QCOW.cpp@ 63714

Last change on this file since 63714 was 63635, checked in by vboxsync, 8 years ago
Storage/QCOW,Parallels: Fix a few possible crashes possible when opening corrupted image files
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1	/* $Id: QCOW.cpp 63635 2016-08-25 13:44:59Z vboxsync $ */
2	/** @file
3	* QCOW - QCOW Disk image.
4	*/
5
6	/*
7	* Copyright (C) 2011-2016 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_QCOW
23	#include <VBox/vd-plugin.h>
24	#include <VBox/err.h>
25
26	#include <VBox/log.h>
27	#include <iprt/asm.h>
28	#include <iprt/assert.h>
29	#include <iprt/string.h>
30	#include <iprt/alloc.h>
31	#include <iprt/path.h>
32	#include <iprt/list.h>
33
34	#include "VDBackends.h"
35
36	/** @page pg_storage_qcow QCOW Storage Backend
37	* The QCOW backend implements support for the qemu copy on write format (short QCOW).
38	* There is no official specification available but the format is described
39	* at http://people.gnome.org/~markmc/qcow-image-format.html for version 2
40	* and http://people.gnome.org/~markmc/qcow-image-format-version-1.html for version 1.
41	*
42	* Missing things to implement:
43	* - v2 image creation and handling of the reference count table. (Blocker to enable support for V2 images)
44	* - cluster encryption
45	* - cluster compression
46	* - compaction
47	* - resizing
48	*/
49
50
51	/*********************************************************************************************************************************
52	* Structures in a QCOW image, big endian *
53	*********************************************************************************************************************************/
54
55	#pragma pack(1) /* Completely unnecessary. */
56	typedef struct QCowHeader
57	{
58	/** Magic value. */
59	uint32_t u32Magic;
60	/** Version of the image. */
61	uint32_t u32Version;
62	/** Version dependent data. */
63	union
64	{
65	/** Version 1. */
66	struct
67	{
68	/** Backing file offset. */
69	uint64_t u64BackingFileOffset;
70	/** Size of the backing file. */
71	uint32_t u32BackingFileSize;
72	/** mtime (Modification time?) - can be ignored. */
73	uint32_t u32MTime;
74	/** Logical size of the image in bytes. */
75	uint64_t u64Size;
76	/** Number of bits in the virtual offset used as a cluster offset. */
77	uint8_t u8ClusterBits;
78	/** Number of bits in the virtual offset used for the L2 index. */
79	uint8_t u8L2Bits;
80	/** Padding because the header is not packed in the original source. */
81	uint16_t u16Padding;
82	/** Used cryptographic method. */
83	uint32_t u32CryptMethod;
84	/** Offset of the L1 table in the image in bytes. */
85	uint64_t u64L1TableOffset;
86	} v1;
87	/** Version 2. */
88	struct
89	{
90	/** Backing file offset. */
91	uint64_t u64BackingFileOffset;
92	/** Size of the backing file. */
93	uint32_t u32BackingFileSize;
94	/** Number of bits in the virtual offset used as a cluster offset. */
95	uint32_t u32ClusterBits;
96	/** Logical size of the image. */
97	uint64_t u64Size;
98	/** Used cryptographic method. */
99	uint32_t u32CryptMethod;
100	/** Size of the L1 table in entries (each 8bytes big). */
101	uint32_t u32L1Size;
102	/** Offset of the L1 table in the image in bytes. */
103	uint64_t u64L1TableOffset;
104	/** Start of the refcount table in the image. */
105	uint64_t u64RefcountTableOffset;
106	/** Size of the refcount table in clusters. */
107	uint32_t u32RefcountTableClusters;
108	/** Number of snapshots in the image. */
109	uint32_t u32NbSnapshots;
110	/** Offset of the first snapshot header in the image. */
111	uint64_t u64SnapshotsOffset;
112	} v2;
113	} Version;
114	} QCowHeader;
115	#pragma pack()
116	/** Pointer to a on disk QCOW header. */
117	typedef QCowHeader *PQCowHeader;
118
119	/** QCOW magic value. */
120	#define QCOW_MAGIC UINT32_C(0x514649fb) /* QFI\0xfb */
121	/** Size of the V1 header. */
122	#define QCOW_V1_HDR_SIZE (48)
123	/** Size of the V2 header. */
124	#define QCOW_V2_HDR_SIZE (72)
125
126	/** Cluster is compressed flag for QCOW images. */
127	#define QCOW_V1_COMPRESSED_FLAG RT_BIT_64(63)
128
129	/** Copied flag for QCOW2 images. */
130	#define QCOW_V2_COPIED_FLAG RT_BIT_64(63)
131	/** Cluster is compressed flag for QCOW2 images. */
132	#define QCOW_V2_COMPRESSED_FLAG RT_BIT_64(62)
133
134
135	/*********************************************************************************************************************************
136	* Constants And Macros, Structures and Typedefs *
137	*********************************************************************************************************************************/
138
139	/**
140	* QCOW L2 cache entry.
141	*/
142	typedef struct QCOWL2CACHEENTRY
143	{
144	/** List node for the search list. */
145	RTLISTNODE NodeSearch;
146	/** List node for the LRU list. */
147	RTLISTNODE NodeLru;
148	/** Reference counter. */
149	uint32_t cRefs;
150	/** The offset of the L2 table, used as search key. */
151	uint64_t offL2Tbl;
152	/** Pointer to the cached L2 table. */
153	uint64_t *paL2Tbl;
154	} QCOWL2CACHEENTRY, *PQCOWL2CACHEENTRY;
155
156	/** Maximum amount of memory the cache is allowed to use. */
157	#define QCOW_L2_CACHE_MEMORY_MAX (2*_1M)
158
159	/** QCOW default cluster size for image version 2. */
160	#define QCOW2_CLUSTER_SIZE_DEFAULT (64*_1K)
161	/** QCOW default cluster size for image version 1. */
162	#define QCOW_CLUSTER_SIZE_DEFAULT (4*_1K)
163	/** QCOW default L2 table size in clusters. */
164	#define QCOW_L2_CLUSTERS_DEFAULT (1)
165
166	/**
167	* QCOW image data structure.
168	*/
169	typedef struct QCOWIMAGE
170	{
171	/** Image name. */
172	const char *pszFilename;
173	/** Storage handle. */
174	PVDIOSTORAGE pStorage;
175
176	/** Pointer to the per-disk VD interface list. */
177	PVDINTERFACE pVDIfsDisk;
178	/** Pointer to the per-image VD interface list. */
179	PVDINTERFACE pVDIfsImage;
180	/** Error interface. */
181	PVDINTERFACEERROR pIfError;
182	/** I/O interface. */
183	PVDINTERFACEIOINT pIfIo;
184
185	/** Open flags passed by VBoxHD layer. */
186	unsigned uOpenFlags;
187	/** Image flags defined during creation or determined during open. */
188	unsigned uImageFlags;
189	/** Total size of the image. */
190	uint64_t cbSize;
191	/** Physical geometry of this image. */
192	VDGEOMETRY PCHSGeometry;
193	/** Logical geometry of this image. */
194	VDGEOMETRY LCHSGeometry;
195
196	/** Image version. */
197	unsigned uVersion;
198	/** MTime field - used only to preserve value in opened images, unmodified otherwise. */
199	uint32_t MTime;
200
201	/** Filename of the backing file if any. */
202	char *pszBackingFilename;
203	/** Offset of the filename in the image. */
204	uint64_t offBackingFilename;
205	/** Size of the backing filename excluding \0. */
206	uint32_t cbBackingFilename;
207
208	/** Next offset of a new cluster, aligned to sector size. */
209	uint64_t offNextCluster;
210	/** Cluster size in bytes. */
211	uint32_t cbCluster;
212	/** Number of entries in the L1 table. */
213	uint32_t cL1TableEntries;
214	/** Size of an L1 rounded to the next cluster size. */
215	uint32_t cbL1Table;
216	/** Pointer to the L1 table. */
217	uint64_t *paL1Table;
218	/** Offset of the L1 table. */
219	uint64_t offL1Table;
220
221	/** Size of the L2 table in bytes. */
222	uint32_t cbL2Table;
223	/** Number of entries in the L2 table. */
224	uint32_t cL2TableEntries;
225	/** Memory occupied by the L2 table cache. */
226	size_t cbL2Cache;
227	/** The sorted L2 entry list used for searching. */
228	RTLISTNODE ListSearch;
229	/** The LRU L2 entry list used for eviction. */
230	RTLISTNODE ListLru;
231
232	/** Offset of the refcount table. */
233	uint64_t offRefcountTable;
234	/** Size of the refcount table in bytes. */
235	uint32_t cbRefcountTable;
236	/** Number of entries in the refcount table. */
237	uint32_t cRefcountTableEntries;
238	/** Pointer to the refcount table. */
239	uint64_t *paRefcountTable;
240
241	/** Offset mask for a cluster. */
242	uint64_t fOffsetMask;
243	/** Number of bits to shift to get the L1 index. */
244	uint32_t cL1Shift;
245	/** L2 table mask to get the L2 index. */
246	uint64_t fL2Mask;
247	/** Number of bits to shift to get the L2 index. */
248	uint32_t cL2Shift;
249
250	} QCOWIMAGE, *PQCOWIMAGE;
251
252	/**
253	* State of the async cluster allocation.
254	*/
255	typedef enum QCOWCLUSTERASYNCALLOCSTATE
256	{
257	/** Invalid. */
258	QCOWCLUSTERASYNCALLOCSTATE_INVALID = 0,
259	/** L2 table allocation. */
260	QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC,
261	/** Link L2 table into L1. */
262	QCOWCLUSTERASYNCALLOCSTATE_L2_LINK,
263	/** Allocate user data cluster. */
264	QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC,
265	/** Link user data cluster. */
266	QCOWCLUSTERASYNCALLOCSTATE_USER_LINK,
267	/** 32bit blowup. */
268	QCOWCLUSTERASYNCALLOCSTATE_32BIT_HACK = 0x7fffffff
269	} QCOWCLUSTERASYNCALLOCSTATE, *PQCOWCLUSTERASYNCALLOCSTATE;
270
271	/**
272	* Data needed to track async cluster allocation.
273	*/
274	typedef struct QCOWCLUSTERASYNCALLOC
275	{
276	/** The state of the cluster allocation. */
277	QCOWCLUSTERASYNCALLOCSTATE enmAllocState;
278	/** Old image size to rollback in case of an error. */
279	uint64_t offNextClusterOld;
280	/** L1 index to link if any. */
281	uint32_t idxL1;
282	/** L2 index to link, required in any case. */
283	uint32_t idxL2;
284	/** Start offset of the allocated cluster. */
285	uint64_t offClusterNew;
286	/** L2 cache entry if a L2 table is allocated. */
287	PQCOWL2CACHEENTRY pL2Entry;
288	/** Number of bytes to write. */
289	size_t cbToWrite;
290	} QCOWCLUSTERASYNCALLOC, *PQCOWCLUSTERASYNCALLOC;
291
292
293	/*********************************************************************************************************************************
294	* Static Variables *
295	*********************************************************************************************************************************/
296
297	/** NULL-terminated array of supported file extensions. */
298	static const VDFILEEXTENSION s_aQCowFileExtensions[] =
299	{
300	{"qcow", VDTYPE_HDD},
301	{"qcow2", VDTYPE_HDD},
302	{NULL, VDTYPE_INVALID}
303	};
304
305
306	/*********************************************************************************************************************************
307	* Internal Functions *
308	*********************************************************************************************************************************/
309
310	/**
311	* Return power of 2 or 0 if num error.
