[SRU][Trusty][PATCH 5/5] rtnl/do_setlink(): notify when a netdev is modified

[Joseph Salisbury]

From: Nicolas Dichtel <nicolas.dichtel at 6wind.com>

BugLink: http://bugs.launchpad.net/bugs/1690094

Depending on which parameters were updated, the changes were not propagated via
the notifier chain and netlink.

The new flag has been set only when the change did not cause a call to the
notifier chain and/or to the netlink notification functions.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel at 6wind.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit ba9989069f4e426b1e0ed7018eacc9e1ba607095)
Signed-off-by: Joseph Salisbury <joseph.salisbury at canonical.com>
---
 net/core/rtnetlink.c | 35 +++++++++++++++++++++--------------
 1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 7b45e74..f32efab 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1452,6 +1452,8 @@ static int do_set_master(struct net_device *dev, int ifindex)
 }
 
 #define DO_SETLINK_MODIFIED	0x01
+/* notify flag means notify + modified. */
+#define DO_SETLINK_NOTIFY	0x03
 static int do_setlink(const struct sk_buff *skb,
 		      struct net_device *dev, struct ifinfomsg *ifm,
 		      struct nlattr **tb, char *ifname, int status)
@@ -1503,7 +1505,7 @@ static int do_setlink(const struct sk_buff *skb,
 		if (err < 0)
 			goto errout;
 
-		status |= DO_SETLINK_MODIFIED;
+		status |= DO_SETLINK_NOTIFY;
 	}
 
 	if (tb[IFLA_ADDRESS]) {
@@ -1535,7 +1537,7 @@ static int do_setlink(const struct sk_buff *skb,
 
 	if (tb[IFLA_GROUP]) {
 		dev_set_group(dev, nla_get_u32(tb[IFLA_GROUP]));
-		status |= DO_SETLINK_MODIFIED;
+		status |= DO_SETLINK_NOTIFY;
 	}
 
 	/*
@@ -1555,7 +1557,7 @@ static int do_setlink(const struct sk_buff *skb,
 				    nla_len(tb[IFLA_IFALIAS]));
 		if (err < 0)
 			goto errout;
-		status |= DO_SETLINK_MODIFIED;
+		status |= DO_SETLINK_NOTIFY;
 	}
 
 	if (tb[IFLA_BROADCAST]) {
@@ -1587,7 +1589,7 @@ static int do_setlink(const struct sk_buff *skb,
 		unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]);
 
 		if (dev->tx_queue_len ^ value)
-			status |= DO_SETLINK_MODIFIED;
+			status |= DO_SETLINK_NOTIFY;
 
 		dev->tx_queue_len = value;
 	}
@@ -1600,7 +1602,7 @@ static int do_setlink(const struct sk_buff *skb,
 
 		write_lock_bh(&dev_base_lock);
 		if (dev->link_mode ^ value)
-			status |= DO_SETLINK_MODIFIED;
+			status |= DO_SETLINK_NOTIFY;
 		dev->link_mode = value;
 		write_unlock_bh(&dev_base_lock);
 	}
@@ -1623,7 +1625,7 @@ static int do_setlink(const struct sk_buff *skb,
 			err = do_setvfinfo(dev, vfinfo);
 			if (err < 0)
 				goto errout;
-			status |= DO_SETLINK_MODIFIED;
+			status |= DO_SETLINK_NOTIFY;
 		}
 	}
 	err = 0;
@@ -1653,7 +1655,7 @@ static int do_setlink(const struct sk_buff *skb,
 			err = ops->ndo_set_vf_port(dev, vf, port);
 			if (err < 0)
 				goto errout;
-			status |= DO_SETLINK_MODIFIED;
+			status |= DO_SETLINK_NOTIFY;
 		}
 	}
 	err = 0;
@@ -1671,7 +1673,7 @@ static int do_setlink(const struct sk_buff *skb,
 			err = ops->ndo_set_vf_port(dev, PORT_SELF_VF, port);
 		if (err < 0)
 			goto errout;
-		status |= DO_SETLINK_MODIFIED;
+		status |= DO_SETLINK_NOTIFY;
 	}
 
 	if (tb[IFLA_AF_SPEC]) {
@@ -1688,15 +1690,20 @@ static int do_setlink(const struct sk_buff *skb,
 			if (err < 0)
 				goto errout;
 
-			status |= DO_SETLINK_MODIFIED;
+			status |= DO_SETLINK_NOTIFY;
 		}
 	}
 	err = 0;
 
 errout:
-	if (err < 0 && status & DO_SETLINK_MODIFIED)
-		net_warn_ratelimited("A link change request failed with some changes committed already. Interface %s may have been left with an inconsistent configuration, please check.\n",
-				     dev->name);
+	if (status & DO_SETLINK_MODIFIED) {
+		if (status & DO_SETLINK_NOTIFY)
+			netdev_state_change(dev);
+
+		if (err < 0)
+			net_warn_ratelimited("A link change request failed with some changes committed already. Interface %s may have been left with an inconsistent configuration, please check.\n",
+					     dev->name);
+	}
 
 	return err;
 }
@@ -1991,7 +1998,7 @@ replay:
 				err = ops->changelink(dev, tb, data);
 				if (err < 0)
 					return err;
-				status |= DO_SETLINK_MODIFIED;
+				status |= DO_SETLINK_NOTIFY;
 			}
 
 			if (linkinfo[IFLA_INFO_SLAVE_DATA]) {
@@ -2002,7 +2009,7 @@ replay:
 							      tb, slave_data);
 				if (err < 0)
 					return err;
-				status |= DO_SETLINK_MODIFIED;
+				status |= DO_SETLINK_NOTIFY;
 			}
 
 			return do_setlink(skb, dev, ifm, tb, ifname, status);
-- 
2.7.4