From mboxrd@z Thu Jan  1 00:00:00 1970
From: Cong Wang <xiyou.wangcong@gmail.com>
Subject: Re: [Patch net-next] act_mirred: get rid of mirred_list_lock spinlock
Date: Thu, 30 Nov 2017 17:02:38 -0800
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References: <20171130225335.6957-1-xiyou.wangcong@gmail.com>
 <20171130225335.6957-2-xiyou.wangcong@gmail.com> <1512083524.19682.29.camel@gmail.com>
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Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        Jiri Pirko <jiri@mellanox.com>,
        Jamal Hadi Salim <jhs@mojatatu.com>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Thu, Nov 30, 2017 at 3:12 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> On Thu, 2017-11-30 at 14:53 -0800, Cong Wang wrote:
>> @@ -55,13 +54,10 @@ static void tcf_mirred_release(struct tc_action
>> *a, int bind)
>>       struct tcf_mirred *m = to_mirred(a);
>>       struct net_device *dev;
>>
>> -     /* We could be called either in a RCU callback or with RTNL
>> lock held. */
>> -     spin_lock_bh(&mirred_list_lock);
>>       list_del(&m->tcfm_list);
>>       dev = rcu_dereference_protected(m->tcfm_dev, 1);
>
> If RTNL is held at this point, I suggest to use
> rtnl_dereference() instead of rcu_dereference_protected() to get proper
> lockdep coverage.

Ah, sure, I missed it. Will send v2 later.