QCOW.cpp@ 63768

Last change on this file since 63768 was 63741, checked in by vboxsync, 8 years ago
Storage/QED,QCOW: Always write the complete L1 and L2 table when allocating a new cluster instead of just the updated entry
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1	/* $Id: QCOW.cpp 63741 2016-09-07 07:53:09Z vboxsync $ */
2	/** @file
3	* QCOW - QCOW Disk image.
4	*/
5
6	/*
7	* Copyright (C) 2011-2016 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18
19	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#define LOG_GROUP LOG_GROUP_VD_QCOW
23	#include <VBox/vd-plugin.h>
24	#include <VBox/err.h>
25
26	#include <VBox/log.h>
27	#include <iprt/asm.h>
28	#include <iprt/assert.h>
29	#include <iprt/string.h>
30	#include <iprt/alloc.h>
31	#include <iprt/path.h>
32	#include <iprt/list.h>
33
34	#include "VDBackends.h"
35
36	/** @page pg_storage_qcow QCOW Storage Backend
37	* The QCOW backend implements support for the qemu copy on write format (short QCOW).
38	* There is no official specification available but the format is described
39	* at http://people.gnome.org/~markmc/qcow-image-format.html for version 2
40	* and http://people.gnome.org/~markmc/qcow-image-format-version-1.html for version 1.
41	*
42	* Missing things to implement:
43	* - v2 image creation and handling of the reference count table. (Blocker to enable support for V2 images)
44	* - cluster encryption
45	* - cluster compression
46	* - compaction
47	* - resizing
48	*/
49
50
51	/*********************************************************************************************************************************
52	* Structures in a QCOW image, big endian *
53	*********************************************************************************************************************************/
54
55	#pragma pack(1) /* Completely unnecessary. */
56	typedef struct QCowHeader
57	{
58	/** Magic value. */
59	uint32_t u32Magic;
60	/** Version of the image. */
61	uint32_t u32Version;
62	/** Version dependent data. */
63	union
64	{
65	/** Version 1. */
66	struct
67	{
68	/** Backing file offset. */
69	uint64_t u64BackingFileOffset;
70	/** Size of the backing file. */
71	uint32_t u32BackingFileSize;
72	/** mtime (Modification time?) - can be ignored. */
73	uint32_t u32MTime;
74	/** Logical size of the image in bytes. */
75	uint64_t u64Size;
76	/** Number of bits in the virtual offset used as a cluster offset. */
77	uint8_t u8ClusterBits;
78	/** Number of bits in the virtual offset used for the L2 index. */
79	uint8_t u8L2Bits;
80	/** Padding because the header is not packed in the original source. */
81	uint16_t u16Padding;
82	/** Used cryptographic method. */
83	uint32_t u32CryptMethod;
84	/** Offset of the L1 table in the image in bytes. */
85	uint64_t u64L1TableOffset;
86	} v1;
87	/** Version 2. */
88	struct
89	{
90	/** Backing file offset. */
91	uint64_t u64BackingFileOffset;
92	/** Size of the backing file. */
93	uint32_t u32BackingFileSize;
94	/** Number of bits in the virtual offset used as a cluster offset. */
95	uint32_t u32ClusterBits;
96	/** Logical size of the image. */
97	uint64_t u64Size;
98	/** Used cryptographic method. */
99	uint32_t u32CryptMethod;
100	/** Size of the L1 table in entries (each 8bytes big). */
101	uint32_t u32L1Size;
102	/** Offset of the L1 table in the image in bytes. */
103	uint64_t u64L1TableOffset;
104	/** Start of the refcount table in the image. */
105	uint64_t u64RefcountTableOffset;
106	/** Size of the refcount table in clusters. */
107	uint32_t u32RefcountTableClusters;
108	/** Number of snapshots in the image. */
109	uint32_t u32NbSnapshots;
110	/** Offset of the first snapshot header in the image. */
111	uint64_t u64SnapshotsOffset;
112	} v2;
113	} Version;
114	} QCowHeader;
115	#pragma pack()
116	/** Pointer to a on disk QCOW header. */
117	typedef QCowHeader *PQCowHeader;
118
119	/** QCOW magic value. */
120	#define QCOW_MAGIC UINT32_C(0x514649fb) /* QFI\0xfb */
121	/** Size of the V1 header. */
122	#define QCOW_V1_HDR_SIZE (48)
123	/** Size of the V2 header. */
124	#define QCOW_V2_HDR_SIZE (72)
125
126	/** Cluster is compressed flag for QCOW images. */
127	#define QCOW_V1_COMPRESSED_FLAG RT_BIT_64(63)
128
129	/** Copied flag for QCOW2 images. */
130	#define QCOW_V2_COPIED_FLAG RT_BIT_64(63)
131	/** Cluster is compressed flag for QCOW2 images. */
132	#define QCOW_V2_COMPRESSED_FLAG RT_BIT_64(62)
133
134
135	/*********************************************************************************************************************************
136	* Constants And Macros, Structures and Typedefs *
137	*********************************************************************************************************************************/
138
139	/**
140	* QCOW L2 cache entry.
141	*/
142	typedef struct QCOWL2CACHEENTRY
143	{
144	/** List node for the search list. */
145	RTLISTNODE NodeSearch;
146	/** List node for the LRU list. */
147	RTLISTNODE NodeLru;
148	/** Reference counter. */
149	uint32_t cRefs;
150	/** The offset of the L2 table, used as search key. */
151	uint64_t offL2Tbl;
152	/** Pointer to the cached L2 table. */
153	uint64_t *paL2Tbl;
154	} QCOWL2CACHEENTRY, *PQCOWL2CACHEENTRY;
155
156	/** Maximum amount of memory the cache is allowed to use. */
157	#define QCOW_L2_CACHE_MEMORY_MAX (2*_1M)
158
159	/** QCOW default cluster size for image version 2. */
160	#define QCOW2_CLUSTER_SIZE_DEFAULT (64*_1K)
161	/** QCOW default cluster size for image version 1. */
162	#define QCOW_CLUSTER_SIZE_DEFAULT (4*_1K)
163	/** QCOW default L2 table size in clusters. */
164	#define QCOW_L2_CLUSTERS_DEFAULT (1)
165
166	/**
167	* QCOW image data structure.
168	*/
169	typedef struct QCOWIMAGE
170	{
171	/** Image name. */
172	const char *pszFilename;
173	/** Storage handle. */
174	PVDIOSTORAGE pStorage;
175
176	/** Pointer to the per-disk VD interface list. */
177	PVDINTERFACE pVDIfsDisk;
178	/** Pointer to the per-image VD interface list. */
179	PVDINTERFACE pVDIfsImage;
180	/** Error interface. */
181	PVDINTERFACEERROR pIfError;
182	/** I/O interface. */
183	PVDINTERFACEIOINT pIfIo;
184
185	/** Open flags passed by VBoxHD layer. */
186	unsigned uOpenFlags;
187	/** Image flags defined during creation or determined during open. */
188	unsigned uImageFlags;
189	/** Total size of the image. */
190	uint64_t cbSize;
191	/** Physical geometry of this image. */
192	VDGEOMETRY PCHSGeometry;
193	/** Logical geometry of this image. */
194	VDGEOMETRY LCHSGeometry;
195
196	/** Image version. */
197	unsigned uVersion;
198	/** MTime field - used only to preserve value in opened images, unmodified otherwise. */
199	uint32_t MTime;
200
201	/** Filename of the backing file if any. */
202	char *pszBackingFilename;
203	/** Offset of the filename in the image. */
204	uint64_t offBackingFilename;
205	/** Size of the backing filename excluding \0. */
206	uint32_t cbBackingFilename;
207
208	/** Next offset of a new cluster, aligned to sector size. */
209	uint64_t offNextCluster;
210	/** Cluster size in bytes. */
211	uint32_t cbCluster;
212	/** Number of entries in the L1 table. */
213	uint32_t cL1TableEntries;
214	/** Size of an L1 rounded to the next cluster size. */
215	uint32_t cbL1Table;
216	/** Pointer to the L1 table. */
217	uint64_t *paL1Table;
218	/** Offset of the L1 table. */
219	uint64_t offL1Table;
220
221	/** Size of the L2 table in bytes. */
222	uint32_t cbL2Table;
223	/** Number of entries in the L2 table. */
224	uint32_t cL2TableEntries;
225	/** Memory occupied by the L2 table cache. */
226	size_t cbL2Cache;
227	/** The sorted L2 entry list used for searching. */
228	RTLISTNODE ListSearch;
229	/** The LRU L2 entry list used for eviction. */
230	RTLISTNODE ListLru;
231
232	/** Offset of the refcount table. */
233	uint64_t offRefcountTable;
234	/** Size of the refcount table in bytes. */
235	uint32_t cbRefcountTable;
236	/** Number of entries in the refcount table. */
237	uint32_t cRefcountTableEntries;
238	/** Pointer to the refcount table. */
239	uint64_t *paRefcountTable;
240
241	/** Offset mask for a cluster. */
242	uint64_t fOffsetMask;
243	/** Number of bits to shift to get the L1 index. */
244	uint32_t cL1Shift;
245	/** L2 table mask to get the L2 index. */
246	uint64_t fL2Mask;
247	/** Number of bits to shift to get the L2 index. */
248	uint32_t cL2Shift;
249
250	} QCOWIMAGE, *PQCOWIMAGE;
251
252	/**
253	* State of the async cluster allocation.
254	*/
255	typedef enum QCOWCLUSTERASYNCALLOCSTATE
256	{
257	/** Invalid. */
258	QCOWCLUSTERASYNCALLOCSTATE_INVALID = 0,
259	/** L2 table allocation. */
260	QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC,
261	/** Link L2 table into L1. */
262	QCOWCLUSTERASYNCALLOCSTATE_L2_LINK,
263	/** Allocate user data cluster. */
264	QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC,
265	/** Link user data cluster. */
266	QCOWCLUSTERASYNCALLOCSTATE_USER_LINK,
267	/** 32bit blowup. */
268	QCOWCLUSTERASYNCALLOCSTATE_32BIT_HACK = 0x7fffffff
269	} QCOWCLUSTERASYNCALLOCSTATE, *PQCOWCLUSTERASYNCALLOCSTATE;
270
271	/**
272	* Data needed to track async cluster allocation.
273	*/
274	typedef struct QCOWCLUSTERASYNCALLOC
275	{
276	/** The state of the cluster allocation. */
277	QCOWCLUSTERASYNCALLOCSTATE enmAllocState;
278	/** Old image size to rollback in case of an error. */
279	uint64_t offNextClusterOld;
280	/** L1 index to link if any. */
281	uint32_t idxL1;
282	/** L2 index to link, required in any case. */
283	uint32_t idxL2;
284	/** Start offset of the allocated cluster. */
285	uint64_t offClusterNew;
286	/** L2 cache entry if a L2 table is allocated. */
287	PQCOWL2CACHEENTRY pL2Entry;
288	/** Number of bytes to write. */
289	size_t cbToWrite;
290	} QCOWCLUSTERASYNCALLOC, *PQCOWCLUSTERASYNCALLOC;
291
292
293	/*********************************************************************************************************************************
294	* Static Variables *
295	*********************************************************************************************************************************/
296
297	/** NULL-terminated array of supported file extensions. */
298	static const VDFILEEXTENSION s_aQCowFileExtensions[] =
299	{
300	{"qcow", VDTYPE_HDD},
301	{"qcow2", VDTYPE_HDD},
302	{NULL, VDTYPE_INVALID}
303	};
304
305
306	/*********************************************************************************************************************************
307	* Internal Functions *
308	*********************************************************************************************************************************/
309
310	/**
311	* Return power of 2 or 0 if num error.
312	*
313	* @returns The power of 2 or 0 if the given number is not a power of 2.
314	* @param u32 The number.
315	*/
316	static uint32_t qcowGetPowerOfTwo(uint32_t u32)
317	{
318	if (u32 == 0)
319	return 0;
320	uint32_t uPower2 = 0;
321	while ((u32 & 1) == 0)
322	{
323	u32 >>= 1;
324	uPower2++;
325	}
326	return u32 == 1 ? uPower2 : 0;
327	}
328
329
330	/**
331	* Converts the image header to the host endianess and performs basic checks.
332	*
333	* @returns Whether the given header is valid or not.
334	* @param pHeader Pointer to the header to convert.
