Partition modify sometimes reverts to original size

[Al Bailey]

Brief Description
-----------------
Sometimes after a partition is created and immediately resized, the new size is not applied

Severity
--------
Minor

Steps to Reproduce
------------------
Create a partition of size 1G
Resize it to be the remainder of the disk
Monitor the resize operation

Expected Behavior
------------------
It should resize

Actual Behavior
----------------
It switches to attempt to resize to the original size

Reproducibility
---------------
Seen using automation tools approximately 1 out of 10 test runs.

System Configuration
--------------------
Duplex

Branch/Pull Time/Commit
-----------------------
Oct 3 2022

Last Pass
---------
Unknown

Timestamp/Logs
--------------
There are no errors
automation logs show an attempt to increase, and the show reverts to the original size

[2022-09-30 17:03:26] host-disk-partition-modify -s 356 compute-1 ed51d027-3b4d-4cfb-a1a3-d0820582ca2d

+-------------+-----------------------------------------------------------------------+
| Property | Value |
+-------------+-----------------------------------------------------------------------+
| device_path | /dev/disk/by-path/pci-0000:08:00.0-sas-0x5001e6757035d000-lun-0-part5 |
| device_node | /dev/sda5 |
| type_guid | ba5eba11-0000-1111-2222-000000000001 |
| type_name | LVM Physical Volume |
| start_mib | 91158 |
| end_mib | 92182 |
| size_mib | 364544 |
| uuid | ed51d027-3b4d-4cfb-a1a3-d0820582ca2d |
| ihost_uuid | 7679e1cd-3884-4105-917b-97a427d1377b |
| idisk_uuid | 74b37ef6-07fa-490e-925a-1d7e4e06dd96 |
| ipv_uuid | None |
| status | Modifying |
| created_at | 2022-09-30T17:03:01.766548+00:00 |
| updated_at | 2022-09-30T17:03:18.811216+00:00 |
+-------------+-----------------------------------------------------------------------+

[2022-09-30 17:03:27] system host-disk-partition-show compute-1 ed51d027-3b4d-4cfb-a1a3-d0820582ca2
+-------------+-----------------------------------------------------------------------+
| Property | Value |
+-------------+-----------------------------------------------------------------------+
| device_path | /dev/disk/by-path/pci-0000:08:00.0-sas-0x5001e6757035d000-lun-0-part5 |
| device_node | /dev/sda5 |
| type_guid | ba5eba11-0000-1111-2222-000000000001 |
| type_name | LVM Physical Volume |
| start_mib | 91158 |
| end_mib | 92182 |
| size_mib | 1024 |
| uuid | ed51d027-3b4d-4cfb-a1a3-d0820582ca2d |
| ihost_uuid | 7679e1cd-3884-4105-917b-97a427d1377b |
| idisk_uuid | 74b37ef6-07fa-490e-925a-1d7e4e06dd96 |
| ipv_uuid | None |
| status | Modifying |
| created_at | 2022-09-30T17:03:01.766548+00:00 |
| updated_at | 2022-09-30T17:03:26.891912+00:00 |
+-------------+-----------------------------------------------------------------------+
Test Activity
-------------
Automated Testing

Workaround
----------
resize the partition again

[Al Bailey (albailey1974)]

The logs show a sequence of INFO logs: "PART update" at the time of these reverts.
There should only ever be one of those for a partition change, and those logs should only occur when upgrading from centos to debian

By instrumenting the code, it turns out that one structure has integers and another has strings. so visually the values are the same, but the equality check was failing and it was causing a previous DB query of data from the agent for the size to be written back to the DB,

https://review.opendev.org/c/starlingx/config/+/867567

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/config/+/867567
Committed: https://opendev.org/starlingx/config/commit/8b23b33d2ca127fcd43fef019ccdbcc500ff0d08
Submitter: "Zuul (22348)"
Branch: master

commit 8b23b33d2ca127fcd43fef019ccdbcc500ff0d08
Author: Al Bailey <email address hidden>
Date: Tue Dec 13 20:01:23 2022 +0000

    Reduce the number of partition DB updates

    When the partition code receives a partition structure
    from sysinv-agent, the fields are strings.
    The database fields are integers, so the comparison
    always considers the values to be mis-matched and attempts
    to update the database.

    This can cause stale 'size' values from the agent query
    to overwrite the DB during a partition resize operation.

    Test Plan:
      PASS: create and update several partitions
      PASS: verify that the 'PART update' log is not created
    once for every partition when doing a partition update.

    Closes-Bug: #1999586
    Signed-off-by: Al Bailey <email address hidden>
    Change-Id: I3113e60a09951aa0efc5a6e549b1614976f75f35