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c++ - C++ WINAPI 在挂载的 VHD 上创建多个分区

问题描述

我设法创建了一个 VHD 并附加了它。之后，我创建了一个磁盘（IOCTL CREATE_DISK）并使用 IOCTL_DISK_SET_DRIVE_LAYOUT_EX 设置它的布局。现在，当我通过磁盘管理检查磁盘时。预计我有一个 14MB 和 7 MB 的分区。

int sign = 80001;
CREATE_DISK disk;
disk.Mbr.Signature = sign;
disk.PartitionStyle = PARTITION_STYLE_MBR;

auto res = DeviceIoControl(device_handle, IOCTL_DISK_CREATE_DISK, &disk, sizeof(disk), NULL, 0, NULL, NULL);
res = DeviceIoControl(device_handle, IOCTL_DISK_UPDATE_PROPERTIES, 0, 0, NULL, 0, NULL, NULL);

LARGE_INTEGER partition_size;
partition_size.QuadPart = 0xF00;
DWORD driver_layout_ex_len = sizeof(DRIVE_LAYOUT_INFORMATION_EX);
DRIVE_LAYOUT_INFORMATION_EX driver_layout_info;
memset(&driver_layout_info, 0, sizeof(DRIVE_LAYOUT_INFORMATION_EX));

driver_layout_info.Mbr.Signature = sign;
driver_layout_info.PartitionCount = 1;
driver_layout_info.PartitionStyle = PARTITION_STYLE_MBR;

PARTITION_INFORMATION_EX part_info;
PARTITION_INFORMATION_MBR mbr_info;
part_info.StartingOffset.QuadPart = 32256;
part_info.RewritePartition = TRUE;
part_info.PartitionLength.QuadPart = partition_size.QuadPart/2 * 4096;
part_info.PartitionNumber = 1;
part_info.PartitionStyle = PARTITION_STYLE_MBR;

mbr_info.BootIndicator = TRUE;
mbr_info.HiddenSectors = 32256 / 512;
mbr_info.PartitionType = PARTITION_FAT32;
mbr_info.RecognizedPartition = 1;
part_info.Mbr = mbr_info;
driver_layout_info.PartitionEntry[0] = part_info;
auto res_layout = DeviceIoControl(device_handle, IOCTL_DISK_SET_DRIVE_LAYOUT_EX, &driver_layout_info, sizeof(driver_layout_info), NULL, 0, NULL, NULL);

现在，如何将此磁盘分区为两个分区？我想从磁盘的未分区部分（基本上是另一半）创建另一个分区。它在文档中说 PartitionEntry 是一个可变大小的数组（不，它不是一个大小为 1 的数组。）我是否为我要创建的每个分区调用 set layout IOCTL ？如果是这样，你会怎么做？是否可以通过 WINAPI 接口进行多分区？

PS：我知道人们通常会为这行工作调用 diskpart。

编辑：添加第二个分区两个布局弄乱了我的堆栈，所以我采取了另一条路线（堆）。

DWORD driver_layout_ex_len = sizeof(DRIVE_LAYOUT_INFORMATION_EX) + sizeof(PARTITION_INFORMATION_EX); // one layout+partition + partition
PDRIVE_LAYOUT_INFORMATION_EX driver_layout_info = (PDRIVE_LAYOUT_INFORMATION_EX) std::calloc(1, driver_layout_ex_len);

driver_layout_info->Mbr.Signature = sign;
driver_layout_info->PartitionCount = 2;
driver_layout_info->PartitionStyle = PARTITION_STYLE_MBR;
// omitted here..
PARTITION_INFORMATION_EX part_info2;
part_info2.StartingOffset.QuadPart = 32256 + part_info.PartitionLength.QuadPart;
part_info2.RewritePartition = TRUE;
part_info2.PartitionLength.QuadPart = partition_size.QuadPart / 2 * 4096;
part_info2.PartitionNumber = 2;
part_info2.PartitionStyle = PARTITION_STYLE_MBR;

part_info2.Mbr = mbr_info;


driver_layout_info->PartitionEntry[0] = part_info;
driver_layout_info->PartitionEntry[1] = part_info2;
auto res_layout = DeviceIoControl(device_handle, IOCTL_DISK_SET_DRIVE_LAYOUT_EX, driver_layout_info, driver_layout_ex_len, NULL, 0, NULL, NULL);
auto res_err = GetLastError();

