VirtualBox

source: vbox/trunk/src/VBox/Storage/VDInternal.h@ 78296

Last change on this file since 78296 was 76578, checked in by vboxsync, 5 years ago

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1/* $Id: VDInternal.h 76578 2019-01-01 06:11:47Z vboxsync $ */
2/** @file
3 * VD - Virtual Disk container implementation, internal header file.
4 */
5
6/*
7 * Copyright (C) 2017-2019 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
22#ifndef VBOX_INCLUDED_SRC_Storage_VDInternal_h
23#define VBOX_INCLUDED_SRC_Storage_VDInternal_h
24#ifndef RT_WITHOUT_PRAGMA_ONCE
25# pragma once
26#endif
27#include <VBox/vd.h>
28#include <VBox/vd-plugin.h>
29
30#include <iprt/avl.h>
31#include <iprt/list.h>
32#include <iprt/memcache.h>
33
34/** Disable dynamic backends on non x86 architectures. This feature
35 * requires the SUPR3 library which is not available there.
36 */
37#if !defined(VBOX_HDD_NO_DYNAMIC_BACKENDS) && !defined(RT_ARCH_X86) && !defined(RT_ARCH_AMD64)
38# define VBOX_HDD_NO_DYNAMIC_BACKENDS
39#endif
40
41/** Magic number contained in the VDISK instance data, used for checking that the passed
42 * pointer contains a valid instance in debug builds. */
43#define VDISK_SIGNATURE 0x6f0e2a7d
44
45/**
46 * Structure containing everything I/O related
47 * for the image and cache descriptors.
48 */
49typedef struct VDIO
50{
51 /** I/O interface to the upper layer. */
52 PVDINTERFACEIO pInterfaceIo;
53
54 /** Per image internal I/O interface. */
55 VDINTERFACEIOINT VDIfIoInt;
56
57 /** Fallback I/O interface, only used if the caller doesn't provide it. */
58 VDINTERFACEIO VDIfIo;
59
60 /** Opaque backend data. */
61 void *pBackendData;
62 /** Disk this image is part of */
63 PVDISK pDisk;
64 /** Flag whether to ignore flush requests. */
65 bool fIgnoreFlush;
66} VDIO, *PVDIO;
67
68/** Forward declaration of an I/O task */
69typedef struct VDIOTASK *PVDIOTASK;
70
71/**
72 * Virtual disk container image descriptor.
73 */
74typedef struct VDIMAGE
75{
76 /** Link to parent image descriptor, if any. */
77 struct VDIMAGE *pPrev;
78 /** Link to child image descriptor, if any. */
79 struct VDIMAGE *pNext;
80 /** Cached image size. */
81 uint64_t cbImage;
82 /** Container base filename. (UTF-8) */
83 char *pszFilename;
84 /** Data managed by the backend which keeps the actual info. */
85 void *pBackendData;
86 /** Cached sanitized image flags. */
87 unsigned uImageFlags;
88 /** Image open flags (only those handled generically in this code and which
89 * the backends will never ever see). */
90 unsigned uOpenFlags;
91
92 /** Function pointers for the various backend methods. */
93 PCVDIMAGEBACKEND Backend;
94 /** Pointer to list of VD interfaces, per-image. */
95 PVDINTERFACE pVDIfsImage;
96 /** I/O related things. */
97 VDIO VDIo;
98} VDIMAGE, *PVDIMAGE;
99
100/** The special uninitialized size value for he image. */
101#define VD_IMAGE_SIZE_UNINITIALIZED UINT64_C(0)
102
103/**
104 * Virtual disk cache image descriptor.
