Date: Tue, 29 Sep 2009 13:57:07 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: rwatson@FreeBSD.org Cc: marcel@FreeBSD.org, jhb@FreeBSD.org, svn-src-all@FreeBSD.org, xcllnt@mac.com, src-committers@FreeBSD.org, svn-src-head@FreeBSD.org Subject: Re: svn commit: r197608 - head/sys/geom/part Message-ID: <20090929.135707.1888883837.imp@bsdimp.com> In-Reply-To: <alpine.BSF.2.00.0909291759180.94746@fledge.watson.org> References: <200909290749.08764.jhb@freebsd.org> <1F22EA6A-2793-45CE-9669-3FFD550CF4E2@mac.com> <alpine.BSF.2.00.0909291759180.94746@fledge.watson.org>
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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
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