Public bug reported:

When a clustered node is detected as failed the remaining node tries to
fence the resources. When using pacemaker with gfs2 on an lvm2 logical
volume dlm_controld calls out to dlm_stonith to release any locks held.

Due to a build issue with the version of libqb that pacemaker is
compiled against, the call to QB_LOG_INIT_DATA which is #defined to
CRM_TRACE_INIT_DATA, fails with an assertion. This prevents the lock
manager from releasing any held locks on the failed node.

At this point the gfs2 filesystem cannot be accessed and after any
resource timeouts are met, the resource is marked as failed.

Calling dlm_stonith by hand with the data that is passed to it by
dlm_controld shows the assertion.

root@u2004-1:~# /usr/sbin/dlm_stonith -n 2 -t 1612361398
dlm_stonith: utils.c:57: common: Assertion `"implicit callsite section is 
observable, otherwise target's and/or libqb's build is at fault, preventing 
reliable logging" && work_s1 != NULL && work_s2 != NULL' failed.

It would appear that the code in libqb is over aggressive on the sanity
checking, or assumes that QB_LOG_INIT_DATA will only be called by the
library. External programs such as pacemaker that end up calling
CRM_TRACE_INIT_DATA will suffer the same assertion.

This patch from clusterlabs is an attempt to resolve the assertion, but
is still not sufficient.
https://lists.clusterlabs.org/pipermail/users/2018-February/023614.html

Taking out the assertion in <qb/qblog.h> and recompiling pacemaker
appears to be the only way to allow dlm_stonith to work.

journalctl shows dlm_controld keeps trying to get a successful response
from dlm_stonith

Feb 16 13:11:57 u2004-1 dlm_controld[9344]: 4389 fence result 2 pid 26568 
result -1 term signal 6
Feb 16 13:11:57 u2004-1 dlm_controld[9344]: 4389 fence status 2 receive -1 from 
1 walltime 1613481117 local 4389
Feb 16 13:11:57 u2004-1 dlm_controld[9344]: 4389 fence request 2 pid 26607 
nodedown time 1613481102 fence_all dlm_stonith
Feb 16 13:11:58 u2004-1 dlm_controld[9344]: 4391 fence result 2 pid 26607 
result -1 term signal 6
Feb 16 13:11:58 u2004-1 dlm_controld[9344]: 4391 fence status 2 receive -1 from 
1 walltime 1613481118 local 4391
Feb 16 13:11:58 u2004-1 dlm_controld[9344]: 4391 fence request 2 pid 26637 
nodedown time 1613481102 fence_all dlm_stonith
Feb 16 13:12:00 u2004-1 dlm_controld[9344]: 4392 fence result 2 pid 26637 
result -1 term signal 6
Feb 16 13:12:00 u2004-1 dlm_controld[9344]: 4392 fence status 2 receive -1 from 
1 walltime 1613481120 local 4392
Feb 16 13:12:00 u2004-1 dlm_controld[9344]: 4392 fence request 2 pid 26693 
nodedown time 1613481102 fence_all dlm_stonith
....

Calling 'dlm_tool fence_ack 2' by hand immediately releases the dlm
resource locks.

root@u2004-1:~# lsb_release -rd
Description:    Ubuntu 20.04 LTS
Release:        20.04


root@u2004-1:~# apt-cache policy pacemaker
pacemaker:
  Installed: 2.0.3-3ubuntu4.1
  Candidate: 2.0.3-3ubuntu4.1
  Version table:
 *** 2.0.3-3ubuntu4.1 500
        500 http://gb.archive.ubuntu.com/ubuntu focal-updates/main amd64 
Packages
        500 http://gb.archive.ubuntu.com/ubuntu focal-security/main amd64 
Packages
        100 /var/lib/dpkg/status
     2.0.3-3ubuntu3 500
        500 http://gb.archive.ubuntu.com/ubuntu focal/main amd64 Packages

** Affects: pacemaker (Ubuntu)
     Importance: Undecided
         Status: New

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https://bugs.launchpad.net/bugs/1915828

Title:
  pacemaker fails to release clustered filesystem dlm locks on failover

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