QCOW.cpp@ 55628

Last change on this file since 55628 was 54430, checked in by vboxsync, 10 years ago
Storage/VD: make use of the image type (hdd/dvd/floppy) for sanity checking when creating disk images
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1	/* $Id: QCOW.cpp 54430 2015-02-24 10:43:16Z vboxsync $ */
2	/** @file
3	* QCOW - QCOW Disk image.
4	*/
5
6	/*
7	* Copyright (C) 2011-2015 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 enmType=%u ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, enmType, ppBackendData));
1498	int rc;
1499	PQCOWIMAGE pImage;
1500
1501	NOREF(enmType); /*< @todo r=klaus make use of the type info. /
1502
1503	/* Check open flags. All valid flags are supported. */
1504	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1505	{
1506	rc = VERR_INVALID_PARAMETER;
1507	goto out;
1508	}
1509
1510	/* Check remaining arguments. */
1511	if ( !VALID_PTR(pszFilename)
1512	\|\| !*pszFilename)
1513	{
1514	rc = VERR_INVALID_PARAMETER;
1515	goto out;
1516	}
1517
1518
1519	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1520	if (!pImage)
1521	{
1522	rc = VERR_NO_MEMORY;
1523	goto out;
1524	}
1525	pImage->pszFilename = pszFilename;
1526	pImage->pStorage = NULL;
1527	pImage->pVDIfsDisk = pVDIfsDisk;
1528	pImage->pVDIfsImage = pVDIfsImage;
1529
1530	rc = qcowOpenImage(pImage, uOpenFlags);
1531	if (RT_SUCCESS(rc))
1532	*ppBackendData = pImage;
1533	else
1534	RTMemFree(pImage);
1535
1536	out:
1537	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1538	return rc;
1539	}
1540
1541	/** @copydoc VBOXHDDBACKEND::pfnCreate */
1542	static int qcowCreate(const char *pszFilename, uint64_t cbSize,
1543	unsigned uImageFlags, const char *pszComment,
1544	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1545	PCRTUUID pUuid, unsigned uOpenFlags,
1546	unsigned uPercentStart, unsigned uPercentSpan,
1547	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1548	PVDINTERFACE pVDIfsOperation, VDTYPE enmType,
1549	void **ppBackendData)
1550	{
1551	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",
1552	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, enmType, ppBackendData));
1553	int rc;
1554	PQCOWIMAGE pImage;
1555
1556	PFNVDPROGRESS pfnProgress = NULL;
1557	void *pvUser = NULL;
1558	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1559	if (pIfProgress)
1560	{
1561	pfnProgress = pIfProgress->pfnProgress;
1562	pvUser = pIfProgress->Core.pvUser;
1563	}
1564
1565	/* Check the VD container type. */
1566	if (enmType != VDTYPE_HDD)
1567	{
1568	rc = VERR_VD_INVALID_TYPE;
1569	goto out;
1570	}
1571
1572	/* Check open flags. All valid flags are supported. */
1573	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1574	{
1575	rc = VERR_INVALID_PARAMETER;
1576	goto out;
1577	}
1578
1579	/* Check remaining arguments. */
1580	if ( !VALID_PTR(pszFilename)
1581	\|\| !*pszFilename
1582	\|\| !VALID_PTR(pPCHSGeometry)
1583	\|\| !VALID_PTR(pLCHSGeometry))
1584	{
1585	rc = VERR_INVALID_PARAMETER;
1586	goto out;
1587	}
1588
1589	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1590	if (!pImage)
1591	{
1592	rc = VERR_NO_MEMORY;
1593	goto out;
1594	}
1595	pImage->pszFilename = pszFilename;
1596	pImage->pStorage = NULL;
1597	pImage->pVDIfsDisk = pVDIfsDisk;
1598	pImage->pVDIfsImage = pVDIfsImage;
1599
