Re: [PATCH v4 3/3] io_uring: allow disabling rings during the creation

[Stefano Garzarella <sgarzare@redhat.com>]

On Wed, Aug 26, 2020 at 12:50:31PM -0700, Kees Cook wrote:
> On Thu, Aug 13, 2020 at 05:32:54PM +0200, Stefano Garzarella wrote:
> > This patch adds a new IORING_SETUP_R_DISABLED flag to start the
> > rings disabled, allowing the user to register restrictions,
> > buffers, files, before to start processing SQEs.
> > 
> > When IORING_SETUP_R_DISABLED is set, SQE are not processed and
> > SQPOLL kthread is not started.
> > 
> > The restrictions registration are allowed only when the rings
> > are disable to prevent concurrency issue while processing SQEs.
> > 
> > The rings can be enabled using IORING_REGISTER_ENABLE_RINGS
> > opcode with io_uring_register(2).
> > 
> > Suggested-by: Jens Axboe <axboe@kernel.dk>
> > Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
> 
> Reviewed-by: Kees Cook <keescook@chromium.org>
> 
> Where can I find the io_uring selftests? I'd expect an additional set of
> patches to implement the selftests for this new feature.

Since the io_uring selftests are stored in the liburing repository, I created
a new test case (test/register-restrictions.c) in my fork and I'll send it
when this series is accepted. It's available in this repository:

https://github.com/stefano-garzarella/liburing (branch: io_uring_restrictions)

Thanks for the review,
Stefano