glibc/sysdeps/unix/sysv/linux/readahead.c

48 lines
1.3 KiB
C

/* Provide kernel hint to read ahead.
Copyright (C) 2002-2013 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 Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sysdep.h>
#include <sys/syscall.h>
#ifdef __NR_readahead
ssize_t
__readahead (int fd, off64_t offset, size_t count)
{
return INLINE_SYSCALL (readahead, 4, fd,
__LONG_LONG_PAIR ((off_t) (offset >> 32),
(off_t) (offset & 0xffffffff)),
count);
}
#else
ssize_t
__readahead (int fd, off64_t offset, size_t count)
{
__set_errno (ENOSYS);
return -1;
}
stub_warning (readahead)
#endif
weak_alias (__readahead, readahead)