312	*
313	* @returns The power of 2 or 0 if the given number is not a power of 2.
314	* @param u32 The number.
315	*/
316	static uint32_t qcowGetPowerOfTwo(uint32_t u32)
317	{
318	if (u32 == 0)
319	return 0;
320	uint32_t uPower2 = 0;
321	while ((u32 & 1) == 0)
322	{
323	u32 >>= 1;
324	uPower2++;
325	}
326	return u32 == 1 ? uPower2 : 0;
327	}
328
329
330	/**
331	* Converts the image header to the host endianess and performs basic checks.
332	*
333	* @returns Whether the given header is valid or not.
334	* @param pHeader Pointer to the header to convert.
335	*/
336	static bool qcowHdrConvertToHostEndianess(PQCowHeader pHeader)
337	{
338	pHeader->u32Magic = RT_BE2H_U32(pHeader->u32Magic);
339	pHeader->u32Version = RT_BE2H_U32(pHeader->u32Version);
340
341	if (pHeader->u32Magic != QCOW_MAGIC)
342	return false;
343
344	if (pHeader->u32Version == 1)
345	{
346	pHeader->Version.v1.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v1.u64BackingFileOffset);
347	pHeader->Version.v1.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v1.u32BackingFileSize);
348	pHeader->Version.v1.u32MTime = RT_BE2H_U32(pHeader->Version.v1.u32MTime);
349	pHeader->Version.v1.u64Size = RT_BE2H_U64(pHeader->Version.v1.u64Size);
350	pHeader->Version.v1.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v1.u32CryptMethod);
351	pHeader->Version.v1.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v1.u64L1TableOffset);
352	}
353	else if (pHeader->u32Version == 2)
354	{
355	pHeader->Version.v2.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v2.u64BackingFileOffset);
356	pHeader->Version.v2.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v2.u32BackingFileSize);
357	pHeader->Version.v2.u32ClusterBits = RT_BE2H_U32(pHeader->Version.v2.u32ClusterBits);
358	pHeader->Version.v2.u64Size = RT_BE2H_U64(pHeader->Version.v2.u64Size);
359	pHeader->Version.v2.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v2.u32CryptMethod);
360	pHeader->Version.v2.u32L1Size = RT_BE2H_U32(pHeader->Version.v2.u32L1Size);
361	pHeader->Version.v2.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v2.u64L1TableOffset);
362	pHeader->Version.v2.u64RefcountTableOffset = RT_BE2H_U64(pHeader->Version.v2.u64RefcountTableOffset);
363	pHeader->Version.v2.u32RefcountTableClusters = RT_BE2H_U32(pHeader->Version.v2.u32RefcountTableClusters);
364	pHeader->Version.v2.u32NbSnapshots = RT_BE2H_U32(pHeader->Version.v2.u32NbSnapshots);
365	pHeader->Version.v2.u64SnapshotsOffset = RT_BE2H_U64(pHeader->Version.v2.u64SnapshotsOffset);
366	}
367	else
368	return false;
369
370	return true;
371	}
372
373	/**
374	* Creates a QCOW header from the given image state.
375	*
376	* @returns nothing.
377	* @param pImage Image instance data.
378	* @param pHeader Pointer to the header to convert.
379	* @param pcbHeader Where to store the size of the header to write.
380	*/
381	static void qcowHdrConvertFromHostEndianess(PQCOWIMAGE pImage, PQCowHeader pHeader,
382	size_t *pcbHeader)
383	{
384	memset(pHeader, 0, sizeof(QCowHeader));
385
386	pHeader->u32Magic = RT_H2BE_U32(QCOW_MAGIC);
387	pHeader->u32Version = RT_H2BE_U32(pImage->uVersion);
388	if (pImage->uVersion == 1)
389	{
390	pHeader->Version.v1.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
391	pHeader->Version.v1.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
392	pHeader->Version.v1.u32MTime = RT_H2BE_U32(pImage->MTime);
393	pHeader->Version.v1.u64Size = RT_H2BE_U64(pImage->cbSize);
394	pHeader->Version.v1.u8ClusterBits = (uint8_t)qcowGetPowerOfTwo(pImage->cbCluster);
395	pHeader->Version.v1.u8L2Bits = (uint8_t)qcowGetPowerOfTwo(pImage->cL2TableEntries);
396	pHeader->Version.v1.u32CryptMethod = RT_H2BE_U32(0);
397	pHeader->Version.v1.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
398	*pcbHeader = QCOW_V1_HDR_SIZE;
399	}
400	else if (pImage->uVersion == 2)
401	{
402	pHeader->Version.v2.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
403	pHeader->Version.v2.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
404	pHeader->Version.v2.u32ClusterBits = RT_H2BE_U32(qcowGetPowerOfTwo(pImage->cbCluster));
405	pHeader->Version.v2.u64Size = RT_H2BE_U64(pImage->cbSize);
406	pHeader->Version.v2.u32CryptMethod = RT_H2BE_U32(0);
407	pHeader->Version.v2.u32L1Size = RT_H2BE_U32(pImage->cL1TableEntries);
408	pHeader->Version.v2.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
409	pHeader->Version.v2.u64RefcountTableOffset = RT_H2BE_U64(pImage->offRefcountTable);
410	pHeader->Version.v2.u32RefcountTableClusters = RT_H2BE_U32(pImage->cbRefcountTable / pImage->cbCluster);
411	pHeader->Version.v2.u32NbSnapshots = RT_H2BE_U32(0);
412	pHeader->Version.v2.u64SnapshotsOffset = RT_H2BE_U64((uint64_t)0);
413	*pcbHeader = QCOW_V2_HDR_SIZE;
414	}
415	else
416	AssertMsgFailed(("Invalid version of the QCOW image format %d\n", pImage->uVersion));
417	}
418
419	/**
420	* Convert table entries from little endian to host endianess.
421	*
422	* @returns nothing.
423	* @param paTbl Pointer to the table.
424	* @param cEntries Number of entries in the table.
425	*/
426	static void qcowTableConvertToHostEndianess(uint64_t *paTbl, uint32_t cEntries)
427	{
428	while(cEntries-- > 0)
429	{
430	paTbl = RT_BE2H_U64(paTbl);
431	paTbl++;
432	}
433	}
434
435	/**
436	* Convert table entries from host to little endian format.
437	*
438	* @returns nothing.
439	* @param paTblImg Pointer to the table which will store the little endian table.
440	* @param paTbl The source table to convert.
441	* @param cEntries Number of entries in the table.
442	*/
443	static void qcowTableConvertFromHostEndianess(uint64_t paTblImg, uint64_t paTbl,
444	uint32_t cEntries)
445	{
446	while(cEntries-- > 0)
447	{
448	paTblImg = RT_H2BE_U64(paTbl);
449	paTbl++;
450	paTblImg++;
451	}
452	}
453
454	#if 0 /* unused */
455	/**
456	* Convert refcount table entries from little endian to host endianess.
457	*
458	* @returns nothing.
459	* @param paTbl Pointer to the table.
460	* @param cEntries Number of entries in the table.
461	*/
462	static void qcowRefcountTableConvertToHostEndianess(uint16_t *paTbl, uint32_t cEntries)
463	{
464	while(cEntries-- > 0)
465	{
466	paTbl = RT_BE2H_U16(paTbl);
467	paTbl++;
468	}
469	}
470	#endif
471
472	#if 0 /* unused */
473	/**
474	* Convert table entries from host to little endian format.
475	*
476	* @returns nothing.
477	* @param paTblImg Pointer to the table which will store the little endian table.
478	* @param paTbl The source table to convert.
479	* @param cEntries Number of entries in the table.
480	*/
481	static void qcowRefcountTableConvertFromHostEndianess(uint16_t paTblImg, uint16_t paTbl,
482	uint32_t cEntries)
483	{
484	while(cEntries-- > 0)
485	{
486	paTblImg = RT_H2BE_U16(paTbl);
487	paTbl++;
488	paTblImg++;
489	}
490	}
491	#endif
492
493	/**
494	* Creates the L2 table cache.
495	*
496	* @returns VBox status code.
497	* @param pImage The image instance data.
498	*/
499	static int qcowL2TblCacheCreate(PQCOWIMAGE pImage)
500	{
501	pImage->cbL2Cache = 0;
502	RTListInit(&pImage->ListSearch);
503	RTListInit(&pImage->ListLru);
504
505	return VINF_SUCCESS;
506	}
507
508	/**
509	* Destroys the L2 table cache.
510	*
511	* @returns nothing.
512	* @param pImage The image instance data.
513	*/
514	static void qcowL2TblCacheDestroy(PQCOWIMAGE pImage)
515	{
516	PQCOWL2CACHEENTRY pL2Entry = NULL;
517	PQCOWL2CACHEENTRY pL2Next = NULL;
518
519	RTListForEachSafe(&pImage->ListSearch, pL2Entry, pL2Next, QCOWL2CACHEENTRY, NodeSearch)
520	{
521	Assert(!pL2Entry->cRefs);
522
523	RTListNodeRemove(&pL2Entry->NodeSearch);
524	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
525	RTMemFree(pL2Entry);
526	}
527
528	pImage->cbL2Cache = 0;
529	RTListInit(&pImage->ListSearch);
530	RTListInit(&pImage->ListLru);
531	}
532
533	/**
534	* Returns the L2 table matching the given offset or NULL if none could be found.
535	*
536	* @returns Pointer to the L2 table cache entry or NULL.
537	* @param pImage The image instance data.
538	* @param offL2Tbl Offset of the L2 table to search for.
539	*/
540	static PQCOWL2CACHEENTRY qcowL2TblCacheRetain(PQCOWIMAGE pImage, uint64_t offL2Tbl)
541	{
542	PQCOWL2CACHEENTRY pL2Entry = NULL;
543
544	RTListForEach(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch)
545	{
546	if (pL2Entry->offL2Tbl == offL2Tbl)
547	break;
548	}
549
550	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
551	{
552	/* Update LRU list. */
553	RTListNodeRemove(&pL2Entry->NodeLru);
554	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
555	pL2Entry->cRefs++;
556	return pL2Entry;
557	}
558	else
559	return NULL;
560	}
561
562	/**
563	* Releases a L2 table cache entry.
564	*
565	* @returns nothing.
566	* @param pL2Entry The L2 cache entry.
567	*/
568	static void qcowL2TblCacheEntryRelease(PQCOWL2CACHEENTRY pL2Entry)
569	{
570	Assert(pL2Entry->cRefs > 0);
571	pL2Entry->cRefs--;
572	}
573
574	/**
575	* Allocates a new L2 table from the cache evicting old entries if required.
