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To: rwatson@FreeBSD.org
From: "M. Warner Losh" <imp@bsdimp.com>
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Cc: marcel@FreeBSD.org, jhb@FreeBSD.org, svn-src-all@FreeBSD.org,
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Subject: Re: svn commit: r197608 - head/sys/geom/part
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In message: <alpine.BSF.2.00.0909291759180.94746@fledge.watson.org>
            Robert Watson <rwatson@FreeBSD.org> writes:
: 
: On Tue, 29 Sep 2009, Marcel Moolenaar wrote:
: 
: >> Why do you check for zeros at all?  AFAIK, the only real check is for AA55 
: >> at the end of the sector (and having an MBR or other Extended MBR partition 
: >> entry point at the sector in question).  The '96' thing seems rather 
: >> arbitrary in the code, and I think the zero's check is overly restrictive.
: >
: > Only checking for a signature that 99% of the boot blocks have isn't enough. 
: > The msdos file system has that signature and the check for all-zeroes is to 
: > prevent false positives there.
: 
: And, as I recall, the msdosfs check has been gradually getting weaker over 
: time as the constraints it places on things like cylinder counts become 
: obsolete.  It's not quite that we'll mount msdosfs on any random pile of 
: bytes, but it might be getting there...

Maybe someday it will be able to mount my old Rainbow disks again :)

Warner