[PATCH 06/16] batman-adv: Set special lockdep classes to avoid lockdep warning
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STALE5106d
From: Antonio Quartulli <hidden>
Date: 2012-10-28 11:18:23
Also in:
batman
Subsystem:
batman advanced, the rest · Maintainers:
Marek Lindner, Simon Wunderlich, Antonio Quartulli, Sven Eckelmann, Linus Torvalds
From: Sven Eckelmann <sven@narfation.org> 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 <redacted> Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Antonio Quartulli <redacted> --- net/batman-adv/soft-interface.c | 44 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+)
diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c
index b9a28d2..948860a 100644
--- a/net/batman-adv/soft-interface.c
+++ b/net/batman-adv/soft-interface.c@@ -347,7 +347,51 @@ out: return; } +/* 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; + +/** + * batadv_set_lockdep_class_one - Set lockdep class for a single tx queue + * @dev: device which owns the tx queue + * @txq: tx queue to modify + * @_unused: always NULL + */ +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); +} + +/** + * batadv_set_lockdep_class - Set txq and addr_list lockdep class + * @dev: network device to modify + */ +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); +} + +/** + * batadv_softif_init - Late stage initialization of soft interface + * @dev: registered network device to modify + * + * Returns error code on failures + */ +static int batadv_softif_init(struct net_device *dev) +{ + batadv_set_lockdep_class(dev); + + return 0; +} + static const struct net_device_ops batadv_netdev_ops = { + .ndo_init = batadv_softif_init, .ndo_open = batadv_interface_open, .ndo_stop = batadv_interface_release, .ndo_get_stats = batadv_interface_stats,
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1.7.12.4