tnfsd won't serve nfs-mounted directories under linux

[johnwiggins]

Running tnfsd on Linux raspberrypi 5.10.103-v7l+ #1529 SMP Tue Mar 8 12:24:00 GMT 2022 armv7l GNU/Linux

tnfs directory nfs mounted under /nfs/tnfsd on server.

Server reports:
[2025-03-09T13:59:54Z] Looking for existing sessions with IP 192.168.16.196
[2025-03-09T13:59:54Z] Allocating new session for 0x00
[2025-03-09T13:59:54Z] Allocated new session for 0x4567
validate_dir: Path='/nfs/tnfs/'
[2025-03-09T13:59:54Z] Freeing session ID index 0
[2025-03-09T13:59:54Z] 192.168.16.196 s=00 c=00 q=00 | Failed to mount
[2025-03-09T13:59:54Z] 192.168.16.196 | Client disconnected, closing socket.

And tnfs client disconnects.

Access to a local tnfs directory works as expected.

tnfs directory is owned by tnfs:tnfs, permissions are rwxrwxr-x on tnfs directory.