static int nvme_rdma_map_sg_pi()

in host/rdma.c [1469:1522]

• 46 lines of code
• 4 McCabe index (conditional complexity)

static int nvme_rdma_map_sg_pi(struct nvme_rdma_queue *queue,
		struct nvme_rdma_request *req, struct nvme_command *c,
		int count, int pi_count)
{
	struct nvme_rdma_sgl *sgl = &req->data_sgl;
	struct ib_reg_wr *wr = &req->reg_wr;
	struct request *rq = blk_mq_rq_from_pdu(req);
	struct nvme_ns *ns = rq->q->queuedata;
	struct bio *bio = rq->bio;
	struct nvme_keyed_sgl_desc *sg = &c->common.dptr.ksgl;
	int nr;

	req->mr = ib_mr_pool_get(queue->qp, &queue->qp->sig_mrs);
	if (WARN_ON_ONCE(!req->mr))
		return -EAGAIN;

	nr = ib_map_mr_sg_pi(req->mr, sgl->sg_table.sgl, count, NULL,
			     req->metadata_sgl->sg_table.sgl, pi_count, NULL,
			     SZ_4K);
	if (unlikely(nr))
		goto mr_put;

	nvme_rdma_set_sig_attrs(blk_get_integrity(bio->bi_bdev->bd_disk), c,
				req->mr->sig_attrs, ns->pi_type);
	nvme_rdma_set_prot_checks(c, &req->mr->sig_attrs->check_mask);

	ib_update_fast_reg_key(req->mr, ib_inc_rkey(req->mr->rkey));

	req->reg_cqe.done = nvme_rdma_sig_done;
	memset(wr, 0, sizeof(*wr));
	wr->wr.opcode = IB_WR_REG_MR_INTEGRITY;
	wr->wr.wr_cqe = &req->reg_cqe;
	wr->wr.num_sge = 0;
	wr->wr.send_flags = 0;
	wr->mr = req->mr;
	wr->key = req->mr->rkey;
	wr->access = IB_ACCESS_LOCAL_WRITE |
		     IB_ACCESS_REMOTE_READ |
		     IB_ACCESS_REMOTE_WRITE;

	sg->addr = cpu_to_le64(req->mr->iova);
	put_unaligned_le24(req->mr->length, sg->length);
	put_unaligned_le32(req->mr->rkey, sg->key);
	sg->type = NVME_KEY_SGL_FMT_DATA_DESC << 4;

	return 0;

mr_put:
	ib_mr_pool_put(queue->qp, &queue->qp->sig_mrs, req->mr);
	req->mr = NULL;
	if (nr < 0)
		return nr;
	return -EINVAL;
}