From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jiri Pirko <jiri@resnulli.us>
Subject: Re: [patch net-next v3 06/10] net: sched: introduce helpers to work
 with filter chains
Date: Wed, 17 May 2017 07:50:11 +0200
Message-ID: <20170517055011.GC1832@nanopsycho>
References: <20170516172802.1317-1-jiri@resnulli.us>
 <20170516172802.1317-7-jiri@resnulli.us>
 <CAM_iQpWDp3kFfCDL0JJ4c1_e9FZQ_-Wg+5HV0txz=KrTgWsq-w@mail.gmail.com>
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Cc: Linux Kernel Network Developers <netdev@vger.kernel.org>,
        David Miller <davem@davemloft.net>,
        Jamal Hadi Salim <jhs@mojatatu.com>,
        David Ahern <dsa@cumulusnetworks.com>,
        Eric Dumazet <edumazet@google.com>,
        Stephen Hemminger <stephen@networkplumber.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
        Alexander Duyck <alexander.h.duyck@intel.com>,
        Simon Horman <simon.horman@netronome.com>, mlxsw@mellanox.com
To: Cong Wang <xiyou.wangcong@gmail.com>
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Wed, May 17, 2017 at 12:17:11AM CEST, xiyou.wangcong@gmail.com wrote:
>On Tue, May 16, 2017 at 10:27 AM, Jiri Pirko <jiri@resnulli.us> wrote:
>> +static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain_info *chain_info)
>> +{
>> +       return rtnl_dereference(*chain_info->pprev);
>> +}
>> +
>> +static void tcf_chain_tp_insert(struct tcf_chain *chain,
>> +                               struct tcf_chain_info *chain_info,
>> +                               struct tcf_proto *tp)
>> +{
>> +       if (chain->p_filter_chain &&
>> +           *chain_info->pprev == chain->filter_chain)
>> +               *chain->p_filter_chain = tp;
>> +       RCU_INIT_POINTER(tp->next, rtnl_dereference(*chain_info->pprev));
>
>Use tcf_chain_tp_prev()?

Ok. Will do that.

>
>
>> +       rcu_assign_pointer(*chain_info->pprev, tp);
>> +}
>> +
>> +static void tcf_chain_tp_remove(struct tcf_chain *chain,
>> +                               struct tcf_chain_info *chain_info,
>> +                               struct tcf_proto *tp)
>> +{
>> +       struct tcf_proto *next = rtnl_dereference(chain_info->next);
>> +
>> +       if (chain->p_filter_chain && tp == chain->filter_chain)
>> +               *chain->p_filter_chain = next;
>> +       RCU_INIT_POINTER(*chain_info->pprev, next);
>> +}
>> +
>> +static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
>> +                                          struct tcf_chain_info *chain_info,
>> +                                          u32 protocol, u32 prio,
>> +                                          bool prio_allocate)
>> +{
>> +       struct tcf_proto **pprev;
>> +       struct tcf_proto *tp;
>> +
>> +       /* Check the chain for existence of proto-tcf with this priority */
>> +       for (pprev = &chain->filter_chain;
>> +            (tp = rtnl_dereference(*pprev)); pprev = &tp->next) {
>
>Use tcf_chain_tp_prev()?

Can't be done.