Re: [PATCH 2/6] MdeModulePkg/RamDiskDxe: replace OpenFileByDevicePath() with UefiLib API

["Zeng, Star" <star.zeng@intel.com>]

That is fine, then I am ok with the patch, Reviewed-by: Star Zeng <star.zeng@intel.com>.

Thanks,
Star
-----Original Message-----
From: Laszlo Ersek [mailto:lersek@redhat.com] 
Sent: Thursday, July 19, 2018 9:21 PM
To: Zeng, Star <star.zeng@intel.com>; edk2-devel-01 <edk2-devel@lists.01.org>
Cc: Dong, Eric <eric.dong@intel.com>; Wu, Jiaxin <jiaxin.wu@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>; Fu, Siyuan <siyuan.fu@intel.com>
Subject: Re: [PATCH 2/6] MdeModulePkg/RamDiskDxe: replace OpenFileByDevicePath() with UefiLib API

Hi Star,

On 07/19/18 12:36, Zeng, Star wrote:
> Hi Laszlo,
> 
> Have you evaluated whether " #include <Protocol/SimpleFileSystem.h> " can be removed from *.h file or not since gEfiSimpleFileSystemProtocolGuid is removed from *.inf?

Yes, I did check for that.

I did not remove the #include directive of the SimpleFileSystem protocol header because the header defines a number of structure types, beyond declaring "gEfiSimpleFileSystemProtocolGuid", and beyond #defining the EFI_SIMPLE_FILE_SYSTEM_PROTOCOL_GUID.

In particular, it defines the (UEFI-standard) type EFI_FILE_PROTOCOL, and the (non-standard) type EFI_FILE_HANDLE. RamDiskDxe uses the EFI_FILE_HANDLE type liberally -- after the application of this patch, four (4) uses of EFI_FILE_HANDLE remain.

Now, in patch #1, I do #include <Protocol/SimpleFileSystem.h> in UefiLib.h. However, that is because all APIs declared by a lib class header should be usable at once, without having to hunt down dependencies manually. This implies that types used in function prototypes should be declared automatically for the client C file.

Therefore, the #include directive added to UefiLib.h, in patch #1, is not a substitute for the existent #include directive in RamDiskDxe.
UefiLib.h needs the #include directive for staying self-contained, and RamDiskDxe needs the #include directive because it uses the EFI_FILE_HANDLE type for its own purposes.

(Same for the rest of the modules, and same for the device path protocol header / GUID, wherever appropriate.)

