slave mounts, private mounts

[Volker Wysk]

Hello

I'm trying to do a slave mount, or a private mount, but both don't
work.

The mount manpage says: "A slave mount receives propagation from its 
master, but not vice versa. A private mount carries no propagation
abilities."

Here's how to try it out:

# cd /tmp
# mkdir a b
# touch a/x
# mount --rbind --make-rslave a b
# ls a/* b/*
a/x  b/x

A change in the new mount should not be propagated to the old one, but
it is:

# touch b/y
# ls a/* b/*
a/x  a/y  b/x  b/y

With a private mount it's the same:
# umount b
# rm a/y
# mount --rbind --make-private a b
# touch b/y
# ls a/* b/*
a/x  a/y  b/x  b/y

What have I done wrong? I've studied the manpage and searched the web,
and it looks like it should work exactly like I've tried... 

Bye
Volker