On Fri, Mar 27, 2020 at 08:15:37PM +0300, Max Gurtovoy wrote:
> From: Israel Rukshin <israelr@xxxxxxxxxxxx>
>
> Allocate the metadata SGL buffers and set metadata fields for the
> request. This is a preparation for adding metadata support over the
> fabrics.
I don't think having this as a separate prep patch is a good idea, it
should go with the code making use of it.
> - req->transfer_len);
> - if (req->sg) {
> - req->p2p_dev = p2p_dev;
> - return 0;
> + data_len);
> + if (!req->sg)
> + goto fallback;
> +
> + if (req->md_len) {
> + req->md_sg =
> + pci_p2pmem_alloc_sgl(p2p_dev,
> + &req->md_sg_cnt,
> + req->md_len);
> + if (!req->md_sg) {
> + pci_p2pmem_free_sgl(req->p2p_dev,
> + req->sg);
> + goto fallback;
> + }
> }
> + req->p2p_dev = p2p_dev;
> + return 0;
> }
>
> /*
> @@ -984,23 +1001,40 @@ int nvmet_req_alloc_sgl(struct nvmet_req *req)
> */
> }
>
> - req->sg = sgl_alloc(req->transfer_len, GFP_KERNEL, &req->sg_cnt);
> +fallback:
> + req->sg = sgl_alloc(data_len, GFP_KERNEL, &req->sg_cnt);
> if (unlikely(!req->sg))
> return -ENOMEM;
>
> + if (req->md_len) {
> + req->md_sg = sgl_alloc(req->md_len, GFP_KERNEL,
> + &req->md_sg_cnt);
> + if (unlikely(!req->md_sg)) {
> + sgl_free(req->sg);
> + return -ENOMEM;
> + }
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(nvmet_req_alloc_sgl);
I suspect this might be a little cleaner with a nvmet_alloc_sgl
helper that returns a scatterlist instead of duplicating all the
code for data vs metadata.
