Possible to reformat a disk that has a Linux fs on it

[msau42]

What happened:
The implementation of IsVolumeFormatted only checks for ntfs filesystem, and it returns false if it doesn't find ntfs. That means it returns unformatted if there's a linux filesystem on it, and then subsequently calling FormatVolume can override the filesystem.

More discussion in https://app.slack.com/client/T09NY5SBT/CN5JCCW31/thread/C8EJ01Z46-1603793388.212200

What you expected to happen:
Format should error if a filesystem is already on the disk.

[fejta-bot]

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/lifecycle stale

[fejta-bot]

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/lifecycle rotten

[ddebroy]

/remove-lifecycle rotten

[jingxu97]

Some discussion from CSI windows meeting. We could consider to add another check, MBR in sector 0 through golang disk reads. Expectation is a fresh provisioned disk has all zeroes. Otherwise, consider disk is already formatted.

The concern is that it might result in false positive. Some disk might returns random data even though it is not formatted. With this logic, volume will not be formatted anymore.

cc @marosset

[jingxu97]

this issue is fixed by #127

[jingxu97]

/close

[k8s-ci-robot]

@jingxu97: Closing this issue.

In response to this:

/close

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