QCOW.cpp@ 49439

Last change on this file since 49439 was 48851, checked in by vboxsync, 11 years ago
Storage: Addressing 64-bit windows warnings.
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1	/* $Id: QCOW.cpp 48851 2013-10-03 20:02:34Z vboxsync $ */
2	/** @file
3	* QCOW - QCOW Disk image.
4	*/
5
6	/*
7	* Copyright (C) 2011-2013 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	* Header Files *
20	*******************************************************************************/
21	#define LOG_GROUP LOG_GROUP_VD_QCOW
22	#include <VBox/vd-plugin.h>
23	#include <VBox/err.h>
24
25	#include <VBox/log.h>
26	#include <iprt/asm.h>
27	#include <iprt/assert.h>
28	#include <iprt/string.h>
29	#include <iprt/alloc.h>
30	#include <iprt/path.h>
31	#include <iprt/list.h>
32
33	/**
34	* The QCOW backend implements support for the qemu copy on write format (short QCOW)
35	* There is no official specification available but the format is described
36	* at http://people.gnome.org/~markmc/qcow-image-format.html for version 2
37	* and http://people.gnome.org/~markmc/qcow-image-format-version-1.html for version 1.
38	*
39	* Missing things to implement:
40	* - v2 image creation and handling of the reference count table. (Blocker to enable support for V2 images)
41	* - cluster encryption
42	* - cluster compression
43	* - compaction
44	* - resizing
45	*/
46
47	/*******************************************************************************
48	* Structures in a QCOW image, big endian *
49	*******************************************************************************/
50
51	#pragma pack(1)
52	typedef struct QCowHeader
53	{
54	/** Magic value. */
55	uint32_t u32Magic;
56	/** Version of the image. */
57	uint32_t u32Version;
58	/** Version dependent data. */
59	union
60	{
61	/** Version 1. */
62	struct
63	{
64	/** Backing file offset. */
65	uint64_t u64BackingFileOffset;
66	/** Size of the backing file. */
67	uint32_t u32BackingFileSize;
68	/** mtime (Modification time?) - can be ignored. */
69	uint32_t u32MTime;
70	/** Logical size of the image in bytes. */
71	uint64_t u64Size;
72	/** Number of bits in the virtual offset used as a cluster offset. */
73	uint8_t u8ClusterBits;
74	/** Number of bits in the virtual offset used for the L2 index. */
75	uint8_t u8L2Bits;
76	/** Padding because the header is not packed in the original source. */
77	uint16_t u16Padding;
78	/** Used cryptographic method. */
79	uint32_t u32CryptMethod;
80	/** Offset of the L1 table in the image in bytes. */
81	uint64_t u64L1TableOffset;
82	} v1;
83	/** Version 2. */
84	struct
85	{
86	/** Backing file offset. */
87	uint64_t u64BackingFileOffset;
88	/** Size of the backing file. */
89	uint32_t u32BackingFileSize;
90	/** Number of bits in the virtual offset used as a cluster offset. */
91	uint32_t u32ClusterBits;
92	/** Logical size of the image. */
93	uint64_t u64Size;
94	/** Used cryptographic method. */
95	uint32_t u32CryptMethod;
96	/** Size of the L1 table in entries (each 8bytes big). */
97	uint32_t u32L1Size;
98	/** Offset of the L1 table in the image in bytes. */
99	uint64_t u64L1TableOffset;
100	/** Start of the refcount table in the image. */
101	uint64_t u64RefcountTableOffset;
102	/** Size of the refcount table in clusters. */
103	uint32_t u32RefcountTableClusters;
104	/** Number of snapshots in the image. */
105	uint32_t u32NbSnapshots;
106	/** Offset of the first snapshot header in the image. */
107	uint64_t u64SnapshotsOffset;
108	} v2;
109	} Version;
110	} QCowHeader;
111	#pragma pack()
112	/** Pointer to a on disk QCOW header. */
113	typedef QCowHeader *PQCowHeader;
114
115	/** QCOW magic value. */
116	#define QCOW_MAGIC UINT32_C(0x514649fb) /* QFI\0xfb */
117	/** Size of the V1 header. */
118	#define QCOW_V1_HDR_SIZE (48)
119	/** Size of the V2 header. */
120	#define QCOW_V2_HDR_SIZE (72)
121
122	/** Cluster is compressed flag for QCOW images. */
123	#define QCOW_V1_COMPRESSED_FLAG RT_BIT_64(63)
124
125	/** Copied flag for QCOW2 images. */
126	#define QCOW_V2_COPIED_FLAG RT_BIT_64(63)
127	/** Cluster is compressed flag for QCOW2 images. */
128	#define QCOW_V2_COMPRESSED_FLAG RT_BIT_64(62)
129
130
131	/*******************************************************************************
132	* Constants And Macros, Structures and Typedefs *
133	*******************************************************************************/
134
135	/**
136	* QCOW L2 cache entry.
137	*/
138	typedef struct QCOWL2CACHEENTRY
139	{
140	/** List node for the search list. */
141	RTLISTNODE NodeSearch;
142	/** List node for the LRU list. */
143	RTLISTNODE NodeLru;
144	/** Reference counter. */
145	uint32_t cRefs;
146	/** The offset of the L2 table, used as search key. */
147	uint64_t offL2Tbl;
148	/** Pointer to the cached L2 table. */
149	uint64_t *paL2Tbl;
150	} QCOWL2CACHEENTRY, *PQCOWL2CACHEENTRY;
151
152	/** Maximum amount of memory the cache is allowed to use. */
153	#define QCOW_L2_CACHE_MEMORY_MAX (2*_1M)
154
155	/** QCOW default cluster size for image version 2. */
156	#define QCOW2_CLUSTER_SIZE_DEFAULT (64*_1K)
157	/** QCOW default cluster size for image version 1. */
158	#define QCOW_CLUSTER_SIZE_DEFAULT (4*_1K)
159	/** QCOW default L2 table size in clusters. */
160	#define QCOW_L2_CLUSTERS_DEFAULT (1)
161
162	/**
163	* QCOW image data structure.
164	*/
165	typedef struct QCOWIMAGE
166	{
167	/** Image name. */
168	const char *pszFilename;
169	/** Storage handle. */
170	PVDIOSTORAGE pStorage;
171
172	/** Pointer to the per-disk VD interface list. */
173	PVDINTERFACE pVDIfsDisk;
174	/** Pointer to the per-image VD interface list. */
175	PVDINTERFACE pVDIfsImage;
176	/** Error interface. */
177	PVDINTERFACEERROR pIfError;
178	/** I/O interface. */
179	PVDINTERFACEIOINT pIfIo;
180
181	/** Open flags passed by VBoxHD layer. */
182	unsigned uOpenFlags;
183	/** Image flags defined during creation or determined during open. */
184	unsigned uImageFlags;
185	/** Total size of the image. */
186	uint64_t cbSize;
187	/** Physical geometry of this image. */
188	VDGEOMETRY PCHSGeometry;
189	/** Logical geometry of this image. */
190	VDGEOMETRY LCHSGeometry;
191
192	/** Image version. */
193	unsigned uVersion;
194	/** MTime field - used only to preserve value in opened images, unmodified otherwise. */
195	uint32_t MTime;
196
197	/** Filename of the backing file if any. */
198	char *pszBackingFilename;
199	/** Offset of the filename in the image. */
200	uint64_t offBackingFilename;
201	/** Size of the backing filename excluding \0. */
202	uint32_t cbBackingFilename;
203
204	/** Next offset of a new cluster, aligned to sector size. */
205	uint64_t offNextCluster;
206	/** Cluster size in bytes. */
207	uint32_t cbCluster;
208	/** Number of entries in the L1 table. */
209	uint32_t cL1TableEntries;
210	/** Size of an L1 rounded to the next cluster size. */
211	uint32_t cbL1Table;
212	/** Pointer to the L1 table. */
213	uint64_t *paL1Table;
214	/** Offset of the L1 table. */
215	uint64_t offL1Table;
216
217	/** Size of the L2 table in bytes. */
218	uint32_t cbL2Table;
219	/** Number of entries in the L2 table. */
220	uint32_t cL2TableEntries;
221	/** Memory occupied by the L2 table cache. */
222	size_t cbL2Cache;
223	/** The sorted L2 entry list used for searching. */
224	RTLISTNODE ListSearch;
225	/** The LRU L2 entry list used for eviction. */
226	RTLISTNODE ListLru;
227
228	/** Offset of the refcount table. */
229	uint64_t offRefcountTable;
230	/** Size of the refcount table in bytes. */
231	uint32_t cbRefcountTable;
232	/** Number of entries in the refcount table. */
233	uint32_t cRefcountTableEntries;
234	/** Pointer to the refcount table. */
235	uint64_t *paRefcountTable;
236
237	/** Offset mask for a cluster. */
238	uint64_t fOffsetMask;
239	/** Number of bits to shift to get the L1 index. */
240	uint32_t cL1Shift;
241	/** L2 table mask to get the L2 index. */
242	uint64_t fL2Mask;
243	/** Number of bits to shift to get the L2 index. */
244	uint32_t cL2Shift;
245
246	} QCOWIMAGE, *PQCOWIMAGE;
247
248	/**
249	* State of the async cluster allocation.
250	*/
251	typedef enum QCOWCLUSTERASYNCALLOCSTATE
252	{
253	/** Invalid. */
254	QCOWCLUSTERASYNCALLOCSTATE_INVALID = 0,
255	/** L2 table allocation. */
256	QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC,
257	/** Link L2 table into L1. */
258	QCOWCLUSTERASYNCALLOCSTATE_L2_LINK,
259	/** Allocate user data cluster. */
260	QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC,
261	/** Link user data cluster. */
262	QCOWCLUSTERASYNCALLOCSTATE_USER_LINK,
263	/** 32bit blowup. */
264	QCOWCLUSTERASYNCALLOCSTATE_32BIT_HACK = 0x7fffffff
265	} QCOWCLUSTERASYNCALLOCSTATE, *PQCOWCLUSTERASYNCALLOCSTATE;
266
267	/**
268	* Data needed to track async cluster allocation.
