From: Cong Wang <xiyou.wangc...@gmail.com> Date: Tue, 22 Aug 2017 21:38:10 -0700
> For TC classes, their ->get() and ->put() are always paired, and the > reference counting is completely useless, because: > > 1) For class modification and dumping paths, we already hold RTNL lock, > so all of these ->get(),->change(),->put() are atomic. > > 2) For filter bindiing/unbinding, we use other reference counter than > this one, and they should have RTNL lock too. > > 3) For ->qlen_notify(), it is special because it is called on ->enqueue() > path, but we already hold qdisc tree lock there, and we hold this > tree lock when graft or delete the class too, so it should not be gone > or changed until we release the tree lock. > > Therefore, this patch removes ->get() and ->put(), but: > > 1) Adds a new ->find() to find the pointer to a class by classid, no > refcnt. > > 2) Move the original class destroy upon the last refcnt into ->delete(), > right after releasing tree lock. This is fine because the class is > already removed from hash when holding the lock. > > For those who also use ->put() as ->unbind(), just rename them to reflect > this change. > > Cc: Jamal Hadi Salim <j...@mojatatu.com> > Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com> This one looks good to me. Jamal, please give it a quick look over and review. Thanks!
