Merge branch 'net_sched-extend-rcu-use-in-dump-methods-ii'

Eric Dumazet says:

====================
net_sched: extend RCU use in dump() methods (II)

Second series adding RCU dump() to three actions

First patch removes BH blocking on modules done in the first series.
====================

Link: https://patch.msgid.link/20250827125349.3505302-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

include/net/tc_act/tc_skbmod.h

@@ -12,6 +12,7 @@
 struct tcf_skbmod_params {
 	struct rcu_head	rcu;
 	u64	flags; /*up to 64 types of operations; extend if needed */
+	int	action;
 	u8	eth_dst[ETH_ALEN];
 	u16	eth_type;
 	u8	eth_src[ETH_ALEN];

include/net/tc_act/tc_tunnel_key.h

@@ -14,6 +14,7 @@
 struct tcf_tunnel_key_params {
 	struct rcu_head		rcu;
 	int			tcft_action;
+	int			action;
 	struct metadata_dst     *tcft_enc_metadata;
 };
 

include/net/tc_act/tc_vlan.h

@@ -10,6 +10,7 @@
 #include <linux/tc_act/tc_vlan.h>
 
 struct tcf_vlan_params {
+	int		  action;
 	int               tcfv_action;
 	unsigned char     tcfv_push_dst[ETH_ALEN];
 	unsigned char     tcfv_push_src[ETH_ALEN];

net/sched/act_connmark.c

@@ -169,10 +169,10 @@ static int tcf_connmark_init(struct net *net, struct nlattr *nla,
 
 	nparms->action = parm->action;
 
-	spin_lock_bh(&ci->tcf_lock);
+	spin_lock(&ci->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparms = rcu_replace_pointer(ci->parms, nparms, lockdep_is_held(&ci->tcf_lock));
-	spin_unlock_bh(&ci->tcf_lock);
+	spin_unlock(&ci->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_csum.c

@@ -101,11 +101,11 @@ static int tcf_csum_init(struct net *net, struct nlattr *nla,
 	params_new->update_flags = parm->update_flags;
 	params_new->action = parm->action;
 
-	spin_lock_bh(&p->tcf_lock);
+	spin_lock(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(p->params, params_new,
 					 lockdep_is_held(&p->tcf_lock));
-	spin_unlock_bh(&p->tcf_lock);
+	spin_unlock(&p->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_ct.c

@@ -1410,11 +1410,11 @@ static int tcf_ct_init(struct net *net, struct nlattr *nla,
 		goto cleanup;
 
 	params->action = parm->action;
-	spin_lock_bh(&c->tcf_lock);
+	spin_lock(&c->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params = rcu_replace_pointer(c->params, params,
 				     lockdep_is_held(&c->tcf_lock));
-	spin_unlock_bh(&c->tcf_lock);
+	spin_unlock(&c->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_ctinfo.c

@@ -258,11 +258,11 @@ static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
 
 	cp_new->action = actparm->action;
 
-	spin_lock_bh(&ci->tcf_lock);
+	spin_lock(&ci->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch);
 	cp_new = rcu_replace_pointer(ci->params, cp_new,
 				     lockdep_is_held(&ci->tcf_lock));
-	spin_unlock_bh(&ci->tcf_lock);
+	spin_unlock(&ci->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_mpls.c

@@ -296,10 +296,10 @@ static int tcf_mpls_init(struct net *net, struct nlattr *nla,
 					     htons(ETH_P_MPLS_UC));
 	p->action = parm->action;
 
-	spin_lock_bh(&m->tcf_lock);
+	spin_lock(&m->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
-	spin_unlock_bh(&m->tcf_lock);
+	spin_unlock(&m->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_nat.c

@@ -95,10 +95,10 @@ static int tcf_nat_init(struct net *net, struct nlattr *nla, struct nlattr *est,
 
 	p = to_tcf_nat(*a);
 