269	*/
270	typedef struct QCOWCLUSTERASYNCALLOC
271	{
272	/** The state of the cluster allocation. */
273	QCOWCLUSTERASYNCALLOCSTATE enmAllocState;
274	/** Old image size to rollback in case of an error. */
275	uint64_t offNextClusterOld;
276	/** L1 index to link if any. */
277	uint32_t idxL1;
278	/** L2 index to link, required in any case. */
279	uint32_t idxL2;
280	/** Start offset of the allocated cluster. */
281	uint64_t offClusterNew;
282	/** L2 cache entry if a L2 table is allocated. */
283	PQCOWL2CACHEENTRY pL2Entry;
284	/** Number of bytes to write. */
285	size_t cbToWrite;
286	} QCOWCLUSTERASYNCALLOC, *PQCOWCLUSTERASYNCALLOC;
287
288	/*******************************************************************************
289	* Static Variables *
290	*******************************************************************************/
291
292	/** NULL-terminated array of supported file extensions. */
293	static const VDFILEEXTENSION s_aQCowFileExtensions[] =
294	{
295	{"qcow", VDTYPE_HDD},
296	{"qcow2", VDTYPE_HDD},
297	{NULL, VDTYPE_INVALID}
298	};
299
300	/*******************************************************************************
301	* Internal Functions *
302	*******************************************************************************/
303
304	/**
305	* Return power of 2 or 0 if num error.
306	*
307	* @returns The power of 2 or 0 if the given number is not a power of 2.
308	* @param u32 The number.
309	*/
310	static uint32_t qcowGetPowerOfTwo(uint32_t u32)
311	{
312	if (u32 == 0)
313	return 0;
314	uint32_t uPower2 = 0;
315	while ((u32 & 1) == 0)
316	{
317	u32 >>= 1;
318	uPower2++;
319	}
320	return u32 == 1 ? uPower2 : 0;
321	}
322
323
324	/**
325	* Converts the image header to the host endianess and performs basic checks.
326	*
327	* @returns Whether the given header is valid or not.
328	* @param pHeader Pointer to the header to convert.
329	*/
330	static bool qcowHdrConvertToHostEndianess(PQCowHeader pHeader)
331	{
332	pHeader->u32Magic = RT_BE2H_U32(pHeader->u32Magic);
333	pHeader->u32Version = RT_BE2H_U32(pHeader->u32Version);
334
335	if (pHeader->u32Magic != QCOW_MAGIC)
336	return false;
337
338	if (pHeader->u32Version == 1)
339	{
340	pHeader->Version.v1.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v1.u64BackingFileOffset);
341	pHeader->Version.v1.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v1.u32BackingFileSize);
342	pHeader->Version.v1.u32MTime = RT_BE2H_U32(pHeader->Version.v1.u32MTime);
343	pHeader->Version.v1.u64Size = RT_BE2H_U64(pHeader->Version.v1.u64Size);
344	pHeader->Version.v1.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v1.u32CryptMethod);
345	pHeader->Version.v1.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v1.u64L1TableOffset);
346	}
347	else if (pHeader->u32Version == 2)
348	{
349	pHeader->Version.v2.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v2.u64BackingFileOffset);
350	pHeader->Version.v2.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v2.u32BackingFileSize);
351	pHeader->Version.v2.u32ClusterBits = RT_BE2H_U32(pHeader->Version.v2.u32ClusterBits);
352	pHeader->Version.v2.u64Size = RT_BE2H_U64(pHeader->Version.v2.u64Size);
353	pHeader->Version.v2.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v2.u32CryptMethod);
354	pHeader->Version.v2.u32L1Size = RT_BE2H_U32(pHeader->Version.v2.u32L1Size);
355	pHeader->Version.v2.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v2.u64L1TableOffset);
356	pHeader->Version.v2.u64RefcountTableOffset = RT_BE2H_U64(pHeader->Version.v2.u64RefcountTableOffset);
357	pHeader->Version.v2.u32RefcountTableClusters = RT_BE2H_U32(pHeader->Version.v2.u32RefcountTableClusters);
358	pHeader->Version.v2.u32NbSnapshots = RT_BE2H_U32(pHeader->Version.v2.u32NbSnapshots);
359	pHeader->Version.v2.u64SnapshotsOffset = RT_BE2H_U64(pHeader->Version.v2.u64SnapshotsOffset);
360	}
361	else
362	return false;
363
364	return true;
365	}
366
367	/**
368	* Creates a QCOW header from the given image state.
369	*
370	* @returns nothing.
371	* @param pImage Image instance data.
372	* @param pHeader Pointer to the header to convert.
373	* @param pcbHeader Where to store the size of the header to write.
374	*/
375	static void qcowHdrConvertFromHostEndianess(PQCOWIMAGE pImage, PQCowHeader pHeader,
376	size_t *pcbHeader)
377	{
378	memset(pHeader, 0, sizeof(QCowHeader));
379
380	pHeader->u32Magic = RT_H2BE_U32(QCOW_MAGIC);
381	pHeader->u32Version = RT_H2BE_U32(pImage->uVersion);
382	if (pImage->uVersion == 1)
383	{
384	pHeader->Version.v1.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
385	pHeader->Version.v1.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
386	pHeader->Version.v1.u32MTime = RT_H2BE_U32(pImage->MTime);
387	pHeader->Version.v1.u64Size = RT_H2BE_U64(pImage->cbSize);
388	pHeader->Version.v1.u8ClusterBits = (uint8_t)qcowGetPowerOfTwo(pImage->cbCluster);
389	pHeader->Version.v1.u8L2Bits = (uint8_t)qcowGetPowerOfTwo(pImage->cL2TableEntries);
390	pHeader->Version.v1.u32CryptMethod = RT_H2BE_U32(0);
391	pHeader->Version.v1.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
392	*pcbHeader = QCOW_V1_HDR_SIZE;
393	}
394	else if (pImage->uVersion == 2)
395	{
396	pHeader->Version.v2.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
397	pHeader->Version.v2.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
398	pHeader->Version.v2.u32ClusterBits = RT_H2BE_U32(qcowGetPowerOfTwo(pImage->cbCluster));
399	pHeader->Version.v2.u64Size = RT_H2BE_U64(pImage->cbSize);
400	pHeader->Version.v2.u32CryptMethod = RT_H2BE_U32(0);
401	pHeader->Version.v2.u32L1Size = RT_H2BE_U32(pImage->cL1TableEntries);
402	pHeader->Version.v2.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
403	pHeader->Version.v2.u64RefcountTableOffset = RT_H2BE_U64(pImage->offRefcountTable);
404	pHeader->Version.v2.u32RefcountTableClusters = RT_H2BE_U32(pImage->cbRefcountTable / pImage->cbCluster);
405	pHeader->Version.v2.u32NbSnapshots = RT_H2BE_U32(0);
406	pHeader->Version.v2.u64SnapshotsOffset = RT_H2BE_U64((uint64_t)0);
407	*pcbHeader = QCOW_V2_HDR_SIZE;
408	}
409	else
410	AssertMsgFailed(("Invalid version of the QCOW image format %d\n", pImage->uVersion));
411	}
412
413	/**
414	* Convert table entries from little endian to host endianess.
415	*
416	* @returns nothing.
417	* @param paTbl Pointer to the table.
418	* @param cEntries Number of entries in the table.
419	*/
420	static void qcowTableConvertToHostEndianess(uint64_t *paTbl, uint32_t cEntries)
421	{
422	while(cEntries-- > 0)
423	{
424	paTbl = RT_BE2H_U64(paTbl);
425	paTbl++;
426	}
427	}
428
429	/**
430	* Convert table entries from host to little endian format.
431	*
432	* @returns nothing.
433	* @param paTblImg Pointer to the table which will store the little endian table.
434	* @param paTbl The source table to convert.
435	* @param cEntries Number of entries in the table.
436	*/
437	static void qcowTableConvertFromHostEndianess(uint64_t paTblImg, uint64_t paTbl,
438	uint32_t cEntries)
439	{
440	while(cEntries-- > 0)
441	{
442	paTblImg = RT_H2BE_U64(paTbl);
443	paTbl++;
444	paTblImg++;
445	}
446	}
447
448	/**
449	* Convert refcount table entries from little endian to host endianess.
450	*
451	* @returns nothing.
452	* @param paTbl Pointer to the table.
453	* @param cEntries Number of entries in the table.
454	*/
455	static void qcowRefcountTableConvertToHostEndianess(uint16_t *paTbl, uint32_t cEntries)
456	{
457	while(cEntries-- > 0)
458	{
459	paTbl = RT_BE2H_U16(paTbl);
460	paTbl++;
461	}
462	}
463
464	/**
465	* Convert table entries from host to little endian format.
466	*
467	* @returns nothing.
468	* @param paTblImg Pointer to the table which will store the little endian table.
469	* @param paTbl The source table to convert.
470	* @param cEntries Number of entries in the table.
471	*/
472	static void qcowRefcountTableConvertFromHostEndianess(uint16_t paTblImg, uint16_t paTbl,
473	uint32_t cEntries)
474	{
475	while(cEntries-- > 0)
476	{
477	paTblImg = RT_H2BE_U16(paTbl);
478	paTbl++;
479	paTblImg++;
480	}
481	}
482
483	/**
484	* Creates the L2 table cache.
485	*
486	* @returns VBox status code.
487	* @param pImage The image instance data.
488	*/
489	static int qcowL2TblCacheCreate(PQCOWIMAGE pImage)
490	{
491	pImage->cbL2Cache = 0;
492	RTListInit(&pImage->ListSearch);
493	RTListInit(&pImage->ListLru);
494
495	return VINF_SUCCESS;
496	}
497
498	/**
499	* Destroys the L2 table cache.
500	*
501	* @returns nothing.
502	* @param pImage The image instance data.
503	*/
504	static void qcowL2TblCacheDestroy(PQCOWIMAGE pImage)
505	{
506	PQCOWL2CACHEENTRY pL2Entry = NULL;
507	PQCOWL2CACHEENTRY pL2Next = NULL;
508
509	RTListForEachSafe(&pImage->ListSearch, pL2Entry, pL2Next, QCOWL2CACHEENTRY, NodeSearch)
510	{
511	Assert(!pL2Entry->cRefs);
512
513	RTListNodeRemove(&pL2Entry->NodeSearch);
514	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
515	RTMemFree(pL2Entry);
516	}
517
518	pImage->cbL2Cache = 0;
519	RTListInit(&pImage->ListSearch);
520	RTListInit(&pImage->ListLru);
521	}
522
523	/**
524	* Returns the L2 table matching the given offset or NULL if none could be found.
525	*
526	* @returns Pointer to the L2 table cache entry or NULL.
527	* @param pImage The image instance data.
528	* @param offL2Tbl Offset of the L2 table to search for.
