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Tamir Duberstein 74e2712b14 xarray: extract xa_zero_to_null
Patch series "xarray: extract __xa_cmpxchg_raw".

This series reduces duplication between __xa_cmpxchg and __xa_insert by
extracting a new function that does not coerce zero entries to null on the
return path.

The new function may be used by the upcoming Rust xarray abstraction in
its reservation API where it is useful to tell the difference between zero
entries and null slots.


This patch (of 2):

Reduce code duplication by extracting a static inline function that
returns its argument if it is non-zero and NULL otherwise.

This changes xas_result to check for errors before checking for zero but
this cannot change the behavior of existing callers:
- __xa_erase: passes the result of xas_store(_, NULL) which cannot fail.
- __xa_store: passes the result of xas_store(_, entry) which may fail.
  xas_store calls xas_create when entry is not NULL which returns NULL
  on error, which is immediately checked. This should not change
  observable behavior.
- __xa_cmpxchg: passes the result of xas_load(_) which might be zero.
  This would previously return NULL regardless of the outcome of
  xas_store but xas_store cannot fail if xas_load returns zero
  because there is no need to allocate memory.
- xa_store_range: same as __xa_erase.

Link: https://lkml.kernel.org/r/20241112-xarray-insert-cmpxchg-v1-0-dc2bdd8c4136@gmail.com
Link: https://lkml.kernel.org/r/20241112-xarray-insert-cmpxchg-v1-1-dc2bdd8c4136@gmail.com
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Andreas Hindborg <a.hindborg@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-12 20:20:58 -08:00
arch NIOS2: update for v6.14 2025-01-03 14:16:25 -08:00
block block: avoid to reuse hctx not removed from cpuhp callback list 2024-12-18 07:25:37 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: rsassa-pkcs1 - Copy source data for SG list 2024-12-10 13:34:05 +08:00
Documentation Documentation/core-api: min_heap: add author information 2025-01-12 20:20:57 -08:00
drivers A randconfig build fix and a performance fix: 2025-01-05 10:28:34 -08:00
fs 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
include lib min_heap: add brief introduction to Min Heap API 2025-01-12 20:20:57 -08:00
init - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
io_uring io_uring/kbuf: use pre-committed buffer address for non-pollable file 2025-01-03 09:38:37 -07:00
ipc - The series "resource: A couple of cleanups" from Andy Shevchenko 2024-11-25 16:09:48 -08:00
kernel 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
lib xarray: extract xa_zero_to_null 2025-01-12 20:20:58 -08:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Revert "vmstat: disable vmstat_work on vmstat_cpu_down_prep()" 2025-01-06 06:10:24 -08:00
net Nothing major here. Over the last two weeks we gathered only around 2025-01-03 14:36:54 -08:00
rust workqueue: Fixes for v6.13-rc5 2025-01-03 15:03:56 -08:00
samples BPF fixes: 2024-12-06 15:07:48 -08:00
scripts scripts/spelling.txt: add more spellings to spelling.txt 2025-01-12 20:20:58 -08:00
security selinux/stable-6.13 PR 20241217 2024-12-18 12:10:15 -08:00
sound sound fixes for 6.13-rc6 2025-01-03 10:54:51 -08:00
tools 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
usr kbuild: Drop support for include/asm-<arch> in headers_check.pl 2024-12-21 11:43:17 +09:00
virt VFIO updates for v6.13 2024-11-27 12:57:03 -08:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: enable Clippy's check-private-items 2024-10-07 21:39:57 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Kbuild updates for v6.13 2024-11-30 13:41:50 -08:00
.mailmap mailmap: modify the entry for Mathieu Othacehe 2024-12-30 17:59:08 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS cgroup: Changes for v6.13 2024-11-20 09:54:49 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig
MAINTAINERS 25 hotfixes. 16 are cc:stable. 18 are MM and 7 are non-MM. 2025-01-05 10:37:45 -08:00
Makefile Linux 6.13-rc6 2025-01-05 14:13:40 -08:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.