QCOW.cpp@ 77921

Last change on this file since 77921 was 77921, checked in by vboxsync, 5 years ago
Storage/QCOW: Fix extracting offsets from the L1 and L2 table for v2 images and pplug a small memory leak when freeing the image
Property svn:eol-style set to `native` Property svn:keywords set to `Author Date Id Revision`
File size: 89.2 KB

Line
1	/* $Id: QCOW.cpp 77921 2019-03-27 14:37:38Z vboxsync $ */
2	/** @file
3	* QCOW - QCOW Disk image.
4	*/
5
6	/*
7	* Copyright (C) 2011-2019 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	#include "VDBackendsInline.h"
36
37	/** @page pg_storage_qcow QCOW Storage Backend
38	* The QCOW backend implements support for the qemu copy on write format (short QCOW).
39	* There is no official specification available but the format is described
40	* at http://people.gnome.org/~markmc/qcow-image-format.html for version 2
41	* and http://people.gnome.org/~markmc/qcow-image-format-version-1.html for version 1.
42	*
43	* Missing things to implement:
44	* - v2 image creation and handling of the reference count table. (Blocker to enable support for V2 images)
45	* - cluster encryption
46	* - cluster compression
47	* - compaction
48	* - resizing
49	*/
50
51
52	/*********************************************************************************************************************************
53	* Structures in a QCOW image, big endian *
54	*********************************************************************************************************************************/
55
56	#pragma pack(1) /* Completely unnecessary. */
57	typedef struct QCowHeader
58	{
59	/** Magic value. */
60	uint32_t u32Magic;
61	/** Version of the image. */
62	uint32_t u32Version;
63	/** Version dependent data. */
64	union
65	{
66	/** Version 1. */
67	struct
68	{
69	/** Backing file offset. */
70	uint64_t u64BackingFileOffset;
71	/** Size of the backing file. */
72	uint32_t u32BackingFileSize;
73	/** mtime (Modification time?) - can be ignored. */
74	uint32_t u32MTime;
75	/** Logical size of the image in bytes. */
76	uint64_t u64Size;
77	/** Number of bits in the virtual offset used as a cluster offset. */
78	uint8_t u8ClusterBits;
79	/** Number of bits in the virtual offset used for the L2 index. */
80	uint8_t u8L2Bits;
81	/** Padding because the header is not packed in the original source. */
82	uint16_t u16Padding;
83	/** Used cryptographic method. */
84	uint32_t u32CryptMethod;
85	/** Offset of the L1 table in the image in bytes. */
86	uint64_t u64L1TableOffset;
87	} v1;
88	/** Version 2. */
89	struct
90	{
91	/** Backing file offset. */
92	uint64_t u64BackingFileOffset;
93	/** Size of the backing file. */
94	uint32_t u32BackingFileSize;
95	/** Number of bits in the virtual offset used as a cluster offset. */
96	uint32_t u32ClusterBits;
97	/** Logical size of the image. */
98	uint64_t u64Size;
99	/** Used cryptographic method. */
100	uint32_t u32CryptMethod;
101	/** Size of the L1 table in entries (each 8bytes big). */
102	uint32_t u32L1Size;
103	/** Offset of the L1 table in the image in bytes. */
104	uint64_t u64L1TableOffset;
105	/** Start of the refcount table in the image. */
106	uint64_t u64RefcountTableOffset;
107	/** Size of the refcount table in clusters. */
108	uint32_t u32RefcountTableClusters;
109	/** Number of snapshots in the image. */
110	uint32_t u32NbSnapshots;
111	/** Offset of the first snapshot header in the image. */
112	uint64_t u64SnapshotsOffset;
113	} v2;
114	} Version;
115	} QCowHeader;
116	#pragma pack()
117	/** Pointer to a on disk QCOW header. */
118	typedef QCowHeader *PQCowHeader;
119
120	/** QCOW magic value. */
121	#define QCOW_MAGIC UINT32_C(0x514649fb) /* QFI\0xfb */
122	/** Size of the V1 header. */
123	#define QCOW_V1_HDR_SIZE (48)
124	/** Size of the V2 header. */
125	#define QCOW_V2_HDR_SIZE (72)
126
127	/** Cluster is compressed flag for QCOW images. */
128	#define QCOW_V1_COMPRESSED_FLAG RT_BIT_64(63)
129
130	/** Copied flag for QCOW2 images. */
131	#define QCOW_V2_COPIED_FLAG RT_BIT_64(63)
132	/** Cluster is compressed flag for QCOW2 images. */
133	#define QCOW_V2_COMPRESSED_FLAG RT_BIT_64(62)
134	/** The mask for extracting the offset from either the L1 or L2 table. */
135	#define QCOW_V2_TBL_OFFSET_MASK UINT64_C(0x00fffffffffffe00)
136
137
138	/*********************************************************************************************************************************
139	* Constants And Macros, Structures and Typedefs *
140	*********************************************************************************************************************************/
141
142	/**
143	* QCOW L2 cache entry.
144	*/
145	typedef struct QCOWL2CACHEENTRY
146	{
147	/** List node for the search list. */
148	RTLISTNODE NodeSearch;
149	/** List node for the LRU list. */
150	RTLISTNODE NodeLru;
151	/** Reference counter. */
152	uint32_t cRefs;
153	/** The offset of the L2 table, used as search key. */
154	uint64_t offL2Tbl;
155	/** Pointer to the cached L2 table. */
156	uint64_t *paL2Tbl;
157	} QCOWL2CACHEENTRY, *PQCOWL2CACHEENTRY;
158
159	/** Maximum amount of memory the cache is allowed to use. */
160	#define QCOW_L2_CACHE_MEMORY_MAX (2*_1M)
161
162	/** QCOW default cluster size for image version 2. */
163	#define QCOW2_CLUSTER_SIZE_DEFAULT (64*_1K)
164	/** QCOW default cluster size for image version 1. */
165	#define QCOW_CLUSTER_SIZE_DEFAULT (4*_1K)
166	/** QCOW default L2 table size in clusters. */
167	#define QCOW_L2_CLUSTERS_DEFAULT (1)
168
169	/**
170	* QCOW image data structure.
171	*/
172	typedef struct QCOWIMAGE
173	{
174	/** Image name. */
175	const char *pszFilename;
176	/** Storage handle. */
177	PVDIOSTORAGE pStorage;
178
179	/** Pointer to the per-disk VD interface list. */
180	PVDINTERFACE pVDIfsDisk;
181	/** Pointer to the per-image VD interface list. */
182	PVDINTERFACE pVDIfsImage;
183	/** Error interface. */
184	PVDINTERFACEERROR pIfError;
185	/** I/O interface. */
186	PVDINTERFACEIOINT pIfIo;
187
188	/** Open flags passed by VBoxHD layer. */
189	unsigned uOpenFlags;
190	/** Image flags defined during creation or determined during open. */
191	unsigned uImageFlags;
192	/** Total size of the image. */
193	uint64_t cbSize;
194	/** Physical geometry of this image. */
195	VDGEOMETRY PCHSGeometry;
196	/** Logical geometry of this image. */
197	VDGEOMETRY LCHSGeometry;
198
199	/** Image version. */
200	unsigned uVersion;
201	/** MTime field - used only to preserve value in opened images, unmodified otherwise. */
202	uint32_t MTime;
203
204	/** Filename of the backing file if any. */
205	char *pszBackingFilename;
206	/** Offset of the filename in the image. */
207	uint64_t offBackingFilename;
208	/** Size of the backing filename excluding \0. */
209	uint32_t cbBackingFilename;
210
211	/** Next offset of a new cluster, aligned to sector size. */
212	uint64_t offNextCluster;
213	/** Cluster size in bytes. */
214	uint32_t cbCluster;
215	/** Number of entries in the L1 table. */
216	uint32_t cL1TableEntries;
217	/** Size of an L1 rounded to the next cluster size. */
218	uint32_t cbL1Table;
219	/** Pointer to the L1 table. */
220	uint64_t *paL1Table;
221	/** Offset of the L1 table. */
222	uint64_t offL1Table;
223
224	/** Size of the L2 table in bytes. */
225	uint32_t cbL2Table;
226	/** Number of entries in the L2 table. */
227	uint32_t cL2TableEntries;
228	/** Memory occupied by the L2 table cache. */
229	size_t cbL2Cache;
230	/** The sorted L2 entry list used for searching. */
231	RTLISTNODE ListSearch;
232	/** The LRU L2 entry list used for eviction. */
233	RTLISTNODE ListLru;
234
235	/** Offset of the refcount table. */
236	uint64_t offRefcountTable;
237	/** Size of the refcount table in bytes. */
238	uint32_t cbRefcountTable;
239	/** Number of entries in the refcount table. */
240	uint32_t cRefcountTableEntries;
241	/** Pointer to the refcount table. */
242	uint64_t *paRefcountTable;
243
244	/** Offset mask for a cluster. */
245	uint64_t fOffsetMask;
246	/** Number of bits to shift to get the L1 index. */
247	uint32_t cL1Shift;
248	/** L2 table mask to get the L2 index. */
249	uint64_t fL2Mask;
250	/** Number of bits to shift to get the L2 index. */
251	uint32_t cL2Shift;
252
253	/** Pointer to the L2 table we are currently allocating
254	* (can be only one at a time). */
255	PQCOWL2CACHEENTRY pL2TblAlloc;
256	/** The static region list. */
257	VDREGIONLIST RegionList;
258	} QCOWIMAGE, *PQCOWIMAGE;
259
260	/**
261	* State of the async cluster allocation.
262	*/
263	typedef enum QCOWCLUSTERASYNCALLOCSTATE
264	{
265	/** Invalid. */
266	QCOWCLUSTERASYNCALLOCSTATE_INVALID = 0,
267	/** L2 table allocation. */
268	QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC,
269	/** Link L2 table into L1. */
270	QCOWCLUSTERASYNCALLOCSTATE_L2_LINK,
271	/** Allocate user data cluster. */
272	QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC,
273	/** Link user data cluster. */
274	QCOWCLUSTERASYNCALLOCSTATE_USER_LINK,
275	/** 32bit blowup. */
276	QCOWCLUSTERASYNCALLOCSTATE_32BIT_HACK = 0x7fffffff
277	} QCOWCLUSTERASYNCALLOCSTATE, *PQCOWCLUSTERASYNCALLOCSTATE;
278
279	/**
280	* Data needed to track async cluster allocation.
