[ofa-general] Re: dst_ifdown breaks infiniband?

[Alexey Kuznetsov]

Hello!

> If a device driver sets neigh_destructor in neigh_params, this could
> get called after the device has been unregistered and the driver module
> removed.

It is the same problem: if dst->neighbour holds neighbour, it should
not hold device. parms->dev is not supposed to be used after
neigh_parms_release(). F.e. set parms->dev to NULL to catch bad references.


Do you search for a way to find real inifiniband device in
ipoib_neigh_destructor()? I guess you will not be able.
The problem is logical: if destructor needs device, neighbour entry
_somehow_ have to hold reference to the device (via neigh->dev, neigh->parms,
whatever). Hence, if we hold neighbour entry, unregister cannot be completed.
Therefore, destructor cannot refer to device. Q.E.D. :-)

Seems, releasing dst->neighbour is inevitable.

Alexey