VHD.cpp@ 72756

Last change on this file since 72756 was 72577, checked in by vboxsync, 6 years ago
Storage/VHD: Stay within possible limits of the VDH spec for the block allocation table and reject images violating the spec, missing status code check [build fix]
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 118.8 KB

Line
1	/* $Id: VHD.cpp 72577 2018-06-15 21:31:58Z vboxsync $ */
2	/** @file
3	* VHD Disk image, Core Code.
4	*/
5
6	/*
7	* Copyright (C) 2006-2017 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18
19	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#define LOG_GROUP LOG_GROUP_VD_VHD
23	#include <VBox/vd-plugin.h>
24	#include <VBox/err.h>
25
26	#include <VBox/log.h>
27	#include <VBox/version.h>
28	#include <iprt/asm.h>
29	#include <iprt/assert.h>
30	#include <iprt/mem.h>
31	#include <iprt/uuid.h>
32	#include <iprt/path.h>
33	#include <iprt/string.h>
34
35	#include "VDBackends.h"
36
37	#define VHD_RELATIVE_MAX_PATH 512
38	#define VHD_ABSOLUTE_MAX_PATH 512
39
40	#define VHD_SECTOR_SIZE 512
41	#define VHD_BLOCK_SIZE (2 * _1M)
42
43	/** The maximum VHD size is 2TB due to the 32bit sector numbers in the BAT.
44	* Note that this is the maximum file size including all footers and headers
45	* and not the maximum virtual disk size presented to the guest.
46	*/
47	#define VHD_MAX_SIZE (2 * _1T)
48	/** Maximum number of 512 byte sectors for a VHD image. */
49	#define VHD_MAX_SECTORS (VHD_MAX_SIZE / VHD_SECTOR_SIZE)
50
51	/* This is common to all VHD disk types and is located at the end of the image */
52	#pragma pack(1)
53	typedef struct VHDFooter
54	{
55	char Cookie[8];
56	uint32_t Features;
57	uint32_t Version;
58	uint64_t DataOffset;
59	uint32_t Timestamp;
60	uint8_t CreatorApp[4];
61	uint32_t CreatorVer;
62	uint32_t CreatorOS;
63	uint64_t OrigSize;
64	uint64_t CurSize;
65	uint16_t DiskGeometryCylinder;
66	uint8_t DiskGeometryHeads;
67	uint8_t DiskGeometrySectors;
68	uint32_t DiskType;
69	uint32_t Checksum;
70	char UniqueID[16];
71	uint8_t SavedState;
72	uint8_t Reserved[427];
73	} VHDFooter;
74	#pragma pack()
75
76	/* this really is spelled with only one n */
77	#define VHD_FOOTER_COOKIE "conectix"
78	#define VHD_FOOTER_COOKIE_SIZE 8
79
80	#define VHD_FOOTER_FEATURES_NOT_ENABLED 0
81	#define VHD_FOOTER_FEATURES_TEMPORARY 1
82	#define VHD_FOOTER_FEATURES_RESERVED 2
83
84	#define VHD_FOOTER_FILE_FORMAT_VERSION 0x00010000
85	#define VHD_FOOTER_DATA_OFFSET_FIXED UINT64_C(0xffffffffffffffff)
86	#define VHD_FOOTER_DISK_TYPE_FIXED 2
87	#define VHD_FOOTER_DISK_TYPE_DYNAMIC 3
88	#define VHD_FOOTER_DISK_TYPE_DIFFERENCING 4
89
90	#define VHD_MAX_LOCATOR_ENTRIES 8
91	#define VHD_PLATFORM_CODE_NONE 0
92	#define VHD_PLATFORM_CODE_WI2R 0x57693272
93	#define VHD_PLATFORM_CODE_WI2K 0x5769326B
94	#define VHD_PLATFORM_CODE_W2RU 0x57327275
95	#define VHD_PLATFORM_CODE_W2KU 0x57326B75
96	#define VHD_PLATFORM_CODE_MAC 0x4D163220
97	#define VHD_PLATFORM_CODE_MACX 0x4D163258
98
99	/* Header for expanding disk images. */
100	#pragma pack(1)
101	typedef struct VHDParentLocatorEntry
102	{
103	uint32_t u32Code;
104	uint32_t u32DataSpace;
105	uint32_t u32DataLength;
106	uint32_t u32Reserved;
107	uint64_t u64DataOffset;
108	} VHDPLE, *PVHDPLE;
109
110	typedef struct VHDDynamicDiskHeader
111	{
112	char Cookie[8];
113	uint64_t DataOffset;
114	uint64_t TableOffset;
115	uint32_t HeaderVersion;
116	uint32_t MaxTableEntries;
117	uint32_t BlockSize;
118	uint32_t Checksum;
119	uint8_t ParentUuid[16];
120	uint32_t ParentTimestamp;
121	uint32_t Reserved0;
122	uint16_t ParentUnicodeName[256];
123	VHDPLE ParentLocatorEntry[VHD_MAX_LOCATOR_ENTRIES];
124	uint8_t Reserved1[256];
125	} VHDDynamicDiskHeader;
126	#pragma pack()
127
128	#define VHD_DYNAMIC_DISK_HEADER_COOKIE "cxsparse"
129	#define VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE 8
130	#define VHD_DYNAMIC_DISK_HEADER_VERSION 0x00010000
131
132	/**
133	* Complete VHD image data structure.
134	*/
135	typedef struct VHDIMAGE
136	{
137	/** Image file name. */
138	const char *pszFilename;
139	/** Opaque storage handle. */
140	PVDIOSTORAGE pStorage;
141
142	/** Pointer to the per-disk VD interface list. */
143	PVDINTERFACE pVDIfsDisk;
144	/** Pointer to the per-image VD interface list. */
145	PVDINTERFACE pVDIfsImage;
146	/** Error interface. */
147	PVDINTERFACEERROR pIfError;
148	/** I/O interface. */
149	PVDINTERFACEIOINT pIfIo;
150
151	/** Open flags passed by VBoxHDD layer. */
152	unsigned uOpenFlags;
153	/** Image flags defined during creation or determined during open. */
154	unsigned uImageFlags;
155	/** Total size of the image. */
156	uint64_t cbSize;
157
158	/** Physical geometry of this image. */
159	VDGEOMETRY PCHSGeometry;
160	/** Logical geometry of this image. */
161	VDGEOMETRY LCHSGeometry;
162
163	/** Image UUID. */
164	RTUUID ImageUuid;
165	/** Parent image UUID. */
166	RTUUID ParentUuid;
167
168	/** Parent's time stamp at the time of image creation. */
169	uint32_t u32ParentTimestamp;
170	/** Relative path to the parent image. */
171	char *pszParentFilename;
172
173	/** The Block Allocation Table. */
174	uint32_t *pBlockAllocationTable;
175	/** Number of entries in the table. */
176	uint32_t cBlockAllocationTableEntries;
177
178	/** Size of one data block. */
179	uint32_t cbDataBlock;
180	/** Sectors per data block. */
181	uint32_t cSectorsPerDataBlock;
182	/** Length of the sector bitmap in bytes. */
183	uint32_t cbDataBlockBitmap;
184	/** A copy of the disk footer. */
185	VHDFooter vhdFooterCopy;
186	/** Current end offset of the file (without the disk footer). */
187	uint64_t uCurrentEndOfFile;
188	/** Size of the data block bitmap in sectors. */
189	uint32_t cDataBlockBitmapSectors;
190	/** Start of the block allocation table. */
191	uint64_t uBlockAllocationTableOffset;
192	/** Buffer to hold block's bitmap for bit search operations. */
193	uint8_t *pu8Bitmap;
194	/** Offset to the next data structure (dynamic disk header). */
195	uint64_t u64DataOffset;
196	/** Flag to force dynamic disk header update. */
197	bool fDynHdrNeedsUpdate;
198	/** The static region list. */
199	VDREGIONLIST RegionList;
200	} VHDIMAGE, *PVHDIMAGE;
201
202	/**
203	* Structure tracking the expansion process of the image
204	* for async access.
205	*/
206	typedef struct VHDIMAGEEXPAND
207	{
208	/** Flag indicating the status of each step. */
209	volatile uint32_t fFlags;
210	/** The index in the block allocation table which is written. */
211	uint32_t idxBatAllocated;
212	/** Big endian representation of the block index
213	* which is written in the BAT. */
214	uint32_t idxBlockBe;
215	/** Old end of the file - used for rollback in case of an error. */
216	uint64_t cbEofOld;
217	/** Sector bitmap written to the new block - variable in size. */
218	uint8_t au8Bitmap[1];
219	} VHDIMAGEEXPAND, *PVHDIMAGEEXPAND;
220
221	/**
222	* Flag defines
223	*/
224	#define VHDIMAGEEXPAND_STEP_IN_PROGRESS (0x0)
225	#define VHDIMAGEEXPAND_STEP_FAILED (0x2)
226	#define VHDIMAGEEXPAND_STEP_SUCCESS (0x3)
227	/** All steps completed successfully. */
228	#define VHDIMAGEEXPAND_ALL_SUCCESS (0xff)
229	/** All steps completed (no success indicator) */
230	#define VHDIMAGEEXPAND_ALL_COMPLETE (0xaa)
231
232	/** Every status field has 2 bits so we can encode 4 steps in one byte. */
233	#define VHDIMAGEEXPAND_STATUS_MASK 0x03
234	#define VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT 0x00
235	#define VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT 0x02
236	#define VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT 0x04
237	#define VHDIMAGEEXPAND_BAT_STATUS_SHIFT 0x06
238
239	/**
240	* Helper macros to get and set the status field.
241	*/
242	#define VHDIMAGEEXPAND_STATUS_GET(fFlags, cShift) \
243	(((fFlags) >> (cShift)) & VHDIMAGEEXPAND_STATUS_MASK)
244	#define VHDIMAGEEXPAND_STATUS_SET(fFlags, cShift, uVal) \
245	ASMAtomicOrU32(&(fFlags), ((uVal) & VHDIMAGEEXPAND_STATUS_MASK) << (cShift))
246
247
248	/*********************************************************************************************************************************
249	* Static Variables *
250	*********************************************************************************************************************************/
251
252	/** NULL-terminated array of supported file extensions. */
253	static const VDFILEEXTENSION s_aVhdFileExtensions[] =
254	{
255	{"vhd", VDTYPE_HDD},
256	{NULL, VDTYPE_INVALID}
257	};
258
259
260	/*********************************************************************************************************************************
261	* Internal Functions *
262	*********************************************************************************************************************************/
263
264
265	/**
266	* Internal: Compute and update header checksum.
267	*/
268	static uint32_t vhdChecksum(void *pHeader, uint32_t cbSize)
269	{
270	uint32_t u32ChkSum = 0;
271	for (uint32_t i = 0; i < cbSize; i++)
272	u32ChkSum += ((unsigned char *)pHeader)[i];
273	return ~u32ChkSum;
274	}
275
276	/**
277	* Internal: Convert filename to UTF16 with appropriate endianness.
278	*/
279	static int vhdFilenameToUtf16(const char pszFilename, uint16_t pu16Buf,
280	uint32_t cbBufSize, uint32_t *pcbActualSize,
281	bool fBigEndian)
282	{
283	int rc;
284	PRTUTF16 pTmp16 = NULL;
285	size_t cTmp16Len;
286
287	rc = RTStrToUtf16(pszFilename, &pTmp16);
288	if (RT_SUCCESS(rc))
289	{
290	cTmp16Len = RTUtf16Len(pTmp16);
291	if (cTmp16Len * sizeof(*pTmp16) <= cbBufSize)
292	{
293	if (fBigEndian)
294	for (unsigned i = 0; i < cTmp16Len; i++)
295	pu16Buf[i] = RT_H2BE_U16(pTmp16[i]);
296	else
297	memcpy(pu16Buf, pTmp16, cTmp16Len * sizeof(*pTmp16));
298	if (pcbActualSize)
299	pcbActualSize = (uint32_t)(cTmp16Len sizeof(*pTmp16));
300	}
301	else
302	rc = VERR_FILENAME_TOO_LONG;
303	}
304
305	if (pTmp16)
306	RTUtf16Free(pTmp16);
307	return rc;
308	}
309
310	/**
311	* Internal: Update one locator entry.
312	*/
313	static int vhdLocatorUpdate(PVHDIMAGE pImage, PVHDPLE pLocator, const char *pszFilename)
314	{
315	int rc = VINF_SUCCESS;
316	uint32_t cb = 0;
317	uint32_t cbMaxLen = RT_BE2H_U32(pLocator->u32DataSpace);
318	void *pvBuf = RTMemTmpAllocZ(cbMaxLen);
319	char *pszTmp;
320
321	if (!pvBuf)
322	return VERR_NO_MEMORY;
323
324	switch (RT_BE2H_U32(pLocator->u32Code))
325	{
326	case VHD_PLATFORM_CODE_WI2R:
327	{
328	if (RTPathStartsWithRoot(pszFilename))
329	{
330	/* Convert to relative path. */
331	char szPath[RTPATH_MAX];
332	rc = RTPathCalcRelative(szPath, sizeof(szPath), pImage->pszFilename,
333	pszFilename);
334	if (RT_SUCCESS(rc))
335	{
336	/* Update plain relative name. */
337	cb = (uint32_t)strlen(szPath);
338	if (cb > cbMaxLen)
339	{
340	rc = VERR_FILENAME_TOO_LONG;
341	break;
342	}
343	memcpy(pvBuf, szPath, cb);
344	}
345	}
346	else
347	{
348	/* Update plain relative name. */
349	cb = (uint32_t)strlen(pszFilename);
350	if (cb > cbMaxLen)
351	{
352	rc = VERR_FILENAME_TOO_LONG;
353	break;
354	}
355	memcpy(pvBuf, pszFilename, cb);
356	}
357	if (RT_SUCCESS(rc))
358	pLocator->u32DataLength = RT_H2BE_U32(cb);
359	break;
360	}
361	case VHD_PLATFORM_CODE_WI2K:
362	/* Update plain absolute name. */
363	rc = RTPathAbs(pszFilename, (char *)pvBuf, cbMaxLen);
364	if (RT_SUCCESS(rc))
365	{
366	cb = (uint32_t)strlen((const char *)pvBuf);
367	pLocator->u32DataLength = RT_H2BE_U32(cb);
368	}
369	break;
370	case VHD_PLATFORM_CODE_W2RU:
371	if (RTPathStartsWithRoot(pszFilename))
372	{
373	/* Convert to relative path. */
374	char szPath[RTPATH_MAX];
375	rc = RTPathCalcRelative(szPath, sizeof(szPath), pImage->pszFilename,
376	pszFilename);
377	if (RT_SUCCESS(rc))
378	rc = vhdFilenameToUtf16(szPath, (uint16_t *)pvBuf, cbMaxLen, &cb, false);
379	}
380	else
381	{
382	/* Update unicode relative name. */
383	rc = vhdFilenameToUtf16(pszFilename, (uint16_t *)pvBuf, cbMaxLen, &cb, false);
384	}
385
386	if (RT_SUCCESS(rc))
387	pLocator->u32DataLength = RT_H2BE_U32(cb);
388	break;
389	case VHD_PLATFORM_CODE_W2KU:
390	/* Update unicode absolute name. */
391	pszTmp = (char*)RTMemTmpAllocZ(cbMaxLen);
392	if (!pszTmp)
393	{
394	rc = VERR_NO_MEMORY;
395	break;
396	}
397	rc = RTPathAbs(pszFilename, pszTmp, cbMaxLen);
398	if (RT_FAILURE(rc))
399	{
400	RTMemTmpFree(pszTmp);
401	break;
402	}
403	rc = vhdFilenameToUtf16(pszTmp, (uint16_t *)pvBuf, cbMaxLen, &cb, false);
404	RTMemTmpFree(pszTmp);
405	if (RT_SUCCESS(rc))
406	pLocator->u32DataLength = RT_H2BE_U32(cb);
407	break;
408	default:
409	rc = VERR_NOT_IMPLEMENTED;
410	break;
411	}
412
413	if (RT_SUCCESS(rc))
414	{
415	Assert(cb > 0);
416	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
417	RT_BE2H_U64(pLocator->u64DataOffset),
418	pvBuf, cb);
419	}
420
421	if (pvBuf)
422	RTMemTmpFree(pvBuf);
423	return rc;
424	}
425
426	/**
427	* Internal: Update dynamic disk header from VHDIMAGE.
