Re: How do GEOM_PART_* options configure geom_part_* modules??

On Thu, Sep 28, 2017 at 9:13 AM, Warner Losh <imp_at_bsdimp.com> wrote:

> On Thu, Sep 28, 2017 at 10:00 AM, Nick Hibma <nick_at_van-laarhoven.org>
> wrote:
>
> > I created a new kernel config file from scratch, wondered what the
> > GEOM_PART_MBR option and friends were doing, search for them, didn't find
> > them in the tree, and deleted them from my config. But... de resulting
> disk
> > image didn't boot, because of the fact that it didn't recognise the MBR
> > partitions (it only had a single diskid entry on the mount-root prompt).
> >
> > Can anyone explain to me how these kernel options work, as in: they are
> > defined in kernel configs and as a consequence in opt_geom.h, but how are
> > they actually used to select which geom_part_* modules/kernel parts to
> > build? I thought these options were translated to stuff that cpp would
> use,
> > but there are not uses of for example GEOM_PART_MBR anywhere for example!
> >
> >
> > The module always build them because they are listed in the module's
> > Makefile.
> >
> > The kernel only sometimes does. Here's the key lines from conf/files:
> > files:geom/geom_bsd_enc.c optional geom_bsd | geom_part_bsd
> > files:geom/part/g_part_apm.c optional geom_part_apm
> > files:geom/part/g_part_bsd.c optional geom_part_bsd
> > files:geom/part/g_part_bsd64.c optional geom_part_bsd64
> > files:geom/part/g_part_ebr.c optional geom_part_ebr
> > files:geom/part/g_part_gpt.c optional geom_part_gpt
> > files:geom/part/g_part_ldm.c optional geom_part_ldm
> > files:geom/part/g_part_mbr.c optional geom_part_mbr
> > files:geom/part/g_part_vtoc8.c optional geom_part_vtoc8
> >
> > which turn on/off which files get included. config "helpfully" converts
> the
> > upper case options to lower case for this.
> >
> > Warner
> >
> >
> > *slaps forehead* Goose chase!
> >
> > I actually knew that... and, at the time, thought it was weird behaviour.
> > ''grep" would not have failed me if those options would be uppercase
> there
> > ...
> >
>
> I've been nibbled to death by these geese often enough to have a PTSD-like
> reaction when someone mentions it and habitually add -i to my greps...
>
> Warner


This horrid POLA violation seems to have been in FreeBSD configuration
since at least 3.0 and probably goes back to the creation of the
configuration process.

Any idea why such a horrible POLA was ever introduced? Seems like an
obviously bad idea in an OS that is ALMOST always case sensitive.
--
Kevin Oberman, Part time kid herder and retired Network Engineer
E-mail: rkoberman_at_gmail.com
PGP Fingerprint: D03FB98AFA78E3B78C1694B318AB39EF1B055683