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

[Laszlo Ersek <lersek@redhat.com>]

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