Sounds like a very good addition! (and the patch to mount_union.8
	as well :) Presumably an unlink() call just fails with EPERM?
	(Or would that be EROFS?? :)

		David/abs

david@city.ac.uk +44 171 477 8186 (MIME) david@southern.com +44 0181 88 8949
Network Analyst, UCS, City University   System Manager, Southern Studios Ltd
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On Thu, 26 Oct 1995, Rolf Grossmann wrote:

> Hi,
> 
> on Thu, 26 Oct 1995 10:11:25 +0000 (GMT) David Brownlee wrote 
> concerning "Re: Union mount problem?" something like this:
> 
> > 	Is the upper layer a 4.4 filesystem?
> > 	4.2 & 4.3 filesystems do not support whiteouts, which unionfs needs.
> 
> What I don't understand is, why does the upper layer *need* to support
> whiteouts in order to be mounted rw? If it doesn't you can't create
> whiteouts, fine, but you can still alter files in the lower layer or
> write new ones.
> 
> I have removed this limitation in my private kernel sources (just a small
> patch) and it works fine for me. Maybe I should send-pr this?
> 
> Bye, Rolf
>