func DisableDirectIO(f *os.File) error {
	fd := f.Fd()
	_, err := unix.FcntlInt(fd, unix.F_NOCACHE, 0)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {
	return directio.AlignedBlock(blockSize)

	if err != nil {
		return err
	}
	flag &= ^(syscall.O_DIRECT)
	_, err = unix.FcntlInt(fd, unix.F_SETFL, flag)
	return err
}

// AlignedBlock - pass through to directio implementation.
func AlignedBlock(blockSize int) []byte {
	return directio.AlignedBlock(blockSize)

	return os.OpenFile(filePath, flag, perm)
}

// DisableDirectIO is a no-op
func DisableDirectIO(f *os.File) error {
	return nil
}

// AlignedBlock simply returns an unaligned buffer
// for systems that do not support DirectIO.
func AlignedBlock(blockSize int) []byte {
	return make([]byte, blockSize)