Re: [PATCH v3 04/12] rust: xarray: add `XArrayState`

[Tamir Duberstein]

On Tue, Feb 24, 2026 at 9:27 AM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
>
> Tamir Duberstein <tamird@xxxxxxxxx> writes:
>
> > On Mon, Feb 9, 2026 at 6:39 AM Andreas Hindborg <a.hindborg@xxxxxxxxxx> wrote:
> >>
> >> Add `XArrayState` as internal state for XArray iteration and entry
> >> operations. This struct wraps the C `xa_state` structure and holds a
> >> reference to a `Guard` to ensure exclusive access to the XArray for the
> >> lifetime of the state object.
> >>
> >> The `XAS_RESTART` constant is also exposed through the bindings helper
> >> to properly initialize the `xa_node` field.
> >>
> >> The struct and its constructor are marked with `#[expect(dead_code)]` as
> >> there are no users yet. We will remove this annotation in a later patch.
> >>
> >> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxx>
> >> ---
> >>  rust/bindings/bindings_helper.h |  1 +
> >>  rust/kernel/xarray.rs           | 41 ++++++++++++++++++++++++++++++++++++++++-
> >>  2 files changed, 41 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
> >> index a067038b4b422..58605c32e8102 100644
> >> --- a/rust/bindings/bindings_helper.h
> >> +++ b/rust/bindings/bindings_helper.h
> >> @@ -117,6 +117,7 @@ const xa_mark_t RUST_CONST_HELPER_XA_PRESENT = XA_PRESENT;
> >>
> >>  const gfp_t RUST_CONST_HELPER_XA_FLAGS_ALLOC = XA_FLAGS_ALLOC;
> >>  const gfp_t RUST_CONST_HELPER_XA_FLAGS_ALLOC1 = XA_FLAGS_ALLOC1;
> >> +const size_t RUST_CONST_HELPER_XAS_RESTART = (size_t)XAS_RESTART;
> >
> > Please add a comment to explain the cast.
>
> How is this:
>
> // `XAS_RESTART` is defined with type `struct xa_node *`. `bindgen`
> // cannot generate pointer typed constants, so we cast to `size_t`.

Can we include a citation or explain why bindgen can't generate
pointer typed constants?

>
>
> Best regards,
> Andreas Hindborg
>
>