Date: Wed, 28 Sep 2005 09:50:53 +0100 From: Peter Edwards <peadar.edwards@gmail.com> To: Scott Long <scottl@samsco.org> Cc: gayn.winters@bristolsystems.com, re@freebsd.org, fs@freebsd.org, Mikhail Teterin <mi@corbulon.video-collage.com> Subject: Re: can not mount a large FAT32 filesystem Message-ID: <34cb7c840509280150212d2bba@mail.gmail.com> In-Reply-To: <433A32AE.1030802@samsco.org> References: <200509280537.j8S5b1rN050598@corbulon.video-collage.com> <433A32AE.1030802@samsco.org>
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On 9/28/05, Scott Long <scottl@samsco.org> wrote:
> Mikhail Teterin wrote:
> > Thank you very much, Peter!
> >
> > Your patch below makes the card "mountable" and usable. I'm copying
> > my photos right now.
> >
> > I think, this should be merged into 6.0 -- these cards are a popular
> > item... Thanks, again!
> >
> > -mi
> >
> > Index: msdosfs_vfsops.c
> > ===================================================================
> > RCS file: /nfs/dyson/export/home/petere/freebsd-cvs/cvs/FreeBSD/src/sys/fs/msdosfs/msdosfs_vfsops.c,v
> > retrieving revision 1.144
> > diff -u -r1.144 msdosfs_vfsops.c
> > --- msdosfs_vfsops.c 24 Mar 2005 07:36:13 -0000 1.144
> > +++ msdosfs_vfsops.c 27 Sep 2005 09:40:19 -0000
> > @@ -512,9 +512,7 @@
> > #endif /* !MSDOSFS_LARGE */
> >
> > if (pmp->pm_RootDirEnts == 0) {
> > - if (bsp->bs710.bsBootSectSig2 != BOOTSIG2
> > - || bsp->bs710.bsBootSectSig3 != BOOTSIG3
> > - || pmp->pm_Sectors
> > + if (pmp->pm_Sectors
> > || pmp->pm_FATsecs
> > || getushort(b710->bpbFSVers)) {
> > error = EINVAL;
>
> Might this be an attempt by the manufacturer to avoid the potential
> patent litigation from using msdosfs? I.e. create a slightly
> non-conformant filesystem so that it can't claim to explicitely be
> msdosfs/vfat/fat32/whatever, thereby avoiding the patents on those
> technologies?
>
> Since these checks are done after other magic number checks, it's likely
> safe. I'm fine with it going into RELENG_6 once it hass been committed
> to HEAD.
>
> Scott
As I said, I can't see any reference to this signature in the
"official" specification for the FAT boot-sector anyway, so I doubt
you could claim it wasn't a FAT boot-sector based on that change
anyway. I imagine the've just relaxed the spec, and new
implementations don't have the baggage of 20 years of evolving
operating systems and disk technology lying about :-)
I'll commit it this evening.
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