From: Xin Long <lucien....@gmail.com> Date: Tue, 2 Jul 2019 00:54:55 +0800
> For these places are protected by rcu_read_lock, we change from > rcu_dereference_rtnl to rcu_dereference, as there is no need to > check if rtnl lock is held. > > For these places are protected by rtnl_lock, we change from > rcu_dereference_rtnl to rtnl_dereference/rcu_dereference_protected, > as no extra memory barriers are needed under rtnl_lock() which also > protects tn->bearer_list[] and dev->tipc_ptr/b->media_ptr updating. > > rcu_dereference_rtnl will be only used in the places where it could > be under rcu_read_lock or rtnl_lock. > > Signed-off-by: Xin Long <lucien....@gmail.com> In the cases where RTNL is held, even if rcu_read_lock() is also taken, we should use rtnl_dereference() because that avoids the READ_ONCE().