281	*/
282	typedef struct QCOWCLUSTERASYNCALLOC
283	{
284	/** The state of the cluster allocation. */
285	QCOWCLUSTERASYNCALLOCSTATE enmAllocState;
286	/** Old image size to rollback in case of an error. */
287	uint64_t offNextClusterOld;
288	/** L1 index to link if any. */
289	uint32_t idxL1;
290	/** L2 index to link, required in any case. */
291	uint32_t idxL2;
292	/** Start offset of the allocated cluster. */
293	uint64_t offClusterNew;
294	/** L2 cache entry if a L2 table is allocated. */
295	PQCOWL2CACHEENTRY pL2Entry;
296	/** Number of bytes to write. */
297	size_t cbToWrite;
298	} QCOWCLUSTERASYNCALLOC, *PQCOWCLUSTERASYNCALLOC;
299
300
301	/*********************************************************************************************************************************
302	* Static Variables *
303	*********************************************************************************************************************************/
304
305	/** NULL-terminated array of supported file extensions. */
306	static const VDFILEEXTENSION s_aQCowFileExtensions[] =
307	{
308	{"qcow", VDTYPE_HDD},
309	{"qcow2", VDTYPE_HDD},
310	{NULL, VDTYPE_INVALID}
311	};
312
313
314	/*********************************************************************************************************************************
315	* Internal Functions *
316	*********************************************************************************************************************************/
317
318	/**
319	* Return power of 2 or 0 if num error.
320	*
321	* @returns The power of 2 or 0 if the given number is not a power of 2.
322	* @param u32 The number.
323	*/
324	static uint32_t qcowGetPowerOfTwo(uint32_t u32)
325	{
326	if (u32 == 0)
327	return 0;
328	uint32_t uPower2 = 0;
329	while ((u32 & 1) == 0)
330	{
331	u32 >>= 1;
332	uPower2++;
333	}
334	return u32 == 1 ? uPower2 : 0;
335	}
336
337
338	/**
339	* Converts the image header to the host endianess and performs basic checks.
340	*
341	* @returns Whether the given header is valid or not.
342	* @param pHeader Pointer to the header to convert.
343	*/
344	static bool qcowHdrConvertToHostEndianess(PQCowHeader pHeader)
345	{
346	pHeader->u32Magic = RT_BE2H_U32(pHeader->u32Magic);
347	pHeader->u32Version = RT_BE2H_U32(pHeader->u32Version);
348
349	if (pHeader->u32Magic != QCOW_MAGIC)
350	return false;
351
352	if (pHeader->u32Version == 1)
353	{
354	pHeader->Version.v1.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v1.u64BackingFileOffset);
355	pHeader->Version.v1.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v1.u32BackingFileSize);
356	pHeader->Version.v1.u32MTime = RT_BE2H_U32(pHeader->Version.v1.u32MTime);
357	pHeader->Version.v1.u64Size = RT_BE2H_U64(pHeader->Version.v1.u64Size);
358	pHeader->Version.v1.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v1.u32CryptMethod);
359	pHeader->Version.v1.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v1.u64L1TableOffset);
360	}
361	else if (pHeader->u32Version == 2)
362	{
363	pHeader->Version.v2.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v2.u64BackingFileOffset);
364	pHeader->Version.v2.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v2.u32BackingFileSize);
365	pHeader->Version.v2.u32ClusterBits = RT_BE2H_U32(pHeader->Version.v2.u32ClusterBits);
366	pHeader->Version.v2.u64Size = RT_BE2H_U64(pHeader->Version.v2.u64Size);
367	pHeader->Version.v2.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v2.u32CryptMethod);
368	pHeader->Version.v2.u32L1Size = RT_BE2H_U32(pHeader->Version.v2.u32L1Size);
369	pHeader->Version.v2.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v2.u64L1TableOffset);
370	pHeader->Version.v2.u64RefcountTableOffset = RT_BE2H_U64(pHeader->Version.v2.u64RefcountTableOffset);
371	pHeader->Version.v2.u32RefcountTableClusters = RT_BE2H_U32(pHeader->Version.v2.u32RefcountTableClusters);
372	pHeader->Version.v2.u32NbSnapshots = RT_BE2H_U32(pHeader->Version.v2.u32NbSnapshots);
373	pHeader->Version.v2.u64SnapshotsOffset = RT_BE2H_U64(pHeader->Version.v2.u64SnapshotsOffset);
374	}
375	else
376	return false;
377
378	return true;
379	}
380
381	/**
382	* Creates a QCOW header from the given image state.
383	*
384	* @returns nothing.
385	* @param pImage Image instance data.
386	* @param pHeader Pointer to the header to convert.
387	* @param pcbHeader Where to store the size of the header to write.
388	*/
389	static void qcowHdrConvertFromHostEndianess(PQCOWIMAGE pImage, PQCowHeader pHeader,
390	size_t *pcbHeader)
391	{
392	memset(pHeader, 0, sizeof(QCowHeader));
393
394	pHeader->u32Magic = RT_H2BE_U32(QCOW_MAGIC);
395	pHeader->u32Version = RT_H2BE_U32(pImage->uVersion);
396	if (pImage->uVersion == 1)
397	{
398	pHeader->Version.v1.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
399	pHeader->Version.v1.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
400	pHeader->Version.v1.u32MTime = RT_H2BE_U32(pImage->MTime);
401	pHeader->Version.v1.u64Size = RT_H2BE_U64(pImage->cbSize);
402	pHeader->Version.v1.u8ClusterBits = (uint8_t)qcowGetPowerOfTwo(pImage->cbCluster);
403	pHeader->Version.v1.u8L2Bits = (uint8_t)qcowGetPowerOfTwo(pImage->cL2TableEntries);
404	pHeader->Version.v1.u32CryptMethod = RT_H2BE_U32(0);
405	pHeader->Version.v1.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
406	*pcbHeader = QCOW_V1_HDR_SIZE;
407	}
408	else if (pImage->uVersion == 2)
409	{
410	pHeader->Version.v2.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
411	pHeader->Version.v2.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
412	pHeader->Version.v2.u32ClusterBits = RT_H2BE_U32(qcowGetPowerOfTwo(pImage->cbCluster));
413	pHeader->Version.v2.u64Size = RT_H2BE_U64(pImage->cbSize);
414	pHeader->Version.v2.u32CryptMethod = RT_H2BE_U32(0);
415	pHeader->Version.v2.u32L1Size = RT_H2BE_U32(pImage->cL1TableEntries);
416	pHeader->Version.v2.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
417	pHeader->Version.v2.u64RefcountTableOffset = RT_H2BE_U64(pImage->offRefcountTable);
418	pHeader->Version.v2.u32RefcountTableClusters = RT_H2BE_U32(pImage->cbRefcountTable / pImage->cbCluster);
419	pHeader->Version.v2.u32NbSnapshots = RT_H2BE_U32(0);
420	pHeader->Version.v2.u64SnapshotsOffset = RT_H2BE_U64((uint64_t)0);
421	*pcbHeader = QCOW_V2_HDR_SIZE;
422	}
423	else
424	AssertMsgFailed(("Invalid version of the QCOW image format %d\n", pImage->uVersion));
425	}
426
427	/**
428	* Convert table entries from little endian to host endianess.
429	*
430	* @returns nothing.
431	* @param paTbl Pointer to the table.
432	* @param cEntries Number of entries in the table.
433	*/
434	static void qcowTableConvertToHostEndianess(uint64_t *paTbl, uint32_t cEntries)
435	{
436	while(cEntries-- > 0)
437	{
438	paTbl = RT_BE2H_U64(paTbl);
439	paTbl++;
440	}
441	}
442
443	/**
444	* Convert table entries from host to little endian format.
445	*
446	* @returns nothing.
447	* @param paTblImg Pointer to the table which will store the little endian table.
448	* @param paTbl The source table to convert.
449	* @param cEntries Number of entries in the table.
450	*/
451	static void qcowTableConvertFromHostEndianess(uint64_t paTblImg, uint64_t paTbl,
452	uint32_t cEntries)
453	{
454	while(cEntries-- > 0)
455	{
456	paTblImg = RT_H2BE_U64(paTbl);
457	paTbl++;
458	paTblImg++;
459	}
460	}
461
462	/**
463	* Creates the L2 table cache.
464	*
465	* @returns VBox status code.
466	* @param pImage The image instance data.
467	*/
468	static int qcowL2TblCacheCreate(PQCOWIMAGE pImage)
469	{
470	pImage->cbL2Cache = 0;
471	RTListInit(&pImage->ListSearch);
472	RTListInit(&pImage->ListLru);
473
474	return VINF_SUCCESS;
475	}
476
477	/**
478	* Destroys the L2 table cache.
479	*
480	* @returns nothing.
481	* @param pImage The image instance data.
482	*/
483	static void qcowL2TblCacheDestroy(PQCOWIMAGE pImage)
484	{
485	PQCOWL2CACHEENTRY pL2Entry;
486	PQCOWL2CACHEENTRY pL2Next;
487	RTListForEachSafe(&pImage->ListSearch, pL2Entry, pL2Next, QCOWL2CACHEENTRY, NodeSearch)
488	{
489	Assert(!pL2Entry->cRefs);
490
491	RTListNodeRemove(&pL2Entry->NodeSearch);
492	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
493	RTMemFree(pL2Entry);
494	}
495
496	pImage->cbL2Cache = 0;
497	RTListInit(&pImage->ListSearch);
498	RTListInit(&pImage->ListLru);
499	}
500
501	/**
502	* Returns the L2 table matching the given offset or NULL if none could be found.
503	*
504	* @returns Pointer to the L2 table cache entry or NULL.
505	* @param pImage The image instance data.
506	* @param offL2Tbl Offset of the L2 table to search for.
507	*/
508	static PQCOWL2CACHEENTRY qcowL2TblCacheRetain(PQCOWIMAGE pImage, uint64_t offL2Tbl)
509	{
510	if ( pImage->pL2TblAlloc
511	&& pImage->pL2TblAlloc->offL2Tbl == offL2Tbl)
512	{
513	pImage->pL2TblAlloc->cRefs++;
514	return pImage->pL2TblAlloc;
515	}
516
517	PQCOWL2CACHEENTRY pL2Entry;
518	RTListForEach(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch)
519	{
520	if (pL2Entry->offL2Tbl == offL2Tbl)
521	break;
522	}
523
524	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
525	{
526	/* Update LRU list. */
527	RTListNodeRemove(&pL2Entry->NodeLru);
528	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
529	pL2Entry->cRefs++;
530	return pL2Entry;
531	}
532
533	return NULL;
534	}
535
536	/**
537	* Releases a L2 table cache entry.
538	*
539	* @returns nothing.
540	* @param pL2Entry The L2 cache entry.
541	*/
542	static void qcowL2TblCacheEntryRelease(PQCOWL2CACHEENTRY pL2Entry)
543	{
544	Assert(pL2Entry->cRefs > 0);
545	pL2Entry->cRefs--;
546	}
547
548	/**
549	* Allocates a new L2 table from the cache evicting old entries if required.
550	*
551	* @returns Pointer to the L2 cache entry or NULL.
552	* @param pImage The image instance data.
