Re: [PATCH v2 net-next 0/5] Make SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE blocking

On Fri, Aug 20, 2021 at 12:16:10PM +0300, Ido Schimmel wrote:

On Thu, Aug 19, 2021 at 07:07:18PM +0300, Vladimir Oltean wrote:

quoted

Problem statement:

Any time a driver needs to create a private association between a bridge
upper interface and use that association within its
SWITCHDEV_FDB_{ADD,DEL}_TO_DEVICE handler, we have an issue with FDB
entries deleted by the bridge when the port leaves. The issue is that
all switchdev drivers schedule a work item to have sleepable context,
and that work item can be actually scheduled after the port has left the
bridge, which means the association might have already been broken by
the time the scheduled FDB work item attempts to use it.

This is handled in mlxsw by telling the device to flush the FDB entries
pointing to the {port, FID} when the VLAN is deleted (synchronously).

If you have FDB entries pointing to bridge ports that are foreign
interfaces and you offload them, do you catch the VLAN deletion on the
foreign port and flush your entries towards it at that time?