Sun, May 21, 2017 at 08:27:21PM CEST, xiyou.wangc...@gmail.com wrote:
>On Sat, May 20, 2017 at 10:54 PM, Jiri Pirko <j...@resnulli.us> wrote:
>> Sun, May 21, 2017 at 02:16:45AM CEST, xiyou.wangc...@gmail.com wrote:
>>>On Sat, May 20, 2017 at 6:01 AM, Jiri Pirko <j...@resnulli.us> wrote:
>>>> +static void tcf_chain_destroy(struct tcf_chain *chain)
>>>> +{
>>>> + list_del(&chain->list);
>>>> + tcf_chain_flush(chain);
>>>> kfree(chain);
>>>> }
>>>>
>>>> @@ -510,7 +517,7 @@ static int tc_ctl_tfilter(struct sk_buff *skb, struct
>>>> nlmsghdr *n,
>>>>
>>>> if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
>>>> tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
>>>> - tcf_chain_destroy(chain);
>>>> + tcf_chain_flush(chain);
>>>
>>>
>>>I wonder if we should return EBUSY and do nothing in case of busy?
>>>The chain is no longer visual to new actions after your list_del(), but
>>>the old one could still use and see it.
>>
>> No. User request to flush the chain, that is what happens in the past
>> and that is what should happen now.
>> If there is still a reference, the chain_put will keep the empty chain.
>
>But if you dump the actions, this chain is still shown "goto chain"?
Yes, it will be shown there.
>You can't claim you really delete it as long as actions can still
>see it and dump it.
No, user just wants to delete all the filters. That is done. User does
not care if the actual chain structure is there or not.