553	*/
554	static PQCOWL2CACHEENTRY qcowL2TblCacheEntryAlloc(PQCOWIMAGE pImage)
555	{
556	PQCOWL2CACHEENTRY pL2Entry = NULL;
557
558	if (pImage->cbL2Cache + pImage->cbL2Table <= QCOW_L2_CACHE_MEMORY_MAX)
559	{
560	/* Add a new entry. */
561	pL2Entry = (PQCOWL2CACHEENTRY)RTMemAllocZ(sizeof(QCOWL2CACHEENTRY));
562	if (pL2Entry)
563	{
564	pL2Entry->paL2Tbl = (uint64_t *)RTMemPageAllocZ(pImage->cbL2Table);
565	if (RT_UNLIKELY(!pL2Entry->paL2Tbl))
566	{
567	RTMemFree(pL2Entry);
568	pL2Entry = NULL;
569	}
570	else
571	{
572	pL2Entry->cRefs = 1;
573	pImage->cbL2Cache += pImage->cbL2Table;
574	}
575	}
576	}
577	else
578	{
579	/* Evict the last not in use entry and use it */
580	Assert(!RTListIsEmpty(&pImage->ListLru));
581
582	RTListForEachReverse(&pImage->ListLru, pL2Entry, QCOWL2CACHEENTRY, NodeLru)
583	{
584	if (!pL2Entry->cRefs)
585	break;
586	}
587
588	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
589	{
590	RTListNodeRemove(&pL2Entry->NodeSearch);
591	RTListNodeRemove(&pL2Entry->NodeLru);
592	pL2Entry->offL2Tbl = 0;
593	pL2Entry->cRefs = 1;
594	}
595	else
596	pL2Entry = NULL;
597	}
598
599	return pL2Entry;
600	}
601
602	/**
603	* Frees a L2 table cache entry.
604	*
605	* @returns nothing.
606	* @param pImage The image instance data.
607	* @param pL2Entry The L2 cache entry to free.
608	*/
609	static void qcowL2TblCacheEntryFree(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
610	{
611	Assert(!pL2Entry->cRefs);
612	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
613	RTMemFree(pL2Entry);
614
615	pImage->cbL2Cache -= pImage->cbL2Table;
616	}
617
618	/**
619	* Inserts an entry in the L2 table cache.
620	*
621	* @returns nothing.
622	* @param pImage The image instance data.
623	* @param pL2Entry The L2 cache entry to insert.
624	*/
625	static void qcowL2TblCacheEntryInsert(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
626	{
627	Assert(pL2Entry->offL2Tbl > 0);
628
629	/* Insert at the top of the LRU list. */
630	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
631
632	if (RTListIsEmpty(&pImage->ListSearch))
633	{
634	RTListAppend(&pImage->ListSearch, &pL2Entry->NodeSearch);
635	}
636	else
637	{
638	/* Insert into search list. */
639	PQCOWL2CACHEENTRY pIt;
640	pIt = RTListGetFirst(&pImage->ListSearch, QCOWL2CACHEENTRY, NodeSearch);
641	if (pIt->offL2Tbl > pL2Entry->offL2Tbl)
642	RTListPrepend(&pImage->ListSearch, &pL2Entry->NodeSearch);
643	else
644	{
645	bool fInserted = false;
646
647	RTListForEach(&pImage->ListSearch, pIt, QCOWL2CACHEENTRY, NodeSearch)
648	{
649	Assert(pIt->offL2Tbl != pL2Entry->offL2Tbl);
650	if (pIt->offL2Tbl < pL2Entry->offL2Tbl)
651	{
652	RTListNodeInsertAfter(&pIt->NodeSearch, &pL2Entry->NodeSearch);
653	fInserted = true;
654	break;
655	}
656	}
657	Assert(fInserted);
658	}
659	}
660	}
661
662	/**
663	* Fetches the L2 from the given offset trying the LRU cache first and
664	* reading it from the image after a cache miss.
665	*
666	* @returns VBox status code.
667	* @param pImage Image instance data.
668	* @param pIoCtx The I/O context.
669	* @param offL2Tbl The offset of the L2 table in the image.
670	* @param ppL2Entry Where to store the L2 table on success.
671	*/
672	static int qcowL2TblCacheFetch(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offL2Tbl,
673	PQCOWL2CACHEENTRY *ppL2Entry)
674	{
675	int rc = VINF_SUCCESS;
676
677	/* Try to fetch the L2 table from the cache first. */
678	PQCOWL2CACHEENTRY pL2Entry = qcowL2TblCacheRetain(pImage, offL2Tbl);
679	if (!pL2Entry)
680	{
681	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
682
683	if (pL2Entry)
684	{
685	/* Read from the image. */
686	PVDMETAXFER pMetaXfer;
687
688	pL2Entry->offL2Tbl = offL2Tbl;
689	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
690	offL2Tbl, pL2Entry->paL2Tbl,
691	pImage->cbL2Table, pIoCtx,
692	&pMetaXfer, NULL, NULL);
693	if (RT_SUCCESS(rc))
694	{
695	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
696	#if defined(RT_LITTLE_ENDIAN)
697	qcowTableConvertToHostEndianess(pL2Entry->paL2Tbl, pImage->cL2TableEntries);
698	#endif
699	qcowL2TblCacheEntryInsert(pImage, pL2Entry);
700	}
701	else
702	{
703	qcowL2TblCacheEntryRelease(pL2Entry);
704	qcowL2TblCacheEntryFree(pImage, pL2Entry);
705	}
706	}
707	else
708	rc = VERR_NO_MEMORY;
709	}
710
711	if (RT_SUCCESS(rc))
712	*ppL2Entry = pL2Entry;
713
714	return rc;
715	}
716
717	/**
718	* Sets the L1, L2 and offset bitmasks and L1 and L2 bit shift members.
719	*
720	* @returns nothing.
721	* @param pImage The image instance data.
722	*/
723	static void qcowTableMasksInit(PQCOWIMAGE pImage)
724	{
725	uint32_t cClusterBits, cL2TableBits;
726
727	cClusterBits = qcowGetPowerOfTwo(pImage->cbCluster);
728	cL2TableBits = qcowGetPowerOfTwo(pImage->cL2TableEntries);
729
730	Assert(cClusterBits + cL2TableBits < 64);
731
732	pImage->fOffsetMask = ((uint64_t)pImage->cbCluster - 1);
733	pImage->fL2Mask = ((uint64_t)pImage->cL2TableEntries - 1) << cClusterBits;
734	pImage->cL2Shift = cClusterBits;
735	pImage->cL1Shift = cClusterBits + cL2TableBits;
736	}
737
738	/**
739	* Converts a given logical offset into the
740	*
741	* @returns nothing.
742	* @param pImage The image instance data.
743	* @param off The logical offset to convert.
744	* @param pidxL1 Where to store the index in the L1 table on success.
745	* @param pidxL2 Where to store the index in the L2 table on success.
746	* @param poffCluster Where to store the offset in the cluster on success.
747	*/
748	DECLINLINE(void) qcowConvertLogicalOffset(PQCOWIMAGE pImage, uint64_t off, uint32_t *pidxL1,
749	uint32_t pidxL2, uint32_t poffCluster)
750	{
751	AssertPtr(pidxL1);
752	AssertPtr(pidxL2);
753	AssertPtr(poffCluster);
754
755	*poffCluster = off & pImage->fOffsetMask;
756	*pidxL1 = off >> pImage->cL1Shift;
757	*pidxL2 = (off & pImage->fL2Mask) >> pImage->cL2Shift;
758	}
759
760	/**
761	* Converts Cluster size to a byte size.
762	*
763	* @returns Number of bytes derived from the given number of clusters.
764	* @param pImage The image instance data.
765	* @param cClusters The clusters to convert.
766	*/
767	DECLINLINE(uint64_t) qcowCluster2Byte(PQCOWIMAGE pImage, uint64_t cClusters)
768	{
769	return cClusters * pImage->cbCluster;
770	}
771
772	/**
773	* Converts number of bytes to cluster size rounding to the next cluster.
774	*
775	* @returns Number of bytes derived from the given number of clusters.
776	* @param pImage The image instance data.
777	* @param cb Number of bytes to convert.
778	*/
779	DECLINLINE(uint64_t) qcowByte2Cluster(PQCOWIMAGE pImage, uint64_t cb)
780	{
781	return cb / pImage->cbCluster + (cb % pImage->cbCluster ? 1 : 0);
782	}
783
784	/**
785	* Allocates a new cluster in the image.
786	*
787	* @returns The start offset of the new cluster in the image.
788	* @param pImage The image instance data.
789	* @param cClusters Number of clusters to allocate.
790	*/
791	DECLINLINE(uint64_t) qcowClusterAllocate(PQCOWIMAGE pImage, uint32_t cClusters)
792	{
793	uint64_t offCluster;
794
795	offCluster = pImage->offNextCluster;
796	pImage->offNextCluster += cClusters*pImage->cbCluster;
797
798	return offCluster;
799	}
800
801	/**
802	* Returns the real image offset for a given cluster or an error if the cluster is not
803	* yet allocated.
804	*
805	* @returns VBox status code.
806	* VERR_VD_BLOCK_FREE if the cluster is not yet allocated.
807	* @param pImage The image instance data.
808	* @param pIoCtx The I/O context.
809	* @param idxL1 The L1 index.
810	* @param idxL2 The L2 index.
811	* @param offCluster Offset inside the cluster.
812	* @param poffImage Where to store the image offset on success;
813	*/
814	static int qcowConvertToImageOffset(PQCOWIMAGE pImage, PVDIOCTX pIoCtx,
815	uint32_t idxL1, uint32_t idxL2,
816	uint32_t offCluster, uint64_t *poffImage)
817	{
818	int rc = VERR_VD_BLOCK_FREE;
819
820	AssertReturn(idxL1 < pImage->cL1TableEntries, VERR_INVALID_PARAMETER);
821	AssertReturn(idxL2 < pImage->cL2TableEntries, VERR_INVALID_PARAMETER);
822
823	if (pImage->paL1Table[idxL1])
824	{
825	PQCOWL2CACHEENTRY pL2Entry;
826
827	uint64_t offL2Tbl = pImage->paL1Table[idxL1];
828	if (pImage->uVersion == 2)
829	offL2Tbl &= QCOW_V2_TBL_OFFSET_MASK;
830	rc = qcowL2TblCacheFetch(pImage, pIoCtx, offL2Tbl, &pL2Entry);
831	if (RT_SUCCESS(rc))
832	{
833	/* Get real file offset. */
834	if (pL2Entry->paL2Tbl[idxL2])
835	{
836	uint64_t off = pL2Entry->paL2Tbl[idxL2];
837
838	/* Strip flags */
839	if (pImage->uVersion == 2)
840	{
841	if (RT_UNLIKELY(off & QCOW_V2_COMPRESSED_FLAG))
842	rc = VERR_NOT_SUPPORTED;
843	else
844	off &= QCOW_V2_TBL_OFFSET_MASK;
845	}
846	else
847	{
848	if (RT_UNLIKELY(off & QCOW_V1_COMPRESSED_FLAG))
849	rc = VERR_NOT_SUPPORTED;
850	else
851	off &= ~QCOW_V1_COMPRESSED_FLAG;
852	}
853
854	*poffImage = off + offCluster;
855	}
856	else
857	rc = VERR_VD_BLOCK_FREE;
858
859	qcowL2TblCacheEntryRelease(pL2Entry);
860	}
861	}
862
863	return rc;
864	}
865
866	/**
867	* Write the given table to image converting to the image endianess if required.
