VCICache.cpp@ 58591

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1	/* $Id: VCICache.cpp 57388 2015-08-17 14:20:55Z vboxsync $ */
2	/** @file
3	* VCICacheCore - VirtualBox Cache Image, Core Code.
4	*/
5
6	/*
7	* Copyright (C) 2006-2013 Oracle Corporation
8	*
9	* This file is part of VirtualBox Open Source Edition (OSE), as
10	* available from http://www.virtualbox.org. This file is free software;
11	* you can redistribute it and/or modify it under the terms of the GNU
12	* General Public License (GPL) as published by the Free Software
13	* Foundation, in version 2 as it comes in the "COPYING" file of the
14	* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15	* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16	*/
17
18
19	/*********************************************************************************************************************************
20	* Header Files *
21	*********************************************************************************************************************************/
22	#define LOG_GROUP LOG_GROUP_VD_RAW /** @todo logging group */
23	#include <VBox/vd-cache-backend.h>
24	#include <VBox/err.h>
25
26	#include <VBox/log.h>
27	#include <iprt/assert.h>
28	#include <iprt/alloc.h>
29	#include <iprt/file.h>
30	#include <iprt/asm.h>
31
32	#include "VDBackends.h"
33
34	/*******************************************************************************
35	* On disk data structures *
36	*******************************************************************************/
37
38	/** @note All structures which are written to the disk are written in camel case
39	* and packed. */
40
41	/** Block size used internally, because we cache sectors the smallest unit we
42	* have to care about is 512 bytes. */
43	#define VCI_BLOCK_SIZE 512
44
45	/** Convert block number/size to byte offset/size. */
46	#define VCI_BLOCK2BYTE(u) ((uint64_t)(u) << 9)
47
48	/** Convert byte offset/size to block number/size. */
49	#define VCI_BYTE2BLOCK(u) ((u) >> 9)
50
51	/**
52	* The VCI header - at the beginning of the file.
53	*
54	* All entries a stored in little endian order.
55	*/
56	#pragma pack(1)
57	typedef struct VciHdr
58	{
59	/** The signature to identify a cache image. */
60	uint32_t u32Signature;
61	/** Version of the layout of metadata in the cache. */
62	uint32_t u32Version;
63	/** Maximum size of the cache file in blocks.
64	* This includes all metadata. */
65	uint64_t cBlocksCache;
66	/** Flag indicating whether the cache was closed cleanly. */
67	uint8_t fUncleanShutdown;
68	/** Cache type. */
69	uint32_t u32CacheType;
70	/** Offset of the B+-Tree root in the image in blocks. */
71	uint64_t offTreeRoot;
72	/** Offset of the block allocation bitmap in blocks. */
73	uint64_t offBlkMap;
74	/** Size of the block allocation bitmap in blocks. */
75	uint32_t cBlkMap;
76	/** UUID of the image. */
77	RTUUID uuidImage;
78	/** Modification UUID for the cache. */
79	RTUUID uuidModification;
80	/** Reserved for future use. */
81	uint8_t abReserved[951];
82	} VciHdr, *PVciHdr;
83	#pragma pack()
84	AssertCompileSize(VciHdr, 2 * VCI_BLOCK_SIZE);
85
86	/** VCI signature to identify a valid image. */
87	#define VCI_HDR_SIGNATURE UINT32_C(0x00494356) /* \0ICV */
88	/** Current version we support. */
89	#define VCI_HDR_VERSION UINT32_C(0x00000001)
90
91	/** Value for an unclean cache shutdown. */
92	#define VCI_HDR_UNCLEAN_SHUTDOWN UINT8_C(0x01)
93	/** Value for a clean cache shutdown. */
94	#define VCI_HDR_CLEAN_SHUTDOWN UINT8_C(0x00)
95
96	/** Cache type: Dynamic image growing to the maximum value. */
97	#define VCI_HDR_CACHE_TYPE_DYNAMIC UINT32_C(0x00000001)
98	/** Cache type: Fixed image, space is preallocated. */
99	#define VCI_HDR_CACHE_TYPE_FIXED UINT32_C(0x00000002)
100
101	/**
102	* On disk representation of an extent describing a range of cached data.
103	*
104	* All entries a stored in little endian order.
105	*/
106	#pragma pack(1)
107	typedef struct VciCacheExtent
108	{
109	/** Block address of the previous extent in the LRU list. */
110	uint64_t u64ExtentPrev;
111	/** Block address of the next extent in the LRU list. */
112	uint64_t u64ExtentNext;
113	/** Flags (for compression, encryption etc.) - currently unused and should be always 0. */
114	uint8_t u8Flags;
115	/** Reserved */
116	uint8_t u8Reserved;
117	/** First block of cached data the extent represents. */
118	uint64_t u64BlockOffset;
119	/** Number of blocks the extent represents. */
120	uint32_t u32Blocks;
121	/** First block in the image where the data is stored. */
122	uint64_t u64BlockAddr;
123	} VciCacheExtent, *PVciCacheExtent;
124	#pragma pack()
125	AssertCompileSize(VciCacheExtent, 38);
126
127	/**
128	* On disk representation of an internal node.
129	*
130	* All entries a stored in little endian order.
131	*/
132	#pragma pack(1)
133	typedef struct VciTreeNodeInternal
134	{
135	/** First block of cached data the internal node represents. */
136	uint64_t u64BlockOffset;
137	/** Number of blocks the internal node represents. */
138	uint32_t u32Blocks;
139	/** Block address in the image where the next node in the tree is stored. */
140	uint64_t u64ChildAddr;
141	} VciTreeNodeInternal, *PVciTreeNodeInternal;
142	#pragma pack()
143	AssertCompileSize(VciTreeNodeInternal, 20);
144
145	/**
146	* On-disk representation of a node in the B+-Tree.
147	*
148	* All entries a stored in little endian order.
149	*/
150	#pragma pack(1)
151	typedef struct VciTreeNode
152	{
153	/** Type of the node (root, internal, leaf). */
154	uint8_t u8Type;
155	/** Data in the node. */
156	uint8_t au8Data[4095];
157	} VciTreeNode, *PVciTreeNode;
158	#pragma pack()
159	AssertCompileSize(VciTreeNode, 8 * VCI_BLOCK_SIZE);
160
161	/** Node type: Internal node containing links to other nodes (VciTreeNodeInternal). */
162	#define VCI_TREE_NODE_TYPE_INTERNAL UINT8_C(0x01)
163	/** Node type: Leaf of the tree (VciCacheExtent). */
164	#define VCI_TREE_NODE_TYPE_LEAF UINT8_C(0x02)
165
166	/** Number of cache extents described by one node. */
167	#define VCI_TREE_EXTENTS_PER_NODE ((sizeof(VciTreeNode)-1) / sizeof(VciCacheExtent))
168	/** Number of internal nodes managed by one tree node. */
169	#define VCI_TREE_INTERNAL_NODES_PER_NODE ((sizeof(VciTreeNode)-1) / sizeof(VciTreeNodeInternal))
170
171	/**
172	* VCI block bitmap header.
173	*
174	* All entries a stored in little endian order.
175	*/
176	#pragma pack(1)
177	typedef struct VciBlkMap
178	{
179	/** Magic of the block bitmap. */
180	uint32_t u32Magic;
181	/** Version of the block bitmap. */
182	uint32_t u32Version;
183	/** Number of blocks this block map manages. */
184	uint64_t cBlocks;
185	/** Number of free blocks. */
186	uint64_t cBlocksFree;
187	/** Number of blocks allocated for metadata. */
188	uint64_t cBlocksAllocMeta;
189	/** Number of blocks allocated for actual cached data. */
190	uint64_t cBlocksAllocData;
191	/** Reserved for future use. */
192	uint8_t au8Reserved[472];
193	} VciBlkMap, *PVciBlkMap;
194	#pragma pack()
195	AssertCompileSize(VciBlkMap, VCI_BLOCK_SIZE);
196
197	/** The magic which identifies a block map. */
198	#define VCI_BLKMAP_MAGIC UINT32_C(0x4b4c4256) /* KLBV */
199	/** Current version. */
200	#define VCI_BLKMAP_VERSION UINT32_C(0x00000001)
201
202	/** Block bitmap entry */
203	typedef uint8_t VciBlkMapEnt;
204
205
206	/*********************************************************************************************************************************
207	* Constants And Macros, Structures and Typedefs *
208	*********************************************************************************************************************************/
209
210	/**
211	* Block range descriptor.
212	*/
213	typedef struct VCIBLKRANGEDESC
214	{
215	/** Previous entry in the list. */
216	struct VCIBLKRANGEDESC *pPrev;
217	/** Next entry in the list. */
218	struct VCIBLKRANGEDESC *pNext;
219	/** Start address of the range. */
220	uint64_t offAddrStart;
221	/** Number of blocks in the range. */
222	uint64_t cBlocks;
223	/** Flag whether the range is free or allocated. */
224	bool fFree;
225	} VCIBLKRANGEDESC, *PVCIBLKRANGEDESC;
226
227	/**
228	* Block map for the cache image - in memory structure.
229	*/
230	typedef struct VCIBLKMAP
231	{
232	/** Number of blocks the map manages. */
233	uint64_t cBlocks;
234	/** Number of blocks allocated for metadata. */
235	uint64_t cBlocksAllocMeta;
236	/** Number of blocks allocated for actual cached data. */
237	uint64_t cBlocksAllocData;
238	/** Number of free blocks. */
239	uint64_t cBlocksFree;
240
241	/** Pointer to the head of the block range list. */
242	PVCIBLKRANGEDESC pRangesHead;
243	/** Pointer to the tail of the block range list. */
244	PVCIBLKRANGEDESC pRangesTail;
245
246	} VCIBLKMAP;
247	/** Pointer to a block map. */
248	typedef VCIBLKMAP *PVCIBLKMAP;
249
250	/**
251	* B+-Tree node header.
