From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Buslov Subject: Re: [PATCH 07/14] net: sched: use reference counting action init Date: Tue, 15 May 2018 14:32:51 +0300 Message-ID: References: <1526308035-12484-1-git-send-email-vladbu@mellanox.com> <1526308035-12484-8-git-send-email-vladbu@mellanox.com> <20180515112404.GL2134@nanopsycho.orion> Mime-Version: 1.0 Content-Type: text/plain Cc: netdev@vger.kernel.org, davem@davemloft.net, jhs@mojatatu.com, xiyou.wangcong@gmail.com, pablo@netfilter.org, kadlec@blackhole.kfki.hu, fw@strlen.de, ast@kernel.org, daniel@iogearbox.net, edumazet@google.com, keescook@chromium.org, linux-kernel@vger.kernel.org, netfilter-devel@vger.kernel.org, coreteam@netfilter.org, kliteyn@mellanox.com To: Jiri Pirko Return-path: In-reply-to: <20180515112404.GL2134@nanopsycho.orion> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue 15 May 2018 at 11:24, Jiri Pirko wrote: > Mon, May 14, 2018 at 04:27:08PM CEST, vladbu@mellanox.com wrote: >>Change action API to assume that action init function always takes >>reference to action, even when overwriting existing action. This is >>necessary because action API continues to use action pointer after init >>function is done. At this point action becomes accessible for concurrent >>modifications so user must always hold reference to it. >> >>Implement helper put list function to atomically release list of actions >>after action API init code is done using them. >> >>Signed-off-by: Vlad Buslov >>--- >> net/sched/act_api.c | 38 +++++++++++++++++--------------------- >> 1 file changed, 17 insertions(+), 21 deletions(-) >> > > [...] > > >>@@ -1196,8 +1190,7 @@ tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n, >> return ret; >> } >> err: >>- if (event != RTM_GETACTION) > > Howcome you do this for RTM_GETACTION now too? Where is the related > "get"? In patch 5. There is always a possibility of concurrent delete without rtnl lock so all usages of action pointers were converted to hold reference to action. > > >>- tcf_action_destroy(&actions, 0); >>+ tcf_action_put_lst(&actions); >> return ret; >> } >> > > [...]