VirtualBox

source: vbox/trunk/src/VBox/Storage/VDInternal.h@ 75440

Last change on this file since 75440 was 75349, checked in by vboxsync, 6 years ago

Storage/VD: Fix error during merge if the target is bigger than the source image
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  • Property svn:keywords set to Author Date Id Revision
File size: 10.4 KB
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1/* $Id: VDInternal.h 75349 2018-11-09 10:36:54Z vboxsync $ */
2/** @file
3 * VD - Virtual Disk container implementation, internal header file.
4 */
5
6/*
7 * Copyright (C) 2017 Oracle Corporation
8 *
9 * This file is part of VirtualBox Open Source Edition (OSE), as
10 * available from http://www.virtualbox.org. This file is free software;
11 * you can redistribute it and/or modify it under the terms of the GNU
12 * General Public License (GPL) as published by the Free Software
13 * Foundation, in version 2 as it comes in the "COPYING" file of the
14 * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
15 * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
16 */
17
18/*********************************************************************************************************************************
19* Header Files *
20*********************************************************************************************************************************/
21#ifndef ___VDInternal_h
22#define ___VDInternal_h
23#include <VBox/vd.h>
24#include <VBox/vd-plugin.h>
25
26#include <iprt/avl.h>
27#include <iprt/list.h>
28#include <iprt/memcache.h>
29
30/** Disable dynamic backends on non x86 architectures. This feature
31 * requires the SUPR3 library which is not available there.
32 */
33#if !defined(VBOX_HDD_NO_DYNAMIC_BACKENDS) && !defined(RT_ARCH_X86) && !defined(RT_ARCH_AMD64)
34# define VBOX_HDD_NO_DYNAMIC_BACKENDS
35#endif
36
37/** Magic number contained in the VDISK instance data, used for checking that the passed
38 * pointer contains a valid instance in debug builds. */
39#define VDISK_SIGNATURE 0x6f0e2a7d
40
41/**
42 * Structure containing everything I/O related
43 * for the image and cache descriptors.
44 */
45typedef struct VDIO
46{
47 /** I/O interface to the upper layer. */
48 PVDINTERFACEIO pInterfaceIo;
49
50 /** Per image internal I/O interface. */
51 VDINTERFACEIOINT VDIfIoInt;
52
53 /** Fallback I/O interface, only used if the caller doesn't provide it. */
54 VDINTERFACEIO VDIfIo;
55
56 /** Opaque backend data. */
57 void *pBackendData;
58 /** Disk this image is part of */
59 PVDISK pDisk;
60 /** Flag whether to ignore flush requests. */
61 bool fIgnoreFlush;
62} VDIO, *PVDIO;
63
64/** Forward declaration of an I/O task */
65typedef struct VDIOTASK *PVDIOTASK;
66
67/**
68 * Virtual disk container image descriptor.
69 */
70typedef struct VDIMAGE
71{
72 /** Link to parent image descriptor, if any. */
73 struct VDIMAGE *pPrev;
74 /** Link to child image descriptor, if any. */
75 struct VDIMAGE *pNext;
76 /** Cached image size. */
77 uint64_t cbImage;
78 /** Container base filename. (UTF-8) */
79 char *pszFilename;
80 /** Data managed by the backend which keeps the actual info. */
81 void *pBackendData;
82 /** Cached sanitized image flags. */
83 unsigned uImageFlags;
84 /** Image open flags (only those handled generically in this code and which
85 * the backends will never ever see). */
86 unsigned uOpenFlags;
87
88 /** Function pointers for the various backend methods. */
89 PCVDIMAGEBACKEND Backend;
90 /** Pointer to list of VD interfaces, per-image. */
91 PVDINTERFACE pVDIfsImage;
92 /** I/O related things. */
93 VDIO VDIo;
94} VDIMAGE, *PVDIMAGE;
95
96/** The special uninitialized size value for he image. */
97#define VD_IMAGE_SIZE_UNINITIALIZED UINT64_C(0)
98
99/**
100 * Virtual disk cache image descriptor.
