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

["Gao, Zhichao" <zhichao.gao@intel.com>]

Yes. But I need to confirm the comment #3. The directly revert would make the title of the commit message larger which may be larger than 72 chars. That is another reason I didn't use revert directly.

Thanks,
Zhichao

> -----Original Message-----
> From: Ni, Ray <ray.ni@intel.com>
> Sent: Monday, October 19, 2020 1:56 PM
> To: Gao, Zhichao <zhichao.gao@intel.com>; devel@edk2.groups.io;
> glin@suse.com; Laszlo Ersek <lersek@redhat.com>
> Cc: Wu, Hao A <hao.a.wu@intel.com>
> Subject: RE: [edk2-devel] [PATCH] MdeModulePkg/PartitionDxe: Revert the child
> handler blocksize change
> 
> 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
> > > >
> > >
> > >
> > >
> > > 
> > >