netvsc: check error return when restoring channels and mtu

If setting new values fails, and the attempt to restore original
settings fails. Then log an error and leave device down.
This should never happen, but if it does don't go down in flames.

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 07015b1c42c6300b9a47e415c5a595fdc693cc75..c7391889938bd6efdc533180d9ecd9f38a68ab61 100644 (file)
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -845,7 +845,13 @@ static int netvsc_set_channels(struct net_device *net,
        } else {
                ret = PTR_ERR(nvdev);
                device_info.num_chn = orig;
-               rndis_filter_device_add(dev, &device_info);
+               nvdev = rndis_filter_device_add(dev, &device_info);
+
+               if (IS_ERR(nvdev)) {
+                       netdev_err(net, "restoring channel setting failed: %ld\n",
+                                  PTR_ERR(nvdev));
+                       return ret;
+               }
        }
 
        if (was_opened)
@@ -953,10 +959,16 @@ static int netvsc_change_mtu(struct net_device *ndev, int mtu)
 
                /* Attempt rollback to original MTU */
                ndev->mtu = orig_mtu;
-               rndis_filter_device_add(hdev, &device_info);
+               nvdev = rndis_filter_device_add(hdev, &device_info);
 
                if (vf_netdev)
                        dev_set_mtu(vf_netdev, orig_mtu);
+
+               if (IS_ERR(nvdev)) {
+                       netdev_err(ndev, "restoring mtu failed: %ld\n",
+                                  PTR_ERR(nvdev));
+                       return ret;
+               }
        }
 
        if (was_opened)