Subject: Re: new kpi proposal, sysdisk(9)
To: YAMAMOTO Takashi <>
From: Bill Studenmund <>
List: tech-kern
Date: 12/30/2006 10:35:31
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On Sun, Dec 31, 2006 at 02:24:46AM +0900, YAMAMOTO Takashi wrote:
> > I agree we have a problem with wedges in that they act as independent=
> > devices as opposed to magic, free-form partitions. Thus detecting overl=
> > is harder; we don't have a central repository like we do with a partiti=
> > table. But that's arguably a bug of our wedge implementation. ;-)
> dkwedge_add() has code to detect overlapped wedges.
> isn't it what you are talking about?

Kinda. Jason and I have a difference of opinion on this. :-)

I personally think we should permit overlapping wedges and enforce the=20
no-overlap on open. Jason, obviously, believes we should only have=20
non-overlapping ones and thus no overlap problem.

I want conceptual support for overlapping wedges mainly for how MBR disks=
get partitioned. I'd like a wedge for an extended partition, and a wedge=20
for the file system there-in and a wedge for the extended partition in the=
extended partition and a wedge for the file system in that and so on. I'd=
like the non-file-system ones as they are what the partitioning tools work=

How exactly we maintain a name space of these, I'm not sure. :-|

Take care,


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