Re: [PATCH v7 06/13] nvme-pci: implement dma-buf backed requests

[Christoph Hellwig]

On Mon, Sep 28, 2026 at 02:32:22PM +0100, Pavel Begunkov wrote:
> +static void nvme_dmabuf_map_sync_for_cpu(struct nvme_dev *nvme_dev,
> +		struct request *req)
> +{
> +	struct device *dev = nvme_dev->dev;
> +	enum dma_data_direction dma_dir;
> +	struct bio *bio = req->bio;
> +	struct nvme_dmabuf_map *map = to_nvme_dmabuf_map(bio->bi_dmabuf_map);
> +
> +	dma_dir = rq_data_dir(req) == READ ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
> +	dma_sync_sgtable_for_cpu(dev, map->sgt, dma_dir);

This can use rq_dma_dir in the argument.  Same for the other DMA API
calls.

Btw, given how larger the dmabuf code is now, have you considered
splitting it into a new nvme-pci-dmabuf.c file?