1600	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1601	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1602	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1603	if (RT_SUCCESS(rc))
1604	{
1605	/* So far the image is opened in read/write mode. Make sure the
1606	* image is opened in read-only mode if the caller requested that. */
1607	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1608	{
1609	qcowFreeImage(pImage, false);
1610	rc = qcowOpenImage(pImage, uOpenFlags);
1611	if (RT_FAILURE(rc))
1612	{
1613	RTMemFree(pImage);
1614	goto out;
1615	}
1616	}
1617	*ppBackendData = pImage;
1618	}
1619	else
1620	RTMemFree(pImage);
1621
1622	out:
1623	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1624	return rc;
1625	}
1626
1627	/** @copydoc VBOXHDDBACKEND::pfnRename */
1628	static int qcowRename(void pBackendData, const char pszFilename)
1629	{
1630	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1631	int rc = VINF_SUCCESS;
1632	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1633
1634	/* Check arguments. */
1635	if ( !pImage
1636	\|\| !pszFilename
1637	\|\| !*pszFilename)
1638	{
1639	rc = VERR_INVALID_PARAMETER;
1640	goto out;
1641	}
1642
1643	/* Close the image. */
1644	rc = qcowFreeImage(pImage, false);
1645	if (RT_FAILURE(rc))
1646	goto out;
1647
1648	/* Rename the file. */
1649	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1650	if (RT_FAILURE(rc))
1651	{
1652	/* The move failed, try to reopen the original image. */
1653	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1654	if (RT_FAILURE(rc2))
1655	rc = rc2;
1656
1657	goto out;
1658	}
1659
1660	/* Update pImage with the new information. */
1661	pImage->pszFilename = pszFilename;
1662
1663	/* Open the old image with new name. */
1664	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1665	if (RT_FAILURE(rc))
1666	goto out;
1667
1668	out:
1669	LogFlowFunc(("returns %Rrc\n", rc));
1670	return rc;
1671	}
1672
1673	/** @copydoc VBOXHDDBACKEND::pfnClose */
1674	static int qcowClose(void *pBackendData, bool fDelete)
1675	{
1676	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1677	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1678	int rc;
1679
1680	rc = qcowFreeImage(pImage, fDelete);
1681	RTMemFree(pImage);
1682
1683	LogFlowFunc(("returns %Rrc\n", rc));
1684	return rc;
1685	}
1686
1687	static int qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1688	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1689	{
1690	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1691	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1692	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1693	uint32_t offCluster = 0;
1694	uint32_t idxL1 = 0;
1695	uint32_t idxL2 = 0;
1696	uint64_t offFile = 0;
1697	int rc;
1698
1699	AssertPtr(pImage);
1700	Assert(uOffset % 512 == 0);
1701	Assert(cbToRead % 512 == 0);
1702
1703	if (!VALID_PTR(pIoCtx) \|\| !cbToRead)
1704	{
1705	rc = VERR_INVALID_PARAMETER;
1706	goto out;
1707	}
1708
1709	if ( uOffset + cbToRead > pImage->cbSize
1710	\|\| cbToRead == 0)
1711	{
1712	rc = VERR_INVALID_PARAMETER;
1713	goto out;
1714	}
1715
1716	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1717
1718	/* Clip read size to remain in the cluster. */
1719	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1720
1721	/* Get offset in image. */
1722	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1723	if (RT_SUCCESS(rc))
1724	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1725	pIoCtx, cbToRead);