101 */
102typedef struct VDCACHE
103{
104 /** Cache base filename. (UTF-8) */
105 char *pszFilename;
106 /** Data managed by the backend which keeps the actual info. */
107 void *pBackendData;
108 /** Cached sanitized image flags. */
109 unsigned uImageFlags;
110 /** Image open flags (only those handled generically in this code and which
111 * the backends will never ever see). */
112 unsigned uOpenFlags;
113
114 /** Function pointers for the various backend methods. */
115 PCVDCACHEBACKEND Backend;
116
117 /** Pointer to list of VD interfaces, per-cache. */
118 PVDINTERFACE pVDIfsCache;
119 /** I/O related things. */
120 VDIO VDIo;
121} VDCACHE, *PVDCACHE;
122
123/**
124 * A block waiting for a discard.
125 */
126typedef struct VDDISCARDBLOCK
127{
128 /** AVL core. */
129 AVLRU64NODECORE Core;
130 /** LRU list node. */
131 RTLISTNODE NodeLru;
132 /** Number of bytes to discard. */
133 size_t cbDiscard;
134 /** Bitmap of allocated sectors. */
135 void *pbmAllocated;
136} VDDISCARDBLOCK, *PVDDISCARDBLOCK;
137
138/**
139 * VD discard state.
140 */
141typedef struct VDDISCARDSTATE
142{
143 /** Number of bytes waiting for a discard. */
144 size_t cbDiscarding;
145 /** AVL tree with blocks waiting for a discard.
146 * The uOffset + cbDiscard range is the search key. */
147 PAVLRU64TREE pTreeBlocks;
148 /** LRU list of the least frequently discarded blocks.
149 * If there are to many blocks waiting the least frequently used
150 * will be removed and the range will be set to 0.
151 */
152 RTLISTNODE ListLru;
153} VDDISCARDSTATE, *PVDDISCARDSTATE;
154
155/**
156 * VD filter instance.
157 */
158typedef struct VDFILTER
159{
160 /** List node for the read filter chain. */
161 RTLISTNODE ListNodeChainRead;
162 /** List node for the write filter chain. */
163 RTLISTNODE ListNodeChainWrite;
164 /** Number of references to this filter. */
165 uint32_t cRefs;
166 /** Opaque VD filter backend instance data. */
167 void *pvBackendData;
168 /** Pointer to the filter backend interface. */
169 PCVDFILTERBACKEND pBackend;
170 /** Pointer to list of VD interfaces, per-filter. */
171 PVDINTERFACE pVDIfsFilter;
172 /** I/O related things. */
173 VDIO VDIo;
174} VDFILTER;
175/** Pointer to a VD filter instance. */
176typedef VDFILTER *PVDFILTER;
177
178/**
179 * Virtual disk container main structure, private part.
180 */
181struct VDISK
182{
183 /** Structure signature (VDISK_SIGNATURE). */
184 uint32_t u32Signature;
185
186 /** Image type. */
187 VDTYPE enmType;
188
189 /** Number of opened images. */
190 unsigned cImages;
191
192 /** Base image. */
193 PVDIMAGE pBase;
194
195 /** Last opened image in the chain.
196 * The same as pBase if only one image is used. */
197 PVDIMAGE pLast;
198
199 /** If a merge to one of the parents is running this may be non-NULL
200 * to indicate to what image the writes should be additionally relayed. */
201 PVDIMAGE pImageRelay;
202
203 /** Flags representing the modification state. */
204 unsigned uModified;
205
206 /** Cached size of this disk. */
207 uint64_t cbSize;
208 /** Cached PCHS geometry for this disk. */
209 VDGEOMETRY PCHSGeometry;
210 /** Cached LCHS geometry for this disk. */
211 VDGEOMETRY LCHSGeometry;
212
213 /** Pointer to list of VD interfaces, per-disk. */
214 PVDINTERFACE pVDIfsDisk;
215 /** Pointer to the common interface structure for error reporting. */
216 PVDINTERFACEERROR pInterfaceError;
217 /** Pointer to the optional thread synchronization callbacks. */
218 PVDINTERFACETHREADSYNC pInterfaceThreadSync;
219
220 /** Memory cache for I/O contexts */
221 RTMEMCACHE hMemCacheIoCtx;
222 /** Memory cache for I/O tasks. */
223 RTMEMCACHE hMemCacheIoTask;
224 /** An I/O context is currently using the disk structures
225 * Every I/O context must be placed on one of the lists below. */
226 volatile bool fLocked;
227 /** Head of pending I/O tasks waiting for completion - LIFO order. */
228 volatile PVDIOTASK pIoTasksPendingHead;
229 /** Head of newly queued I/O contexts - LIFO order. */
230 volatile PVDIOCTX pIoCtxHead;
231 /** Head of halted I/O contexts which are given back to generic
232 * disk framework by the backend. - LIFO order. */
233 volatile PVDIOCTX pIoCtxHaltedHead;
234
235 /** Head of blocked I/O contexts, processed only
236 * after pIoCtxLockOwner was freed - LIFO order. */
237 volatile PVDIOCTX pIoCtxBlockedHead;
238 /** I/O context which locked the disk for a growing write or flush request.
