From patchwork Fri Aug 10 17:51:51 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vlad Buslov X-Patchwork-Id: 956374 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 41nCQ70mspz9rxx for ; Sat, 11 Aug 2018 03:52:47 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728855AbeHJUXT (ORCPT ); Fri, 10 Aug 2018 16:23:19 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:47084 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728655AbeHJUXS (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 w7AHqKqc027609; 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 11/15] net: sched: act_vlan: remove dependency on rtnl lock Date: Fri, 10 Aug 2018 20:51:51 +0300 Message-Id: <1533923515-5664-12-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 spinlock to protect vlan action private data from concurrent modification during dump and init. 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 assertion that is no longer necessary. Signed-off-by: Vlad Buslov --- net/sched/act_vlan.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/net/sched/act_vlan.c b/net/sched/act_vlan.c index 15a0ee214c9c..5bde17fe3608 100644 --- a/net/sched/act_vlan.c +++ b/net/sched/act_vlan.c @@ -109,7 +109,7 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, { struct tc_action_net *tn = net_generic(net, vlan_net_id); struct nlattr *tb[TCA_VLAN_MAX + 1]; - struct tcf_vlan_params *p, *p_old; + struct tcf_vlan_params *p; struct tc_vlan *parm; struct tcf_vlan *v; int action; @@ -202,26 +202,24 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla, v = to_vlan(*a); - ASSERT_RTNL(); p = kzalloc(sizeof(*p), GFP_KERNEL); if (!p) { tcf_idr_release(*a, bind); return -ENOMEM; } - v->tcf_action = parm->action; - - p_old = rtnl_dereference(v->vlan_p); - p->tcfv_action = action; p->tcfv_push_vid = push_vid; p->tcfv_push_prio = push_prio; p->tcfv_push_proto = push_proto; - rcu_assign_pointer(v->vlan_p, p); + spin_lock(&v->tcf_lock); + v->tcf_action = parm->action; + rcu_swap_protected(v->vlan_p, p, lockdep_is_held(&v->tcf_lock)); + spin_unlock(&v->tcf_lock); - if (p_old) - kfree_rcu(p_old, rcu); + if (p) + kfree_rcu(p, rcu); if (ret == ACT_P_CREATED) tcf_idr_insert(tn, *a); @@ -243,16 +241,18 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a, { unsigned char *b = skb_tail_pointer(skb); struct tcf_vlan *v = to_vlan(a); - struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p); + struct tcf_vlan_params *p; struct tc_vlan opt = { .index = v->tcf_index, .refcnt = refcount_read(&v->tcf_refcnt) - ref, .bindcnt = atomic_read(&v->tcf_bindcnt) - bind, - .action = v->tcf_action, - .v_action = p->tcfv_action, }; struct tcf_t t; + spin_lock(&v->tcf_lock); + opt.action = v->tcf_action; + p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock)); + opt.v_action = p->tcfv_action; if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt)) goto nla_put_failure; @@ -268,9 +268,12 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a, tcf_tm_dump(&t, &v->tcf_tm); if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD)) goto nla_put_failure; + spin_unlock(&v->tcf_lock); + return skb->len; nla_put_failure: + spin_unlock(&v->tcf_lock); nlmsg_trim(skb, b); return -1; }