Re: [PATCH 3/3] rust: add abstraction for `struct page`

[Andreas Hindborg]

Alice Ryhl <aliceryhl@xxxxxxxxxx> writes:

> On Thu, Feb 1, 2024 at 7:02 AM Trevor Gross <tmgross@xxxxxxxxx> wrote:
>>
>> On Wed, Jan 24, 2024 at 6:22 AM Alice Ryhl <aliceryhl@xxxxxxxxxx> wrote:
>> > +/// A pointer to a page that owns the page allocation.
>> > +///
>> > +/// # Invariants
>> > +///
>> > +/// The pointer points at a page, and has ownership over the page.
>> > +pub struct Page {
>> > +    page: NonNull<bindings::page>,
>> > +}
>>
>> Shouldn't this be UnsafeCell / Opaque? Since `struct page` contains locks.
>
> That only matters when we use a reference. Here, it's behind a raw pointer.

Why is it behind a pointer rather than being transparent over
`Opaque<bindings::page>` and using a `&Page` instead?

BR Andreas