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/* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If not,
write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include <sys/types.h>
#include <endian.h>
#include <errno.h>
#include <unistd.h>
#include <sysdep.h>
#include <sys/syscall.h>
#include "kernel-features.h"
#ifdef __NR_truncate64
#ifndef __ASSUME_TRUNCATE64_SYSCALL
/* The variable is shared between all wrappers around *truncate64 calls. */
int __have_no_truncate64;
#endif
/* The order of hight, low depends on endianness. */
extern int __syscall_truncate64 (const char *path, int dummy,
int high_length, int low_length);
/* Truncate the file FD refers to to LENGTH bytes. */
int
truncate64 (const char *path, off64_t length)
{
#ifndef __ASSUME_TRUNCATE64_SYSCALL
if (! __have_no_truncate64)
#endif
{
unsigned int low = length & 0xffffffff;
unsigned int high = length >> 32;
#ifndef __ASSUME_TRUNCATE64_SYSCALL
int saved_errno = errno;
#endif
#if __BYTE_ORDER == __LITTLE_ENDIAN
/* Use a fill argument to pass low, high in an aligned pair of
arguments (here 2/3). */
int result = INLINE_SYSCALL (truncate64, 3, path, 0, low, high);
#elif __BYTE_ORDER == __BIG_ENDIAN
int result = INLINE_SYSCALL (truncate64, 3, path, 0, high, low);
#endif
#ifndef __ASSUME_TRUNCATE64_SYSCALL
if (result != -1 || errno != ENOSYS)
#endif
return result;
#ifndef __ASSUME_TRUNCATE64_SYSCALL
__set_errno (saved_errno);
__have_no_truncate64 = 1;
#endif
}
#ifndef __ASSUME_TRUNCATE64_SYSCALL
if ((off_t) length != length)
{
__set_errno (EINVAL);
return -1;
}
return truncate (path, (off_t) length);
#endif
}
#else
/* Use the generic implementation. */
# include <sysdeps/generic/truncate64.c>
#endif
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