fsck.vfat hangs, eats CPU on problematic file

Hi, thank you for your bug report.

We've just been trying to reproduce this bug, but couldn't. Is there anything you can tell us about your computer that might give more information. For example:

* Was a specific file, or group of files, involved?
* What names did affected files have?
* Were they all in the same directory, what was the name of that directory?
* How big was the partition that contained the files?
* Which language was the file system?
* Was the file of a particular size?
* Was the file a Windows .lnk file?
* What other symptoms did you notice?

We realise that we're asking lots of questions, but the bug you reported has potentially been identified as being part of a problem tucked away in the internal workings of the operating system and if that is the case, it may affect many users.

Thanks,
Stefan and Onno

Hi guys,

I'm afraid it's so long ago that I don't remember many details. I've
answered below as best I can...

On 12/17/06, Onno Benschop <email address hidden> wrote:
> Hi, thank you for your bug report.
>
> We've just been trying to reproduce this bug, but couldn't. Is there
> anything you can tell us about your computer that might give more
> information. For example:
>
> * Was a specific file, or group of files, involved?

It seemed to be a single file. That is, the fsck only complained
about that file, and I'm *pretty* sure that I only needed to delete
that one file to make the problem go away.

> * What names did affected files have?

It's listed in the original problem report.

> * Were they all in the same directory, what was the name of that directory?

Just one file. My *guess* is that it was in the root directory of
that partition, but that the partition was mounted somewhere like
"/mount/windows_f-drive/" or something like that.

> * How big was the partition that contained the files?

I don't remember - probably not super huge. This was just one of
several partitions residing on my 60 GB laptop hard drive. Almost
certainly smaller than 20 GB.

> * Which language was the file system?

I didn't realize they had languages. I've always told my OS installs
that I'm using American English.

> * Was the file of a particular size?

Don't remember. It wouldn't have been very small, because it was a
backup of a bunch of files. It was probably over 10 MB, and maybe
even a few GB in size. I don't remember.

> * Was the file a Windows .lnk file?

No.

> * What other symptoms did you notice?

None that I remember.

>
> We realise that we're asking lots of questions, but the bug you reported
> has potentially been identified as being part of a problem tucked away
> in the internal workings of the operating system and if that is the
> case, it may affect many users.

No problem. Thanks for looking into it.

- Christian

>
> Thanks,
> Stefan and Onno
>
> --
> fsck.vfat hangs, eats CPU on problematic file
> https://launchpad.net/bugs/47215
>

Hi,

this might be a duplicate of #62831, not sure though. At least the code in question that's near the check of file size vs. cluster chain length contained an integer overflow (very large files affected only).

Too sad you don't have the file any longer, so that you could test my proposed fix. Would you mind if I close that bug, once the fix for bug #62831 is uploaded?

Cheers,
   Stefan.

May as well close my bug - we don't really have a way of making
progress on it even if it's not fixed :(

On 12/18/06, StefanPotyra <email address hidden> wrote:
> Hi,
>
> this might be a duplicate of #62831, not sure though. At least the code
> in question that's near the check of file size vs. cluster chain length
> contained an integer overflow (very large files affected only).
>
> Too sad you don't have the file any longer, so that you could test my
> proposed fix. Would you mind if I close that bug, once the fix for bug
> #62831 is uploaded?
>
> Cheers,
> Stefan.
>
> --
> fsck.vfat hangs, eats CPU on problematic file
> https://launchpad.net/bugs/47215
>

Ok, I'm closing this bug now, since the newer version is in the archive. In case you stumble upon problems with dosfsck again, please reopen (or file a new bug).

Thanks.