"Reverse union" mount possible?

[Alex Povolotsky]

On Thu, 20 Nov 2003 21:01:31 -0500
Erez Zadok <ezk at cs.sunysb.edu> wrote:

EZ> > > Right now, I'm readonly mount_null'ing /bin, /sbin, /usr/bin,
EZ> > > /usr/sbin,/usr/lib, /usr/include, /usr/libexec, /usr/share. With
EZ> > > a dozen jails, there are too many mounts to my liking, and about
EZ> > > twice a week I experience panic. Probabily it's nullfs-related.
EZ> > 
EZ> > Nullfs is known to be buggy in -stable. In particular, it seems to
EZ> > deadlock under load / when vnodes start getting recycled.
EZ> 
EZ> My fist stackable templates were ported to fbsd 4.x and 5.0 not too
EZ> long ago.  We ran extensive tests to ensure that the code is stable.
EZ>  While it's
EZ> possible we missed stuff, it might help if someone checked what is
EZ> different about my "wrapfs" vs. Nullfs.  We may have fixed bugs in
EZ> wrapfs not realizing that they originally came from the base Nullfs
EZ> we started with.

Sounds cool. Where can I get the source?

BTW, I've heard that nullfs/unionfs doesn't allow code sharing. Does wrapfs do it?

-- 
Alex.