Comment 3 for bug 477053

I confirm it using uml (user mode linux) with karmic host and karmic guest.

uname -a
-----------------------------------------------------
Linux divinelaptop 2.6.31-20-server #57-Ubuntu SMP Mon Feb 8 09:59:59 UTC 2010 x86_64 GNU/Linux
-----------------------------------------------------

boot message:
-----------------------------------------------------
[42949373.760000] ReiserFS: ubda: checking transaction log (ubda)
[42949373.760000] ReiserFS: ubda: Using tea hash to sort names
[42949373.760000] VFS: Mounted root (reiserfs filesystem) readonly.
[42949373.760000] line_ioctl: tty0: ioctl KDSIGACCEPT called
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mountall: root filesystem isn't mounted
init: mountall main process (637) terminated with status 1
General error mounting filesystems.
A maintenance shell will now be started.
CONTROL-D will terminate this shell and re-try.
-----------------------------------------------------

so I try mountall --debug
-----------------------------------------------------
root@divinelaptop:~# mountall --debug
track_usplash: will not start usplash
parse_filesystems: reading filesystems
parse_filesystems: sysfs (nodev)
parse_filesystems: rootfs (nodev)
parse_filesystems: bdev (nodev)
parse_filesystems: proc (nodev)
parse_filesystems: debugfs (nodev)
parse_filesystems: sockfs (nodev)
parse_filesystems: pipefs (nodev)
parse_filesystems: anon_inodefs (nodev)
parse_filesystems: futexfs (nodev)
parse_filesystems: tmpfs (nodev)
parse_filesystems: inotifyfs (nodev)
parse_filesystems: devpts (nodev)
parse_filesystems: reiserfs
parse_filesystems: ext3
parse_filesystems: ext4dev
parse_filesystems: ext2
parse_filesystems: ramfs (nodev)
parse_filesystems: jfs
parse_filesystems: xfs
parse_filesystems: hostfs (nodev)
parse_filesystems: hppfs (nodev)
parse_filesystems: mqueue (nodev)
new_mount: /: /dev/root rootfs defaults check
new_mount: /proc: - proc nodev,noexec,nosuid
new_mount: /proc/sys/fs/binfmt_misc: - binfmt_misc nodev,noexec,nosuid,optional
new_mount: /sys: - sysfs nodev,noexec,nosuid
new_mount: /sys/fs/fuse/connections: - fusectl optional
new_mount: /sys/kernel/debug: - debugfs optional
new_mount: /sys/kernel/security: - securityfs optional
new_mount: /spu: - spufs gid=spu,optional
new_mount: /dev: - tmpfs mode=0755 hook
new_mount: /dev/pts: - devpts noexec,nosuid,gid=tty,mode=0620
new_mount: /dev/shm: - tmpfs nosuid,nodev
new_mount: /tmp: - - - hook
new_mount: /var/run: - tmpfs mode=0755,nosuid,showthrough hook
new_mount: /var/lock: - tmpfs nodev,noexec,nosuid,showthrough
new_mount: /lib/init/rw: - tmpfs mode=0755,nosuid,optional
parse_fstab: updating mounts
update_mount: /: /dev/ubd0 reiserfs defaults check
update_mount: /proc: proc proc defaults
mount_proc: mounting /proc
mountall:/proc: unable to mount: Device or resource busy
mountall:/proc/self/mountinfo: No such file or directory
mount_policy: /proc/sys/fs/binfmt_misc: dropping unknown filesystem
mount_policy: /sys/fs/fuse/connections: dropping unknown filesystem
mount_policy: /sys/kernel/security: dropping unknown filesystem
mount_policy: /spu: dropping unknown filesystem
mount_policy: / is local (root)
mount_policy: /proc can be mounted while root readonly
mount_policy: /proc prior fstab entry /
mount_policy: /proc is virtual
mount_policy: /sys can be mounted while root readonly
mount_policy: /sys is virtual
mount_policy: /sys/kernel/debug parent is /sys
mount_policy: /sys/kernel/debug is virtual
mount_policy: /dev can be mounted while root readonly
mount_policy: /dev is virtual
mount_policy: /dev/pts parent is /dev
mount_policy: /dev/pts is virtual
mount_policy: /dev/shm parent is /dev
mount_policy: /dev/shm is virtual
mount_policy: /tmp parent is /
mount_policy: /tmp is local
mount_policy: /var/run can be mounted while root readonly
mount_policy: /var/run is virtual
mount_policy: /var/lock can be mounted while root readonly
mount_policy: /var/lock is virtual
mount_policy: /lib/init/rw can be mounted while root readonly
mount_policy: /lib/init/rw is virtual
mountall: root filesystem isn't mounted
-----------------------------------------------------

WTH?