sysdeps/unix/sysv/linux/posix_fadvise.c

   1 /* Copyright (C) 2003-2013 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 <errno.h>
  19 #include <fcntl.h>
  20 #include <sysdep.h>
  21
  22 /* Advice the system about the expected behaviour of the application with
  23    respect to the file associated with FD.  */
  24
  25 int
  26 posix_fadvise (int fd, off_t offset, off_t len, int advise)
  27 {
  28 #if defined(__NR_fadvise64) || defined(__NR_fadvise64_64)
  29   INTERNAL_SYSCALL_DECL (err);
  30 # ifdef __NR_fadvise64
  31   int ret = INTERNAL_SYSCALL (fadvise64, err, 5, fd,
  32                               __LONG_LONG_PAIR (offset >> 31, offset), len,
  33                               advise);
  34 # else
  35   int ret = INTERNAL_SYSCALL (fadvise64_64, err, 6, fd,
  36                               __LONG_LONG_PAIR ((long) (offset >> 31),
  37                                                 (long) offset),
  38                               __LONG_LONG_PAIR ((long) (len >> 31),
  39                                                 (long) len),
  40                               advise);
  41 # endif
  42   if (INTERNAL_SYSCALL_ERROR_P (ret, err))
  43     return INTERNAL_SYSCALL_ERRNO (ret, err);
  44   return 0;
  45 #else
  46   return ENOSYS;
  47 #endif
  48 }