FILE_FS_FULL_SIZE_INFORMATION structure (ntddk.h)
The FILE_FS_FULL_SIZE_INFORMATION structure is used to query sector size information for a file system volume.
typedef struct _FILE_FS_FULL_SIZE_INFORMATION {
LARGE_INTEGER TotalAllocationUnits;
LARGE_INTEGER CallerAvailableAllocationUnits;
LARGE_INTEGER ActualAvailableAllocationUnits;
ULONG SectorsPerAllocationUnit;
ULONG BytesPerSector;
} FILE_FS_FULL_SIZE_INFORMATION, *PFILE_FS_FULL_SIZE_INFORMATION;
TotalAllocationUnits
Total number of allocation units on the volume that are available to the user associated with the calling thread.
Microsoft Windows 2000 and later: If per-user quotas are in use, this value may be less than the total number of allocation units on the disk.
CallerAvailableAllocationUnits
Total number of free allocation units on the volume that are available to the user associated with the calling thread.
Windows 2000 and later: If per-user quotas are in use, this value may be less than the total number of free allocation units on the disk.
ActualAvailableAllocationUnits
Total number of free allocation units on the volume.
SectorsPerAllocationUnit
Number of sectors in each allocation unit.
BytesPerSector
Number of bytes in each sector.
This information can be queried in either of the following ways:
- Call FltQueryVolumeInformation or ZwQueryVolumeInformationFile, passing FileFsFullSizeInformation as the value of FileInformationClass and passing a caller-allocated, FILE_FS_FULL_SIZE_INFORMATION-structured buffer as the value of FileInformation.
- Create an IRP with major function code IRP_MJ_QUERY_VOLUME_INFORMATION.
The size of the buffer passed in the FileInformation parameter to FltQueryVolumeInformation or ZwQueryVolumeInformationFile must be at least sizeof (FILE_FS_FULL_SIZE_INFORMATION).
This structure must be aligned on a LONGLONG (8-byte) boundary.
Requirement | Value |
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Header | ntddk.h (include Ntddk.h, Ntifs.h, Fltkernel.h) |