[PATCH net 1/6] rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_event

[Xin Long]

Commit 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU
events") tried to fix the redundant notifications issue when ip link
set mtu by removing NETDEV_CHANGEMTU event process in rtnetlink_event.

But it also resulted in no notification generated when dev's mtu is
changed via other methods, like:
  'ifconfig eth1 mtu 1400' or 'echo 1400 > /sys/class/net/eth1/mtu'
It would cause users not to be notified by this change.

This patch is to fix it by bringing NETDEV_CHANGEMTU event back into
rtnetlink_event, and the redundant notifications issue will be fixed
in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in
do_setlink'.

Fixes: 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU events")
Signed-off-by: Xin Long <lucien....@gmail.com>
---
 net/core/rtnetlink.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index d4bcdcc..72053ed 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -4279,6 +4279,7 @@ static int rtnetlink_event(struct notifier_block *this, 
unsigned long event, voi
 
        switch (event) {
        case NETDEV_REBOOT:
+       case NETDEV_CHANGEMTU:
        case NETDEV_CHANGEADDR:
        case NETDEV_CHANGENAME:
        case NETDEV_FEAT_CHANGE:
-- 
2.1.0