void)
{
#define ARCHSTATDIR XLOGDIR "/archive_status"
DIR *xldir;
struct dirent *xlde;
char path[MAXPGPATH + sizeof(ARCHSTATDIR)];
xldir = opendir(ARCHSTATDIR);
if (xldir == NULL)
{
pg_log_error("could not open directory \"%s\": %m", ARCHSTATDIR);
exit(1);
}
while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
if (strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_FNAME_LEN &&
(strcmp(xlde->d_name + XLOG_FNAME_LEN, ".ready") == 0 ||
strcmp(xlde->d_name + XLOG_FNAME_LEN, ".done") == 0 ||
strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.ready") == 0 ||
strcmp(xlde->d_name + XLOG_FNAME_LEN, ".partial.done") == 0))
{
snprintf(path, sizeof(path), "%s/%s", ARCHSTATDIR, xlde->d_name);
if (unlink(path) < 0)
{
pg_log_error("could not delete file \"%s\": %m", path);
exit(1);
}
}
}
if (errno)
{
pg_log_error("could not read directory \"%s\": %m", ARCHSTATDIR);
exit(1);
}
if (closedir(xldir))
{
pg_log_error("could not close directory \"%s\": %m", ARCHSTATDIR);
exit(1);
}
}
/*
* Write an empty XLOG file, containing only the checkpoint record
* already set up in ControlFile.
*/
static void
WriteEmptyXLOG(void)
{
PGAlignedXLogBlock buffer;
XLogPageHeader page;
XLogLongPageHeader longpage;
XLogRecord *record;
pg_crc32c crc;
char path[MAXPGPATH];
int fd;
int nbytes;
char *recptr;
memset(buffer.data, 0, XLOG_BLCKSZ);
/* Set up the XLOG page header */
page = (XLogPageHeader) buffer.data;
page->xlp_magic = XLOG_PAGE_MAGIC;
page->xlp_info = XLP_LONG_HEADER;
page->xlp_tli = ControlFile.checkPointCopy.ThisTimeLineID;
page->xlp_pageaddr = ControlFile.checkPointCopy.redo - SizeOfXLogLongPHD;
longpage = (XLogLongPageHeader) page;
longpage->xlp_sysid = ControlFile.system_identifier;
longpage->xlp_seg_size = WalSegSz;
longpage->xlp_xlog_blcksz = XLOG_BLCKSZ;
/* Insert the initial checkpoint record */
recptr = (char *) page + SizeOfXLogLongPHD;
record = (XLogRecord *) recptr;
record->xl_prev = 0;
record->xl_xid = InvalidTransactionId;
record->xl_tot_len = SizeOfXLogRecord + SizeOfXLogRecordDataHeaderShort + sizeof(CheckPoint);
record->xl_info = XLOG_CHECKPOINT_SHUTDOWN;
record->xl_rmid = RM_XLOG_ID;
recptr += SizeOfXLogRecord;
*(recptr++) = (char) XLR_BLOCK_ID_DATA_SHORT;
*(recptr++) = sizeof(CheckPoint);
memcpy(recptr, &ControlFile.checkPointCopy,
sizeof(CheckPoint));
INIT_CRC32C(crc);
COMP_CRC32C(crc, ((char *) record) + SizeOfXLogRecord, record->xl_tot_len - SizeOfXLogRecord);
COMP_CRC32C(crc, (char *) record, offsetof(XLogRecord, xl_crc));
FIN_CRC32C(crc);
record->xl_crc = crc;
/* Write the first page */
XLogFilePath(path, ControlFile.checkPointCopy.ThisTimeLineID,
newXlogSegNo, WalSegSz);
unlink(path);
fd = open(path, O_RDWR | O_CREAT | O_EXCL | PG_BINARY,
pg_file_create_mode);
if (fd < 0)
{
pg_log_error("could not open file \"%s\": %m", path);
exit(1);
}
errno = 0;
if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
/* if write didn't set errno, assume problem is no disk space */
if (errno == 0)
errno = ENOSPC;
pg_log_error("could not write file \"%s\": %m", path);
exit(1);
}
/* Fill the rest of the file with zeroes */
memset(buffer.data, 0, XLOG_BLCKSZ);
for (nbytes = XLOG_BLCKSZ; nbytes < WalSegSz; nbytes += XLOG_BLCKSZ)
{
errno = 0;
if (write(fd, buffer.data, XLOG_BLCKSZ) != XLOG_BLCKSZ)
{
if (errno == 0)
errno = ENOSPC;
pg_log_error("could not write file \"%s\": %m", path);
exit(1);
}
}
if (fsync(fd) != 0)
{
pg_log_error("fsync error: %m");
exit(1);
}
close(fd);
}
static void
usage(void)
{
printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
printf(_("Usage:\n %s [OPTION]... DATADIR\n\n"), progname);
printf(_("Options:\n"));
printf(_(" -c, --commit-timestamp-ids=XID,XID\n"
" set oldest and newest transactions bearing\n"
" commit timestamp (zero means no change)\n"));
printf(_(" [-D, --pgdata=]DATADIR data directory\n"));
printf(_(" -e, --epoch=XIDEPOCH set next transaction ID epoch\n"));
printf(_(" -f, --force force update to be done\n"));
printf(_(" -l, --next-wal-file=WALFILE set minimum starting location for new WAL\n"));
printf(_(" -m, --multixact-ids=MXID,MXID set next and oldest multitransaction ID\n"));
printf(_(" -n, --dry-run no update, just show what would be done\n"));
printf(_(" -o, --next-oid=OID set next OID\n"));
printf(_(" -O, --multixact-offset=OFFSET set next multitransaction offset\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" -x, --next-transaction-id=XID set next transaction ID\n"));
printf(_(" --wal-segsize=SIZE size of WAL segments, in megabytes\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\nReport bugs to <pgsql-bugs@lists.postgresql.org>.\n"));
}
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