868	*
869	* @returns VBox status code.
870	* @param pImage The image instance data.
871	* @param pIoCtx The I/O context.
872	* @param offTbl The offset the table should be written to.
873	* @param paTbl The table to write.
874	* @param cbTbl Size of the table in bytes.
875	* @param cTblEntries Number entries in the table.
876	* @param pfnComplete Callback called when the write completes.
877	* @param pvUser Opaque user data to pass in the completion callback.
878	*/
879	static int qcowTblWrite(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offTbl, uint64_t *paTbl,
880	size_t cbTbl, unsigned cTblEntries,
881	PFNVDXFERCOMPLETED pfnComplete, void *pvUser)
882	{
883	int rc = VINF_SUCCESS;
884
885	#if defined(RT_LITTLE_ENDIAN)
886	uint64_t paTblImg = (uint64_t )RTMemAllocZ(cbTbl);
887	if (paTblImg)
888	{
889	qcowTableConvertFromHostEndianess(paTblImg, paTbl, cTblEntries);
890	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
891	offTbl, paTblImg, cbTbl,
892	pIoCtx, pfnComplete, pvUser);
893	RTMemFree(paTblImg);
894	}
895	else
896	rc = VERR_NO_MEMORY;
897	#else
898	/* Write table directly. */
899	RT_NOREF(cTblEntries);
900	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
901	offTbl, paTbl, cbTbl, pIoCtx,
902	pfnComplete, pvUser);
903	#endif
904
905	return rc;
906	}
907
908	/**
909	* Internal. Flush image data to disk.
910	*/
911	static int qcowFlushImage(PQCOWIMAGE pImage)
912	{
913	int rc = VINF_SUCCESS;
914
915	if ( pImage->pStorage
916	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
917	&& pImage->cbL1Table)
918	{
919	QCowHeader Header;
920
921	#if defined(RT_LITTLE_ENDIAN)
922	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
923	if (paL1TblImg)
924	{
925	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
926	pImage->cL1TableEntries);
927	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
928	pImage->offL1Table, paL1TblImg,
929	pImage->cbL1Table);
930	RTMemFree(paL1TblImg);
931	}
932	else
933	rc = VERR_NO_MEMORY;
934	#else
935	/* Write L1 table directly. */
936	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->offL1Table,
937	pImage->paL1Table, pImage->cbL1Table);
938	#endif
939	if (RT_SUCCESS(rc))
940	{
941	/* Write header. */
942	size_t cbHeader = 0;
943	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
944	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Header,
945	cbHeader);
946	if (RT_SUCCESS(rc))
947	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
948	}
949	}
950
951	return rc;
952	}
953
954	/**
955	* Internal. Free all allocated space for representing an image except pImage,
956	* and optionally delete the image from disk.
957	*/
958	static int qcowFreeImage(PQCOWIMAGE pImage, bool fDelete)
959	{
960	int rc = VINF_SUCCESS;
961
962	/* Freeing a never allocated image (e.g. because the open failed) is
963	* not signalled as an error. After all nothing bad happens. */
964	if (pImage)
965	{
966	if (pImage->pStorage)
967	{
968	/* No point updating the file that is deleted anyway. */
969	if (!fDelete)
970	qcowFlushImage(pImage);
971
972	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
973	pImage->pStorage = NULL;
974	}
975
976	if (pImage->paRefcountTable)
977	RTMemFree(pImage->paRefcountTable);
978	pImage->paRefcountTable = NULL;
979
980	if (pImage->paL1Table)
981	RTMemFree(pImage->paL1Table);
982
983	if (pImage->pszBackingFilename)
984	{
985	RTStrFree(pImage->pszBackingFilename);
986	pImage->pszBackingFilename = NULL;
987	}
988
989	qcowL2TblCacheDestroy(pImage);
990
991	if (fDelete && pImage->pszFilename)
992	vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
993	}
994
995	LogFlowFunc(("returns %Rrc\n", rc));
996	return rc;
997	}
998
999	/**
1000	* Validates the header.
1001	*
1002	* @returns VBox status code.
1003	* @param pImage Image backend instance data.
1004	* @param pHdr The header to validate.
1005	* @param cbFile The image file size in bytes.
1006	*/
1007	static int qcowHdrValidate(PQCOWIMAGE pImage, PQCowHeader pHdr, uint64_t cbFile)
1008	{
1009	if (pHdr->u32Version == 1)
1010	{
1011	/* Check that the backing filename is contained in the file. */
1012	if (pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize > cbFile)
1013	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1014	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1015	pImage->pszFilename, pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize,
1016	cbFile);
1017
1018	/* Check that the cluster bits indicate at least a 512byte sector size. */
1019	if (RT_BIT_32(pHdr->Version.v1.u8ClusterBits) < 512)
1020	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1021	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1022	pImage->pszFilename, RT_BIT_32(pHdr->Version.v1.u8ClusterBits), 512);
1023
1024	/*
1025	* Check for possible overflow when multiplying cluster size and L2 entry count because it is used
1026	* to calculate the number of L1 table entries later on.
1027	*/
1028	if (RT_BIT_32(pHdr->Version.v1.u8L2Bits) * RT_BIT_32(pHdr->Version.v1.u8ClusterBits) == 0)
1029	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1030	N_("QCOW: Overflow during L1 table size calculation for image '%s'"),
1031	pImage->pszFilename);
1032	}
1033	else if (pHdr->u32Version == 2)
1034	{
1035	/* Check that the backing filename is contained in the file. */
1036	if (pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize > cbFile)
1037	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1038	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1039	pImage->pszFilename, pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize,
1040	cbFile);
1041
1042	/* Check that the cluster bits indicate at least a 512byte sector size. */
1043	if (RT_BIT_32(pHdr->Version.v2.u32ClusterBits) < 512)
1044	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1045	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1046	pImage->pszFilename, RT_BIT_32(pHdr->Version.v2.u32ClusterBits), 512);
1047	}
1048	else
1049	return vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1050	N_("QCOW: Version %u in image '%s' is not supported"),
1051	pHdr->u32Version, pImage->pszFilename);
1052
1053	return VINF_SUCCESS;
1054	}
1055
1056	/**
1057	* Internal: Open an image, constructing all necessary data structures.
1058	*/
1059	static int qcowOpenImage(PQCOWIMAGE pImage, unsigned uOpenFlags)
1060	{
1061	pImage->uOpenFlags = uOpenFlags;
1062
1063	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1064	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1065	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1066
1067	int rc = qcowL2TblCacheCreate(pImage);
1068	if (RT_SUCCESS(rc))
1069	{
1070	/* Open the image. */
1071	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1072	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1073	false /* fCreate */),
1074	&pImage->pStorage);
1075	if (RT_SUCCESS(rc))
1076	{
1077	uint64_t cbFile;
1078	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1079	if ( RT_SUCCESS(rc)
1080	&& cbFile > sizeof(QCowHeader))
1081	{
1082	QCowHeader Header;
1083
1084	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0, &Header, sizeof(Header));
1085	if ( RT_SUCCESS(rc)
1086	&& qcowHdrConvertToHostEndianess(&Header))
1087	{
1088	pImage->offNextCluster = RT_ALIGN_64(cbFile, 512); /* Align image to sector boundary. */
1089	Assert(pImage->offNextCluster >= cbFile);
1090
1091	rc = qcowHdrValidate(pImage, &Header, cbFile);
1092	if (RT_SUCCESS(rc))
1093	{
1094	if (Header.u32Version == 1)
1095	{
1096	if (!Header.Version.v1.u32CryptMethod)
1097	{
1098	pImage->uVersion = 1;
1099	pImage->offBackingFilename = Header.Version.v1.u64BackingFileOffset;
1100	pImage->cbBackingFilename = Header.Version.v1.u32BackingFileSize;
1101	pImage->MTime = Header.Version.v1.u32MTime;
1102	pImage->cbSize = Header.Version.v1.u64Size;
1103	pImage->cbCluster = RT_BIT_32(Header.Version.v1.u8ClusterBits);
1104	pImage->cL2TableEntries = RT_BIT_32(Header.Version.v1.u8L2Bits);
1105	pImage->cbL2Table = RT_ALIGN_64(pImage->cL2TableEntries * sizeof(uint64_t), pImage->cbCluster);
1106	pImage->offL1Table = Header.Version.v1.u64L1TableOffset;
1107	pImage->cL1TableEntries = pImage->cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1108	if (pImage->cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1109	pImage->cL1TableEntries++;
1110	}
1111	else
1112	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1113	N_("QCow: Encrypted image '%s' is not supported"),
1114	pImage->pszFilename);
1115	}
1116	else if (Header.u32Version == 2)
1117	{
1118	if (Header.Version.v2.u32CryptMethod)
1119	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1120	N_("QCow: Encrypted image '%s' is not supported"),
1121	pImage->pszFilename);
1122	else if (Header.Version.v2.u32NbSnapshots)
1123	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1124	N_("QCow: Image '%s' contains snapshots which is not supported"),
1125	pImage->pszFilename);
1126	else
1127	{
1128	pImage->uVersion = 2;
1129	pImage->offBackingFilename = Header.Version.v2.u64BackingFileOffset;
1130	pImage->cbBackingFilename = Header.Version.v2.u32BackingFileSize;
1131	pImage->cbSize = Header.Version.v2.u64Size;
1132	pImage->cbCluster = RT_BIT_32(Header.Version.v2.u32ClusterBits);
1133	pImage->cL2TableEntries = pImage->cbCluster / sizeof(uint64_t);
1134	pImage->cbL2Table = pImage->cbCluster;
1135	pImage->offL1Table = Header.Version.v2.u64L1TableOffset;
1136	pImage->cL1TableEntries = Header.Version.v2.u32L1Size;
1137	pImage->offRefcountTable = Header.Version.v2.u64RefcountTableOffset;
1138	pImage->cbRefcountTable = qcowCluster2Byte(pImage, Header.Version.v2.u32RefcountTableClusters);
1139	pImage->cRefcountTableEntries = pImage->cbRefcountTable / sizeof(uint64_t);
1140	}
1141	}
1142	else
1143	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1144	N_("QCow: Image '%s' uses version %u which is not supported"),
1145	pImage->pszFilename, Header.u32Version);
1146
1147	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1148	if ((uint64_t)pImage->cbL1Table != RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster))
1149	rc = vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1150	N_("QCOW: L1 table size overflow in image '%s'"),
1151	pImage->pszFilename);
1152	}
1153
1154	/** @todo Check that there are no compressed clusters in the image
1155	* (by traversing the L2 tables and checking each offset).
