Re: turning off COMPAT_386BSD_MBRPART in disklabel

[David Holland <dholland-tech%netbsd.org@localhost>]

On Thu, Feb 03, 2011 at 08:04:26AM +0000, David Laight wrote:
 > > > The PR rather leads to the conclusion that the support for
 > > > old Partition IDs in disklabel(8) is suboptimal.
 > > > Originally, the code did only consider a partition with the
 > > > old ID if no new one was found. This apparently got broken
 > > > when extended partition support was added years later.
 > > 
 > > Yeah, that's a valid point. I guess the question then is whether
 > > fixing that will prevent any problematic cases from arising...  and
 > > whether at this point it's worth worrying about.
 > 
 > Possibly the code should be willing to locate and process such a label.
 > Possibly even write it back.
 > But it probably shouldn't 'corrupt' it - ie leave it as a valid label
 > (doesn't it contain sector number relative to the ptn iteself?
 > so can't describe any other parts of the disk?)

Are *our* ancient disklabels partition-relative? It's so long ago that
I'm not sure... but the code in currently in disklabel(8) doesn't appear
to know anything at all about partition-relative labels.

Given the rest of the discussion here, the fact that fixing
disklabel(8) properly isn't completely trivial, and tls's recent
experience, I think the feature should just be turned off in
disklabel... but, just in case, not removed entirely until we branch
netbsd-6.

Does anyone object to this course of action?

-- 
David A. Holland
dholland%netbsd.org@localhost