Re: [PATCH v2] rust: aref: make `AlwaysRefCounted::inc_ref` an associated function

[Alice Ryhl <aliceryhl@google.com>]

On Tue, Sep 02, 2025 at 05:06:38PM +0800, Trevor Chan wrote:
> `AlwaysRefCounted::inc_ref` is a function that shouldn't be called lightly.
> 
> To prevent accidentally calling it, `inc_ref` is now changed to be an
> associated function.
> 
> Modifies all `AlwaysRefCounted` implementors to work with this change.
> 
> Suggested-by: Benno Lossin <lossin@kernel.org>
> Closes: https://github.com/Rust-for-Linux/linux/issues/1177
> Signed-off-by: Trevor Chan <trev@trevrosa.dev>

One nit below, but:

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

> diff --git a/rust/kernel/sync/aref.rs b/rust/kernel/sync/aref.rs
> index dbd77bb68617..3a3d5052786c 100644
> --- a/rust/kernel/sync/aref.rs
> +++ b/rust/kernel/sync/aref.rs
> @@ -24,7 +24,9 @@
>  /// alive.)
>  pub unsafe trait AlwaysRefCounted {
>      /// Increments the reference count on the object.
> -    fn inc_ref(&self);
> +    ///
> +    /// This function should not be called lightly.
> +    fn inc_ref(obj: &Self);
>  
>      /// Decrements the reference count on the object.
>      ///
> @@ -103,7 +105,7 @@ pub unsafe fn from_raw(ptr: NonNull<T>) -> Self {
>      ///
>      /// # // SAFETY: TODO.
>      /// unsafe impl AlwaysRefCounted for Empty {
> -    ///     fn inc_ref(&self) {}
> +    ///     fn inc_ref(obj: &Self) {}
>      ///     unsafe fn dec_ref(_obj: NonNull<Self>) {}

We probably want _obj for inc_ref like we have for dec_ref.

Alice