576	*
577	* @returns Pointer to the L2 cache entry or NULL.
578	* @param pImage The image instance data.
579	*/
580	static PQCOWL2CACHEENTRY qcowL2TblCacheEntryAlloc(PQCOWIMAGE pImage)
581	{
582	PQCOWL2CACHEENTRY pL2Entry = NULL;
583
584	if (pImage->cbL2Cache + pImage->cbL2Table <= QCOW_L2_CACHE_MEMORY_MAX)
585	{
586	/* Add a new entry. */
587	pL2Entry = (PQCOWL2CACHEENTRY)RTMemAllocZ(sizeof(QCOWL2CACHEENTRY));
588	if (pL2Entry)
589	{
590	pL2Entry->paL2Tbl = (uint64_t *)RTMemPageAllocZ(pImage->cbL2Table);
591	if (RT_UNLIKELY(!pL2Entry->paL2Tbl))
592	{
593	RTMemFree(pL2Entry);
594	pL2Entry = NULL;
595	}
596	else
597	{
598	pL2Entry->cRefs = 1;
599	pImage->cbL2Cache += pImage->cbL2Table;
600	}
601	}
602	}
603	else
604	{
605	/* Evict the last not in use entry and use it */
606	Assert(!RTListIsEmpty(&pImage->ListLru));
607
608	RTListForEachReverse(&pImage->ListLru, pL2Entry, QCOWL2CACHEENTRY, NodeLru)
609	{
610	if (!pL2Entry->cRefs)
611	break;
612	}
613
614	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
615	{
616	RTListNodeRemove(&pL2Entry->NodeSearch);
617	RTListNodeRemove(&pL2Entry->NodeLru);
618	pL2Entry->offL2Tbl = 0;
619	pL2Entry->cRefs = 1;
620	}
621	else
622	pL2Entry = NULL;
623	}
624
625	return pL2Entry;
626	}
627
628	/**
629	* Frees a L2 table cache entry.
630	*
631	* @returns nothing.
632	* @param pImage The image instance data.
633	* @param pL2Entry The L2 cache entry to free.
634	*/
635	static void qcowL2TblCacheEntryFree(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
636	{
637	Assert(!pL2Entry->cRefs);
638	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
639	RTMemFree(pL2Entry);
640
641	pImage->cbL2Cache -= pImage->cbL2Table;
642	}
643
644	/**
645	* Inserts an entry in the L2 table cache.
646	*
647	* @returns nothing.
648	* @param pImage The image instance data.
649	* @param pL2Entry The L2 cache entry to insert.
650	*/
651	static void qcowL2TblCacheEntryInsert(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
652	{
653	PQCOWL2CACHEENTRY pIt = NULL;
654
655	Assert(pL2Entry->offL2Tbl > 0);
656
657	/* Insert at the top of the LRU list. */
658	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
659
660	if (RTListIsEmpty(&pImage->ListSearch))
661	{
662	RTListAppend(&pImage->ListSearch, &pL2Entry->NodeSearch);
663	}
664	else
665	{
666	/* Insert into search list. */
667	pIt = RTListGetFirst(&pImage->ListSearch, QCOWL2CACHEENTRY, NodeSearch);
668	if (pIt->offL2Tbl > pL2Entry->offL2Tbl)
669	RTListPrepend(&pImage->ListSearch, &pL2Entry->NodeSearch);
670	else
671	{
672	bool fInserted = false;
673
674	RTListForEach(&pImage->ListSearch, pIt, QCOWL2CACHEENTRY, NodeSearch)
675	{
676	Assert(pIt->offL2Tbl != pL2Entry->offL2Tbl);
677	if (pIt->offL2Tbl < pL2Entry->offL2Tbl)
678	{
679	RTListNodeInsertAfter(&pIt->NodeSearch, &pL2Entry->NodeSearch);
680	fInserted = true;
681	break;
682	}
683	}
684	Assert(fInserted);
685	}
686	}
687	}
688
689	/**
690	* Fetches the L2 from the given offset trying the LRU cache first and
691	* reading it from the image after a cache miss.
692	*
693	* @returns VBox status code.
694	* @param pImage Image instance data.
695	* @param pIoCtx The I/O context.
696	* @param offL2Tbl The offset of the L2 table in the image.
697	* @param ppL2Entry Where to store the L2 table on success.
698	*/
699	static int qcowL2TblCacheFetch(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offL2Tbl,
700	PQCOWL2CACHEENTRY *ppL2Entry)
701	{
702	int rc = VINF_SUCCESS;
703
704	/* Try to fetch the L2 table from the cache first. */
705	PQCOWL2CACHEENTRY pL2Entry = qcowL2TblCacheRetain(pImage, offL2Tbl);
706	if (!pL2Entry)
707	{
708	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
709
710	if (pL2Entry)
711	{
712	/* Read from the image. */
713	PVDMETAXFER pMetaXfer;
714
715	pL2Entry->offL2Tbl = offL2Tbl;
716	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
717	offL2Tbl, pL2Entry->paL2Tbl,
718	pImage->cbL2Table, pIoCtx,
719	&pMetaXfer, NULL, NULL);
720	if (RT_SUCCESS(rc))
721	{
722	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
723	#if defined(RT_LITTLE_ENDIAN)
724	qcowTableConvertToHostEndianess(pL2Entry->paL2Tbl, pImage->cL2TableEntries);
725	#endif
726	qcowL2TblCacheEntryInsert(pImage, pL2Entry);
727	}
728	else
729	{
730	qcowL2TblCacheEntryRelease(pL2Entry);
731	qcowL2TblCacheEntryFree(pImage, pL2Entry);
732	}
733	}
734	else
735	rc = VERR_NO_MEMORY;
736	}
737
738	if (RT_SUCCESS(rc))
739	*ppL2Entry = pL2Entry;
740
741	return rc;
742	}
743
744	/**
745	* Sets the L1, L2 and offset bitmasks and L1 and L2 bit shift members.
746	*
747	* @returns nothing.
748	* @param pImage The image instance data.
749	*/
750	static void qcowTableMasksInit(PQCOWIMAGE pImage)
751	{
752	uint32_t cClusterBits, cL2TableBits;
753
754	cClusterBits = qcowGetPowerOfTwo(pImage->cbCluster);
755	cL2TableBits = qcowGetPowerOfTwo(pImage->cL2TableEntries);
756
757	Assert(cClusterBits + cL2TableBits < 64);
758
759	pImage->fOffsetMask = ((uint64_t)pImage->cbCluster - 1);
760	pImage->fL2Mask = ((uint64_t)pImage->cL2TableEntries - 1) << cClusterBits;
761	pImage->cL2Shift = cClusterBits;
762	pImage->cL1Shift = cClusterBits + cL2TableBits;
763	}
764
765	/**
766	* Converts a given logical offset into the
767	*
768	* @returns nothing.
769	* @param pImage The image instance data.
770	* @param off The logical offset to convert.
771	* @param pidxL1 Where to store the index in the L1 table on success.
772	* @param pidxL2 Where to store the index in the L2 table on success.
773	* @param poffCluster Where to store the offset in the cluster on success.
774	*/
775	DECLINLINE(void) qcowConvertLogicalOffset(PQCOWIMAGE pImage, uint64_t off, uint32_t *pidxL1,
776	uint32_t pidxL2, uint32_t poffCluster)
777	{
778	AssertPtr(pidxL1);
779	AssertPtr(pidxL2);
780	AssertPtr(poffCluster);
781
782	*poffCluster = off & pImage->fOffsetMask;
783	*pidxL1 = off >> pImage->cL1Shift;
784	*pidxL2 = (off & pImage->fL2Mask) >> pImage->cL2Shift;
785	}
786
787	/**
788	* Converts Cluster size to a byte size.
789	*
790	* @returns Number of bytes derived from the given number of clusters.
791	* @param pImage The image instance data.
792	* @param cClusters The clusters to convert.
793	*/
794	DECLINLINE(uint64_t) qcowCluster2Byte(PQCOWIMAGE pImage, uint64_t cClusters)
795	{
796	return cClusters * pImage->cbCluster;
797	}
798
799	/**
800	* Converts number of bytes to cluster size rounding to the next cluster.
801	*
802	* @returns Number of bytes derived from the given number of clusters.
803	* @param pImage The image instance data.
804	* @param cb Number of bytes to convert.
805	*/
806	DECLINLINE(uint64_t) qcowByte2Cluster(PQCOWIMAGE pImage, uint64_t cb)
807	{
808	return cb / pImage->cbCluster + (cb % pImage->cbCluster ? 1 : 0);
809	}
810
811	/**
812	* Allocates a new cluster in the image.
813	*
814	* @returns The start offset of the new cluster in the image.
815	* @param pImage The image instance data.
816	* @param cCLusters Number of clusters to allocate.
817	*/
818	DECLINLINE(uint64_t) qcowClusterAllocate(PQCOWIMAGE pImage, uint32_t cClusters)
819	{
820	uint64_t offCluster;
821
822	offCluster = pImage->offNextCluster;
823	pImage->offNextCluster += cClusters*pImage->cbCluster;
824
825	return offCluster;
826	}
827
828	/**
829	* Returns the real image offset for a given cluster or an error if the cluster is not
830	* yet allocated.
831	*
832	* @returns VBox status code.
833	* VERR_VD_BLOCK_FREE if the cluster is not yet allocated.
834	* @param pImage The image instance data.
835	* @param pIoCtx The I/O context.
836	* @param idxL1 The L1 index.
837	* @param idxL2 The L2 index.
838	* @param offCluster Offset inside the cluster.
839	* @param poffImage Where to store the image offset on success;
840	*/
841	static int qcowConvertToImageOffset(PQCOWIMAGE pImage, PVDIOCTX pIoCtx,
842	uint32_t idxL1, uint32_t idxL2,
843	uint32_t offCluster, uint64_t *poffImage)
844	{
845	int rc = VERR_VD_BLOCK_FREE;
846
847	AssertReturn(idxL1 < pImage->cL1TableEntries, VERR_INVALID_PARAMETER);
848	AssertReturn(idxL2 < pImage->cL2TableEntries, VERR_INVALID_PARAMETER);
849
850	if (pImage->paL1Table[idxL1])
851	{
852	PQCOWL2CACHEENTRY pL2Entry;
853
854	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1], &pL2Entry);
855	if (RT_SUCCESS(rc))
856	{
857	/* Get real file offset. */
858	if (pL2Entry->paL2Tbl[idxL2])
859	{
860	uint64_t off = pL2Entry->paL2Tbl[idxL2];
861
862	/* Strip flags */
863	if (pImage->uVersion == 2)
864	{
865	if (RT_UNLIKELY(off & QCOW_V2_COMPRESSED_FLAG))
866	rc = VERR_NOT_SUPPORTED;
867	else
868	off &= ~(QCOW_V2_COMPRESSED_FLAG \| QCOW_V2_COPIED_FLAG);
869	}
870	else
871	{
872	if (RT_UNLIKELY(off & QCOW_V1_COMPRESSED_FLAG))
873	rc = VERR_NOT_SUPPORTED;
874	else
875	off &= ~QCOW_V1_COMPRESSED_FLAG;
876	}
877
878	*poffImage = off + offCluster;
879	}
880	else
881	rc = VERR_VD_BLOCK_FREE;
882
883	qcowL2TblCacheEntryRelease(pL2Entry);
884	}
885	}
886
887	return rc;
888	}
889
890
891	/**
892	* Internal. Flush image data to disk.
