[PATCH] mm/hugetlb: Fix vmsplice case on memory leak once more

[Peter Xu]

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
 mm/hugetlb.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 417fc5cdb6ee..1ca102013561 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5961,10 +5961,13 @@ static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
 
 retry_avoidcopy:
 	/*
-	 * If no-one else is actually using this page, we're the exclusive
-	 * owner and can reuse this page.
+	 * If the page is marked exlusively owned (e.g. longterm pinned),
+	 * we can reuse it.  Otherwise if no-one else is using this page,
+	 * we can savely set the exclusive bit and reuse it.
 	 */
-	if (folio_mapcount(old_folio) == 1 && folio_test_anon(old_folio)) {
+	if (folio_test_anon(old_folio) &&
+	    (PageAnonExclusive(&old_folio->page) ||
+	     folio_ref_count(old_folio) == 1)) {
 		if (!PageAnonExclusive(&old_folio->page)) {
 			folio_move_anon_rmap(old_folio, vma);
 			SetPageAnonExclusive(&old_folio->page);
-- 
2.44.0


-- 
Peter Xu