Re: [PATCH v3 4/7] rust: page: define trait IntoPageIter

[Alice Ryhl <aliceryhl@google.com>]

On Fri, Aug 08, 2025 at 08:10:18PM +0200, Danilo Krummrich wrote:
> The IntoPageIter trait provides a common interface for types that
> provide a page iterator, such as VmallocPageIter.
> 
> Subsequent patches will leverage this to let VBox and VVec provide a
> VmallocPageIter though this trait.
> 
> Signed-off-by: Danilo Krummrich <dakr@kernel.org>
> ---
>  rust/kernel/page.rs | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/rust/kernel/page.rs b/rust/kernel/page.rs
> index 631718a6ad7d..bfb5898ab4b5 100644
> --- a/rust/kernel/page.rs
> +++ b/rust/kernel/page.rs
> @@ -103,6 +103,16 @@ fn deref(&self) -> &Self::Target {
>      }
>  }
>  
> +/// Trait to be implemented by types, which provide an [`Iterator`] implementation of
> +/// [`BorrowedPage`] items, such as [`VmallocPageIter`](kernel::alloc::allocator::VmallocPageIter).
> +pub trait IntoPageIter<'a> {
> +    /// The [`Iterator`] type, e.g. [`VmallocPageIter`](kernel::alloc::allocator::VmallocPageIter).
> +    type Iter: Iterator<Item = BorrowedPage<'a>>;

Oh, also, I would put the lifetime on Iter.

trait AsPageIter {
    type Iter<'a>: Iterator<Item = BorrowedPage<'a>>;
    fn page_iter(&mut self) -> Self::Iter<'_>;
}

Alice