pg_resetwal.c File Reference

#include "postgres.h"
#include <dirent.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/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 "fe_utils/option_utils.h"
#include "getopt_long.h"
#include "pg_getopt.h"
#include "storage/large_object.h"

Include dependency graph for pg_resetwal.c:

Go to the source code of this file.

Macros
#define	FRONTEND   1
#define	ARCHSTATDIR   XLOGDIR "/archive_status"
#define	WALSUMMARYDIR   XLOGDIR "/summaries"
#define	WALSUMMARY_NHEXCHARS   40

Functions
static void	CheckDataVersion (void)
static bool	read_controlfile (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	KillExistingWALSummaries (void)
static void	WriteEmptyXLOG (void)
static void	usage (void)
int	main (int argc, char *argv[])

Variables
static ControlFileData	ControlFile
static XLogSegNo	newXlogSegNo
static bool	guessed = false
static const char *	progname
static uint32	set_xid_epoch = (uint32) -1
static TransactionId	set_oldest_xid = 0
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 TimeLineID	minXlogTli = 0
static XLogSegNo	minXlogSegNo = 0
static int	WalSegSz
static int	set_wal_segsize

Macro Definition Documentation

ARCHSTATDIR

#define ARCHSTATDIR   XLOGDIR "/archive_status"

FRONTEND

#define FRONTEND   1

Definition at line 35 of file pg_resetwal.c.

WALSUMMARY_NHEXCHARS

#define WALSUMMARY_NHEXCHARS   40

WALSUMMARYDIR

#define WALSUMMARYDIR   XLOGDIR "/summaries"

Function Documentation

CheckDataVersion()

static void CheckDataVersion ( void  )

static

Definition at line 518 of file pg_resetwal.c.

{
    const char *ver_file = "PG_VERSION";
    FILE       *ver_fd;
    char        rawline[64];
 
    if ((ver_fd = fopen(ver_file, "r")) == NULL)
        pg_fatal("could not open file \"%s\" for reading: %m",
                 ver_file);
 
    /* version number has to be the first line read */
    if (!fgets(rawline, sizeof(rawline), ver_fd))
    {
        if (!ferror(ver_fd))
            pg_fatal("unexpected empty file \"%s\"", ver_file);
        else
            pg_fatal("could not read file \"%s\": %m", ver_file);
    }
 
    /* 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_error_detail("File \"%s\" contains \"%s\", which is not compatible with this program's version \"%s\".",
                            ver_file, rawline, PG_MAJORVERSION);
        exit(1);
    }
 
    fclose(ver_fd);
}

References exit(), pg_fatal, pg_log_error, pg_log_error_detail, and pg_strip_crlf().

Referenced by main().

FindEndOfXLOG()

static void FindEndOfXLOG ( void  )

static

Definition at line 907 of file pg_resetwal.c.

{
    DIR        *xldir;
    struct dirent *xlde;
    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.
     */
    XLByteToSeg(ControlFile.checkPointCopy.redo, newXlogSegNo,
                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_fatal("could not open directory \"%s\": %m", XLOGDIR);
 
    while (errno = 0, (xlde = readdir(xldir)) != NULL)
    {
        if (IsXLogFileName(xlde->d_name) ||
            IsPartialXLogFileName(xlde->d_name))
        {
            TimeLineID  tli;
            XLogSegNo   segno;
 
            /* Use the segment size from the control file */
            XLogFromFileName(xlde->d_name, &tli, &segno,
                             ControlFile.xlog_seg_size);
 
            /*
             * 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_fatal("could not read directory \"%s\": %m", XLOGDIR);
 
    if (closedir(xldir))
        pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
 
    /*
     * 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++;
}

References ControlFileData::checkPointCopy, closedir(), ControlFile, dirent::d_name, IsPartialXLogFileName(), IsXLogFileName(), newXlogSegNo, opendir(), pg_fatal, readdir(), CheckPoint::redo, WalSegSz, XLByteToSeg, ControlFileData::xlog_seg_size, XLOGDIR, and XLogFromFileName().

Referenced by main().

GuessControlValues()

static void GuessControlValues ( void  )

static

Definition at line 633 of file pg_resetwal.c.

