VCICache.cpp@ 104747

Last change on this file since 104747 was 103005, checked in by vboxsync, 11 months ago
iprt/asm.h,: Split out the ASMMem and related stuff into a separate header, asm-mem.h, so that we can get the RT_ASM_PAGE_SIZE stuff out of the way.
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1	/* $Id: VCICache.cpp 103005 2024-01-23 23:55:58Z vboxsync $ */
2	/** @file
3	* VCICacheCore - VirtualBox Cache Image, Core Code.
4	*/
5
6	/*
7	* Copyright (C) 2006-2023 Oracle and/or its affiliates.
8	*
9	* This file is part of VirtualBox base platform packages, as
10	* available from https://www.virtualbox.org.
11	*
12	* This program is free software; you can redistribute it and/or
13	* modify it under the terms of the GNU General Public License
14	* as published by the Free Software Foundation, in version 3 of the
15	* License.
16	*
17	* This program is distributed in the hope that it will be useful, but
18	* WITHOUT ANY WARRANTY; without even the implied warranty of
19	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20	* General Public License for more details.
21	*
22	* You should have received a copy of the GNU General Public License
23	* along with this program; if not, see <https://www.gnu.org/licenses>.
24	*
25	* SPDX-License-Identifier: GPL-3.0-only
26	*/
27
28
29	/*********************************************************************************************************************************
30	* Header Files *
31	*********************************************************************************************************************************/
32	#define LOG_GROUP LOG_GROUP_VD_RAW /** @todo logging group */
33	#include <VBox/vd-cache-backend.h>
34	#include <VBox/err.h>
35
36	#include <VBox/log.h>
37	#include <iprt/assert.h>
38	#include <iprt/asm-mem.h>
39	#include <iprt/asm.h>
40	#include <iprt/mem.h>
41	#include <iprt/file.h>
42
43	#include "VDBackends.h"
44
45	/*******************************************************************************
46	* On disk data structures *
47	*******************************************************************************/
48
49	/** @note All structures which are written to the disk are written in camel case
50	* and packed. */
51
52	/** Block size used internally, because we cache sectors the smallest unit we
53	* have to care about is 512 bytes. */
54	#define VCI_BLOCK_SIZE 512
55
56	/** Convert block number/size to byte offset/size. */
57	#define VCI_BLOCK2BYTE(u) ((uint64_t)(u) << 9)
58
59	/** Convert byte offset/size to block number/size. */
60	#define VCI_BYTE2BLOCK(u) ((u) >> 9)
61
62	/**
63	* The VCI header - at the beginning of the file.
64	*
65	* All entries a stored in little endian order.
66	*/
67	#pragma pack(1)
68	typedef struct VciHdr
69	{
70	/** The signature to identify a cache image. */
71	uint32_t u32Signature;
72	/** Version of the layout of metadata in the cache. */
73	uint32_t u32Version;
74	/** Maximum size of the cache file in blocks.
75	* This includes all metadata. */
76	uint64_t cBlocksCache;
77	/** Flag indicating whether the cache was closed cleanly. */
78	uint8_t fUncleanShutdown;
79	/** Cache type. */
80	uint32_t u32CacheType;
81	/** Offset of the B+-Tree root in the image in blocks. */
82	uint64_t offTreeRoot;
83	/** Offset of the block allocation bitmap in blocks. */
84	uint64_t offBlkMap;
85	/** Size of the block allocation bitmap in blocks. */
86	uint32_t cBlkMap;
87	/** UUID of the image. */
88	RTUUID uuidImage;
89	/** Modification UUID for the cache. */
90	RTUUID uuidModification;
91	/** Reserved for future use. */
92	uint8_t abReserved[951];
93	} VciHdr, *PVciHdr;
94	#pragma pack()
95	AssertCompileSize(VciHdr, 2 * VCI_BLOCK_SIZE);
96
97	/** VCI signature to identify a valid image. */
98	#define VCI_HDR_SIGNATURE UINT32_C(0x00494356) /* \0ICV */
99	/** Current version we support. */
100	#define VCI_HDR_VERSION UINT32_C(0x00000001)
101
102	/** Value for an unclean cache shutdown. */
103	#define VCI_HDR_UNCLEAN_SHUTDOWN UINT8_C(0x01)
104	/** Value for a clean cache shutdown. */
105	#define VCI_HDR_CLEAN_SHUTDOWN UINT8_C(0x00)
106
107	/** Cache type: Dynamic image growing to the maximum value. */
108	#define VCI_HDR_CACHE_TYPE_DYNAMIC UINT32_C(0x00000001)
109	/** Cache type: Fixed image, space is preallocated. */
110	#define VCI_HDR_CACHE_TYPE_FIXED UINT32_C(0x00000002)
111
112	/**
113	* On disk representation of an extent describing a range of cached data.
114	*
115	* All entries a stored in little endian order.
116	*/
117	#pragma pack(1)
118	typedef struct VciCacheExtent
119	{
120	/** Block address of the previous extent in the LRU list. */
121	uint64_t u64ExtentPrev;
122	/** Block address of the next extent in the LRU list. */
123	uint64_t u64ExtentNext;
124	/** Flags (for compression, encryption etc.) - currently unused and should be always 0. */
125	uint8_t u8Flags;
126	/** Reserved */
127	uint8_t u8Reserved;
128	/** First block of cached data the extent represents. */
129	uint64_t u64BlockOffset;
130	/** Number of blocks the extent represents. */
131	uint32_t u32Blocks;
132	/** First block in the image where the data is stored. */
133	uint64_t u64BlockAddr;
134	} VciCacheExtent, *PVciCacheExtent;
135	#pragma pack()
136	AssertCompileSize(VciCacheExtent, 38);
137
138	/**
139	* On disk representation of an internal node.
140	*
141	* All entries a stored in little endian order.
142	*/
143	#pragma pack(1)
144	typedef struct VciTreeNodeInternal
145	{
146	/** First block of cached data the internal node represents. */
147	uint64_t u64BlockOffset;
148	/** Number of blocks the internal node represents. */
149	uint32_t u32Blocks;
150	/** Block address in the image where the next node in the tree is stored. */
151	uint64_t u64ChildAddr;
152	} VciTreeNodeInternal, *PVciTreeNodeInternal;
153	#pragma pack()
154	AssertCompileSize(VciTreeNodeInternal, 20);
155
156	/**
157	* On-disk representation of a node in the B+-Tree.
158	*
159	* All entries a stored in little endian order.
160	*/
161	#pragma pack(1)
162	typedef struct VciTreeNode
163	{
164	/** Type of the node (root, internal, leaf). */
165	uint8_t u8Type;
166	/** Data in the node. */
167	uint8_t au8Data[4095];
168	} VciTreeNode, *PVciTreeNode;
169	#pragma pack()
170	AssertCompileSize(VciTreeNode, 8 * VCI_BLOCK_SIZE);
171
172	/** Node type: Internal node containing links to other nodes (VciTreeNodeInternal). */
173	#define VCI_TREE_NODE_TYPE_INTERNAL UINT8_C(0x01)
174	/** Node type: Leaf of the tree (VciCacheExtent). */
175	#define VCI_TREE_NODE_TYPE_LEAF UINT8_C(0x02)
176
177	/** Number of cache extents described by one node. */
178	#define VCI_TREE_EXTENTS_PER_NODE ((sizeof(VciTreeNode)-1) / sizeof(VciCacheExtent))
179	/** Number of internal nodes managed by one tree node. */
180	#define VCI_TREE_INTERNAL_NODES_PER_NODE ((sizeof(VciTreeNode)-1) / sizeof(VciTreeNodeInternal))
181
182	/**
183	* VCI block bitmap header.
184	*
185	* All entries a stored in little endian order.
186	*/
187	#pragma pack(1)
188	typedef struct VciBlkMap
189	{
190	/** Magic of the block bitmap. */
191	uint32_t u32Magic;
192	/** Version of the block bitmap. */
193	uint32_t u32Version;
194	/** Number of blocks this block map manages. */
195	uint64_t cBlocks;
196	/** Number of free blocks. */
197	uint64_t cBlocksFree;
198	/** Number of blocks allocated for metadata. */
199	uint64_t cBlocksAllocMeta;
200	/** Number of blocks allocated for actual cached data. */
201	uint64_t cBlocksAllocData;
202	/** Reserved for future use. */
203	uint8_t au8Reserved[472];
204	} VciBlkMap, *PVciBlkMap;
205	#pragma pack()
206	AssertCompileSize(VciBlkMap, VCI_BLOCK_SIZE);
207
208	/** The magic which identifies a block map. */
209	#define VCI_BLKMAP_MAGIC UINT32_C(0x4b4c4256) /* KLBV */
210	/** Current version. */
211	#define VCI_BLKMAP_VERSION UINT32_C(0x00000001)
212
213	/** Block bitmap entry */
214	typedef uint8_t VciBlkMapEnt;
215
216
217	/*********************************************************************************************************************************
218	* Constants And Macros, Structures and Typedefs *
219	*********************************************************************************************************************************/
220
221	/**
222	* Block range descriptor.
223	*/
224	typedef struct VCIBLKRANGEDESC
225	{
226	/** Previous entry in the list. */
227	struct VCIBLKRANGEDESC *pPrev;
228	/** Next entry in the list. */
229	struct VCIBLKRANGEDESC *pNext;
230	/** Start address of the range. */
231	uint64_t offAddrStart;
232	/** Number of blocks in the range. */
233	uint64_t cBlocks;
234	/** Flag whether the range is free or allocated. */
235	bool fFree;
236	} VCIBLKRANGEDESC, *PVCIBLKRANGEDESC;
237
238	/**
239	* Block map for the cache image - in memory structure.
240	*/
241	typedef struct VCIBLKMAP
242	{
243	/** Number of blocks the map manages. */
244	uint64_t cBlocks;
245	/** Number of blocks allocated for metadata. */
246	uint64_t cBlocksAllocMeta;
247	/** Number of blocks allocated for actual cached data. */
248	uint64_t cBlocksAllocData;
249	/** Number of free blocks. */
250	uint64_t cBlocksFree;
251
252	/** Pointer to the head of the block range list. */
253	PVCIBLKRANGEDESC pRangesHead;
254	/** Pointer to the tail of the block range list. */
255	PVCIBLKRANGEDESC pRangesTail;
256
257	} VCIBLKMAP;
258	/** Pointer to a block map. */
259	typedef VCIBLKMAP *PVCIBLKMAP;
260
261	/**
262	* B+-Tree node header.
