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
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?
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.