I have an odd nfs issue with the current mainline kernel, where a
mount hangs and eventually times out when attempting a mount with nfs
version 4 and that is not offered by the server. With prior kernels
it fails quickly with "mount.nfs: Protocol not supported".
To reproduce, I have rpc.nfsd start with "-N 4", then try to mount
something local with -o nfsvers=4, for instance:
$ mount -t nfs -o nfsvers=4 localhost:/s /mnt
I bisected the behaviour down to commit 06b5fc3ad94e ("Merge tag
'nfs-rdma-for-5.1-1' of
git://git.linux-nfs.org/projects/anna/linux-nfs"). It's a merge
commit, but one that has quite a bit of conflict resolution. I also
verified that the 2 parent commits of the merge (5085607d2091 and
2c94b8eca1a2) both behave as old kernels did.
Thanks
Marc
