[PATCH v4 10/11] mm: lru: add VM_BUG_ON_FOLIO to lru maintenance function

[Muchun Song]

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@xxxxxxxxxxxxx>
---
 include/linux/mm_inline.h | 6 ++++++
 mm/vmscan.c               | 1 -
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index ac32125745ab..30d2393da613 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -97,6 +97,8 @@ void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
 			folio_nr_pages(folio));
 	if (lru != LRU_UNEVICTABLE)
@@ -114,6 +116,8 @@ void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
 			folio_nr_pages(folio));
 	/* This is not expected to be used on LRU_UNEVICTABLE */
@@ -131,6 +135,8 @@ void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	if (lru != LRU_UNEVICTABLE)
 		list_del(&folio->lru);
 	update_lru_size(lruvec, lru, folio_zonenum(folio),
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 761d5e0dd78d..6c9e2eafc8f9 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2281,7 +2281,6 @@ 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