17         vfs::{file::File, mount::MountFS, FileSystem, FileType},
24 use super::{file::FileMode, utils::rsplit_path, IndexNode, InodeId};
232     let mut file: File = File::new(inode, mode)?;  in do_open()  localVariable
236         file.lseek(SeekFrom::SeekEnd(0))?;  in do_open()
240     return current_pcb().alloc_fd(file);  in do_open()
251     let file: Option<&mut File> = current_pcb().get_file_mut_by_fd(fd);  in do_read()  localVariable
252     if file.is_none() {  in do_read()
255     let file: &mut File = file.unwrap();  in do_read()  localVariable
257     return file.read(buf.len(), buf);  in do_read()
268     let file: Option<&mut File> = current_pcb().get_file_mut_by_fd(fd);  in do_write()  localVariable
269     if file.is_none() {  in do_write()
272     let file: &mut File = file.unwrap();  in do_write()  localVariable
274     return file.write(buf.len(), buf);  in do_write()
285     let file: Option<&mut File> = current_pcb().get_file_mut_by_fd(fd);  in do_lseek()  localVariable
286     if file.is_none() {  in do_lseek()
289     let file: &mut File = file.unwrap();  in do_lseek()  localVariable
290     return file.lseek(seek);  in do_lseek()