Bug#833925: nfs-kernel-server: no_root_squash broken on amd64

[Greg Wooledge <greg@wooledge.org>]

Package: nfs-kernel-server
Version: 1:1.2.8-9
Severity: normal

The no_root_squash option appears to work on i386, but not on amd64.

wooledg@wooledg:~$ grep '^[^#]' /etc/exports
/home		-no_subtree_check arc1(ro,no_root_squash,sync)

arc1:~# ls /net/hosts/wooledg/home/wooledg/.bash*
/net/hosts/wooledg/home/wooledg/.bash_history
/net/hosts/wooledg/home/wooledg/.bash_logout
/net/hosts/wooledg/home/wooledg/.bashrc
arc1:~# ls /net/hosts/wooledg/home/wooledg/Maildir
ls: cannot open directory /net/hosts/wooledg/home/wooledg/Maildir: Permission denied

This is somewhat similar to bug #492970, but it's architecture specific
and it appears to be on the server side, not the client side.  I've
confirmed with NFSv3 and NFSv4 mounts from other Debian systems, and
with an HP-UX client.

See also:
https://lists.debian.org/debian-user/2016/08/msg00245.html
https://lists.debian.org/debian-user/2016/08/msg00275.html

I filed the bug report from "wooledg" (my desktop box) because it has an
absolutely minimal configuration that still demonstrates the problem.
The real problem that I care about is on a server with many other exports
as well.  Same problem: jessie, amd64, no_root_squash is ignored.

Jessie i386 systems work fine.

-- Package-specific info:
-- rpcinfo --
   program vers proto   port  service
    100000    4   tcp    111  portmapper
    100000    3   tcp    111  portmapper
    100000    2   tcp    111  portmapper
    100000    4   udp    111  portmapper
    100000    3   udp    111  portmapper
    100000    2   udp    111  portmapper
    100024    1   udp  55248  status
    100024    1   tcp  48807  status
    100003    2   tcp   2049  nfs
    100003    3   tcp   2049  nfs
    100003    4   tcp   2049  nfs
    100227    2   tcp   2049
    100227    3   tcp   2049
    100003    2   udp   2049  nfs
    100003    3   udp   2049  nfs
    100003    4   udp   2049  nfs
    100227    2   udp   2049
    100227    3   udp   2049
    100021    1   udp  55895  nlockmgr
    100021    3   udp  55895  nlockmgr
    100021    4   udp  55895  nlockmgr
    100021    1   tcp  38500  nlockmgr
    100021    3   tcp  38500  nlockmgr
    100021    4   tcp  38500  nlockmgr
    100005    1   udp  43131  mountd
    100005    1   tcp  49060  mountd
    100005    2   udp  47185  mountd
    100005    2   tcp  49686  mountd
    100005    3   udp  52717  mountd
    100005    3   tcp  35670  mountd
-- /etc/default/nfs-kernel-server --
RPCNFSDCOUNT=8
RPCNFSDPRIORITY=0
RPCMOUNTDOPTS="--manage-gids"
NEED_SVCGSSD=""
RPCSVCGSSDOPTS=""
-- /etc/exports --
/home		-no_subtree_check arc1(ro,no_root_squash,sync)
-- /proc/fs/nfs/exports --
# Version 1.1
# Path Client(Flags) # IPs

-- System Information:
Debian Release: 8.5
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages nfs-kernel-server depends on:
ii  libblkid1     2.25.2-6
ii  libc6         2.19-18+deb8u4
ii  libcap2       1:2.24-8
ii  libsqlite3-0  3.8.7.1-1+deb8u1
ii  libtirpc1     0.2.5-1
ii  libwrap0      7.6.q-25
ii  lsb-base      4.1+Debian13+nmu1
ii  nfs-common    1:1.2.8-9
ii  ucf           3.0030

nfs-kernel-server recommends no packages.

nfs-kernel-server suggests no packages.

-- debconf-show failed