252	*/
253	typedef struct VCITREENODE
254	{
255	/** Type of the node (VCI_TREE_NODE_TYPE_). /
256	uint8_t u8Type;
257	/** Block address where the node is stored. */
258	uint64_t u64BlockAddr;
259	/** Pointer to the parent. */
260	struct VCITREENODE *pParent;
261	} VCITREENODE, *PVCITREENODE;
262
263	/**
264	* B+-Tree node pointer.
265	*/
266	typedef struct VCITREENODEPTR
267	{
268	/** Flag whether the node is in memory or still on the disk. */
269	bool fInMemory;
270	/** Type dependent data. */
271	union
272	{
273	/** Pointer to a in memory node. */
274	PVCITREENODE pNode;
275	/** Start block address of the node. */
276	uint64_t offAddrBlockNode;
277	} u;
278	} VCITREENODEPTR, *PVCITREENODEPTR;
279
280	/**
281	* Internal node.
282	*/
283	typedef struct VCINODEINTERNAL
284	{
285	/** First block of cached data the internal node represents. */
286	uint64_t u64BlockOffset;
287	/** Number of blocks the internal node represents. */
288	uint32_t u32Blocks;
289	/** Pointer to the child node. */
290	VCITREENODEPTR PtrChild;
291	} VCINODEINTERNAL, *PVCINODEINTERNAL;
292
293	/**
294	* A in memory internal B+-tree node.
295	*/
296	typedef struct VCITREENODEINT
297	{
298	/** Node core. */
299	VCITREENODE Core;
300	/** Number of used nodes. */
301	unsigned cUsedNodes;
302	/** Array of internal nodes. */
303	VCINODEINTERNAL aIntNodes[VCI_TREE_INTERNAL_NODES_PER_NODE];
304	} VCITREENODEINT, *PVCITREENODEINT;
305
306	/**
307	* A in memory cache extent.
308	*/
309	typedef struct VCICACHEEXTENT
310	{
311	/** First block of cached data the extent represents. */
312	uint64_t u64BlockOffset;
313	/** Number of blocks the extent represents. */
314	uint32_t u32Blocks;
315	/** First block in the image where the data is stored. */
316	uint64_t u64BlockAddr;
317	} VCICACHEEXTENT, *PVCICACHEEXTENT;
318
319	/**
320	* A in memory leaf B+-tree node.
321	*/
322	typedef struct VCITREENODELEAF
323	{
324	/** Node core. */
325	VCITREENODE Core;
326	/** Next leaf node in the list. */
327	struct VCITREENODELEAF *pNext;
328	/** Number of used nodes. */
329	unsigned cUsedNodes;
330	/** The extents in the node. */
331	VCICACHEEXTENT aExtents[VCI_TREE_EXTENTS_PER_NODE];
332	} VCITREENODELEAF, *PVCITREENODELEAF;
333
334	/**
335	* VCI image data structure.
336	*/
337	typedef struct VCICACHE
338	{
339	/** Image name. */
340	const char *pszFilename;
341	/** Storage handle. */
342	PVDIOSTORAGE pStorage;
343
344	/** Pointer to the per-disk VD interface list. */
345	PVDINTERFACE pVDIfsDisk;
346	/** Pointer to the per-image VD interface list. */
347	PVDINTERFACE pVDIfsImage;
348	/** Error interface. */
349	PVDINTERFACEERROR pIfError;
350	/** I/O interface. */
351	PVDINTERFACEIOINT pIfIo;
352
353	/** Open flags passed by VBoxHD layer. */
354	unsigned uOpenFlags;
355	/** Image flags defined during creation or determined during open. */
356	unsigned uImageFlags;
357	/** Total size of the image. */
358	uint64_t cbSize;
359
360	/** Offset of the B+-Tree in the image in bytes. */
361	uint64_t offTreeRoot;
362	/** Pointer to the root node of the B+-Tree. */
363	PVCITREENODE pRoot;
364	/** Offset to the block allocation bitmap in bytes. */
365	uint64_t offBlksBitmap;
366	/** Block map. */
367	PVCIBLKMAP pBlkMap;
368	} VCICACHE, *PVCICACHE;
369
370	/** No block free in bitmap error code. */
371	#define VERR_VCI_NO_BLOCKS_FREE (-65536)
372
373	/** Flags for the block map allocator. */
374	#define VCIBLKMAP_ALLOC_DATA 0
375	#define VCIBLKMAP_ALLOC_META RT_BIT(0)
376	#define VCIBLKMAP_ALLOC_MASK 0x1
377
378
379	/*********************************************************************************************************************************
380	* Static Variables *
381	*********************************************************************************************************************************/
382
383	/** NULL-terminated array of supported file extensions. */
384	static const char *const s_apszVciFileExtensions[] =
385	{
386	"vci",
387	NULL
388	};
389
390
391	/*********************************************************************************************************************************
392	* Internal Functions *
393	*********************************************************************************************************************************/
394
395	/**
396	* Internal. Flush image data to disk.
397	*/
398	static int vciFlushImage(PVCICACHE pCache)
399	{
400	int rc = VINF_SUCCESS;
401
402	if ( pCache->pStorage
403	&& !(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
404	{
405	rc = vdIfIoIntFileFlushSync(pCache->pIfIo, pCache->pStorage);
406	}
407
408	return rc;
409	}
410
411	/**
412	* Internal. Free all allocated space for representing an image except pCache,
413	* and optionally delete the image from disk.
414	*/
415	static int vciFreeImage(PVCICACHE pCache, bool fDelete)
416	{
417	int rc = VINF_SUCCESS;
418
419	/* Freeing a never allocated image (e.g. because the open failed) is
420	* not signalled as an error. After all nothing bad happens. */
421	if (pCache)
422	{
423	if (pCache->pStorage)
424	{
425	/* No point updating the file that is deleted anyway. */
426	if (!fDelete)
427	vciFlushImage(pCache);
428
429	vdIfIoIntFileClose(pCache->pIfIo, pCache->pStorage);
430	pCache->pStorage = NULL;
431	}
432
433	if (fDelete && pCache->pszFilename)
434	vdIfIoIntFileDelete(pCache->pIfIo, pCache->pszFilename);
435	}
436
437	LogFlowFunc(("returns %Rrc\n", rc));
438	return rc;
439	}
440
441	/**
442	* Creates a new block map which can manage the given number of blocks.
443	*
444	* The size of the bitmap is aligned to the VCI block size.
445	*
446	* @returns VBox status code.
447	* @param cBlocks The number of blocks the bitmap can manage.
448	* @param ppBlkMap Where to store the pointer to the block bitmap.
449	* @param pcbBlkMap Where to store the size of the block bitmap in blocks
450	* needed on the disk.
451	*/
452	static int vciBlkMapCreate(uint64_t cBlocks, PVCIBLKMAP ppBlkMap, uint32_t pcBlkMap)
453	{
454	int rc = VINF_SUCCESS;
455	uint32_t cbBlkMap = RT_ALIGN_Z(cBlocks / sizeof(VciBlkMapEnt) / 8, VCI_BLOCK_SIZE);
456	PVCIBLKMAP pBlkMap = (PVCIBLKMAP)RTMemAllocZ(sizeof(VCIBLKMAP));
457	PVCIBLKRANGEDESC pFree = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
458
459	LogFlowFunc(("cBlocks=%u ppBlkMap=%#p pcBlkMap=%#p\n", cBlocks, ppBlkMap, pcBlkMap));
460
461	if (pBlkMap && pFree)
462	{
463	pBlkMap->cBlocks = cBlocks;
464	pBlkMap->cBlocksAllocMeta = 0;
465	pBlkMap->cBlocksAllocData = 0;
466	pBlkMap->cBlocksFree = cBlocks;
467
468	pFree->pPrev = NULL;
469	pFree->pNext = NULL;
470	pFree->offAddrStart = 0;
471	pFree->cBlocks = cBlocks;
472	pFree->fFree = true;
473
474	pBlkMap->pRangesHead = pFree;
475	pBlkMap->pRangesTail = pFree;
476
477	Assert(!((cbBlkMap + sizeof(VciBlkMap)) % VCI_BLOCK_SIZE));
478	*ppBlkMap = pBlkMap;
479	*pcBlkMap = VCI_BYTE2BLOCK(cbBlkMap + sizeof(VciBlkMap));
480	}
481	else
482	{
483	if (pBlkMap)
484	RTMemFree(pBlkMap);
485	if (pFree)
486	RTMemFree(pFree);
487
488	rc = VERR_NO_MEMORY;
489	}
490
491	LogFlowFunc(("returns rc=%Rrc cBlkMap=%u\n", rc, *pcBlkMap));
492	return rc;
493	}
494
495	/**
496	* Frees a block map.
497	*
498	* @returns nothing.
499	* @param pBlkMap The block bitmap to destroy.
500	*/
501	static void vciBlkMapDestroy(PVCIBLKMAP pBlkMap)
502	{
503	LogFlowFunc(("pBlkMap=%#p\n", pBlkMap));
504
505	PVCIBLKRANGEDESC pRangeCur = pBlkMap->pRangesHead;
506
507	while (pRangeCur)
508	{
509	PVCIBLKRANGEDESC pTmp = pRangeCur;
510
511	RTMemFree(pTmp);
512
513	pRangeCur = pRangeCur->pNext;
514	}
515
516	RTMemFree(pBlkMap);
517
518	LogFlowFunc(("returns\n"));
519	}
520
521	/**
522	* Loads the block map from the specified medium and creates all necessary
523	* in memory structures to manage used and free blocks.
524	*
525	* @returns VBox status code.
526	* @param pStorage Storage handle to read the block bitmap from.
527	* @param offBlkMap Start of the block bitmap in blocks.
528	* @param cBlkMap Size of the block bitmap on the disk in blocks.
529	* @param ppBlkMap Where to store the block bitmap on success.