263	*/
264	typedef struct VCITREENODE
265	{
266	/** Type of the node (VCI_TREE_NODE_TYPE_). /
267	uint8_t u8Type;
268	/** Block address where the node is stored. */
269	uint64_t u64BlockAddr;
270	/** Pointer to the parent. */
271	struct VCITREENODE *pParent;
272	} VCITREENODE, *PVCITREENODE;
273
274	/**
275	* B+-Tree node pointer.
276	*/
277	typedef struct VCITREENODEPTR
278	{
279	/** Flag whether the node is in memory or still on the disk. */
280	bool fInMemory;
281	/** Type dependent data. */
282	union
283	{
284	/** Pointer to a in memory node. */
285	PVCITREENODE pNode;
286	/** Start block address of the node. */
287	uint64_t offAddrBlockNode;
288	} u;
289	} VCITREENODEPTR, *PVCITREENODEPTR;
290
291	/**
292	* Internal node.
293	*/
294	typedef struct VCINODEINTERNAL
295	{
296	/** First block of cached data the internal node represents. */
297	uint64_t u64BlockOffset;
298	/** Number of blocks the internal node represents. */
299	uint32_t u32Blocks;
300	/** Pointer to the child node. */
301	VCITREENODEPTR PtrChild;
302	} VCINODEINTERNAL, *PVCINODEINTERNAL;
303
304	/**
305	* A in memory internal B+-tree node.
306	*/
307	typedef struct VCITREENODEINT
308	{
309	/** Node core. */
310	VCITREENODE Core;
311	/** Number of used nodes. */
312	unsigned cUsedNodes;
313	/** Array of internal nodes. */
314	VCINODEINTERNAL aIntNodes[VCI_TREE_INTERNAL_NODES_PER_NODE];
315	} VCITREENODEINT, *PVCITREENODEINT;
316
317	/**
318	* A in memory cache extent.
319	*/
320	typedef struct VCICACHEEXTENT
321	{
322	/** First block of cached data the extent represents. */
323	uint64_t u64BlockOffset;
324	/** Number of blocks the extent represents. */
325	uint32_t u32Blocks;
326	/** First block in the image where the data is stored. */
327	uint64_t u64BlockAddr;
328	} VCICACHEEXTENT, *PVCICACHEEXTENT;
329
330	/**
331	* A in memory leaf B+-tree node.
332	*/
333	typedef struct VCITREENODELEAF
334	{
335	/** Node core. */
336	VCITREENODE Core;
337	/** Next leaf node in the list. */
338	struct VCITREENODELEAF *pNext;
339	/** Number of used nodes. */
340	unsigned cUsedNodes;
341	/** The extents in the node. */
342	VCICACHEEXTENT aExtents[VCI_TREE_EXTENTS_PER_NODE];
343	} VCITREENODELEAF, *PVCITREENODELEAF;
344
345	/**
346	* VCI image data structure.
347	*/
348	typedef struct VCICACHE
349	{
350	/** Image name. */
351	const char *pszFilename;
352	/** Storage handle. */
353	PVDIOSTORAGE pStorage;
354
355	/** Pointer to the per-disk VD interface list. */
356	PVDINTERFACE pVDIfsDisk;
357	/** Pointer to the per-image VD interface list. */
358	PVDINTERFACE pVDIfsImage;
359	/** Error interface. */
360	PVDINTERFACEERROR pIfError;
361	/** I/O interface. */
362	PVDINTERFACEIOINT pIfIo;
363
364	/** Open flags passed by VBoxHD layer. */
365	unsigned uOpenFlags;
366	/** Image flags defined during creation or determined during open. */
367	unsigned uImageFlags;
368	/** Total size of the image. */
369	uint64_t cbSize;
370
371	/** Offset of the B+-Tree in the image in bytes. */
372	uint64_t offTreeRoot;
373	/** Pointer to the root node of the B+-Tree. */
374	PVCITREENODE pRoot;
375	/** Offset to the block allocation bitmap in bytes. */
376	uint64_t offBlksBitmap;
377	/** Block map. */
378	PVCIBLKMAP pBlkMap;
379	} VCICACHE, *PVCICACHE;
380
381	/** No block free in bitmap error code. */
382	#define VERR_VCI_NO_BLOCKS_FREE (-65536)
383
384	/** Flags for the block map allocator. */
385	#define VCIBLKMAP_ALLOC_DATA 0
386	#define VCIBLKMAP_ALLOC_META RT_BIT(0)
387	#define VCIBLKMAP_ALLOC_MASK 0x1
388
389
390	/*********************************************************************************************************************************
391	* Static Variables *
392	*********************************************************************************************************************************/
393
394	/** NULL-terminated array of supported file extensions. */
395	static const char *const s_apszVciFileExtensions[] =
396	{
397	"vci",
398	NULL
399	};
400
401
402	/*********************************************************************************************************************************
403	* Internal Functions *
404	*********************************************************************************************************************************/
405
406	/**
407	* Internal. Flush image data to disk.
408	*/
409	static int vciFlushImage(PVCICACHE pCache)
410	{
411	int rc = VINF_SUCCESS;
412
413	if ( pCache->pStorage
414	&& !(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
415	{
416	rc = vdIfIoIntFileFlushSync(pCache->pIfIo, pCache->pStorage);
417	}
418
419	return rc;
420	}
421
422	/**
423	* Internal. Free all allocated space for representing an image except pCache,
424	* and optionally delete the image from disk.
425	*/
426	static int vciFreeImage(PVCICACHE pCache, bool fDelete)
427	{
428	int rc = VINF_SUCCESS;
429
430	/* Freeing a never allocated image (e.g. because the open failed) is
431	* not signalled as an error. After all nothing bad happens. */
432	if (pCache)
433	{
434	if (pCache->pStorage)
435	{
436	/* No point updating the file that is deleted anyway. */
437	if (!fDelete)
438	vciFlushImage(pCache);
439
440	vdIfIoIntFileClose(pCache->pIfIo, pCache->pStorage);
441	pCache->pStorage = NULL;
442	}
443
444	if (fDelete && pCache->pszFilename)
445	vdIfIoIntFileDelete(pCache->pIfIo, pCache->pszFilename);
446	}
447
448	LogFlowFunc(("returns %Rrc\n", rc));
449	return rc;
450	}
451
452	/**
453	* Creates a new block map which can manage the given number of blocks.
454	*
455	* The size of the bitmap is aligned to the VCI block size.
456	*
457	* @returns VBox status code.
458	* @param cBlocks The number of blocks the bitmap can manage.
459	* @param ppBlkMap Where to store the pointer to the block bitmap.
460	* @param pcBlkMap Where to store the size of the block bitmap in blocks
461	* needed on the disk.
462	*/
463	static int vciBlkMapCreate(uint64_t cBlocks, PVCIBLKMAP ppBlkMap, uint32_t pcBlkMap)
464	{
465	int rc = VINF_SUCCESS;
466	uint32_t cbBlkMap = RT_ALIGN_Z(cBlocks / sizeof(VciBlkMapEnt) / 8, VCI_BLOCK_SIZE);
467	PVCIBLKMAP pBlkMap = (PVCIBLKMAP)RTMemAllocZ(sizeof(VCIBLKMAP));
468	PVCIBLKRANGEDESC pFree = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
469
470	LogFlowFunc(("cBlocks=%u ppBlkMap=%#p pcBlkMap=%#p\n", cBlocks, ppBlkMap, pcBlkMap));
471
472	if (pBlkMap && pFree)
473	{
474	pBlkMap->cBlocks = cBlocks;
475	pBlkMap->cBlocksAllocMeta = 0;
476	pBlkMap->cBlocksAllocData = 0;
477	pBlkMap->cBlocksFree = cBlocks;
478
479	pFree->pPrev = NULL;
480	pFree->pNext = NULL;
481	pFree->offAddrStart = 0;
482	pFree->cBlocks = cBlocks;
483	pFree->fFree = true;
484
485	pBlkMap->pRangesHead = pFree;
486	pBlkMap->pRangesTail = pFree;
487
488	Assert(!((cbBlkMap + sizeof(VciBlkMap)) % VCI_BLOCK_SIZE));
489	*ppBlkMap = pBlkMap;
490	*pcBlkMap = VCI_BYTE2BLOCK(cbBlkMap + sizeof(VciBlkMap));
491	}
492	else
493	{
494	if (pBlkMap)
495	RTMemFree(pBlkMap);
496	if (pFree)
497	RTMemFree(pFree);
498
499	rc = VERR_NO_MEMORY;
500	}
501
502	LogFlowFunc(("returns rc=%Rrc cBlkMap=%u\n", rc, *pcBlkMap));
503	return rc;
504	}
505
506	#if 0 /** @todo unsued vciBlkMapDestroy */
507	/**
508	* Frees a block map.
509	*
510	* @param pBlkMap The block bitmap to destroy.
511	*/
512	static void vciBlkMapDestroy(PVCIBLKMAP pBlkMap)
513	{
514	LogFlowFunc(("pBlkMap=%#p\n", pBlkMap));
515
516	PVCIBLKRANGEDESC pRangeCur = pBlkMap->pRangesHead;
517
518	while (pRangeCur)
519	{
520	PVCIBLKRANGEDESC pTmp = pRangeCur;
521
522	RTMemFree(pTmp);
523
524	pRangeCur = pRangeCur->pNext;
525	}
526
527	RTMemFree(pBlkMap);
528
529	LogFlowFunc(("returns\n"));
530	}
531	#endif
532
533	/**
534	* Loads the block map from the specified medium and creates all necessary
535	* in memory structures to manage used and free blocks.
536	*
537	* @returns VBox status code.
538	* @param pStorage Storage handle to read the block bitmap from.
539	* @param offBlkMap Start of the block bitmap in blocks.
540	* @param cBlkMap Size of the block bitmap on the disk in blocks.
541	* @param ppBlkMap Where to store the block bitmap on success.
