FSCTL_DELETE_EXTERNAL_BACKING control code
The FSCTL_DELETE_EXTERNAL_BACKING control code removes the association of a file with an external backing provider, including the Windows Image Format (WIM) provider or compressed file provider. As a result of this operation, the entire contents of a backed file are read, decompressed, and written into the file.
To perform this operation, call FltFsControlFile or ZwFsControlFile with the following parameters.
Parameters
Instance [in]: FltFsControlFile only. An opaque instance pointer for the caller. This parameter is required and cannot be NULL.
FileObject: [in]: FltFsControlFile only. The file pointer object of the file for which backing association is deleted. This parameter is required and cannot be NULL.
FileHandle [in]: ZwFsControlFile only. The handle of the file for which backing association is deleted. This parameter is required and cannot be NULL.
FsControlCode [in]: The control code for the operation. Use FSCTL_DELETE_EXTERNAL_BACKING for this operation.
InputBuffer [in]: None. Set to NULL.
InputBufferLength [in]: Set to 0.
OutputBuffer [out]: None. Set to NULL.
OutputBufferLength [out]: Set to 0.
Status block
FltFsControlFile or ZwFsControlFile returns STATUS_SUCCESS if the operation succeeds. Otherwise, the appropriate function might return one of the following NTSTATUS values.
| Code | Meaning |
|---|---|
| STATUS_OBJECT_NOT_EXTERNALLY_BACKED | The file is not externally backed. |
| STATUS_INVALID_DEVICE_REQUEST | The backing service is not present or not started. |
| STATUS_ACCESS_DENIED | The requestor does not have permission to delete the backing associations for the file. |
Remarks
As a result of the delete operation, the contents of the file are read from the backing source and the entire file is written to the volume.
Requirements
| Requirement type | Requirement |
|---|---|
| Minimum supported client | Windows 8.1 Update |
| Header | Ntifs.h (include Ntifs.h or Fltkernel.h) |