{
    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.nextXid =
        FullTransactionIdFromEpochAndXid(0, FirstNormalTransactionId);
    ControlFile.checkPointCopy.nextOid = FirstGenbkiObjectId;
    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 = FirstNormalUnloggedLSN;
 
    /* 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.float8ByVal = FLOAT8PASSBYVAL;
 
    /*
     * XXX eventually, should try to grovel through old XLOG to develop more
     * accurate values for TimeLineID, nextXID, etc.
     */
}

References ControlFileData::blcksz, CATALOG_VERSION_NO, ControlFileData::catalog_version_no, ControlFileData::checkPoint, ControlFileData::checkPointCopy, ControlFile, DB_SHUTDOWNED, DEFAULT_XLOG_SEG_SIZE, FirstGenbkiObjectId, FirstMultiXactId, FirstNormalTransactionId, FirstNormalUnloggedLSN, ControlFileData::float8ByVal, FLOAT8PASSBYVAL, ControlFileData::floatFormat, FLOATFORMAT_VALUE, CheckPoint::fullPageWrites, FullTransactionIdFromEpochAndXid(), gettimeofday(), guessed, INDEX_MAX_KEYS, ControlFileData::indexMaxKeys, InvalidOid, InvalidTransactionId, ControlFileData::loblksize, LOBLKSIZE, ControlFileData::max_locks_per_xact, ControlFileData::max_prepared_xacts, ControlFileData::max_wal_senders, ControlFileData::max_worker_processes, ControlFileData::maxAlign, ControlFileData::MaxConnections, ControlFileData::nameDataLen, NAMEDATALEN, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, CheckPoint::nextOid, CheckPoint::nextXid, CheckPoint::oldestActiveXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, CheckPoint::oldestXid, CheckPoint::oldestXidDB, PG_CONTROL_VERSION, ControlFileData::pg_control_version, CheckPoint::PrevTimeLineID, CheckPoint::redo, ControlFileData::relseg_size, SizeOfXLogLongPHD, ControlFileData::state, ControlFileData::system_identifier, CheckPoint::ThisTimeLineID, CheckPoint::time, ControlFileData::time, TOAST_MAX_CHUNK_SIZE, ControlFileData::toast_max_chunk_size, ControlFileData::track_commit_timestamp, ControlFileData::unloggedLSN, ControlFileData::wal_level, WAL_LEVEL_MINIMAL, ControlFileData::wal_log_hints, ControlFileData::xlog_blcksz, and ControlFileData::xlog_seg_size.

Referenced by main().

KillExistingArchiveStatus()

static void KillExistingArchiveStatus ( void  )

static

Definition at line 1006 of file pg_resetwal.c.

{
#define ARCHSTATDIR XLOGDIR "/archive_status"
 
    DIR        *xldir;
    struct dirent *xlde;
    char        path[MAXPGPATH + sizeof(ARCHSTATDIR)];
 
    xldir = opendir(ARCHSTATDIR);
    if (xldir == NULL)
        pg_fatal("could not open directory \"%s\": %m", ARCHSTATDIR);
 
    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_fatal("could not delete file \"%s\": %m", path);
        }
    }
 
    if (errno)
        pg_fatal("could not read directory \"%s\": %m", ARCHSTATDIR);
 
    if (closedir(xldir))
        pg_fatal("could not close directory \"%s\": %m", ARCHSTATDIR);
}

References ARCHSTATDIR, closedir(), dirent::d_name, MAXPGPATH, opendir(), pg_fatal, readdir(), snprintf, and XLOG_FNAME_LEN.

Referenced by main().

KillExistingWALSummaries()

static void KillExistingWALSummaries ( void  )

static

Definition at line 1043 of file pg_resetwal.c.

