CIFS-Utils multiuser SMB mount : File Name too Long

[Andrew Wasylyk]

Using cifs-utils to mount a multiuser SMB mount on Ubuntu Server 16.04 creates random "File name too Long" errors. Issue does not occur if I mount the share as a single user.

mount opts:
auto,sec=krb5i,multiuser,file_mode=0600,dir_mode=0700,vers=3.0,noserverino,mfsymlinks,_netdev

Issue occurs on
Linux biocompute1 4.4.0-98-generic #121-Ubuntu SMP Tue Oct 10 14:24:03 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
cifs kernel module 2.8
mount.cifs version: 6.4

Issue does not occur on
Linux biocompute2 4.4.0-93-generic #116-Ubuntu SMP Fri Aug 11 21:17:51 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux
cifs kernel module 2.8
mount.cifs version: 6.4

Debian has caught the bug, this is the exact same behavior and was logged the day before I had my issue:
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=880504 . Apparently the issue

I feel like it applies but I'm not familiar with Linux releases, I don't know if this change was backported all the way to 4.4.0 or if that's even the right name for that.

Example:

ls: cannot access '/mnt/csfg-fs3/ProjectData/Genozymes/GenozymesShare/HomologyModeling/pdb_files/qs/pdb4qsz.ent.gz': File name too long

directory listing looks like:

drwxr-xr-x 2 awasylyk awasylyk 32768 Jul 2 2015 .
drwxr-xr-x 2 awasylyk awasylyk 196608 Apr 25 2007 ..
-????????? ? ? ? ? ? pdb1qs0.ent.gz
-????????? ? ? ? ? ? pdb1qs1.ent.gz
-????????? ? ? ? ? ? pdb1qs2.ent.gz
-????????? ? ? ? ? ? pdb1qs3.ent.gz
-????????? ? ? ? ? ? pdb1qs4.ent.gz
-????????? ? ? ? ? ? pdb1qs5.ent.gz
-????????? ? ? ? ? ? pdb1qs7.ent.gz
-????????? ? ? ? ? ? pdb1qs8.ent.gz
-????????? ? ? ? ? ? pdb1qs9.ent.gz
-????????? ? ? ? ? ? pdb1qsa.ent.gz
-????????? ? ? ? ? ? pdb1qsb.ent.gz
-????????? ? ? ? ? ? pdb1qsc.ent.gz
-????????? ? ? ? ? ? pdb1qsd.ent.gz
-????????? ? ? ? ? ? pdb1qse.ent.gz
-????????? ? ? ? ? ? pdb1qsf.ent.gz
-????????? ? ? ? ? ? pdb1qsg.ent.gz
-????????? ? ? ? ? ? pdb1qsh.ent.gz
-????????? ? ? ? ? ? pdb1qsi.ent.gz
-????????? ? ? ? ? ? pdb1qsj.ent.gz
-????????? ? ? ? ? ? pdb1qsk.ent.gz
-????????? ? ? ? ? ? pdb1qsl.ent.gz
-????????? ? ? ? ? ? pdb1qsm.ent.gz
-????????? ? ? ? ? ? pdb1qsn.ent.gz
-????????? ? ? ? ? ? pdb1qso.ent.gz
-????????? ? ? ? ? ? pdb1qsp.ent.gz
-????????? ? ? ? ? ? pdb1qsq.ent.gz
-????????? ? ? ? ? ? pdb1qsr.ent.gz
-????????? ? ? ? ? ? pdb1qss.ent.gz
-????????? ? ? ? ? ? pdb1qst.ent.gz
-rwxr-xr-x 1 awasylyk awasylyk 21639 Feb 3 2009 pdb1qsu.ent.gz
-????????? ? ? ? ? ? pdb1qsv.ent.gz
-????????? ? ? ? ? ? pdb1qsw.ent.gz
-rwxr-xr-x 1 awasylyk awasylyk 19775 Mar 1 2009 pdb1qsx.ent.gz
-????????? ? ? ? ? ? pdb1qsy.ent.gz
-rwxr-xr-x 1 awasylyk awasylyk 31234 Feb 3 2009 pdb1qsz.ent.gz
-????????? ? ? ? ? ? pdb2qs1.ent.gz
-????????? ? ? ? ? ? pdb2qs2.ent.gz
-????????? ? ? ? ? ? pdb2qs3.ent.gz
-????????? ? ? ? ? ? pdb2qs4.ent.gz
-????????? ? ? ? ? ? pdb2qs6.ent.gz
-????????? ? ? ? ? ? pdb2qs7.ent.gz
-????????? ? ? ? ? ? pdb2qs8.ent.gz
-????????? ? ? ? ? ? pdb2qs9.ent.gz
-rwxr-xr-x 1 awasylyk awasylyk 30923 May 8 2011 pdb2qsa.ent.gz

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: cifs-utils 2:6.4-1ubuntu1
ProcVersionSignature: Ubuntu 4.4.0-98.121-generic 4.4.90
Uname: Linux 4.4.0-98-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.10
Architecture: amd64
Date: Tue Nov 14 13:50:59 2017
InstallationDate: Installed on 2016-08-31 (440 days ago)
InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: cifs-utils
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Tom van Leeuwen (mrzx4l98d4tp89jab6giohdrjqysbyjs4npz2ccq25kvjmf5h8u4cmidcko7s4tfr6ur1teuv4ju1af4klpdqp0vd87ddz5sh53mwfrw5819ohmadctcbsrykdp4exz2w0xzyv54zb4ksnirbzfvybudw577zswcymukpheqeiptvlrx87cyumfa232omr5gcyxpni3rwgnjdqw38fhshrdw19z5s2fyst45o0e5sk2nk-ubuntu)]

I had the same problem, didn't test it for a while but now I don't see the problem any more. It seems that the bugfix from kernel 4.9.61 has made its way Ubuntu, closing this bug.

Linux tlexps13 4.15.0-22-generic #24~16.04.1-Ubuntu SMP Fri May 18 09:46:31 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
cifs kernel module 2.10
mount.cifs version: 6.4

https://github.com/torvalds/linux/commit/f74bc7c6679200a4a83156bb89cbf6c229fe8ec0.patch

[Kamil Markowicz (kamil-markowicz)]

Where can we find the evidence of this patch being backported into the current LTS kernel?

I thank you for, and trust your report, but would also rather make sure before updating kernels on my machines.