bridge: vlan: move back vlan_flush

Ido Schimmel reported a problem with switchdev devices because of the
order change of del_nbp operations, more specifically the move of
nbp_vlan_flush() which deletes all vlans and frees vlgrp after the
rx_handler has been unregistered. So in order to fix this move
vlan_flush back where it was and make it destroy the rhtable after
NULLing vlgrp and waiting a grace period to make sure noone can see it.

Reported-by: Ido Schimmel <idosch@mellanox.com>
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_if.c b/net/bridge/br_if.c
index 934cae9..45e4757 100644 (file)
--- a/net/bridge/br_if.c
+++ b/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);
 

diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 8835642..216018c 100644 (file)
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -132,7 +132,6 @@ struct net_bridge_vlan_group {
        struct list_head                vlan_list;
        u16                             num_vlans;
        u16                             pvid;
-       struct rcu_head                 rcu;
 };
 
 struct net_bridge_fdb_entry

diff --git a/net/bridge/br_vlan.c b/net/bridge/br_vlan.c
index 85e6756..5f0d0cc 100644 (file)
--- a/net/bridge/br_vlan.c
+++ b/net/bridge/br_vlan.c
@@ -307,15 +307,20 @@ out:
        return err;
 }
 
-static void __vlan_flush(struct net_bridge_vlan_group *vlgrp)
+static void __vlan_group_free(struct net_bridge_vlan_group *vg)
+{
+       WARN_ON(!list_empty(&vg->vlan_list));
+       rhashtable_destroy(&vg->vlan_hash);
+       kfree(vg);
+}
+
+static void __vlan_flush(struct net_bridge_vlan_group *vg)
 {
        struct net_bridge_vlan *vlan, *tmp;
 
-       __vlan_delete_pvid(vlgrp, vlgrp->pvid);
-       list_for_each_entry_safe(vlan, tmp, &vlgrp->vlan_list, vlist)
+       __vlan_delete_pvid(vg, vg->pvid);
+       list_for_each_entry_safe(vlan, tmp, &vg->vlan_list, vlist)
                __vlan_del(vlan);
-       rhashtable_destroy(&vlgrp->vlan_hash);
-       kfree_rcu(vlgrp, rcu);
 }
 
 struct sk_buff *br_handle_vlan(struct net_bridge *br,
@@ -571,9 +576,15 @@ int br_vlan_delete(struct net_bridge *br, u16 vid)
 
 void br_vlan_flush(struct net_bridge *br)
 {
+       struct net_bridge_vlan_group *vg;
+
        ASSERT_RTNL();
 
-       __vlan_flush(br_vlan_group(br));
+       vg = br_vlan_group(br);
+       __vlan_flush(vg);
+       RCU_INIT_POINTER(br->vlgrp, NULL);
+       synchronize_rcu();
+       __vlan_group_free(vg);
 }
 
 struct net_bridge_vlan *br_vlan_find(struct net_bridge_vlan_group *vg, u16 vid)
@@ -959,7 +970,13 @@ int nbp_vlan_delete(struct net_bridge_port *port, u16 vid)
 
 void nbp_vlan_flush(struct net_bridge_port *port)
 {
+       struct net_bridge_vlan_group *vg;
+
        ASSERT_RTNL();
 
-       __vlan_flush(nbp_vlan_group(port));
+       vg = nbp_vlan_group(port);
+       __vlan_flush(vg);
+       RCU_INIT_POINTER(port->vlgrp, NULL);
+       synchronize_rcu();
+       __vlan_group_free(vg);
 }