[v13,0/2] rust: xarray: Add a minimal abstraction for XArray

Message

Tamir Duberstein Dec. 13, 2024, 7:55 p.m. UTC

This is a reimagining relative to earlier versions[0] by Asahi Lina and
Maíra Canal.

It is needed to support rust-binder, though this version only provides
enough machinery to support rnull.

Link: https://lore.kernel.org/rust-for-linux/[e-mail]/ [0]
---
Changes in v13:
- Replace `bool::then` with `if`. (Miguel Ojeda)
- Replace `match` with `let` + `if`. (Miguel Ojeda)
- Link to v12: https://lore.kernel.org/r/[e-mail]

Changes in v12:
- Import `core::ptr::NonNull`. (Alice Ryhl)
- Introduce `StoreError` to allow `?` to be used with `Guard::store`.
  (Alice Ryhl)
- Replace `{crate,core}::ffi::c_ulong` and clarify TODO with respect to
  `usize`. (Alice Ryhl)
- Drop `T: Sync` bound on `impl Sync for XArray<T>`. (Alice Ryhl)
- Reword `Send` and `Sync` safety comments to match the style used in
  `lock.rs`. (Alice Ryhl and Andreas
  Hindborg)
- Link to v11: https://lore.kernel.org/r/[e-mail]

Changes in v11:
- Consolidate imports. (Alice Ryhl)
- Use literal `0` rather than `MIN`. (Alice Ryhl)
- Use bulleted list in SAFETY comment. (Alice Ryhl)
- Document (un)locking behavior of `Guard::store`. (Alice Ryhl)
- Document Normal API behavior WRT `XA_ZERO_ENTRY`. (Alice Ryhl)
- Rewrite `unsafe impl Sync` SAFETY comment. (Andreas Hindborg)
- Link to v10: https://lore.kernel.org/r/[e-mail]

Changes in v10:
- Guard::get takes &self instead of &mut self. (Andreas Hindborg)
- Guard is !Send. (Boqun Feng)
- Add Inspired-by tags. (Maíra Canal and Asahi Lina)
- Rebase on linux-next, use NotThreadSafe. (Alice Ryhl)
- Link to v9: https://lore.kernel.org/r/[e-mail]

---
Tamir Duberstein (2):
      rust: types: add `ForeignOwnable::PointedTo`
      rust: xarray: Add an abstraction for XArray

 rust/bindings/bindings_helper.h |   6 +
 rust/helpers/helpers.c          |   1 +
 rust/helpers/xarray.c           |  28 ++++
 rust/kernel/alloc.rs            |   5 +
 rust/kernel/alloc/kbox.rs       |  38 +++---
 rust/kernel/lib.rs              |   1 +
 rust/kernel/miscdevice.rs       |   6 +-
 rust/kernel/sync/arc.rs         |  21 +--
 rust/kernel/types.rs            |  46 ++++---
 rust/kernel/xarray.rs           | 289 ++++++++++++++++++++++++++++++++++++++++
 10 files changed, 396 insertions(+), 45 deletions(-)
---
base-commit: fac04efc5c793dccbd07e2d59af9f90b7fc0dca4
change-id: 20241020-rust-xarray-bindings-bef514142968
prerequisite-change-id: 20241030-borrow-mut-75f181feef4c:v6
prerequisite-patch-id: f801fb31bb4f202b3327f5fdb50d3018e25347d1
prerequisite-patch-id: b57aa4f44b238d4cb80f00276a188d9ba0c743cc
prerequisite-patch-id: 2387ec5af1cc03614d3dff5a95cefcd243befd65
prerequisite-patch-id: 75e26dd500888d9a27f8eac3d8304eab8d75c366
prerequisite-patch-id: 7f845443f373f975a888f01c3761fe8aa04b8a3c
prerequisite-patch-id: 5a9856c7363b33f0adfe8658e076b35abf960d23

Best regards,

Comments

Miguel Ojeda Dec. 13, 2024, 9:31 p.m. UTC | #1

On Fri, Dec 13, 2024 at 9:02 PM Tamir Duberstein <[e-mail]> wrote:
>
> Changes in v13:
> - Replace `bool::then` with `if`. (Miguel Ojeda)
> - Replace `match` with `let` + `if`. (Miguel Ojeda)

Personally, I would also use the early return style in both of these,
like in C. I think you may also omit the parenthesis in the first one.

(No need for a new version just for this)

Thanks!

Cheers,
Miguel

Tamir Duberstein Dec. 13, 2024, 11:22 p.m. UTC | #2

On Fri, Dec 13, 2024 at 4:31 PM Miguel Ojeda
<[e-mail]> wrote:
>
> On Fri, Dec 13, 2024 at 9:02 PM Tamir Duberstein <[e-mail]> wrote:
> >
> > Changes in v13:
> > - Replace `bool::then` with `if`. (Miguel Ojeda)
> > - Replace `match` with `let` + `if`. (Miguel Ojeda)
>
> Personally, I would also use the early return style in both of these,
> like in C.

My personal preference is to leave it as-is as the return keyword
isn't used anywhere in this file at the moment. I don't mind you
changing it if/when applying, though.

> I think you may also omit the parenthesis in the first one.

Oops, you're right.