From mboxrd@z Thu Jan  1 00:00:00 1970
From: Claude Code Review Bot <claude-review@example.com>
To: dri-devel-reviews@example.com
Subject: Claude review: rust: implement `ForeignOwnable` for `Owned`
Date: Fri, 27 Feb 2026 15:11:58 +1000
Message-ID: <review-patch9-20260224-unique-ref-v16-9-c21afcb118d3@kernel.org>
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Patch Review

The `ForeignOwnable` impl allows `Owned<T>` to be stored in C data structur=
es like `XArray`.

```rust
#[repr(transparent)]
pub struct Owned<T: Ownable> {
    ptr: NonNull<T>,
}
```

The `#[repr(transparent)]` is added here, needed for the `ForeignOwnable` i=
mplementation since it ensures `Owned<T>` has the same layout as `NonNull<T=
>`.

The `BorrowedMut` type is `Pin<&'a mut T>`, which is correct =E2=80=94 it m=
aintains the pin invariant since `Owned` pins its contents.

```rust
unsafe fn borrow_mut<'a>(ptr: *mut kernel::ffi::c_void) -> Self::BorrowedMu=
t<'a> {
    let inner =3D unsafe { &mut *ptr.cast() };
    unsafe { Pin::new_unchecked(inner) }
}
```

The safety reasoning about not moving out of `inner` and not handing out mu=
table references when `T: !Unpin` is correct =E2=80=94 `Pin<&mut T>` only p=
rovides `DerefMut` when `T: Unpin`.

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