[GIT PULL] Rust XArray for v7.4

[Daniel Gomez <da.gomez@kernel.org>]

Hi Matthew,

I'm sending the Rust XArray for the current v7.4 cycle, although it is
probably too late for it. Just let me know if you need me to resend it
later, rebased or under a different tag.

Thanks,
Daniel

The following changes since commit cee9395acd8043be0644b25c34bfa86623f2b935:

  Linux 7.3-rc1 (2026-08-30 13:34:40 -0700)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/da.gomez/linux.git tags/rxarray-v7.4

for you to fetch changes up to 4ce73d98a0a6e5bba46ed1fc9a61511bdccea776:

  rust: rxarray: add rust xarray support (2026-10-12 08:36:28 +0200)

----------------------------------------------------------------
Rust XArray for v7.4

Add a Rust implementation of the XArray (rust/kernel/rxarray.rs),
introduced as an experimental Rust reference implementation [1] of
lib/xarray.c, as discussed at LPC26 [2]. This lets Rust users, such as
the null block driver and possibly Tyr (under evaluation), experiment
with and evaluate both implementations.

The goal is to evaluate whether Rust helps with the most common class of
XArray bugs, misuse of the API by its callers, such as the long-dormant
page cache corruption that almost blocked the LBS work [3]. The RFC v1
cover letter has the full motivation, benchmark baseline and
roadmap [4].

This initial version supports store, load, load_mut and erase. It has
been tested with the included KUnit tests and doctests.

Outside of rust/kernel/rxarray.rs, this touches:
 - MAINTAINERS: new XARRAY [RUST] entry, maintained by Daniel Gomez and
   Matthew Wilcox, with Andreas Hindborg as reviewer.
 - lib/Kconfig: new XARRAY_RUST option.
 - rust/kernel/lib.rs: register the rxarray module.
The C XArray implementation is unchanged.

Link: https://rust-for-linux.com/rust-reference-drivers/ [1]
Link: https://lore.kernel.org/all/20261009212431.0-da.gomez@kernel.org/ [2]
Link: https://lore.kernel.org/all/A5A976CB-DB57-4513-A700-656580488AB6@flyingcircus.io/ [3]
Link: https://lore.kernel.org/all/20260923-rxarray-next-v1-0-92eedf185649@samsung.com/ [4]
----------------------------------------------------------------
Daniel Gomez (1):
      rust: rxarray: add rust xarray support

 MAINTAINERS            |   12 +
 lib/Kconfig            |   11 +
 rust/kernel/lib.rs     |    2 +
 rust/kernel/rxarray.rs | 1407 ++++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 1432 insertions(+)
 create mode 100644 rust/kernel/rxarray.rs