WUBI Ubuntu 8.04, access permissions on "/host" folder cannot be changed

Hello,

I am now facing the same problem. In the related question (#35664) Agostino Russo mentioned: "You might have to pass them as a kernel boot parameter in menu.lst via rootflags=YOURMOUNTOPTIONS"

Would it be possible for someone to provide a working an example of this? To be honest, I've looked in the usual places (mtab, fstab, menu.lst) and I can't see where /host is mounted. (When I say umount /host or mount -o remount /host the system says unmountable/unable to remount.) I would think that the loopback mount needs rw access to /host/ubuntu/disk/* but to make all files in /host 777 is maybe overkill... Any help out there?

The mounting for /host is done in the initramfs, which makes this tricky (for me anyway) to track down. I've found a workaround for the problem:

Edit /usr/share/initramfs-tools/scripts/local-premount/root_locale

Append ,umask=022 to this line:

   echo ROOTFLAGS=\"${ROOTFLAGS}locale=$ROOT_LOCALE\" >> /conf/param.conf

so that it reads:

   echo ROOTFLAGS=\"${ROOTFLAGS}locale=$ROOT_LOCALE,umask=022\" >> /conf/param.conf

Save, run:

update-initramfs -k all -u

Reboot. /host will now be 755.

There may be a more appropriate place to make this change, but after hours of googling and poking around various scripts, that worked for me.

A slightly neater way, rather than modifying root_locale is to add a new root_opts file:

1) Create "/usr/share/initramfs-tools/conf.d/root_opts" containing "export ROOTFLAGS" <----[ this is the root cause of step 2 not working alone]
2) Append "rootflags=gid=115,fmask=113,dmask=002" to the end of the "#kopt=" line in /boot/grub/menu.lst
3) Run "sudo update-initramfs -k all -u" and "sudo update-grub"

Thank you for the update.

If I'm not wrong, this would make it easier for end-users to "tweak" permissions if you don't put a password on the grub menu entries (which you should do anyway, as otherwise unprivileged users could be dropped to a root shell)

I know it's a bit of security-through-obscurity and is certainly less flexible, but I think it might be safer to have the desired permissions hard-coded in the initramfs. Perhaps I'm worng/misguided. Wouldn't be the first time.

Anyway, either way it does the job. It'd be just fantastic if there was a nice little GUI that would do this for you (or at least documentation, which I guess is what this is now.) Alas, I'm not volunteering to do it. This workaround was my best effort.

Thank you Andrew, these last instructions worked very well for me (I
applied them on the 12 windows XP machines with WUBI 8.04 that i have in
the computer lab of the school i work for as a teacher).

Georgios Kolomvos
Patras, Greece

Andrew Flegg:
> A slightly neater way, rather than modifying root_locale is to add a new
> root_opts file:
>
> 1) Create "/usr/share/initramfs-tools/conf.d/root_opts" containing "export ROOTFLAGS" <----[ this is the root cause of step 2 not working alone]
> 2) Append "rootflags=gid=115,fmask=113,dmask=002" to the end of the "#kopt=" line in /boot/grub/menu.lst
> 3) Run "sudo update-initramfs -k all -u" and "sudo update-grub"
>
>

I don't see why a separate 'export ROOTFLAGS' is necessary. init already exports ROOTFLAGS right up at the top, which is sufficient to export all later settings of it. If this doesn't work it's a shell bug, but one I can't reproduce in isolated testing on Intrepid.

Agostino points out that 'export ROOTFLAGS' was introduced in initramfs-tools in intrepid, so this was needed in hardy but is no longer needed in intrepid.

I think that Andrew is referring to a Hardy installation, where export ROOTFLAGS is required. This was corrected in Intrepid (0.92a), so there is no need for step 1 and 3 in 8.10. In intrepid, it should be sufficient to pass any required rootflags argument in menu.lst (step #2) and run update-grub. In hardy, follow Andrew's recipe above.