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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 Library
* General Public License, version 2.
* %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 "et/com_err.h"
#include "ext2fs/ext2_io.h"
#ifdef __linux__
#include <linux/unistd.h>
static ext2_loff_t my_llseek (int fd, ext2_loff_t offset, int origin)
{
#if SIZEOF_OFF_T >= 8
return lseek(fd, offset, origin);
#elif HAVE_LSEEK64_PROTOTYPE
return lseek64(fd, offset, origin);
#elif HAVE_LLSEEK_PROTOTYPE
return llseek(fd, offset, origin);
#elif defined(__NR__llseek)
loff_t result;
int retval;
retval = syscall(__NR__llseek, fd,
(unsigned long)(offset >> 32),
(unsigned long)(offset & 0xffffffff),
&result, origin);
return (retval == -1 ? retval : result);
#else
errno = ENOSYS;
return -1;
#endif
}
ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin)
{
ext2_loff_t result;
static int do_compat = 0;
if (do_compat)
goto fallback;
result = my_llseek (fd, offset, origin);
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++;
fallback:
if (offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))
return lseek(fd, (off_t) offset, origin);
errno = EINVAL;
return -1;
}
return result;
}
#else /* !linux */
#ifndef EINVAL
#define EINVAL EXT2_ET_INVALID_ARGUMENT
#endif
ext2_loff_t ext2fs_llseek (int fd, ext2_loff_t offset, int origin)
{
#if defined(HAVE_LSEEK64) && defined(HAVE_LSEEK64_PROTOTYPE)
return lseek64 (fd, offset, origin);
#else
if ((sizeof(off_t) < sizeof(ext2_loff_t)) &&
(offset >= ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1)))) {
errno = EINVAL;
return -1;
}
return lseek (fd, (off_t) offset, origin);
#endif
}
#endif /* linux */
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