While handling netdevice events, br_device_event() sometimes uses br_stp_(disable|enable)_port which unconditionally send a notification, but then a second notification for the same event is sent at the end of the br_device_event() function. To avoid sending duplicate notifications in such cases, check if one has already been sent (i.e. br_stp_enable/disable_port have been called). The patch is based on a change by Satish Ashok.
Signed-off-by: Nikolay Aleksandrov <[email protected]> --- We've been running with a similar patch for over an year, it's been thoroughly tested. Sending for net-next since it's an improvement and not really a bug fix. net/bridge/br.c | 12 ++++++++---- net/bridge/br_if.c | 11 ++++++++--- net/bridge/br_private.h | 2 +- 3 files changed, 17 insertions(+), 8 deletions(-) diff --git a/net/bridge/br.c b/net/bridge/br.c index 671d13c10f6f..2ca035054664 100644 --- a/net/bridge/br.c +++ b/net/bridge/br.c @@ -34,6 +34,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v struct net_device *dev = netdev_notifier_info_to_dev(ptr); struct net_bridge_port *p; struct net_bridge *br; + bool notified = false; bool changed_addr; int err; @@ -67,7 +68,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v break; case NETDEV_CHANGE: - br_port_carrier_check(p); + br_port_carrier_check(p, ¬ified); break; case NETDEV_FEAT_CHANGE: @@ -76,8 +77,10 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v case NETDEV_DOWN: spin_lock_bh(&br->lock); - if (br->dev->flags & IFF_UP) + if (br->dev->flags & IFF_UP) { br_stp_disable_port(p); + notified = true; + } spin_unlock_bh(&br->lock); break; @@ -85,6 +88,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v if (netif_running(br->dev) && netif_oper_up(dev)) { spin_lock_bh(&br->lock); br_stp_enable_port(p); + notified = true; spin_unlock_bh(&br->lock); } break; @@ -110,8 +114,8 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v } /* Events that may cause spanning tree to refresh */ - if (event == NETDEV_CHANGEADDR || event == NETDEV_UP || - event == NETDEV_CHANGE || event == NETDEV_DOWN) + if (!notified && (event == NETDEV_CHANGEADDR || event == NETDEV_UP || + event == NETDEV_CHANGE || event == NETDEV_DOWN)) br_ifinfo_notify(RTM_NEWLINK, NULL, p); return NOTIFY_DONE; diff --git a/net/bridge/br_if.c b/net/bridge/br_if.c index 82c1a6f430b3..e3a8ea1bcbe2 100644 --- a/net/bridge/br_if.c +++ b/net/bridge/br_if.c @@ -64,7 +64,7 @@ static int port_cost(struct net_device *dev) /* Check for port carrier transitions. */ -void br_port_carrier_check(struct net_bridge_port *p) +void br_port_carrier_check(struct net_bridge_port *p, bool *notified) { struct net_device *dev = p->dev; struct net_bridge *br = p->br; @@ -73,16 +73,21 @@ void br_port_carrier_check(struct net_bridge_port *p) netif_running(dev) && netif_oper_up(dev)) p->path_cost = port_cost(dev); + *notified = false; if (!netif_running(br->dev)) return; spin_lock_bh(&br->lock); if (netif_running(dev) && netif_oper_up(dev)) { - if (p->state == BR_STATE_DISABLED) + if (p->state == BR_STATE_DISABLED) { br_stp_enable_port(p); + *notified = true; + } } else { - if (p->state != BR_STATE_DISABLED) + if (p->state != BR_STATE_DISABLED) { br_stp_disable_port(p); + *notified = true; + } } spin_unlock_bh(&br->lock); } diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 1a5093115534..0ddeeea2c6a7 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -573,7 +573,7 @@ void br_flood(struct net_bridge *br, struct sk_buff *skb, enum br_pkt_type pkt_type, bool local_rcv, bool local_orig); /* br_if.c */ -void br_port_carrier_check(struct net_bridge_port *p); +void br_port_carrier_check(struct net_bridge_port *p, bool *notified); int br_add_bridge(struct net *net, const char *name); int br_del_bridge(struct net *net, const char *name); int br_add_if(struct net_bridge *br, struct net_device *dev, -- 2.11.0