529	*/
530	static PQCOWL2CACHEENTRY qcowL2TblCacheRetain(PQCOWIMAGE pImage, uint64_t offL2Tbl)
531	{
532	PQCOWL2CACHEENTRY pL2Entry = NULL;
533
534	RTListForEach(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch)
535	{
536	if (pL2Entry->offL2Tbl == offL2Tbl)
537	break;
538	}
539
540	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
541	{
542	/* Update LRU list. */
543	RTListNodeRemove(&pL2Entry->NodeLru);
544	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
545	pL2Entry->cRefs++;
546	return pL2Entry;
547	}
548	else
549	return NULL;
550	}
551
552	/**
553	* Releases a L2 table cache entry.
554	*
555	* @returns nothing.
556	* @param pL2Entry The L2 cache entry.
557	*/
558	static void qcowL2TblCacheEntryRelease(PQCOWL2CACHEENTRY pL2Entry)
559	{
560	Assert(pL2Entry->cRefs > 0);
561	pL2Entry->cRefs--;
562	}
563
564	/**
565	* Allocates a new L2 table from the cache evicting old entries if required.
566	*
567	* @returns Pointer to the L2 cache entry or NULL.
568	* @param pImage The image instance data.
569	*/
570	static PQCOWL2CACHEENTRY qcowL2TblCacheEntryAlloc(PQCOWIMAGE pImage)
571	{
572	PQCOWL2CACHEENTRY pL2Entry = NULL;
573	int rc = VINF_SUCCESS;
574
575	if (pImage->cbL2Cache + pImage->cbL2Table <= QCOW_L2_CACHE_MEMORY_MAX)
576	{
577	/* Add a new entry. */
578	pL2Entry = (PQCOWL2CACHEENTRY)RTMemAllocZ(sizeof(QCOWL2CACHEENTRY));
579	if (pL2Entry)
580	{
581	pL2Entry->paL2Tbl = (uint64_t *)RTMemPageAllocZ(pImage->cbL2Table);
582	if (RT_UNLIKELY(!pL2Entry->paL2Tbl))
583	{
584	RTMemFree(pL2Entry);
585	pL2Entry = NULL;
586	}
587	else
588	{
589	pL2Entry->cRefs = 1;
590	pImage->cbL2Cache += pImage->cbL2Table;
591	}
592	}
593	}
594	else
595	{
596	/* Evict the last not in use entry and use it */
597	Assert(!RTListIsEmpty(&pImage->ListLru));
598
599	RTListForEachReverse(&pImage->ListLru, pL2Entry, QCOWL2CACHEENTRY, NodeLru)
600	{
601	if (!pL2Entry->cRefs)
602	break;
603	}
604
605	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
606	{
607	RTListNodeRemove(&pL2Entry->NodeSearch);
608	RTListNodeRemove(&pL2Entry->NodeLru);
609	pL2Entry->offL2Tbl = 0;
610	pL2Entry->cRefs = 1;
611	}
612	else
613	pL2Entry = NULL;
614	}
615
616	return pL2Entry;
617	}
618
619	/**
620	* Frees a L2 table cache entry.
621	*
622	* @returns nothing.
623	* @param pImage The image instance data.
624	* @param pL2Entry The L2 cache entry to free.
625	*/
626	static void qcowL2TblCacheEntryFree(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
627	{
628	Assert(!pL2Entry->cRefs);
629	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
630	RTMemFree(pL2Entry);
631
632	pImage->cbL2Cache -= pImage->cbL2Table;
633	}
634
635	/**
636	* Inserts an entry in the L2 table cache.
637	*
638	* @returns nothing.
639	* @param pImage The image instance data.
640	* @param pL2Entry The L2 cache entry to insert.
641	*/
642	static void qcowL2TblCacheEntryInsert(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
643	{
644	PQCOWL2CACHEENTRY pIt = NULL;
645
646	Assert(pL2Entry->offL2Tbl > 0);
647
648	/* Insert at the top of the LRU list. */
649	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
650
651	if (RTListIsEmpty(&pImage->ListSearch))
652	{
653	RTListAppend(&pImage->ListSearch, &pL2Entry->NodeSearch);
654	}
655	else
656	{
657	/* Insert into search list. */
658	pIt = RTListGetFirst(&pImage->ListSearch, QCOWL2CACHEENTRY, NodeSearch);
659	if (pIt->offL2Tbl > pL2Entry->offL2Tbl)
660	RTListPrepend(&pImage->ListSearch, &pL2Entry->NodeSearch);
661	else
662	{
663	bool fInserted = false;
664
665	RTListForEach(&pImage->ListSearch, pIt, QCOWL2CACHEENTRY, NodeSearch)
666	{
667	Assert(pIt->offL2Tbl != pL2Entry->offL2Tbl);
668	if (pIt->offL2Tbl < pL2Entry->offL2Tbl)
669	{
670	RTListNodeInsertAfter(&pIt->NodeSearch, &pL2Entry->NodeSearch);
671	fInserted = true;
672	break;
673	}
674	}
675	Assert(fInserted);
676	}
677	}
678	}
679
680	/**
681	* Fetches the L2 from the given offset trying the LRU cache first and
682	* reading it from the image after a cache miss.
683	*
684	* @returns VBox status code.
685	* @param pImage Image instance data.
686	* @param pIoCtx The I/O context.
687	* @param offL2Tbl The offset of the L2 table in the image.
688	* @param ppL2Entry Where to store the L2 table on success.
689	*/
690	static int qcowL2TblCacheFetch(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offL2Tbl,
691	PQCOWL2CACHEENTRY *ppL2Entry)
692	{
693	int rc = VINF_SUCCESS;
694
695	/* Try to fetch the L2 table from the cache first. */
696	PQCOWL2CACHEENTRY pL2Entry = qcowL2TblCacheRetain(pImage, offL2Tbl);
697	if (!pL2Entry)
698	{
699	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
700
701	if (pL2Entry)
702	{
703	/* Read from the image. */
704	PVDMETAXFER pMetaXfer;
705
706	pL2Entry->offL2Tbl = offL2Tbl;
707	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
708	offL2Tbl, pL2Entry->paL2Tbl,
709	pImage->cbL2Table, pIoCtx,
710	&pMetaXfer, NULL, NULL);
711	if (RT_SUCCESS(rc))
712	{
713	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
714	#if defined(RT_LITTLE_ENDIAN)
715	qcowTableConvertToHostEndianess(pL2Entry->paL2Tbl, pImage->cL2TableEntries);
716	#endif
717	qcowL2TblCacheEntryInsert(pImage, pL2Entry);
718	}
719	else
720	{
721	qcowL2TblCacheEntryRelease(pL2Entry);
722	qcowL2TblCacheEntryFree(pImage, pL2Entry);
723	}
724	}
725	else
726	rc = VERR_NO_MEMORY;
727	}
728
729	if (RT_SUCCESS(rc))
730	*ppL2Entry = pL2Entry;
731
732	return rc;
733	}
734
735	/**
736	* Sets the L1, L2 and offset bitmasks and L1 and L2 bit shift members.
737	*
738	* @returns nothing.
739	* @param pImage The image instance data.
740	*/
741	static void qcowTableMasksInit(PQCOWIMAGE pImage)
742	{
743	uint32_t cClusterBits, cL2TableBits;
744
745	cClusterBits = qcowGetPowerOfTwo(pImage->cbCluster);
746	cL2TableBits = qcowGetPowerOfTwo(pImage->cL2TableEntries);
747
748	Assert(cClusterBits + cL2TableBits < 64);
749
750	pImage->fOffsetMask = ((uint64_t)pImage->cbCluster - 1);
751	pImage->fL2Mask = ((uint64_t)pImage->cL2TableEntries - 1) << cClusterBits;
752	pImage->cL2Shift = cClusterBits;
753	pImage->cL1Shift = cClusterBits + cL2TableBits;
754	}
755
756	/**
757	* Converts a given logical offset into the
758	*
759	* @returns nothing.
760	* @param pImage The image instance data.
761	* @param off The logical offset to convert.
762	* @param pidxL1 Where to store the index in the L1 table on success.
763	* @param pidxL2 Where to store the index in the L2 table on success.
764	* @param poffCluster Where to store the offset in the cluster on success.
765	*/
766	DECLINLINE(void) qcowConvertLogicalOffset(PQCOWIMAGE pImage, uint64_t off, uint32_t *pidxL1,
767	uint32_t pidxL2, uint32_t poffCluster)
768	{
769	AssertPtr(pidxL1);
770	AssertPtr(pidxL2);
771	AssertPtr(poffCluster);
772
773	*poffCluster = off & pImage->fOffsetMask;
774	*pidxL1 = off >> pImage->cL1Shift;
775	*pidxL2 = (off & pImage->fL2Mask) >> pImage->cL2Shift;
776	}
777
778	/**
779	* Converts Cluster size to a byte size.
780	*
781	* @returns Number of bytes derived from the given number of clusters.
782	* @param pImage The image instance data.
783	* @param cClusters The clusters to convert.
784	*/
785	DECLINLINE(uint64_t) qcowCluster2Byte(PQCOWIMAGE pImage, uint64_t cClusters)
786	{
787	return cClusters * pImage->cbCluster;
788	}
789
790	/**
791	* Converts number of bytes to cluster size rounding to the next cluster.
792	*
793	* @returns Number of bytes derived from the given number of clusters.
794	* @param pImage The image instance data.
795	* @param cb Number of bytes to convert.
796	*/
797	DECLINLINE(uint64_t) qcowByte2Cluster(PQCOWIMAGE pImage, uint64_t cb)
798	{
799	return cb / pImage->cbCluster + (cb % pImage->cbCluster ? 1 : 0);
800	}
801
802	/**
803	* Allocates a new cluster in the image.
804	*
805	* @returns The start offset of the new cluster in the image.
806	* @param pImage The image instance data.
807	* @param cCLusters Number of clusters to allocate.
808	*/
809	DECLINLINE(uint64_t) qcowClusterAllocate(PQCOWIMAGE pImage, uint32_t cClusters)
810	{
811	uint64_t offCluster;
812
813	offCluster = pImage->offNextCluster;
814	pImage->offNextCluster += cClusters*pImage->cbCluster;
815
816	return offCluster;
817	}
818
819	/**
820	* Returns the real image offset for a given cluster or an error if the cluster is not
821	* yet allocated.
822	*
823	* @returns VBox status code.
824	* VERR_VD_BLOCK_FREE if the cluster is not yet allocated.
825	* @param pImage The image instance data.
826	* @param pIoCtx The I/O context.
827	* @param idxL1 The L1 index.
828	* @param idxL2 The L2 index.
829	* @param offCluster Offset inside the cluster.
