cvs commit: src/sys/sys conf.h src/sys/fs/specfs spec_vnops.c

[M. Warner Losh]

In message: <46551.1066250432 at critter.freebsd.dk>
            "Poul-Henning Kamp" <phk at phk.freebsd.dk> writes:
: In message <20031015133353.W35236 at root.org>, Nate Lawson writes:
: 
: >I assume this is to avoid a trip through a vnode when doing IO to a
: >device?  Can you point me at the analysis of this approach?  I've heard
: >you talking about it before but don't have a reference.
: 
: See the streams driver for an example why this can be considered
: merely a cleanup.
: 
: >> @@ -223,6 +224,7 @@
: >>  	u_int		d_flags;
: >>  	const char	*d_name;
: >>  	d_open_t	*d_open;
: >> +	d_fdopen_t	*d_fdopen;
: >>  	d_close_t	*d_close;
: >>  	d_read_t	*d_read;
: >>  	d_write_t	*d_write;
: >
: >Sure we have C99 now but for binary compatibility with third party
: >drivers, shouldn't this be added at the end of the structure?  Especially
: >since this is an optional function.
: 
: This was deliberately put in the logical place in order to encourage
: 3rdparty drivers to use the correct C99 initialization for cdevsw.

That doesn't do anything to make it binary compatible, which is nate's
point.

Warner