1726
1727	if ( ( RT_SUCCESS(rc)
1728	\|\| rc == VERR_VD_BLOCK_FREE
1729	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1730	&& pcbActuallyRead)
1731	*pcbActuallyRead = cbToRead;
1732
1733	out:
1734	LogFlowFunc(("returns %Rrc\n", rc));
1735	return rc;
1736	}
1737
1738	static int qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1739	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1740	size_t *pcbPostRead, unsigned fWrite)
1741	{
1742	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1743	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1744	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1745	uint32_t offCluster = 0;
1746	uint32_t idxL1 = 0;
1747	uint32_t idxL2 = 0;
1748	uint64_t offImage = 0;
1749	int rc = VINF_SUCCESS;
1750
1751	AssertPtr(pImage);
1752	Assert(!(uOffset % 512));
1753	Assert(!(cbToWrite % 512));
1754
1755	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1756	{
1757	rc = VERR_VD_IMAGE_READ_ONLY;
1758	goto out;
1759	}
1760
1761	if (!VALID_PTR(pIoCtx) \|\| !cbToWrite)
1762	{
1763	rc = VERR_INVALID_PARAMETER;
1764	goto out;
1765	}
1766
1767	if ( uOffset + cbToWrite > pImage->cbSize
1768	\|\| cbToWrite == 0)
1769	{
1770	rc = VERR_INVALID_PARAMETER;
1771	goto out;
1772	}
1773
1774	/* Convert offset to L1, L2 index and cluster offset. */
1775	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1776
1777	/* Clip write size to remain in the cluster. */
1778	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1779	Assert(!(cbToWrite % 512));
1780
1781	/* Get offset in image. */
1782	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1783	if (RT_SUCCESS(rc))
1784	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1785	offImage, pIoCtx, cbToWrite, NULL, NULL);
1786	else if (rc == VERR_VD_BLOCK_FREE)
1787	{
1788	if ( cbToWrite == pImage->cbCluster
1789	&& !(fWrite & VD_WRITE_NO_ALLOC))
1790	{
1791	PQCOWL2CACHEENTRY pL2Entry = NULL;
1792
1793	/* Full cluster write to previously unallocated cluster.
1794	* Allocate cluster and write data. */
1795	Assert(!offCluster);
1796
1797	do
1798	{
1799	uint64_t idxUpdateLe = 0;
1800
1801	/* Check if we have to allocate a new cluster for L2 tables. */
1802	if (!pImage->paL1Table[idxL1])
1803	{
1804	uint64_t offL2Tbl;
1805	PQCOWCLUSTERASYNCALLOC pL2ClusterAlloc = NULL;
1806
1807	/* Allocate new async cluster allocation state. */
1808	pL2ClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1809	if (RT_UNLIKELY(!pL2ClusterAlloc))
1810	{
1811	rc = VERR_NO_MEMORY;
1812	break;
1813	}
1814
1815	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
1816	if (!pL2Entry)
1817	{
1818	rc = VERR_NO_MEMORY;
1819	RTMemFree(pL2ClusterAlloc);
1820	break;
1821	}
1822
1823	offL2Tbl = qcowClusterAllocate(pImage, qcowByte2Cluster(pImage, pImage->cbL2Table));
1824	pL2Entry->offL2Tbl = offL2Tbl;
1825	memset(pL2Entry->paL2Tbl, 0, pImage->cbL2Table);
1826
1827	pL2ClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC;
1828	pL2ClusterAlloc->offNextClusterOld = offL2Tbl;
1829	pL2ClusterAlloc->offClusterNew = offL2Tbl;
1830	pL2ClusterAlloc->idxL1 = idxL1;
1831	pL2ClusterAlloc->idxL2 = idxL2;
1832	pL2ClusterAlloc->cbToWrite = cbToWrite;
1833	pL2ClusterAlloc->pL2Entry = pL2Entry;
1834
1835	/*
1836	* Write the L2 table first and link to the L1 table afterwards.
1837	* If something unexpected happens the worst case which can happen
1838	* is a leak of some clusters.
