Re: [PATCH net-next] net: sched: remove redundant NULL check in change hook function

[shaozhengchao]

On 2022/8/29 13:36, Cong Wang wrote:
> On Sat, Aug 27, 2022 at 09:49:10AM +0800, Zhengchao Shao wrote:
> > Currently, the change function can be called by two ways. The one way is
> > that qdisc_change() will call it. Before calling change function,
> > qdisc_change() ensures tca[TCA_OPTIONS] is not empty. The other way is
> > that .init() will call it. The opt parameter is also checked before
> > calling change function in .init(). Therefore, it's no need to check the
> > input parameter opt in change function.
>
> Right.. but the one below:
>
> > diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
> > index c50a0853dcb9..e23d3dbb7272 100644
> > --- a/net/sched/sch_gred.c
> > +++ b/net/sched/sch_gred.c
> > @@ -413,9 +413,6 @@ static int gred_change_table_def(struct Qdisc *sch, struct nlattr *dps,
> >   	bool red_flags_changed;
> >   	int i;
> >   
> > -	if (!dps)
> > -		return -EINVAL;
> > -
>
> I don't think anyone checks tb[TCA_GRED_DPS]. What you intended to patch
> is gred_change(), right?
>
> Thanks.

Hi Wang:
	Thank you for your reply. You are right. I will send v2.

Zhengchao Shao