893	*/
894	static int qcowFlushImage(PQCOWIMAGE pImage)
895	{
896	int rc = VINF_SUCCESS;
897
898	if ( pImage->pStorage
899	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
900	&& pImage->cbL1Table)
901	{
902	QCowHeader Header;
903
904	#if defined(RT_LITTLE_ENDIAN)
905	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
906	if (paL1TblImg)
907	{
908	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
909	pImage->cL1TableEntries);
910	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
911	pImage->offL1Table, paL1TblImg,
912	pImage->cbL1Table);
913	RTMemFree(paL1TblImg);
914	}
915	else
916	rc = VERR_NO_MEMORY;
917	#else
918	/* Write L1 table directly. */
919	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->offL1Table,
920	pImage->paL1Table, pImage->cbL1Table);
921	#endif
922	if (RT_SUCCESS(rc))
923	{
924	/* Write header. */
925	size_t cbHeader = 0;
926	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
927	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Header,
928	cbHeader);
929	if (RT_SUCCESS(rc))
930	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
931	}
932	}
933
934	return rc;
935	}
936
937	/**
938	* Flush image data to disk - version for async I/O.
939	*
940	* @returns VBox status code.
941	* @param pImage The image instance data.
942	* @param pIoCtx The I/o context
943	*/
944	static int qcowFlushImageAsync(PQCOWIMAGE pImage, PVDIOCTX pIoCtx)
945	{
946	int rc = VINF_SUCCESS;
947
948	if ( pImage->pStorage
949	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
950	{
951	QCowHeader Header;
952
953	#if defined(RT_LITTLE_ENDIAN)
954	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
955	if (paL1TblImg)
956	{
957	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
958	pImage->cL1TableEntries);
959	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
960	pImage->offL1Table, paL1TblImg,
961	pImage->cbL1Table, pIoCtx, NULL, NULL);
962	RTMemFree(paL1TblImg);
963	}
964	else
965	rc = VERR_NO_MEMORY;
966	#else
967	/* Write L1 table directly. */
968	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
969	pImage->offL1Table, pImage->paL1Table,
970	pImage->cbL1Table, pIoCtx, NULL, NULL);
971	#endif
972	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
973	{
974	/* Write header. */
975	size_t cbHeader = 0;
976	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
977	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
978	0, &Header, cbHeader,
979	pIoCtx, NULL, NULL);
980	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
981	rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage,
982	pIoCtx, NULL, NULL);
983	}
984	}
985
986	return rc;
987	}
988
989	/**
990	* Internal. Free all allocated space for representing an image except pImage,
991	* and optionally delete the image from disk.
992	*/
993	static int qcowFreeImage(PQCOWIMAGE pImage, bool fDelete)
994	{
995	int rc = VINF_SUCCESS;
996
997	/* Freeing a never allocated image (e.g. because the open failed) is
998	* not signalled as an error. After all nothing bad happens. */
999	if (pImage)
1000	{
1001	if (pImage->pStorage)
1002	{
1003	/* No point updating the file that is deleted anyway. */
1004	if (!fDelete)
1005	qcowFlushImage(pImage);
1006
1007	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
1008	pImage->pStorage = NULL;
1009	}
1010
1011	if (pImage->paL1Table)
1012	RTMemFree(pImage->paL1Table);
1013
1014	if (pImage->pszBackingFilename)
1015	{
1016	RTMemFree(pImage->pszBackingFilename);
1017	pImage->pszBackingFilename = NULL;
1018	}
1019
1020	qcowL2TblCacheDestroy(pImage);
1021
1022	if (fDelete && pImage->pszFilename)
1023	vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
1024	}
1025
1026	LogFlowFunc(("returns %Rrc\n", rc));
1027	return rc;
1028	}
1029
1030	/**
1031	* Validates the header.
1032	*
1033	* @returns VBox status code.
1034	* @param pImage Image backend instance data.
1035	* @param pHdr The header to validate.
1036	* @param cbFile The image file size in bytes.
1037	*/
1038	static int qcowHdrValidate(PQCOWIMAGE pImage, PQCowHeader pHdr, uint64_t cbFile)
1039	{
1040	if (pHdr->u32Version == 1)
1041	{
1042	/* Check that the backing filename is contained in the file. */
1043	if (pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize > cbFile)
1044	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1045	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1046	pImage->pszFilename, pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize,
1047	cbFile);
1048
1049	/* Check that the cluster bits indicate at least a 512byte sector size. */
1050	if (RT_BIT_32(pHdr->Version.v1.u8ClusterBits) < 512)
1051	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1052	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1053	pImage->pszFilename, RT_BIT_32(pHdr->Version.v1.u8ClusterBits), 512);
1054
1055	/*
1056	* Check for possible overflow when multiplying cluster size and L2 entry count because it is used
1057	* to calculate the number of L1 table entries later on.
1058	*/
1059	if (RT_BIT_32(pHdr->Version.v1.u8L2Bits) * RT_BIT_32(pHdr->Version.v1.u8ClusterBits) == 0)
1060	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1061	N_("QCOW: Overflow during L1 table size calculation for image '%s'"),
1062	pImage->pszFilename);
1063	}
1064	else if (pHdr->u32Version == 2)
1065	{
1066	/* Check that the backing filename is contained in the file. */
1067	if (pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize > cbFile)
1068	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1069	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1070	pImage->pszFilename, pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize,
1071	cbFile);
1072
1073	/* Check that the cluster bits indicate at least a 512byte sector size. */
1074	if (RT_BIT_32(pHdr->Version.v2.u32ClusterBits) < 512)
1075	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1076	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1077	pImage->pszFilename, RT_BIT_32(pHdr->Version.v2.u32ClusterBits), 512);
1078	}
1079	else
1080	return vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1081	N_("QCOW: Version %u in image '%s' is not supported"),
1082	pHdr->u32Version, pImage->pszFilename);
1083
1084	return VINF_SUCCESS;
1085	}
1086
1087	/**
1088	* Internal: Open an image, constructing all necessary data structures.
1089	*/
1090	static int qcowOpenImage(PQCOWIMAGE pImage, unsigned uOpenFlags)
1091	{
1092	int rc;
1093
1094	pImage->uOpenFlags = uOpenFlags;
1095
1096	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1097	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1098	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1099
1100	rc = qcowL2TblCacheCreate(pImage);
1101	AssertRC(rc);
1102
1103	/*
1104	* Open the image.
1105	*/
1106	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1107	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1108	false /* fCreate */),
1109	&pImage->pStorage);
1110	if (RT_FAILURE(rc))
1111	{
1112	/* Do NOT signal an appropriate error here, as the VD layer has the
1113	* choice of retrying the open if it failed. */
1114	goto out;
1115	}
1116
1117	uint64_t cbFile;
1118	QCowHeader Header;
1119	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1120	if (RT_FAILURE(rc))
1121	goto out;
1122	if (cbFile > sizeof(Header))
1123	{
1124	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0, &Header, sizeof(Header));
1125	if ( RT_SUCCESS(rc)
1126	&& qcowHdrConvertToHostEndianess(&Header))
1127	{
1128	pImage->offNextCluster = RT_ALIGN_64(cbFile, 512); /* Align image to sector boundary. */
1129	Assert(pImage->offNextCluster >= cbFile);
1130
1131	rc = qcowHdrValidate(pImage, &Header, cbFile);
1132	if (RT_SUCCESS(rc))
1133	{
1134	if (Header.u32Version == 1)
1135	{
1136	if (!Header.Version.v1.u32CryptMethod)
1137	{
1138	pImage->uVersion = 1;
1139	pImage->offBackingFilename = Header.Version.v1.u64BackingFileOffset;
1140	pImage->cbBackingFilename = Header.Version.v1.u32BackingFileSize;
1141	pImage->MTime = Header.Version.v1.u32MTime;
1142	pImage->cbSize = Header.Version.v1.u64Size;
1143	pImage->cbCluster = RT_BIT_32(Header.Version.v1.u8ClusterBits);
1144	pImage->cL2TableEntries = RT_BIT_32(Header.Version.v1.u8L2Bits);
1145	pImage->cbL2Table = RT_ALIGN_64(pImage->cL2TableEntries * sizeof(uint64_t), pImage->cbCluster);
1146	pImage->offL1Table = Header.Version.v1.u64L1TableOffset;
1147	pImage->cL1TableEntries = pImage->cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1148	if (pImage->cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1149	pImage->cL1TableEntries++;
1150	}
1151	else
1152	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1153	N_("QCow: Encrypted image '%s' is not supported"),
1154	pImage->pszFilename);
1155	}
1156	else if (Header.u32Version == 2)
1157	{
1158	if (Header.Version.v2.u32CryptMethod)
1159	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1160	N_("QCow: Encrypted image '%s' is not supported"),
1161	pImage->pszFilename);
1162	else if (Header.Version.v2.u32NbSnapshots)
1163	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1164	N_("QCow: Image '%s' contains snapshots which is not supported"),
1165	pImage->pszFilename);
1166	else
1167	{
1168	pImage->uVersion = 2;
1169	pImage->offBackingFilename = Header.Version.v2.u64BackingFileOffset;
1170	pImage->cbBackingFilename = Header.Version.v2.u32BackingFileSize;
1171	pImage->cbSize = Header.Version.v2.u64Size;
1172	pImage->cbCluster = RT_BIT_32(Header.Version.v2.u32ClusterBits);
1173	pImage->cL2TableEntries = pImage->cbCluster / sizeof(uint64_t);
1174	pImage->cbL2Table = pImage->cbCluster;
1175	pImage->offL1Table = Header.Version.v2.u64L1TableOffset;
1176	pImage->cL1TableEntries = Header.Version.v2.u32L1Size;
1177	pImage->offRefcountTable = Header.Version.v2.u64RefcountTableOffset;
1178	pImage->cbRefcountTable = qcowCluster2Byte(pImage, Header.Version.v2.u32RefcountTableClusters);
1179	pImage->cRefcountTableEntries = pImage->cbRefcountTable / sizeof(uint64_t);
1180	}
1181	}
1182	else
1183	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1184	N_("QCow: Image '%s' uses version %u which is not supported"),
1185	pImage->pszFilename, Header.u32Version);
1186
1187	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1188	if ((uint64_t)pImage->cbL1Table != RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster))
1189	rc = vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1190	N_("QCOW: L1 table size overflow in image '%s'"),
1191	pImage->pszFilename);
1192	}
1193
1194	/** @todo Check that there are no compressed clusters in the image
1195	* (by traversing the L2 tables and checking each offset).