1839	*/
1840	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1841	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1842	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1843	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1844	break;
1845	else if (RT_FAILURE(rc))
1846	{
1847	RTMemFree(pL2ClusterAlloc);
1848	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1849	break;
1850	}
1851
1852	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1853	}
1854	else
1855	{
1856	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1857	&pL2Entry);
1858	if (RT_SUCCESS(rc))
1859	{
1860	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1861
1862	/* Allocate new async cluster allocation state. */
1863	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1864	if (RT_UNLIKELY(!pDataClusterAlloc))
1865	{
1866	rc = VERR_NO_MEMORY;
1867	break;
1868	}
1869
1870	/* Allocate new cluster for the data. */
1871	uint64_t offData = qcowClusterAllocate(pImage, 1);
1872
1873	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1874	pDataClusterAlloc->offNextClusterOld = offData;
1875	pDataClusterAlloc->offClusterNew = offData;
1876	pDataClusterAlloc->idxL1 = idxL1;
1877	pDataClusterAlloc->idxL2 = idxL2;
1878	pDataClusterAlloc->cbToWrite = cbToWrite;
1879	pDataClusterAlloc->pL2Entry = pL2Entry;
1880
1881	/* Write data. */
1882	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1883	offData, pIoCtx, cbToWrite,
1884	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1885	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1886	break;
1887	else if (RT_FAILURE(rc))
1888	{
1889	RTMemFree(pDataClusterAlloc);
1890	break;
1891	}
1892
1893	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1894	}
1895	}
1896
1897	} while (0);
1898
1899	*pcbPreRead = 0;
1900	*pcbPostRead = 0;
1901	}
1902	else
1903	{
1904	/* Trying to do a partial write to an unallocated cluster. Don't do
1905	* anything except letting the upper layer know what to do. */
1906	*pcbPreRead = offCluster;
1907	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
1908	}
1909	}
1910
1911	if (pcbWriteProcess)
1912	*pcbWriteProcess = cbToWrite;
1913
1914
1915	out:
1916	LogFlowFunc(("returns %Rrc\n", rc));
1917	return rc;
1918	}
1919
1920	static int qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
1921	{
1922	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1923	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1924	int rc = VINF_SUCCESS;
1925
1926	Assert(pImage);
1927
1928	if (VALID_PTR(pIoCtx))
1929	rc = qcowFlushImageAsync(pImage, pIoCtx);
1930	else
1931	rc = VERR_INVALID_PARAMETER;
1932
1933	LogFlowFunc(("returns %Rrc\n", rc));
1934	return rc;
1935	}
1936
1937	/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
1938	static unsigned qcowGetVersion(void *pBackendData)
1939	{
1940	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1941	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1942
1943	AssertPtr(pImage);
1944
1945	if (pImage)
1946	return pImage->uVersion;
1947	else
1948	return 0;
1949	}
1950
1951	/** @copydoc VBOXHDDBACKEND::pfnGetSectorSize */
1952	static uint32_t qcowGetSectorSize(void *pBackendData)
1953	{
1954	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1955	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1956	uint32_t cb = 0;
1957
1958	AssertPtr(pImage);
1959
1960	if (pImage && pImage->pStorage)
1961	cb = 512;
1962
1963	LogFlowFunc(("returns %u\n", cb));
1964	return cb;
1965	}
1966
1967	/** @copydoc VBOXHDDBACKEND::pfnGetSize */
1968	static uint64_t qcowGetSize(void *pBackendData)
1969	{
1970	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1971	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1972	uint64_t cb = 0;
1973
1974	AssertPtr(pImage);
1975
1976	if (pImage && pImage->pStorage)
1977	cb = pImage->cbSize;
1978
1979	LogFlowFunc(("returns %llu\n", cb));