830	* @param poffImage Where to store the image offset on success;
831	*/
832	static int qcowConvertToImageOffset(PQCOWIMAGE pImage, PVDIOCTX pIoCtx,
833	uint32_t idxL1, uint32_t idxL2,
834	uint32_t offCluster, uint64_t *poffImage)
835	{
836	int rc = VERR_VD_BLOCK_FREE;
837
838	AssertReturn(idxL1 < pImage->cL1TableEntries, VERR_INVALID_PARAMETER);
839	AssertReturn(idxL2 < pImage->cL2TableEntries, VERR_INVALID_PARAMETER);
840
841	if (pImage->paL1Table[idxL1])
842	{
843	PQCOWL2CACHEENTRY pL2Entry;
844
845	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1], &pL2Entry);
846	if (RT_SUCCESS(rc))
847	{
848	/* Get real file offset. */
849	if (pL2Entry->paL2Tbl[idxL2])
850	{
851	uint64_t off = pL2Entry->paL2Tbl[idxL2];
852
853	/* Strip flags */
854	if (pImage->uVersion == 2)
855	{
856	if (RT_UNLIKELY(off & QCOW_V2_COMPRESSED_FLAG))
857	rc = VERR_NOT_SUPPORTED;
858	else
859	off &= ~(QCOW_V2_COMPRESSED_FLAG \| QCOW_V2_COPIED_FLAG);
860	}
861	else
862	{
863	if (RT_UNLIKELY(off & QCOW_V1_COMPRESSED_FLAG))
864	rc = VERR_NOT_SUPPORTED;
865	else
866	off &= ~QCOW_V1_COMPRESSED_FLAG;
867	}
868
869	*poffImage = off + offCluster;
870	}
871	else
872	rc = VERR_VD_BLOCK_FREE;
873
874	qcowL2TblCacheEntryRelease(pL2Entry);
875	}
876	}
877
878	return rc;
879	}
880
881
882	/**
883	* Internal. Flush image data to disk.
884	*/
885	static int qcowFlushImage(PQCOWIMAGE pImage)
886	{
887	int rc = VINF_SUCCESS;
888
889	if ( pImage->pStorage
890	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
891	&& pImage->cbL1Table)
892	{
893	QCowHeader Header;
894
895	#if defined(RT_LITTLE_ENDIAN)
896	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
897	if (paL1TblImg)
898	{
899	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
900	pImage->cL1TableEntries);
901	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
902	pImage->offL1Table, paL1TblImg,
903	pImage->cbL1Table);
904	RTMemFree(paL1TblImg);
905	}
906	else
907	rc = VERR_NO_MEMORY;
908	#else
909	/* Write L1 table directly. */
910	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->offL1Table,
911	pImage->paL1Table, pImage->cbL1Table);
912	#endif
913	if (RT_SUCCESS(rc))
914	{
915	/* Write header. */
916	size_t cbHeader = 0;
917	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
918	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Header,
919	cbHeader);
920	if (RT_SUCCESS(rc))
921	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
922	}
923	}
924
925	return rc;
926	}
927
928	/**
929	* Flush image data to disk - version for async I/O.
930	*
931	* @returns VBox status code.
932	* @param pImage The image instance data.
933	* @param pIoCtx The I/o context
934	*/
935	static int qcowFlushImageAsync(PQCOWIMAGE pImage, PVDIOCTX pIoCtx)
936	{
937	int rc = VINF_SUCCESS;
938
939	if ( pImage->pStorage
940	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
941	{
942	QCowHeader Header;
943
944	#if defined(RT_LITTLE_ENDIAN)
945	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
946	if (paL1TblImg)
947	{
948	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
949	pImage->cL1TableEntries);
950	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
951	pImage->offL1Table, paL1TblImg,
952	pImage->cbL1Table, pIoCtx, NULL, NULL);
953	RTMemFree(paL1TblImg);
954	}
955	else
956	rc = VERR_NO_MEMORY;
957	#else
958	/* Write L1 table directly. */
959	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
960	pImage->offL1Table, pImage->paL1Table,
961	pImage->cbL1Table, pIoCtx, NULL, NULL);
962	#endif
963	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
964	{
965	/* Write header. */
966	size_t cbHeader = 0;
967	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
968	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
969	0, &Header, cbHeader,
970	pIoCtx, NULL, NULL);
971	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
972	rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage,
973	pIoCtx, NULL, NULL);
974	}
975	}
976
977	return rc;
978	}
979
980	/**
981	* Internal. Free all allocated space for representing an image except pImage,
982	* and optionally delete the image from disk.
983	*/
984	static int qcowFreeImage(PQCOWIMAGE pImage, bool fDelete)
985	{
986	int rc = VINF_SUCCESS;
987
988	/* Freeing a never allocated image (e.g. because the open failed) is
989	* not signalled as an error. After all nothing bad happens. */
990	if (pImage)
991	{
992	if (pImage->pStorage)
993	{
994	/* No point updating the file that is deleted anyway. */
995	if (!fDelete)
996	qcowFlushImage(pImage);
997
998	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
999	pImage->pStorage = NULL;
1000	}
1001
1002	if (pImage->paL1Table)
1003	RTMemFree(pImage->paL1Table);
1004
1005	if (pImage->pszBackingFilename)
1006	{
1007	RTMemFree(pImage->pszBackingFilename);
1008	pImage->pszBackingFilename = NULL;
1009	}
1010
1011	qcowL2TblCacheDestroy(pImage);
1012
1013	if (fDelete && pImage->pszFilename)
1014	vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
1015	}
1016
1017	LogFlowFunc(("returns %Rrc\n", rc));
1018	return rc;
1019	}
1020
1021	/**
1022	* Internal: Open an image, constructing all necessary data structures.
1023	*/
1024	static int qcowOpenImage(PQCOWIMAGE pImage, unsigned uOpenFlags)
1025	{
1026	int rc;
1027
1028	pImage->uOpenFlags = uOpenFlags;
1029
1030	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1031	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1032	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1033
1034	/*
1035	* Open the image.
1036	*/
1037	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1038	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1039	false /* fCreate */),
1040	&pImage->pStorage);
1041	if (RT_FAILURE(rc))
1042	{
1043	/* Do NOT signal an appropriate error here, as the VD layer has the
1044	* choice of retrying the open if it failed. */
1045	goto out;
1046	}
1047
1048	uint64_t cbFile;
1049	QCowHeader Header;
1050	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1051	if (RT_FAILURE(rc))
1052	goto out;
1053	if (cbFile > sizeof(Header))
1054	{
1055	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0, &Header, sizeof(Header));
1056	if ( RT_SUCCESS(rc)
1057	&& qcowHdrConvertToHostEndianess(&Header))
1058	{
1059	pImage->offNextCluster = RT_ALIGN_64(cbFile, 512); /* Align image to sector boundary. */
1060	Assert(pImage->offNextCluster >= cbFile);
1061
1062	rc = qcowL2TblCacheCreate(pImage);
1063	AssertRC(rc);
1064
1065	if (Header.u32Version == 1)
1066	{
1067	if (!Header.Version.v1.u32CryptMethod)
1068	{
1069	pImage->uVersion = 1;
1070	pImage->offBackingFilename = Header.Version.v1.u64BackingFileOffset;
1071	pImage->cbBackingFilename = Header.Version.v1.u32BackingFileSize;
1072	pImage->MTime = Header.Version.v1.u32MTime;
1073	pImage->cbSize = Header.Version.v1.u64Size;
1074	pImage->cbCluster = RT_BIT_32(Header.Version.v1.u8ClusterBits);
1075	pImage->cL2TableEntries = RT_BIT_32(Header.Version.v1.u8L2Bits);
1076	pImage->cbL2Table = RT_ALIGN_64(pImage->cL2TableEntries * sizeof(uint64_t), pImage->cbCluster);
1077	pImage->offL1Table = Header.Version.v1.u64L1TableOffset;
1078	pImage->cL1TableEntries = pImage->cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1079	if (pImage->cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1080	pImage->cL1TableEntries++;
1081	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1082	}
1083	else
1084	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1085	N_("QCow: Encrypted image '%s' is not supported"),
1086	pImage->pszFilename);
1087	}
1088	else if (Header.u32Version == 2)
1089	{
1090	if (Header.Version.v2.u32CryptMethod)
1091	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1092	N_("QCow: Encrypted image '%s' is not supported"),
1093	pImage->pszFilename);
1094	else if (Header.Version.v2.u32NbSnapshots)
1095	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1096	N_("QCow: Image '%s' contains snapshots which is not supported"),
1097	pImage->pszFilename);
1098	else
1099	{
1100	pImage->uVersion = 2;
1101	pImage->offBackingFilename = Header.Version.v2.u64BackingFileOffset;
1102	pImage->cbBackingFilename = Header.Version.v2.u32BackingFileSize;
1103	pImage->cbSize = Header.Version.v2.u64Size;
1104	pImage->cbCluster = RT_BIT_32(Header.Version.v2.u32ClusterBits);
1105	pImage->cL2TableEntries = pImage->cbCluster / sizeof(uint64_t);
1106	pImage->cbL2Table = pImage->cbCluster;
1107	pImage->offL1Table = Header.Version.v2.u64L1TableOffset;
1108	pImage->cL1TableEntries = Header.Version.v2.u32L1Size;
1109	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1110	pImage->offRefcountTable = Header.Version.v2.u64RefcountTableOffset;
1111	pImage->cbRefcountTable = qcowCluster2Byte(pImage, Header.Version.v2.u32RefcountTableClusters);
1112	pImage->cRefcountTableEntries = pImage->cbRefcountTable / sizeof(uint64_t);
1113	}
1114	}
1115	else
1116	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1117	N_("QCow: Image '%s' uses version %u which is not supported"),
1118	pImage->pszFilename, Header.u32Version);
1119
1120	/** @todo: Check that there are no compressed clusters in the image
1121	* (by traversing the L2 tables and checking each offset).
1122	* Refuse to open such images.
