Re: [edk2-devel] [PATCH] MdeModulePkg/PartitionDxe: Revert the child handler blocksize change

["Ni, Ray" <ray.ni@intel.com>]

Zhichao,
Can you please update the commit message to address Laszlo's comments?

Thanks,
Ray

> -----Original Message-----
> From: Gao, Zhichao <zhichao.gao@intel.com>
> Sent: Monday, October 19, 2020 10:46 AM
> To: devel@edk2.groups.io; glin@suse.com; Laszlo Ersek <lersek@redhat.com>
> Cc: Ni, Ray <ray.ni@intel.com>; Wu, Hao A <hao.a.wu@intel.com>
> Subject: RE: [edk2-devel] [PATCH] MdeModulePkg/PartitionDxe: Revert the
> child handler blocksize change
> 
> Thanks Gary for your test. I have give my comments base on Laszlo's reply. I
> don't think the regression would affect Linux ISO image except there is one
> Linux image with boot catalog media type not NO_EMULATOR. Anyway, thanks
> for your test and your quickly response.
> 
> Thanks,
> Zhichao
> 
> > -----Original Message-----
> > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Gary Lin
> > Sent: Friday, October 16, 2020 2:42 PM
> > To: Laszlo Ersek <lersek@redhat.com>
> > Cc: Gao, Zhichao <zhichao.gao@intel.com>; devel@edk2.groups.io; Ni, Ray
> > <ray.ni@intel.com>; Wu, Hao A <hao.a.wu@intel.com>
> > Subject: Re: [edk2-devel] [PATCH] MdeModulePkg/PartitionDxe: Revert the
> child
> > handler blocksize change
> >
> > On Thu, Oct 15, 2020 at 12:17:50PM +0200, Laszlo Ersek wrote:
> > > On 10/12/20 09:22, Gao, Zhichao wrote:
> > > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2843
> > > >
> > > > Revert the patch to change the block size in child handler. It would
> > > > block the CD (Eltorito) Hard disk media type's sub partition being
> > > > observed.
> > > > The blocksize patch used to fix the CD image's MBR table issue. The
> > > > CD MBR table would always be ignored because it would be handled by
> > > > the Eltorito partition handler first and never go into the MBR
> > > > handler. So directly revert it.
> > > >
> > > > Cc: Ray Ni <ray.ni@intel.com>
> > > > Cc: Hao A Wu <hao.a.wu@intel.com>
> > > > Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
> > > > ---
> > > >  MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c | 12
> > > > +++++++++---
> > > >  1 file changed, 9 insertions(+), 3 deletions(-)
> > > >
> > > > diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > > > b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > > > index f10ce7c65b..473e091320 100644
> > > > --- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > > > +++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > > > @@ -1149,8 +1149,8 @@ PartitionInstallChildHandle (
> > > >
> > > >    Private->Signature        = PARTITION_PRIVATE_DATA_SIGNATURE;
> > > >
> > > > -  Private->Start            = MultU64x32 (Start, BlockSize);
> > > > -  Private->End              = MultU64x32 (End + 1, BlockSize);
> > > > +  Private->Start            = MultU64x32 (Start, ParentBlockIo->Media-
> > >BlockSize);
> > > > +  Private->End              = MultU64x32 (End + 1, ParentBlockIo->Media-
> > >BlockSize);
> > > >
> > > >    Private->BlockSize        = BlockSize;
> > > >    Private->ParentBlockIo    = ParentBlockIo;
> > > > @@ -1187,7 +1187,13 @@ PartitionInstallChildHandle (
> > > >
> > > >    Private->Media.IoAlign   = 0;
> > > >    Private->Media.LogicalPartition = TRUE;
> > > > -  Private->Media.LastBlock = End - Start;
> > > > +  Private->Media.LastBlock = DivU64x32 (
> > > > +                               MultU64x32 (
> > > > +                                 End - Start + 1,
> > > > +                                 ParentBlockIo->Media->BlockSize
> > > > +                                 ),
> > > > +                                BlockSize
> > > > +                               ) - 1;
> > > >
> > > >    Private->Media.BlockSize = (UINT32) BlockSize;
> > > >
> > > >
> > >