428	*/
429	static int vhdDynamicHeaderUpdate(PVHDIMAGE pImage)
430	{
431	VHDDynamicDiskHeader ddh;
432	int rc, i;
433
434	if (!pImage)
435	return VERR_VD_NOT_OPENED;
436
437	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
438	pImage->u64DataOffset, &ddh, sizeof(ddh));
439	if (RT_FAILURE(rc))
440	return rc;
441	if (memcmp(ddh.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE) != 0)
442	return VERR_VD_VHD_INVALID_HEADER;
443
444	uint32_t u32Checksum = RT_BE2H_U32(ddh.Checksum);
445	ddh.Checksum = 0;
446	if (u32Checksum != vhdChecksum(&ddh, sizeof(ddh)))
447	return VERR_VD_VHD_INVALID_HEADER;
448
449	/* Update parent's timestamp. */
450	ddh.ParentTimestamp = RT_H2BE_U32(pImage->u32ParentTimestamp);
451	/* Update parent's filename. */
452	if (pImage->pszParentFilename)
453	{
454	rc = vhdFilenameToUtf16(RTPathFilename(pImage->pszParentFilename),
455	ddh.ParentUnicodeName, sizeof(ddh.ParentUnicodeName) - 1, NULL, true);
456	if (RT_FAILURE(rc))
457	return rc;
458	}
459
460	/* Update parent's locators. */
461	for (i = 0; i < VHD_MAX_LOCATOR_ENTRIES; i++)
462	{
463	/* Skip empty locators */
464	if ( ddh.ParentLocatorEntry[i].u32Code != RT_H2BE_U32(VHD_PLATFORM_CODE_NONE)
465	&& pImage->pszParentFilename)
466	{
467	rc = vhdLocatorUpdate(pImage, &ddh.ParentLocatorEntry[i], pImage->pszParentFilename);
468	if (RT_FAILURE(rc))
469	return rc;
470	}
471	}
472	/* Update parent's UUID */
473	memcpy(ddh.ParentUuid, pImage->ParentUuid.au8, sizeof(ddh.ParentUuid));
474
475	/* Update data offset and number of table entries. */
476	ddh.MaxTableEntries = RT_H2BE_U32(pImage->cBlockAllocationTableEntries);
477
478	ddh.Checksum = 0;
479	ddh.Checksum = RT_H2BE_U32(vhdChecksum(&ddh, sizeof(ddh)));
480	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
481	pImage->u64DataOffset, &ddh, sizeof(ddh));
482	return rc;
483	}
484
485	/**
486	* Internal: Update the VHD footer.
487	*/
488	static int vhdUpdateFooter(PVHDIMAGE pImage)
489	{
490	int rc = VINF_SUCCESS;
491
492	/* Update fields which can change. */
493	pImage->vhdFooterCopy.CurSize = RT_H2BE_U64(pImage->cbSize);
494	pImage->vhdFooterCopy.DiskGeometryCylinder = RT_H2BE_U16(pImage->PCHSGeometry.cCylinders);
495	pImage->vhdFooterCopy.DiskGeometryHeads = pImage->PCHSGeometry.cHeads;
496	pImage->vhdFooterCopy.DiskGeometrySectors = pImage->PCHSGeometry.cSectors;
497
498	pImage->vhdFooterCopy.Checksum = 0;
499	pImage->vhdFooterCopy.Checksum = RT_H2BE_U32(vhdChecksum(&pImage->vhdFooterCopy, sizeof(VHDFooter)));
500
501	if (pImage->pBlockAllocationTable)
502	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0,
503	&pImage->vhdFooterCopy, sizeof(VHDFooter));
504
505	if (RT_SUCCESS(rc))
506	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
507	pImage->uCurrentEndOfFile, &pImage->vhdFooterCopy,
508	sizeof(VHDFooter));
509
510	return rc;
511	}
512
513	/**
514	* Internal. Flush image data to disk.
515	*/
516	static int vhdFlushImage(PVHDIMAGE pImage)
517	{
518	int rc = VINF_SUCCESS;
519
520	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
521	return VINF_SUCCESS;
522
523	if (pImage->pBlockAllocationTable)
524	{
525	/*
526	* This is an expanding image. Write the BAT and copy of the disk footer.
527	*/
528	size_t cbBlockAllocationTableToWrite = pImage->cBlockAllocationTableEntries * sizeof(uint32_t);
529	uint32_t pBlockAllocationTableToWrite = (uint32_t )RTMemAllocZ(cbBlockAllocationTableToWrite);
530
531	if (!pBlockAllocationTableToWrite)
532	return VERR_NO_MEMORY;
533
534	/*
535	* The BAT entries have to be stored in big endian format.
536	*/
537	for (unsigned i = 0; i < pImage->cBlockAllocationTableEntries; i++)
538	pBlockAllocationTableToWrite[i] = RT_H2BE_U32(pImage->pBlockAllocationTable[i]);
539
540	/*
541	* Write the block allocation table after the copy of the disk footer and the dynamic disk header.
542	*/
543	vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->uBlockAllocationTableOffset,
544	pBlockAllocationTableToWrite, cbBlockAllocationTableToWrite);
545	if (pImage->fDynHdrNeedsUpdate)
546	rc = vhdDynamicHeaderUpdate(pImage);
547	RTMemFree(pBlockAllocationTableToWrite);
548	}
549
550	if (RT_SUCCESS(rc))
551	rc = vhdUpdateFooter(pImage);
552
553	if (RT_SUCCESS(rc))
554	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
555
556	return rc;
557	}
558
559	/**
560	* Internal. Free all allocated space for representing an image except pImage,
561	* and optionally delete the image from disk.
562	*/
563	static int vhdFreeImage(PVHDIMAGE pImage, bool fDelete)
564	{
565	int rc = VINF_SUCCESS;
566
567	/* Freeing a never allocated image (e.g. because the open failed) is
568	* not signalled as an error. After all nothing bad happens. */
569	if (pImage)
570	{
571	if (pImage->pStorage)
572	{
573	/* No point updating the file that is deleted anyway. */
574	if (!fDelete)
575	vhdFlushImage(pImage);
576
577	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
578	pImage->pStorage = NULL;
579	}
580
581	if (pImage->pszParentFilename)
582	{
583	RTStrFree(pImage->pszParentFilename);
584	pImage->pszParentFilename = NULL;
585	}
586	if (pImage->pBlockAllocationTable)
587	{
588	RTMemFree(pImage->pBlockAllocationTable);
589	pImage->pBlockAllocationTable = NULL;
590	}
591	if (pImage->pu8Bitmap)
592	{
593	RTMemFree(pImage->pu8Bitmap);
594	pImage->pu8Bitmap = NULL;
595	}
596
597	if (fDelete && pImage->pszFilename)
598	{
599	int rc2 = vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
600	if (RT_SUCCESS(rc))
601	rc = rc2;
602	}
603	}
604
605	LogFlowFunc(("returns %Rrc\n", rc));
606	return rc;
607	}
608
609	/* 946684800 is the number of seconds between 1/1/1970 and 1/1/2000 */
610	#define VHD_TO_UNIX_EPOCH_SECONDS UINT64_C(946684800)
611
612	static uint32_t vhdRtTime2VhdTime(PCRTTIMESPEC pRtTimestamp)
613	{
614	uint64_t u64Seconds = RTTimeSpecGetSeconds(pRtTimestamp);
615	return (uint32_t)(u64Seconds - VHD_TO_UNIX_EPOCH_SECONDS);
616	}
617
618	static void vhdTime2RtTime(PRTTIMESPEC pRtTimestamp, uint32_t u32VhdTimestamp)
619	{
620	RTTimeSpecSetSeconds(pRtTimestamp, VHD_TO_UNIX_EPOCH_SECONDS + u32VhdTimestamp);
621	}
622
623	/**
624	* Internal: Allocates the block bitmap rounding up to the next 32bit or 64bit boundary.
625	* Can be freed with RTMemFree. The memory is zeroed.
626	*/
627	DECLINLINE(uint8_t *)vhdBlockBitmapAllocate(PVHDIMAGE pImage)
628	{
629	#ifdef RT_ARCH_AMD64
630	return (uint8_t *)RTMemAllocZ(pImage->cbDataBlockBitmap + 8);
631	#else
632	return (uint8_t *)RTMemAllocZ(pImage->cbDataBlockBitmap + 4);
633	#endif
634	}
635
636	/**
637	* Internal: called when the async expansion process completed (failure or success).
638	* Will do the necessary rollback if an error occurred.
639	*/
640	static int vhdAsyncExpansionComplete(PVHDIMAGE pImage, PVDIOCTX pIoCtx, PVHDIMAGEEXPAND pExpand)
641	{
642	int rc = VINF_SUCCESS;
643	uint32_t fFlags = ASMAtomicReadU32(&pExpand->fFlags);
644	bool fIoInProgress = false;
645
646	/* Quick path, check if everything succeeded. */
647	if (fFlags == VHDIMAGEEXPAND_ALL_SUCCESS)
648	{
649	pImage->pBlockAllocationTable[pExpand->idxBatAllocated] = RT_BE2H_U32(pExpand->idxBlockBe);
650	RTMemFree(pExpand);
651	}
652	else
653	{
654	uint32_t uStatus;
655
656	uStatus = VHDIMAGEEXPAND_STATUS_GET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT);
657	if ( uStatus == VHDIMAGEEXPAND_STEP_FAILED
658	\|\| uStatus == VHDIMAGEEXPAND_STEP_SUCCESS)
659	{
660	/* Undo and restore the old value. */
661	pImage->pBlockAllocationTable[pExpand->idxBatAllocated] = ~0U;
662
663	/* Restore the old value on the disk.
664	* No need for a completion callback because we can't
665	* do anything if this fails. */
666	if (uStatus == VHDIMAGEEXPAND_STEP_SUCCESS)
667	{
668	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
669	pImage->uBlockAllocationTableOffset
670	+ pExpand->idxBatAllocated * sizeof(uint32_t),
671	&pImage->pBlockAllocationTable[pExpand->idxBatAllocated],
672	sizeof(uint32_t), pIoCtx, NULL, NULL);
673	fIoInProgress \|= rc == VERR_VD_ASYNC_IO_IN_PROGRESS;
674	}
675	}
676
677	/* Restore old size (including the footer because another application might
678	* fill up the free space making it impossible to add the footer)
679	* and add the footer at the right place again. */
680	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
681	pExpand->cbEofOld + sizeof(VHDFooter));
682	AssertRC(rc);
683
684	pImage->uCurrentEndOfFile = pExpand->cbEofOld;
685	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
686	pImage->uCurrentEndOfFile,
687	&pImage->vhdFooterCopy, sizeof(VHDFooter),
688	pIoCtx, NULL, NULL);
689	fIoInProgress \|= rc == VERR_VD_ASYNC_IO_IN_PROGRESS;
690	}
691
692	return fIoInProgress ? VERR_VD_ASYNC_IO_IN_PROGRESS : rc;
693	}
694
695	static int vhdAsyncExpansionStepCompleted(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq, unsigned iStep)
696	{
697	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
698	PVHDIMAGEEXPAND pExpand = (PVHDIMAGEEXPAND)pvUser;
699
700	LogFlowFunc(("pBackendData=%#p pIoCtx=%#p pvUser=%#p rcReq=%Rrc iStep=%u\n",
701	pBackendData, pIoCtx, pvUser, rcReq, iStep));
702
703	if (RT_SUCCESS(rcReq))
704	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, iStep, VHDIMAGEEXPAND_STEP_SUCCESS);
705	else
706	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, iStep, VHDIMAGEEXPAND_STEP_FAILED);
707
708	if ((pExpand->fFlags & VHDIMAGEEXPAND_ALL_COMPLETE) == VHDIMAGEEXPAND_ALL_COMPLETE)
709	return vhdAsyncExpansionComplete(pImage, pIoCtx, pExpand);
710
711	return VERR_VD_ASYNC_IO_IN_PROGRESS;
712	}
713
714	static DECLCALLBACK(int) vhdAsyncExpansionDataBlockBitmapComplete(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
715	{
716	return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT);
717	}
718
719	static DECLCALLBACK(int) vhdAsyncExpansionDataComplete(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
720	{
721	return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT);
722	}
723
724	static DECLCALLBACK(int) vhdAsyncExpansionBatUpdateComplete(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
725	{
726	return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_BAT_STATUS_SHIFT);
727	}
728
729	static DECLCALLBACK(int) vhdAsyncExpansionFooterUpdateComplete(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
730	{
731	return vhdAsyncExpansionStepCompleted(pBackendData, pIoCtx, pvUser, rcReq, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT);
732	}
733
734	static int vhdLoadDynamicDisk(PVHDIMAGE pImage, uint64_t uDynamicDiskHeaderOffset)
735	{
736	VHDDynamicDiskHeader vhdDynamicDiskHeader;
737	int rc = VINF_SUCCESS;
738	uint32_t *pBlockAllocationTable;
739	uint64_t uBlockAllocationTableOffset;
740	unsigned i = 0;
741
742	Log(("Open a dynamic disk.\n"));
743
744	/*
745	* Read the dynamic disk header.
746	*/
747	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, uDynamicDiskHeaderOffset,
748	&vhdDynamicDiskHeader, sizeof(VHDDynamicDiskHeader));
749	if (memcmp(vhdDynamicDiskHeader.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, VHD_DYNAMIC_DISK_HEADER_COOKIE_SIZE))
750	return VERR_INVALID_PARAMETER;
751
752	pImage->cbDataBlock = RT_BE2H_U32(vhdDynamicDiskHeader.BlockSize);
753	LogFlowFunc(("BlockSize=%u\n", pImage->cbDataBlock));
754	pImage->cBlockAllocationTableEntries = RT_BE2H_U32(vhdDynamicDiskHeader.MaxTableEntries);
755	LogFlowFunc(("MaxTableEntries=%lu\n", pImage->cBlockAllocationTableEntries));
756	AssertMsg(!(pImage->cbDataBlock % VHD_SECTOR_SIZE), ("%s: Data block size is not a multiple of %!\n", __FUNCTION__, VHD_SECTOR_SIZE));
757
758	/*
759	* Bail out if the number of BAT entries exceeds the number of sectors for a maximum image.
760	* Lower the number of sectors in the BAT as a few sectors are already occupied by the footers
761	* and headers.
762	*/
763	if (pImage->cBlockAllocationTableEntries > (VHD_MAX_SECTORS - 2))
764	return VERR_VD_VHD_INVALID_HEADER;
765
766	pImage->cSectorsPerDataBlock = pImage->cbDataBlock / VHD_SECTOR_SIZE;
767	LogFlowFunc(("SectorsPerDataBlock=%u\n", pImage->cSectorsPerDataBlock));
768
769	/*
770	* Every block starts with a bitmap indicating which sectors are valid and which are not.
771	* We store the size of it to be able to calculate the real offset.
772	*/
773	pImage->cbDataBlockBitmap = pImage->cSectorsPerDataBlock / 8;
774	pImage->cDataBlockBitmapSectors = pImage->cbDataBlockBitmap / VHD_SECTOR_SIZE;
775	/* Round up to full sector size */
776	if (pImage->cbDataBlockBitmap % VHD_SECTOR_SIZE > 0)
777	pImage->cDataBlockBitmapSectors++;
778	LogFlowFunc(("cbDataBlockBitmap=%u\n", pImage->cbDataBlockBitmap));
779	LogFlowFunc(("cDataBlockBitmapSectors=%u\n", pImage->cDataBlockBitmapSectors));
780
781	pImage->pu8Bitmap = vhdBlockBitmapAllocate(pImage);
782	if (!pImage->pu8Bitmap)
783	return VERR_NO_MEMORY;
784
785	pBlockAllocationTable = (uint32_t )RTMemAllocZ(pImage->cBlockAllocationTableEntries sizeof(uint32_t));
786	if (!pBlockAllocationTable)
787	return VERR_NO_MEMORY;
788
789	/*
790	* Read the table.
