bridge: vlan: use proper rcu for the vlgrp member
The bridge and port's vlgrp member is already used in RCU way, currently
we rely on the fact that it cannot disappear while the port exists but
that is error-prone and we might miss places with improper locking
(either RCU or RTNL must be held to walk the vlan_list). So make it
official and use RCU for vlgrp to catch offenders. Introduce proper vlgrp
accessors and use them consistently throughout the code.
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index ba0c67b..8835642 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -132,6 +132,7 @@
struct list_head vlan_list;
u16 num_vlans;
u16 pvid;
+ struct rcu_head rcu;
};
struct net_bridge_fdb_entry
@@ -229,7 +230,7 @@
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 +338,7 @@
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 +701,25 @@
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 +866,19 @@
{
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 {