530	*/
531	static int vciBlkMapLoad(PVCICACHE pStorage, uint64_t offBlkMap, uint32_t cBlkMap, PVCIBLKMAP *ppBlkMap)
532	{
533	int rc = VINF_SUCCESS;
534	VciBlkMap BlkMap;
535
536	LogFlowFunc(("pStorage=%#p offBlkMap=%llu cBlkMap=%u ppBlkMap=%#p\n",
537	pStorage, offBlkMap, cBlkMap, ppBlkMap));
538
539	if (cBlkMap >= VCI_BYTE2BLOCK(sizeof(VciBlkMap)))
540	{
541	cBlkMap -= VCI_BYTE2BLOCK(sizeof(VciBlkMap));
542
543	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage, offBlkMap,
544	&BlkMap, VCI_BYTE2BLOCK(sizeof(VciBlkMap)));
545	if (RT_SUCCESS(rc))
546	{
547	offBlkMap += VCI_BYTE2BLOCK(sizeof(VciBlkMap));
548
549	BlkMap.u32Magic = RT_LE2H_U32(BlkMap.u32Magic);
550	BlkMap.u32Version = RT_LE2H_U32(BlkMap.u32Version);
551	BlkMap.cBlocks = RT_LE2H_U32(BlkMap.cBlocks);
552	BlkMap.cBlocksFree = RT_LE2H_U32(BlkMap.cBlocksFree);
553	BlkMap.cBlocksAllocMeta = RT_LE2H_U32(BlkMap.cBlocksAllocMeta);
554	BlkMap.cBlocksAllocData = RT_LE2H_U32(BlkMap.cBlocksAllocData);
555
556	if ( BlkMap.u32Magic == VCI_BLKMAP_MAGIC
557	&& BlkMap.u32Version == VCI_BLKMAP_VERSION
558	&& BlkMap.cBlocks == BlkMap.cBlocksFree + BlkMap.cBlocksAllocMeta + BlkMap.cBlocksAllocData
559	&& VCI_BYTE2BLOCK(BlkMap.cBlocks / 8) == cBlkMap)
560	{
561	PVCIBLKMAP pBlkMap = (PVCIBLKMAP)RTMemAllocZ(sizeof(VCIBLKMAP));
562	if (pBlkMap)
563	{
564	pBlkMap->cBlocks = BlkMap.cBlocks;
565	pBlkMap->cBlocksFree = BlkMap.cBlocksFree;
566	pBlkMap->cBlocksAllocMeta = BlkMap.cBlocksAllocMeta;
567	pBlkMap->cBlocksAllocData = BlkMap.cBlocksAllocData;
568
569	/* Load the bitmap and construct the range list. */
570	uint32_t cBlocksFree = 0;
571	uint32_t cBlocksAllocated = 0;
572	PVCIBLKRANGEDESC pRangeCur = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
573
574	if (pRangeCur)
575	{
576	uint8_t abBitmapBuffer[16 * _1K];
577	uint32_t cBlocksRead = 0;
578	uint64_t cBlocksLeft = VCI_BYTE2BLOCK(pBlkMap->cBlocks / 8);
579
580	cBlocksRead = RT_MIN(VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)), cBlocksLeft);
581	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage,
582	offBlkMap, abBitmapBuffer,
583	cBlocksRead);
584
585	if (RT_SUCCESS(rc))
586	{
587	pRangeCur->fFree = !(abBitmapBuffer[0] & 0x01);
588	pRangeCur->offAddrStart = 0;
589	pRangeCur->cBlocks = 0;
590	pRangeCur->pNext = NULL;
591	pRangeCur->pPrev = NULL;
592	pBlkMap->pRangesHead = pRangeCur;
593	pBlkMap->pRangesTail = pRangeCur;
594	}
595	else
596	RTMemFree(pRangeCur);
597
598	while ( RT_SUCCESS(rc)
599	&& cBlocksLeft)
600	{
601	int iBit = 0;
602	uint32_t cBits = VCI_BLOCK2BYTE(cBlocksRead) * 8;
603	uint32_t iBitPrev = 0xffffffff;
604
605	while (cBits)
606	{
607	if (pRangeCur->fFree)
608	{
609	/* Check for the first set bit. */
610	iBit = ASMBitNextSet(abBitmapBuffer, cBits, iBitPrev);
611	}
612	else
613	{
614	/* Check for the first free bit. */
615	iBit = ASMBitNextClear(abBitmapBuffer, cBits, iBitPrev);
616	}
617
618	if (iBit == -1)
619	{
620	/* No change. */
621	pRangeCur->cBlocks += cBits;
622	cBits = 0;
623	}
624	else
625	{
626	Assert((uint32_t)iBit < cBits);
627	pRangeCur->cBlocks += iBit;
628
629	/* Create a new range descriptor. */
630	PVCIBLKRANGEDESC pRangeNew = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
631	if (!pRangeNew)
632	{
633	rc = VERR_NO_MEMORY;
634	break;
635	}
636
637	pRangeNew->fFree = !pRangeCur->fFree;
638	pRangeNew->offAddrStart = pRangeCur->offAddrStart + pRangeCur->cBlocks;
639	pRangeNew->cBlocks = 0;
640	pRangeNew->pPrev = pRangeCur;
641	pRangeCur->pNext = pRangeNew;
642	pBlkMap->pRangesTail = pRangeNew;
643	pRangeCur = pRangeNew;
644	cBits -= iBit;
645	iBitPrev = iBit;
646	}
647	}
648
649	cBlocksLeft -= cBlocksRead;
650	offBlkMap += cBlocksRead;
651
652	if ( RT_SUCCESS(rc)
653	&& cBlocksLeft)
654	{
655	/* Read next chunk. */
656	cBlocksRead = RT_MIN(VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)), cBlocksLeft);
657	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage,
658	offBlkMap, abBitmapBuffer, cBlocksRead);
659	}
660	}
661	}
662	else
663	rc = VERR_NO_MEMORY;
664
665	if (RT_SUCCESS(rc))
666	{
667	*ppBlkMap = pBlkMap;
668	LogFlowFunc(("return success\n"));
669	return VINF_SUCCESS;
670	}
671	else
672	RTMemFree(pBlkMap);
673	}
674	else
675	rc = VERR_NO_MEMORY;
676	}
677	else
678	rc = VERR_VD_GEN_INVALID_HEADER;
679	}
680	else
681	rc = VERR_VD_GEN_INVALID_HEADER;
682	}
683	else
684	rc = VERR_VD_GEN_INVALID_HEADER;
685
686	LogFlowFunc(("returns rc=%Rrc\n", rc));
687	return rc;
688	}
689
690	/**
691	* Saves the block map in the cache image. All necessary on disk structures
692	* are written.
693	*
694	* @returns VBox status code.
695	* @param pBlkMap The block bitmap to save.
696	* @param pStorage Where the block bitmap should be written to.
697	* @param offBlkMap Start of the block bitmap in blocks.
698	* @param cBlkMap Size of the block bitmap on the disk in blocks.
699	*/
700	static int vciBlkMapSave(PVCIBLKMAP pBlkMap, PVCICACHE pStorage, uint64_t offBlkMap, uint32_t cBlkMap)
701	{
702	int rc = VINF_SUCCESS;
703	VciBlkMap BlkMap;
704
705	LogFlowFunc(("pBlkMap=%#p pStorage=%#p offBlkMap=%llu cBlkMap=%u\n",
706	pBlkMap, pStorage, offBlkMap, cBlkMap));
707
708	/* Make sure the number of blocks allocated for us match our expectations. */
709	if (VCI_BYTE2BLOCK(pBlkMap->cBlocks / 8) + VCI_BYTE2BLOCK(sizeof(VciBlkMap)) == cBlkMap)
710	{
711	/* Setup the header */
712	memset(&BlkMap, 0, sizeof(VciBlkMap));
713
714	BlkMap.u32Magic = RT_H2LE_U32(VCI_BLKMAP_MAGIC);
715	BlkMap.u32Version = RT_H2LE_U32(VCI_BLKMAP_VERSION);
716	BlkMap.cBlocks = RT_H2LE_U32(pBlkMap->cBlocks);
717	BlkMap.cBlocksFree = RT_H2LE_U32(pBlkMap->cBlocksFree);
718	BlkMap.cBlocksAllocMeta = RT_H2LE_U32(pBlkMap->cBlocksAllocMeta);
719	BlkMap.cBlocksAllocData = RT_H2LE_U32(pBlkMap->cBlocksAllocData);
720
721	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage, offBlkMap,
722	&BlkMap, VCI_BYTE2BLOCK(sizeof(VciBlkMap)));
723	if (RT_SUCCESS(rc))
724	{
725	uint8_t abBitmapBuffer[16*_1K];
726	unsigned iBit = 0;
727	PVCIBLKRANGEDESC pCur = pBlkMap->pRangesHead;
728
729	offBlkMap += VCI_BYTE2BLOCK(sizeof(VciBlkMap));
730
731	/* Write the descriptor ranges. */
732	while (pCur)
733	{
734	uint64_t cBlocks = pCur->cBlocks;
735
736	while (cBlocks)
737	{
738	uint64_t cBlocksMax = RT_MIN(cBlocks, sizeof(abBitmapBuffer) * 8 - iBit);
739
740	if (pCur->fFree)
741	ASMBitClearRange(abBitmapBuffer, iBit, iBit + cBlocksMax);
742	else
743	ASMBitSetRange(abBitmapBuffer, iBit, iBit + cBlocksMax);
744
745	iBit += cBlocksMax;
746	cBlocks -= cBlocksMax;
747
748	if (iBit == sizeof(abBitmapBuffer) * 8)
749	{
750	/* Buffer is full, write to file and reset. */
751	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage,
752	offBlkMap, abBitmapBuffer,
753	VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)));
754	if (RT_FAILURE(rc))
755	break;
756
757	offBlkMap += VCI_BYTE2BLOCK(sizeof(abBitmapBuffer));
758	iBit = 0;
759	}
760	}
761
762	pCur = pCur->pNext;
763	}
764
765	Assert(iBit % 8 == 0);
766
767	if (RT_SUCCESS(rc) && iBit)
768	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage,
769	offBlkMap, abBitmapBuffer, VCI_BYTE2BLOCK(iBit / 8));
770	}
771	}
772	else
773	rc = VERR_INTERNAL_ERROR; /* @todo Better error code. */
774
775	LogFlowFunc(("returns rc=%Rrc\n", rc));
776	return rc;
777	}
778
779	/**
780	* Finds the range block describing the given block address.
