[PATCH v2 0/3] rust: configfs abstractions

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

This series adds a safe Rust API that allows Rust modules to interface
the `configfs` machinery.

The series contains an example for the samples folder to demonstrate
usage of the API. As such, there is no inline example in the
documentation.

The last patch adds a maintainer entry for the Rust configfs
abstractions, to make it absolutely clear that I will commit to maintain
these abstractions, if required. Feel free to drop this patch if this is
not required.

The series is a dependency of `rnull`, the Rust null block driver.
Please see [1] for initial `configfs` support in `rnull`.

[1] https://github.com/metaspace/linux/tree/9ac53130f5fb05b9b3074fa261b445b8fde547dd/drivers/block/rnull

Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
---
Changes in v2:
- Remove generalization over pointer type and enforce use of `Arc`.
- Use type system to enforce connection between `ItemType` and
  `Subsystem` or `Group`. Differentiate construction of vtables on this
  type difference.
- Move drop logic of child nodes from parent to child.
- Pick `ForeignOwnable::PointedTo` patch as dependency instead of
  including it here.
- Fix some rustdoc warnings.
- Use CamelCase for generic type parameter declaration.
- Destroy mutex in `Subsystem::drop`.
- Move `GroupOperationsVTable` struct definition next to implementation.
- Rebase on v6.14-rc1.
- Link to v1: https://lore.kernel.org/r/20250131-configfs-v1-0-87947611401c@kernel.org

---
Andreas Hindborg (3):
      rust: sync: change `<Arc<T> as ForeignOwnable>::PointedTo` to `T`
      rust: configfs: introduce rust support for configfs
      MAINTAINERS: add entry for configfs Rust abstractions

 MAINTAINERS                     |   7 +
 rust/bindings/bindings_helper.h |   1 +
 rust/helpers/mutex.c            |   5 +
 rust/kernel/configfs.rs         | 860 ++++++++++++++++++++++++++++++++++++++++
 rust/kernel/lib.rs              |   2 +
 rust/kernel/sync/arc.rs         |  21 +-
 samples/rust/Kconfig            |  11 +
 samples/rust/Makefile           |   1 +
 samples/rust/rust_configfs.rs   | 186 +++++++++
 9 files changed, 1089 insertions(+), 5 deletions(-)
---
base-commit: 379487e17ca406b47392e7ab6cf35d1c3bacb371
change-id: 20250131-configfs-b888cd82d84a
prerequisite-patch-id: 275efe8e08839e3a0de28ed26e8de80be9852024

Best regards,
-- 
Andreas Hindborg <a.hindborg@kernel.org>