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FltGetVolumeFromFileObject routine

The FltGetVolumeFromFileObject routine returns an opaque pointer for the volume that a given file stream resides on.

Syntax


NTSTATUS FltGetVolumeFromFileObject(
  _In_   PFLT_FILTER Filter,
  _In_   PFILE_OBJECT FileObject,
  _Out_  PFLT_VOLUME *RetVolume
);

Parameters

Filter [in]

Opaque filter pointer for the caller. This parameter is required and cannot be NULL.

FileObject [in]

File object pointer for a file stream that resides on the volume.

RetVolume [out]

Pointer to a caller-allocated variable that receives an opaque pointer for the volume. This parameter is required and cannot be NULL.

Return value

FltGetVolumeFromFileObject returns STATUS_SUCCESS or an appropriate NTSTATUS value, such as one of the following:

Return codeDescription
STATUS_FLT_DELETING_OBJECT

The volume is being torn down. This is an error code.

STATUS_INVALID_PARAMETER

No matching volume was found. This is an error code.

 

Remarks

FltGetVolumeFromFileObject adds a rundown reference to the opaque volume pointer returned in the RetVolume parameter. When this pointer is no longer needed, the caller must release it by calling FltObjectDereference. Thus every successful call to FltGetVolumeFromFileObject must be matched by a subsequent call to FltObjectDereference.

To get a pointer to the device object for a given volume, call FltGetDeviceObject.

Requirements

Header

Fltkernel.h (include Fltkernel.h)

Library

FltMgr.lib

IRQL

<= APC_LEVEL

See also

FltGetDeviceObject
FltGetDiskDeviceObject
FltGetVolumeFromDeviceObject
FltObjectDereference

 

 

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