[PATCH RFC batadv v4 0/8] batman-adv: tt: atomic sashiko fixes

There were a couple of sashiko reports regarding the
batadv-next-pullrequest-20260728 PR. I went through the TT code and tried
to handle them and at the same time already predict what else sashiko might
report as next. I needed to change the batadv_tt_local_remove() hash
interaction as preparation for the related NEW flag (and counter) handling.

And the netdev maintainers rejected this approach (for now). I had to
re-add the atomic_t code parts back in this patchset. But since the netdev
maintainers didn't like the atomic_t implementation, everything was changed
to atomic_t with the help of scoped_guard() or spin_(un)lock_bh (when the
routine used "goto").

Signed-off-by: Sven Eckelmann <[email protected]>
---
Changes in v4:
- fix setting of BATADV_TT_CLIENT_ROAM batadv_tt_local_add_roam()
- move the roam_at setting in batadv_tt_global_del_roaming() before the
  setting of the flag
- don't unset BATADV_TT_CLIENT_NEW when avoiding the
  batadv_tt_local_size_dec() - it is simply not needed
- new patch: fix lock precondition for batadv_tt_local_size_inc() and
  document it
- clean up mini-helpers to avoid goto. precondition for using scoped_guard
- switch routines with goto's from scoped_guard to spin_(un)lock_bh
- Link to v3: https://patch.msgid.link/[email protected]

Changes in v3:
- switched to spinlock_bh due to rejection atomic_t by netdev (and
  potentially easier code)
- switch back to RFC
- Link to v2: https://patch.msgid.link/[email protected]

Changes in v2:
- rebase on main
- add "batman-adv: tt: use atomic flag modifications" and "batman-adv: tt:
  simplify NEW flag transition code" because they are reverted on main
- add patch to extract the roam "add" code in a separate function
- make the "simplify NEW flag transition code" patch independent of atomic_t code
- Link to v1: https://patch.msgid.link/[email protected]

To: [email protected]

---
Sven Eckelmann (8):
      batman-adv: tt: remove only the entry which was looked up from the hash
      batman-adv: tt: extract code handling a roam on add
      batman-adv: tt: simplify NEW flag transition code
      batman-adv: tt: drop unnecessary cleanup goto in helpers
      batman-adv: tt: use protected flag modifications
      batman-adv: tt: transition NEW local entries only under lock
      batman-adv: tt: don't uncount never committed clients on pending purge
      batman-adv: tt: decrement count for committed client on local_remove

 net/batman-adv/translation-table.c | 487 +++++++++++++++++++++++++------------
 net/batman-adv/types.h             |   8 +-
 2 files changed, 340 insertions(+), 155 deletions(-)
---
base-commit: 46e983472304d8875436a23ccb996ea18856081a
change-id: 20260730-tt-fixes-fca2b722ebbd

Best regards,
--  
Sven Eckelmann <[email protected]>