QCOW.cpp@ 53369

Last change on this file since 53369 was 51626, checked in by vboxsync, 11 years ago
QCOW: Initialize the L2 cache always, fixes a crash if opening the image file fails
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1	/* $Id: QCOW.cpp 51626 2014-06-16 20:15:14Z 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	#include "VDBackends.h"
34
35	/**
36	* The QCOW backend implements support for the qemu copy on write format (short QCOW)
37	* There is no official specification available but the format is described
38	* at http://people.gnome.org/~markmc/qcow-image-format.html for version 2
39	* and http://people.gnome.org/~markmc/qcow-image-format-version-1.html for version 1.
40	*
41	* Missing things to implement:
42	* - v2 image creation and handling of the reference count table. (Blocker to enable support for V2 images)
43	* - cluster encryption
44	* - cluster compression
45	* - compaction
46	* - resizing
47	*/
48
49	/*******************************************************************************
50	* Structures in a QCOW image, big endian *
51	*******************************************************************************/
52
53	#pragma pack(1)
54	typedef struct QCowHeader
55	{
56	/** Magic value. */
57	uint32_t u32Magic;
58	/** Version of the image. */
59	uint32_t u32Version;
60	/** Version dependent data. */
61	union
62	{
63	/** Version 1. */
64	struct
65	{
66	/** Backing file offset. */
67	uint64_t u64BackingFileOffset;
68	/** Size of the backing file. */
69	uint32_t u32BackingFileSize;
70	/** mtime (Modification time?) - can be ignored. */
71	uint32_t u32MTime;
72	/** Logical size of the image in bytes. */
73	uint64_t u64Size;
74	/** Number of bits in the virtual offset used as a cluster offset. */
75	uint8_t u8ClusterBits;
76	/** Number of bits in the virtual offset used for the L2 index. */
77	uint8_t u8L2Bits;
78	/** Padding because the header is not packed in the original source. */
79	uint16_t u16Padding;
80	/** Used cryptographic method. */
81	uint32_t u32CryptMethod;
82	/** Offset of the L1 table in the image in bytes. */
83	uint64_t u64L1TableOffset;
84	} v1;
85	/** Version 2. */
86	struct
87	{
88	/** Backing file offset. */
89	uint64_t u64BackingFileOffset;
90	/** Size of the backing file. */
91	uint32_t u32BackingFileSize;
92	/** Number of bits in the virtual offset used as a cluster offset. */
93	uint32_t u32ClusterBits;
94	/** Logical size of the image. */
95	uint64_t u64Size;
96	/** Used cryptographic method. */
97	uint32_t u32CryptMethod;
98	/** Size of the L1 table in entries (each 8bytes big). */
99	uint32_t u32L1Size;
100	/** Offset of the L1 table in the image in bytes. */
101	uint64_t u64L1TableOffset;
102	/** Start of the refcount table in the image. */
103	uint64_t u64RefcountTableOffset;
104	/** Size of the refcount table in clusters. */
105	uint32_t u32RefcountTableClusters;
106	/** Number of snapshots in the image. */
107	uint32_t u32NbSnapshots;
108	/** Offset of the first snapshot header in the image. */
109	uint64_t u64SnapshotsOffset;
110	} v2;
111	} Version;
112	} QCowHeader;
113	#pragma pack()
114	/** Pointer to a on disk QCOW header. */
115	typedef QCowHeader *PQCowHeader;
116
117	/** QCOW magic value. */
118	#define QCOW_MAGIC UINT32_C(0x514649fb) /* QFI\0xfb */
119	/** Size of the V1 header. */
120	#define QCOW_V1_HDR_SIZE (48)
121	/** Size of the V2 header. */
122	#define QCOW_V2_HDR_SIZE (72)
123
124	/** Cluster is compressed flag for QCOW images. */
125	#define QCOW_V1_COMPRESSED_FLAG RT_BIT_64(63)
126
127	/** Copied flag for QCOW2 images. */
128	#define QCOW_V2_COPIED_FLAG RT_BIT_64(63)
129	/** Cluster is compressed flag for QCOW2 images. */
130	#define QCOW_V2_COMPRESSED_FLAG RT_BIT_64(62)
131
132
133	/*******************************************************************************
134	* Constants And Macros, Structures and Typedefs *
135	*******************************************************************************/
136
137	/**
138	* QCOW L2 cache entry.
139	*/
140	typedef struct QCOWL2CACHEENTRY
141	{
142	/** List node for the search list. */
143	RTLISTNODE NodeSearch;
144	/** List node for the LRU list. */
145	RTLISTNODE NodeLru;
146	/** Reference counter. */
147	uint32_t cRefs;
148	/** The offset of the L2 table, used as search key. */
149	uint64_t offL2Tbl;
150	/** Pointer to the cached L2 table. */
151	uint64_t *paL2Tbl;
152	} QCOWL2CACHEENTRY, *PQCOWL2CACHEENTRY;
153
154	/** Maximum amount of memory the cache is allowed to use. */
155	#define QCOW_L2_CACHE_MEMORY_MAX (2*_1M)
156
157	/** QCOW default cluster size for image version 2. */
158	#define QCOW2_CLUSTER_SIZE_DEFAULT (64*_1K)
159	/** QCOW default cluster size for image version 1. */
160	#define QCOW_CLUSTER_SIZE_DEFAULT (4*_1K)
161	/** QCOW default L2 table size in clusters. */
162	#define QCOW_L2_CLUSTERS_DEFAULT (1)
163
164	/**
165	* QCOW image data structure.
166	*/
167	typedef struct QCOWIMAGE
168	{
169	/** Image name. */
170	const char *pszFilename;
171	/** Storage handle. */
172	PVDIOSTORAGE pStorage;
173
174	/** Pointer to the per-disk VD interface list. */
175	PVDINTERFACE pVDIfsDisk;
176	/** Pointer to the per-image VD interface list. */
177	PVDINTERFACE pVDIfsImage;
178	/** Error interface. */
179	PVDINTERFACEERROR pIfError;
180	/** I/O interface. */
181	PVDINTERFACEIOINT pIfIo;
182
183	/** Open flags passed by VBoxHD layer. */
184	unsigned uOpenFlags;
185	/** Image flags defined during creation or determined during open. */
186	unsigned uImageFlags;
187	/** Total size of the image. */
188	uint64_t cbSize;
189	/** Physical geometry of this image. */
190	VDGEOMETRY PCHSGeometry;
191	/** Logical geometry of this image. */
192	VDGEOMETRY LCHSGeometry;
193
194	/** Image version. */
195	unsigned uVersion;
196	/** MTime field - used only to preserve value in opened images, unmodified otherwise. */
197	uint32_t MTime;
198
199	/** Filename of the backing file if any. */
200	char *pszBackingFilename;
201	/** Offset of the filename in the image. */
202	uint64_t offBackingFilename;
203	/** Size of the backing filename excluding \0. */
204	uint32_t cbBackingFilename;
205
206	/** Next offset of a new cluster, aligned to sector size. */
207	uint64_t offNextCluster;
208	/** Cluster size in bytes. */
209	uint32_t cbCluster;
210	/** Number of entries in the L1 table. */
211	uint32_t cL1TableEntries;
212	/** Size of an L1 rounded to the next cluster size. */
213	uint32_t cbL1Table;
214	/** Pointer to the L1 table. */
215	uint64_t *paL1Table;
216	/** Offset of the L1 table. */
217	uint64_t offL1Table;
218
219	/** Size of the L2 table in bytes. */
220	uint32_t cbL2Table;
221	/** Number of entries in the L2 table. */
222	uint32_t cL2TableEntries;
223	/** Memory occupied by the L2 table cache. */
224	size_t cbL2Cache;
225	/** The sorted L2 entry list used for searching. */
226	RTLISTNODE ListSearch;
227	/** The LRU L2 entry list used for eviction. */
228	RTLISTNODE ListLru;
229
230	/** Offset of the refcount table. */
231	uint64_t offRefcountTable;
232	/** Size of the refcount table in bytes. */
233	uint32_t cbRefcountTable;
234	/** Number of entries in the refcount table. */
235	uint32_t cRefcountTableEntries;
236	/** Pointer to the refcount table. */
237	uint64_t *paRefcountTable;
238
239	/** Offset mask for a cluster. */
240	uint64_t fOffsetMask;
241	/** Number of bits to shift to get the L1 index. */
242	uint32_t cL1Shift;
243	/** L2 table mask to get the L2 index. */
244	uint64_t fL2Mask;
245	/** Number of bits to shift to get the L2 index. */
246	uint32_t cL2Shift;
247
248	} QCOWIMAGE, *PQCOWIMAGE;
249
250	/**
251	* State of the async cluster allocation.
252	*/
253	typedef enum QCOWCLUSTERASYNCALLOCSTATE
254	{
255	/** Invalid. */
256	QCOWCLUSTERASYNCALLOCSTATE_INVALID = 0,
257	/** L2 table allocation. */
258	QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC,
259	/** Link L2 table into L1. */
260	QCOWCLUSTERASYNCALLOCSTATE_L2_LINK,
261	/** Allocate user data cluster. */
262	QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC,
263	/** Link user data cluster. */
264	QCOWCLUSTERASYNCALLOCSTATE_USER_LINK,
265	/** 32bit blowup. */
266	QCOWCLUSTERASYNCALLOCSTATE_32BIT_HACK = 0x7fffffff
267	} QCOWCLUSTERASYNCALLOCSTATE, *PQCOWCLUSTERASYNCALLOCSTATE;
268
269	/**
270	* Data needed to track async cluster allocation.