781	*
782	* @returns Pointer to the block range descriptor or NULL if none could be found.
783	* @param pBlkMap The block bitmap to search on.
784	* @param offBlockAddr The block address to search for.
785	*/
786	static PVCIBLKRANGEDESC vciBlkMapFindByBlock(PVCIBLKMAP pBlkMap, uint64_t offBlockAddr)
787	{
788	PVCIBLKRANGEDESC pBlk = pBlkMap->pRangesHead;
789
790	while ( pBlk
791	&& pBlk->offAddrStart < offBlockAddr)
792	pBlk = pBlk->pNext;
793
794	return pBlk;
795	}
796
797	/**
798	* Allocates the given number of blocks in the bitmap and returns the start block address.
799	*
800	* @returns VBox status code.
801	* @param pBlkMap The block bitmap to allocate the blocks from.
802	* @param cBlocks How many blocks to allocate.
803	* @param fFlags Allocation flags, comgination of VCIBLKMAP_ALLOC_*.
804	* @param poffBlockAddr Where to store the start address of the allocated region.
805	*/
806	static int vciBlkMapAllocate(PVCIBLKMAP pBlkMap, uint32_t cBlocks, uint32_t fFlags,
807	uint64_t *poffBlockAddr)
808	{
809	PVCIBLKRANGEDESC pBestFit = NULL;
810	PVCIBLKRANGEDESC pCur = NULL;
811	int rc = VINF_SUCCESS;
812
813	LogFlowFunc(("pBlkMap=%#p cBlocks=%u poffBlockAddr=%#p\n",
814	pBlkMap, cBlocks, poffBlockAddr));
815
816	pCur = pBlkMap->pRangesHead;
817
818	while (pCur)
819	{
820	if ( pCur->fFree
821	&& pCur->cBlocks >= cBlocks)
822	{
823	if ( !pBestFit
824	\|\| pCur->cBlocks < pBestFit->cBlocks)
825	{
826	pBestFit = pCur;
827	/* Stop searching if the size is matching exactly. */
828	if (pBestFit->cBlocks == cBlocks)
829	break;
830	}
831	}
832	pCur = pCur->pNext;
833	}
834
835	Assert(!pBestFit \|\| pBestFit->fFree);
836
837	if (pBestFit)
838	{
839	pBestFit->fFree = false;
840
841	if (pBestFit->cBlocks > cBlocks)
842	{
843	/* Create a new free block. */
844	PVCIBLKRANGEDESC pFree = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
845
846	if (pFree)
847	{
848	pFree->fFree = true;
849	pFree->cBlocks = pBestFit->cBlocks - cBlocks;
850	pBestFit->cBlocks -= pFree->cBlocks;
851	pFree->offAddrStart = pBestFit->offAddrStart + cBlocks;
852
853	/* Link into the list. */
854	pFree->pNext = pBestFit->pNext;
855	pBestFit->pNext = pFree;
856	pFree->pPrev = pBestFit;
857	if (!pFree->pNext)
858	pBlkMap->pRangesTail = pFree;
859
860	*poffBlockAddr = pBestFit->offAddrStart;
861	}
862	else
863	{
864	rc = VERR_NO_MEMORY;
865	pBestFit->fFree = true;
866	}
867	}
868	}
869	else
870	rc = VERR_VCI_NO_BLOCKS_FREE;
871
872	if (RT_SUCCESS(rc))
873	{
874	if ((fFlags & VCIBLKMAP_ALLOC_MASK) == VCIBLKMAP_ALLOC_DATA)
875	pBlkMap->cBlocksAllocMeta += cBlocks;
876	else
877	pBlkMap->cBlocksAllocData += cBlocks;
878
879	pBlkMap->cBlocksFree -= cBlocks;
880	}
881
882	LogFlowFunc(("returns rc=%Rrc offBlockAddr=%llu\n", rc, *poffBlockAddr));
883	return rc;
884	}
885
886	/**
887	* Try to extend the space of an already allocated block.
888	*
889	* @returns VBox status code.
890	* @param pBlkMap The block bitmap to allocate the blocks from.
891	* @param cBlocksNew How many blocks the extended block should have.
892	* @param offBlockAddrOld The start address of the block to reallocate.
893	* @param poffBlockAddr Where to store the start address of the allocated region.
894	*/
895	static int vciBlkMapRealloc(PVCIBLKMAP pBlkMap, uint32_t cBlocksNew, uint64_t offBlockAddrOld,
896	uint64_t *poffBlockAddr)
897	{
898	int rc = VINF_SUCCESS;
899
900	LogFlowFunc(("pBlkMap=%#p cBlocksNew=%u offBlockAddrOld=%llu poffBlockAddr=%#p\n",
901	pBlkMap, cBlocksNew, offBlockAddrOld, poffBlockAddr));
902
903	AssertMsgFailed(("Implement\n"));
904
905	LogFlowFunc(("returns rc=%Rrc offBlockAddr=%llu\n", rc, *poffBlockAddr));
906	return rc;
907	}
908
909	/**
910	* Frees a range of blocks.
911	*
912	* @returns nothing.
913	* @param pBlkMap The block bitmap.
914	* @param offBlockAddr Address of the first block to free.
915	* @param cBlocks How many blocks to free.
916	* @param fFlags Allocation flags, comgination of VCIBLKMAP_ALLOC_*.
917	*/
918	static void vciBlkMapFree(PVCIBLKMAP pBlkMap, uint64_t offBlockAddr, uint32_t cBlocks,
919	uint32_t fFlags)
920	{
921	PVCIBLKRANGEDESC pBlk;
922
923	LogFlowFunc(("pBlkMap=%#p offBlockAddr=%llu cBlocks=%u\n",
924	pBlkMap, offBlockAddr, cBlocks));
925
926	while (cBlocks)
927	{
928	pBlk = vciBlkMapFindByBlock(pBlkMap, offBlockAddr);
929	AssertPtr(pBlk);
930
931	/* Easy case, the whole block is freed. */
932	if ( pBlk->offAddrStart == offBlockAddr
933	&& pBlk->cBlocks <= cBlocks)
934	{
935	pBlk->fFree = true;
936	cBlocks -= pBlk->cBlocks;
937	offBlockAddr += pBlk->cBlocks;
938
939	/* Check if it is possible to merge free blocks. */
940	if ( pBlk->pPrev
941	&& pBlk->pPrev->fFree)
942	{
943	PVCIBLKRANGEDESC pBlkPrev = pBlk->pPrev;
944
945	Assert(pBlkPrev->offAddrStart + pBlkPrev->cBlocks == pBlk->offAddrStart);
946	pBlkPrev->cBlocks += pBlk->cBlocks;
947	pBlkPrev->pNext = pBlk->pNext;
948	if (pBlk->pNext)
949	pBlk->pNext->pPrev = pBlkPrev;
950	else
951	pBlkMap->pRangesTail = pBlkPrev;
952
953	RTMemFree(pBlk);
954	pBlk = pBlkPrev;
955	}
956
957	/* Now the one to the right. */
958	if ( pBlk->pNext
959	&& pBlk->pNext->fFree)
960	{
961	PVCIBLKRANGEDESC pBlkNext = pBlk->pNext;
962
963	Assert(pBlk->offAddrStart + pBlk->cBlocks == pBlkNext->offAddrStart);
964	pBlk->cBlocks += pBlkNext->cBlocks;
965	pBlk->pNext = pBlkNext->pNext;
966	if (pBlkNext->pNext)
967	pBlkNext->pNext->pPrev = pBlk;
968	else
969	pBlkMap->pRangesTail = pBlk;
970
971	RTMemFree(pBlkNext);
972	}
973	}
974	else
975	{
976	/* The block is intersecting. */
977	AssertMsgFailed(("TODO\n"));
978	}
979	}
980
981	if ((fFlags & VCIBLKMAP_ALLOC_MASK) == VCIBLKMAP_ALLOC_DATA)
982	pBlkMap->cBlocksAllocMeta -= cBlocks;
983	else
984	pBlkMap->cBlocksAllocData -= cBlocks;
985
986	pBlkMap->cBlocksFree += cBlocks;
987
988	LogFlowFunc(("returns\n"));
989	}
990
991	/**
992	* Converts a tree node from the image to the in memory structure.
993	*
994	* @returns Pointer to the in memory tree node.
995	* @param offBlockAddrNode Block address of the node.
996	* @param pNodeImage Pointer to the image representation of the node.
