Re: 16+ GID issue, mountd's --manage-gids not helping

["J. Bruce Fields" <bfields@fieldses.org>]

On Mon, Sep 16, 2013 at 09:43:51AM -0500, Contact wrote:
> Hi all,
> 
> I'm having an issue with my NFS mount and being able to access it from
> my normal user account. The mount point is chmod'ed to 2770 with a GID
> of 1100 (nfs) which is the same on both systems. I can access it if I
> change my active group using newgrp, but not normally.
> 
> ====================================
> noir ~ # ls -lhd /home/nfs/share
> drwxrws--- 8 nfs nfs 4.0K Sep  4 15:30 /home/nfs/share
> 
> rypervenche@svelte ~ $ pwd
> /home/rypervenche
> rypervenche@svelte ~ $ cd nfs
> -su: cd: nfs: Permission denied
> rypervenche@svelte ~ $ newgrp nfs
> rypervenche@svelte ~ $ cd nfs
> rypervenche@svelte ~/nfs $ 
> 
> svelte ~ # grep nfs /etc/group
> nfs:x:1100:rypervenche
> ====================================
> 
> You can find the details of my NFS server and client here:
> 
> ====================================
> svelte = client
> noir = server
> 
> svelte ~ # tail -1 /etc/fstab
> 192.168.1.100:/ /home/rypervenche/nfs   nfs
> rw,noauto,noexec,nodev,nosuid   0       0
> 
> noir ~ # cat /etc/exports 
> # /etc/exports: NFS file systems being exported.  See exports(5).
> /home/nfs/share 192.168.1.205(rw,sync,fsid=0,no_root_squash,no_subtree_check) 192.168.2.100(rw,sync,fsid=0,no_root_squash,no_subtree_check)
> 
> noir ~ # id nfs
> uid=1100(nfs) gid=1100(nfs) groups=1100(nfs)
> 
> noir ~ # grep -v ^# /etc/conf.d/nfs | grep -v ^$
> NFS_NEEDED_SERVICES="rpc.idmapd"
> OPTS_RPC_NFSD="8"
> OPTS_RPC_MOUNTD="-V 4 --manage-gids -p 32767"
> OPTS_RPC_STATD="-p 32765 -o 32766"
> OPTS_RPC_IDMAPD=""
> OPTS_RPC_GSSD=""
> OPTS_RPC_SVCGSSD=""
> OPTS_RPC_RQUOTAD=""
> EXPORTFS_TIMEOUT=30
> 
> noir ~ # iptables-save | egrep '(NFS|T -m conn)'
> -A INPUT -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
> -A INPUT -s 192.168.1.205/32 -p tcp -m tcp -m multiport --dports 111,2049,4001,32765:32767 -m conntrack --ctstate NEW -m comment --comment NFS -j ACCEPT
> -A INPUT -s 192.168.1.205/32 -p udp -m udp -m multiport --dports 111,2049,4001,32765:32767 -m conntrack --ctstate NEW -m comment --comment NFS -j ACCEPT
> -A INPUT -s 192.168.2.100/32 -p tcp -m tcp -m multiport --dports 111,2049,4001,32765:32767 -m conntrack --ctstate NEW -m comment --comment NFS -j ACCEPT
> -A INPUT -s 192.168.2.100/32 -p udp -m udp -m multiport --dports 111,2049,4001,32765:32767 -m conntrack --ctstate NEW -m comment --comment NFS -j ACCEPT
> 
> svelte:
> net-fs/nfs-utils-1.2.6 was built with the following:
> USE="ipv6 nfsdcld nfsidmap nfsv4 nfsv41 tcpd -caps -kerberos (-selinux)"
> 
> noir:
> net-fs/nfs-utils-1.2.6 was built with the following:
> USE="ipv6 (multilib) nfsdcld nfsidmap nfsv4 nfsv41 tcpd -caps -kerberos (-selinux)" ABI_X86="64"
> 
> svelte ~ # uname -a
> Linux svelte 3.10.7-gentoo-svelte #1 SMP Thu Aug 22 17:46:44 CDT 2013 i686 Intel(R) Atom(TM) CPU N450 @ 1.66GHz GenuineIntel GNU/Linux
> 
> noir ~ # uname -a
> Linux noir 3.10.7-gentoo-noir #1 SMP Wed Aug 28 11:19:43 CDT 2013 x86_64 AMD Athlon(tm) II X2 260 Processor AuthenticAMD GNU/Linux
> ====================================
> 
> 
> I found online that the issue is due to NFS not being able to grab
> over 16 GIDs. I found help in the following two links:
> 
> https://xkyle.com/solving-the-nfs-16-group-limit-problem/
> https://wiki.archlinux.org/index.php/NFS_Troubleshooting
> 
> I tried adding the --manage-gids flag to mountd (which can be seen in
> the /etc/conf.d/nfs file above), however, it does not appear to
> resolve the issue.
> 
> ====================================
> noir ~ #
> cat /proc/net/rpc/auth.unix.gid/content #uid cnt: gids...
> 0 10: 0 1 2 3 4 6 10 11 26 27
> 1000 9: 10 18 19 27 78 85 100 250 1000
> 
> noir ~ # date +%s > /proc/net/rpc/auth.unix.gid/flush     
>                                                                                                                               
> noir ~ #
> cat /proc/net/rpc/auth.unix.gid/content #uid cnt: gids...
> 
> Then I mount the NFS again:
> 
> noir ~ # cat /proc/net/rpc/auth.unix.gid/content
> #uid cnt: gids...
> 0 10: 0 1 2 3 4 6 10 11 26 27
> 1000 9: 10 18 19 27 78 85 100 250 1000
> ====================================
> 
> It looks as though it is not grabbing all of my GIDs.

What do you expect the list to be?  Which groups is uid 1000 a member of
on the server?

--b.