Description of problem:
The resource-agent  "lvmlockd"  returns success in setup_lvm_config(), even if use_lvmlockd was not changed to 1.

If "global/use_lvmlockd" is commented out or does not exist, then function setup_lvm_config() will still returns a success return code which implies that /etc/lvm/lvm.conf is properly configured. That function returns success no matter what occurs.

The main issue is that if the option "use_lvmlockd" is comment out or does not exist then when we use lvmconfig to check the current value then "cut" the output it will return an empty string and we never run sed commands to change the value from 0 to 1.

We need to do 2 things for when the "use_lvmlockd" is comment out:
  • Add another if check if there exists a line that is comment out: "# use_lvmlockd =" . Does not matter value as it is commented out, so would be default which is disabled. 
  • If so, need similar sed command that will change a commented out line to not use comments and enable use_lvmlockd. 

In addition:
  • If use_lvmlockd does not exist, then return error and log message saying that user needs to manually enable "use_lvmlockd".
  • Add a check that "use_lvmlockd" is enabled before function returns. If not enable, return success if enabled, otherwise return a failure. For example, log an error if "use_lvmlockd" does not equal 1 and not commented out after it was suppose to be enabled but was not. The details of error should inform the user to manually enable "use_lvmlockd". 
  

   
With that said, the above approach does not fix the case where the option does not exist and also assumes that if "sed" does find "use_lvmlockd" that "use_lvmlockd" is in the global section of /etc/lvm/lvm.conf. Ideally, we should request an RFE for "lvmconfig" to create some new options to enable/disable use_lvmlockd. 

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Our current documentation states that user has to manually enable the option "use_lvmlockd" before creating the lvmlockd resource. I believe a better approach if possible is to have that step automated by the resource-agent lvmlockd. 

  - Chapter 7\. GFS2 file systems in a cluster Red Hat Enterprise Linux 8 | 7.1. Configuring a GFS2 file system in a cluster (Step 3)
    https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/configuring_and_managing_high_availability_clusters/assembly_configuring-gfs2-in-a-cluster-configuring-and-managing-high-availability-clusters)

Version-Release number of selected component (if applicable):
# rpm -qa | grep -ie resource-agents -ie lvm2 | sort
lvm2-2.03.14-3.el8.x86_64
lvm2-libs-2.03.14-3.el8.x86_64
lvm2-lockd-2.03.14-3.el8.x86_64
resource-agents-4.9.0-16.el8.x86_64

How reproducible:
Everytime

Steps to Reproduce:
1. Comment out "use_lvmlockd" in the /etc/lvm/lvm.conf
2. Create a lvmlockd resource


Actual results:
The option use_lvmlockd option is still commented out. This means that use_lvmlockd=0 (disabled).

Expected results:
The option use_lvmlockd option should return an error in setup_lvm_config() if the option "use_lvmlockd" in /etc/lvm/lvm.conf was not enabled.

Additional info:

Do note that "locking_type" option is not used (or possibly does not exist) on RHEL 8, so validating it is the correct value is not important, but we still might want to consider someway of validating "locking_type" in upstream like we do with "use_lvmlockd" proposed above for those clusters that do not support lvmlockd as an option. 

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On a related issue, we should see if there is away to automate enabling/disabling "use_lvmlockd" via lvmconfig with an option like: # lvmconfig [--enable,--disable]_lvmlockd.

Currently we are using "sed" to enable "use_lvmlockd" if it is disable. The "sed" approach would not work if the option "use_lvmlockd" does not exist.

I think the best approach would be to open another bug for "lvm2" that will do the following:
  • Add option for lvmconfig to enable "use_lvmlockd":  lvmconfig --enable_lvmlockd.
  • Add option for lvmconfig to disable "use_lvmlockd": lvmconfig --disable_lvmlockd
  * Add ability somehow (unless already exists) for lvmconfig to be able to determine the value of "global/use_lvmlockd" when option is enabled, disable, comment out, or does not exist (the later two is ones I could not find a way to do).