997	*/
998	static PVCITREENODE vciTreeNodeImage2Host(uint64_t offBlockAddrNode, PVciTreeNode pNodeImage)
999	{
1000	PVCITREENODE pNode = NULL;
1001
1002	if (pNodeImage->u8Type == VCI_TREE_NODE_TYPE_LEAF)
1003	{
1004	PVCITREENODELEAF pLeaf = (PVCITREENODELEAF)RTMemAllocZ(sizeof(VCITREENODELEAF));
1005
1006	if (pLeaf)
1007	{
1008	PVciCacheExtent pExtent = (PVciCacheExtent)&pNodeImage->au8Data[0];
1009
1010	pLeaf->Core.u8Type = VCI_TREE_NODE_TYPE_LEAF;
1011
1012	for (unsigned idx = 0; idx < RT_ELEMENTS(pLeaf->aExtents); idx++)
1013	{
1014	pLeaf->aExtents[idx].u64BlockOffset = RT_LE2H_U64(pExtent->u64BlockOffset);
1015	pLeaf->aExtents[idx].u32Blocks = RT_LE2H_U32(pExtent->u32Blocks);
1016	pLeaf->aExtents[idx].u64BlockAddr = RT_LE2H_U64(pExtent->u64BlockAddr);
1017	pExtent++;
1018
1019	if ( pLeaf->aExtents[idx].u32Blocks
1020	&& pLeaf->aExtents[idx].u64BlockAddr)
1021	pLeaf->cUsedNodes++;
1022	}
1023
1024	pNode = &pLeaf->Core;
1025	}
1026	}
1027	else if (pNodeImage->u8Type == VCI_TREE_NODE_TYPE_INTERNAL)
1028	{
1029	PVCITREENODEINT pInt = (PVCITREENODEINT)RTMemAllocZ(sizeof(VCITREENODEINT));
1030
1031	if (pInt)
1032	{
1033	PVciTreeNodeInternal pIntImage = (PVciTreeNodeInternal)&pNodeImage->au8Data[0];
1034
1035	pInt->Core.u8Type = VCI_TREE_NODE_TYPE_INTERNAL;
1036
1037	for (unsigned idx = 0; idx < RT_ELEMENTS(pInt->aIntNodes); idx++)
1038	{
1039	pInt->aIntNodes[idx].u64BlockOffset = RT_LE2H_U64(pIntImage->u64BlockOffset);
1040	pInt->aIntNodes[idx].u32Blocks = RT_LE2H_U32(pIntImage->u32Blocks);
1041	pInt->aIntNodes[idx].PtrChild.fInMemory = false;
1042	pInt->aIntNodes[idx].PtrChild.u.offAddrBlockNode = RT_LE2H_U64(pIntImage->u64ChildAddr);
1043	pIntImage++;
1044
1045	if ( pInt->aIntNodes[idx].u32Blocks
1046	&& pInt->aIntNodes[idx].PtrChild.u.offAddrBlockNode)
1047	pInt->cUsedNodes++;
1048	}
1049
1050	pNode = &pInt->Core;
1051	}
1052	}
1053	else
1054	AssertMsgFailed(("Invalid node type %d\n", pNodeImage->u8Type));
1055
1056	if (pNode)
1057	pNode->u64BlockAddr = offBlockAddrNode;
1058
1059	return pNode;
1060	}
1061
1062	/**
1063	* Looks up the cache extent for the given virtual block address.
1064	*
1065	* @returns Pointer to the cache extent or NULL if none could be found.
1066	* @param pCache The cache image instance.
1067	* @param offBlockOffset The block offset to search for.
1068	* @param ppNextBestFit Where to store the pointer to the next best fit
1069	* cache extent above offBlockOffset if existing. - Optional
1070	* This is always filled if possible even if the function returns NULL.
1071	*/
1072	static PVCICACHEEXTENT vciCacheExtentLookup(PVCICACHE pCache, uint64_t offBlockOffset,
1073	PVCICACHEEXTENT *ppNextBestFit)
1074	{
1075	int rc = VINF_SUCCESS;
1076	PVCICACHEEXTENT pExtent = NULL;
1077	PVCITREENODE pNodeCur = pCache->pRoot;
1078
1079	while ( RT_SUCCESS(rc)
1080	&& pNodeCur
1081	&& pNodeCur->u8Type != VCI_TREE_NODE_TYPE_LEAF)
1082	{
1083	PVCITREENODEINT pNodeInt = (PVCITREENODEINT)pNodeCur;
1084
1085	Assert(pNodeCur->u8Type == VCI_TREE_NODE_TYPE_INTERNAL);
1086
1087	/* Search for the correct internal node. */
1088	unsigned idxMin = 0;
1089	unsigned idxMax = pNodeInt->cUsedNodes;
1090	unsigned idxCur = pNodeInt->cUsedNodes / 2;
1091
1092	while (idxMin < idxMax)
1093	{
1094	PVCINODEINTERNAL pInt = &pNodeInt->aIntNodes[idxCur];
1095
1096	/* Determine the search direction. */
1097	if (offBlockOffset < pInt->u64BlockOffset)
1098	{
1099	/* Search left from the current extent. */
1100	idxMax = idxCur;
1101	}
1102	else if (offBlockOffset >= pInt->u64BlockOffset + pInt->u32Blocks)
1103	{
1104	/* Search right from the current extent. */
1105	idxMin = idxCur;
1106	}
1107	else
1108	{
1109	/* The block lies in the node, stop searching. */
1110	if (pInt->PtrChild.fInMemory)
1111	pNodeCur = pInt->PtrChild.u.pNode;
1112	else
1113	{
1114	PVCITREENODE pNodeNew;
1115	VciTreeNode NodeTree;
1116
1117	/* Read from disk and add to the tree. */
1118	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage,
1119	VCI_BLOCK2BYTE(pInt->PtrChild.u.offAddrBlockNode),
1120	&NodeTree, sizeof(NodeTree));
1121	AssertRC(rc);
1122
1123	pNodeNew = vciTreeNodeImage2Host(pInt->PtrChild.u.offAddrBlockNode, &NodeTree);
1124	if (pNodeNew)
1125	{
1126	/* Link to the parent. */
1127	pInt->PtrChild.fInMemory = true;
1128	pInt->PtrChild.u.pNode = pNodeNew;
1129	pNodeNew->pParent = pNodeCur;
1130	pNodeCur = pNodeNew;
1131	}
1132	else
1133	rc = VERR_NO_MEMORY;
1134	}
1135	break;
1136	}
1137
1138	idxCur = idxMin + (idxMax - idxMin) / 2;
1139	}
1140	}
1141
1142	if ( RT_SUCCESS(rc)
1143	&& pNodeCur)
1144	{
1145	PVCITREENODELEAF pLeaf = (PVCITREENODELEAF)pNodeCur;
1146	Assert(pNodeCur->u8Type == VCI_TREE_NODE_TYPE_LEAF);
1147
1148	/* Search the range. */
1149	unsigned idxMin = 0;
1150	unsigned idxMax = pLeaf->cUsedNodes;
1151	unsigned idxCur = pLeaf->cUsedNodes / 2;
1152
1153	while (idxMin < idxMax)
1154	{
1155	PVCICACHEEXTENT pExtentCur = &pLeaf->aExtents[idxCur];
1156
1157	/* Determine the search direction. */
1158	if (offBlockOffset < pExtentCur->u64BlockOffset)
1159	{
1160	/* Search left from the current extent. */
1161	idxMax = idxCur;
1162	}
1163	else if (offBlockOffset >= pExtentCur->u64BlockOffset + pExtentCur->u32Blocks)
1164	{
1165	/* Search right from the current extent. */
1166	idxMin = idxCur;
1167	}
1168	else
1169	{
1170	/* We found the extent, stop searching. */
1171	pExtent = pExtentCur;
1172	break;
1173	}
1174
1175	idxCur = idxMin + (idxMax - idxMin) / 2;
1176	}
1177
1178	/* Get the next best fit extent if it exists. */
1179	if (ppNextBestFit)
1180	{
1181	if (idxCur < pLeaf->cUsedNodes - 1)
1182	*ppNextBestFit = &pLeaf->aExtents[idxCur + 1];
1183	else
1184	{
1185	/*
1186	* Go up the tree and find the best extent
1187	* in the leftmost tree of the child subtree to the right.
1188	*/
1189	PVCITREENODEINT pInt = (PVCITREENODEINT)pLeaf->Core.pParent;
1190
1191	while (pInt)
1192	{
1193
1194	}
1195	}
1196	}
1197	}
1198
1199	return pExtent;
1200	}
1201
1202	/**
1203	* Internal: Open an image, constructing all necessary data structures.
1204	*/
1205	static int vciOpenImage(PVCICACHE pCache, unsigned uOpenFlags)
1206	{
1207	VciHdr Hdr;
1208	uint64_t cbFile;
1209	int rc;
1210
1211	pCache->uOpenFlags = uOpenFlags;
1212
1213	pCache->pIfError = VDIfErrorGet(pCache->pVDIfsDisk);
1214	pCache->pIfIo = VDIfIoIntGet(pCache->pVDIfsImage);
1215	AssertPtrReturn(pCache->pIfIo, VERR_INVALID_PARAMETER);
1216
1217	/*
1218	* Open the image.
