[GIT PULL] Rust XArray for v7.5

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

Hi Matthew,

As mentioned in [1], this replaces the earlier v7.4 PULL, which missed
the merge window. This PR is rebased onto v7.4-rc2 (no changes), for the
next merge window (v7.5). It has been in linux-next since next-20261102.

Could you let me know by v7.4-rc5 whether you can pick it up?

[1] https://lore.kernel.org/all/20261030101626.0-da.gomez@kernel.org/

Thanks

The following changes since commit 7475ea8b58616b33c04afb976cf0fbaad9dd63fb:

  Linux 7.4-rc2 (2026-11-08 16:22:20 -0800)

are available in the Git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/da.gomez/linux.git tags/rxarray-v7.5

for you to fetch changes up to 29f1617aa1dbd0803736403cd63c4965873fa621:

  rust: rxarray: add rust xarray support (2026-11-12 10:14:36 +0100)

----------------------------------------------------------------
Rust XArray for v7.5

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 on v7.4-rc2, and
has been in linux-next since next-20261102.

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]

Signed-off-by: Daniel Gomez <da.gomez@samsung.com>

----------------------------------------------------------------
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