271	*/
272	typedef struct QCOWCLUSTERASYNCALLOC
273	{
274	/** The state of the cluster allocation. */
275	QCOWCLUSTERASYNCALLOCSTATE enmAllocState;
276	/** Old image size to rollback in case of an error. */
277	uint64_t offNextClusterOld;
278	/** L1 index to link if any. */
279	uint32_t idxL1;
280	/** L2 index to link, required in any case. */
281	uint32_t idxL2;
282	/** Start offset of the allocated cluster. */
283	uint64_t offClusterNew;
284	/** L2 cache entry if a L2 table is allocated. */
285	PQCOWL2CACHEENTRY pL2Entry;
286	/** Number of bytes to write. */
287	size_t cbToWrite;
288	} QCOWCLUSTERASYNCALLOC, *PQCOWCLUSTERASYNCALLOC;
289
290	/*******************************************************************************
291	* Static Variables *
292	*******************************************************************************/
293
294	/** NULL-terminated array of supported file extensions. */
295	static const VDFILEEXTENSION s_aQCowFileExtensions[] =
296	{
297	{"qcow", VDTYPE_HDD},
298	{"qcow2", VDTYPE_HDD},
299	{NULL, VDTYPE_INVALID}
300	};
301
302	/*******************************************************************************
303	* Internal Functions *
304	*******************************************************************************/
305
306	/**
307	* Return power of 2 or 0 if num error.
308	*
309	* @returns The power of 2 or 0 if the given number is not a power of 2.
310	* @param u32 The number.
311	*/
312	static uint32_t qcowGetPowerOfTwo(uint32_t u32)
313	{
314	if (u32 == 0)
315	return 0;
316	uint32_t uPower2 = 0;
317	while ((u32 & 1) == 0)
318	{
319	u32 >>= 1;
320	uPower2++;
321	}
322	return u32 == 1 ? uPower2 : 0;
323	}
324
325
326	/**
327	* Converts the image header to the host endianess and performs basic checks.
328	*
329	* @returns Whether the given header is valid or not.
330	* @param pHeader Pointer to the header to convert.
331	*/
332	static bool qcowHdrConvertToHostEndianess(PQCowHeader pHeader)
333	{
334	pHeader->u32Magic = RT_BE2H_U32(pHeader->u32Magic);
335	pHeader->u32Version = RT_BE2H_U32(pHeader->u32Version);
336
337	if (pHeader->u32Magic != QCOW_MAGIC)
338	return false;
339
340	if (pHeader->u32Version == 1)
341	{
342	pHeader->Version.v1.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v1.u64BackingFileOffset);
343	pHeader->Version.v1.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v1.u32BackingFileSize);
344	pHeader->Version.v1.u32MTime = RT_BE2H_U32(pHeader->Version.v1.u32MTime);
345	pHeader->Version.v1.u64Size = RT_BE2H_U64(pHeader->Version.v1.u64Size);
346	pHeader->Version.v1.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v1.u32CryptMethod);
347	pHeader->Version.v1.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v1.u64L1TableOffset);
348	}
349	else if (pHeader->u32Version == 2)
350	{
351	pHeader->Version.v2.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v2.u64BackingFileOffset);
352	pHeader->Version.v2.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v2.u32BackingFileSize);
353	pHeader->Version.v2.u32ClusterBits = RT_BE2H_U32(pHeader->Version.v2.u32ClusterBits);
354	pHeader->Version.v2.u64Size = RT_BE2H_U64(pHeader->Version.v2.u64Size);
355	pHeader->Version.v2.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v2.u32CryptMethod);
356	pHeader->Version.v2.u32L1Size = RT_BE2H_U32(pHeader->Version.v2.u32L1Size);
357	pHeader->Version.v2.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v2.u64L1TableOffset);
358	pHeader->Version.v2.u64RefcountTableOffset = RT_BE2H_U64(pHeader->Version.v2.u64RefcountTableOffset);
359	pHeader->Version.v2.u32RefcountTableClusters = RT_BE2H_U32(pHeader->Version.v2.u32RefcountTableClusters);
360	pHeader->Version.v2.u32NbSnapshots = RT_BE2H_U32(pHeader->Version.v2.u32NbSnapshots);
361	pHeader->Version.v2.u64SnapshotsOffset = RT_BE2H_U64(pHeader->Version.v2.u64SnapshotsOffset);
362	}
363	else
364	return false;
365
366	return true;
367	}
368
369	/**
370	* Creates a QCOW header from the given image state.
371	*
372	* @returns nothing.
373	* @param pImage Image instance data.
374	* @param pHeader Pointer to the header to convert.
375	* @param pcbHeader Where to store the size of the header to write.
376	*/
377	static void qcowHdrConvertFromHostEndianess(PQCOWIMAGE pImage, PQCowHeader pHeader,
378	size_t *pcbHeader)
379	{
380	memset(pHeader, 0, sizeof(QCowHeader));
381
382	pHeader->u32Magic = RT_H2BE_U32(QCOW_MAGIC);
383	pHeader->u32Version = RT_H2BE_U32(pImage->uVersion);
384	if (pImage->uVersion == 1)
385	{
386	pHeader->Version.v1.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
387	pHeader->Version.v1.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
388	pHeader->Version.v1.u32MTime = RT_H2BE_U32(pImage->MTime);
389	pHeader->Version.v1.u64Size = RT_H2BE_U64(pImage->cbSize);
390	pHeader->Version.v1.u8ClusterBits = (uint8_t)qcowGetPowerOfTwo(pImage->cbCluster);
391	pHeader->Version.v1.u8L2Bits = (uint8_t)qcowGetPowerOfTwo(pImage->cL2TableEntries);
392	pHeader->Version.v1.u32CryptMethod = RT_H2BE_U32(0);
393	pHeader->Version.v1.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
394	*pcbHeader = QCOW_V1_HDR_SIZE;
395	}
396	else if (pImage->uVersion == 2)
397	{
398	pHeader->Version.v2.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
399	pHeader->Version.v2.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
400	pHeader->Version.v2.u32ClusterBits = RT_H2BE_U32(qcowGetPowerOfTwo(pImage->cbCluster));
401	pHeader->Version.v2.u64Size = RT_H2BE_U64(pImage->cbSize);
402	pHeader->Version.v2.u32CryptMethod = RT_H2BE_U32(0);
403	pHeader->Version.v2.u32L1Size = RT_H2BE_U32(pImage->cL1TableEntries);
404	pHeader->Version.v2.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
405	pHeader->Version.v2.u64RefcountTableOffset = RT_H2BE_U64(pImage->offRefcountTable);
406	pHeader->Version.v2.u32RefcountTableClusters = RT_H2BE_U32(pImage->cbRefcountTable / pImage->cbCluster);
407	pHeader->Version.v2.u32NbSnapshots = RT_H2BE_U32(0);
408	pHeader->Version.v2.u64SnapshotsOffset = RT_H2BE_U64((uint64_t)0);
409	*pcbHeader = QCOW_V2_HDR_SIZE;
410	}
411	else
412	AssertMsgFailed(("Invalid version of the QCOW image format %d\n", pImage->uVersion));
413	}
414
415	/**
416	* Convert table entries from little endian to host endianess.
417	*
418	* @returns nothing.
419	* @param paTbl Pointer to the table.
420	* @param cEntries Number of entries in the table.
421	*/
422	static void qcowTableConvertToHostEndianess(uint64_t *paTbl, uint32_t cEntries)
423	{
424	while(cEntries-- > 0)
425	{
426	paTbl = RT_BE2H_U64(paTbl);
427	paTbl++;
428	}
429	}
430
431	/**
432	* Convert table entries from host to little endian format.
433	*
434	* @returns nothing.
435	* @param paTblImg Pointer to the table which will store the little endian table.
436	* @param paTbl The source table to convert.
437	* @param cEntries Number of entries in the table.
438	*/
439	static void qcowTableConvertFromHostEndianess(uint64_t paTblImg, uint64_t paTbl,
440	uint32_t cEntries)
441	{
442	while(cEntries-- > 0)
443	{
444	paTblImg = RT_H2BE_U64(paTbl);
445	paTbl++;
446	paTblImg++;
447	}
448	}
449
450	/**
451	* Convert refcount table entries from little endian to host endianess.
452	*
453	* @returns nothing.
454	* @param paTbl Pointer to the table.
455	* @param cEntries Number of entries in the table.
456	*/
457	static void qcowRefcountTableConvertToHostEndianess(uint16_t *paTbl, uint32_t cEntries)
458	{
459	while(cEntries-- > 0)
460	{
461	paTbl = RT_BE2H_U16(paTbl);
462	paTbl++;
463	}
464	}
465
466	/**
467	* Convert table entries from host to little endian format.
468	*
469	* @returns nothing.
470	* @param paTblImg Pointer to the table which will store the little endian table.
471	* @param paTbl The source table to convert.
472	* @param cEntries Number of entries in the table.
473	*/
474	static void qcowRefcountTableConvertFromHostEndianess(uint16_t paTblImg, uint16_t paTbl,
475	uint32_t cEntries)
476	{
477	while(cEntries-- > 0)
478	{
479	paTblImg = RT_H2BE_U16(paTbl);
480	paTbl++;
481	paTblImg++;
482	}
483	}
484
485	/**
486	* Creates the L2 table cache.
487	*
488	* @returns VBox status code.
489	* @param pImage The image instance data.
490	*/
491	static int qcowL2TblCacheCreate(PQCOWIMAGE pImage)
492	{
493	pImage->cbL2Cache = 0;
494	RTListInit(&pImage->ListSearch);
495	RTListInit(&pImage->ListLru);
496
497	return VINF_SUCCESS;
498	}
499
500	/**
501	* Destroys the L2 table cache.
502	*
503	* @returns nothing.
504	* @param pImage The image instance data.