{
#define WALSUMMARYDIR XLOGDIR   "/summaries"
#define WALSUMMARY_NHEXCHARS    40
 
    DIR        *xldir;
    struct dirent *xlde;
    char        path[MAXPGPATH + sizeof(WALSUMMARYDIR)];
 
    xldir = opendir(WALSUMMARYDIR);
    if (xldir == NULL)
        pg_fatal("could not open directory \"%s\": %m", WALSUMMARYDIR);
 
    while (errno = 0, (xlde = readdir(xldir)) != NULL)
    {
        if (strspn(xlde->d_name, "0123456789ABCDEF") == WALSUMMARY_NHEXCHARS &&
            strcmp(xlde->d_name + WALSUMMARY_NHEXCHARS, ".summary") == 0)
        {
            snprintf(path, sizeof(path), "%s/%s", WALSUMMARYDIR, xlde->d_name);
            if (unlink(path) < 0)
                pg_fatal("could not delete file \"%s\": %m", path);
        }
    }
 
    if (errno)
        pg_fatal("could not read directory \"%s\": %m", WALSUMMARYDIR);
 
    if (closedir(xldir))
        pg_fatal("could not close directory \"%s\": %m", ARCHSTATDIR);
}

References ARCHSTATDIR, closedir(), dirent::d_name, MAXPGPATH, opendir(), pg_fatal, readdir(), snprintf, WALSUMMARY_NHEXCHARS, and WALSUMMARYDIR.

Referenced by main().

KillExistingXLOG()

static void KillExistingXLOG ( void  )

static

Definition at line 973 of file pg_resetwal.c.

{
    DIR        *xldir;
    struct dirent *xlde;
    char        path[MAXPGPATH + sizeof(XLOGDIR)];
 
    xldir = opendir(XLOGDIR);
    if (xldir == NULL)
        pg_fatal("could not open directory \"%s\": %m", XLOGDIR);
 
    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_fatal("could not delete file \"%s\": %m", path);
        }
    }
 
    if (errno)
        pg_fatal("could not read directory \"%s\": %m", XLOGDIR);
 
    if (closedir(xldir))
        pg_fatal("could not close directory \"%s\": %m", XLOGDIR);
}

References closedir(), dirent::d_name, IsPartialXLogFileName(), IsXLogFileName(), MAXPGPATH, opendir(), pg_fatal, readdir(), snprintf, and XLOGDIR.

Referenced by main().

main()

int main	(	int	argc,
		char *	argv[]
	)

Definition at line 94 of file pg_resetwal.c.

{
    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'},
        {"oldest-transaction-id", required_argument, NULL, 'u'},
        {"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:u:x:", long_options, NULL)) != -1)
    {
        switch (c)
        {
            case 'D':
                DataDir = optarg;
                break;
 
            case 'f':
                force = true;
                break;
 
            case 'n':
                noupdate = true;
                break;
 
            case 'e':
                errno = 0;
                set_xid_epoch = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != '\0' || errno != 0)
                {
                    /*------
                      translator: the second %s is a command line argument (-e, etc) */
                    pg_log_error("invalid argument for option %s", "-e");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (set_xid_epoch == -1)
                    pg_fatal("transaction ID epoch (-e) must not be -1");
                break;
 
            case 'u':
                errno = 0;
                set_oldest_xid = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-u");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (!TransactionIdIsNormal(set_oldest_xid))
                    pg_fatal("oldest transaction ID (-u) must be greater than or equal to %u", FirstNormalTransactionId);
                break;
 
            case 'x':
                errno = 0;
                set_xid = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-x");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (!TransactionIdIsNormal(set_xid))
                    pg_fatal("transaction ID (-x) must be greater than or equal to %u", FirstNormalTransactionId);
                break;
 
            case 'c':
                errno = 0;
                set_oldest_commit_ts_xid = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != ',' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-c");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                set_newest_commit_ts_xid = strtoul(endptr + 1, &endptr2, 0);
                if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-c");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
 
                if (set_oldest_commit_ts_xid < FirstNormalTransactionId &&
                    set_oldest_commit_ts_xid != InvalidTransactionId)
                    pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
 
                if (set_newest_commit_ts_xid < FirstNormalTransactionId &&
                    set_newest_commit_ts_xid != InvalidTransactionId)
                    pg_fatal("transaction ID (-c) must be either %u or greater than or equal to %u", InvalidTransactionId, FirstNormalTransactionId);
                break;
 
            case 'o':
                errno = 0;
                set_oid = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-o");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (set_oid == 0)
                    pg_fatal("OID (-o) must not be 0");
                break;
 
            case 'm':
                errno = 0;
                set_mxid = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != ',' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-m");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
 
                set_oldestmxid = strtoul(endptr + 1, &endptr2, 0);
                if (endptr2 == endptr + 1 || *endptr2 != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-m");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (set_mxid == 0)
                    pg_fatal("multitransaction ID (-m) must not be 0");
 
