x25: decrement netdev reference counts on unload

[ Upstream commit 171995e5d82dcc92bea37a7d2a2ecc21068a0f19]

x25 does not decrement the network device reference counts on module unload.
Thus unregistering any pre-existing interface after unloading the x25 module
hangs and results in

 unregister_netdevice: waiting for tap0 to become free. Usage count = 1

This patch decrements the reference counts of all interfaces in x25_link_free,
the way it is already done in x25_link_device_down for NETDEV_DOWN events.

Signed-off-by: Apollon Oikonomopoulos <apollon@noc.grnet.gr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Andi Kleen <ak@linux.intel.com>

diff --git a/net/x25/x25_link.c b/net/x25/x25_link.c
index 73e7b954ad288229df4d03bc164f07da183444cc..b25c6463c3e996cf536454603f4f0257f3b8b51c 100644 (file)
--- a/net/x25/x25_link.c
+++ b/net/x25/x25_link.c
@@ -394,6 +394,7 @@ void __exit x25_link_free(void)
        list_for_each_safe(entry, tmp, &x25_neigh_list) {
                nb = list_entry(entry, struct x25_neigh, node);
                __x25_remove_neigh(nb);
+               dev_put(nb->dev);
        }
        write_unlock_bh(&x25_neigh_list_lock);
 }