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glibc  2.9
readahead.c
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00001 /* Provide kernel hint to read ahead.
00002    Copyright (C) 2002, 2003, 2004, 2007 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <fcntl.h>
00022 #include <sys/types.h>
00023 
00024 #include <sysdep.h>
00025 #include <sys/syscall.h>
00026 
00027 
00028 #ifdef __NR_readahead
00029 
00030 ssize_t
00031 __readahead (int fd, off64_t offset, size_t count)
00032 {
00033   return INLINE_SYSCALL (readahead, 4, fd,
00034                       __LONG_LONG_PAIR ((off_t) (offset >> 32),
00035                                       (off_t) (offset & 0xffffffff)),
00036                       count);
00037 }
00038 #else
00039 ssize_t
00040 __readahead (int fd, off64_t offset, size_t count)
00041 {
00042   __set_errno (ENOSYS);
00043   return -1;
00044 }
00045 stub_warning (readahead)
00046 
00047 # include <stub-tag.h>
00048 #endif
00049 
00050 weak_alias (__readahead, readahead)