542	*/
543	static int vciBlkMapLoad(PVCICACHE pStorage, uint64_t offBlkMap, uint32_t cBlkMap, PVCIBLKMAP *ppBlkMap)
544	{
545	int rc = VINF_SUCCESS;
546	VciBlkMap BlkMap;
547
548	LogFlowFunc(("pStorage=%#p offBlkMap=%llu cBlkMap=%u ppBlkMap=%#p\n",
549	pStorage, offBlkMap, cBlkMap, ppBlkMap));
550
551	if (cBlkMap >= VCI_BYTE2BLOCK(sizeof(VciBlkMap)))
552	{
553	cBlkMap -= VCI_BYTE2BLOCK(sizeof(VciBlkMap));
554
555	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage, offBlkMap,
556	&BlkMap, VCI_BYTE2BLOCK(sizeof(VciBlkMap)));
557	if (RT_SUCCESS(rc))
558	{
559	offBlkMap += VCI_BYTE2BLOCK(sizeof(VciBlkMap));
560
561	BlkMap.u32Magic = RT_LE2H_U32(BlkMap.u32Magic);
562	BlkMap.u32Version = RT_LE2H_U32(BlkMap.u32Version);
563	BlkMap.cBlocks = RT_LE2H_U32(BlkMap.cBlocks);
564	BlkMap.cBlocksFree = RT_LE2H_U32(BlkMap.cBlocksFree);
565	BlkMap.cBlocksAllocMeta = RT_LE2H_U32(BlkMap.cBlocksAllocMeta);
566	BlkMap.cBlocksAllocData = RT_LE2H_U32(BlkMap.cBlocksAllocData);
567
568	if ( BlkMap.u32Magic == VCI_BLKMAP_MAGIC
569	&& BlkMap.u32Version == VCI_BLKMAP_VERSION
570	&& BlkMap.cBlocks == BlkMap.cBlocksFree + BlkMap.cBlocksAllocMeta + BlkMap.cBlocksAllocData
571	&& VCI_BYTE2BLOCK(BlkMap.cBlocks / 8) == cBlkMap)
572	{
573	PVCIBLKMAP pBlkMap = (PVCIBLKMAP)RTMemAllocZ(sizeof(VCIBLKMAP));
574	if (pBlkMap)
575	{
576	pBlkMap->cBlocks = BlkMap.cBlocks;
577	pBlkMap->cBlocksFree = BlkMap.cBlocksFree;
578	pBlkMap->cBlocksAllocMeta = BlkMap.cBlocksAllocMeta;
579	pBlkMap->cBlocksAllocData = BlkMap.cBlocksAllocData;
580
581	/* Load the bitmap and construct the range list. */
582	PVCIBLKRANGEDESC pRangeCur = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
583
584	if (pRangeCur)
585	{
586	uint8_t abBitmapBuffer[16 * _1K];
587	uint32_t cBlocksRead = 0;
588	uint64_t cBlocksLeft = VCI_BYTE2BLOCK(pBlkMap->cBlocks / 8);
589
590	cBlocksRead = RT_MIN(VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)), cBlocksLeft);
591	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage,
592	offBlkMap, abBitmapBuffer,
593	cBlocksRead);
594
595	if (RT_SUCCESS(rc))
596	{
597	pRangeCur->fFree = !(abBitmapBuffer[0] & 0x01);
598	pRangeCur->offAddrStart = 0;
599	pRangeCur->cBlocks = 0;
600	pRangeCur->pNext = NULL;
601	pRangeCur->pPrev = NULL;
602	pBlkMap->pRangesHead = pRangeCur;
603	pBlkMap->pRangesTail = pRangeCur;
604	}
605	else
606	RTMemFree(pRangeCur);
607
608	while ( RT_SUCCESS(rc)
609	&& cBlocksLeft)
610	{
611	int iBit = 0;
612	uint32_t cBits = VCI_BLOCK2BYTE(cBlocksRead) * 8;
613	uint32_t iBitPrev = 0xffffffff;
614
615	while (cBits)
616	{
617	if (pRangeCur->fFree)
618	{
619	/* Check for the first set bit. */
620	iBit = ASMBitNextSet(abBitmapBuffer, cBits, iBitPrev);
621	}
622	else
623	{
624	/* Check for the first free bit. */
625	iBit = ASMBitNextClear(abBitmapBuffer, cBits, iBitPrev);
626	}
627
628	if (iBit == -1)
629	{
630	/* No change. */
631	pRangeCur->cBlocks += cBits;
632	cBits = 0;
633	}
634	else
635	{
636	Assert((uint32_t)iBit < cBits);
637	pRangeCur->cBlocks += iBit;
638
639	/* Create a new range descriptor. */
640	PVCIBLKRANGEDESC pRangeNew = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
641	if (!pRangeNew)
642	{
643	rc = VERR_NO_MEMORY;
644	break;
645	}
646
647	pRangeNew->fFree = !pRangeCur->fFree;
648	pRangeNew->offAddrStart = pRangeCur->offAddrStart + pRangeCur->cBlocks;
649	pRangeNew->cBlocks = 0;
650	pRangeNew->pPrev = pRangeCur;
651	pRangeCur->pNext = pRangeNew;
652	pBlkMap->pRangesTail = pRangeNew;
653	pRangeCur = pRangeNew;
654	cBits -= iBit;
655	iBitPrev = iBit;
656	}
657	}
658
659	cBlocksLeft -= cBlocksRead;
660	offBlkMap += cBlocksRead;
661
662	if ( RT_SUCCESS(rc)
663	&& cBlocksLeft)
664	{
665	/* Read next chunk. */
666	cBlocksRead = RT_MIN(VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)), cBlocksLeft);
667	rc = vdIfIoIntFileReadSync(pStorage->pIfIo, pStorage->pStorage,
668	offBlkMap, abBitmapBuffer, cBlocksRead);
669	}
670	}
671	}
672	else
673	rc = VERR_NO_MEMORY;
674
675	if (RT_SUCCESS(rc))
676	{
677	*ppBlkMap = pBlkMap;
678	LogFlowFunc(("return success\n"));
679	return VINF_SUCCESS;
680	}
681
682	RTMemFree(pBlkMap);
683	}
684	else
685	rc = VERR_NO_MEMORY;
686	}
687	else
688	rc = VERR_VD_GEN_INVALID_HEADER;
689	}
690	else
691	rc = VERR_VD_GEN_INVALID_HEADER;
692	}
693	else
694	rc = VERR_VD_GEN_INVALID_HEADER;
695
696	LogFlowFunc(("returns rc=%Rrc\n", rc));
697	return rc;
698	}
699
700	/**
701	* Saves the block map in the cache image. All necessary on disk structures
702	* are written.
703	*
704	* @returns VBox status code.
705	* @param pBlkMap The block bitmap to save.
706	* @param pStorage Where the block bitmap should be written to.
707	* @param offBlkMap Start of the block bitmap in blocks.
708	* @param cBlkMap Size of the block bitmap on the disk in blocks.
709	*/
710	static int vciBlkMapSave(PVCIBLKMAP pBlkMap, PVCICACHE pStorage, uint64_t offBlkMap, uint32_t cBlkMap)
711	{
712	int rc = VINF_SUCCESS;
713	VciBlkMap BlkMap;
714
715	LogFlowFunc(("pBlkMap=%#p pStorage=%#p offBlkMap=%llu cBlkMap=%u\n",
716	pBlkMap, pStorage, offBlkMap, cBlkMap));
717
718	/* Make sure the number of blocks allocated for us match our expectations. */
719	if (VCI_BYTE2BLOCK(pBlkMap->cBlocks / 8) + VCI_BYTE2BLOCK(sizeof(VciBlkMap)) == cBlkMap)
720	{
721	/* Setup the header */
722	memset(&BlkMap, 0, sizeof(VciBlkMap));
723
724	BlkMap.u32Magic = RT_H2LE_U32(VCI_BLKMAP_MAGIC);
725	BlkMap.u32Version = RT_H2LE_U32(VCI_BLKMAP_VERSION);
726	BlkMap.cBlocks = RT_H2LE_U32(pBlkMap->cBlocks);
727	BlkMap.cBlocksFree = RT_H2LE_U32(pBlkMap->cBlocksFree);
728	BlkMap.cBlocksAllocMeta = RT_H2LE_U32(pBlkMap->cBlocksAllocMeta);
729	BlkMap.cBlocksAllocData = RT_H2LE_U32(pBlkMap->cBlocksAllocData);
730
731	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage, offBlkMap,
732	&BlkMap, VCI_BYTE2BLOCK(sizeof(VciBlkMap)));
733	if (RT_SUCCESS(rc))
734	{
735	uint8_t abBitmapBuffer[16*_1K];
736	unsigned iBit = 0;
737	PVCIBLKRANGEDESC pCur = pBlkMap->pRangesHead;
738
739	offBlkMap += VCI_BYTE2BLOCK(sizeof(VciBlkMap));
740
741	/* Write the descriptor ranges. */
742	while (pCur)
743	{
744	uint64_t cBlocks = pCur->cBlocks;
745
746	while (cBlocks)
747	{
748	uint64_t cBlocksMax = RT_MIN(cBlocks, sizeof(abBitmapBuffer) * 8 - iBit);
749
750	if (pCur->fFree)
751	ASMBitClearRange(abBitmapBuffer, iBit, iBit + cBlocksMax);
752	else
753	ASMBitSetRange(abBitmapBuffer, iBit, iBit + cBlocksMax);
754
755	iBit += cBlocksMax;
756	cBlocks -= cBlocksMax;
757
758	if (iBit == sizeof(abBitmapBuffer) * 8)
759	{
760	/* Buffer is full, write to file and reset. */
761	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage,
762	offBlkMap, abBitmapBuffer,
763	VCI_BYTE2BLOCK(sizeof(abBitmapBuffer)));
764	if (RT_FAILURE(rc))
765	break;
766
767	offBlkMap += VCI_BYTE2BLOCK(sizeof(abBitmapBuffer));
768	iBit = 0;
769	}
770	}
771
772	pCur = pCur->pNext;
773	}
774
775	Assert(iBit % 8 == 0);
776
777	if (RT_SUCCESS(rc) && iBit)
778	rc = vdIfIoIntFileWriteSync(pStorage->pIfIo, pStorage->pStorage,
779	offBlkMap, abBitmapBuffer, VCI_BYTE2BLOCK(iBit / 8));
780	}
781	}
782	else
783	rc = VERR_INTERNAL_ERROR; /** @todo Better error code. */
784
785	LogFlowFunc(("returns rc=%Rrc\n", rc));
786	return rc;
787	}
788
789	#if 0 /* unused */
790	/**
791	* Finds the range block describing the given block address.
792	*
793	* @returns Pointer to the block range descriptor or NULL if none could be found.
794	* @param pBlkMap The block bitmap to search on.
795	* @param offBlockAddr The block address to search for.
