[Yaffs] Yaffs2 create bad blocks?

[Chun Kit Edwin Lau]

Hi everyone,

	I have two questions.  First, I lost all the files when I umount a
yaffs2 partition.  I read somewhere in this mailing list that it was an
known issue from mtd.  May I know if there is a quick fix for it?
Second, I tried to dd a file containing all zeros of ~155MB to the
yaffs2 partition.

~ # dd if=/dev/zero of=/mnt/mtd/zeros bs=128k count=2000

And after that, all block in that partition became bad block.  I don't
think the nand had that many bad block all of a sudden.  So is there a
way to "retrieve" those bad block (BTW, I know which block was bad
before this incidence)?   flash_erase/all didn't help because it was
skipping all the bad block.  I am using 2.6.12-rc1 kernel (from San
People for Atmel AT91RM9200).  It is Samsung K9F2G08U0M (256MB, 128k
sector)  Please help me! thanx.

Edwin Lau