compared to the old NFS client via email to the freebsd-fs@ mailing list.
For the new client, when multiple clients attempted to create a symbolic
link concurrently, more that one client would report success instead of
EEXIST. This was caused by code in the new client that mapped EEXIST to
OK assuming it was caused by a retried RPC request.
Since the old client did not do this, the patch defaults to the old
behaviour and permits the new behaviour to be enabled via a sysctl.
Reported by: alex.burlyga.ietf@gmail.com
Tested by: alex.burlyga.ietf@gmail.com
MFC after: 2 weeks