Re: [PATCH v4 9/9] nvme-rdma: return BLK_STS_P2PDMA for unsupported P2P transfers

[Logan Gunthorpe]

On 2026-07-22 12:58, Mykola Marzhan wrote:
> diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
> index 6909e3542794..2f50509a7a61 100644
> --- a/drivers/nvme/host/rdma.c
> +++ b/drivers/nvme/host/rdma.c
> @@ -1469,6 +1469,7 @@ static int nvme_rdma_dma_map_req(struct ib_device *ibdev, struct request *rq,
>  		int *count, int *pi_count)
>  {
>  	struct nvme_rdma_request *req = blk_mq_rq_to_pdu(rq);
> +	struct sg_table sgt;
>  	int ret;
>  
>  	req->data_sgl.sg_table.sgl = (struct scatterlist *)(req + 1);
> @@ -1480,12 +1481,14 @@ static int nvme_rdma_dma_map_req(struct ib_device *ibdev, struct request *rq,
>  
>  	req->data_sgl.nents = blk_rq_map_sg(rq, req->data_sgl.sg_table.sgl);
>  
> -	*count = ib_dma_map_sg(ibdev, req->data_sgl.sg_table.sgl,
> -			       req->data_sgl.nents, rq_dma_dir(rq));
> -	if (unlikely(*count <= 0)) {
> -		ret = -EIO;
> +	sgt = (struct sg_table) {
> +		.sgl		= req->data_sgl.sg_table.sgl,
> +		.orig_nents	= req->data_sgl.nents,
> +	};

Maybe we could make this patch a little clearer by splitting the change
to sg_table into it's own patch? That would make it much easier for me
to review. I've looked through it now a couple times and think it's ok,
but it's a little more complex than I can really untangle in my head.

Per your other email, I think that will make things good from my
perspective for v5, but I reserve the right to find something new when I
look at it ;)

Thanks for your efforts cleaning this up.

Logan