-	spin_lock_bh(&p->tcf_lock);
+	spin_lock(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparm = rcu_replace_pointer(p->parms, nparm, lockdep_is_held(&p->tcf_lock));
-	spin_unlock_bh(&p->tcf_lock);
+	spin_unlock(&p->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);

net/sched/act_pedit.c

@@ -280,10 +280,10 @@ static int tcf_pedit_init(struct net *net, struct nlattr *nla,
 
 	p = to_pedit(*a);
 	nparms->action = parm->action;
-	spin_lock_bh(&p->tcf_lock);
+	spin_lock(&p->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	oparms = rcu_replace_pointer(p->parms, nparms, 1);
-	spin_unlock_bh(&p->tcf_lock);
+	spin_unlock(&p->tcf_lock);
 
 	if (oparms)
 		call_rcu(&oparms->rcu, tcf_pedit_cleanup_rcu);

net/sched/act_skbedit.c

@@ -261,11 +261,11 @@ static int tcf_skbedit_init(struct net *net, struct nlattr *nla,
 		params_new->mask = *mask;
 
 	params_new->action = parm->action;
-	spin_lock_bh(&d->tcf_lock);
+	spin_lock(&d->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(d->params, params_new,
 					 lockdep_is_held(&d->tcf_lock));
-	spin_unlock_bh(&d->tcf_lock);
+	spin_unlock(&d->tcf_lock);
 	if (params_new)
 		kfree_rcu(params_new, rcu);
 	if (goto_ch)

net/sched/act_skbmod.c

@@ -27,19 +27,18 @@ TC_INDIRECT_SCOPE int tcf_skbmod_act(struct sk_buff *skb,
 				     struct tcf_result *res)
 {
 	struct tcf_skbmod *d = to_skbmod(a);
-	int action, max_edit_len, err;
 	struct tcf_skbmod_params *p;
+	int max_edit_len, err;
 	u64 flags;
 
 	tcf_lastuse_update(&d->tcf_tm);
 	bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb);
 
-	action = READ_ONCE(d->tcf_action);
-	if (unlikely(action == TC_ACT_SHOT))
+	p = rcu_dereference_bh(d->skbmod_p);
+	if (unlikely(p->action == TC_ACT_SHOT))
 		goto drop;
 
 	max_edit_len = skb_mac_header_len(skb);
-	p = rcu_dereference_bh(d->skbmod_p);
 	flags = p->flags;
 
 	/* tcf_skbmod_init() guarantees "flags" to be one of the following:
@@ -85,7 +84,7 @@ TC_INDIRECT_SCOPE int tcf_skbmod_act(struct sk_buff *skb,
 		INET_ECN_set_ce(skb);
 
 out:
-	return action;
+	return p->action;
 
 drop:
 	qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats));
@@ -193,9 +192,9 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 	}
 
 	p->flags = lflags;
-
+	p->action = parm->action;
 	if (ovr)
-		spin_lock_bh(&d->tcf_lock);
+		spin_lock(&d->tcf_lock);
 	/* Protected by tcf_lock if overwriting existing action. */
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	p_old = rcu_dereference_protected(d->skbmod_p, 1);
@@ -209,7 +208,7 @@ static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
 
 	rcu_assign_pointer(d->skbmod_p, p);
 	if (ovr)
-		spin_unlock_bh(&d->tcf_lock);
+		spin_unlock(&d->tcf_lock);
 
 	if (p_old)
 		kfree_rcu(p_old, rcu);
@@ -248,10 +247,9 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
 	opt.index   = d->tcf_index;
 	opt.refcnt  = refcount_read(&d->tcf_refcnt) - ref;
 	opt.bindcnt = atomic_read(&d->tcf_bindcnt) - bind;
-	spin_lock_bh(&d->tcf_lock);
-	opt.action = d->tcf_action;
-	p = rcu_dereference_protected(d->skbmod_p,
-				      lockdep_is_held(&d->tcf_lock));
+	rcu_read_lock();
+	p = rcu_dereference(d->skbmod_p);
+	opt.action = p->action;
 	opt.flags  = p->flags;
 	if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt))
 		goto nla_put_failure;
@@ -269,10 +267,10 @@ static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
 	if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD))
 		goto nla_put_failure;
 
-	spin_unlock_bh(&d->tcf_lock);
+	rcu_read_unlock();
 	return skb->len;
 nla_put_failure:
-	spin_unlock_bh(&d->tcf_lock);
+	rcu_read_unlock();
 	nlmsg_trim(skb, b);
 	return -1;
 }

net/sched/act_tunnel_key.c

@@ -29,13 +29,11 @@ TC_INDIRECT_SCOPE int tunnel_key_act(struct sk_buff *skb,
 {
 	struct tcf_tunnel_key *t = to_tunnel_key(a);
 	struct tcf_tunnel_key_params *params;
-	int action;
 
 	params = rcu_dereference_bh(t->params);
 
 	tcf_lastuse_update(&t->tcf_tm);
 	tcf_action_update_bstats(&t->common, skb);
-	action = READ_ONCE(t->tcf_action);
 
 	switch (params->tcft_action) {
 	case TCA_TUNNEL_KEY_ACT_RELEASE:
@@ -51,7 +49,7 @@ TC_INDIRECT_SCOPE int tunnel_key_act(struct sk_buff *skb,
 		break;
 	}
 
