Merge branch 'mptcp-next'

Mat Martineau says:

====================
mptcp: New features and cleanup

These patches have been tested in the MPTCP tree for a longer than usual
time (thanks to holiday schedules), and are ready for the net-next
branch. Changes include feature updates, small fixes, refactoring, and
some selftest changes.

Patch 1 fixes an OUTQ ioctl issue with TCP fallback sockets.

Patches 2, 3, and 6 add support of the MPTCP fastclose option (quick
shutdown of the full MPTCP connection, similar to TCP RST in regular
TCP), and a related self test.

Patch 4 cleans up some accept and poll code that is no longer needed
after the fastclose changes.

Patch 5 add userspace disconnect using AF_UNSPEC, which is used when
testing fastclose and makes the MPTCP socket's handling of AF_UNSPEC in
connect() more TCP-like.

Patches 7-11 refactor subflow creation to make better use of multiple
local endpoints and to better handle individual connection failures when
creating multiple subflows. Includes self test updates.

Patch 12 cleans up the way subflows are added to the MPTCP connection
list, eliminating the need for calls throughout the MPTCP code that had
to check the intermediate "join list" for entries to shift over to the
main "connection list".

Patch 13 refactors the MPTCP release_cb flags to use separate storage
for values only accessed with the socket lock held (no atomic ops
needed), and for values that need atomic operations.
====================

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