Bug 796436

Summary:	nfs4 regression - cannot cd into sub-filesystems
Product:	Red Hat Enterprise Linux 5	Reporter:	David Brodbeck <brodbd>
Component:	kernel	Assignee:	nfs-maint
Status:	CLOSED DUPLICATE	QA Contact:	Red Hat Kernel QE team <kernel-qe>
Severity:	high	Docs Contact:
Priority:	unspecified
Version:	5.8	CC:	blocke, dwysocha, ikent, jlayton, nfs-maint, rwheeler
Target Milestone:	rc
Target Release:	---
Hardware:	x86_64
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2012-03-01 16:32:07 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description David Brodbeck 2012-02-22 21:34:51 UTC

Description of problem:
We have an OpenSolaris server that exports some top-level ZFS filesystems that our Linux workstations mount via nfs4.  We rely on nfs4 to auto-mount filesystems below these mountpoints as needed.  Up through kernel-2.6.18-274 this worked fine; however, with 2.6.18-308 I now get a "Not a directory" error.

Version-Release number of selected component (if applicable):
2.6.18-308

How reproducible:
It happens every time in our environment, against both of our OpenSolaris servers.  I have not tried it against other NFS servers.

Steps to Reproduce:
1. mount an NFS4 filesystem that has other filesystems exported below it.
2. Try to cd into one of the sub filesystems or otherwise access it
  
Actual results:
$ uname -a
Linux colobus 2.6.18-308.el5 #1 SMP Fri Jan 27 17:17:51 EST 2012 x86_64 x86_64 x86_64 GNU/Linux
$ mount | grep 'corpora'
192.168.100.100:/tank/corpora on /corpora type nfs4 (rw,noatime,bg,addr=192.168.100.100)
$ ls -ld /corpora/LDC
drwxrwsr-x 134 root corpora-w 136 Feb 10 16:27 /corpora/LDC
$ cd /corpora/LDC
-bash: cd: /corpora/LDC: Not a directory


Expected results:
$ uname -a
Linux colobus 2.6.18-274.12.1.el5 #1 SMP Tue Nov 8 21:37:35 EST 2011 x86_64 x86_64 x86_64 GNU/Linux
$ mount | grep 'corpora'
192.168.100.100:/tank/corpora on /corpora type nfs4 (rw,noatime,bg,addr=192.168.100.100)
$ ls -ld /corpora/LDC
drwxrwsr-x 134 root corpora-w 136 Feb 10 16:27 /corpora/LDC
$ cd /corpora/LDC
$ pwd
/corpora/LDC


Additional info:

Comment 1 Bruce A. Locke 2012-02-29 23:05:52 UTC

This occurs with a pure RHELv5 environment also.

# cd /mnt/test-fs/test-cfs
-bash: cd: /mnt/test-fs/test-cfs: Not a directory
# file /mnt/test-fs/test-cfs
/mnt/test-fs/test-cfs: directory

Behavior occurs if NFSv4 client is running the 2.6.18-308.el5 kernel.  It does not occur with 
If the client is running 2.6.18-274.17.1.el5.

Red Hat case #00608611