1156	* Refuse to open such images.
1157	*/
1158
1159	if ( RT_SUCCESS(rc)
1160	&& pImage->cbBackingFilename
1161	&& pImage->offBackingFilename)
1162	{
1163	/* Load backing filename from image. */
1164	pImage->pszBackingFilename = RTStrAlloc(pImage->cbBackingFilename + 1); /* +1 for \0 terminator. */
1165	if (pImage->pszBackingFilename)
1166	{
1167	RT_BZERO(pImage->pszBackingFilename, pImage->cbBackingFilename + 1);
1168	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1169	pImage->offBackingFilename, pImage->pszBackingFilename,
1170	pImage->cbBackingFilename);
1171	if (RT_SUCCESS(rc))
1172	rc = RTStrValidateEncoding(pImage->pszBackingFilename);
1173	}
1174	else
1175	rc = VERR_NO_STR_MEMORY;
1176	}
1177
1178	if ( RT_SUCCESS(rc)
1179	&& pImage->cbRefcountTable
1180	&& pImage->offRefcountTable)
1181	{
1182	/* Load refcount table. */
1183	Assert(pImage->cRefcountTableEntries);
1184	pImage->paRefcountTable = (uint64_t *)RTMemAllocZ(pImage->cbRefcountTable);
1185	if (RT_LIKELY(pImage->paRefcountTable))
1186	{
1187	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1188	pImage->offRefcountTable, pImage->paRefcountTable,
1189	pImage->cbRefcountTable);
1190	if (RT_SUCCESS(rc))
1191	qcowTableConvertToHostEndianess(pImage->paRefcountTable,
1192	pImage->cRefcountTableEntries);
1193	else
1194	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1195	N_("QCow: Reading refcount table of image '%s' failed"),
1196	pImage->pszFilename);
1197	}
1198	else
1199	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1200	N_("QCow: Allocating memory for refcount table of image '%s' failed"),
1201	pImage->pszFilename);
1202	}
1203
1204	if (RT_SUCCESS(rc))
1205	{
1206	qcowTableMasksInit(pImage);
1207
1208	/* Allocate L1 table. */
1209	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1210	if (pImage->paL1Table)
1211	{
1212	/* Read from the image. */
1213	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1214	pImage->offL1Table, pImage->paL1Table,
1215	pImage->cbL1Table);
1216	if (RT_SUCCESS(rc))
1217	qcowTableConvertToHostEndianess(pImage->paL1Table, pImage->cL1TableEntries);
1218	else
1219	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1220	N_("QCow: Reading the L1 table for image '%s' failed"),
1221	pImage->pszFilename);
1222	}
1223	else
1224	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1225	N_("QCow: Out of memory allocating L1 table for image '%s'"),
1226	pImage->pszFilename);
1227	}
1228	}
1229	else if (RT_SUCCESS(rc))
1230	rc = VERR_VD_GEN_INVALID_HEADER;
1231	}
1232	else if (RT_SUCCESS(rc))
1233	rc = VERR_VD_GEN_INVALID_HEADER;
1234	}
1235	/* else: Do NOT signal an appropriate error here, as the VD layer has the
1236	* choice of retrying the open if it failed. */
1237	}
1238	else
1239	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1240	N_("Qcow: Creating the L2 table cache for image '%s' failed"),
1241	pImage->pszFilename);
1242
1243	if (RT_SUCCESS(rc))
1244	{
1245	PVDREGIONDESC pRegion = &pImage->RegionList.aRegions[0];
1246	pImage->RegionList.fFlags = 0;
1247	pImage->RegionList.cRegions = 1;
1248
1249	pRegion->offRegion = 0; /* Disk start. */
1250	pRegion->cbBlock = 512;
1251	pRegion->enmDataForm = VDREGIONDATAFORM_RAW;
1252	pRegion->enmMetadataForm = VDREGIONMETADATAFORM_NONE;
1253	pRegion->cbData = 512;
1254	pRegion->cbMetadata = 0;
1255	pRegion->cRegionBlocksOrBytes = pImage->cbSize;
1256	}
1257	else
1258	qcowFreeImage(pImage, false);
1259	return rc;
1260	}
1261
1262	/**
1263	* Internal: Create a qcow image.
1264	*/
1265	static int qcowCreateImage(PQCOWIMAGE pImage, uint64_t cbSize,
1266	unsigned uImageFlags, const char *pszComment,
1267	PCVDGEOMETRY pPCHSGeometry,
1268	PCVDGEOMETRY pLCHSGeometry, unsigned uOpenFlags,
1269	PVDINTERFACEPROGRESS pIfProgress,
1270	unsigned uPercentStart, unsigned uPercentSpan)
1271	{
1272	RT_NOREF1(pszComment);
1273	int rc;
1274	int32_t fOpen;
1275
1276	if (!(uImageFlags & VD_IMAGE_FLAGS_FIXED))
1277	{
1278	rc = qcowL2TblCacheCreate(pImage);
1279	if (RT_SUCCESS(rc))
1280	{
1281	pImage->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1282	pImage->uImageFlags = uImageFlags;
1283	pImage->PCHSGeometry = *pPCHSGeometry;
1284	pImage->LCHSGeometry = *pLCHSGeometry;
1285	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1286	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1287	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1288
1289	/* Create image file. */
1290	fOpen = VDOpenFlagsToFileOpenFlags(pImage->uOpenFlags, true /* fCreate */);
1291	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename, fOpen, &pImage->pStorage);
1292	if (RT_SUCCESS(rc))
1293	{
1294	/* Init image state. */
1295	pImage->uVersion = 1; /* We create only version 1 images at the moment. */
1296	pImage->cbSize = cbSize;
1297	pImage->cbCluster = QCOW_CLUSTER_SIZE_DEFAULT;
1298	pImage->cbL2Table = qcowCluster2Byte(pImage, QCOW_L2_CLUSTERS_DEFAULT);
1299	pImage->cL2TableEntries = pImage->cbL2Table / sizeof(uint64_t);
1300	pImage->cL1TableEntries = cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1301	if (cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1302	pImage->cL1TableEntries++;
1303	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1304	pImage->offL1Table = QCOW_V1_HDR_SIZE;
1305	pImage->cbBackingFilename = 0;
1306	pImage->offBackingFilename = 0;
1307	pImage->offNextCluster = RT_ALIGN_64(QCOW_V1_HDR_SIZE + pImage->cbL1Table, pImage->cbCluster);
1308	qcowTableMasksInit(pImage);
1309
1310	/* Init L1 table. */
1311	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1312	if (RT_LIKELY(pImage->paL1Table))
1313	{
1314	if (RT_SUCCESS(rc))
1315	vdIfProgress(pIfProgress, uPercentStart + uPercentSpan * 98 / 100);
1316
1317	rc = qcowFlushImage(pImage);
1318	if (RT_SUCCESS(rc))
1319	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pImage->offNextCluster);
1320	}
1321	else
1322	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("QCow: cannot allocate memory for L1 table of image '%s'"),
1323	pImage->pszFilename);
1324	}
1325	else
1326	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: cannot create image '%s'"), pImage->pszFilename);
1327	}
1328	else
1329	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: Failed to create L2 cache for image '%s'"),
1330	pImage->pszFilename);
1331	}
1332	else
1333	rc = vdIfError(pImage->pIfError, VERR_VD_INVALID_TYPE, RT_SRC_POS, N_("QCow: cannot create fixed image '%s'"), pImage->pszFilename);
1334
1335	if (RT_SUCCESS(rc))
1336	vdIfProgress(pIfProgress, uPercentStart + uPercentSpan);
1337
1338	if (RT_SUCCESS(rc))
1339	{
1340	PVDREGIONDESC pRegion = &pImage->RegionList.aRegions[0];
1341	pImage->RegionList.fFlags = 0;
1342	pImage->RegionList.cRegions = 1;
1343
1344	pRegion->offRegion = 0; /* Disk start. */
1345	pRegion->cbBlock = 512;
1346	pRegion->enmDataForm = VDREGIONDATAFORM_RAW;
1347	pRegion->enmMetadataForm = VDREGIONMETADATAFORM_NONE;
1348	pRegion->cbData = 512;
1349	pRegion->cbMetadata = 0;
1350	pRegion->cRegionBlocksOrBytes = pImage->cbSize;
1351	}
1352	else
1353	qcowFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1354	return rc;
1355	}
1356
1357	/**
1358	* Rollback anything done during async cluster allocation.
1359	*
1360	* @returns VBox status code.
1361	* @param pImage The image instance data.
1362	* @param pIoCtx The I/O context.
1363	* @param pClusterAlloc The cluster allocation to rollback.
1364	*/
1365	static int qcowAsyncClusterAllocRollback(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, PQCOWCLUSTERASYNCALLOC pClusterAlloc)
1366	{
1367	RT_NOREF1(pIoCtx);
1368	int rc = VINF_SUCCESS;
1369
1370	switch (pClusterAlloc->enmAllocState)
1371	{
1372	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1373	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1374	{
1375	/* Revert the L1 table entry */
1376	pImage->paL1Table[pClusterAlloc->idxL1] = 0;
1377	pImage->pL2TblAlloc = NULL;
1378
1379	/* Assumption right now is that the L1 table is not modified on storage if the link fails. */
1380	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1381	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1382	Assert(!pClusterAlloc->pL2Entry->cRefs);
1383	qcowL2TblCacheEntryFree(pImage, pClusterAlloc->pL2Entry); /* Free it, it is not in the cache yet. */
1384	break;
1385	}
1386	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1387	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1388	{
1389	/* Assumption right now is that the L2 table is not modified if the link fails. */
1390	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = 0;
1391	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1392	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1393	break;
1394	}
1395	default:
1396	AssertMsgFailed(("Invalid cluster allocation state %d\n", pClusterAlloc->enmAllocState));
1397	rc = VERR_INVALID_STATE;
1398	}
1399
1400	RTMemFree(pClusterAlloc);
1401	return rc;
1402	}
1403
1404	/**
1405	* Updates the state of the async cluster allocation.
1406	*
1407	* @returns VBox status code.
1408	* @param pBackendData The opaque backend data.
1409	* @param pIoCtx I/O context associated with this request.
1410	* @param pvUser Opaque user data passed during a read/write request.
1411	* @param rcReq Status code for the completed request.
