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

69 lines
2.4 KiB
C

/* Copyright (C) 2003-2020 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
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <fcntl.h>
#include <sysdep.h>
/* Advice the system about the expected behaviour of the application with
respect to the file associated with FD. */
#ifndef __OFF_T_MATCHES_OFF64_T
/* Default implementation will use __NR_fadvise64 with expected argument
positions (for instance i386 and powerpc32 that uses __ALIGNMENT_ARG).
Second option will be used by arm which define __NR_arm_fadvise64_64
(redefined to __NR_fadvise64_64 in kernel-features.h) that behaves as
__NR_fadvise64_64 (without the aligment argument required for the ABI).
Third option will be used by mips o32. Mips will use a 7 argument
syscall with __NR_fadvise64.
s390 implements fadvice64_64 using a specific struct with arguments
packed inside. This is the only implementation handled in arch-specific
code. */
int
posix_fadvise (int fd, off_t offset, off_t len, int advise)
{
INTERNAL_SYSCALL_DECL (err);
# if defined (__NR_fadvise64) && !defined (__ASSUME_FADVISE64_AS_64_64)
int ret = INTERNAL_SYSCALL_CALL (fadvise64, err, fd,
__ALIGNMENT_ARG SYSCALL_LL (offset),
len, advise);
# else
# ifdef __ASSUME_FADVISE64_64_6ARG
int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd, advise,
SYSCALL_LL (offset), SYSCALL_LL (len));
# else
# ifndef __NR_fadvise64_64
# define __NR_fadvise64_64 __NR_fadvise64
# endif
int ret = INTERNAL_SYSCALL_CALL (fadvise64_64, err, fd,
__ALIGNMENT_ARG SYSCALL_LL (offset),
SYSCALL_LL (len), advise);
# endif
# endif
if (INTERNAL_SYSCALL_ERROR_P (ret, err))
return INTERNAL_SYSCALL_ERRNO (ret, err);
return 0;
}
#endif /* __OFF_T_MATCHES_OFF64_T */