VHDHDDCore.cpp revision c4416f84c6e2ffa9549354c4d196858b455500b3
/* $Id$ */
/** @file
* VHD Disk image, Core Code.
*/
/*
* Copyright (C) 2006-2010 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
*/
/*******************************************************************************
* Header Files *
*******************************************************************************/
#define LOG_GROUP LOG_GROUP_VD_VHD
#include <VBox/VBoxHDD-Plugin.h>
#include <VBox/err.h>
#include <VBox/log.h>
#include <VBox/version.h>
#include <iprt/asm.h>
#include <iprt/assert.h>
#include <iprt/mem.h>
#include <iprt/uuid.h>
#include <iprt/path.h>
#include <iprt/string.h>
#define VHD_RELATIVE_MAX_PATH 512
#define VHD_ABSOLUTE_MAX_PATH 512
#define VHD_SECTOR_SIZE 512
#define VHD_BLOCK_SIZE (2 * _1M)
/* This is common to all VHD disk types and is located at the end of the image */
#pragma pack(1)
typedef struct VHDFooter
{
char Cookie[8];
uint32_t Features;
uint32_t Version;
uint64_t DataOffset;
uint32_t TimeStamp;
uint8_t CreatorApp[4];
uint32_t CreatorVer;
uint32_t CreatorOS;
uint64_t OrigSize;
uint64_t CurSize;
uint16_t DiskGeometryCylinder;
uint8_t DiskGeometryHeads;
uint8_t DiskGeometrySectors;
uint32_t DiskType;
uint32_t Checksum;
char UniqueID[16];
uint8_t SavedState;
uint8_t Reserved[427];
} VHDFooter;
#pragma pack()
#define VHD_FOOTER_COOKIE "conectix"
#define VHD_FOOTER_COOKIE_SIZE 8
#define VHD_FOOTER_FEATURES_NOT_ENABLED 0
#define VHD_FOOTER_FEATURES_TEMPORARY 1
#define VHD_FOOTER_FEATURES_RESERVED 2
#define VHD_FOOTER_FILE_FORMAT_VERSION 0x00010000
#define VHD_FOOTER_DATA_OFFSET_FIXED UINT64_C(0xffffffffffffffff)
#define VHD_FOOTER_DISK_TYPE_FIXED 2
#define VHD_FOOTER_DISK_TYPE_DYNAMIC 3
#define VHD_FOOTER_DISK_TYPE_DIFFERENCING 4
#define VHD_MAX_LOCATOR_ENTRIES 8
#define VHD_PLATFORM_CODE_NONE 0
#define VHD_PLATFORM_CODE_WI2R 0x57693272
#define VHD_PLATFORM_CODE_WI2K 0x5769326B
#define VHD_PLATFORM_CODE_W2RU 0x57327275
#define VHD_PLATFORM_CODE_W2KU 0x57326B75
#define VHD_PLATFORM_CODE_MAC 0x4D163220
#define VHD_PLATFORM_CODE_MACX 0x4D163258
/* Header for expanding disk images. */
#pragma pack(1)
typedef struct VHDParentLocatorEntry
{
uint32_t u32Code;
uint32_t u32DataSpace;
uint32_t u32DataLength;
uint32_t u32Reserved;
uint64_t u64DataOffset;
} VHDPLE, *PVHDPLE;
typedef struct VHDDynamicDiskHeader
{
char Cookie[8];
uint64_t DataOffset;
uint64_t TableOffset;
uint32_t HeaderVersion;
uint32_t MaxTableEntries;
uint32_t BlockSize;
uint32_t Checksum;
uint8_t ParentUuid[16];
uint32_t ParentTimeStamp;
uint32_t Reserved0;
uint16_t ParentUnicodeName[256];
VHDPLE ParentLocatorEntry[VHD_MAX_LOCATOR_ENTRIES];
uint8_t Reserved1[256];
} VHDDynamicDiskHeader;
#pragma pack()
#define VHD_DYNAMIC_DISK_HEADER_COOKIE "cxsparse"
#define VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE 8
#define VHD_DYNAMIC_DISK_HEADER_VERSION 0x00010000
/**
* Complete VHD image data structure.
*/
typedef struct VHDIMAGE
{
/** Image file name. */
const char *pszFilename;
/** Opaque storage handle. */
PVDIOSTORAGE pStorage;
/** I/O interface. */
PVDINTERFACE pInterfaceIO;
/** I/O interface callbacks. */
PVDINTERFACEIOINT pInterfaceIOCallbacks;
/** Pointer to the per-disk VD interface list. */
PVDINTERFACE pVDIfsDisk;
/** Pointer to the per-image VD interface list. */
PVDINTERFACE pVDIfsImage;
/** Error interface. */
PVDINTERFACE pInterfaceError;
/** Error interface callback table. */
PVDINTERFACEERROR pInterfaceErrorCallbacks;
/** Open flags passed by VBoxHDD layer. */
unsigned uOpenFlags;
/** Image flags defined during creation or determined during open. */
unsigned uImageFlags;
/** Total size of the image. */
uint64_t cbSize;
/** Physical geometry of this image. */
VDGEOMETRY PCHSGeometry;
/** Logical geometry of this image. */
VDGEOMETRY LCHSGeometry;
/** Image UUID. */
RTUUID ImageUuid;
/** Parent image UUID. */
RTUUID ParentUuid;
/** Parent's time stamp at the time of image creation. */
uint32_t u32ParentTimeStamp;
/** Relative path to the parent image. */
char *pszParentFilename;
/** The Block Allocation Table. */
uint32_t *pBlockAllocationTable;
/** Number of entries in the table. */
uint32_t cBlockAllocationTableEntries;
/** Size of one data block. */
uint32_t cbDataBlock;
/** Sectors per data block. */
uint32_t cSectorsPerDataBlock;
/** Length of the sector bitmap in bytes. */
uint32_t cbDataBlockBitmap;
/** A copy of the disk footer. */
VHDFooter vhdFooterCopy;
/** Current end offset of the file (without the disk footer). */
uint64_t uCurrentEndOfFile;
/** Size of the data block bitmap in sectors. */
uint32_t cDataBlockBitmapSectors;
/** Start of the block allocation table. */
uint64_t uBlockAllocationTableOffset;
/** Buffer to hold block's bitmap for bit search operations. */
uint8_t *pu8Bitmap;
/** Offset to the next data structure (dynamic disk header). */
uint64_t u64DataOffset;
/** Flag to force dynamic disk header update. */
bool fDynHdrNeedsUpdate;
} VHDIMAGE, *PVHDIMAGE;
/**
* Structure tracking the expansion process of the image
* for async access.
*/
typedef struct VHDIMAGEEXPAND
{
/** Flag indicating the status of each step. */
volatile uint32_t fFlags;
/** The index in the block allocation table which is written. */
uint32_t idxBatAllocated;
/** Big endian representation of the block index
* which is written in the BAT. */
uint32_t idxBlockBe;
/** Old end of the file - used for rollback in case of an error. */
uint64_t cbEofOld;
/** Sector bitmap written to the new block - variable in size. */
uint8_t au8Bitmap[1];
} VHDIMAGEEXPAND, *PVHDIMAGEEXPAND;
/**
* Flag defines
*/
#define VHDIMAGEEXPAND_STEP_IN_PROGRESS (0x0)
#define VHDIMAGEEXPAND_STEP_FAILED (0x2)
#define VHDIMAGEEXPAND_STEP_SUCCESS (0x3)
/** All steps completed successfully. */
#define VHDIMAGEEXPAND_ALL_SUCCESS (0xff)
/** All steps completed (no success indicator) */
#define VHDIMAGEEXPAND_ALL_COMPLETE (0xaa)
/** Every status field has 2 bits so we can encode 4 steps in one byte. */
#define VHDIMAGEEXPAND_STATUS_MASK 0x03
#define VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT 0x00
#define VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT 0x02
#define VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT 0x04
#define VHDIMAGEEXPAND_BAT_STATUS_SHIFT 0x06
/**
* Helper macros to get and set the status field.
*/
#define VHDIMAGEEXPAND_STATUS_GET(fFlags, cShift) \
(((fFlags) >> (cShift)) & VHDIMAGEEXPAND_STATUS_MASK)
#define VHDIMAGEEXPAND_STATUS_SET(fFlags, cShift, uVal) \
ASMAtomicOrU32(&(fFlags), ((uVal) & VHDIMAGEEXPAND_STATUS_MASK) << (cShift))
/*******************************************************************************
* Static Variables *
*******************************************************************************/
/** NULL-terminated array of supported file extensions. */
static const char *const s_apszVhdFileExtensions[] =
{
"vhd",
NULL
};
/*******************************************************************************
* Internal Functions *
*******************************************************************************/
/**
* Internal: signal an error to the frontend.
*/
DECLINLINE(int) vhdError(PVHDIMAGE pImage, int rc, RT_SRC_POS_DECL,
const char *pszFormat, ...)
{
va_list va;
va_start(va, pszFormat);
if (pImage->pInterfaceError && pImage->pInterfaceErrorCallbacks)
pImage->pInterfaceErrorCallbacks->pfnError(pImage->pInterfaceError->pvUser, rc, RT_SRC_POS_ARGS,
pszFormat, va);
va_end(va);
return rc;
}
/**
* Internal: signal an informational message to the frontend.
*/
DECLINLINE(int) vhdMessage(PVHDIMAGE pImage, const char *pszFormat, ...)
