When a workqueue is shut down, delayed work that is pending but not
scheduled does not get properly cleaned up, so it's not safe to use
`enqueue_delayed` on a workqueue that might be destroyed. To fix this,
restricted `enqueue_delayed` to static queues.
This may be fixed in the future by an approach along the lines of [1].
Cc: stable@vger.kernel.org
Fixes: 7c098cd5eaae ("workqueue: rust: add delayed work items")
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20250423-destroy-workqueue-flush-v1-1-3d74820780a5@google.com [1]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/kernel/workqueue.rs | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/rust/kernel/workqueue.rs b/rust/kernel/workqueue.rs
index 706e833e9702..1acd113c04ee 100644
--- a/rust/kernel/workqueue.rs
+++ b/rust/kernel/workqueue.rs
@@ -296,8 +296,15 @@ pub fn enqueue<W, const ID: u64>(&self, w: W) -> W::EnqueueOutput
///
/// This may fail if the work item is already enqueued in a workqueue.
///
+ /// This is only valid for global workqueues (with static lifetimes) because those are the only
+ /// ones that outlive all possible delayed work items.
+ ///
/// The work item will be submitted using `WORK_CPU_UNBOUND`.
- pub fn enqueue_delayed<W, const ID: u64>(&self, w: W, delay: Jiffies) -> W::EnqueueOutput
+ pub fn enqueue_delayed<W, const ID: u64>(
+ &'static self,
+ w: W,
+ delay: Jiffies,
+ ) -> W::EnqueueOutput
where
W: RawDelayedWorkItem<ID> + Send + 'static,
{
--
2.53.0.473.g4a7958ca14-goog