openvswitch: do not ignore netdev errors when creating tunnel vports

The creation of a tunnel vport (geneve, gre, vxlan) brings up a
corresponding netdev, a multi-step operation which can fail.

For example, changing a vxlan vport's netdev state to 'up' binds the
vport's socket to a UDP port - if the binding fails (e.g. due to the
port being in use), the error is currently ignored giving the
appearance that the tunnel vport creation completed successfully.
Signed-off-by: Martynas Pumputis <martynas@weave.works>
Acked-by: Pravin B Shelar <pshelar@ovn.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/openvswitch/vport-geneve.c

@@ -93,7 +93,14 @@ static struct vport *geneve_tnl_create(const struct vport_parms *parms)
 		return ERR_CAST(dev);
 	}
 
-	dev_change_flags(dev, dev->flags | IFF_UP);
+	err = dev_change_flags(dev, dev->flags | IFF_UP);
+	if (err < 0) {
+		rtnl_delete_link(dev);
+		rtnl_unlock();
+		ovs_vport_free(vport);
+		goto error;
+	}
+
 	rtnl_unlock();
 	return vport;
 error:

net/openvswitch/vport-gre.c

@@ -54,6 +54,7 @@ static struct vport *gre_tnl_create(const struct vport_parms *parms)
 	struct net *net = ovs_dp_get_net(parms->dp);
 	struct net_device *dev;
 	struct vport *vport;
+	int err;
 
 	vport = ovs_vport_alloc(0, &ovs_gre_vport_ops, parms);
 	if (IS_ERR(vport))
@@ -67,9 +68,15 @@ static struct vport *gre_tnl_create(const struct vport_parms *parms)
 		return ERR_CAST(dev);
 	}
 
-	dev_change_flags(dev, dev->flags | IFF_UP);
-	rtnl_unlock();
+	err = dev_change_flags(dev, dev->flags | IFF_UP);
+	if (err < 0) {
+		rtnl_delete_link(dev);
+		rtnl_unlock();
+		ovs_vport_free(vport);
+		return ERR_PTR(err);
+	}
 
+	rtnl_unlock();
 	return vport;
 }
 

net/openvswitch/vport-vxlan.c

@@ -130,7 +130,14 @@ static struct vport *vxlan_tnl_create(const struct vport_parms *parms)
 		return ERR_CAST(dev);
 	}
 
-	dev_change_flags(dev, dev->flags | IFF_UP);
+	err = dev_change_flags(dev, dev->flags | IFF_UP);
+	if (err < 0) {
+		rtnl_delete_link(dev);
+		rtnl_unlock();
+		ovs_vport_free(vport);
+		goto error;
+	}
+
 	rtnl_unlock();
 	return vport;
 error: