On Wed, Feb 12, 2020 at 12:41 PM Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > > On Wed, Feb 12, 2020 at 08:38:33PM +0000, Al Viro wrote: > > > > Wait, I thought the whole point of that had been to allow multiple > > procfs instances for the same userns? Confused... > > s/userns/pidns/, sorry Right, but we still hold the ref to it here... [ Looks more ] Oooh. No we don't. Exactly because we don't hold the lock, only the rcu lifetime, the ref can go away from under us. I see what your concern is. Ouch, this is more painful than I expected - the code flow looked so simple. I really wanted to avoid a new lock during process shutdown, because that has always been somewhat painful. Linus