1196	* Refuse to open such images.
1197	*/
1198
1199	if ( RT_SUCCESS(rc)
1200	&& pImage->cbBackingFilename
1201	&& pImage->offBackingFilename)
1202	{
1203	/* Load backing filename from image. */
1204	pImage->pszBackingFilename = (char )RTMemAllocZ(pImage->cbBackingFilename + 1); / +1 for \0 terminator. */
1205	if (pImage->pszBackingFilename)
1206	{
1207	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1208	pImage->offBackingFilename, pImage->pszBackingFilename,
1209	pImage->cbBackingFilename);
1210	}
1211	else
1212	rc = VERR_NO_MEMORY;
1213	}
1214
1215	if ( RT_SUCCESS(rc)
1216	&& pImage->cbRefcountTable
1217	&& pImage->offRefcountTable)
1218	{
1219	/* Load refcount table. */
1220	Assert(pImage->cRefcountTableEntries);
1221	pImage->paRefcountTable = (uint64_t *)RTMemAllocZ(pImage->cbRefcountTable);
1222	if (RT_LIKELY(pImage->paRefcountTable))
1223	{
1224	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1225	pImage->offRefcountTable, pImage->paRefcountTable,
1226	pImage->cbRefcountTable);
1227	if (RT_SUCCESS(rc))
1228	qcowTableConvertToHostEndianess(pImage->paRefcountTable,
1229	pImage->cRefcountTableEntries);
1230	else
1231	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1232	N_("QCow: Reading refcount table of image '%s' failed"),
1233	pImage->pszFilename);
1234	}
1235	else
1236	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1237	N_("QCow: Allocating memory for refcount table of image '%s' failed"),
1238	pImage->pszFilename);
1239	}
1240
1241	if (RT_SUCCESS(rc))
1242	{
1243	qcowTableMasksInit(pImage);
1244
1245	/* Allocate L1 table. */
1246	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1247	if (pImage->paL1Table)
1248	{
1249	/* Read from the image. */
1250	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1251	pImage->offL1Table, pImage->paL1Table,
1252	pImage->cbL1Table);
1253	if (RT_SUCCESS(rc))
1254	qcowTableConvertToHostEndianess(pImage->paL1Table, pImage->cL1TableEntries);
1255	else
1256	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1257	N_("QCow: Reading the L1 table for image '%s' failed"),
1258	pImage->pszFilename);
1259	}
1260	else
1261	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1262	N_("QCow: Out of memory allocating L1 table for image '%s'"),
1263	pImage->pszFilename);
1264	}
1265	}
1266	else if (RT_SUCCESS(rc))
1267	rc = VERR_VD_GEN_INVALID_HEADER;
1268	}
1269	else
1270	rc = VERR_VD_GEN_INVALID_HEADER;
1271
1272	out:
1273	if (RT_FAILURE(rc))
1274	qcowFreeImage(pImage, false);
1275	return rc;
1276	}
1277
1278	/**
1279	* Internal: Create a qcow image.
1280	*/
1281	static int qcowCreateImage(PQCOWIMAGE pImage, uint64_t cbSize,
1282	unsigned uImageFlags, const char *pszComment,
1283	PCVDGEOMETRY pPCHSGeometry,
1284	PCVDGEOMETRY pLCHSGeometry, unsigned uOpenFlags,
1285	PFNVDPROGRESS pfnProgress, void *pvUser,
1286	unsigned uPercentStart, unsigned uPercentSpan)
1287	{
1288	RT_NOREF1(pszComment);
1289	int rc;
1290	int32_t fOpen;
1291
1292	if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
1293	{
1294	rc = vdIfError(pImage->pIfError, VERR_VD_INVALID_TYPE, RT_SRC_POS, N_("QCow: cannot create fixed image '%s'"), pImage->pszFilename);
1295	goto out;
1296	}
1297
1298	pImage->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1299	pImage->uImageFlags = uImageFlags;
1300	pImage->PCHSGeometry = *pPCHSGeometry;
1301	pImage->LCHSGeometry = *pLCHSGeometry;
1302
1303	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1304	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1305	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1306
1307	/* Create image file. */
1308	fOpen = VDOpenFlagsToFileOpenFlags(pImage->uOpenFlags, true /* fCreate */);
1309	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename, fOpen, &pImage->pStorage);
1310	if (RT_FAILURE(rc))
1311	{
1312	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: cannot create image '%s'"), pImage->pszFilename);
1313	goto out;
1314	}
1315
1316	/* Init image state. */
1317	pImage->uVersion = 1; /* We create only version 1 images at the moment. */
1318	pImage->cbSize = cbSize;
1319	pImage->cbCluster = QCOW_CLUSTER_SIZE_DEFAULT;
1320	pImage->cbL2Table = qcowCluster2Byte(pImage, QCOW_L2_CLUSTERS_DEFAULT);
1321	pImage->cL2TableEntries = pImage->cbL2Table / sizeof(uint64_t);
1322	pImage->cL1TableEntries = cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1323	if (cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1324	pImage->cL1TableEntries++;
1325	pImage->cbL1Table = pImage->cL1TableEntries * sizeof(uint64_t);
1326	pImage->offL1Table = QCOW_V1_HDR_SIZE;
1327	pImage->cbBackingFilename = 0;
1328	pImage->offBackingFilename = 0;
1329	pImage->offNextCluster = RT_ALIGN_64(QCOW_V1_HDR_SIZE + pImage->cbL1Table, pImage->cbCluster);
1330	qcowTableMasksInit(pImage);
1331
1332	/* Init L1 table. */
1333	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1334	if (!pImage->paL1Table)
1335	{
1336	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("QCow: cannot allocate memory for L1 table of image '%s'"),
1337	pImage->pszFilename);
1338	goto out;
1339	}
1340
1341	rc = qcowL2TblCacheCreate(pImage);
1342	if (RT_FAILURE(rc))
1343	{
1344	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: Failed to create L2 cache for image '%s'"),
1345	pImage->pszFilename);
1346	goto out;
1347	}
1348
1349	if (RT_SUCCESS(rc) && pfnProgress)
1350	pfnProgress(pvUser, uPercentStart + uPercentSpan * 98 / 100);
1351
1352	rc = qcowFlushImage(pImage);
1353	if (RT_SUCCESS(rc))
1354	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pImage->offNextCluster);
1355
1356	out:
1357	if (RT_SUCCESS(rc) && pfnProgress)
1358	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1359
1360	if (RT_FAILURE(rc))
1361	qcowFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1362	return rc;
1363	}
1364
1365	/**
1366	* Rollback anything done during async cluster allocation.
1367	*
1368	* @returns VBox status code.
1369	* @param pImage The image instance data.
1370	* @param pIoCtx The I/O context.
1371	* @param pClusterAlloc The cluster allocation to rollback.
1372	*/
1373	static int qcowAsyncClusterAllocRollback(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, PQCOWCLUSTERASYNCALLOC pClusterAlloc)
1374	{
1375	RT_NOREF1(pIoCtx);
1376	int rc = VINF_SUCCESS;
1377
1378	switch (pClusterAlloc->enmAllocState)
1379	{
1380	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1381	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1382	{
1383	/* Assumption right now is that the L1 table is not modified if the link fails. */
1384	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1385	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1386	qcowL2TblCacheEntryFree(pImage, pClusterAlloc->pL2Entry); /* Free it, it is not in the cache yet. */
1387	break;
1388	}
1389	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1390	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1391	{
1392	/* Assumption right now is that the L2 table is not modified if the link fails. */
1393	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1394	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1395	break;
1396	}
1397	default:
1398	AssertMsgFailed(("Invalid cluster allocation state %d\n", pClusterAlloc->enmAllocState));
1399	rc = VERR_INVALID_STATE;
1400	}
1401
1402	RTMemFree(pClusterAlloc);
1403	return rc;
1404	}
1405
1406	/**
1407	* Updates the state of the async cluster allocation.
1408	*
1409	* @returns VBox status code.
1410	* @param pBackendData The opaque backend data.
1411	* @param pIoCtx I/O context associated with this request.
1412	* @param pvUser Opaque user data passed during a read/write request.
1413	* @param rcReq Status code for the completed request.
1414	*/
1415	static DECLCALLBACK(int) qcowAsyncClusterAllocUpdate(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
1416	{
1417	int rc = VINF_SUCCESS;
1418	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1419	PQCOWCLUSTERASYNCALLOC pClusterAlloc = (PQCOWCLUSTERASYNCALLOC)pvUser;
1420
1421	if (RT_FAILURE(rcReq))
1422	return qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1423
1424	AssertPtr(pClusterAlloc->pL2Entry);
1425
1426	switch (pClusterAlloc->enmAllocState)
1427	{
1428	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1429	{
1430	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->pL2Entry->offL2Tbl);
1431
1432	/* Update the link in the on disk L1 table now. */
1433	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_LINK;
1434	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1435	pImage->offL1Table + pClusterAlloc->idxL1*sizeof(uint64_t),
1436	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1437	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1438	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1439	break;
1440	else if (RT_FAILURE(rc))
1441	{
1442	/* Rollback. */
1443	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1444	break;
1445	}
1446	/* Success, fall through. */
1447	}
1448	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1449	{
1450	/* L2 link updated in L1 , save L2 entry in cache and allocate new user data cluster. */
1451	uint64_t offData = qcowClusterAllocate(pImage, 1);
1452
1453	/* Update the link in the in memory L1 table now. */
1454	pImage->paL1Table[pClusterAlloc->idxL1] = pClusterAlloc->pL2Entry->offL2Tbl;
1455	qcowL2TblCacheEntryInsert(pImage, pClusterAlloc->pL2Entry);
1456
1457	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1458	pClusterAlloc->offNextClusterOld = offData;
1459	pClusterAlloc->offClusterNew = offData;
1460
1461	/* Write data. */
1462	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1463	offData, pIoCtx, pClusterAlloc->cbToWrite,
1464	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1465	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1466	break;
1467	else if (RT_FAILURE(rc))
1468	{
1469	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1470	RTMemFree(pClusterAlloc);
1471	break;
1472	}
1473	}
1474	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1475	{
1476	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->offClusterNew);
1477
1478	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_LINK;
1479
1480	/* Link L2 table and update it. */
1481	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1482	pImage->paL1Table[pClusterAlloc->idxL1] + pClusterAlloc->idxL2*sizeof(uint64_t),
1483	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1484	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1485	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1486	break;
1487	else if (RT_FAILURE(rc))
1488	{
1489	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1490	RTMemFree(pClusterAlloc);
1491	break;
1492	}
1493	}
1494	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1495	{
1496	/* Everything done without errors, signal completion. */
1497	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = pClusterAlloc->offClusterNew;
1498	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry);
1499	RTMemFree(pClusterAlloc);
1500	rc = VINF_SUCCESS;
1501	break;
1502	}
1503	default:
1504	AssertMsgFailed(("Invalid async cluster allocation state %d\n",
1505	pClusterAlloc->enmAllocState));
1506	}
1507
1508	return rc;
1509	}
1510
1511	/** @copydoc VBOXHDDBACKEND::pfnCheckIfValid */
1512	static DECLCALLBACK(int) qcowCheckIfValid(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1513	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1514	{
1515	RT_NOREF1(pVDIfsDisk);
1516	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1517	PVDIOSTORAGE pStorage = NULL;
1518	uint64_t cbFile;
1519	int rc = VINF_SUCCESS;
1520
1521	/* Get I/O interface. */
1522	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1523	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1524
1525	if ( !VALID_PTR(pszFilename)
1526	\|\| !*pszFilename)
1527	{
1528	rc = VERR_INVALID_PARAMETER;
1529	goto out;
1530	}
1531
1532	/*
1533	* Open the file and read the footer.
