From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [PATCH 12/14] net: sched: retry action check-insert on concurrent modification Date: Wed, 16 May 2018 11:59:53 +0200 Message-ID: <20180516095953.GI1972@nanopsycho> References: <1526308035-12484-1-git-send-email-vladbu@mellanox.com> <1526308035-12484-13-git-send-email-vladbu@mellanox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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: Vlad Buslov Return-path: Content-Disposition: inline In-Reply-To: <1526308035-12484-13-git-send-email-vladbu@mellanox.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netfilter-devel.vger.kernel.org Mon, May 14, 2018 at 04:27:13PM CEST, vladbu@mellanox.com wrote: >Retry check-insert sequence in action init functions if action with same >index was inserted concurrently. > >Signed-off-by: Vlad Buslov >--- > net/sched/act_bpf.c | 8 +++++++- > net/sched/act_connmark.c | 8 +++++++- > net/sched/act_csum.c | 8 +++++++- > net/sched/act_gact.c | 8 +++++++- > net/sched/act_ife.c | 8 +++++++- > net/sched/act_ipt.c | 8 +++++++- > net/sched/act_mirred.c | 8 +++++++- > net/sched/act_nat.c | 8 +++++++- > net/sched/act_pedit.c | 8 +++++++- > net/sched/act_police.c | 9 ++++++++- > net/sched/act_sample.c | 8 +++++++- > net/sched/act_simple.c | 9 ++++++++- > net/sched/act_skbedit.c | 8 +++++++- > net/sched/act_skbmod.c | 8 +++++++- > net/sched/act_tunnel_key.c | 9 ++++++++- > net/sched/act_vlan.c | 9 ++++++++- > 16 files changed, 116 insertions(+), 16 deletions(-) > >diff --git a/net/sched/act_bpf.c b/net/sched/act_bpf.c >index 5554bf7..7e20fdc 100644 >--- a/net/sched/act_bpf.c >+++ b/net/sched/act_bpf.c >@@ -299,10 +299,16 @@ static int tcf_bpf_init(struct net *net, struct nlattr *nla, > > parm = nla_data(tb[TCA_ACT_BPF_PARMS]); > >+replay: > if (!tcf_idr_check(tn, parm->index, act, bind)) { > ret = tcf_idr_create(tn, parm->index, est, act, > &act_bpf_ops, bind, true); >- if (ret < 0) >+ /* Action with specified index was created concurrently. >+ * Check again. >+ */ >+ if (parm->index && ret == -ENOSPC) >+ goto replay; >+ else if (ret) Hmm, looks like you are doing the same/very similar thing in every act code. I think it would make sense to introduce a helper function for this purpose. [...]