Re: ubifs: mounting fails due to error in orphan file handling

[Steve deRosier <derosier@xxxxxxxxx>]

On Wed, Feb 5, 2020 at 7:25 AM Jef Driesen <jef.driesen@xxxxxxx> wrote:
>
> On 2/5/20 9:22 AM, Miquel Raynal wrote:
> > "Driesen Jef (JDI)" <Jef.Driesen@xxxxxxx> wrote on Tue, 28
> > Jan 2020 10:51:39 +0000:
> >> ...
> >>
> >> I'm not really sure what's going on under the hood, but it looks like a
> >> problem with the handling of the orphan files. With this knowledge, we
> >> are now able to reproduce the problem reliable, by doing a power cut
> >> while running the attached script. The scripts creates many files in a
> >> loop, keeps them all open and removes them again. With this approach we
> >> hit the problem about once every two attempts.
> >>
> >> The problem appeared for the first time after we switched from kernel
> >> v4.7 to v5.3. I tried with v5.4 and master too, in case we are hitting a
> >> problem that is already fixed, but they show the same problem. After
> >> doing some bisecting, this commit appears to have introduced the problem:
> >>
> >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/fs/ubifs/orphan.c?id=ee1438ce5dc4d67dd8dd1ff51583122a61f5bd9e
> >>
> >> How can we fix this?
> >
> > Just adding Richard into the loop, he is not available right now but
> > will probably be interested by this issue. On my side, I have no clue :)
>
> Thanks. If additional info is needed, or some extra testing is
> necessary, just ask. I'm happy to help to get this fixed.
>
> For now, we have reverted the above commit. That appears to work (e.g.
> no more device that fail to boot), but I'm not convinced it's a good
> long-term solution.
>

Looking at the comment in the mentioned commit: "This corner case
needs to get addressed in the orphans subsystem too."

Was it addressed?  Was there a second commit for that?  If so, is it
in your tree?

Beyond that, no ideas, it's not a chunk of code I am familiar with.

- Steve

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