Description of problem:
fsstress running on nfs using btrfs as the backend fs would be stuck on host hp-dl120g6-01.rhts.eng.bos.redhat.com.
This is not a regression and only happens on host hp-dl120g6-01.rhts.eng.bos.redhat.com(or I only found failure on this host).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
run /kernel/filesystems/btrfs/fsstress on host hp-dl120g6-01.rhts.eng.bos.redhat.com
Pass the test
I tried fsstress on btrfs partition directly(without nfs) and test passed.
Josef can you take a look?
The backtraces aren't very informative, can I get a sysrq+w? And are we sure we're actually hung and not just taking forever to finish? There have been cases where sync writeback was pretty crappy and taking forever, but eventually finished. Thanks,
The fsstress itself was finished eventually and passed, just with these annoying messages showed up. I'll get sysrq+w as soon as I get the host.
Created attachment 446162 [details]
fsstress stuck backtrace and sysrq-w state
I attached the full sysrq-w log when got stuck. Hope this can help.
How are you running fsstress btw? And how exactly is this setup, are you exporting the NFS volume from a different machine or the same machine? Have you tried to reproduce this on NFS with an ext4 backend to see if it's just NFS related? I'm trying the fsstress test from xfs and I'll see how that works, but it would be good to be running the same fsstress command as you.
That's reasonable. I'll try more cases(ext4 backend, ext4 without nfs).
It's a locally exported loop device.
Sorry for the late reply.
I tried different configurations, and the results are:
(NFS exports with rw,fsid=0,insecure,no_subtree_check,sync,no_root_squash)
Use NFS NFS mount option [Backend] FS Stuck
yes -o hard,intr  btrfs Yes
yes ---- btrfs No 
yes -o hard,intr ext4 ?? 
yes ---- ext4 No
no ---- btrfs No
no ---- ext4 No
 The hard option is default on for NFS
 No stuck found, but got "NFS: file server not responding: still trying. " from console
 I'll try this once I get the host again.
(In reply to comment #8)
> I tried different configurations, and the results are:
> (NFS exports with rw,fsid=0,insecure,no_subtree_check,sync,no_root_squash)
> Use NFS NFS mount option [Backend] FS Stuck
> yes -o hard,intr  btrfs Yes
> yes ---- btrfs No 
> yes -o hard,intr ext4 ?? 
Confirmed mount nfs with -o hard,intr and ext4 as backend fs can pass the test.
Run fsstress with -d testdir -p 200 -n 100
This request was evaluated by Red Hat Product Management for
inclusion in the current release of Red Hat Enterprise Linux.
Because the affected component is not scheduled to be updated
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This request was erroneously denied for the current release of Red Hat
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re-proposed for the current release.
This request was erroneously denied for the current release of
Red Hat Enterprise Linux. The error has been fixed and this
request has been re-proposed for the current release.
Should be fixed in the backport of btrfs.
*** This bug has been marked as a duplicate of bug 663749 ***