netdev: preserve NETIF_F_ALL_FOR_ALL across TSO updates

Directly increment the TSO features incurs a side effect: it will also
directly clear the flags in NETIF_F_ALL_FOR_ALL on the master device,
which can cause issues such as the inability to enable the nocache copy
feature on the bonding driver.

The fix is to include NETIF_F_ALL_FOR_ALL in the update mask, thereby
preventing it from being cleared.

Fixes: b0ce350 ("bonding: allow TSO being set on bonding master")
Signed-off-by: Di Zhu <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>

Author: Di Zhu

include/linux/netdevice.h

@@ -5323,7 +5323,8 @@ netdev_features_t netdev_increment_features(netdev_features_t all,
 static inline netdev_features_t netdev_add_tso_features(netdev_features_t features,
 							netdev_features_t mask)
 {
-	return netdev_increment_features(features, NETIF_F_ALL_TSO, mask);
+	return netdev_increment_features(features, NETIF_F_ALL_TSO |
+					 NETIF_F_ALL_FOR_ALL, mask);
 }
 
 int __netdev_update_features(struct net_device *dev);