[PATCH v14 2/9] rust: rename `AlwaysRefCounted` to `RefCounted`.

[Gary Guo]

On Thu Feb 5, 2026 at 1:31 PM GMT, Gary Guo wrote:
> On Wed Feb 4, 2026 at 11:56 AM GMT, Andreas Hindborg wrote:
>> From: Oliver Mangold <oliver.mangold at 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.
>> 
>> Original patch by Oliver Mangold <oliver.mangold at pm.me> [1].
>> 
>> Link: https://lore.kernel.org/r/20251117-unique-ref-v13-2-b5b243df1250@pm.me [1]
>> Suggested-by: Alice Ryhl <aliceryhl at google.com>
>> Reviewed-by: Daniel Almeida <daniel.almeida at collabora.com>
>> Signed-off-by: Andreas Hindborg <a.hindborg at kernel.org>
>
> I think you also need to update the `AlwaysRefCounted` reference mentioned in
> the `Owned` patch too? (Or perhaps this patch should be moved before `Owned`
> instead?)

Actually I re-read the comment in first patch, the text indeed should refer to
`AlwaysRefCounted`. Please disregard this comment.

Best,
Gary

>
> With that fixed:
>
> Reviewed-by: Gary Guo <gary at garyguo.net>
>
>> ---
>>  rust/kernel/auxiliary.rs        |  7 +++++-
>>  rust/kernel/block/mq/request.rs | 15 +++++++------
>>  rust/kernel/cred.rs             | 13 ++++++++++--
>>  rust/kernel/device.rs           | 10 ++++++---
>>  rust/kernel/device/property.rs  |  7 +++++-
>>  rust/kernel/drm/device.rs       | 10 ++++++---
>>  rust/kernel/drm/gem/mod.rs      |  8 ++++---
>>  rust/kernel/fs/file.rs          | 16 ++++++++++----
>>  rust/kernel/i2c.rs              | 16 +++++++++-----
>>  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        | 47 ++++++++++++++++++++++++++---------------
>>  rust/kernel/task.rs             | 10 ++++++---
>>  rust/kernel/types.rs            |  3 ++-
>>  19 files changed, 164 insertions(+), 63 deletions(-)