Re: [PATCH v17 06/10] rust: rename `AlwaysRefCounted` to `RefCounted`.

[Andreas Hindborg <a.hindborg@kernel.org>]

Onur Özkan <work@onurozkan.dev> writes:

> On Thu, 04 Jun 2026 22:11:18 +0200
> Andreas Hindborg <a.hindborg@kernel.org> wrote:
>
>> From: Oliver Mangold <oliver.mangold@pm.me>
>> 
>> There are types where it may both be reference counted in some cases and
>> owned in others. In such cases, obtaining `ARef<T>` from `&T` would be
>> unsound as it allows creation of `ARef<T>` copy from `&Owned<T>`.
>> 
>> Therefore, we split `AlwaysRefCounted` into `RefCounted` (which `ARef<T>`
>> would require) and a marker trait to indicate that the type is always
>> reference counted (and not `Ownable`) so the `&T` -> `ARef<T>` conversion
>> is possible.
>> 
>> - Rename `AlwaysRefCounted` to `RefCounted`.
>> - Add a new unsafe trait `AlwaysRefCounted`.
>> - Implement the new trait `AlwaysRefCounted` for the newly renamed
>>   `RefCounted` implementations. This leaves functionality of existing
>>   implementers of `AlwaysRefCounted` intact.
>> 
>> Suggested-by: Alice Ryhl <aliceryhl@google.com>
>> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
>> Signed-off-by: Oliver Mangold <oliver.mangold@pm.me>
>> [ Andreas: Updated commit message and rebase on rust-6.20-7.0 ]
>> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
>> Acked-by: Danilo Krummrich <dakr@kernel.org>
>> Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
>> Reviewed-by: Gary Guo <gary@garyguo.net>
>> Co-developed-by: Andreas Hindborg <a.hindborg@kernel.org>
>> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
>> ---
>>  rust/kernel/auxiliary.rs        |  7 +++++-
>>  rust/kernel/block/mq/request.rs | 15 ++++++++-----
>>  rust/kernel/cred.rs             | 13 +++++++++--
>>  rust/kernel/device.rs           | 12 ++++++++--
>>  rust/kernel/device/property.rs  | 11 +++++++--
>>  rust/kernel/drm/device.rs       |  9 ++++++--
>>  rust/kernel/drm/gem/mod.rs      | 16 ++++++++++----
>>  rust/kernel/fs/file.rs          | 16 ++++++++++----
>>  rust/kernel/i2c.rs              | 13 ++++++++---
>>  rust/kernel/mm.rs               | 15 +++++++++----
>>  rust/kernel/mm/mmput_async.rs   |  9 ++++++--
>>  rust/kernel/opp.rs              | 10 ++++++---
>>  rust/kernel/owned.rs            |  2 +-
>>  rust/kernel/pci.rs              | 10 ++++++++-
>>  rust/kernel/pid_namespace.rs    | 12 ++++++++--
>>  rust/kernel/platform.rs         |  7 +++++-
>>  rust/kernel/sync/aref.rs        | 49 ++++++++++++++++++++++++++---------------
>>  rust/kernel/task.rs             | 13 +++++++++--
>>  rust/kernel/types.rs            |  3 ++-
>>  rust/kernel/usb.rs              | 17 +++++++++++---
>>  20 files changed, 195 insertions(+), 64 deletions(-)
>> 
>> diff --git a/rust/kernel/auxiliary.rs b/rust/kernel/auxiliary.rs
>> index 93c0db1f6655..49f07740f657 100644
>> --- a/rust/kernel/auxiliary.rs
>> +++ b/rust/kernel/auxiliary.rs
>> @@ -19,6 +19,7 @@
>>          to_result, //
>>      },
>>      prelude::*,
>> +    sync::aref::{AlwaysRefCounted, RefCounted},
>
> This patch has multiple horizontal use statements around.

Thanks, I'll take another pass to fix that.


Best regards,
Andreas Hindborg