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FltGetVolumeName function (fltkernel.h)

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The FltGetVolumeName routine gets the volume name for a given volume.

Syntax

NTSTATUS FLTAPI FltGetVolumeName(
  [in]                PFLT_VOLUME     Volume,
  [in, out, optional] PUNICODE_STRING VolumeName,
  [out, optional]     PULONG          BufferSizeNeeded
);

Parameters

[in] Volume

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

[in, out, optional] VolumeName

Pointer to a caller-allocated UNICODE_STRING structure that contains the volume's non-persistent device object name (for example, "\Device\HarddiskVolume1") when STATUS_SUCCESS is returned. Be aware that pool for VolumeName->Buffer is also caller-allocated.

This parameter is optional and can be NULL; however it must be non-NULL if BufferSizeNeeded is NULL. If this parameter is NULL and BufferSizeNeeded is not NULL, FltGetVolumeName stores the buffer size needed for the requested volume name in the BufferSizeNeeded parameter and returns STATUS_BUFFER_TOO_SMALL. See Remarks.

[out, optional] BufferSizeNeeded

Pointer to a caller-allocated variable that receives the size, in bytes, of the requested volume name. This parameter is optional and can be NULL; however, it must be non-NULL if VolumeName is NULL so that FltGetVolumeName can store the buffer size needed for the requested volume name.

Return value

FltGetVolumeName returns one of the following NTSTATUS values:

Return code Description
STATUS_SUCCESS The UNICODE_STRING structure, pointed to by VolumeName, contains the name of the volume in the Buffer member for the structure and the length of the name, in bytes, in the Length member.
STATUS_BUFFER_TOO_SMALL The Buffer member of the UNICODE_STRING structure, pointed to by VolumeName, is too small (as indicated by its MaximumLength member) to contain the entire volume name. This is an error code.
STATUS_INVALID_PARAMETER VolumeName and BufferSizeNeeded are both NULL. This is an error code.

Remarks

For this routine to succeed, the Buffer member of the UNICODE_STRING structure (pointed to by VolumeName) must be large enough, as indicated by its MaximumLength member, to contain the entire volume name string.

The following pseudocode shows one possible method to successfully acquire a volume name if BufferSizeNeeded is unknown:

  • Call FltGetVolumeName to determine the required pool for Buffer and the required size for MaximumLength. For example: FltGetVolumeName(VolumePtr, NULL, &VolumeNameSize);

  • Allocate VolumeNameSize bytes of pool for Buffer and set MaximumLength to VolumeNameSize.

  • Call FltGetVolumeName again to acquire the volume name. For example: FltGetVolumeName(VolumePtr, &VolumeNameStruct, NULL);

VolumeNameStruct.Buffer contains the Unicode volume name string, which is VolumeNameStruct.Length bytes in length.

To get the volume GUID name for a given volume, call FltGetVolumeGuidName.

To get an opaque volume pointer for a volume with a given name, call FltGetVolumeFromName.

For more information about how to name a volume, see Supporting Mount Manager Requests in a Storage Class Driver**.

Requirements

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

See also

FilterGetDosName

FltGetVolumeFromName

FltGetVolumeGuidName

UNICODE_STRING