{
int rc = VINF_SUCCESS;
va_list va;
va_start(va, pszFormat);
if (pImage->pInterfaceError && pImage->pInterfaceErrorCallbacks)
rc = pImage->pInterfaceErrorCallbacks->pfnMessage(pImage->pInterfaceError->pvUser,
pszFormat, va);
va_end(va);
return rc;
}
DECLINLINE(int) vhdFileOpen(PVHDIMAGE pImage, const char *pszFilename,
uint32_t fOpen)
{
return pImage->pInterfaceIOCallbacks->pfnOpen(pImage->pInterfaceIO->pvUser,
pszFilename, fOpen,
&pImage->pStorage);
}
DECLINLINE(int) vhdFileClose(PVHDIMAGE pImage)
{
return pImage->pInterfaceIOCallbacks->pfnClose(pImage->pInterfaceIO->pvUser,
pImage->pStorage);
}
DECLINLINE(int) vhdFileDelete(PVHDIMAGE pImage, const char *pszFilename)
{
return pImage->pInterfaceIOCallbacks->pfnDelete(pImage->pInterfaceIO->pvUser,
pszFilename);
}
DECLINLINE(int) vhdFileMove(PVHDIMAGE pImage, const char *pszSrc,
const char *pszDst, unsigned fMove)
{
return pImage->pInterfaceIOCallbacks->pfnMove(pImage->pInterfaceIO->pvUser,
pszSrc, pszDst, fMove);
}
DECLINLINE(int) vhdFileGetFreeSpace(PVHDIMAGE pImage, const char *pszFilename,
int64_t *pcbFree)
{
return pImage->pInterfaceIOCallbacks->pfnGetFreeSpace(pImage->pInterfaceIO->pvUser,
pszFilename, pcbFree);
}
DECLINLINE(int) vhdFileGetModificationTime(PVHDIMAGE pImage,
const char *pszFilename,
PRTTIMESPEC pModificationTime)
{
return pImage->pInterfaceIOCallbacks->pfnGetModificationTime(pImage->pInterfaceIO->pvUser,
pszFilename,
pModificationTime);
}
DECLINLINE(int) vhdFileGetSize(PVHDIMAGE pImage, uint64_t *pcbSize)
{
return pImage->pInterfaceIOCallbacks->pfnGetSize(pImage->pInterfaceIO->pvUser,
pImage->pStorage, pcbSize);
}
DECLINLINE(int) vhdFileSetSize(PVHDIMAGE pImage, uint64_t cbSize)
{
return pImage->pInterfaceIOCallbacks->pfnSetSize(pImage->pInterfaceIO->pvUser,
pImage->pStorage, cbSize);
}
DECLINLINE(int) vhdFileWriteSync(PVHDIMAGE pImage, uint64_t uOffset,
const void *pvBuffer, size_t cbBuffer,
size_t *pcbWritten)
{
return pImage->pInterfaceIOCallbacks->pfnWriteSync(pImage->pInterfaceIO->pvUser,
pImage->pStorage, uOffset,
pvBuffer, cbBuffer, pcbWritten);
}
DECLINLINE(int) vhdFileReadSync(PVHDIMAGE pImage, uint64_t uOffset,
void *pvBuffer, size_t cbBuffer, size_t *pcbRead)
{
return pImage->pInterfaceIOCallbacks->pfnReadSync(pImage->pInterfaceIO->pvUser,
pImage->pStorage, uOffset,
pvBuffer, cbBuffer, pcbRead);
}
DECLINLINE(int) vhdFileFlushSync(PVHDIMAGE pImage)
{
return pImage->pInterfaceIOCallbacks->pfnFlushSync(pImage->pInterfaceIO->pvUser,
pImage->pStorage);
}
DECLINLINE(int) vhdFileReadUserAsync(PVHDIMAGE pImage, uint64_t uOffset,
PVDIOCTX pIoCtx, size_t cbRead)
{
return pImage->pInterfaceIOCallbacks->pfnReadUserAsync(pImage->pInterfaceIO->pvUser,
pImage->pStorage,
uOffset, pIoCtx,
cbRead);
}
DECLINLINE(int) vhdFileWriteUserAsync(PVHDIMAGE pImage, uint64_t uOffset,
PVDIOCTX pIoCtx, size_t cbWrite,
PFNVDXFERCOMPLETED pfnComplete,
void *pvCompleteUser)
{
return pImage->pInterfaceIOCallbacks->pfnWriteUserAsync(pImage->pInterfaceIO->pvUser,
pImage->pStorage,
uOffset, pIoCtx,
cbWrite,
pfnComplete,
pvCompleteUser);
}
DECLINLINE(int) vhdFileReadMetaAsync(PVHDIMAGE pImage, uint64_t uOffset,
void *pvBuffer, size_t cbBuffer,
PVDIOCTX pIoCtx, PPVDMETAXFER ppMetaXfer,
PFNVDXFERCOMPLETED pfnComplete,
void *pvCompleteUser)
{
return pImage->pInterfaceIOCallbacks->pfnReadMetaAsync(pImage->pInterfaceIO->pvUser,
pImage->pStorage,
uOffset, pvBuffer,
cbBuffer, pIoCtx,
ppMetaXfer,
pfnComplete,
pvCompleteUser);
}
DECLINLINE(int) vhdFileWriteMetaAsync(PVHDIMAGE pImage, uint64_t uOffset,
void *pvBuffer, size_t cbBuffer,
PVDIOCTX pIoCtx,
PFNVDXFERCOMPLETED pfnComplete,
void *pvCompleteUser)
{
return pImage->pInterfaceIOCallbacks->pfnWriteMetaAsync(pImage->pInterfaceIO->pvUser,
pImage->pStorage,
uOffset, pvBuffer,
cbBuffer, pIoCtx,
pfnComplete,
pvCompleteUser);
}
DECLINLINE(int) vhdFileFlushAsync(PVHDIMAGE pImage, PVDIOCTX pIoCtx,
PFNVDXFERCOMPLETED pfnComplete,
void *pvCompleteUser)
{
return pImage->pInterfaceIOCallbacks->pfnFlushAsync(pImage->pInterfaceIO->pvUser,
pImage->pStorage,
pIoCtx, pfnComplete,
pvCompleteUser);
}
DECLINLINE(void) vhdFileMetaXferRelease(PVHDIMAGE pImage, PVDMETAXFER pMetaXfer)
{
pImage->pInterfaceIOCallbacks->pfnMetaXferRelease(pImage->pInterfaceIO->pvUser,
pMetaXfer);
}
/**
* Internal: Compute and update header checksum.
*/
static uint32_t vhdChecksum(void *pHeader, uint32_t cbSize)
{
uint32_t checksum = 0;
for (uint32_t i = 0; i < cbSize; i++)
checksum += ((unsigned char *)pHeader)[i];
return ~checksum;
}
/**
* Internal: Convert filename to UTF16 with appropriate endianness.
*/
static int vhdFilenameToUtf16(const char *pszFilename, uint16_t *pu16Buf,
uint32_t cbBufSize, uint32_t *pcbActualSize,
bool fBigEndian)
{
int rc;
PRTUTF16 tmp16 = NULL;
size_t cTmp16Len;
rc = RTStrToUtf16(pszFilename, &tmp16);
if (RT_FAILURE(rc))
goto out;
cTmp16Len = RTUtf16Len(tmp16);
if (cTmp16Len * sizeof(*tmp16) > cbBufSize)
{
rc = VERR_FILENAME_TOO_LONG;
goto out;
}
if (fBigEndian)
for (unsigned i = 0; i < cTmp16Len; i++)
pu16Buf[i] = RT_H2BE_U16(tmp16[i]);
else
memcpy(pu16Buf, tmp16, cTmp16Len * sizeof(*tmp16));
if (pcbActualSize)
*pcbActualSize = (uint32_t)(cTmp16Len * sizeof(*tmp16));
out:
if (tmp16)
RTUtf16Free(tmp16);
return rc;
}
/**
* Internal: Update one locator entry.
*/
static int vhdLocatorUpdate(PVHDIMAGE pImage, PVHDPLE pLocator, const char *pszFilename)
{
int rc;
uint32_t cb, cbMaxLen = RT_BE2H_U32(pLocator->u32DataSpace) * VHD_SECTOR_SIZE;
void *pvBuf = RTMemTmpAllocZ(cbMaxLen);
char *pszTmp;
if (!pvBuf)
{
rc = VERR_NO_MEMORY;
goto out;
}
switch (RT_BE2H_U32(pLocator->u32Code))
{
case VHD_PLATFORM_CODE_WI2R:
/* Update plain relative name. */
cb = (uint32_t)strlen(pszFilename);
if (cb > cbMaxLen)
{
rc = VERR_FILENAME_TOO_LONG;
goto out;
}
memcpy(pvBuf, pszFilename, cb);
pLocator->u32DataLength = RT_H2BE_U32(cb);
break;
case VHD_PLATFORM_CODE_WI2K:
/* Update plain absolute name. */
rc = RTPathAbs(pszFilename, (char *)pvBuf, cbMaxLen);
if (RT_FAILURE(rc))
goto out;
pLocator->u32DataLength = RT_H2BE_U32((uint32_t)strlen((const char *)pvBuf));
break;
case VHD_PLATFORM_CODE_W2RU:
/* Update unicode relative name. */
rc = vhdFilenameToUtf16(pszFilename, (uint16_t *)pvBuf, cbMaxLen, &cb, false);
if (RT_FAILURE(rc))
goto out;
pLocator->u32DataLength = RT_H2BE_U32(cb);
break;
case VHD_PLATFORM_CODE_W2KU:
/* Update unicode absolute name. */
pszTmp = (char*)RTMemTmpAllocZ(cbMaxLen);
if (!pszTmp)
{
rc = VERR_NO_MEMORY;
goto out;
}
rc = RTPathAbs(pszFilename, pszTmp, cbMaxLen);
if (RT_FAILURE(rc))
{
RTMemTmpFree(pszTmp);
goto out;
}
rc = vhdFilenameToUtf16(pszTmp, (uint16_t *)pvBuf, cbMaxLen, &cb, false);
RTMemTmpFree(pszTmp);
if (RT_FAILURE(rc))
goto out;
pLocator->u32DataLength = RT_H2BE_U32(cb);
break;
default:
rc = VERR_NOT_IMPLEMENTED;
goto out;
}
rc = vhdFileWriteSync(pImage, RT_BE2H_U64(pLocator->u64DataOffset),
pvBuf, RT_BE2H_U32(pLocator->u32DataSpace) * VHD_SECTOR_SIZE,
NULL);
out:
if (pvBuf)
RTMemTmpFree(pvBuf);
return rc;
}
/**
* Internal: Update dynamic disk header from VHDIMAGE.
*/
static int vhdDynamicHeaderUpdate(PVHDIMAGE pImage)
{
VHDDynamicDiskHeader ddh;
int rc, i;
if (!pImage)
return VERR_VD_NOT_OPENED;
rc = vhdFileReadSync(pImage, pImage->u64DataOffset, &ddh, sizeof(ddh), NULL);
if (RT_FAILURE(rc))
return rc;
if (memcmp(ddh.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE) != 0)
return VERR_VD_VHD_INVALID_HEADER;
uint32_t u32Checksum = RT_BE2H_U32(ddh.Checksum);
ddh.Checksum = 0;
if (u32Checksum != vhdChecksum(&ddh, sizeof(ddh)))
return VERR_VD_VHD_INVALID_HEADER;
/* Update parent's timestamp. */
ddh.ParentTimeStamp = RT_H2BE_U32(pImage->u32ParentTimeStamp);
/* Update parent's filename. */
if (pImage->pszParentFilename)
{
rc = vhdFilenameToUtf16(RTPathFilename(pImage->pszParentFilename),
ddh.ParentUnicodeName, sizeof(ddh.ParentUnicodeName) - 1, NULL, true);
if (RT_FAILURE(rc))
return rc;
}
/* Update parent's locators. */
for (i = 0; i < VHD_MAX_LOCATOR_ENTRIES; i++)
{
/* Skip empty locators */
if (ddh.ParentLocatorEntry[i].u32Code != RT_H2BE_U32(VHD_PLATFORM_CODE_NONE))
{
if (pImage->pszParentFilename)
{
rc = vhdLocatorUpdate(pImage, &ddh.ParentLocatorEntry[i], pImage->pszParentFilename);
if (RT_FAILURE(rc))
return rc;
}
else
{
/* The parent was deleted. */
ddh.ParentLocatorEntry[i].u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_NONE);
}
}
}
/* Update parent's UUID */
memcpy(ddh.ParentUuid, pImage->ParentUuid.au8, sizeof(ddh.ParentUuid));
/* Update data offset and number of table entries. */
ddh.MaxTableEntries = RT_H2BE_U32(pImage->cBlockAllocationTableEntries);
ddh.Checksum = 0;
ddh.Checksum = RT_H2BE_U32(vhdChecksum(&ddh, sizeof(ddh)));
rc = vhdFileWriteSync(pImage, pImage->u64DataOffset, &ddh, sizeof(ddh), NULL);
return rc;
}
/**
* Internal: Update the VHD footer.
*/
static int vhdUpdateFooter(PVHDIMAGE pImage)
{
int rc = VINF_SUCCESS;
/* Update fields which can change. */
pImage->vhdFooterCopy.CurSize = RT_H2BE_U64(pImage->cbSize);
pImage->vhdFooterCopy.DiskGeometryCylinder = RT_H2BE_U16(pImage->PCHSGeometry.cCylinders);
pImage->vhdFooterCopy.DiskGeometryHeads = pImage->PCHSGeometry.cHeads;
pImage->vhdFooterCopy.DiskGeometrySectors = pImage->PCHSGeometry.cSectors;
pImage->vhdFooterCopy.Checksum = 0;
pImage->vhdFooterCopy.Checksum = RT_H2BE_U32(vhdChecksum(&pImage->vhdFooterCopy, sizeof(VHDFooter)));
if (pImage->pBlockAllocationTable)
rc = vhdFileWriteSync(pImage, 0, &pImage->vhdFooterCopy,
sizeof(VHDFooter), NULL);
if (RT_SUCCESS(rc))
rc = vhdFileWriteSync(pImage, pImage->uCurrentEndOfFile,
&pImage->vhdFooterCopy, sizeof(VHDFooter), NULL);
return rc;
}
/**
* Internal. Flush image data to disk.
*/
static int vhdFlushImage(PVHDIMAGE pImage)
{
int rc = VINF_SUCCESS;
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
return VINF_SUCCESS;
if (pImage->pBlockAllocationTable)
{
/*
* This is an expanding image. Write the BAT and copy of the disk footer.
*/
size_t cbBlockAllocationTableToWrite = pImage->cBlockAllocationTableEntries * sizeof(uint32_t);
uint32_t *pBlockAllocationTableToWrite = (uint32_t *)RTMemAllocZ(cbBlockAllocationTableToWrite);
if (!pBlockAllocationTableToWrite)
return VERR_NO_MEMORY;
/*
* The BAT entries have to be stored in big endian format.
*/
for (unsigned i = 0; i < pImage->cBlockAllocationTableEntries; i++)
pBlockAllocationTableToWrite[i] = RT_H2BE_U32(pImage->pBlockAllocationTable[i]);
/*
* Write the block allocation table after the copy of the disk footer and the dynamic disk header.