1219	*/
1220	rc = vdIfIoIntFileOpen(pCache->pIfIo, pCache->pszFilename,
1221	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1222	false /* fCreate */),
1223	&pCache->pStorage);
1224	if (RT_FAILURE(rc))
1225	{
1226	/* Do NOT signal an appropriate error here, as the VD layer has the
1227	* choice of retrying the open if it failed. */
1228	goto out;
1229	}
1230
1231	rc = vdIfIoIntFileGetSize(pCache->pIfIo, pCache->pStorage, &cbFile);
1232	if (RT_FAILURE(rc) \|\| cbFile < sizeof(VciHdr))
1233	{
1234	rc = VERR_VD_GEN_INVALID_HEADER;
1235	goto out;
1236	}
1237
1238	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage, 0, &Hdr,
1239	VCI_BYTE2BLOCK(sizeof(Hdr)));
1240	if (RT_FAILURE(rc))
1241	{
1242	rc = VERR_VD_GEN_INVALID_HEADER;
1243	goto out;
1244	}
1245
1246	Hdr.u32Signature = RT_LE2H_U32(Hdr.u32Signature);
1247	Hdr.u32Version = RT_LE2H_U32(Hdr.u32Version);
1248	Hdr.cBlocksCache = RT_LE2H_U64(Hdr.cBlocksCache);
1249	Hdr.u32CacheType = RT_LE2H_U32(Hdr.u32CacheType);
1250	Hdr.offTreeRoot = RT_LE2H_U64(Hdr.offTreeRoot);
1251	Hdr.offBlkMap = RT_LE2H_U64(Hdr.offBlkMap);
1252	Hdr.cBlkMap = RT_LE2H_U32(Hdr.cBlkMap);
1253
1254	if ( Hdr.u32Signature == VCI_HDR_SIGNATURE
1255	&& Hdr.u32Version == VCI_HDR_VERSION)
1256	{
1257	pCache->offTreeRoot = Hdr.offTreeRoot;
1258	pCache->offBlksBitmap = Hdr.offBlkMap;
1259
1260	/* Load the block map. */
1261	rc = vciBlkMapLoad(pCache, pCache->offBlksBitmap, Hdr.cBlkMap, &pCache->pBlkMap);
1262	if (RT_SUCCESS(rc))
1263	{
1264	/* Load the first tree node. */
1265	VciTreeNode RootNode;
1266
1267	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage,
1268	pCache->offTreeRoot, &RootNode,
1269	VCI_BYTE2BLOCK(sizeof(VciTreeNode)));
1270	if (RT_SUCCESS(rc))
1271	{
1272	pCache->pRoot = vciTreeNodeImage2Host(pCache->offTreeRoot, &RootNode);
1273	if (!pCache->pRoot)
1274	rc = VERR_NO_MEMORY;
1275	}
1276	}
1277	}
1278	else
1279	rc = VERR_VD_GEN_INVALID_HEADER;
1280
1281	out:
1282	if (RT_FAILURE(rc))
1283	vciFreeImage(pCache, false);
1284	return rc;
1285	}
1286
1287	/**
1288	* Internal: Create a vci image.
1289	*/
1290	static int vciCreateImage(PVCICACHE pCache, uint64_t cbSize,
1291	unsigned uImageFlags, const char *pszComment,
1292	unsigned uOpenFlags, PFNVDPROGRESS pfnProgress,
1293	void *pvUser, unsigned uPercentStart,
1294	unsigned uPercentSpan)
1295	{
1296	VciHdr Hdr;
1297	VciTreeNode NodeRoot;
1298	int rc;
1299	uint64_t cBlocks = cbSize / VCI_BLOCK_SIZE; /* Size of the cache in blocks. */
1300
1301	pCache->uImageFlags = uImageFlags;
1302	pCache->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1303
1304	pCache->pIfError = VDIfErrorGet(pCache->pVDIfsDisk);
1305	pCache->pIfIo = VDIfIoIntGet(pCache->pVDIfsImage);
1306	AssertPtrReturn(pCache->pIfIo, VERR_INVALID_PARAMETER);
1307
1308	if (uImageFlags & VD_IMAGE_FLAGS_DIFF)
1309	{
1310	rc = vdIfError(pCache->pIfError, VERR_VD_RAW_INVALID_TYPE, RT_SRC_POS, N_("VCI: cannot create diff image '%s'"), pCache->pszFilename);
1311	return rc;
1312	}
1313
1314	do
1315	{
1316	/* Create image file. */
1317	rc = vdIfIoIntFileOpen(pCache->pIfIo, pCache->pszFilename,
1318	VDOpenFlagsToFileOpenFlags(uOpenFlags & ~VD_OPEN_FLAGS_READONLY,
1319	true /* fCreate */),
1320	&pCache->pStorage);
1321	if (RT_FAILURE(rc))
1322	{
1323	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot create image '%s'"), pCache->pszFilename);
1324	break;
1325	}
1326
1327	/* Allocate block bitmap. */
1328	uint32_t cBlkMap = 0;
1329	rc = vciBlkMapCreate(cBlocks, &pCache->pBlkMap, &cBlkMap);
1330	if (RT_FAILURE(rc))
1331	{
1332	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot create block bitmap '%s'"), pCache->pszFilename);
1333	break;
1334	}
1335
1336	/*
1337	* Allocate space for the header in the block bitmap.
1338	* Because the block map is empty the header has to start at block 0
1339	*/
1340	uint64_t offHdr = 0;
1341	rc = vciBlkMapAllocate(pCache->pBlkMap, VCI_BYTE2BLOCK(sizeof(VciHdr)), VCIBLKMAP_ALLOC_META, &offHdr);
1342	if (RT_FAILURE(rc))
1343	{
1344	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for header in block bitmap '%s'"), pCache->pszFilename);
1345	break;
1346	}
1347
1348	Assert(offHdr == 0);
1349
1350	/*
1351	* Allocate space for the block map itself.
1352	*/
1353	uint64_t offBlkMap = 0;
1354	rc = vciBlkMapAllocate(pCache->pBlkMap, cBlkMap, VCIBLKMAP_ALLOC_META, &offBlkMap);
1355	if (RT_FAILURE(rc))
1356	{
1357	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for block map in block map '%s'"), pCache->pszFilename);
1358	break;
1359	}
1360
1361	/*
1362	* Allocate space for the tree root node.
1363	*/
1364	uint64_t offTreeRoot = 0;
1365	rc = vciBlkMapAllocate(pCache->pBlkMap, VCI_BYTE2BLOCK(sizeof(VciTreeNode)), VCIBLKMAP_ALLOC_META, &offTreeRoot);
1366	if (RT_FAILURE(rc))
1367	{
1368	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for block map in block map '%s'"), pCache->pszFilename);
1369	break;
1370	}
1371
1372	/*
1373	* Allocate the in memory root node.
1374	*/
1375	pCache->pRoot = (PVCITREENODE)RTMemAllocZ(sizeof(VCITREENODELEAF));
1376	if (!pCache->pRoot)
1377	{
1378	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate B+-Tree root pointer '%s'"), pCache->pszFilename);
1379	break;
1380	}
1381
1382	pCache->pRoot->u8Type = VCI_TREE_NODE_TYPE_LEAF;
1383	/* Rest remains 0 as the tree is still empty. */
1384
1385	/*
1386	* Now that we are here we have all the basic structures and know where to place them in the image.
1387	* It's time to write it now.
1388	*/
1389
1390	/* Setup the header. */
1391	memset(&Hdr, 0, sizeof(VciHdr));
1392	Hdr.u32Signature = RT_H2LE_U32(VCI_HDR_SIGNATURE);
1393	Hdr.u32Version = RT_H2LE_U32(VCI_HDR_VERSION);
1394	Hdr.cBlocksCache = RT_H2LE_U64(cBlocks);
1395	Hdr.fUncleanShutdown = VCI_HDR_UNCLEAN_SHUTDOWN;
1396	Hdr.u32CacheType = uImageFlags & VD_IMAGE_FLAGS_FIXED
1397	? RT_H2LE_U32(VCI_HDR_CACHE_TYPE_FIXED)
1398	: RT_H2LE_U32(VCI_HDR_CACHE_TYPE_DYNAMIC);
1399	Hdr.offTreeRoot = RT_H2LE_U64(offTreeRoot);
1400	Hdr.offBlkMap = RT_H2LE_U64(offBlkMap);
1401	Hdr.cBlkMap = RT_H2LE_U32(cBlkMap);
1402
1403	rc = vdIfIoIntFileWriteSync(pCache->pIfIo, pCache->pStorage, offHdr, &Hdr,
1404	VCI_BYTE2BLOCK(sizeof(VciHdr)));
1405	if (RT_FAILURE(rc))
1406	{
1407	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write header '%s'"), pCache->pszFilename);
1408	break;
1409	}
1410
1411	rc = vciBlkMapSave(pCache->pBlkMap, pCache, offBlkMap, cBlkMap);
1412	if (RT_FAILURE(rc))
1413	{
1414	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write block map '%s'"), pCache->pszFilename);
1415	break;
1416	}
1417
1418	/* Setup the root tree. */
1419	memset(&NodeRoot, 0, sizeof(VciTreeNode));
1420	NodeRoot.u8Type = RT_H2LE_U32(VCI_TREE_NODE_TYPE_LEAF);
1421
1422	rc = vdIfIoIntFileWriteSync(pCache->pIfIo, pCache->pStorage, offTreeRoot,
1423	&NodeRoot, VCI_BYTE2BLOCK(sizeof(VciTreeNode)));
1424	if (RT_FAILURE(rc))
1425	{
1426	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write root node '%s'"), pCache->pszFilename);
1427	break;
1428	}
1429
1430	rc = vciFlushImage(pCache);
1431	if (RT_FAILURE(rc))
1432	{
1433	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot flush '%s'"), pCache->pszFilename);
1434	break;
1435	}
1436
1437	pCache->cbSize = cbSize;
1438
1439	} while (0);
1440
1441	if (RT_SUCCESS(rc) && pfnProgress)
1442	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1443
1444	if (RT_FAILURE(rc))
1445	vciFreeImage(pCache, rc != VERR_ALREADY_EXISTS);
1446	return rc;
1447	}
1448
1449	/** @copydoc VDCACHEBACKEND::pfnProbe */
1450	static DECLCALLBACK(int) vciProbe(const char *pszFilename, PVDINTERFACE pVDIfsCache,
1451	PVDINTERFACE pVDIfsImage)
1452	{
1453	VciHdr Hdr;
1454	PVDIOSTORAGE pStorage = NULL;
1455	uint64_t cbFile;
1456	int rc = VINF_SUCCESS;
1457
1458	LogFlowFunc(("pszFilename=\"%s\"\n", pszFilename));
1459
