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/*
* llseek.c -- stub calling the llseek system call
*
* Copyright (C) 1994, 1995, 1996, 1997 Theodore Ts'o.
*
* %Begin-Header%
* This file may be redistributed under the terms of the
* GNU Lesser General Public License.
* %End-Header%
*/
#ifndef _LARGEFILE_SOURCE
#define _LARGEFILE_SOURCE
#endif
#ifndef _LARGEFILE64_SOURCE
#define _LARGEFILE64_SOURCE
#endif
#include "config.h"
#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#if HAVE_ERRNO_H
#include <errno.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef __MSDOS__
#include <io.h>
#endif
#include "blkidP.h"
#ifdef __linux__
#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
#define my_llseek lseek64
#elif defined(HAVE_LLSEEK)
#include <sys/syscall.h>
#ifndef HAVE_LLSEEK_PROTOTYPE
extern long long llseek(int fd, long long offset, int origin);
#endif
#define my_llseek llseek
#else /* ! HAVE_LLSEEK */
#if SIZEOF_LONG == SIZEOF_LONG_LONG
#define llseek lseek
#else /* SIZEOF_LONG != SIZEOF_LONG_LONG */
#include <linux/unistd.h>
#ifndef __NR__llseek
#define __NR__llseek 140
#endif
#ifndef __i386__
static int _llseek(unsigned int, unsigned long, unsigned long,
blkid_loff_t *, unsigned int);
static _syscall5(int, _llseek, unsigned int, fd, unsigned long, offset_high,
unsigned long, offset_low, blkid_loff_t *, result,
unsigned int, origin)
#endif
static blkid_loff_t my_llseek(int fd, blkid_loff_t offset, int origin)
{
blkid_loff_t result;
int retval;
#ifndef __i386__
retval = _llseek(fd, ((unsigned long long) offset) >> 32,
((unsigned long long)offset) & 0xffffffff,
&result, origin);
#else
retval = syscall(__NR__llseek, fd, ((unsigned long long) offset) >> 32,
((unsigned long long)offset) & 0xffffffff,
&result, origin);
#endif
return (retval == -1 ? (blkid_loff_t) retval : result);
}
#endif /* __alpha__ || __ia64__ */
#endif /* HAVE_LLSEEK */
blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int whence)
{
blkid_loff_t result;
static int do_compat = 0;
if ((sizeof(off_t) >= sizeof(blkid_loff_t)) ||
(offset < ((blkid_loff_t) 1 << ((sizeof(off_t)*8) -1))))
return lseek(fd, (off_t) offset, whence);
if (do_compat) {
errno = EOVERFLOW;
return -1;
}
result = my_llseek(fd, offset, whence);
if (result == -1 && errno == ENOSYS) {
/*
* Just in case this code runs on top of an old kernel
* which does not support the llseek system call
*/
do_compat++;
errno = EOVERFLOW;
}
return result;
}
#else /* !linux */
#ifndef EOVERFLOW
#ifdef EXT2_ET_INVALID_ARGUMENT
#define EOVERFLOW EXT2_ET_INVALID_ARGUMENT
#else
#define EOVERFLOW 112
#endif
#endif
blkid_loff_t blkid_llseek(int fd, blkid_loff_t offset, int origin)
{
#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
return lseek64 (fd, offset, origin);
#else
if ((sizeof(off_t) < sizeof(blkid_loff_t)) &&
(offset >= ((blkid_loff_t) 1 << ((sizeof(off_t)*8) - 1)))) {
errno = EOVERFLOW;
return -1;
}
return lseek(fd, (off_t) offset, origin);
#endif
}
#endif /* linux */
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