On Wed, Aug 26, 2020 at 01:52:38PM -0600, Andreas Dilger wrote:
> On Aug 26, 2020, at 1:43 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> >
> > On Thu, Aug 13, 2020 at 05:32:52PM +0200, Stefano Garzarella wrote:
> >> The enumeration allows us to keep track of the last
> >> io_uring_register(2) opcode available.
> >>
> >> Behaviour and opcodes names don't change.
> >>
> >> Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> >> ---
> >> include/uapi/linux/io_uring.h | 27 ++++++++++++++++-----------
> >> 1 file changed, 16 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> >> index d65fde732518..cdc98afbacc3 100644
> >> --- a/include/uapi/linux/io_uring.h
> >> +++ b/include/uapi/linux/io_uring.h
> >> @@ -255,17 +255,22 @@ struct io_uring_params {
> >> /*
> >> * io_uring_register(2) opcodes and arguments
> >> */
> >> -#define IORING_REGISTER_BUFFERS 0
> >> -#define IORING_UNREGISTER_BUFFERS 1
> >> -#define IORING_REGISTER_FILES 2
> >> -#define IORING_UNREGISTER_FILES 3
> >> -#define IORING_REGISTER_EVENTFD 4
> >> -#define IORING_UNREGISTER_EVENTFD 5
> >> -#define IORING_REGISTER_FILES_UPDATE 6
> >> -#define IORING_REGISTER_EVENTFD_ASYNC 7
> >> -#define IORING_REGISTER_PROBE 8
> >> -#define IORING_REGISTER_PERSONALITY 9
> >> -#define IORING_UNREGISTER_PERSONALITY 10
> >> +enum {
> >> + IORING_REGISTER_BUFFERS,
> >
> > Actually, one *tiny* thought. Since this is UAPI, do we want to be extra
> > careful here and explicitly assign values? We can't change the meaning
> > of a number (UAPI) but we can add new ones, etc? This would help if an
> > OP were removed (to stop from triggering a cascade of changed values)...
> >
> > for example:
> >
> > enum {
> > IORING_REGISTER_BUFFERS = 0,
> > IORING_UNREGISTER_BUFFERS = 1,
> > ...
>
> Definitely that is preferred, IMHO, for enums used as part of UAPI,
> as it avoids accidental changes to the values, and it also makes it
> easier to see what the actual values are.
>
Sure, I agree.
I'll put the values in the enumerations in the v5.
Thanks,
Stefano
