[merged mm-hotfixes-stable] mm-hugetlb-do-not-dissolve-gigantic-pages-without-runtime-support.patch removed from -mm tree

[merged mm-hotfixes-stable] mm-hugetlb-do-not-dissolve-gigantic-pages-without-runtime-support.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/hugetlb: do not dissolve gigantic pages without runtime support
has been removed from the -mm tree.  Its filename was
     mm-hugetlb-do-not-dissolve-gigantic-pages-without-runtime-support.patch

This patch was dropped because it was merged into the mm-hotfixes-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Longlong Xia <xialonglong@kylinos.cn>
Subject: mm/hugetlb: do not dissolve gigantic pages without runtime support
Date: Sun, 23 Aug 2026 12:40:51 +0800

dissolve_free_hugetlb_folio() doesn't check
hstate_is_gigantic_no_runtime(h) though remove_hugetlb_folio()/
update_and_free_hugetlb_folio() silently bail for such folios, so it frees
a still-listed folio and, on vmemmap restore failure, the
add_hugetlb_folio() rollback corrupts the free list.

Link: https://lore.kernel.org/20260823044118.1097121-2-xialonglong2025@163.com
Fixes: 6eb4e88a6d27 ("hugetlb: create remove_hugetlb_page() to separate functionality")
Signed-off-by: Longlong Xia <xialonglong@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Assisted-by: Codex:gpt-5.6-sol
Acked-by: Muchun Song <muchun.song@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
---

 mm/hugetlb.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/mm/hugetlb.c~mm-hugetlb-do-not-dissolve-gigantic-pages-without-runtime-support
+++ a/mm/hugetlb.c
@@ -1967,6 +1967,15 @@ retry:
 		struct hstate *h = folio_hstate(folio);
 		bool adjust_surplus = false;
 
+		/*
+		 * remove_hugetlb_folio()/update_and_free_hugetlb_folio() bail
+		 * for gigantic hstates without runtime support, so dissolving one
+		 * here would leave it on the free list and, on vmemmap restore
+		 * failure, the add_hugetlb_folio() rollback corrupts that list.
+		 */
+		if (hstate_is_gigantic_no_runtime(h))
+			goto out;
+
 		if (!available_huge_pages(h))
 			goto out;
 
_

Patches currently in -mm which might be from xialonglong@kylinos.cn are

mm-hugetlb-warn-instead-of-silently-bailing-gigantic-pages-without-runtime-support.patch
mm-hugetlb-preserve-source-surplus-accounting-during-demotion.patch
mm-hugetlb-cap-demotion-at-currently-available-free-pages.patch
mm-zswap-publish-the-initial-pool-with-list_add_rcu.patch
mm-zswap-enable-zswap_ever_enabled-in-zswap_pool_create.patch