Bug#760148: grub-common: grub-mount hangs forever, trying to mount ext4 partition, causing 100% CPU load

[Colin Watson]

On Sat, Sep 06, 2014 at 11:23:25PM +0200, Johannes Rohr wrote:
> I get as far as this
> 
> root@:~# [ -e /mnt/sda9/etc/lsb-release ]
> root@:~# [ -e /mnt/sda9/servers/exec ]
> root@:~# [ -e /mnt/sda9/minix ]
> root@:~# [ -e /mnt/sda9/boot/image_big ]
> root@:~# [ -e /mnt/sda9/lib*/ld*.so*
> root@:~# ls /mnt/sda9/lib*/ld*.so*
> 
> 
> So, as soon as I run the ls command, the grub-mount process shoots
> up to 99% CPU load and stays there until I kill it with SIGKILL

Great, that's very useful.  I'd now like the output of "ls -al
/mnt/sda9/lib*/", where the filesystem has been mounted using the
ordinary mount utility rather than grub-mount.  Also, if you have the
spare disk space, I'd like you to try the following, where /path/to/file
is a new file on some filesystem with enough free space:

 1) work out how much space in MiB is consumed by the lib* directories
    at the top level of the filesystem on /dev/sda9, add a bit for good
    measure, and call that $size_in_mib

 2) dd if=/dev/zero of=/path/to/file bs=1048576 count=$size_in_mib

 3) mount -o loop /path/to/file /mnt

 4) copy the top-level lib* directories from the filesystem on /dev/sda9
    to /mnt - make sure to use 'cp -a' to preserve all file attributes

 5) umount /mnt

 6) see if you can now reproduce the same hang using grub-mount on
    /path/to/file

 7) if so, compress /path/to/file using xz, and put it somewhere for me
    to download

Thanks,

-- 
Colin Watson                                       [cjwatson at debian.org]