505	*/
506	static void qcowL2TblCacheDestroy(PQCOWIMAGE pImage)
507	{
508	PQCOWL2CACHEENTRY pL2Entry = NULL;
509	PQCOWL2CACHEENTRY pL2Next = NULL;
510
511	RTListForEachSafe(&pImage->ListSearch, pL2Entry, pL2Next, QCOWL2CACHEENTRY, NodeSearch)
512	{
513	Assert(!pL2Entry->cRefs);
514
515	RTListNodeRemove(&pL2Entry->NodeSearch);
516	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
517	RTMemFree(pL2Entry);
518	}
519
520	pImage->cbL2Cache = 0;
521	RTListInit(&pImage->ListSearch);
522	RTListInit(&pImage->ListLru);
523	}
524
525	/**
526	* Returns the L2 table matching the given offset or NULL if none could be found.
527	*
528	* @returns Pointer to the L2 table cache entry or NULL.
529	* @param pImage The image instance data.
530	* @param offL2Tbl Offset of the L2 table to search for.
531	*/
532	static PQCOWL2CACHEENTRY qcowL2TblCacheRetain(PQCOWIMAGE pImage, uint64_t offL2Tbl)
533	{
534	PQCOWL2CACHEENTRY pL2Entry = NULL;
535
536	RTListForEach(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch)
537	{
538	if (pL2Entry->offL2Tbl == offL2Tbl)
539	break;
540	}
541
542	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
543	{
544	/* Update LRU list. */
545	RTListNodeRemove(&pL2Entry->NodeLru);
546	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
547	pL2Entry->cRefs++;
548	return pL2Entry;
549	}
550	else
551	return NULL;
552	}
553
554	/**
555	* Releases a L2 table cache entry.
556	*
557	* @returns nothing.
558	* @param pL2Entry The L2 cache entry.
559	*/
560	static void qcowL2TblCacheEntryRelease(PQCOWL2CACHEENTRY pL2Entry)
561	{
562	Assert(pL2Entry->cRefs > 0);
563	pL2Entry->cRefs--;
564	}
565
566	/**
567	* Allocates a new L2 table from the cache evicting old entries if required.
568	*
569	* @returns Pointer to the L2 cache entry or NULL.
570	* @param pImage The image instance data.
571	*/
572	static PQCOWL2CACHEENTRY qcowL2TblCacheEntryAlloc(PQCOWIMAGE pImage)
573	{
574	PQCOWL2CACHEENTRY pL2Entry = NULL;
575	int rc = VINF_SUCCESS;
576
577	if (pImage->cbL2Cache + pImage->cbL2Table <= QCOW_L2_CACHE_MEMORY_MAX)
578	{
579	/* Add a new entry. */
580	pL2Entry = (PQCOWL2CACHEENTRY)RTMemAllocZ(sizeof(QCOWL2CACHEENTRY));
581	if (pL2Entry)
582	{
583	pL2Entry->paL2Tbl = (uint64_t *)RTMemPageAllocZ(pImage->cbL2Table);
584	if (RT_UNLIKELY(!pL2Entry->paL2Tbl))
585	{
586	RTMemFree(pL2Entry);
587	pL2Entry = NULL;
588	}
589	else
590	{
591	pL2Entry->cRefs = 1;
592	pImage->cbL2Cache += pImage->cbL2Table;
593	}
594	}
595	}
596	else
597	{
598	/* Evict the last not in use entry and use it */
599	Assert(!RTListIsEmpty(&pImage->ListLru));
600
601	RTListForEachReverse(&pImage->ListLru, pL2Entry, QCOWL2CACHEENTRY, NodeLru)
602	{
603	if (!pL2Entry->cRefs)
604	break;
605	}
606
607	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
608	{
609	RTListNodeRemove(&pL2Entry->NodeSearch);
610	RTListNodeRemove(&pL2Entry->NodeLru);
611	pL2Entry->offL2Tbl = 0;
612	pL2Entry->cRefs = 1;
613	}
614	else
615	pL2Entry = NULL;
616	}
617
618	return pL2Entry;
619	}
620
621	/**
622	* Frees a L2 table cache entry.
623	*
624	* @returns nothing.
625	* @param pImage The image instance data.
626	* @param pL2Entry The L2 cache entry to free.
627	*/
628	static void qcowL2TblCacheEntryFree(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
629	{
630	Assert(!pL2Entry->cRefs);
631	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
632	RTMemFree(pL2Entry);
633
634	pImage->cbL2Cache -= pImage->cbL2Table;
635	}
636
637	/**
638	* Inserts an entry in the L2 table cache.
639	*
640	* @returns nothing.
641	* @param pImage The image instance data.
642	* @param pL2Entry The L2 cache entry to insert.
643	*/
644	static void qcowL2TblCacheEntryInsert(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
645	{
646	PQCOWL2CACHEENTRY pIt = NULL;
647
648	Assert(pL2Entry->offL2Tbl > 0);
649
650	/* Insert at the top of the LRU list. */
651	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
652
653	if (RTListIsEmpty(&pImage->ListSearch))
654	{
655	RTListAppend(&pImage->ListSearch, &pL2Entry->NodeSearch);
656	}
657	else
658	{
659	/* Insert into search list. */
660	pIt = RTListGetFirst(&pImage->ListSearch, QCOWL2CACHEENTRY, NodeSearch);
661	if (pIt->offL2Tbl > pL2Entry->offL2Tbl)
662	RTListPrepend(&pImage->ListSearch, &pL2Entry->NodeSearch);
663	else
664	{
665	bool fInserted = false;
666
667	RTListForEach(&pImage->ListSearch, pIt, QCOWL2CACHEENTRY, NodeSearch)
668	{
669	Assert(pIt->offL2Tbl != pL2Entry->offL2Tbl);
670	if (pIt->offL2Tbl < pL2Entry->offL2Tbl)
671	{
672	RTListNodeInsertAfter(&pIt->NodeSearch, &pL2Entry->NodeSearch);
673	fInserted = true;
674	break;
675	}
676	}
677	Assert(fInserted);
678	}
679	}
680	}
681
682	/**
683	* Fetches the L2 from the given offset trying the LRU cache first and
684	* reading it from the image after a cache miss.
685	*
686	* @returns VBox status code.
687	* @param pImage Image instance data.
688	* @param pIoCtx The I/O context.
689	* @param offL2Tbl The offset of the L2 table in the image.
690	* @param ppL2Entry Where to store the L2 table on success.
691	*/
692	static int qcowL2TblCacheFetch(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offL2Tbl,
693	PQCOWL2CACHEENTRY *ppL2Entry)
694	{
695	int rc = VINF_SUCCESS;
696
697	/* Try to fetch the L2 table from the cache first. */
698	PQCOWL2CACHEENTRY pL2Entry = qcowL2TblCacheRetain(pImage, offL2Tbl);
699	if (!pL2Entry)
700	{
701	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
702
703	if (pL2Entry)
704	{
705	/* Read from the image. */
706	PVDMETAXFER pMetaXfer;
707
708	pL2Entry->offL2Tbl = offL2Tbl;
709	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
710	offL2Tbl, pL2Entry->paL2Tbl,
711	pImage->cbL2Table, pIoCtx,
712	&pMetaXfer, NULL, NULL);
713	if (RT_SUCCESS(rc))
714	{
715	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
716	#if defined(RT_LITTLE_ENDIAN)
717	qcowTableConvertToHostEndianess(pL2Entry->paL2Tbl, pImage->cL2TableEntries);
718	#endif
719	qcowL2TblCacheEntryInsert(pImage, pL2Entry);
720	}
721	else
722	{
723	qcowL2TblCacheEntryRelease(pL2Entry);
724	qcowL2TblCacheEntryFree(pImage, pL2Entry);
725	}
726	}
727	else
728	rc = VERR_NO_MEMORY;
729	}
730
731	if (RT_SUCCESS(rc))
732	*ppL2Entry = pL2Entry;
733
734	return rc;
735	}
736
737	/**
738	* Sets the L1, L2 and offset bitmasks and L1 and L2 bit shift members.
739	*
740	* @returns nothing.
741	* @param pImage The image instance data.
742	*/
743	static void qcowTableMasksInit(PQCOWIMAGE pImage)
744	{
745	uint32_t cClusterBits, cL2TableBits;
746
747	cClusterBits = qcowGetPowerOfTwo(pImage->cbCluster);
748	cL2TableBits = qcowGetPowerOfTwo(pImage->cL2TableEntries);
749
750	Assert(cClusterBits + cL2TableBits < 64);
751
752	pImage->fOffsetMask = ((uint64_t)pImage->cbCluster - 1);
753	pImage->fL2Mask = ((uint64_t)pImage->cL2TableEntries - 1) << cClusterBits;
754	pImage->cL2Shift = cClusterBits;
755	pImage->cL1Shift = cClusterBits + cL2TableBits;
756	}
757
758	/**
759	* Converts a given logical offset into the
760	*
761	* @returns nothing.
762	* @param pImage The image instance data.
763	* @param off The logical offset to convert.
764	* @param pidxL1 Where to store the index in the L1 table on success.
765	* @param pidxL2 Where to store the index in the L2 table on success.
766	* @param poffCluster Where to store the offset in the cluster on success.
767	*/
768	DECLINLINE(void) qcowConvertLogicalOffset(PQCOWIMAGE pImage, uint64_t off, uint32_t *pidxL1,
769	uint32_t pidxL2, uint32_t poffCluster)
770	{
771	AssertPtr(pidxL1);
772	AssertPtr(pidxL2);
773	AssertPtr(poffCluster);
774
775	*poffCluster = off & pImage->fOffsetMask;
776	*pidxL1 = off >> pImage->cL1Shift;
777	*pidxL2 = (off & pImage->fL2Mask) >> pImage->cL2Shift;
778	}
779
780	/**
781	* Converts Cluster size to a byte size.
782	*
783	* @returns Number of bytes derived from the given number of clusters.
784	* @param pImage The image instance data.
785	* @param cClusters The clusters to convert.
786	*/
787	DECLINLINE(uint64_t) qcowCluster2Byte(PQCOWIMAGE pImage, uint64_t cClusters)
788	{
789	return cClusters * pImage->cbCluster;
790	}
791
792	/**
793	* Converts number of bytes to cluster size rounding to the next cluster.
