[PATCH] mm/gup: Add folio to list when folio_isolate_lru() succeed

[Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx>]

If we call folio_isolate_lru() successfully, we will get
return value 0. We need to add this folio to the
movable_pages_list.

Fixes: 67e139b02d99 ("mm/gup.c: refactor check_and_migrate_movable_pages()")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@xxxxxxxxxxxx>
---
 mm/gup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/gup.c b/mm/gup.c
index f3d2cccb89f8..918c364d01ac 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -1914,7 +1914,7 @@ static unsigned long collect_longterm_unpinnable_pages(
 			drain_allow = false;
 		}
 
-		if (!folio_isolate_lru(folio))
+		if (folio_isolate_lru(folio))
 			continue;
 
 		list_add_tail(&folio->lru, movable_page_list);
-- 
2.18.0