Bug#609814: "grub-probe --target=device /" shows useless /dev/root

[Roderich Schupp]

Package: grub-common
Version: 1.99~20110104-2
Severity: important
Tags: experimental

# /usr/sbin/grub-probe --target=device /
/dev/root

which makes for an unbootable /boot/grub/grub.cfg (kernel command line has
"root=/dev/root").
This used to work correctly (result should be /dev/md0) in the
previous version in experimental (1.99~20101221-1). It's still wrong in
1.99~20110111-1.

Note: My root is on MD RAID1 /dev/md0 (using old-style kernel auto-detection,
no initrd or initramfs).
Running the above with -vv shows however that grub-probe correctly detects
/dev/md0.

Some more information:

#  mount
/dev/md0 on / type ext4 (rw,noatime,errors=remount-ro,commit=0)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,mode=0755)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
....

 # cat /proc/self/mountinfo
11 1 9:0 / / rw,noatime - ext4 /dev/root rw,errors=remount-
ro,barrier=1,data=ordered
12 11 0:11 / /lib/init/rw rw,nosuid,relatime - tmpfs tmpfs rw,mode=755
13 11 0:3 / /proc rw,nosuid,nodev,noexec,relatime - proc proc rw
14 11 0:12 / /sys rw,nosuid,nodev,noexec,relatime - sysfs sysfs rw
....

# cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdb1[1] sda1[0]
      390708736 blocks [2/2] [UU]

unused devices: <none>





-- System Information:
Debian Release: 6.0
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.37 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages grub-common depends on:
ii  base-files                6.0            Debian base system miscellaneous f
ii  dpkg                      1.15.8.8       Debian package management system
ii  gettext-base              0.18.1.1-3     GNU Internationalization utilities
ii  install-info              4.13a.dfsg.1-6 Manage installed documentation in 
ii  libc6                     2.11.2-7       Embedded GNU C Library: Shared lib
ii  libdevmapper1.02.1        2:1.02.48-4    The Linux Kernel Device Mapper use
ii  libfreetype6              2.4.2-2.1      FreeType 2 font engine, shared lib
ii  liblzma2                  5.0.0-2        XZ-format compression library
ii  zlib1g                    1:1.2.5.dfsg-1 compression library - runtime

Versions of packages grub-common recommends:
pn  os-prober                     <none>     (no description available)

Versions of packages grub-common suggests:
pn  grub-emu                    <none>       (no description available)
pn  multiboot-doc               <none>       (no description available)
ii  xorriso                     0.5.6.pl00-2 command line iso9660+RR manipulati

-- no debconf information