linux 9p: uid & gid

Hi, all.

I wrote a 9p fs with help of libixp and after mounting i see strange uid and
gid numbers for files:

~# mount -t 9p -o trans=unix,noextend q t
~# ls -l t
-rw-rw-rw- 1 4294967294 4294967294 1 Jan  1  1970 conf
-rw-rw-rw- 1 4294967294 4294967294 1 Jan  1  1970 data
-rw-rw-rw- 1 4294967294 4294967294 1 Jan  1  1970 stat

If i do mount with dfltuid and dfltgid, i get normal values:

~# mount -t 9p -o trans=unix,noextend,trans=unix,noextend,dfltuid=0,dfltgid=0 q t
~# ls -l t
-rw-rw-rw- 1 root root 1 Jan  1  1970 conf
-rw-rw-rw- 1 root root 1 Jan  1  1970 data
-rw-rw-rw- 1 root root 1 Jan  1  1970 stat

But in any case chown call to these files sends empty uid and gid strings in
wstat T-message.

Is there any way to make uid & gid works as expected?

Thanks.

-- 
Олег Неманов (Oleg Nemanov)