-	return action;
+	return params->action;
 }
 
 static const struct nla_policy
@@ -532,11 +530,12 @@ static int tunnel_key_init(struct net *net, struct nlattr *nla,
 	params_new->tcft_action = parm->t_action;
 	params_new->tcft_enc_metadata = metadata;
 
-	spin_lock_bh(&t->tcf_lock);
+	params_new->action = parm->action;
+	spin_lock(&t->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	params_new = rcu_replace_pointer(t->params, params_new,
 					 lockdep_is_held(&t->tcf_lock));
-	spin_unlock_bh(&t->tcf_lock);
+	spin_unlock(&t->tcf_lock);
 	tunnel_key_release_params(params_new);
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);
@@ -726,10 +725,9 @@ static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
 	};
 	struct tcf_t tm;
 
-	spin_lock_bh(&t->tcf_lock);
-	params = rcu_dereference_protected(t->params,
-					   lockdep_is_held(&t->tcf_lock));
-	opt.action   = t->tcf_action;
+	rcu_read_lock();
+	params = rcu_dereference(t->params);
+	opt.action   = params->action;
 	opt.t_action = params->tcft_action;
 
 	if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt))
@@ -766,12 +764,12 @@ 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_bh(&t->tcf_lock);
+	rcu_read_unlock();
 
 	return skb->len;
 
 nla_put_failure:
-	spin_unlock_bh(&t->tcf_lock);
+	rcu_read_unlock();
 	nlmsg_trim(skb, b);
 	return -1;
 }

net/sched/act_vlan.c

@@ -25,7 +25,6 @@ TC_INDIRECT_SCOPE int tcf_vlan_act(struct sk_buff *skb,
 {
 	struct tcf_vlan *v = to_vlan(a);
 	struct tcf_vlan_params *p;
-	int action;
 	int err;
 	u16 tci;
 
@@ -38,8 +37,6 @@ TC_INDIRECT_SCOPE int tcf_vlan_act(struct sk_buff *skb,
 	if (skb_at_tc_ingress(skb))
 		skb_push_rcsum(skb, skb->mac_len);
 
-	action = READ_ONCE(v->tcf_action);
-
 	p = rcu_dereference_bh(v->vlan_p);
 
 	switch (p->tcfv_action) {
@@ -97,7 +94,7 @@ out:
 		skb_pull_rcsum(skb, skb->mac_len);
 
 	skb_reset_mac_len(skb);
-	return action;
+	return p->action;
 
 drop:
 	tcf_action_inc_drop_qstats(&v->common);
@@ -255,10 +252,11 @@ static int tcf_vlan_init(struct net *net, struct nlattr *nla,
 			   ETH_ALEN);
 	}
 
-	spin_lock_bh(&v->tcf_lock);
+	p->action = parm->action;
+	spin_lock(&v->tcf_lock);
 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
 	p = rcu_replace_pointer(v->vlan_p, p, lockdep_is_held(&v->tcf_lock));
-	spin_unlock_bh(&v->tcf_lock);
+	spin_unlock(&v->tcf_lock);
 
 	if (goto_ch)
 		tcf_chain_put_by_act(goto_ch);
@@ -297,9 +295,9 @@ static int tcf_vlan_dump(struct sk_buff *skb, struct tc_action *a,
 	};
 	struct tcf_t t;
 
-	spin_lock_bh(&v->tcf_lock);
-	opt.action = v->tcf_action;
-	p = rcu_dereference_protected(v->vlan_p, lockdep_is_held(&v->tcf_lock));
+	rcu_read_lock();
+	p = rcu_dereference(v->vlan_p);
+	opt.action = p->action;
 	opt.v_action = p->tcfv_action;
 	if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
 		goto nla_put_failure;
@@ -325,12 +323,12 @@ 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_bh(&v->tcf_lock);
+	rcu_read_unlock();
 
 	return skb->len;
 
 nla_put_failure:
-	spin_unlock_bh(&v->tcf_lock);
+	rcu_read_unlock();
 	nlmsg_trim(skb, b);
 	return -1;
 }