empty             250 kernel/fs.c      struct inode *ip, *empty;
empty             255 kernel/fs.c      empty = 0;
empty             262 kernel/fs.c        if(empty == 0 && ip->ref == 0)    // Remember empty slot.
empty             263 kernel/fs.c          empty = ip;
empty             267 kernel/fs.c      if(empty == 0)
empty             270 kernel/fs.c      ip = empty;