794	*
795	* @returns Number of bytes derived from the given number of clusters.
796	* @param pImage The image instance data.
797	* @param cb Number of bytes to convert.
798	*/
799	DECLINLINE(uint64_t) qcowByte2Cluster(PQCOWIMAGE pImage, uint64_t cb)
800	{
801	return cb / pImage->cbCluster + (cb % pImage->cbCluster ? 1 : 0);
802	}
803
804	/**
805	* Allocates a new cluster in the image.
806	*
807	* @returns The start offset of the new cluster in the image.
808	* @param pImage The image instance data.
809	* @param cCLusters Number of clusters to allocate.
810	*/
811	DECLINLINE(uint64_t) qcowClusterAllocate(PQCOWIMAGE pImage, uint32_t cClusters)
812	{
813	uint64_t offCluster;
814
815	offCluster = pImage->offNextCluster;
816	pImage->offNextCluster += cClusters*pImage->cbCluster;
817
818	return offCluster;
819	}
820
821	/**
822	* Returns the real image offset for a given cluster or an error if the cluster is not
823	* yet allocated.
824	*
825	* @returns VBox status code.
826	* VERR_VD_BLOCK_FREE if the cluster is not yet allocated.
827	* @param pImage The image instance data.
828	* @param pIoCtx The I/O context.
829	* @param idxL1 The L1 index.
830	* @param idxL2 The L2 index.
831	* @param offCluster Offset inside the cluster.
832	* @param poffImage Where to store the image offset on success;
833	*/
834	static int qcowConvertToImageOffset(PQCOWIMAGE pImage, PVDIOCTX pIoCtx,
835	uint32_t idxL1, uint32_t idxL2,
836	uint32_t offCluster, uint64_t *poffImage)
837	{
838	int rc = VERR_VD_BLOCK_FREE;
839
840	AssertReturn(idxL1 < pImage->cL1TableEntries, VERR_INVALID_PARAMETER);
841	AssertReturn(idxL2 < pImage->cL2TableEntries, VERR_INVALID_PARAMETER);
842
843	if (pImage->paL1Table[idxL1])
844	{
845	PQCOWL2CACHEENTRY pL2Entry;
846
847	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1], &pL2Entry);
848	if (RT_SUCCESS(rc))
849	{
850	/* Get real file offset. */
851	if (pL2Entry->paL2Tbl[idxL2])
852	{
853	uint64_t off = pL2Entry->paL2Tbl[idxL2];
854
855	/* Strip flags */
856	if (pImage->uVersion == 2)
857	{
858	if (RT_UNLIKELY(off & QCOW_V2_COMPRESSED_FLAG))
859	rc = VERR_NOT_SUPPORTED;
860	else
861	off &= ~(QCOW_V2_COMPRESSED_FLAG \| QCOW_V2_COPIED_FLAG);
862	}
863	else
864	{
865	if (RT_UNLIKELY(off & QCOW_V1_COMPRESSED_FLAG))
866	rc = VERR_NOT_SUPPORTED;
867	else
868	off &= ~QCOW_V1_COMPRESSED_FLAG;
869	}
870
871	*poffImage = off + offCluster;
872	}
873	else
874	rc = VERR_VD_BLOCK_FREE;
875
876	qcowL2TblCacheEntryRelease(pL2Entry);
877	}
878	}
879
880	return rc;
881	}
882
883
884	/**
885	* Internal. Flush image data to disk.
886	*/
887	static int qcowFlushImage(PQCOWIMAGE pImage)
888	{
889	int rc = VINF_SUCCESS;
890
891	if ( pImage->pStorage
892	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
893	&& pImage->cbL1Table)
894	{
895	QCowHeader Header;
896
897	#if defined(RT_LITTLE_ENDIAN)
898	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
899	if (paL1TblImg)
900	{
901	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
902	pImage->cL1TableEntries);
903	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
904	pImage->offL1Table, paL1TblImg,
905	pImage->cbL1Table);
906	RTMemFree(paL1TblImg);
907	}
908	else
909	rc = VERR_NO_MEMORY;
910	#else
911	/* Write L1 table directly. */
912	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->offL1Table,
913	pImage->paL1Table, pImage->cbL1Table);
914	#endif
915	if (RT_SUCCESS(rc))
916	{
917	/* Write header. */
918	size_t cbHeader = 0;
919	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
920	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Header,
921	cbHeader);
922	if (RT_SUCCESS(rc))
923	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
924	}
925	}
926
927	return rc;
928	}
929
930	/**
931	* Flush image data to disk - version for async I/O.
932	*
933	* @returns VBox status code.
934	* @param pImage The image instance data.
935	* @param pIoCtx The I/o context
936	*/
937	static int qcowFlushImageAsync(PQCOWIMAGE pImage, PVDIOCTX pIoCtx)
938	{
939	int rc = VINF_SUCCESS;
940
941	if ( pImage->pStorage
942	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
943	{
944	QCowHeader Header;
945
946	#if defined(RT_LITTLE_ENDIAN)
947	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
948	if (paL1TblImg)
949	{
950	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
951	pImage->cL1TableEntries);
952	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
953	pImage->offL1Table, paL1TblImg,
954	pImage->cbL1Table, pIoCtx, NULL, NULL);
955	RTMemFree(paL1TblImg);
956	}
957	else
958	rc = VERR_NO_MEMORY;
959	#else
960	/* Write L1 table directly. */
961	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
962	pImage->offL1Table, pImage->paL1Table,
963	pImage->cbL1Table, pIoCtx, NULL, NULL);
964	#endif
965	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
966	{
967	/* Write header. */
968	size_t cbHeader = 0;
969	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
970	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
971	0, &Header, cbHeader,
972	pIoCtx, NULL, NULL);
973	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
974	rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage,
975	pIoCtx, NULL, NULL);
976	}
977	}
978
979	return rc;
980	}
981
982	/**
983	* Internal. Free all allocated space for representing an image except pImage,
984	* and optionally delete the image from disk.
985	*/
986	static int qcowFreeImage(PQCOWIMAGE pImage, bool fDelete)
987	{
988	int rc = VINF_SUCCESS;
989
990	/* Freeing a never allocated image (e.g. because the open failed) is
991	* not signalled as an error. After all nothing bad happens. */
992	if (pImage)
993	{
994	if (pImage->pStorage)
995	{
996	/* No point updating the file that is deleted anyway. */
997	if (!fDelete)
998	qcowFlushImage(pImage);
999
1000	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
1001	pImage->pStorage = NULL;
1002	}
1003
1004	if (pImage->paL1Table)
1005	RTMemFree(pImage->paL1Table);
1006
1007	if (pImage->pszBackingFilename)
1008	{
1009	RTMemFree(pImage->pszBackingFilename);
1010	pImage->pszBackingFilename = NULL;
1011	}
1012
1013	qcowL2TblCacheDestroy(pImage);
1014
1015	if (fDelete && pImage->pszFilename)
1016	vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
1017	}
1018
1019	LogFlowFunc(("returns %Rrc\n", rc));
1020	return rc;
1021	}
1022
1023	/**
1024	* Internal: Open an image, constructing all necessary data structures.
1025	*/
1026	static int qcowOpenImage(PQCOWIMAGE pImage, unsigned uOpenFlags)
1027	{
1028	int rc;
1029
1030	pImage->uOpenFlags = uOpenFlags;
1031
1032	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1033	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1034	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1035
1036	rc = qcowL2TblCacheCreate(pImage);
1037	AssertRC(rc);
1038
1039	/*
1040	* Open the image.
1041	*/
1042	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1043	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1044	false /* fCreate */),
1045	&pImage->pStorage);
1046	if (RT_FAILURE(rc))
1047	{
1048	/* Do NOT signal an appropriate error here, as the VD layer has the
1049	* choice of retrying the open if it failed. */
1050	goto out;
1051	}
1052
1053	uint64_t cbFile;
1054	QCowHeader Header;
1055	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1056	if (RT_FAILURE(rc))
1057	goto out;
1058	if (cbFile > sizeof(Header))
1059	{
1060	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0, &Header, sizeof(Header));
1061	if ( RT_SUCCESS(rc)
1062	&& qcowHdrConvertToHostEndianess(&Header))
1063	{
1064	pImage->offNextCluster = RT_ALIGN_64(cbFile, 512); /* Align image to sector boundary. */
1065	Assert(pImage->offNextCluster >= cbFile);
1066
1067	if (Header.u32Version == 1)
1068	{
1069	if (!Header.Version.v1.u32CryptMethod)
1070	{
1071	pImage->uVersion = 1;
1072	pImage->offBackingFilename = Header.Version.v1.u64BackingFileOffset;
1073	pImage->cbBackingFilename = Header.Version.v1.u32BackingFileSize;
1074	pImage->MTime = Header.Version.v1.u32MTime;
1075	pImage->cbSize = Header.Version.v1.u64Size;
1076	pImage->cbCluster = RT_BIT_32(Header.Version.v1.u8ClusterBits);
1077	pImage->cL2TableEntries = RT_BIT_32(Header.Version.v1.u8L2Bits);
1078	pImage->cbL2Table = RT_ALIGN_64(pImage->cL2TableEntries * sizeof(uint64_t), pImage->cbCluster);
1079	pImage->offL1Table = Header.Version.v1.u64L1TableOffset;
1080	pImage->cL1TableEntries = pImage->cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1081	if (pImage->cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1082	pImage->cL1TableEntries++;
1083	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1084	}
1085	else
1086	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1087	N_("QCow: Encrypted image '%s' is not supported"),
1088	pImage->pszFilename);
1089	}
1090	else if (Header.u32Version == 2)
1091	{
1092	if (Header.Version.v2.u32CryptMethod)
1093	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1094	N_("QCow: Encrypted image '%s' is not supported"),
1095	pImage->pszFilename);
1096	else if (Header.Version.v2.u32NbSnapshots)
1097	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1098	N_("QCow: Image '%s' contains snapshots which is not supported"),
1099	pImage->pszFilename);
1100	else
1101	{
1102	pImage->uVersion = 2;
1103	pImage->offBackingFilename = Header.Version.v2.u64BackingFileOffset;
1104	pImage->cbBackingFilename = Header.Version.v2.u32BackingFileSize;
1105	pImage->cbSize = Header.Version.v2.u64Size;
1106	pImage->cbCluster = RT_BIT_32(Header.Version.v2.u32ClusterBits);
1107	pImage->cL2TableEntries = pImage->cbCluster / sizeof(uint64_t);
1108	pImage->cbL2Table = pImage->cbCluster;
1109	pImage->offL1Table = Header.Version.v2.u64L1TableOffset;
1110	pImage->cL1TableEntries = Header.Version.v2.u32L1Size;
1111	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1112	pImage->offRefcountTable = Header.Version.v2.u64RefcountTableOffset;
1113	pImage->cbRefcountTable = qcowCluster2Byte(pImage, Header.Version.v2.u32RefcountTableClusters);
1114	pImage->cRefcountTableEntries = pImage->cbRefcountTable / sizeof(uint64_t);
1115	}
1116	}
1117	else
1118	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1119	N_("QCow: Image '%s' uses version %u which is not supported"),
1120	pImage->pszFilename, Header.u32Version);
1121
1122	/** @todo: Check that there are no compressed clusters in the image
1123	* (by traversing the L2 tables and checking each offset).
