
static int io_req_prep_async(struct io_kiocb *req)
{
	const struct io_op_def *def = &io_op_defs[req->opcode];

	/* assign early for deferred execution for non-fixed file */
	if (def->needs_file && !(req->flags & REQ_F_FIXED_FILE))
		req->file = io_file_get_normal(req, req->cqe.fd);
	if (!def->needs_async_setup)
		return 0;
	if (WARN_ON_ONCE(req_has_async_data(req)))
		return -EFAULT;
	if (io_alloc_async_data(req))
		return -EAGAIN;

	switch (req->opcode) {
	case IORING_OP_READV:
		return io_readv_prep_async(req);
	case IORING_OP_WRITEV:
		return io_writev_prep_async(req);
	case IORING_OP_SENDMSG:
		return io_sendmsg_prep_async(req);
	case IORING_OP_RECVMSG:
		return io_recvmsg_prep_async(req);
	case IORING_OP_CONNECT:
		return io_connect_prep_async(req);
	case IORING_OP_URING_CMD:
		return io_uring_cmd_prep_async(req);
	}
	printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n",
		    req->opcode);
	return -EFAULT;

static int io_req_prep_async(struct io_kiocb *req)
{
	const struct io_op_def *def = &io_op_defs[req->opcode];

	 
	if (def->needs_file && !(req->flags & REQ_F_FIXED_FILE))
		req->file = io_file_get_normal(req, req->cqe.fd);
	if (!def->needs_async_setup)
		return 0;
	if (WARN_ON_ONCE(req_has_async_data(req)))
		return -EFAULT;
	if (io_alloc_async_data(req))
		return -EAGAIN;

	switch (req->opcode) {
	case IORING_OP_READV:
		return io_readv_prep_async(req);
	case IORING_OP_WRITEV:
		return io_writev_prep_async(req);
	case IORING_OP_SENDMSG:
		return io_sendmsg_prep_async(req);
	case IORING_OP_RECVMSG:
		return io_recvmsg_prep_async(req);
	case IORING_OP_CONNECT:
		return io_connect_prep_async(req);
	case IORING_OP_URING_CMD:
		return io_uring_cmd_prep_async(req);
	}
	printk_once(KERN_WARNING "io_uring: prep_async() bad opcode %d\n",
		    req->opcode);
	return -EFAULT;