[bionic] fence_scsi not working properly with Pacemaker 1.1.18-2ubuntu1.1

OBS: This bug was originally into LP: #1865523 but it was split.

#### SRU: pacemaker

[Impact]

 * fence_scsi is not currently working in a share disk environment

 * all clusters relying in fence_scsi and/or fence_scsi + watchdog won't be able to start the fencing agents OR, in worst case scenarios, the fence_scsi agent might start but won't make scsi reservations in the shared scsi disk.

 * this bug is taking care of pacemaker 1.1.18 issues with fence_scsi, since the later was fixed at LP: #1865523.

[Test Case]

 * having a 3-node setup, nodes called "clubionic01, clubionic02, clubionic03", with a shared scsi disk (fully supporting persistent reservations) /dev/sda, with corosync and pacemaker operational and running, one might try:

rafaeldtinoco@clubionic01:~$ crm configure
crm(live)configure# property stonith-enabled=on
crm(live)configure# property stonith-action=off
crm(live)configure# property no-quorum-policy=stop
crm(live)configure# property have-watchdog=true
crm(live)configure# commit
crm(live)configure# end
crm(live)# end

rafaeldtinoco@clubionic01:~$ crm configure primitive fence_clubionic \
    stonith:fence_scsi params \
    pcmk_host_list="clubionic01 clubionic02 clubionic03" \
    devices="/dev/sda" \
    meta provides=unfencing

And see the following errors:

Failed Actions:
* fence_clubionic_start_0 on clubionic02 'unknown error' (1): call=6, status=Error, exitreason='',
    last-rc-change='Wed Mar 4 19:53:12 2020', queued=0ms, exec=1105ms
* fence_clubionic_start_0 on clubionic03 'unknown error' (1): call=6, status=Error, exitreason='',
    last-rc-change='Wed Mar 4 19:53:13 2020', queued=0ms, exec=1109ms
* fence_clubionic_start_0 on clubionic01 'unknown error' (1): call=6, status=Error, exitreason='',
    last-rc-change='Wed Mar 4 19:53:11 2020', queued=0ms, exec=1108ms

and corosync.log will show:

warning: unpack_rsc_op_failure: Processing failed op start for fence_clubionic on clubionic01: unknown error (1)

[Regression Potential]

 * LP: #1865523 shows fence_scsi fully operational after SRU for that bug is done.

 * LP: #1865523 used pacemaker 1.1.19 (vanilla) in order to fix fence_scsi.

 * There are changes to: cluster resource manager daemon, local resource manager daemon and police engine. From all the changes, the police engine fix is the biggest, but still not big for a SRU. This could cause police engine, thus cluster decisions, to mal function.

 * All patches are based in upstream fixes made right after Pacemaker-1.1.18, used by Ubuntu Bionic and were tested with fence_scsi to make sure it fixed the issues.

[Other Info]

 * Original Description:

Trying to setup a cluster with an iscsi shared disk, using fence_scsi as the fencing mechanism, I realized that fence_scsi is not working in Ubuntu Bionic. I first thought it was related to Azure environment (LP: #1864419), where I was trying this environment, but then, trying locally, I figured out that somehow pacemaker 1.1.18 is not fencing the shared scsi disk properly.

Note: I was able to "backport" vanilla 1.1.19 from upstream and fence_scsi worked. I have then tried 1.1.18 without all quilt patches and it didnt work as well. I think that bisecting 1.1.18 <-> 1.1.19 might tell us which commit has fixed the behaviour needed by the fence_scsi agent.

(k)rafaeldtinoco@clubionic01:~$ crm conf show
node 1: clubionic01.private
node 2: clubionic02.private
node 3: clubionic03.private
primitive fence_clubionic stonith:fence_scsi \
        params pcmk_host_list="10.250.3.10 10.250.3.11 10.250.3.12" devices="/dev/sda" \
        meta provides=unfencing
property cib-bootstrap-options: \
        have-watchdog=false \
        dc-version=1.1.18-2b07d5c5a9 \
        cluster-infrastructure=corosync \
        cluster-name=clubionic \
        stonith-enabled=on \
        stonith-action=off \
        no-quorum-policy=stop \
        symmetric-cluster=true

----

(k)rafaeldtinoco@clubionic02:~$ sudo crm_mon -1
Stack: corosync
Current DC: clubionic01.private (version 1.1.18-2b07d5c5a9) - partition with quorum
Last updated: Mon Mar 2 15:55:30 2020
Last change: Mon Mar 2 15:45:33 2020 by root via cibadmin on clubionic01.private

3 nodes configured
1 resource configured

Online: [ clubionic01.private clubionic02.private clubionic03.private ]

Active resources:

 fence_clubionic (stonith:fence_scsi): Started clubionic01.private

----

(k)rafaeldtinoco@clubionic02:~$ sudo sg_persist --in --read-keys --device=/dev/sda
  LIO-ORG cluster.bionic. 4.0
  Peripheral device type: disk
  PR generation=0x0, there are NO registered reservation keys

(k)rafaeldtinoco@clubionic02:~$ sudo sg_persist -r /dev/sda
  LIO-ORG cluster.bionic. 4.0
  Peripheral device type: disk
  PR generation=0x0, there is NO reservation held