buffer: Remove calls to set and clear the folio error flag

The folio error flag is not tested anywhere, so we can stop setting
and clearing it.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240530202110.2653630-17-willy@infradead.orgSigned-off-by: Christian Brauner <brauner@kernel.org>

fs/buffer.c

@@ -258,7 +258,6 @@ static void end_buffer_async_read(struct buffer_head *bh, int uptodate)
 	} else {
 		clear_buffer_uptodate(bh);
 		buffer_io_error(bh, ", async page read");
-		folio_set_error(folio);
 	}
 
 	/*
@@ -391,7 +390,6 @@ static void end_buffer_async_write(struct buffer_head *bh, int uptodate)
 		buffer_io_error(bh, ", lost async page write");
 		mark_buffer_write_io_error(bh);
 		clear_buffer_uptodate(bh);
-		folio_set_error(folio);
 	}
 
 	first = folio_buffers(folio);
@@ -1960,7 +1958,6 @@ int __block_write_full_folio(struct inode *inode, struct folio *folio,
 			clear_buffer_dirty(bh);
 		}
 	} while ((bh = bh->b_this_page) != head);
-	folio_set_error(folio);
 	BUG_ON(folio_test_writeback(folio));
 	mapping_set_error(folio->mapping, err);
 	folio_start_writeback(folio);
@@ -2405,11 +2402,9 @@ int block_read_full_folio(struct folio *folio, get_block_t *get_block)
 			if (iblock < lblock) {
 				WARN_ON(bh->b_size != blocksize);
 				err = get_block(inode, iblock, bh, 0);
-				if (err) {
-					folio_set_error(folio);
+				if (err)
 					page_error = true;
 			}
-			}
 			if (!buffer_mapped(bh)) {
 				folio_zero_range(folio, i * blocksize,
 						blocksize);

fs/mpage.c

@@ -48,13 +48,8 @@ static void mpage_read_end_io(struct bio *bio)
 	struct folio_iter fi;
 	int err = blk_status_to_errno(bio->bi_status);
 
-	bio_for_each_folio_all(fi, bio) {
-		if (err)
-			folio_set_error(fi.folio);
-		else
-			folio_mark_uptodate(fi.folio);
-		folio_unlock(fi.folio);
-	}
+	bio_for_each_folio_all(fi, bio)
+		folio_end_read(fi.folio, err == 0);
 
 	bio_put(bio);
 }
@@ -65,10 +60,8 @@ static void mpage_write_end_io(struct bio *bio)
 	int err = blk_status_to_errno(bio->bi_status);
 
 	bio_for_each_folio_all(fi, bio) {
-		if (err) {
-			folio_set_error(fi.folio);
+		if (err)
 			mapping_set_error(fi.folio->mapping, err);
-		}
 		folio_end_writeback(fi.folio);
 	}