Preventing JFFS2 partial page writes?

[Peter Barada]

On 06/22/2011 01:07 PM, Ivan Djelic wrote:
>
> On one hand it sure would be nice (and a bit complicated) to accurately
> describe OOB write constraints, for easier JFFS2/YAFFS2 integration.
> On the other hand, I am not sure such a complication is really worth the
> trouble, given that on next nand generation:
> - OOB areas will not be usable anymore for metadata storage (8-bit ecc leaves
>    only 6 spare bytes out of 64)
> - partial writes will probably be limited to 1 (like in MLC), meaning that
>    JFFS2 clean marking step will be forbidden anyway
> Furthermore, userspace will probably need to handle case 3) anyway (no
> protected oob bytes) to stay portable...
>
SLC parts (including this one) look to be around for a while, as well as 
the products they are already in.  So I think the issue of JFFS2's 
cleanmarker in the context of this Micron NAND needs to be solved, 
preferably in a general way so the next oddball NAND chip that comes 
along doesn't cause MTD, mtd-utils, JFFS2 (and other NAND FS) fits.

Does UBIFS do any of the "partial writes" (i.e. write OOB/data area 
multiple times) as JFFS2 does?



-- 
Peter Barada
peter.barada at gmail.com