Re: UBI bitrot checking and scrubbing

[Richard Weinberger <richard.weinberger@gmail.com>]

Carsten,

On Tue, Jun 27, 2017 at 12:59 PM, Stelling Carsten
<Carsten.Stelling@goerlitz.com> wrote:
> Hi,
>
> I found Richard’s patches http://lists.infradead.org/pipermail/linux-mtd/2015-April/058677.html or
> http://lists.infradead.org/pipermail/linux-mtd/2015-November/063122.html, but can't identify any
> of the code in newer kernel versions (e.g. 4.9 or 4.11).
> I wonder, if ubihealthd http://lists.infradead.org/pipermail/linux-mtd/2015-November/063128.html
> was never released with mtd-utils (actually 1.5.2). Possibly, I have missed some information on
> this topic.
> Is there actually a comparable mechanism in UBI, I haven’t found yet?
> Like wear levelling, reading and scrubbing (if necessary) *all* PEB’s from time to time is an
> essential task to ensure durability of information. Especially, for PEB’s which are not accessed
> frequently. With Fastmap enabled, one can't rely on cyclic reboots, because not all UBI
> VID/EC headers are read at boot time.
> Regarding bitrot checking, a lot of effort was made by several contributors, but I can't find
> their work in mainline kernel driver code. Have I overlooked something?
> Any hints or suggestions are greatly appreciated.

Since the MLC topic kind of faded away I had no chance to work on the
bitrot stuff.
But you are right we should revive ubihealthd and the needed kernel
interface because for Fastmap
this is a topic.

Would you volunteer to forward port the patches?

-- 
Thanks,
//richard