[Yaffs] how to recover from power failure

Hi, all:

When a program writes something on nand and then power failure happens, how
does yaffs to recover it?

I mount the partition again, it pops messages like this:
**>> yaffs: BlockBits block 41965 is not valid
==>> yaffs bug: fs/yaffs2/yaffs_guts.c 343
**>> yaffs: Chunk Id (41965:109) invalid
==>> yaffs bug: fs/yaffs2/yaffs_guts.c 355

What can I do for this?
do some commands or call any functions?

Thanks.