On Thu, Aug 24, 2017 at 12:32 PM, David Miller <da...@davemloft.net> wrote: > 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. >
Hold on, I spot a problem near ->delete(), need a fix like I did for tc actions... The reason why I didn't catch it in my test is actually we don't notify delete event for classes when deleting the whole tree. Anyway, v2 is coming.
