Bug#573761: initramfs-tools: mkinitramfs fails with MODULES=dep if crypto-root fs has snapshot

[Nikolaus Schulz <microschulz@web.de>]

On Wed, Mar 24, 2010 at 03:15:02AM +0100, maximilian attems wrote:
> On Wed, Mar 24, 2010 at 02:58:47AM +0100, Nikolaus Schulz wrote:
> > I really don't think that the - indeed not very helpful - error message
> > is the problem, but the fact that mkinitramfs (and thus
> > update-initramfs) doesn't work in the given scenario.
> > 
> > And how does one fix it when removing the snapshot isn't an acceptable
> > option?  Perhaps severity important would be more appropriate for this
> > bug.
> > 
> > Btw, from what I see on my box, the fix involves just catching yet
> > another indirection via /sys/block/${block}/slaves in dep_add_modules()
> > when chasing the root block device.
> 
> if you'd provided a tested patch on that issue,
> I'd be more than happy to apply it to latest initramfs-tools.
> 
> polishing klibc atm and starting to catch with initramfs-tools backlog,
> you'll find latest git here, if you need instructions how to use it,
> just ask, i'd be happy to guide:
> http://git.debian.org/?p=kernel/initramfs-tools.git;a=summary

OK, patch follows.  Take it with a big disclaimer: I just learned about
the sysfs interface in question, I don't know how raid would fit in
here, so raid may still be broken with lvm snapshots, and I tested it
only on two boxes: one with root on luks+lvm+snapshot, and one with
plain lvm.  Worked fine though. :)

Nikolaus