                /*
                 * 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_fatal("oldest multitransaction ID (-m) must not be 0");
                break;
 
            case 'O':
                errno = 0;
                set_mxoff = strtoul(optarg, &endptr, 0);
                if (endptr == optarg || *endptr != '\0' || errno != 0)
                {
                    pg_log_error("invalid argument for option %s", "-O");
                    pg_log_error_hint("Try \"%s --help\" for more information.", progname);
                    exit(1);
                }
                if (set_mxoff == -1)
                    pg_fatal("multitransaction offset (-O) must not be -1");
                break;
 
            case 'l':
                if (strspn(optarg, "01234567890ABCDEFabcdef") != XLOG_FNAME_LEN)
                {
                    pg_log_error("invalid argument for option %s", "-l");
                    pg_log_error_hint("Try \"%s --help\" for more information.", 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:
                {
                    int         wal_segsize_mb;
 
                    if (!option_parse_int(optarg, "--wal-segsize", 1, 1024, &wal_segsize_mb))
                        exit(1);
                    set_wal_segsize = wal_segsize_mb * 1024 * 1024;
                    if (!IsValidWalSegSize(set_wal_segsize))
                        pg_fatal("argument of %s must be a power of two between 1 and 1024", "--wal-segsize");
                    break;
                }
 
            default:
                /* getopt_long already emitted a complaint */
                pg_log_error_hint("Try \"%s --help\" for more information.", 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]);
        pg_log_error_hint("Try \"%s --help\" for more information.", progname);
        exit(1);
    }
 
    if (DataDir == NULL)
    {
        pg_log_error("no data directory specified");
        pg_log_error_hint("Try \"%s --help\" for more information.", 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_error_hint("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_fatal("could not read permissions of directory \"%s\": %m",
                 DataDir);
 
    umask(pg_mode_mask);
 
    if (chdir(DataDir) < 0)
        pg_fatal("could not change directory to \"%s\": %m",
                 DataDir);
 
    /* 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_fatal("could not open file \"%s\" for reading: %m",
                     "postmaster.pid");
    }
    else
    {
        pg_log_error("lock file \"%s\" exists", "postmaster.pid");
        pg_log_error_hint("Is a server running?  If not, delete the lock file and try again.");
        exit(1);
    }
 
    /*
     * Attempt to read the existing pg_control file
     */
    if (!read_controlfile())
        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.nextXid =
            FullTransactionIdFromEpochAndXid(set_xid_epoch,
                                             XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
 
    if (set_oldest_xid != 0)
    {
        ControlFile.checkPointCopy.oldestXid = set_oldest_xid;
        ControlFile.checkPointCopy.oldestXidDB = InvalidOid;
    }
 
    if (set_xid != 0)
        ControlFile.checkPointCopy.nextXid =
            FullTransactionIdFromEpochAndXid(EpochFromFullTransactionId(ControlFile.checkPointCopy.nextXid),
                                             set_xid);
 
    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 (noupdate)
    {
        PrintNewControlValues();
        exit(0);
    }
 
    /*
     * If we had to guess anything, and -f was not given, just print the
     * guessed values and exit.
     */
    if (guessed && !force)
    {
        PrintNewControlValues();
        pg_log_error("not proceeding because control file values were guessed");
        pg_log_error_hint("If these values seem acceptable, use -f to force reset.");
        exit(1);
    }
 
    /*
     * Don't reset from a dirty pg_control without -f, either.
     */
    if (ControlFile.state != DB_SHUTDOWNED && !force)
    {
        pg_log_error("database server was not shut down cleanly");
        pg_log_error_detail("Resetting the write-ahead log might cause data to be lost.");
        pg_log_error_hint("If you want to proceed anyway, use -f to force reset.");
        exit(1);
    }
 
