Merge branch 'bridge-vlan'

Nikolay Aleksandrov says:

====================
bridge: vlan: cleanups & fixes (part 3)

Patch 01 converts the vlgrp member to use rcu as it was already used in a
similar way so better to make it official and use all the available RCU
instrumentation. Patch 02 fixes a bug where the vlan_list can be traversed
without rtnl or rcu held which could lead to using freed entries.
Patch 03 removes some redundant code that isn't needed anymore.
Patch 04 fixes a bug reported by Ido Schimmel about the vlan_flush order
and switchdevs, it moves it back.

v2: patch 03 and 04 are new, couldn't escape the second synchronize_rcu()
since the rhtable destruction can sleep
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/bridge/br_device.c

@@ -56,7 +56,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev)
 	skb_reset_mac_header(skb);
 	skb_pull(skb, ETH_HLEN);
 
-	if (!br_allowed_ingress(br, br_vlan_group(br), skb, &vid))
+	if (!br_allowed_ingress(br, br_vlan_group_rcu(br), skb, &vid))
 		goto out;
 
 	if (is_broadcast_ether_addr(dest))

net/bridge/br_forward.c

@@ -32,7 +32,7 @@ static inline int should_deliver(const struct net_bridge_port *p,
 {
 	struct net_bridge_vlan_group *vg;
 
-	vg = nbp_vlan_group(p);
+	vg = nbp_vlan_group_rcu(p);
 	return ((p->flags & BR_HAIRPIN_MODE) || skb->dev != p->dev) &&
 		br_allowed_egress(vg, skb) && p->state == BR_STATE_FORWARDING;
 }
@@ -80,7 +80,7 @@ static void __br_deliver(const struct net_bridge_port *to, struct sk_buff *skb)
 {
 	struct net_bridge_vlan_group *vg;
 
-	vg = nbp_vlan_group(to);
+	vg = nbp_vlan_group_rcu(to);
 	skb = br_handle_vlan(to->br, vg, skb);
 	if (!skb)
 		return;
@@ -112,7 +112,7 @@ static void __br_forward(const struct net_bridge_port *to, struct sk_buff *skb)
 		return;
 	}
 
-	vg = nbp_vlan_group(to);
+	vg = nbp_vlan_group_rcu(to);
 	skb = br_handle_vlan(to->br, vg, skb);
 	if (!skb)
 		return;

net/bridge/br_if.c

@@ -248,6 +248,7 @@ static void del_nbp(struct net_bridge_port *p)
 
 	list_del_rcu(&p->list);
 
+	nbp_vlan_flush(p);
 	br_fdb_delete_by_port(br, p, 0, 1);
 	nbp_update_port_count(br);
 
@@ -256,8 +257,6 @@ static void del_nbp(struct net_bridge_port *p)
 	dev->priv_flags &= ~IFF_BRIDGE_PORT;
 
 	netdev_rx_handler_unregister(dev);
-	/* use the synchronize_rcu done by netdev_rx_handler_unregister */
-	nbp_vlan_flush(p);
 
 	br_multicast_del_port(p);
 

net/bridge/br_input.c

@@ -44,7 +44,7 @@ static int br_pass_frame_up(struct sk_buff *skb)
 	brstats->rx_bytes += skb->len;
 	u64_stats_update_end(&brstats->syncp);
 
-	vg = br_vlan_group(br);
+	vg = br_vlan_group_rcu(br);
 	/* Bridge is just like any other port.  Make sure the
 	 * packet is allowed except in promisc modue when someone
 	 * may be running packet capture.
@@ -140,7 +140,7 @@ int br_handle_frame_finish(struct net *net, struct sock *sk, struct sk_buff *skb
 	if (!p || p->state == BR_STATE_DISABLED)
 		goto drop;
 
-	if (!br_allowed_ingress(p->br, nbp_vlan_group(p), skb, &vid))
+	if (!br_allowed_ingress(p->br, nbp_vlan_group_rcu(p), skb, &vid))
 		goto out;
 
