IPoIB: Fix deadlock between ipoib_open() and child interface create
Fix a deadlock between child interface creation/deletion and ipoib
start/stop. The former takes vlan_mutex, and then might take RTNL via
register_netdev()/unregister_netdev(). The latter is executed with
RTNL held, and tries to take vlan_mutex, which can lead to an AB-BA
deadlock.
Fix this by having the child interface creation/deletion code take the
RTNL first so vlan_mutex always nests inside RTNL. We can use
register_netdevice() for child interfaces because we form the
interface name from the parent interface and hence don't need the '%'
expansion of register_netdev().
Reported-by: Yossi Etigin <yosefe@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
1 file changed