791	*/
792	uBlockAllocationTableOffset = RT_BE2H_U64(vhdDynamicDiskHeader.TableOffset);
793	LogFlowFunc(("uBlockAllocationTableOffset=%llu\n", uBlockAllocationTableOffset));
794	pImage->uBlockAllocationTableOffset = uBlockAllocationTableOffset;
795	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
796	uBlockAllocationTableOffset, pBlockAllocationTable,
797	pImage->cBlockAllocationTableEntries * sizeof(uint32_t));
798	if (RT_FAILURE(rc))
799	return rc;
800
801	/*
802	* Because the offset entries inside the allocation table are stored big endian
803	* we need to convert them into host endian.
804	*/
805	pImage->pBlockAllocationTable = (uint32_t )RTMemAllocZ(pImage->cBlockAllocationTableEntries sizeof(uint32_t));
806	if (!pImage->pBlockAllocationTable)
807	{
808	RTMemFree(pBlockAllocationTable);
809	return VERR_NO_MEMORY;
810	}
811
812	for (i = 0; i < pImage->cBlockAllocationTableEntries; i++)
813	pImage->pBlockAllocationTable[i] = RT_BE2H_U32(pBlockAllocationTable[i]);
814
815	RTMemFree(pBlockAllocationTable);
816
817	if (pImage->uImageFlags & VD_IMAGE_FLAGS_DIFF)
818	memcpy(pImage->ParentUuid.au8, vhdDynamicDiskHeader.ParentUuid, sizeof(pImage->ParentUuid));
819
820	return rc;
821	}
822
823	static int vhdOpenImage(PVHDIMAGE pImage, unsigned uOpenFlags)
824	{
825	uint64_t FileSize;
826	VHDFooter vhdFooter;
827
828	pImage->uOpenFlags = uOpenFlags;
829
830	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
831	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
832	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
833
834	/*
835	* Open the image.
836	*/
837	int rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
838	VDOpenFlagsToFileOpenFlags(uOpenFlags,
839	false /* fCreate */),
840	&pImage->pStorage);
841	if (RT_FAILURE(rc))
842	{
843	/* Do NOT signal an appropriate error here, as the VD layer has the
844	* choice of retrying the open if it failed. */
845	return rc;
846	}
847
848	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &FileSize);
849	pImage->uCurrentEndOfFile = FileSize - sizeof(VHDFooter);
850
851	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, pImage->uCurrentEndOfFile,
852	&vhdFooter, sizeof(VHDFooter));
853	if (RT_SUCCESS(rc))
854	{
855	if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
856	{
857	/*
858	* There is also a backup header at the beginning in case the image got corrupted.
859	* Such corrupted images are detected here to let the open handler repair it later.
860	*/
861	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0,
862	&vhdFooter, sizeof(VHDFooter));
863	if (RT_SUCCESS(rc))
864	{
865	if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
866	rc = VERR_VD_VHD_INVALID_HEADER;
867	else
868	rc = VERR_VD_IMAGE_CORRUPTED;
869	}
870	}
871	}
872
873	if (RT_FAILURE(rc))
874	return rc;
875
876	switch (RT_BE2H_U32(vhdFooter.DiskType))
877	{
878	case VHD_FOOTER_DISK_TYPE_FIXED:
879	pImage->uImageFlags \|= VD_IMAGE_FLAGS_FIXED;
880	break;
881	case VHD_FOOTER_DISK_TYPE_DYNAMIC:
882	pImage->uImageFlags &= ~VD_IMAGE_FLAGS_FIXED;
883	break;
884	case VHD_FOOTER_DISK_TYPE_DIFFERENCING:
885	pImage->uImageFlags \|= VD_IMAGE_FLAGS_DIFF;
886	pImage->uImageFlags &= ~VD_IMAGE_FLAGS_FIXED;
887	break;
888	default:
889	return VERR_NOT_IMPLEMENTED;
890	}
891
892	pImage->cbSize = RT_BE2H_U64(vhdFooter.CurSize);
893	pImage->LCHSGeometry.cCylinders = 0;
894	pImage->LCHSGeometry.cHeads = 0;
895	pImage->LCHSGeometry.cSectors = 0;
896	pImage->PCHSGeometry.cCylinders = RT_BE2H_U16(vhdFooter.DiskGeometryCylinder);
897	pImage->PCHSGeometry.cHeads = vhdFooter.DiskGeometryHeads;
898	pImage->PCHSGeometry.cSectors = vhdFooter.DiskGeometrySectors;
899
900	/*
901	* Copy of the disk footer.
902	* If we allocate new blocks in differencing disks on write access
903	* the footer is overwritten. We need to write it at the end of the file.
904	*/
905	memcpy(&pImage->vhdFooterCopy, &vhdFooter, sizeof(VHDFooter));
906
907	/*
908	* Is there a better way?
909	*/
910	memcpy(&pImage->ImageUuid, &vhdFooter.UniqueID, 16);
911
912	pImage->u64DataOffset = RT_BE2H_U64(vhdFooter.DataOffset);
913	LogFlowFunc(("DataOffset=%llu\n", pImage->u64DataOffset));
914
915	if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
916	rc = vhdLoadDynamicDisk(pImage, pImage->u64DataOffset);
917
918	if (RT_SUCCESS(rc))
919	{
920	PVDREGIONDESC pRegion = &pImage->RegionList.aRegions[0];
921	pImage->RegionList.fFlags = 0;
922	pImage->RegionList.cRegions = 1;
923
924	pRegion->offRegion = 0; /* Disk start. */
925	pRegion->cbBlock = 512;
926	pRegion->enmDataForm = VDREGIONDATAFORM_RAW;
927	pRegion->enmMetadataForm = VDREGIONMETADATAFORM_NONE;
928	pRegion->cbData = 512;
929	pRegion->cbMetadata = 0;
930	pRegion->cRegionBlocksOrBytes = pImage->cbSize;
931	}
932	else
933	vhdFreeImage(pImage, false);
934	return rc;
935	}
936
937	/**
938	* Internal: Checks if a sector in the block bitmap is set
939	*/
940	DECLINLINE(bool) vhdBlockBitmapSectorContainsData(PVHDIMAGE pImage, uint32_t cBlockBitmapEntry)
941	{
942	uint32_t iBitmap = (cBlockBitmapEntry / 8); /* Byte in the block bitmap. */
943
944	/*
945	* The index of the bit in the byte of the data block bitmap.
946	* The most significant bit stands for a lower sector number.
947	*/
948	uint8_t iBitInByte = (8-1) - (cBlockBitmapEntry % 8);
949	uint8_t *puBitmap = pImage->pu8Bitmap + iBitmap;
950
951	AssertMsg(puBitmap < (pImage->pu8Bitmap + pImage->cbDataBlockBitmap),
952	("VHD: Current bitmap position exceeds maximum size of the bitmap\n"));
953
954	return ((*puBitmap) & RT_BIT(iBitInByte)) != 0;
955	}
956
957	/**
958	* Internal: Sets the given sector in the sector bitmap.
959	*/
960	DECLINLINE(bool) vhdBlockBitmapSectorSet(PVHDIMAGE pImage, uint8_t *pu8Bitmap, uint32_t cBlockBitmapEntry)
961	{
962	RT_NOREF1(pImage);
963	uint32_t iBitmap = (cBlockBitmapEntry / 8); /* Byte in the block bitmap. */
964
965	/*
966	* The index of the bit in the byte of the data block bitmap.
967	* The most significant bit stands for a lower sector number.
968	*/
969	uint8_t iBitInByte = (8-1) - (cBlockBitmapEntry % 8);
970	uint8_t *puBitmap = pu8Bitmap + iBitmap;
971
972	AssertMsg(puBitmap < (pu8Bitmap + pImage->cbDataBlockBitmap),
973	("VHD: Current bitmap position exceeds maximum size of the bitmap\n"));
974
975	bool fClear = ((*puBitmap) & RT_BIT(iBitInByte)) == 0;
976	*puBitmap \|= RT_BIT(iBitInByte);
977	return fClear;
978	}
979
980	/**
981	* Internal: Derive drive geometry from its size.
982	*/
983	static void vhdSetDiskGeometry(PVHDIMAGE pImage, uint64_t cbSize)
984	{
985	uint64_t u64TotalSectors = cbSize / VHD_SECTOR_SIZE;
986	uint32_t u32CylinderTimesHeads, u32Heads, u32SectorsPerTrack;
987
988	if (u64TotalSectors > 65535 * 16 * 255)
989	{
990	/* ATA disks limited to 127 GB. */
991	u64TotalSectors = 65535 * 16 * 255;
992	}
993
994	if (u64TotalSectors >= 65535 * 16 * 63)
995	{
996	u32SectorsPerTrack = 255;
997	u32Heads = 16;
998	u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
999	}
1000	else
1001	{
1002	u32SectorsPerTrack = 17;
1003	u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
1004
1005	u32Heads = (u32CylinderTimesHeads + 1023) / 1024;
1006
1007	if (u32Heads < 4)
1008	{
1009	u32Heads = 4;
1010	}
1011	if (u32CylinderTimesHeads >= (u32Heads * 1024) \|\| u32Heads > 16)
1012	{
1013	u32SectorsPerTrack = 31;
1014	u32Heads = 16;
1015	u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
1016	}
1017	if (u32CylinderTimesHeads >= (u32Heads * 1024))
1018	{
1019	u32SectorsPerTrack = 63;
1020	u32Heads = 16;
1021	u32CylinderTimesHeads = u64TotalSectors / u32SectorsPerTrack;
1022	}
1023	}
1024	pImage->PCHSGeometry.cCylinders = u32CylinderTimesHeads / u32Heads;
1025	pImage->PCHSGeometry.cHeads = u32Heads;
1026	pImage->PCHSGeometry.cSectors = u32SectorsPerTrack;
1027	pImage->LCHSGeometry.cCylinders = 0;
1028	pImage->LCHSGeometry.cHeads = 0;
1029	pImage->LCHSGeometry.cSectors = 0;
1030	}
1031
1032
1033	static uint32_t vhdAllocateParentLocators(PVHDIMAGE pImage, VHDDynamicDiskHeader *pDDH, uint64_t u64Offset)
1034	{
1035	RT_NOREF1(pImage);
1036	PVHDPLE pLocator = pDDH->ParentLocatorEntry;
1037
1038	/*
1039	* The VHD spec states that the DataSpace field holds the number of sectors
1040	* required to store the parent locator path.
1041	* As it turned out VPC and Hyper-V store the amount of bytes reserved for the
1042	* path and not the number of sectors.
1043	*/
1044
1045	/* Unicode absolute Windows path. */
1046	pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_W2KU);
1047	pLocator->u32DataSpace = RT_H2BE_U32(VHD_ABSOLUTE_MAX_PATH * sizeof(RTUTF16));
1048	pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
1049	pLocator++;
1050	u64Offset += VHD_ABSOLUTE_MAX_PATH * sizeof(RTUTF16);
1051	/* Unicode relative Windows path. */
1052	pLocator->u32Code = RT_H2BE_U32(VHD_PLATFORM_CODE_W2RU);
1053	pLocator->u32DataSpace = RT_H2BE_U32(VHD_RELATIVE_MAX_PATH * sizeof(RTUTF16));
1054	pLocator->u64DataOffset = RT_H2BE_U64(u64Offset);
1055	u64Offset += VHD_RELATIVE_MAX_PATH * sizeof(RTUTF16);
1056	return u64Offset;
1057	}
1058
1059	/**
1060	* Internal: Additional code for dynamic VHD image creation.
1061	*/
1062	static int vhdCreateDynamicImage(PVHDIMAGE pImage, uint64_t cbSize)
1063	{
1064	int rc;
1065	VHDDynamicDiskHeader DynamicDiskHeader;
1066	uint32_t u32BlockAllocationTableSectors;
1067	void *pvTmp = NULL;
1068
1069	memset(&DynamicDiskHeader, 0, sizeof(DynamicDiskHeader));
1070
1071	pImage->u64DataOffset = sizeof(VHDFooter);
1072	pImage->cbDataBlock = VHD_BLOCK_SIZE; /* 2 MB */
1073	pImage->cSectorsPerDataBlock = pImage->cbDataBlock / VHD_SECTOR_SIZE;
1074	pImage->cbDataBlockBitmap = pImage->cSectorsPerDataBlock / 8;
1075	pImage->cDataBlockBitmapSectors = pImage->cbDataBlockBitmap / VHD_SECTOR_SIZE;
1076	/* Align to sector boundary */
1077	if (pImage->cbDataBlockBitmap % VHD_SECTOR_SIZE > 0)
1078	pImage->cDataBlockBitmapSectors++;
1079	pImage->pu8Bitmap = vhdBlockBitmapAllocate(pImage);
1080	if (!pImage->pu8Bitmap)
1081	return vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot allocate memory for bitmap storage"));
1082
1083	/* Initialize BAT. */
1084	pImage->uBlockAllocationTableOffset = (uint64_t)sizeof(VHDFooter) + sizeof(VHDDynamicDiskHeader);
1085	pImage->cBlockAllocationTableEntries = (uint32_t)((cbSize + pImage->cbDataBlock - 1) / pImage->cbDataBlock); /* Align table to the block size. */
1086	u32BlockAllocationTableSectors = (pImage->cBlockAllocationTableEntries * sizeof(uint32_t) + VHD_SECTOR_SIZE - 1) / VHD_SECTOR_SIZE;
1087	pImage->pBlockAllocationTable = (uint32_t )RTMemAllocZ(pImage->cBlockAllocationTableEntries sizeof(uint32_t));
1088	if (!pImage->pBlockAllocationTable)
1089	return vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot allocate memory for BAT"));
1090
1091	for (unsigned i = 0; i < pImage->cBlockAllocationTableEntries; i++)
1092	{
1093	pImage->pBlockAllocationTable[i] = 0xFFFFFFFF; /* It is actually big endian. */
1094	}
1095
1096	/* Round up to the sector size. */
1097	if (pImage->uImageFlags & VD_IMAGE_FLAGS_DIFF) /* fix hyper-v unreadable error */
1098	pImage->uCurrentEndOfFile = vhdAllocateParentLocators(pImage, &DynamicDiskHeader,
1099	pImage->uBlockAllocationTableOffset + u32BlockAllocationTableSectors * VHD_SECTOR_SIZE);
1100	else
1101	pImage->uCurrentEndOfFile = pImage->uBlockAllocationTableOffset + u32BlockAllocationTableSectors * VHD_SECTOR_SIZE;
1102
1103	/* Set dynamic image size. */
1104	pvTmp = RTMemTmpAllocZ(pImage->uCurrentEndOfFile + sizeof(VHDFooter));
1105	if (!pvTmp)
1106	return vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
1107
1108	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, pvTmp,
1109	pImage->uCurrentEndOfFile + sizeof(VHDFooter));
1110	if (RT_FAILURE(rc))
1111	{
1112	RTMemTmpFree(pvTmp);
1113	return vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
1114	}
1115
1116	RTMemTmpFree(pvTmp);
1117
1118	/* Initialize and write the dynamic disk header. */
1119	memcpy(DynamicDiskHeader.Cookie, VHD_DYNAMIC_DISK_HEADER_COOKIE, sizeof(DynamicDiskHeader.Cookie));
1120	DynamicDiskHeader.DataOffset = UINT64_C(0xFFFFFFFFFFFFFFFF); /* Initially the disk has no data. */
1121	DynamicDiskHeader.TableOffset = RT_H2BE_U64(pImage->uBlockAllocationTableOffset);
1122	DynamicDiskHeader.HeaderVersion = RT_H2BE_U32(VHD_DYNAMIC_DISK_HEADER_VERSION);
1123	DynamicDiskHeader.BlockSize = RT_H2BE_U32(pImage->cbDataBlock);
1124	DynamicDiskHeader.MaxTableEntries = RT_H2BE_U32(pImage->cBlockAllocationTableEntries);
1125	/* Compute and update checksum. */
1126	DynamicDiskHeader.Checksum = 0;
1127	DynamicDiskHeader.Checksum = RT_H2BE_U32(vhdChecksum(&DynamicDiskHeader, sizeof(DynamicDiskHeader)));
1128
1129	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, sizeof(VHDFooter),
1130	&DynamicDiskHeader, sizeof(DynamicDiskHeader));
1131	if (RT_FAILURE(rc))
1132	return vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot write dynamic disk header to image '%s'"), pImage->pszFilename);
1133
1134	/* Write BAT. */
1135	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->uBlockAllocationTableOffset,
1136	pImage->pBlockAllocationTable,
1137	pImage->cBlockAllocationTableEntries * sizeof(uint32_t));
1138	if (RT_FAILURE(rc))
1139	return vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot write BAT to image '%s'"), pImage->pszFilename);
1140
1141	return rc;
1142	}
1143
1144	/**
1145	* Internal: The actual code for VHD image creation, both fixed and dynamic.