796	*/
797	static PVCIBLKRANGEDESC vciBlkMapFindByBlock(PVCIBLKMAP pBlkMap, uint64_t offBlockAddr)
798	{
799	PVCIBLKRANGEDESC pBlk = pBlkMap->pRangesHead;
800
801	while ( pBlk
802	&& pBlk->offAddrStart < offBlockAddr)
803	pBlk = pBlk->pNext;
804
805	return pBlk;
806	}
807	#endif
808
809	/**
810	* Allocates the given number of blocks in the bitmap and returns the start block address.
811	*
812	* @returns VBox status code.
813	* @param pBlkMap The block bitmap to allocate the blocks from.
814	* @param cBlocks How many blocks to allocate.
815	* @param fFlags Allocation flags, comgination of VCIBLKMAP_ALLOC_*.
816	* @param poffBlockAddr Where to store the start address of the allocated region.
817	*/
818	static int vciBlkMapAllocate(PVCIBLKMAP pBlkMap, uint32_t cBlocks, uint32_t fFlags,
819	uint64_t *poffBlockAddr)
820	{
821	PVCIBLKRANGEDESC pBestFit = NULL;
822	PVCIBLKRANGEDESC pCur = NULL;
823	int rc = VINF_SUCCESS;
824
825	LogFlowFunc(("pBlkMap=%#p cBlocks=%u poffBlockAddr=%#p\n",
826	pBlkMap, cBlocks, poffBlockAddr));
827
828	pCur = pBlkMap->pRangesHead;
829
830	while (pCur)
831	{
832	if ( pCur->fFree
833	&& pCur->cBlocks >= cBlocks)
834	{
835	if ( !pBestFit
836	\|\| pCur->cBlocks < pBestFit->cBlocks)
837	{
838	pBestFit = pCur;
839	/* Stop searching if the size is matching exactly. */
840	if (pBestFit->cBlocks == cBlocks)
841	break;
842	}
843	}
844	pCur = pCur->pNext;
845	}
846
847	Assert(!pBestFit \|\| pBestFit->fFree);
848
849	if (pBestFit)
850	{
851	pBestFit->fFree = false;
852
853	if (pBestFit->cBlocks > cBlocks)
854	{
855	/* Create a new free block. */
856	PVCIBLKRANGEDESC pFree = (PVCIBLKRANGEDESC)RTMemAllocZ(sizeof(VCIBLKRANGEDESC));
857
858	if (pFree)
859	{
860	pFree->fFree = true;
861	pFree->cBlocks = pBestFit->cBlocks - cBlocks;
862	pBestFit->cBlocks -= pFree->cBlocks;
863	pFree->offAddrStart = pBestFit->offAddrStart + cBlocks;
864
865	/* Link into the list. */
866	pFree->pNext = pBestFit->pNext;
867	pBestFit->pNext = pFree;
868	pFree->pPrev = pBestFit;
869	if (!pFree->pNext)
870	pBlkMap->pRangesTail = pFree;
871
872	*poffBlockAddr = pBestFit->offAddrStart;
873	}
874	else
875	{
876	rc = VERR_NO_MEMORY;
877	pBestFit->fFree = true;
878	}
879	}
880	}
881	else
882	rc = VERR_VCI_NO_BLOCKS_FREE;
883
884	if (RT_SUCCESS(rc))
885	{
886	if ((fFlags & VCIBLKMAP_ALLOC_MASK) == VCIBLKMAP_ALLOC_DATA)
887	pBlkMap->cBlocksAllocMeta += cBlocks;
888	else
889	pBlkMap->cBlocksAllocData += cBlocks;
890
891	pBlkMap->cBlocksFree -= cBlocks;
892	}
893
894	LogFlowFunc(("returns rc=%Rrc offBlockAddr=%llu\n", rc, *poffBlockAddr));
895	return rc;
896	}
897
898	#if 0 /* unused */
899	/**
900	* Try to extend the space of an already allocated block.
901	*
902	* @returns VBox status code.
903	* @param pBlkMap The block bitmap to allocate the blocks from.
904	* @param cBlocksNew How many blocks the extended block should have.
905	* @param offBlockAddrOld The start address of the block to reallocate.
906	* @param poffBlockAddr Where to store the start address of the allocated region.
907	*/
908	static int vciBlkMapRealloc(PVCIBLKMAP pBlkMap, uint32_t cBlocksNew, uint64_t offBlockAddrOld,
909	uint64_t *poffBlockAddr)
910	{
911	int rc = VINF_SUCCESS;
912
913	LogFlowFunc(("pBlkMap=%#p cBlocksNew=%u offBlockAddrOld=%llu poffBlockAddr=%#p\n",
914	pBlkMap, cBlocksNew, offBlockAddrOld, poffBlockAddr));
915
916	AssertMsgFailed(("Implement\n"));
917	RT_NOREF4(pBlkMap, cBlocksNew, offBlockAddrOld, poffBlockAddr);
918
919	LogFlowFunc(("returns rc=%Rrc offBlockAddr=%llu\n", rc, *poffBlockAddr));
920	return rc;
921	}
922	#endif /* unused */
923
924	#if 0 /* unused */
925	/**
926	* Frees a range of blocks.
927	*
928	* @param pBlkMap The block bitmap.
929	* @param offBlockAddr Address of the first block to free.
930	* @param cBlocks How many blocks to free.
931	* @param fFlags Allocation flags, comgination of VCIBLKMAP_ALLOC_*.
932	*/
933	static void vciBlkMapFree(PVCIBLKMAP pBlkMap, uint64_t offBlockAddr, uint32_t cBlocks,
934	uint32_t fFlags)
935	{
936	PVCIBLKRANGEDESC pBlk;
937
938	LogFlowFunc(("pBlkMap=%#p offBlockAddr=%llu cBlocks=%u\n",
939	pBlkMap, offBlockAddr, cBlocks));
940
941	while (cBlocks)
942	{
943	pBlk = vciBlkMapFindByBlock(pBlkMap, offBlockAddr);
944	AssertPtr(pBlk);
945
946	/* Easy case, the whole block is freed. */
947	if ( pBlk->offAddrStart == offBlockAddr
948	&& pBlk->cBlocks <= cBlocks)
949	{
950	pBlk->fFree = true;
951	cBlocks -= pBlk->cBlocks;
952	offBlockAddr += pBlk->cBlocks;
953
954	/* Check if it is possible to merge free blocks. */
955	if ( pBlk->pPrev
956	&& pBlk->pPrev->fFree)
957	{
958	PVCIBLKRANGEDESC pBlkPrev = pBlk->pPrev;
959
960	Assert(pBlkPrev->offAddrStart + pBlkPrev->cBlocks == pBlk->offAddrStart);
961	pBlkPrev->cBlocks += pBlk->cBlocks;
962	pBlkPrev->pNext = pBlk->pNext;
963	if (pBlk->pNext)
964	pBlk->pNext->pPrev = pBlkPrev;
965	else
966	pBlkMap->pRangesTail = pBlkPrev;
967
968	RTMemFree(pBlk);
969	pBlk = pBlkPrev;
970	}
971
972	/* Now the one to the right. */
973	if ( pBlk->pNext
974	&& pBlk->pNext->fFree)
975	{
976	PVCIBLKRANGEDESC pBlkNext = pBlk->pNext;
977
978	Assert(pBlk->offAddrStart + pBlk->cBlocks == pBlkNext->offAddrStart);
979	pBlk->cBlocks += pBlkNext->cBlocks;
980	pBlk->pNext = pBlkNext->pNext;
981	if (pBlkNext->pNext)
982	pBlkNext->pNext->pPrev = pBlk;
983	else
984	pBlkMap->pRangesTail = pBlk;
985
986	RTMemFree(pBlkNext);
987	}
988	}
989	else
990	{
991	/* The block is intersecting. */
992	AssertMsgFailed(("TODO\n"));
993	}
994	}
995
996	if ((fFlags & VCIBLKMAP_ALLOC_MASK) == VCIBLKMAP_ALLOC_DATA)
997	pBlkMap->cBlocksAllocMeta -= cBlocks;
998	else
999	pBlkMap->cBlocksAllocData -= cBlocks;
1000
1001	pBlkMap->cBlocksFree += cBlocks;
1002
1003	LogFlowFunc(("returns\n"));
1004	}
1005	#endif /* unused */
1006
1007	/**
1008	* Converts a tree node from the image to the in memory structure.
1009	*
1010	* @returns Pointer to the in memory tree node.
1011	* @param offBlockAddrNode Block address of the node.
1012	* @param pNodeImage Pointer to the image representation of the node.
1013	*/
1014	static PVCITREENODE vciTreeNodeImage2Host(uint64_t offBlockAddrNode, PVciTreeNode pNodeImage)
1015	{
1016	PVCITREENODE pNode = NULL;
1017
1018	if (pNodeImage->u8Type == VCI_TREE_NODE_TYPE_LEAF)
1019	{
1020	PVCITREENODELEAF pLeaf = (PVCITREENODELEAF)RTMemAllocZ(sizeof(VCITREENODELEAF));
1021
1022	if (pLeaf)
1023	{
1024	PVciCacheExtent pExtent = (PVciCacheExtent)&pNodeImage->au8Data[0];
1025
1026	pLeaf->Core.u8Type = VCI_TREE_NODE_TYPE_LEAF;
1027
1028	for (unsigned idx = 0; idx < RT_ELEMENTS(pLeaf->aExtents); idx++)
1029	{
1030	pLeaf->aExtents[idx].u64BlockOffset = RT_LE2H_U64(pExtent->u64BlockOffset);
1031	pLeaf->aExtents[idx].u32Blocks = RT_LE2H_U32(pExtent->u32Blocks);
1032	pLeaf->aExtents[idx].u64BlockAddr = RT_LE2H_U64(pExtent->u64BlockAddr);
1033	pExtent++;
1034
1035	if ( pLeaf->aExtents[idx].u32Blocks
1036	&& pLeaf->aExtents[idx].u64BlockAddr)
1037	pLeaf->cUsedNodes++;
1038	}
1039
1040	pNode = &pLeaf->Core;
1041	}
1042	}
1043	else if (pNodeImage->u8Type == VCI_TREE_NODE_TYPE_INTERNAL)
1044	{
1045	PVCITREENODEINT pInt = (PVCITREENODEINT)RTMemAllocZ(sizeof(VCITREENODEINT));
1046
1047	if (pInt)
1048	{
1049	PVciTreeNodeInternal pIntImage = (PVciTreeNodeInternal)&pNodeImage->au8Data[0];
1050
1051	pInt->Core.u8Type = VCI_TREE_NODE_TYPE_INTERNAL;
1052
1053	for (unsigned idx = 0; idx < RT_ELEMENTS(pInt->aIntNodes); idx++)
1054	{
1055	pInt->aIntNodes[idx].u64BlockOffset = RT_LE2H_U64(pIntImage->u64BlockOffset);
1056	pInt->aIntNodes[idx].u32Blocks = RT_LE2H_U32(pIntImage->u32Blocks);
1057	pInt->aIntNodes[idx].PtrChild.fInMemory = false;
1058	pInt->aIntNodes[idx].PtrChild.u.offAddrBlockNode = RT_LE2H_U64(pIntImage->u64ChildAddr);
1059	pIntImage++;
1060
1061	if ( pInt->aIntNodes[idx].u32Blocks
1062	&& pInt->aIntNodes[idx].PtrChild.u.offAddrBlockNode)
1063	pInt->cUsedNodes++;
1064	}
1065
1066	pNode = &pInt->Core;
1067	}
1068	}
1069	else
1070	AssertMsgFailed(("Invalid node type %d\n", pNodeImage->u8Type));
1071
1072	if (pNode)
1073	pNode->u64BlockAddr = offBlockAddrNode;
1074
1075	return pNode;
1076	}
1077
1078	/**
1079	* Looks up the cache extent for the given virtual block address.
