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From:   Muchun Song <songmuchun@bytedance.com>
To:     guro@fb.com, hannes@cmpxchg.org, mhocko@kernel.org,
        akpm@linux-foundation.org, shakeelb@google.com,
        vdavydov.dev@gmail.com
Cc:     linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        duanxiongchun@bytedance.com, fam.zheng@bytedance.com,
        bsingharora@gmail.com, shy828301@gmail.com, alexs@kernel.org,
        smuchun@gmail.com, zhengqi.arch@bytedance.com,
        Muchun Song <songmuchun@bytedance.com>
Subject: [PATCH v3 11/12] mm: lru: add VM_BUG_ON_FOLIO to lru maintenance function
Date:   Wed, 16 Feb 2022 19:51:31 +0800
Message-Id: <20220216115132.52602-12-songmuchun@bytedance.com>
In-Reply-To: <20220216115132.52602-1-songmuchun@bytedance.com>
References: <20220216115132.52602-1-songmuchun@bytedance.com>
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We need to make sure that the page is deleted from or added to the
correct lruvec list. So add a VM_BUG_ON_FOLIO() to catch invalid
users.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
---
 include/linux/mm_inline.h | 15 ++++++++++++---
 mm/vmscan.c               |  1 -
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index b725839dfe71..8cc134fd3f0b 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -105,7 +105,10 @@ void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
 static __always_inline void add_page_to_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
-	lruvec_add_folio(lruvec, page_folio(page));
+	struct folio *folio = page_folio(page);
+
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+	lruvec_add_folio(lruvec, folio);
 }
 
 static __always_inline
@@ -121,7 +124,10 @@ void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
 static __always_inline void add_page_to_lru_list_tail(struct page *page,
 				struct lruvec *lruvec)
 {
-	lruvec_add_folio_tail(lruvec, page_folio(page));
+	struct folio *folio = page_folio(page);
+
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+	lruvec_add_folio_tail(lruvec, folio);
 }
 
 static __always_inline
@@ -135,7 +141,10 @@ void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
 static __always_inline void del_page_from_lru_list(struct page *page,
 				struct lruvec *lruvec)
 {
-	lruvec_del_folio(lruvec, page_folio(page));
+	struct folio *folio = page_folio(page);
+
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+	lruvec_del_folio(lruvec, folio);
 }
 
 #ifdef CONFIG_ANON_VMA_NAME
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7beed9041e0a..00207553c419 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2356,7 +2356,6 @@ static unsigned int move_pages_to_lru(struct list_head *list)
 			continue;
 		}
 
-		VM_BUG_ON_PAGE(!folio_matches_lruvec(folio, lruvec), page);
 		add_page_to_lru_list(page, lruvec);
 		nr_pages = thp_nr_pages(page);
 		nr_moved += nr_pages;
-- 
2.11.0