1146	*/
1147	static int vhdCreateImage(PVHDIMAGE pImage, uint64_t cbSize,
1148	unsigned uImageFlags, const char *pszComment,
1149	PCVDGEOMETRY pPCHSGeometry,
1150	PCVDGEOMETRY pLCHSGeometry, PCRTUUID pUuid,
1151	unsigned uOpenFlags,
1152	PVDINTERFACEPROGRESS pIfProgress,
1153	unsigned uPercentStart, unsigned uPercentSpan)
1154	{
1155	RT_NOREF3(pszComment, pPCHSGeometry, pLCHSGeometry);
1156	VHDFooter Footer;
1157	RTTIMESPEC now;
1158
1159	pImage->uOpenFlags = uOpenFlags;
1160	pImage->uImageFlags = uImageFlags;
1161	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1162
1163	int rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1164	VDOpenFlagsToFileOpenFlags(uOpenFlags & ~VD_OPEN_FLAGS_READONLY,
1165	true /* fCreate */),
1166	&pImage->pStorage);
1167	if (RT_SUCCESS(rc))
1168	{
1169	pImage->cbSize = cbSize;
1170	pImage->ImageUuid = *pUuid;
1171	RTUuidClear(&pImage->ParentUuid);
1172	vhdSetDiskGeometry(pImage, cbSize);
1173
1174	/* Initialize the footer. */
1175	memset(&Footer, 0, sizeof(Footer));
1176	memcpy(Footer.Cookie, VHD_FOOTER_COOKIE, sizeof(Footer.Cookie));
1177	Footer.Features = RT_H2BE_U32(0x2);
1178	Footer.Version = RT_H2BE_U32(VHD_FOOTER_FILE_FORMAT_VERSION);
1179	Footer.Timestamp = RT_H2BE_U32(vhdRtTime2VhdTime(RTTimeNow(&now)));
1180	memcpy(Footer.CreatorApp, "vbox", sizeof(Footer.CreatorApp));
1181	Footer.CreatorVer = RT_H2BE_U32(VBOX_VERSION);
1182	#ifdef RT_OS_DARWIN
1183	Footer.CreatorOS = RT_H2BE_U32(0x4D616320); /* "Mac " */
1184	#else /* Virtual PC supports only two platforms atm, so everything else will be Wi2k. */
1185	Footer.CreatorOS = RT_H2BE_U32(0x5769326B); /* "Wi2k" */
1186	#endif
1187	Footer.OrigSize = RT_H2BE_U64(cbSize);
1188	Footer.CurSize = Footer.OrigSize;
1189	Footer.DiskGeometryCylinder = RT_H2BE_U16(pImage->PCHSGeometry.cCylinders);
1190	Footer.DiskGeometryHeads = pImage->PCHSGeometry.cHeads;
1191	Footer.DiskGeometrySectors = pImage->PCHSGeometry.cSectors;
1192	memcpy(Footer.UniqueID, pImage->ImageUuid.au8, sizeof(Footer.UniqueID));
1193	Footer.SavedState = 0;
1194
1195	if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
1196	{
1197	Footer.DiskType = RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_FIXED);
1198	/*
1199	* Initialize fixed image.
1200	* "The size of the entire file is the size of the hard disk in
1201	* the guest operating system plus the size of the footer."
1202	*/
1203	pImage->u64DataOffset = VHD_FOOTER_DATA_OFFSET_FIXED;
1204	pImage->uCurrentEndOfFile = cbSize;
1205	rc = vdIfIoIntFileSetAllocationSize(pImage->pIfIo, pImage->pStorage, pImage->uCurrentEndOfFile + sizeof(VHDFooter),
1206	0 /* fFlags */, pIfProgress,
1207	uPercentStart, uPercentSpan);
1208	if (RT_FAILURE(rc))
1209	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot set the file size for '%s'"), pImage->pszFilename);
1210	}
1211	else
1212	{
1213	/*
1214	* Initialize dynamic image.
1215	*
1216	* The overall structure of dynamic disk is:
1217	*
1218	* [Copy of hard disk footer (512 bytes)]
1219	* [Dynamic disk header (1024 bytes)]
1220	* [BAT (Block Allocation Table)]
1221	* [Parent Locators]
1222	* [Data block 1]
1223	* [Data block 2]
1224	* ...
1225	* [Data block N]
1226	* [Hard disk footer (512 bytes)]
1227	*/
1228	Footer.DiskType = (uImageFlags & VD_IMAGE_FLAGS_DIFF)
1229	? RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_DIFFERENCING)
1230	: RT_H2BE_U32(VHD_FOOTER_DISK_TYPE_DYNAMIC);
1231	/* We are half way thorough with creation of image, let the caller know. */
1232	vdIfProgress(pIfProgress, (uPercentStart + uPercentSpan) / 2);
1233
1234	rc = vhdCreateDynamicImage(pImage, cbSize);
1235	}
1236
1237	if (RT_SUCCESS(rc))
1238	{
1239	/* Compute and update the footer checksum. */
1240	Footer.DataOffset = RT_H2BE_U64(pImage->u64DataOffset);
1241	Footer.Checksum = 0;
1242	Footer.Checksum = RT_H2BE_U32(vhdChecksum(&Footer, sizeof(Footer)));
1243
1244	pImage->vhdFooterCopy = Footer;
1245
1246	/* Store the footer */
1247	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->uCurrentEndOfFile,
1248	&Footer, sizeof(Footer));
1249	if (RT_SUCCESS(rc))
1250	{
1251	/* Dynamic images contain a copy of the footer at the very beginning of the file. */
1252	if (!(uImageFlags & VD_IMAGE_FLAGS_FIXED))
1253	{
1254	/* Write the copy of the footer. */
1255	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Footer, sizeof(Footer));
1256	if (RT_FAILURE(rc))
1257	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot write a copy of footer to image '%s'"), pImage->pszFilename);
1258	}
1259	}
1260	else
1261	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot write footer to image '%s'"), pImage->pszFilename);
1262	}
1263	}
1264	else
1265	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("VHD: cannot create image '%s'"), pImage->pszFilename);
1266
1267	if (RT_SUCCESS(rc))
1268	vdIfProgress(pIfProgress, uPercentStart + uPercentSpan);
1269
1270	if (RT_SUCCESS(rc))
1271	{
1272	PVDREGIONDESC pRegion = &pImage->RegionList.aRegions[0];
1273	pImage->RegionList.fFlags = 0;
1274	pImage->RegionList.cRegions = 1;
1275
1276	pRegion->offRegion = 0; /* Disk start. */
1277	pRegion->cbBlock = 512;
1278	pRegion->enmDataForm = VDREGIONDATAFORM_RAW;
1279	pRegion->enmMetadataForm = VDREGIONMETADATAFORM_NONE;
1280	pRegion->cbData = 512;
1281	pRegion->cbMetadata = 0;
1282	pRegion->cRegionBlocksOrBytes = pImage->cbSize;
1283	}
1284	else
1285	vhdFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1286	return rc;
1287	}
1288
1289
1290	/** @interface_method_impl{VDIMAGEBACKEND,pfnProbe} */
1291	static DECLCALLBACK(int) vhdProbe(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1292	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1293	{
1294	RT_NOREF1(pVDIfsDisk);
1295	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1296	PVDIOSTORAGE pStorage;
1297	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1298	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1299
1300	int rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1301	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1302	false /* fCreate */),
1303	&pStorage);
1304	if (RT_SUCCESS(rc))
1305	{
1306	uint64_t cbFile;
1307
1308	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1309	if ( RT_SUCCESS(rc)
1310	&& cbFile >= sizeof(VHDFooter))
1311	{
1312	VHDFooter vhdFooter;
1313
1314	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, cbFile - sizeof(VHDFooter),
1315	&vhdFooter, sizeof(VHDFooter));
1316	if (RT_SUCCESS(rc))
1317	{
1318	if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
1319	{
1320	/*
1321	* There is also a backup header at the beginning in case the image got corrupted.
1322	* Such corrupted images are detected here to let the open handler repair it later.
1323	*/
1324	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &vhdFooter, sizeof(VHDFooter));
1325	if ( RT_FAILURE(rc)
1326	\|\| (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0))
1327	rc = VERR_VD_VHD_INVALID_HEADER;
1328	}
1329
1330	if (RT_SUCCESS(rc))
1331	*penmType = VDTYPE_HDD;
1332	}
1333	else
1334	rc = VERR_VD_VHD_INVALID_HEADER;
1335	}
1336	else if (RT_SUCCESS(rc))
1337	rc = VERR_VD_VHD_INVALID_HEADER;
1338
1339	vdIfIoIntFileClose(pIfIo, pStorage);
1340	}
1341
1342	LogFlowFunc(("returns %Rrc\n", rc));
1343	return rc;
1344	}
1345
1346	/** @interface_method_impl{VDIMAGEBACKEND,pfnOpen} */
1347	static DECLCALLBACK(int) vhdOpen(const char *pszFilename, unsigned uOpenFlags,
1348	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1349	VDTYPE enmType, void **ppBackendData)
1350	{
1351	RT_NOREF1(enmType); /*< @todo r=klaus make use of the type info. /
1352
1353	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p enmType=%u ppBackendData=%#p\n",
1354	pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, enmType, ppBackendData));
1355	int rc = VINF_SUCCESS;
1356
1357	/* Check open flags. All valid flags are supported. */
1358	AssertReturn(!(uOpenFlags & ~VD_OPEN_FLAGS_MASK), VERR_INVALID_PARAMETER);
1359	AssertReturn((VALID_PTR(pszFilename) && *pszFilename), VERR_INVALID_PARAMETER);
1360
1361	PVHDIMAGE pImage = (PVHDIMAGE)RTMemAllocZ(RT_UOFFSETOF(VHDIMAGE, RegionList.aRegions[1]));
1362	if (RT_LIKELY(pImage))
1363	{
1364	pImage->pszFilename = pszFilename;
1365	pImage->pStorage = NULL;
1366	pImage->pVDIfsDisk = pVDIfsDisk;
1367	pImage->pVDIfsImage = pVDIfsImage;
1368
1369	rc = vhdOpenImage(pImage, uOpenFlags);
1370	if (RT_SUCCESS(rc))
1371	*ppBackendData = pImage;
1372	else
1373	RTMemFree(pImage);
1374	}
1375	else
1376	rc = VERR_NO_MEMORY;
1377
1378	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1379	return rc;
1380	}
1381
1382	/** @interface_method_impl{VDIMAGEBACKEND,pfnCreate} */
1383	static DECLCALLBACK(int) vhdCreate(const char *pszFilename, uint64_t cbSize,
1384	unsigned uImageFlags, const char *pszComment,
1385	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1386	PCRTUUID pUuid, unsigned uOpenFlags,
1387	unsigned uPercentStart, unsigned uPercentSpan,
1388	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1389	PVDINTERFACE pVDIfsOperation, VDTYPE enmType,
1390	void **ppBackendData)
1391	{
1392	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 enmType=%u ppBackendData=%#p",
1393	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, enmType, ppBackendData));
1394	int rc;
1395	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1396
1397	/* Check the VD container type. */
1398	if (enmType != VDTYPE_HDD)
1399	return VERR_VD_INVALID_TYPE;
1400
1401	/* Check open flags. All valid flags are supported. */
1402	AssertReturn(!(uOpenFlags & ~VD_OPEN_FLAGS_MASK), VERR_INVALID_PARAMETER);
1403	AssertReturn( VALID_PTR(pszFilename)
1404	&& *pszFilename
1405	&& VALID_PTR(pPCHSGeometry)
1406	&& VALID_PTR(pLCHSGeometry), VERR_INVALID_PARAMETER);
1407	/** @todo Check the values of other params */
1408
1409	PVHDIMAGE pImage = (PVHDIMAGE)RTMemAllocZ(RT_UOFFSETOF(VHDIMAGE, RegionList.aRegions[1]));
1410	if (RT_LIKELY(pImage))
1411	{
1412	pImage->pszFilename = pszFilename;
1413	pImage->pStorage = NULL;
1414	pImage->pVDIfsDisk = pVDIfsDisk;
1415	pImage->pVDIfsImage = pVDIfsImage;
1416
1417	/* Get I/O interface. */
1418	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1419	if (RT_LIKELY(VALID_PTR(pImage->pIfIo)))
1420	{
1421	rc = vhdCreateImage(pImage, cbSize, uImageFlags, pszComment,
1422	pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags,
1423	pIfProgress, uPercentStart, uPercentSpan);
1424	if (RT_SUCCESS(rc))
1425	{
1426	/* So far the image is opened in read/write mode. Make sure the
1427	* image is opened in read-only mode if the caller requested that. */
1428	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1429	{
1430	vhdFreeImage(pImage, false);
1431	rc = vhdOpenImage(pImage, uOpenFlags);
1432	}
1433
1434	if (RT_SUCCESS(rc))
1435	*ppBackendData = pImage;
1436	}
1437	}
1438	else
1439	rc = VERR_INVALID_PARAMETER;
1440
1441	if (RT_FAILURE(rc))
1442	RTMemFree(pImage);
1443	}
1444	else
1445	rc = VERR_NO_MEMORY;
1446
1447	LogFlowFunc(("returns %Rrc\n", rc));
1448	return rc;
1449	}
1450
1451	/** @interface_method_impl{VDIMAGEBACKEND,pfnRename} */
1452	static DECLCALLBACK(int) vhdRename(void pBackendData, const char pszFilename)
1453	{
1454	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1455	int rc = VINF_SUCCESS;
1456	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1457
1458	/* Check arguments. */
1459	AssertReturn((pImage && pszFilename && *pszFilename), VERR_INVALID_PARAMETER);
1460
1461	/* Close the image. */
1462	rc = vhdFreeImage(pImage, false);
1463	if (RT_SUCCESS(rc))
1464	{
1465	/* Rename the file. */
1466	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1467	if (RT_SUCCESS(rc))
1468	{
1469	/* Update pImage with the new information. */
1470	pImage->pszFilename = pszFilename;
1471
1472	/* Open the old file with new name. */
1473	rc = vhdOpenImage(pImage, pImage->uOpenFlags);
1474	}
1475	else
1476	{
1477	/* The move failed, try to reopen the original image. */
1478	int rc2 = vhdOpenImage(pImage, pImage->uOpenFlags);
1479	if (RT_FAILURE(rc2))
1480	rc = rc2;
1481	}
1482	}
1483
1484	LogFlowFunc(("returns %Rrc\n", rc));
1485	return rc;
1486	}
1487
1488	/** @interface_method_impl{VDIMAGEBACKEND,pfnClose} */
1489	static DECLCALLBACK(int) vhdClose(void *pBackendData, bool fDelete)
1490	{
1491	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1492	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1493
1494	int rc = vhdFreeImage(pImage, fDelete);
1495	RTMemFree(pImage);
1496
1497	LogFlowFunc(("returns %Rrc\n", rc));
1498	return rc;
1499	}
1500
1501	/** @interface_method_impl{VDIMAGEBACKEND,pfnRead} */
1502	static DECLCALLBACK(int) vhdRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1503	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1504	{
1505	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1506	int rc = VINF_SUCCESS;
1507
1508	LogFlowFunc(("pBackendData=%p uOffset=%#llx pIoCtx=%#p cbToRead=%u pcbActuallyRead=%p\n",
1509	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1510
1511	AssertPtr(pImage);
1512	Assert(uOffset % 512 == 0);
1513	Assert(cbToRead % 512 == 0);
1514	AssertReturn((VALID_PTR(pIoCtx) && cbToRead), VERR_INVALID_PARAMETER);
1515	AssertReturn(uOffset + cbToRead <= pImage->cbSize, VERR_INVALID_PARAMETER);
1516
1517	/*
1518	* If we have a dynamic disk image, we need to find the data block and sector to read.