*/
vhdFileWriteSync(pImage, pImage->uBlockAllocationTableOffset,
pBlockAllocationTableToWrite,
cbBlockAllocationTableToWrite, NULL);
if (pImage->fDynHdrNeedsUpdate)
rc = vhdDynamicHeaderUpdate(pImage);
RTMemFree(pBlockAllocationTableToWrite);
}
if (RT_SUCCESS(rc))
rc = vhdUpdateFooter(pImage);
if (RT_SUCCESS(rc))
rc = vhdFileFlushSync(pImage);
return rc;
}
/**
* Internal. Free all allocated space for representing an image except pImage,
* and optionally delete the image from disk.
*/
static int vhdFreeImage(PVHDIMAGE pImage, bool fDelete)
{
int rc = VINF_SUCCESS;
/* Freeing a never allocated image (e.g. because the open failed) is
* not signalled as an error. After all nothing bad happens. */
if (pImage)
{
if (pImage->pStorage)
{
/* No point updating the file that is deleted anyway. */
if (!fDelete)
vhdFlushImage(pImage);
vhdFileClose(pImage);
pImage->pStorage = NULL;
}
if (pImage->pszParentFilename)
{
RTStrFree(pImage->pszParentFilename);
pImage->pszParentFilename = NULL;
}
if (pImage->pBlockAllocationTable)
{
RTMemFree(pImage->pBlockAllocationTable);
pImage->pBlockAllocationTable = NULL;
}
if (pImage->pu8Bitmap)
{
RTMemFree(pImage->pu8Bitmap);
pImage->pu8Bitmap = NULL;
}
if (fDelete && pImage->pszFilename)
rc = vhdFileDelete(pImage, pImage->pszFilename);
}
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/* 946684800 is the number of seconds between 1/1/1970 and 1/1/2000 */
#define VHD_TO_UNIX_EPOCH_SECONDS UINT64_C(946684800)
static uint32_t vhdRtTime2VhdTime(PCRTTIMESPEC pRtTimeStamp)
{
uint64_t u64Seconds = RTTimeSpecGetSeconds(pRtTimeStamp);
return (uint32_t)(u64Seconds - VHD_TO_UNIX_EPOCH_SECONDS);
}
static void vhdTime2RtTime(PRTTIMESPEC pRtTimeStamp, uint32_t u32VhdTimeStamp)
{
RTTimeSpecSetSeconds(pRtTimeStamp, VHD_TO_UNIX_EPOCH_SECONDS + u32VhdTimeStamp);
}
/**
* Internal: Allocates the block bitmap rounding up to the next 32bit or 64bit boundary.
* Can be freed with RTMemFree. The memory is zeroed.
*/
DECLINLINE(uint8_t *)vhdBlockBitmapAllocate(PVHDIMAGE pImage)
{
#ifdef RT_ARCH_AMD64
return (uint8_t *)RTMemAllocZ(pImage->cbDataBlockBitmap + 8);
#else
return (uint8_t *)RTMemAllocZ(pImage->cbDataBlockBitmap + 4);
#endif
}
/**
* Internal: called when the async expansion process completed (failure or success).
* Will do the necessary rollback if an error occurred.
*/
static int vhdAsyncExpansionComplete(PVHDIMAGE pImage, PVDIOCTX pIoCtx, PVHDIMAGEEXPAND pExpand)
{
int rc = VINF_SUCCESS;
uint32_t fFlags = ASMAtomicReadU32(&pExpand->fFlags);
bool fIoInProgress = false;
/* Quick path, check if everything succeeded. */
if (fFlags == VHDIMAGEEXPAND_ALL_SUCCESS)
{
RTMemFree(pExpand);
}
else
{
uint32_t uStatus;
uStatus = VHDIMAGEEXPAND_STATUS_GET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT);
if ( uStatus == VHDIMAGEEXPAND_STEP_FAILED
|| uStatus == VHDIMAGEEXPAND_STEP_SUCCESS)
{
/* Undo and restore the old value. */
pImage->pBlockAllocationTable[pExpand->idxBatAllocated] = ~0U;
/* Restore the old value on the disk.
* No need for a completion callback because we can't
* do anything if this fails. */
if (uStatus == VHDIMAGEEXPAND_STEP_SUCCESS)
{
rc = vhdFileWriteMetaAsync(pImage,
pImage->uBlockAllocationTableOffset
+ pExpand->idxBatAllocated * sizeof(uint32_t),
&pImage->pBlockAllocationTable[pExpand->idxBatAllocated],
sizeof(uint32_t), pIoCtx, NULL, NULL);
fIoInProgress |= rc == VERR_VD_ASYNC_IO_IN_PROGRESS;
}
}
/* Restore old size (including the footer because another application might
* fill up the free space making it impossible to add the footer)
* and add the footer at the right place again. */
rc = vhdFileSetSize(pImage, pExpand->cbEofOld + sizeof(VHDFooter));
AssertRC(rc);
pImage->uCurrentEndOfFile = pExpand->cbEofOld;
rc = vhdFileWriteMetaAsync(pImage, pImage->uCurrentEndOfFile,
&pImage->vhdFooterCopy, sizeof(VHDFooter),
pIoCtx, NULL, NULL);
fIoInProgress |= rc == VERR_VD_ASYNC_IO_IN_PROGRESS;
}
return fIoInProgress ? VERR_VD_ASYNC_IO_IN_PROGRESS : rc;
}
static int vhdAsyncExpansionStepCompleted(void *pBackendData, PVDIOCTX pIoCtx, void *pvUser, int rcReq, unsigned iStep)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
PVHDIMAGEEXPAND pExpand = (PVHDIMAGEEXPAND)pvUser;
LogFlowFunc(("pBackendData=%#p pIoCtx=%#p pvUser=%#p rcReq=%Rrc iStep=%u\n",
pBackendData, pIoCtx, pvUser, rcReq, iStep));
if (RT_SUCCESS(rcReq))
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, iStep, VHDIMAGEEXPAND_STEP_SUCCESS);
else
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, iStep, VHDIMAGEEXPAND_STEP_FAILED);
if ((pExpand->fFlags & VHDIMAGEEXPAND_ALL_COMPLETE) == VHDIMAGEEXPAND_ALL_COMPLETE)
return vhdAsyncExpansionComplete(pImage, pIoCtx, pExpand);
return VERR_VD_ASYNC_IO_IN_PROGRESS;
}
static int vhdAsyncExpansionDataBlockBitmapComplete(void *pBackendData, PVDIOCTX pIoCtx, void *pvUser, int rcReq)
{
return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT);
}
static int vhdAsyncExpansionDataComplete(void *pBackendData, PVDIOCTX pIoCtx, void *pvUser, int rcReq)
{
return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT);
}
static int vhdAsyncExpansionBatUpdateComplete(void *pBackendData, PVDIOCTX pIoCtx, void *pvUser, int rcReq)
{
return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_BAT_STATUS_SHIFT);
}
static int vhdAsyncExpansionFooterUpdateComplete(void *pBackendData, PVDIOCTX pIoCtx, void *pvUser, int rcReq)
{
return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT);
}
static int vhdLoadDynamicDisk(PVHDIMAGE pImage, uint64_t uDynamicDiskHeaderOffset)
{
VHDDynamicDiskHeader vhdDynamicDiskHeader;
int rc = VINF_SUCCESS;
uint32_t *pBlockAllocationTable;
uint64_t uBlockAllocationTableOffset;
unsigned i = 0;
Log(("Open a dynamic disk.\n"));
/*
* Read the dynamic disk header.
*/
rc = vhdFileReadSync(pImage, uDynamicDiskHeaderOffset,
&vhdDynamicDiskHeader, sizeof(VHDDynamicDiskHeader),
NULL);
if (memcmp(vhdDynamicDiskHeader.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE))
return VERR_INVALID_PARAMETER;
pImage->cbDataBlock = RT_BE2H_U32(vhdDynamicDiskHeader.BlockSize);
LogFlowFunc(("BlockSize=%u\n", pImage->cbDataBlock));
pImage->cBlockAllocationTableEntries = RT_BE2H_U32(vhdDynamicDiskHeader.MaxTableEntries);
LogFlowFunc(("MaxTableEntries=%lu\n", pImage->cBlockAllocationTableEntries));
AssertMsg(!(pImage->cbDataBlock % VHD_SECTOR_SIZE), ("%s: Data block size is not a multiple of %!\n", __FUNCTION__, VHD_SECTOR_SIZE));
pImage->cSectorsPerDataBlock = pImage->cbDataBlock / VHD_SECTOR_SIZE;
LogFlowFunc(("SectorsPerDataBlock=%u\n", pImage->cSectorsPerDataBlock));
/*
* Every block starts with a bitmap indicating which sectors are valid and which are not.
* We store the size of it to be able to calculate the real offset.
*/
pImage->cbDataBlockBitmap = pImage->cSectorsPerDataBlock / 8;
pImage->cDataBlockBitmapSectors = pImage->cbDataBlockBitmap / VHD_SECTOR_SIZE;
/* Round up to full sector size */
if (pImage->cbDataBlockBitmap % VHD_SECTOR_SIZE > 0)
pImage->cDataBlockBitmapSectors++;
LogFlowFunc(("cbDataBlockBitmap=%u\n", pImage->cbDataBlockBitmap));
LogFlowFunc(("cDataBlockBitmapSectors=%u\n", pImage->cDataBlockBitmapSectors));
pImage->pu8Bitmap = vhdBlockBitmapAllocate(pImage);
if (!pImage->pu8Bitmap)
return VERR_NO_MEMORY;
pBlockAllocationTable = (uint32_t *)RTMemAllocZ(pImage->cBlockAllocationTableEntries * sizeof(uint32_t));
if (!pBlockAllocationTable)
return VERR_NO_MEMORY;
/*
* Read the table.
*/
uBlockAllocationTableOffset = RT_BE2H_U64(vhdDynamicDiskHeader.TableOffset);
LogFlowFunc(("uBlockAllocationTableOffset=%llu\n", uBlockAllocationTableOffset));
pImage->uBlockAllocationTableOffset = uBlockAllocationTableOffset;
rc = vhdFileReadSync(pImage, uBlockAllocationTableOffset,
pBlockAllocationTable,
pImage->cBlockAllocationTableEntries * sizeof(uint32_t),
NULL);
/*
* Because the offset entries inside the allocation table are stored big endian
* we need to convert them into host endian.
*/
pImage->pBlockAllocationTable = (uint32_t *)RTMemAllocZ(pImage->cBlockAllocationTableEntries * sizeof(uint32_t));
if (!pImage->pBlockAllocationTable)
{
RTMemFree(pBlockAllocationTable);
return VERR_NO_MEMORY;
}
for (i = 0; i < pImage->cBlockAllocationTableEntries; i++)
pImage->pBlockAllocationTable[i] = RT_BE2H_U32(pBlockAllocationTable[i]);
RTMemFree(pBlockAllocationTable);
if (pImage->uImageFlags & VD_IMAGE_FLAGS_DIFF)
memcpy(pImage->ParentUuid.au8, vhdDynamicDiskHeader.ParentUuid, sizeof(pImage->ParentUuid));
return rc;
}
static int vhdOpenImage(PVHDIMAGE pImage, unsigned uOpenFlags)
{
uint64_t FileSize;
VHDFooter vhdFooter;
pImage->uOpenFlags = uOpenFlags;
pImage->pInterfaceError = VDInterfaceGet(pImage->pVDIfsDisk, VDINTERFACETYPE_ERROR);
if (pImage->pInterfaceError)
pImage->pInterfaceErrorCallbacks = VDGetInterfaceError(pImage->pInterfaceError);
/* Get I/O interface. */
pImage->pInterfaceIO = VDInterfaceGet(pImage->pVDIfsImage, VDINTERFACETYPE_IOINT);
AssertPtrReturn(pImage->pInterfaceIO, VERR_INVALID_PARAMETER);
pImage->pInterfaceIOCallbacks = VDGetInterfaceIOInt(pImage->pInterfaceIO);
AssertPtrReturn(pImage->pInterfaceIOCallbacks, VERR_INVALID_PARAMETER);
/*
* Open the image.
