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/*
* llseek.c -- stub calling the llseek system call
*
* Copyright (C) 1994 Remy Card. This file may be redistributed
* under the terms of the GNU Public License.
*/
#include <sys/types.h>
#include <errno.h>
#include <unistd.h>
#if defined(__GNUC__) || defined(HAS_LONG_LONG)
typedef long long ext2_loff_t;
#else
typedef long ext2_loff_t;
#endif
extern ext2_loff_t ext2_llseek (unsigned int, ext2_loff_t, unsigned int);
#ifdef __linux__
#ifdef HAVE_LLSEEK
#include <syscall.h>
#else /* HAVE_LLSEEK */
#ifdef __alpha__
#define my_llseek lseek
#else
#include <linux/unistd.h> /* for __NR__llseek */
static int _llseek (unsigned int, unsigned long,
unsigned long, ext2_loff_t *, unsigned int);
static _syscall5(int,_llseek,unsigned int,fd,unsigned long,offset_high,
unsigned long, offset_low,ext2_loff_t *,result,
unsigned int, origin)
static ext2_loff_t my_llseek (unsigned int fd, ext2_loff_t offset,
unsigned int origin)
{
ext2_loff_t result;
int retval;
retval = _llseek (fd, ((unsigned long long) offset) >> 32,
((unsigned long long) offset) & 0xffffffff,
&result, origin);
return (retval == -1 ? (ext2_loff_t) retval : result);
}
#endif /* __alpha__ */
#endif /* HAVE_LLSEEK */
ext2_loff_t ext2_llseek (unsigned int fd, ext2_loff_t offset,
unsigned int origin)
{
ext2_loff_t result;
static int do_compat = 0;
if (!do_compat) {
result = my_llseek (fd, offset, origin);
if (!(result == -1 && errno == ENOSYS))
return result;
/*
* Just in case this code runs on top of an old kernel
* which does not support the llseek system call
*/
do_compat = 1;
/*
* Now try ordinary lseek.
*/
}
if ((sizeof(off_t) >= sizeof(ext2_loff_t)) ||
(offset < ((ext2_loff_t) 1 << ((sizeof(off_t)*8) -1))))
return lseek(fd, (off_t) offset, origin);
errno = EINVAL;
return -1;
}
#else /* !linux */
ext2_loff_t ext2_llseek (unsigned int fd, ext2_loff_t offset,
unsigned int origin)
{
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 /* linux */
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