static unsigned int dtlk_poll(struct file *, poll_table *);
static int dtlk_open(struct inode *, struct file *);
static int dtlk_release(struct inode *, struct file *);
static unsigned int dtlk_poll(struct file *, poll_table *);
static int dtlk_open(struct inode *, struct file *);
static int dtlk_release(struct inode *, struct file *);