239 * Other flush or growing write requests need to wait until
240 * the current one completes. - NIL_VDIOCTX if unlocked. */
241 volatile PVDIOCTX pIoCtxLockOwner;
242 /** If the disk was locked by a growing write, flush or discard request this
243 * contains the start offset to check for interfering I/O while it is in progress. */
244 uint64_t uOffsetStartLocked;
245 /** If the disk was locked by a growing write, flush or discard request this contains
246 * the first non affected offset to check for interfering I/O while it is in progress. */
247 uint64_t uOffsetEndLocked;
248
249 /** Pointer to the L2 disk cache if any. */
250 PVDCACHE pCache;
251 /** Pointer to the discard state if any. */
252 PVDDISCARDSTATE pDiscard;
253
254 /** Read filter chain - PVDFILTER. */
255 RTLISTANCHOR ListFilterChainRead;
256 /** Write filter chain - PVDFILTER. */
257 RTLISTANCHOR ListFilterChainWrite;
258};
259
260
261DECLHIDDEN(int) vdPluginInit(void);
262DECLHIDDEN(int) vdPluginTerm(void);
263DECLHIDDEN(bool) vdPluginIsInitialized(void);
264DECLHIDDEN(int) vdPluginUnloadFromPath(const char *pszPath);
265DECLHIDDEN(int) vdPluginUnloadFromFilename(const char *pszFilename);
266DECLHIDDEN(int) vdPluginLoadFromPath(const char *pszPath);
267DECLHIDDEN(int) vdPluginLoadFromFilename(const char *pszFilename);
268
269DECLHIDDEN(uint32_t) vdGetImageBackendCount(void);
270DECLHIDDEN(int) vdQueryImageBackend(uint32_t idx, PCVDIMAGEBACKEND *ppBackend);
271DECLHIDDEN(int) vdFindImageBackend(const char *pszBackend, PCVDIMAGEBACKEND *ppBackend);
272DECLHIDDEN(uint32_t) vdGetCacheBackendCount(void);
273DECLHIDDEN(int) vdQueryCacheBackend(uint32_t idx, PCVDCACHEBACKEND *ppBackend);
274DECLHIDDEN(int) vdFindCacheBackend(const char *pszBackend, PCVDCACHEBACKEND *ppBackend);
275DECLHIDDEN(uint32_t) vdGetFilterBackendCount(void);
276DECLHIDDEN(int) vdQueryFilterBackend(uint32_t idx, PCVDFILTERBACKEND *ppBackend);
277DECLHIDDEN(int) vdFindFilterBackend(const char *pszFilter, PCVDFILTERBACKEND *ppBackend);
278
279DECLHIDDEN(int) vdIoIterQueryStartNext(VDIOITER hVdIoIter, uint64_t *pu64Start);
280DECLHIDDEN(int) vdIoIterQuerySegSizeByStart(VDIOITER hVdIoIter, uint64_t u64Start, size_t *pcRegSize);
281DECLHIDDEN(int) vdIoIterAdvance(VDIOITER hVdIoIter, uint64_t cBlocksOrBytes);
282
283#endif /* !___VDInternal_h */
284
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