controldata_utils.c File Reference

#include "postgres.h"
#include <unistd.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "catalog/pg_control.h"
#include "common/controldata_utils.h"
#include "port/pg_crc32c.h"

Include dependency graph for controldata_utils.c:

Go to the source code of this file.

Functions
ControlFileData *	get_controlfile (const char *DataDir, const char *progname, bool *crc_ok_p)

Function Documentation

get_controlfile()

ControlFileData* get_controlfile	(	const char *	DataDir,
		const char *	progname,
		bool *	crc_ok_p
	)

Definition at line 41 of file controldata_utils.c.

References _, AssertArg, close, COMP_CRC32C, ControlFile, elog, EQ_CRC32C, ereport, errcode_for_file_access(), errmsg(), ERROR, EXIT_FAILURE, fd(), FIN_CRC32C, INIT_CRC32C, MAXPGPATH, offsetof, palloc(), PG_BINARY, read, snprintf(), and strerror().

Referenced by get_control_dbstate(), main(), pg_control_checkpoint(), pg_control_init(), pg_control_recovery(), and pg_control_system().

{
    ControlFileData *ControlFile;
    int         fd;
    char        ControlFilePath[MAXPGPATH];
    pg_crc32c   crc;

    AssertArg(crc_ok_p);

    ControlFile = palloc(sizeof(ControlFileData));
    snprintf(ControlFilePath, MAXPGPATH, "%s/global/pg_control", DataDir);

    if ((fd = open(ControlFilePath, O_RDONLY | PG_BINARY, 0)) == -1)
#ifndef FRONTEND
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not open file \"%s\" for reading: %m",
                        ControlFilePath)));
#else
    {
        fprintf(stderr, _("%s: could not open file \"%s\" for reading: %s\n"),
                progname, ControlFilePath, strerror(errno));
        exit(EXIT_FAILURE);
    }
#endif

    if (read(fd, ControlFile, sizeof(ControlFileData)) != sizeof(ControlFileData))
#ifndef FRONTEND
        ereport(ERROR,
                (errcode_for_file_access(),
                 errmsg("could not read file \"%s\": %m", ControlFilePath)));
#else
    {
        fprintf(stderr, _("%s: could not read file \"%s\": %s\n"),
                progname, ControlFilePath, strerror(errno));
        exit(EXIT_FAILURE);
    }
#endif

    close(fd);

    /* Check the CRC. */
    INIT_CRC32C(crc);
    COMP_CRC32C(crc,
                (char *) ControlFile,
                offsetof(ControlFileData, crc));
    FIN_CRC32C(crc);

    *crc_ok_p = EQ_CRC32C(crc, ControlFile->crc);

    /* Make sure the control file is valid byte order. */
    if (ControlFile->pg_control_version % 65536 == 0 &&
        ControlFile->pg_control_version / 65536 != 0)
#ifndef FRONTEND
        elog(ERROR, _("byte ordering mismatch"));
#else
        printf(_("WARNING: possible byte ordering mismatch\n"
                 "The byte ordering used to store the pg_control file might not match the one\n"
                 "used by this program.  In that case the results below would be incorrect, and\n"
                 "the PostgreSQL installation would be incompatible with this data directory.\n"));
#endif

    return ControlFile;
}