    /*
     * Else, do the dirty deed.
     */
    RewriteControlFile();
    KillExistingXLOG();
    KillExistingArchiveStatus();
    KillExistingWALSummaries();
    WriteEmptyXLOG();
 
    printf(_("Write-ahead log reset\n"));
    return 0;
}

References _, CheckDataVersion(), ControlFileData::checkPointCopy, ControlFile, DataDir, DB_SHUTDOWNED, EpochFromFullTransactionId, exit(), fd(), FindEndOfXLOG(), FirstMultiXactId, FirstNormalTransactionId, FullTransactionIdFromEpochAndXid(), get_progname(), get_restricted_token(), GetDataDirectoryCreatePerm(), getopt_long(), GuessControlValues(), guessed, InvalidOid, InvalidTransactionId, IsValidWalSegSize, KillExistingArchiveStatus(), KillExistingWALSummaries(), KillExistingXLOG(), minXlogSegNo, minXlogTli, CheckPoint::newestCommitTsXid, newXlogSegNo, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, CheckPoint::nextOid, CheckPoint::nextXid, no_argument, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, CheckPoint::oldestXid, CheckPoint::oldestXidDB, optarg, optind, option_parse_int(), pg_fatal, pg_log_error, pg_log_error_detail, pg_log_error_hint, pg_logging_init(), pg_mode_mask, pg_strdup(), PG_TEXTDOMAIN, CheckPoint::PrevTimeLineID, PrintControlValues(), printf, PrintNewControlValues(), progname, read_controlfile(), required_argument, RewriteControlFile(), set_mxid, set_mxoff, set_newest_commit_ts_xid, set_oid, set_oldest_commit_ts_xid, set_oldest_xid, set_pglocale_pgservice(), set_wal_segsize, set_xid, set_xid_epoch, ControlFileData::state, CheckPoint::ThisTimeLineID, TransactionIdIsNormal, usage(), WalSegSz, WriteEmptyXLOG(), XidFromFullTransactionId, XLOG_FNAME_LEN, ControlFileData::xlog_seg_size, and XLogFromFileName().

PrintControlValues()

static void PrintControlValues ( bool  guessed )

static

Definition at line 716 of file pg_resetwal.c.

{
    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.nextXid),
           XidFromFullTransactionId(ControlFile.checkPointCopy.nextXid));
    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(_("Float8 argument passing:              %s\n"),
           (ControlFile.float8ByVal ? _("by value") : _("by reference")));
    printf(_("Data page checksum version:           %u\n"),
           ControlFile.data_checksum_version);
}

References _, ControlFileData::blcksz, ControlFileData::catalog_version_no, ControlFileData::checkPointCopy, ControlFile, ControlFileData::data_checksum_version, EpochFromFullTransactionId, ControlFileData::float8ByVal, CheckPoint::fullPageWrites, guessed, ControlFileData::indexMaxKeys, ControlFileData::loblksize, ControlFileData::maxAlign, ControlFileData::nameDataLen, CheckPoint::newestCommitTsXid, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, CheckPoint::nextOid, CheckPoint::nextXid, CheckPoint::oldestActiveXid, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, CheckPoint::oldestXid, CheckPoint::oldestXidDB, ControlFileData::pg_control_version, printf, ControlFileData::relseg_size, ControlFileData::system_identifier, CheckPoint::ThisTimeLineID, ControlFileData::toast_max_chunk_size, XidFromFullTransactionId, ControlFileData::xlog_blcksz, and ControlFileData::xlog_seg_size.

Referenced by main().

PrintNewControlValues()

static void PrintNewControlValues ( void  )

static

Definition at line 789 of file pg_resetwal.c.