105 */
106typedef struct VDCACHE
107{
108 /** Cache base filename. (UTF-8) */
109 char *pszFilename;
110 /** Data managed by the backend which keeps the actual info. */
111 void *pBackendData;
112 /** Cached sanitized image flags. */
113 unsigned uImageFlags;
114 /** Image open flags (only those handled generically in this code and which
115 * the backends will never ever see). */
116 unsigned uOpenFlags;
117
118 /** Function pointers for the various backend methods. */
119 PCVDCACHEBACKEND Backend;
120
121 /** Pointer to list of VD interfaces, per-cache. */
122 PVDINTERFACE pVDIfsCache;
123 /** I/O related things. */
124 VDIO VDIo;
125} VDCACHE, *PVDCACHE;
126
127/**
128 * A block waiting for a discard.
129 */
130typedef struct VDDISCARDBLOCK
131{
132 /** AVL core. */
133 AVLRU64NODECORE Core;
134 /** LRU list node. */
135 RTLISTNODE NodeLru;
136 /** Number of bytes to discard. */
137 size_t cbDiscard;
138 /** Bitmap of allocated sectors. */
139 void *pbmAllocated;
140} VDDISCARDBLOCK, *PVDDISCARDBLOCK;
141
142/**
143 * VD discard state.
144 */
145typedef struct VDDISCARDSTATE
146{
147 /** Number of bytes waiting for a discard. */
148 size_t cbDiscarding;
149 /** AVL tree with blocks waiting for a discard.
150 * The uOffset + cbDiscard range is the search key. */
151 PAVLRU64TREE pTreeBlocks;
152 /** LRU list of the least frequently discarded blocks.
153 * If there are to many blocks waiting the least frequently used
154 * will be removed and the range will be set to 0.
155 */
156 RTLISTNODE ListLru;
157} VDDISCARDSTATE, *PVDDISCARDSTATE;
158
159/**
160 * VD filter instance.
161 */
162typedef struct VDFILTER
163{
164 /** List node for the read filter chain. */
165 RTLISTNODE ListNodeChainRead;
166 /** List node for the write filter chain. */
167 RTLISTNODE ListNodeChainWrite;
168 /** Number of references to this filter. */
169 uint32_t cRefs;
170 /** Opaque VD filter backend instance data. */
171 void *pvBackendData;
172 /** Pointer to the filter backend interface. */
173 PCVDFILTERBACKEND pBackend;
174 /** Pointer to list of VD interfaces, per-filter. */
175 PVDINTERFACE pVDIfsFilter;
176 /** I/O related things. */
177 VDIO VDIo;
178} VDFILTER;
179/** Pointer to a VD filter instance. */
180typedef VDFILTER *PVDFILTER;
181
182/**
183 * Virtual disk container main structure, private part.
184 */
185struct VDISK
186{
187 /** Structure signature (VDISK_SIGNATURE). */
188 uint32_t u32Signature;
189
190 /** Image type. */
191 VDTYPE enmType;
192
193 /** Number of opened images. */
194 unsigned cImages;
195
196 /** Base image. */
197 PVDIMAGE pBase;
198
199 /** Last opened image in the chain.
200 * The same as pBase if only one image is used. */
201 PVDIMAGE pLast;
202
203 /** If a merge to one of the parents is running this may be non-NULL
204 * to indicate to what image the writes should be additionally relayed. */
205 PVDIMAGE pImageRelay;
206
207 /** Flags representing the modification state. */
208 unsigned uModified;
209
210 /** Cached size of this disk. */
211 uint64_t cbSize;
212 /** Cached PCHS geometry for this disk. */
213 VDGEOMETRY PCHSGeometry;
214 /** Cached LCHS geometry for this disk. */
215 VDGEOMETRY LCHSGeometry;
216
217 /** Pointer to list of VD interfaces, per-disk. */
218 PVDINTERFACE pVDIfsDisk;
219 /** Pointer to the common interface structure for error reporting. */
220 PVDINTERFACEERROR pInterfaceError;
221 /** Pointer to the optional thread synchronization callbacks. */
222 PVDINTERFACETHREADSYNC pInterfaceThreadSync;
223
224 /** Memory cache for I/O contexts */
225 RTMEMCACHE hMemCacheIoCtx;
226 /** Memory cache for I/O tasks. */
227 RTMEMCACHE hMemCacheIoTask;
228 /** An I/O context is currently using the disk structures
229 * Every I/O context must be placed on one of the lists below. */
230 volatile bool fLocked;
231 /** Head of pending I/O tasks waiting for completion - LIFO order. */
232 volatile PVDIOTASK pIoTasksPendingHead;
233 /** Head of newly queued I/O contexts - LIFO order. */
234 volatile PVDIOCTX pIoCtxHead;
235 /** Head of halted I/O contexts which are given back to generic
236 * disk framework by the backend. - LIFO order. */
237 volatile PVDIOCTX pIoCtxHaltedHead;
238
239 /** Head of blocked I/O contexts, processed only
240 * after pIoCtxLockOwner was freed - LIFO order. */
241 volatile PVDIOCTX pIoCtxBlockedHead;
242 /** I/O context which locked the disk for a growing write or flush request.
