To: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: tridge@samba.org, john.lanza@linux.com, linux-kernel@vger.kernel.org,
       OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>,
       linux-fsdevel@vger.kernel.org,
       Dave Kleikamp <shaggy@linux.vnet.ibm.com>,
       Steve French <sfrench@us.ibm.com>, Mingming Cao <cmm@us.ibm.com>,
       Paul McKenney <paulmck@linux.vnet.ibm.com>
References: <19013.8005.541836.436991@samba.org>
	<m1d48p5dil.fsf@fess.ebiederm.org>
	<19014.54044.484370.187018@samba.org>
	<m1vdmh2e26.fsf@fess.ebiederm.org> <19015.482.794111.612472@samba.org>
	<87ab3sx4ch.fsf@devron.myhome.or.jp>
	<m1k52wxhki.fsf@fess.ebiederm.org>
	<1246219994.4190.28.camel@mulgrave.site>
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Sun, 28 Jun 2009 13:45:57 -0700
In-Reply-To: <1246219994.4190.28.camel@mulgrave.site> (James Bottomley's message of "Sun\, 28 Jun 2009 15\:13\:14 -0500")
Message-ID: <m163egw0hm.fsf@fess.ebiederm.org>
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Subject: Re: [PATCH] Added CONFIG_VFAT_FS_DUALNAMES option
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James Bottomley <James.Bottomley@HansenPartnership.com> writes:

> On Sun, 2009-06-28 at 12:51 -0700, Eric W. Biederman wrote:
>> OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> writes:
>> 
>> > tridge@samba.org writes:
>> >
>> >>  > Given what you have said our interpretation of vfat has a bug,
>> >>  > and that small change is a candidate for -stable.  If it could
>> >>  > be it's own patch.
>> >>
>> >> good point. 
>> >>
>> >> Hirofumi-san, would you support putting the last_u change into stable?
>> >
>> > If you want, I have no problem to do. However, I'm not thinking that
>> > part is a bug.  And -stable rule is also "a real bug that bothers
>> > people", but there is even a no bug reporter which tell actual problem.
>> 
>> 
>> Tridge.  Is there any reason to believe that Microsoft will continue
>> to treat Longfilenames without short filenames as valid in vfat?
>> 
>> If this turns into a contest of who can do the silliest things in
>> their vfat code microsoft could easily introduce a stricter directory
>> parser and cause all kinds of grief.
>> 
>> It wouldn't even surprise me if you haven't seen such shenanigans
>> while working on samba.
>
> If you own the platform, like Microsoft does, there are many things you
> *could* do to make life difficult for others (like shipping a slightly
> incompatible version of java, for instance ...).  However, having had
> one or two consumer and regulatory backlashes from shipping updates
> primarily designed to hobble what you think of as a competitor, you tend
> to be much more wary about doing it so openly ... particularly when
> you're trying to convince a wary customer base that you're the champion
> of interoperability nowadays.
>
> The bottom line is that we need to consider the current patch on its
> merits for evading the vfat patent.  Speculating about what Microsoft
> might or might not do to retaliate doesn't really help with this.

This is a technical question.  Are we really in spec with the patch?

If we are not in spec. If we break things like checkdisk.exe.   Microsoft
can legitimately say we broke things and take technical measures to avoid
broken filesystems.  We have dome similar things to close source binary
modules.

My impression is that this patch puts us on the hairy edge.  If no
one is generating files without a short filename now.  That may cause
problems.

All else being equal this is a technically problematic patch as it
reduces the chances of interoperability.  I am just trying to gage
what those chances are.

Eric
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