From b36184553d41c59e6712f9d4699aca24577fbd4a Mon Sep 17 00:00:00 2001 From: Miaohe Lin Date: Fri, 16 Sep 2022 15:22:49 +0800 Subject: [PATCH] mm/page_alloc: add missing is_migrate_isolate() check in set_page_guard() In MIGRATE_ISOLATE case, zone freepage state shouldn't be modified as caller will take care of it. Add missing is_migrate_isolate() here to avoid possible unbalanced freepage state. This would happen if someone isolates the block, and then we face an MCE failure/soft-offline on a page within that block. __mod_zone_freepage_state() will be triggered via below call trace which already had been triggered back when block was isolated: take_page_off_buddy break_down_buddy_pages set_page_guard Link: https://lkml.kernel.org/r/20220916072257.9639-9-linmiaohe@huawei.com Fixes: 06be6ff3d2ec ("mm,hwpoison: rework soft offline for free pages") Signed-off-by: Miaohe Lin Reviewed-by: Oscar Salvador Reviewed-by: David Hildenbrand Cc: Anshuman Khandual Cc: Matthew Wilcox Signed-off-by: Andrew Morton --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 43114e172592..c055b4cd37f0 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -873,7 +873,8 @@ static inline bool set_page_guard(struct zone *zone, struct page *page, INIT_LIST_HEAD(&page->buddy_list); set_page_private(page, order); /* Guard pages are not available for any usage */ - __mod_zone_freepage_state(zone, -(1 << order), migratetype); + if (!is_migrate_isolate(migratetype)) + __mod_zone_freepage_state(zone, -(1 << order), migratetype); return true; }