Serve NFS from within a jail?

Hello,

I'm hoping to configure NFS service within a jail on a 5.1-CURRENT box.

The host envjailedment isn't running any services except ssh, and the
jail(8) man page leads me to believe the author thought NFS service
would work from within a jail.

However, neither mountd nor nfsd are happy running inside the jail:

Oct 22 23:32:06 jailed mountd[1249]: can't delete exports for /: Operation not permitted
Oct 22 23:32:06 jailed mountd[1249]: can't delete exports for /tmp: Operation not permitted
Oct 22 23:32:06 jailed mountd[1249]: can't delete exports for /usr: Operation not permitted
Oct 22 23:32:06 jailed mountd[1249]: can't delete exports for /var: Operation not permitted
Oct 22 23:32:06 jailed mountd[1249]: can't delete exports for /foo: Operation not permitted
Oct 22 23:32:06 jailed mountd[1249]: can't change attributes for /foo/share
Oct 22 23:32:06 jailed mountd[1249]: bad exports list line /foo/share   -maproot
Oct 22 23:32:06 jailed nfsd[1255]: nfssvc: Operation not permitted
Oct 22 23:32:06 jailed nfsd[1256]: nfssvc: Operation not permitted
Oct 22 23:32:06 jailed nfsd[1257]: nfssvc: Operation not permitted
Oct 22 23:32:06 jailed nfsd[1254]: nfssvc: Operation not permitted
Oct 22 23:32:06 jailed nfsd[1252]: can't Add UDP socket

Any suggestions?

Thanks,

-nick