Re: [PATCH net v2] net/sched: dualpi2: clear stale classification on filter miss

[Samuel Moelius]

On Wed, Jun 10, 2026 at 6:06 AM Jamal Hadi Salim <jhs@xxxxxxxxxxxx> wrote:
>
> On Tue, Jun 9, 2026 at 7:26 PM Samuel Moelius
> <sam.moelius@xxxxxxxxxxxxxxx> wrote:
> >
> > DualPI2 leaves previous classification state attached to an skb when
> > filter classification returns no match.  The enqueue path can then act
> > on stale state from an earlier classification attempt.
> >
> > A filter miss should fall back to the default path without reusing old
> > per-packet classification data.
> >
> > Clear the classification result when the filter lookup does not match.
> >
>
> Why not just initialize at the top of the function? Something like this:
>
> --- a/net/sched/sch_dualpi2.c
> +++ b/net/sched/sch_dualpi2.c
> @@ -346,6 +346,8 @@ static int dualpi2_skb_classify(struct
> dualpi2_sched_data *q,
>         struct tcf_proto *fl;
>         int result;
>
> +       cb->classified = DUALPI2_C_CLASSIC;
>
> Then you can even remove check around if (!fl)
>
> -       if (!fl) {
> -               cb->classified = DUALPI2_C_CLASSIC;
> +       if (!fl)
>                 return NET_XMIT_SUCCESS;
> -       }
>
> Would improve readability.

I am getting ready to travel and I will address this when I return in
about two weeks. Thank you for understanding.