Fix Volume Size Rounding Issue in PowerFlex

[KshitijaKakde]

Description

When creating a volume in PowerFlex, it appears to round down instead of up for sizes that are multiples of 8GB, fixing this issue.

GitHub Issues

List the GitHub issues impacted by this PR:

GitHub Issue #
dell/csm#1608

Checklist:

• I have performed a self-review of my own code to ensure there are no formatting, vetting, linting, or security issues
• I have verified that new and existing unit tests pass locally with my changes
• I have not allowed coverage numbers to degenerate
• I have maintained at least 90% code coverage
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• Backward compatibility is not broken

How Has This Been Tested?

1. Deployed the driver using csm-operator, created a PVC with a storage size of 51200000Ki, it correctly rounds up to 56 GiB. Previously, it rounded down to 48 GiB.
2. Added and executed UT
3. Executed cert-csi
   pflex-cert-csi.txt

pflex-integration.txt

[adarsh-dell]

Could we add more test cases with higher decimal precision values? Additionally, let's use the same input that helped us identify this issue for consistency.

[KshitijaKakde]

Done

[adarsh-dell]

Please perform end-to-end integration testing to ensure nothing is impacted. Are there any additional scenarios we can consider here, especially related to expanding volume size? I assume a similar check will be reused for those cases as well, correct?

[adarsh-dell]

As these checks are focused on block storage, I am particularly interested in having similar validations for NFS as well, especially with the same input sizes. That how it behaves, I think should work but better to double check on this as well.

[KshitijaKakde]

I have tested NFS with filesystem sizes of 48.8 GiB and 3.001 GiB (3073 MiB). In both cases, the filesystems were successfully created. The only requirement for filesystem creation is that the size must not be less than 3 GiB, which is handled in the code.

[KshitijaKakde]

Please perform end-to-end integration testing to ensure nothing is impacted. Are there any additional scenarios we can consider here, especially related to expanding volume size? I assume a similar check will be reused for those cases as well, correct?

I have executed the integration test. The ControllerExpandVolume call also invokes the validateVolSize function to perform similar checks on the expanding volume size.