IB/mlx4: Verify net device validity on port change event
IB/mlx4: Verify net device validity on port change event

Processing an event is done in a different context from the one when
the event was dispatched. This requires a check that the slave
net device is still valid when the event is being processed. The check is done
under the iboe lock which ensure correctness.

Fixes: a57500903093 ('IB/mlx4: Add port aggregation support')
Signed-off-by: Moni Shoua <82f7eb136882fcd734e8a5cba82c0447dc78e8e3@mellanox.com>
Signed-off-by: Or Gerlitz <de1b678a59344538ef9f2ddb34a5f9486544e2f9@mellanox.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs