System is reporting wrong free space for multipath disks with nova-local partitions

[Felipe Sanches Zanoni]

Brief Description
-----------------
The command system host-disk-list is not reporting correctly the free space when creating a new partition and adding it to nova-local logical volume group.

This only happens on with multipath enabled.

Severity
--------
Minor

Steps to Reproduce
------------------
 - Fresh install AIO-SX with multipath enabled;
 - With controller locked, create a new partition on any disk with any size that does not use the entire disk;
 - Add this partition to nova-local lvm;
 - Unlock controller;
 - Check if the disk shows free space when running system host-disk-list controller-0 command.

Expected Behavior
------------------
The free space column will show the correct information about free space on the disk with nova-local partition.

Actual Behavior
----------------
The free space column is showing 0 (zero) despite there is free space on the disk with nova-local partition.

Reproducibility
---------------
100%

System Configuration
--------------------
System using multipath disks

Branch/Pull Time/Commit
-----------------------
STX 7.0 with multipath enabled

Last Pass
---------
N/A

Timestamp/Logs
--------------
N/A

Test Activity
-------------
Developer Testing

Workaround
----------
No workaround

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/starlingx/config/+/874087

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.opendev.org/c/starlingx/config/+/874087
Committed: https://opendev.org/starlingx/config/commit/b0eb83f6acab94335648b48e496278eb85fbaac7
Submitter: "Zuul (22348)"
Branch: master

commit b0eb83f6acab94335648b48e496278eb85fbaac7
Author: Felipe Sanches Zanoni <email address hidden>
Date: Tue Feb 14 11:39:14 2023 -0500

    Adjust function to report correctly free space for multipath disks

    The command host-disk-list was reporting free space wrongly for
    multipath disks that have partitions added to nova-local
    logical volume.

    This happens when the device node path has a dash in it like in
    '/dev/mapper/mpathc-part1'. A 'grep -w' command was used to verify
    if the device node is a physical volume. The command 'grep -w'
    searchs for whole word, but the dash is considered a word separator,
    causing the device node '/dev/mapper/mpathc' to be matched with
    '/dev/mapper/mpathc-part1', once 'grep -w' detects the word
    '/dev/mapper/mpathc'.

    To fix this, the command is changed to detect the device node as
    a string with an extra space at the end, for instance,
    '/dev/mapper/mpathc '.

    As an example consider device_node='/dev/mapper/mpathc' and
    the output of 'pvs' command below:
      PV VG Fmt Attr PSize PFree
      /dev/mapper/mpatha-part5 cgts-vg lvm2 a-- <488.41g 251.59g
      /dev/mapper/mpathb cgts-vg lvm2 a-- <20.00g <20.00g
      /dev/mapper/mpathc-part1 cgts-vg lvm2 a-- <15.00g <15.00g

    The 'pvs | grep -w /dev/mapper/mpathc' will match the string
    '/dev/mapper/mpathc-part1', but it should not.

    The 'pvs | grep "/dev/mapper/mpathc "' will not match any
    string in that output.

    Test Plan:
        PASS: Install AIO-SX with multipath disks, add a new partition
              to a spare multipath disk using half of its capacity.
              Add this partition to nova-local logical volume group and
              run 'system host-disk-list controller-0'. The available_gib
              column should report the expected free space correctly.
        PASS: Install AIO-SX without multipath disks, add a new partition
              to a spare disk using half of its capacity.
              Add this partition to nova-local logical volume group and
              run 'system host-disk-list controller-0'. The available_gib
              column should report the expected free space correctly.

    Closes-bug: 2007309
    Signed-off-by: Felipe Sanches Zanoni <email address hidden>
    Change-Id: If7636f39c0ff3d0858623d7ada8a391fd783ca32