Remounting as read-only

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

With NetBSD 5, it seems it is not possible anymore to remount a
filesystem read-only:

# mount
/dev/md0a on / type ffs (local)
/dev/wd0a on /flash type ffs (read-only, local)
# cat /etc/fstab                                                               
/dev/md0a       /       ffs     rw,softdep 0 0
/dev/wd0a       /flash  ffs     ro 0 0
# mount -uw /flash
# mount -ur /flash
mount_ffs: /dev/wd0a on /flash: Operation not supported
# mount -u -o ro /dev/wd0a /flash
mount_ffs: /dev/wd0a on /flash: Operation not supported
# mount -f -u -o ro /dev/wd0a /flash
mount_ffs: /dev/wd0a on /flash: Operation not supported

Of course I acan umount and remount, but that invalidate file descriptors
that had been open read-only on the filesystem. Isthere any trick to get
it working as it worked on NetBSD 4?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost