526     pub fn close(fd: usize) -> Result<usize, SystemError> {  in close()
529         let _file = fd_table_guard.drop_fd(fd as i32)?;  in close()
541     pub fn ioctl(fd: usize, cmd: u32, data: usize) -> Result<usize, SystemError> {  in ioctl()
546             .get_file_by_fd(fd as i32)  in ioctl()
562     pub fn read(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {  in read()
566         let file = fd_table_guard.get_file_by_fd(fd);  in read()
584     pub fn write(fd: i32, buf: &[u8]) -> Result<usize, SystemError> {  in write()
589             .get_file_by_fd(fd)  in write()
604     pub fn lseek(fd: i32, offset: i64, seek: u32) -> Result<usize, SystemError> {  in lseek()
616             .get_file_by_fd(fd)  in lseek()
631     pub fn pread(fd: i32, buf: &mut [u8], len: usize, offset: usize) -> Result<usize, SystemError> {  in pread()
635         let file = fd_table_guard.get_file_by_fd(fd);  in pread()
653     pub fn pwrite(fd: i32, buf: &[u8], len: usize, offset: usize) -> Result<usize, SystemError> {  in pwrite()
657         let file = fd_table_guard.get_file_by_fd(fd);  in pwrite()
773     pub fn getdents(fd: i32, buf: &mut [u8]) -> Result<usize, SystemError> {  in getdents()
777         if fd < 0 || fd as usize > FileDescriptorVec::PROCESS_MAX_FD {  in getdents()
785             .get_file_by_fd(fd)  in getdents()
1157     pub fn fcntl(fd: i32, cmd: FcntlCommand, arg: i32) -> Result<usize, SystemError> {  in fcntl()
1170                             return Self::do_dup2(fd, i as i32, &mut fd_table_guard);  in fcntl()
1173                                 fd,  in fcntl()
1188                 if let Some(file) = fd_table_guard.get_file_by_fd(fd) {  in fcntl()
1205                 if let Some(file) = fd_table_guard.get_file_by_fd(fd) {  in fcntl()
1224                 if let Some(file) = fd_table_guard.get_file_by_fd(fd) {  in fcntl()
1237                 if let Some(file) = fd_table_guard.get_file_by_fd(fd) {  in fcntl()
1274     pub fn ftruncate(fd: i32, len: usize) -> Result<usize, SystemError> {  in ftruncate()
1278         if let Some(file) = fd_table_guard.get_file_by_fd(fd) {  in ftruncate()
1288     fn do_fstat(fd: i32) -> Result<PosixKstat, SystemError> {  in do_fstat()
1292             .get_file_by_fd(fd)  in do_fstat()
1333     pub fn fstat(fd: i32, usr_kstat: *mut PosixKstat) -> Result<usize, SystemError> {  in fstat()
1335         let kstat = Self::do_fstat(fd)?;  in fstat()
1342         let fd = Self::open(  in stat()  localVariable
1348         let r = Self::fstat(fd as i32, user_kstat);  in stat()
1349         Self::close(fd).ok();  in stat()
1354         let fd = Self::open(  in lstat()  localVariable
1360         let r = Self::fstat(fd as i32, user_kstat);  in lstat()
1361         Self::close(fd).ok();  in lstat()
1367         let fd = Self::open(  in statfs()  localVariable
1378         let (_inode_begin, remain_path) = user_path_at(&pcb, fd as i32, &path)?;  in statfs()
1385     pub fn fstatfs(fd: i32, user_statfs: *mut PosixStatfs) -> Result<usize, SystemError> {  in fstatfs()
1390             .get_file_by_fd(fd)  in fstatfs()
1399         fd: i32,  in do_statx()
1502         Self::close(fd as usize).ok();  in do_statx()
1534     pub fn writev(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> {  in writev()
1540         Self::write(fd, &data)  in writev()
1543     pub fn readv(fd: i32, iov: usize, count: usize) -> Result<usize, SystemError> {  in readv()
1549         let len = Self::read(fd, &mut data)?;  in readv()
1631     pub fn fchmod(fd: i32, mode: u32) -> Result<usize, SystemError> {  in fchmod()
1636             .get_file_by_fd(fd)  in fchmod()
1686     pub fn fchown(fd: i32, uid: usize, gid: usize) -> Result<usize, SystemError> {  in fchown()
1687         return ksys_fchown(fd, uid, gid);  in fchown()