[v1,11/12] mm: lru: add VM_BUG_ON_FOLIO to lru maintenance function

Commit Message

Muchun Song Aug. 14, 2021, 5:25 a.m. UTC

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 <[e-mail]>
---
 include/linux/mm_inline.h | 15 ++++++++++++---
 mm/vmscan.c               |  1 -
 2 files changed, 12 insertions(+), 4 deletions(-)

Patch

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index e2ec68b0515c..60eb827a41fe 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -103,7 +103,10 @@  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
@@ -119,7 +122,10 @@  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
@@ -133,6 +139,9 @@  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);
 }
 #endif
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8ce42858ad5d..902d36ec91a3 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2204,7 +2204,6 @@  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;