Change Details

``` First, we need to ensure that in and out lower vnodes are compatible for the call to VOP_COPY_FILE_RANGE() on lower fs, otherwise fall back to vn_generic_copy_file_range(). Second, lower vnodes need to be referenced around the calls. Noted by: mjg ```

``` First, we need to ensure that in and out lower vnodes are compatible for the call to VOP_COPY_FILE_RANGE() on lower fs, otherwise fall back to vn_generic_copy_file_range(). Second, lower vnodes need to be referenced around the calls. Noted by: mjg Tested by: pho ```

``` First, we need to ensure that in and out lower vnodes are compatible for the call to VOP_COPY_FILE_RANGE() on lower fs, otherwise fall back to vn_generic_copy_file_range(). Second, lower vnodes need to be referenced around the calls. Noted by: mjg Tested by: pho ```