[PATCH NET-PREV 47/51] netvsc: Call dev_change_net_namespace() under nd_lock

[Kirill Tkhai]

We want to provide "nd_lock is locked" context during
NETDEV_REGISTER (and later for NETDEV_UNREGISTER)
events. When calling from __register_netdevice(),
notifiers are already in that context, and we do the
same for dev_change_net_namespace() here.

Signed-off-by: Kirill Tkhai <tkhai@xxxxx>
---
 drivers/net/hyperv/netvsc_drv.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index be8038e6393f..cc9f07f8d499 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2365,6 +2365,7 @@ static int netvsc_register_vf(struct net_device *vf_netdev, int context)
 	struct netvsc_device *netvsc_dev;
 	struct bpf_prog *prog;
 	struct net_device *ndev;
+	struct nd_lock *nd_lock;
 	int ret;
 
 	if (vf_netdev->addr_len != ETH_ALEN)
@@ -2384,8 +2385,10 @@ static int netvsc_register_vf(struct net_device *vf_netdev, int context)
 	 * done again in that context.
 	 */
 	if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
+		lock_netdev(vf_netdev, &nd_lock);
 		ret = dev_change_net_namespace(vf_netdev,
 					       dev_net(ndev), "eth%d");
+		unlock_netdev(nd_lock);
 		if (ret)
 			netdev_err(vf_netdev,
 				   "could not move to same namespace as %s: %d\n",