由于它压倒了我device_handle，我根本无法使用 IOCTL。这种改进消除了这一点。不要忘记在此更改后传递 driver_layout_info 而不是 &driver_layout_info。

标签： c++winapiioctlvirtual-disk

解决方案

它在文档中说 PartitionEntry 是一个可变大小的数组（不，它不是一个大小为 1 的数组。）

“一些 Windows 结构是可变大小的，从一个固定的标头开始，然后是一个可变大小的数组。在声明这些结构时，它们通常会声明一个大小为 1 的数组，而可变大小的数组应该是。” 请参阅@Raymond 博客。

这里DRIVE_LAYOUT_INFORMATION_EX 结构是一个例子：

typedef struct _DRIVE_LAYOUT_INFORMATION_EX {
  DWORD                    PartitionStyle;
  DWORD                    PartitionCount;
  union {
    DRIVE_LAYOUT_INFORMATION_MBR Mbr;
    DRIVE_LAYOUT_INFORMATION_GPT Gpt;
  } DUMMYUNIONNAME;
  PARTITION_INFORMATION_EX PartitionEntry[1];
} DRIVE_LAYOUT_INFORMATION_EX, *PDRIVE_LAYOUT_INFORMATION_EX;

使用此声明，您将为这样一个可变大小的 DRIVE_LAYOUT_INFORMATION_EX 结构分配内存，如下所示：

PDRIVE_LAYOUT_INFORMATION_EX driver_layout_info = (PDRIVE_LAYOUT_INFORMATION_EX)malloc(FIELD_OFFSET(DRIVE_LAYOUT_INFORMATION_EX, PartitionEntry[NumberOfPartitions]));

您将像这样初始化结构（以 2 个分区为例）：

DWORD NumberOfPartitions = 2;
LARGE_INTEGER partition_size;
partition_size.QuadPart = 0xF00;

PARTITION_INFORMATION_MBR mbr_info;
mbr_info.BootIndicator = TRUE;
mbr_info.HiddenSectors = 32256 / 512;
mbr_info.PartitionType = PARTITION_FAT32;
mbr_info.RecognizedPartition = TRUE;

PDRIVE_LAYOUT_INFORMATION_EX driver_layout_info = (PDRIVE_LAYOUT_INFORMATION_EX)malloc(FIELD_OFFSET(DRIVE_LAYOUT_INFORMATION_EX, PartitionEntry[NumberOfPartitions]));
for (DWORD Index = 0; Index < NumberOfPartitions ; Index++) {

    driver_layout_info->PartitionEntry[Index].PartitionStyle = PARTITION_STYLE_MBR;
    driver_layout_info->PartitionEntry[Index].PartitionNumber = Index + 1;
    driver_layout_info->PartitionEntry[Index].RewritePartition = TRUE;
    driver_layout_info->PartitionEntry[Index].PartitionLength.QuadPart = partition_size.QuadPart / 2 * 4096;
    driver_layout_info->PartitionEntry[Index].Mbr = mbr_info;
}

driver_layout_info->Mbr.Signature = sign;
driver_layout_info->PartitionCount = 1;
driver_layout_info->PartitionStyle = PARTITION_STYLE_MBR;

driver_layout_info->PartitionEntry[0].StartingOffset.QuadPart = 32256;
driver_layout_info->PartitionEntry[1].StartingOffset.QuadPart = 32256 + driver_layout_info->PartitionEntry->StartingOffset.QuadPart;

DWORD driver_layout_ex_len = sizeof(DRIVE_LAYOUT_INFORMATION_EX) + sizeof(PARTITION_INFORMATION_EX);

free(driver_layout_info);用完后打电话。

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