Support for what I called the "9-byte tags" mode, as used in the 
original Yaffs and more recently by the folks using the 
Routerboard products, has been integrated into Yaffs mainline. 
To enable this mode use config option CONFIG_YAFFS_9BYTE_TAGS 
AND see the note in yaffs_mtdif1.c regarding the configuration 
of MTD.

Note, this mainline feature how replaces the functionality that 
was, up to now, only included in the patched version at 
http://users.actrix.co.nz/manningc/yaffs2-ian-20070523.tgz
This tarfile will disappear soon.

-imcd