sysdeps/unix/sysv/linux/mips/ftruncate64.c

   1 /* Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Library General Public License as
   6    published by the Free Software Foundation; either version 2 of the
   7    License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Library General Public License for more details.
  13
  14    You should have received a copy of the GNU Library General Public
  15    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  16    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17    Boston, MA 02111-1307, USA.  */
  18
  19 #include <sys/types.h>
  20 #include <errno.h>
  21 #include <endian.h>
  22 #include <unistd.h>
  23
  24 #include <sysdep.h>
  25 #include <sys/syscall.h>
  26
  27 #include "kernel-features.h"
  28
  29 #ifdef __NR_ftruncate64
  30 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  31 /* The variable is shared between all wrappers around *truncate64 calls.  */
  32 extern int __have_no_truncate64;
  33 #endif
  34
  35 /* The order of hight, low depends on endianness.  */
  36 extern int __syscall_ftruncate64 (int fd, int dummy, int high_length,
  37                                   int low_length);
  38
  39
  40 /* Truncate the file FD refers to to LENGTH bytes.  */
  41 int
  42 ftruncate64 (int fd, off64_t length)
  43 {
  44 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  45   if (! __have_no_truncate64)
  46 #endif
  47     {
  48       unsigned int low = length & 0xffffffff;
  49       unsigned int high = length >> 32;
  50 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  51       int saved_errno = errno;
  52 #endif
  53       int result = INLINE_SYSCALL (ftruncate64, 3, fd, 0,
  54                                    __LONG_LONG_PAIR (high, low));
  55 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  56       if (result != -1 || errno != ENOSYS)
  57 #endif
  58         return result;
  59
  60 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  61       __set_errno (saved_errno);
  62       __have_no_truncate64 = 1;
  63 #endif
  64     }
  65
  66 #ifndef __ASSUME_TRUNCATE64_SYSCALL
  67   if ((off_t) length != length)
  68     {
  69       __set_errno (EINVAL);
  70       return -1;
  71     }
  72   return __ftruncate (fd, (off_t) length);
  73 #endif
  74 }
  75
  76 #else
  77 /* Use the generic implementation.  */
  78 # include <sysdeps/generic/ftruncate64.c>
  79 #endif