From owner-freebsd-fs@FreeBSD.ORG Thu Sep 29 13:37:38 2005 Return-Path: X-Original-To: fs@freebsd.org Delivered-To: freebsd-fs@FreeBSD.ORG Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 58E6816A41F for ; Thu, 29 Sep 2005 13:37:38 +0000 (GMT) (envelope-from peadar.edwards@gmail.com) Received: from zproxy.gmail.com (zproxy.gmail.com [64.233.162.198]) by mx1.FreeBSD.org (Postfix) with ESMTP id D5F0143D48 for ; Thu, 29 Sep 2005 13:37:37 +0000 (GMT) (envelope-from peadar.edwards@gmail.com) Received: by zproxy.gmail.com with SMTP id z31so220499nzd for ; Thu, 29 Sep 2005 06:37:37 -0700 (PDT) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:reply-to:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=m6PGO6AJsZFCRan53mKVxgfN4i3Ael1+VBTjDnKBlasWhGGX1KBiwD0lbeRxoVCD4s6dgBrfVEHrv4irM/PfGNRlpCTbqhXGhzvqfHt04D/Fvdqr9HzUgBKUZLubjZihPWrpeW2bmQSEUxukQLVRhA+dEAQXHFgInFddePRAV4g= Received: by 10.36.13.11 with SMTP id 11mr4477041nzm; Thu, 29 Sep 2005 06:37:37 -0700 (PDT) Received: by 10.36.68.16 with HTTP; Thu, 29 Sep 2005 06:37:37 -0700 (PDT) Message-ID: <34cb7c8405092906377231b78e@mail.gmail.com> Date: Thu, 29 Sep 2005 14:37:37 +0100 From: Peter Edwards To: Bruce Evans In-Reply-To: <20050929221805.Y31383@delplex.bde.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline References: <20050928125435.620941BBD4@citi.umich.edu> <34cb7c84050928060976c15ecf@mail.gmail.com> <20050929221805.Y31383@delplex.bde.org> Cc: fs@freebsd.org Subject: Re: can not mount a large FAT32 filesystem X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: Peter Edwards List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 29 Sep 2005 13:37:38 -0000 On 9/29/05, Bruce Evans wrote: > On Wed, 28 Sep 2005, Peter Edwards wrote: > > > On 9/28/05, Jim Rees wrote: > >> Note that the check also must be removed near the top of mountmsdosfs(= ), at > >> least in the cvs head version. > >> > > The only reference to BOOTSIG[23] in msdosfs_vnops.c were the ones I > > removed: Do you mean here (line 445 of msdos_vfsops.c v 1.144) > > > >> #ifndef MSDOSFS_NOCHECKSIG > >> if (bsp->bs50.bsBootSectSig0 !=3D BOOTSIG0 > >> || bsp->bs50.bsBootSectSig1 !=3D BOOTSIG1) { > >> error =3D EINVAL; > >> goto error_exit; > >> } > >> #endif > > > > This is a different check: It's testing a different signature: the > > "0xAA55" marker at the end of the bootblock, which _is_ actually > > documented. > > Surely this one is very standard? Yes: that's what I was saying: I haven't touched the AA55 stuff at all, and I don't really intend to: even if it's #ifdeffed away, it makes sense that the code at least documents the expected layout, even if it doesn't enforce it. > I think the checking for BOOTSIG[0-1] shouldn't be removed or a compile- > time option. I'd be somewhat reticent about re-inserting the check: I have to assume it was removed for valid reasons, and breaking existing filesystems doesn't seem wise. The argument is of course somewhat orthogonal to the original patch, which was to remove the BOOTSIG[23] stuff. > > The \x55\xAA signature also occurs in the fsinfo and is messed up by > newfs_msdos for unusual sector sizes. This results in msdosfs just > ignoring the fsinfo for unusual sector sizes. Since the fsinfo is > mostly an optional optimization hint, this is almost harmless. > When I get some of that mythical free time, I might shove some patches for newfs_msdos in front of you for review :-)