Wrong behaviour with stacked mounts

Hi list,

% jarjarbinks:/mnt/msdos:129# echo $PWD
% /mnt/msdos
% jarjarbinks:/mnt/msdos:130# mount -t msdosfs
% /dev/ad0s5 on /mnt/msdos (msdosfs, local)
% jarjarbinks:/mnt/msdos:131# mount -t msdosfs /dev/da0s1 /mnt/msdos/
% jarjarbinks:/mnt/msdos:132# mount -t msdosfs
% /dev/ad0s5 on /mnt/msdos (msdosfs, local)
% /dev/da0s1 on /mnt/msdos (msdosfs, local)
% jarjarbinks:/mnt/msdos:133# umount /mnt/msdos/
% umount: unmount of /mnt/msdos failed: Device busy

Whilst the current shell current directory vnode (I'm not sure I'm
totally right here) is still the lower mount point (/dev/ad0s5),
umount(8) refuses to umount the upper mount point.


Regards,
-- 
Jeremie Le Hen
< jeremie at le-hen dot org >< ttz at chchile dot org >