Re: [PATCH net-next 6/6] inet: use xa_array iterator to implement inet_dump_ifaddr()

[Jakub Kicinski <kuba@kernel.org>]

On Thu, 29 Feb 2024 11:40:16 +0000 Eric Dumazet wrote:
> +	if (err < 0 && likely(skb->len))
> +		err = skb->len;

I think Ido may have commented on one of your early series, but if we
set err to skb->len we'll have to do an extra empty message to terminate
the dump.

You basically only want to return skb->len when message has
overflown, so the somewhat idiomatic way to do this is:

	err = (err == -EMSGSIZE) ? skb->len : err;

Assuming err can't be set to some weird positive value.

IDK if you want to do this in future patches or it's risky, but I have
the itch to tell you every time I see a conversion which doesn't follow
this pattern :)