--- y/mm/filemap.c
+++ x/mm/filemap.c
@@ -1953,6 +1953,7 @@ repeat:
 		goto no_page;
 
 	if (fgp_flags & FGP_LOCK) {
+		VM_BUG_ON_FOLIO(!folio_contains(folio, index), folio);
 		if (fgp_flags & FGP_NOWAIT) {
 			if (!folio_trylock(folio)) {
 				folio_put(folio);
@@ -1963,7 +1964,7 @@ repeat:
 		}
 
 		/* Has the page been truncated? */
-		if (unlikely(folio->mapping != mapping)) {
+		if (unlikely(folio->mapping != mapping || !folio_contains(folio, index))) {
 			folio_unlock(folio);
 			folio_put(folio);
 			goto repeat;