hv_netvsc: fix rtnl locking in callback

The function get_netvsc_net_device had conditional locking. This was
unnecessary, incorrect, but harmless. It was unnecessary since the
code is only called from netlink netdev event callback where RTNL
is always acquired before the callbacks are run. It was incorrect
because of use of trylock and then continuing.
Fix by replacing with proper assertion.

Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index eb2c122ec10a1b230a5ae6cccb951bb394600e23..6924d01a794e1f0cb9a8db9abb194a322bcd7524 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -1167,9 +1167,8 @@ static void netvsc_free_netdev(struct net_device *netdev)
 static struct net_device *get_netvsc_net_device(char *mac)
 {
        struct net_device *dev, *found = NULL;
-       int rtnl_locked;
 
-       rtnl_locked = rtnl_trylock();
+       ASSERT_RTNL();
 
        for_each_netdev(&init_net, dev) {
                if (memcmp(dev->dev_addr, mac, ETH_ALEN) == 0) {
@@ -1179,8 +1178,6 @@ static struct net_device *get_netvsc_net_device(char *mac)
                        break;
                }
        }
-       if (rtnl_locked)
-               rtnl_unlock();
 
        return found;
 }