Bug 1309186 - file creates fail with " failed to open '<filename>': Too many levels of symbolic links for file create/write when restarting NFS using vol start force
Summary: file creates fail with " failed to open '<filename>': Too many levels of symb...
Keywords:
Status: CLOSED CURRENTRELEASE
Alias: None
Product: Red Hat Gluster Storage
Classification: Red Hat Storage
Component: gluster-nfs
Version: rhgs-3.1
Hardware: Unspecified
OS: Unspecified
high
high
Target Milestone: ---
: ---
Assignee: Niels de Vos
QA Contact: storage-qa-internal@redhat.com
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2016-02-17 06:12 UTC by Nag Pavan Chilakam
Modified: 2017-02-14 07:15 UTC (History)
6 users (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2017-02-14 07:15:23 UTC
Embargoed:


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System ID Private Priority Status Summary Last Updated
Red Hat Bugzilla 1328451 0 unspecified CLOSED observing " Too many levels of symbolic links" after adding bricks and then issuing a replace brick 2021-02-22 00:41:40 UTC

Internal Links: 1328451

Description Nag Pavan Chilakam 2016-02-17 06:12:54 UTC
Description of problem:
========================
When a volume is mounted on NFS and , I started to perform IOs using dd command in loop and found that if i restarted NFS process during the IOs, I get the following error for a file which is being created/written at that point of time


>>dd: failed to open ‘smf.17’: Too many levels of symbolic links


Following is the dmesg log of the client:
===================================
 [2405704.573740] SELinux: initialized (dev 0:42, type nfs), uses genfs_contexts
<nag> [2480898.670390] VFS: Lookup of 'smf.107' in nfs 0:42 would have caused loop
<nag> [2481059.716509] VFS: Lookup of 'smf.227' in nfs 0:42 would have caused loop
<nag> [2481537.243509] VFS: Lookup of 'smf.17' in nfs 0:42 would have caused loop





Version-Release number of selected component (if applicable):
=================
3.7.5-19


How reproducible:
===================
reporduced it twice on two different clients

Steps to Reproduce:
1. create a volume and start it
2.mount it on nfs client
3. start IOs using dd command in loop to create files as below:
for i in {1..100000};do dd if=/dev/urandom of=smf.$i bs=1024 count=10000;done 
4. Now force start the volume(to cause a restart of nfs process) while the IOs are happening. We can see the following error for the file which is being created at that point of time.


>>dd: failed to open ‘smf.17’: Too many levels of symbolic links


Also the file create fails 
Following is the dmesg log of the client:
===================================
 [2405704.573740] SELinux: initialized (dev 0:42, type nfs), uses genfs_contexts
<nag> [2480898.670390] VFS: Lookup of 'smf.107' in nfs 0:42 would have caused loop
<nag> [2481059.716509] VFS: Lookup of 'smf.227' in nfs 0:42 would have caused loop
<nag> [2481537.243509] VFS: Lookup of 'smf.17' in nfs 0:42 would have caused loop

Comment 2 Niels de Vos 2016-02-17 11:04:35 UTC
Is this a new test? Did it work without problems on previous releases?
Do you have a distaf testcase that I can use to reproduce this behaviour?

Comment 3 Nag Pavan Chilakam 2016-03-01 13:19:59 UTC
I saw this problem when testing tiering, and then re-tried it on a regular volume  where I hit the problem here too, to see if tiering issue or not.


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