problems with chown as root on nfs4 export

[Craig Yoshioka]

I’ve posted this same email to the linux NFS mailing list since I think it might be client-side problem, but thought I might look for input here as well.

problem: when using chown as root on a nfs4 filesystem on newer linux releases file owners get sets to nobody.
        the user type doesn’t seem to matter (/etc/passwd, LDAP, Samba4)

setup: Server is FreeBSD 10 system with NFSv4 share.
      Server and clients are all configured with the same idmap domain
      Network users have consistent uid/gid on server and clients
      clients with older linux releases work OK (Ubuntu 12.04, CentOS 5 and 6)
      clients with newer linux releases do not work ( Fedora 20, Ubuntu 14.04, Mint 16 )

clues:

1. working and non-working systems get to the same fchownat() system call with the same arguments (via strace).

example (identical on working and non-working client):
...
fchownat(AT_FDCWD, "/mnt/test", 11111, 4294967295, 0) = 0
close(1)                                = 0
close(2)                                = 0
close(4)                                = 0
exit_group(0)                           = ?
+++ exited with 0 +++

2. working system sends NFSV4 SETATTR request with owner set to: matlab at nimgs.com and non-working as 11111 (via wireshark)



3. I can’t rule out misconfiguration.  but I’ve configured as identically as I could, and tried a lot of small vairations. these are my current settings (the pipefs settings are the distro defaults)