1980	return cb;
1981	}
1982
1983	/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
1984	static uint64_t qcowGetFileSize(void *pBackendData)
1985	{
1986	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1987	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1988	uint64_t cb = 0;
1989
1990	AssertPtr(pImage);
1991
1992	if (pImage)
1993	{
1994	uint64_t cbFile;
1995	if (pImage->pStorage)
1996	{
1997	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1998	if (RT_SUCCESS(rc))
1999	cb += cbFile;
2000	}
2001	}
2002
2003	LogFlowFunc(("returns %lld\n", cb));
2004	return cb;
2005	}
2006
2007	/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
2008	static int qcowGetPCHSGeometry(void *pBackendData,
2009	PVDGEOMETRY pPCHSGeometry)
2010	{
2011	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
2012	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2013	int rc;
2014
2015	AssertPtr(pImage);
2016
2017	if (pImage)
2018	{
2019	if (pImage->PCHSGeometry.cCylinders)
2020	{
2021	*pPCHSGeometry = pImage->PCHSGeometry;
2022	rc = VINF_SUCCESS;
2023	}
2024	else
2025	rc = VERR_VD_GEOMETRY_NOT_SET;
2026	}
2027	else
2028	rc = VERR_VD_NOT_OPENED;
2029
2030	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2031	return rc;
2032	}
2033
2034	/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
2035	static int qcowSetPCHSGeometry(void *pBackendData,
2036	PCVDGEOMETRY pPCHSGeometry)
2037	{
2038	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2039	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2040	int rc;
2041
2042	AssertPtr(pImage);
2043
2044	if (pImage)
2045	{
2046	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2047	{
2048	rc = VERR_VD_IMAGE_READ_ONLY;
2049	goto out;
2050	}
2051
2052	pImage->PCHSGeometry = *pPCHSGeometry;
2053	rc = VINF_SUCCESS;
2054	}
2055	else
2056	rc = VERR_VD_NOT_OPENED;
2057
2058	out:
2059	LogFlowFunc(("returns %Rrc\n", rc));
2060	return rc;
2061	}
2062
2063	/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
2064	static int qcowGetLCHSGeometry(void *pBackendData,
2065	PVDGEOMETRY pLCHSGeometry)
2066	{
2067	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2068	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2069	int rc;
2070
2071	AssertPtr(pImage);
2072
2073	if (pImage)
2074	{
2075	if (pImage->LCHSGeometry.cCylinders)
2076	{
2077	*pLCHSGeometry = pImage->LCHSGeometry;
2078	rc = VINF_SUCCESS;
2079	}
2080	else
2081	rc = VERR_VD_GEOMETRY_NOT_SET;
2082	}
2083	else
2084	rc = VERR_VD_NOT_OPENED;
2085
2086	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2087	return rc;
2088	}
2089
2090	/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
2091	static int qcowSetLCHSGeometry(void *pBackendData,
2092	PCVDGEOMETRY pLCHSGeometry)
2093	{
2094	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData, pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2095	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2096	int rc;
2097
2098	AssertPtr(pImage);
2099
2100	if (pImage)
2101	{
2102	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2103	{
2104	rc = VERR_VD_IMAGE_READ_ONLY;
2105	goto out;
2106	}
2107
2108	pImage->LCHSGeometry = *pLCHSGeometry;
2109	rc = VINF_SUCCESS;
2110	}
2111	else
2112	rc = VERR_VD_NOT_OPENED;
2113
2114	out:
2115	LogFlowFunc(("returns %Rrc\n", rc));
2116	return rc;
2117	}
2118
2119	/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
2120	static unsigned qcowGetImageFlags(void *pBackendData)
2121	{
2122	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2123	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2124	unsigned uImageFlags;
2125
2126	AssertPtr(pImage);
2127
2128	if (pImage)
2129	uImageFlags = pImage->uImageFlags;
2130	else
2131	uImageFlags = 0;
2132
2133	LogFlowFunc(("returns %#x\n", uImageFlags));
2134	return uImageFlags;
2135	}
2136
2137	/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