{
    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.nextXid));
        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.nextXid));
    }
 
    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);
    }
}

References _, ControlFileData::checkPointCopy, ControlFile, EpochFromFullTransactionId, MAXFNAMELEN, CheckPoint::newestCommitTsXid, newXlogSegNo, CheckPoint::nextMulti, CheckPoint::nextMultiOffset, CheckPoint::nextOid, CheckPoint::nextXid, CheckPoint::oldestCommitTsXid, CheckPoint::oldestMulti, CheckPoint::oldestMultiDB, CheckPoint::oldestXid, CheckPoint::oldestXidDB, printf, set_mxid, set_mxoff, set_newest_commit_ts_xid, set_oid, set_oldest_commit_ts_xid, set_wal_segsize, set_xid, set_xid_epoch, CheckPoint::ThisTimeLineID, WalSegSz, XidFromFullTransactionId, ControlFileData::xlog_seg_size, and XLogFileName().

Referenced by main().

read_controlfile()

static bool read_controlfile ( void  )

static

Definition at line 559 of file pg_resetwal.c.

{
    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_error_hint("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_fatal("could not read file \"%s\": %m", XLOG_CONTROL_FILE);
    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;
}

References close, COMP_CRC32C, ControlFile, crc, EQ_CRC32C, exit(), fd(), FIN_CRC32C, guessed, INIT_CRC32C, IsValidWalSegSize, len, ngettext, PG_BINARY, PG_CONTROL_FILE_SIZE, PG_CONTROL_VERSION, pg_fatal, pg_log_error, pg_log_error_hint, pg_log_warning, pg_malloc(), read, XLOG_CONTROL_FILE, and ControlFileData::xlog_seg_size.

Referenced by main().

RewriteControlFile()

static void RewriteControlFile ( void  )

static

Definition at line 861 of file pg_resetwal.c.

{
    /*
     * 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.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);
}

References ControlFileData::backupEndPoint, ControlFileData::backupEndRequired, ControlFileData::backupStartPoint, ControlFileData::checkPoint, ControlFileData::checkPointCopy, ControlFile, DB_SHUTDOWNED, ControlFileData::max_locks_per_xact, ControlFileData::max_prepared_xacts, ControlFileData::max_wal_senders, ControlFileData::max_worker_processes, ControlFileData::MaxConnections, ControlFileData::minRecoveryPoint, ControlFileData::minRecoveryPointTLI, newXlogSegNo, CheckPoint::redo, SizeOfXLogLongPHD, ControlFileData::state, CheckPoint::time, ControlFileData::track_commit_timestamp, update_controlfile(), ControlFileData::wal_level, WAL_LEVEL_MINIMAL, ControlFileData::wal_log_hints, WalSegSz, and XLogSegNoOffsetToRecPtr.

Referenced by main().

usage()

static void usage ( void  )

static

Definition at line 1166 of file pg_resetwal.c.

{
    printf(_("%s resets the PostgreSQL write-ahead log.\n\n"), progname);
    printf(_("Usage:\n"));
    printf(_("  %s [OPTION]... DATADIR\n"), progname);
 
    printf(_("\nOptions:\n"));
    printf(_(" [-D, --pgdata=]DATADIR  data directory\n"));
    printf(_("  -f, --force            force update to be done even after unclean shutdown or\n"
             "                         if pg_control values had to be guessed\n"));
    printf(_("  -n, --dry-run          no update, just show what would be done\n"));
    printf(_("  -V, --version          output version information, then exit\n"));
    printf(_("  -?, --help             show this help, then exit\n"));
 
    printf(_("\nOptions to override control file values:\n"));
    printf(_("  -c, --commit-timestamp-ids=XID,XID\n"
             "                                   set oldest and newest transactions bearing\n"
             "                                   commit timestamp (zero means no change)\n"));
    printf(_("  -e, --epoch=XIDEPOCH             set next transaction ID epoch\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(_("  -o, --next-oid=OID               set next OID\n"));
    printf(_("  -O, --multixact-offset=OFFSET    set next multitransaction offset\n"));
    printf(_("  -u, --oldest-transaction-id=XID  set oldest transaction ID\n"));
    printf(_("  -x, --next-transaction-id=XID    set next transaction ID\n"));
    printf(_("      --wal-segsize=SIZE           size of WAL segments, in megabytes\n"));
 
    printf(_("\nReport bugs to <%s>.\n"), PACKAGE_BUGREPORT);
    printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}

References _, printf, and progname.

Referenced by main().