*/
int rc = vhdFileOpen(pImage, pImage->pszFilename,
VDOpenFlagsToFileOpenFlags(uOpenFlags,
false /* fCreate */));
if (RT_FAILURE(rc))
{
/* Do NOT signal an appropriate error here, as the VD layer has the
* choice of retrying the open if it failed. */
return rc;
}
rc = vhdFileGetSize(pImage, &FileSize);
pImage->uCurrentEndOfFile = FileSize - sizeof(VHDFooter);
rc = vhdFileReadSync(pImage, pImage->uCurrentEndOfFile,
&vhdFooter, sizeof(VHDFooter), NULL);
if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
return VERR_VD_VHD_INVALID_HEADER;
switch (RT_BE2H_U32(vhdFooter.DiskType))
{
case VHD_FOOTER_DISK_TYPE_FIXED:
{
pImage->uImageFlags |= VD_IMAGE_FLAGS_FIXED;
}
break;
case VHD_FOOTER_DISK_TYPE_DYNAMIC:
{
pImage->uImageFlags &= ~VD_IMAGE_FLAGS_FIXED;
}
break;
case VHD_FOOTER_DISK_TYPE_DIFFERENCING:
{
pImage->uImageFlags |= VD_IMAGE_FLAGS_DIFF;
pImage->uImageFlags &= ~VD_IMAGE_FLAGS_FIXED;
}
break;
default:
return VERR_NOT_IMPLEMENTED;
}
pImage->cbSize = RT_BE2H_U64(vhdFooter.CurSize);
pImage->LCHSGeometry.cCylinders = 0;
pImage->LCHSGeometry.cHeads = 0;
pImage->LCHSGeometry.cSectors = 0;
pImage->PCHSGeometry.cCylinders = RT_BE2H_U16(vhdFooter.DiskGeometryCylinder);
pImage->PCHSGeometry.cHeads = vhdFooter.DiskGeometryHeads;
pImage->PCHSGeometry.cSectors = vhdFooter.DiskGeometrySectors;
/*
* Copy of the disk footer.
* If we allocate new blocks in differencing disks on write access
* the footer is overwritten. We need to write it at the end of the file.
*/
memcpy(&pImage->vhdFooterCopy, &vhdFooter, sizeof(VHDFooter));
/*
* Is there a better way?
*/
memcpy(&pImage->ImageUuid, &vhdFooter.UniqueID, 16);
pImage->u64DataOffset = RT_BE2H_U64(vhdFooter.DataOffset);
LogFlowFunc(("DataOffset=%llu\n", pImage->u64DataOffset));
if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
rc = vhdLoadDynamicDisk(pImage, pImage->u64DataOffset);
if (RT_FAILURE(rc))
vhdFreeImage(pImage, false);
return rc;
}
/**
* Internal: Checks if a sector in the block bitmap is set
*/
DECLINLINE(bool) vhdBlockBitmapSectorContainsData(PVHDIMAGE pImage, uint32_t cBlockBitmapEntry)
{
uint32_t iBitmap = (cBlockBitmapEntry / 8); /* Byte in the block bitmap. */
/*
* The index of the bit in the byte of the data block bitmap.
* The most signifcant bit stands for a lower sector number.
*/
uint8_t iBitInByte = (8-1) - (cBlockBitmapEntry % 8);
uint8_t *puBitmap = pImage->pu8Bitmap + iBitmap;
AssertMsg(puBitmap < (pImage->pu8Bitmap + pImage->cbDataBlockBitmap),
("VHD: Current bitmap position exceeds maximum size of the bitmap\n"));
return ASMBitTest(puBitmap, iBitInByte);
}
/**
* Internal: Sets the given sector in the sector bitmap.
*/
DECLINLINE(bool) vhdBlockBitmapSectorSet(PVHDIMAGE pImage, uint8_t *pu8Bitmap, uint32_t cBlockBitmapEntry)
{
uint32_t iBitmap = (cBlockBitmapEntry / 8); /* Byte in the block bitmap. */
/*
* The index of the bit in the byte of the data block bitmap.
* The most significant bit stands for a lower sector number.
*/
uint8_t iBitInByte = (8-1) - (cBlockBitmapEntry % 8);
uint8_t *puBitmap = pu8Bitmap + iBitmap;
AssertMsg(puBitmap < (pu8Bitmap + pImage->cbDataBlockBitmap),
("VHD: Current bitmap position exceeds maximum size of the bitmap\n"));
return !ASMBitTestAndSet(puBitmap, iBitInByte);
}
/**
* Internal: Derive drive geometry from its size.
*/
static void vhdSetDiskGeometry(PVHDIMAGE pImage, uint64_t cbSize)
{
uint64_t u64TotalSectors = cbSize / VHD_SECTOR_SIZE;
uint32_t u32CylinderTimesHeads, u32Heads, u32SectorsPerTrack;
if (u64TotalSectors > 65535 * 16 * 255)
{
/* ATA disks limited to 127 GB. */
u64TotalSectors = 65535 * 16 * 255;
}
if (u64TotalSectors >= 65535 * 16 * 63)
{
u32SectorsPerTrack = 255;
u32Heads = 16;
u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
}
else
{
u32SectorsPerTrack = 17;
u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
u32Heads = (u32CylinderTimesHeads + 1023) / 1024;
if (u32Heads < 4)
{
u32Heads = 4;
}
if (u32CylinderTimesHeads >= (u32Heads * 1024) || u32Heads > 16)
{
u32SectorsPerTrack = 31;
u32Heads = 16;
u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
}
if (u32CylinderTimesHeads >= (u32Heads * 1024))
{
u32SectorsPerTrack = 63;
u32Heads = 16;
u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
}
}
pImage->PCHSGeometry.cCylinders = u32CylinderTimesHeads / u32Heads;
pImage->PCHSGeometry.cHeads = u32Heads;
pImage->PCHSGeometry.cSectors = u32SectorsPerTrack;
pImage->LCHSGeometry.cCylinders = 0;
pImage->LCHSGeometry.cHeads = 0;
pImage->LCHSGeometry.cSectors = 0;
}
static uint32_t vhdAllocateParentLocators(PVHDIMAGE pImage, VHDDynamicDiskHeader *pDDH, uint64_t u64Offset)
{
PVHDPLE pLocator = pDDH->ParentLocatorEntry;
/* Relative Windows path. */
pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_WI2R);
pLocator->u32DataSpace = RT_H2BE_U32(VHD_RELATIVE_MAX_PATH / VHD_SECTOR_SIZE);
pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
u64Offset += VHD_RELATIVE_MAX_PATH;
pLocator++;
/* Absolute Windows path. */
pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_WI2K);
pLocator->u32DataSpace = RT_H2BE_U32(VHD_ABSOLUTE_MAX_PATH / VHD_SECTOR_SIZE);
pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
u64Offset += VHD_ABSOLUTE_MAX_PATH;
pLocator++;
/* Unicode relative Windows path. */
pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_W2RU);
pLocator->u32DataSpace = RT_H2BE_U32(VHD_RELATIVE_MAX_PATH * sizeof(RTUTF16) / VHD_SECTOR_SIZE);
pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
u64Offset += VHD_RELATIVE_MAX_PATH * sizeof(RTUTF16);
pLocator++;
/* Unicode absolute Windows path. */
pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_W2KU);
pLocator->u32DataSpace = RT_H2BE_U32(VHD_ABSOLUTE_MAX_PATH * sizeof(RTUTF16) / VHD_SECTOR_SIZE);
pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
return u64Offset + VHD_ABSOLUTE_MAX_PATH * sizeof(RTUTF16);
}
/**
* Internal: Additional code for dynamic VHD image creation.
*/
static int vhdCreateDynamicImage(PVHDIMAGE pImage, uint64_t cbSize)
{
int rc;
VHDDynamicDiskHeader DynamicDiskHeader;
uint32_t u32BlockAllocationTableSectors;
void *pvTmp = NULL;
memset(&DynamicDiskHeader, 0, sizeof(DynamicDiskHeader));
pImage->u64DataOffset = sizeof(VHDFooter);
pImage->cbDataBlock = VHD_BLOCK_SIZE; /* 2 MB */
pImage->cSectorsPerDataBlock = pImage->cbDataBlock / VHD_SECTOR_SIZE;
pImage->cbDataBlockBitmap = pImage->cSectorsPerDataBlock / 8;
pImage->cDataBlockBitmapSectors = pImage->cbDataBlockBitmap / VHD_SECTOR_SIZE;
/* Align to sector boundary */
if (pImage->cbDataBlockBitmap % VHD_SECTOR_SIZE > 0)
pImage->cDataBlockBitmapSectors++;
pImage->pu8Bitmap = vhdBlockBitmapAllocate(pImage);
if (!pImage->pu8Bitmap)
return vhdError(pImage, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot allocate memory for bitmap storage"));
/* Initialize BAT. */
pImage->uBlockAllocationTableOffset = (uint64_t)sizeof(VHDFooter) + sizeof(VHDDynamicDiskHeader);
pImage->cBlockAllocationTableEntries = (uint32_t)((cbSize + pImage->cbDataBlock - 1) / pImage->cbDataBlock); /* Align table to the block size. */
u32BlockAllocationTableSectors = (pImage->cBlockAllocationTableEntries * sizeof(uint32_t) + VHD_SECTOR_SIZE - 1) / VHD_SECTOR_SIZE;
pImage->pBlockAllocationTable = (uint32_t *)RTMemAllocZ(pImage->cBlockAllocationTableEntries * sizeof(uint32_t));
if (!pImage->pBlockAllocationTable)
return vhdError(pImage, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot allocate memory for BAT"));
for (unsigned i = 0; i < pImage->cBlockAllocationTableEntries; i++)
{
pImage->pBlockAllocationTable[i] = 0xFFFFFFFF; /* It is actually big endian. */
}
/* Round up to the sector size. */
if (pImage->uImageFlags & VD_IMAGE_FLAGS_DIFF) /* fix hyper-v unreadable error */
pImage->uCurrentEndOfFile = vhdAllocateParentLocators(pImage, &DynamicDiskHeader,
pImage->uBlockAllocationTableOffset + u32BlockAllocationTableSectors * VHD_SECTOR_SIZE);
else
pImage->uCurrentEndOfFile = pImage->uBlockAllocationTableOffset + u32BlockAllocationTableSectors * VHD_SECTOR_SIZE;
/* Set dynamic image size. */
pvTmp = RTMemTmpAllocZ(pImage->uCurrentEndOfFile + sizeof(VHDFooter));
if (!pvTmp)
return vhdError(pImage, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
rc = vhdFileWriteSync(pImage, 0, pvTmp,
pImage->uCurrentEndOfFile + sizeof(VHDFooter), NULL);
if (RT_FAILURE(rc))
{
RTMemTmpFree(pvTmp);
return vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
}
RTMemTmpFree(pvTmp);
/* Initialize and write the dynamic disk header. */
memcpy(DynamicDiskHeader.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, sizeof(DynamicDiskHeader.Cookie));
DynamicDiskHeader.DataOffset = UINT64_C(0xFFFFFFFFFFFFFFFF); /* Initially the disk has no data. */
DynamicDiskHeader.TableOffset = RT_H2BE_U64(pImage->uBlockAllocationTableOffset);
DynamicDiskHeader.HeaderVersion = RT_H2BE_U32(VHD_DYNAMIC_DISK_HEADER_VERSION);
DynamicDiskHeader.BlockSize = RT_H2BE_U32(pImage->cbDataBlock);
DynamicDiskHeader.MaxTableEntries = RT_H2BE_U32(pImage->cBlockAllocationTableEntries);
/* Compute and update checksum. */
DynamicDiskHeader.Checksum = 0;
DynamicDiskHeader.Checksum = RT_H2BE_U32(vhdChecksum(&DynamicDiskHeader, sizeof(DynamicDiskHeader)));
rc = vhdFileWriteSync(pImage, sizeof(VHDFooter), &DynamicDiskHeader,
sizeof(DynamicDiskHeader), NULL);
if (RT_FAILURE(rc))
return vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot write dynamic disk header to image '%s'"), pImage->pszFilename);
/* Write BAT. */
rc = vhdFileWriteSync(pImage, pImage->uBlockAllocationTableOffset,
pImage->pBlockAllocationTable,
pImage->cBlockAllocationTableEntries * sizeof(uint32_t),
NULL);
if (RT_FAILURE(rc))
return vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot write BAT to image '%s'"), pImage->pszFilename);
return rc;
}
/**
* Internal: The actual code for VHD image creation, both fixed and dynamic.
