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Subject: Re: MTD : Kernel oops when remounting ubifs as read/write
From: Artem Bityutskiy <dedekind1@gmail.com>
To: Mark Jackson <mpfj-list@mimc.co.uk>
Date: Fri, 15 Mar 2013 10:42:01 +0200
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On Thu, 2013-03-14 at 11:13 +0200, Artem Bityutskiy wrote:
> On Wed, 2013-03-13 at 11:12 +0000, Mark Jackson wrote:
> > Sorry ... this just locks up the unit.
> 
> OK, I've reproduced the issue with 3.9-rc2 in nandsim, see the details
> below. The patch I proposed did not get the error path correctly, but it
> does fix the issue.
> 
> I think what you treat as "lockup" is the fixup process. UBIFS basically
> reads the entire UBI volume and writes it back. And it uses the atomic
> change UBI service, which means it also calculates CRC of everything it
> writes. And this all just takes a lot of time. This has to be done only
> once on the first mount.
> 
> I've attached the following:
> 
> 1. The patch which fixes the issue when I use nandsim. It is also
>    inlined in the end. Please, give it a try and be more patient -
>    wait longer. Please, do report your results back.

>>From your last e-mail I see that the patch solves the issue for you if
the CRC32 problem is worked-around. I am pushing this fix to the ubifs
git tree. Thanks for the report.

-- 
Best Regards,
Artem Bityutskiy