335	*/
336	static bool qcowHdrConvertToHostEndianess(PQCowHeader pHeader)
337	{
338	pHeader->u32Magic = RT_BE2H_U32(pHeader->u32Magic);
339	pHeader->u32Version = RT_BE2H_U32(pHeader->u32Version);
340
341	if (pHeader->u32Magic != QCOW_MAGIC)
342	return false;
343
344	if (pHeader->u32Version == 1)
345	{
346	pHeader->Version.v1.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v1.u64BackingFileOffset);
347	pHeader->Version.v1.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v1.u32BackingFileSize);
348	pHeader->Version.v1.u32MTime = RT_BE2H_U32(pHeader->Version.v1.u32MTime);
349	pHeader->Version.v1.u64Size = RT_BE2H_U64(pHeader->Version.v1.u64Size);
350	pHeader->Version.v1.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v1.u32CryptMethod);
351	pHeader->Version.v1.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v1.u64L1TableOffset);
352	}
353	else if (pHeader->u32Version == 2)
354	{
355	pHeader->Version.v2.u64BackingFileOffset = RT_BE2H_U64(pHeader->Version.v2.u64BackingFileOffset);
356	pHeader->Version.v2.u32BackingFileSize = RT_BE2H_U32(pHeader->Version.v2.u32BackingFileSize);
357	pHeader->Version.v2.u32ClusterBits = RT_BE2H_U32(pHeader->Version.v2.u32ClusterBits);
358	pHeader->Version.v2.u64Size = RT_BE2H_U64(pHeader->Version.v2.u64Size);
359	pHeader->Version.v2.u32CryptMethod = RT_BE2H_U32(pHeader->Version.v2.u32CryptMethod);
360	pHeader->Version.v2.u32L1Size = RT_BE2H_U32(pHeader->Version.v2.u32L1Size);
361	pHeader->Version.v2.u64L1TableOffset = RT_BE2H_U64(pHeader->Version.v2.u64L1TableOffset);
362	pHeader->Version.v2.u64RefcountTableOffset = RT_BE2H_U64(pHeader->Version.v2.u64RefcountTableOffset);
363	pHeader->Version.v2.u32RefcountTableClusters = RT_BE2H_U32(pHeader->Version.v2.u32RefcountTableClusters);
364	pHeader->Version.v2.u32NbSnapshots = RT_BE2H_U32(pHeader->Version.v2.u32NbSnapshots);
365	pHeader->Version.v2.u64SnapshotsOffset = RT_BE2H_U64(pHeader->Version.v2.u64SnapshotsOffset);
366	}
367	else
368	return false;
369
370	return true;
371	}
372
373	/**
374	* Creates a QCOW header from the given image state.
375	*
376	* @returns nothing.
377	* @param pImage Image instance data.
378	* @param pHeader Pointer to the header to convert.
379	* @param pcbHeader Where to store the size of the header to write.
380	*/
381	static void qcowHdrConvertFromHostEndianess(PQCOWIMAGE pImage, PQCowHeader pHeader,
382	size_t *pcbHeader)
383	{
384	memset(pHeader, 0, sizeof(QCowHeader));
385
386	pHeader->u32Magic = RT_H2BE_U32(QCOW_MAGIC);
387	pHeader->u32Version = RT_H2BE_U32(pImage->uVersion);
388	if (pImage->uVersion == 1)
389	{
390	pHeader->Version.v1.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
391	pHeader->Version.v1.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
392	pHeader->Version.v1.u32MTime = RT_H2BE_U32(pImage->MTime);
393	pHeader->Version.v1.u64Size = RT_H2BE_U64(pImage->cbSize);
394	pHeader->Version.v1.u8ClusterBits = (uint8_t)qcowGetPowerOfTwo(pImage->cbCluster);
395	pHeader->Version.v1.u8L2Bits = (uint8_t)qcowGetPowerOfTwo(pImage->cL2TableEntries);
396	pHeader->Version.v1.u32CryptMethod = RT_H2BE_U32(0);
397	pHeader->Version.v1.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
398	*pcbHeader = QCOW_V1_HDR_SIZE;
399	}
400	else if (pImage->uVersion == 2)
401	{
402	pHeader->Version.v2.u64BackingFileOffset = RT_H2BE_U64(pImage->offBackingFilename);
403	pHeader->Version.v2.u32BackingFileSize = RT_H2BE_U32(pImage->cbBackingFilename);
404	pHeader->Version.v2.u32ClusterBits = RT_H2BE_U32(qcowGetPowerOfTwo(pImage->cbCluster));
405	pHeader->Version.v2.u64Size = RT_H2BE_U64(pImage->cbSize);
406	pHeader->Version.v2.u32CryptMethod = RT_H2BE_U32(0);
407	pHeader->Version.v2.u32L1Size = RT_H2BE_U32(pImage->cL1TableEntries);
408	pHeader->Version.v2.u64L1TableOffset = RT_H2BE_U64(pImage->offL1Table);
409	pHeader->Version.v2.u64RefcountTableOffset = RT_H2BE_U64(pImage->offRefcountTable);
410	pHeader->Version.v2.u32RefcountTableClusters = RT_H2BE_U32(pImage->cbRefcountTable / pImage->cbCluster);
411	pHeader->Version.v2.u32NbSnapshots = RT_H2BE_U32(0);
412	pHeader->Version.v2.u64SnapshotsOffset = RT_H2BE_U64((uint64_t)0);
413	*pcbHeader = QCOW_V2_HDR_SIZE;
414	}
415	else
416	AssertMsgFailed(("Invalid version of the QCOW image format %d\n", pImage->uVersion));
417	}
418
419	/**
420	* Convert table entries from little endian to host endianess.
421	*
422	* @returns nothing.
423	* @param paTbl Pointer to the table.
424	* @param cEntries Number of entries in the table.
425	*/
426	static void qcowTableConvertToHostEndianess(uint64_t *paTbl, uint32_t cEntries)
427	{
428	while(cEntries-- > 0)
429	{
430	paTbl = RT_BE2H_U64(paTbl);
431	paTbl++;
432	}
433	}
434
435	/**
436	* Convert table entries from host to little endian format.
437	*
438	* @returns nothing.
439	* @param paTblImg Pointer to the table which will store the little endian table.
440	* @param paTbl The source table to convert.
441	* @param cEntries Number of entries in the table.
442	*/
443	static void qcowTableConvertFromHostEndianess(uint64_t paTblImg, uint64_t paTbl,
444	uint32_t cEntries)
445	{
446	while(cEntries-- > 0)
447	{
448	paTblImg = RT_H2BE_U64(paTbl);
449	paTbl++;
450	paTblImg++;
451	}
452	}
453
454	#if 0 /* unused */
455	/**
456	* Convert refcount table entries from little endian to host endianess.
457	*
458	* @returns nothing.
459	* @param paTbl Pointer to the table.
460	* @param cEntries Number of entries in the table.
461	*/
462	static void qcowRefcountTableConvertToHostEndianess(uint16_t *paTbl, uint32_t cEntries)
463	{
464	while(cEntries-- > 0)
465	{
466	paTbl = RT_BE2H_U16(paTbl);
467	paTbl++;
468	}
469	}
470	#endif
471
472	#if 0 /* unused */
473	/**
474	* Convert table entries from host to little endian format.
475	*
476	* @returns nothing.
477	* @param paTblImg Pointer to the table which will store the little endian table.
478	* @param paTbl The source table to convert.
479	* @param cEntries Number of entries in the table.
480	*/
481	static void qcowRefcountTableConvertFromHostEndianess(uint16_t paTblImg, uint16_t paTbl,
482	uint32_t cEntries)
483	{
484	while(cEntries-- > 0)
485	{
486	paTblImg = RT_H2BE_U16(paTbl);
487	paTbl++;
488	paTblImg++;
489	}
490	}
491	#endif
492
493	/**
494	* Creates the L2 table cache.
495	*
496	* @returns VBox status code.
497	* @param pImage The image instance data.
498	*/
499	static int qcowL2TblCacheCreate(PQCOWIMAGE pImage)
500	{
501	pImage->cbL2Cache = 0;
502	RTListInit(&pImage->ListSearch);
503	RTListInit(&pImage->ListLru);
504
505	return VINF_SUCCESS;
506	}
507
508	/**
509	* Destroys the L2 table cache.
510	*
511	* @returns nothing.
512	* @param pImage The image instance data.
513	*/
514	static void qcowL2TblCacheDestroy(PQCOWIMAGE pImage)
515	{
516	PQCOWL2CACHEENTRY pL2Entry = NULL;
517	PQCOWL2CACHEENTRY pL2Next = NULL;
518
519	RTListForEachSafe(&pImage->ListSearch, pL2Entry, pL2Next, QCOWL2CACHEENTRY, NodeSearch)
520	{
521	Assert(!pL2Entry->cRefs);
522
523	RTListNodeRemove(&pL2Entry->NodeSearch);
524	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
525	RTMemFree(pL2Entry);
526	}
527
528	pImage->cbL2Cache = 0;
529	RTListInit(&pImage->ListSearch);
530	RTListInit(&pImage->ListLru);
531	}
532
533	/**
534	* Returns the L2 table matching the given offset or NULL if none could be found.
535	*
536	* @returns Pointer to the L2 table cache entry or NULL.
537	* @param pImage The image instance data.
538	* @param offL2Tbl Offset of the L2 table to search for.
539	*/
540	static PQCOWL2CACHEENTRY qcowL2TblCacheRetain(PQCOWIMAGE pImage, uint64_t offL2Tbl)
541	{
542	PQCOWL2CACHEENTRY pL2Entry = NULL;
543
544	RTListForEach(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch)
545	{
546	if (pL2Entry->offL2Tbl == offL2Tbl)
547	break;
548	}
549
550	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
551	{
552	/* Update LRU list. */
553	RTListNodeRemove(&pL2Entry->NodeLru);
554	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
555	pL2Entry->cRefs++;
556	return pL2Entry;
557	}
558	else
559	return NULL;
560	}
561
562	/**
563	* Releases a L2 table cache entry.
564	*
565	* @returns nothing.
566	* @param pL2Entry The L2 cache entry.
567	*/
568	static void qcowL2TblCacheEntryRelease(PQCOWL2CACHEENTRY pL2Entry)
569	{
570	Assert(pL2Entry->cRefs > 0);
571	pL2Entry->cRefs--;
572	}
573
574	/**
575	* Allocates a new L2 table from the cache evicting old entries if required.
576	*
577	* @returns Pointer to the L2 cache entry or NULL.
578	* @param pImage The image instance data.
579	*/
580	static PQCOWL2CACHEENTRY qcowL2TblCacheEntryAlloc(PQCOWIMAGE pImage)
581	{
582	PQCOWL2CACHEENTRY pL2Entry = NULL;
583
584	if (pImage->cbL2Cache + pImage->cbL2Table <= QCOW_L2_CACHE_MEMORY_MAX)
585	{
586	/* Add a new entry. */
587	pL2Entry = (PQCOWL2CACHEENTRY)RTMemAllocZ(sizeof(QCOWL2CACHEENTRY));
588	if (pL2Entry)
589	{
590	pL2Entry->paL2Tbl = (uint64_t *)RTMemPageAllocZ(pImage->cbL2Table);
591	if (RT_UNLIKELY(!pL2Entry->paL2Tbl))
592	{
593	RTMemFree(pL2Entry);
594	pL2Entry = NULL;
595	}
596	else
597	{
598	pL2Entry->cRefs = 1;
599	pImage->cbL2Cache += pImage->cbL2Table;
600	}
601	}
602	}
603	else
604	{
605	/* Evict the last not in use entry and use it */
606	Assert(!RTListIsEmpty(&pImage->ListLru));
607
608	RTListForEachReverse(&pImage->ListLru, pL2Entry, QCOWL2CACHEENTRY, NodeLru)
609	{
610	if (!pL2Entry->cRefs)
611	break;
612	}
613
614	if (!RTListNodeIsDummy(&pImage->ListSearch, pL2Entry, QCOWL2CACHEENTRY, NodeSearch))
615	{
616	RTListNodeRemove(&pL2Entry->NodeSearch);
617	RTListNodeRemove(&pL2Entry->NodeLru);
618	pL2Entry->offL2Tbl = 0;
619	pL2Entry->cRefs = 1;
620	}
621	else
622	pL2Entry = NULL;
623	}
624
625	return pL2Entry;
626	}
627
628	/**
629	* Frees a L2 table cache entry.
630	*
631	* @returns nothing.
632	* @param pImage The image instance data.
633	* @param pL2Entry The L2 cache entry to free.
634	*/
635	static void qcowL2TblCacheEntryFree(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
636	{
637	Assert(!pL2Entry->cRefs);
638	RTMemPageFree(pL2Entry->paL2Tbl, pImage->cbL2Table);
639	RTMemFree(pL2Entry);
640
641	pImage->cbL2Cache -= pImage->cbL2Table;
642	}
643
644	/**
645	* Inserts an entry in the L2 table cache.
646	*
647	* @returns nothing.
648	* @param pImage The image instance data.
