Btrfs: set scrub page's io_error if failing to submit io

Scrub repairs data by the unit called scrub_block, which may contain
several pages.  Scrub always tries to look up a good copy of a whole
block, but if there's no such copy, it tries to do repair page by page.

If we don't set page's io_error when checking this bad copy, in the last
step, we may skip this page when repairing bad copy from good copy.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: NLiu Bo <bo.li.liu@oracle.com>
Reviewed-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/scrub.c

@@ -1497,14 +1497,18 @@ static void scrub_recheck_block(struct btrfs_fs_info *fs_info,
 
 		bio_add_page(bio, page->page, PAGE_SIZE, 0);
 		if (!retry_failed_mirror && scrub_is_page_on_raid56(page)) {
-			if (scrub_submit_raid56_bio_wait(fs_info, bio, page))
+			if (scrub_submit_raid56_bio_wait(fs_info, bio, page)) {
+				page->io_error = 1;
 				sblock->no_io_error_seen = 0;
+			}
 		} else {
 			bio->bi_iter.bi_sector = page->physical >> 9;
 			bio_set_op_attrs(bio, REQ_OP_READ, 0);
 
-			if (btrfsic_submit_bio_wait(bio))
+			if (btrfsic_submit_bio_wait(bio)) {
+				page->io_error = 1;
 				sblock->no_io_error_seen = 0;
+			}
 		}
 
 		bio_put(bio);