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

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/* Provide kernel hint to read ahead.
Copyright (C) 2002 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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <errno.h>
#include <sys/types.h>
#include <sysdep.h>
#include <sys/syscall.h>
#ifdef __NR_readahead
extern int __syscall_readahead (int fd, off_t offset_hi, off_t offset_lo,
size_t count);
ssize_t
__readahead (int fd, loff_t offset, size_t count)
{
return INLINE_SYSCALL (readahead, 4, fd, (off_t) (offset >> 32),
(off_t) (offset & 0xffffffff), count);
}
#else
ssize_t
__readahead (int fd, loff_t offset, size_t count)
{
__set_errno (ENOSYS);
return -1;
}
stub_warning (readahead)
# include <stub-tag.h>
#endif
weak_alias (__readahead, readahead)