From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vlad Buslov Subject: [PATCH net-next 07/14] net: sched: act_sample: remove dependency on rtnl lock Date: Mon, 6 Aug 2018 09:54:18 +0300 Message-ID: <1533538465-23199-8-git-send-email-vladbu@mellanox.com> References: <1533538465-23199-1-git-send-email-vladbu@mellanox.com> 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 To: netdev@vger.kernel.org Return-path: Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:56369 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726572AbeHFJCd (ORCPT ); Mon, 6 Aug 2018 05:02:33 -0400 In-Reply-To: <1533538465-23199-1-git-send-email-vladbu@mellanox.com> Sender: netdev-owner@vger.kernel.org List-ID: Use tcf spinlock to protect private sample action data from concurrent modification during dump and init. Signed-off-by: Vlad Buslov --- net/sched/act_sample.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/net/sched/act_sample.c b/net/sched/act_sample.c index 2608ccc83e5e..81071afe1b43 100644 --- a/net/sched/act_sample.c +++ b/net/sched/act_sample.c @@ -80,11 +80,13 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla, } s = to_sample(*a); + spin_lock(&s->tcf_lock); s->tcf_action = parm->action; s->rate = nla_get_u32(tb[TCA_SAMPLE_RATE]); s->psample_group_num = nla_get_u32(tb[TCA_SAMPLE_PSAMPLE_GROUP]); psample_group = psample_group_get(net, s->psample_group_num); if (!psample_group) { + spin_unlock(&s->tcf_lock); tcf_idr_release(*a, bind); return -ENOMEM; } @@ -94,6 +96,7 @@ static int tcf_sample_init(struct net *net, struct nlattr *nla, s->truncate = true; s->trunc_size = nla_get_u32(tb[TCA_SAMPLE_TRUNC_SIZE]); } + spin_unlock(&s->tcf_lock); if (ret == ACT_P_CREATED) tcf_idr_insert(tn, *a); @@ -105,7 +108,8 @@ static void tcf_sample_cleanup(struct tc_action *a) struct tcf_sample *s = to_sample(a); struct psample_group *psample_group; - psample_group = rtnl_dereference(s->psample_group); + /* last reference to action, no need to lock */ + psample_group = rcu_dereference_protected(s->psample_group, 1); RCU_INIT_POINTER(s->psample_group, NULL); if (psample_group) psample_group_put(psample_group); @@ -174,12 +178,13 @@ static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, struct tcf_sample *s = to_sample(a); struct tc_sample opt = { .index = s->tcf_index, - .action = s->tcf_action, .refcnt = refcount_read(&s->tcf_refcnt) - ref, .bindcnt = atomic_read(&s->tcf_bindcnt) - bind, }; struct tcf_t t; + spin_lock(&s->tcf_lock); + opt.action = s->tcf_action; if (nla_put(skb, TCA_SAMPLE_PARMS, sizeof(opt), &opt)) goto nla_put_failure; @@ -196,9 +201,12 @@ static int tcf_sample_dump(struct sk_buff *skb, struct tc_action *a, if (nla_put_u32(skb, TCA_SAMPLE_PSAMPLE_GROUP, s->psample_group_num)) goto nla_put_failure; + spin_unlock(&s->tcf_lock); + return skb->len; nla_put_failure: + spin_unlock(&s->tcf_lock); nlmsg_trim(skb, b); return -1; } -- 2.7.5