erofs: set error to bio if file-backed IO fails

If a file-backed IO fails before submitting the bio to the lower
filesystem, an error is returned, but the bio->bi_status is not
marked as an error. However, the error information should be passed
to the end_io handler. Otherwise, the IO request will be treated as
successful.

Fixes: 2832137 ("erofs: support compressed inodes for fileio")
Signed-off-by: Sheng Yong <shengyong1@xiaomi.com>
Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20250408122351.2104507-1-shengyong1@xiaomi.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

fs/erofs/fileio.c

@@ -32,6 +32,8 @@ static void erofs_fileio_ki_complete(struct kiocb *iocb, long ret)
 		ret = 0;
 	}
 	if (rq->bio.bi_end_io) {
+		if (ret < 0 && !rq->bio.bi_status)
+			rq->bio.bi_status = errno_to_blk_status(ret);
 		rq->bio.bi_end_io(&rq->bio);
 	} else {
 		bio_for_each_folio_all(fi, &rq->bio) {