1460	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1461	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1462
1463	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1464	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1465	false /* fCreate */),
1466	&pStorage);
1467	if (RT_FAILURE(rc))
1468	goto out;
1469
1470	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1471	if (RT_FAILURE(rc) \|\| cbFile < sizeof(VciHdr))
1472	{
1473	rc = VERR_VD_GEN_INVALID_HEADER;
1474	goto out;
1475	}
1476
1477	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Hdr, sizeof(Hdr));
1478	if (RT_FAILURE(rc))
1479	{
1480	rc = VERR_VD_GEN_INVALID_HEADER;
1481	goto out;
1482	}
1483
1484	Hdr.u32Signature = RT_LE2H_U32(Hdr.u32Signature);
1485	Hdr.u32Version = RT_LE2H_U32(Hdr.u32Version);
1486	Hdr.cBlocksCache = RT_LE2H_U64(Hdr.cBlocksCache);
1487	Hdr.u32CacheType = RT_LE2H_U32(Hdr.u32CacheType);
1488	Hdr.offTreeRoot = RT_LE2H_U64(Hdr.offTreeRoot);
1489	Hdr.offBlkMap = RT_LE2H_U64(Hdr.offBlkMap);
1490	Hdr.cBlkMap = RT_LE2H_U32(Hdr.cBlkMap);
1491
1492	if ( Hdr.u32Signature == VCI_HDR_SIGNATURE
1493	&& Hdr.u32Version == VCI_HDR_VERSION)
1494	rc = VINF_SUCCESS;
1495	else
1496	rc = VERR_VD_GEN_INVALID_HEADER;
1497
1498	out:
1499	if (pStorage)
1500	vdIfIoIntFileClose(pIfIo, pStorage);
1501
1502	LogFlowFunc(("returns %Rrc\n", rc));
1503	return rc;
1504	}
1505
1506	/** @copydoc VDCACHEBACKEND::pfnOpen */
1507	static DECLCALLBACK(int) vciOpen(const char *pszFilename, unsigned uOpenFlags,
1508	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1509	void **ppBackendData)
1510	{
1511	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, ppBackendData));
1512	int rc;
1513	PVCICACHE pCache;
1514
1515	/* Check open flags. All valid flags are supported. */
1516	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1517	{
1518	rc = VERR_INVALID_PARAMETER;
1519	goto out;
1520	}
1521
1522	/* Check remaining arguments. */
1523	if ( !VALID_PTR(pszFilename)
1524	\|\| !*pszFilename)
1525	{
1526	rc = VERR_INVALID_PARAMETER;
1527	goto out;
1528	}
1529
1530
1531	pCache = (PVCICACHE)RTMemAllocZ(sizeof(VCICACHE));
1532	if (!pCache)
1533	{
1534	rc = VERR_NO_MEMORY;
1535	goto out;
1536	}
1537	pCache->pszFilename = pszFilename;
1538	pCache->pStorage = NULL;
1539	pCache->pVDIfsDisk = pVDIfsDisk;
1540	pCache->pVDIfsImage = pVDIfsImage;
1541
1542	rc = vciOpenImage(pCache, uOpenFlags);
1543	if (RT_SUCCESS(rc))
1544	*ppBackendData = pCache;
1545	else
1546	RTMemFree(pCache);
1547
1548	out:
1549	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1550	return rc;
1551	}
1552
1553	/** @copydoc VDCACHEBACKEND::pfnCreate */
1554	static DECLCALLBACK(int) vciCreate(const char *pszFilename, uint64_t cbSize,
1555	unsigned uImageFlags, const char *pszComment,
1556	PCRTUUID pUuid, unsigned uOpenFlags,
1557	unsigned uPercentStart, unsigned uPercentSpan,
1558	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1559	PVDINTERFACE pVDIfsOperation, void **ppBackendData)
1560	{
1561	LogFlowFunc(("pszFilename=\"%s\" cbSize=%llu uImageFlags=%#x pszComment=\"%s\" Uuid=%RTuuid uOpenFlags=%#x uPercentStart=%u uPercentSpan=%u pVDIfsDisk=%#p pVDIfsImage=%#p pVDIfsOperation=%#p ppBackendData=%#p",
1562	pszFilename, cbSize, uImageFlags, pszComment, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, ppBackendData));
1563	int rc;
1564	PVCICACHE pCache;
1565
1566	PFNVDPROGRESS pfnProgress = NULL;
1567	void *pvUser = NULL;
1568	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1569	if (pIfProgress)
1570	{
1571	pfnProgress = pIfProgress->pfnProgress;
1572	pvUser = pIfProgress->Core.pvUser;
1573	}
1574
1575	/* Check open flags. All valid flags are supported. */
1576	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1577	{
1578	rc = VERR_INVALID_PARAMETER;
1579	goto out;
1580	}
1581
1582	/* Check remaining arguments. */
1583	if ( !VALID_PTR(pszFilename)
1584	\|\| !*pszFilename)
1585	{
1586	rc = VERR_INVALID_PARAMETER;
1587	goto out;
1588	}
1589
1590	pCache = (PVCICACHE)RTMemAllocZ(sizeof(VCICACHE));
1591	if (!pCache)
1592	{
1593	rc = VERR_NO_MEMORY;
1594	goto out;
1595	}
1596	pCache->pszFilename = pszFilename;
1597	pCache->pStorage = NULL;
1598	pCache->pVDIfsDisk = pVDIfsDisk;
1599	pCache->pVDIfsImage = pVDIfsImage;
1600
1601	rc = vciCreateImage(pCache, cbSize, uImageFlags, pszComment, 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	vciFreeImage(pCache, false);
1610	rc = vciOpenImage(pCache, uOpenFlags);
1611	if (RT_FAILURE(rc))
1612	{
1613	RTMemFree(pCache);
1614	goto out;
1615	}
1616	}
1617	*ppBackendData = pCache;
1618	}
1619	else
1620	RTMemFree(pCache);
1621
1622	out:
1623	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1624	return rc;
1625	}
1626
1627	/** @copydoc VDCACHEBACKEND::pfnClose */
1628	static DECLCALLBACK(int) vciClose(void *pBackendData, bool fDelete)
1629	{
1630	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1631	PVCICACHE pCache = (PVCICACHE)pBackendData;
1632	int rc;
1633
1634	rc = vciFreeImage(pCache, fDelete);
1635	RTMemFree(pCache);
1636
1637	LogFlowFunc(("returns %Rrc\n", rc));
1638	return rc;
1639	}
1640
1641	/** @copydoc VDCACHEBACKEND::pfnRead */
1642	static DECLCALLBACK(int) vciRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1643	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1644	{
1645	LogFlowFunc(("pBackendData=%#p uOffset=%llu cbToRead=%zu pIoCtx=%#p pcbActuallyRead=%#p\n",
1646	pBackendData, uOffset, cbToRead, pIoCtx, pcbActuallyRead));
1647	PVCICACHE pCache = (PVCICACHE)pBackendData;
1648	int rc = VINF_SUCCESS;
1649	PVCICACHEEXTENT pExtent;
1650	uint64_t cBlocksToRead = VCI_BYTE2BLOCK(cbToRead);
1651	uint64_t offBlockAddr = VCI_BYTE2BLOCK(uOffset);
1652
1653	AssertPtr(pCache);
1654	Assert(uOffset % 512 == 0);
1655	Assert(cbToRead % 512 == 0);
1656
1657	pExtent = vciCacheExtentLookup(pCache, offBlockAddr, NULL);
1658	if (pExtent)
1659	{
1660	uint64_t offRead = offBlockAddr - pExtent->u64BlockOffset;
1661	cBlocksToRead = RT_MIN(cBlocksToRead, pExtent->u32Blocks - offRead);
1662
1663	rc = vdIfIoIntFileReadUser(pCache->pIfIo, pCache->pStorage,
1664	pExtent->u64BlockAddr + offRead,
1665	pIoCtx, cBlocksToRead);
1666	}
1667	else
1668	{
1669	/** @todo Best fit to check whether we have cached data later and set
1670	* pcbActuallyRead accordingly. */
1671	rc = VERR_VD_BLOCK_FREE;
1672	}
1673
1674	if (pcbActuallyRead)
1675	*pcbActuallyRead = VCI_BLOCK2BYTE(cBlocksToRead);
1676
1677	LogFlowFunc(("returns %Rrc\n", rc));
1678	return rc;
1679	}
1680
1681	/** @copydoc VDCACHEBACKEND::pfnWrite */
1682	static DECLCALLBACK(int) vciWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1683	PVDIOCTX pIoCtx, size_t *pcbWriteProcess)
1684	{
1685	LogFlowFunc(("pBackendData=%#p uOffset=%llu cbToWrite=%zu pIoCtx=%#p pcbWriteProcess=%#p\n",
1686	pBackendData, uOffset, cbToWrite, pIoCtx, pcbWriteProcess));
1687	PVCICACHE pCache = (PVCICACHE)pBackendData;
1688	int rc = VINF_SUCCESS;
1689	uint64_t cBlocksToWrite = VCI_BYTE2BLOCK(cbToWrite);
1690	uint64_t offBlockAddr = VCI_BYTE2BLOCK(uOffset);
1691
1692	AssertPtr(pCache);
1693	Assert(uOffset % 512 == 0);
1694	Assert(cbToWrite % 512 == 0);
1695
1696	while (cBlocksToWrite)
1697	{
1698
1699	}
1700
1701	pcbWriteProcess = cbToWrite; /* @todo: Implement. */
1702
1703	LogFlowFunc(("returns %Rrc\n", rc));
1704	return rc;
1705	}
1706
1707	/** @copydoc VDCACHEBACKEND::pfnFlush */
1708	static DECLCALLBACK(int) vciFlush(void *pBackendData, PVDIOCTX pIoCtx)
1709	{
1710	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1711	PVCICACHE pCache = (PVCICACHE)pBackendData;
1712	int rc = VINF_SUCCESS;
1713
1714	rc = vciFlushImage(pCache);
1715	LogFlowFunc(("returns %Rrc\n", rc));
1716	return rc;
1717	}
1718
1719	/** @copydoc VDCACHEBACKEND::pfnGetVersion */
1720	static DECLCALLBACK(unsigned) vciGetVersion(void *pBackendData)
1721	{
1722	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1723	PVCICACHE pCache = (PVCICACHE)pBackendData;