> > Hi Laszlo,
> >
> > > (1) Adding Gary Lin to the CC list.
> > >
> > Thanks for noticing me :)
> >
> > >
> > > (2) I can see that the TianoCore bugzilla ticket, namely
> > > <https://bugzilla.tianocore.org/show_bug.cgi?id=2843>, has been reopened.
> > >
> > > That's wrong.
> > >
> > > TianoCore#2843 was about calculating the starting and ending LBAs with
> > > incorrect block sizes. It was fixed by commit e0eacd7daa6f. Therefore
> > > TianoCore#2843 should stay in RESOLVED|FIXED status.
> > >
> > > Now that we have realized that commit e0eacd7daa6f caused a
> > > regression, a *new BZ* should be filed, stating the particular
> > > compatibility issue (regression). It is a different symptom from the
> > > symptom originally reported under TianoCore#2843, so it belongs in a
> > different ticket.
> > >
> > > In particular, the statement in
> > > <https://bugzilla.tianocore.org/show_bug.cgi?id=2843#c8> that the
> > > original commit (which now should be reverted) "doesn't fix any
> > > specific issue", is *completely wrong*. If you look at commit
> > > e0eacd7daa6f, it contains the tag
> > >
> > >     Tested-by: Gary Lin <glin@suse.com>
> > >
> > > Furthermore, if you look at the mailing list archive, you will find
> > > the following confirmation from Gary:
> > >
> > >     After applying this patch series, the firmware recognizes
> > >     openSUSE/SUSE iso images again.
> > >
> > > In the v1 thread at
> > >
> > >   [edk2-devel] [PATCH 0/3]
> > >   MdeModulePkg/PartitionDxe: Make the parition driver match the spec
> > >
> > >   https://edk2.groups.io/g/devel/message/63972
> > >   http://mid.mail-
> archive.com/20200811075443.GG21538@GaryWorkstation
> > >
> > > And then, in the v2 thread, Gary wrote
> > >
> > >     I've tested the following ISO images and all booted as expected.
> > >     [...]
> > >
> > > again giving a Tested-by:
> > >
> > >   [edk2-devel] [PATCH V2 0/3]
> > >   MdeModulePkg/PartitionDxe: Make the parition driver match the spec
> > >
> > >   https://edk2.groups.io/g/devel/message/64047
> > >   http://mid.mail-
> archive.com/20200812062652.GL21538@GaryWorkstation
> > >
> > >
> > > Now that you are proposing a revert, you have missed all of the above
> > > feedback from Gary. That's because you never bothered to link the v1
> > > and
> > > v2 mailing list threads into the bugzilla ticket.
> > >
> > > So this patch risks reintroducing the issue that Gary reported originally.
> > >
> > > (Of course, the original bug report from Gary is *also* not linked
> > > into
> > > TianoCore#2843:
> > >
> > >   https://edk2.groups.io/g/devel/message/62648
> > >   https://bugzilla.tianocore.org/show_bug.cgi?id=2823#c6
> > >   http://mid.mail-archive.com/20200716033255.GL6058@GaryWorkstation
> > >
> > > so it's no wonder we have no idea whose use case we could regress with
> > > a
> > > revert!)
> > >
> > > This patch should *NOT* be merged until Gary confirms it's OK.
> > >
> > > (And if it's not OK, then a solution is needed that fixes both Gary's
> > > use case, and the compatibility regression. It might even need a PCD,
> > > if there is media out there that needs one kind of logic, and other
> > > media that needs the other kind of logic.)
> > >
> > I just tested the patch with the ISO files with SLE15-SP2, openSUSE Leap 15.2,
> > Fedora 32, and ubuntu 20.04, and the VM loads them without any problem, so
> > there is no regression I had before.
> >
> > I'd give it my Tested-by.
> >
> > Tested-by: Gary Lin <glin@suse.com>
> >
> > Gary Lin
> >
> > >
> > > (3) If this patch is a revert of commit e0eacd7daa6f, then the revert
> > > should be prepared with the "git revert" command. In particular, the
> > > commit message should very clearly state that this patch reverts
> > > commit e0eacd7daa6f.
> > >
> > >
> > > Thanks
> > > Laszlo
> > >
> >
> >
> >
> > 
> >