1124	* Refuse to open such images.
1125	*/
1126
1127	if ( RT_SUCCESS(rc)
1128	&& pImage->cbBackingFilename
1129	&& pImage->offBackingFilename)
1130	{
1131	/* Load backing filename from image. */
1132	pImage->pszBackingFilename = (char )RTMemAllocZ(pImage->cbBackingFilename + 1); / +1 for \0 terminator. */
1133	if (pImage->pszBackingFilename)
1134	{
1135	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1136	pImage->offBackingFilename, pImage->pszBackingFilename,
1137	pImage->cbBackingFilename);
1138	}
1139	else
1140	rc = VERR_NO_MEMORY;
1141	}
1142
1143	if ( RT_SUCCESS(rc)
1144	&& pImage->cbRefcountTable
1145	&& pImage->offRefcountTable)
1146	{
1147	/* Load refcount table. */
1148	Assert(pImage->cRefcountTableEntries);
1149	pImage->paRefcountTable = (uint64_t *)RTMemAllocZ(pImage->cbRefcountTable);
1150	if (RT_LIKELY(pImage->paRefcountTable))
1151	{
1152	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1153	pImage->offRefcountTable, pImage->paRefcountTable,
1154	pImage->cbRefcountTable);
1155	if (RT_SUCCESS(rc))
1156	qcowTableConvertToHostEndianess(pImage->paRefcountTable,
1157	pImage->cRefcountTableEntries);
1158	else
1159	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1160	N_("QCow: Reading refcount table of image '%s' failed"),
1161	pImage->pszFilename);
1162	}
1163	else
1164	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1165	N_("QCow: Allocating memory for refcount table of image '%s' failed"),
1166	pImage->pszFilename);
1167	}
1168
1169	if (RT_SUCCESS(rc))
1170	{
1171	qcowTableMasksInit(pImage);
1172
1173	/* Allocate L1 table. */
1174	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1175	if (pImage->paL1Table)
1176	{
1177	/* Read from the image. */
1178	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1179	pImage->offL1Table, pImage->paL1Table,
1180	pImage->cbL1Table);
1181	if (RT_SUCCESS(rc))
1182	qcowTableConvertToHostEndianess(pImage->paL1Table, pImage->cL1TableEntries);
1183	else
1184	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1185	N_("QCow: Reading the L1 table for image '%s' failed"),
1186	pImage->pszFilename);
1187	}
1188	else
1189	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1190	N_("QCow: Out of memory allocating L1 table for image '%s'"),
1191	pImage->pszFilename);
1192	}
1193	}
1194	else if (RT_SUCCESS(rc))
1195	rc = VERR_VD_GEN_INVALID_HEADER;
1196	}
1197	else
1198	rc = VERR_VD_GEN_INVALID_HEADER;
1199
1200	out:
1201	if (RT_FAILURE(rc))
1202	qcowFreeImage(pImage, false);
1203	return rc;
1204	}
1205
1206	/**
1207	* Internal: Create a qcow image.
1208	*/
1209	static int qcowCreateImage(PQCOWIMAGE pImage, uint64_t cbSize,
1210	unsigned uImageFlags, const char *pszComment,
1211	PCVDGEOMETRY pPCHSGeometry,
1212	PCVDGEOMETRY pLCHSGeometry, unsigned uOpenFlags,
1213	PFNVDPROGRESS pfnProgress, void *pvUser,
1214	unsigned uPercentStart, unsigned uPercentSpan)
1215	{
1216	int rc;
1217	int32_t fOpen;
1218
1219	if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
1220	{
1221	rc = vdIfError(pImage->pIfError, VERR_VD_INVALID_TYPE, RT_SRC_POS, N_("QCow: cannot create fixed image '%s'"), pImage->pszFilename);
1222	goto out;
1223	}
1224
1225	pImage->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1226	pImage->uImageFlags = uImageFlags;
1227	pImage->PCHSGeometry = *pPCHSGeometry;
1228	pImage->LCHSGeometry = *pLCHSGeometry;
1229
1230	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1231	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1232	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1233
1234	/* Create image file. */
1235	fOpen = VDOpenFlagsToFileOpenFlags(pImage->uOpenFlags, true /* fCreate */);
1236	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename, fOpen, &pImage->pStorage);
1237	if (RT_FAILURE(rc))
1238	{
1239	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: cannot create image '%s'"), pImage->pszFilename);
1240	goto out;
1241	}
1242
1243	/* Init image state. */
1244	pImage->uVersion = 1; /* We create only version 1 images at the moment. */
1245	pImage->cbSize = cbSize;
1246	pImage->cbCluster = QCOW_CLUSTER_SIZE_DEFAULT;
1247	pImage->cbL2Table = qcowCluster2Byte(pImage, QCOW_L2_CLUSTERS_DEFAULT);
1248	pImage->cL2TableEntries = pImage->cbL2Table / sizeof(uint64_t);
1249	pImage->cL1TableEntries = cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1250	if (cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1251	pImage->cL1TableEntries++;
1252	pImage->cbL1Table = pImage->cL1TableEntries * sizeof(uint64_t);
1253	pImage->offL1Table = QCOW_V1_HDR_SIZE;
1254	pImage->cbBackingFilename = 0;
1255	pImage->offBackingFilename = 0;
1256	pImage->offNextCluster = RT_ALIGN_64(QCOW_V1_HDR_SIZE + pImage->cbL1Table, pImage->cbCluster);
1257	qcowTableMasksInit(pImage);
1258
1259	/* Init L1 table. */
1260	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1261	if (!pImage->paL1Table)
1262	{
1263	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("QCow: cannot allocate memory for L1 table of image '%s'"),
1264	pImage->pszFilename);
1265	goto out;
1266	}
1267
1268	rc = qcowL2TblCacheCreate(pImage);
1269	if (RT_FAILURE(rc))
1270	{
1271	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: Failed to create L2 cache for image '%s'"),
1272	pImage->pszFilename);
1273	goto out;
1274	}
1275
1276	if (RT_SUCCESS(rc) && pfnProgress)
1277	pfnProgress(pvUser, uPercentStart + uPercentSpan * 98 / 100);
1278
1279	rc = qcowFlushImage(pImage);
1280	if (RT_SUCCESS(rc))
1281	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pImage->offNextCluster);
1282
1283	out:
1284	if (RT_SUCCESS(rc) && pfnProgress)
1285	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1286
1287	if (RT_FAILURE(rc))
1288	qcowFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1289	return rc;
1290	}
1291
1292	/**
1293	* Rollback anything done during async cluster allocation.
1294	*
1295	* @returns VBox status code.
1296	* @param pImage The image instance data.
1297	* @param pIoCtx The I/O context.
1298	* @param pClusterAlloc The cluster allocation to rollback.
1299	*/
1300	static int qcowAsyncClusterAllocRollback(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, PQCOWCLUSTERASYNCALLOC pClusterAlloc)
1301	{
1302	int rc = VINF_SUCCESS;
1303
1304	switch (pClusterAlloc->enmAllocState)
1305	{
1306	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1307	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1308	{
1309	/* Assumption right now is that the L1 table is not modified if the link fails. */
1310	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1311	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1312	qcowL2TblCacheEntryFree(pImage, pClusterAlloc->pL2Entry); /* Free it, it is not in the cache yet. */
1313	}
1314	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1315	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1316	{
1317	/* Assumption right now is that the L2 table is not modified if the link fails. */
1318	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1319	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1320	break;
1321	}
1322	default:
1323	AssertMsgFailed(("Invalid cluster allocation state %d\n", pClusterAlloc->enmAllocState));
1324	rc = VERR_INVALID_STATE;
1325	}
1326
1327	RTMemFree(pClusterAlloc);
1328	return rc;
1329	}
1330
1331	/**
1332	* Updates the state of the async cluster allocation.
1333	*
1334	* @returns VBox status code.
1335	* @param pBackendData The opaque backend data.
1336	* @param pIoCtx I/O context associated with this request.
1337	* @param pvUser Opaque user data passed during a read/write request.
1338	* @param rcReq Status code for the completed request.
