static int nvme_tcp_recv_data()

in host/tcp.c [707:776]

• 56 lines of code
• 10 McCabe index (conditional complexity)

static int nvme_tcp_recv_data(struct nvme_tcp_queue *queue, struct sk_buff *skb,
			      unsigned int *offset, size_t *len)
{
	struct nvme_tcp_data_pdu *pdu = (void *)queue->pdu;
	struct request *rq =
		nvme_cid_to_rq(nvme_tcp_tagset(queue), pdu->command_id);
	struct nvme_tcp_request *req = blk_mq_rq_to_pdu(rq);

	while (true) {
		int recv_len, ret;

		recv_len = min_t(size_t, *len, queue->data_remaining);
		if (!recv_len)
			break;

		if (!iov_iter_count(&req->iter)) {
			req->curr_bio = req->curr_bio->bi_next;

			/*
			 * If we don`t have any bios it means that controller
			 * sent more data than we requested, hence error
			 */
			if (!req->curr_bio) {
				dev_err(queue->ctrl->ctrl.device,
					"queue %d no space in request %#x",
					nvme_tcp_queue_id(queue), rq->tag);
				nvme_tcp_init_recv_ctx(queue);
				return -EIO;
			}
			nvme_tcp_init_iter(req, READ);
		}

		/* we can read only from what is left in this bio */
		recv_len = min_t(size_t, recv_len,
				iov_iter_count(&req->iter));

		if (queue->data_digest)
			ret = skb_copy_and_hash_datagram_iter(skb, *offset,
				&req->iter, recv_len, queue->rcv_hash);
		else
			ret = skb_copy_datagram_iter(skb, *offset,
					&req->iter, recv_len);
		if (ret) {
			dev_err(queue->ctrl->ctrl.device,
				"queue %d failed to copy request %#x data",
				nvme_tcp_queue_id(queue), rq->tag);
			return ret;
		}

		*len -= recv_len;
		*offset += recv_len;
		queue->data_remaining -= recv_len;
	}

	if (!queue->data_remaining) {
		if (queue->data_digest) {
			nvme_tcp_ddgst_final(queue->rcv_hash, &queue->exp_ddgst);
			queue->ddgst_remaining = NVME_TCP_DIGEST_LENGTH;
		} else {
			if (pdu->hdr.flags & NVME_TCP_F_DATA_SUCCESS) {
				nvme_tcp_end_request(rq,
						le16_to_cpu(req->status));
				queue->nr_cqe++;
			}
			nvme_tcp_init_recv_ctx(queue);
		}
	}

	return 0;
}