WriteEmptyXLOG()

static void WriteEmptyXLOG ( void  )

static

Definition at line 1079 of file pg_resetwal.c.

{
    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_fatal("could not open file \"%s\": %m", path);
 
    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_fatal("could not write file \"%s\": %m", path);
    }
 
    /* 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_fatal("could not write file \"%s\": %m", path);
        }
    }
 
    if (fsync(fd) != 0)
        pg_fatal("fsync error: %m");
 
    close(fd);
}

References ControlFileData::checkPointCopy, close, COMP_CRC32C, ControlFile, crc, PGAlignedXLogBlock::data, fd(), FIN_CRC32C, fsync, INIT_CRC32C, InvalidTransactionId, MAXPGPATH, newXlogSegNo, PG_BINARY, pg_fatal, pg_file_create_mode, CheckPoint::redo, SizeOfXLogLongPHD, SizeOfXLogRecord, SizeOfXLogRecordDataHeaderShort, ControlFileData::system_identifier, CheckPoint::ThisTimeLineID, WalSegSz, write, XLogRecord::xl_crc, XLogRecord::xl_info, XLogRecord::xl_prev, XLogRecord::xl_rmid, XLogRecord::xl_tot_len, XLogRecord::xl_xid, XLOG_CHECKPOINT_SHUTDOWN, XLOG_PAGE_MAGIC, XLogFilePath(), XLogPageHeaderData::xlp_info, XLP_LONG_HEADER, XLogPageHeaderData::xlp_magic, XLogPageHeaderData::xlp_pageaddr, XLogLongPageHeaderData::xlp_seg_size, XLogLongPageHeaderData::xlp_sysid, XLogPageHeaderData::xlp_tli, XLogLongPageHeaderData::xlp_xlog_blcksz, and XLR_BLOCK_ID_DATA_SHORT.

Referenced by main().

Variable Documentation

ControlFile

ControlFileData ControlFile

static

Definition at line 62 of file pg_resetwal.c.

Referenced by FindEndOfXLOG(), GuessControlValues(), main(), PrintControlValues(), PrintNewControlValues(), read_controlfile(), RewriteControlFile(), and WriteEmptyXLOG().

guessed

bool guessed = false

static

Definition at line 64 of file pg_resetwal.c.

Referenced by GuessControlValues(), main(), PrintControlValues(), and read_controlfile().

minXlogSegNo

XLogSegNo minXlogSegNo = 0

static

Definition at line 75 of file pg_resetwal.c.

Referenced by main().

minXlogTli

TimeLineID minXlogTli = 0

static

Definition at line 74 of file pg_resetwal.c.

Referenced by main().

newXlogSegNo

XLogSegNo newXlogSegNo

static

Definition at line 63 of file pg_resetwal.c.

Referenced by FindEndOfXLOG(), main(), PrintNewControlValues(), RewriteControlFile(), and WriteEmptyXLOG().

progname

const char* progname

static

Definition at line 65 of file pg_resetwal.c.

Referenced by main(), and usage().

set_mxid

MultiXactId set_mxid = 0

static

Definition at line 72 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_mxoff

MultiXactOffset set_mxoff = (MultiXactOffset) -1

static

Definition at line 73 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_newest_commit_ts_xid

TransactionId set_newest_commit_ts_xid = 0

static

Definition at line 70 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_oid

Oid set_oid = 0

static

Definition at line 71 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_oldest_commit_ts_xid

TransactionId set_oldest_commit_ts_xid = 0

static

Definition at line 69 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_oldest_xid

TransactionId set_oldest_xid = 0

static

Definition at line 67 of file pg_resetwal.c.

Referenced by main().

set_wal_segsize

int set_wal_segsize

static

Definition at line 77 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_xid

TransactionId set_xid = 0

static

Definition at line 68 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

set_xid_epoch

uint32 set_xid_epoch = (uint32) -1

static

Definition at line 66 of file pg_resetwal.c.

Referenced by main(), and PrintNewControlValues().

WalSegSz

int WalSegSz

static

Definition at line 76 of file pg_resetwal.c.

Referenced by FindEndOfXLOG(), main(), PrintNewControlValues(), RewriteControlFile(), and WriteEmptyXLOG().