Regression in handling of unsafe UBI shutdown

[Daniel Mack]

On Wed, Jul 20, 2011 at 7:21 AM, Artem Bityutskiy <dedekind1 at gmail.com> wrote:
> On Tue, 2011-07-19 at 15:57 +0200, Daniel Mack wrote:
>> UBIFS: recovery needed
>> Error reading superblock on volume 'ubi:RootFS'!
>> UBIFS not mounted, use ubifs mount to mount volume first!
>> Wrong Image Format for bootm command
>> ERROR: can't get kernel image!
>>
>>
>> Hence my question is: were there any radical changes in the UBI/UBIFS
>> code on the kernel side that make older code not like the new content
>> anymore?
>
> Daniel, sorry, I have no time to look at this now, could you please try
> to bisect the issue?

It's not really easy to bisect as the issue is not always fully
reproducable, and also because the flash needs to be re-initialized
after it happened.

Also note that it's not the kernel itself that complains about the
state of the file system in this case but U-Boot. If we boot a 3.0-rc7
kernel in such a situation (via USB for example), the kernel will
recover the FS and continue.

I don't know how many people use the UBI code in U-Boot, and I don't
know either whether it was a good idea to go this way in the first
place, but we didn't want to waste much space on the NAND for a
fixed-size partition just for the kernel, and have a hard limit for it
in the future. And as I said, this approach has worked just fine in
the past.

So, let me re-phrase my question: is anyone aware of changes in the
UBIFS code between 2.6.36 and 3.0 that might cause trouble to U-Boot's
UBI code from 2009?


Thanks,
Daniel