[Bug 921403] Re: duplicate files when listing NFS exporting ext4 with large number of files

[Chris Adamson]

** Attachment added: "The program used to produce the output described, derived from getdents man page"
   https://bugs.launchpad.net/bugs/921403/+attachment/2692328/+files/list_directory.c

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to nfs-utils in Ubuntu.
https://bugs.launchpad.net/bugs/921403

Title:
  duplicate files when listing NFS exporting ext4 with large number of
  files

Status in “nfs-utils” package in Ubuntu:
  New

Bug description:
  When a directory on an NFS server contained within an ext4 filesystem
  contains a large number of files (I was able to reliably produce the
  bug with 450000 and 500000 files respectively), an ls command on a
  client will produce duplicate files or get caught in an infinite loop
  on one file and continuously allocate more and more RAM.

  I wrote a simple program to process the directory entries (hacked the
  example on the getdents man page) and can reliably reproduce the bug.
  The program prints out a filename if the previous file was the same
  name and the position and previous position of the pointer in the
  directory entry:

  file1 585952 586024
  file2 428896 428968
  file3 761616 761688
  file4 996264 996344
  file4 996344 996424
  file4 996424 996504
  file4 996504 996584
  file4 996584 996664
  ....
  the file4 entries repeat forever

  I googled and found these pages that explain the issue:

  https://bugzilla.redhat.com/show_bug.cgi?id=739222
  http://marc.info/?l=linux-nfs&m=131281788003178&w=2

  This problem does not occur with an XFS filesystem and occurs with
  NFSv3 and NFSv4.

  ProblemType: Bug
  DistroRelease: Ubuntu 11.04
  Package: nfs-kernel-server 1:1.2.2-4ubuntu5.1
  ProcVersionSignature: Ubuntu 2.6.38-13.53-generic 2.6.38.8
  Uname: Linux 2.6.38-13-generic x86_64
  NonfreeKernelModules: nvidia
  Architecture: amd64
  Date: Wed Jan 25 16:46:03 2012
  InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110426)
  ProcEnviron:
   SHELL=/bin/bash
   PATH=(custom, user)
   LANG=en_AU.UTF-8
   LANGUAGE=en_AU:en
  SourcePackage: nfs-utils
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/nfs-utils/+bug/921403/+subscriptions