jail, unionfs, pwd

[takawata at jp.freebsd.org]

In message <87y8iqptdp.fsf at neva.vlink.ru>, Denis Shaposhnikov wrote:
>Hi!
>
>Something wrong with unionfs, look at this:
>
>[dsh at neva dsh]$ mkdir /mnt/.ro
>[dsh at neva dsh]$ cp -R /bin /lib /libexec /mnt/
>[dsh at neva dsh]$ mount_unionfs -r /usr /mnt/.ro
>[dsh at neva dsh]$ jail /mnt x.x 127.0.0.1 /bin/tcsh
># pwd
>/
># cd /.ro
># pwd
>/.ro
># cd /.ro/bin
># pwd
>pwd: .: No such file or directory
>
>Why pwd said this? What is wrong?

If the filesystem  /mnt is using is same as /usr,
it is something like the problem which I encounted once.

http://docs.FreeBSD.org/cgi/mid.cgi?200202251435.XAA91094