649	* @param pL2Entry The L2 cache entry to insert.
650	*/
651	static void qcowL2TblCacheEntryInsert(PQCOWIMAGE pImage, PQCOWL2CACHEENTRY pL2Entry)
652	{
653	PQCOWL2CACHEENTRY pIt = NULL;
654
655	Assert(pL2Entry->offL2Tbl > 0);
656
657	/* Insert at the top of the LRU list. */
658	RTListPrepend(&pImage->ListLru, &pL2Entry->NodeLru);
659
660	if (RTListIsEmpty(&pImage->ListSearch))
661	{
662	RTListAppend(&pImage->ListSearch, &pL2Entry->NodeSearch);
663	}
664	else
665	{
666	/* Insert into search list. */
667	pIt = RTListGetFirst(&pImage->ListSearch, QCOWL2CACHEENTRY, NodeSearch);
668	if (pIt->offL2Tbl > pL2Entry->offL2Tbl)
669	RTListPrepend(&pImage->ListSearch, &pL2Entry->NodeSearch);
670	else
671	{
672	bool fInserted = false;
673
674	RTListForEach(&pImage->ListSearch, pIt, QCOWL2CACHEENTRY, NodeSearch)
675	{
676	Assert(pIt->offL2Tbl != pL2Entry->offL2Tbl);
677	if (pIt->offL2Tbl < pL2Entry->offL2Tbl)
678	{
679	RTListNodeInsertAfter(&pIt->NodeSearch, &pL2Entry->NodeSearch);
680	fInserted = true;
681	break;
682	}
683	}
684	Assert(fInserted);
685	}
686	}
687	}
688
689	/**
690	* Fetches the L2 from the given offset trying the LRU cache first and
691	* reading it from the image after a cache miss.
692	*
693	* @returns VBox status code.
694	* @param pImage Image instance data.
695	* @param pIoCtx The I/O context.
696	* @param offL2Tbl The offset of the L2 table in the image.
697	* @param ppL2Entry Where to store the L2 table on success.
698	*/
699	static int qcowL2TblCacheFetch(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offL2Tbl,
700	PQCOWL2CACHEENTRY *ppL2Entry)
701	{
702	int rc = VINF_SUCCESS;
703
704	/* Try to fetch the L2 table from the cache first. */
705	PQCOWL2CACHEENTRY pL2Entry = qcowL2TblCacheRetain(pImage, offL2Tbl);
706	if (!pL2Entry)
707	{
708	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
709
710	if (pL2Entry)
711	{
712	/* Read from the image. */
713	PVDMETAXFER pMetaXfer;
714
715	pL2Entry->offL2Tbl = offL2Tbl;
716	rc = vdIfIoIntFileReadMeta(pImage->pIfIo, pImage->pStorage,
717	offL2Tbl, pL2Entry->paL2Tbl,
718	pImage->cbL2Table, pIoCtx,
719	&pMetaXfer, NULL, NULL);
720	if (RT_SUCCESS(rc))
721	{
722	vdIfIoIntMetaXferRelease(pImage->pIfIo, pMetaXfer);
723	#if defined(RT_LITTLE_ENDIAN)
724	qcowTableConvertToHostEndianess(pL2Entry->paL2Tbl, pImage->cL2TableEntries);
725	#endif
726	qcowL2TblCacheEntryInsert(pImage, pL2Entry);
727	}
728	else
729	{
730	qcowL2TblCacheEntryRelease(pL2Entry);
731	qcowL2TblCacheEntryFree(pImage, pL2Entry);
732	}
733	}
734	else
735	rc = VERR_NO_MEMORY;
736	}
737
738	if (RT_SUCCESS(rc))
739	*ppL2Entry = pL2Entry;
740
741	return rc;
742	}
743
744	/**
745	* Sets the L1, L2 and offset bitmasks and L1 and L2 bit shift members.
746	*
747	* @returns nothing.
748	* @param pImage The image instance data.
749	*/
750	static void qcowTableMasksInit(PQCOWIMAGE pImage)
751	{
752	uint32_t cClusterBits, cL2TableBits;
753
754	cClusterBits = qcowGetPowerOfTwo(pImage->cbCluster);
755	cL2TableBits = qcowGetPowerOfTwo(pImage->cL2TableEntries);
756
757	Assert(cClusterBits + cL2TableBits < 64);
758
759	pImage->fOffsetMask = ((uint64_t)pImage->cbCluster - 1);
760	pImage->fL2Mask = ((uint64_t)pImage->cL2TableEntries - 1) << cClusterBits;
761	pImage->cL2Shift = cClusterBits;
762	pImage->cL1Shift = cClusterBits + cL2TableBits;
763	}
764
765	/**
766	* Converts a given logical offset into the
767	*
768	* @returns nothing.
769	* @param pImage The image instance data.
770	* @param off The logical offset to convert.
771	* @param pidxL1 Where to store the index in the L1 table on success.
772	* @param pidxL2 Where to store the index in the L2 table on success.
773	* @param poffCluster Where to store the offset in the cluster on success.
774	*/
775	DECLINLINE(void) qcowConvertLogicalOffset(PQCOWIMAGE pImage, uint64_t off, uint32_t *pidxL1,
776	uint32_t pidxL2, uint32_t poffCluster)
777	{
778	AssertPtr(pidxL1);
779	AssertPtr(pidxL2);
780	AssertPtr(poffCluster);
781
782	*poffCluster = off & pImage->fOffsetMask;
783	*pidxL1 = off >> pImage->cL1Shift;
784	*pidxL2 = (off & pImage->fL2Mask) >> pImage->cL2Shift;
785	}
786
787	/**
788	* Converts Cluster size to a byte size.
789	*
790	* @returns Number of bytes derived from the given number of clusters.
791	* @param pImage The image instance data.
792	* @param cClusters The clusters to convert.
793	*/
794	DECLINLINE(uint64_t) qcowCluster2Byte(PQCOWIMAGE pImage, uint64_t cClusters)
795	{
796	return cClusters * pImage->cbCluster;
797	}
798
799	/**
800	* Converts number of bytes to cluster size rounding to the next cluster.
801	*
802	* @returns Number of bytes derived from the given number of clusters.
803	* @param pImage The image instance data.
804	* @param cb Number of bytes to convert.
805	*/
806	DECLINLINE(uint64_t) qcowByte2Cluster(PQCOWIMAGE pImage, uint64_t cb)
807	{
808	return cb / pImage->cbCluster + (cb % pImage->cbCluster ? 1 : 0);
809	}
810
811	/**
812	* Allocates a new cluster in the image.
813	*
814	* @returns The start offset of the new cluster in the image.
815	* @param pImage The image instance data.
816	* @param cCLusters Number of clusters to allocate.
817	*/
818	DECLINLINE(uint64_t) qcowClusterAllocate(PQCOWIMAGE pImage, uint32_t cClusters)
819	{
820	uint64_t offCluster;
821
822	offCluster = pImage->offNextCluster;
823	pImage->offNextCluster += cClusters*pImage->cbCluster;
824
825	return offCluster;
826	}
827
828	/**
829	* Returns the real image offset for a given cluster or an error if the cluster is not
830	* yet allocated.
831	*
832	* @returns VBox status code.
833	* VERR_VD_BLOCK_FREE if the cluster is not yet allocated.
834	* @param pImage The image instance data.
835	* @param pIoCtx The I/O context.
836	* @param idxL1 The L1 index.
837	* @param idxL2 The L2 index.
838	* @param offCluster Offset inside the cluster.
839	* @param poffImage Where to store the image offset on success;
840	*/
841	static int qcowConvertToImageOffset(PQCOWIMAGE pImage, PVDIOCTX pIoCtx,
842	uint32_t idxL1, uint32_t idxL2,
843	uint32_t offCluster, uint64_t *poffImage)
844	{
845	int rc = VERR_VD_BLOCK_FREE;
846
847	AssertReturn(idxL1 < pImage->cL1TableEntries, VERR_INVALID_PARAMETER);
848	AssertReturn(idxL2 < pImage->cL2TableEntries, VERR_INVALID_PARAMETER);
849
850	if (pImage->paL1Table[idxL1])
851	{
852	PQCOWL2CACHEENTRY pL2Entry;
853
854	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1], &pL2Entry);
855	if (RT_SUCCESS(rc))
856	{
857	/* Get real file offset. */
858	if (pL2Entry->paL2Tbl[idxL2])
859	{
860	uint64_t off = pL2Entry->paL2Tbl[idxL2];
861
862	/* Strip flags */
863	if (pImage->uVersion == 2)
864	{
865	if (RT_UNLIKELY(off & QCOW_V2_COMPRESSED_FLAG))
866	rc = VERR_NOT_SUPPORTED;
867	else
868	off &= ~(QCOW_V2_COMPRESSED_FLAG \| QCOW_V2_COPIED_FLAG);
869	}
870	else
871	{
872	if (RT_UNLIKELY(off & QCOW_V1_COMPRESSED_FLAG))
873	rc = VERR_NOT_SUPPORTED;
874	else
875	off &= ~QCOW_V1_COMPRESSED_FLAG;
876	}
877
878	*poffImage = off + offCluster;
879	}
880	else
881	rc = VERR_VD_BLOCK_FREE;
882
883	qcowL2TblCacheEntryRelease(pL2Entry);
884	}
885	}
886
887	return rc;
888	}
889
890	/**
891	* Write the given table to image converting to the image endianess if required.
892	*
893	* @returns VBox status code.
894	* @param pImage The image instance data.
895	* @param pIoCtx The I/O context.
896	* @param offTbl The offset the table should be written to.
897	* @param paTbl The table to write.
898	* @param pfnComplete Callback called when the write completes.
899	* @param pvUser Opaque user data to pass in the completion callback.
900	*/
901	static int qcowTblWrite(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, uint64_t offTbl, uint64_t *paTbl,
902	size_t cbTbl, unsigned cTblEntries,
903	PFNVDXFERCOMPLETED pfnComplete, void *pvUser)
904	{
905	int rc = VINF_SUCCESS;
906
907	#if defined(RT_LITTLE_ENDIAN)
908	uint64_t paTblImg = (uint64_t )RTMemAllocZ(cbTbl);
909	if (paTblImg)
910	{
911	qcowTableConvertFromHostEndianess(paTblImg, paTbl, cTblEntries);
912	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
913	offTbl, paTblImg, cbTbl,
914	pIoCtx, pfnComplete, pvUser);
915	RTMemFree(paTblImg);
916	}
917	else
918	rc = VERR_NO_MEMORY;
919	#else
920	/* Write table directly. */
921	RT_NOREF(cTblEntries);
922	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
923	offTbl, paTbl, cbTbl, pIoCtx,
924	pfnComplete, pvUser);
925	#endif
926
927	return rc;
928	}
929
930	/**
931	* Internal. Flush image data to disk.
932	*/
933	static int qcowFlushImage(PQCOWIMAGE pImage)
934	{
935	int rc = VINF_SUCCESS;
936
937	if ( pImage->pStorage
938	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
939	&& pImage->cbL1Table)
940	{
941	QCowHeader Header;
942
943	#if defined(RT_LITTLE_ENDIAN)
944	uint64_t paL1TblImg = (uint64_t )RTMemAllocZ(pImage->cbL1Table);
945	if (paL1TblImg)
946	{
947	qcowTableConvertFromHostEndianess(paL1TblImg, pImage->paL1Table,
948	pImage->cL1TableEntries);
949	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
950	pImage->offL1Table, paL1TblImg,
951	pImage->cbL1Table);
952	RTMemFree(paL1TblImg);
953	}
954	else
955	rc = VERR_NO_MEMORY;
956	#else
957	/* Write L1 table directly. */
958	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, pImage->offL1Table,
959	pImage->paL1Table, pImage->cbL1Table);
960	#endif
961	if (RT_SUCCESS(rc))
962	{
963	/* Write header. */
964	size_t cbHeader = 0;
965	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
966	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage, 0, &Header,
967	cbHeader);
968	if (RT_SUCCESS(rc))
969	rc = vdIfIoIntFileFlushSync(pImage->pIfIo, pImage->pStorage);
970	}
971	}
972
973	return rc;
974	}
975
976	/**
977	* Flush image data to disk - version for async I/O.
978	*
979	* @returns VBox status code.
980	* @param pImage The image instance data.
