Re: [PATCH] revocable: hide the implementation details from users

[Johan Hovold <johan@kernel.org>]

On Tue, Feb 10, 2026 at 08:59:20PM -0800, Paul E. McKenney wrote:
> On Wed, Feb 11, 2026 at 02:05:26AM +0000, Tzung-Bi Shih wrote:
> > On Mon, Feb 09, 2026 at 05:13:17AM -0600, Bartosz Golaszewski wrote:
> > > On Fri, 6 Feb 2026 23:02:44 +0100, "Paul E. McKenney" <paulmck@kernel.org> said:
> > > > On Fri, Feb 06, 2026 at 11:32:06AM +0100, Bartosz Golaszewski wrote:

> > > >> Could you please take a look and say if the design looks sane to you?
> > > >> Especially the double SRCU on the revocable_provider.
> > > >
> > > > The first patch in the above URL adds SRCU, and the other
> > > > two add various tests.  I do not see a double SRCU, just an
> > > > srcu_read_lock() in revocable_try_access() and an srcu_read_unlock()
> > > > in revocable_withdraw_access().

> > > This series didn't have it yet, it appeared as a fix to a race reported after
> > > it was queued, sorry for the confusion. I'm talking about this bit[1] here.
> > > It returns an __rcu-annotated pointer, forcing the user to keep and manage it.

> > Please hold off on reviewing the patch and the "double SRCU" usage for now.
> > I'll remove the second RCU in the next version, which should serve as a
> > better starting point for a clean review.

In case Paul or anyone else reading this wonders, the "revocable" code
was reverted last Friday so that's why the links Bartosz posted are
broken:

	https://lore.kernel.org/lkml/20260204142849.22055-1-johan@kernel.org/

Johan