Addressing comments around GetMultiWriter checks.

Author: sjswerdlow

pkg/gce-cloud-provider/compute/cloud-disk.go

@@ -224,6 +224,17 @@ func (d *CloudDisk) GetKMSKeyName() string {
 	return ""
 }
 
+func (d *CloudDisk) GetMultiWriter() bool {
+	switch {
+	case d.disk != nil:
+		return false
+	case d.betaDisk != nil:
+		return d.betaDisk.MultiWriter
+	default:
+		return false
+	}
+}
+
 func (d *CloudDisk) GetEnableConfidentialCompute() bool {
 	switch {
 	case d.disk != nil:

pkg/gce-cloud-provider/compute/fake-gce.go

@@ -216,6 +216,10 @@ func (cloud *FakeCloudProvider) ValidateExistingDisk(ctx context.Context, resp *
 			params.DiskType, respType[len(respType)-1])
 	}
 
+	// We are assuming here that a multiWriter disk could be used as non-multiWriter
+	if multiWriter && !resp.GetMultiWriter() {
+		return fmt.Errorf("disk already exists with incompatible capability. Need MultiWriter. Got non-MultiWriter")
+	}
 	klog.V(4).Infof("Compatible disk already exists")
 	return ValidateDiskParameters(resp, params)
 }

pkg/gce-cloud-provider/compute/gce-compute.go

@@ -395,6 +395,11 @@ func (cloud *CloudProvider) ValidateExistingDisk(ctx context.Context, resp *Clou
 			reqBytes, common.GbToBytes(resp.GetSizeGb()), limBytes)
 	}
 
+	// We are assuming here that a multiWriter disk could be used as non-multiWriter
+	if multiWriter && !resp.GetMultiWriter() {
+		return fmt.Errorf("disk already exists with incompatible capability. Need MultiWriter. Got non-MultiWriter")
+	}
+
 	return ValidateDiskParameters(resp, params)
 }