v3:
 - drop "EXPORT_SYMBOL(tcp_sock_set_maxseg)" as Matt suggested.
 - use mptcp_getsockopt_first_sf_only instead of mptcp_put_int_option.
 - drop selftest
 - add a packetdrill test.

v2:
 - add a new helper tcp_sock_set_maxseg.
 - add maxseg member of struct mptcp_sock.
 - add mptcp_setsockopt_all_subflows helper.
 - invoke mptcp_setsockopt_all_subflows under the msk socket lock.
 - drop mptcp_getsockopt_sol_tcp_maxseg, use mptcp_put_int_option
   instead.

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/515

Geliang Tang (2):
  tcp: add tcp_sock_set_maxseg
  mptcp: add TCP_MAXSEG sockopt support

 include/linux/tcp.h  |  1 +
 net/ipv4/tcp.c       | 23 ++++++++++++++---------
 net/mptcp/protocol.h |  1 +
 net/mptcp/sockopt.c  | 25 +++++++++++++++++++++++++
 4 files changed, 41 insertions(+), 9 deletions(-)

-- 
2.43.0