1534	*/
1535	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1536	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1537	false /* fCreate */),
1538	&pStorage);
1539	if (RT_SUCCESS(rc))
1540	{
1541	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1542	if ( RT_SUCCESS(rc)
1543	&& cbFile > sizeof(QCowHeader))
1544	{
1545	QCowHeader Header;
1546
1547	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Header, sizeof(Header));
1548	if ( RT_SUCCESS(rc)
1549	&& qcowHdrConvertToHostEndianess(&Header))
1550	{
1551	*penmType = VDTYPE_HDD;
1552	rc = VINF_SUCCESS;
1553	}
1554	else
1555	rc = VERR_VD_GEN_INVALID_HEADER;
1556	}
1557	else
1558	rc = VERR_VD_GEN_INVALID_HEADER;
1559	}
1560
1561	if (pStorage)
1562	vdIfIoIntFileClose(pIfIo, pStorage);
1563
1564	out:
1565	LogFlowFunc(("returns %Rrc\n", rc));
1566	return rc;
1567	}
1568
1569	/** @copydoc VBOXHDDBACKEND::pfnOpen */
1570	static DECLCALLBACK(int) qcowOpen(const char *pszFilename, unsigned uOpenFlags,
1571	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1572	VDTYPE enmType, void **ppBackendData)
1573	{
1574	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p enmType=%u ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, enmType, ppBackendData));
1575	int rc;
1576	PQCOWIMAGE pImage;
1577
1578	NOREF(enmType); /*< @todo r=klaus make use of the type info. /
1579
1580	/* Check open flags. All valid flags are supported. */
1581	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1582	{
1583	rc = VERR_INVALID_PARAMETER;
1584	goto out;
1585	}
1586
1587	/* Check remaining arguments. */
1588	if ( !VALID_PTR(pszFilename)
1589	\|\| !*pszFilename)
1590	{
1591	rc = VERR_INVALID_PARAMETER;
1592	goto out;
1593	}
1594
1595
1596	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1597	if (!pImage)
1598	{
1599	rc = VERR_NO_MEMORY;
1600	goto out;
1601	}
1602	pImage->pszFilename = pszFilename;
1603	pImage->pStorage = NULL;
1604	pImage->pVDIfsDisk = pVDIfsDisk;
1605	pImage->pVDIfsImage = pVDIfsImage;
1606
1607	rc = qcowOpenImage(pImage, uOpenFlags);
1608	if (RT_SUCCESS(rc))
1609	*ppBackendData = pImage;
1610	else
1611	RTMemFree(pImage);
1612
1613	out:
1614	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1615	return rc;
1616	}
1617
1618	/** @copydoc VBOXHDDBACKEND::pfnCreate */
1619	static DECLCALLBACK(int) qcowCreate(const char *pszFilename, uint64_t cbSize,
1620	unsigned uImageFlags, const char *pszComment,
1621	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1622	PCRTUUID pUuid, unsigned uOpenFlags,
1623	unsigned uPercentStart, unsigned uPercentSpan,
1624	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1625	PVDINTERFACE pVDIfsOperation, VDTYPE enmType,
1626	void **ppBackendData)
1627	{
1628	RT_NOREF1(pUuid);
1629	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",
1630	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, enmType, ppBackendData));
1631	int rc;
1632	PQCOWIMAGE pImage;
1633
1634	PFNVDPROGRESS pfnProgress = NULL;
1635	void *pvUser = NULL;
1636	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1637	if (pIfProgress)
1638	{
1639	pfnProgress = pIfProgress->pfnProgress;
1640	pvUser = pIfProgress->Core.pvUser;
1641	}
1642
1643	/* Check the VD container type. */
1644	if (enmType != VDTYPE_HDD)
1645	{
1646	rc = VERR_VD_INVALID_TYPE;
1647	goto out;
1648	}
1649
1650	/* Check open flags. All valid flags are supported. */
1651	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1652	{
1653	rc = VERR_INVALID_PARAMETER;
1654	goto out;
1655	}
1656
1657	/* Check remaining arguments. */
1658	if ( !VALID_PTR(pszFilename)
1659	\|\| !*pszFilename
1660	\|\| !VALID_PTR(pPCHSGeometry)
1661	\|\| !VALID_PTR(pLCHSGeometry))
1662	{
1663	rc = VERR_INVALID_PARAMETER;
1664	goto out;
1665	}
1666
1667	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1668	if (!pImage)
1669	{
1670	rc = VERR_NO_MEMORY;
1671	goto out;
1672	}
1673	pImage->pszFilename = pszFilename;
1674	pImage->pStorage = NULL;
1675	pImage->pVDIfsDisk = pVDIfsDisk;
1676	pImage->pVDIfsImage = pVDIfsImage;
1677
1678	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1679	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1680	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1681	if (RT_SUCCESS(rc))
1682	{
1683	/* So far the image is opened in read/write mode. Make sure the
1684	* image is opened in read-only mode if the caller requested that. */
1685	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1686	{
1687	qcowFreeImage(pImage, false);
1688	rc = qcowOpenImage(pImage, uOpenFlags);
1689	if (RT_FAILURE(rc))
1690	{
1691	RTMemFree(pImage);
1692	goto out;
1693	}
1694	}
1695	*ppBackendData = pImage;
1696	}
1697	else
1698	RTMemFree(pImage);
1699
1700	out:
1701	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1702	return rc;
1703	}
1704
1705	/** @copydoc VBOXHDDBACKEND::pfnRename */
1706	static DECLCALLBACK(int) qcowRename(void pBackendData, const char pszFilename)
1707	{
1708	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1709	int rc = VINF_SUCCESS;
1710	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1711
1712	/* Check arguments. */
1713	if ( !pImage
1714	\|\| !pszFilename
1715	\|\| !*pszFilename)
1716	{
1717	rc = VERR_INVALID_PARAMETER;
1718	goto out;
1719	}
1720
1721	/* Close the image. */
1722	rc = qcowFreeImage(pImage, false);
1723	if (RT_FAILURE(rc))
1724	goto out;
1725
1726	/* Rename the file. */
1727	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1728	if (RT_FAILURE(rc))
1729	{
1730	/* The move failed, try to reopen the original image. */
1731	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1732	if (RT_FAILURE(rc2))
1733	rc = rc2;
1734
1735	goto out;
1736	}
1737
1738	/* Update pImage with the new information. */
1739	pImage->pszFilename = pszFilename;
1740
1741	/* Open the old image with new name. */
1742	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1743	if (RT_FAILURE(rc))
1744	goto out;
1745
1746	out:
1747	LogFlowFunc(("returns %Rrc\n", rc));
1748	return rc;
1749	}
1750
1751	/** @copydoc VBOXHDDBACKEND::pfnClose */
1752	static DECLCALLBACK(int) qcowClose(void *pBackendData, bool fDelete)
1753	{
1754	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1755	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1756	int rc;
1757
1758	rc = qcowFreeImage(pImage, fDelete);
1759	RTMemFree(pImage);
1760
1761	LogFlowFunc(("returns %Rrc\n", rc));
1762	return rc;
1763	}
1764
1765	static DECLCALLBACK(int) qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1766	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1767	{
1768	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1769	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1770	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1771	uint32_t offCluster = 0;
1772	uint32_t idxL1 = 0;
1773	uint32_t idxL2 = 0;
1774	uint64_t offFile = 0;
1775	int rc;
1776
1777	AssertPtr(pImage);
1778	Assert(uOffset % 512 == 0);
1779	Assert(cbToRead % 512 == 0);
1780
1781	if (!VALID_PTR(pIoCtx) \|\| !cbToRead)
1782	{
1783	rc = VERR_INVALID_PARAMETER;
1784	goto out;
1785	}
1786
1787	if ( uOffset + cbToRead > pImage->cbSize
1788	\|\| cbToRead == 0)
1789	{
1790	rc = VERR_INVALID_PARAMETER;
1791	goto out;
1792	}
1793
1794	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1795
1796	/* Clip read size to remain in the cluster. */
1797	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1798
1799	/* Get offset in image. */
1800	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1801	if (RT_SUCCESS(rc))
1802	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1803	pIoCtx, cbToRead);
1804
1805	if ( ( RT_SUCCESS(rc)
1806	\|\| rc == VERR_VD_BLOCK_FREE
1807	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1808	&& pcbActuallyRead)
1809	*pcbActuallyRead = cbToRead;
1810
1811	out:
1812	LogFlowFunc(("returns %Rrc\n", rc));
1813	return rc;
1814	}
1815
1816	static DECLCALLBACK(int) qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1817	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1818	size_t *pcbPostRead, unsigned fWrite)
1819	{
1820	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1821	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1822	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1823	uint32_t offCluster = 0;
1824	uint32_t idxL1 = 0;
1825	uint32_t idxL2 = 0;
1826	uint64_t offImage = 0;
1827	int rc = VINF_SUCCESS;
1828
1829	AssertPtr(pImage);
1830	Assert(!(uOffset % 512));
1831	Assert(!(cbToWrite % 512));
1832
1833	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1834	{
1835	rc = VERR_VD_IMAGE_READ_ONLY;
1836	goto out;
1837	}
1838
1839	if (!VALID_PTR(pIoCtx) \|\| !cbToWrite)
1840	{
1841	rc = VERR_INVALID_PARAMETER;
1842	goto out;
1843	}
1844
1845	if ( uOffset + cbToWrite > pImage->cbSize
1846	\|\| cbToWrite == 0)
1847	{
1848	rc = VERR_INVALID_PARAMETER;
1849	goto out;
1850	}
1851
1852	/* Convert offset to L1, L2 index and cluster offset. */
1853	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1854
1855	/* Clip write size to remain in the cluster. */
1856	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1857	Assert(!(cbToWrite % 512));
1858
1859	/* Get offset in image. */
1860	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1861	if (RT_SUCCESS(rc))
1862	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1863	offImage, pIoCtx, cbToWrite, NULL, NULL);
1864	else if (rc == VERR_VD_BLOCK_FREE)
1865	{
1866	if ( cbToWrite == pImage->cbCluster
1867	&& !(fWrite & VD_WRITE_NO_ALLOC))
1868	{
1869	PQCOWL2CACHEENTRY pL2Entry = NULL;
1870
1871	/* Full cluster write to previously unallocated cluster.
