7     syscall::SystemError,
160     ) -> Result<(), SystemError> {  in open()  argument
164     fn close(&self, _data: &mut super::vfs::FilePrivateData) -> Result<(), SystemError> {  in close()  argument
174     ) -> Result<usize, SystemError> {  in read_at()  argument
175         return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP);  in read_at()
184     ) -> Result<usize, SystemError> {  in write_at()  argument
185         return Err(SystemError::EOPNOTSUPP_OR_ENOTSUP);  in write_at()
188     fn poll(&self) -> Result<super::vfs::PollStatus, SystemError> {  in poll()  argument
194             return Err(SystemError::EISDIR);  in poll()
200     fn metadata(&self) -> Result<Metadata, SystemError> {  in metadata()  argument
208     fn get_entry_name(&self, ino: super::vfs::InodeId) -> Result<String, SystemError> {  in get_entry_name()  argument
211             return Err(SystemError::ENOTDIR);  in get_entry_name()
232                     0=>{return Err(SystemError::ENOENT);}  in get_entry_name()
240     fn find(&self, name: &str) -> Result<Arc<dyn IndexNode>, SystemError> {  in find()  argument
244             return Err(SystemError::ENOTDIR);  in find()
249                 return Ok(inode.self_ref.upgrade().ok_or(SystemError::ENOENT)?);  in find()
252                 return Ok(inode.parent.upgrade().ok_or(SystemError::ENOENT)?);  in find()
260                 return Ok(inode.children.get(name).ok_or(SystemError::ENOENT)?.clone());  in find()
265     fn ioctl(&self, _cmd: u32, _data: usize) -> Result<usize, SystemError> {  in ioctl()  argument
266         Err(SystemError::EOPNOTSUPP_OR_ENOTSUP)  in ioctl()
269     fn list(&self) -> Result<Vec<String>, SystemError> {  in list()  argument
272             return Err(SystemError::ENOTDIR);  in list()
292     ) -> Result<Arc<dyn IndexNode>, SystemError> {  in do_create_with_data()  argument
294             return Err(SystemError::ENOTDIR);  in do_create_with_data()
299             return Err(SystemError::EEXIST);  in do_create_with_data()
339     pub fn add_dir(&self, name: &str) -> Result<Arc<dyn IndexNode>, SystemError> {  in add_dir()  argument
343             return Err(SystemError::EEXIST);  in add_dir()
359     pub fn add_file(&self, name: &str, file: Arc<dyn IndexNode>) -> Result<(), SystemError> {  in add_file()  argument
363             return Err(SystemError::EEXIST);  in add_file()
382             .ok_or(SystemError::E2BIG)  in link()
386     pub fn remove(&self, name: &str) -> Result<(), SystemError> {  in remove()  argument
392             .ok_or(SystemError::ENOENT)?;  in remove()