1339	*/
1340	static DECLCALLBACK(int) qcowAsyncClusterAllocUpdate(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
1341	{
1342	int rc = VINF_SUCCESS;
1343	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1344	PQCOWCLUSTERASYNCALLOC pClusterAlloc = (PQCOWCLUSTERASYNCALLOC)pvUser;
1345
1346	if (RT_FAILURE(rcReq))
1347	return qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1348
1349	AssertPtr(pClusterAlloc->pL2Entry);
1350
1351	switch (pClusterAlloc->enmAllocState)
1352	{
1353	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1354	{
1355	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->pL2Entry->offL2Tbl);
1356
1357	/* Update the link in the on disk L1 table now. */
1358	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_LINK;
1359	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1360	pImage->offL1Table + pClusterAlloc->idxL1*sizeof(uint64_t),
1361	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1362	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1363	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1364	break;
1365	else if (RT_FAILURE(rc))
1366	{
1367	/* Rollback. */
1368	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1369	break;
1370	}
1371	/* Success, fall through. */
1372	}
1373	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1374	{
1375	/* L2 link updated in L1 , save L2 entry in cache and allocate new user data cluster. */
1376	uint64_t offData = qcowClusterAllocate(pImage, 1);
1377
1378	/* Update the link in the in memory L1 table now. */
1379	pImage->paL1Table[pClusterAlloc->idxL1] = pClusterAlloc->pL2Entry->offL2Tbl;
1380	qcowL2TblCacheEntryInsert(pImage, pClusterAlloc->pL2Entry);
1381
1382	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1383	pClusterAlloc->offNextClusterOld = offData;
1384	pClusterAlloc->offClusterNew = offData;
1385
1386	/* Write data. */
1387	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1388	offData, pIoCtx, pClusterAlloc->cbToWrite,
1389	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1390	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1391	break;
1392	else if (RT_FAILURE(rc))
1393	{
1394	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1395	RTMemFree(pClusterAlloc);
1396	break;
1397	}
1398	}
1399	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1400	{
1401	uint64_t offUpdateLe = RT_H2BE_U64(pClusterAlloc->offClusterNew);
1402
1403	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_LINK;
1404
1405	/* Link L2 table and update it. */
1406	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1407	pImage->paL1Table[pClusterAlloc->idxL1] + pClusterAlloc->idxL2*sizeof(uint64_t),
1408	&offUpdateLe, sizeof(uint64_t), pIoCtx,
1409	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1410	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1411	break;
1412	else if (RT_FAILURE(rc))
1413	{
1414	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1415	RTMemFree(pClusterAlloc);
1416	break;
1417	}
1418	}
1419	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1420	{
1421	/* Everything done without errors, signal completion. */
1422	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = pClusterAlloc->offClusterNew;
1423	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry);
1424	RTMemFree(pClusterAlloc);
1425	rc = VINF_SUCCESS;
1426	break;
1427	}
1428	default:
1429	AssertMsgFailed(("Invalid async cluster allocation state %d\n",
1430	pClusterAlloc->enmAllocState));
1431	}
1432
1433	return rc;
1434	}
1435
1436	/** @copydoc VBOXHDDBACKEND::pfnCheckIfValid */
1437	static int qcowCheckIfValid(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1438	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1439	{
1440	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1441	PVDIOSTORAGE pStorage = NULL;
1442	uint64_t cbFile;
1443	int rc = VINF_SUCCESS;
1444
1445	/* Get I/O interface. */
1446	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1447	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1448
1449	if ( !VALID_PTR(pszFilename)
1450	\|\| !*pszFilename)
1451	{
1452	rc = VERR_INVALID_PARAMETER;
1453	goto out;
1454	}
1455
1456	/*
1457	* Open the file and read the footer.
1458	*/
1459	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1460	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1461	false /* fCreate */),
1462	&pStorage);
1463	if (RT_SUCCESS(rc))
1464	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1465
1466	if ( RT_SUCCESS(rc)
1467	&& cbFile > sizeof(QCowHeader))
1468	{
1469	QCowHeader Header;
1470
1471	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Header, sizeof(Header));
1472	if ( RT_SUCCESS(rc)
1473	&& qcowHdrConvertToHostEndianess(&Header))
1474	{
1475	*penmType = VDTYPE_HDD;
1476	rc = VINF_SUCCESS;
1477	}
1478	else
1479	rc = VERR_VD_GEN_INVALID_HEADER;
1480	}
1481	else
1482	rc = VERR_VD_GEN_INVALID_HEADER;
1483
1484	if (pStorage)
1485	vdIfIoIntFileClose(pIfIo, pStorage);
1486
1487	out:
1488	LogFlowFunc(("returns %Rrc\n", rc));
1489	return rc;
1490	}
1491
1492	/** @copydoc VBOXHDDBACKEND::pfnOpen */
1493	static int qcowOpen(const char *pszFilename, unsigned uOpenFlags,
1494	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1495	VDTYPE enmType, void **ppBackendData)
1496	{
1497	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, ppBackendData));
1498	int rc;
1499	PQCOWIMAGE pImage;
1500
1501	/* Check open flags. All valid flags are supported. */
1502	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1503	{
1504	rc = VERR_INVALID_PARAMETER;
1505	goto out;
1506	}
1507
1508	/* Check remaining arguments. */
1509	if ( !VALID_PTR(pszFilename)
1510	\|\| !*pszFilename)
1511	{
1512	rc = VERR_INVALID_PARAMETER;
1513	goto out;
1514	}
1515
1516
1517	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1518	if (!pImage)
1519	{
1520	rc = VERR_NO_MEMORY;
1521	goto out;
1522	}
1523	pImage->pszFilename = pszFilename;
1524	pImage->pStorage = NULL;
1525	pImage->pVDIfsDisk = pVDIfsDisk;
1526	pImage->pVDIfsImage = pVDIfsImage;
1527
1528	rc = qcowOpenImage(pImage, uOpenFlags);
1529	if (RT_SUCCESS(rc))
1530	*ppBackendData = pImage;
1531	else
1532	RTMemFree(pImage);
1533
1534	out:
1535	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1536	return rc;
1537	}
1538
1539	/** @copydoc VBOXHDDBACKEND::pfnCreate */
1540	static int qcowCreate(const char *pszFilename, uint64_t cbSize,
1541	unsigned uImageFlags, const char *pszComment,
1542	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1543	PCRTUUID pUuid, unsigned uOpenFlags,
1544	unsigned uPercentStart, unsigned uPercentSpan,
1545	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1546	PVDINTERFACE pVDIfsOperation, void **ppBackendData)
1547	{
1548	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",
1549	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, ppBackendData));
1550	int rc;
1551	PQCOWIMAGE pImage;
1552
1553	PFNVDPROGRESS pfnProgress = NULL;
1554	void *pvUser = NULL;
1555	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1556	if (pIfProgress)
1557	{
1558	pfnProgress = pIfProgress->pfnProgress;
1559	pvUser = pIfProgress->Core.pvUser;
1560	}
1561
1562	/* Check open flags. All valid flags are supported. */
1563	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1564	{
1565	rc = VERR_INVALID_PARAMETER;
1566	goto out;
1567	}
1568
1569	/* Check remaining arguments. */
1570	if ( !VALID_PTR(pszFilename)
1571	\|\| !*pszFilename
1572	\|\| !VALID_PTR(pPCHSGeometry)
1573	\|\| !VALID_PTR(pLCHSGeometry))
1574	{
1575	rc = VERR_INVALID_PARAMETER;
1576	goto out;
1577	}
1578
1579	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1580	if (!pImage)
1581	{
1582	rc = VERR_NO_MEMORY;
1583	goto out;
1584	}
1585	pImage->pszFilename = pszFilename;
1586	pImage->pStorage = NULL;
1587	pImage->pVDIfsDisk = pVDIfsDisk;
1588	pImage->pVDIfsImage = pVDIfsImage;
1589
1590	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1591	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1592	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1593	if (RT_SUCCESS(rc))
1594	{
1595	/* So far the image is opened in read/write mode. Make sure the
1596	* image is opened in read-only mode if the caller requested that. */
1597	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1598	{
1599	qcowFreeImage(pImage, false);
1600	rc = qcowOpenImage(pImage, uOpenFlags);
1601	if (RT_FAILURE(rc))
1602	{
1603	RTMemFree(pImage);
1604	goto out;
1605	}
1606	}
1607	*ppBackendData = pImage;
1608	}
1609	else
1610	RTMemFree(pImage);
1611
1612	out:
1613	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1614	return rc;
1615	}
1616
1617	/** @copydoc VBOXHDDBACKEND::pfnRename */
1618	static int qcowRename(void pBackendData, const char pszFilename)
1619	{
1620	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1621	int rc = VINF_SUCCESS;
1622	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1623
1624	/* Check arguments. */
1625	if ( !pImage
1626	\|\| !pszFilename
1627	\|\| !*pszFilename)
1628	{
1629	rc = VERR_INVALID_PARAMETER;
1630	goto out;
1631	}
1632
1633	/* Close the image. */
1634	rc = qcowFreeImage(pImage, false);
1635	if (RT_FAILURE(rc))
1636	goto out;
1637
1638	/* Rename the file. */
1639	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1640	if (RT_FAILURE(rc))
1641	{
1642	/* The move failed, try to reopen the original image. */
1643	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1644	if (RT_FAILURE(rc2))
1645	rc = rc2;
1646
1647	goto out;
1648	}
1649
1650	/* Update pImage with the new information. */
1651	pImage->pszFilename = pszFilename;
1652
1653	/* Open the old image with new name. */
1654	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1655	if (RT_FAILURE(rc))
1656	goto out;
1657
1658	out:
1659	LogFlowFunc(("returns %Rrc\n", rc));
1660	return rc;
1661	}
1662
1663	/** @copydoc VBOXHDDBACKEND::pfnClose */
1664	static int qcowClose(void *pBackendData, bool fDelete)
1665	{
1666	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1667	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1668	int rc;
1669
1670	rc = qcowFreeImage(pImage, fDelete);
1671	RTMemFree(pImage);
1672
1673	LogFlowFunc(("returns %Rrc\n", rc));
1674	return rc;
1675	}
1676
1677	static int qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1678	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1679	{
