static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
{
	struct io_kiocb *nxt;

	if (!(req->flags & REQ_F_LINK_HEAD))
		return NULL;
	if (req->flags & REQ_F_LINK_TIMEOUT)
		return NULL;

	nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
					link_list);
	if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
		return NULL;

	req->flags |= REQ_F_LINK_TIMEOUT;
	return nxt;
}
static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
{
	struct io_kiocb *nxt;

	if (!(req->flags & REQ_F_LINK_HEAD))
		return NULL;
	if (req->flags & REQ_F_LINK_TIMEOUT)
		return NULL;

	nxt = list_first_entry_or_null(&req->link_list, struct io_kiocb,
					link_list);
	if (!nxt || nxt->opcode != IORING_OP_LINK_TIMEOUT)
		return NULL;

	req->flags |= REQ_F_LINK_TIMEOUT;
	return nxt;
}