Re: [PATCH v3] bonding: force enable lacp port after link state recovery for 802.3ad

[David Miller]

From: <zhangsha.zhang@xxxxxxxxxx>
Date: Wed, 18 Sep 2019 21:06:20 +0800

> From: Sha Zhang <zhangsha.zhang@xxxxxxxxxx>
> 
> After the commit 334031219a84 ("bonding/802.3ad: fix slave link
> initialization transition states") merged,
> the slave's link status will be changed to BOND_LINK_FAIL
> from BOND_LINK_DOWN in the following scenario:
> - Driver reports loss of carrier and
>   bonding driver receives NETDEV_DOWN notifier
> - slave's duplex and speed is zerod and
>   its port->is_enabled is cleard to 'false';
> - Driver reports link recovery and
>   bonding driver receives NETDEV_UP notifier;
> - If speed/duplex getting failed here, the link status
>   will be changed to BOND_LINK_FAIL;
> - The MII monotor later recover the slave's speed/duplex
>   and set link status to BOND_LINK_UP, but remains
>   the 'port->is_enabled' to 'false'.
> 
> In this scenario, the lacp port will not be enabled even its speed
> and duplex are valid. The bond will not send LACPDU's, and its
> state is 'AD_STATE_DEFAULTED' forever. The simplest fix I think
> is to call bond_3ad_handle_link_change() in bond_miimon_commit,
> this function can enable lacp after port slave speed check.
> As enabled, the lacp port can run its state machine normally
> after link recovery.
> 
> Signed-off-by: Sha Zhang <zhangsha.zhang@xxxxxxxxxx>

Please work out with Jay and Aleksei how to properly fix this.