1872	* Allocate cluster and write data. */
1873	Assert(!offCluster);
1874
1875	do
1876	{
1877	/* Check if we have to allocate a new cluster for L2 tables. */
1878	if (!pImage->paL1Table[idxL1])
1879	{
1880	uint64_t offL2Tbl;
1881	PQCOWCLUSTERASYNCALLOC pL2ClusterAlloc = NULL;
1882
1883	/* Allocate new async cluster allocation state. */
1884	pL2ClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1885	if (RT_UNLIKELY(!pL2ClusterAlloc))
1886	{
1887	rc = VERR_NO_MEMORY;
1888	break;
1889	}
1890
1891	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
1892	if (!pL2Entry)
1893	{
1894	rc = VERR_NO_MEMORY;
1895	RTMemFree(pL2ClusterAlloc);
1896	break;
1897	}
1898
1899	offL2Tbl = qcowClusterAllocate(pImage, qcowByte2Cluster(pImage, pImage->cbL2Table));
1900	pL2Entry->offL2Tbl = offL2Tbl;
1901	memset(pL2Entry->paL2Tbl, 0, pImage->cbL2Table);
1902
1903	pL2ClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC;
1904	pL2ClusterAlloc->offNextClusterOld = offL2Tbl;
1905	pL2ClusterAlloc->offClusterNew = offL2Tbl;
1906	pL2ClusterAlloc->idxL1 = idxL1;
1907	pL2ClusterAlloc->idxL2 = idxL2;
1908	pL2ClusterAlloc->cbToWrite = cbToWrite;
1909	pL2ClusterAlloc->pL2Entry = pL2Entry;
1910
1911	/*
1912	* Write the L2 table first and link to the L1 table afterwards.
1913	* If something unexpected happens the worst case which can happen
1914	* is a leak of some clusters.
1915	*/
1916	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1917	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1918	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1919	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1920	break;
1921	else if (RT_FAILURE(rc))
1922	{
1923	RTMemFree(pL2ClusterAlloc);
1924	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1925	break;
1926	}
1927
1928	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1929	}
1930	else
1931	{
1932	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1933	&pL2Entry);
1934	if (RT_SUCCESS(rc))
1935	{
1936	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1937
1938	/* Allocate new async cluster allocation state. */
1939	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1940	if (RT_UNLIKELY(!pDataClusterAlloc))
1941	{
1942	rc = VERR_NO_MEMORY;
1943	break;
1944	}
1945
1946	/* Allocate new cluster for the data. */
1947	uint64_t offData = qcowClusterAllocate(pImage, 1);
1948
1949	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1950	pDataClusterAlloc->offNextClusterOld = offData;
1951	pDataClusterAlloc->offClusterNew = offData;
1952	pDataClusterAlloc->idxL1 = idxL1;
1953	pDataClusterAlloc->idxL2 = idxL2;
1954	pDataClusterAlloc->cbToWrite = cbToWrite;
1955	pDataClusterAlloc->pL2Entry = pL2Entry;
1956
1957	/* Write data. */
1958	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1959	offData, pIoCtx, cbToWrite,
1960	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1961	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1962	break;
1963	else if (RT_FAILURE(rc))
1964	{
1965	RTMemFree(pDataClusterAlloc);
1966	break;
1967	}
1968
1969	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1970	}
1971	}
1972
1973	} while (0);
1974
1975	*pcbPreRead = 0;
1976	*pcbPostRead = 0;
1977	}
1978	else
1979	{
1980	/* Trying to do a partial write to an unallocated cluster. Don't do
1981	* anything except letting the upper layer know what to do. */
1982	*pcbPreRead = offCluster;
1983	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
1984	}
1985	}
1986
1987	if (pcbWriteProcess)
1988	*pcbWriteProcess = cbToWrite;
1989
1990
1991	out:
1992	LogFlowFunc(("returns %Rrc\n", rc));
1993	return rc;
1994	}
1995
1996	static DECLCALLBACK(int) qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
1997	{
1998	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1999	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2000	int rc = VINF_SUCCESS;
2001
2002	Assert(pImage);
2003
2004	if (VALID_PTR(pIoCtx))
2005	rc = qcowFlushImageAsync(pImage, pIoCtx);
2006	else
2007	rc = VERR_INVALID_PARAMETER;
2008
2009	LogFlowFunc(("returns %Rrc\n", rc));
2010	return rc;
2011	}
2012
2013	/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
2014	static DECLCALLBACK(unsigned) qcowGetVersion(void *pBackendData)
2015	{
2016	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2017	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2018
2019	AssertPtr(pImage);
2020
2021	if (pImage)
2022	return pImage->uVersion;
2023	else
2024	return 0;
2025	}
2026
2027	/** @copydoc VBOXHDDBACKEND::pfnGetSectorSize */
2028	static DECLCALLBACK(uint32_t) qcowGetSectorSize(void *pBackendData)
2029	{
2030	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2031	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2032	uint32_t cb = 0;
2033
2034	AssertPtr(pImage);
2035
2036	if (pImage && pImage->pStorage)
2037	cb = 512;
2038
2039	LogFlowFunc(("returns %u\n", cb));
2040	return cb;
2041	}
2042
2043	/** @copydoc VBOXHDDBACKEND::pfnGetSize */
2044	static DECLCALLBACK(uint64_t) qcowGetSize(void *pBackendData)
2045	{
2046	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2047	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2048	uint64_t cb = 0;
2049
2050	AssertPtr(pImage);
2051
2052	if (pImage && pImage->pStorage)
2053	cb = pImage->cbSize;
2054
2055	LogFlowFunc(("returns %llu\n", cb));
2056	return cb;
2057	}
2058
2059	/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
2060	static DECLCALLBACK(uint64_t) qcowGetFileSize(void *pBackendData)
2061	{
2062	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2063	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2064	uint64_t cb = 0;
2065
2066	AssertPtr(pImage);
2067
2068	if (pImage)
2069	{
2070	uint64_t cbFile;
2071	if (pImage->pStorage)
2072	{
2073	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
2074	if (RT_SUCCESS(rc))
2075	cb += cbFile;
2076	}
2077	}
2078
2079	LogFlowFunc(("returns %lld\n", cb));
2080	return cb;
2081	}
2082
2083	/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
2084	static DECLCALLBACK(int) qcowGetPCHSGeometry(void *pBackendData,
2085	PVDGEOMETRY pPCHSGeometry)
2086	{
2087	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
2088	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2089	int rc;
2090
2091	AssertPtr(pImage);
2092
2093	if (pImage)
2094	{
2095	if (pImage->PCHSGeometry.cCylinders)
2096	{
2097	*pPCHSGeometry = pImage->PCHSGeometry;
2098	rc = VINF_SUCCESS;
2099	}
2100	else
2101	rc = VERR_VD_GEOMETRY_NOT_SET;
2102	}
2103	else
2104	rc = VERR_VD_NOT_OPENED;
2105
2106	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2107	return rc;
2108	}
2109
2110	/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
2111	static DECLCALLBACK(int) qcowSetPCHSGeometry(void *pBackendData,
2112	PCVDGEOMETRY pPCHSGeometry)
2113	{
2114	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2115	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2116	int rc;
2117
2118	AssertPtr(pImage);
2119
2120	if (pImage)
2121	{
2122	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2123	{
2124	rc = VERR_VD_IMAGE_READ_ONLY;
2125	goto out;
2126	}
2127
2128	pImage->PCHSGeometry = *pPCHSGeometry;
2129	rc = VINF_SUCCESS;
2130	}
2131	else
2132	rc = VERR_VD_NOT_OPENED;
2133
2134	out:
2135	LogFlowFunc(("returns %Rrc\n", rc));
2136	return rc;
2137	}
2138
2139	/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
2140	static DECLCALLBACK(int) qcowGetLCHSGeometry(void *pBackendData,
2141	PVDGEOMETRY pLCHSGeometry)
2142	{
2143	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2144	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2145	int rc;
2146
2147	AssertPtr(pImage);
2148
2149	if (pImage)
2150	{
2151	if (pImage->LCHSGeometry.cCylinders)
2152	{
2153	*pLCHSGeometry = pImage->LCHSGeometry;
2154	rc = VINF_SUCCESS;
2155	}
2156	else
2157	rc = VERR_VD_GEOMETRY_NOT_SET;
2158	}
2159	else
2160	rc = VERR_VD_NOT_OPENED;
2161
2162	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2163	return rc;
2164	}
2165
2166	/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
2167	static DECLCALLBACK(int) qcowSetLCHSGeometry(void *pBackendData,
2168	PCVDGEOMETRY pLCHSGeometry)
2169	{
2170	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData, pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2171	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2172	int rc;
2173
2174	AssertPtr(pImage);
2175
2176	if (pImage)
2177	{
2178	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2179	{
2180	rc = VERR_VD_IMAGE_READ_ONLY;
2181	goto out;
2182	}
2183
2184	pImage->LCHSGeometry = *pLCHSGeometry;
2185	rc = VINF_SUCCESS;
2186	}
2187	else
2188	rc = VERR_VD_NOT_OPENED;
2189
2190	out:
2191	LogFlowFunc(("returns %Rrc\n", rc));
2192	return rc;
2193	}
2194
2195	/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
2196	static DECLCALLBACK(unsigned) qcowGetImageFlags(void *pBackendData)
2197	{
2198	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2199	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2200	unsigned uImageFlags;
2201
2202	AssertPtr(pImage);
2203
2204	if (pImage)
2205	uImageFlags = pImage->uImageFlags;
2206	else
2207	uImageFlags = 0;
2208
2209	LogFlowFunc(("returns %#x\n", uImageFlags));
2210	return uImageFlags;
2211	}
2212
2213	/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
2214	static DECLCALLBACK(unsigned) qcowGetOpenFlags(void *pBackendData)
2215	{
2216	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2217	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2218	unsigned uOpenFlags;
2219
2220	AssertPtr(pImage);
2221
2222	if (pImage)
2223	uOpenFlags = pImage->uOpenFlags;
2224	else
2225	uOpenFlags = 0;
2226
2227	LogFlowFunc(("returns %#x\n", uOpenFlags));
2228	return uOpenFlags;
2229	}
2230
2231	/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
2232	static DECLCALLBACK(int) qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2233	{
2234	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2235	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2236	int rc;
2237
2238	/* Image must be opened and the new flags must be valid. */
2239	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2240	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2241	{
2242	rc = VERR_INVALID_PARAMETER;
2243	goto out;
2244	}
2245
2246	/* Implement this operation via reopening the image. */
2247	rc = qcowFreeImage(pImage, false);
2248	if (RT_FAILURE(rc))
2249	goto out;
2250	rc = qcowOpenImage(pImage, uOpenFlags);
2251
2252	out:
2253	LogFlowFunc(("returns %Rrc\n", rc));
2254	return rc;
2255	}
2256
2257	/** @copydoc VBOXHDDBACKEND::pfnGetComment */
2258	static DECLCALLBACK(int) qcowGetComment(void pBackendData, char pszComment, size_t cbComment)
