f6cc9c054e
For tunnels created with IFLA_MTU, MTU of the netdevice is set by
rtnl_create_link() (called from rtnl_newlink()) before the device is
registered. However without IFLA_MTU that's not done.
rtnl_newlink() proceeds by calling struct rtnl_link_ops.newlink, which
via ip_tunnel_newlink() calls register_netdevice(), and that emits
NETDEV_REGISTER. Thus any listeners that inspect the netdevice get the
MTU of 0.
After ip_tunnel_newlink() corrects the MTU after registering the
netdevice, but since there's no event, the listeners don't get to know
about the MTU until something else happens--such as a NETDEV_UP event.
That's not ideal.
So instead of setting the MTU directly, go through dev_set_mtu(), which
takes care of distributing the necessary NETDEV_PRECHANGEMTU and
NETDEV_CHANGEMTU events.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Petr Machata <petrm@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.