problem with mountd --manage-gids and uid higher than 2147483647

[Peter Wirdemo]

Binary package hint: nfs-kernel-server

Problem:

Unable to access an NFS file share with uid higher than 2147483647 when using /usr/sbin/rpc.mountd --manage-gids.

We have seen this behaviour both in jaunty(9.04) and in hardy(8.04.02).
 hardy: nfs-kernel-server: 1:1.1.2-2ubuntu2.2
 jaunty: nfs-kernel-version: 1:1.1.4-1ubuntu1

This was discovered as the default value for "RPCMOUNTDOPTS" in /etc/default/nfs-kernel-server has been changed in jaunty.
In previous versions RPCMOUNTDOPTS was empty but in jaunty it is set to "--manage-gids".

Background:

We are using ubuntu as an NFS server and a Juniper SA2500 as an NFS client.
Juniper uses uid and gid -1 for all NFS access. Using tcpdump we verified that -1 translates into 4294967295.

Using an ubuntu client to test different uids, we found that a uid higher than 2147483647 fails to access the share.

This problem may be caused by mixed use of unsigned/signed integer...

Have a nice day
/Peter & Björn