1080	*
1081	* @returns Pointer to the cache extent or NULL if none could be found.
1082	* @param pCache The cache image instance.
1083	* @param offBlockOffset The block offset to search for.
1084	* @param ppNextBestFit Where to store the pointer to the next best fit
1085	* cache extent above offBlockOffset if existing. - Optional
1086	* This is always filled if possible even if the function returns NULL.
1087	*/
1088	static PVCICACHEEXTENT vciCacheExtentLookup(PVCICACHE pCache, uint64_t offBlockOffset,
1089	PVCICACHEEXTENT *ppNextBestFit)
1090	{
1091	int rc = VINF_SUCCESS;
1092	PVCICACHEEXTENT pExtent = NULL;
1093	PVCITREENODE pNodeCur = pCache->pRoot;
1094
1095	while ( RT_SUCCESS(rc)
1096	&& pNodeCur
1097	&& pNodeCur->u8Type != VCI_TREE_NODE_TYPE_LEAF)
1098	{
1099	PVCITREENODEINT pNodeInt = (PVCITREENODEINT)pNodeCur;
1100
1101	Assert(pNodeCur->u8Type == VCI_TREE_NODE_TYPE_INTERNAL);
1102
1103	/* Search for the correct internal node. */
1104	unsigned idxMin = 0;
1105	unsigned idxMax = pNodeInt->cUsedNodes;
1106	unsigned idxCur = pNodeInt->cUsedNodes / 2;
1107
1108	while (idxMin < idxMax)
1109	{
1110	PVCINODEINTERNAL pInt = &pNodeInt->aIntNodes[idxCur];
1111
1112	/* Determine the search direction. */
1113	if (offBlockOffset < pInt->u64BlockOffset)
1114	{
1115	/* Search left from the current extent. */
1116	idxMax = idxCur;
1117	}
1118	else if (offBlockOffset >= pInt->u64BlockOffset + pInt->u32Blocks)
1119	{
1120	/* Search right from the current extent. */
1121	idxMin = idxCur;
1122	}
1123	else
1124	{
1125	/* The block lies in the node, stop searching. */
1126	if (pInt->PtrChild.fInMemory)
1127	pNodeCur = pInt->PtrChild.u.pNode;
1128	else
1129	{
1130	PVCITREENODE pNodeNew;
1131	VciTreeNode NodeTree;
1132
1133	/* Read from disk and add to the tree. */
1134	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage,
1135	VCI_BLOCK2BYTE(pInt->PtrChild.u.offAddrBlockNode),
1136	&NodeTree, sizeof(NodeTree));
1137	AssertRC(rc);
1138
1139	pNodeNew = vciTreeNodeImage2Host(pInt->PtrChild.u.offAddrBlockNode, &NodeTree);
1140	if (pNodeNew)
1141	{
1142	/* Link to the parent. */
1143	pInt->PtrChild.fInMemory = true;
1144	pInt->PtrChild.u.pNode = pNodeNew;
1145	pNodeNew->pParent = pNodeCur;
1146	pNodeCur = pNodeNew;
1147	}
1148	else
1149	rc = VERR_NO_MEMORY;
1150	}
1151	break;
1152	}
1153
1154	idxCur = idxMin + (idxMax - idxMin) / 2;
1155	}
1156	}
1157
1158	if ( RT_SUCCESS(rc)
1159	&& pNodeCur)
1160	{
1161	PVCITREENODELEAF pLeaf = (PVCITREENODELEAF)pNodeCur;
1162	Assert(pNodeCur->u8Type == VCI_TREE_NODE_TYPE_LEAF);
1163
1164	/* Search the range. */
1165	unsigned idxMin = 0;
1166	unsigned idxMax = pLeaf->cUsedNodes;
1167	unsigned idxCur = pLeaf->cUsedNodes / 2;
1168
1169	while (idxMin < idxMax)
1170	{
1171	PVCICACHEEXTENT pExtentCur = &pLeaf->aExtents[idxCur];
1172
1173	/* Determine the search direction. */
1174	if (offBlockOffset < pExtentCur->u64BlockOffset)
1175	{
1176	/* Search left from the current extent. */
1177	idxMax = idxCur;
1178	}
1179	else if (offBlockOffset >= pExtentCur->u64BlockOffset + pExtentCur->u32Blocks)
1180	{
1181	/* Search right from the current extent. */
1182	idxMin = idxCur;
1183	}
1184	else
1185	{
1186	/* We found the extent, stop searching. */
1187	pExtent = pExtentCur;
1188	break;
1189	}
1190
1191	idxCur = idxMin + (idxMax - idxMin) / 2;
1192	}
1193
1194	/* Get the next best fit extent if it exists. */
1195	if (ppNextBestFit)
1196	{
1197	if (idxCur < pLeaf->cUsedNodes - 1)
1198	*ppNextBestFit = &pLeaf->aExtents[idxCur + 1];
1199	else
1200	{
1201	/*
1202	* Go up the tree and find the best extent
1203	* in the leftmost tree of the child subtree to the right.
1204	*/
1205	PVCITREENODEINT pInt = (PVCITREENODEINT)pLeaf->Core.pParent;
1206
1207	while (pInt)
1208	{
1209
1210	}
1211	}
1212	}
1213	}
1214
1215	return pExtent;
1216	}
1217
1218	/**
1219	* Internal: Open an image, constructing all necessary data structures.
1220	*/
1221	static int vciOpenImage(PVCICACHE pCache, unsigned uOpenFlags)
1222	{
1223	VciHdr Hdr;
1224	uint64_t cbFile;
1225	int rc;
1226
1227	pCache->uOpenFlags = uOpenFlags;
1228
1229	pCache->pIfError = VDIfErrorGet(pCache->pVDIfsDisk);
1230	pCache->pIfIo = VDIfIoIntGet(pCache->pVDIfsImage);
1231	AssertPtrReturn(pCache->pIfIo, VERR_INVALID_PARAMETER);
1232
1233	/*
1234	* Open the image.
1235	*/
1236	rc = vdIfIoIntFileOpen(pCache->pIfIo, pCache->pszFilename,
1237	VDOpenFlagsToFileOpenFlags(uOpenFlags,
1238	false /* fCreate */),
1239	&pCache->pStorage);
1240	if (RT_FAILURE(rc))
1241	{
1242	/* Do NOT signal an appropriate error here, as the VD layer has the
1243	* choice of retrying the open if it failed. */
1244	goto out;
1245	}
1246
1247	rc = vdIfIoIntFileGetSize(pCache->pIfIo, pCache->pStorage, &cbFile);
1248	if (RT_FAILURE(rc) \|\| cbFile < sizeof(VciHdr))
1249	{
1250	rc = VERR_VD_GEN_INVALID_HEADER;
1251	goto out;
1252	}
1253
1254	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage, 0, &Hdr,
1255	VCI_BYTE2BLOCK(sizeof(Hdr)));
1256	if (RT_FAILURE(rc))
1257	{
1258	rc = VERR_VD_GEN_INVALID_HEADER;
1259	goto out;
1260	}
1261
1262	Hdr.u32Signature = RT_LE2H_U32(Hdr.u32Signature);
1263	Hdr.u32Version = RT_LE2H_U32(Hdr.u32Version);
1264	Hdr.cBlocksCache = RT_LE2H_U64(Hdr.cBlocksCache);
1265	Hdr.u32CacheType = RT_LE2H_U32(Hdr.u32CacheType);
1266	Hdr.offTreeRoot = RT_LE2H_U64(Hdr.offTreeRoot);
1267	Hdr.offBlkMap = RT_LE2H_U64(Hdr.offBlkMap);
1268	Hdr.cBlkMap = RT_LE2H_U32(Hdr.cBlkMap);
1269
1270	if ( Hdr.u32Signature == VCI_HDR_SIGNATURE
1271	&& Hdr.u32Version == VCI_HDR_VERSION)
1272	{
1273	pCache->offTreeRoot = Hdr.offTreeRoot;
1274	pCache->offBlksBitmap = Hdr.offBlkMap;
1275
1276	/* Load the block map. */
1277	rc = vciBlkMapLoad(pCache, pCache->offBlksBitmap, Hdr.cBlkMap, &pCache->pBlkMap);
1278	if (RT_SUCCESS(rc))
1279	{
1280	/* Load the first tree node. */
1281	VciTreeNode RootNode;
1282
1283	rc = vdIfIoIntFileReadSync(pCache->pIfIo, pCache->pStorage,
1284	pCache->offTreeRoot, &RootNode,
1285	VCI_BYTE2BLOCK(sizeof(VciTreeNode)));
1286	if (RT_SUCCESS(rc))
1287	{
1288	pCache->pRoot = vciTreeNodeImage2Host(pCache->offTreeRoot, &RootNode);
1289	if (!pCache->pRoot)
1290	rc = VERR_NO_MEMORY;
1291	}
1292	}
1293	}
1294	else
1295	rc = VERR_VD_GEN_INVALID_HEADER;
1296
1297	out:
1298	if (RT_FAILURE(rc))
1299	vciFreeImage(pCache, false);
1300	return rc;
1301	}
1302
1303	/**
1304	* Internal: Create a vci image.
