How to NFS mount with nullfs file system

[KIRIYAMA Kazuhiko]

Hi, all

I'd like to NFS mount of remote site being mounted by nullfs
to view of all files nullfs mounted remote site. How to do
that ? NFS hosted site (vm) is like:

root at vm:~ # df -htnullfs
Filesystem       Size    Used   Avail Capacity  Mounted on
/ds/distfiles     13T     21G     13T     0%    /.dake/pub/FreeBSD/distfiles
/ds/packages      13T     33G     13T     0%    /.dake/pub/FreeBSD/packages
root at vm:~ # cat /etc/fstab
# Device                Mountpoint      FStype  Options         Dump    Pass#
/dev/mirror/swap        none            swap    sw              0       0
/ds/distfiles           /.dake/pub/FreeBSD/distfiles    nullfs  ro,late 0       0
/ds/packages            /.dake/pub/FreeBSD/packages     nullfs  ro,late 0       0
root at vm:~ # showmount -e
Exports list on localhost:
/ds/obj                            192.168.1.0 foo ftp 
/ds/ports                          192.168.1.0 foo ftp 
/ds/packages                       192.168.1.0 foo ftp 
/.dake                             foo ftp bar 192.168.1.0 
/ds/src                            192.168.1.0 foo ftp 
/ds/distfiles                      192.168.1.0 foo ftp 
/vm                                foo ftp 
root at vm:~ # uname -a
FreeBSD vm 13.0-CURRENT FreeBSD 13.0-CURRENT #0 r353025: Thu Oct  3 19:38:47 JST 2019     admin at vm:/ds/obj/current/13.0/r353025/ds/src/current/13.0/r353025/amd64.amd64/sys/GENERIC  amd64
root at vm:~ # 
root at vm:~ # ll /.dake/pub/FreeBSD/distfiles/
total 14327935
-rw-r--r--   1 root  wheel      214894 Aug 21  2018 01org-libva-2.1.0_GH0.tar.gz
-rw-r--r--   1 root  wheel      218971 Aug 30  2018 01org-libva-2.2.0_GH0.tar.gz
-rw-r--r--   1 root  wheel      120603 Nov  8  2018 08a395c66e42.tar.gz
-rw-r--r--   1 root  wheel        1001 Aug 21  2018 18675a51fca2.patch
-rw-r--r--   1 root  wheel         703 Aug 30  2018 450421921079
-rw-r--r--   1 root  wheel        1091 Sep 13 04:59 5cfcd31635b1.patch
-rw-r--r--   1 root  wheel        1126 Aug 30  2018 8089fa02122f.patch
-rw-r--r--   1 root  wheel       86799 Mar 27  2019 878541319ea1
-rw-r--r--   1 root  wheel       12523 Aug 16  2014 Algorithm-C3-0.10.tar.gz
  :
(snip)
  :
-rw-r--r--   1 root  wheel      698846 Aug 24  2018 xvidcore-1.3.5.tar.bz2
-rw-r--r--   1 root  wheel      109704 Nov  8  2018 yaoweibin-nginx_ajp_module-bf6cd93_GH0.tar.gz
-rw-r--r--   1 root  wheel      130039 Nov  8  2018 yaoweibin-nginx_upstream_check_module-9aecf15_GH0.tar.gz
-rw-r--r--   1 root  wheel       92230 Nov  8  2018 yaoweibin-ngx_http_substitutions_filter_module-v0.6.4_GH0.tar.gz
-rw-r--r--   1 root  wheel     1492156 Aug 11  2014 yasm-1.3.0.tar.gz
-rw-r--r--   1 root  wheel     1118845 Sep 24  2008 zip30.tar.gz
-rw-r--r--   1 root  wheel       10763 May 17  2019 zipp-0.5.1.tar.gz
drwxr-xr-x   2 root  wheel           4 Nov 13  2018 zope/
-rw-r--r--   1 root  wheel      685770 Mar 12  2012 zziplib-0.13.62.tar.bz2
root at vm:~ # 

On the other hand, NFS client site (ftp):

admin at ftp:~ % df -h
Filesystem                          Size    Used   Avail Capacity  Mounted on
/dev/vtbd0p2                        13G    3.0G    8.6G    26%    /
devfs                               1.0K    1.0K      0B   100%    /dev
vm:/.dake                           13T    415G     13T     3%    /.dake
vm:/ds/src/current/13.0/r339677     13T     29G     13T     0%    /usr/src
vm:/ds/obj/current/13.0/r339677     13T    157G     13T     1%    /usr/obj
vm:/.dake/pub                       13T    415G     13T     3%    /var/ftp/pub
admin at ftp:~ % ll /var/ftp/pub/FreeBSD/distfiles/
total 0
admin at ftp:~ % showmount -a
^C
admin at ftp:~ % showmount 
^C
admin at ftp:~ % cat /etc/fstab
# Device        Mountpoint      FStype  Options Dump    Pass#
/dev/vtbd0p2    /               ufs     rw      1       1
/dev/vtbd0p3    none            swap    sw      0       0
vm:/.dake       /.dake          nfs     rw      0       0
vm:/ds/src/current/13.0/r339677      /usr/src        nfs     ro      0       0
vm:/ds/obj/current/13.0/r339677      /usr/obj        nfs     rw      0       0
vm:/.dake/pub   /var/ftp/pub    nfs     ro,nolockd      0       0
admin at ftp:~ % ll /var/ftp/pub/FreeBSD/distfiles/
total 0
admin at ftp:~ % uname -a
FreeBSD ftp 13.0-CURRENT FreeBSD 13.0-CURRENT r339677 GENERIC  amd64
admin at ftp:~ % 

Is there any suggetions ?

Regards

---
Kazuhiko Kiriyama <kiri at truefc.org>