Author: pschweitzer Date: Tue Oct 28 19:17:59 2014 New Revision: 65082 URL: http://svn.reactos.org/svn/reactos?rev=65082&view=rev Log: [NTFS] Finally, implement NtfsGetFreeClusters() which will just read the $Data stream from $BITMAP file record to get the amount of free clusters to allow estimating the free space on a volume. The implementation is likely under-optimized... But wwell, the rest of the FSD is not better. Who talked about caching?! ;-)
Because pictures are more relevant than words in such case: http://www.heisspiter.net/~Pierre/rostests/NTFS_disksize.png Modified: trunk/reactos/drivers/filesystems/ntfs/volinfo.c Modified: trunk/reactos/drivers/filesystems/ntfs/volinfo.c URL: http://svn.reactos.org/svn/reactos/trunk/reactos/drivers/filesystems/ntfs/volinfo.c?rev=65082&r1=65081&r2=65082&view=diff ============================================================================== --- trunk/reactos/drivers/filesystems/ntfs/volinfo.c [iso-8859-1] (original) +++ trunk/reactos/drivers/filesystems/ntfs/volinfo.c [iso-8859-1] Tue Oct 28 19:17:59 2014 @@ -36,8 +36,67 @@ ULONGLONG NtfsGetFreeClusters(PDEVICE_EXTENSION DeviceExt) { - UNIMPLEMENTED; - return 0; + NTSTATUS Status; + PFILE_RECORD_HEADER BitmapRecord; + PNTFS_ATTR_CONTEXT DataContext; + ULONGLONG BitmapDataSize; + PCHAR BitmapData; + ULONGLONG FreeClusters = 0; + ULONG Read = 0; + RTL_BITMAP Bitmap; + + DPRINT1("NtfsGetFreeClusters(%p)\n", DeviceExt); + + BitmapRecord = ExAllocatePoolWithTag(NonPagedPool, + DeviceExt->NtfsInfo.BytesPerFileRecord, + TAG_NTFS); + if (BitmapRecord == NULL) + { + return 0; + } + + Status = ReadFileRecord(DeviceExt, NTFS_FILE_BITMAP, BitmapRecord); + if (!NT_SUCCESS(Status)) + { + ExFreePoolWithTag(BitmapRecord, TAG_NTFS); + return 0; + } + + Status = FindAttribute(DeviceExt, BitmapRecord, AttributeData, L"", 0, &DataContext); + if (!NT_SUCCESS(Status)) + { + ExFreePoolWithTag(BitmapRecord, TAG_NTFS); + return 0; + } + + BitmapDataSize = AttributeDataLength(&DataContext->Record); + ASSERT((BitmapDataSize * 8) >= (DeviceExt->NtfsInfo.SectorCount / DeviceExt->NtfsInfo.SectorsPerCluster)); + BitmapData = ExAllocatePoolWithTag(NonPagedPool, BitmapDataSize, TAG_NTFS); + if (BitmapData == NULL) + { + ReleaseAttributeContext(DataContext); + ExFreePoolWithTag(BitmapRecord, TAG_NTFS); + return 0; + } + + /* FIXME: Totally underoptimized! */ + for (; Read < BitmapDataSize; Read += DeviceExt->NtfsInfo.BytesPerSector) + { + ReadAttribute(DeviceExt, DataContext, Read, (PCHAR)((ULONG_PTR)BitmapData + Read), DeviceExt->NtfsInfo.BytesPerSector); + } + ReleaseAttributeContext(DataContext); + + DPRINT1("Total clusters: %I64x\n", DeviceExt->NtfsInfo.SectorCount / DeviceExt->NtfsInfo.SectorsPerCluster); + DPRINT1("Total clusters in bitmap: %I64x\n", BitmapDataSize * 8); + DPRINT1("Diff in size: %I64d B\n", ((BitmapDataSize * 8) - (DeviceExt->NtfsInfo.SectorCount / DeviceExt->NtfsInfo.SectorsPerCluster)) * DeviceExt->NtfsInfo.SectorsPerCluster * DeviceExt->NtfsInfo.BytesPerSector); + + RtlInitializeBitMap(&Bitmap, (PULONG)BitmapData, DeviceExt->NtfsInfo.SectorCount / DeviceExt->NtfsInfo.SectorsPerCluster); + FreeClusters = RtlNumberOfClearBits(&Bitmap); + + ExFreePoolWithTag(BitmapData, TAG_NTFS); + ExFreePoolWithTag(BitmapRecord, TAG_NTFS); + + return FreeClusters; } static
