net: Call netdev_features_change() from netdev_update_features()

Issue FEAT_CHANGE notification when features are changed by
netdev_update_features().  This will allow changes made by extra constraints
on e.g. MTU change to be properly propagated like changes via ethtool.

Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 21 insertions, 9 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 5eeb2cd3631c..423a5447d2ed 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2550,6 +2550,7 @@ static inline u32 netdev_get_wanted_features(struct net_device *dev)
 }
 u32 netdev_increment_features(u32 all, u32 one, u32 mask);
 u32 netdev_fix_features(struct net_device *dev, u32 features);
+int __netdev_update_features(struct net_device *dev);
 void netdev_update_features(struct net_device *dev);
 
 void netif_stacked_transfer_operstate(const struct net_device *rootdev,
diff --git a/net/core/dev.c b/net/core/dev.c
index 3da9fb06d47a..02f56376fe99 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5236,7 +5236,7 @@ u32 netdev_fix_features(struct net_device *dev, u32 features)
 }
 EXPORT_SYMBOL(netdev_fix_features);
 
-void netdev_update_features(struct net_device *dev)
+int __netdev_update_features(struct net_device *dev)
 {
         u32 features;
         int err = 0;
@@ -5250,7 +5250,7 @@ void netdev_update_features(struct net_device *dev)
         features = netdev_fix_features(dev, features);
 
         if (dev->features == features)
-                return;
+                return 0;
 
         netdev_info(dev, "Features changed: 0x%08x -> 0x%08x\n",
                 dev->features, features);
@@ -5258,12 +5258,23 @@ void netdev_update_features(struct net_device *dev)
         if (dev->netdev_ops->ndo_set_features)
                 err = dev->netdev_ops->ndo_set_features(dev, features);
 
-        if (!err)
-                dev->features = features;
-        else if (err < 0)
+        if (unlikely(err < 0)) {
                 netdev_err(dev,
                         "set_features() failed (%d); wanted 0x%08x, left 0x%08x\n",
                         err, features, dev->features);
+                return -1;
+        }
+
+        if (!err)
+                dev->features = features;
+
+        return 1;
+}
+
+void netdev_update_features(struct net_device *dev)
+{
+        if (__netdev_update_features(dev))
+                netdev_features_change(dev);
 }
 EXPORT_SYMBOL(netdev_update_features);
 
@@ -5430,7 +5441,7 @@ int register_netdevice(struct net_device *dev)
                 goto err_uninit;
         dev->reg_state = NETREG_REGISTERED;
 
-        netdev_update_features(dev);
+        __netdev_update_features(dev);
 
         /*
          *      Default initial state at registry is that the
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 74ead9eca126..439e4b0e1312 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -317,7 +317,7 @@ static int ethtool_set_features(struct net_device *dev, void __user *useraddr)
 
         dev->wanted_features &= ~features[0].valid;
         dev->wanted_features |= features[0].valid & features[0].requested;
-        netdev_update_features(dev);
+        __netdev_update_features(dev);
 
         if ((dev->wanted_features ^ dev->features) & features[0].valid)
                 ret |= ETHTOOL_F_WISH;
@@ -499,7 +499,7 @@ static int ethtool_set_one_feature(struct net_device *dev,
                 else
                         dev->wanted_features &= ~mask;
 
-                netdev_update_features(dev);
+                __netdev_update_features(dev);
                 return 0;
         }
 
@@ -551,7 +551,7 @@ int __ethtool_set_flags(struct net_device *dev, u32 data)
         dev->wanted_features =
                 (dev->wanted_features & ~changed) | data;
 
-        netdev_update_features(dev);
+        __netdev_update_features(dev);
 
         return 0;
 }