1680	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1681	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1682	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1683	uint32_t offCluster = 0;
1684	uint32_t idxL1 = 0;
1685	uint32_t idxL2 = 0;
1686	uint64_t offFile = 0;
1687	int rc;
1688
1689	AssertPtr(pImage);
1690	Assert(uOffset % 512 == 0);
1691	Assert(cbToRead % 512 == 0);
1692
1693	if (!VALID_PTR(pIoCtx) \|\| !cbToRead)
1694	{
1695	rc = VERR_INVALID_PARAMETER;
1696	goto out;
1697	}
1698
1699	if ( uOffset + cbToRead > pImage->cbSize
1700	\|\| cbToRead == 0)
1701	{
1702	rc = VERR_INVALID_PARAMETER;
1703	goto out;
1704	}
1705
1706	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1707
1708	/* Clip read size to remain in the cluster. */
1709	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1710
1711	/* Get offset in image. */
1712	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1713	if (RT_SUCCESS(rc))
1714	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1715	pIoCtx, cbToRead);
1716
1717	if ( ( RT_SUCCESS(rc)
1718	\|\| rc == VERR_VD_BLOCK_FREE
1719	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1720	&& pcbActuallyRead)
1721	*pcbActuallyRead = cbToRead;
1722
1723	out:
1724	LogFlowFunc(("returns %Rrc\n", rc));
1725	return rc;
1726	}
1727
1728	static int qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1729	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1730	size_t *pcbPostRead, unsigned fWrite)
1731	{
1732	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1733	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1734	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1735	uint32_t offCluster = 0;
1736	uint32_t idxL1 = 0;
1737	uint32_t idxL2 = 0;
1738	uint64_t offImage = 0;
1739	int rc = VINF_SUCCESS;
1740
1741	AssertPtr(pImage);
1742	Assert(!(uOffset % 512));
1743	Assert(!(cbToWrite % 512));
1744
1745	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1746	{
1747	rc = VERR_VD_IMAGE_READ_ONLY;
1748	goto out;
1749	}
1750
1751	if (!VALID_PTR(pIoCtx) \|\| !cbToWrite)
1752	{
1753	rc = VERR_INVALID_PARAMETER;
1754	goto out;
1755	}
1756
1757	if ( uOffset + cbToWrite > pImage->cbSize
1758	\|\| cbToWrite == 0)
1759	{
1760	rc = VERR_INVALID_PARAMETER;
1761	goto out;
1762	}
1763
1764	/* Convert offset to L1, L2 index and cluster offset. */
1765	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1766
1767	/* Clip write size to remain in the cluster. */
1768	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1769	Assert(!(cbToWrite % 512));
1770
1771	/* Get offset in image. */
1772	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1773	if (RT_SUCCESS(rc))
1774	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1775	offImage, pIoCtx, cbToWrite, NULL, NULL);
1776	else if (rc == VERR_VD_BLOCK_FREE)
1777	{
1778	if ( cbToWrite == pImage->cbCluster
1779	&& !(fWrite & VD_WRITE_NO_ALLOC))
1780	{
1781	PQCOWL2CACHEENTRY pL2Entry = NULL;
1782
1783	/* Full cluster write to previously unallocated cluster.
1784	* Allocate cluster and write data. */
1785	Assert(!offCluster);
1786
1787	do
1788	{
1789	uint64_t idxUpdateLe = 0;
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	/*
1826	* Write the L2 table first and link to the L1 table afterwards.
1827	* If something unexpected happens the worst case which can happen
1828	* is a leak of some clusters.
1829	*/
1830	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1831	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1832	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1833	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1834	break;
1835	else if (RT_FAILURE(rc))
1836	{
1837	RTMemFree(pL2ClusterAlloc);
1838	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1839	break;
1840	}
1841
1842	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1843	}
1844	else
1845	{
1846	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1847	&pL2Entry);
1848	if (RT_SUCCESS(rc))
1849	{
1850	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1851
1852	/* Allocate new async cluster allocation state. */
1853	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1854	if (RT_UNLIKELY(!pDataClusterAlloc))
1855	{
1856	rc = VERR_NO_MEMORY;
1857	break;
1858	}
1859
1860	/* Allocate new cluster for the data. */
1861	uint64_t offData = qcowClusterAllocate(pImage, 1);
1862
1863	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1864	pDataClusterAlloc->offNextClusterOld = offData;
1865	pDataClusterAlloc->offClusterNew = offData;
1866	pDataClusterAlloc->idxL1 = idxL1;
1867	pDataClusterAlloc->idxL2 = idxL2;
1868	pDataClusterAlloc->cbToWrite = cbToWrite;
1869	pDataClusterAlloc->pL2Entry = pL2Entry;
1870
1871	/* Write data. */
1872	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1873	offData, pIoCtx, cbToWrite,
1874	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1875	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1876	break;
1877	else if (RT_FAILURE(rc))
1878	{
1879	RTMemFree(pDataClusterAlloc);
1880	break;
1881	}
1882
1883	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1884	}
1885	}
1886
1887	} while (0);
1888
1889	*pcbPreRead = 0;
1890	*pcbPostRead = 0;
1891	}
1892	else
1893	{
1894	/* Trying to do a partial write to an unallocated cluster. Don't do
1895	* anything except letting the upper layer know what to do. */
1896	*pcbPreRead = offCluster;
1897	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
1898	}
1899	}
1900
1901	if (pcbWriteProcess)
1902	*pcbWriteProcess = cbToWrite;
1903
1904
1905	out:
1906	LogFlowFunc(("returns %Rrc\n", rc));
1907	return rc;
1908	}
1909
1910	static int qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
1911	{
1912	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1913	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1914	int rc = VINF_SUCCESS;
1915
1916	Assert(pImage);
1917
1918	if (VALID_PTR(pIoCtx))
1919	rc = qcowFlushImageAsync(pImage, pIoCtx);
1920	else
1921	rc = VERR_INVALID_PARAMETER;
1922
1923	LogFlowFunc(("returns %Rrc\n", rc));
1924	return rc;
1925	}
1926
1927	/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
1928	static unsigned qcowGetVersion(void *pBackendData)
1929	{
1930	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1931	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1932
1933	AssertPtr(pImage);
1934
1935	if (pImage)
1936	return pImage->uVersion;
1937	else
1938	return 0;
1939	}
1940
1941	/** @copydoc VBOXHDDBACKEND::pfnGetSectorSize */
1942	static uint32_t qcowGetSectorSize(void *pBackendData)
1943	{
1944	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1945	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1946	uint32_t cb = 0;
1947
1948	AssertPtr(pImage);
1949
1950	if (pImage && pImage->pStorage)
1951	cb = 512;
1952
1953	LogFlowFunc(("returns %u\n", cb));
1954	return cb;
1955	}
1956
1957	/** @copydoc VBOXHDDBACKEND::pfnGetSize */
1958	static uint64_t qcowGetSize(void *pBackendData)
1959	{
1960	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1961	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1962	uint64_t cb = 0;
1963
1964	AssertPtr(pImage);
1965
1966	if (pImage && pImage->pStorage)
1967	cb = pImage->cbSize;
1968
1969	LogFlowFunc(("returns %llu\n", cb));
1970	return cb;
1971	}
1972
1973	/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
1974	static uint64_t qcowGetFileSize(void *pBackendData)
1975	{
1976	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1977	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1978	uint64_t cb = 0;
1979
1980	AssertPtr(pImage);
1981
1982	if (pImage)
1983	{
1984	uint64_t cbFile;
1985	if (pImage->pStorage)
1986	{
1987	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1988	if (RT_SUCCESS(rc))
1989	cb += cbFile;
1990	}
1991	}
1992
1993	LogFlowFunc(("returns %lld\n", cb));
1994	return cb;
1995	}
1996
1997	/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
1998	static int qcowGetPCHSGeometry(void *pBackendData,
1999	PVDGEOMETRY pPCHSGeometry)
2000	{
2001	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
2002	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2003	int rc;
2004
2005	AssertPtr(pImage);
2006
2007	if (pImage)
2008	{
2009	if (pImage->PCHSGeometry.cCylinders)
2010	{
2011	*pPCHSGeometry = pImage->PCHSGeometry;
2012	rc = VINF_SUCCESS;
2013	}
2014	else
2015	rc = VERR_VD_GEOMETRY_NOT_SET;
2016	}
2017	else
2018	rc = VERR_VD_NOT_OPENED;
2019
2020	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2021	return rc;
2022	}
2023
2024	/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
2025	static int qcowSetPCHSGeometry(void *pBackendData,
2026	PCVDGEOMETRY pPCHSGeometry)
2027	{
2028	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2029	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2030	int rc;
2031
2032	AssertPtr(pImage);
2033
2034	if (pImage)
2035	{
2036	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2037	{
2038	rc = VERR_VD_IMAGE_READ_ONLY;
2039	goto out;
2040	}
2041
2042	pImage->PCHSGeometry = *pPCHSGeometry;
2043	rc = VINF_SUCCESS;
2044	}
2045	else
2046	rc = VERR_VD_NOT_OPENED;
2047
2048	out:
2049	LogFlowFunc(("returns %Rrc\n", rc));
2050	return rc;
2051	}
2052
2053	/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
2054	static int qcowGetLCHSGeometry(void *pBackendData,
2055	PVDGEOMETRY pLCHSGeometry)
2056	{
2057	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2058	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2059	int rc;
2060
2061	AssertPtr(pImage);
2062
2063	if (pImage)
2064	{
2065	if (pImage->LCHSGeometry.cCylinders)
2066	{
2067	*pLCHSGeometry = pImage->LCHSGeometry;
2068	rc = VINF_SUCCESS;
2069	}
2070	else
2071	rc = VERR_VD_GEOMETRY_NOT_SET;
2072	}
2073	else
2074	rc = VERR_VD_NOT_OPENED;
2075
2076	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2077	return rc;
2078	}
2079
2080	/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
2081	static int qcowSetLCHSGeometry(void *pBackendData,
2082	PCVDGEOMETRY pLCHSGeometry)
2083	{
2084	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData, pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2085	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2086	int rc;
2087
2088	AssertPtr(pImage);
2089
2090	if (pImage)
2091	{
2092	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2093	{
2094	rc = VERR_VD_IMAGE_READ_ONLY;
2095	goto out;
2096	}
2097
2098	pImage->LCHSGeometry = *pLCHSGeometry;
2099	rc = VINF_SUCCESS;