1123	*/
1124
1125	if ( RT_SUCCESS(rc)
1126	&& pImage->cbBackingFilename
1127	&& pImage->offBackingFilename)
1128	{
1129	/* Load backing filename from image. */
1130	pImage->pszBackingFilename = (char )RTMemAllocZ(pImage->cbBackingFilename + 1); / +1 for \0 terminator. */
1131	if (pImage->pszBackingFilename)
1132	{
1133	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1134	pImage->offBackingFilename, pImage->pszBackingFilename,
1135	pImage->cbBackingFilename);
1136	}
1137	else
1138	rc = VERR_NO_MEMORY;
1139	}
1140
1141	if ( RT_SUCCESS(rc)
1142	&& pImage->cbRefcountTable
1143	&& pImage->offRefcountTable)
1144	{
1145	/* Load refcount table. */
1146	Assert(pImage->cRefcountTableEntries);
1147	pImage->paRefcountTable = (uint64_t *)RTMemAllocZ(pImage->cbRefcountTable);
1148	if (RT_LIKELY(pImage->paRefcountTable))
1149	{
1150	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1151	pImage->offRefcountTable, pImage->paRefcountTable,
1152	pImage->cbRefcountTable);
1153	if (RT_SUCCESS(rc))
1154	qcowTableConvertToHostEndianess(pImage->paRefcountTable,
1155	pImage->cRefcountTableEntries);
1156	else
1157	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1158	N_("QCow: Reading refcount table of image '%s' failed"),
1159	pImage->pszFilename);
1160	}
1161	else
1162	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1163	N_("QCow: Allocating memory for refcount table of image '%s' failed"),
1164	pImage->pszFilename);
1165	}
1166
1167	if (RT_SUCCESS(rc))
1168	{
1169	qcowTableMasksInit(pImage);
1170
1171	/* Allocate L1 table. */
1172	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1173	if (pImage->paL1Table)
1174	{
1175	/* Read from the image. */
1176	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1177	pImage->offL1Table, pImage->paL1Table,
1178	pImage->cbL1Table);
1179	if (RT_SUCCESS(rc))
1180	qcowTableConvertToHostEndianess(pImage->paL1Table, pImage->cL1TableEntries);
1181	else
1182	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1183	N_("QCow: Reading the L1 table for image '%s' failed"),
1184	pImage->pszFilename);
1185	}
1186	else
1187	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1188	N_("QCow: Out of memory allocating L1 table for image '%s'"),
1189	pImage->pszFilename);
1190	}
1191	}
1192	else if (RT_SUCCESS(rc))
1193	rc = VERR_VD_GEN_INVALID_HEADER;
1194	}
1195	else
1196	rc = VERR_VD_GEN_INVALID_HEADER;
1197
1198	out:
1199	if (RT_FAILURE(rc))
1200	qcowFreeImage(pImage, false);
1201	return rc;
1202	}
1203
1204	/**
1205	* Internal: Create a qcow image.
1206	*/
1207	static int qcowCreateImage(PQCOWIMAGE pImage, uint64_t cbSize,
1208	unsigned uImageFlags, const char *pszComment,
1209	PCVDGEOMETRY pPCHSGeometry,
1210	PCVDGEOMETRY pLCHSGeometry, unsigned uOpenFlags,
1211	PFNVDPROGRESS pfnProgress, void *pvUser,
1212	unsigned uPercentStart, unsigned uPercentSpan)
1213	{
1214	int rc;
1215	int32_t fOpen;
1216
1217	if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
1218	{
1219	rc = vdIfError(pImage->pIfError, VERR_VD_INVALID_TYPE, RT_SRC_POS, N_("QCow: cannot create fixed image '%s'"), pImage->pszFilename);
1220	goto out;
1221	}
1222
1223	pImage->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1224	pImage->uImageFlags = uImageFlags;
1225	pImage->PCHSGeometry = *pPCHSGeometry;
1226	pImage->LCHSGeometry = *pLCHSGeometry;
1227
1228	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1229	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1230	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1231
1232	/* Create image file. */
1233	fOpen = VDOpenFlagsToFileOpenFlags(pImage->uOpenFlags, true /* fCreate */);
1234	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename, fOpen, &pImage->pStorage);
1235	if (RT_FAILURE(rc))
1236	{
1237	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: cannot create image '%s'"), pImage->pszFilename);
1238	goto out;
1239	}
1240
1241	/* Init image state. */
1242	pImage->uVersion = 1; /* We create only version 1 images at the moment. */
1243	pImage->cbSize = cbSize;
1244	pImage->cbCluster = QCOW_CLUSTER_SIZE_DEFAULT;
1245	pImage->cbL2Table = qcowCluster2Byte(pImage, QCOW_L2_CLUSTERS_DEFAULT);
1246	pImage->cL2TableEntries = pImage->cbL2Table / sizeof(uint64_t);
1247	pImage->cL1TableEntries = cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1248	if (cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1249	pImage->cL1TableEntries++;
1250	pImage->cbL1Table = pImage->cL1TableEntries * sizeof(uint64_t);
1251	pImage->offL1Table = QCOW_V1_HDR_SIZE;
1252	pImage->cbBackingFilename = 0;
1253	pImage->offBackingFilename = 0;
1254	pImage->offNextCluster = RT_ALIGN_64(QCOW_V1_HDR_SIZE + pImage->cbL1Table, pImage->cbCluster);
1255	qcowTableMasksInit(pImage);
1256
1257	/* Init L1 table. */
1258	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1259	if (!pImage->paL1Table)
1260	{
1261	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("QCow: cannot allocate memory for L1 table of image '%s'"),
1262	pImage->pszFilename);
1263	goto out;
1264	}
1265
1266	rc = qcowL2TblCacheCreate(pImage);
1267	if (RT_FAILURE(rc))
1268	{
1269	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: Failed to create L2 cache for image '%s'"),
1270	pImage->pszFilename);
1271	goto out;
1272	}
1273
1274	if (RT_SUCCESS(rc) && pfnProgress)
1275	pfnProgress(pvUser, uPercentStart + uPercentSpan * 98 / 100);
1276
1277	rc = qcowFlushImage(pImage);
1278	if (RT_SUCCESS(rc))
1279	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pImage->offNextCluster);
1280
1281	out:
1282	if (RT_SUCCESS(rc) && pfnProgress)
1283	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1284
1285	if (RT_FAILURE(rc))
1286	qcowFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1287	return rc;
1288	}
1289
1290	/**
1291	* Rollback anything done during async cluster allocation.
1292	*
1293	* @returns VBox status code.
1294	* @param pImage The image instance data.
1295	* @param pIoCtx The I/O context.
1296	* @param pClusterAlloc The cluster allocation to rollback.
1297	*/
1298	static int qcowAsyncClusterAllocRollback(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, PQCOWCLUSTERASYNCALLOC pClusterAlloc)
1299	{
1300	int rc = VINF_SUCCESS;
1301
1302	switch (pClusterAlloc->enmAllocState)
1303	{
1304	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1305	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1306	{
1307	/* Assumption right now is that the L1 table is not modified if the link fails. */
1308	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1309	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1310	qcowL2TblCacheEntryFree(pImage, pClusterAlloc->pL2Entry); /* Free it, it is not in the cache yet. */
1311	}
1312	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1313	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1314	{
1315	/* Assumption right now is that the L2 table is not modified if the link fails. */
1316	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1317	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1318	break;
1319	}
1320	default:
1321	AssertMsgFailed(("Invalid cluster allocation state %d\n", pClusterAlloc->enmAllocState));
1322	rc = VERR_INVALID_STATE;
1323	}
1324
1325	RTMemFree(pClusterAlloc);
1326	return rc;
1327	}
1328
1329	/**
1330	* Updates the state of the async cluster allocation.
1331	*
1332	* @returns VBox status code.
1333	* @param pBackendData The opaque backend data.
1334	* @param pIoCtx I/O context associated with this request.
1335	* @param pvUser Opaque user data passed during a read/write request.
1336	* @param rcReq Status code for the completed request.
1337	*/
1338	static DECLCALLBACK(int) qcowAsyncClusterAllocUpdate(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
1339	{
1340	int rc = VINF_SUCCESS;
1341	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1342	PQCOWCLUSTERASYNCALLOC pClusterAlloc = (PQCOWCLUSTERASYNCALLOC)pvUser;
1343
1344	if (RT_FAILURE(rcReq))
1345	return qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1346
1347	AssertPtr(pClusterAlloc->pL2Entry);
1348
1349	switch (pClusterAlloc->enmAllocState)
1350	{
1351	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1352	{
1353	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->pL2Entry->offL2Tbl);
1354
1355	/* Update the link in the on disk L1 table now. */
1356	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_LINK;
1357	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1358	pImage->offL1Table + pClusterAlloc->idxL1*sizeof(uint64_t),
1359	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1360	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1361	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1362	break;
1363	else if (RT_FAILURE(rc))
1364	{
1365	/* Rollback. */
1366	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1367	break;
1368	}
1369	/* Success, fall through. */
1370	}
1371	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1372	{
1373	/* L2 link updated in L1 , save L2 entry in cache and allocate new user data cluster. */
1374	uint64_t offData = qcowClusterAllocate(pImage, 1);
1375
1376	/* Update the link in the in memory L1 table now. */
1377	pImage->paL1Table[pClusterAlloc->idxL1] = pClusterAlloc->pL2Entry->offL2Tbl;
1378	qcowL2TblCacheEntryInsert(pImage, pClusterAlloc->pL2Entry);
1379
1380	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1381	pClusterAlloc->offNextClusterOld = offData;
1382	pClusterAlloc->offClusterNew = offData;
1383
1384	/* Write data. */
1385	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1386	offData, pIoCtx, pClusterAlloc->cbToWrite,
1387	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1388	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1389	break;
1390	else if (RT_FAILURE(rc))
1391	{
1392	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1393	RTMemFree(pClusterAlloc);
1394	break;
1395	}
1396	}
1397	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1398	{
1399	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->offClusterNew);
1400
1401	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_LINK;
1402
1403	/* Link L2 table and update it. */
1404	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1405	pImage->paL1Table[pClusterAlloc->idxL1] + pClusterAlloc->idxL2*sizeof(uint64_t),
1406	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1407	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1408	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1409	break;
1410	else if (RT_FAILURE(rc))
1411	{
1412	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1413	RTMemFree(pClusterAlloc);
1414	break;
1415	}
1416	}
1417	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1418	{
1419	/* Everything done without errors, signal completion. */
1420	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = pClusterAlloc->offClusterNew;
1421	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry);
1422	RTMemFree(pClusterAlloc);
1423	rc = VINF_SUCCESS;
1424	break;
1425	}
1426	default:
1427	AssertMsgFailed(("Invalid async cluster allocation state %d\n",
1428	pClusterAlloc->enmAllocState));
1429	}
1430
1431	return rc;
1432	}
1433
1434	/** @copydoc VBOXHDDBACKEND::pfnCheckIfValid */
1435	static int qcowCheckIfValid(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1436	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1437	{
1438	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1439	PVDIOSTORAGE pStorage = NULL;
1440	uint64_t cbFile;
1441	int rc = VINF_SUCCESS;
1442
1443	/* Get I/O interface. */
1444	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1445	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1446
1447	if ( !VALID_PTR(pszFilename)
1448	\|\| !*pszFilename)
1449	{
1450	rc = VERR_INVALID_PARAMETER;
1451	goto out;
1452	}
1453
1454	/*
1455	* Open the file and read the footer.
