fix: for ISO base disk remove premature return after creating and empty volume for diff disk so Convert executes.

Ensure diffDisk is converted to the requested format instead of staying sparse.

Signed-off-by: ashwat287 <ashwatpas@gmail.com>

Author: ashwat287

pkg/driverutil/disk.go

@@ -38,23 +38,21 @@ func EnsureDisk(ctx context.Context, instDir, diskSize string, diskImageFormat i
 	if err != nil {
 		return err
 	}
+	destDisk := baseDisk
 	if isBaseDiskISO {
-		// Create an empty data volume (sparse)
+		destDisk = diffDisk
+
+		// Create an empty data volume for the diff disk
 		diffDiskF, err := os.Create(diffDisk)
 		if err != nil {
 			return err
 		}
 
-		err = diskUtil.MakeSparse(ctx, diffDiskF, 0)
-		if err != nil {
-			diffDiskF.Close()
-			return fmt.Errorf("failed to create sparse diff disk %q: %w", diffDisk, err)
-		}
-		return diffDiskF.Close()
+		diffDiskF.Close()
 	}
 	// Check whether to use ASIF format
 
-	if err = diskUtil.Convert(ctx, diskImageFormat, baseDisk, diffDisk, &diskSizeInBytes, false); err != nil {
+	if err = diskUtil.Convert(ctx, diskImageFormat, destDisk, diffDisk, &diskSizeInBytes, false); err != nil {
 		return fmt.Errorf("failed to convert %q to a disk %q: %w", baseDisk, diffDisk, err)
 	}
 	return err

pkg/imgutil/nativeimgutil/nativeimgutil.go

@@ -62,10 +62,10 @@ func convertTo(destType image.Type, source, dest string, size *int64, allowSourc
 	logrus.Infof("Converting %q (%s) to a %s disk %q", source, srcImg.Type(), destType, dest)
 	switch t := srcImg.Type(); t {
 	case raw.Type:
-		if err = srcF.Close(); err != nil {
-			return err
-		}
 		if destType == raw.Type {
+			if err = srcF.Close(); err != nil {
+				return err
+			}
 			return convertRawToRaw(source, dest, size)
 		}
 	case qcow2.Type: