269     pub fn create_for_size_and_path(size: u64, backing_file: Option<&str>) -> Result<QcowHeader> {  in create_for_size_and_path()
274         if let Some(path) = backing_file {  in create_for_size_and_path()
288             backing_file_offset: (if backing_file.is_none() {  in create_for_size_and_path()
293             backing_file_size: backing_file.map_or(0, |x| x.len()) as u32,  in create_for_size_and_path()
323             backing_file_path: backing_file.map(String::from),  in create_for_size_and_path()
417     backing_file: Option<Box<dyn DiskFile>>,  field
446         let backing_file = if let Some(backing_file_path) = header.backing_file_path.as_ref() {  in from()  localVariable
452             let backing_file = create_disk_file(backing_raw_file)  in from()  localVariable
454             Some(backing_file)  in from()
559             backing_file,  in from()
589         let backing_file =  in new_from_backing()  localVariable
591         let size = backing_file.get_len().map_err(Error::BackingFileIo)?;  in new_from_backing()
594         result.backing_file = Some(backing_file);  in new_from_backing()
623         self.backing_file = backing;  in set_backing_file()
1088                 let initial_data = if let Some(backing) = self.backing_file.as_mut() {  in file_offset_write()
1335             if self.backing_file.is_none() && count == self.raw_file.cluster_size() as usize {  in zero_bytes()
1340                 let offset = if self.backing_file.is_some() {  in zero_bytes()
1491             } else if let Some(backing) = self.backing_file.as_mut() {  in read_cb()
1538         if let Some(backing) = &self.backing_file {  in as_raw_descriptors()