freebsd stable - Jan 2006 - cpdup, chflags and ext2fs: undeletable forever :-)

Hi,
I have a little problem with chflags and ext2fs partition.

My env is :
# uname -a
FreeBSD multimedia.giovannelli.com 6.0-STABLE FreeBSD 6.0-STABLE #0: 
Sat Jan 21 22:55:27 CET 
2006     gmarco@multimedia.giovannelli.com:/usr/obj/usr/src/sys/FREEBSD  i386

I have mounted an ext2fs disk rw and I used part of it for storing a 
"snapshot" of my / fs.

Something like:

# mount -t extfs /dev/ad1s1 /mnt/ad1
# mkdir /mnt/ad1/chroot
# cpdup -vv / /mnt/ad1/chroot

Obviusly cpdup trying to reproduce all the permissions of the srcs 
file, so also the special flags  schg,uchg of some files.
The problem is that cpdup was able (or at least seems to be able to 
set them) but I am not able anymore to remove them :-)

So these files are not deletable anymore.
One of this file (i.e. rcp) looks in this way:
multimedia:/bin# ll -lo rcp
-r-sr-xr-x  1 root  wheel  schg,uchg 18332 Jan 21 09:37 /bin/rcp

The copy on the ext2fs look in these other way:
multimedia:/mnt/ad1/chroot/bin# ll -lo rcp
-r-sr-xr-x  1 root  wheel  - 18332 Jan 27 07:55 rcp

If I try:
multimedia:/mnt/ad1/chroot/bin# chflags noschg rcp
multimedia:/mnt/ad1/chroot/bin# chflags nouchg rcp
multimedia:/mnt/ad1/chroot/bin# chmod 777 rcp
multimedia:/mnt/ad1/chroot/bin# ll -lo rcp
multimedia:/mnt/ad1/chroot/bin# ll -lo
total 20
-rwxrwxrwx  1 root  wheel  - 18332 Jan 27 07:55 rcp
multimedia:/mnt/ad1/chroot/bin# rm -f rcp
rm: rcp: Operation not permitted

Even running a live linux distro by cdrom seems to be able to remove 
them anymore giving a strange error 30.

Any idea ? I have tried also the obliterate utility from ports which 
seems able to remove files on ro volume without any results.

Probably the only solutions is to newfs the volume but :

multimedia:/mnt/ad1/chroot/bin# df -h
Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/ad1s1     275G    254G    7.2G    97%    /mnt/ad1

Any idea/tips to remove this folder ?
Probably we have to deny the chflags on volume others than ufs even 
if we can mount them rw ?



Best Regards,
Gianmarco Giovannelli ,  "Unix expert since yesterday"
http://utenti.gufi.org/~gmarco/