net: make dev_set_mtu() honor notification return code

Currently, after changing the MTU for a device, dev_set_mtu() calls
NETDEV_CHANGEMTU notification, however doesn't verify it's return code -
which can be NOTIFY_BAD - i.e. some of the net notifier blocks refused this
change, and continues nevertheless.

To fix this, verify the return code, and if it's an error - then revert the
MTU to the original one, notify again and pass the error code.

CC: Jiri Pirko <[email protected]>
CC: "David S. Miller" <[email protected]>
CC: Eric Dumazet <[email protected]>
CC: Alexander Duyck <[email protected]>
CC: Nicolas Dichtel <[email protected]>
Signed-off-by: Veaceslav Falico <[email protected]>
Reviewed-by: Jiri Pirko <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions