Re: [PATCH 04/31] net: add support for ->poll_mask in proto_ops

[Christoph Hellwig <hch@xxxxxx>]

On Sat, Jan 06, 2018 at 07:16:22PM +0000, Al Viro wrote:
> > +	__poll_t	(*poll_mask) (struct file *file, struct socket *sock,
> > +				      __poll_t events);
> 
> Does that sucker need struct file?

It turns out udp needs it:

	/* Check for false positives due to checksum errors */
	if ((mask & POLLRDNORM) && !(file->f_flags & O_NONBLOCK) &&
	    !(sk->sk_shutdown & RCV_SHUTDOWN) && first_packet_length(sk) == -1)
		mask &= ~(POLLIN | POLLRDNORM);