net: remove rtmsg_ifinfo used in bridge and bonding

It's better to send notifications to userspace by the events in rtnetlink_event, instead of calling rtmsg_ifinfo directly.

This patcheset is to remove rtmsg_ifinfo called in bonding and bridge, the notifications can be handled by NETDEV_CHANGEUPPER and NETDEV_CHANGELOWERSTATE events in rtnetlink_event.

It could also fix some redundant notifications from bonding and bridge.

v1->v2:
- post to net-next.git instead of net.git, for it's more like an improvement for bonding
v2->v3:
- add patch 1/4 to remove rtmsg_ifinfo called in add_del_if

Xin Long (4):
bridge: remove rtmsg_ifinfo called in add_del_if
bonding: remove rtmsg_ifinfo called in bond_master_upper_dev_link
rtnetlink: bring NETDEV_CHANGELOWERSTATE event process back to
rtnetlink_event
bonding: remove rtmsg_ifinfo called after bond_lower_state_changed

 drivers/net/bonding/bond_main.c | 11 +++--------
 include/net/bonding.h           |  4 ----
 net/bridge/br_ioctl.c           |  3 ---
 net/core/rtnetlink.c            |  2 +-
 4 files changed, 4 insertions(+), 16 deletions(-)

2.1.0

Since commit dc709f375743 ("rtnetlink: bring NETDEV_CHANGEUPPER event process back in rtnetlink_event"), rtnetlink_event would process the NETDEV_CHANGEUPPER event and send a notification to userspace.

In add_del_if, it would generate NETDEV_CHANGEUPPER event by whether netdev_master_upper_dev_link or netdev_upper_dev_unlink. There's no need to call rtmsg_ifinfo to send the notification any more.

So this patch is to remove it from add_del_if also to avoid redundant notifications.

---
 net/bridge/br_ioctl.c | 3 ---
 1 file changed, 3 deletions(-)

index 8f29103..16d01a3 100644
@@ -102,9 +102,6 @@ static int add_del_if(struct net_bridge *br, int ifindex, int isadd)
 	else
 		ret = br_del_if(br, dev);
 
-	if (!ret)
-		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_MASTER, GFP_KERNEL);
-
 	return ret;
 }
 

2.1.0

Since commit 42e52bf9e3ae ("net: add netnotifier event for upper device change"), netdev_master_upper_dev_link has generated NETDEV_CHANGEUPPER event which would send a notification to userspace in rtnetlink_event.

There's no need to call rtmsg_ifinfo to send the notification any more. So this patch is to remove it from bond_master_upper_dev_link as well as bond_upper_dev_unlink to avoid the redundant notifications.

---
 drivers/net/bonding/bond_main.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

index 172eeeb..18b58e1 100644
@@ -1221,22 +1221,17 @@ static int bond_master_upper_dev_link(struct bonding *bond, struct slave *slave,
 				      struct netlink_ext_ack *extack)
 {
 	struct netdev_lag_upper_info lag_upper_info;
-	int err;
 
 	lag_upper_info.tx_type = bond_lag_tx_type(bond);
-	err = netdev_master_upper_dev_link(slave->dev, bond->dev, slave,
-					   &lag_upper_info, extack);
-	if (err)
-		return err;
-	rtmsg_ifinfo(RTM_NEWLINK, slave->dev, IFF_SLAVE, GFP_KERNEL);
-	return 0;
+
+	return netdev_master_upper_dev_link(slave->dev, bond->dev, slave,
+					    &lag_upper_info, extack);
 }
 
 static void bond_upper_dev_unlink(struct bonding *bond, struct slave *slave)
 {
 	netdev_upper_dev_unlink(slave->dev, bond->dev);
 	slave->dev->flags &= ~IFF_SLAVE;
-	rtmsg_ifinfo(RTM_NEWLINK, slave->dev, IFF_SLAVE, GFP_KERNEL);
 }
 
 static struct slave *bond_alloc_slave(struct bonding *bond)

2.1.0

This patch is to bring NETDEV_CHANGELOWERSTATE event process back to rtnetlink_event so that bonding could use it instead of calling rtmsg_ifinfo to send a notification to userspace after netdev lower state is changed in the later patch.

---
 net/core/rtnetlink.c | 1 +
 1 file changed, 1 insertion(+)

index df8dba9..854a848 100644
@@ -4385,6 +4385,7 @@ static int rtnetlink_event(struct notifier_block *this, unsigned long event, voi
 	case NETDEV_CHANGEUPPER:
 	case NETDEV_RESEND_IGMP:
 	case NETDEV_CHANGEINFODATA:
+	case NETDEV_CHANGELOWERSTATE:
 	case NETDEV_CHANGE_TX_QUEUE_LEN:
 		rtmsg_ifinfo_event(RTM_NEWLINK, dev, 0, rtnl_get_event(event),
 				   GFP_KERNEL, NULL);

2.1.0

After the patch 'rtnetlink: bring NETDEV_CHANGELOWERSTATE event process back to rtnetlink_event', bond_lower_state_changed would generate NETDEV_CHANGEUPPER event which would send a notification to userspace in rtnetlink_event.

There's no need to call rtmsg_ifinfo to send the notification any more. So this patch is to remove it from these places after bond_lower_state_changed.

Besides, after this, rtmsg_ifinfo is not needed to be exported.

---
 include/net/bonding.h | 4 ----
 net/core/rtnetlink.c  | 1 -
 2 files changed, 5 deletions(-)

index 2860cc6..f801fc9 100644
@@ -330,7 +330,6 @@ static inline void bond_set_active_slave(struct slave *slave)
 		slave->backup = 0;
 		bond_queue_slave_event(slave);
 		bond_lower_state_changed(slave);
-		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 	}
 }
 

@@ -340,7 +339,6 @@ static inline void bond_set_backup_slave(struct slave *slave)
 		slave->backup = 1;
 		bond_queue_slave_event(slave);
 		bond_lower_state_changed(slave);
-		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 	}
 }
 

@@ -353,7 +351,6 @@ static inline void bond_set_slave_state(struct slave *slave,
 	slave->backup = slave_state;
 	if (notify) {
 		bond_lower_state_changed(slave);
-		rtmsg_ifinfo(RTM_NEWLINK, slave->dev, 0, GFP_ATOMIC);
 		bond_queue_slave_event(slave);
 		slave->should_notify = 0;
 	} else {

@@ -385,7 +382,6 @@ static inline void bond_slave_state_notify(struct bonding *bond)
 	bond_for_each_slave(bond, tmp, iter) {
 		if (tmp->should_notify) {
 			bond_lower_state_changed(tmp);
-			rtmsg_ifinfo(RTM_NEWLINK, tmp->dev, 0, GFP_ATOMIC);
 			tmp->should_notify = 0;
 		}
 	}

index 854a848..de24d39 100644
@@ -2989,7 +2989,6 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
 {
 	rtmsg_ifinfo_event(type, dev, change, rtnl_get_event(0), flags, NULL);
 }
-EXPORT_SYMBOL(rtmsg_ifinfo);
 
 void rtmsg_ifinfo_newnet(int type, struct net_device *dev, unsigned int change,
 			 gfp_t flags, int *new_nsid)

2.1.0

From: Xin Long <[email protected]>
Date: Tue, 24 Oct 2017 13:54:16 +0800

Series applied, thanks.