On Mon, 17 Nov 2025 10:07:57 +0000
Oliver Mangold <[email protected]> wrote:
> `AlwaysRefCounted` will become a marker trait to indicate that it is
> allowed to obtain an `ARef<T>` from a `&T`, which cannot be allowed for
> types which are also Ownable.
The message needs a rationale for making the change rather than relying
on the reader to deduce so.
For example:
There are types where it may both be referenced counted in some
cases and owned in other. 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.
Best,
Gary
>
> Signed-off-by: Oliver Mangold <[email protected]>
> Co-developed-by: Andreas Hindborg <[email protected]>
> Signed-off-by: Andreas Hindborg <[email protected]>
> Suggested-by: Alice Ryhl <[email protected]>
> ---
> rust/kernel/auxiliary.rs | 7 +++++-
> rust/kernel/block/mq/request.rs | 15 +++++++------
> rust/kernel/cred.rs | 13 ++++++++++--
> rust/kernel/device.rs | 13 ++++++++----
> rust/kernel/device/property.rs | 7 +++++-
> rust/kernel/drm/device.rs | 10 ++++++---
> rust/kernel/drm/gem/mod.rs | 10 ++++++---
> rust/kernel/fs/file.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 | 2 +-
> 18 files changed, 154 insertions(+), 61 deletions(-)