1519	*/
1520	if (pImage->pBlockAllocationTable)
1521	{
1522	/*
1523	* Get the data block first.
1524	*/
1525	uint32_t cBlockAllocationTableEntry = (uOffset / VHD_SECTOR_SIZE) / pImage->cSectorsPerDataBlock;
1526	uint32_t cBATEntryIndex = (uOffset / VHD_SECTOR_SIZE) % pImage->cSectorsPerDataBlock;
1527	uint64_t uVhdOffset;
1528
1529	LogFlowFunc(("cBlockAllocationTableEntry=%u cBatEntryIndex=%u\n", cBlockAllocationTableEntry, cBATEntryIndex));
1530	LogFlowFunc(("BlockAllocationEntry=%u\n", pImage->pBlockAllocationTable[cBlockAllocationTableEntry]));
1531
1532	/*
1533	* Clip read range to remain in this data block.
1534	*/
1535	cbToRead = RT_MIN(cbToRead, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
1536
1537	/*
1538	* If the block is not allocated the content of the entry is ~0
1539	*/
1540	if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
1541	rc = VERR_VD_BLOCK_FREE;
1542	else
1543	{
1544	uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
1545	LogFlowFunc(("uVhdOffset=%llu cbToRead=%u\n", uVhdOffset, cbToRead));
1546
1547	/* Read in the block's bitmap. */
1548	PVDMETAXFER pMetaXfer;
1549	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
1550	((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
1551	pImage->pu8Bitmap, pImage->cbDataBlockBitmap,
1552	pIoCtx, &pMetaXfer, NULL, NULL);
1553
1554	if (RT_SUCCESS(rc))
1555	{
1556	uint32_t cSectors = 0;
1557
1558	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
1559	if (vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
1560	{
1561	cBATEntryIndex++;
1562	cSectors = 1;
1563
1564	/*
1565	* The first sector being read is marked dirty, read as much as we
1566	* can from child. Note that only sectors that are marked dirty
1567	* must be read from child.
1568	*/
1569	while ( (cSectors < (cbToRead / VHD_SECTOR_SIZE))
1570	&& vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
1571	{
1572	cBATEntryIndex++;
1573	cSectors++;
1574	}
1575
1576	cbToRead = cSectors * VHD_SECTOR_SIZE;
1577
1578	LogFlowFunc(("uVhdOffset=%llu cbToRead=%u\n", uVhdOffset, cbToRead));
1579	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage,
1580	uVhdOffset, pIoCtx, cbToRead);
1581	}
1582	else
1583	{
1584	/*
1585	* The first sector being read is marked clean, so we should read from
1586	* our parent instead, but only as much as there are the following
1587	* clean sectors, because the block may still contain dirty sectors
1588	* further on. We just need to compute the number of clean sectors
1589	* and pass it to our caller along with the notification that they
1590	* should be read from the parent.
1591	*/
1592	cBATEntryIndex++;
1593	cSectors = 1;
1594
1595	while ( (cSectors < (cbToRead / VHD_SECTOR_SIZE))
1596	&& !vhdBlockBitmapSectorContainsData(pImage, cBATEntryIndex))
1597	{
1598	cBATEntryIndex++;
1599	cSectors++;
1600	}
1601
1602	cbToRead = cSectors * VHD_SECTOR_SIZE;
1603	LogFunc(("Sectors free: uVhdOffset=%llu cbToRead=%u\n", uVhdOffset, cbToRead));
1604	rc = VERR_VD_BLOCK_FREE;
1605	}
1606	}
1607	else
1608	AssertMsg(rc == VERR_VD_NOT_ENOUGH_METADATA, ("Reading block bitmap failed rc=%Rrc\n", rc));
1609	}
1610	}
1611	else
1612	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, uOffset, pIoCtx, cbToRead);
1613
1614	if (pcbActuallyRead)
1615	*pcbActuallyRead = cbToRead;
1616
1617	LogFlowFunc(("returns rc=%Rrc\n", rc));
1618	return rc;
1619	}
1620
1621	/** @interface_method_impl{VDIMAGEBACKEND,pfnWrite} */
1622	static DECLCALLBACK(int) vhdWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1623	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1624	size_t *pcbPostRead, unsigned fWrite)
1625	{
1626	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1627	int rc = VINF_SUCCESS;
1628
1629	LogFlowFunc(("pBackendData=%p uOffset=%llu pIoCtx=%#p cbToWrite=%u pcbWriteProcess=%p pcbPreRead=%p pcbPostRead=%p fWrite=%u\n",
1630	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead, fWrite));
1631
1632	AssertPtr(pImage);
1633	Assert(!(uOffset % VHD_SECTOR_SIZE));
1634	Assert(!(cbToWrite % VHD_SECTOR_SIZE));
1635	AssertReturn((VALID_PTR(pIoCtx) && cbToWrite), VERR_INVALID_PARAMETER);
1636	AssertReturn(uOffset + cbToWrite <= pImage->cbSize, VERR_INVALID_PARAMETER);
1637
1638	if (pImage->pBlockAllocationTable)
1639	{
1640	/*
1641	* Get the data block first.
1642	*/
1643	uint32_t cSector = uOffset / VHD_SECTOR_SIZE;
1644	uint32_t cBlockAllocationTableEntry = cSector / pImage->cSectorsPerDataBlock;
1645	uint32_t cBATEntryIndex = cSector % pImage->cSectorsPerDataBlock;
1646	uint64_t uVhdOffset;
1647
1648	/*
1649	* Clip write range.
1650	*/
1651	cbToWrite = RT_MIN(cbToWrite, (pImage->cbDataBlock - (cBATEntryIndex * VHD_SECTOR_SIZE)));
1652
1653	/*
1654	* If the block is not allocated the content of the entry is ~0
1655	* and we need to allocate a new block. Note that while blocks are
1656	* allocated with a relatively big granularity, each sector has its
1657	* own bitmap entry, indicating whether it has been written or not.
1658	* So that means for the purposes of the higher level that the
1659	* granularity is invisible. This means there's no need to return
1660	* VERR_VD_BLOCK_FREE unless the block hasn't been allocated yet.
1661	*/
1662	if (pImage->pBlockAllocationTable[cBlockAllocationTableEntry] == ~0U)
1663	{
1664	/* Check if the block allocation should be suppressed. */
1665	if ( (fWrite & VD_WRITE_NO_ALLOC)
1666	\|\| (cbToWrite != pImage->cbDataBlock))
1667	{
1668	pcbPreRead = cBATEntryIndex VHD_SECTOR_SIZE;
1669	pcbPostRead = pImage->cSectorsPerDataBlock VHD_SECTOR_SIZE - cbToWrite - *pcbPreRead;
1670
1671	if (pcbWriteProcess)
1672	*pcbWriteProcess = cbToWrite;
1673	return VERR_VD_BLOCK_FREE;
1674	}
1675
1676	PVHDIMAGEEXPAND pExpand = (PVHDIMAGEEXPAND)RTMemAllocZ(RT_OFFSETOF(VHDIMAGEEXPAND, au8Bitmap[pImage->cDataBlockBitmapSectors * VHD_SECTOR_SIZE]));
1677	bool fIoInProgress = false;
1678
1679	if (!pExpand)
1680	return VERR_NO_MEMORY;
1681
1682	pExpand->cbEofOld = pImage->uCurrentEndOfFile;
1683	pExpand->idxBatAllocated = cBlockAllocationTableEntry;
1684	pExpand->idxBlockBe = RT_H2BE_U32(pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE);
1685
1686	/* Set the bits for all sectors having been written. */
1687	for (uint32_t iSector = 0; iSector < (cbToWrite / VHD_SECTOR_SIZE); iSector++)
1688	{
1689	/* No need to check for a changed value because this is an initial write. */
1690	vhdBlockBitmapSectorSet(pImage, pExpand->au8Bitmap, cBATEntryIndex);
1691	cBATEntryIndex++;
1692	}
1693
1694	do
1695	{
1696	/*
1697	* Start with the sector bitmap.
1698	*/
1699	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1700	pImage->uCurrentEndOfFile,
1701	pExpand->au8Bitmap,
1702	pImage->cDataBlockBitmapSectors * VHD_SECTOR_SIZE, pIoCtx,
1703	vhdAsyncExpansionDataBlockBitmapComplete,
1704	pExpand);
1705	if (RT_SUCCESS(rc))
1706	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
1707	else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1708	fIoInProgress = true;
1709	else
1710	{
1711	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BLOCKBITMAP_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1712	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1713	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1714	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1715	break;
1716	}
1717
1718
1719	/*
1720	* Write the new block at the current end of the file.
1721	*/
1722	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1723	pImage->uCurrentEndOfFile + (pImage->cDataBlockBitmapSectors + (cSector % pImage->cSectorsPerDataBlock)) * VHD_SECTOR_SIZE,
1724	pIoCtx, cbToWrite,
1725	vhdAsyncExpansionDataComplete,
1726	pExpand);
1727	if (RT_SUCCESS(rc))
1728	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
1729	else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1730	fIoInProgress = true;
1731	else
1732	{
1733	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_USERBLOCK_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1734	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1735	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1736	break;
1737	}
1738
1739	/*
1740	* Write entry in the BAT.
1741	*/
1742	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1743	pImage->uBlockAllocationTableOffset + cBlockAllocationTableEntry * sizeof(uint32_t),
1744	&pExpand->idxBlockBe, sizeof(uint32_t), pIoCtx,
1745	vhdAsyncExpansionBatUpdateComplete,
1746	pExpand);
1747	if (RT_SUCCESS(rc))
1748	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
1749	else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1750	fIoInProgress = true;
1751	else
1752	{
1753	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_BAT_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1754	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1755	break;
1756	}
1757
1758	/*
1759	* Set the new end of the file and link the new block into the BAT.
1760	*/
1761	pImage->uCurrentEndOfFile += pImage->cDataBlockBitmapSectors * VHD_SECTOR_SIZE + pImage->cbDataBlock;
1762
1763	/* Update the footer. */
1764	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1765	pImage->uCurrentEndOfFile,
1766	&pImage->vhdFooterCopy,
1767	sizeof(VHDFooter), pIoCtx,
1768	vhdAsyncExpansionFooterUpdateComplete,
1769	pExpand);
1770	if (RT_SUCCESS(rc))
1771	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_SUCCESS);
1772	else if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1773	fIoInProgress = true;
1774	else
1775	{
1776	VHDIMAGEEXPAND_STATUS_SET(pExpand->fFlags, VHDIMAGEEXPAND_FOOTER_STATUS_SHIFT, VHDIMAGEEXPAND_STEP_FAILED);
1777	break;
1778	}
1779
1780	} while (0);
1781
1782	if (!fIoInProgress)
1783	vhdAsyncExpansionComplete(pImage, pIoCtx, pExpand);
1784	else
1785	rc = VERR_VD_ASYNC_IO_IN_PROGRESS;
1786	}
1787	else
1788	{
1789	/*
1790	* Calculate the real offset in the file.
1791	*/
1792	uVhdOffset = ((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry] + pImage->cDataBlockBitmapSectors + cBATEntryIndex) * VHD_SECTOR_SIZE;
1793
1794	/* Read in the block's bitmap. */
1795	PVDMETAXFER pMetaXfer;
1796	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
1797	((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
1798	pImage->pu8Bitmap,
1799	pImage->cbDataBlockBitmap, pIoCtx,
1800	&pMetaXfer, NULL, NULL);
1801	if (RT_SUCCESS(rc))
1802	{
1803	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
1804
1805	/* Write data. */
1806	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1807	uVhdOffset, pIoCtx, cbToWrite,
1808	NULL, NULL);
1809	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1810	{
1811	bool fChanged = false;
1812
1813	/* Set the bits for all sectors having been written. */
1814	for (uint32_t iSector = 0; iSector < (cbToWrite / VHD_SECTOR_SIZE); iSector++)
1815	{
1816	fChanged \|= vhdBlockBitmapSectorSet(pImage, pImage->pu8Bitmap, cBATEntryIndex);
1817	cBATEntryIndex++;
1818	}
1819
1820	/* Only write the bitmap if it was changed. */
1821	if (fChanged)
1822	{
1823	/*
1824	* Write the bitmap back.
1825	*
1826	* @note We don't have a completion callback here because we
1827	* can't do anything if the write fails for some reason.
1828	* The error will propagated to the device/guest
1829	* by the generic VD layer already and we don't need
1830	* to rollback anything here.
