Reverse-engineered: enum DF_DEVICE_TYPE

df_device_type.h

// reverse engineered based on Windows 10 version 21H1
// used in defragsvc.dll, dfrgui.exe, and probably other places
// (the specific enum member names seen here were invented by me)

enum DF_DEVICE_TYPE
{                                                   // CORRESPONDING "MEDIA TYPE" STRING [with string table index from DfrgUI.exe.mui]
    TYPE_UNKNOWN                             = 0x0, // 1188 "Unknown"
    TYPE_HARD_DISK_DRIVE                     = 0x1, // 1179 "Hard disk drive"
    TYPE_REMOVABLE_DRIVE                     = 0x2, // 1180 "Removable drive"
    TYPE_SOLID_STATE_DRIVE                   = 0x3, // 1181 "Solid state drive"
    TYPE_SOLID_STATE_DRIVE__NTFS_OR_REFS     = 0x4, // 1181 "Solid state drive"
    TYPE_THIN_PROVISIONED_DRIVE              = 0x5, // 1184 "Thin provisioned drive"
    TYPE_STORAGE_SPACE                       = 0x6, // 1182 "Storage space"
    TYPE_THIN_PROVISIONED_SPACE              = 0x7, // 1183 "Thin provisioned space"
    TYPE_VIRTUAL_HARD_DRIVE                  = 0x8, // 1187 "Virtual hard drive"
    TYPE_VIRTUAL_HARD_DRIVE__PARENT          = 0x9, // 1185 "Virtual hard drive"
    TYPE_VIRTUAL_HARD_DRIVE__FULLY_ALLOCATED = 0xA, // 1186 "Virtual hard drive"
    TYPE_TIERED_SPACE                        = 0xB, // 1204 "Tiered space"
    TYPE_STORAGE_SPACE__SSD                  = 0xC, // 1182 "Storage space"
    TYPE_STORAGE_SPACE__SSD__NTFS_OR_REFS    = 0xD, // 1182 "Storage space"
};

// here's the rough logic tree from defragsvc.dll:
//
// SxQueryVolume
// - calls SxIsRemovableFatVolume:
//   - if GetDriveTypeW(...) == DRIVE_REMOVABLE and GetVolumeInformationW(...) FS type is "FAT32" or "FAT": TYPE_REMOVABLE_DRIVE
// - calls SxQueryDeviceType:
//   - calls DeviceIoControl with IOCTL_STORAGE_QUERY_PROPERTY and StorageAdapterProperty:
//     - if successful and BusType == BusTypeFileBackedVirtual: calls SxQueryDeviceTypeVirtualDiskSub:
//       - calls GetStorageDependencyInformation:
//         -   if successful and DependencyTypeFlags has DEPENDENT_DISK_FLAG_PARENT: TYPE_VIRTUAL_HARD_DRIVE__PARENT
//         - elif successful and DependencyTypeFlags has DEPENDENT_DISK_FLAG_FULLY_ALLOCATED: TYPE_VIRTUAL_HARD_DRIVE__FULLY_ALLOCATED
//         - elif successful: TYPE_VIRTUAL_HARD_DRIVE
//     - else:
//       - if successful and BusType == BusTypeSpaces: this is noted down for later
//       - calls DeviceIoControl with IOCTL_STORAGE_QUERY_PROPERTY and StorageDeviceLBProvisioningProperty:
//         - if successful and ThinProvisioningEnabled != 0 and OptimalUnmapGranularity > 0:
//           - if BusTypeSpaces from earlier: TYPE_THIN_PROVISIONED_SPACE
//           - else: TYPE_THIN_PROVISIONED_DRIVE
//         - else: calls DeviceIoControl with IOCTL_STORAGE_QUERY_PROPERTY and StorageSeekPenaltyProperty:
//           - if successful and IncursSeekPenalty == FALSE:
//             - if BusTypeSpaces from earlier: TYPE_STORAGE_SPACE__SSD
//             - else: TYPE_SOLID_STATE_DRIVE
//           - else:
//             - if BusTypeSpaces from earlier: TYPE_STORAGE_SPACE
//             - else: calls DeviceIoControl with IOCTL_ATA_PASS_THROUGH and command IDENTIFY DEVICE:
//               - if successful and word 217 (NominalMediaRotationRate) == 1: TYPE_SOLID_STATE_DRIVE
//               - else: calls SxQueryDeviceRandomReadDiskScore (gets WinSAT score):
//                 - if successful and score < 0x20001: TYPE_HARD_DISK_DRIVE
//                 - else: TYPE_SOLID_STATE_DRIVE
// - if all volume extents pass SxQueryDeviceDefragAppropriate(...): TYPE_SOLID_STATE_DRIVE
// - if type is TYPE_STORAGE_SPACE or TYPE_STORAGE_SPACE__SSD:
//   - calls DeviceIoControl with FSCTL_QUERY_STORAGE_CLASSES:
//     - if successful and TotalNumberOfTiers > 1: TYPE_TIERED_SPACE
// - if type is TYPE_SOLID_STATE_DRIVE or TYPE_STORAGE_SPACE__SSD:
//   - if GetVolumeInformationW(...) FS type is "NTFS" or "REFS":
//     - TYPE_SOLID_STATE_DRIVE becomes TYPE_SOLID_STATE_DRIVE__NTFS_OR_REFS
//     - TYPE_STORAGE_SPACE__SSD becomes TYPE_STORAGE_SPACE__SSD__NTFS_OR_REFS