Comment # 33 on bug 1209457 from St���phane DESNEUX

Well, I installed both kernels (.46.1 and .55.3). 

At boot time (grub), I select the "good" or the "bad" kernel. 

Then I simply try to run 'showmount -e <nfs_server_hostname>' or 'mount -t nfs
server:/myshare /mnt/foo' (I ass

With kernel .55.3:
=> showmount is just blocked and doesn't reply
=> mount usually blocks too, but it works, when I try to list the content of
the mounted directory, the permissions are wrong ("all marked '???'")

With kernel .46.1: 
=> everything works!

So the setup to reproduce should be fairly easy.

If that helps, here's lsmod output (from .46.1):

$ lsmod| grep nfs
nfsv3                  57344  0
nfsv4                 913408  2
dns_resolver           16384  1 nfsv4
nfs                   425984  3 nfsv4,nfsv3
fscache               401408  1 nfs
nfsd                  630784  9
auth_rpcgss           155648  2 nfsd,rpcsec_gss_krb5
nfs_acl                16384  2 nfsd,nfsv3
lockd                 122880  3 nfsd,nfsv3,nfs
grace                  16384  2 nfsd,lockd
sunrpc                651264  25
nfsd,nfsv4,auth_rpcgss,lockd,nfsv3,rpcsec_gss_krb5,nfs_acl,nfs

So I guess I'm using NFS v4.

The server is an old QNAP NAS Server that has never been upgraded recently): so
nothing changed on this side => the problem is on the client, not the server.

Also, I reproduced the same behaviour on 1 desktop and 2 laptops, all running
Leap 15.4, all up-to-date.

Definitely, the issue is between .46 and .49 IMO, as .55 is just the next
failing version.