1831	*/
1832	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1833	((uint64_t)pImage->pBlockAllocationTable[cBlockAllocationTableEntry]) * VHD_SECTOR_SIZE,
1834	pImage->pu8Bitmap,
1835	pImage->cbDataBlockBitmap,
1836	pIoCtx, NULL, NULL);
1837	}
1838	}
1839	}
1840	}
1841	}
1842	else
1843	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1844	uOffset, pIoCtx, cbToWrite, NULL, NULL);
1845
1846	if (pcbWriteProcess)
1847	*pcbWriteProcess = cbToWrite;
1848
1849	/* Stay on the safe side. Do not run the risk of confusing the higher
1850	* level, as that can be pretty lethal to image consistency. */
1851	*pcbPreRead = 0;
1852	*pcbPostRead = 0;
1853
1854	return rc;
1855	}
1856
1857	/** @interface_method_impl{VDIMAGEBACKEND,pfnFlush} */
1858	static DECLCALLBACK(int) vhdFlush(void *pBackendData, PVDIOCTX pIoCtx)
1859	{
1860	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1861	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1862
1863	/* No need to write anything here. Data is always updated on a write. */
1864	int rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage, pIoCtx, NULL, NULL);
1865	LogFlowFunc(("returns %Rrc\n", rc));
1866	return rc;
1867	}
1868
1869	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetVersion} */
1870	static DECLCALLBACK(unsigned) vhdGetVersion(void *pBackendData)
1871	{
1872	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1873	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1874
1875	AssertPtrReturn(pImage, 0);
1876
1877	unsigned uVersion = 1; /*< @todo use correct version /
1878
1879	LogFlowFunc(("returns %u\n", uVersion));
1880	return uVersion;
1881	}
1882
1883	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetFileSize} */
1884	static DECLCALLBACK(uint64_t) vhdGetFileSize(void *pBackendData)
1885	{
1886	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1887	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1888	uint64_t cb = 0;
1889
1890	AssertPtrReturn(pImage, 0);
1891
1892	if (pImage->pStorage)
1893	cb = pImage->uCurrentEndOfFile + sizeof(VHDFooter);
1894
1895	LogFlowFunc(("returns %lld\n", cb));
1896	return cb;
1897	}
1898
1899	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetPCHSGeometry} */
1900	static DECLCALLBACK(int) vhdGetPCHSGeometry(void *pBackendData, PVDGEOMETRY pPCHSGeometry)
1901	{
1902	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
1903	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1904	int rc = VINF_SUCCESS;
1905
1906	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
1907
1908	if (pImage->PCHSGeometry.cCylinders)
1909	*pPCHSGeometry = pImage->PCHSGeometry;
1910	else
1911	rc = VERR_VD_GEOMETRY_NOT_SET;
1912
1913	LogFlowFunc(("returns %Rrc (CHS=%u/%u/%u)\n", rc, pImage->PCHSGeometry.cCylinders,
1914	pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors));
1915	return rc;
1916	}
1917
1918	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetPCHSGeometry} */
1919	static DECLCALLBACK(int) vhdSetPCHSGeometry(void *pBackendData, PCVDGEOMETRY pPCHSGeometry)
1920	{
1921	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n",
1922	pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
1923	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1924	int rc = VINF_SUCCESS;
1925
1926	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
1927
1928	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1929	rc = VERR_VD_IMAGE_READ_ONLY;
1930	else
1931	pImage->PCHSGeometry = *pPCHSGeometry;
1932
1933	LogFlowFunc(("returns %Rrc\n", rc));
1934	return rc;
1935	}
1936
1937	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetLCHSGeometry} */
1938	static DECLCALLBACK(int) vhdGetLCHSGeometry(void *pBackendData, PVDGEOMETRY pLCHSGeometry)
1939	{
1940	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
1941	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1942	int rc = VINF_SUCCESS;
1943
1944	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
1945
1946	if (pImage->LCHSGeometry.cCylinders)
1947	*pLCHSGeometry = pImage->LCHSGeometry;
1948	else
1949	rc = VERR_VD_GEOMETRY_NOT_SET;
1950
1951	LogFlowFunc(("returns %Rrc (CHS=%u/%u/%u)\n", rc, pImage->LCHSGeometry.cCylinders,
1952	pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors));
1953	return rc;
1954	}
1955
1956	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetLCHSGeometry} */
1957	static DECLCALLBACK(int) vhdSetLCHSGeometry(void *pBackendData, PCVDGEOMETRY pLCHSGeometry)
1958	{
1959	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
1960	int rc = VINF_SUCCESS;
1961
1962	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
1963
1964	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1965	rc = VERR_VD_IMAGE_READ_ONLY;
1966	else
1967	pImage->LCHSGeometry = *pLCHSGeometry;
1968
1969	LogFlowFunc(("returns %Rrc\n", rc));
1970	return rc;
1971	}
1972
1973	/** @copydoc VDIMAGEBACKEND::pfnQueryRegions */
1974	static DECLCALLBACK(int) vhdQueryRegions(void pBackendData, PCVDREGIONLIST ppRegionList)
1975	{
1976	LogFlowFunc(("pBackendData=%#p ppRegionList=%#p\n", pBackendData, ppRegionList));
1977	PVHDIMAGE pThis = (PVHDIMAGE)pBackendData;
1978
1979	AssertPtrReturn(pThis, VERR_VD_NOT_OPENED);
1980
1981	*ppRegionList = &pThis->RegionList;
1982	LogFlowFunc(("returns %Rrc\n", VINF_SUCCESS));
1983	return VINF_SUCCESS;
1984	}
1985
1986	/** @copydoc VDIMAGEBACKEND::pfnRegionListRelease */
1987	static DECLCALLBACK(void) vhdRegionListRelease(void *pBackendData, PCVDREGIONLIST pRegionList)
1988	{
1989	RT_NOREF1(pRegionList);
1990	LogFlowFunc(("pBackendData=%#p pRegionList=%#p\n", pBackendData, pRegionList));
1991	PVHDIMAGE pThis = (PVHDIMAGE)pBackendData;
1992	AssertPtr(pThis); RT_NOREF(pThis);
1993
1994	/* Nothing to do here. */
1995	}
1996
1997	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetImageFlags} */
1998	static DECLCALLBACK(unsigned) vhdGetImageFlags(void *pBackendData)
1999	{
2000	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2001	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2002
2003	AssertPtrReturn(pImage, 0);
2004
2005	LogFlowFunc(("returns %#x\n", pImage->uImageFlags));
2006	return pImage->uImageFlags;
2007	}
2008
2009	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetOpenFlags} */
2010	static DECLCALLBACK(unsigned) vhdGetOpenFlags(void *pBackendData)
2011	{
2012	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2013	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2014
2015	AssertPtrReturn(pImage, 0);
2016
2017	LogFlowFunc(("returns %#x\n", pImage->uOpenFlags));
2018	return pImage->uOpenFlags;
2019	}
2020
2021	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetOpenFlags} */
2022	static DECLCALLBACK(int) vhdSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2023	{
2024	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2025	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2026	int rc = VINF_SUCCESS;
2027
2028	/* Image must be opened and the new flags must be valid. */
2029	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2030	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SHAREABLE
2031	\| VD_OPEN_FLAGS_SEQUENTIAL \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2032	rc = VERR_INVALID_PARAMETER;
2033	else
2034	{
2035	/* Implement this operation via reopening the image. */
2036	rc = vhdFreeImage(pImage, false);
2037	if (RT_SUCCESS(rc))
2038	rc = vhdOpenImage(pImage, uOpenFlags);
2039	}
2040
2041	LogFlowFunc(("returns %Rrc\n", rc));
2042	return rc;
2043	}
2044
2045	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetComment} */
2046	static DECLCALLBACK(int) vhdGetComment(void pBackendData, char pszComment,
2047	size_t cbComment)
2048	{
2049	RT_NOREF2(pszComment, cbComment);
2050	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2051	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2052
2053	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2054
2055	LogFlowFunc(("returns %Rrc comment='%s'\n", VERR_NOT_SUPPORTED, pszComment));
2056	return VERR_NOT_SUPPORTED;
2057	}
2058
2059	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetComment} */
2060	static DECLCALLBACK(int) vhdSetComment(void pBackendData, const char pszComment)
2061	{
2062	RT_NOREF1(pszComment);
2063	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2064	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2065
2066	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2067
2068	int rc;
2069	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2070	rc = VERR_VD_IMAGE_READ_ONLY;
2071	else
2072	rc = VERR_NOT_SUPPORTED;
2073
2074	LogFlowFunc(("returns %Rrc\n", rc));
2075	return rc;
2076	}
2077
2078	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetUuid} */
2079	static DECLCALLBACK(int) vhdGetUuid(void *pBackendData, PRTUUID pUuid)
2080	{
2081	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2082	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2083
2084	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2085
2086	*pUuid = pImage->ImageUuid;
2087
2088	LogFlowFunc(("returns %Rrc (%RTuuid)\n", VINF_SUCCESS, pUuid));
2089	return VINF_SUCCESS;
2090	}
2091
2092	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetUuid} */
2093	static DECLCALLBACK(int) vhdSetUuid(void *pBackendData, PCRTUUID pUuid)
2094	{
2095	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2096	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2097	int rc = VINF_SUCCESS;
2098
2099	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2100
2101	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2102	{
2103	pImage->ImageUuid = *pUuid;
2104	/* Update the footer copy. It will get written to disk when the image is closed. */
2105	memcpy(&pImage->vhdFooterCopy.UniqueID, pUuid, 16);
2106	/* Update checksum. */
2107	pImage->vhdFooterCopy.Checksum = 0;
2108	pImage->vhdFooterCopy.Checksum = RT_H2BE_U32(vhdChecksum(&pImage->vhdFooterCopy, sizeof(VHDFooter)));
2109
2110	/* Need to update the dynamic disk header to update the disk footer copy at the beginning. */
2111	if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
2112	pImage->fDynHdrNeedsUpdate = true;
2113	}
2114	else
2115	rc = VERR_VD_IMAGE_READ_ONLY;
2116
2117	LogFlowFunc(("returns %Rrc\n", rc));
2118	return rc;
2119	}
2120
2121	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetModificationUuid} */
2122	static DECLCALLBACK(int) vhdGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2123	{
2124	RT_NOREF1(pUuid);
2125	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2126	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2127
2128	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2129
2130	LogFlowFunc(("returns %Rrc (%RTuuid)\n", VERR_NOT_SUPPORTED, pUuid));
2131	return VERR_NOT_SUPPORTED;
2132	}
2133
2134	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetModificationUuid} */
2135	static DECLCALLBACK(int) vhdSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2136	{
2137	RT_NOREF1(pUuid);
2138	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2139	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2140
2141	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2142
2143	int rc;
2144	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2145	rc = VERR_VD_IMAGE_READ_ONLY;
2146	else
2147	rc = VERR_NOT_SUPPORTED;
2148
2149	LogFlowFunc(("returns %Rrc\n", rc));
2150	return rc;
2151	}
2152
2153	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetParentUuid} */
2154	static DECLCALLBACK(int) vhdGetParentUuid(void *pBackendData, PRTUUID pUuid)
2155	{
2156	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2157	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2158
2159	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2160
2161	*pUuid = pImage->ParentUuid;
2162
2163	LogFlowFunc(("returns %Rrc (%RTuuid)\n", VINF_SUCCESS, pUuid));
2164	return VINF_SUCCESS;
2165	}
2166
2167	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetParentUuid} */
2168	static DECLCALLBACK(int) vhdSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2169	{
2170	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2171	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2172	int rc = VINF_SUCCESS;
2173
2174	if (pImage && pImage->pStorage)
2175	{
2176	if (!(pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED))
2177	{
2178	pImage->ParentUuid = *pUuid;
2179	pImage->fDynHdrNeedsUpdate = true;
2180	}
2181	else
2182	rc = VERR_VD_IMAGE_READ_ONLY;
2183	}
2184	else
2185	rc = VERR_VD_NOT_OPENED;
2186
2187	LogFlowFunc(("returns %Rrc\n", rc));
2188	return rc;
2189	}
2190
2191	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetParentModificationUuid} */
2192	static DECLCALLBACK(int) vhdGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2193	{
2194	RT_NOREF1(pUuid);
2195	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2196	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2197
2198	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2199
2200	LogFlowFunc(("returns %Rrc (%RTuuid)\n", VERR_NOT_SUPPORTED, pUuid));
2201	return VERR_NOT_SUPPORTED;
2202	}
2203
2204	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetParentModificationUuid} */
2205	static DECLCALLBACK(int) vhdSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2206	{
2207	RT_NOREF1(pUuid);
2208	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2209	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2210
2211	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2212
2213	int rc;
2214	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2215	rc = VERR_VD_IMAGE_READ_ONLY;
2216	else
2217	rc = VERR_NOT_SUPPORTED;
2218
2219	LogFlowFunc(("returns %Rrc\n", rc));
2220	return rc;
2221	}
2222
2223	/** @interface_method_impl{VDIMAGEBACKEND,pfnDump} */
2224	static DECLCALLBACK(void) vhdDump(void *pBackendData)
2225	{
2226	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2227
2228	AssertPtrReturnVoid(pImage);
2229	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cbSector=%u\n",
2230	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2231	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2232	VHD_SECTOR_SIZE);
2233	vdIfErrorMessage(pImage->pIfError, "Header: uuidCreation={%RTuuid}\n", &pImage->ImageUuid);
2234	vdIfErrorMessage(pImage->pIfError, "Header: uuidParent={%RTuuid}\n", &pImage->ParentUuid);
2235	}
2236
2237	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetTimestamp} */
2238	static DECLCALLBACK(int) vhdGetTimestamp(void *pBackendData, PRTTIMESPEC pTimestamp)
2239	{
2240	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2241
2242	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2243
2244	int rc = vdIfIoIntFileGetModificationTime(pImage->pIfIo, pImage->pszFilename, pTimestamp);
2245
2246	LogFlowFunc(("returns %Rrc\n", rc));
2247	return rc;
2248	}
2249
2250	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetParentTimestamp} */
2251	static DECLCALLBACK(int) vhdGetParentTimestamp(void *pBackendData, PRTTIMESPEC pTimestamp)
2252	{
2253	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2254
2255	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2256
2257	vhdTime2RtTime(pTimestamp, pImage->u32ParentTimestamp);
2258	LogFlowFunc(("returns %Rrc\n", VINF_SUCCESS));
2259	return VINF_SUCCESS;
2260	}
2261
2262	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetParentTimestamp} */
2263	static DECLCALLBACK(int) vhdSetParentTimestamp(void *pBackendData, PCRTTIMESPEC pTimestamp)
2264	{
2265	int rc = VINF_SUCCESS;
2266	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2267
2268	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2269	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2270	rc = VERR_VD_IMAGE_READ_ONLY;
2271	else
2272	{
2273	pImage->u32ParentTimestamp = vhdRtTime2VhdTime(pTimestamp);
2274	pImage->fDynHdrNeedsUpdate = true;
2275	}
2276
2277	LogFlowFunc(("returns %Rrc\n", rc));
2278	return rc;
2279	}
2280
2281	/** @interface_method_impl{VDIMAGEBACKEND,pfnGetParentFilename} */
2282	static DECLCALLBACK(int) vhdGetParentFilename(void pBackendData, char *ppszParentFilename)
2283	{
2284	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2285
2286	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2287	*ppszParentFilename = RTStrDup(pImage->pszParentFilename);
