[PATCH v3 0/4] Subject: [PATCH v3 0/4] mm/hugetlb: Fix CMA parsing, flags and usage accounting

[Kaitao Cheng]

From: Kaitao Cheng <chengkaitao@xxxxxxxxxx>

This series fixes three independent HugeTLB issues reported by Sashiko
and includes a follow-up cleanup of NR_HUGETLB accounting.

Patch 1 rejects a global hugetlb_cma size following node-specific entries.
This prevents malformed input from overwriting valid per-node reservations
with an incorrectly parsed global size.

Patch 2 preserves persistent folio flags when a failed vmemmap restore
returns a folio to the pool. This retains CMA allocation tracking and
raw hardware poison information, while ensuring transient flags are
cleared before returning the folio.

Patch 3 retains the minimal NR_HUGETLB accounting fix, as suggested by
Muchun Song, to keep it straightforward to backport. It balances the
counter before freeing unused surplus folios during reservation
gathering or after a failed overcommit recheck.

Patch 4 moves NR_HUGETLB node accounting to the underlying folio state
transitions and separates it from memcg statistics. This cleans up
the accounting in the allocation and surplus cleanup paths.

Changes in v3:
- Retain patch 3/3 from v1.
- Fix code alignment.

Changes in v2:
- Patch 2: Preserve persistent flags, clear transient flags, and warn
  about unexpected flags.
- Patch 3: Account at folio state transitions and separate node and
  memcg statistics.

Link to v2:
https://lore.kernel.org/all/20261102024910.31486-1-kaitao.cheng@xxxxxxxxx/

Link to v1:
https://lore.kernel.org/all/20261028113319.38544-1-kaitao.cheng@xxxxxxxxx/

Kaitao Cheng (4):
  mm/hugetlb_cma: fix incorrect hugetlb_cma_size assignment on malformed
    input
  mm/hugetlb: Preserve persistent flags when returning folios to the
    pool
  mm/hugetlb: fix NR_HUGETLB accounting for unused surplus folios
  mm/hugetlb: Account NR_HUGETLB at folio state transitions

 mm/hugetlb.c     | 52 +++++++++++++++++++++++++++++++-----------------
 mm/hugetlb_cma.c |  3 +++
 mm/memcontrol.c  |  6 +-----
 3 files changed, 38 insertions(+), 23 deletions(-)

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2.53.0