mount-utils: Add support for btrfs resize

[RomanBednar]

Mount utils support resizing of btrfs volume, however it lacks btrfs
device block size and total size detection needed to determine if
resize is needed.

What type of PR is this?

/kind feature

What this PR does / why we need it:

Adding btrfs support is useful for certain CSI drivers (e.g. Azure)
which now have to implement custom solution for btrfs resize.

With this patch it should be easy for such drivers to use mount-utils
module instead and help unify (and correct) the resize flows.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?

Added support for btrfs resizing

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

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @RomanBednar. Thanks for your PR.

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[andyzhangx]

/ok-to-test

[RomanBednar]

/retest

[jsafrane]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: jsafrane, RomanBednar

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[jberkus]

This feature feels like it should have a release note.

@AuraSinis

[AuraSinis]

Thank you @jberkus
@RomanBednar does this only concern CSPs? Either way a release note would be nice.

Would "Added support for btrfs resizing" be sufficient, or is more detail needed?

[RomanBednar]

@AuraSinis I think so, I've posted this patch so we can properly implement volume resizing in Azure CSI driver. Not sure how, or if other CSPs are concerned. This effort is tracked here and applies to all CSI drivers. So in order for Azure to use mount-utils this patch was required - hope that explains the situation well.

I've also added a short release note as requested.

[andyzhangx]

@AuraSinis I think so, I've posted this patch so we can properly implement volume resizing in Azure CSI driver. Not sure how, or if other CSPs are concerned. This effort is tracked here and applies to all CSI drivers. So in order for Azure to use mount-utils this patch was required - hope that explains the situation well.

I've also added a short release note as requested.

@RomanBednar here is the PR for azure disk csi driver support on btrfs resize: kubernetes-sigs/azuredisk-csi-driver#1225, it just upgrade mount-utils vendor packages.

[RomanBednar]

@RomanBednar here is the PR for azure disk csi driver support on btrfs resize: kubernetes-sigs/azuredisk-csi-driver#1225, it just upgrade mount-utils vendor packages.

@andyzhangx Awesome, thanks for letting me know. I'll wait for it to merge and then proceed with my planned patch.