Subject: Re: [PATCHv3 net-next] sctp: prepare asoc stream for stream reconf

From: Marcelo Ricardo Leitner <[email-masked]>
Date: Fri, 6 Jan 2017 13:56:38 -0200

On Fri, Jan 06, 2017 at 03:50:36PM +0000, David Laight wrote:
> From: Xin Long
> > Sent: 06 January 2017 14:19
> > sctp stream reconf, described in RFC 6525, needs a structure to
> > save per stream information in assoc, like stream state.
> > 
> > In the future, sctp stream scheduler also needs it to save some
> > stream scheduler params and queues.
> > 
> > This patchset is to prepare the stream array in assoc for stream
> > reconf. It defines sctp_stream that includes stream arrays inside
> > to replace ssnmap.
> > 
> > Note that we use different structures for IN and OUT streams, as
> > the members in per OUT stream will get more and more different
> > from per IN stream.
> ...
> >  /* What is the current SSN number for this stream? */
> > -static inline __u16 sctp_ssn_peek(struct sctp_stream *stream, __u16 id)
> > -{
> > -	return stream->ssn[id];
> > -}
> > +#define sctp_ssn_peek(stream, type, sid) \
> > +	((stream)->type[sid].ssn)
> > 
> >  /* Return the next SSN number for this stream.	*/
> > -static inline __u16 sctp_ssn_next(struct sctp_stream *stream, __u16 id)
> > -{
> > -	return stream->ssn[id]++;
> > -}
> > +#define sctp_ssn_next(stream, type, sid) \
> > +	((stream)->type[sid].ssn++)
> > 
> >  /* Skip over this ssn and all below. */
> > -static inline void sctp_ssn_skip(struct sctp_stream *stream, __u16 id,
> > -				 __u16 ssn)
> > -{
> > -	stream->ssn[id] = ssn+1;
> > -}
> > -
> > +#define sctp_ssn_skip(stream, type, sid, ssn) \
> > +	((stream)->type[sid].ssn = ssn + 1)
> ...
> 
> Is there any reason to convert these from inline functions to #defines?
> Inline functions give better type checking and are usually preferred.

Yes, it's to avoid specializing these and also avoid a condition in
them. Now inbound and outbound streams are handled by different structs.
Please see the new struct sctp_stream definition.

  Marcelo