[PATCH v19 4/8] rust: page: convert to `Ownable`

[Alice Ryhl]

On Fri, Jun 26, 2026 at 1:56 PM Andreas Hindborg <a.hindborg at kernel.org> wrote:
>
> From: Asahi Lina <lina at asahilina.net>
>
> This allows Page references to be returned as borrowed references,
> without necessarily owning the struct page.
>
> Remove `BorrowedPage` and update users to use `Owned<Page>`.
>
> Signed-off-by: Asahi Lina <lina at asahilina.net>
> [ Andreas: Fix formatting and add a safety comment, update users. ]
> Signed-off-by: Andreas Hindborg <a.hindborg at kernel.org>
> Reviewed-by: Gary Guo <gary at garyguo.net>

Reviewed-by: Alice Ryhl <aliceryhl at google.com>

>      /// Returns a raw pointer to the page.
>      pub fn as_ptr(&self) -> *mut bindings::page {
> -        self.page.as_ptr()
> +        Opaque::cast_into(&self.page)

cast_into() is mainly used when you have a raw pointer to opaque. When
you have a reference, you can just do self.page.get()

Alice