On Fri, Dec 29, 2023 at 11:08:35AM +0100, Nicolas Dichtel wrote:
> The below commit adds support for:
> > ip link set dummy0 down
> > ip link set dummy0 master bond0 up
>
> but breaks the opposite:
> > ip link set dummy0 up
> > ip link set dummy0 master bond0 down
>
> Let's add a workaround to have both commands working.
>
> Cc: stable@xxxxxxxxxxxxxxx
> Fixes: a4abfa627c38 ("net: rtnetlink: Enslave device before bringing it up")
> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@xxxxxxxxx>
> ---
> net/core/rtnetlink.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
> index e8431c6c8490..dd79693c2d91 100644
> --- a/net/core/rtnetlink.c
> +++ b/net/core/rtnetlink.c
> @@ -2905,6 +2905,14 @@ static int do_setlink(const struct sk_buff *skb,
> call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
> }
>
> + /* Backward compat: enable to set interface down before enslaving it */
> + if (!(ifm->ifi_flags & IFF_UP) && ifm->ifi_change & IFF_UP) {
> + err = dev_change_flags(dev, rtnl_dev_combine_flags(dev, ifm),
> + extack);
> + if (err < 0)
> + goto errout;
> + }
> +
> if (tb[IFLA_MASTER]) {
> err = do_set_master(dev, nla_get_u32(tb[IFLA_MASTER]), extack);
> if (err)
Doesn't this merely revert to the old behaviour of setting the interface
up before enslaving if both IFF_UP and IFLA_MASTER are present? Did you
test this with a bond-type master?
Cheers, Phil