243 * Other flush or growing write requests need to wait until
244 * the current one completes. - NIL_VDIOCTX if unlocked. */
245 volatile PVDIOCTX pIoCtxLockOwner;
246 /** If the disk was locked by a growing write, flush or discard request this
247 * contains the start offset to check for interfering I/O while it is in progress. */
248 uint64_t uOffsetStartLocked;
249 /** If the disk was locked by a growing write, flush or discard request this contains
250 * the first non affected offset to check for interfering I/O while it is in progress. */
251 uint64_t uOffsetEndLocked;
252
253 /** Pointer to the L2 disk cache if any. */
254 PVDCACHE pCache;
255 /** Pointer to the discard state if any. */
256 PVDDISCARDSTATE pDiscard;
257
258 /** Read filter chain - PVDFILTER. */
259 RTLISTANCHOR ListFilterChainRead;
260 /** Write filter chain - PVDFILTER. */
261 RTLISTANCHOR ListFilterChainWrite;
262};
263
264
265DECLHIDDEN(int) vdPluginInit(void);
266DECLHIDDEN(int) vdPluginTerm(void);
267DECLHIDDEN(bool) vdPluginIsInitialized(void);
268DECLHIDDEN(int) vdPluginUnloadFromPath(const char *pszPath);
269DECLHIDDEN(int) vdPluginUnloadFromFilename(const char *pszFilename);
270DECLHIDDEN(int) vdPluginLoadFromPath(const char *pszPath);
271DECLHIDDEN(int) vdPluginLoadFromFilename(const char *pszFilename);
272
273DECLHIDDEN(uint32_t) vdGetImageBackendCount(void);
274DECLHIDDEN(int) vdQueryImageBackend(uint32_t idx, PCVDIMAGEBACKEND *ppBackend);
275DECLHIDDEN(int) vdFindImageBackend(const char *pszBackend, PCVDIMAGEBACKEND *ppBackend);
276DECLHIDDEN(uint32_t) vdGetCacheBackendCount(void);
277DECLHIDDEN(int) vdQueryCacheBackend(uint32_t idx, PCVDCACHEBACKEND *ppBackend);
278DECLHIDDEN(int) vdFindCacheBackend(const char *pszBackend, PCVDCACHEBACKEND *ppBackend);
279DECLHIDDEN(uint32_t) vdGetFilterBackendCount(void);
280DECLHIDDEN(int) vdQueryFilterBackend(uint32_t idx, PCVDFILTERBACKEND *ppBackend);
281DECLHIDDEN(int) vdFindFilterBackend(const char *pszFilter, PCVDFILTERBACKEND *ppBackend);
282
283DECLHIDDEN(int) vdIoIterQueryStartNext(VDIOITER hVdIoIter, uint64_t *pu64Start);
284DECLHIDDEN(int) vdIoIterQuerySegSizeByStart(VDIOITER hVdIoIter, uint64_t u64Start, size_t *pcRegSize);
285DECLHIDDEN(int) vdIoIterAdvance(VDIOITER hVdIoIter, uint64_t cBlocksOrBytes);
286
287#endif /* !VBOX_INCLUDED_SRC_Storage_VDInternal_h */
288
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