From 8d91c1e411f55d7ea91b1183a2e9f8088fb4d5be Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Tue, 15 Dec 2015 14:52:16 -0300 Subject: Linux-libre 4.3.2-gnu --- net/sched/act_gact.c | 44 +++++++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 19 deletions(-) (limited to 'net/sched/act_gact.c') diff --git a/net/sched/act_gact.c b/net/sched/act_gact.c index 7fffc2272..5c1b05170 100644 --- a/net/sched/act_gact.c +++ b/net/sched/act_gact.c @@ -28,14 +28,18 @@ #ifdef CONFIG_GACT_PROB static int gact_net_rand(struct tcf_gact *gact) { - if (!gact->tcfg_pval || prandom_u32() % gact->tcfg_pval) + smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ + if (prandom_u32() % gact->tcfg_pval) return gact->tcf_action; return gact->tcfg_paction; } static int gact_determ(struct tcf_gact *gact) { - if (!gact->tcfg_pval || gact->tcf_bstats.packets % gact->tcfg_pval) + u32 pack = atomic_inc_return(&gact->packets); + + smp_rmb(); /* coupled with smp_wmb() in tcf_gact_init() */ + if (pack % gact->tcfg_pval) return gact->tcf_action; return gact->tcfg_paction; } @@ -85,7 +89,8 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla, #endif if (!tcf_hash_check(parm->index, a, bind)) { - ret = tcf_hash_create(parm->index, est, a, sizeof(*gact), bind); + ret = tcf_hash_create(parm->index, est, a, sizeof(*gact), + bind, true); if (ret) return ret; ret = ACT_P_CREATED; @@ -99,16 +104,19 @@ static int tcf_gact_init(struct net *net, struct nlattr *nla, gact = to_gact(a); - spin_lock_bh(&gact->tcf_lock); + ASSERT_RTNL(); gact->tcf_action = parm->action; #ifdef CONFIG_GACT_PROB if (p_parm) { gact->tcfg_paction = p_parm->paction; - gact->tcfg_pval = p_parm->pval; + gact->tcfg_pval = max_t(u16, 1, p_parm->pval); + /* Make sure tcfg_pval is written before tcfg_ptype + * coupled with smp_rmb() in gact_net_rand() & gact_determ() + */ + smp_wmb(); gact->tcfg_ptype = p_parm->ptype; } #endif - spin_unlock_bh(&gact->tcf_lock); if (ret == ACT_P_CREATED) tcf_hash_insert(a); return ret; @@ -118,23 +126,21 @@ static int tcf_gact(struct sk_buff *skb, const struct tc_action *a, struct tcf_result *res) { struct tcf_gact *gact = a->priv; - int action = TC_ACT_SHOT; + int action = READ_ONCE(gact->tcf_action); - spin_lock(&gact->tcf_lock); #ifdef CONFIG_GACT_PROB - if (gact->tcfg_ptype) - action = gact_rand[gact->tcfg_ptype](gact); - else - action = gact->tcf_action; -#else - action = gact->tcf_action; + { + u32 ptype = READ_ONCE(gact->tcfg_ptype); + + if (ptype) + action = gact_rand[ptype](gact); + } #endif - gact->tcf_bstats.bytes += qdisc_pkt_len(skb); - gact->tcf_bstats.packets++; + bstats_cpu_update(this_cpu_ptr(gact->common.cpu_bstats), skb); if (action == TC_ACT_SHOT) - gact->tcf_qstats.drops++; - gact->tcf_tm.lastuse = jiffies; - spin_unlock(&gact->tcf_lock); + qstats_drop_inc(this_cpu_ptr(gact->common.cpu_qstats)); + + tcf_lastuse_update(&gact->tcf_tm); return action; } -- cgit v1.2.3-54-g00ecf