Thanks,
Laszlo

> 
> Thanks,
> Star
> -----Original Message-----
> From: Laszlo Ersek [mailto:lersek@redhat.com]
> Sent: Thursday, July 19, 2018 4:51 AM
> To: edk2-devel-01 <edk2-devel@lists.01.org>
> Cc: Dong, Eric <eric.dong@intel.com>; Wu, Jiaxin 
> <jiaxin.wu@intel.com>; Ni, Ruiyu <ruiyu.ni@intel.com>; Fu, Siyuan 
> <siyuan.fu@intel.com>; Zeng, Star <star.zeng@intel.com>
> Subject: [PATCH 2/6] MdeModulePkg/RamDiskDxe: replace 
> OpenFileByDevicePath() with UefiLib API
> 
> Replace the OpenFileByDevicePath() function with EfiOpenFileByDevicePath() from UefiLib, correcting the following issues:
> 
> - imprecise comments on OpenFileByDevicePath(),
> - code duplication between this module and other modules,
> - local variable name "EfiSimpleFileSystemProtocol" starting with "Efi"
>   prefix,
> - bogus "FileHandle = NULL" assignments,
> - passing a potentially unaligned "FILEPATH_DEVICE_PATH.PathName" field to
>   a protocol member function (forbidden by the UEFI spec),
> - leaking "Handle1" when the device path type/subtype check fails in the
>   loop,
> - stale SHELL_FILE_HANDLE reference in a comment.
> 
> Cc: Eric Dong <eric.dong@intel.com>
> Cc: Jiaxin Wu <jiaxin.wu@intel.com>
> Cc: Ruiyu Ni <ruiyu.ni@intel.com>
> Cc: Siyuan Fu <siyuan.fu@intel.com>
> Cc: Star Zeng <star.zeng@intel.com>
> Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=1008
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: Laszlo Ersek <lersek@redhat.com>
> ---
>  MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf        |   1 -
>  MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.h         |  39 ------
>  MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskFileExplorer.c | 140 --------------------
>  MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.c         |   2 +-
>  4 files changed, 1 insertion(+), 181 deletions(-)
> 
> diff --git a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf 
> b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> index cdd2da690411..da00e4a420e7 100644
> --- a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> +++ b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskDxe.inf
> @@ -75,7 +75,6 @@ [Protocols]
>    gEfiDevicePathProtocolGuid                     ## PRODUCES
>    gEfiBlockIoProtocolGuid                        ## PRODUCES
>    gEfiBlockIo2ProtocolGuid                       ## PRODUCES
> -  gEfiSimpleFileSystemProtocolGuid               ## SOMETIMES_CONSUMES
>    gEfiAcpiTableProtocolGuid                      ## SOMETIMES_CONSUMES
>    gEfiAcpiSdtProtocolGuid                        ## SOMETIMES_CONSUMES
>  
> diff --git a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.h 
> b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.h
> index 077bb77b25bf..08a8ca94c9db 100644
> --- a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.h
> +++ b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.h
> @@ -605,45 +605,6 @@ FileInfo (
>    );
>  
>  
> -/**
> -  This function will open a file or directory referenced by DevicePath.
> -
> -  This function opens a file with the open mode according to the file 
> path. The
> -  Attributes is valid only for EFI_FILE_MODE_CREATE.
> -
> -  @param[in, out] FilePath   On input, the device path to the file.
> -                             On output, the remaining device path.
> -  @param[out]     FileHandle Pointer to the file handle.
> -  @param[in]      OpenMode   The mode to open the file with.
> -  @param[in]      Attributes The file's file attributes.
> -
> -  @retval EFI_SUCCESS             The information was set.
> -  @retval EFI_INVALID_PARAMETER   One of the parameters has an invalid value.
> -  @retval EFI_UNSUPPORTED         Could not open the file path.
> -  @retval EFI_NOT_FOUND           The specified file could not be found on the
> -                                  device or the file system could not be found
> -                                  on the device.
> -  @retval EFI_NO_MEDIA            The device has no medium.
> -  @retval EFI_MEDIA_CHANGED       The device has a different medium in it or
> -                                  the medium is no longer supported.
> -  @retval EFI_DEVICE_ERROR        The device reported an error.
> -  @retval EFI_VOLUME_CORRUPTED    The file system structures are corrupted.
> -  @retval EFI_WRITE_PROTECTED     The file or medium is write protected.
> -  @retval EFI_ACCESS_DENIED       The file was opened read only.
> -  @retval EFI_OUT_OF_RESOURCES    Not enough resources were available to open
> -                                  the file.
> -  @retval EFI_VOLUME_FULL         The volume is full.
> -**/
> -EFI_STATUS
> -EFIAPI
> -OpenFileByDevicePath(
> -  IN OUT EFI_DEVICE_PATH_PROTOCOL           **FilePath,
> -  OUT EFI_FILE_HANDLE                       *FileHandle,
> -  IN UINT64                                 OpenMode,
> -  IN UINT64                                 Attributes
> -  );
> -
> -
>  /**
>    Publish the RAM disk NVDIMM Firmware Interface Table (NFIT) to the ACPI
>    table.
> diff --git 
> a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskFileExplorer.c 
> b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskFileExplorer.c
> index 2cfd4bbf6ce8..95d676fc3939 100644
> --- a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskFileExplorer.c
> +++ b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskFileExplorer.c
> @@ -111,143 +111,3 @@ FileInfo (
>  
>    return Buffer;
>  }
> -
> -
> -/**
> -  This function will open a file or directory referenced by DevicePath.
> -