981	* @param pIoCtx The I/o context
982	*/
983	static int qcowFlushImageAsync(PQCOWIMAGE pImage, PVDIOCTX pIoCtx)
984	{
985	int rc = VINF_SUCCESS;
986
987	if ( pImage->pStorage
988	&& !(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
989	{
990	QCowHeader Header;
991
992	rc = qcowTblWrite(pImage, pIoCtx, pImage->offL1Table, pImage->paL1Table,
993	pImage->cbL1Table, pImage->cL1TableEntries, NULL, NULL);
994	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
995	{
996	/* Write header. */
997	size_t cbHeader = 0;
998	qcowHdrConvertFromHostEndianess(pImage, &Header, &cbHeader);
999	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1000	0, &Header, cbHeader,
1001	pIoCtx, NULL, NULL);
1002	if (RT_SUCCESS(rc) \|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1003	rc = vdIfIoIntFileFlush(pImage->pIfIo, pImage->pStorage,
1004	pIoCtx, NULL, NULL);
1005	}
1006	}
1007
1008	return rc;
1009	}
1010
1011	/**
1012	* Internal. Free all allocated space for representing an image except pImage,
1013	* and optionally delete the image from disk.
1014	*/
1015	static int qcowFreeImage(PQCOWIMAGE pImage, bool fDelete)
1016	{
1017	int rc = VINF_SUCCESS;
1018
1019	/* Freeing a never allocated image (e.g. because the open failed) is
1020	* not signalled as an error. After all nothing bad happens. */
1021	if (pImage)
1022	{
1023	if (pImage->pStorage)
1024	{
1025	/* No point updating the file that is deleted anyway. */
1026	if (!fDelete)
1027	qcowFlushImage(pImage);
1028
1029	rc = vdIfIoIntFileClose(pImage->pIfIo, pImage->pStorage);
1030	pImage->pStorage = NULL;
1031	}
1032
1033	if (pImage->paL1Table)
1034	RTMemFree(pImage->paL1Table);
1035
1036	if (pImage->pszBackingFilename)
1037	{
1038	RTMemFree(pImage->pszBackingFilename);
1039	pImage->pszBackingFilename = NULL;
1040	}
1041
1042	qcowL2TblCacheDestroy(pImage);
1043
1044	if (fDelete && pImage->pszFilename)
1045	vdIfIoIntFileDelete(pImage->pIfIo, pImage->pszFilename);
1046	}
1047
1048	LogFlowFunc(("returns %Rrc\n", rc));
1049	return rc;
1050	}
1051
1052	/**
1053	* Validates the header.
1054	*
1055	* @returns VBox status code.
1056	* @param pImage Image backend instance data.
1057	* @param pHdr The header to validate.
1058	* @param cbFile The image file size in bytes.
1059	*/
1060	static int qcowHdrValidate(PQCOWIMAGE pImage, PQCowHeader pHdr, uint64_t cbFile)
1061	{
1062	if (pHdr->u32Version == 1)
1063	{
1064	/* Check that the backing filename is contained in the file. */
1065	if (pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize > cbFile)
1066	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1067	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1068	pImage->pszFilename, pHdr->Version.v1.u64BackingFileOffset + pHdr->Version.v1.u32BackingFileSize,
1069	cbFile);
1070
1071	/* Check that the cluster bits indicate at least a 512byte sector size. */
1072	if (RT_BIT_32(pHdr->Version.v1.u8ClusterBits) < 512)
1073	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1074	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1075	pImage->pszFilename, RT_BIT_32(pHdr->Version.v1.u8ClusterBits), 512);
1076
1077	/*
1078	* Check for possible overflow when multiplying cluster size and L2 entry count because it is used
1079	* to calculate the number of L1 table entries later on.
1080	*/
1081	if (RT_BIT_32(pHdr->Version.v1.u8L2Bits) * RT_BIT_32(pHdr->Version.v1.u8ClusterBits) == 0)
1082	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1083	N_("QCOW: Overflow during L1 table size calculation for image '%s'"),
1084	pImage->pszFilename);
1085	}
1086	else if (pHdr->u32Version == 2)
1087	{
1088	/* Check that the backing filename is contained in the file. */
1089	if (pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize > cbFile)
1090	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1091	N_("QCOW: Backing file offset and size exceed size of image '%s' (%u vs %u)"),
1092	pImage->pszFilename, pHdr->Version.v2.u64BackingFileOffset + pHdr->Version.v2.u32BackingFileSize,
1093	cbFile);
1094
1095	/* Check that the cluster bits indicate at least a 512byte sector size. */
1096	if (RT_BIT_32(pHdr->Version.v2.u32ClusterBits) < 512)
1097	return vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1098	N_("QCOW: Cluster size is too small for image '%s' (%u vs %u)"),
1099	pImage->pszFilename, RT_BIT_32(pHdr->Version.v2.u32ClusterBits), 512);
1100	}
1101	else
1102	return vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1103	N_("QCOW: Version %u in image '%s' is not supported"),
1104	pHdr->u32Version, pImage->pszFilename);
1105
1106	return VINF_SUCCESS;
1107	}
1108
1109	/**
1110	* Internal: Open an image, constructing all necessary data structures.
1111	*/
1112	static int qcowOpenImage(PQCOWIMAGE pImage, unsigned uOpenFlags)
1113	{
1114	int rc;
1115
1116	pImage->uOpenFlags = uOpenFlags;
1117
1118	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1119	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1120	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1121
1122	rc = qcowL2TblCacheCreate(pImage);
1123	AssertRC(rc);
1124
1125	/*
1126	* Open the image.
1127	*/
1128	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename,
1129	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1130	false /* fCreate */),
1131	&pImage->pStorage);
1132	if (RT_FAILURE(rc))
1133	{
1134	/* Do NOT signal an appropriate error here, as the VD layer has the
1135	* choice of retrying the open if it failed. */
1136	goto out;
1137	}
1138
1139	uint64_t cbFile;
1140	QCowHeader Header;
1141	rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
1142	if (RT_FAILURE(rc))
1143	goto out;
1144	if (cbFile > sizeof(Header))
1145	{
1146	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage, 0, &Header, sizeof(Header));
1147	if ( RT_SUCCESS(rc)
1148	&& qcowHdrConvertToHostEndianess(&Header))
1149	{
1150	pImage->offNextCluster = RT_ALIGN_64(cbFile, 512); /* Align image to sector boundary. */
1151	Assert(pImage->offNextCluster >= cbFile);
1152
1153	rc = qcowHdrValidate(pImage, &Header, cbFile);
1154	if (RT_SUCCESS(rc))
1155	{
1156	if (Header.u32Version == 1)
1157	{
1158	if (!Header.Version.v1.u32CryptMethod)
1159	{
1160	pImage->uVersion = 1;
1161	pImage->offBackingFilename = Header.Version.v1.u64BackingFileOffset;
1162	pImage->cbBackingFilename = Header.Version.v1.u32BackingFileSize;
1163	pImage->MTime = Header.Version.v1.u32MTime;
1164	pImage->cbSize = Header.Version.v1.u64Size;
1165	pImage->cbCluster = RT_BIT_32(Header.Version.v1.u8ClusterBits);
1166	pImage->cL2TableEntries = RT_BIT_32(Header.Version.v1.u8L2Bits);
1167	pImage->cbL2Table = RT_ALIGN_64(pImage->cL2TableEntries * sizeof(uint64_t), pImage->cbCluster);
1168	pImage->offL1Table = Header.Version.v1.u64L1TableOffset;
1169	pImage->cL1TableEntries = pImage->cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1170	if (pImage->cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1171	pImage->cL1TableEntries++;
1172	}
1173	else
1174	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1175	N_("QCow: Encrypted image '%s' is not supported"),
1176	pImage->pszFilename);
1177	}
1178	else if (Header.u32Version == 2)
1179	{
1180	if (Header.Version.v2.u32CryptMethod)
1181	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1182	N_("QCow: Encrypted image '%s' is not supported"),
1183	pImage->pszFilename);
1184	else if (Header.Version.v2.u32NbSnapshots)
1185	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1186	N_("QCow: Image '%s' contains snapshots which is not supported"),
1187	pImage->pszFilename);
1188	else
1189	{
1190	pImage->uVersion = 2;
1191	pImage->offBackingFilename = Header.Version.v2.u64BackingFileOffset;
1192	pImage->cbBackingFilename = Header.Version.v2.u32BackingFileSize;
1193	pImage->cbSize = Header.Version.v2.u64Size;
1194	pImage->cbCluster = RT_BIT_32(Header.Version.v2.u32ClusterBits);
1195	pImage->cL2TableEntries = pImage->cbCluster / sizeof(uint64_t);
1196	pImage->cbL2Table = pImage->cbCluster;
1197	pImage->offL1Table = Header.Version.v2.u64L1TableOffset;
1198	pImage->cL1TableEntries = Header.Version.v2.u32L1Size;
1199	pImage->offRefcountTable = Header.Version.v2.u64RefcountTableOffset;
1200	pImage->cbRefcountTable = qcowCluster2Byte(pImage, Header.Version.v2.u32RefcountTableClusters);
1201	pImage->cRefcountTableEntries = pImage->cbRefcountTable / sizeof(uint64_t);
1202	}
1203	}
1204	else
1205	rc = vdIfError(pImage->pIfError, VERR_NOT_SUPPORTED, RT_SRC_POS,
1206	N_("QCow: Image '%s' uses version %u which is not supported"),
1207	pImage->pszFilename, Header.u32Version);
1208
1209	pImage->cbL1Table = RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster);
1210	if ((uint64_t)pImage->cbL1Table != RT_ALIGN_64(pImage->cL1TableEntries * sizeof(uint64_t), pImage->cbCluster))
1211	rc = vdIfError(pImage->pIfError, VERR_INVALID_STATE, RT_SRC_POS,
1212	N_("QCOW: L1 table size overflow in image '%s'"),
1213	pImage->pszFilename);
1214	}
1215
1216	/** @todo Check that there are no compressed clusters in the image
1217	* (by traversing the L2 tables and checking each offset).
1218	* Refuse to open such images.
1219	*/
1220
1221	if ( RT_SUCCESS(rc)
1222	&& pImage->cbBackingFilename
1223	&& pImage->offBackingFilename)
1224	{
1225	/* Load backing filename from image. */
1226	pImage->pszBackingFilename = (char )RTMemAllocZ(pImage->cbBackingFilename + 1); / +1 for \0 terminator. */
1227	if (pImage->pszBackingFilename)
1228	{
1229	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1230	pImage->offBackingFilename, pImage->pszBackingFilename,
1231	pImage->cbBackingFilename);
1232	}
1233	else
1234	rc = VERR_NO_MEMORY;
1235	}
1236
1237	if ( RT_SUCCESS(rc)
1238	&& pImage->cbRefcountTable
1239	&& pImage->offRefcountTable)
1240	{
1241	/* Load refcount table. */
1242	Assert(pImage->cRefcountTableEntries);
1243	pImage->paRefcountTable = (uint64_t *)RTMemAllocZ(pImage->cbRefcountTable);
1244	if (RT_LIKELY(pImage->paRefcountTable))
1245	{
1246	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1247	pImage->offRefcountTable, pImage->paRefcountTable,
1248	pImage->cbRefcountTable);
1249	if (RT_SUCCESS(rc))
1250	qcowTableConvertToHostEndianess(pImage->paRefcountTable,
1251	pImage->cRefcountTableEntries);
1252	else
1253	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1254	N_("QCow: Reading refcount table of image '%s' failed"),
1255	pImage->pszFilename);
1256	}
1257	else
1258	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1259	N_("QCow: Allocating memory for refcount table of image '%s' failed"),
1260	pImage->pszFilename);
1261	}
1262
1263	if (RT_SUCCESS(rc))
1264	{
1265	qcowTableMasksInit(pImage);
1266
1267	/* Allocate L1 table. */
1268	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1269	if (pImage->paL1Table)
1270	{
1271	/* Read from the image. */
1272	rc = vdIfIoIntFileReadSync(pImage->pIfIo, pImage->pStorage,
1273	pImage->offL1Table, pImage->paL1Table,
1274	pImage->cbL1Table);
1275	if (RT_SUCCESS(rc))
1276	qcowTableConvertToHostEndianess(pImage->paL1Table, pImage->cL1TableEntries);
1277	else
1278	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS,
1279	N_("QCow: Reading the L1 table for image '%s' failed"),
1280	pImage->pszFilename);
1281	}
1282	else
1283	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS,
1284	N_("QCow: Out of memory allocating L1 table for image '%s'"),
1285	pImage->pszFilename);
1286	}
1287	}
1288	else if (RT_SUCCESS(rc))
1289	rc = VERR_VD_GEN_INVALID_HEADER;
1290	}
1291	else
1292	rc = VERR_VD_GEN_INVALID_HEADER;
1293
1294	out:
1295	if (RT_FAILURE(rc))
1296	qcowFreeImage(pImage, false);
1297	return rc;
1298	}
1299
1300	/**
1301	* Internal: Create a qcow image.
