[S390] s390: use simple_read_from_buffer()

			      unsigned long nr_segs, loff_t offset)

{

	char *data;

	size_t len;

	ssize_t ret;

	struct file *filp = iocb->ki_filp;

	/* XXX: temporary */

	char __user *buf = iov[0].iov_base;

	size_t count = iov[0].iov_len;

	if (nr_segs != 1) {

		count = -EINVAL;

		goto out;

	}

	if (nr_segs != 1)

		return -EINVAL;

	data = filp->private_data;

	len = strlen(data);

	if (offset > len) {

		count = 0;

		goto out;

	}

	if (count > len - offset)

		count = len - offset;

	if (copy_to_user(buf, data + offset, count)) {

		count = -EFAULT;

		goto out;

	}

	iocb->ki_pos += count;

	ret = simple_read_from_buffer(buf, count, &offset, data, strlen(data));

	if (ret <= 0)

		return ret;

	iocb->ki_pos += ret;

	file_accessed(filp);

out:

	return count;

	return ret;

}

static ssize_t hypfs_aio_write(struct kiocb *iocb, const struct iovec *iov,

			      unsigned long nr_segs, loff_t offset)