Comment 0 for bug 1641049

When using NFSv4 client in Ubuntu 16.04 the the following sequence of actions fails.

You need a NFS server (S) and two clients (A and B).

Let the NFS share be mounted at /nfsdata

A: echo test > /nfsdata/file
B: cat /nfsdata/file ===> test
A: rm /nfsdata/file
B: cat /nfsdata/file ===> cat: No such file or directory
A: echo test > /nfsdata/file
B: cat /nfsdata/file ===> cat: No such file or directory (!)

Doing echo 3 > proc/sys/vm/drop_caches as root makes the file visible on B.

14.04 works without any problem.

NFSv4 server is CentOS 6.7 in our case.

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: linux-image-4.4.0-45-generic 4.4.0-45.66
ProcVersionSignature: Ubuntu 4.4.0-45.66-generic 4.4.21
Uname: Linux 4.4.0-45-generic x86_64
AlsaDevices:
 total 0
 crw-rw---- 1 root audio 116, 1 Nov 8 03:13 seq
 crw-rw---- 1 root audio 116, 33 Nov 8 03:13 timer
AplayDevices: Error: [Errno 2] No such file or directory: 'aplay'
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord'
AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1:
Date: Fri Nov 11 17:06:51 2016
HibernationDevice: RESUME=UUID=7b92d2e2-e481-471a-bc38-e178a9418aa1
InstallationDate: Installed on 2016-11-07 (3 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig'
Lsusb:
 Bus 002 Device 002: ID 8087:8002 Intel Corp.
 Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
 Bus 001 Device 003: ID 413c:a001 Dell Computer Corp. Hub
 Bus 001 Device 002: ID 8087:800a Intel Corp.
 Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
MachineType: Dell Inc. PowerEdge R630
PciMultimedia:

ProcEnviron:
 LC_CTYPE=en_US.UTF-8
 TERM=screen-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
ProcFB: 0 EFI VGA
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.4.0-45-generic.efi.signed root=UUID=11e697e5-38f8-41ae-863c-2755793044a6 ro
RelatedPackageVersions:
 linux-restricted-modules-4.4.0-45-generic N/A
 linux-backports-modules-4.4.0-45-generic N/A
 linux-firmware 1.157.4
RfKill: Error: [Errno 2] No such file or directory: 'rfkill'
SourcePackage: linux
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 02/12/2016
dmi.bios.vendor: Dell Inc.
dmi.bios.version: 2.0.1
dmi.board.name: 02C2CP
dmi.board.vendor: Dell Inc.
dmi.board.version: A01
dmi.chassis.type: 23
dmi.chassis.vendor: Dell Inc.
dmi.modalias: dmi:bvnDellInc.:bvr2.0.1:bd02/12/2016:svnDellInc.:pnPowerEdgeR630:pvr:rvnDellInc.:rn02C2CP:rvrA01:cvnDellInc.:ct23:cvr:
dmi.product.name: PowerEdge R630
dmi.sys.vendor: Dell Inc.