From: Sven Eckelmann sven@narfation.org

If an interface changes the MTU, it is expected that an NETDEV_PRECHANGEMTU and NETDEV_CHANGEMTU notification events is triggered. This worked fine for .ndo_change_mtu based changes because core networking code took care of it. But for auto-adjustments after hard-interfaces changes, these events were simply missing.

Due to this problem, non-batman-adv components weren't aware of MTU changes and thus couldn't perform their own tasks correctly.

Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Cc: stable@vger.kernel.org Signed-off-by: Sven Eckelmann sven@narfation.org Signed-off-by: Simon Wunderlich sw@simonwunderlich.de --- net/batman-adv/hard-interface.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c index 41c1ad33d009..ae5762af0146 100644 --- a/net/batman-adv/hard-interface.c +++ b/net/batman-adv/hard-interface.c @@ -630,7 +630,7 @@ int batadv_hardif_min_mtu(struct net_device *soft_iface) */ void batadv_update_min_mtu(struct net_device *soft_iface) { - soft_iface->mtu = batadv_hardif_min_mtu(soft_iface); + dev_set_mtu(soft_iface, batadv_hardif_min_mtu(soft_iface));

/* Check if the local translate table should be cleaned up to match a * new (and smaller) MTU.