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1 // Copyright (c) 1996-2009 Nokia Corporation and/or its subsidiary(-ies). |
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2 // All rights reserved. |
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3 // This component and the accompanying materials are made available |
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4 // under the terms of the License "Eclipse Public License v1.0" |
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5 // which accompanies this distribution, and is available |
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6 // at the URL "http://www.eclipse.org/legal/epl-v10.html". |
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7 // |
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8 // Initial Contributors: |
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9 // Nokia Corporation - initial contribution. |
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10 // |
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11 // Contributors: |
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12 // |
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13 // Description: |
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14 // f32\sfat\fat_table.cpp |
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15 // FAT12/16 File Allocation Table classes implementation |
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16 // |
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17 // |
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18 |
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19 /** |
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20 @file |
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21 @internalTechnology |
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22 */ |
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23 |
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24 |
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25 |
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26 #include "sl_std.h" |
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27 #include "sl_fatcache.h" |
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28 #include "fat_table.h" |
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29 |
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30 |
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31 //####################################################################################################################################### |
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32 //# CFatTable class implementation |
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33 //####################################################################################################################################### |
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34 |
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35 /** |
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36 FAT object factory method. |
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37 Constructs either CAtaFatTable or CRamFatTable depending on the media type parameter |
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38 |
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39 @param aOwner Pointer to the owning mount |
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40 @param aLocDrvCaps local drive attributes |
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41 @leave KErrNoMemory |
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42 @return Pointer to the Fat table |
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43 */ |
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44 CFatTable* CFatTable::NewL(CFatMountCB& aOwner, const TLocalDriveCaps& aLocDrvCaps) |
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45 { |
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46 CFatTable* pFatTable=NULL; |
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47 |
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48 |
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49 switch(aLocDrvCaps.iType) |
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50 { |
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51 case EMediaRam: |
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52 {//-- this is RAM media, try to create CRamFatTable instance. |
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53 const TFatType fatType = aOwner.FatType(); |
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54 |
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55 if(fatType != EFat16 ) |
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56 {//-- CRamFatTable doesn't support FAT12; FAT16 only. |
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57 __PRINT1(_L("CFatTable::NewL() CRamFatTable doesn't support this FAT type:%d"), fatType); |
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58 ASSERT(0); |
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59 return NULL; |
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60 } |
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61 |
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62 pFatTable = CRamFatTable::NewL(aOwner); |
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63 } |
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64 break; |
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65 |
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66 default: |
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67 //-- other media |
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68 pFatTable = CAtaFatTable::NewL(aOwner); |
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69 break; |
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70 }; |
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71 |
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72 return pFatTable; |
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73 } |
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74 |
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75 CFatTable::CFatTable(CFatMountCB& aOwner) |
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76 { |
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77 iOwner = &aOwner; |
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78 ASSERT(iOwner); |
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79 } |
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80 |
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81 CFatTable::~CFatTable() |
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82 { |
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83 //-- destroy cache ignoring dirty data in cache |
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84 //-- the destructor isn't an appropriate place to flush the data. |
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85 Dismount(ETrue); |
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86 } |
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87 |
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88 //----------------------------------------------------------------------------- |
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89 |
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90 /** |
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91 Initialise the object, get data from the owning CFatMountCB |
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92 */ |
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93 void CFatTable::InitializeL() |
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94 { |
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95 ASSERT(iOwner); |
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96 |
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97 //-- get FAT type from the owner |
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98 iFatType = iOwner->FatType(); |
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99 ASSERT(IsFat12() || IsFat16()); |
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100 |
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101 iFreeClusterHint = KFatFirstSearchCluster; |
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102 |
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103 //-- cache the media attributes |
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104 TLocalDriveCapsV2 caps; |
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105 TPckg<TLocalDriveCapsV2> capsPckg(caps); |
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106 User::LeaveIfError(iOwner->LocalDrive()->Caps(capsPckg)); |
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107 iMediaAtt = caps.iMediaAtt; |
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108 |
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109 //-- obtain maximal number of entries in the table |
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110 iMaxEntries = iOwner->UsableClusters()+KFatFirstSearchCluster; //-- FAT[0] & FAT[1] are not in use |
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111 |
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112 __PRINT3(_L("CFatTable::InitializeL(), drv:%d, iMediaAtt = %08X, max Entries:%d"), iOwner->DriveNumber(), iMediaAtt, iMaxEntries); |
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113 } |
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114 |
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115 //----------------------------------------------------------------------------- |
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116 |
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117 /** |
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118 Decrements the free cluster count. |
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119 Note that can be quite expensive operation (especially for overrides with synchronisation), if it is called for every |
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120 cluster of a large file. Use more than one cluster granularity. |
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121 |
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122 @param aCount a number of clusters |
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123 */ |
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124 void CFatTable::DecrementFreeClusterCount(TUint32 aCount) |
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125 { |