1302	*/
1303	static int qcowCreateImage(PQCOWIMAGE pImage, uint64_t cbSize,
1304	unsigned uImageFlags, const char *pszComment,
1305	PCVDGEOMETRY pPCHSGeometry,
1306	PCVDGEOMETRY pLCHSGeometry, unsigned uOpenFlags,
1307	PFNVDPROGRESS pfnProgress, void *pvUser,
1308	unsigned uPercentStart, unsigned uPercentSpan)
1309	{
1310	RT_NOREF1(pszComment);
1311	int rc;
1312	int32_t fOpen;
1313
1314	if (uImageFlags & VD_IMAGE_FLAGS_FIXED)
1315	{
1316	rc = vdIfError(pImage->pIfError, VERR_VD_INVALID_TYPE, RT_SRC_POS, N_("QCow: cannot create fixed image '%s'"), pImage->pszFilename);
1317	goto out;
1318	}
1319
1320	pImage->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1321	pImage->uImageFlags = uImageFlags;
1322	pImage->PCHSGeometry = *pPCHSGeometry;
1323	pImage->LCHSGeometry = *pLCHSGeometry;
1324
1325	pImage->pIfError = VDIfErrorGet(pImage->pVDIfsDisk);
1326	pImage->pIfIo = VDIfIoIntGet(pImage->pVDIfsImage);
1327	AssertPtrReturn(pImage->pIfIo, VERR_INVALID_PARAMETER);
1328
1329	/* Create image file. */
1330	fOpen = VDOpenFlagsToFileOpenFlags(pImage->uOpenFlags, true /* fCreate */);
1331	rc = vdIfIoIntFileOpen(pImage->pIfIo, pImage->pszFilename, fOpen, &pImage->pStorage);
1332	if (RT_FAILURE(rc))
1333	{
1334	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: cannot create image '%s'"), pImage->pszFilename);
1335	goto out;
1336	}
1337
1338	/* Init image state. */
1339	pImage->uVersion = 1; /* We create only version 1 images at the moment. */
1340	pImage->cbSize = cbSize;
1341	pImage->cbCluster = QCOW_CLUSTER_SIZE_DEFAULT;
1342	pImage->cbL2Table = qcowCluster2Byte(pImage, QCOW_L2_CLUSTERS_DEFAULT);
1343	pImage->cL2TableEntries = pImage->cbL2Table / sizeof(uint64_t);
1344	pImage->cL1TableEntries = cbSize / (pImage->cbCluster * pImage->cL2TableEntries);
1345	if (cbSize % (pImage->cbCluster * pImage->cL2TableEntries))
1346	pImage->cL1TableEntries++;
1347	pImage->cbL1Table = pImage->cL1TableEntries * sizeof(uint64_t);
1348	pImage->offL1Table = QCOW_V1_HDR_SIZE;
1349	pImage->cbBackingFilename = 0;
1350	pImage->offBackingFilename = 0;
1351	pImage->offNextCluster = RT_ALIGN_64(QCOW_V1_HDR_SIZE + pImage->cbL1Table, pImage->cbCluster);
1352	qcowTableMasksInit(pImage);
1353
1354	/* Init L1 table. */
1355	pImage->paL1Table = (uint64_t *)RTMemAllocZ(pImage->cbL1Table);
1356	if (!pImage->paL1Table)
1357	{
1358	rc = vdIfError(pImage->pIfError, VERR_NO_MEMORY, RT_SRC_POS, N_("QCow: cannot allocate memory for L1 table of image '%s'"),
1359	pImage->pszFilename);
1360	goto out;
1361	}
1362
1363	rc = qcowL2TblCacheCreate(pImage);
1364	if (RT_FAILURE(rc))
1365	{
1366	rc = vdIfError(pImage->pIfError, rc, RT_SRC_POS, N_("QCow: Failed to create L2 cache for image '%s'"),
1367	pImage->pszFilename);
1368	goto out;
1369	}
1370
1371	if (RT_SUCCESS(rc) && pfnProgress)
1372	pfnProgress(pvUser, uPercentStart + uPercentSpan * 98 / 100);
1373
1374	rc = qcowFlushImage(pImage);
1375	if (RT_SUCCESS(rc))
1376	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pImage->offNextCluster);
1377
1378	out:
1379	if (RT_SUCCESS(rc) && pfnProgress)
1380	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1381
1382	if (RT_FAILURE(rc))
1383	qcowFreeImage(pImage, rc != VERR_ALREADY_EXISTS);
1384	return rc;
1385	}
1386
1387	/**
1388	* Rollback anything done during async cluster allocation.
1389	*
1390	* @returns VBox status code.
1391	* @param pImage The image instance data.
1392	* @param pIoCtx The I/O context.
1393	* @param pClusterAlloc The cluster allocation to rollback.
1394	*/
1395	static int qcowAsyncClusterAllocRollback(PQCOWIMAGE pImage, PVDIOCTX pIoCtx, PQCOWCLUSTERASYNCALLOC pClusterAlloc)
1396	{
1397	RT_NOREF1(pIoCtx);
1398	int rc = VINF_SUCCESS;
1399
1400	switch (pClusterAlloc->enmAllocState)
1401	{
1402	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1403	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1404	{
1405	/* Revert the L1 table entry */
1406	pImage->paL1Table[pClusterAlloc->idxL1] = 0;
1407
1408	/* Assumption right now is that the L1 table is not modified on storage if the link fails. */
1409	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1410	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1411	qcowL2TblCacheEntryFree(pImage, pClusterAlloc->pL2Entry); /* Free it, it is not in the cache yet. */
1412	break;
1413	}
1414	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1415	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1416	{
1417	/* Assumption right now is that the L2 table is not modified if the link fails. */
1418	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = 0;
1419	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage, pClusterAlloc->offNextClusterOld);
1420	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry); /* Release L2 cache entry. */
1421	break;
1422	}
1423	default:
1424	AssertMsgFailed(("Invalid cluster allocation state %d\n", pClusterAlloc->enmAllocState));
1425	rc = VERR_INVALID_STATE;
1426	}
1427
1428	RTMemFree(pClusterAlloc);
1429	return rc;
1430	}
1431
1432	/**
1433	* Updates the state of the async cluster allocation.
1434	*
1435	* @returns VBox status code.
1436	* @param pBackendData The opaque backend data.
1437	* @param pIoCtx I/O context associated with this request.
1438	* @param pvUser Opaque user data passed during a read/write request.
1439	* @param rcReq Status code for the completed request.
1440	*/
1441	static DECLCALLBACK(int) qcowAsyncClusterAllocUpdate(void pBackendData, PVDIOCTX pIoCtx, void pvUser, int rcReq)
1442	{
1443	int rc = VINF_SUCCESS;
1444	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1445	PQCOWCLUSTERASYNCALLOC pClusterAlloc = (PQCOWCLUSTERASYNCALLOC)pvUser;
1446
1447	if (RT_FAILURE(rcReq))
1448	return qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1449
1450	AssertPtr(pClusterAlloc->pL2Entry);
1451
1452	switch (pClusterAlloc->enmAllocState)
1453	{
1454	case QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC:
1455	{
1456	/* Update the link in the in memory L1 table now. */
1457	pImage->paL1Table[pClusterAlloc->idxL1] = pClusterAlloc->pL2Entry->offL2Tbl;
1458
1459	/* Update the link in the on disk L1 table now. */
1460	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_LINK;
1461	rc = qcowTblWrite(pImage, pIoCtx, pImage->offL1Table, pImage->paL1Table,
1462	pImage->cbL1Table, pImage->cL1TableEntries,
1463	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1464	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1465	break;
1466	else if (RT_FAILURE(rc))
1467	{
1468	/* Rollback. */
1469	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1470	break;
1471	}
1472	/* Success, fall through. */
1473	}
1474	case QCOWCLUSTERASYNCALLOCSTATE_L2_LINK:
1475	{
1476	/* L2 link updated in L1 , save L2 entry in cache and allocate new user data cluster. */
1477	uint64_t offData = qcowClusterAllocate(pImage, 1);
1478
1479	qcowL2TblCacheEntryInsert(pImage, pClusterAlloc->pL2Entry);
1480
1481	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1482	pClusterAlloc->offNextClusterOld = offData;
1483	pClusterAlloc->offClusterNew = offData;
1484
1485	/* Write data. */
1486	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1487	offData, pIoCtx, pClusterAlloc->cbToWrite,
1488	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1489	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1490	break;
1491	else if (RT_FAILURE(rc))
1492	{
1493	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1494	RTMemFree(pClusterAlloc);
1495	break;
1496	}
1497	}
1498	case QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC:
1499	{
1500	pClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_LINK;
1501	pClusterAlloc->pL2Entry->paL2Tbl[pClusterAlloc->idxL2] = pClusterAlloc->offClusterNew;
1502
1503	/* Link L2 table and update it. */
1504	rc = qcowTblWrite(pImage, pIoCtx, pImage->paL1Table[pClusterAlloc->idxL1],
1505	pClusterAlloc->pL2Entry->paL2Tbl,
1506	pImage->cbL2Table, pImage->cL2TableEntries,
1507	qcowAsyncClusterAllocUpdate, pClusterAlloc);
1508	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1509	break;
1510	else if (RT_FAILURE(rc))
1511	{
1512	qcowAsyncClusterAllocRollback(pImage, pIoCtx, pClusterAlloc);
1513	RTMemFree(pClusterAlloc);
1514	break;
1515	}
1516	}
1517	case QCOWCLUSTERASYNCALLOCSTATE_USER_LINK:
1518	{
1519	/* Everything done without errors, signal completion. */
1520	qcowL2TblCacheEntryRelease(pClusterAlloc->pL2Entry);
1521	RTMemFree(pClusterAlloc);
1522	rc = VINF_SUCCESS;
1523	break;
1524	}
1525	default:
1526	AssertMsgFailed(("Invalid async cluster allocation state %d\n",
1527	pClusterAlloc->enmAllocState));
1528	}
1529
1530	return rc;
1531	}
1532
1533	/** @copydoc VBOXHDDBACKEND::pfnCheckIfValid */
1534	static DECLCALLBACK(int) qcowCheckIfValid(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1535	PVDINTERFACE pVDIfsImage, VDTYPE *penmType)
1536	{
1537	RT_NOREF1(pVDIfsDisk);
1538	LogFlowFunc(("pszFilename=\"%s\" pVDIfsDisk=%#p pVDIfsImage=%#p\n", pszFilename, pVDIfsDisk, pVDIfsImage));
1539	PVDIOSTORAGE pStorage = NULL;
1540	uint64_t cbFile;
1541	int rc = VINF_SUCCESS;
1542
1543	/* Get I/O interface. */
1544	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1545	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1546
1547	if ( !VALID_PTR(pszFilename)
1548	\|\| !*pszFilename)
1549	{
1550	rc = VERR_INVALID_PARAMETER;
1551	goto out;
1552	}
1553
1554	/*
1555	* Open the file and read the footer.
