Subject: Re: Supporting sector size != DEV_BSIZE
To: Trevin Beattie <trevin@xmission.com>
From: Konrad Schroder <perseant@hhhh.org>
List: tech-kern
Date: 06/25/2002 17:00:39
On Tue, 25 Jun 2002, Trevin Beattie wrote:

> Right now I'm of the opinion that the existing conversion macros and unit
> affixes should keep their historical meaning.  Specifically, 'db' means
> "disk blocks" a.k.a. physical sectors.  (I think that's what it used to be,

I still disagree with this.  It currently is true that "db" means
DEV_BSIZE means sector size; the fact that you're going to differentiate
DEV_BSIZE from sectors doesn't mean that "db" needs to mean one or the
other.

If we get to choose what it means, I'd like it to mean DEV_BSIZE;  both
because of the similarity in the name, and because I imagine that most
calls to fsbtodb() are setting up to call bread()/VOP_BWRITE (I'm fairly
certain this is true for LFS, though I haven't counted the lines).  If I
am right about this, your patches would be significantly smaller in
addition to avoiding what seem to me to be gratuitous changes.  (Are we
ever going to try to sell this change to, say, FreeBSD?  Are we ever going
to want to buy back changes from FreeBSD?  We've done it before.)

Could you generate a version of this patch that uses macros (the names are
not that important yet, since the process of converting the names to the
yet-to-be-determined right names is mechanical)?  I'd prefer to say, "oh
yes, convert blocks to sectors" when I'm trying to audit, instead of
"`fs->lfs_bshift - fs->lfs_fsbshift' means converting between what and
what again?"

Thanks,
						Konrad Schroder
						perseant@hhhh.org