Re: [PATCH v16 2/4] rust: types: add `ForeignOwnable::PointedTo`

[Danilo Krummrich <dakr@kernel.org>]

On Mon, Feb 17, 2025 at 09:02:12AM -0500, Tamir Duberstein wrote:
> > > diff --git a/rust/kernel/pci.rs b/rust/kernel/pci.rs
> > > index 6c3bc14b42ad..eb25fabbff9c 100644
> > > --- a/rust/kernel/pci.rs
> > > +++ b/rust/kernel/pci.rs
> > > @@ -73,6 +73,7 @@ extern "C" fn probe_callback(
> > >          match T::probe(&mut pdev, info) {
> > >              Ok(data) => {
> > >                  let data = data.into_foreign();
> > > +                let data = data.cast();
> >
> > Same here and below, see also [2].
> 
> You're the maintainer,

This isn't true. I'm the original author, but I'm not an official maintainer of
this code. :)

> so I'll do what you ask here as well. I did it
> this way because it avoids shadowing the git history with this change,
> which I thought was the dominant preference.

As mentioned in [2], if you do it the other way around first the "rust: types:
add `ForeignOwnable::PointedTo`" patch and then the conversion to cast() it's
even cleaner and less code to change.

> 
> > I understand you like this style and I'm not saying it's wrong or forbidden and
> > for code that you maintain such nits are entirely up to you as far as I'm
> > concerned.
> >
> > But I also don't think there is a necessity to convert things to your preference
> > wherever you touch existing code.
> 
> This isn't a conversion, it's a choice made specifically to avoid
> touching code that doesn't need to be touched (in this instance).

See above.

> 
> > I already explicitly asked you not to do so in [3] and yet you did so while
> > keeping my ACK. :(
> >
> > (Only saying the latter for reference, no need to send a new version of [3],
> > otherwise I would have replied.)
> >
> > [2] https://lore.kernel.org/rust-for-linux/Z7MYNQgo28sr_4RS@cassiopeiae/
> > [3] https://lore.kernel.org/rust-for-linux/20250213-aligned-alloc-v7-1-d2a2d0be164b@gmail.com/
> 
> I will drop [2] and leave the `as _` casts in place to minimize
> controversy here.

As mentioned I think the conversion to cast() is great, just do it after this
one and keep it a single line -- no controversy. :)