Re: [PATCH bpf-next v4 05/21] bpf: implement bpf_seq_read() for bpf iterator

[Alexei Starovoitov]

On Sat, May 09, 2020 at 10:59:04AM -0700, Yonghong Song wrote:
> +
> +             err = seq->op->show(seq, p);
> +             if (err > 0) {
> +                     seq->count = offs;

as far as I can see this condition can never happen.
I understand that seq_read() has this logic, but four iterators
implemented don't exercise this path.
I guess it's ok to keep it, but may be add warn_once so we notice
when things change?