1456	*/
1457	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1458	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1459	false /* fCreate */),
1460	&pStorage);
1461	if (RT_SUCCESS(rc))
1462	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1463
1464	if ( RT_SUCCESS(rc)
1465	&& cbFile > sizeof(QCowHeader))
1466	{
1467	QCowHeader Header;
1468
1469	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Header, sizeof(Header));
1470	if ( RT_SUCCESS(rc)
1471	&& qcowHdrConvertToHostEndianess(&Header))
1472	{
1473	*penmType = VDTYPE_HDD;
1474	rc = VINF_SUCCESS;
1475	}
1476	else
1477	rc = VERR_VD_GEN_INVALID_HEADER;
1478	}
1479	else
1480	rc = VERR_VD_GEN_INVALID_HEADER;
1481
1482	if (pStorage)
1483	vdIfIoIntFileClose(pIfIo, pStorage);
1484
1485	out:
1486	LogFlowFunc(("returns %Rrc\n", rc));
1487	return rc;
1488	}
1489
1490	/** @copydoc VBOXHDDBACKEND::pfnOpen */
1491	static int qcowOpen(const char *pszFilename, unsigned uOpenFlags,
1492	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1493	VDTYPE enmType, void **ppBackendData)
1494	{
1495	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, ppBackendData));
1496	int rc;
1497	PQCOWIMAGE pImage;
1498
1499	/* Check open flags. All valid flags are supported. */
1500	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1501	{
1502	rc = VERR_INVALID_PARAMETER;
1503	goto out;
1504	}
1505
1506	/* Check remaining arguments. */
1507	if ( !VALID_PTR(pszFilename)
1508	\|\| !*pszFilename)
1509	{
1510	rc = VERR_INVALID_PARAMETER;
1511	goto out;
1512	}
1513
1514
1515	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1516	if (!pImage)
1517	{
1518	rc = VERR_NO_MEMORY;
1519	goto out;
1520	}
1521	pImage->pszFilename = pszFilename;
1522	pImage->pStorage = NULL;
1523	pImage->pVDIfsDisk = pVDIfsDisk;
1524	pImage->pVDIfsImage = pVDIfsImage;
1525
1526	rc = qcowOpenImage(pImage, uOpenFlags);
1527	if (RT_SUCCESS(rc))
1528	*ppBackendData = pImage;
1529	else
1530	RTMemFree(pImage);
1531
1532	out:
1533	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1534	return rc;
1535	}
1536
1537	/** @copydoc VBOXHDDBACKEND::pfnCreate */
1538	static int qcowCreate(const char *pszFilename, uint64_t cbSize,
1539	unsigned uImageFlags, const char *pszComment,
1540	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1541	PCRTUUID pUuid, unsigned uOpenFlags,
1542	unsigned uPercentStart, unsigned uPercentSpan,
1543	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1544	PVDINTERFACE pVDIfsOperation, void **ppBackendData)
1545	{
1546	LogFlowFunc(("pszFilename=\"%s\" cbSize=%llu uImageFlags=%#x pszComment=\"%s\" pPCHSGeometry=%#p pLCHSGeometry=%#p Uuid=%RTuuid uOpenFlags=%#x uPercentStart=%u uPercentSpan=%u pVDIfsDisk=%#p pVDIfsImage=%#p pVDIfsOperation=%#p ppBackendData=%#p",
1547	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, ppBackendData));
1548	int rc;
1549	PQCOWIMAGE pImage;
1550
1551	PFNVDPROGRESS pfnProgress = NULL;
1552	void *pvUser = NULL;
1553	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1554	if (pIfProgress)
1555	{
1556	pfnProgress = pIfProgress->pfnProgress;
1557	pvUser = pIfProgress->Core.pvUser;
1558	}
1559
1560	/* Check open flags. All valid flags are supported. */
1561	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1562	{
1563	rc = VERR_INVALID_PARAMETER;
1564	goto out;
1565	}
1566
1567	/* Check remaining arguments. */
1568	if ( !VALID_PTR(pszFilename)
1569	\|\| !*pszFilename
1570	\|\| !VALID_PTR(pPCHSGeometry)
1571	\|\| !VALID_PTR(pLCHSGeometry))
1572	{
1573	rc = VERR_INVALID_PARAMETER;
1574	goto out;
1575	}
1576
1577	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1578	if (!pImage)
1579	{
1580	rc = VERR_NO_MEMORY;
1581	goto out;
1582	}
1583	pImage->pszFilename = pszFilename;
1584	pImage->pStorage = NULL;
1585	pImage->pVDIfsDisk = pVDIfsDisk;
1586	pImage->pVDIfsImage = pVDIfsImage;
1587
1588	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1589	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1590	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1591	if (RT_SUCCESS(rc))
1592	{
1593	/* So far the image is opened in read/write mode. Make sure the
1594	* image is opened in read-only mode if the caller requested that. */
1595	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1596	{
1597	qcowFreeImage(pImage, false);
1598	rc = qcowOpenImage(pImage, uOpenFlags);
1599	if (RT_FAILURE(rc))
1600	{
1601	RTMemFree(pImage);
1602	goto out;
1603	}
1604	}
1605	*ppBackendData = pImage;
1606	}
1607	else
1608	RTMemFree(pImage);
1609
1610	out:
1611	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1612	return rc;
1613	}
1614
1615	/** @copydoc VBOXHDDBACKEND::pfnRename */
1616	static int qcowRename(void pBackendData, const char pszFilename)
1617	{
1618	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1619	int rc = VINF_SUCCESS;
1620	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1621
1622	/* Check arguments. */
1623	if ( !pImage
1624	\|\| !pszFilename
1625	\|\| !*pszFilename)
1626	{
1627	rc = VERR_INVALID_PARAMETER;
1628	goto out;
1629	}
1630
1631	/* Close the image. */
1632	rc = qcowFreeImage(pImage, false);
1633	if (RT_FAILURE(rc))
1634	goto out;
1635
1636	/* Rename the file. */
1637	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1638	if (RT_FAILURE(rc))
1639	{
1640	/* The move failed, try to reopen the original image. */
1641	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1642	if (RT_FAILURE(rc2))
1643	rc = rc2;
1644
1645	goto out;
1646	}
1647
1648	/* Update pImage with the new information. */
1649	pImage->pszFilename = pszFilename;
1650
1651	/* Open the old image with new name. */
1652	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1653	if (RT_FAILURE(rc))
1654	goto out;
1655
1656	out:
1657	LogFlowFunc(("returns %Rrc\n", rc));
1658	return rc;
1659	}
1660
1661	/** @copydoc VBOXHDDBACKEND::pfnClose */
1662	static int qcowClose(void *pBackendData, bool fDelete)
1663	{
1664	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1665	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1666	int rc;
1667
1668	rc = qcowFreeImage(pImage, fDelete);
1669	RTMemFree(pImage);
1670
1671	LogFlowFunc(("returns %Rrc\n", rc));
1672	return rc;
1673	}
1674
1675	static int qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1676	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1677	{
1678	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1679	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1680	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1681	uint32_t offCluster = 0;
1682	uint32_t idxL1 = 0;
1683	uint32_t idxL2 = 0;
1684	uint64_t offFile = 0;
1685	int rc;
1686
1687	AssertPtr(pImage);
1688	Assert(uOffset % 512 == 0);
1689	Assert(cbToRead % 512 == 0);
1690
1691	if (!VALID_PTR(pIoCtx) \|\| !cbToRead)
1692	{
1693	rc = VERR_INVALID_PARAMETER;
1694	goto out;
1695	}
1696
1697	if ( uOffset + cbToRead > pImage->cbSize
1698	\|\| cbToRead == 0)
1699	{
1700	rc = VERR_INVALID_PARAMETER;
1701	goto out;
1702	}
1703
1704	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1705
1706	/* Clip read size to remain in the cluster. */
1707	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1708
1709	/* Get offset in image. */
1710	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1711	if (RT_SUCCESS(rc))
1712	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1713	pIoCtx, cbToRead);
1714
1715	if ( ( RT_SUCCESS(rc)
1716	\|\| rc == VERR_VD_BLOCK_FREE
1717	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1718	&& pcbActuallyRead)
1719	*pcbActuallyRead = cbToRead;
1720
1721	out:
1722	LogFlowFunc(("returns %Rrc\n", rc));
1723	return rc;
1724	}
1725
1726	static int qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1727	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1728	size_t *pcbPostRead, unsigned fWrite)
1729	{
1730	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1731	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1732	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1733	uint32_t offCluster = 0;
1734	uint32_t idxL1 = 0;
1735	uint32_t idxL2 = 0;
1736	uint64_t offImage = 0;
1737	int rc = VINF_SUCCESS;
1738
1739	AssertPtr(pImage);
1740	Assert(!(uOffset % 512));
1741	Assert(!(cbToWrite % 512));
1742
1743	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1744	{
1745	rc = VERR_VD_IMAGE_READ_ONLY;
1746	goto out;
1747	}
1748
1749	if (!VALID_PTR(pIoCtx) \|\| !cbToWrite)
1750	{
1751	rc = VERR_INVALID_PARAMETER;
1752	goto out;
1753	}
1754
1755	if ( uOffset + cbToWrite > pImage->cbSize
1756	\|\| cbToWrite == 0)
1757	{
1758	rc = VERR_INVALID_PARAMETER;
1759	goto out;
1760	}
1761
1762	/* Convert offset to L1, L2 index and cluster offset. */
1763	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1764
1765	/* Clip write size to remain in the cluster. */
1766	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1767	Assert(!(cbToWrite % 512));
1768
1769	/* Get offset in image. */
1770	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1771	if (RT_SUCCESS(rc))
1772	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1773	offImage, pIoCtx, cbToWrite, NULL, NULL);
1774	else if (rc == VERR_VD_BLOCK_FREE)
1775	{
1776	if ( cbToWrite == pImage->cbCluster
1777	&& !(fWrite & VD_WRITE_NO_ALLOC))
1778	{
1779	PQCOWL2CACHEENTRY pL2Entry = NULL;
1780
1781	/* Full cluster write to previously unallocated cluster.
