On Tue, Jul 24, 2018 at 11:49 PM Jiri Pirko <j...@resnulli.us> wrote: > > Wed, Jul 25, 2018 at 01:20:08AM CEST, xiyou.wangc...@gmail.com wrote: > >So, you only send out notification when the last refcnt is gone. > > > >If the chain that is being deleted by a user is still used by an action, > >you return 0 or -EPERM? > > 0 and the chain stays there until the action is removed. Hmm, do you thing > that -EPERM should be returned in that case? The thing is, we have to > flush the chain in order to see the action references are there. We would > have to have 2 ref counters, one for filter, one for actions. > What do you think?
_If_ RTM_DELCHAIN does decrease the chain refcnt, then it is broken: # tc chain add X... (refcnt == 1) # tc action add ... goto chain X (refcnt==2) # tc chain del X ... (refcnt== 1) # tc chain del X ... (refcnt==0) RTM_DELCHAIN should just test if refcnt is 1, if it is, delete it, otherwise return -EPERM. This is how we handle tc standalone actions, see tcf_idr_delete_index(). Yes, you might need two refcnt's here.
