Comment 0 for bug 1327563

Summary:

After upgrading the kernel on Ubuntu 14.04 to 3.13.0-29-generic I found that I was unable to mount NFS shares from other Ubuntu machines.

How to reproduce:

1. Install Ubuntu 14.04 on two machines. A minimal server install should be fine. One will act as a server, the other as a client.
2. Upgrade the kernel on the client machine to at least 3.13.0-27-generic.
3. Install the nfs-kernel-server package on the server.
4. Add a directory to /etc/exports and run service nfs-kernel-server start.
5. Install the nfs-common package on the client.
6. Attempt to mount the shared directory on the client.

Expected result:

The shared directory should be mounted on the client.

Actual result:

The mount command hangs. Further NFS mounts are not possible.

Regression:

I have been able to reproduce the problem on clients running Linux 3.13.0-27-generic and later. The problem is not reproducable on clients running Linux 3.13.0-24-generic. The problem is reproducable no matter which kernel version is used on the server.

Tested client kernel versions:

Linux 3.13.0-29-generic #53-Ubuntu FAIL
Linux 3.13.0-27-generic #50-Ubuntu FAIL
Linux 3.13.0-24-generic #47-Ubuntu OK

Tested server kernel versions:

Linux 3.13.0-29-generic #53-Ubuntu OK
Linux 3.13.0-27-generic #50-Ubuntu OK
Linux 3.13.0-24-generic #47-Ubuntu OK

lsb_release -rd:

Description: Ubuntu 14.04 LTS
Release: 14.04

apt-cache policy linux-image-generic:

linux-image-generic:
  Installed: (none)
  Candidate: 3.13.0.29.35
  Version table:
     3.13.0.29.35 0
        500 http://se.archive.ubuntu.com/ubuntu/ trusty-updates/main amd64 Packages
        500 http://security.ubuntu.com/ubuntu/ trusty-security/main amd64 Packages
     3.13.0.24.28 0
        500 http://se.archive.ubuntu.com/ubuntu/ trusty/main amd64 Packages

ProblemType: Bug
DistroRelease: Ubuntu 14.04
Package: linux-image-3.13.0-29-generic 3.13.0-29.53
ProcVersionSignature: Ubuntu 3.13.0-29.53-generic 3.13.11.2
Uname: Linux 3.13.0-29-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Jun 7 16:26 seq
 crw-rw---- 1 root audio 116, 33 Jun 7 16:26 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.14.1-0ubuntu3.2
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: [Errno 2] No such file or directory: 'fuser'
CRDA: Error: [Errno 2] No such file or directory: 'iw'
Date: Sat Jun 7 16:30:02 2014
HibernationDevice: RESUME=UUID=9c13108b-d40a-4881-b563-c477ed2e6804
InstallationDate: Installed on 2014-06-07 (0 days ago)
InstallationMedia: Ubuntu-Server 14.04 LTS "Trusty Tahr" - Release amd64 (20140416.2)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
 Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
MachineType: QEMU Standard PC (i440FX + PIIX, 1996)
ProcFB: 0 VESA VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-3.13.0-29-generic root=UUID=9068010d-8332-47c8-ae62-ccc62ca57290 ro
RelatedPackageVersions:
 linux-restricted-modules-3.13.0-29-generic N/A
 linux-backports-modules-3.13.0-29-generic N/A
 linux-firmware N/A
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 01/01/2011
dmi.bios.vendor: Bochs
dmi.bios.version: Bochs
dmi.chassis.type: 1
dmi.chassis.vendor: Bochs
dmi.modalias: dmi:bvnBochs:bvrBochs:bd01/01/2011:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-2.0:cvnBochs:ct1:cvr:
dmi.product.name: Standard PC (i440FX + PIIX, 1996)
dmi.product.version: pc-i440fx-2.0
dmi.sys.vendor: QEMU