Comment 0 for bug 1915828

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