1305	*/
1306	static int vciCreateImage(PVCICACHE pCache, uint64_t cbSize,
1307	unsigned uImageFlags, const char *pszComment,
1308	unsigned uOpenFlags, PFNVDPROGRESS pfnProgress,
1309	void *pvUser, unsigned uPercentStart,
1310	unsigned uPercentSpan)
1311	{
1312	RT_NOREF1(pszComment);
1313	VciHdr Hdr;
1314	VciTreeNode NodeRoot;
1315	int rc;
1316	uint64_t cBlocks = cbSize / VCI_BLOCK_SIZE; /* Size of the cache in blocks. */
1317
1318	pCache->uImageFlags = uImageFlags;
1319	pCache->uOpenFlags = uOpenFlags & ~VD_OPEN_FLAGS_READONLY;
1320
1321	pCache->pIfError = VDIfErrorGet(pCache->pVDIfsDisk);
1322	pCache->pIfIo = VDIfIoIntGet(pCache->pVDIfsImage);
1323	AssertPtrReturn(pCache->pIfIo, VERR_INVALID_PARAMETER);
1324
1325	if (uImageFlags & VD_IMAGE_FLAGS_DIFF)
1326	{
1327	rc = vdIfError(pCache->pIfError, VERR_VD_RAW_INVALID_TYPE, RT_SRC_POS, N_("VCI: cannot create diff image '%s'"), pCache->pszFilename);
1328	return rc;
1329	}
1330
1331	do
1332	{
1333	/* Create image file. */
1334	rc = vdIfIoIntFileOpen(pCache->pIfIo, pCache->pszFilename,
1335	VDOpenFlagsToFileOpenFlags(uOpenFlags & ~VD_OPEN_FLAGS_READONLY,
1336	true /* fCreate */),
1337	&pCache->pStorage);
1338	if (RT_FAILURE(rc))
1339	{
1340	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot create image '%s'"), pCache->pszFilename);
1341	break;
1342	}
1343
1344	/* Allocate block bitmap. */
1345	uint32_t cBlkMap = 0;
1346	rc = vciBlkMapCreate(cBlocks, &pCache->pBlkMap, &cBlkMap);
1347	if (RT_FAILURE(rc))
1348	{
1349	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot create block bitmap '%s'"), pCache->pszFilename);
1350	break;
1351	}
1352
1353	/*
1354	* Allocate space for the header in the block bitmap.
1355	* Because the block map is empty the header has to start at block 0
1356	*/
1357	uint64_t offHdr = 0;
1358	rc = vciBlkMapAllocate(pCache->pBlkMap, VCI_BYTE2BLOCK(sizeof(VciHdr)), VCIBLKMAP_ALLOC_META, &offHdr);
1359	if (RT_FAILURE(rc))
1360	{
1361	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for header in block bitmap '%s'"), pCache->pszFilename);
1362	break;
1363	}
1364
1365	Assert(offHdr == 0);
1366
1367	/*
1368	* Allocate space for the block map itself.
1369	*/
1370	uint64_t offBlkMap = 0;
1371	rc = vciBlkMapAllocate(pCache->pBlkMap, cBlkMap, VCIBLKMAP_ALLOC_META, &offBlkMap);
1372	if (RT_FAILURE(rc))
1373	{
1374	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for block map in block map '%s'"), pCache->pszFilename);
1375	break;
1376	}
1377
1378	/*
1379	* Allocate space for the tree root node.
1380	*/
1381	uint64_t offTreeRoot = 0;
1382	rc = vciBlkMapAllocate(pCache->pBlkMap, VCI_BYTE2BLOCK(sizeof(VciTreeNode)), VCIBLKMAP_ALLOC_META, &offTreeRoot);
1383	if (RT_FAILURE(rc))
1384	{
1385	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate space for block map in block map '%s'"), pCache->pszFilename);
1386	break;
1387	}
1388
1389	/*
1390	* Allocate the in memory root node.
1391	*/
1392	pCache->pRoot = (PVCITREENODE)RTMemAllocZ(sizeof(VCITREENODELEAF));
1393	if (!pCache->pRoot)
1394	{
1395	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot allocate B+-Tree root pointer '%s'"), pCache->pszFilename);
1396	break;
1397	}
1398
1399	pCache->pRoot->u8Type = VCI_TREE_NODE_TYPE_LEAF;
1400	/* Rest remains 0 as the tree is still empty. */
1401
1402	/*
1403	* Now that we are here we have all the basic structures and know where to place them in the image.
1404	* It's time to write it now.
1405	*/
1406
1407	/* Setup the header. */
1408	memset(&Hdr, 0, sizeof(VciHdr));
1409	Hdr.u32Signature = RT_H2LE_U32(VCI_HDR_SIGNATURE);
1410	Hdr.u32Version = RT_H2LE_U32(VCI_HDR_VERSION);
1411	Hdr.cBlocksCache = RT_H2LE_U64(cBlocks);
1412	Hdr.fUncleanShutdown = VCI_HDR_UNCLEAN_SHUTDOWN;
1413	Hdr.u32CacheType = uImageFlags & VD_IMAGE_FLAGS_FIXED
1414	? RT_H2LE_U32(VCI_HDR_CACHE_TYPE_FIXED)
1415	: RT_H2LE_U32(VCI_HDR_CACHE_TYPE_DYNAMIC);
1416	Hdr.offTreeRoot = RT_H2LE_U64(offTreeRoot);
1417	Hdr.offBlkMap = RT_H2LE_U64(offBlkMap);
1418	Hdr.cBlkMap = RT_H2LE_U32(cBlkMap);
1419
1420	rc = vdIfIoIntFileWriteSync(pCache->pIfIo, pCache->pStorage, offHdr, &Hdr,
1421	VCI_BYTE2BLOCK(sizeof(VciHdr)));
1422	if (RT_FAILURE(rc))
1423	{
1424	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write header '%s'"), pCache->pszFilename);
1425	break;
1426	}
1427
1428	rc = vciBlkMapSave(pCache->pBlkMap, pCache, offBlkMap, cBlkMap);
1429	if (RT_FAILURE(rc))
1430	{
1431	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write block map '%s'"), pCache->pszFilename);
1432	break;
1433	}
1434
1435	/* Setup the root tree. */
1436	memset(&NodeRoot, 0, sizeof(VciTreeNode));
1437	NodeRoot.u8Type = VCI_TREE_NODE_TYPE_LEAF;
1438
1439	rc = vdIfIoIntFileWriteSync(pCache->pIfIo, pCache->pStorage, offTreeRoot,
1440	&NodeRoot, VCI_BYTE2BLOCK(sizeof(VciTreeNode)));
1441	if (RT_FAILURE(rc))
1442	{
1443	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot write root node '%s'"), pCache->pszFilename);
1444	break;
1445	}
1446
1447	rc = vciFlushImage(pCache);
1448	if (RT_FAILURE(rc))
1449	{
1450	rc = vdIfError(pCache->pIfError, rc, RT_SRC_POS, N_("VCI: cannot flush '%s'"), pCache->pszFilename);
1451	break;
1452	}
1453
1454	pCache->cbSize = cbSize;
1455
1456	} while (0);
1457
1458	if (RT_SUCCESS(rc) && pfnProgress)
1459	pfnProgress(pvUser, uPercentStart + uPercentSpan);
1460
1461	if (RT_FAILURE(rc))
1462	vciFreeImage(pCache, rc != VERR_ALREADY_EXISTS);
1463	return rc;
1464	}
1465
1466	/** @copydoc VDCACHEBACKEND::pfnProbe */
1467	static DECLCALLBACK(int) vciProbe(const char *pszFilename, PVDINTERFACE pVDIfsDisk,
1468	PVDINTERFACE pVDIfsImage)
1469	{
1470	RT_NOREF1(pVDIfsDisk);
1471	VciHdr Hdr;
1472	PVDIOSTORAGE pStorage = NULL;
1473	uint64_t cbFile;
1474	int rc = VINF_SUCCESS;
1475
1476	LogFlowFunc(("pszFilename=\"%s\"\n", pszFilename));
1477
1478	PVDINTERFACEIOINT pIfIo = VDIfIoIntGet(pVDIfsImage);
1479	AssertPtrReturn(pIfIo, VERR_INVALID_PARAMETER);
1480
1481	rc = vdIfIoIntFileOpen(pIfIo, pszFilename,
1482	VDOpenFlagsToFileOpenFlags(VD_OPEN_FLAGS_READONLY,
1483	false /* fCreate */),
1484	&pStorage);
1485	if (RT_FAILURE(rc))
1486	goto out;
1487
1488	rc = vdIfIoIntFileGetSize(pIfIo, pStorage, &cbFile);
1489	if (RT_FAILURE(rc) \|\| cbFile < sizeof(VciHdr))
1490	{
1491	rc = VERR_VD_GEN_INVALID_HEADER;
1492	goto out;
1493	}
1494
1495	rc = vdIfIoIntFileReadSync(pIfIo, pStorage, 0, &Hdr, sizeof(Hdr));
1496	if (RT_FAILURE(rc))
1497	{
1498	rc = VERR_VD_GEN_INVALID_HEADER;
1499	goto out;
1500	}
1501
1502	Hdr.u32Signature = RT_LE2H_U32(Hdr.u32Signature);
1503	Hdr.u32Version = RT_LE2H_U32(Hdr.u32Version);
1504	Hdr.cBlocksCache = RT_LE2H_U64(Hdr.cBlocksCache);
1505	Hdr.u32CacheType = RT_LE2H_U32(Hdr.u32CacheType);
1506	Hdr.offTreeRoot = RT_LE2H_U64(Hdr.offTreeRoot);
1507	Hdr.offBlkMap = RT_LE2H_U64(Hdr.offBlkMap);
1508	Hdr.cBlkMap = RT_LE2H_U32(Hdr.cBlkMap);
1509
1510	if ( Hdr.u32Signature == VCI_HDR_SIGNATURE
1511	&& Hdr.u32Version == VCI_HDR_VERSION)
1512	rc = VINF_SUCCESS;
1513	else
1514	rc = VERR_VD_GEN_INVALID_HEADER;
1515
1516	out:
1517	if (pStorage)
1518	vdIfIoIntFileClose(pIfIo, pStorage);
1519
1520	LogFlowFunc(("returns %Rrc\n", rc));
1521	return rc;
1522	}
1523
1524	/** @copydoc VDCACHEBACKEND::pfnOpen */
1525	static DECLCALLBACK(int) vciOpen(const char *pszFilename, unsigned uOpenFlags,
1526	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1527	void **ppBackendData)
1528	{
