how to view mapping between a given ubifs volume, its set of LEBs, and its corresponding set of PEBS

how to view mapping between a given ubifs volume, its set of LEBs, and its corresponding set of PEBS

[Davis Roman]

Hello all,

I'm trying to understand the mapping between a ubifs volume and the
set of LEBs that get mapped to it.

More so, I'd like to also understand the mapping between a given LEB
and its designated PEB.

Although the mapping between LEBs and PEBs can change during runtime,
I figure that there should be a way to see this mapping via the
command line.

Does such a method exist ?

I've looked high and low though the mtd tools and I haven't been able
to find a way to do this.

Thank you,

Davis

Re: how to view mapping between a given ubifs volume, its set of LEBs, and its corresponding set of PEBS

[Richard Weinberger]

On Thu, Apr 21, 2016 at 4:13 AM, Davis Roman <davis.roman84@gmail.com> wrote:
> Hello all,
>
> I'm trying to understand the mapping between a ubifs volume and the

UBIFS does not have volumes. UBI does.

> set of LEBs that get mapped to it.
>
> More so, I'd like to also understand the mapping between a given LEB
> and its designated PEB.
>
> Although the mapping between LEBs and PEBs can change during runtime,
> I figure that there should be a way to see this mapping via the
> command line.
>
> Does such a method exist ?

No, the mappings are internals and change also often.

But with a few lines of C you can add a debugfs file to print the corresponding
EBA table of an volume.
That way you can learn the mappings.

-- 
Thanks,
//richard

Re: how to view mapping between a given ubifs volume, its set of LEBs, and its corresponding set of PEBS

[Artem Bityutskiy]

On Wed, 2016-04-20 at 22:13 -0400, Davis Roman wrote:
> Hello all,
> 
> I'm trying to understand the mapping between a ubifs volume and the
> set of LEBs that get mapped to it.
> 
> More so, I'd like to also understand the mapping between a given LEB
> and its designated PEB.
> 
> Although the mapping between LEBs and PEBs can change during runtime,
> I figure that there should be a way to see this mapping via the
> command line.
> 
> Does such a method exist ?
> 
> I've looked high and low though the mtd tools and I haven't been able
> to find a way to do this.

Technically it is easy to create an ioctl returning this information.
You can just do it for your research purposes. But if you want this
upstream, you should also provide a plausible use-case for this kind of
ioctl.

Artem.