team: set qdisc_tx_busylock to avoid LOCKDEP splat

If a qdisc is installed on a team device, its possible to get
a lockdep splat under stress, because nested dev_queue_xmit() can
lock busylock a second time (on a different device, so its a false
positive)

Avoid this problem using a distinct lock_class_key for team
devices.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jpirko@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 5c7547c4f802550426c8f9769f9d9ba9a93becf9..d44cca327588858e26023a99cee8c64a940cf173 100644 (file)
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -1315,6 +1315,7 @@ static const struct team_option team_options[] = {
 
 static struct lock_class_key team_netdev_xmit_lock_key;
 static struct lock_class_key team_netdev_addr_lock_key;
+static struct lock_class_key team_tx_busylock_key;
 
 static void team_set_lockdep_class_one(struct net_device *dev,
                                       struct netdev_queue *txq,
@@ -1327,6 +1328,7 @@ static void team_set_lockdep_class(struct net_device *dev)
 {
        lockdep_set_class(&dev->addr_list_lock, &team_netdev_addr_lock_key);
        netdev_for_each_tx_queue(dev, team_set_lockdep_class_one, NULL);
+       dev->qdisc_tx_busylock = &team_tx_busylock_key;
 }
 
 static int team_init(struct net_device *dev)