1556	*/
1557	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1558	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1559	false /* fCreate */),
1560	&pStorage);
1561	if (RT_SUCCESS(rc))
1562	{
1563	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1564	if ( RT_SUCCESS(rc)
1565	&& cbFile > sizeof(QCowHeader))
1566	{
1567	QCowHeader Header;
1568
1569	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Header, sizeof(Header));
1570	if ( RT_SUCCESS(rc)
1571	&& qcowHdrConvertToHostEndianess(&Header))
1572	{
1573	*penmType = VDTYPE_HDD;
1574	rc = VINF_SUCCESS;
1575	}
1576	else
1577	rc = VERR_VD_GEN_INVALID_HEADER;
1578	}
1579	else
1580	rc = VERR_VD_GEN_INVALID_HEADER;
1581	}
1582
1583	if (pStorage)
1584	vdIfIoIntFileClose(pIfIo, pStorage);
1585
1586	out:
1587	LogFlowFunc(("returns %Rrc\n", rc));
1588	return rc;
1589	}
1590
1591	/** @copydoc VBOXHDDBACKEND::pfnOpen */
1592	static DECLCALLBACK(int) qcowOpen(const char *pszFilename, unsigned uOpenFlags,
1593	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1594	VDTYPE enmType, void **ppBackendData)
1595	{
1596	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p enmType=%u ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, enmType, ppBackendData));
1597	int rc;
1598	PQCOWIMAGE pImage;
1599
1600	NOREF(enmType); /*< @todo r=klaus make use of the type info. /
1601
1602	/* Check open flags. All valid flags are supported. */
1603	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1604	{
1605	rc = VERR_INVALID_PARAMETER;
1606	goto out;
1607	}
1608
1609	/* Check remaining arguments. */
1610	if ( !VALID_PTR(pszFilename)
1611	\|\| !*pszFilename)
1612	{
1613	rc = VERR_INVALID_PARAMETER;
1614	goto out;
1615	}
1616
1617
1618	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1619	if (!pImage)
1620	{
1621	rc = VERR_NO_MEMORY;
1622	goto out;
1623	}
1624	pImage->pszFilename = pszFilename;
1625	pImage->pStorage = NULL;
1626	pImage->pVDIfsDisk = pVDIfsDisk;
1627	pImage->pVDIfsImage = pVDIfsImage;
1628
1629	rc = qcowOpenImage(pImage, uOpenFlags);
1630	if (RT_SUCCESS(rc))
1631	*ppBackendData = pImage;
1632	else
1633	RTMemFree(pImage);
1634
1635	out:
1636	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1637	return rc;
1638	}
1639
1640	/** @copydoc VBOXHDDBACKEND::pfnCreate */
1641	static DECLCALLBACK(int) qcowCreate(const char *pszFilename, uint64_t cbSize,
1642	unsigned uImageFlags, const char *pszComment,
1643	PCVDGEOMETRY pPCHSGeometry, PCVDGEOMETRY pLCHSGeometry,
1644	PCRTUUID pUuid, unsigned uOpenFlags,
1645	unsigned uPercentStart, unsigned uPercentSpan,
1646	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1647	PVDINTERFACE pVDIfsOperation, VDTYPE enmType,
1648	void **ppBackendData)
1649	{
1650	RT_NOREF1(pUuid);
1651	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",
1652	pszFilename, cbSize, uImageFlags, pszComment, pPCHSGeometry, pLCHSGeometry, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, enmType, ppBackendData));
1653	int rc;
1654	PQCOWIMAGE pImage;
1655
1656	PFNVDPROGRESS pfnProgress = NULL;
1657	void *pvUser = NULL;
1658	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1659	if (pIfProgress)
1660	{
1661	pfnProgress = pIfProgress->pfnProgress;
1662	pvUser = pIfProgress->Core.pvUser;
1663	}
1664
1665	/* Check the VD container type. */
1666	if (enmType != VDTYPE_HDD)
1667	{
1668	rc = VERR_VD_INVALID_TYPE;
1669	goto out;
1670	}
1671
1672	/* Check open flags. All valid flags are supported. */
1673	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1674	{
1675	rc = VERR_INVALID_PARAMETER;
1676	goto out;
1677	}
1678
1679	/* Check remaining arguments. */
1680	if ( !VALID_PTR(pszFilename)
1681	\|\| !*pszFilename
1682	\|\| !VALID_PTR(pPCHSGeometry)
1683	\|\| !VALID_PTR(pLCHSGeometry))
1684	{
1685	rc = VERR_INVALID_PARAMETER;
1686	goto out;
1687	}
1688
1689	pImage = (PQCOWIMAGE)RTMemAllocZ(sizeof(QCOWIMAGE));
1690	if (!pImage)
1691	{
1692	rc = VERR_NO_MEMORY;
1693	goto out;
1694	}
1695	pImage->pszFilename = pszFilename;
1696	pImage->pStorage = NULL;
1697	pImage->pVDIfsDisk = pVDIfsDisk;
1698	pImage->pVDIfsImage = pVDIfsImage;
1699
1700	rc = qcowCreateImage(pImage, cbSize, uImageFlags, pszComment,
1701	pPCHSGeometry, pLCHSGeometry, uOpenFlags,
1702	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1703	if (RT_SUCCESS(rc))
1704	{
1705	/* So far the image is opened in read/write mode. Make sure the
1706	* image is opened in read-only mode if the caller requested that. */
1707	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1708	{
1709	qcowFreeImage(pImage, false);
1710	rc = qcowOpenImage(pImage, uOpenFlags);
1711	if (RT_FAILURE(rc))
1712	{
1713	RTMemFree(pImage);
1714	goto out;
1715	}
1716	}
1717	*ppBackendData = pImage;
1718	}
1719	else
1720	RTMemFree(pImage);
1721
1722	out:
1723	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1724	return rc;
1725	}
1726
1727	/** @copydoc VBOXHDDBACKEND::pfnRename */
1728	static DECLCALLBACK(int) qcowRename(void pBackendData, const char pszFilename)
1729	{
1730	LogFlowFunc(("pBackendData=%#p pszFilename=%#p\n", pBackendData, pszFilename));
1731	int rc = VINF_SUCCESS;
1732	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1733
1734	/* Check arguments. */
1735	if ( !pImage
1736	\|\| !pszFilename
1737	\|\| !*pszFilename)
1738	{
1739	rc = VERR_INVALID_PARAMETER;
1740	goto out;
1741	}
1742
1743	/* Close the image. */
1744	rc = qcowFreeImage(pImage, false);
1745	if (RT_FAILURE(rc))
1746	goto out;
1747
1748	/* Rename the file. */
1749	rc = vdIfIoIntFileMove(pImage->pIfIo, pImage->pszFilename, pszFilename, 0);
1750	if (RT_FAILURE(rc))
1751	{
1752	/* The move failed, try to reopen the original image. */
1753	int rc2 = qcowOpenImage(pImage, pImage->uOpenFlags);
1754	if (RT_FAILURE(rc2))
1755	rc = rc2;
1756
1757	goto out;
1758	}
1759
1760	/* Update pImage with the new information. */
1761	pImage->pszFilename = pszFilename;
1762
1763	/* Open the old image with new name. */
1764	rc = qcowOpenImage(pImage, pImage->uOpenFlags);
1765	if (RT_FAILURE(rc))
1766	goto out;
1767
1768	out:
1769	LogFlowFunc(("returns %Rrc\n", rc));
1770	return rc;
1771	}
1772
1773	/** @copydoc VBOXHDDBACKEND::pfnClose */
1774	static DECLCALLBACK(int) qcowClose(void *pBackendData, bool fDelete)
1775	{
1776	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1777	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1778	int rc;
1779
1780	rc = qcowFreeImage(pImage, fDelete);
1781	RTMemFree(pImage);
1782
1783	LogFlowFunc(("returns %Rrc\n", rc));
1784	return rc;
1785	}
1786
1787	static DECLCALLBACK(int) qcowRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1788	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1789	{
1790	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToRead=%zu pcbActuallyRead=%#p\n",
1791	pBackendData, uOffset, pIoCtx, cbToRead, pcbActuallyRead));
1792	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1793	uint32_t offCluster = 0;
1794	uint32_t idxL1 = 0;
1795	uint32_t idxL2 = 0;
1796	uint64_t offFile = 0;
1797	int rc;
1798
1799	AssertPtr(pImage);
1800	Assert(uOffset % 512 == 0);
1801	Assert(cbToRead % 512 == 0);
1802
1803	if (!VALID_PTR(pIoCtx) \|\| !cbToRead)
1804	{
1805	rc = VERR_INVALID_PARAMETER;
1806	goto out;
1807	}
1808
1809	if ( uOffset + cbToRead > pImage->cbSize
1810	\|\| cbToRead == 0)
1811	{
1812	rc = VERR_INVALID_PARAMETER;
1813	goto out;
1814	}
1815
1816	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1817
1818	/* Clip read size to remain in the cluster. */
1819	cbToRead = RT_MIN(cbToRead, pImage->cbCluster - offCluster);
1820
1821	/* Get offset in image. */
1822	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offFile);
1823	if (RT_SUCCESS(rc))
1824	rc = vdIfIoIntFileReadUser(pImage->pIfIo, pImage->pStorage, offFile,
1825	pIoCtx, cbToRead);
1826
1827	if ( ( RT_SUCCESS(rc)
1828	\|\| rc == VERR_VD_BLOCK_FREE
1829	\|\| rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1830	&& pcbActuallyRead)
1831	*pcbActuallyRead = cbToRead;
1832
1833	out:
1834	LogFlowFunc(("returns %Rrc\n", rc));
1835	return rc;
1836	}
1837
1838	static DECLCALLBACK(int) qcowWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1839	PVDIOCTX pIoCtx, size_t pcbWriteProcess, size_t pcbPreRead,
1840	size_t *pcbPostRead, unsigned fWrite)
1841	{
1842	LogFlowFunc(("pBackendData=%#p uOffset=%llu pIoCtx=%#p cbToWrite=%zu pcbWriteProcess=%#p pcbPreRead=%#p pcbPostRead=%#p\n",
1843	pBackendData, uOffset, pIoCtx, cbToWrite, pcbWriteProcess, pcbPreRead, pcbPostRead));
1844	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
1845	uint32_t offCluster = 0;
1846	uint32_t idxL1 = 0;
1847	uint32_t idxL2 = 0;
1848	uint64_t offImage = 0;
1849	int rc = VINF_SUCCESS;
1850
1851	AssertPtr(pImage);
1852	Assert(!(uOffset % 512));
1853	Assert(!(cbToWrite % 512));
1854
1855	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1856	{
1857	rc = VERR_VD_IMAGE_READ_ONLY;
1858	goto out;
1859	}
1860
1861	if (!VALID_PTR(pIoCtx) \|\| !cbToWrite)
1862	{
1863	rc = VERR_INVALID_PARAMETER;
1864	goto out;
1865	}
1866
1867	if ( uOffset + cbToWrite > pImage->cbSize
1868	\|\| cbToWrite == 0)
1869	{
1870	rc = VERR_INVALID_PARAMETER;
1871	goto out;
1872	}
1873
1874	/* Convert offset to L1, L2 index and cluster offset. */
1875	qcowConvertLogicalOffset(pImage, uOffset, &idxL1, &idxL2, &offCluster);
1876
1877	/* Clip write size to remain in the cluster. */
1878	cbToWrite = RT_MIN(cbToWrite, pImage->cbCluster - offCluster);
1879	Assert(!(cbToWrite % 512));
1880
1881	/* Get offset in image. */
1882	rc = qcowConvertToImageOffset(pImage, pIoCtx, idxL1, idxL2, offCluster, &offImage);
1883	if (RT_SUCCESS(rc))
1884	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1885	offImage, pIoCtx, cbToWrite, NULL, NULL);
1886	else if (rc == VERR_VD_BLOCK_FREE)
1887	{
1888	if ( cbToWrite == pImage->cbCluster
1889	&& !(fWrite & VD_WRITE_NO_ALLOC))
1890	{
1891	PQCOWL2CACHEENTRY pL2Entry = NULL;
1892
1893	/* Full cluster write to previously unallocated cluster.
1894	* Allocate cluster and write data. */
1895	Assert(!offCluster);
1896
1897	do
1898	{
1899	/* Check if we have to allocate a new cluster for L2 tables. */
1900	if (!pImage->paL1Table[idxL1])
1901	{
1902	uint64_t offL2Tbl;
1903	PQCOWCLUSTERASYNCALLOC pL2ClusterAlloc = NULL;
1904
1905	/* Allocate new async cluster allocation state. */
1906	pL2ClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1907	if (RT_UNLIKELY(!pL2ClusterAlloc))
1908	{
1909	rc = VERR_NO_MEMORY;
1910	break;
1911	}
1912
1913	pL2Entry = qcowL2TblCacheEntryAlloc(pImage);
1914	if (!pL2Entry)
1915	{
1916	rc = VERR_NO_MEMORY;
1917	RTMemFree(pL2ClusterAlloc);
1918	break;
1919	}
1920
1921	offL2Tbl = qcowClusterAllocate(pImage, qcowByte2Cluster(pImage, pImage->cbL2Table));
1922	pL2Entry->offL2Tbl = offL2Tbl;
1923	memset(pL2Entry->paL2Tbl, 0, pImage->cbL2Table);
1924
1925	pL2ClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_L2_ALLOC;
1926	pL2ClusterAlloc->offNextClusterOld = offL2Tbl;
1927	pL2ClusterAlloc->offClusterNew = offL2Tbl;
1928	pL2ClusterAlloc->idxL1 = idxL1;
1929	pL2ClusterAlloc->idxL2 = idxL2;
1930	pL2ClusterAlloc->cbToWrite = cbToWrite;
1931	pL2ClusterAlloc->pL2Entry = pL2Entry;
1932
1933	/*
1934	* Write the L2 table first and link to the L1 table afterwards.
1935	* If something unexpected happens the worst case which can happen
1936	* is a leak of some clusters.
