From: Nikolay Aleksandrov <[email protected]> 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 <[email protected]> Signed-off-by: Nikolay Aleksandrov <[email protected]> --- v2: use synchronize_rcu() explicitly and free the vlan_group afterwards also added a WARN_ON() to catch non-empty vlan lists. net/bridge/br_if.c | 3 +-- net/bridge/br_private.h | 1 - net/bridge/br_vlan.c | 31 ++++++++++++++++++++++++------- 3 files changed, 25 insertions(+), 10 deletions(-) diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 934cae9fa317..45e4757c6fd2 100644 --- 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 8835642a6326..216018c76018 100644 --- 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 573ddfc31fb1..fbb9f8ce36c7 100644 --- a/net/bridge/br_vlan.c +++ b/net/bridge/br_vlan.c @@ -321,15 +321,20 @@ 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, @@ -585,9 +590,15 @@ 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) @@ -973,7 +984,13 @@ 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); } -- 2.4.3 -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
