Merge branch 'rtnetlink_vf_ports'

Merge branch 'rtnetlink_vf_ports'

David Gibson says:

====================
Fix problems with with IFLA_VF_PORTS (v2)

I've had a customer encounter a problem with getifaddrs(3) freezing up
on a system with a Cisco enic device.

I've discovered that the problem is caused by an enic device with a
large number of SR-IOV virtual functions overflowing the normal sized
packet buffer for netlink, leading to interfaces not being reported
from an RTM_GETLINK request.

The first patch here just makes the problem easier to locate if it
occurs again in a different way, by adding a WARN_ON() when we run out
of room in a netlink packet in this manner.

The second patch actually fixes the problem, by only reporting
IFLA_VF_PORTS information when the RTEXT_FILTER_VF flag is specified.

v2: Corrected some CodingStyle problems
====================

Signed-off-by: David S. Miller <davem@davemloft.net>