Re: [PATCH v2 1/1] rust: workqueue: add ScopedQueue for lifetime bound items

["Danilo Krummrich" <dakr@kernel.org>]

On Wed Jun 17, 2026 at 4:45 PM CEST, Onur Özkan wrote:
> Add a workqueue wrapper for work items that are not 'static.
>
> Tyr reset work is queued from a handle that owns a Controller<'bound>
> where the work item holds references tied to the lifetime of the bound
> device and its mapped IO state. The existing API only accepts 'static
> work items which cannot express that relationship.
>
> Introduce ScopedQueue for this case. It owns the underlying workqueue
> and ties enqueued work to the queue lifetime so borrowed state cannot
> outlive the queue that may still run it.
>
> Construction is unsafe because the queue must not be leaked.
>
> `compile_fail` doc-tests are ignored for now as KUnit doesn't support
> that. Enabling those tests as regular code block would raise this error:
>
>     ERROR:root:error[E0597]: `data` does not live long enough
> 	 --> rust/doctests_kernel_generated.rs:22029:44
> 	  |
>     22027 |         let data = ();
> 	  |             ---- binding `data` declared here
>     22028 |         // SAFETY: Queue is not leaked.
>     22029 |         queue = unsafe { new_queue(&data)? };
> 	  |                                            ^^^^^ borrowed value does not live long enough
>     22030 |     }
> 	  |     - `data` dropped here while still borrowed
>     ...
>     22034 | }
> 	  | - borrow might be used here, when `queue` is dropped and runs the `Drop` code for type `ScopedQueue`
> 	  |
> 	  = note: values in a scope are dropped in the opposite order they are defined
>
> which is exactly the constraint ScopedQueue is meant to enforce.
>
> This series is based on Alice's "Creation of workqueues in Rust" [1]
> series.
>
> Link: https://lore.kernel.org/all/20260312-create-workqueue-v4-0-ea39c351c38f@google.com [1]
> Suggested-by: Danilo Krummrich <dakr@kernel.org>
> Signed-off-by: Onur Özkan <work@onurozkan.dev>

Reviewed-by: Danilo Krummrich <dakr@kernel.org>