SRU Request for LP: #563895

SRU Justification:

Impact: When /boot and / are in an LVM VG and a snapshot is made of an LVM LV in that VG the system will not boot and grub can not be modified (updated, reinstalled) until all snapshots are removed.

Testcase:
Steps to reproduce:

1. Install Ubuntu from either the "server" or "alternate" ISO image to a system with an otherwise empty boot diskl
2. Use "manual partitioning" and create a single partition over the entire boot disk with type "Logical Volume Manager"
3. Configure LVM with a volume group containing the boot disk.
3A. Create a logical volume for swap.
3B. Create a logical volume for the root filesystem.
3C. Leave some free space in the volume group for future snapshots.
3D. Do not make a separate /boot file system.
4. Finish installation, reboot, apply patches, reboot.
5. Use "lvcreate" to make a snapshot of the logical volume containing the root file system.
6. Reboot. You will be at the "grub-rescue>" prompt.

You cannot recover from this by using an ISO in recovery mode until you remove the snapshot as grub-probe fails during attempts to re-install or update grub2 while a snapshot if fixed.

Fix:

Cherry-picked patch from upstream grub2 that only modifies one source code file: ... disk/lvm.c inside grub2.

See attachment for patch.

See also:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=574863
LP: #563895

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: grub-pc 1.98-1ubuntu12
ProcVersionSignature: Ubuntu 2.6.32-35.78-generic 2.6.32.46+drm33.20
Uname: Linux 2.6.32-35-generic i686
Architecture: i386
Date: Wed Nov 9 08:48:59 2011
InstallationMedia: Ubuntu 10.04.2 LTS "Lucid Lynx" - Release i386 (20110211.1)
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: grub2