Can't umount a read-only FS ?

[Olivier Bonvalet <btrfs.list@daevel.fr>]

Hi,

I have a strange problem with a btrfs partition : after an error, btrfs was forced readonly.

So I try to umount it, to launch btrfsck, but it doesn't work :

root! sofia:~# umount /backup/
root! sofia:~# btrfsck /dev/vg-sofia/backup
/dev/vg-sofia/backup is currently mounted. Aborting.
root! sofia:~# umount /backup/
umount: /backup/: not mounted
root! sofia:~# btrfsck /dev/vg-sofia/backup
/dev/vg-sofia/backup is currently mounted. Aborting.
root! sofia:~#



And I can't remount it :

root! sofia:~# mount /backup/
mount: /dev/mapper/vg--sofia-backup already mounted or /backup busy



Or access to the content :

root! sofia:~# ls /backup/
root! sofia:~#




It's on a v3.4.7 kernel, with btrfs-tools version 0.19+20120328-7 (from Debian unstable).

What should I do ? Reboot ?


Thanks,

Olivier