Call the handler function with the lock held, return unlocked as we
might free the entry. Rework functions later in the call graph to be
either called with the lock held or, only if needed, unlocked.
Place asserts to document and tighten assumptions on various lle locking,
which were not always true before.
We call nd6_ns_output() unlocked and the assignment of ip6->ip6_src was
decentralized to minimize possible complexity introduced with the formerly
missing locking there. This also resulted in a push down of local
variable scopes into smaller blocks.
Reported by: many
PR: kern/148857
Submitted by: Dmitrij Tejblum (tejblum yandex-team.ru) (original version)
MFC After: 4 days
e6950476b9