Repository : ssh://git@open-mesh.org/batman-adv

On branch : master

commit e27bb6fa916451e9eaced16e7c21d5b71a3b7f30 Author: Sven Eckelmann sven@narfation.org Date: Mon Aug 20 09:03:59 2012 +0200

batman-adv: Set special lockdep classes to avoid lockdep warning

Transmissions over batman-adv devices always start another nested transmission over devices attached to the batman-adv interface. These devices usually use the ethernet lockdep class for the tx_queue lock which is also set by default for all batman-adv devices. Lockdep will detect a nested locking attempt of two locks with the same class and warn about a possible deadlock.

This is the default and expected behavior and should not alarm the locking correctness prove mechanism. Therefore, the locks for all netdevice specific tx queues get a special batman-adv lock class to avoid a false positive for each transmission.

Reported-by: Linus Luessing linus.luessing@web.de Signed-off-by: Sven Eckelmann sven@narfation.org

e27bb6fa916451e9eaced16e7c21d5b71a3b7f30 soft-interface.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+)

diff --git a/soft-interface.c b/soft-interface.c index 1aee7db..909ab54 100644 --- a/soft-interface.c +++ b/soft-interface.c @@ -354,6 +354,26 @@ static const struct net_device_ops batadv_netdev_ops = { .ndo_validate_addr = eth_validate_addr };

+/* batman-adv network devices have devices nesting below it and are a special + * "super class" of normal network devices; split their locks off into a + * separate class since they always nest. + */ +static struct lock_class_key batadv_netdev_xmit_lock_key; +static struct lock_class_key batadv_netdev_addr_lock_key; + +static void batadv_set_lockdep_class_one(struct net_device *dev, + struct netdev_queue *txq, + void *_unused) +{ + lockdep_set_class(&txq->_xmit_lock, &batadv_netdev_xmit_lock_key); +} + +static void batadv_set_lockdep_class(struct net_device *dev) +{ + lockdep_set_class(&dev->addr_list_lock, &batadv_netdev_addr_lock_key); + netdev_for_each_tx_queue(dev, batadv_set_lockdep_class_one, NULL); +} + static void batadv_interface_setup(struct net_device *dev) { struct batadv_priv *priv = netdev_priv(dev); @@ -363,6 +383,7 @@ static void batadv_interface_setup(struct net_device *dev) dev->netdev_ops = &batadv_netdev_ops; dev->destructor = free_netdev; dev->tx_queue_len = 0; + batadv_set_lockdep_class(dev);

/* can't call min_mtu, because the needed variables * have not been initialized yet