1529	LogFlowFunc(("pszFilename=\"%s\" uOpenFlags=%#x pVDIfsDisk=%#p pVDIfsImage=%#p ppBackendData=%#p\n", pszFilename, uOpenFlags, pVDIfsDisk, pVDIfsImage, ppBackendData));
1530	int rc;
1531	PVCICACHE pCache;
1532
1533	/* Check open flags. All valid flags are supported. */
1534	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1535	{
1536	rc = VERR_INVALID_PARAMETER;
1537	goto out;
1538	}
1539
1540	/* Check remaining arguments. */
1541	if ( !RT_VALID_PTR(pszFilename)
1542	\|\| !*pszFilename)
1543	{
1544	rc = VERR_INVALID_PARAMETER;
1545	goto out;
1546	}
1547
1548
1549	pCache = (PVCICACHE)RTMemAllocZ(sizeof(VCICACHE));
1550	if (!pCache)
1551	{
1552	rc = VERR_NO_MEMORY;
1553	goto out;
1554	}
1555	pCache->pszFilename = pszFilename;
1556	pCache->pStorage = NULL;
1557	pCache->pVDIfsDisk = pVDIfsDisk;
1558	pCache->pVDIfsImage = pVDIfsImage;
1559
1560	rc = vciOpenImage(pCache, uOpenFlags);
1561	if (RT_SUCCESS(rc))
1562	*ppBackendData = pCache;
1563	else
1564	RTMemFree(pCache);
1565
1566	out:
1567	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1568	return rc;
1569	}
1570
1571	/** @copydoc VDCACHEBACKEND::pfnCreate */
1572	static DECLCALLBACK(int) vciCreate(const char *pszFilename, uint64_t cbSize,
1573	unsigned uImageFlags, const char *pszComment,
1574	PCRTUUID pUuid, unsigned uOpenFlags,
1575	unsigned uPercentStart, unsigned uPercentSpan,
1576	PVDINTERFACE pVDIfsDisk, PVDINTERFACE pVDIfsImage,
1577	PVDINTERFACE pVDIfsOperation, void **ppBackendData)
1578	{
1579	RT_NOREF1(pUuid);
1580	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",
1581	pszFilename, cbSize, uImageFlags, pszComment, pUuid, uOpenFlags, uPercentStart, uPercentSpan, pVDIfsDisk, pVDIfsImage, pVDIfsOperation, ppBackendData));
1582	int rc;
1583	PVCICACHE pCache;
1584
1585	PFNVDPROGRESS pfnProgress = NULL;
1586	void *pvUser = NULL;
1587	PVDINTERFACEPROGRESS pIfProgress = VDIfProgressGet(pVDIfsOperation);
1588	if (pIfProgress)
1589	{
1590	pfnProgress = pIfProgress->pfnProgress;
1591	pvUser = pIfProgress->Core.pvUser;
1592	}
1593
1594	/* Check open flags. All valid flags are supported. */
1595	if (uOpenFlags & ~VD_OPEN_FLAGS_MASK)
1596	{
1597	rc = VERR_INVALID_PARAMETER;
1598	goto out;
1599	}
1600
1601	/* Check remaining arguments. */
1602	if ( !RT_VALID_PTR(pszFilename)
1603	\|\| !*pszFilename)
1604	{
1605	rc = VERR_INVALID_PARAMETER;
1606	goto out;
1607	}
1608
1609	pCache = (PVCICACHE)RTMemAllocZ(sizeof(VCICACHE));
1610	if (!pCache)
1611	{
1612	rc = VERR_NO_MEMORY;
1613	goto out;
1614	}
1615	pCache->pszFilename = pszFilename;
1616	pCache->pStorage = NULL;
1617	pCache->pVDIfsDisk = pVDIfsDisk;
1618	pCache->pVDIfsImage = pVDIfsImage;
1619
1620	rc = vciCreateImage(pCache, cbSize, uImageFlags, pszComment, uOpenFlags,
1621	pfnProgress, pvUser, uPercentStart, uPercentSpan);
1622	if (RT_SUCCESS(rc))
1623	{
1624	/* So far the image is opened in read/write mode. Make sure the
1625	* image is opened in read-only mode if the caller requested that. */
1626	if (uOpenFlags & VD_OPEN_FLAGS_READONLY)
1627	{
1628	vciFreeImage(pCache, false);
1629	rc = vciOpenImage(pCache, uOpenFlags);
1630	if (RT_FAILURE(rc))
1631	{
1632	RTMemFree(pCache);
1633	goto out;
1634	}
1635	}
1636	*ppBackendData = pCache;
1637	}
1638	else
1639	RTMemFree(pCache);
1640
1641	out:
1642	LogFlowFunc(("returns %Rrc (pBackendData=%#p)\n", rc, *ppBackendData));
1643	return rc;
1644	}
1645
1646	/** @copydoc VDCACHEBACKEND::pfnClose */
1647	static DECLCALLBACK(int) vciClose(void *pBackendData, bool fDelete)
1648	{
1649	LogFlowFunc(("pBackendData=%#p fDelete=%d\n", pBackendData, fDelete));
1650	PVCICACHE pCache = (PVCICACHE)pBackendData;
1651	int rc;
1652
1653	rc = vciFreeImage(pCache, fDelete);
1654	RTMemFree(pCache);
1655
1656	LogFlowFunc(("returns %Rrc\n", rc));
1657	return rc;
1658	}
1659
1660	/** @copydoc VDCACHEBACKEND::pfnRead */
1661	static DECLCALLBACK(int) vciRead(void *pBackendData, uint64_t uOffset, size_t cbToRead,
1662	PVDIOCTX pIoCtx, size_t *pcbActuallyRead)
1663	{
1664	LogFlowFunc(("pBackendData=%#p uOffset=%llu cbToRead=%zu pIoCtx=%#p pcbActuallyRead=%#p\n",
1665	pBackendData, uOffset, cbToRead, pIoCtx, pcbActuallyRead));
1666	PVCICACHE pCache = (PVCICACHE)pBackendData;
1667	int rc = VINF_SUCCESS;
1668	PVCICACHEEXTENT pExtent;
1669	uint64_t cBlocksToRead = VCI_BYTE2BLOCK(cbToRead);
1670	uint64_t offBlockAddr = VCI_BYTE2BLOCK(uOffset);
1671
1672	AssertPtr(pCache);
1673	Assert(uOffset % 512 == 0);
1674	Assert(cbToRead % 512 == 0);
1675
1676	pExtent = vciCacheExtentLookup(pCache, offBlockAddr, NULL);
1677	if (pExtent)
1678	{
1679	uint64_t offRead = offBlockAddr - pExtent->u64BlockOffset;
1680	cBlocksToRead = RT_MIN(cBlocksToRead, pExtent->u32Blocks - offRead);
1681
1682	rc = vdIfIoIntFileReadUser(pCache->pIfIo, pCache->pStorage,
1683	pExtent->u64BlockAddr + offRead,
1684	pIoCtx, cBlocksToRead);
1685	}
1686	else
1687	{
1688	/** @todo Best fit to check whether we have cached data later and set
1689	* pcbActuallyRead accordingly. */
1690	rc = VERR_VD_BLOCK_FREE;
1691	}
1692
1693	if (pcbActuallyRead)
1694	*pcbActuallyRead = VCI_BLOCK2BYTE(cBlocksToRead);
1695
1696	LogFlowFunc(("returns %Rrc\n", rc));
1697	return rc;
1698	}
1699
1700	/** @copydoc VDCACHEBACKEND::pfnWrite */
1701	static DECLCALLBACK(int) vciWrite(void *pBackendData, uint64_t uOffset, size_t cbToWrite,
1702	PVDIOCTX pIoCtx, size_t *pcbWriteProcess)
1703	{
1704	RT_NOREF5(pBackendData, uOffset, cbToWrite, pIoCtx, pcbWriteProcess);
1705	LogFlowFunc(("pBackendData=%#p uOffset=%llu cbToWrite=%zu pIoCtx=%#p pcbWriteProcess=%#p\n",
1706	pBackendData, uOffset, cbToWrite, pIoCtx, pcbWriteProcess));
1707	PVCICACHE pCache = (PVCICACHE)pBackendData;
1708	int rc = VINF_SUCCESS;
1709	uint64_t cBlocksToWrite = VCI_BYTE2BLOCK(cbToWrite);
1710	//uint64_t offBlockAddr = VCI_BYTE2BLOCK(uOffset);
1711
1712	AssertPtr(pCache); NOREF(pCache);
1713	Assert(uOffset % 512 == 0);
1714	Assert(cbToWrite % 512 == 0);
1715	while (cBlocksToWrite)
1716	{
1717
1718	}
1719
1720	pcbWriteProcess = cbToWrite; /* @todo Implement. */
1721
1722	LogFlowFunc(("returns %Rrc\n", rc));
1723	return rc;
1724	}
1725
1726	/** @copydoc VDCACHEBACKEND::pfnFlush */
1727	static DECLCALLBACK(int) vciFlush(void *pBackendData, PVDIOCTX pIoCtx)
1728	{
1729	RT_NOREF1(pIoCtx);
1730	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1731	PVCICACHE pCache = (PVCICACHE)pBackendData;
1732
1733	int rc = vciFlushImage(pCache);
1734	LogFlowFunc(("returns %Rrc\n", rc));
1735	return rc;
1736	}
1737
1738	/** @copydoc VDCACHEBACKEND::pfnGetVersion */
1739	static DECLCALLBACK(unsigned) vciGetVersion(void *pBackendData)
1740	{
1741	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1742	PVCICACHE pCache = (PVCICACHE)pBackendData;
1743
1744	AssertPtr(pCache);
1745
1746	if (pCache)
1747	return 1;
1748	else
1749	return 0;
1750	}
1751
1752	/** @copydoc VDCACHEBACKEND::pfnGetSize */
1753	static DECLCALLBACK(uint64_t) vciGetSize(void *pBackendData)
1754	{
1755	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1756	PVCICACHE pCache = (PVCICACHE)pBackendData;
1757	uint64_t cb = 0;
1758
1759	AssertPtr(pCache);
1760
1761	if (pCache && pCache->pStorage)
1762	cb = pCache->cbSize;
1763
1764	LogFlowFunc(("returns %llu\n", cb));
1765	return cb;
1766	}
1767
1768	/** @copydoc VDCACHEBACKEND::pfnGetFileSize */
1769	static DECLCALLBACK(uint64_t) vciGetFileSize(void *pBackendData)
1770	{
1771	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1772	PVCICACHE pCache = (PVCICACHE)pBackendData;
