Re: [edk2-devel] [PATCH] MdeModulePkg/PartitionDxe: Seperate the Udf handler

["Laszlo Ersek" <lersek@redhat.com>]

On 06/24/20 10:32, Ni, Ray wrote:
> Zhichao,
> Will two BlockIo child devices cover the same range in the ISO after your patch?
> 
> I don't think that's a valid behavior.

Right; I'm surprised to find the Red Hat reference in both the commit
message and the BZ.

I can't say I understand the issue at hand, but are we sure this isn't a
bug -- a standards conformance problem -- with the ISO in question?

Zhichao, do you have a link to an ISO image that triggers the problem,
and can you provide a hexdump of the part of the image that is either
buggy, or triggers the problem in edk2? With a more specific issue
description, I might be able to find someone at Red Hat who could
comment with more insight than myself.

Thanks!
Laszlo

> 
> Thanks,
> Ray
> 
>> -----Original Message-----
>> From: Gao, Zhichao <zhichao.gao@intel.com>
>> Sent: Wednesday, June 24, 2020 1:56 PM
>> To: devel@edk2.groups.io
>> Cc: Wu, Hao A <hao.a.wu@intel.com>; Ni, Ray <ray.ni@intel.com>; Wang, Jian J <jian.j.wang@intel.com>; Gao, Liming
>> <liming.gao@intel.com>
>> Subject: [PATCH] MdeModulePkg/PartitionDxe: Seperate the Udf handler
>>
>> REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2823
>>
>> Some linux iso like Redhat would contain both MBR info in the first
>> 512 bytes and volume info at the beginning of 32KB offset.
>> But the partition driver would only choose one of the GPT, MBR, and
>> UDF(el torito compatible) to install the partition. That would lose
>> one info for such linux ISO during one connect. And UDF(el torito
>> compatible) is not conflicted with MBR/GPT. So partition driver should
>> check UDF and MBR/GPT separately.
>>
>> Cc: Hao A Wu <hao.a.wu@intel.com>
>> Cc: Ray Ni <ray.ni@intel.com>
>> Cc: Jian J Wang <jian.j.wang@intel.com>
>> Cc: Liming Gao <liming.gao@intel.com>
>> Signed-off-by: Zhichao Gao <zhichao.gao@intel.com>
>> ---
>>  .../Universal/Disk/PartitionDxe/Partition.c   | 52 +++++++++++++------
>>  1 file changed, 37 insertions(+), 15 deletions(-)
>>
>> diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
>> b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
>> index d1c878ad2e..562490db4f 100644
>> --- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
>> +++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c
>> @@ -5,7 +5,7 @@
>>    MBR, and GPT partition schemes are supported.
>>
>>  Copyright (c) 2018 Qualcomm Datacenter Technologies, Inc.
>> -Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
>> +Copyright (c) 2006 - 2020, Intel Corporation. All rights reserved.<BR>
>>  SPDX-License-Identifier: BSD-2-Clause-Patent
>>
>>  **/
>> @@ -39,7 +39,6 @@ EFI_DRIVER_BINDING_PROTOCOL gPartitionDriverBinding = {
>>  PARTITION_DETECT_ROUTINE mPartitionDetectRoutineTable[] = {
>>    PartitionInstallGptChildHandles,
>>    PartitionInstallMbrChildHandles,
>> -  PartitionInstallUdfChildHandles,
>>    NULL
>>  };
>>
>> @@ -189,6 +188,8 @@ PartitionDriverBindingStart (
>>  {
>>    EFI_STATUS                Status;
>>    EFI_STATUS                OpenStatus;
>> +  EFI_STATUS                UdfStatus;
>> +  EFI_STATUS                GptMbrStatus;
>>    EFI_BLOCK_IO_PROTOCOL     *BlockIo;
>>    EFI_BLOCK_IO2_PROTOCOL    *BlockIo2;
>>    EFI_DISK_IO_PROTOCOL      *DiskIo;
>> @@ -300,26 +301,47 @@ PartitionDriverBindingStart (
>>    if (BlockIo->Media->MediaPresent ||
>>        (BlockIo->Media->RemovableMedia && !BlockIo->Media->LogicalPartition)) {
>>      //
>> -    // Try for GPT, then legacy MBR partition types, and then UDF and El Torito.
>> -    // If the media supports a given partition type install child handles to
>> -    // represent the partitions described by the media.
>> +    // Try for UDF (El TOrito compatible) and GPT/MBR partition types.
>> +    // If the media supports a given partition type, it would install child handles
>> +    // to represent the partitions described by the media.
>> +    // Notes: GPT is conflicted with MBR. It would only install one of them to describe
>> +    // the partition. UDF (or El Torito) can exist with MBR, so need to check it along with
>> +    // GPT/MBR.
>>      //
>> +    UdfStatus = PartitionInstallUdfChildHandles (
>> +                  This,
>> +                  ControllerHandle,
>> +                  DiskIo,
>> +                  DiskIo2,
>> +                  BlockIo,
>> +                  BlockIo2,
>> +                  ParentDevicePath
>> +                  );
>> +
>>      Routine = &mPartitionDetectRoutineTable[0];
>>      while (*Routine != NULL) {
>> -      Status = (*Routine) (
>> -                   This,
>> -                   ControllerHandle,
>> -                   DiskIo,
>> -                   DiskIo2,
>> -                   BlockIo,
>> -                   BlockIo2,
>> -                   ParentDevicePath
>> -                   );
>> -      if (!EFI_ERROR (Status) || Status == EFI_MEDIA_CHANGED || Status == EFI_NO_MEDIA) {
>> +      GptMbrStatus = (*Routine) (
>> +                        This,
>> +                        ControllerHandle,
>> +                        DiskIo,
>> +                        DiskIo2,
>> +                        BlockIo,
>> +                        BlockIo2,
>> +                        ParentDevicePath
>> +                        );
>> +      if (!EFI_ERROR (GptMbrStatus) || GptMbrStatus == EFI_MEDIA_CHANGED || GptMbrStatus == EFI_NO_MEDIA) {
>>          break;
>>        }
>>        Routine++;
>>      }
>> +
>> +    if (!EFI_ERROR (UdfStatus) || !EFI_ERROR (GptMbrStatus)) {
>> +      Status = EFI_SUCCESS;
>> +    } else if (UdfStatus == EFI_MEDIA_CHANGED || GptMbrStatus == EFI_MEDIA_CHANGED) {
>> +      Status = EFI_MEDIA_CHANGED;
>> +    } else if (UdfStatus == EFI_NO_MEDIA || GptMbrStatus == EFI_NO_MEDIA) {
>> +      Status = EFI_NO_MEDIA;
>> +    }
>>    }
>>    //
>>    // In the case that the driver is already started (OpenStatus == EFI_ALREADY_STARTED),
>> --
>> 2.21.0.windows.1
> 
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> 
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