sysdeps/unix/sysv/linux/posix_fallocate.c

   1 /* Copyright (C) 2007 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 Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the 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    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <fcntl.h>
  20 #include <kernel-features.h>
  21 #include <sysdep.h>
  22
  23 #define posix_fallocate static internal_fallocate
  24 #include <sysdeps/posix/posix_fallocate.c>
  25 #undef posix_fallocate
  26
  27 #if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
  28 int __have_fallocate attribute_hidden;
  29 #endif
  30
  31
  32 /* Reserve storage for the data of the file associated with FD.  */
  33 int
  34 posix_fallocate (int fd, __off_t offset, __off_t len)
  35 {
  36 #ifdef __NR_fallocate
  37 # ifndef __ASSUME_FALLOCATE
  38   if (__builtin_expect (__have_fallocate >= 0, 1))
  39 # endif
  40     {
  41       INTERNAL_SYSCALL_DECL (err);
  42       int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
  43                                   __LONG_LONG_PAIR (offset >> 31, offset),
  44                                   __LONG_LONG_PAIR (len >> 31, len));
  45
  46       if (! INTERNAL_SYSCALL_ERROR_P (res, err))
  47         return 0;
  48
  49 # ifndef __ASSUME_FALLOCATE
  50       if (__builtin_expect (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS, 0))
  51         __have_fallocate = -1;
  52       else
  53 # endif
  54         if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
  55           return INTERNAL_SYSCALL_ERRNO (res, err);
  56     }
  57 #endif
  58
  59   return internal_fallocate (fd, offset, len);
  60 }