1782	* Allocate cluster and write data. */
1783	Assert(!offCluster);
1784
1785	do
1786	{
1787	uint64_t idxUpdateLe = 0;
1788
1789	/* Check if we have to allocate a new cluster for L2 tables. */
1790	if (!pImage->paL1Table[idxL1])
1791	{
1792	uint64_t offL2Tbl;
1793	PQCOWCLUSTERASYNCALLOC pL2ClusterAlloc = NULL;
1794
1795	/* Allocate new async cluster allocation state. */
1796	pL2ClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1797	if (RT_UNLIKELY(!pL2ClusterAlloc))
1798	{
1799	rc = VERR_NO_MEMORY;
1800	break;
1801	}
1802
1803	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
1804	if (!pL2Entry)
1805	{
1806	rc = VERR_NO_MEMORY;
1807	RTMemFree(pL2ClusterAlloc);
1808	break;
1809	}
1810
1811	offL2Tbl = qcowClusterAllocate(pImage, qcowByte2Cluster(pImage, pImage->cbL2Table));
1812	pL2Entry->offL2Tbl = offL2Tbl;
1813	memset(pL2Entry->paL2Tbl, 0, pImage->cbL2Table);
1814
1815	pL2ClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC;
1816	pL2ClusterAlloc->offNextClusterOld = offL2Tbl;
1817	pL2ClusterAlloc->offClusterNew = offL2Tbl;
1818	pL2ClusterAlloc->idxL1 = idxL1;
1819	pL2ClusterAlloc->idxL2 = idxL2;
1820	pL2ClusterAlloc->cbToWrite = cbToWrite;
1821	pL2ClusterAlloc->pL2Entry = pL2Entry;
1822
1823	/*
1824	* Write the L2 table first and link to the L1 table afterwards.
1825	* If something unexpected happens the worst case which can happen
1826	* is a leak of some clusters.
1827	*/
1828	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1829	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1830	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1831	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1832	break;
1833	else if (RT_FAILURE(rc))
1834	{
1835	RTMemFree(pL2ClusterAlloc);
1836	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1837	break;
1838	}
1839
1840	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1841	}
1842	else
1843	{
1844	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1845	&pL2Entry);
1846	if (RT_SUCCESS(rc))
1847	{
1848	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1849
1850	/* Allocate new async cluster allocation state. */
1851	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1852	if (RT_UNLIKELY(!pDataClusterAlloc))
1853	{
1854	rc = VERR_NO_MEMORY;
1855	break;
1856	}
1857
1858	/* Allocate new cluster for the data. */
1859	uint64_t offData = qcowClusterAllocate(pImage, 1);
1860
1861	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1862	pDataClusterAlloc->offNextClusterOld = offData;
1863	pDataClusterAlloc->offClusterNew = offData;
1864	pDataClusterAlloc->idxL1 = idxL1;
1865	pDataClusterAlloc->idxL2 = idxL2;
1866	pDataClusterAlloc->cbToWrite = cbToWrite;
1867	pDataClusterAlloc->pL2Entry = pL2Entry;
1868
1869	/* Write data. */
1870	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1871	offData, pIoCtx, cbToWrite,
1872	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1873	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1874	break;
1875	else if (RT_FAILURE(rc))
1876	{
1877	RTMemFree(pDataClusterAlloc);
1878	break;
1879	}
1880
1881	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1882	}
1883	}
1884
1885	} while (0);
1886
1887	*pcbPreRead = 0;
1888	*pcbPostRead = 0;
1889	}
1890	else
1891	{
1892	/* Trying to do a partial write to an unallocated cluster. Don't do
1893	* anything except letting the upper layer know what to do. */
1894	*pcbPreRead = offCluster;
1895	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
1896	}
1897	}
1898
1899	if (pcbWriteProcess)
1900	*pcbWriteProcess = cbToWrite;
1901
1902
1903	out:
1904	LogFlowFunc(("returns %Rrc\n", rc));
1905	return rc;
1906	}
1907
1908	static int qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
1909	{
1910	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1911	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1912	int rc = VINF_SUCCESS;
1913
1914	Assert(pImage);
1915
1916	if (VALID_PTR(pIoCtx))
1917	rc = qcowFlushImageAsync(pImage, pIoCtx);
1918	else
1919	rc = VERR_INVALID_PARAMETER;
1920
1921	LogFlowFunc(("returns %Rrc\n", rc));
1922	return rc;
1923	}
1924
1925	/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
1926	static unsigned qcowGetVersion(void *pBackendData)
1927	{
1928	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1929	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1930
1931	AssertPtr(pImage);
1932
1933	if (pImage)
1934	return pImage->uVersion;
1935	else
1936	return 0;
1937	}
1938
1939	/** @copydoc VBOXHDDBACKEND::pfnGetSectorSize */
1940	static uint32_t qcowGetSectorSize(void *pBackendData)
1941	{
1942	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1943	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1944	uint32_t cb = 0;
1945
1946	AssertPtr(pImage);
1947
1948	if (pImage && pImage->pStorage)
1949	cb = 512;
1950
1951	LogFlowFunc(("returns %u\n", cb));
1952	return cb;
1953	}
1954
1955	/** @copydoc VBOXHDDBACKEND::pfnGetSize */
1956	static uint64_t qcowGetSize(void *pBackendData)
1957	{
1958	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1959	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1960	uint64_t cb = 0;
1961
1962	AssertPtr(pImage);
1963
1964	if (pImage && pImage->pStorage)
1965	cb = pImage->cbSize;
1966
1967	LogFlowFunc(("returns %llu\n", cb));
1968	return cb;
1969	}
1970
1971	/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
1972	static uint64_t qcowGetFileSize(void *pBackendData)
1973	{
1974	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1975	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1976	uint64_t cb = 0;
1977
1978	AssertPtr(pImage);
1979
1980	if (pImage)
1981	{
1982	uint64_t cbFile;
1983	if (pImage->pStorage)
1984	{
1985	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1986	if (RT_SUCCESS(rc))
1987	cb += cbFile;
1988	}
1989	}
1990
1991	LogFlowFunc(("returns %lld\n", cb));
1992	return cb;
1993	}
1994
1995	/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
1996	static int qcowGetPCHSGeometry(void *pBackendData,
1997	PVDGEOMETRY pPCHSGeometry)
1998	{
1999	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
2000	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2001	int rc;
2002
2003	AssertPtr(pImage);
2004
2005	if (pImage)
2006	{
2007	if (pImage->PCHSGeometry.cCylinders)
2008	{
2009	*pPCHSGeometry = pImage->PCHSGeometry;
2010	rc = VINF_SUCCESS;
2011	}
2012	else
2013	rc = VERR_VD_GEOMETRY_NOT_SET;
2014	}
2015	else
2016	rc = VERR_VD_NOT_OPENED;
2017
2018	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2019	return rc;
2020	}
2021
2022	/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
2023	static int qcowSetPCHSGeometry(void *pBackendData,
2024	PCVDGEOMETRY pPCHSGeometry)
2025	{
2026	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2027	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2028	int rc;
2029
2030	AssertPtr(pImage);
2031
2032	if (pImage)
2033	{
2034	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2035	{
2036	rc = VERR_VD_IMAGE_READ_ONLY;
2037	goto out;
2038	}
2039
2040	pImage->PCHSGeometry = *pPCHSGeometry;
2041	rc = VINF_SUCCESS;
2042	}
2043	else
2044	rc = VERR_VD_NOT_OPENED;
2045
2046	out:
2047	LogFlowFunc(("returns %Rrc\n", rc));
2048	return rc;
2049	}
2050
2051	/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
2052	static int qcowGetLCHSGeometry(void *pBackendData,
2053	PVDGEOMETRY pLCHSGeometry)
2054	{
2055	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2056	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2057	int rc;
2058
2059	AssertPtr(pImage);
2060
2061	if (pImage)
2062	{
2063	if (pImage->LCHSGeometry.cCylinders)
2064	{
2065	*pLCHSGeometry = pImage->LCHSGeometry;
2066	rc = VINF_SUCCESS;
2067	}
2068	else
2069	rc = VERR_VD_GEOMETRY_NOT_SET;
2070	}
2071	else
2072	rc = VERR_VD_NOT_OPENED;
2073
2074	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2075	return rc;
2076	}
2077
2078	/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
2079	static int qcowSetLCHSGeometry(void *pBackendData,
2080	PCVDGEOMETRY pLCHSGeometry)
2081	{
2082	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData, pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2083	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2084	int rc;
2085
2086	AssertPtr(pImage);
2087
2088	if (pImage)
2089	{
2090	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2091	{
2092	rc = VERR_VD_IMAGE_READ_ONLY;
2093	goto out;
2094	}
2095
2096	pImage->LCHSGeometry = *pLCHSGeometry;
2097	rc = VINF_SUCCESS;
2098	}
2099	else
2100	rc = VERR_VD_NOT_OPENED;
2101
2102	out:
2103	LogFlowFunc(("returns %Rrc\n", rc));
2104	return rc;
2105	}
2106
2107	/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
2108	static unsigned qcowGetImageFlags(void *pBackendData)
2109	{
2110	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2111	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2112	unsigned uImageFlags;
2113
2114	AssertPtr(pImage);
2115
2116	if (pImage)
2117	uImageFlags = pImage->uImageFlags;
2118	else
2119	uImageFlags = 0;
2120
2121	LogFlowFunc(("returns %#x\n", uImageFlags));
2122	return uImageFlags;
2123	}
2124
2125	/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
2126	static unsigned qcowGetOpenFlags(void *pBackendData)
2127	{
2128	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2129	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2130	unsigned uOpenFlags;
2131
2132	AssertPtr(pImage);
2133
2134	if (pImage)
2135	uOpenFlags = pImage->uOpenFlags;
2136	else
2137	uOpenFlags = 0;
2138
2139	LogFlowFunc(("returns %#x\n", uOpenFlags));
2140	return uOpenFlags;
2141	}
2142
2143	/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
2144	static int qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2145	{
2146	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2147	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2148	int rc;
2149
2150	/* Image must be opened and the new flags must be valid. */
2151	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2152	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2153	{
2154	rc = VERR_INVALID_PARAMETER;
2155	goto out;
2156	}
2157
2158	/* Implement this operation via reopening the image. */
2159	rc = qcowFreeImage(pImage, false);
2160	if (RT_FAILURE(rc))
2161	goto out;
2162	rc = qcowOpenImage(pImage, uOpenFlags);
2163
2164	out:
2165	LogFlowFunc(("returns %Rrc\n", rc));
2166	return rc;
2167	}