1937	*/
1938	rc = vdIfIoIntFileWriteMeta(pImage->pIfIo, pImage->pStorage,
1939	offL2Tbl, pL2Entry->paL2Tbl, pImage->cbL2Table, pIoCtx,
1940	qcowAsyncClusterAllocUpdate, pL2ClusterAlloc);
1941	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1942	break;
1943	else if (RT_FAILURE(rc))
1944	{
1945	RTMemFree(pL2ClusterAlloc);
1946	qcowL2TblCacheEntryFree(pImage, pL2Entry);
1947	break;
1948	}
1949
1950	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pL2ClusterAlloc, rc);
1951	}
1952	else
1953	{
1954	rc = qcowL2TblCacheFetch(pImage, pIoCtx, pImage->paL1Table[idxL1],
1955	&pL2Entry);
1956	if (RT_SUCCESS(rc))
1957	{
1958	PQCOWCLUSTERASYNCALLOC pDataClusterAlloc = NULL;
1959
1960	/* Allocate new async cluster allocation state. */
1961	pDataClusterAlloc = (PQCOWCLUSTERASYNCALLOC)RTMemAllocZ(sizeof(QCOWCLUSTERASYNCALLOC));
1962	if (RT_UNLIKELY(!pDataClusterAlloc))
1963	{
1964	rc = VERR_NO_MEMORY;
1965	break;
1966	}
1967
1968	/* Allocate new cluster for the data. */
1969	uint64_t offData = qcowClusterAllocate(pImage, 1);
1970
1971	pDataClusterAlloc->enmAllocState = QCOWCLUSTERASYNCALLOCSTATE_USER_ALLOC;
1972	pDataClusterAlloc->offNextClusterOld = offData;
1973	pDataClusterAlloc->offClusterNew = offData;
1974	pDataClusterAlloc->idxL1 = idxL1;
1975	pDataClusterAlloc->idxL2 = idxL2;
1976	pDataClusterAlloc->cbToWrite = cbToWrite;
1977	pDataClusterAlloc->pL2Entry = pL2Entry;
1978
1979	/* Write data. */
1980	rc = vdIfIoIntFileWriteUser(pImage->pIfIo, pImage->pStorage,
1981	offData, pIoCtx, cbToWrite,
1982	qcowAsyncClusterAllocUpdate, pDataClusterAlloc);
1983	if (rc == VERR_VD_ASYNC_IO_IN_PROGRESS)
1984	break;
1985	else if (RT_FAILURE(rc))
1986	{
1987	RTMemFree(pDataClusterAlloc);
1988	break;
1989	}
1990
1991	rc = qcowAsyncClusterAllocUpdate(pImage, pIoCtx, pDataClusterAlloc, rc);
1992	}
1993	}
1994
1995	} while (0);
1996
1997	*pcbPreRead = 0;
1998	*pcbPostRead = 0;
1999	}
2000	else
2001	{
2002	/* Trying to do a partial write to an unallocated cluster. Don't do
2003	* anything except letting the upper layer know what to do. */
2004	*pcbPreRead = offCluster;
2005	pcbPostRead = pImage->cbCluster - cbToWrite - pcbPreRead;
2006	}
2007	}
2008
2009	if (pcbWriteProcess)
2010	*pcbWriteProcess = cbToWrite;
2011
2012
2013	out:
2014	LogFlowFunc(("returns %Rrc\n", rc));
2015	return rc;
2016	}
2017
2018	static DECLCALLBACK(int) qcowFlush(void *pBackendData, PVDIOCTX pIoCtx)
2019	{
2020	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2021	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2022	int rc = VINF_SUCCESS;
2023
2024	Assert(pImage);
2025
2026	if (VALID_PTR(pIoCtx))
2027	rc = qcowFlushImageAsync(pImage, pIoCtx);
2028	else
2029	rc = VERR_INVALID_PARAMETER;
2030
2031	LogFlowFunc(("returns %Rrc\n", rc));
2032	return rc;
2033	}
2034
2035	/** @copydoc VBOXHDDBACKEND::pfnGetVersion */
2036	static DECLCALLBACK(unsigned) qcowGetVersion(void *pBackendData)
2037	{
2038	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2039	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2040
2041	AssertPtr(pImage);
2042
2043	if (pImage)
2044	return pImage->uVersion;
2045	else
2046	return 0;
2047	}
2048
2049	/** @copydoc VBOXHDDBACKEND::pfnGetSectorSize */
2050	static DECLCALLBACK(uint32_t) qcowGetSectorSize(void *pBackendData)
2051	{
2052	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2053	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2054	uint32_t cb = 0;
2055
2056	AssertPtr(pImage);
2057
2058	if (pImage && pImage->pStorage)
2059	cb = 512;
2060
2061	LogFlowFunc(("returns %u\n", cb));
2062	return cb;
2063	}
2064
2065	/** @copydoc VBOXHDDBACKEND::pfnGetSize */
2066	static DECLCALLBACK(uint64_t) qcowGetSize(void *pBackendData)
2067	{
2068	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2069	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2070	uint64_t cb = 0;
2071
2072	AssertPtr(pImage);
2073
2074	if (pImage && pImage->pStorage)
2075	cb = pImage->cbSize;
2076
2077	LogFlowFunc(("returns %llu\n", cb));
2078	return cb;
2079	}
2080
2081	/** @copydoc VBOXHDDBACKEND::pfnGetFileSize */
2082	static DECLCALLBACK(uint64_t) qcowGetFileSize(void *pBackendData)
2083	{
2084	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2085	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2086	uint64_t cb = 0;
2087
2088	AssertPtr(pImage);
2089
2090	if (pImage)
2091	{
2092	uint64_t cbFile;
2093	if (pImage->pStorage)
2094	{
2095	int rc = vdIfIoIntFileGetSize(pImage->pIfIo, pImage->pStorage, &cbFile);
2096	if (RT_SUCCESS(rc))
2097	cb += cbFile;
2098	}
2099	}
2100
2101	LogFlowFunc(("returns %lld\n", cb));
2102	return cb;
2103	}
2104
2105	/** @copydoc VBOXHDDBACKEND::pfnGetPCHSGeometry */
2106	static DECLCALLBACK(int) qcowGetPCHSGeometry(void *pBackendData,
2107	PVDGEOMETRY pPCHSGeometry)
2108	{
2109	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p\n", pBackendData, pPCHSGeometry));
2110	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2111	int rc;
2112
2113	AssertPtr(pImage);
2114
2115	if (pImage)
2116	{
2117	if (pImage->PCHSGeometry.cCylinders)
2118	{
2119	*pPCHSGeometry = pImage->PCHSGeometry;
2120	rc = VINF_SUCCESS;
2121	}
2122	else
2123	rc = VERR_VD_GEOMETRY_NOT_SET;
2124	}
2125	else
2126	rc = VERR_VD_NOT_OPENED;
2127
2128	LogFlowFunc(("returns %Rrc (PCHS=%u/%u/%u)\n", rc, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2129	return rc;
2130	}
2131
2132	/** @copydoc VBOXHDDBACKEND::pfnSetPCHSGeometry */
2133	static DECLCALLBACK(int) qcowSetPCHSGeometry(void *pBackendData,
2134	PCVDGEOMETRY pPCHSGeometry)
2135	{
2136	LogFlowFunc(("pBackendData=%#p pPCHSGeometry=%#p PCHS=%u/%u/%u\n", pBackendData, pPCHSGeometry, pPCHSGeometry->cCylinders, pPCHSGeometry->cHeads, pPCHSGeometry->cSectors));
2137	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2138	int rc;
2139
2140	AssertPtr(pImage);
2141
2142	if (pImage)
2143	{
2144	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2145	{
2146	rc = VERR_VD_IMAGE_READ_ONLY;
2147	goto out;
2148	}
2149
2150	pImage->PCHSGeometry = *pPCHSGeometry;
2151	rc = VINF_SUCCESS;
2152	}
2153	else
2154	rc = VERR_VD_NOT_OPENED;
2155
2156	out:
2157	LogFlowFunc(("returns %Rrc\n", rc));
2158	return rc;
2159	}
2160
2161	/** @copydoc VBOXHDDBACKEND::pfnGetLCHSGeometry */
2162	static DECLCALLBACK(int) qcowGetLCHSGeometry(void *pBackendData,
2163	PVDGEOMETRY pLCHSGeometry)
2164	{
2165	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p\n", pBackendData, pLCHSGeometry));
2166	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2167	int rc;
2168
2169	AssertPtr(pImage);
2170
2171	if (pImage)
2172	{
2173	if (pImage->LCHSGeometry.cCylinders)
2174	{
2175	*pLCHSGeometry = pImage->LCHSGeometry;
2176	rc = VINF_SUCCESS;
2177	}
2178	else
2179	rc = VERR_VD_GEOMETRY_NOT_SET;
2180	}
2181	else
2182	rc = VERR_VD_NOT_OPENED;
2183
2184	LogFlowFunc(("returns %Rrc (LCHS=%u/%u/%u)\n", rc, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2185	return rc;
2186	}
2187
2188	/** @copydoc VBOXHDDBACKEND::pfnSetLCHSGeometry */
2189	static DECLCALLBACK(int) qcowSetLCHSGeometry(void *pBackendData,
2190	PCVDGEOMETRY pLCHSGeometry)
2191	{
2192	LogFlowFunc(("pBackendData=%#p pLCHSGeometry=%#p LCHS=%u/%u/%u\n", pBackendData, pLCHSGeometry, pLCHSGeometry->cCylinders, pLCHSGeometry->cHeads, pLCHSGeometry->cSectors));
2193	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2194	int rc;
2195
2196	AssertPtr(pImage);
2197
2198	if (pImage)
2199	{
2200	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2201	{
2202	rc = VERR_VD_IMAGE_READ_ONLY;
2203	goto out;
2204	}
2205
2206	pImage->LCHSGeometry = *pLCHSGeometry;
2207	rc = VINF_SUCCESS;
2208	}
2209	else
2210	rc = VERR_VD_NOT_OPENED;
2211
2212	out:
2213	LogFlowFunc(("returns %Rrc\n", rc));
2214	return rc;
2215	}
2216
2217	/** @copydoc VBOXHDDBACKEND::pfnGetImageFlags */
2218	static DECLCALLBACK(unsigned) qcowGetImageFlags(void *pBackendData)
2219	{
2220	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2221	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2222	unsigned uImageFlags;
2223
2224	AssertPtr(pImage);
2225
2226	if (pImage)
2227	uImageFlags = pImage->uImageFlags;
2228	else
2229	uImageFlags = 0;
2230
2231	LogFlowFunc(("returns %#x\n", uImageFlags));
2232	return uImageFlags;
2233	}
2234
2235	/** @copydoc VBOXHDDBACKEND::pfnGetOpenFlags */
2236	static DECLCALLBACK(unsigned) qcowGetOpenFlags(void *pBackendData)
2237	{
2238	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
2239	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2240	unsigned uOpenFlags;
2241
2242	AssertPtr(pImage);
2243
2244	if (pImage)
2245	uOpenFlags = pImage->uOpenFlags;
2246	else
2247	uOpenFlags = 0;
2248
2249	LogFlowFunc(("returns %#x\n", uOpenFlags));
2250	return uOpenFlags;
2251	}
2252
2253	/** @copydoc VBOXHDDBACKEND::pfnSetOpenFlags */
2254	static DECLCALLBACK(int) qcowSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
2255	{
2256	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
2257	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2258	int rc;
2259
2260	/* Image must be opened and the new flags must be valid. */
2261	if (!pImage \|\| (uOpenFlags & ~( VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO
2262	\| VD_OPEN_FLAGS_ASYNC_IO \| VD_OPEN_FLAGS_SKIP_CONSISTENCY_CHECKS)))
2263	{
2264	rc = VERR_INVALID_PARAMETER;
2265	goto out;
2266	}
2267
2268	/* Implement this operation via reopening the image. */
2269	rc = qcowFreeImage(pImage, false);
2270	if (RT_FAILURE(rc))
2271	goto out;
2272	rc = qcowOpenImage(pImage, uOpenFlags);
2273
2274	out:
2275	LogFlowFunc(("returns %Rrc\n", rc));
2276	return rc;
2277	}
2278
2279	/** @copydoc VBOXHDDBACKEND::pfnGetComment */
2280	static DECLCALLBACK(int) qcowGetComment(void pBackendData, char pszComment, size_t cbComment)
2281	{
2282	RT_NOREF2(pszComment, cbComment);
2283	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
2284	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2285	int rc;
2286
2287	AssertPtr(pImage);
2288
2289	if (pImage)
2290	rc = VERR_NOT_SUPPORTED;
2291	else
2292	rc = VERR_VD_NOT_OPENED;
2293
2294	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
2295	return rc;
2296	}
2297
2298	/** @copydoc VBOXHDDBACKEND::pfnSetComment */
2299	static DECLCALLBACK(int) qcowSetComment(void pBackendData, const char pszComment)
2300	{
2301	RT_NOREF1(pszComment);
