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: 8009e9f7ac4f ("set bat0 MTU according to the MTUs of the hard interfaces") Signed-off-by: Sven Eckelmann sven@narfation.org --- 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 41c1ad33..ae5762af 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.