*/
static int vhdCreateImage(PVHDIMAGE pImage, uint64_t cbSize,
unsigned uImageFlags, const char *pszComment,
PCVDGEOMETRY pPCHSGeometry,
PCVDGEOMETRY pLCHSGeometry, PCRTUUID pUuid,
unsigned uOpenFlags,
PFNVDPROGRESS pfnProgress, void *pvUser,
unsigned uPercentStart, unsigned uPercentSpan)
{
int rc;
VHDFooter Footer;
RTTIMESPEC now;
pImage->uOpenFlags = uOpenFlags;
pImage->uImageFlags = uImageFlags;
pImage->pInterfaceError = VDInterfaceGet(pImage->pVDIfsDisk, VDINTERFACETYPE_ERROR);
if (pImage->pInterfaceError)
pImage->pInterfaceErrorCallbacks = VDGetInterfaceError(pImage->pInterfaceError);
rc = vhdFileOpen(pImage, pImage->pszFilename,
VDOpenFlagsToFileOpenFlags(uOpenFlags & ~VD_OPEN_FLAGS_READONLY,
true /* fCreate */));
if (RT_FAILURE(rc))
return vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot create image '%s'"), pImage->pszFilename);
pImage->cbSize = cbSize;
pImage->ImageUuid = *pUuid;
RTUuidClear(&pImage->ParentUuid);
vhdSetDiskGeometry(pImage, cbSize);
/* Initialize the footer. */
memset(&Footer, 0, sizeof(Footer));
memcpy(Footer.Cookie, VHD_FOOTER_COOKIE, sizeof(Footer.Cookie));
Footer.Features = RT_H2BE_U32(0x2);
Footer.Version = RT_H2BE_U32(VHD_FOOTER_FILE_FORMAT_VERSION);
Footer.TimeStamp = RT_H2BE_U32(vhdRtTime2VhdTime(RTTimeNow(&now)));
memcpy(Footer.CreatorApp, "vbox", sizeof(Footer.CreatorApp));
Footer.CreatorVer = RT_H2BE_U32(VBOX_VERSION);
#ifdef RT_OS_DARWIN
Footer.CreatorOS = RT_H2BE_U32(0x4D616320); /* "Mac " */
#else /* Virtual PC supports only two platforms atm, so everything else will be Wi2k. */
Footer.CreatorOS = RT_H2BE_U32(0x5769326B); /* "Wi2k" */
#endif
Footer.OrigSize = RT_H2BE_U64(cbSize);
Footer.CurSize = Footer.OrigSize;
Footer.DiskGeometryCylinder = RT_H2BE_U16(pImage->PCHSGeometry.cCylinders);
Footer.DiskGeometryHeads = pImage->PCHSGeometry.cHeads;
Footer.DiskGeometrySectors = pImage->PCHSGeometry.cSectors;
memcpy(Footer.UniqueID, pImage->ImageUuid.au8, sizeof(Footer.UniqueID));
Footer.SavedState = 0;
if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
{
Footer.DiskType = RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_FIXED);
/*
* Initialize fixed image.
* "The size of the entire file is the size of the hard disk in
* the guest operating system plus the size of the footer."
*/
pImage->u64DataOffset = VHD_FOOTER_DATA_OFFSET_FIXED;
pImage->uCurrentEndOfFile = cbSize;
/** @todo r=klaus replace this with actual data writes, see the experience
* with VDI files on Windows, can cause long freezes when writing. */
rc = vhdFileSetSize(pImage, pImage->uCurrentEndOfFile + sizeof(VHDFooter));
if (RT_FAILURE(rc))
{
vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
goto out;
}
}
else
{
/*
* Initialize dynamic image.
*
* The overall structure of dynamic disk is:
*
* [Copy of hard disk footer (512 bytes)]
* [Dynamic disk header (1024 bytes)]
* [BAT (Block Allocation Table)]
* [Parent Locators]
* [Data block 1]
* [Data block 2]
* ...
* [Data block N]
* [Hard disk footer (512 bytes)]
*/
Footer.DiskType = (uImageFlags & VD_IMAGE_FLAGS_DIFF)
? RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_DIFFERENCING)
: RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_DYNAMIC);
/* We are half way thourgh with creation of image, let the caller know. */
if (pfnProgress)
pfnProgress(pvUser, (uPercentStart + uPercentSpan) / 2);
rc = vhdCreateDynamicImage(pImage, cbSize);
if (RT_FAILURE(rc))
goto out;
}
Footer.DataOffset = RT_H2BE_U64(pImage->u64DataOffset);
/* Compute and update the footer checksum. */
Footer.Checksum = 0;
Footer.Checksum = RT_H2BE_U32(vhdChecksum(&Footer, sizeof(Footer)));
pImage->vhdFooterCopy = Footer;
/* Store the footer */
rc = vhdFileWriteSync(pImage, pImage->uCurrentEndOfFile, &Footer,
sizeof(Footer), NULL);
if (RT_FAILURE(rc))
{
vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot write footer to image '%s'"), pImage->pszFilename);
goto out;
}
/* Dynamic images contain a copy of the footer at the very beginning of the file. */
if (!(uImageFlags & VD_IMAGE_FLAGS_FIXED))
{
/* Write the copy of the footer. */
rc = vhdFileWriteSync(pImage, 0, &Footer, sizeof(Footer), NULL);
if (RT_FAILURE(rc))
{
vhdError(pImage, rc, RT_SRC_POS, N_("VHD: cannot write a copy of footer to image '%s'"), pImage->pszFilename);
goto out;
}
}
out:
if (RT_SUCCESS(rc) && pfnProgress)
pfnProgress(pvUser, uPercentStart + uPercentSpan);
if (RT_FAILURE(rc))
vhdFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnCheckIfValid */
static int vhdCheckIfValid(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
PVDINTERFACE pVDIfsImage)
{
LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
int rc;
PVDIOSTORAGE pStorage;
uint64_t cbFile;
VHDFooter vhdFooter;
/* Get I/O interface. */
PVDINTERFACE pInterfaceIO = VDInterfaceGet(pVDIfsImage, VDINTERFACETYPE_IOINT);
AssertPtrReturn(pInterfaceIO, VERR_INVALID_PARAMETER);
PVDINTERFACEIOINT pInterfaceIOCallbacks = VDGetInterfaceIOInt(pInterfaceIO);
AssertPtrReturn(pInterfaceIOCallbacks, VERR_INVALID_PARAMETER);
rc = pInterfaceIOCallbacks->pfnOpen(pInterfaceIO->pvUser, pszFilename,
VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
false /* fCreate */),
&pStorage);
if (RT_FAILURE(rc))
goto out;
rc = pInterfaceIOCallbacks->pfnGetSize(pInterfaceIO->pvUser, pStorage,
&cbFile);
if (RT_FAILURE(rc))
{
pInterfaceIOCallbacks->pfnClose(pInterfaceIO->pvUser, pStorage);
rc = VERR_VD_VHD_INVALID_HEADER;
goto out;
}
rc = pInterfaceIOCallbacks->pfnReadSync(pInterfaceIO->pvUser, pStorage,
cbFile - sizeof(VHDFooter),
&vhdFooter, sizeof(VHDFooter), NULL);
if (RT_FAILURE(rc) || (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0))
rc = VERR_VD_VHD_INVALID_HEADER;
else
rc = VINF_SUCCESS;
pInterfaceIOCallbacks->pfnClose(pInterfaceIO->pvUser, pStorage);
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnOpen */
static int vhdOpen(const char *pszFilename, unsigned uOpenFlags,
PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
void **ppBackendData)
{
LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, ppBackendData));
int rc = VINF_SUCCESS;
PVHDIMAGE pImage;
/* Check open flags. All valid flags are supported. */
if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
{
rc = VERR_INVALID_PARAMETER;
goto out;
}
/* Check remaining arguments. */
if ( !VALID_PTR(pszFilename)
|| !*pszFilename)
{
rc = VERR_INVALID_PARAMETER;
goto out;
}
pImage = (PVHDIMAGE)RTMemAllocZ(sizeof(VHDIMAGE));
if (!pImage)
{
rc = VERR_NO_MEMORY;
goto out;
}
pImage->pszFilename = pszFilename;
pImage->pStorage = NULL;
pImage->pVDIfsDisk = pVDIfsDisk;
pImage->pVDIfsImage = pVDIfsImage;
rc = vhdOpenImage(pImage, uOpenFlags);
if (RT_SUCCESS(rc))
*ppBackendData = pImage;
else
RTMemFree(pImage);
out:
LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnCreate */
static int vhdCreate(const char *pszFilename, uint64_t cbSize,
unsigned uImageFlags, const char *pszComment,
PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
PCRTUUID pUuid, unsigned uOpenFlags,
unsigned uPercentStart, unsigned uPercentSpan,
PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
PVDINTERFACE pVDIfsOperation, void **ppBackendData)
{
LogFlowFunc(("pszFilename=\"%s\" cbSize=%llu uImageFlags=%#x pszComment=\"%s\" pPCHSGeometry=%#p pLCHSGeometry=%#p Uuid=%RTuuid uOpenFlags=%#x uPercentStart=%u uPercentSpan=%u pVDIfsDisk=%#p pVDIfsImage=%#p pVDIfsOperation=%#p ppBackendData=%#p", pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, ppBackendData));
int rc = VINF_SUCCESS;
PVHDIMAGE pImage;
PFNVDPROGRESS pfnProgress = NULL;
void *pvUser = NULL;
PVDINTERFACE pIfProgress = VDInterfaceGet(pVDIfsOperation,
VDINTERFACETYPE_PROGRESS);
PVDINTERFACEPROGRESS pCbProgress = NULL;
if (pIfProgress)
{
pCbProgress = VDGetInterfaceProgress(pIfProgress);
if (pCbProgress)
pfnProgress = pCbProgress->pfnProgress;
pvUser = pIfProgress->pvUser;
}
/* Check open flags. All valid flags are supported. */
if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
{
rc = VERR_INVALID_PARAMETER;
return rc;
}
/* @todo Check the values of other params */
pImage = (PVHDIMAGE)RTMemAllocZ(sizeof(VHDIMAGE));
if (!pImage)
{
rc = VERR_NO_MEMORY;
return rc;
}
pImage->pszFilename = pszFilename;
pImage->pStorage = NULL;
pImage->pVDIfsDisk = pVDIfsDisk;
pImage->pVDIfsImage = pVDIfsImage;
/* Get I/O interface. */
pImage->pInterfaceIO = VDInterfaceGet(pImage->pVDIfsImage, VDINTERFACETYPE_IOINT);
if (RT_UNLIKELY(!VALID_PTR(pImage->pInterfaceIO)))
{
RTMemFree(pImage);
return VERR_INVALID_PARAMETER;
}
pImage->pInterfaceIOCallbacks = VDGetInterfaceIOInt(pImage->pInterfaceIO);
if (RT_UNLIKELY(!VALID_PTR(pImage->pInterfaceIOCallbacks)))
{
RTMemFree(pImage);
return VERR_INVALID_PARAMETER;
}
rc = vhdCreateImage(pImage, cbSize, uImageFlags, pszComment,
pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags,
pfnProgress, pvUser, uPercentStart, uPercentSpan);
if (RT_SUCCESS(rc))
{
/* So far the image is opened in read/write mode. Make sure the
* image is opened in read-only mode if the caller requested that. */
if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
{
vhdFreeImage(pImage, false);
rc = vhdOpenImage(pImage, uOpenFlags);
if (RT_FAILURE(rc))
{
RTMemFree(pImage);
goto out;
}
}
*ppBackendData = pImage;
}
else
RTMemFree(pImage);
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnRename */
static int vhdRename(void *pBackendData, const char *pszFilename)
{
LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
/* Check arguments. */
if ( !pImage
|| !pszFilename
|| !*pszFilename)
{
rc = VERR_INVALID_PARAMETER;
goto out;
}
/* Close the image. */
rc = vhdFreeImage(pImage, false);
if (RT_FAILURE(rc))
goto out;
/* Rename the file. */
rc = vhdFileMove(pImage, pImage->pszFilename, pszFilename, 0);
if (RT_FAILURE(rc))
{
/* The move failed, try to reopen the original image. */
int rc2 = vhdOpenImage(pImage, pImage->uOpenFlags);
if (RT_FAILURE(rc2))
rc = rc2;
goto out;
}
/* Update pImage with the new information. */
pImage->pszFilename = pszFilename;
/* Open the old file with new name. */
rc = vhdOpenImage(pImage, pImage->uOpenFlags);
if (RT_FAILURE(rc))
goto out;
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnClose */
static int vhdClose(void *pBackendData, bool fDelete)
{
LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
rc = vhdFreeImage(pImage, fDelete);
RTMemFree(pImage);
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnRead */
static int vhdRead(void *pBackendData, uint64_t uOffset, void *pvBuf,
size_t cbBuf, size_t *pcbActuallyRead)
{
LogFlowFunc(("pBackendData=%p uOffset=%#llx pvBuf=%p cbBuf=%u pcbActuallyRead=%p\n", pBackendData, uOffset, pvBuf, cbBuf, pcbActuallyRead));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
if (uOffset + cbBuf > pImage->cbSize)
{
rc = VERR_INVALID_PARAMETER;
goto out;
}
/*
* If we have a dynamic disk image, we need to find the data block and sector to read.
