As already discussed on ML, please add the NFS_V4_1 and NFS_V4_2 config options to the current kernel. BTW, here is the config file changes, just need to be applied in the next build:

--- x86_64.config.orig	2017-07-01 19:48:20.374721597 +0200
+++ x86_64.config	2017-07-03 22:45:47.121632667 +0200
@@ -7904,8 +7975,11 @@
 CONFIG_NFS_V3=m
 CONFIG_NFS_V3_ACL=y
 CONFIG_NFS_V4=m
-# CONFIG_NFS_SWAP is not set
-# CONFIG_NFS_V4_1 is not set
+CONFIG_NFS_SWAP=y
+CONFIG_NFS_V4_1=y
+CONFIG_NFS_V4_2=y
+CONFIG_NFS_V4_1_IMPLEMENTATION_ID_DOMAIN="kernel.org"
+CONFIG_NFS_V4_1_MIGRATION=y
 CONFIG_NFS_FSCACHE=y
 # CONFIG_NFS_USE_LEGACY_DNS is not set
 CONFIG_NFS_USE_KERNEL_DNS=y
@@ -7916,10 +7990,10 @@
 CONFIG_NFSD_V3_ACL=y
 CONFIG_NFSD_V4=y
 CONFIG_NFSD_PNFS=y
-# CONFIG_NFSD_BLOCKLAYOUT is not set
-# CONFIG_NFSD_SCSILAYOUT is not set
+CONFIG_NFSD_BLOCKLAYOUT=y
+CONFIG_NFSD_SCSILAYOUT=y
 CONFIG_NFSD_FLEXFILELAYOUT=y
-# CONFIG_NFSD_V4_SECURITY_LABEL is not set
+CONFIG_NFSD_V4_SECURITY_LABEL=y
 # CONFIG_NFSD_FAULT_INJECTION is not set
 CONFIG_GRACE_PERIOD=m
 CONFIG_LOCKD=m