FSCTL_ENUM_OVERLAY control code

The FSCTL_ENUM_OVERLAY control code enumerates all the data sources from a backing provider for a specified volume.

To perform this operation, call FltFsControlFile or ZwFsControlFile with the following parameters.

Parameters

• Instance [in]: FltFsControlFile only. Opaque instance pointer for the caller. This parameter is required and cannot be NULL.

• FileObject [in]: FltFsControlFile only. The file pointer object specifying the volume to be dismounted. This parameter is required and cannot be NULL.

• FileHandle [in]: ZwFsControlFile only. The file handle of the volume to be dismounted. This parameter is required and cannot be NULL.

• FsControlCode [in]: Control code for the operation. Use FSCTL_REMOVE_OVERLAY for this operation.

• InputBuffer [in]: A pointer to the input buffer, which must contain a WOF_EXTERNAL_INFO structure.

• InputBufferLength [in]: Set to sizeof(WOF_EXTERNAL_INFO).

• OutputBuffer [out]: Pointer to an output buffer which will receive one or more WIM_PROVIDER_OVERLAY_ENTRY structures for data sources backing the volume.

• OutputBufferLength [out]: Size of the buffer pointed to by OutputBuffer, in bytes.

• LengthReturned [out]: Specifies the number of bytes written into OutputBuffer on successful completion.

Status block

FltFsControlFile or ZwFsControlFile returns STATUS_SUCCESS if the operation succeeds. Otherwise, the appropriate function might return one of the following NTSTATUS values.

Remarks

When enumerating the data sources for the WIM provider, the output buffer will contain an array of WIM_PROVIDER_OVERLAY_ENTRY structures. The size of the output buffer must be large enough to contain all the overlay entries or the call will return STATUS_BUFFER_TOO_SMALL.

Additional backing providers will define their own specific enumeration structures.

Requirements

See also

FltFsControlFile

ZwFsControlFile

FSCTL_ADD_OVERLAY

WOF_EXTERNAL_INFO