2138	static unsigned qcowGetOpenFlags(void *pBackendData)
2139	{
2140	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2141	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2142	unsigned uOpenFlags;
2143
2144	AssertPtr(pImage);
2145
2146	if (pImage)
2147	uOpenFlags = pImage->uOpenFlags;
2148	else
2149	uOpenFlags = 0;
2150
2151	LogFlowFunc(("returns %#x\n", uOpenFlags));
2152	return uOpenFlags;
2153	}
2154
2155	/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
2156	static int qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2157	{
2158	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2159	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2160	int rc;
2161
2162	/* Image must be opened and the new flags must be valid. */
2163	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2164	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2165	{
2166	rc = VERR_INVALID_PARAMETER;
2167	goto out;
2168	}
2169
2170	/* Implement this operation via reopening the image. */
2171	rc = qcowFreeImage(pImage, false);
2172	if (RT_FAILURE(rc))
2173	goto out;
2174	rc = qcowOpenImage(pImage, uOpenFlags);
2175
2176	out:
2177	LogFlowFunc(("returns %Rrc\n", rc));
2178	return rc;
2179	}
2180
2181	/** @copydoc VBOXHDDBACKEND::pfnGetComment */
2182	static int qcowGetComment(void pBackendData, char pszComment,
2183	size_t cbComment)
2184	{
2185	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2186	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2187	int rc;
2188
2189	AssertPtr(pImage);
2190
2191	if (pImage)
2192	rc = VERR_NOT_SUPPORTED;
2193	else
2194	rc = VERR_VD_NOT_OPENED;
2195
2196	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
2197	return rc;
2198	}
2199
2200	/** @copydoc VBOXHDDBACKEND::pfnSetComment */
2201	static int qcowSetComment(void pBackendData, const char pszComment)
2202	{
2203	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2204	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2205	int rc;
2206
2207	AssertPtr(pImage);
2208
2209	if (pImage)
2210	{
2211	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2212	rc = VERR_VD_IMAGE_READ_ONLY;
2213	else
2214	rc = VERR_NOT_SUPPORTED;
2215	}
2216	else
2217	rc = VERR_VD_NOT_OPENED;
2218
2219	LogFlowFunc(("returns %Rrc\n", rc));
2220	return rc;
2221	}
2222
2223	/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
2224	static int qcowGetUuid(void *pBackendData, PRTUUID pUuid)
2225	{
2226	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2227	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2228	int rc;
2229
2230	AssertPtr(pImage);
2231
2232	if (pImage)
2233	rc = VERR_NOT_SUPPORTED;
2234	else
2235	rc = VERR_VD_NOT_OPENED;
2236
2237	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2238	return rc;
2239	}
2240
2241	/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
2242	static int qcowSetUuid(void *pBackendData, PCRTUUID pUuid)
2243	{
2244	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2245	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2246	int rc;
2247
2248	LogFlowFunc(("%RTuuid\n", pUuid));
2249	AssertPtr(pImage);
2250
2251	if (pImage)
2252	{
2253	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2254	rc = VERR_NOT_SUPPORTED;
2255	else
2256	rc = VERR_VD_IMAGE_READ_ONLY;
2257	}
2258	else
2259	rc = VERR_VD_NOT_OPENED;
2260
2261	LogFlowFunc(("returns %Rrc\n", rc));
2262	return rc;
2263	}
2264
2265	/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
2266	static int qcowGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2267	{
2268	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2269	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2270	int rc;
2271
2272	AssertPtr(pImage);
2273
2274	if (pImage)
2275	rc = VERR_NOT_SUPPORTED;
2276	else
2277	rc = VERR_VD_NOT_OPENED;
2278
2279	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2280	return rc;
2281	}
