Subject: Re: CVS commit: src/sys
To: Quentin Garnier <cube@cubidou.net>
From: Brett Lymn <blymn@baesystems.com.au>
List: source-changes
Date: 05/08/2006 13:59:17
On Sun, May 07, 2006 at 02:52:32PM +0200, Quentin Garnier wrote:
> 
> I'm probably as guilty as you are for getting on you about this so
> late after the commit, but replacing the MIB number by something
> incompatible was a very, very poor decision.
> 

Yes, that's my fault I ASSuMEd that the only consumers of this
information were the in tree sources.

> I can understand that you'd want to remove support for the old
> HW_DISKSTATS API, but that's not a reason to close the door to any mean
> of providing binary compatibility for older binaries.
> 

My testing may have been flawed but an old iostat binary I had did
work with a kernel containing the updated sysctl.

I just checked the old struct disk_sysctl that was returned prior to
my changes and the only field I added was a type field that was
previously just a pad entry to fix up 64bit alignment.  So, the only
difference is that the nfs mounts will now be returned as extra
storage.

> 
> So please, please, have a MIB number dynamically allocated for iostats,
> and leave HW_DISKSTATS as it was, so that maybe someone could provide
> the necessary COMPAT_30 stub to support older binaries.
> 

OK - can you point me at a sample of a dynamically allocated MIB
number?  I will fix the code up.  The COMPAT_30 stub should just be a
matter of filtering out the NFS storage from the returns.

> I haven't looked at the details of the involved struct, but it'd better
> be COMPAT_NETBSD32-friendly or I'll be really angry :-)
> 

Well, don't get angry at me :)  I didn't mess with the alignment of
the structure.

> I'm kind of sorry I couldn't check that earlier.
> 

That's ok, I don't see that there is a major body of work involved
here.  Sorry for the stuff up.

-- 
Brett Lymn