ext4: remove calls to to set/clear the folio error flag

Nobody checks this flag on ext4 folios, stop setting and clearing it.

Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: linux-ext4@vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240420025029.2166544-11-willy@infradead.orgSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/move_extent.c

@@ -199,10 +199,8 @@ mext_page_mkuptodate(struct folio *folio, unsigned from, unsigned to)
 			continue;
 		if (!buffer_mapped(bh)) {
 			err = ext4_get_block(inode, block, bh, 0);
-			if (err) {
-				folio_set_error(folio);
+			if (err)
 				return err;
-			}
 			if (!buffer_mapped(bh)) {
 				folio_zero_range(folio, block_start, blocksize);
 				set_buffer_uptodate(bh);

fs/ext4/page-io.c

@@ -117,7 +117,6 @@ static void ext4_finish_bio(struct bio *bio)
 
 		if (bio->bi_status) {
 			int err = blk_status_to_errno(bio->bi_status);
-			folio_set_error(folio);
 			mapping_set_error(folio->mapping, err);
 		}
 		bh = head = folio_buffers(folio);
@@ -441,8 +440,6 @@ int ext4_bio_write_folio(struct ext4_io_submit *io, struct folio *folio,
 	BUG_ON(!folio_test_locked(folio));
 	BUG_ON(folio_test_writeback(folio));
 
-	folio_clear_error(folio);
-
 	/*
 	 * Comments copied from block_write_full_folio:
 	 *

fs/ext4/readpage.c

@@ -289,7 +289,6 @@ int ext4_mpage_readpages(struct inode *inode,
 
 				if (ext4_map_blocks(NULL, inode, &map, 0) < 0) {
 				set_error_page:
-					folio_set_error(folio);
 					folio_zero_segment(folio, 0,
 							  folio_size(folio));
 					folio_unlock(folio);