*/
if (pImage->pBlockAllocationTable)
{
/*
* Get the data block first.
*/
uint32_t cBlockAllocationTableEntry = (uOffset / VHD_SECTOR_SIZE) / pImage->cSectorsPerDataBlock;
uint32_t cBATEntryIndex = (uOffset / VHD_SECTOR_SIZE) % pImage->cSectorsPerDataBlock;
uint64_t uVhdOffset;
LogFlowFunc(("cBlockAllocationTableEntry=%u cBatEntryIndex=%u\n", cBlockAllocationTableEntry, cBATEntryIndex));
LogFlowFunc(("BlockAllocationEntry=%u\n", pImage->pBlockAllocationTable[cBlockAllocationTableEntry]));
/*
* If the block is not allocated the content of the entry is ~0
*/
if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
{
/* Return block size as read. */
*pcbActuallyRead = RT_MIN(cbBuf, pImage->cSectorsPerDataBlock * VHD_SECTOR_SIZE);
rc = VERR_VD_BLOCK_FREE;
goto out;
}
uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
LogFlowFunc(("uVhdOffset=%llu cbBuf=%u\n", uVhdOffset, cbBuf));
/*
* Clip read range to remain in this data block.
*/
cbBuf = RT_MIN(cbBuf, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
/* Read in the block's bitmap. */
rc = vhdFileReadSync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap, pImage->cbDataBlockBitmap,
NULL);
if (RT_SUCCESS(rc))
{
uint32_t cSectors = 0;
if (vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors = 1;
/*
* The first sector being read is marked dirty, read as much as we
* can from child. Note that only sectors that are marked dirty
* must be read from child.
*/
while ( (cSectors < (cbBuf / VHD_SECTOR_SIZE))
&& vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors++;
}
cbBuf = cSectors * VHD_SECTOR_SIZE;
LogFlowFunc(("uVhdOffset=%llu cbBuf=%u\n", uVhdOffset, cbBuf));
rc = vhdFileReadSync(pImage, uVhdOffset, pvBuf, cbBuf, NULL);
}
else
{
/*
* The first sector being read is marked clean, so we should read from
* our parent instead, but only as much as there are the following
* clean sectors, because the block may still contain dirty sectors
* further on. We just need to compute the number of clean sectors
* and pass it to our caller along with the notification that they
* should be read from the parent.
*/
cBATEntryIndex++;
cSectors = 1;
while ( (cSectors < (cbBuf / VHD_SECTOR_SIZE))
&& !vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors++;
}
cbBuf = cSectors * VHD_SECTOR_SIZE;
LogFunc(("Sectors free: uVhdOffset=%llu cbBuf=%u\n", uVhdOffset, cbBuf));
rc = VERR_VD_BLOCK_FREE;
}
}
else
AssertMsgFailed(("Reading block bitmap failed rc=%Rrc\n", rc));
}
else
{
rc = vhdFileReadSync(pImage, uOffset, pvBuf, cbBuf, NULL);
}
if (RT_SUCCESS(rc))
{
if (pcbActuallyRead)
*pcbActuallyRead = cbBuf;
Log2(("vhdRead: off=%#llx pvBuf=%p cbBuf=%d\n"
"%.*Rhxd\n",
uOffset, pvBuf, cbBuf, cbBuf, pvBuf));
}
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnWrite */
static int vhdWrite(void *pBackendData, uint64_t uOffset, const void *pvBuf,
size_t cbBuf, size_t *pcbWriteProcess,
size_t *pcbPreRead, size_t *pcbPostRead, unsigned fWrite)
{
LogFlowFunc(("pBackendData=%#p uOffset=%llu pvBuf=%#p cbBuf=%zu pcbWriteProcess=%#p\n", pBackendData, uOffset, pvBuf, cbBuf, pcbWriteProcess));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
LogFlowFunc(("pBackendData=%p uOffset=%llu pvBuf=%p cbBuf=%u pcbWriteProcess=%p pcbPreRead=%p pcbPostRead=%p fWrite=%u\n",
pBackendData, uOffset, pvBuf, cbBuf, pcbWriteProcess, pcbPreRead, pcbPostRead, fWrite));
AssertPtr(pImage);
Assert(uOffset % VHD_SECTOR_SIZE == 0);
Assert(cbBuf % VHD_SECTOR_SIZE == 0);
if (pImage->pBlockAllocationTable)
{
/*
* Get the data block first.
*/
uint32_t cSector = uOffset / VHD_SECTOR_SIZE;
uint32_t cBlockAllocationTableEntry = cSector / pImage->cSectorsPerDataBlock;
uint32_t cBATEntryIndex = cSector % pImage->cSectorsPerDataBlock;
uint64_t uVhdOffset;
/*
* Clip write range.
*/
cbBuf = RT_MIN(cbBuf, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
/*
* If the block is not allocated the content of the entry is ~0
* and we need to allocate a new block. Note that while blocks are
* allocated with a relatively big granularity, each sector has its
* own bitmap entry, indicating whether it has been written or not.
* So that means for the purposes of the higher level that the
* granularity is invisible. This means there's no need to return
* VERR_VD_BLOCK_FREE unless the block hasn't been allocated yet.
*/
if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
{
/* Check if the block allocation should be suppressed. */
if (fWrite & VD_WRITE_NO_ALLOC)
{
*pcbPreRead = cBATEntryIndex * VHD_SECTOR_SIZE;
*pcbPostRead = pImage->cSectorsPerDataBlock * VHD_SECTOR_SIZE - cbBuf - *pcbPreRead;
if (pcbWriteProcess)
*pcbWriteProcess = cbBuf;
rc = VERR_VD_BLOCK_FREE;
goto out;
}
size_t cbNewBlock = pImage->cbDataBlock + (pImage->cDataBlockBitmapSectors * VHD_SECTOR_SIZE);
uint8_t *pNewBlock = (uint8_t *)RTMemAllocZ(cbNewBlock);
if (!pNewBlock)
{
rc = VERR_NO_MEMORY;
goto out;
}
/*
* Write the new block at the current end of the file.
*/
rc = vhdFileWriteSync(pImage, pImage->uCurrentEndOfFile,
pNewBlock, cbNewBlock, NULL);
AssertRC(rc);
/*
* Set the new end of the file and link the new block into the BAT.
*/
pImage->pBlockAllocationTable[cBlockAllocationTableEntry] = pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE;
pImage->uCurrentEndOfFile += cbNewBlock;
RTMemFree(pNewBlock);
/* Write the updated BAT and the footer to remain in a consistent state. */
rc = vhdFlushImage(pImage);
AssertRC(rc);
}
/*
* Calculate the real offset in the file.
*/
uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
/* Write data. */
vhdFileWriteSync(pImage, uVhdOffset, pvBuf, cbBuf, NULL);
/* Read in the block's bitmap. */
rc = vhdFileReadSync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap, pImage->cbDataBlockBitmap,
NULL);
if (RT_SUCCESS(rc))
{
bool fChanged = false;
/* Set the bits for all sectors having been written. */
for (uint32_t iSector = 0; iSector < (cbBuf / VHD_SECTOR_SIZE); iSector++)
{
fChanged |= vhdBlockBitmapSectorSet(pImage, pImage->pu8Bitmap, cBATEntryIndex);
cBATEntryIndex++;
}
if (fChanged)
{
/* Write the bitmap back. */
rc = vhdFileWriteSync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap, pImage->cbDataBlockBitmap,
NULL);
}
}
}
else
{
rc = vhdFileWriteSync(pImage, uOffset, pvBuf, cbBuf, NULL);
}
if (pcbWriteProcess)
*pcbWriteProcess = cbBuf;
/* Stay on the safe side. Do not run the risk of confusing the higher
* level, as that can be pretty lethal to image consistency. */
*pcbPreRead = 0;
*pcbPostRead = 0;
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnFlush */
static int vhdFlush(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
rc = vhdFlushImage(pImage);
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
static unsigned vhdGetVersion(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p\n", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
unsigned ver = 0;
AssertPtr(pImage);
if (pImage)
ver = 1; /**< @todo use correct version */
LogFlowFunc(("returns %u\n", ver));
return ver;
}
/** @copydoc VBOXHDDBACKEND::pfnGetSize */
static uint64_t vhdGetSize(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p\n", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
uint64_t cb = 0;
AssertPtr(pImage);
if (pImage && pImage->pStorage)
cb = pImage->cbSize;
LogFlowFunc(("returns %llu\n", cb));
return cb;
}
/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
static uint64_t vhdGetFileSize(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p\n", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
uint64_t cb = 0;
AssertPtr(pImage);
if (pImage && pImage->pStorage)
cb = pImage->uCurrentEndOfFile + sizeof(VHDFooter);
LogFlowFunc(("returns %lld\n", cb));
return cb;
}
/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
static int vhdGetPCHSGeometry(void *pBackendData, PVDGEOMETRY pPCHSGeometry)
{
LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (pImage->PCHSGeometry.cCylinders)
{
*pPCHSGeometry = pImage->PCHSGeometry;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_GEOMETRY_NOT_SET;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (CHS=%u/%u/%u)\n", rc, pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
static int vhdSetPCHSGeometry(void *pBackendData, PCVDGEOMETRY pPCHSGeometry)
{
LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
{
rc = VERR_VD_IMAGE_READ_ONLY;
goto out;
}
pImage->PCHSGeometry = *pPCHSGeometry;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_NOT_OPENED;
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
static int vhdGetLCHSGeometry(void *pBackendData, PVDGEOMETRY pLCHSGeometry)
{
LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (pImage->LCHSGeometry.cCylinders)
{
*pLCHSGeometry = pImage->LCHSGeometry;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_GEOMETRY_NOT_SET;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (CHS=%u/%u/%u)\n", rc, pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
static int vhdSetLCHSGeometry(void *pBackendData, PCVDGEOMETRY pLCHSGeometry)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
{
rc = VERR_VD_IMAGE_READ_ONLY;
goto out;
}
pImage->LCHSGeometry = *pLCHSGeometry;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_NOT_OPENED;
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
static unsigned vhdGetImageFlags(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p\n", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
unsigned uImageFlags;
AssertPtr(pImage);
if (pImage)
uImageFlags = pImage->uImageFlags;
else
uImageFlags = 0;
LogFlowFunc(("returns %#x\n", uImageFlags));
return uImageFlags;
}
/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
static unsigned vhdGetOpenFlags(void *pBackendData)
{
LogFlowFunc(("pBackendData=%#p\n", pBackendData));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
unsigned uOpenFlags;
AssertPtr(pImage);
if (pImage)
uOpenFlags = pImage->uOpenFlags;
else
uOpenFlags = 0;
LogFlowFunc(("returns %#x\n", uOpenFlags));
return uOpenFlags;
}
/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
static int vhdSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
{
LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
/* Image must be opened and the new flags must be valid. */
if (!pImage || (uOpenFlags & ~(VD_OPEN_FLAGS_READONLY | VD_OPEN_FLAGS_INFO | VD_OPEN_FLAGS_ASYNC_IO | VD_OPEN_FLAGS_SHAREABLE | VD_OPEN_FLAGS_SEQUENTIAL)))
{
rc = VERR_INVALID_PARAMETER;
goto out;
}
/* Implement this operation via reopening the image. */
rc = vhdFreeImage(pImage, false);
if (RT_FAILURE(rc))
goto out;
rc = vhdOpenImage(pImage, uOpenFlags);
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetComment */
static int vhdGetComment(void *pBackendData, char *pszComment,
size_t cbComment)
{
LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetComment */
static int vhdSetComment(void *pBackendData, const char *pszComment)
{
LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
{
rc = VERR_VD_IMAGE_READ_ONLY;
goto out;
}
if (pImage)
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_NOT_OPENED;
out:
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
static int vhdGetUuid(void *pBackendData, PRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
*pUuid = pImage->ImageUuid;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
static int vhdSetUuid(void *pBackendData, PCRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
