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References: <20210329225322.143135-1-memxor@gmail.com>
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From:   Cong Wang <xiyou.wangcong@gmail.com>
Date:   Tue, 30 Mar 2021 21:40:45 -0700
Message-ID: <CAM_iQpVAo+Zxus-FC59xzwcmbS7UOi6F8kNMzsrEVrBY2YRtNA@mail.gmail.com>
Subject: Re: [PATCH v2 1/1] net: sched: bump refcount for new action in ACT
 replace mode
To:     Kumar Kartikeya Dwivedi <memxor@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>,
        =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= <toke@redhat.com>
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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()?

Thanks.