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

[Andreas Hindborg]

"Tamir Duberstein" <tamird@xxxxxxxxx> writes:

> 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?

If you have one, I can add it. I don't know why this is the case. My
guess is that it's just not implemented yet.

Best regards,
Andreas Hindborg