2168
2169	/** @copydoc VBOXHDDBACKEND::pfnGetComment */
2170	static int qcowGetComment(void pBackendData, char pszComment,
2171	size_t cbComment)
2172	{
2173	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2174	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2175	int rc;
2176
2177	AssertPtr(pImage);
2178
2179	if (pImage)
2180	rc = VERR_NOT_SUPPORTED;
2181	else
2182	rc = VERR_VD_NOT_OPENED;
2183
2184	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
2185	return rc;
2186	}
2187
2188	/** @copydoc VBOXHDDBACKEND::pfnSetComment */
2189	static int qcowSetComment(void pBackendData, const char pszComment)
2190	{
2191	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2192	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2193	int rc;
2194
2195	AssertPtr(pImage);
2196
2197	if (pImage)
2198	{
2199	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2200	rc = VERR_VD_IMAGE_READ_ONLY;
2201	else
2202	rc = VERR_NOT_SUPPORTED;
2203	}
2204	else
2205	rc = VERR_VD_NOT_OPENED;
2206
2207	LogFlowFunc(("returns %Rrc\n", rc));
2208	return rc;
2209	}
2210
2211	/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
2212	static int qcowGetUuid(void *pBackendData, PRTUUID pUuid)
2213	{
2214	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2215	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2216	int rc;
2217
2218	AssertPtr(pImage);
2219
2220	if (pImage)
2221	rc = VERR_NOT_SUPPORTED;
2222	else
2223	rc = VERR_VD_NOT_OPENED;
2224
2225	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2226	return rc;
2227	}
2228
2229	/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
2230	static int qcowSetUuid(void *pBackendData, PCRTUUID pUuid)
2231	{
2232	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2233	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2234	int rc;
2235
2236	LogFlowFunc(("%RTuuid\n", pUuid));
2237	AssertPtr(pImage);
2238
2239	if (pImage)
2240	{
2241	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2242	rc = VERR_NOT_SUPPORTED;
2243	else
2244	rc = VERR_VD_IMAGE_READ_ONLY;
2245	}
2246	else
2247	rc = VERR_VD_NOT_OPENED;
2248
2249	LogFlowFunc(("returns %Rrc\n", rc));
2250	return rc;
2251	}
2252
2253	/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
2254	static int qcowGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2255	{
2256	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2257	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2258	int rc;
2259
2260	AssertPtr(pImage);
2261
2262	if (pImage)
2263	rc = VERR_NOT_SUPPORTED;
2264	else
2265	rc = VERR_VD_NOT_OPENED;
2266
2267	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2268	return rc;
2269	}
2270
2271	/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
2272	static int qcowSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2273	{
2274	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2275	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2276	int rc;
2277
2278	AssertPtr(pImage);
2279
2280	if (pImage)
2281	{
2282	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2283	rc = VERR_NOT_SUPPORTED;
2284	else
2285	rc = VERR_VD_IMAGE_READ_ONLY;
2286	}
2287	else
2288	rc = VERR_VD_NOT_OPENED;
2289
2290	LogFlowFunc(("returns %Rrc\n", rc));
2291	return rc;
2292	}
2293
2294	/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
2295	static int qcowGetParentUuid(void *pBackendData, PRTUUID pUuid)
2296	{
2297	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2298	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2299	int rc;
2300
2301	AssertPtr(pImage);
2302
2303	if (pImage)
2304	rc = VERR_NOT_SUPPORTED;
2305	else
2306	rc = VERR_VD_NOT_OPENED;
2307
2308	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2309	return rc;
2310	}
2311
2312	/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
2313	static int qcowSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2314	{
2315	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2316	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2317	int rc;
2318
2319	AssertPtr(pImage);
2320
2321	if (pImage)
2322	{
2323	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2324	rc = VERR_NOT_SUPPORTED;
2325	else
2326	rc = VERR_VD_IMAGE_READ_ONLY;
2327	}
2328	else
2329	rc = VERR_VD_NOT_OPENED;
2330
2331	LogFlowFunc(("returns %Rrc\n", rc));
2332	return rc;
2333	}
2334
2335	/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
2336	static int qcowGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2337	{
2338	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2339	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2340	int rc;
2341
2342	AssertPtr(pImage);
2343
2344	if (pImage)
2345	rc = VERR_NOT_SUPPORTED;
2346	else
2347	rc = VERR_VD_NOT_OPENED;
2348
2349	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2350	return rc;
2351	}
2352
2353	/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
2354	static int qcowSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2355	{
2356	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2357	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2358	int rc;
2359
2360	AssertPtr(pImage);
2361
2362	if (pImage)
2363	{
2364	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2365	rc = VERR_NOT_SUPPORTED;
2366	else
2367	rc = VERR_VD_IMAGE_READ_ONLY;
2368	}
2369	else
2370	rc = VERR_VD_NOT_OPENED;
2371
2372	LogFlowFunc(("returns %Rrc\n", rc));
2373	return rc;
2374	}
2375
2376	/** @copydoc VBOXHDDBACKEND::pfnDump */
2377	static void qcowDump(void *pBackendData)
2378	{
2379	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2380
2381	AssertPtr(pImage);
2382	if (pImage)
2383	{
2384	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cSector=%llu\n",
2385	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2386	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2387	pImage->cbSize / 512);
2388	}
2389	}
2390
2391	/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
2392	static int qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2393	{
2394	int rc = VINF_SUCCESS;
2395	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2396
2397	AssertPtr(pImage);
2398	if (pImage)
2399	if (pImage->pszBackingFilename)
2400	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2401	else
2402	rc = VERR_NOT_SUPPORTED;
2403	else
2404	rc = VERR_VD_NOT_OPENED;
2405
2406	LogFlowFunc(("returns %Rrc\n", rc));
2407	return rc;
2408	}
2409
2410	/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
2411	static int qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2412	{
2413	int rc = VINF_SUCCESS;
2414	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2415
2416	AssertPtr(pImage);
2417	if (pImage)
2418	{
2419	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2420	rc = VERR_VD_IMAGE_READ_ONLY;
2421	else if ( pImage->pszBackingFilename
2422	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2423	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2424	else
2425	{
2426	if (pImage->pszBackingFilename)
2427	RTStrFree(pImage->pszBackingFilename);
2428	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2429	if (!pImage->pszBackingFilename)
2430	rc = VERR_NO_MEMORY;
2431	else
2432	{
2433	if (!pImage->offBackingFilename)
2434	{
2435	/* Allocate new cluster. */
2436	uint64_t offData = qcowClusterAllocate(pImage, 1);
2437
2438	Assert((offData & UINT32_MAX) == offData);
2439	pImage->offBackingFilename = (uint32_t)offData;
2440	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2441	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2442	offData + pImage->cbCluster);
2443	}
2444
2445	if (RT_SUCCESS(rc))
2446	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2447	pImage->offBackingFilename,
2448	pImage->pszBackingFilename,
2449	strlen(pImage->pszBackingFilename));
2450	}
2451	}
2452	}
2453	else
2454	rc = VERR_VD_NOT_OPENED;
2455
2456	LogFlowFunc(("returns %Rrc\n", rc));
2457	return rc;
2458	}
2459
2460
2461
2462	VBOXHDDBACKEND g_QCowBackend =
2463	{
2464	/* pszBackendName */
2465	"QCOW",
2466	/* cbSize */
2467	sizeof(VBOXHDDBACKEND),
2468	/* uBackendCaps */
2469	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2470	/* paFileExtensions */
2471	s_aQCowFileExtensions,
2472	/* paConfigInfo */
2473	NULL,
2474	/* hPlugin */
2475	NIL_RTLDRMOD,
2476	/* pfnCheckIfValid */
2477	qcowCheckIfValid,
2478	/* pfnOpen */
2479	qcowOpen,
2480	/* pfnCreate */
2481	qcowCreate,
2482	/* pfnRename */
2483	qcowRename,
2484	/* pfnClose */
2485	qcowClose,
2486	/* pfnRead */
2487	qcowRead,
2488	/* pfnWrite */
2489	qcowWrite,
2490	/* pfnFlush */
2491	qcowFlush,
2492	/* pfnDiscard */
2493	NULL,
2494	/* pfnGetVersion */
2495	qcowGetVersion,
2496	/* pfnGetSectorSize */
2497	qcowGetSectorSize,
2498	/* pfnGetSize */
2499	qcowGetSize,
2500	/* pfnGetFileSize */
2501	qcowGetFileSize,
2502	/* pfnGetPCHSGeometry */
2503	qcowGetPCHSGeometry,
2504	/* pfnSetPCHSGeometry */
2505	qcowSetPCHSGeometry,
2506	/* pfnGetLCHSGeometry */
2507	qcowGetLCHSGeometry,
2508	/* pfnSetLCHSGeometry */
2509	qcowSetLCHSGeometry,
2510	/* pfnGetImageFlags */
2511	qcowGetImageFlags,
2512	/* pfnGetOpenFlags */
2513	qcowGetOpenFlags,
2514	/* pfnSetOpenFlags */
2515	qcowSetOpenFlags,
2516	/* pfnGetComment */
2517	qcowGetComment,
2518	/* pfnSetComment */
2519	qcowSetComment,
2520	/* pfnGetUuid */
2521	qcowGetUuid,
2522	/* pfnSetUuid */
2523	qcowSetUuid,
2524	/* pfnGetModificationUuid */
2525	qcowGetModificationUuid,
2526	/* pfnSetModificationUuid */
2527	qcowSetModificationUuid,
2528	/* pfnGetParentUuid */
2529	qcowGetParentUuid,
2530	/* pfnSetParentUuid */
2531	qcowSetParentUuid,
2532	/* pfnGetParentModificationUuid */
2533	qcowGetParentModificationUuid,
2534	/* pfnSetParentModificationUuid */
2535	qcowSetParentModificationUuid,
2536	/* pfnDump */
2537	qcowDump,
2538	/* pfnGetTimeStamp */
2539	NULL,
2540	/* pfnGetParentTimeStamp */
2541	NULL,
2542	/* pfnSetParentTimeStamp */
2543	NULL,
2544	/* pfnGetParentFilename */
2545	qcowGetParentFilename,
2546	/* pfnSetParentFilename */
2547	qcowSetParentFilename,
2548	/* pfnComposeLocation */
2549	genericFileComposeLocation,
2550	/* pfnComposeName */
2551	genericFileComposeName,
2552	/* pfnCompact */
2553	NULL,
2554	/* pfnResize */
2555	NULL,
2556	/* pfnRepair */
2557	NULL
2558	};

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source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 49439

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