From patchwork Fri Aug 10 17:51:50 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlad Buslov X-Patchwork-Id: 956371 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=mellanox.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 41nCQ21lnjz9rxx for ; Sat, 11 Aug 2018 03:52:42 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729036AbeHJUXT (ORCPT ); Fri, 10 Aug 2018 16:23:19 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:47059 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728605AbeHJUXS (ORCPT ); Fri, 10 Aug 2018 16:23:18 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from vladbu@mellanox.com) with ESMTPS (AES256-SHA encrypted); 10 Aug 2018 20:55:57 +0300 Received: from reg-r-vrt-018-180.mtr.labs.mlnx (reg-r-vrt-018-180.mtr.labs.mlnx [10.213.18.180]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id w7AHqKqb027609; Fri, 10 Aug 2018 20:52:22 +0300 From: Vlad Buslov To: netdev@vger.kernel.org Cc: davem@davemloft.net, jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us, pablo@netfilter.org, kadlec@blackhole.kfki.hu, fw@strlen.de, ast@kernel.org, daniel@iogearbox.net, edumazet@google.com, keescook@chromium.org, marcelo.leitner@gmail.com, Vlad Buslov Subject: [PATCH net-next v2 10/15] net: sched: act_tunnel_key: remove dependency on rtnl lock Date: Fri, 10 Aug 2018 20:51:50 +0300 Message-Id: <1533923515-5664-11-git-send-email-vladbu@mellanox.com> X-Mailer: git-send-email 2.7.5 In-Reply-To: <1533923515-5664-1-git-send-email-vladbu@mellanox.com> References: <1533923515-5664-1-git-send-email-vladbu@mellanox.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Use tcf lock to protect tunnel key action struct private data from concurrent modification in init and dump. Use rcu swap operation to reassign params pointer under protection of tcf lock. (old params value is not used by init, so there is no need of standalone rcu dereference step) Remove rtnl lock assertion that is no longer required. Signed-off-by: Vlad Buslov --- net/sched/act_tunnel_key.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/net/sched/act_tunnel_key.c b/net/sched/act_tunnel_key.c index d42d9e112789..ba2ae9f75ef5 100644 --- a/net/sched/act_tunnel_key.c +++ b/net/sched/act_tunnel_key.c @@ -204,7 +204,6 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, { struct tc_action_net *tn = net_generic(net, tunnel_key_net_id); struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1]; - struct tcf_tunnel_key_params *params_old; struct tcf_tunnel_key_params *params_new; struct metadata_dst *metadata = NULL; struct tc_tunnel_key *parm; @@ -346,24 +345,22 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla, t = to_tunnel_key(*a); - ASSERT_RTNL(); params_new = kzalloc(sizeof(*params_new), GFP_KERNEL); if (unlikely(!params_new)) { tcf_idr_release(*a, bind); NL_SET_ERR_MSG(extack, "Cannot allocate tunnel key parameters"); return -ENOMEM; } - - params_old = rtnl_dereference(t->params); - - t->tcf_action = parm->action; params_new->tcft_action = parm->t_action; params_new->tcft_enc_metadata = metadata; - rcu_assign_pointer(t->params, params_new); - - if (params_old) - kfree_rcu(params_old, rcu); + spin_lock(&t->tcf_lock); + t->tcf_action = parm->action; + rcu_swap_protected(t->params, params_new, + lockdep_is_held(&t->tcf_lock)); + spin_unlock(&t->tcf_lock); + if (params_new) + kfree_rcu(params_new, rcu); if (ret == ACT_P_CREATED) tcf_idr_insert(tn, *a); @@ -485,12 +482,13 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a, .index = t->tcf_index, .refcnt = refcount_read(&t->tcf_refcnt) - ref, .bindcnt = atomic_read(&t->tcf_bindcnt) - bind, - .action = t->tcf_action, }; struct tcf_t tm; - params = rtnl_dereference(t->params); - + spin_lock(&t->tcf_lock); + params = rcu_dereference_protected(t->params, + lockdep_is_held(&t->tcf_lock)); + opt.action = t->tcf_action; opt.t_action = params->tcft_action; if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt)) @@ -522,10 +520,12 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a, if (nla_put_64bit(skb, TCA_TUNNEL_KEY_TM, sizeof(tm), &tm, TCA_TUNNEL_KEY_PAD)) goto nla_put_failure; + spin_unlock(&t->tcf_lock); return skb->len; nla_put_failure: + spin_unlock(&t->tcf_lock); nlmsg_trim(skb, b); return -1; }