2100	}
2101	else
2102	rc = VERR_VD_NOT_OPENED;
2103
2104	out:
2105	LogFlowFunc(("returns %Rrc\n", rc));
2106	return rc;
2107	}
2108
2109	/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
2110	static unsigned qcowGetImageFlags(void *pBackendData)
2111	{
2112	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2113	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2114	unsigned uImageFlags;
2115
2116	AssertPtr(pImage);
2117
2118	if (pImage)
2119	uImageFlags = pImage->uImageFlags;
2120	else
2121	uImageFlags = 0;
2122
2123	LogFlowFunc(("returns %#x\n", uImageFlags));
2124	return uImageFlags;
2125	}
2126
2127	/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
2128	static unsigned qcowGetOpenFlags(void *pBackendData)
2129	{
2130	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2131	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2132	unsigned uOpenFlags;
2133
2134	AssertPtr(pImage);
2135
2136	if (pImage)
2137	uOpenFlags = pImage->uOpenFlags;
2138	else
2139	uOpenFlags = 0;
2140
2141	LogFlowFunc(("returns %#x\n", uOpenFlags));
2142	return uOpenFlags;
2143	}
2144
2145	/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
2146	static int qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2147	{
2148	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2149	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2150	int rc;
2151
2152	/* Image must be opened and the new flags must be valid. */
2153	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2154	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2155	{
2156	rc = VERR_INVALID_PARAMETER;
2157	goto out;
2158	}
2159
2160	/* Implement this operation via reopening the image. */
2161	rc = qcowFreeImage(pImage, false);
2162	if (RT_FAILURE(rc))
2163	goto out;
2164	rc = qcowOpenImage(pImage, uOpenFlags);
2165
2166	out:
2167	LogFlowFunc(("returns %Rrc\n", rc));
2168	return rc;
2169	}
2170
2171	/** @copydoc VBOXHDDBACKEND::pfnGetComment */
2172	static int qcowGetComment(void pBackendData, char pszComment,
2173	size_t cbComment)
2174	{
2175	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2176	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2177	int rc;
2178
2179	AssertPtr(pImage);
2180
2181	if (pImage)
2182	rc = VERR_NOT_SUPPORTED;
2183	else
2184	rc = VERR_VD_NOT_OPENED;
2185
2186	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
2187	return rc;
2188	}
2189
2190	/** @copydoc VBOXHDDBACKEND::pfnSetComment */
2191	static int qcowSetComment(void pBackendData, const char pszComment)
2192	{
2193	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2194	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2195	int rc;
2196
2197	AssertPtr(pImage);
2198
2199	if (pImage)
2200	{
2201	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2202	rc = VERR_VD_IMAGE_READ_ONLY;
2203	else
2204	rc = VERR_NOT_SUPPORTED;
2205	}
2206	else
2207	rc = VERR_VD_NOT_OPENED;
2208
2209	LogFlowFunc(("returns %Rrc\n", rc));
2210	return rc;
2211	}
2212
2213	/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
2214	static int qcowGetUuid(void *pBackendData, PRTUUID pUuid)
2215	{
2216	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2217	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2218	int rc;
2219
2220	AssertPtr(pImage);
2221
2222	if (pImage)
2223	rc = VERR_NOT_SUPPORTED;
2224	else
2225	rc = VERR_VD_NOT_OPENED;
2226
2227	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2228	return rc;
2229	}
2230
2231	/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
2232	static int qcowSetUuid(void *pBackendData, PCRTUUID pUuid)
2233	{
2234	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2235	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2236	int rc;
2237
2238	LogFlowFunc(("%RTuuid\n", pUuid));
2239	AssertPtr(pImage);
2240
2241	if (pImage)
2242	{
2243	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2244	rc = VERR_NOT_SUPPORTED;
2245	else
2246	rc = VERR_VD_IMAGE_READ_ONLY;
2247	}
2248	else
2249	rc = VERR_VD_NOT_OPENED;
2250
2251	LogFlowFunc(("returns %Rrc\n", rc));
2252	return rc;
2253	}
2254
2255	/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
2256	static int qcowGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2257	{
2258	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2259	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2260	int rc;
2261
2262	AssertPtr(pImage);
2263
2264	if (pImage)
2265	rc = VERR_NOT_SUPPORTED;
2266	else
2267	rc = VERR_VD_NOT_OPENED;
2268
2269	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2270	return rc;
2271	}
2272
2273	/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
2274	static int qcowSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2275	{
2276	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2277	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2278	int rc;
2279
2280	AssertPtr(pImage);
2281
2282	if (pImage)
2283	{
2284	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2285	rc = VERR_NOT_SUPPORTED;
2286	else
2287	rc = VERR_VD_IMAGE_READ_ONLY;
2288	}
2289	else
2290	rc = VERR_VD_NOT_OPENED;
2291
2292	LogFlowFunc(("returns %Rrc\n", rc));
2293	return rc;
2294	}
2295
2296	/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
2297	static int qcowGetParentUuid(void *pBackendData, PRTUUID pUuid)
2298	{
2299	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2300	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2301	int rc;
2302
2303	AssertPtr(pImage);
2304
2305	if (pImage)
2306	rc = VERR_NOT_SUPPORTED;
2307	else
2308	rc = VERR_VD_NOT_OPENED;
2309
2310	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2311	return rc;
2312	}
2313
2314	/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
2315	static int qcowSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2316	{
2317	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2318	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2319	int rc;
2320
2321	AssertPtr(pImage);
2322
2323	if (pImage)
2324	{
2325	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2326	rc = VERR_NOT_SUPPORTED;
2327	else
2328	rc = VERR_VD_IMAGE_READ_ONLY;
2329	}
2330	else
2331	rc = VERR_VD_NOT_OPENED;
2332
2333	LogFlowFunc(("returns %Rrc\n", rc));
2334	return rc;
2335	}
2336
2337	/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
2338	static int qcowGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2339	{
2340	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2341	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2342	int rc;
2343
2344	AssertPtr(pImage);
2345
2346	if (pImage)
2347	rc = VERR_NOT_SUPPORTED;
2348	else
2349	rc = VERR_VD_NOT_OPENED;
2350
2351	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2352	return rc;
2353	}
2354
2355	/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
2356	static int qcowSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2357	{
2358	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2359	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2360	int rc;
2361
2362	AssertPtr(pImage);
2363
2364	if (pImage)
2365	{
2366	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2367	rc = VERR_NOT_SUPPORTED;
2368	else
2369	rc = VERR_VD_IMAGE_READ_ONLY;
2370	}
2371	else
2372	rc = VERR_VD_NOT_OPENED;
2373
2374	LogFlowFunc(("returns %Rrc\n", rc));
2375	return rc;
2376	}
2377
2378	/** @copydoc VBOXHDDBACKEND::pfnDump */
2379	static void qcowDump(void *pBackendData)
2380	{
2381	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2382
2383	AssertPtr(pImage);
2384	if (pImage)
2385	{
2386	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cSector=%llu\n",
2387	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2388	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2389	pImage->cbSize / 512);
2390	}
2391	}
2392
2393	/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
2394	static int qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2395	{
2396	int rc = VINF_SUCCESS;
2397	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2398
2399	AssertPtr(pImage);
2400	if (pImage)
2401	if (pImage->pszBackingFilename)
2402	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2403	else
2404	rc = VERR_NOT_SUPPORTED;
2405	else
2406	rc = VERR_VD_NOT_OPENED;
2407
2408	LogFlowFunc(("returns %Rrc\n", rc));
2409	return rc;
2410	}
2411
2412	/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
2413	static int qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2414	{
2415	int rc = VINF_SUCCESS;
2416	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2417
2418	AssertPtr(pImage);
2419	if (pImage)
2420	{
2421	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2422	rc = VERR_VD_IMAGE_READ_ONLY;
2423	else if ( pImage->pszBackingFilename
2424	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2425	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2426	else
2427	{
2428	if (pImage->pszBackingFilename)
2429	RTStrFree(pImage->pszBackingFilename);
2430	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2431	if (!pImage->pszBackingFilename)
2432	rc = VERR_NO_MEMORY;
2433	else
2434	{
2435	if (!pImage->offBackingFilename)
2436	{
2437	/* Allocate new cluster. */
2438	uint64_t offData = qcowClusterAllocate(pImage, 1);
2439
2440	Assert((offData & UINT32_MAX) == offData);
2441	pImage->offBackingFilename = (uint32_t)offData;
2442	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2443	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2444	offData + pImage->cbCluster);
2445	}
2446
2447	if (RT_SUCCESS(rc))
2448	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2449	pImage->offBackingFilename,
2450	pImage->pszBackingFilename,
2451	strlen(pImage->pszBackingFilename));
2452	}
2453	}
2454	}
2455	else
2456	rc = VERR_VD_NOT_OPENED;
2457
2458	LogFlowFunc(("returns %Rrc\n", rc));
2459	return rc;
2460	}
2461
2462
2463
2464	const VBOXHDDBACKEND g_QCowBackend =
2465	{
2466	/* pszBackendName */
2467	"QCOW",
2468	/* cbSize */
2469	sizeof(VBOXHDDBACKEND),
2470	/* uBackendCaps */
2471	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2472	/* paFileExtensions */
2473	s_aQCowFileExtensions,
2474	/* paConfigInfo */
2475	NULL,
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	/* pfnTraverseMetadata */
2559	NULL
2560	};

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source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 53369

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