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FSCTL_DELETE_EXTERNAL_BACKING control code

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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)

See also

FltFsControlFile

ZwFsControlFile

FSCTL_SET_EXTERNAL_BACKING