[PATCH v4 31/31] mm: lru: add VM_WARN_ON_ONCE_FOLIO to lru maintenance helpers

[Qi Zheng <qi.zheng@linux.dev>]

From: Muchun Song <songmuchun@bytedance.com>

We must ensure the folio is deleted from or added to the correct lruvec
list. So, add VM_WARN_ON_ONCE_FOLIO() to catch invalid users. The
VM_BUG_ON_PAGE() in move_pages_to_lru() can be removed as
add_page_to_lru_list() will perform the necessary check.

Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
---
 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 fa2d6ba811b53..ad50688d89dba 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -342,6 +342,8 @@ void lruvec_add_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	if (lru_gen_add_folio(lruvec, folio, false))
 		return;
 
@@ -356,6 +358,8 @@ void lruvec_add_folio_tail(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	if (lru_gen_add_folio(lruvec, folio, true))
 		return;
 
@@ -370,6 +374,8 @@ void lruvec_del_folio(struct lruvec *lruvec, struct folio *folio)
 {
 	enum lru_list lru = folio_lru_list(folio);
 
+	VM_WARN_ON_ONCE_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
+
 	if (lru_gen_del_folio(lruvec, folio, false))
 		return;
 
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 4dc52b4b4af50..5f69b252b403e 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1921,7 +1921,6 @@ static unsigned int move_folios_to_lru(struct list_head *list)
 			continue;
 		}
 
-		VM_BUG_ON_FOLIO(!folio_matches_lruvec(folio, lruvec), folio);
 		lruvec_add_folio(lruvec, folio);
 		nr_pages = folio_nr_pages(folio);
 		nr_moved += nr_pages;
-- 
2.20.1