1412	*/
1413	static DECLCALLBACK(int) qcowAsyncClusterAllocUpdate(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
1414	{
1415	int rc = VINF_SUCCESS;
1416	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1417	PQCOWCLUSTERASYNCALLOC pClusterAlloc = (PQCOWCLUSTERASYNCALLOC)pvUser;
1418
1419	if (RT_FAILURE(rcReq))
1420	return qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1421
1422	AssertPtr(pClusterAlloc->pL2Entry);
1423
1424	switch (pClusterAlloc->enmAllocState)
1425	{
1426	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1427	{
1428	/* Update the link in the in memory L1 table now. */
1429	pImage->paL1Table[pClusterAlloc->idxL1] = pClusterAlloc->pL2Entry->offL2Tbl;
1430
1431	/* Update the link in the on disk L1 table now. */
1432	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_LINK;
1433	rc = qcowTblWrite(pImage, pIoCtx, pImage->offL1Table, pImage->paL1Table,
1434	pImage->cbL1Table, pImage->cL1TableEntries,
1435	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1436	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1437	break;
1438	else if (RT_FAILURE(rc))
1439	{
1440	/* Rollback. */
1441	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1442	break;
1443	}
1444	/* Success, fall through. */
1445	}
1446	RT_FALL_THRU();
1447	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1448	{
1449	/* L2 link updated in L1 , save L2 entry in cache and allocate new user data cluster. */
1450	uint64_t offData = qcowClusterAllocate(pImage, 1);
1451
1452	pImage->pL2TblAlloc = NULL;
1453	qcowL2TblCacheEntryInsert(pImage, pClusterAlloc->pL2Entry);
1454
1455	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1456	pClusterAlloc->offNextClusterOld = offData;
1457	pClusterAlloc->offClusterNew = offData;
1458
1459	/* Write data. */
1460	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1461	offData, pIoCtx, pClusterAlloc->cbToWrite,
1462	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1463	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1464	break;
1465	else if (RT_FAILURE(rc))
1466	{
1467	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1468	RTMemFree(pClusterAlloc);
1469	break;
1470	}
1471	}
1472	RT_FALL_THRU();
1473	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1474	{
1475	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_LINK;
1476	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = pClusterAlloc->offClusterNew;
1477
1478	/* Link L2 table and update it. */
1479	rc = qcowTblWrite(pImage, pIoCtx, pImage->paL1Table[pClusterAlloc->idxL1],
1480	pClusterAlloc->pL2Entry->paL2Tbl,
1481	pImage->cbL2Table, pImage->cL2TableEntries,
1482	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1483	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1484	break;
1485	else if (RT_FAILURE(rc))
1486	{
1487	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1488	RTMemFree(pClusterAlloc);
1489	break;
1490	}
1491	}
1492	RT_FALL_THRU();
1493	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1494	{
1495	/* Everything done without errors, signal completion. */
1496	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry);
1497	RTMemFree(pClusterAlloc);
1498	rc = VINF_SUCCESS;
1499	break;
1500	}
1501	default:
1502	AssertMsgFailed(("Invalid async cluster allocation state %d\n",
1503	pClusterAlloc->enmAllocState));
1504	}
1505
1506	return rc;
1507	}
1508
1509	/** @copydoc VDIMAGEBACKEND::pfnProbe */
1510	static DECLCALLBACK(int) qcowProbe(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1511	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1512	{
1513	RT_NOREF1(pVDIfsDisk);
1514	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1515	PVDIOSTORAGE pStorage = NULL;
1516	uint64_t cbFile;
1517	int rc = VINF_SUCCESS;
1518
1519	/* Get I/O interface. */
1520	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1521	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1522	AssertReturn((VALID_PTR(pszFilename) && *pszFilename), VERR_INVALID_PARAMETER);
1523
1524	/*
1525	* Open the file and read the footer.
1526	*/
1527	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1528	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1529	false /* fCreate */),
1530	&pStorage);
1531	if (RT_SUCCESS(rc))
1532	{
1533	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1534	if ( RT_SUCCESS(rc)
1535	&& cbFile > sizeof(QCowHeader))
1536	{
1537	QCowHeader Header;
1538
1539	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Header, sizeof(Header));
1540	if ( RT_SUCCESS(rc)
1541	&& qcowHdrConvertToHostEndianess(&Header))
1542	*penmType = VDTYPE_HDD;
1543	else
1544	rc = VERR_VD_GEN_INVALID_HEADER;
1545	}
1546	else
1547	rc = VERR_VD_GEN_INVALID_HEADER;
1548	}
1549
1550	if (pStorage)
1551	vdIfIoIntFileClose(pIfIo, pStorage);
1552
1553	LogFlowFunc(("returns %Rrc\n", rc));
1554	return rc;
1555	}
1556
1557	/** @copydoc VDIMAGEBACKEND::pfnOpen */
1558	static DECLCALLBACK(int) qcowOpen(const char *pszFilename, unsigned uOpenFlags,
1559	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1560	VDTYPE enmType, void **ppBackendData)
1561	{
1562	RT_NOREF1(enmType); /*< @todo r=klaus make use of the type info. /
1563
1564	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p enmType=%u ppBackendData=%#p\n",
1565	pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, enmType, ppBackendData));
1566	int rc;
1567
1568	/* Check open flags. All valid flags are supported. */
1569	AssertReturn(!(uOpenFlags & ~VD_OPEN_FLAGS_MASK), VERR_INVALID_PARAMETER);
1570	AssertReturn((VALID_PTR(pszFilename) && *pszFilename), VERR_INVALID_PARAMETER);
1571
1572	PQCOWIMAGE pImage = (PQCOWIMAGE)RTMemAllocZ(RT_UOFFSETOF(QCOWIMAGE, RegionList.aRegions[1]));
1573	if (RT_LIKELY(pImage))
1574	{
1575	pImage->pszFilename = pszFilename;
1576	pImage->pStorage = NULL;
1577	pImage->pVDIfsDisk = pVDIfsDisk;
1578	pImage->pVDIfsImage = pVDIfsImage;
1579
1580	rc = qcowOpenImage(pImage, uOpenFlags);
1581	if (RT_SUCCESS(rc))
1582	*ppBackendData = pImage;
1583	else
1584	RTMemFree(pImage);
1585	}
1586	else
1587	rc = VERR_NO_MEMORY;
1588
1589	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1590	return rc;
1591	}
1592
1593	/** @copydoc VDIMAGEBACKEND::pfnCreate */
1594	static DECLCALLBACK(int) qcowCreate(const char *pszFilename, uint64_t cbSize,
1595	unsigned uImageFlags, const char *pszComment,
1596	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1597	PCRTUUID pUuid, unsigned uOpenFlags,
1598	unsigned uPercentStart, unsigned uPercentSpan,
1599	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1600	PVDINTERFACE pVDIfsOperation, VDTYPE enmType,
1601	void **ppBackendData)
1602	{
1603	RT_NOREF1(pUuid);
1604	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\n",
1605	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, enmType, ppBackendData));
1606	int rc;
1607
1608	/* Check the VD container type. */
1609	if (enmType != VDTYPE_HDD)
1610	return VERR_VD_INVALID_TYPE;
1611
1612	/* Check open flags. All valid flags are supported. */
1613	AssertReturn(!(uOpenFlags & ~VD_OPEN_FLAGS_MASK), VERR_INVALID_PARAMETER);
1614	AssertReturn( VALID_PTR(pszFilename)
1615	&& *pszFilename
1616	&& VALID_PTR(pPCHSGeometry)
1617	&& VALID_PTR(pLCHSGeometry), VERR_INVALID_PARAMETER);
1618
1619	PQCOWIMAGE pImage = (PQCOWIMAGE)RTMemAllocZ(RT_UOFFSETOF(QCOWIMAGE, RegionList.aRegions[1]));
1620	if (RT_LIKELY(pImage))
1621	{
1622	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1623
1624	pImage->pszFilename = pszFilename;
1625	pImage->pStorage = NULL;
1626	pImage->pVDIfsDisk = pVDIfsDisk;
1627	pImage->pVDIfsImage = pVDIfsImage;
1628
1629	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1630	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1631	pIfProgress, uPercentStart, uPercentSpan);
1632	if (RT_SUCCESS(rc))
1633	{
1634	/* So far the image is opened in read/write mode. Make sure the
1635	* image is opened in read-only mode if the caller requested that. */
1636	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1637	{
1638	qcowFreeImage(pImage, false);
1639	rc = qcowOpenImage(pImage, uOpenFlags);
1640	}
1641
1642	if (RT_SUCCESS(rc))
1643	*ppBackendData = pImage;
1644	}
1645
1646	if (RT_FAILURE(rc))
1647	RTMemFree(pImage);
1648	}
1649	else
1650	rc = VERR_NO_MEMORY;
1651
1652	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1653	return rc;
1654	}
1655
1656	/** @copydoc VDIMAGEBACKEND::pfnRename */
1657	static DECLCALLBACK(int) qcowRename(void pBackendData, const char pszFilename)
1658	{
1659	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1660	int rc = VINF_SUCCESS;
1661	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1662
1663	/* Check arguments. */
1664	AssertReturn((pImage && pszFilename && *pszFilename), VERR_INVALID_PARAMETER);
1665
1666	/* Close the image. */
1667	rc = qcowFreeImage(pImage, false);
1668	if (RT_SUCCESS(rc))
1669	{
1670	/* Rename the file. */
1671	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1672	if (RT_SUCCESS(rc))
1673	{
1674	/* Update pImage with the new information. */
1675	pImage->pszFilename = pszFilename;
1676
1677	/* Open the old image with new name. */
1678	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1679	}
1680	else
1681	{
1682	/* The move failed, try to reopen the original image. */
1683	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1684	if (RT_FAILURE(rc2))
1685	rc = rc2;
1686	}
1687	}
1688
1689	LogFlowFunc(("returns %Rrc\n", rc));
1690	return rc;
1691	}
1692
1693	/** @copydoc VDIMAGEBACKEND::pfnClose */
1694	static DECLCALLBACK(int) qcowClose(void *pBackendData, bool fDelete)
1695	{
1696	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1697	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1698
1699	int rc = qcowFreeImage(pImage, fDelete);
1700	RTMemFree(pImage);
1701
1702	LogFlowFunc(("returns %Rrc\n", rc));
1703	return rc;
1704	}
1705
1706	static DECLCALLBACK(int) qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1707	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1708	{
1709	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1710	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1711	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1712	uint32_t offCluster = 0;
1713	uint32_t idxL1 = 0;
1714	uint32_t idxL2 = 0;
1715	uint64_t offFile = 0;
1716	int rc;
1717
1718	AssertPtr(pImage);
1719	Assert(uOffset % 512 == 0);
1720	Assert(cbToRead % 512 == 0);
1721	AssertReturn((VALID_PTR(pIoCtx) && cbToRead), VERR_INVALID_PARAMETER);
1722	AssertReturn(uOffset + cbToRead <= pImage->cbSize, VERR_INVALID_PARAMETER);
1723
1724	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1725
1726	/* Clip read size to remain in the cluster. */
1727	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1728
1729	/* Get offset in image. */
1730	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1731	if (RT_SUCCESS(rc))
1732	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1733	pIoCtx, cbToRead);
1734
1735	if ( ( RT_SUCCESS(rc)
1736	\|\| rc == VERR_VD_BLOCK_FREE
1737	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1738	&& pcbActuallyRead)
1739	*pcbActuallyRead = cbToRead;
1740
1741	LogFlowFunc(("returns %Rrc\n", rc));
1742	return rc;
1743	}
1744
1745	static DECLCALLBACK(int) qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1746	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1747	size_t *pcbPostRead, unsigned fWrite)
1748	{
1749	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1750	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1751	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1752	uint32_t offCluster = 0;
1753	uint32_t idxL1 = 0;
1754	uint32_t idxL2 = 0;
1755	uint64_t offImage = 0;
1756	int rc = VINF_SUCCESS;
1757
1758	AssertPtr(pImage);
1759	Assert(!(uOffset % 512));
1760	Assert(!(cbToWrite % 512));
1761	AssertReturn((VALID_PTR(pIoCtx) && cbToWrite), VERR_INVALID_PARAMETER);
1762	AssertReturn(uOffset + cbToWrite <= pImage->cbSize, VERR_INVALID_PARAMETER);
1763
1764	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1765	{
1766	/* Convert offset to L1, L2 index and cluster offset. */
1767	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1768
1769	/* Clip write size to remain in the cluster. */
1770	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1771	Assert(!(cbToWrite % 512));
1772
1773	/* Get offset in image. */
1774	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1775	if (RT_SUCCESS(rc))
1776	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1777	offImage, pIoCtx, cbToWrite, NULL, NULL);
1778	else if (rc == VERR_VD_BLOCK_FREE)
1779	{
1780	if ( cbToWrite == pImage->cbCluster
1781	&& !(fWrite & VD_WRITE_NO_ALLOC))
1782	{
1783	PQCOWL2CACHEENTRY pL2Entry = NULL;
1784
1785	/* Full cluster write to previously unallocated cluster.
