Validate CSI Inline Migration unconditionally

[tedyu]

What type of PR is this?
/kind bug

What this PR does / why we need it:
As @msau42 pointed out in #80931, we should perform validation unconditionally for downgrading to a version with the feature disabled.

Which issue(s) this PR fixes:
Fixes #80931

Special notes for your reviewer:

Fixes validation of VolumeAttachment API objects created with inline volume sources.

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[tedyu]

cc @msau42

[tedyu]

/test pull-kubernetes-integration

[tedyu]

@msau42
Can you see if I missed something ?

[ddebroy]

Looks good with one suggestion.

[tedyu]

@ddebroy
Your comment has been addressed.

[ddebroy]

/lgtm

[ddebroy]

/assign @msau42 @jsafrane

[davidz627]

/assign @liggitt

[liggitt]

one comment about restoring the conditional validation message, then lgtm

this will need to be picked back to 1.15

[tedyu]

@liggitt
Your comment has been addressed.

[liggitt]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: liggitt, tedyu

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• pkg/apis/OWNERS [liggitt]

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[liggitt]

/sig storage
/priority critical-urgent

[davidz627]

thanks @tedyu @liggitt !

[liggitt]

let me know when the 1.15 pick is open and I'll tag that as well

[tedyu]

I ran the following for master branch of my local repo:

GITHUB_USER=tedyu hack/cherry_pick_pull.sh upstream/release-1.5 80945

Falling back to patching base and 3-way merge...
Auto-merging pkg/apis/storage/validation/validation_test.go
CONFLICT (content): Merge conflict in pkg/apis/storage/validation/validation_test.go
Auto-merging pkg/apis/storage/validation/validation.go
CONFLICT (content): Merge conflict in pkg/apis/storage/validation/validation.go
error: Failed to merge in the changes.
Patch failed at 0001 Validate CSI Inline Migration unconditionally
Use 'git am --show-current-patch' to see the failed patch
When you have resolved this problem, run "git am --continue".

I wonder if the command I used was wrong.

[liggitt]

you probably want upstream/release-1.15

[tedyu]

Created #81038