+ hugetlbfs-release-subpool-on-fill_super-failure.patch added to mm-new branch

The patch titled
     Subject: hugetlbfs: release subpool on fill_super failure
has been added to the -mm mm-new branch.  Its filename is
     hugetlbfs-release-subpool-on-fill_super-failure.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/hugetlbfs-release-subpool-on-fill_super-failure.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: hugetlbfs: release subpool on fill_super failure
Date: Mon, 20 Jul 2026 10:18:59 +0800

hugetlbfs_fill_super() allocates a hugepage subpool when size or min_size
mount options are specified.  hugepage_new_subpool() may also reserve huge
pages for min_size.

If root dentry creation fails after the subpool is created, the failure
path frees the subpool with kfree().  This bypasses hugepage_put_subpool()
and can leave min_size reservations charged.

Use hugepage_put_subpool() on the failure path, matching the normal
put_super path.

Link: https://lore.kernel.org/[email protected]
Fixes: 7ca02d0ae586 ("hugetlbfs: accept subpool min_size mount option and setup accordingly")
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 |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/hugetlbfs/inode.c~hugetlbfs-release-subpool-on-fill_super-failure
+++ a/fs/hugetlbfs/inode.c
@@ -1419,7 +1419,8 @@ hugetlbfs_fill_super(struct super_block
 		goto out_free;
 	return 0;
 out_free:
-	kfree(sbinfo->spool);
+	if (sbinfo->spool)
+		hugepage_put_subpool(sbinfo->spool);
 	kfree(sbinfo);
 	return -ENOMEM;
 }
_

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
fat-release-buffer-head-after-rebuilding-parent.patch