On 04/07/2017 05:25 PM, David Ahern wrote:
> Changing MTU on a link currently causes 3 messages to be sent to userspace:
>
> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1490 qdisc noqueue state
> UNKNOWN group default event PRE_CHANGE_MTU
> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
>
> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state
> UNKNOWN group default event CHANGE_MTU
> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
>
> [LINK]11: dummy1: <BROADCAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state
> UNKNOWN group default
> link/ether f2:52:5c:6d:21:f3 brd ff:ff:ff:ff:ff:ff
>
> Remove the PRE_CHANGE_MTU and CHANGE_MTU messages.
Actually, I have plans for the CHANGE_MTU event. The last message is not an
event. If you
remove the event, it is much harder to track mtu changes.
-vlad
>
> Signed-off-by: David Ahern <d...@cumulusnetworks.com>
> ---
> include/uapi/linux/if_link.h | 2 --
> net/core/rtnetlink.c | 8 -------
> 2 files changed, 10 deletions(-)
>
> diff --git a/include/uapi/linux/if_link.h b/include/uapi/linux/if_link.h
> index 97f6d302f627..e8b7e9342cc0 100644
> --- a/include/uapi/linux/if_link.h
> +++ b/include/uapi/linux/if_link.h
> @@ -903,7 +903,6 @@ enum {
> enum {
> IFLA_EVENT_UNSPEC,
> IFLA_EVENT_REBOOT,
> - IFLA_EVENT_CHANGE_MTU,
> IFLA_EVENT_CHANGE_ADDR,
> IFLA_EVENT_CHANGE_NAME,
> IFLA_EVENT_FEAT_CHANGE,
> @@ -912,7 +911,6 @@ enum {
> IFLA_EVENT_NOTIFY_PEERS,
> IFLA_EVENT_CHANGE_UPPER,
> IFLA_EVENT_RESEND_IGMP,
> - IFLA_EVENT_PRE_CHANGE_MTU,
> IFLA_EVENT_CHANGE_INFO_DATA,
> IFLA_EVENT_PRE_CHANGE_UPPER,
> IFLA_EVENT_CHANGE_LOWER_STATE,
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index b2bd4c9ee860..72d365ae14b3 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -1285,9 +1285,6 @@ static int rtnl_fill_link_event(struct sk_buff *skb,
> unsigned long event)
> case NETDEV_REBOOT:
> rtnl_event = IFLA_EVENT_REBOOT;
> break;
> - case NETDEV_CHANGEMTU:
> - rtnl_event = IFLA_EVENT_CHANGE_MTU;
> - break;
> case NETDEV_CHANGEADDR:
> rtnl_event = IFLA_EVENT_CHANGE_ADDR;
> break;
> @@ -1312,9 +1309,6 @@ static int rtnl_fill_link_event(struct sk_buff *skb,
> unsigned long event)
> case NETDEV_RESEND_IGMP:
> rtnl_event = IFLA_EVENT_RESEND_IGMP;
> break;
> - case NETDEV_PRECHANGEMTU:
> - rtnl_event = IFLA_EVENT_PRE_CHANGE_MTU;
> - break;
> case NETDEV_CHANGEINFODATA:
> rtnl_event = IFLA_EVENT_CHANGE_INFO_DATA;
> break;
> @@ -4191,7 +4185,6 @@ 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:
> @@ -4200,7 +4193,6 @@ static int rtnetlink_event(struct notifier_block *this,
> unsigned long event, voi
> case NETDEV_NOTIFY_PEERS:
> case NETDEV_CHANGEUPPER:
> case NETDEV_RESEND_IGMP:
> - case NETDEV_PRECHANGEMTU:
> case NETDEV_CHANGEINFODATA:
> case NETDEV_PRECHANGEUPPER:
> case NETDEV_CHANGELOWERSTATE:
>