1724
1725	AssertPtr(pCache);
1726
1727	if (pCache)
1728	return 1;
1729	else
1730	return 0;
1731	}
1732
1733	/** @copydoc VDCACHEBACKEND::pfnGetSize */
1734	static DECLCALLBACK(uint64_t) vciGetSize(void *pBackendData)
1735	{
1736	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1737	PVCICACHE pCache = (PVCICACHE)pBackendData;
1738	uint64_t cb = 0;
1739
1740	AssertPtr(pCache);
1741
1742	if (pCache && pCache->pStorage)
1743	cb = pCache->cbSize;
1744
1745	LogFlowFunc(("returns %llu\n", cb));
1746	return cb;
1747	}
1748
1749	/** @copydoc VDCACHEBACKEND::pfnGetFileSize */
1750	static DECLCALLBACK(uint64_t) vciGetFileSize(void *pBackendData)
1751	{
1752	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1753	PVCICACHE pCache = (PVCICACHE)pBackendData;
1754	uint64_t cb = 0;
1755
1756	AssertPtr(pCache);
1757
1758	if (pCache)
1759	{
1760	uint64_t cbFile;
1761	if (pCache->pStorage)
1762	{
1763	int rc = vdIfIoIntFileGetSize(pCache->pIfIo, pCache->pStorage, &cbFile);
1764	if (RT_SUCCESS(rc))
1765	cb = cbFile;
1766	}
1767	}
1768
1769	LogFlowFunc(("returns %lld\n", cb));
1770	return cb;
1771	}
1772
1773	/** @copydoc VDCACHEBACKEND::pfnGetImageFlags */
1774	static DECLCALLBACK(unsigned) vciGetImageFlags(void *pBackendData)
1775	{
1776	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1777	PVCICACHE pCache = (PVCICACHE)pBackendData;
1778	unsigned uImageFlags;
1779
1780	AssertPtr(pCache);
1781
1782	if (pCache)
1783	uImageFlags = pCache->uImageFlags;
1784	else
1785	uImageFlags = 0;
1786
1787	LogFlowFunc(("returns %#x\n", uImageFlags));
1788	return uImageFlags;
1789	}
1790
1791	/** @copydoc VDCACHEBACKEND::pfnGetOpenFlags */
1792	static DECLCALLBACK(unsigned) vciGetOpenFlags(void *pBackendData)
1793	{
1794	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1795	PVCICACHE pCache = (PVCICACHE)pBackendData;
1796	unsigned uOpenFlags;
1797
1798	AssertPtr(pCache);
1799
1800	if (pCache)
1801	uOpenFlags = pCache->uOpenFlags;
1802	else
1803	uOpenFlags = 0;
1804
1805	LogFlowFunc(("returns %#x\n", uOpenFlags));
1806	return uOpenFlags;
1807	}
1808
1809	/** @copydoc VDCACHEBACKEND::pfnSetOpenFlags */
1810	static DECLCALLBACK(int) vciSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
1811	{
1812	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
1813	PVCICACHE pCache = (PVCICACHE)pBackendData;
1814	int rc;
1815
1816	/* Image must be opened and the new flags must be valid. Just readonly and
1817	* info flags are supported. */
1818	if (!pCache \|\| (uOpenFlags & ~(VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO)))
1819	{
1820	rc = VERR_INVALID_PARAMETER;
1821	goto out;
1822	}
1823
1824	/* Implement this operation via reopening the image. */
1825	rc = vciFreeImage(pCache, false);
1826	if (RT_FAILURE(rc))
1827	goto out;
1828	rc = vciOpenImage(pCache, uOpenFlags);
1829
1830	out:
1831	LogFlowFunc(("returns %Rrc\n", rc));
1832	return rc;
1833	}
1834
1835	/** @copydoc VDCACHEBACKEND::pfnGetComment */
1836	static DECLCALLBACK(int) vciGetComment(void pBackendData, char pszComment,
1837	size_t cbComment)
1838	{
1839	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
1840	PVCICACHE pCache = (PVCICACHE)pBackendData;
1841	int rc;
1842
1843	AssertPtr(pCache);
1844
1845	if (pCache)
1846	rc = VERR_NOT_SUPPORTED;
1847	else
1848	rc = VERR_VD_NOT_OPENED;
1849
1850	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
1851	return rc;
1852	}
1853
1854	/** @copydoc VDCACHEBACKEND::pfnSetComment */
1855	static DECLCALLBACK(int) vciSetComment(void pBackendData, const char pszComment)
1856	{
1857	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
1858	PVCICACHE pCache = (PVCICACHE)pBackendData;
1859	int rc;
1860
1861	AssertPtr(pCache);
1862
1863	if (pCache)
1864	{
1865	if (pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1866	rc = VERR_VD_IMAGE_READ_ONLY;
1867	else
1868	rc = VERR_NOT_SUPPORTED;
1869	}
1870	else
1871	rc = VERR_VD_NOT_OPENED;
1872
1873	LogFlowFunc(("returns %Rrc\n", rc));
1874	return rc;
1875	}
1876
1877	/** @copydoc VDCACHEBACKEND::pfnGetUuid */
1878	static DECLCALLBACK(int) vciGetUuid(void *pBackendData, PRTUUID pUuid)
1879	{
1880	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
1881	PVCICACHE pCache = (PVCICACHE)pBackendData;
1882	int rc;
1883
1884	AssertPtr(pCache);
1885
1886	if (pCache)
1887	rc = VERR_NOT_SUPPORTED;
1888	else
1889	rc = VERR_VD_NOT_OPENED;
1890
1891	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
1892	return rc;
1893	}
1894
1895	/** @copydoc VDCACHEBACKEND::pfnSetUuid */
1896	static DECLCALLBACK(int) vciSetUuid(void *pBackendData, PCRTUUID pUuid)
1897	{
1898	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
1899	PVCICACHE pCache = (PVCICACHE)pBackendData;
1900	int rc;
1901
1902	LogFlowFunc(("%RTuuid\n", pUuid));
1903	AssertPtr(pCache);
1904
1905	if (pCache)
1906	{
1907	if (!(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1908	rc = VERR_NOT_SUPPORTED;
1909	else
1910	rc = VERR_VD_IMAGE_READ_ONLY;
1911	}
1912	else
1913	rc = VERR_VD_NOT_OPENED;
1914
1915	LogFlowFunc(("returns %Rrc\n", rc));
1916	return rc;
1917	}
1918
1919	/** @copydoc VDCACHEBACKEND::pfnGetModificationUuid */
1920	static DECLCALLBACK(int) vciGetModificationUuid(void *pBackendData, PRTUUID pUuid)
1921	{
1922	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
1923	PVCICACHE pCache = (PVCICACHE)pBackendData;
1924	int rc;
1925
1926	AssertPtr(pCache);
1927
1928	if (pCache)
1929	rc = VERR_NOT_SUPPORTED;
1930	else
1931	rc = VERR_VD_NOT_OPENED;
1932
1933	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
1934	return rc;
1935	}
1936
1937	/** @copydoc VDCACHEBACKEND::pfnSetModificationUuid */
1938	static DECLCALLBACK(int) vciSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
1939	{
1940	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
1941	PVCICACHE pCache = (PVCICACHE)pBackendData;
1942	int rc;
1943
1944	AssertPtr(pCache);
1945
1946	if (pCache)
1947	{
1948	if (!(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1949	rc = VERR_NOT_SUPPORTED;
1950	else
1951	rc = VERR_VD_IMAGE_READ_ONLY;
1952	}
1953	else
1954	rc = VERR_VD_NOT_OPENED;
1955
1956	LogFlowFunc(("returns %Rrc\n", rc));
1957	return rc;
1958	}
1959
1960	/** @copydoc VDCACHEBACKEND::pfnDump */
1961	static DECLCALLBACK(void) vciDump(void *pBackendData)
1962	{
1963	NOREF(pBackendData);
1964	}
1965
1966
1967	const VDCACHEBACKEND g_VciCacheBackend =
1968	{
1969	/* pszBackendName */
1970	"vci",
1971	/* cbSize */
1972	sizeof(VDCACHEBACKEND),
1973	/* uBackendCaps */
1974	VD_CAP_CREATE_FIXED \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_FILE \| VD_CAP_VFS,
1975	/* papszFileExtensions */
1976	s_apszVciFileExtensions,
1977	/* paConfigInfo */
1978	NULL,
1979	/* pfnProbe */
1980	vciProbe,
1981	/* pfnOpen */
1982	vciOpen,
1983	/* pfnCreate */
1984	vciCreate,
1985	/* pfnClose */
1986	vciClose,
1987	/* pfnRead */
1988	vciRead,
1989	/* pfnWrite */
1990	vciWrite,
1991	/* pfnFlush */
1992	vciFlush,
1993	/* pfnDiscard */
1994	NULL,
1995	/* pfnGetVersion */
1996	vciGetVersion,
1997	/* pfnGetSize */
1998	vciGetSize,
1999	/* pfnGetFileSize */
2000	vciGetFileSize,
2001	/* pfnGetImageFlags */
2002	vciGetImageFlags,
2003	/* pfnGetOpenFlags */
2004	vciGetOpenFlags,
2005	/* pfnSetOpenFlags */
2006	vciSetOpenFlags,
2007	/* pfnGetComment */
2008	vciGetComment,
2009	/* pfnSetComment */
2010	vciSetComment,
2011	/* pfnGetUuid */
2012	vciGetUuid,
2013	/* pfnSetUuid */
2014	vciSetUuid,
2015	/* pfnGetModificationUuid */
2016	vciGetModificationUuid,
2017	/* pfnSetModificationUuid */
2018	vciSetModificationUuid,
2019	/* pfnDump */
2020	vciDump,
2021	/* pfnComposeLocation */
2022	NULL,
2023	/* pfnComposeName */
2024	NULL
2025	};
2026

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source: vbox/trunk/src/VBox/Storage/VCICache.cpp@ 58591

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