From: Nikolay Aleksandrov
Date: Sat, 6 Jun 2015 06:49:00 -0700
> br_fdb_update() can be called in process context in the following way:
> br_fdb_add() -> __br_fdb_add() -> br_fdb_update() (if NTF_USE flag is set)
> so we need to disable softirqs because there are softirq users of the
> hash_lock
br_fdb_update() can be called in process context in the following way:
br_fdb_add() -> __br_fdb_add() -> br_fdb_update() (if NTF_USE flag is set)
so we need to disable softirqs because there are softirq users of the
hash_lock. One easy way to reproduce this is to modify the bridge utility
to set NT
