Re: [resend PATCH v2 2/2] fuse: ensure that submounts lookup their parent

From: Krister Johansen
Date: Wed Oct 11 2023 - 12:32:36 EST


On Wed, Oct 11, 2023 at 09:07:33AM +0200, Miklos Szeredi wrote:
> On Wed, 11 Oct 2023 at 03:26, Krister Johansen <kjlx@xxxxxxxxxxxxxxxxxx> wrote:
>
> > I am curious what you have in mind in order to move this towards a
> > proper fix? I shied away from the approach of stealing a nlookup from
> > mp_fi beacuse it wasn't clear that I could always count on the nlookup
> > in the parent staying positive. E.g. I was afraid I was either going to
> > not have enough nlookups to move to submounts, or trigger a forget from
> > an exiting container that leads to an EBADF from the initial mount
> > namespace.
>
> One idea is to transfer the nlookup to a separately refcounted object
> that is referenced from mp_fi as well as all the submounts.

That seems possible. Would the idea be to move all tracking of nlookup
to a separate refcounted object for the particular nodeid, or just do
this for the first lookup of a submount?

Would you like me to put together a v3 that heads this direction?

Thanks,

-K