{
pImage->ImageUuid = *pUuid;
/* Update the footer copy. It will get written to disk when the image is closed. */
memcpy(&pImage->vhdFooterCopy.UniqueID, pUuid, 16);
/* Update checksum. */
pImage->vhdFooterCopy.Checksum = 0;
pImage->vhdFooterCopy.Checksum = RT_H2BE_U32(vhdChecksum(&pImage->vhdFooterCopy, sizeof(VHDFooter)));
/* Need to update the dynamic disk header to update the disk footer copy at the beginning. */
if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
pImage->fDynHdrNeedsUpdate = true;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_IMAGE_READ_ONLY;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
static int vhdGetModificationUuid(void *pBackendData, PRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
static int vhdSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_IMAGE_READ_ONLY;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
static int vhdGetParentUuid(void *pBackendData, PRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
*pUuid = pImage->ParentUuid;
rc = VINF_SUCCESS;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
static int vhdSetParentUuid(void *pBackendData, PCRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
AssertPtr(pImage);
if (pImage && pImage->pStorage)
{
if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
{
pImage->ParentUuid = *pUuid;
pImage->fDynHdrNeedsUpdate = true;
}
else
rc = VERR_VD_IMAGE_READ_ONLY;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
static int vhdGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
static int vhdSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
{
LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc;
AssertPtr(pImage);
if (pImage)
{
if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
rc = VERR_NOT_SUPPORTED;
else
rc = VERR_VD_IMAGE_READ_ONLY;
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnDump */
static void vhdDump(void *pBackendData)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
{
vhdMessage(pImage, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cbSector=%llu\n",
pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
VHD_SECTOR_SIZE);
vhdMessage(pImage, "Header: uuidCreation={%RTuuid}\n", &pImage->ImageUuid);
vhdMessage(pImage, "Header: uuidParent={%RTuuid}\n", &pImage->ParentUuid);
}
}
/** @copydoc VBOXHDDBACKEND::pfnGetTimestamp */
static int vhdGetTimeStamp(void *pBackendData, PRTTIMESPEC pTimeStamp)
{
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
rc = vhdFileGetModificationTime(pImage, pImage->pszFilename, pTimeStamp);
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetParentTimeStamp */
static int vhdGetParentTimeStamp(void *pBackendData, PRTTIMESPEC pTimeStamp)
{
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
vhdTime2RtTime(pTimeStamp, pImage->u32ParentTimeStamp);
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetParentTimeStamp */
static int vhdSetParentTimeStamp(void *pBackendData, PCRTTIMESPEC pTimeStamp)
{
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
{
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
rc = VERR_VD_IMAGE_READ_ONLY;
else
{
pImage->u32ParentTimeStamp = vhdRtTime2VhdTime(pTimeStamp);
pImage->fDynHdrNeedsUpdate = true;
}
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
static int vhdGetParentFilename(void *pBackendData, char **ppszParentFilename)
{
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
*ppszParentFilename = RTStrDup(pImage->pszParentFilename);
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
static int vhdSetParentFilename(void *pBackendData, const char *pszParentFilename)
{
int rc = VINF_SUCCESS;
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
AssertPtr(pImage);
if (pImage)
{
if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
rc = VERR_VD_IMAGE_READ_ONLY;
else
{
if (pImage->pszParentFilename)
RTStrFree(pImage->pszParentFilename);
pImage->pszParentFilename = RTStrDup(pszParentFilename);
if (!pImage->pszParentFilename)
rc = VERR_NO_MEMORY;
else
pImage->fDynHdrNeedsUpdate = true;
}
}
else
rc = VERR_VD_NOT_OPENED;
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnIsAsyncIOSupported */
static bool vhdIsAsyncIOSupported(void *pBackendData)
{
return true;
}
/** @copydoc VBOXHDDBACKEND::pfnAsyncRead */
static int vhdAsyncRead(void *pBackendData, uint64_t uOffset, size_t cbRead,
PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
LogFlowFunc(("pBackendData=%p uOffset=%#llx pIoCtx=%#p cbRead=%u pcbActuallyRead=%p\n", pBackendData, uOffset, pIoCtx, cbRead, pcbActuallyRead));
if (uOffset + cbRead > pImage->cbSize)
return VERR_INVALID_PARAMETER;
/*
* If we have a dynamic disk image, we need to find the data block and sector to read.
*/
if (pImage->pBlockAllocationTable)
{
/*
* Get the data block first.
*/
uint32_t cBlockAllocationTableEntry = (uOffset / VHD_SECTOR_SIZE) / pImage->cSectorsPerDataBlock;
uint32_t cBATEntryIndex = (uOffset / VHD_SECTOR_SIZE) % pImage->cSectorsPerDataBlock;
uint64_t uVhdOffset;
LogFlowFunc(("cBlockAllocationTableEntry=%u cBatEntryIndex=%u\n", cBlockAllocationTableEntry, cBATEntryIndex));
LogFlowFunc(("BlockAllocationEntry=%u\n", pImage->pBlockAllocationTable[cBlockAllocationTableEntry]));
/*
* If the block is not allocated the content of the entry is ~0
*/
if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
{
/* Return block size as read. */
*pcbActuallyRead = RT_MIN(cbRead, pImage->cSectorsPerDataBlock * VHD_SECTOR_SIZE);
return VERR_VD_BLOCK_FREE;
}
uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
LogFlowFunc(("uVhdOffset=%llu cbRead=%u\n", uVhdOffset, cbRead));
/*
* Clip read range to remain in this data block.
*/
cbRead = RT_MIN(cbRead, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
/* Read in the block's bitmap. */
PVDMETAXFER pMetaXfer;
rc = vhdFileReadMetaAsync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap, pImage->cbDataBlockBitmap,
pIoCtx, &pMetaXfer, NULL, NULL);
if (RT_SUCCESS(rc))
{
uint32_t cSectors = 0;
vhdFileMetaXferRelease(pImage, pMetaXfer);
if (vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors = 1;
/*
* The first sector being read is marked dirty, read as much as we
* can from child. Note that only sectors that are marked dirty
* must be read from child.
*/
while ( (cSectors < (cbRead / VHD_SECTOR_SIZE))
&& vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors++;
}
cbRead = cSectors * VHD_SECTOR_SIZE;
LogFlowFunc(("uVhdOffset=%llu cbRead=%u\n", uVhdOffset, cbRead));
rc = vhdFileReadUserAsync(pImage, uVhdOffset, pIoCtx, cbRead);
}
else
{
/*
* The first sector being read is marked clean, so we should read from
* our parent instead, but only as much as there are the following
* clean sectors, because the block may still contain dirty sectors
* further on. We just need to compute the number of clean sectors
* and pass it to our caller along with the notification that they
* should be read from the parent.
*/
cBATEntryIndex++;
cSectors = 1;
while ( (cSectors < (cbRead / VHD_SECTOR_SIZE))
&& !vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
{
cBATEntryIndex++;
cSectors++;
}
cbRead = cSectors * VHD_SECTOR_SIZE;
LogFunc(("Sectors free: uVhdOffset=%llu cbRead=%u\n", uVhdOffset, cbRead));
rc = VERR_VD_BLOCK_FREE;
}
}
else
AssertMsg(rc == VERR_VD_NOT_ENOUGH_METADATA, ("Reading block bitmap failed rc=%Rrc\n", rc));
}
else
{
rc = vhdFileReadUserAsync(pImage, uOffset, pIoCtx, cbRead);
}
if (pcbActuallyRead)
*pcbActuallyRead = cbRead;
LogFlowFunc(("returns rc=%Rrc\n", rc));
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnAsyncWrite */
static int vhdAsyncWrite(void *pBackendData, uint64_t uOffset, size_t cbWrite,
PVDIOCTX pIoCtx,
size_t *pcbWriteProcess, size_t *pcbPreRead,
size_t *pcbPostRead, unsigned fWrite)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
LogFlowFunc(("pBackendData=%p uOffset=%llu pIoCtx=%#p cbWrite=%u pcbWriteProcess=%p pcbPreRead=%p pcbPostRead=%p fWrite=%u\n",
pBackendData, uOffset, pIoCtx, cbWrite, pcbWriteProcess, pcbPreRead, pcbPostRead, fWrite));
AssertPtr(pImage);
Assert(uOffset % VHD_SECTOR_SIZE == 0);
Assert(cbWrite % VHD_SECTOR_SIZE == 0);
if (pImage->pBlockAllocationTable)
{
/*
* Get the data block first.
*/
uint32_t cSector = uOffset / VHD_SECTOR_SIZE;
uint32_t cBlockAllocationTableEntry = cSector / pImage->cSectorsPerDataBlock;
uint32_t cBATEntryIndex = cSector % pImage->cSectorsPerDataBlock;
uint64_t uVhdOffset;
/*
* Clip write range.
*/
cbWrite = RT_MIN(cbWrite, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
/*
* If the block is not allocated the content of the entry is ~0
* and we need to allocate a new block. Note that while blocks are
* allocated with a relatively big granularity, each sector has its
* own bitmap entry, indicating whether it has been written or not.
* So that means for the purposes of the higher level that the
* granularity is invisible. This means there's no need to return
* VERR_VD_BLOCK_FREE unless the block hasn't been allocated yet.
*/
if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
{
/* Check if the block allocation should be suppressed. */
if (fWrite & VD_WRITE_NO_ALLOC)
{
*pcbPreRead = cBATEntryIndex * VHD_SECTOR_SIZE;
*pcbPostRead = pImage->cSectorsPerDataBlock * VHD_SECTOR_SIZE - cbWrite - *pcbPreRead;
if (pcbWriteProcess)
*pcbWriteProcess = cbWrite;
return VERR_VD_BLOCK_FREE;
}
PVHDIMAGEEXPAND pExpand = (PVHDIMAGEEXPAND)RTMemAllocZ(RT_OFFSETOF(VHDIMAGEEXPAND, au8Bitmap[pImage->cDataBlockBitmapSectors * VHD_SECTOR_SIZE]));
bool fIoInProgress = false;
if (!pExpand)
return VERR_NO_MEMORY;
pExpand->cbEofOld = pImage->uCurrentEndOfFile;
pExpand->idxBatAllocated = cBlockAllocationTableEntry;
pExpand->idxBlockBe = RT_H2BE_U32(pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE);
/* Set the bits for all sectors having been written. */
for (uint32_t iSector = 0; iSector < (cbWrite / VHD_SECTOR_SIZE); iSector++)
{
/* No need to check for a changed value because this is an initial write. */
vhdBlockBitmapSectorSet(pImage, pExpand->au8Bitmap, cBATEntryIndex);
cBATEntryIndex++;
}
do
{
/*
* Start with the sector bitmap.
*/
rc = vhdFileWriteMetaAsync(pImage, pImage->uCurrentEndOfFile,
pExpand->au8Bitmap,
pImage->cbDataBlockBitmap, pIoCtx,
vhdAsyncExpansionDataBlockBitmapComplete,
pExpand);
if (RT_SUCCESS(rc))
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
fIoInProgress = true;
else
{
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
break;
}
/*
* Write the new block at the current end of the file.
*/
rc = vhdFileWriteUserAsync(pImage,
pImage->uCurrentEndOfFile + pImage->cbDataBlockBitmap,
pIoCtx, cbWrite,
vhdAsyncExpansionDataComplete,
pExpand);
if (RT_SUCCESS(rc))
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
fIoInProgress = true;
else
{
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
break;
}
/*
* Write entry in the BAT.
*/
rc = vhdFileWriteMetaAsync(pImage,
pImage->uBlockAllocationTableOffset + cBlockAllocationTableEntry * sizeof(uint32_t),
&pExpand->idxBlockBe,
sizeof(uint32_t), pIoCtx,
vhdAsyncExpansionBatUpdateComplete,
pExpand);
if (RT_SUCCESS(rc))
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
fIoInProgress = true;
else
{
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
break;
}
/*
* Set the new end of the file and link the new block into the BAT.
