The initial intension was to increase the limits, but some fixes were
needed, then when looking at the code around, other fixes had to be
added too. So now I ended up with 8 fixes (including one early exit
while at it), followed by 3 patches increasing limits, 3 to validate the
modifications, one small improvement in the selftests, and some
renaming.

The patches with a Fixes tag are for -net, the rest for net-next.

The last patch contains multiple renaming: please tell me what you
think before I start splitting in smaller commits.

Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
---
Changes in v3:
- patch 1: new: retransmit ADD_ADDR for ID 0 with right ID.
- patch 5: moved below + support calling sk_free().
- patch 13: new: allow flushing more than 8 endpoints.
- patch 12: clarify single batch of 8 subflows as known limit.
- patch 16: fix typo in comment.
- Link to v2: https://patch.msgid.link/20260410-mptcp-inc-limits-v2-0-5402209f05d3@kernel.org

Changes in v2:
- patch 2: new: fix potential data-race.
- re-order patches 1 to 5 and use shorter prefix (ADD_ADDR rtx).
- patch 6: restore accidentally deleted icsk->icsk_rto > max check.
- patch 16: fix already present checkpatch warning.
- Link to v1: https://patch.msgid.link/20260409-mptcp-inc-limits-v1-0-0e45fa30d914@kernel.org

---
Matthieu Baerts (NGI0) (19):
      mptcp: pm: kernel: correctly retransmit ADD_ADDR ID 0
      mptcp: pm: ADD_ADDR rtx: fix potential data-race
      mptcp: pm: ADD_ADDR rtx: allow ID 0
      mptcp: pm: ADD_ADDR rtx: always decrease sk refcount
      mptcp: pm: ADD_ADDR rtx: free sk if last
      mptcp: pm: ADD_ADDR rtx: resched blocked ADD_ADDR quicker
      mptcp: pm: ADD_ADDR rtx: skip inactive subflows
      mptcp: pm: retrans ADD_ADDR: return early if no retrans
      mptcp: pm: prio: skip closed subflows
      selftests: mptcp: pm: restrict 'unknown' check to pm_nl_ctl
      mptcp: pm: in-kernel: explicitly limit batches to array size
      mptcp: pm: in-kernel: increase all limits to 64
      mptcp: pm: kernel: allow flushing more than 8 endpoints
      mptcp: pm: in-kernel: increase endpoints limit
      selftests: mptcp: join: allow changing ifaces nr per test
      selftests: mptcp: join: validate 8x8 subflows
      selftests: mptcp: pm: validate new limits
      selftests: mptcp: pm: use simpler send/recv forms
      mptcp: pm: clearer ADD_ADDR related helpers names

 net/mptcp/options.c                             |   2 +-
 net/mptcp/pm.c                                  | 184 +++++++++++++-----------
 net/mptcp/pm_kernel.c                           | 106 +++++++++-----
 net/mptcp/pm_userspace.c                        |   6 +-
 net/mptcp/protocol.h                            |  19 +--
 net/mptcp/subflow.c                             |   4 +-
 tools/testing/selftests/net/mptcp/mptcp_join.sh |  33 ++++-
 tools/testing/selftests/net/mptcp/pm_netlink.sh |  62 ++++----
 tools/testing/selftests/net/mptcp/pm_nl_ctl.c   |   8 +-
 9 files changed, 259 insertions(+), 165 deletions(-)
---
base-commit: 0d8ee8bb5ee08c331531dc4ee482409d7fcef713
change-id: 20260403-mptcp-inc-limits-ce9811024066

Best regards,
--  
Matthieu Baerts (NGI0) <matttbe@kernel.org>

Hi Matthieu,

Thank you for your modifications, that's great!

But sadly, our CI spotted some issues with it when trying to build it.

You can find more details there:

  https://github.com/multipath-tcp/mptcp_net-next/actions/runs/24349397805

Status: failure
Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/dd49feeb5952
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1080761

Feel free to reply to this email if you cannot access logs, if you need
some support to fix the error, if this doesn't seem to be caused by your
modifications or if the error is a false positive one.

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)

Hi Matthieu,

Thank you for your modifications, that's great!

Our CI did some validations and here is its report:

- KVM Validation: normal (except selftest_mptcp_join): Success! ✅
- KVM Validation: normal (only selftest_mptcp_join): Success! ✅
- KVM Validation: debug (except selftest_mptcp_join): Success! ✅
- KVM Validation: debug (only selftest_mptcp_join): Success! ✅
- KVM Validation: btf-normal (only bpftest_all): Success! ✅
- KVM Validation: btf-debug (only bpftest_all): Success! ✅
- Task: https://github.com/multipath-tcp/mptcp_net-next/actions/runs/24349397795

Initiator: Patchew Applier
Commits: https://github.com/multipath-tcp/mptcp_net-next/commits/dd49feeb5952
Patchwork: https://patchwork.kernel.org/project/mptcp/list/?series=1080761


If there are some issues, you can reproduce them using the same environment as
the one used by the CI thanks to a docker image, e.g.:

    $ cd [kernel source code]
    $ docker run -v "${PWD}:${PWD}:rw" -w "${PWD}" --privileged --rm -it \
        --pull always mptcp/mptcp-upstream-virtme-docker:latest \
        auto-normal

For more details:

    https://github.com/multipath-tcp/mptcp-upstream-virtme-docker


Please note that despite all the efforts that have been already done to have a
stable tests suite when executed on a public CI like here, it is possible some
reported issues are not due to your modifications. Still, do not hesitate to
help us improve that ;-)

Cheers,
MPTCP GH Action bot
Bot operated by Matthieu Baerts (NGI0 Core)