mm/hugetlb: extract sysfs into hugetlb_sysfs.c

Patch series "mm/hugetlb: refactor sysfs/sysctl interfaces", v5.

hugetlb.c has grown significantly and become difficult to maintain.  This
patch series extracts the sysfs and sysctl interface code into separate
dedicated files to improve code organization.

The refactoring includes:
- Patch 1: Extract sysfs interface into mm/hugetlb_sysfs.c
- Patch 2: Extract sysctl interface into mm/hugetlb_sysctl.c

No functional changes are introduced in this series.  The code is moved
as-is, with only minor formatting adjustments for code style consistency. 
This should make future maintenance and enhancements to the hugetlb
subsystem easier.

Testing: The patch series has been compile-tested and maintains the same
functionality as the original code.


This patch (of 2):

Currently, hugetlb.c contains both core management logic and sysfs
interface implementations, making it difficult to maintain.  This patch
extracts the sysfs-related code into a dedicated file to improve code
organization.

The following components are moved to mm/hugetlb_sysfs.c:
- sysfs attribute definitions and handlers
- sysfs kobject management functions
- NUMA per-node hstate attribute registration

Several inline helper functions and macros are moved to
mm/hugetlb_internal.h:
- hstate_is_gigantic_no_runtime()
- next_node_allowed()
- get_valid_node_allowed()
- hstate_next_node_to_alloc()
- hstate_next_node_to_free()
- for_each_node_mask_to_alloc/to_free macros

To support code sharing, these functions are changed from static to
exported symbols:
- remove_hugetlb_folio()
- add_hugetlb_folio()
- init_new_hugetlb_folio()
- prep_and_add_allocated_folios()
- demote_pool_huge_page()
- __nr_hugepages_store_common()

The Makefile is updated to compile hugetlb_sysfs.o when CONFIG_HUGETLBFS
is enabled.  This maintains all existing functionality while improving
maintainability by separating concerns.

MAINTAINERS is updated to add new file hugetlb_sysfs.c.

Link: https://lkml.kernel.org/r/cover.1762398359.git.zhuhui@kylinos.cn
Link: https://lkml.kernel.org/r/656a03dff7e2bb20e24e841ede81fdca01d21410.1762398359.git.zhuhui@kylinos.cn
Signed-off-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Hui Zhu <zhuhui@kylinos.cn>
Cc: David Hildenbrand <david@redhat.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

0 files changed, 0 insertions, 0 deletions