+ hugetlb-make-hugepage_put_subpool-tolerate-null.patch added to mm-new branch

The patch titled
     Subject: hugetlb: make hugepage_put_subpool() tolerate NULL
has been added to the -mm mm-new branch.  Its filename is
     hugetlb-make-hugepage_put_subpool-tolerate-null.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlb-make-hugepage_put_subpool-tolerate-null.patch

This patch will later appear in the mm-new branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Yichong Chen <[email protected]>
Subject: hugetlb: make hugepage_put_subpool() tolerate NULL
Date: Mon, 20 Jul 2026 15:38:41 +0800

Both callers of hugepage_put_subpool() check whether the subpool pointer
is NULL before calling it.  Move the NULL check into
hugepage_put_subpool() so callers can use the helper unconditionally.

This is a follow-up cleanup after using hugepage_put_subpool() from the
hugetlbfs_fill_super() failure path.

Link: https://lore.kernel.org/[email protected]
Signed-off-by: Yichong Chen <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Mike Kravetz <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: Oscar Salvador <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 fs/hugetlbfs/inode.c |    6 ++----
 mm/hugetlb.c         |    3 +++
 2 files changed, 5 insertions(+), 4 deletions(-)

--- a/fs/hugetlbfs/inode.c~hugetlb-make-hugepage_put_subpool-tolerate-null
+++ a/fs/hugetlbfs/inode.c
@@ -1129,8 +1129,7 @@ static void hugetlbfs_put_super(struct s
 	if (sbi) {
 		sb->s_fs_info = NULL;
 
-		if (sbi->spool)
-			hugepage_put_subpool(sbi->spool);
+		hugepage_put_subpool(sbi->spool);
 
 		kfree(sbi);
 	}
@@ -1419,8 +1418,7 @@ hugetlbfs_fill_super(struct super_block
 		goto out_free;
 	return 0;
 out_free:
-	if (sbinfo->spool)
-		hugepage_put_subpool(sbinfo->spool);
+	hugepage_put_subpool(sbinfo->spool);
 	kfree(sbinfo);
 	return -ENOMEM;
 }
--- a/mm/hugetlb.c~hugetlb-make-hugepage_put_subpool-tolerate-null
+++ a/mm/hugetlb.c
@@ -182,6 +182,9 @@ void hugepage_put_subpool(struct hugepag
 {
 	unsigned long flags;
 
+	if (!spool)
+		return;
+
 	spin_lock_irqsave(&spool->lock, flags);
 	BUG_ON(!spool->count);
 	spool->count--;
_

Patches currently in -mm which might be from [email protected] are

tools-mm-page_owner_sort-return-explicit-filter-results.patch
tools-mm-page_owner_sort-free-per-record-allocations.patch
tools-mm-page_owner_sort-bound-pattern-output-copies.patch
hugetlbfs-release-subpool-on-fill_super-failure.patch
hugetlb-make-hugepage_put_subpool-tolerate-null.patch
fat-release-buffer-head-after-rebuilding-parent.patch