1773	uint64_t cb = 0;
1774
1775	AssertPtr(pCache);
1776
1777	if (pCache)
1778	{
1779	uint64_t cbFile;
1780	if (pCache->pStorage)
1781	{
1782	int rc = vdIfIoIntFileGetSize(pCache->pIfIo, pCache->pStorage, &cbFile);
1783	if (RT_SUCCESS(rc))
1784	cb = cbFile;
1785	}
1786	}
1787
1788	LogFlowFunc(("returns %lld\n", cb));
1789	return cb;
1790	}
1791
1792	/** @copydoc VDCACHEBACKEND::pfnGetImageFlags */
1793	static DECLCALLBACK(unsigned) vciGetImageFlags(void *pBackendData)
1794	{
1795	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1796	PVCICACHE pCache = (PVCICACHE)pBackendData;
1797	unsigned uImageFlags;
1798
1799	AssertPtr(pCache);
1800
1801	if (pCache)
1802	uImageFlags = pCache->uImageFlags;
1803	else
1804	uImageFlags = 0;
1805
1806	LogFlowFunc(("returns %#x\n", uImageFlags));
1807	return uImageFlags;
1808	}
1809
1810	/** @copydoc VDCACHEBACKEND::pfnGetOpenFlags */
1811	static DECLCALLBACK(unsigned) vciGetOpenFlags(void *pBackendData)
1812	{
1813	LogFlowFunc(("pBackendData=%#p\n", pBackendData));
1814	PVCICACHE pCache = (PVCICACHE)pBackendData;
1815	unsigned uOpenFlags;
1816
1817	AssertPtr(pCache);
1818
1819	if (pCache)
1820	uOpenFlags = pCache->uOpenFlags;
1821	else
1822	uOpenFlags = 0;
1823
1824	LogFlowFunc(("returns %#x\n", uOpenFlags));
1825	return uOpenFlags;
1826	}
1827
1828	/** @copydoc VDCACHEBACKEND::pfnSetOpenFlags */
1829	static DECLCALLBACK(int) vciSetOpenFlags(void *pBackendData, unsigned uOpenFlags)
1830	{
1831	LogFlowFunc(("pBackendData=%#p\n uOpenFlags=%#x", pBackendData, uOpenFlags));
1832	PVCICACHE pCache = (PVCICACHE)pBackendData;
1833	int rc;
1834
1835	/* Image must be opened and the new flags must be valid. Just readonly and
1836	* info flags are supported. */
1837	if (!pCache \|\| (uOpenFlags & ~(VD_OPEN_FLAGS_READONLY \| VD_OPEN_FLAGS_INFO)))
1838	{
1839	rc = VERR_INVALID_PARAMETER;
1840	goto out;
1841	}
1842
1843	/* Implement this operation via reopening the image. */
1844	rc = vciFreeImage(pCache, false);
1845	if (RT_FAILURE(rc))
1846	goto out;
1847	rc = vciOpenImage(pCache, uOpenFlags);
1848
1849	out:
1850	LogFlowFunc(("returns %Rrc\n", rc));
1851	return rc;
1852	}
1853
1854	/** @copydoc VDCACHEBACKEND::pfnGetComment */
1855	static DECLCALLBACK(int) vciGetComment(void pBackendData, char pszComment,
1856	size_t cbComment)
1857	{
1858	RT_NOREF2(pszComment, cbComment);
1859	LogFlowFunc(("pBackendData=%#p pszComment=%#p cbComment=%zu\n", pBackendData, pszComment, cbComment));
1860	PVCICACHE pCache = (PVCICACHE)pBackendData;
1861	int rc;
1862
1863	AssertPtr(pCache);
1864
1865	if (pCache)
1866	rc = VERR_NOT_SUPPORTED;
1867	else
1868	rc = VERR_VD_NOT_OPENED;
1869
1870	LogFlowFunc(("returns %Rrc comment='%s'\n", rc, pszComment));
1871	return rc;
1872	}
1873
1874	/** @copydoc VDCACHEBACKEND::pfnSetComment */
1875	static DECLCALLBACK(int) vciSetComment(void pBackendData, const char pszComment)
1876	{
1877	RT_NOREF1(pszComment);
1878	LogFlowFunc(("pBackendData=%#p pszComment=\"%s\"\n", pBackendData, pszComment));
1879	PVCICACHE pCache = (PVCICACHE)pBackendData;
1880	int rc;
1881
1882	AssertPtr(pCache);
1883
1884	if (pCache)
1885	{
1886	if (pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY)
1887	rc = VERR_VD_IMAGE_READ_ONLY;
1888	else
1889	rc = VERR_NOT_SUPPORTED;
1890	}
1891	else
1892	rc = VERR_VD_NOT_OPENED;
1893
1894	LogFlowFunc(("returns %Rrc\n", rc));
1895	return rc;
1896	}
1897
1898	/** @copydoc VDCACHEBACKEND::pfnGetUuid */
1899	static DECLCALLBACK(int) vciGetUuid(void *pBackendData, PRTUUID pUuid)
1900	{
1901	RT_NOREF1(pUuid);
1902	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
1903	PVCICACHE pCache = (PVCICACHE)pBackendData;
1904	int rc;
1905
1906	AssertPtr(pCache);
1907
1908	if (pCache)
1909	rc = VERR_NOT_SUPPORTED;
1910	else
1911	rc = VERR_VD_NOT_OPENED;
1912
1913	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
1914	return rc;
1915	}
1916
1917	/** @copydoc VDCACHEBACKEND::pfnSetUuid */
1918	static DECLCALLBACK(int) vciSetUuid(void *pBackendData, PCRTUUID pUuid)
1919	{
1920	RT_NOREF1(pUuid);
1921	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
1922	PVCICACHE pCache = (PVCICACHE)pBackendData;
1923	int rc;
1924
1925	LogFlowFunc(("%RTuuid\n", pUuid));
1926	AssertPtr(pCache);
1927
1928	if (pCache)
1929	{
1930	if (!(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1931	rc = VERR_NOT_SUPPORTED;
1932	else
1933	rc = VERR_VD_IMAGE_READ_ONLY;
1934	}
1935	else
1936	rc = VERR_VD_NOT_OPENED;
1937
1938	LogFlowFunc(("returns %Rrc\n", rc));
1939	return rc;
1940	}
1941
1942	/** @copydoc VDCACHEBACKEND::pfnGetModificationUuid */
1943	static DECLCALLBACK(int) vciGetModificationUuid(void *pBackendData, PRTUUID pUuid)
1944	{
1945	RT_NOREF1(pUuid);
1946	LogFlowFunc(("pBackendData=%#p pUuid=%#p\n", pBackendData, pUuid));
1947	PVCICACHE pCache = (PVCICACHE)pBackendData;
1948	int rc;
1949
1950	AssertPtr(pCache);
1951
1952	if (pCache)
1953	rc = VERR_NOT_SUPPORTED;
1954	else
1955	rc = VERR_VD_NOT_OPENED;
1956
1957	LogFlowFunc(("returns %Rrc (%RTuuid)\n", rc, pUuid));
1958	return rc;
1959	}
1960
1961	/** @copydoc VDCACHEBACKEND::pfnSetModificationUuid */
1962	static DECLCALLBACK(int) vciSetModificationUuid(void *pBackendData, PCRTUUID pUuid)
1963	{
1964	RT_NOREF1(pUuid);
1965	LogFlowFunc(("pBackendData=%#p Uuid=%RTuuid\n", pBackendData, pUuid));
1966	PVCICACHE pCache = (PVCICACHE)pBackendData;
1967	int rc;
1968
1969	AssertPtr(pCache);
1970
1971	if (pCache)
1972	{
1973	if (!(pCache->uOpenFlags & VD_OPEN_FLAGS_READONLY))
1974	rc = VERR_NOT_SUPPORTED;
1975	else
1976	rc = VERR_VD_IMAGE_READ_ONLY;
1977	}
1978	else
1979	rc = VERR_VD_NOT_OPENED;
1980
1981	LogFlowFunc(("returns %Rrc\n", rc));
1982	return rc;
1983	}
1984
1985	/** @copydoc VDCACHEBACKEND::pfnDump */
1986	static DECLCALLBACK(void) vciDump(void *pBackendData)
1987	{
1988	NOREF(pBackendData);
1989	}
1990
1991
1992	const VDCACHEBACKEND g_VciCacheBackend =
1993	{
1994	/* u32Version */
1995	VD_CACHEBACKEND_VERSION,
1996	/* pszBackendName */
1997	"vci",
1998	/* uBackendCaps */
1999	VD_CAP_CREATE_FIXED \| VD_CAP_CREATE_DYNAMIC \| VD_CAP_FILE \| VD_CAP_VFS,
2000	/* papszFileExtensions */
2001	s_apszVciFileExtensions,
2002	/* paConfigInfo */
2003	NULL,
2004	/* pfnProbe */
2005	vciProbe,
2006	/* pfnOpen */
2007	vciOpen,
2008	/* pfnCreate */
2009	vciCreate,
2010	/* pfnClose */
2011	vciClose,
2012	/* pfnRead */
2013	vciRead,
2014	/* pfnWrite */
2015	vciWrite,
2016	/* pfnFlush */
2017	vciFlush,
2018	/* pfnDiscard */
2019	NULL,
2020	/* pfnGetVersion */
2021	vciGetVersion,
2022	/* pfnGetSize */
2023	vciGetSize,
2024	/* pfnGetFileSize */
2025	vciGetFileSize,
2026	/* pfnGetImageFlags */
2027	vciGetImageFlags,
2028	/* pfnGetOpenFlags */
2029	vciGetOpenFlags,
2030	/* pfnSetOpenFlags */
2031	vciSetOpenFlags,
2032	/* pfnGetComment */
2033	vciGetComment,
2034	/* pfnSetComment */
2035	vciSetComment,
2036	/* pfnGetUuid */
2037	vciGetUuid,
2038	/* pfnSetUuid */
2039	vciSetUuid,
2040	/* pfnGetModificationUuid */
2041	vciGetModificationUuid,
2042	/* pfnSetModificationUuid */
2043	vciSetModificationUuid,
2044	/* pfnDump */
2045	vciDump,
2046	/* pfnComposeLocation */
2047	NULL,
2048	/* pfnComposeName */
2049	NULL,
2050	/* u32VersionEnd */
2051	VD_CACHEBACKEND_VERSION
2052	};
2053

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source: vbox/trunk/src/VBox/Storage/VCICache.cpp@ 104747

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