[RFC] read-only filesystem support for NAND flash devices

[Jörn Engel]

On Wed, 10 May 2006 12:20:58 -0500, Josh Boyer wrote:
> On 5/10/06, Atsushi Nemoto <anemo at mba.ocn.ne.jp> wrote:
> >
> >If I mounted a JFFS2 filesystem on NAND and _never_ write anything (or
> >mounted read-only), does current MTD/NAND/JFFS2 layer handle those bit
> >flips?  I've thought JFFS2 only reassign blocks on writing, so JFFS2
> >also suffer those "bit flips on read" problem, is it right?
> 
> If you truly never write anything, then yes it probably suffers from
> the same problem.  In a typical JFFS2 setup where writes do occur, the
> theory is that garbage collection will eventually reclaim that block. 
> Whether that actually happens or not is largely determined on a per
> use case basis.

The fact remains that jffs2 only scrubs bad blocks by accident on a
random basis.  And it couldn't do more anyway.  Nothing in mtd
indicates a correctable error that would require scrubbing.

Jörn

-- 
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