2302	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
2303	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2304	int rc;
2305
2306	AssertPtr(pImage);
2307
2308	if (pImage)
2309	{
2310	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2311	rc = VERR_VD_IMAGE_READ_ONLY;
2312	else
2313	rc = VERR_NOT_SUPPORTED;
2314	}
2315	else
2316	rc = VERR_VD_NOT_OPENED;
2317
2318	LogFlowFunc(("returns %Rrc\n", rc));
2319	return rc;
2320	}
2321
2322	/** @copydoc VBOXHDDBACKEND::pfnGetUuid */
2323	static DECLCALLBACK(int) qcowGetUuid(void *pBackendData, PRTUUID pUuid)
2324	{
2325	RT_NOREF1(pUuid);
2326	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2327	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2328	int rc;
2329
2330	AssertPtr(pImage);
2331
2332	if (pImage)
2333	rc = VERR_NOT_SUPPORTED;
2334	else
2335	rc = VERR_VD_NOT_OPENED;
2336
2337	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2338	return rc;
2339	}
2340
2341	/** @copydoc VBOXHDDBACKEND::pfnSetUuid */
2342	static DECLCALLBACK(int) qcowSetUuid(void *pBackendData, PCRTUUID pUuid)
2343	{
2344	RT_NOREF1(pUuid);
2345	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2346	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2347	int rc;
2348
2349	LogFlowFunc(("%RTuuid\n", pUuid));
2350	AssertPtr(pImage);
2351
2352	if (pImage)
2353	{
2354	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2355	rc = VERR_NOT_SUPPORTED;
2356	else
2357	rc = VERR_VD_IMAGE_READ_ONLY;
2358	}
2359	else
2360	rc = VERR_VD_NOT_OPENED;
2361
2362	LogFlowFunc(("returns %Rrc\n", rc));
2363	return rc;
2364	}
2365
2366	/** @copydoc VBOXHDDBACKEND::pfnGetModificationUuid */
2367	static DECLCALLBACK(int) qcowGetModificationUuid(void *pBackendData, PRTUUID pUuid)
2368	{
2369	RT_NOREF1(pUuid);
2370	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2371	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2372	int rc;
2373
2374	AssertPtr(pImage);
2375
2376	if (pImage)
2377	rc = VERR_NOT_SUPPORTED;
2378	else
2379	rc = VERR_VD_NOT_OPENED;
2380
2381	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2382	return rc;
2383	}
2384
2385	/** @copydoc VBOXHDDBACKEND::pfnSetModificationUuid */
2386	static DECLCALLBACK(int) qcowSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
2387	{
2388	RT_NOREF1(pUuid);
2389	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2390	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2391	int rc;
2392
2393	AssertPtr(pImage);
2394
2395	if (pImage)
2396	{
2397	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2398	rc = VERR_NOT_SUPPORTED;
2399	else
2400	rc = VERR_VD_IMAGE_READ_ONLY;
2401	}
2402	else
2403	rc = VERR_VD_NOT_OPENED;
2404
2405	LogFlowFunc(("returns %Rrc\n", rc));
2406	return rc;
2407	}
2408
2409	/** @copydoc VBOXHDDBACKEND::pfnGetParentUuid */
2410	static DECLCALLBACK(int) qcowGetParentUuid(void *pBackendData, PRTUUID pUuid)
2411	{
2412	RT_NOREF1(pUuid);
2413	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2414	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2415	int rc;
2416
2417	AssertPtr(pImage);
2418
2419	if (pImage)
2420	rc = VERR_NOT_SUPPORTED;
2421	else
2422	rc = VERR_VD_NOT_OPENED;
2423
2424	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2425	return rc;
2426	}
2427
2428	/** @copydoc VBOXHDDBACKEND::pfnSetParentUuid */
2429	static DECLCALLBACK(int) qcowSetParentUuid(void *pBackendData, PCRTUUID pUuid)
2430	{
2431	RT_NOREF1(pUuid);
2432	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2433	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2434	int rc;
2435
2436	AssertPtr(pImage);
2437
2438	if (pImage)
2439	{
2440	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2441	rc = VERR_NOT_SUPPORTED;
2442	else
2443	rc = VERR_VD_IMAGE_READ_ONLY;
2444	}
2445	else
2446	rc = VERR_VD_NOT_OPENED;
2447
2448	LogFlowFunc(("returns %Rrc\n", rc));
2449	return rc;
2450	}
2451
2452	/** @copydoc VBOXHDDBACKEND::pfnGetParentModificationUuid */
2453	static DECLCALLBACK(int) qcowGetParentModificationUuid(void *pBackendData, PRTUUID pUuid)
2454	{
2455	RT_NOREF1(pUuid);
2456	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
2457	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2458	int rc;
2459
2460	AssertPtr(pImage);
2461
2462	if (pImage)
2463	rc = VERR_NOT_SUPPORTED;
2464	else
2465	rc = VERR_VD_NOT_OPENED;
2466
2467	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
2468	return rc;
2469	}
2470
2471	/** @copydoc VBOXHDDBACKEND::pfnSetParentModificationUuid */
2472	static DECLCALLBACK(int) qcowSetParentModificationUuid(void *pBackendData, PCRTUUID pUuid)
2473	{
2474	RT_NOREF1(pUuid);
2475	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
2476	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2477	int rc;
2478
2479	AssertPtr(pImage);
2480
2481	if (pImage)
2482	{
2483	if (!(pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY))
2484	rc = VERR_NOT_SUPPORTED;
2485	else
2486	rc = VERR_VD_IMAGE_READ_ONLY;
2487	}
2488	else
2489	rc = VERR_VD_NOT_OPENED;
2490
2491	LogFlowFunc(("returns %Rrc\n", rc));
2492	return rc;
2493	}
2494
2495	/** @copydoc VBOXHDDBACKEND::pfnDump */
2496	static DECLCALLBACK(void) qcowDump(void *pBackendData)
2497	{
2498	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2499
2500	AssertPtr(pImage);
2501	if (pImage)
2502	{
2503	vdIfErrorMessage(pImage->pIfError, "Header: Geometry PCHS=%u/%u/%u LCHS=%u/%u/%u cSector=%llu\n",
2504	pImage->PCHSGeometry.cCylinders, pImage->PCHSGeometry.cHeads, pImage->PCHSGeometry.cSectors,
2505	pImage->LCHSGeometry.cCylinders, pImage->LCHSGeometry.cHeads, pImage->LCHSGeometry.cSectors,
2506	pImage->cbSize / 512);
2507	}
2508	}
2509
2510	/** @copydoc VBOXHDDBACKEND::pfnGetParentFilename */
2511	static DECLCALLBACK(int) qcowGetParentFilename(void pBackendData, char *ppszParentFilename)
2512	{
2513	int rc = VINF_SUCCESS;
2514	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2515
2516	AssertPtr(pImage);
2517	if (pImage)
2518	if (pImage->pszBackingFilename)
2519	*ppszParentFilename = RTStrDup(pImage->pszBackingFilename);
2520	else
2521	rc = VERR_NOT_SUPPORTED;
2522	else
2523	rc = VERR_VD_NOT_OPENED;
2524
2525	LogFlowFunc(("returns %Rrc\n", rc));
2526	return rc;
2527	}
2528
2529	/** @copydoc VBOXHDDBACKEND::pfnSetParentFilename */
2530	static DECLCALLBACK(int) qcowSetParentFilename(void pBackendData, const char pszParentFilename)
2531	{
2532	int rc = VINF_SUCCESS;
2533	PQCOWIMAGE pImage = (PQCOWIMAGE)pBackendData;
2534
2535	AssertPtr(pImage);
2536	if (pImage)
2537	{
2538	if (pImage->uOpenFlags & VD_OPEN_FLAGS_READONLY)
2539	rc = VERR_VD_IMAGE_READ_ONLY;
2540	else if ( pImage->pszBackingFilename
2541	&& (strlen(pszParentFilename) > pImage->cbBackingFilename))
2542	rc = VERR_NOT_SUPPORTED; /* The new filename is longer than the old one. */
2543	else
2544	{
2545	if (pImage->pszBackingFilename)
2546	RTStrFree(pImage->pszBackingFilename);
2547	pImage->pszBackingFilename = RTStrDup(pszParentFilename);
2548	if (!pImage->pszBackingFilename)
2549	rc = VERR_NO_MEMORY;
2550	else
2551	{
2552	if (!pImage->offBackingFilename)
2553	{
2554	/* Allocate new cluster. */
2555	uint64_t offData = qcowClusterAllocate(pImage, 1);
2556
2557	Assert((offData & UINT32_MAX) == offData);
2558	pImage->offBackingFilename = (uint32_t)offData;
2559	pImage->cbBackingFilename = (uint32_t)strlen(pszParentFilename);
2560	rc = vdIfIoIntFileSetSize(pImage->pIfIo, pImage->pStorage,
2561	offData + pImage->cbCluster);
2562	}
2563
2564	if (RT_SUCCESS(rc))
2565	rc = vdIfIoIntFileWriteSync(pImage->pIfIo, pImage->pStorage,
2566	pImage->offBackingFilename,
2567	pImage->pszBackingFilename,
2568	strlen(pImage->pszBackingFilename));
2569	}
2570	}
2571	}
2572	else
2573	rc = VERR_VD_NOT_OPENED;
2574
2575	LogFlowFunc(("returns %Rrc\n", rc));
2576	return rc;
2577	}
2578
2579
2580
2581	const VBOXHDDBACKEND g_QCowBackend =
2582	{
2583	/* pszBackendName */
2584	"QCOW",
2585	/* cbSize */
2586	sizeof(VBOXHDDBACKEND),
2587	/* uBackendCaps */
2588	VD_CAP_FILE \| VD_CAP_VFS \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_DIFF \| VD_CAP_ASYNC,
2589	/* paFileExtensions */
2590	s_aQCowFileExtensions,
2591	/* paConfigInfo */
2592	NULL,
2593	/* pfnCheckIfValid */
2594	qcowCheckIfValid,
2595	/* pfnOpen */
2596	qcowOpen,
2597	/* pfnCreate */
2598	qcowCreate,
2599	/* pfnRename */
2600	qcowRename,
2601	/* pfnClose */
2602	qcowClose,
2603	/* pfnRead */
2604	qcowRead,
2605	/* pfnWrite */
2606	qcowWrite,
2607	/* pfnFlush */
2608	qcowFlush,
2609	/* pfnDiscard */
2610	NULL,
2611	/* pfnGetVersion */
2612	qcowGetVersion,
2613	/* pfnGetSectorSize */
2614	qcowGetSectorSize,
2615	/* pfnGetSize */
2616	qcowGetSize,
2617	/* pfnGetFileSize */
2618	qcowGetFileSize,
2619	/* pfnGetPCHSGeometry */
2620	qcowGetPCHSGeometry,
2621	/* pfnSetPCHSGeometry */
2622	qcowSetPCHSGeometry,
2623	/* pfnGetLCHSGeometry */
2624	qcowGetLCHSGeometry,
2625	/* pfnSetLCHSGeometry */
2626	qcowSetLCHSGeometry,
2627	/* pfnGetImageFlags */
2628	qcowGetImageFlags,
2629	/* pfnGetOpenFlags */
2630	qcowGetOpenFlags,
2631	/* pfnSetOpenFlags */
2632	qcowSetOpenFlags,
2633	/* pfnGetComment */
2634	qcowGetComment,
2635	/* pfnSetComment */
2636	qcowSetComment,
2637	/* pfnGetUuid */
2638	qcowGetUuid,
2639	/* pfnSetUuid */
2640	qcowSetUuid,
2641	/* pfnGetModificationUuid */
2642	qcowGetModificationUuid,
2643	/* pfnSetModificationUuid */
2644	qcowSetModificationUuid,
2645	/* pfnGetParentUuid */
2646	qcowGetParentUuid,
2647	/* pfnSetParentUuid */
2648	qcowSetParentUuid,
2649	/* pfnGetParentModificationUuid */
2650	qcowGetParentModificationUuid,
2651	/* pfnSetParentModificationUuid */
2652	qcowSetParentModificationUuid,
2653	/* pfnDump */
2654	qcowDump,
2655	/* pfnGetTimestamp */
2656	NULL,
2657	/* pfnGetParentTimestamp */
2658	NULL,
2659	/* pfnSetParentTimestamp */
2660	NULL,
2661	/* pfnGetParentFilename */
2662	qcowGetParentFilename,
2663	/* pfnSetParentFilename */
2664	qcowSetParentFilename,
2665	/* pfnComposeLocation */
2666	genericFileComposeLocation,
2667	/* pfnComposeName */
2668	genericFileComposeName,
2669	/* pfnCompact */
2670	NULL,
2671	/* pfnResize */
2672	NULL,
2673	/* pfnRepair */
2674	NULL,
2675	/* pfnTraverseMetadata */
2676	NULL
2677	};

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source: vbox/trunk/src/VBox/Storage/QCOW.cpp@ 63768

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