2282
2283	/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
2284	static int qcowSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2285	{
2286	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2287	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2288	int rc;
2289
2290	AssertPtr(pImage);
2291
2292	if (pImage)
2293	{
2294	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2295	rc = VERR_NOT_SUPPORTED;
2296	else
2297	rc = VERR_VD_IMAGE_READ_ONLY;
2298	}
2299	else
2300	rc = VERR_VD_NOT_OPENED;
2301
2302	LogFlowFunc(("returns %Rrc\n", rc));
2303	return rc;
2304	}
2305
2306	/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
2307	static int qcowGetParentUuid(void *pBackendData, PRTUUID pUuid)
2308	{
2309	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2310	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2311	int rc;
2312
2313	AssertPtr(pImage);
2314
2315	if (pImage)
2316	rc = VERR_NOT_SUPPORTED;
2317	else
2318	rc = VERR_VD_NOT_OPENED;
2319
2320	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2321	return rc;
2322	}
2323
2324	/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
2325	static int qcowSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2326	{
2327	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2328	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2329	int rc;
2330
2331	AssertPtr(pImage);
2332
2333	if (pImage)
2334	{
2335	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2336	rc = VERR_NOT_SUPPORTED;
2337	else
2338	rc = VERR_VD_IMAGE_READ_ONLY;
2339	}
2340	else
2341	rc = VERR_VD_NOT_OPENED;
2342
2343	LogFlowFunc(("returns %Rrc\n", rc));
2344	return rc;
2345	}
2346
2347	/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
2348	static int qcowGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2349	{
2350	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2351	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2352	int rc;
2353
2354	AssertPtr(pImage);
2355
2356	if (pImage)
2357	rc = VERR_NOT_SUPPORTED;
2358	else
2359	rc = VERR_VD_NOT_OPENED;
2360
2361	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2362	return rc;
2363	}
2364
2365	/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
2366	static int qcowSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2367	{
2368	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2369	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2370	int rc;
2371
2372	AssertPtr(pImage);
2373
2374	if (pImage)
2375	{
2376	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2377	rc = VERR_NOT_SUPPORTED;
2378	else
2379	rc = VERR_VD_IMAGE_READ_ONLY;
2380	}
2381	else
2382	rc = VERR_VD_NOT_OPENED;
2383
2384	LogFlowFunc(("returns %Rrc\n", rc));
2385	return rc;
2386	}
2387
2388	/** @copydoc VBOXHDDBACKEND::pfnDump */
2389	static void qcowDump(void *pBackendData)
2390	{
2391	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2392
2393	AssertPtr(pImage);
2394	if (pImage)
2395	{
2396	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cSector=%llu\n",
2397	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2398	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2399	pImage->cbSize / 512);
2400	}
2401	}
2402
2403	/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
2404	static int qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2405	{
2406	int rc = VINF_SUCCESS;
2407	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2408
2409	AssertPtr(pImage);
2410	if (pImage)
2411	if (pImage->pszBackingFilename)
2412	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2413	else
2414	rc = VERR_NOT_SUPPORTED;
2415	else
2416	rc = VERR_VD_NOT_OPENED;
2417
2418	LogFlowFunc(("returns %Rrc\n", rc));
2419	return rc;
2420	}
2421
2422	/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
2423	static int qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2424	{
