ext4: Use a folio iterator in __read_end_io()

Iterate once per folio, not once per page.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20230324180129.1220691-27-willy@infradead.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/readpage.c

@@ -68,18 +68,16 @@ struct bio_post_read_ctx {
 
 static void __read_end_io(struct bio *bio)
 {
-	struct page *page;
-	struct bio_vec *bv;
-	struct bvec_iter_all iter_all;
+	struct folio_iter fi;
 
-	bio_for_each_segment_all(bv, bio, iter_all) {
-		page = bv->bv_page;
+	bio_for_each_folio_all(fi, bio) {
+		struct folio *folio = fi.folio;
 
 		if (bio->bi_status)
-			ClearPageUptodate(page);
+			folio_clear_uptodate(folio);
 		else
-			SetPageUptodate(page);
-		unlock_page(page);
+			folio_mark_uptodate(folio);
+		folio_unlock(folio);
 	}
 	if (bio->bi_private)
 		mempool_free(bio->bi_private, bio_post_read_ctx_pool);