1786	* Allocate cluster and write data. */
1787	Assert(!offCluster);
1788
1789	do
1790	{
1791	/* Check if we have to allocate a new cluster for L2 tables. */
1792	if (!pImage->paL1Table[idxL1])
1793	{
1794	uint64_t offL2Tbl;
1795	PQCOWCLUSTERASYNCALLOC pL2ClusterAlloc = NULL;
1796
1797	/* Allocate new async cluster allocation state. */
1798	pL2ClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1799	if (RT_UNLIKELY(!pL2ClusterAlloc))
1800	{
1801	rc = VERR_NO_MEMORY;
1802	break;
1803	}
1804
1805	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
1806	if (!pL2Entry)
1807	{
1808	rc = VERR_NO_MEMORY;
1809	RTMemFree(pL2ClusterAlloc);
1810	break;
1811	}
1812
1813	offL2Tbl = qcowClusterAllocate(pImage, qcowByte2Cluster(pImage, pImage->cbL2Table));
1814	pL2Entry->offL2Tbl = offL2Tbl;
1815	memset(pL2Entry->paL2Tbl, 0, pImage->cbL2Table);
1816
1817	pL2ClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC;
1818	pL2ClusterAlloc->offNextClusterOld = offL2Tbl;
1819	pL2ClusterAlloc->offClusterNew = offL2Tbl;
1820	pL2ClusterAlloc->idxL1 = idxL1;
1821	pL2ClusterAlloc->idxL2 = idxL2;
1822	pL2ClusterAlloc->cbToWrite = cbToWrite;
1823	pL2ClusterAlloc->pL2Entry = pL2Entry;
1824
1825	pImage->pL2TblAlloc = pL2Entry;
1826
1827	LogFlowFunc(("Allocating new L2 table at cluster offset %llu\n", offL2Tbl));
1828
1829	/*
1830	* Write the L2 table first and link to the L1 table afterwards.
1831	* If something unexpected happens the worst case which can happen
1832	* is a leak of some clusters.
1833	*/
1834	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1835	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1836	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1837	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1838	break;
1839	else if (RT_FAILURE(rc))
1840	{
1841	RTMemFree(pL2ClusterAlloc);
1842	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1843	break;
1844	}
1845
1846	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1847	}
1848	else
1849	{
1850	LogFlowFunc(("Fetching L2 table at cluster offset %llu\n", pImage->paL1Table[idxL1]));
1851
1852	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1853	&pL2Entry);
1854	if (RT_SUCCESS(rc))
1855	{
1856	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1857
1858	/* Allocate new async cluster allocation state. */
1859	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1860	if (RT_UNLIKELY(!pDataClusterAlloc))
1861	{
1862	rc = VERR_NO_MEMORY;
1863	break;
1864	}
1865
1866	/* Allocate new cluster for the data. */
1867	uint64_t offData = qcowClusterAllocate(pImage, 1);
1868
1869	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1870	pDataClusterAlloc->offNextClusterOld = offData;
1871	pDataClusterAlloc->offClusterNew = offData;
1872	pDataClusterAlloc->idxL1 = idxL1;
1873	pDataClusterAlloc->idxL2 = idxL2;
1874	pDataClusterAlloc->cbToWrite = cbToWrite;
1875	pDataClusterAlloc->pL2Entry = pL2Entry;
1876
1877	/* Write data. */
1878	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1879	offData, pIoCtx, cbToWrite,
1880	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1881	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1882	break;
1883	else if (RT_FAILURE(rc))
1884	{
1885	RTMemFree(pDataClusterAlloc);
1886	break;
1887	}
1888
1889	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1890	}
1891	}
1892
1893	} while (0);
1894
1895	*pcbPreRead = 0;
1896	*pcbPostRead = 0;
1897	}
1898	else
1899	{
1900	/* Trying to do a partial write to an unallocated cluster. Don't do
1901	* anything except letting the upper layer know what to do. */
1902	*pcbPreRead = offCluster;
1903	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
1904	}
1905	}
1906
1907	if (pcbWriteProcess)
1908	*pcbWriteProcess = cbToWrite;
1909	}
1910	else
1911	rc = VERR_VD_IMAGE_READ_ONLY;
1912
1913	LogFlowFunc(("returns %Rrc\n", rc));
1914	return rc;
1915	}
1916
1917	static DECLCALLBACK(int) qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
1918	{
1919	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1920	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1921	int rc = VINF_SUCCESS;
1922
1923	AssertPtr(pImage);
1924	AssertPtrReturn(pIoCtx, VERR_INVALID_PARAMETER);
1925
1926	if ( pImage->pStorage
1927	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1928	{
1929	QCowHeader Header;
1930
1931	rc = qcowTblWrite(pImage, pIoCtx, pImage->offL1Table, pImage->paL1Table,
1932	pImage->cbL1Table, pImage->cL1TableEntries, NULL, NULL);
1933	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1934	{
1935	/* Write header. */
1936	size_t cbHeader = 0;
1937	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
1938	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1939	0, &Header, cbHeader,
1940	pIoCtx, NULL, NULL);
1941	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1942	rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage,
1943	pIoCtx, NULL, NULL);
1944	}
1945	}
1946
1947	LogFlowFunc(("returns %Rrc\n", rc));
1948	return rc;
1949	}
1950
1951	/** @copydoc VDIMAGEBACKEND::pfnGetVersion */
1952	static DECLCALLBACK(unsigned) qcowGetVersion(void *pBackendData)
1953	{
1954	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1955	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1956
1957	AssertPtrReturn(pImage, 0);
1958
1959	return pImage->uVersion;
1960	}
1961
1962	/** @copydoc VDIMAGEBACKEND::pfnGetFileSize */
1963	static DECLCALLBACK(uint64_t) qcowGetFileSize(void *pBackendData)
1964	{
1965	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1966	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1967	uint64_t cb = 0;
1968
1969	AssertPtrReturn(pImage, 0);
1970
1971	uint64_t cbFile;
1972	if (pImage->pStorage)
1973	{
1974	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1975	if (RT_SUCCESS(rc))
1976	cb += cbFile;
1977	}
1978
1979	LogFlowFunc(("returns %lld\n", cb));
1980	return cb;
1981	}
1982
1983	/** @copydoc VDIMAGEBACKEND::pfnGetPCHSGeometry */
1984	static DECLCALLBACK(int) qcowGetPCHSGeometry(void *pBackendData, PVDGEOMETRY pPCHSGeometry)
1985	{
1986	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
1987	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1988	int rc = VINF_SUCCESS;
1989
1990	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
1991
1992	if (pImage->PCHSGeometry.cCylinders)
1993	*pPCHSGeometry = pImage->PCHSGeometry;
1994	else
1995	rc = VERR_VD_GEOMETRY_NOT_SET;
1996
1997	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
1998	return rc;
1999	}
2000
2001	/** @copydoc VDIMAGEBACKEND::pfnSetPCHSGeometry */
2002	static DECLCALLBACK(int) qcowSetPCHSGeometry(void *pBackendData, PCVDGEOMETRY pPCHSGeometry)
2003	{
2004	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n",
2005	pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2006	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2007	int rc = VINF_SUCCESS;
2008
2009	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2010
2011	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2012	rc = VERR_VD_IMAGE_READ_ONLY;
2013	else
2014	pImage->PCHSGeometry = *pPCHSGeometry;
2015
2016	LogFlowFunc(("returns %Rrc\n", rc));
2017	return rc;
2018	}
2019
2020	/** @copydoc VDIMAGEBACKEND::pfnGetLCHSGeometry */
2021	static DECLCALLBACK(int) qcowGetLCHSGeometry(void *pBackendData, PVDGEOMETRY pLCHSGeometry)
2022	{
2023	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2024	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2025	int rc = VINF_SUCCESS;
2026
2027	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2028
2029	if (pImage->LCHSGeometry.cCylinders)
2030	*pLCHSGeometry = pImage->LCHSGeometry;
2031	else
2032	rc = VERR_VD_GEOMETRY_NOT_SET;
2033
2034	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders,
2035	pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2036	return rc;
2037	}
2038
2039	/** @copydoc VDIMAGEBACKEND::pfnSetLCHSGeometry */
2040	static DECLCALLBACK(int) qcowSetLCHSGeometry(void *pBackendData, PCVDGEOMETRY pLCHSGeometry)
2041	{
2042	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData,
2043	pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2044	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2045	int rc = VINF_SUCCESS;
2046
2047	AssertPtrReturn(pImage, VERR_VD_NOT_OPENED);
2048
2049	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2050	rc = VERR_VD_IMAGE_READ_ONLY;
2051	else
2052	pImage->LCHSGeometry = *pLCHSGeometry;
2053
2054	LogFlowFunc(("returns %Rrc\n", rc));
2055	return rc;
2056	}
2057
2058	/** @copydoc VDIMAGEBACKEND::pfnQueryRegions */
2059	static DECLCALLBACK(int) qcowQueryRegions(void pBackendData, PCVDREGIONLIST ppRegionList)
2060	{
2061	LogFlowFunc(("pBackendData=%#p ppRegionList=%#p\n", pBackendData, ppRegionList));
2062	PQCOWIMAGE pThis = (PQCOWIMAGE)pBackendData;
