Bug#270967: Why purging gconf2-common might erase your /etc

[Josselin Mouette]

severity 270967 normal
clone 270967 -1
retitle 270967 gconf2-common fails to purge when /etc isn't removable
reassign -1 coreutils
retitle -1 rmdir should check emptiness before permissions
thanks

Le lundi 30 janvier 2006 à 03:23 +0100, Adrian Bunk a écrit :
> severity 270967 critical
> thanks

This is by no means a critical bug. There's no way this script can wipe
out your /etc.

> Hi Sebastien,
> 
> I think I can answer the following question you raised:
> 
> <--  snip  -->
> 
> The weird point is that running "sh /var/lib/dpkg/info/gconf2.postrm
> purge" doesn't display any error, but the same line called by apt raises
> an error ...
> 
> <--  snip  -->
> 
> The problem is only triggered when /etc/gconf2/ is empty.

This error message is triggered by rmdir trying to remove /etc.
Normally, rmdir -p --ignore-fail-on-non-empty will try to
remove /etc/gconf/2, then /etc/gconf, then /etc, and will stop with /etc
because it isn't empty.

On your system, the chattr -i prevents the removal of /etc, and rmdir
fails on "permission denied" instead of "directory not empty".

I'd say that, so that rmdir -p --ignore-fail-on-non-empty can work on
such systems, it should be made to check first if the directory is
empty, and then if it has the permissions to remove it. I'm creating a
clone report on coreutils, but maybe it is caused directly by the kernel
or libc - in which case it should still be possible to work around the
issue in coreutils.

Currently, rmdir --ignore-fail-on-non-empty seems to do the following:
      * call rmdir(2)
      * check errno
      * ignore ENOTEMPTY
Maybe it could be modified to do the following:
      * check if the directory is empty
      * call rmdir(2)
I don't know whether this would be acceptable. Depending on the
coreutils maintainers' advice and decision, I will modify - or not - the
gconf2 scripts.

Regards,
-- 
 .''`.           Josselin Mouette        /\./\
: :' :           josselin.mouette at ens-lyon.org
`. `'                        joss at debian.org
   `-  Debian GNU/Linux -- The power of freedom