Re: [PATCH v2 1/1] net: sched: bump refcount for new action in ACT replace mode

From: Kumar Kartikeya Dwivedi <memxor@gmail.com>
To: Cong Wang <xiyou.wangcong@gmail.com>
Cc: "Vlad Buslov" <vladbu@nvidia.com>,
	"David Miller" <davem@davemloft.net>,
	"Jamal Hadi Salim" <jhs@mojatatu.com>,
	"Jiri Pirko" <jiri@resnulli.us>,
	"Jakub Kicinski" <kuba@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>,
	"Linux Kernel Network Developers" <netdev@vger.kernel.org>,
	"Toke Høiland-Jørgensen" <toke@redhat.com>
Subject: Re: [PATCH v2 1/1] net: sched: bump refcount for new action in ACT replace mode
Date: Wed, 31 Mar 2021 14:08:00 +0530	[thread overview]
Message-ID: <20210331083800.b3b2ewfgxklo76ri@apollo> (raw)
In-Reply-To: <CAM_iQpVAo+Zxus-FC59xzwcmbS7UOi6F8kNMzsrEVrBY2YRtNA@mail.gmail.com>

On Wed, Mar 31, 2021 at 10:10:45AM IST, Cong Wang wrote:
> On Mon, Mar 29, 2021 at 3:55 PM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> > diff --git a/net/sched/act_api.c b/net/sched/act_api.c
> > index b919826939e0..43cceb924976 100644
> > --- a/net/sched/act_api.c
> > +++ b/net/sched/act_api.c
> > @@ -1042,6 +1042,9 @@ struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
> >         if (err != ACT_P_CREATED)
> >                 module_put(a_o->owner);
> >
> > +       if (!bind && ovr && err == ACT_P_CREATED)
> > +               refcount_set(&a->tcfa_refcnt, 2);
> > +
>
> Hmm, if we set the refcnt to 2 here, how could tcf_action_destroy()
> destroy them when we rollback from a failure in the middle of the loop
> in tcf_action_init()?
>

You are right, it wouldn't. I sent a new version with a fix. PTAL.

> Thanks.

--
Kartikeya