2063
2064	AssertPtrReturn(pThis, VERR_VD_NOT_OPENED);
2065
2066	*ppRegionList = &pThis->RegionList;
2067	LogFlowFunc(("returns %Rrc\n", VINF_SUCCESS));
2068	return VINF_SUCCESS;
2069	}
2070
2071	/** @copydoc VDIMAGEBACKEND::pfnRegionListRelease */
2072	static DECLCALLBACK(void) qcowRegionListRelease(void *pBackendData, PCVDREGIONLIST pRegionList)
2073	{
2074	RT_NOREF1(pRegionList);
2075	LogFlowFunc(("pBackendData=%#p pRegionList=%#p\n", pBackendData, pRegionList));
2076	PQCOWIMAGE pThis = (PQCOWIMAGE)pBackendData;
2077	AssertPtr(pThis); RT_NOREF(pThis);
2078
2079	/* Nothing to do here. */
2080	}
2081
2082	/** @copydoc VDIMAGEBACKEND::pfnGetImageFlags */
2083	static DECLCALLBACK(unsigned) qcowGetImageFlags(void *pBackendData)
2084	{
2085	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2086	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2087
2088	AssertPtrReturn(pImage, 0);
2089
2090	LogFlowFunc(("returns %#x\n", pImage->uImageFlags));
2091	return pImage->uImageFlags;
2092	}
2093
2094	/** @copydoc VDIMAGEBACKEND::pfnGetOpenFlags */
2095	static DECLCALLBACK(unsigned) qcowGetOpenFlags(void *pBackendData)
2096	{
2097	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2098	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2099
2100	AssertPtrReturn(pImage, 0);
2101
2102	LogFlowFunc(("returns %#x\n", pImage->uOpenFlags));
2103	return pImage->uOpenFlags;
2104	}
2105
2106	/** @copydoc VDIMAGEBACKEND::pfnSetOpenFlags */
2107	static DECLCALLBACK(int) qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2108	{
2109	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2110	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2111	int rc = VINF_SUCCESS;
2112
2113	/* Image must be opened and the new flags must be valid. */
2114	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2115	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SHAREABLE
2116	\| VD_OPEN_FLAGS_SEQUENTIAL \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2117	rc = VERR_INVALID_PARAMETER;
2118	else
2119	{
2120	/* Implement this operation via reopening the image. */
2121	rc = qcowFreeImage(pImage, false);
2122	if (RT_SUCCESS(rc))
2123	rc = qcowOpenImage(pImage, uOpenFlags);
2124	}
2125
2126	LogFlowFunc(("returns %Rrc\n", rc));
2127	return rc;
2128	}
2129
2130	/** @copydoc VDIMAGEBACKEND::pfnGetComment */
2131	VD_BACKEND_CALLBACK_GET_COMMENT_DEF_NOT_SUPPORTED(qcowGetComment);
2132
2133	/** @copydoc VDIMAGEBACKEND::pfnSetComment */
2134	VD_BACKEND_CALLBACK_SET_COMMENT_DEF_NOT_SUPPORTED(qcowSetComment, PQCOWIMAGE);
2135
2136	/** @copydoc VDIMAGEBACKEND::pfnGetUuid */
2137	VD_BACKEND_CALLBACK_GET_UUID_DEF_NOT_SUPPORTED(qcowGetUuid);
2138
2139	/** @copydoc VDIMAGEBACKEND::pfnSetUuid */
2140	VD_BACKEND_CALLBACK_SET_UUID_DEF_NOT_SUPPORTED(qcowSetUuid, PQCOWIMAGE);
2141
2142	/** @copydoc VDIMAGEBACKEND::pfnGetModificationUuid */
2143	VD_BACKEND_CALLBACK_GET_UUID_DEF_NOT_SUPPORTED(qcowGetModificationUuid);
2144
2145	/** @copydoc VDIMAGEBACKEND::pfnSetModificationUuid */
2146	VD_BACKEND_CALLBACK_SET_UUID_DEF_NOT_SUPPORTED(qcowSetModificationUuid, PQCOWIMAGE);
2147
2148	/** @copydoc VDIMAGEBACKEND::pfnGetParentUuid */
2149	VD_BACKEND_CALLBACK_GET_UUID_DEF_NOT_SUPPORTED(qcowGetParentUuid);
2150
2151	/** @copydoc VDIMAGEBACKEND::pfnSetParentUuid */
2152	VD_BACKEND_CALLBACK_SET_UUID_DEF_NOT_SUPPORTED(qcowSetParentUuid, PQCOWIMAGE);
2153
2154	/** @copydoc VDIMAGEBACKEND::pfnGetParentModificationUuid */
2155	VD_BACKEND_CALLBACK_GET_UUID_DEF_NOT_SUPPORTED(qcowGetParentModificationUuid);
2156
2157	/** @copydoc VDIMAGEBACKEND::pfnSetParentModificationUuid */
2158	VD_BACKEND_CALLBACK_SET_UUID_DEF_NOT_SUPPORTED(qcowSetParentModificationUuid, PQCOWIMAGE);
2159
2160	/** @copydoc VDIMAGEBACKEND::pfnDump */
2161	static DECLCALLBACK(void) qcowDump(void *pBackendData)
2162	{
2163	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2164
2165	AssertPtrReturnVoid(pImage);
2166	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cbSector=%llu\n",
2167	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2168	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2169	pImage->cbSize / 512);
2170	}
2171
2172	/** @copydoc VDIMAGEBACKEND::pfnGetParentFilename */
2173	static DECLCALLBACK(int) qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2174	{
2175	int rc = VINF_SUCCESS;
2176	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2177
2178	AssertPtr(pImage);
2179	if (pImage)
2180	if (pImage->pszBackingFilename)
2181	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2182	else
2183	rc = VERR_NOT_SUPPORTED;
2184	else
2185	rc = VERR_VD_NOT_OPENED;
2186
2187	LogFlowFunc(("returns %Rrc\n", rc));
2188	return rc;
2189	}
2190
2191	/** @copydoc VDIMAGEBACKEND::pfnSetParentFilename */
2192	static DECLCALLBACK(int) qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2193	{
2194	int rc = VINF_SUCCESS;
2195	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2196
2197	AssertPtr(pImage);
2198	if (pImage)
2199	{
2200	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2201	rc = VERR_VD_IMAGE_READ_ONLY;
2202	else if ( pImage->pszBackingFilename
2203	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2204	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2205	else
2206	{
2207	if (pImage->pszBackingFilename)
2208	RTStrFree(pImage->pszBackingFilename);
2209	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2210	if (!pImage->pszBackingFilename)
2211	rc = VERR_NO_STR_MEMORY;
2212	else
2213	{
2214	if (!pImage->offBackingFilename)
2215	{
2216	/* Allocate new cluster. */
2217	uint64_t offData = qcowClusterAllocate(pImage, 1);
2218
2219	Assert((offData & UINT32_MAX) == offData);
2220	pImage->offBackingFilename = (uint32_t)offData;
2221	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2222	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2223	offData + pImage->cbCluster);
2224	}
2225
2226	if (RT_SUCCESS(rc))
2227	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2228	pImage->offBackingFilename,
2229	pImage->pszBackingFilename,
2230	strlen(pImage->pszBackingFilename));
2231	}
2232	}
2233	}
2234	else
2235	rc = VERR_VD_NOT_OPENED;
2236
2237	LogFlowFunc(("returns %Rrc\n", rc));
2238	return rc;
2239	}
2240
2241
2242
2243	const VDIMAGEBACKEND g_QCowBackend =
2244	{
2245	/* u32Version */
2246	VD_IMGBACKEND_VERSION,
2247	/* pszBackendName */
2248	"QCOW",
2249	/* uBackendCaps */
2250	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2251	/* paFileExtensions */
2252	s_aQCowFileExtensions,
2253	/* paConfigInfo */
2254	NULL,
2255	/* pfnProbe */
2256	qcowProbe,
2257	/* pfnOpen */
2258	qcowOpen,
2259	/* pfnCreate */
2260	qcowCreate,
2261	/* pfnRename */
2262	qcowRename,
2263	/* pfnClose */
2264	qcowClose,
2265	/* pfnRead */
2266	qcowRead,
2267	/* pfnWrite */
2268	qcowWrite,
2269	/* pfnFlush */
2270	qcowFlush,
2271	/* pfnDiscard */
2272	NULL,
2273	/* pfnGetVersion */
2274	qcowGetVersion,
2275	/* pfnGetFileSize */
2276	qcowGetFileSize,
2277	/* pfnGetPCHSGeometry */
2278	qcowGetPCHSGeometry,
2279	/* pfnSetPCHSGeometry */
2280	qcowSetPCHSGeometry,
2281	/* pfnGetLCHSGeometry */
2282	qcowGetLCHSGeometry,
2283	/* pfnSetLCHSGeometry */
2284	qcowSetLCHSGeometry,
2285	/* pfnQueryRegions */
2286	qcowQueryRegions,
2287	/* pfnRegionListRelease */
2288	qcowRegionListRelease,
2289	/* pfnGetImageFlags */
2290	qcowGetImageFlags,
2291	/* pfnGetOpenFlags */
2292	qcowGetOpenFlags,
2293	/* pfnSetOpenFlags */
2294	qcowSetOpenFlags,
2295	/* pfnGetComment */
2296	qcowGetComment,
2297	/* pfnSetComment */
2298	qcowSetComment,
2299	/* pfnGetUuid */
2300	qcowGetUuid,
2301	/* pfnSetUuid */
2302	qcowSetUuid,
2303	/* pfnGetModificationUuid */
2304	qcowGetModificationUuid,
2305	/* pfnSetModificationUuid */
2306	qcowSetModificationUuid,
2307	/* pfnGetParentUuid */
2308	qcowGetParentUuid,
2309	/* pfnSetParentUuid */
2310	qcowSetParentUuid,
2311	/* pfnGetParentModificationUuid */
2312	qcowGetParentModificationUuid,
2313	/* pfnSetParentModificationUuid */
2314	qcowSetParentModificationUuid,
2315	/* pfnDump */
2316	qcowDump,
2317	/* pfnGetTimestamp */
2318	NULL,
2319	/* pfnGetParentTimestamp */
2320	NULL,
2321	/* pfnSetParentTimestamp */
2322	NULL,
2323	/* pfnGetParentFilename */
2324	qcowGetParentFilename,
2325	/* pfnSetParentFilename */
2326	qcowSetParentFilename,
2327	/* pfnComposeLocation */
2328	genericFileComposeLocation,
2329	/* pfnComposeName */
2330	genericFileComposeName,
2331	/* pfnCompact */
2332	NULL,
2333	/* pfnResize */
2334	NULL,
2335	/* pfnRepair */
2336	NULL,
2337	/* pfnTraverseMetadata */
2338	NULL,
2339	/* u32VersionEnd */
2340	VD_IMGBACKEND_VERSION
2341	};

Note: See TracBrowser for help on using the repository browser.

source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 77921

Download in other formats: