sysdeps/unix/sysv/linux/posix_fallocate.c

   1 /* Copyright (C) 2007-2014 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, see
  16    <http://www.gnu.org/licenses/>.  */
  17
  18 #include <fcntl.h>
  19 #include <kernel-features.h>
  20 #include <sysdep.h>
  21
  22 #define posix_fallocate static internal_fallocate
  23 #include <sysdeps/posix/posix_fallocate.c>
  24 #undef posix_fallocate
  25
  26 #if !defined __ASSUME_FALLOCATE && defined __NR_fallocate
  27 int __have_fallocate attribute_hidden;
  28 #endif
  29
  30
  31 /* Reserve storage for the data of the file associated with FD.  */
  32 int
  33 posix_fallocate (int fd, __off_t offset, __off_t len)
  34 {
  35 #ifdef __NR_fallocate
  36 # ifndef __ASSUME_FALLOCATE
  37   if (__builtin_expect (__have_fallocate >= 0, 1))
  38 # endif
  39     {
  40       INTERNAL_SYSCALL_DECL (err);
  41       int res = INTERNAL_SYSCALL (fallocate, err, 6, fd, 0,
  42                                   __LONG_LONG_PAIR (offset >> 31, offset),
  43                                   __LONG_LONG_PAIR (len >> 31, len));
  44
  45       if (! INTERNAL_SYSCALL_ERROR_P (res, err))
  46         return 0;
  47
  48 # ifndef __ASSUME_FALLOCATE
  49       if (__builtin_expect (INTERNAL_SYSCALL_ERRNO (res, err) == ENOSYS, 0))
  50         __have_fallocate = -1;
  51       else
  52 # endif
  53         if (INTERNAL_SYSCALL_ERRNO (res, err) != EOPNOTSUPP)
  54           return INTERNAL_SYSCALL_ERRNO (res, err);
  55     }
  56 #endif
  57
  58   return internal_fallocate (fd, offset, len);
  59 }