[Yaffs] yaffs2 and mtd nand_write_ecc problem

hello everyone

I use yaffs2 on samsung nand flash(2k page 512M) now. I download latest mtd
CVS from ftp://ftp.uk.linux.org/pub/people/dwmw2/mtd/cvs/
when I umount and remount, file disappear.I knew about the interface
between yaffs2 and mtd have some problem.but in my yaffs2 source code this
problem seems just fixed.yaffs2 put and read tags just in 2-38 field of oob.

I traced the code and found problem is here. in nand_base.c. I found that if
I use option NAND_ECC_NONE, the function nand_write_ecc would not read any
oob data. However,in yaffs2 side, it suppose mtd->write_ecc will write data
and tags.

code is here

$Id: nand_base.c,v 1.166 2006/03/13 06:09:08 vwool Exp $

static int nand_write_page (struct mtd_info *mtd, struct
nand_chip *this, int page,u_char *oob_buf, struct nand_oobinfo *oobsel,
int cached)
{
......

switch (eccmode) {
/* No ecc, write all */
case NAND_ECC_NONE:
printk (KERN_WARNING "Writing data without ECC to NAND-FLASH is not
recommended\n");
this->write_buf(mtd, this->data_poi, mtd->oobblock);
break;

nand_write_ecc calls nand_write_page, but if the option is NAND_ECC_NONE, it
just simple writes 2048 byte data, break and return.
so yaffs2'tag is not written to oob.

I change nand_base.c to previous one whose nand_write_page will write oob,
and yaffs2 works perfectly.

Does anyone have the same problem ? and Does this problem( nand_write_page
do not write data to oob with option NAND_ECC_NONE) is a bug?

apologize for my poor english.