Re: not sure if this a relevant article for this group-might be of interest

On Sat, 2007-09-15 at 22:45 +0200, Max Vozeler wrote:
> Hi all, Hi Eero,
> 
> On Sat, Sep 15, 2007 at 08:35:42PM +0200, markus reichelt wrote:
> > * rodger ellis <[email protected]> wrote:
> > 
> > > http://groups.google.com/group/linux.debian.kernel/browse_thread/thread/b53dfc2c858687a0/4a5993178f83bb67
> > 
> > It certainly is of interest to Max Vozeler, and all Debian users
> > lurking; it definitely complicates things for Debian users.
> 
> This is not actually a fundamental problem with the Debian kernel,
> or other kernels configured with CONFIG_BLK_DEV_LOOP=m.
> 
> | When trying to mount a device crypted with loop-aes I get this error:
> | ioctl: LOOP_MULTI_KEY_SETUP_V3: Invalid argument
> 
> This error usually indicates that the wrong (as in: "not loop-AES")
> loop module is loaded into the kernel.
> 
>  a) There is no loop-aes-modules-$KERNEL package installed for
>     the running kernel, and the "normal" loop module gets auto-
>     loaded. Make sure that you have such a package installed for
>     your running kernel:
> 
>       $ dpkg -s loop-aes-modules-$(uname -r) | grep Status
>       Status: install ok installed
> 
>  b) The loop-aes-modules-$KERNEL package was installed _after_ 
>     the "normal" loop module was already loaded. In that case, 
>     reloading loop should get you the correct module:
>      
>       # rmmod loop; modprobe -v loop
> 
>     Note that you should need to do this only once. The packages 
>     are setup in such a way that the loop-AES module takes pre-
>     cedence over the normal in-kernel loop module.
> 
> If that still doesn't work, we're looking at a as-of-yet unknown
> problem, but likely one in the Debian loop-AES packages, and not in
> the Debian kernel or loop-AES itself. I would appreciate if you 
> could file a bug against the package "loop-aes" in that case.
> 
> | The loop-aes documentation says that CONFIG_BLK_DEV_LOOP must be set to "n",
> | but in Debian Etch it is set to "m". Could this be changed to "n"?
> 
> This should not be necessary. 
> 
> There is no fundamental incompatiblity between loop-AES and the
> CONFIG_BLK_DEV_LOOP=m setting in Debian kernels. 
> 
> Since the introduction of module-init-tools for 2.6, it is possible
> for a module to "override" a kernel-shipped version of the same module,
> by being installed in the /lib/modules/$KERNEL/updates directory; This
> is what Debian loop-aes-modules-$KERNEL packages do for loop.ko
> 
> Having the normal loop module available can complicate module loading
> in some corner cases, one of which you probably experienced (but let's
> find out). Ruling out such problems is, I suppose, the reason for the 
> recommendation for CONFIG_BLK_DEV_LOOP=n in the loop-AES documentation.
> 
> I'll make this more clear in README.Debian of the loop-AES packages 
> and add a postinst check for an already loaded loop module.
> 
> 	Max

Hi and thanks for an advice!
Loop-aes module was installed, but I think there was some wrong loop
module loaded. Command "rmmod loop; modprobe -v loop" did not work
because cryptoloop was already using the loop module. I tried to load
all kinds of modules earlier to get loop-aes working and I wasn't sure
which modules were necessary anymore so I rebooted the machine. After it
came up I was able to mount loop-aes encrypted disks and those encrypted
disks that were made during Debian installation (cryptsetup with LUKS).
It seems like the correct loop module loads only after rebooting.
-- 
Eero


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