Do not fall back to using filenames for PVC disk backup (#724)

When recording PVC disk data for the backup, we added code that first
checks disks by their filenames first before falling back to using
UUIDs.  This was done to support partial (disk only restore).

Since partial restore no longer relies on the PVC disk data, we no
longer need to do this.  The current code also has a side effect of
not handling disks restored with a new PVC name.

This effectively reverts the commit: c3a0c36.

pkg/providers/vsphere/virtualmachine/backup.go

@@ -7,7 +7,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"maps"
-	"path"
 	"strconv"
 	"strings"
 
@@ -419,36 +418,10 @@ func getDesiredDiskDataForBackup(
 		classicDiskData []vmopbackup.ClassicDiskData
 	)
 
-	// Vendor's partial restore (e.g. single disk) method may create a new,
-	// non-FCD disk. The restored disk has new UUID and lives the the VM's
-	// directory, not the fcd/ directory. Given that FCD disk names are unique,
-	// we consult the backup data to compare using `FileName` before `Uuid`.
-	pvcDiskDataPrevious := make(map[string]vmopbackup.PVCDiskData)
-	curBackup, ok := extraConfig.GetString(vmopv1.PVCDiskDataExtraConfigKey)
-	if ok {
-		decoded, err := pkgutil.TryToDecodeBase64Gzip([]byte(curBackup))
-		if err != nil {
-			return "", "", err
-		}
-
-		var data []vmopbackup.PVCDiskData
-		dec := json.NewDecoder(strings.NewReader(decoded))
-		if err = dec.Decode(&data); err != nil {
-			return "", "", err
-		}
-
-		for _, pvc := range data {
-			pvcDiskDataPrevious[path.Base(pvc.FileName)] = pvc
-		}
-	}
-
 	for _, device := range deviceList.SelectByType((*vimtypes.VirtualDisk)(nil)) {
 		if disk, ok := device.(*vimtypes.VirtualDisk); ok {
 			if b, ok := disk.Backing.(*vimtypes.VirtualDiskFlatVer2BackingInfo); ok {
-				if disk, ok := pvcDiskDataPrevious[path.Base(b.FileName)]; ok {
-					disk.FileName = b.FileName
-					pvcDiskData = append(pvcDiskData, disk)
-				} else if pvc, ok := opts.DiskUUIDToPVC[b.Uuid]; ok {
+				if pvc, ok := opts.DiskUUIDToPVC[b.Uuid]; ok {
 					pvcDiskData = append(pvcDiskData, vmopbackup.PVCDiskData{
 						FileName:    b.FileName,
 						PVCName:     pvc.Name,
@@ -473,6 +446,7 @@ func getDesiredDiskDataForBackup(
 	}
 
 	// Return an empty string to skip backup if PVC disk data is unchanged.
+	curBackup, _ := extraConfig.GetString(vmopv1.PVCDiskDataExtraConfigKey)
 	if pvcDiskDataBackup == curBackup {
 		pvcDiskDataBackup = ""
 	}

pkg/providers/vsphere/virtualmachine/backup_test.go

@@ -12,11 +12,9 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client"
 	"sigs.k8s.io/yaml"
 
-	"github.com/google/uuid"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 	"github.com/vmware/govmomi/object"
-	"github.com/vmware/govmomi/simulator"
 	"github.com/vmware/govmomi/vim25/mo"
 	vimtypes "github.com/vmware/govmomi/vim25/types"
 
@@ -689,22 +687,6 @@ func backupTests() {
 							verifyBackupDataInExtraConfig(ctx, vcVM, vmopv1.BackupVersionExtraConfigKey, vT2, false)
 							Expect(vmCtx.VM.Annotations[vmopv1.VirtualMachineBackupVersionAnnotation]).To(Equal(vT2))
 						}
-
-						By("detect disk file backing change", func() {
-							vm := simulator.Map.Get(vcVM.Reference()).(*simulator.VirtualMachine)
-							deviceList := object.VirtualDeviceList(vm.Config.Hardware.Device)
-
-							for _, device := range deviceList.SelectByType((*vimtypes.VirtualDisk)(nil)) {
-								disk := device.(*vimtypes.VirtualDisk)
-								if b, ok := disk.Backing.(*vimtypes.VirtualDiskFlatVer2BackingInfo); ok {
-									b.Uuid = uuid.NewString()
-									break
-								}
-							}
-
-							Expect(virtualmachine.BackupVirtualMachine(backupOpts)).To(Succeed())
-							verifyBackupDataInExtraConfig(ctx, vcVM, vmopv1.PVCDiskDataExtraConfigKey, string(diskDataJSON), true)
-						})
 					})
 				})
 			})