Re: [RFC PATCH net-next v5 2/2] net: add netmem to skb_frag_t

[Yunsheng Lin <linyunsheng@huawei.com>]

On 2024/1/9 9:14, Mina Almasry wrote:

...

>  
> +		if (WARN_ON_ONCE(!skb_frag_page(&skb_shinfo(skb)->frags[0]))) {

I am really hate to bring it up again.
If you are not willing to introduce a new helper, do you care to use some
existing API like skb_frag_address_safe()?

> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
>  		iov_iter_bvec(&msg.msg_iter, ITER_SOURCE,
> -			      skb_shinfo(skb)->frags, skb_shinfo(skb)->nr_frags,
> -			      msize);
> +			      (const struct bio_vec *)skb_shinfo(skb)->frags,
> +			      skb_shinfo(skb)->nr_frags, msize);

I think we need to use some built-time checking to ensure some consistency
between skb_frag_t and bio_vec.

>  		iov_iter_advance(&msg.msg_iter, txm->frag_offset);
>  
>  		do {
>