 	/* insert into forwarding database after filtering to avoid spoofing */

net/bridge/br_netlink.c

@@ -102,10 +102,10 @@ static size_t br_get_link_af_size_filtered(const struct net_device *dev,
 	rcu_read_lock();
 	if (br_port_exists(dev)) {
 		p = br_port_get_rcu(dev);
-		vg = nbp_vlan_group(p);
+		vg = nbp_vlan_group_rcu(p);
 	} else if (dev->priv_flags & IFF_EBRIDGE) {
 		br = netdev_priv(dev);
-		vg = br_vlan_group(br);
+		vg = br_vlan_group_rcu(br);
 	}
 	num_vlan_infos = br_get_num_vlan_infos(vg, filter_mask);
 	rcu_read_unlock();
@@ -253,7 +253,7 @@ static int br_fill_ifvlaninfo_compressed(struct sk_buff *skb,
 	 * if vlaninfo represents a range
 	 */
 	pvid = br_get_pvid(vg);
-	list_for_each_entry(v, &vg->vlan_list, vlist) {
+	list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
 		flags = 0;
 		if (!br_vlan_should_use(v))
 			continue;
@@ -303,7 +303,7 @@ static int br_fill_ifvlaninfo(struct sk_buff *skb,
 	u16 pvid;
 
 	pvid = br_get_pvid(vg);
-	list_for_each_entry(v, &vg->vlan_list, vlist) {
+	list_for_each_entry_rcu(v, &vg->vlan_list, vlist) {
 		if (!br_vlan_should_use(v))
 			continue;
 
@@ -386,22 +386,27 @@ static int br_fill_ifinfo(struct sk_buff *skb,
 		struct nlattr *af;
 		int err;
 
+		/* RCU needed because of the VLAN locking rules (rcu || rtnl) */
+		rcu_read_lock();
 		if (port)
-			vg = nbp_vlan_group(port);
+			vg = nbp_vlan_group_rcu(port);
 		else
-			vg = br_vlan_group(br);
+			vg = br_vlan_group_rcu(br);
 
-		if (!vg || !vg->num_vlans)
+		if (!vg || !vg->num_vlans) {
+			rcu_read_unlock();
 			goto done;
-
+		}
 		af = nla_nest_start(skb, IFLA_AF_SPEC);
-		if (!af)
+		if (!af) {
+			rcu_read_unlock();
 			goto nla_put_failure;
-
+		}
 		if (filter_mask & RTEXT_FILTER_BRVLAN_COMPRESSED)
 			err = br_fill_ifvlaninfo_compressed(skb, vg);
 		else
 			err = br_fill_ifvlaninfo(skb, vg);
+		rcu_read_unlock();
 		if (err)
 			goto nla_put_failure;
 		nla_nest_end(skb, af);

net/bridge/br_private.h

@@ -229,7 +229,7 @@ struct net_bridge_port
 	struct netpoll			*np;
 #endif
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-	struct net_bridge_vlan_group	*vlgrp;
+	struct net_bridge_vlan_group	__rcu *vlgrp;
 #endif
 };
 
@@ -337,7 +337,7 @@ struct net_bridge
 	struct kobject			*ifobj;
 	u32				auto_cnt;
 #ifdef CONFIG_BRIDGE_VLAN_FILTERING
-	struct net_bridge_vlan_group	*vlgrp;
+	struct net_bridge_vlan_group	__rcu *vlgrp;
 	u8				vlan_enabled;
 	__be16				vlan_proto;
 	u16				default_pvid;
@@ -700,13 +700,25 @@ int nbp_get_num_vlan_infos(struct net_bridge_port *p, u32 filter_mask);
 static inline struct net_bridge_vlan_group *br_vlan_group(
 					const struct net_bridge *br)
 {
-	return br->vlgrp;
+	return rtnl_dereference(br->vlgrp);
 }
 
 static inline struct net_bridge_vlan_group *nbp_vlan_group(
 					const struct net_bridge_port *p)
 {
-	return p->vlgrp;
+	return rtnl_dereference(p->vlgrp);
+}
+
+static inline struct net_bridge_vlan_group *br_vlan_group_rcu(
+					const struct net_bridge *br)
+{
+	return rcu_dereference(br->vlgrp);
+}
+
+static inline struct net_bridge_vlan_group *nbp_vlan_group_rcu(
+					const struct net_bridge_port *p)
+{
+	return rcu_dereference(p->vlgrp);
 }
 
 /* Since bridge now depends on 8021Q module, but the time bridge sees the
@@ -853,6 +865,19 @@ static inline struct net_bridge_vlan_group *nbp_vlan_group(
 {
 	return NULL;
 }
+
+static inline struct net_bridge_vlan_group *br_vlan_group_rcu(
+					const struct net_bridge *br)
+{
+	return NULL;
+}
+
+static inline struct net_bridge_vlan_group *nbp_vlan_group_rcu(
+					const struct net_bridge_port *p)
+{
+	return NULL;
+}
+
 #endif
 
 struct nf_br_ops {