[Bug 1000202] [NEW] Unable to unmount NFSv3 or NFSv4 mounts when mounted using IPv6 address

[Scott Duckworth]

Public bug reported:

I am unable to unmount NFS (v3 or v4) mount points if they were mounted
using the server's IPv6 address instead of the server's hostname (which
resolves to an IPv6 address).  umount says "<mountpoint> was not found
in /proc/mounts" even though the file system is clearly mounted.

I do not get the expected result when using IPv6 addresses (NFSv3
example):

root at gecko23:~# mount -t nfs [2620:103:a000:401::1:9]:/vol/public /mnt2
root at gecko23:~# mount | grep /mnt2
[2620:103:a000:401::1:9]:/vol/public on /mnt2 type nfs (rw,vers=4,addr=2620:103:a000:401::1:9,clientaddr=2620:103:a000:401:7880:a21c:f25:d073)
root at gecko23:~# cat /proc/mounts | grep /mnt2
2620:103:a000:401::1:9:/vol/public/ /mnt2 nfs4 rw,relatime,vers=4,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp6,port=0,timeo=600,retrans=2,sec=sys,clientaddr=2620:103:a000:401:7880:a21c:f25:d073,minorversion=0,local_lock=none,addr=2620:103:a000:401::1:9 0 0
root at gecko23:~# umount /mnt2
/mnt2 was not found in /proc/mounts
/mnt2 was not found in /proc/mounts

This problem also happens when using NFSv4.

When mounting using a hostname which resolves to an IPv6 address, I get
the expected result (NFSv4 example):

root at gecko23:~# mount -t nfs4 netapp2a-v6.cs.clemson.edu:/vol/public /mnt2
root at gecko23:~# mount | grep /mnt2
netapp2a-v6.cs.clemson.edu:/vol/public on /mnt2 type nfs4 (rw,addr=2620:103:a000:401::1:9,clientaddr=2620:103:a000:401:7880:a21c:f25:d073)
root at gecko23:~# cat /proc/mounts | grep /mnt2
netapp2a-v6.cs.clemson.edu:/vol/public/ /mnt2 nfs4 rw,relatime,vers=4,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp6,port=0,timeo=600,retrans=2,sec=sys,clientaddr=2620:103:a000:401:7880:a21c:f25:d073,minorversion=0,local_lock=none,addr=2620:103:a000:401::1:9 0 0
root at gecko23:~# umount /mnt2

Using a hostname with NFSv3 works as expected too:

root at gecko23:~# mount -t nfs netapp2a-v6.cs.clemson.edu:/vol/public /mnt2
root at gecko23:~# umount /mnt2

Perhaps the colons (':') in the IPv6 addresses get confused with the
delimiter (a colon) between NFS server and share point?

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: mount 2.20.1-1ubuntu3
ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
Uname: Linux 3.2.0-23-generic x86_64
ApportVersion: 2.0.1-0ubuntu7
Architecture: amd64
Date: Wed May 16 08:20:50 2012
InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: util-linux
UpgradeStatus: No upgrade log present (probably fresh install)

** Affects: util-linux (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: amd64 apport-bug precise

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https://bugs.launchpad.net/bugs/1000202

Title:
  Unable to unmount NFSv3 or NFSv4 mounts when mounted using IPv6
  address

Status in “util-linux” package in Ubuntu:
  New

Bug description:
  I am unable to unmount NFS (v3 or v4) mount points if they were
  mounted using the server's IPv6 address instead of the server's
  hostname (which resolves to an IPv6 address).  umount says
  "<mountpoint> was not found in /proc/mounts" even though the file
  system is clearly mounted.

  I do not get the expected result when using IPv6 addresses (NFSv3
  example):

  root at gecko23:~# mount -t nfs [2620:103:a000:401::1:9]:/vol/public /mnt2
  root at gecko23:~# mount | grep /mnt2
  [2620:103:a000:401::1:9]:/vol/public on /mnt2 type nfs (rw,vers=4,addr=2620:103:a000:401::1:9,clientaddr=2620:103:a000:401:7880:a21c:f25:d073)
  root at gecko23:~# cat /proc/mounts | grep /mnt2
  2620:103:a000:401::1:9:/vol/public/ /mnt2 nfs4 rw,relatime,vers=4,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp6,port=0,timeo=600,retrans=2,sec=sys,clientaddr=2620:103:a000:401:7880:a21c:f25:d073,minorversion=0,local_lock=none,addr=2620:103:a000:401::1:9 0 0
  root at gecko23:~# umount /mnt2
  /mnt2 was not found in /proc/mounts
  /mnt2 was not found in /proc/mounts

  This problem also happens when using NFSv4.

  When mounting using a hostname which resolves to an IPv6 address, I
  get the expected result (NFSv4 example):

  root at gecko23:~# mount -t nfs4 netapp2a-v6.cs.clemson.edu:/vol/public /mnt2
  root at gecko23:~# mount | grep /mnt2
  netapp2a-v6.cs.clemson.edu:/vol/public on /mnt2 type nfs4 (rw,addr=2620:103:a000:401::1:9,clientaddr=2620:103:a000:401:7880:a21c:f25:d073)
  root at gecko23:~# cat /proc/mounts | grep /mnt2
  netapp2a-v6.cs.clemson.edu:/vol/public/ /mnt2 nfs4 rw,relatime,vers=4,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp6,port=0,timeo=600,retrans=2,sec=sys,clientaddr=2620:103:a000:401:7880:a21c:f25:d073,minorversion=0,local_lock=none,addr=2620:103:a000:401::1:9 0 0
  root at gecko23:~# umount /mnt2

  Using a hostname with NFSv3 works as expected too:

  root at gecko23:~# mount -t nfs netapp2a-v6.cs.clemson.edu:/vol/public /mnt2
  root at gecko23:~# umount /mnt2

  Perhaps the colons (':') in the IPv6 addresses get confused with the
  delimiter (a colon) between NFS server and share point?

  ProblemType: Bug
  DistroRelease: Ubuntu 12.04
  Package: mount 2.20.1-1ubuntu3
  ProcVersionSignature: Ubuntu 3.2.0-23.36-generic 3.2.14
  Uname: Linux 3.2.0-23-generic x86_64
  ApportVersion: 2.0.1-0ubuntu7
  Architecture: amd64
  Date: Wed May 16 08:20:50 2012
  InstallationMedia: Ubuntu 12.04 LTS "Precise Pangolin" - Release amd64 (20120425)
  ProcEnviron:
   TERM=xterm
   LANG=en_US.UTF-8
   SHELL=/bin/bash
  SourcePackage: util-linux
  UpgradeStatus: No upgrade log present (probably fresh install)

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