Re: [PATCH V2 3/3] MdeModulePkg/PartitionDxe: Fix the incorrect LBA size in child hander

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

For additional info,

I have test patch #3 without #1 and #2, and revert "MdeModulePkg/PartitionDxe: Skip the MBR that add for CD-ROM". The CD's FAT can be observed with MBR path and I can load the EFI application successfully. But the behavior is different as I mention in patch #1 commit message. Test with open SUSE 15.2, RedHat 8.2, Ubuntu 18.04 and Fedora 20.
Only Ubuntu can enter the installation selection but it output a "error: unknown filesystem".
Anyway, CDROM's MBR can be checked and handled correctly.

Thanks,
Zhichao

> -----Original Message-----
> From: Wu, Hao A <hao.a.wu@intel.com>
> Sent: Wednesday, August 12, 2020 2:35 PM
> To: Gao, Zhichao <zhichao.gao@intel.com>; devel@edk2.groups.io
> Cc: Wang, Jian J <jian.j.wang@intel.com>; Ni, Ray <ray.ni@intel.com>; Gary Lin
> <glin@suse.com>; Andrew Fish <afish@apple.com>
> Subject: RE: [PATCH V2 3/3] MdeModulePkg/PartitionDxe: Fix the incorrect LBA
> size in child hander
> 
> > -----Original Message-----
> > From: Gao, Zhichao <zhichao.gao@intel.com>
> > Sent: Wednesday, August 12, 2020 9:21 AM
> > To: devel@edk2.groups.io
> > Cc: Wang, Jian J <jian.j.wang@intel.com>; Wu, Hao A
> > <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>; Gary Lin
> > <glin@suse.com>; Andrew Fish <afish@apple.com>
> > Subject: [PATCH V2 3/3] MdeModulePkg/PartitionDxe: Fix the incorrect
> > LBA size in child hander
> >
> > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2843
> >
> > PartitionInstallChildHandle's parameters Start and End is counted by
> > the BlockSize, but in the implementation it uses the parent device's
> > BlockSize to calculate the new Start, End and LastBlock.
> > It would cause the driver report incorrect block scope and the file
> > system would fail to be found with right block scope.
> > So correct it to the right value.
> >
> > Cc: Jian J Wang <jian.j.wang@intel.com>
> > Cc: Hao A Wu <hao.a.wu@intel.com>
> > Cc: Ray Ni <ray.ni@intel.com>
> > Cc: Gary Lin <glin@suse.com>
> > Cc: Andrew Fish <afish@apple.com>
> > Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
> > Reviewed-by: Ray Ni <ray.ni@intel.com>
> > ---
> >  MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c | 12
> > +++---------
> >  1 file changed, 3 insertions(+), 9 deletions(-)
> >
> > diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
> > index 473e091320..f10ce7c65b 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, ParentBlockIo->Media-
> > >BlockSize);
> > -  Private->End              = MultU64x32 (End + 1, ParentBlockIo->Media-
> > >BlockSize);
> > +  Private->Start            = MultU64x32 (Start, BlockSize);
> > +  Private->End              = MultU64x32 (End + 1, BlockSize);
> 
> 
> For function PartitionInstallChildHandle(), the input parameters 'Start' and 'End'
> (which denote the block index) should be of unit indicated by the input parameter
> 'BlockSize'.
> 
> I checked all the callers of PartitionInstallChildHandle(), it looks to me that GPT,
> MBR and UDF follow the above rule. While I am not able to get a straight-
> forward match for the El Torito case. It seems fine with me, but I am not sure.
> Anyway, if the CDROM content can be properly identified then I think the change
> will be good.
> 
> Reviewed-by: Hao A Wu <hao.a.wu@intel.com>
> 
> Best Regards,
> Hao Wu
> 
> 
> >
> >    Private->BlockSize        = BlockSize;
> >    Private->ParentBlockIo    = ParentBlockIo;
> > @@ -1187,13 +1187,7 @@ PartitionInstallChildHandle (
> >
> >    Private->Media.IoAlign   = 0;
> >    Private->Media.LogicalPartition = TRUE;
> > -  Private->Media.LastBlock = DivU64x32 (
> > -                               MultU64x32 (
> > -                                 End - Start + 1,
> > -                                 ParentBlockIo->Media->BlockSize
> > -                                 ),
> > -                                BlockSize
> > -                               ) - 1;
> > +  Private->Media.LastBlock = End - Start;
> >
> >    Private->Media.BlockSize = (UINT32) BlockSize;
> >
> > --
> > 2.21.0.windows.1