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FltGetVolumeFromFileObject function (fltkernel.h)

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

Syntax

NTSTATUS FLTAPI FltGetVolumeFromFileObject(
  [in]  PFLT_FILTER  Filter,
  [in]  PFILE_OBJECT FileObject,
  [out] PFLT_VOLUME  *RetVolume
);

Parameters

[in] Filter

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

[in] FileObject

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

[out] RetVolume

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 code Description
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

Requirement Value
Target Platform Universal
Header fltkernel.h (include Fltkernel.h)
Library FltMgr.lib
DLL Fltmgr.sys
IRQL <= APC_LEVEL

See also

FltGetDeviceObject

FltGetDiskDeviceObject

FltGetVolumeFromDeviceObject

FltObjectDereference