*/
pImage->pBlockAllocationTable[cBlockAllocationTableEntry] = pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE;
pImage->uCurrentEndOfFile += pImage->cbDataBlockBitmap + pImage->cbDataBlock;
/* Update the footer. */
rc = vhdFileWriteMetaAsync(pImage, pImage->uCurrentEndOfFile,
&pImage->vhdFooterCopy,
sizeof(VHDFooter), pIoCtx,
vhdAsyncExpansionFooterUpdateComplete,
pExpand);
if (RT_SUCCESS(rc))
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
fIoInProgress = true;
else
{
VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
break;
}
} while (0);
if (!fIoInProgress)
vhdAsyncExpansionComplete(pImage, pIoCtx, pExpand);
else
rc = VERR_VD_ASYNC_IO_IN_PROGRESS;
}
else
{
/*
* Calculate the real offset in the file.
*/
uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
/* Read in the block's bitmap. */
PVDMETAXFER pMetaXfer;
rc = vhdFileReadMetaAsync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap,
pImage->cbDataBlockBitmap, pIoCtx,
&pMetaXfer, NULL, NULL);
if (RT_SUCCESS(rc))
{
vhdFileMetaXferRelease(pImage, pMetaXfer);
/* Write data. */
rc = vhdFileWriteUserAsync(pImage, uVhdOffset, pIoCtx, cbWrite,
NULL, NULL);
if (RT_SUCCESS(rc) || rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
{
bool fChanged = false;
/* Set the bits for all sectors having been written. */
for (uint32_t iSector = 0; iSector < (cbWrite / VHD_SECTOR_SIZE); iSector++)
{
fChanged |= vhdBlockBitmapSectorSet(pImage, pImage->pu8Bitmap, cBATEntryIndex);
cBATEntryIndex++;
}
/* Only write the bitmap if it was changed. */
if (fChanged)
{
/*
* Write the bitmap back.
*
* @note We don't have a completion callback here because we
* can't do anything if the write fails for some reason.
* The error will propagated to the device/guest
* by the generic VD layer already and we don't need
* to rollback anything here.
*/
rc = vhdFileWriteMetaAsync(pImage,
((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
pImage->pu8Bitmap,
pImage->cbDataBlockBitmap,
pIoCtx, NULL, NULL);
}
}
}
}
}
else
{
rc = vhdFileWriteUserAsync(pImage, uOffset, pIoCtx, cbWrite, NULL, NULL);
}
if (pcbWriteProcess)
*pcbWriteProcess = cbWrite;
/* Stay on the safe side. Do not run the risk of confusing the higher
* level, as that can be pretty lethal to image consistency. */
*pcbPreRead = 0;
*pcbPostRead = 0;
return rc;
}
/** @copydoc VBOXHDDBACKEND::pfnAsyncFlush */
static int vhdAsyncFlush(void *pBackendData, PVDIOCTX pIoCtx)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
/* No need to write anything here. Data is always updated on a write. */
return vhdFileFlushAsync(pImage, pIoCtx, NULL, NULL);
}
/** @copydoc VBOXHDDBACKEND::pfnResize */
static int vhdResize(void *pBackendData, uint64_t cbSize,
PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
unsigned uPercentStart, unsigned uPercentSpan,
PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
PVDINTERFACE pVDIfsOperation)
{
PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
int rc = VINF_SUCCESS;
PFNVDPROGRESS pfnProgress = NULL;
void *pvUser = NULL;
PVDINTERFACE pIfProgress = VDInterfaceGet(pVDIfsOperation,
VDINTERFACETYPE_PROGRESS);
PVDINTERFACEPROGRESS pCbProgress = NULL;
if (pIfProgress)
{
pCbProgress = VDGetInterfaceProgress(pIfProgress);
if (pCbProgress)
pfnProgress = pCbProgress->pfnProgress;
pvUser = pIfProgress->pvUser;
}
/* Making the image smaller is not supported at the moment. */
if ( cbSize < pImage->cbSize
|| pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED)
rc = VERR_NOT_SUPPORTED;
else if (cbSize > pImage->cbSize)
{
unsigned cBlocksAllocated = 0;
size_t cbBlock = pImage->cbDataBlock + pImage->cbDataBlockBitmap; /** < Size of a block including the sector bitmap. */
uint32_t cBlocksNew = cbSize / pImage->cbDataBlock; /** < New number of blocks in the image after the resize */
if (cbSize % pImage->cbDataBlock)
cBlocksNew++;
uint32_t cBlocksOld = pImage->cBlockAllocationTableEntries; /** < Number of blocks before the resize. */
uint64_t cbBlockspaceNew = RT_ALIGN_32(cBlocksNew * sizeof(uint32_t), VHD_SECTOR_SIZE); /** < Required space for the block array after the resize. */
uint64_t offStartDataNew = RT_ALIGN_32(pImage->uBlockAllocationTableOffset + cbBlockspaceNew, VHD_SECTOR_SIZE); /** < New start offset for block data after the resize */
uint64_t offStartDataOld = ~0ULL;
/* Go through the BAT and finde the data start offset. */
for (unsigned idxBlock = 0; idxBlock < pImage->cBlockAllocationTableEntries; idxBlock++)
{
if (pImage->pBlockAllocationTable[idxBlock] != ~0U)
{
uint64_t offStartBlock = pImage->pBlockAllocationTable[idxBlock] * VHD_SECTOR_SIZE;
if (offStartBlock < offStartDataOld)
offStartDataOld = offStartBlock;
cBlocksAllocated++;
}
}
if ( offStartDataOld != offStartDataNew
&& cBlocksAllocated > 0)
{
/* Calculate how many sectors nee to be relocated. */
uint64_t cbOverlapping = offStartDataNew - offStartDataOld;
unsigned cBlocksReloc = cbOverlapping / cbBlock;
if (cbOverlapping % cbBlock)
cBlocksReloc++;
cBlocksReloc = RT_MIN(cBlocksReloc, cBlocksAllocated);
offStartDataNew = offStartDataOld;
/* Do the relocation. */
LogFlow(("Relocating %u blocks\n", cBlocksReloc));
/*
* Get the blocks we need to relocate first, they are appended to the end
* of the image.
*/
void *pvBuf = NULL, *pvZero = NULL;
do
{
/* Allocate data buffer. */
pvBuf = RTMemAllocZ(cbBlock);
if (!pvBuf)
{
rc = VERR_NO_MEMORY;
break;
}
/* Allocate buffer for overwrting with zeroes. */
pvZero = RTMemAllocZ(cbBlock);
if (!pvZero)
{
rc = VERR_NO_MEMORY;
break;
}
for (unsigned i = 0; i < cBlocksReloc; i++)
{
uint32_t uBlock = offStartDataNew / VHD_SECTOR_SIZE;
/* Search the index in the block table. */
for (unsigned idxBlock = 0; idxBlock < cBlocksOld; idxBlock++)
{
if (pImage->pBlockAllocationTable[idxBlock] == uBlock)
{
/* Read data and append to the end of the image. */
rc = vhdFileReadSync(pImage, offStartDataNew, pvBuf, cbBlock, NULL);
if (RT_FAILURE(rc))
break;
rc = vhdFileWriteSync(pImage, pImage->uCurrentEndOfFile, pvBuf, cbBlock, NULL);
if (RT_FAILURE(rc))
break;
/* Zero out the old block area. */
rc = vhdFileWriteSync(pImage, offStartDataNew, pvZero, cbBlock, NULL);
if (RT_FAILURE(rc))
break;
/* Update block counter. */
pImage->pBlockAllocationTable[idxBlock] = pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE;
pImage->uCurrentEndOfFile += cbBlock;
/* Continue with the next block. */
break;
}
}
if (RT_FAILURE(rc))
break;
offStartDataNew += cbBlock;
}
} while (0);
if (pvBuf)
RTMemFree(pvBuf);
if (pvZero)
RTMemFree(pvZero);
}
/*
* Relocation done, expand the block array and update the header with
* the new data.
*/
if (RT_SUCCESS(rc))
{
uint32_t *paBlocksNew = (uint32_t *)RTMemRealloc(pImage->pBlockAllocationTable, cBlocksNew * sizeof(uint32_t));
if (paBlocksNew)
{
pImage->pBlockAllocationTable = paBlocksNew;
/* Mark the new blocks as unallocated. */
for (unsigned idxBlock = cBlocksOld; idxBlock < cBlocksNew; idxBlock++)
pImage->pBlockAllocationTable[idxBlock] = ~0U;
}
else
rc = VERR_NO_MEMORY;
if (RT_SUCCESS(rc))
{
/* Write the block array before updating the rest. */
rc = vhdFileWriteSync(pImage, pImage->uBlockAllocationTableOffset, pImage->pBlockAllocationTable,
cBlocksNew * sizeof(uint32_t), NULL);
}
if (RT_SUCCESS(rc))
{
/* Update size and new block count. */
pImage->cBlockAllocationTableEntries = cBlocksNew;
pImage->cbSize = cbSize;
/* Update geometry. */
pImage->PCHSGeometry = *pPCHSGeometry;
pImage->LCHSGeometry = *pLCHSGeometry;
}
}
/* Update header information in base image file. */
pImage->fDynHdrNeedsUpdate = true;
vhdFlush(pImage);
}
/* Same size doesn't change the image at all. */
LogFlowFunc(("returns %Rrc\n", rc));
return rc;
}
VBOXHDDBACKEND g_VhdBackend =
{
/* pszBackendName */
"VHD",
/* cbSize */
sizeof(VBOXHDDBACKEND),
/* uBackendCaps */
VD_CAP_UUID | VD_CAP_DIFF | VD_CAP_FILE |
VD_CAP_CREATE_FIXED | VD_CAP_CREATE_DYNAMIC |
VD_CAP_ASYNC | VD_CAP_VFS,
/* papszFileExtensions */
s_apszVhdFileExtensions,
/* paConfigInfo */
NULL,
/* hPlugin */
NIL_RTLDRMOD,
/* pfnCheckIfValid */
vhdCheckIfValid,
/* pfnOpen */
vhdOpen,
/* pfnCreate */
vhdCreate,
/* pfnRename */
vhdRename,
/* pfnClose */
vhdClose,
/* pfnRead */
vhdRead,
/* pfnWrite */
vhdWrite,
/* pfnFlush */
vhdFlush,
/* pfnGetVersion */
vhdGetVersion,
/* pfnGetSize */
vhdGetSize,
/* pfnGetFileSize */
vhdGetFileSize,
/* pfnGetPCHSGeometry */
vhdGetPCHSGeometry,
/* pfnSetPCHSGeometry */
vhdSetPCHSGeometry,
/* pfnGetLCHSGeometry */
vhdGetLCHSGeometry,
/* pfnSetLCHSGeometry */
vhdSetLCHSGeometry,
/* pfnGetImageFlags */
vhdGetImageFlags,
/* pfnGetOpenFlags */
vhdGetOpenFlags,
/* pfnSetOpenFlags */
vhdSetOpenFlags,
/* pfnGetComment */
vhdGetComment,
/* pfnSetComment */
vhdSetComment,
/* pfnGetUuid */
vhdGetUuid,
/* pfnSetUuid */
vhdSetUuid,
/* pfnGetModificationUuid */
vhdGetModificationUuid,
/* pfnSetModificationUuid */
vhdSetModificationUuid,
/* pfnGetParentUuid */
vhdGetParentUuid,
/* pfnSetParentUuid */
vhdSetParentUuid,
/* pfnGetParentModificationUuid */
vhdGetParentModificationUuid,
/* pfnSetParentModificationUuid */
vhdSetParentModificationUuid,
/* pfnDump */
vhdDump,
/* pfnGetTimeStamp */
vhdGetTimeStamp,
/* pfnGetParentTimeStamp */
vhdGetParentTimeStamp,
/* pfnSetParentTimeStamp */
vhdSetParentTimeStamp,
/* pfnGetParentFilename */
vhdGetParentFilename,
/* pfnSetParentFilename */
vhdSetParentFilename,
/* pfnIsAsyncIOSupported */
vhdIsAsyncIOSupported,
/* pfnAsyncRead */
vhdAsyncRead,
/* pfnAsyncWrite */
vhdAsyncWrite,
/* pfnAsyncFlush */
vhdAsyncFlush,
/* pfnComposeLocation */
genericFileComposeLocation,
/* pfnComposeName */
genericFileComposeName,
/* pfnCompact */
NULL,
/* pfnResize */
vhdResize
};