OvmfPkg/VirtioFsDxe: implement EFI_FILE_PROTOCOL.GetPosition, .SetPosition

[mirror_edk2.git] / OvmfPkg / VirtioFsDxe / SimpleFsSetPosition.c

diff --git a/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c b/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
index ee8cb1f4e465282e1a58e94c819b59c9c0eaaf7e..ac62853026529cd101e2ae43c558c2e4e122c69c 100644 (file)
--- a/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
+++ b/OvmfPkg/VirtioFsDxe/SimpleFsSetPosition.c
@@ -16,5 +16,43 @@ VirtioFsSimpleFileSetPosition (
   IN UINT64            Position\r
   )\r
 {\r
-  return EFI_DEVICE_ERROR;\r
+  VIRTIO_FS_FILE                     *VirtioFsFile;\r
+  VIRTIO_FS                          *VirtioFs;\r
+  EFI_STATUS                         Status;\r
+  VIRTIO_FS_FUSE_ATTRIBUTES_RESPONSE FuseAttr;\r
+\r
+  VirtioFsFile = VIRTIO_FS_FILE_FROM_SIMPLE_FILE (This);\r
+\r
+  //\r
+  // Directories can only be rewound, per spec.\r
+  //\r
+  if (VirtioFsFile->IsDirectory) {\r
+    if (Position != 0) {\r
+      return EFI_UNSUPPORTED;\r
+    }\r
+    VirtioFsFile->FilePosition = 0;\r
+    return EFI_SUCCESS;\r
+  }\r
+\r
+  //\r
+  // Regular file.\r
+  //\r
+  if (Position < MAX_UINT64) {\r
+    //\r
+    // Caller is requesting absolute file position.\r
+    //\r
+    VirtioFsFile->FilePosition = Position;\r
+    return EFI_SUCCESS;\r
+  }\r
+\r
+  //\r
+  // Caller is requesting a seek to EOF.\r
+  //\r
+  VirtioFs = VirtioFsFile->OwnerFs;\r
+  Status = VirtioFsFuseGetAttr (VirtioFs, VirtioFsFile->NodeId, &FuseAttr);\r
+  if (EFI_ERROR (Status)) {\r
+    return Status;\r
+  }\r
+  VirtioFsFile->FilePosition = FuseAttr.Size;\r
+  return EFI_SUCCESS;\r
 }\r