rmdir on non-empty directory does not fail

[Wolf Geldmacher]

Binary package hint: unionfs-fuse

Ubuntu Release:
        10.04 / Lucid Lynx
Package Version:
        unionfs-fuse 0.23.hg.20090611-1

Running the following command sequence:

01 $ cd /tmp
02 $ mkdir tmp
03 $ cd tmp
04 $ ls
05 $ mkdir ro ro/subdir rw union
06 $ touch ro/subdir/file
07 $ unionfs-fuse -o cow /tmp/tmp/rw=RW:/tmp/tmp/ro=RO /tmp/tmp/union
08 $ ls -l union/subdir
insgesamt 0
-rw-r--r-- 1 wjg wjg 0 2010-05-31 16:09 file
09 $ rmdir union/subdir
10 $ ls -l union/subdir
ls: Zugriff auf union/subdir nicht möglich: No such file or directory
11 $ fusermount -u /tmp/tmp/union

Expected outcome:
        I expect the command on line 09 to fail, as the directory union/subdir is not empty.

Actual outcome:
        Instead it succeeds. The contents below the directory are "lost".

Some additional context:
I want to use unionfs-fuse in the context of the Ubuntu Customization Toolkit to avoid having to extract ISO and squashfs images. Several (python) packages do a "rmdir -f /usr/lib/pymodules/python2.6/*" to clean up packages no longer relevant, relying on rmdir to fail silently when there are non-empty directories. Unfortunately this strategy does not work with unionfs-fuse and makes it unusable for UCK.

[Bernd Schubert (aakef)]

Thanks for your report Wolfgang. I just fixed that in my 0.25 branch:
http://podgorny.cz/~bernd/hg/hgwebdir.cgi/0.25

Building should be easy, but if you should need a package, I can also upload it to my home page.

However, I'm presently out of ideas what I shall do about Debian and Ubuntu. I'm one of the upstream authors and also the package maintainer. However, as I'm not a DD (debian developer) I cannot upload to Debian without a sponsor. But already for a couple of months, I cannot find a sponsor for this package (a newer version is at mentors.debian.net for a long time already). And Ubuntu simply takes the Debian package. Unless I find a sponsor within the next two weeks, I will request to remove that package from Debian and Ubuntu, as both ship a broken beta version and do not let me fix it. IMHO it is out of question to list me for something which impossible to fulfill.

Thanks,
Bernd

[Wolf Geldmacher (wolf-womaro)]

Thanks a lot for your speedy response.

I downloaded, built and installed your patched version and can confirm that the problem is solved.

Now I've encountered another issue with unionfs-fuse, though: Within the union mount the directory .unionfs is visible - which IMHO it should not be. Do you want me to open a separated bug report for this as it's obviously not related to the rmdir issue?

[Bernd Schubert (aakef)]

Hello Wolfgang,

I'm glad that it works :) Version 0.25 is still a bit experimental, but thans to several Gentoo users, which seem to do similar things as you do, I got a chance to debug it.

And again thanks to Gentoo you are luckily, 0.25 includes a new feature to hide the metadata directory.

-o hide_meta_dir

It is optional to hide that directory, as it will slightly slow down unionfs-fuse and at is not important to hide that directory for diskless NFS environments and live USB-sticks (those two are my own usage pattern).

Cheers,
Bernd

[Wolf Geldmacher (wolf-womaro)]

Hi Bernd,

tried that option - works as specified, but only solves half my problem
as now I have files named '.fuse_hidden[0-9]*' in some directories - one
of them being the image of the previous rootfs blowing the new ISO to
double the size. I've now changed the strategy to exclude .unionfs
and .fuse_hidden* files from being included - seems to work.

Thanks again for your support!
Wolf

Am Dienstag, den 01.06.2010, 09:10 +0000 schrieb Bernd Schubert:
> Hello Wolfgang,
>
> I'm glad that it works :) Version 0.25 is still a bit experimental, but
> thans to several Gentoo users, which seem to do similar things as you
> do, I got a chance to debug it.
>
> And again thanks to Gentoo you are luckily, 0.25 includes a new feature
> to hide the metadata directory.
>
> -o hide_meta_dir
>
> It is optional to hide that directory, as it will slightly slow down
> unionfs-fuse and at is not important to hide that directory for diskless
> NFS environments and live USB-sticks (those two are my own usage
> pattern).
>
>
> Cheers,
> Bernd
>

--
Just when you discovered the meaning of life IT changed.

[Bernd Schubert (aakef)]

Hello Wolfgang,

next try, could you please pull from my branch again, it should now also hide .fuse_hidden files. The option is now called
-o hide_meta_files and -o hide_meta_dir is deprecated, although it still exists.

Thanks,
Bernd

[JC Hulce (soaringsky)]

This bug has been marked as Fix Committed for over a year. If the fix has made it into Ubuntu, please mark this bug as Fix Released. If the fix has been released upstream, but not Ubuntu, create a new bug asking for the new version and tag it with upgrade-software-version. If this bug has not been fixed anywhere, change the status back to Confirmed.

[Francois Gouget (fgouget)]

This bug is still present in Ubuntu 14.10 with unionfs-fuse 0.24-2.2ubuntu.