Merge branch 'rds-tcp-netns'

Sowmini Varadhan says:

====================
RDS-TCP: Network namespace support

This patch series contains the set of changes to correctly set up
the infra for PF_RDS sockets that use TCP as the transport in multiple
network namespaces.

Patch 1 in the series is the minimal set of changes to allow
a single instance of RDS-TCP to run in any (i.e init_net or other) net
namespace.  The changes in this patch set ensure that the execution of
'modprobe [-r] rds_tcp' sets up the kernel TCP sockets
relative to the current netns, so that RDS applications can send/recv
packets from that netns, and the netns can later be deleted cleanly.

Patch 2 of the series further allows multiple RDS-TCP instances,
one per network namespace. The changes in this patch allows dynamic
creation/tear-down of RDS-TCP client and server sockets  across all
current and future namespaces.

v2 changes from RFC sent out earlier:
    David Ahern comments in patch 1, net_device notifier in patch 2,
    patch 3 broken off and submitted separately.
v3: Cong Wang review comments.
====================

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