> -  This function opens a file with the open mode according to the file 
> path. The
> -  Attributes is valid only for EFI_FILE_MODE_CREATE.
> -
> -  @param[in, out] FilePath   On input, the device path to the file.
> -                             On output, the remaining device path.
> -  @param[out]     FileHandle Pointer to the file handle.
> -  @param[in]      OpenMode   The mode to open the file with.
> -  @param[in]      Attributes The file's file attributes.
> -
> -  @retval EFI_SUCCESS             The information was set.
> -  @retval EFI_INVALID_PARAMETER   One of the parameters has an invalid value.
> -  @retval EFI_UNSUPPORTED         Could not open the file path.
> -  @retval EFI_NOT_FOUND           The specified file could not be found on the
> -                                  device or the file system could not be found
> -                                  on the device.
> -  @retval EFI_NO_MEDIA            The device has no medium.
> -  @retval EFI_MEDIA_CHANGED       The device has a different medium in it or
> -                                  the medium is no longer supported.
> -  @retval EFI_DEVICE_ERROR        The device reported an error.
> -  @retval EFI_VOLUME_CORRUPTED    The file system structures are corrupted.
> -  @retval EFI_WRITE_PROTECTED     The file or medium is write protected.
> -  @retval EFI_ACCESS_DENIED       The file was opened read only.
> -  @retval EFI_OUT_OF_RESOURCES    Not enough resources were available to open
> -                                  the file.
> -  @retval EFI_VOLUME_FULL         The volume is full.
> -**/
> -EFI_STATUS
> -EFIAPI
> -OpenFileByDevicePath(
> -  IN OUT EFI_DEVICE_PATH_PROTOCOL           **FilePath,
> -  OUT EFI_FILE_HANDLE                       *FileHandle,
> -  IN UINT64                                 OpenMode,
> -  IN UINT64                                 Attributes
> -  )
> -{
> -  EFI_STATUS                           Status;
> -  EFI_SIMPLE_FILE_SYSTEM_PROTOCOL      *EfiSimpleFileSystemProtocol;
> -  EFI_FILE_PROTOCOL                    *Handle1;
> -  EFI_FILE_PROTOCOL                    *Handle2;
> -  EFI_HANDLE                           DeviceHandle;
> -
> -  if ((FilePath == NULL || FileHandle == NULL)) {
> -    return EFI_INVALID_PARAMETER;
> -  }
> -
> -  Status = gBS->LocateDevicePath (
> -                  &gEfiSimpleFileSystemProtocolGuid,
> -                  FilePath,
> -                  &DeviceHandle
> -                  );
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
> -  Status = gBS->OpenProtocol(
> -                  DeviceHandle,
> -                  &gEfiSimpleFileSystemProtocolGuid,
> -                  (VOID**)&EfiSimpleFileSystemProtocol,
> -                  gImageHandle,
> -                  NULL,
> -                  EFI_OPEN_PROTOCOL_GET_PROTOCOL
> -                  );
> -  if (EFI_ERROR (Status)) {
> -    return Status;
> -  }
> -
> -  Status = 
> EfiSimpleFileSystemProtocol->OpenVolume(EfiSimpleFileSystemProtocol, 
> &Handle1);
> -  if (EFI_ERROR (Status)) {
> -    FileHandle = NULL;
> -    return Status;
> -  }
> -
> -  //
> -  // go down directories one node at a time.
> -  //
> -  while (!IsDevicePathEnd (*FilePath)) {
> -    //
> -    // For file system access each node should be a file path component
> -    //
> -    if (DevicePathType    (*FilePath) != MEDIA_DEVICE_PATH ||
> -        DevicePathSubType (*FilePath) != MEDIA_FILEPATH_DP
> -       ) {
> -      FileHandle = NULL;
> -      return (EFI_INVALID_PARAMETER);
> -    }
> -    //
> -    // Open this file path node
> -    //
> -    Handle2  = Handle1;
> -    Handle1 = NULL;
> -
> -    //
> -    // Try to test opening an existing file
> -    //
> -    Status = Handle2->Open (
> -                          Handle2,
> -                          &Handle1,
> -                          ((FILEPATH_DEVICE_PATH*)*FilePath)->PathName,
> -                          OpenMode &~EFI_FILE_MODE_CREATE,
> -                          0
> -                         );
> -
> -    //
> -    // see if the error was that it needs to be created
> -    //
> -    if ((EFI_ERROR (Status)) && (OpenMode != (OpenMode &~EFI_FILE_MODE_CREATE))) {
> -      Status = Handle2->Open (
> -                            Handle2,
> -                            &Handle1,
> -                            ((FILEPATH_DEVICE_PATH*)*FilePath)->PathName,
> -                            OpenMode,
> -                            Attributes
> -                           );
> -    }
> -    //
> -    // Close the last node
> -    //
> -    Handle2->Close (Handle2);
> -
> -    if (EFI_ERROR(Status)) {
> -      return (Status);
> -    }
> -
> -    //
> -    // Get the next node
> -    //
> -    *FilePath = NextDevicePathNode (*FilePath);
> -  }
> -
> -  //
> -  // This is a weak spot since if the undefined SHELL_FILE_HANDLE format changes this must change also!
> -  //
> -  *FileHandle = (VOID*)Handle1;
> -  return EFI_SUCCESS;
> -}
> diff --git a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.c 
> b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.c
> index 7ebd397fe68a..62933a2d6201 100644
> --- a/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.c
> +++ b/MdeModulePkg/Universal/Disk/RamDiskDxe/RamDiskImpl.c
> @@ -656,7 +656,7 @@ RamDiskCallback (
>          //
>          // Open the file.
>          //
> -        Status = OpenFileByDevicePath (
> +        Status = EfiOpenFileByDevicePath (
>                     &FileDevPath,
>                     &FileHandle,
>                     EFI_FILE_MODE_READ,
> --
> 2.14.1.3.gb7cf6e02401b
> 
>