2425	int rc = VINF_SUCCESS;
2426	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2427
2428	AssertPtr(pImage);
2429	if (pImage)
2430	{
2431	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2432	rc = VERR_VD_IMAGE_READ_ONLY;
2433	else if ( pImage->pszBackingFilename
2434	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2435	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2436	else
2437	{
2438	if (pImage->pszBackingFilename)
2439	RTStrFree(pImage->pszBackingFilename);
2440	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2441	if (!pImage->pszBackingFilename)
2442	rc = VERR_NO_MEMORY;
2443	else
2444	{
2445	if (!pImage->offBackingFilename)
2446	{
2447	/* Allocate new cluster. */
2448	uint64_t offData = qcowClusterAllocate(pImage, 1);
2449
2450	Assert((offData & UINT32_MAX) == offData);
2451	pImage->offBackingFilename = (uint32_t)offData;
2452	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2453	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2454	offData + pImage->cbCluster);
2455	}
2456
2457	if (RT_SUCCESS(rc))
2458	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2459	pImage->offBackingFilename,
2460	pImage->pszBackingFilename,
2461	strlen(pImage->pszBackingFilename));
2462	}
2463	}
2464	}
2465	else
2466	rc = VERR_VD_NOT_OPENED;
2467
2468	LogFlowFunc(("returns %Rrc\n", rc));
2469	return rc;
2470	}
2471
2472
2473
2474	const VBOXHDDBACKEND g_QCowBackend =
2475	{
2476	/* pszBackendName */
2477	"QCOW",
2478	/* cbSize */
2479	sizeof(VBOXHDDBACKEND),
2480	/* uBackendCaps */
2481	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2482	/* paFileExtensions */
2483	s_aQCowFileExtensions,
2484	/* paConfigInfo */
2485	NULL,
2486	/* pfnCheckIfValid */
2487	qcowCheckIfValid,
2488	/* pfnOpen */
2489	qcowOpen,
2490	/* pfnCreate */
2491	qcowCreate,
2492	/* pfnRename */
2493	qcowRename,
2494	/* pfnClose */
2495	qcowClose,
2496	/* pfnRead */
2497	qcowRead,
2498	/* pfnWrite */
2499	qcowWrite,
2500	/* pfnFlush */
2501	qcowFlush,
2502	/* pfnDiscard */
2503	NULL,
2504	/* pfnGetVersion */
2505	qcowGetVersion,
2506	/* pfnGetSectorSize */
2507	qcowGetSectorSize,
2508	/* pfnGetSize */
2509	qcowGetSize,
2510	/* pfnGetFileSize */
2511	qcowGetFileSize,
2512	/* pfnGetPCHSGeometry */
2513	qcowGetPCHSGeometry,
2514	/* pfnSetPCHSGeometry */
2515	qcowSetPCHSGeometry,
2516	/* pfnGetLCHSGeometry */
2517	qcowGetLCHSGeometry,
2518	/* pfnSetLCHSGeometry */
2519	qcowSetLCHSGeometry,
2520	/* pfnGetImageFlags */
2521	qcowGetImageFlags,
2522	/* pfnGetOpenFlags */
2523	qcowGetOpenFlags,
2524	/* pfnSetOpenFlags */
2525	qcowSetOpenFlags,
2526	/* pfnGetComment */
2527	qcowGetComment,
2528	/* pfnSetComment */
2529	qcowSetComment,
2530	/* pfnGetUuid */
2531	qcowGetUuid,
2532	/* pfnSetUuid */
2533	qcowSetUuid,
2534	/* pfnGetModificationUuid */
2535	qcowGetModificationUuid,
2536	/* pfnSetModificationUuid */
2537	qcowSetModificationUuid,
2538	/* pfnGetParentUuid */
2539	qcowGetParentUuid,
2540	/* pfnSetParentUuid */
2541	qcowSetParentUuid,
2542	/* pfnGetParentModificationUuid */
2543	qcowGetParentModificationUuid,
2544	/* pfnSetParentModificationUuid */
2545	qcowSetParentModificationUuid,
2546	/* pfnDump */
2547	qcowDump,
2548	/* pfnGetTimeStamp */
2549	NULL,
2550	/* pfnGetParentTimeStamp */
2551	NULL,
2552	/* pfnSetParentTimeStamp */
2553	NULL,
2554	/* pfnGetParentFilename */
2555	qcowGetParentFilename,
2556	/* pfnSetParentFilename */
2557	qcowSetParentFilename,
2558	/* pfnComposeLocation */
2559	genericFileComposeLocation,
2560	/* pfnComposeName */
2561	genericFileComposeName,
2562	/* pfnCompact */
2563	NULL,
2564	/* pfnResize */
2565	NULL,
2566	/* pfnRepair */
2567	NULL,
2568	/* pfnTraverseMetadata */
2569	NULL
2570	};

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source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 55628

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