[PATCH net-next 2/9] net: bridge: vlan: annotate lockless pvid use

[Nikolay Aleksandrov <razor@blackwall.org>]

Use READ/WRITE_ONCE to annotate lockless pvid use, br_get_pvid() is the
helper that should be used outside of the bridge vlan code. The rest of
the vlan places that access pvid directly all have rtnl.

Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
---
 net/bridge/br_private.h | 2 +-
 net/bridge/br_vlan.c    | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 5b2c22ad669e..0efd2e79e255 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -1687,7 +1687,7 @@ static inline u16 br_get_pvid(const struct net_bridge_vlan_group *vg)
 	if (!vg)
 		return 0;
 
-	return vg->pvid;
+	return READ_ONCE(vg->pvid);
 }
 
 static inline u16 br_vlan_flags(const struct net_bridge_vlan *v, u16 pvid)
diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 2ae6ffb23399..a53054fcc093 100644
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -41,7 +41,7 @@ static void __vlan_add_pvid(struct net_bridge_vlan_group *vg,
 		return;
 
 	br_vlan_set_pvid_state(vg, v->state);
-	vg->pvid = v->vid;
+	WRITE_ONCE(vg->pvid, v->vid);
 }
 
 static void __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
@@ -49,7 +49,7 @@ static void __vlan_delete_pvid(struct net_bridge_vlan_group *vg, u16 vid)
 	if (vg->pvid != vid)
 		return;
 
-	vg->pvid = 0;
+	WRITE_ONCE(vg->pvid, 0);
 }
 
 /* Update the BRIDGE_VLAN_INFO_PVID and BRIDGE_VLAN_INFO_UNTAGGED flags of @v.
-- 
2.47.3