2259	{
2260	RT_NOREF2(pszComment, cbComment);
2261	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2262	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2263	int rc;
2264
2265	AssertPtr(pImage);
2266
2267	if (pImage)
2268	rc = VERR_NOT_SUPPORTED;
2269	else
2270	rc = VERR_VD_NOT_OPENED;
2271
2272	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
2273	return rc;
2274	}
2275
2276	/** @copydoc VBOXHDDBACKEND::pfnSetComment */
2277	static DECLCALLBACK(int) qcowSetComment(void pBackendData, const char pszComment)
2278	{
2279	RT_NOREF1(pszComment);
2280	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2281	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2282	int rc;
2283
2284	AssertPtr(pImage);
2285
2286	if (pImage)
2287	{
2288	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2289	rc = VERR_VD_IMAGE_READ_ONLY;
2290	else
2291	rc = VERR_NOT_SUPPORTED;
2292	}
2293	else
2294	rc = VERR_VD_NOT_OPENED;
2295
2296	LogFlowFunc(("returns %Rrc\n", rc));
2297	return rc;
2298	}
2299
2300	/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
2301	static DECLCALLBACK(int) qcowGetUuid(void *pBackendData, PRTUUID pUuid)
2302	{
2303	RT_NOREF1(pUuid);
2304	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2305	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2306	int rc;
2307
2308	AssertPtr(pImage);
2309
2310	if (pImage)
2311	rc = VERR_NOT_SUPPORTED;
2312	else
2313	rc = VERR_VD_NOT_OPENED;
2314
2315	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2316	return rc;
2317	}
2318
2319	/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
2320	static DECLCALLBACK(int) qcowSetUuid(void *pBackendData, PCRTUUID pUuid)
2321	{
2322	RT_NOREF1(pUuid);
2323	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2324	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2325	int rc;
2326
2327	LogFlowFunc(("%RTuuid\n", pUuid));
2328	AssertPtr(pImage);
2329
2330	if (pImage)
2331	{
2332	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2333	rc = VERR_NOT_SUPPORTED;
2334	else
2335	rc = VERR_VD_IMAGE_READ_ONLY;
2336	}
2337	else
2338	rc = VERR_VD_NOT_OPENED;
2339
2340	LogFlowFunc(("returns %Rrc\n", rc));
2341	return rc;
2342	}
2343
2344	/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
2345	static DECLCALLBACK(int) qcowGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2346	{
2347	RT_NOREF1(pUuid);
2348	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2349	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2350	int rc;
2351
2352	AssertPtr(pImage);
2353
2354	if (pImage)
2355	rc = VERR_NOT_SUPPORTED;
2356	else
2357	rc = VERR_VD_NOT_OPENED;
2358
2359	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2360	return rc;
2361	}
2362
2363	/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
2364	static DECLCALLBACK(int) qcowSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2365	{
2366	RT_NOREF1(pUuid);
2367	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2368	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2369	int rc;
2370
2371	AssertPtr(pImage);
2372
2373	if (pImage)
2374	{
2375	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2376	rc = VERR_NOT_SUPPORTED;
2377	else
2378	rc = VERR_VD_IMAGE_READ_ONLY;
2379	}
2380	else
2381	rc = VERR_VD_NOT_OPENED;
2382
2383	LogFlowFunc(("returns %Rrc\n", rc));
2384	return rc;
2385	}
2386
2387	/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
2388	static DECLCALLBACK(int) qcowGetParentUuid(void *pBackendData, PRTUUID pUuid)
2389	{
2390	RT_NOREF1(pUuid);
2391	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2392	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2393	int rc;
2394
2395	AssertPtr(pImage);
2396
2397	if (pImage)
2398	rc = VERR_NOT_SUPPORTED;
2399	else
2400	rc = VERR_VD_NOT_OPENED;
2401
2402	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2403	return rc;
2404	}
2405
2406	/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
2407	static DECLCALLBACK(int) qcowSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2408	{
2409	RT_NOREF1(pUuid);
2410	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2411	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2412	int rc;
2413
2414	AssertPtr(pImage);
2415
2416	if (pImage)
2417	{
2418	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2419	rc = VERR_NOT_SUPPORTED;
2420	else
2421	rc = VERR_VD_IMAGE_READ_ONLY;
2422	}
2423	else
2424	rc = VERR_VD_NOT_OPENED;
2425
2426	LogFlowFunc(("returns %Rrc\n", rc));
2427	return rc;
2428	}
2429
2430	/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
2431	static DECLCALLBACK(int) qcowGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2432	{
2433	RT_NOREF1(pUuid);
2434	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2435	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2436	int rc;
2437
2438	AssertPtr(pImage);
2439
2440	if (pImage)
2441	rc = VERR_NOT_SUPPORTED;
2442	else
2443	rc = VERR_VD_NOT_OPENED;
2444
2445	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2446	return rc;
2447	}
2448
2449	/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
2450	static DECLCALLBACK(int) qcowSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2451	{
2452	RT_NOREF1(pUuid);
2453	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2454	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2455	int rc;
2456
2457	AssertPtr(pImage);
2458
2459	if (pImage)
2460	{
2461	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2462	rc = VERR_NOT_SUPPORTED;
2463	else
2464	rc = VERR_VD_IMAGE_READ_ONLY;
2465	}
2466	else
2467	rc = VERR_VD_NOT_OPENED;
2468
2469	LogFlowFunc(("returns %Rrc\n", rc));
2470	return rc;
2471	}
2472
2473	/** @copydoc VBOXHDDBACKEND::pfnDump */
2474	static DECLCALLBACK(void) qcowDump(void *pBackendData)
2475	{
2476	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2477
2478	AssertPtr(pImage);
2479	if (pImage)
2480	{
2481	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cSector=%llu\n",
2482	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2483	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2484	pImage->cbSize / 512);
2485	}
2486	}
2487
2488	/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
2489	static DECLCALLBACK(int) qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2490	{
2491	int rc = VINF_SUCCESS;
2492	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2493
2494	AssertPtr(pImage);
2495	if (pImage)
2496	if (pImage->pszBackingFilename)
2497	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2498	else
2499	rc = VERR_NOT_SUPPORTED;
2500	else
2501	rc = VERR_VD_NOT_OPENED;
2502
2503	LogFlowFunc(("returns %Rrc\n", rc));
2504	return rc;
2505	}
2506
2507	/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
2508	static DECLCALLBACK(int) qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2509	{
2510	int rc = VINF_SUCCESS;
2511	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2512
2513	AssertPtr(pImage);
2514	if (pImage)
2515	{
2516	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2517	rc = VERR_VD_IMAGE_READ_ONLY;
2518	else if ( pImage->pszBackingFilename
2519	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2520	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2521	else
2522	{
2523	if (pImage->pszBackingFilename)
2524	RTStrFree(pImage->pszBackingFilename);
2525	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2526	if (!pImage->pszBackingFilename)
2527	rc = VERR_NO_MEMORY;
2528	else
2529	{
2530	if (!pImage->offBackingFilename)
2531	{
2532	/* Allocate new cluster. */
2533	uint64_t offData = qcowClusterAllocate(pImage, 1);
2534
2535	Assert((offData & UINT32_MAX) == offData);
2536	pImage->offBackingFilename = (uint32_t)offData;
2537	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2538	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2539	offData + pImage->cbCluster);
2540	}
2541
2542	if (RT_SUCCESS(rc))
2543	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2544	pImage->offBackingFilename,
2545	pImage->pszBackingFilename,
2546	strlen(pImage->pszBackingFilename));
2547	}
2548	}
2549	}
2550	else
2551	rc = VERR_VD_NOT_OPENED;
2552
2553	LogFlowFunc(("returns %Rrc\n", rc));
2554	return rc;
2555	}
2556
2557
2558
2559	const VBOXHDDBACKEND g_QCowBackend =
2560	{
2561	/* pszBackendName */
2562	"QCOW",
2563	/* cbSize */
2564	sizeof(VBOXHDDBACKEND),
2565	/* uBackendCaps */
2566	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2567	/* paFileExtensions */
2568	s_aQCowFileExtensions,
2569	/* paConfigInfo */
2570	NULL,
2571	/* pfnCheckIfValid */
2572	qcowCheckIfValid,
2573	/* pfnOpen */
2574	qcowOpen,
2575	/* pfnCreate */
2576	qcowCreate,
2577	/* pfnRename */
2578	qcowRename,
2579	/* pfnClose */
2580	qcowClose,
2581	/* pfnRead */
2582	qcowRead,
2583	/* pfnWrite */
2584	qcowWrite,
2585	/* pfnFlush */
2586	qcowFlush,
2587	/* pfnDiscard */
2588	NULL,
2589	/* pfnGetVersion */
2590	qcowGetVersion,
2591	/* pfnGetSectorSize */
2592	qcowGetSectorSize,
2593	/* pfnGetSize */
2594	qcowGetSize,
2595	/* pfnGetFileSize */
2596	qcowGetFileSize,
2597	/* pfnGetPCHSGeometry */
2598	qcowGetPCHSGeometry,
2599	/* pfnSetPCHSGeometry */
2600	qcowSetPCHSGeometry,
2601	/* pfnGetLCHSGeometry */
2602	qcowGetLCHSGeometry,
2603	/* pfnSetLCHSGeometry */
2604	qcowSetLCHSGeometry,
2605	/* pfnGetImageFlags */
2606	qcowGetImageFlags,
2607	/* pfnGetOpenFlags */
2608	qcowGetOpenFlags,
2609	/* pfnSetOpenFlags */
2610	qcowSetOpenFlags,
2611	/* pfnGetComment */
2612	qcowGetComment,
2613	/* pfnSetComment */
2614	qcowSetComment,
2615	/* pfnGetUuid */
2616	qcowGetUuid,
2617	/* pfnSetUuid */
2618	qcowSetUuid,
2619	/* pfnGetModificationUuid */
2620	qcowGetModificationUuid,
2621	/* pfnSetModificationUuid */
2622	qcowSetModificationUuid,
2623	/* pfnGetParentUuid */
2624	qcowGetParentUuid,
2625	/* pfnSetParentUuid */
2626	qcowSetParentUuid,
2627	/* pfnGetParentModificationUuid */
2628	qcowGetParentModificationUuid,
2629	/* pfnSetParentModificationUuid */
2630	qcowSetParentModificationUuid,
2631	/* pfnDump */
2632	qcowDump,
2633	/* pfnGetTimestamp */
2634	NULL,
2635	/* pfnGetParentTimestamp */
2636	NULL,
2637	/* pfnSetParentTimestamp */
2638	NULL,
2639	/* pfnGetParentFilename */
2640	qcowGetParentFilename,
2641	/* pfnSetParentFilename */
2642	qcowSetParentFilename,
2643	/* pfnComposeLocation */
2644	genericFileComposeLocation,
2645	/* pfnComposeName */
2646	genericFileComposeName,
2647	/* pfnCompact */
2648	NULL,
2649	/* pfnResize */
2650	NULL,
2651	/* pfnRepair */
2652	NULL,
2653	/* pfnTraverseMetadata */
2654	NULL
2655	};

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source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 63714

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