if ((ret = fd_lock(fd, FD_RDWR)) == OK) {
if ((ret = fd_lock(fd, FD_RDWR, NULL)) == OK) {
off_t lseek(int fd, off_t offset, int whence){	int ret;	 if ((ret = fd_lock(fd, FD_RDWR)) == OK) {     	ret = fd_table[fd]->ops->seek(fd_table[fd]->fd,		  fd_table[fd]->flags, offset, whence);         fd_unlock(fd, FD_RDWR);    }    return(ret);}