2288
2289	LogFlowFunc(("returns %Rrc\n", VINF_SUCCESS));
2290	return VINF_SUCCESS;
2291	}
2292
2293	/** @interface_method_impl{VDIMAGEBACKEND,pfnSetParentFilename} */
2294	static DECLCALLBACK(int) vhdSetParentFilename(void pBackendData, const char pszParentFilename)
2295	{
2296	int rc = VINF_SUCCESS;
2297	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2298
2299	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2300
2301	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2302	rc = VERR_VD_IMAGE_READ_ONLY;
2303	else
2304	{
2305	if (pImage->pszParentFilename)
2306	RTStrFree(pImage->pszParentFilename);
2307	pImage->pszParentFilename = RTStrDup(pszParentFilename);
2308	if (!pImage->pszParentFilename)
2309	rc = VERR_NO_MEMORY;
2310	else
2311	pImage->fDynHdrNeedsUpdate = true;
2312	}
2313
2314	LogFlowFunc(("returns %Rrc\n", rc));
2315	return rc;
2316	}
2317
2318	/** @interface_method_impl{VDIMAGEBACKEND,pfnCompact} */
2319	static DECLCALLBACK(int) vhdCompact(void *pBackendData, unsigned uPercentStart,
2320	unsigned uPercentSpan, PVDINTERFACE pVDIfsDisk,
2321	PVDINTERFACE pVDIfsImage, PVDINTERFACE pVDIfsOperation)
2322	{
2323	RT_NOREF2(pVDIfsDisk, pVDIfsImage);
2324	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2325	int rc = VINF_SUCCESS;
2326	void *pvBuf = NULL;
2327	uint32_t *paBlocks = NULL;
2328	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
2329
2330	DECLCALLBACKMEMBER(int, pfnParentRead)(void , uint64_t, void , size_t) = NULL;
2331	void *pvParent = NULL;
2332	PVDINTERFACEPARENTSTATE pIfParentState = VDIfParentStateGet(pVDIfsOperation);
2333	if (pIfParentState)
2334	{
2335	pfnParentRead = pIfParentState->pfnParentRead;
2336	pvParent = pIfParentState->Core.pvUser;
2337	}
2338
2339	do
2340	{
2341	AssertBreakStmt(pImage, rc = VERR_INVALID_PARAMETER);
2342
2343	AssertBreakStmt(!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY),
2344	rc = VERR_VD_IMAGE_READ_ONLY);
2345
2346	/* Reject fixed images as they don't have a BAT. */
2347	if (pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED)
2348	{
2349	rc = VERR_NOT_SUPPORTED;
2350	break;
2351	}
2352
2353	if (pfnParentRead)
2354	{
2355	pvParent = RTMemTmpAlloc(pImage->cbDataBlock);
2356	AssertBreakStmt(pvParent, rc = VERR_NO_MEMORY);
2357	}
2358	pvBuf = RTMemTmpAlloc(pImage->cbDataBlock);
2359	AssertBreakStmt(pvBuf, rc = VERR_NO_MEMORY);
2360
2361	unsigned cBlocksAllocated = 0;
2362	unsigned cBlocksToMove = 0;
2363	unsigned cBlocks = pImage->cBlockAllocationTableEntries;
2364	uint32_t offBlocksStart = ~0U; /* Start offset of data blocks in sectors. */
2365	uint32_t *paBat = pImage->pBlockAllocationTable;
2366
2367	/* Count the number of allocated blocks and find the start offset for the data blocks. */
2368	for (unsigned i = 0; i < cBlocks; i++)
2369	if (paBat[i] != ~0U)
2370	{
2371	cBlocksAllocated++;
2372	if (paBat[i] < offBlocksStart)
2373	offBlocksStart = paBat[i];
2374	}
2375
2376	if (!cBlocksAllocated)
2377	{
2378	/* Nothing to do. */
2379	rc = VINF_SUCCESS;
2380	break;
2381	}
2382
2383	paBlocks = (uint32_t )RTMemTmpAllocZ(cBlocksAllocated sizeof(uint32_t));
2384	AssertBreakStmt(paBlocks, rc = VERR_NO_MEMORY);
2385
2386	/* Invalidate the back resolving array. */
2387	for (unsigned i = 0; i < cBlocksAllocated; i++)
2388	paBlocks[i] = ~0U;
2389
2390	/* Fill the back resolving table. */
2391	for (unsigned i = 0; i < cBlocks; i++)
2392	if (paBat[i] != ~0U)
2393	{
2394	unsigned idxBlock = (paBat[i] - offBlocksStart) / pImage->cSectorsPerDataBlock;
2395	if ( idxBlock < cBlocksAllocated
2396	&& paBlocks[idxBlock] == ~0U)
2397	paBlocks[idxBlock] = i;
2398	else
2399	{
2400	/* The image is in an inconsistent state. Don't go further. */
2401	rc = VERR_INVALID_STATE;
2402	break;
2403	}
2404	}
2405
2406	if (RT_FAILURE(rc))
2407	break;
2408
2409	/* Find redundant information and update the block pointers
2410	* accordingly, creating bubbles. Keep disk up to date, as this
2411	* enables cancelling. */
2412	for (unsigned i = 0; i < cBlocks; i++)
2413	{
2414	if (paBat[i] != ~0U)
2415	{
2416	unsigned idxBlock = (paBat[i] - offBlocksStart) / pImage->cSectorsPerDataBlock;
2417
2418	/* Block present in image file, read relevant data. */
2419	uint64_t u64Offset = ((uint64_t)paBat[i] + pImage->cDataBlockBitmapSectors) * VHD_SECTOR_SIZE;
2420	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
2421	u64Offset, pvBuf, pImage->cbDataBlock);
2422	if (RT_FAILURE(rc))
2423	break;
2424
2425	if (ASMBitFirstSet((volatile void )pvBuf, (uint32_t)pImage->cbDataBlock 8) == -1)
2426	{
2427	paBat[i] = UINT32_MAX;
2428	paBlocks[idxBlock] = ~0U;
2429	/* Adjust progress info, one block to be relocated. */
2430	cBlocksToMove++;
2431	}
2432	else if (pfnParentRead)
2433	{
2434	rc = pfnParentRead(pvParent, (uint64_t)i * pImage->cbDataBlock, pvParent, pImage->cbDataBlock);
2435	if (RT_FAILURE(rc))
2436	break;
2437	if (!memcmp(pvParent, pvBuf, pImage->cbDataBlock))
2438	{
2439	paBat[i] = ~0U;
2440	paBlocks[idxBlock] = ~0U;
2441	/* Adjust progress info, one block to be relocated. */
2442	cBlocksToMove++;
2443	}
2444	}
2445	}
2446
2447	vdIfProgress(pIfProgress, (uint64_t)i * uPercentSpan / (cBlocks + cBlocksToMove) + uPercentStart);
2448	}
2449
2450	if (RT_SUCCESS(rc))
2451	{
2452	/* Fill bubbles with other data (if available). */
2453	unsigned cBlocksMoved = 0;
2454	unsigned uBlockUsedPos = cBlocksAllocated;
2455	size_t cbBlock = pImage->cbDataBlock + pImage->cbDataBlockBitmap; /** < Size of whole block containing the bitmap and the user data. */
2456
2457	/* Allocate data buffer to hold the data block and allocation bitmap in front of the actual data. */
2458	RTMemTmpFree(pvBuf);
2459	pvBuf = RTMemTmpAllocZ(cbBlock);
2460	AssertBreakStmt(pvBuf, rc = VERR_NO_MEMORY);
2461
2462	for (unsigned i = 0; i < cBlocksAllocated; i++)
2463	{
2464	unsigned uBlock = paBlocks[i];
2465	if (uBlock == ~0U)
2466	{
2467	unsigned uBlockData = ~0U;
2468	while (uBlockUsedPos > i && uBlockData == ~0U)
2469	{
2470	uBlockUsedPos--;
2471	uBlockData = paBlocks[uBlockUsedPos];
2472	}
2473	/* Terminate early if there is no block which needs copying. */
2474	if (uBlockUsedPos == i)
2475	break;
2476	uint64_t u64Offset = (uint64_t)uBlockUsedPos * cbBlock
2477	+ (offBlocksStart * VHD_SECTOR_SIZE);
2478	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
2479	u64Offset, pvBuf, cbBlock);
2480	if (RT_FAILURE(rc))
2481	break;
2482
2483	u64Offset = (uint64_t)i * cbBlock
2484	+ (offBlocksStart * VHD_SECTOR_SIZE);
2485	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2486	u64Offset, pvBuf, cbBlock);
2487	if (RT_FAILURE(rc))
2488	break;
2489
2490	paBat[uBlockData] = i*(pImage->cSectorsPerDataBlock + pImage->cDataBlockBitmapSectors) + offBlocksStart;
2491
2492	/* Truncate the file but leave enough room for the footer to avoid
2493	* races if other processes fill the whole harddisk. */
2494	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2495	pImage->uCurrentEndOfFile - cbBlock + VHD_SECTOR_SIZE);
2496	if (RT_FAILURE(rc))
2497	break;
2498
2499	/* Update pointers and write footer. */
2500	pImage->uCurrentEndOfFile -= cbBlock;
2501
2502	/* We're kinda screwed if this failes. */
2503	rc = vhdUpdateFooter(pImage);
2504	if (RT_FAILURE(rc))
2505	break;
2506
2507	paBlocks[i] = uBlockData;
2508	paBlocks[uBlockUsedPos] = ~0U;
2509	cBlocksMoved++;
2510	}
2511
2512	rc = vdIfProgress(pIfProgress, (uint64_t)(cBlocks + cBlocksMoved) * uPercentSpan / (cBlocks + cBlocksToMove) + uPercentStart);
2513	}
2514	}
2515
2516	/* Write the new BAT in any case. */
2517	rc = vhdFlushImage(pImage);
2518	} while (0);
2519
2520	if (paBlocks)
2521	RTMemTmpFree(paBlocks);
2522	if (pvParent)
2523	RTMemTmpFree(pvParent);
2524	if (pvBuf)
2525	RTMemTmpFree(pvBuf);
2526
2527	if (RT_SUCCESS(rc))
2528	vdIfProgress(pIfProgress, uPercentStart + uPercentSpan);
2529
2530	LogFlowFunc(("returns %Rrc\n", rc));
2531	return rc;
2532	}
2533
2534	/** @interface_method_impl{VDIMAGEBACKEND,pfnResize} */
2535	static DECLCALLBACK(int) vhdResize(void *pBackendData, uint64_t cbSize,
2536	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
2537	unsigned uPercentStart, unsigned uPercentSpan,
2538	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
2539	PVDINTERFACE pVDIfsOperation)
2540	{
2541	RT_NOREF5(uPercentSpan, uPercentStart, pVDIfsDisk, pVDIfsImage, pVDIfsOperation);
2542	PVHDIMAGE pImage = (PVHDIMAGE)pBackendData;
2543	int rc = VINF_SUCCESS;
2544
2545	/* Making the image smaller is not supported at the moment. */
2546	if ( cbSize < pImage->cbSize
2547	\|\| pImage->uImageFlags & VD_IMAGE_FLAGS_FIXED)
2548	rc = VERR_NOT_SUPPORTED;
2549	else if (cbSize > pImage->cbSize)
2550	{
2551	unsigned cBlocksAllocated = 0;
2552	size_t cbBlock = pImage->cbDataBlock + pImage->cbDataBlockBitmap; /** < Size of a block including the sector bitmap. */
2553	uint32_t cBlocksNew = cbSize / pImage->cbDataBlock; /** < New number of blocks in the image after the resize */
2554	if (cbSize % pImage->cbDataBlock)
2555	cBlocksNew++;
2556
2557	uint32_t cBlocksOld = pImage->cBlockAllocationTableEntries; /** < Number of blocks before the resize. */
2558	uint64_t cbBlockspaceNew = RT_ALIGN_32(cBlocksNew * sizeof(uint32_t), VHD_SECTOR_SIZE); /** < Required space for the block array after the resize. */
2559	uint64_t offStartDataNew = RT_ALIGN_32(pImage->uBlockAllocationTableOffset + cbBlockspaceNew, VHD_SECTOR_SIZE); /** < New start offset for block data after the resize */
2560	uint64_t offStartDataOld = ~0ULL;
2561
2562	/* Go through the BAT and find the data start offset. */
2563	for (unsigned idxBlock = 0; idxBlock < pImage->cBlockAllocationTableEntries; idxBlock++)
2564	{
2565	if (pImage->pBlockAllocationTable[idxBlock] != ~0U)
2566	{
2567	uint64_t offStartBlock = (uint64_t)pImage->pBlockAllocationTable[idxBlock] * VHD_SECTOR_SIZE;
2568	if (offStartBlock < offStartDataOld)
2569	offStartDataOld = offStartBlock;
2570	cBlocksAllocated++;
2571	}
2572	}
2573
2574	if ( offStartDataOld != offStartDataNew
2575	&& cBlocksAllocated > 0)
2576	{
2577	/* Calculate how many sectors nee to be relocated. */
2578	uint64_t cbOverlapping = offStartDataNew - offStartDataOld;
2579	unsigned cBlocksReloc = (unsigned)(cbOverlapping / cbBlock);
2580	if (cbOverlapping % cbBlock)
2581	cBlocksReloc++;
2582
2583	cBlocksReloc = RT_MIN(cBlocksReloc, cBlocksAllocated);
2584	offStartDataNew = offStartDataOld;
2585
2586	/* Do the relocation. */
2587	LogFlow(("Relocating %u blocks\n", cBlocksReloc));
2588
2589	/*
2590	* Get the blocks we need to relocate first, they are appended to the end
2591	* of the image.
2592	*/
2593	void pvBuf = NULL, pvZero = NULL;
2594	do
2595	{
2596	/* Allocate data buffer. */
2597	pvBuf = RTMemAllocZ(cbBlock);
2598	if (!pvBuf)
2599	{
2600	rc = VERR_NO_MEMORY;
2601	break;
2602	}
2603
2604	/* Allocate buffer for overwriting with zeroes. */
2605	pvZero = RTMemAllocZ(cbBlock);
2606	if (!pvZero)
2607	{
2608	rc = VERR_NO_MEMORY;
2609	break;
2610	}
2611
2612	for (unsigned i = 0; i < cBlocksReloc; i++)
2613	{
2614	uint32_t uBlock = offStartDataNew / VHD_SECTOR_SIZE;
2615
2616	/* Search the index in the block table. */
2617	for (unsigned idxBlock = 0; idxBlock < cBlocksOld; idxBlock++)
2618	{
2619	if (pImage->pBlockAllocationTable[idxBlock] == uBlock)
2620	{
2621	/* Read data and append to the end of the image. */
2622	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
2623	offStartDataNew, pvBuf, cbBlock);
2624	if (RT_FAILURE(rc))
2625	break;
2626
2627	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2628	pImage->uCurrentEndOfFile, pvBuf, cbBlock);
2629	if (RT_FAILURE(rc))
2630	break;
2631
2632	/* Zero out the old block area. */
2633	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2634	offStartDataNew, pvZero, cbBlock);
2635	if (RT_FAILURE(rc))
2636	break;
2637
2638	/* Update block counter. */
2639	pImage->pBlockAllocationTable[idxBlock] = pImage->uCurrentEndOfFile / VHD_SECTOR_SIZE;
2640
2641	pImage->uCurrentEndOfFile += cbBlock;
2642
2643	/* Continue with the next block. */
2644	break;
2645	}
2646	}
2647
2648	if (RT_FAILURE(rc))
2649	break;
2650
2651	offStartDataNew += cbBlock;
2652	}
2653	} while (0);
2654
2655	if (pvBuf)
2656	RTMemFree(pvBuf);
2657	if (pvZero)
2658	RTMemFree(pvZero);
2659	}
2660
2661	/*
2662	* Relocation done, expand the block array and update the header with
2663	* the new data.
2664	*/
2665	if (RT_SUCCESS(rc))
2666	{
2667	uint32_t paBlocksNew = (uint32_t )RTMemRealloc(pImage->pBlockAllocationTable, cBlocksNew * sizeof(uint32_t));
2668	if (paBlocksNew)
2669	{
2670	pImage->pBlockAllocationTable = paBlocksNew;
2671
2672	/* Mark the new blocks as unallocated. */
2673	for (unsigned idxBlock = cBlocksOld; idxBlock < cBlocksNew; idxBlock++)
2674	pImage->pBlockAllocationTable[idxBlock] = ~0U;
2675	}
2676	else
2677	rc = VERR_NO_MEMORY;
2678
2679	if (RT_SUCCESS(rc))
2680	{
2681	/* Write the block array before updating the rest. */
2682	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2683	pImage->uBlockAllocationTableOffset,
2684	pImage->pBlockAllocationTable,
2685	cBlocksNew * sizeof(uint32_t));
2686	}
2687
2688	if (RT_SUCCESS(rc))
2689	{
2690	/* Update size and new block count. */
2691	pImage->cBlockAllocationTableEntries = cBlocksNew;
2692	pImage->cbSize = cbSize;
2693
2694	/* Update geometry. */
2695	pImage->PCHSGeometry = *pPCHSGeometry;
2696	pImage->LCHSGeometry = *pLCHSGeometry;
2697	}
2698	}
2699
2700	/* Update header information in base image file. */
2701	pImage->fDynHdrNeedsUpdate = true;
2702	vhdFlushImage(pImage);
2703	}
2704	/* Same size doesn't change the image at all. */
2705
2706	LogFlowFunc(("returns %Rrc\n", rc));
2707	return rc;
2708	}
2709
2710	/** @interface_method_impl{VDIMAGEBACKEND,pfnRepair} */
2711	static DECLCALLBACK(int) vhdRepair(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
2712	PVDINTERFACE pVDIfsImage, uint32_t fFlags)
2713	{
2714	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
2715	int rc;
2716	PVDINTERFACEERROR pIfError;
2717	PVDINTERFACEIOINT pIfIo;
2718	PVDIOSTORAGE pStorage;
2719	uint64_t cbFile;
2720	VHDFooter vhdFooter;
2721	VHDDynamicDiskHeader dynamicDiskHeader;
2722	uint32_t *paBat = NULL;
2723	uint32_t *pu32BlockBitmap = NULL;
2724
2725	pIfIo = VDIfIoIntGet(pVDIfsImage);
2726	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
2727
2728	pIfError = VDIfErrorGet(pVDIfsDisk);
2729
2730	do
2731	{
2732	uint64_t offDynamicDiskHeader = 0;
2733	uint64_t offBat = 0;
2734	uint64_t offFooter = 0;
2735	uint32_t cBatEntries = 0;
2736	bool fDynamic = false;
2737	bool fRepairFooter = false;
2738	bool fRepairBat = false;
2739	bool fRepairDynHeader = false;
2740
2741	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
2742	VDOpenFlagsToFileOpenFlags( fFlags & VD_REPAIR_DRY_RUN
2743	? VD_OPEN_FLAGS_READONLY
2744	: 0,
2745	false /* fCreate */),
2746	&pStorage);
2747	if (RT_FAILURE(rc))
2748	{
2749	rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to open image \"%s\"", pszFilename);
2750	break;
2751	}
2752
2753	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
2754	if (RT_FAILURE(rc))
2755	{
2756	rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to query image size");
2757	break;
2758	}
2759
2760	if (cbFile < sizeof(VHDFooter))
2761	{
2762	rc = vdIfError(pIfError, VERR_VD_INVALID_SIZE, RT_SRC_POS,
2763	"Image must be at least %u bytes (got %llu)",
2764	sizeof(VHDFooter), cbFile);
2765	break;
2766	}
2767
2768	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, cbFile - sizeof(VHDFooter),
2769	&vhdFooter, sizeof(VHDFooter));
2770	if (RT_FAILURE(rc))
2771	{
2772	rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to read footer of image");
2773	break;
2774	}
2775
2776	if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
2777	{
2778	/* Dynamic images have a backup at the beginning of the image. */
2779	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0,
2780	&vhdFooter, sizeof(VHDFooter));
2781	if (RT_FAILURE(rc))
2782	{
2783	rc = vdIfError(pIfError, rc, RT_SRC_POS, "Failed to read header of image");
2784	break;
2785	}
2786
2787	/*
2788	* Check for the header, if this fails the image is either completely corrupted
2789	* and impossible to repair or in another format.
