[PATCH v3 net-next 00/15] ipmr: No RTNL for RTNL_FAMILY_IPMR rtnetlink.

[Kuniyuki Iwashima <kuniyu@google.com>]

This series removes RTNL from ipmr rtnetlink handlers.

After this series, there are a few RTNL left in net/ipv4/ipmr.c
and such users will be converted to per-netns RTNL in another
series.

Patch 1 adds a selftest to exercise most? of the RTNL paths
 in net/ipv4/ipmr.c

Patch 2 - 6 converts RTM_GETLINK / RTM_GETROUTE handlers
 to RCU.

Patch 7 - 9 converts ->exit_batch() to ->exit_rtnl() to
 save one RTNL in cleanup_net().

Patch 10 - 11 removes unnecessary RTNL during setup_net()
 failure.

Patch 12 is a random cleanup.

Patch 13 - 15 drops RTNL for RTM_NEWROUTE and RTM_DELROUTE.


Changes:
  v3:
    Patch 1: Init @unused in nl_add_rtattr().
    Patch 2: Use READ_ONCE() for mrt->mroute_do_pim in ip_mr_forward()
              and pim_rcv_v1()

  v2: https://lore.kernel.org/netdev/20260227033903.3307272-1-kuniyu@google.com/
    Patch 1: Add ipmr to .gitignore
    Patch 3: Add READ_ONCE() for mrt->maxvif in ipmr_rtm_dumplink().
    Patch 10: Use a local list in ipmr_free_table()

  v1: https://lore.kernel.org/netdev/20260226023637.1335854-1-kuniyu@google.com/


Kuniyuki Iwashima (15):
  selftest: net: Add basic functionality tests for ipmr.
  ipmr: Annotate access to mrt->mroute_do_{pim,assert,wrvifwhole}.
  ipmr: Convert ipmr_rtm_dumplink() to RCU.
  ipmr: Use MAXVIFS in mroute_msgsize().
  ipmr: Convert ipmr_rtm_getroute() to RCU.
  ipmr: Convert ipmr_rtm_dumproute() to RCU.
  ipmr: Move unregister_netdevice_many() out of mroute_clean_tables().
  ipmr: Move unregister_netdevice_many() out of ipmr_free_table().
  ipmr: Convert ipmr_net_exit_batch() to ->exit_rtnl().
  ipmr: Remove RTNL in ipmr_rules_init() and ipmr_net_init().
  ipmr: Call fib_rules_unregister() without RTNL.
  ipmr: Define net->ipv4.{ipmr_notifier_ops,ipmr_seq} under
    CONFIG_IP_MROUTE.
  ipmr/ip6mr: Convert net->ipv[46].ipmr_seq to atomic_t.
  ipmr: Add dedicated mutex for mrt->{mfc_hash,mfc_cache_list}.
  ipmr: Don't hold RTNL for ipmr_rtm_route().

 include/linux/mroute_base.h                   |   9 +-
 include/net/netns/ipv4.h                      |   6 +-
 include/net/netns/ipv6.h                      |   2 +-
 net/ipv4/ipmr.c                               | 265 ++++++----
 net/ipv4/ipmr_base.c                          |   4 +-
 net/ipv6/ip6mr.c                              |   4 +-
 .../selftests/net/forwarding/.gitignore       |   1 +
 .../testing/selftests/net/forwarding/Makefile |   4 +
 tools/testing/selftests/net/forwarding/ipmr.c | 455 ++++++++++++++++++
 9 files changed, 636 insertions(+), 114 deletions(-)
 create mode 100644 tools/testing/selftests/net/forwarding/ipmr.c

-- 
2.53.0.473.g4a7958ca14-goog