2790	*/
2791	if (memcmp(vhdFooter.Cookie, VHD_FOOTER_COOKIE, VHD_FOOTER_COOKIE_SIZE) != 0)
2792	{
2793	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2794	"No valid VHD structures found");
2795	break;
2796	}
2797	else
2798	vdIfErrorMessage(pIfError, "Missing footer structure, using backup\n");
2799
2800	/* Remember to fix the footer structure. */
2801	fRepairFooter = true;
2802	}
2803
2804	offFooter = cbFile - sizeof(VHDFooter);
2805
2806	/* Verify that checksums match. */
2807	uint32_t u32ChkSumOld = RT_BE2H_U32(vhdFooter.Checksum);
2808	vhdFooter.Checksum = 0;
2809	uint32_t u32ChkSum = vhdChecksum(&vhdFooter, sizeof(VHDFooter));
2810
2811	vhdFooter.Checksum = RT_H2BE_U32(u32ChkSum);
2812
2813	if (u32ChkSumOld != u32ChkSum)
2814	{
2815	vdIfErrorMessage(pIfError, "Checksum is invalid (should be %u got %u), repairing\n",
2816	u32ChkSum, u32ChkSumOld);
2817	fRepairFooter = true;
2818	break;
2819	}
2820
2821	switch (RT_BE2H_U32(vhdFooter.DiskType))
2822	{
2823	case VHD_FOOTER_DISK_TYPE_FIXED:
2824	fDynamic = false;
2825	break;
2826	case VHD_FOOTER_DISK_TYPE_DYNAMIC:
2827	fDynamic = true;
2828	break;
2829	case VHD_FOOTER_DISK_TYPE_DIFFERENCING:
2830	fDynamic = true;
2831	break;
2832	default:
2833	{
2834	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2835	"VHD image type %u is not supported",
2836	RT_BE2H_U32(vhdFooter.DiskType));
2837	break;
2838	}
2839	}
2840
2841	/* Load and check dynamic disk header if required. */
2842	if (fDynamic)
2843	{
2844	size_t cbBlock;
2845
2846	offDynamicDiskHeader = RT_BE2H_U64(vhdFooter.DataOffset);
2847	if (offDynamicDiskHeader + sizeof(VHDDynamicDiskHeader) > cbFile)
2848	{
2849	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2850	"VHD image type is not supported");
2851	break;
2852	}
2853
2854	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, offDynamicDiskHeader,
2855	&dynamicDiskHeader, sizeof(VHDDynamicDiskHeader));
2856	if (RT_FAILURE(rc))
2857	{
2858	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2859	"Failed to read dynamic disk header (at %llu), %Rrc",
2860	offDynamicDiskHeader, rc);
2861	break;
2862	}
2863
2864	/* Verify that checksums match. */
2865	u32ChkSumOld = RT_BE2H_U32(dynamicDiskHeader.Checksum);
2866	dynamicDiskHeader.Checksum = 0;
2867	u32ChkSum = vhdChecksum(&dynamicDiskHeader, sizeof(VHDDynamicDiskHeader));
2868
2869	dynamicDiskHeader.Checksum = RT_H2BE_U32(u32ChkSum);
2870
2871	if (u32ChkSumOld != u32ChkSum)
2872	{
2873	vdIfErrorMessage(pIfError, "Checksum of dynamic disk header is invalid (should be %u got %u), repairing\n",
2874	u32ChkSum, u32ChkSumOld);
2875	fRepairDynHeader = true;
2876	break;
2877	}
2878
2879	/* Read the block allocation table and fix any inconsistencies. */
2880	offBat = RT_BE2H_U64(dynamicDiskHeader.TableOffset);
2881	cBatEntries = RT_BE2H_U32(dynamicDiskHeader.MaxTableEntries);
2882	cbBlock = RT_BE2H_U32(dynamicDiskHeader.BlockSize);
2883	cbBlock += cbBlock / VHD_SECTOR_SIZE / 8;
2884
2885	if (offBat + cBatEntries * sizeof(uint32_t) > cbFile)
2886	{
2887	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2888	"Block allocation table is not inside the image");
2889	break;
2890	}
2891
2892	paBat = (uint32_t )RTMemAllocZ(cBatEntries sizeof(uint32_t));
2893	if (!paBat)
2894	{
2895	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2896	"Could not allocate memory for the block allocation table (%u bytes)",
2897	cBatEntries * sizeof(uint32_t));
2898	break;
2899	}
2900
2901	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, offBat, paBat,
2902	cBatEntries * sizeof(uint32_t));
2903	if (RT_FAILURE(rc))
2904	{
2905	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2906	"Could not read block allocation table (at %llu), %Rrc",
2907	offBat, rc);
2908	break;
2909	}
2910
2911	pu32BlockBitmap = (uint32_t *)RTMemAllocZ(RT_ALIGN_Z(cBatEntries / 8, 4));
2912	if (!pu32BlockBitmap)
2913	{
2914	rc = vdIfError(pIfError, VERR_NO_MEMORY, RT_SRC_POS,
2915	"Failed to allocate memory for block bitmap");
2916	break;
2917	}
2918
2919	uint32_t idxMinBlock = UINT32_C(0xffffffff);
2920	for (uint32_t i = 0; i < cBatEntries; i++)
2921	{
2922	paBat[i] = RT_BE2H_U32(paBat[i]);
2923	if (paBat[i] < idxMinBlock)
2924	idxMinBlock = paBat[i];
2925	}
2926
2927	vdIfErrorMessage(pIfError, "First data block at sector %u\n", idxMinBlock);
2928
2929	for (uint32_t i = 0; i < cBatEntries; i++)
2930	{
2931	if (paBat[i] != UINT32_C(0xffffffff))
2932	{
2933	uint64_t offBlock =(uint64_t)paBat[i] * VHD_SECTOR_SIZE;
2934
2935	/*
2936	* Check that the offsets are valid (inside of the image) and
2937	* that there are no double references.
2938	*/
2939	if (offBlock + cbBlock > cbFile)
2940	{
2941	vdIfErrorMessage(pIfError, "Entry %u points to invalid offset %llu, clearing\n",
2942	i, offBlock);
2943	paBat[i] = UINT32_C(0xffffffff);
2944	fRepairBat = true;
2945	}
2946	else if (offBlock + cbBlock > offFooter)
2947	{
2948	vdIfErrorMessage(pIfError, "Entry %u intersects with footer, aligning footer\n",
2949	i);
2950	offFooter = offBlock + cbBlock;
2951	fRepairBat = true;
2952	}
2953
2954	if ( paBat[i] != UINT32_C(0xffffffff)
2955	&& ASMBitTestAndSet(pu32BlockBitmap, (uint32_t)((paBat[i] - idxMinBlock) / (cbBlock / VHD_SECTOR_SIZE))))
2956	{
2957	vdIfErrorMessage(pIfError, "Entry %u points to an already referenced data block, clearing\n",
2958	i);
2959	paBat[i] = UINT32_C(0xffffffff);
2960	fRepairBat = true;
2961	}
2962	}
2963	}
2964	}
2965
2966	/* Write repaired structures now. */
2967	if (!(fRepairBat \|\| fRepairDynHeader \|\| fRepairFooter))
2968	vdIfErrorMessage(pIfError, "VHD image is in a consistent state, no repair required\n");
2969	else if (!(fFlags & VD_REPAIR_DRY_RUN))
2970	{
2971	if (fRepairBat)
2972	{
2973	for (uint32_t i = 0; i < cBatEntries; i++)
2974	paBat[i] = RT_H2BE_U32(paBat[i]);
2975
2976	vdIfErrorMessage(pIfError, "Writing repaired block allocation table...\n");
2977
2978	rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offBat, paBat,
2979	cBatEntries * sizeof(uint32_t));
2980	if (RT_FAILURE(rc))
2981	{
2982	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2983	"Could not write repaired block allocation table (at %llu), %Rrc",
2984	offBat, rc);
2985	break;
2986	}
2987	}
2988
2989	if (fRepairDynHeader)
2990	{
2991	Assert(fDynamic);
2992
2993	vdIfErrorMessage(pIfError, "Writing repaired dynamic disk header...\n");
2994	rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offDynamicDiskHeader, &dynamicDiskHeader,
2995	sizeof(VHDDynamicDiskHeader));
2996	if (RT_FAILURE(rc))
2997	{
2998	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
2999	"Could not write repaired dynamic disk header (at %llu), %Rrc",
3000	offDynamicDiskHeader, rc);
3001	break;
3002	}
3003	}
3004
3005	if (fRepairFooter)
3006	{
3007	vdIfErrorMessage(pIfError, "Writing repaired Footer...\n");
3008
3009	if (fDynamic)
3010	{
3011	/* Write backup at image beginning. */
3012	rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, 0, &vhdFooter,
3013	sizeof(VHDFooter));
3014	if (RT_FAILURE(rc))
3015	{
3016	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
3017	"Could not write repaired backup footer (at %llu), %Rrc",
3018	0, rc);
3019	break;
3020	}
3021	}
3022
3023	rc = vdIfIoIntFileWriteSync(pIfIo, pStorage, offFooter, &vhdFooter,
3024	sizeof(VHDFooter));
3025	if (RT_FAILURE(rc))
3026	{
3027	rc = vdIfError(pIfError, VERR_VD_IMAGE_REPAIR_IMPOSSIBLE, RT_SRC_POS,
3028	"Could not write repaired footer (at %llu), %Rrc",
3029	cbFile - sizeof(VHDFooter), rc);
3030	break;
3031	}
3032	}
3033
3034	vdIfErrorMessage(pIfError, "Corrupted VHD image repaired successfully\n");
3035	}
3036	} while(0);
3037
3038	if (paBat)
3039	RTMemFree(paBat);
3040
3041	if (pu32BlockBitmap)
3042	RTMemFree(pu32BlockBitmap);
3043
3044	if (pStorage)
3045	{
3046	int rc2 = vdIfIoIntFileClose(pIfIo, pStorage);
3047	if (RT_SUCCESS(rc))
3048	rc = rc2; /* Propagate status code only when repairing the image was successful. */
3049	}
3050
3051	LogFlowFunc(("returns %Rrc\n", rc));
3052	return rc;
3053	}
3054
3055
3056	const VDIMAGEBACKEND g_VhdBackend =
3057	{
3058	/* u32Version */
3059	VD_IMGBACKEND_VERSION,
3060	/* pszBackendName */
3061	"VHD",
3062	/* uBackendCaps */
3063	VD_CAP_UUID \| VD_CAP_DIFF \| VD_CAP_FILE \|
3064	VD_CAP_CREATE_FIXED \| VD_CAP_CREATE_DYNAMIC \|
3065	VD_CAP_ASYNC \| VD_CAP_VFS \| VD_CAP_PREFERRED,
3066	/* paFileExtensions */
3067	s_aVhdFileExtensions,
3068	/* paConfigInfo */
3069	NULL,
3070	/* pfnProbe */
3071	vhdProbe,
3072	/* pfnOpen */
3073	vhdOpen,
3074	/* pfnCreate */
3075	vhdCreate,
3076	/* pfnRename */
3077	vhdRename,
3078	/* pfnClose */
3079	vhdClose,
3080	/* pfnRead */
3081	vhdRead,
3082	/* pfnWrite */
3083	vhdWrite,
3084	/* pfnFlush */
3085	vhdFlush,
3086	/* pfnDiscard */
3087	NULL,
3088	/* pfnGetVersion */
3089	vhdGetVersion,
3090	/* pfnGetFileSize */
3091	vhdGetFileSize,
3092	/* pfnGetPCHSGeometry */
3093	vhdGetPCHSGeometry,
3094	/* pfnSetPCHSGeometry */
3095	vhdSetPCHSGeometry,
3096	/* pfnGetLCHSGeometry */
3097	vhdGetLCHSGeometry,
3098	/* pfnSetLCHSGeometry */
3099	vhdSetLCHSGeometry,
3100	/* pfnQueryRegions */
3101	vhdQueryRegions,
3102	/* pfnRegionListRelease */
3103	vhdRegionListRelease,
3104	/* pfnGetImageFlags */
3105	vhdGetImageFlags,
3106	/* pfnGetOpenFlags */
3107	vhdGetOpenFlags,
3108	/* pfnSetOpenFlags */
3109	vhdSetOpenFlags,
3110	/* pfnGetComment */
3111	vhdGetComment,
3112	/* pfnSetComment */
3113	vhdSetComment,
3114	/* pfnGetUuid */
3115	vhdGetUuid,
3116	/* pfnSetUuid */
3117	vhdSetUuid,
3118	/* pfnGetModificationUuid */
3119	vhdGetModificationUuid,
3120	/* pfnSetModificationUuid */
3121	vhdSetModificationUuid,
3122	/* pfnGetParentUuid */
3123	vhdGetParentUuid,
3124	/* pfnSetParentUuid */
3125	vhdSetParentUuid,
3126	/* pfnGetParentModificationUuid */
3127	vhdGetParentModificationUuid,
3128	/* pfnSetParentModificationUuid */
3129	vhdSetParentModificationUuid,
3130	/* pfnDump */
3131	vhdDump,
3132	/* pfnGetTimestamp */
3133	vhdGetTimestamp,
3134	/* pfnGetParentTimestamp */
3135	vhdGetParentTimestamp,
3136	/* pfnSetParentTimestamp */
3137	vhdSetParentTimestamp,
3138	/* pfnGetParentFilename */
3139	vhdGetParentFilename,
3140	/* pfnSetParentFilename */
3141	vhdSetParentFilename,
3142	/* pfnComposeLocation */
3143	genericFileComposeLocation,
3144	/* pfnComposeName */
3145	genericFileComposeName,
3146	/* pfnCompact */
3147	vhdCompact,
3148	/* pfnResize */
3149	vhdResize,
3150	/* pfnRepair */
3151	vhdRepair,
3152	/* pfnTraverseMetadata */
3153	NULL,
3154	/* u32VersionEnd */
3155	VD_IMGBACKEND_VERSION
3156	};

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source: vbox/trunk/src/VBox/Storage/VHD.cpp@ 72756

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