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126 __ASSERT_DEBUG(iFreeClusters >= aCount, Fault(EFatCorrupt)); |
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127 iFreeClusters -= aCount; |
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128 } |
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129 |
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130 /** |
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131 Increments the free cluster count. |
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132 Note that can be quite expensive operation (especially for overrides with synchronisation), if it is called for every |
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133 cluster of a large file. Use more than one cluster granularity. |
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134 |
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135 @param aCount a number of clusters |
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136 */ |
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137 void CFatTable::IncrementFreeClusterCount(TUint32 aCount) |
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138 { |
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139 const TUint32 newVal = iFreeClusters+aCount; |
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140 __ASSERT_DEBUG(newVal<=MaxEntries(), Fault(EFatCorrupt)); |
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141 |
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142 iFreeClusters = newVal; |
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143 } |
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144 |
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145 /** @return number of free clusters in the FAT */ |
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146 TUint32 CFatTable::NumberOfFreeClusters(TBool /*aSyncOperation=EFalse*/) const |
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147 { |
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148 return FreeClusters(); |
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149 } |
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150 |
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151 void CFatTable::SetFreeClusters(TUint32 aFreeClusters) |
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152 { |
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153 iFreeClusters=aFreeClusters; |
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154 } |
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155 |
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156 /** |
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157 Get the hint about the last known free cluster number. |
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158 Note that can be quite expensive operation (especially for overrides with synchronisation), if it is called for every |
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159 cluster of a large file. |
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160 |
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161 @return cluster number supposedly close to the free one. |
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162 */ |
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163 TUint32 CFatTable::FreeClusterHint() const |
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164 { |
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165 ASSERT(ClusterNumberValid(iFreeClusterHint)); |
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166 return iFreeClusterHint; |
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167 } |
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168 |
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169 /** |
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170 Set a free cluster hint. The next search fro the free cluster can start from this value. |
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171 aCluster doesn't have to be a precise number of free FAT entry; it just needs to be as close as possible to the |
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172 free entries chain. |
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173 Note that can be quite expensive operation (especially for overrides with synchronisation), if it is called for every |
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174 cluster of a large file. |
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175 |
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176 @param aCluster cluster number hint. |
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177 */ |
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178 void CFatTable::SetFreeClusterHint(TUint32 aCluster) |
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179 { |
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180 ASSERT(ClusterNumberValid(aCluster)); |
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181 iFreeClusterHint=aCluster; |
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182 } |
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183 |
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184 //----------------------------------------------------------------------------- |
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185 |
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186 /** |
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187 Find out the number of free clusters on the volume. |
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188 Reads whole FAT and counts free clusters. |
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189 */ |
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190 void CFatTable::CountFreeClustersL() |
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191 { |
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192 __PRINT1(_L("#- CFatTable::CountFreeClustersL(), drv:%d"), iOwner->DriveNumber()); |
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193 |
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194 const TUint32 KUsableClusters = iOwner->UsableClusters(); |
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195 (void)KUsableClusters; |
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196 |
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197 TUint32 freeClusters = 0; |
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198 TUint32 firstFreeCluster = 0; |
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199 |
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200 TTime timeStart; |
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201 TTime timeEnd; |
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202 timeStart.UniversalTime(); //-- take start time |
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203 |
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204 //-- walk through whole FAT table looking for free clusters |
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205 for(TUint i=KFatFirstSearchCluster; i<MaxEntries(); ++i) |
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206 { |
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207 if(ReadL(i) == KSpareCluster) |
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208 {//-- found a free cluster |
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209 ++freeClusters; |
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210 |
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211 if(!firstFreeCluster) |
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212 firstFreeCluster = i; |
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213 } |
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214 } |
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215 |
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216 timeEnd.UniversalTime(); //-- take end time |
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217 const TInt msScanTime = (TInt)( (timeEnd.MicroSecondsFrom(timeStart)).Int64() / K1mSec); |
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218 __PRINT1(_L("#- CFatTable::CountFreeClustersL() finished. Taken:%d ms"), msScanTime); |
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219 (void)msScanTime; |
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220 |
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221 if(!firstFreeCluster) //-- haven't found free clusters on the volume |
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222 firstFreeCluster = KFatFirstSearchCluster; |
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223 |
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224 ASSERT(freeClusters <= KUsableClusters); |
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225 |
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226 SetFreeClusters(freeClusters); |
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227 SetFreeClusterHint(firstFreeCluster); |
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228 } |
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229 |
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230 //----------------------------------------------------------------------------- |
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231 |
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232 /** |
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233 Count the number of contiguous cluster from a start cluster |
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234 |
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235 @param aStartCluster cluster to start counting from |
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236 @param anEndCluster contains the end cluster number upon return |
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237 @param aMaxCount Maximum cluster required |
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238 @leave System wide error values |
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239 @return Number of contiguous clusters from aStartCluster. |
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240 */ |
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241 TInt CFatTable::CountContiguousClustersL(TUint32 aStartCluster,TInt& anEndCluster,TUint32 aMaxCount) const |
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242 { |
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243 __PRINT2(_L("CFatTable::CountContiguousClustersL() start:%d, max:%d"),aStartCluster, aMaxCount); |
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244 TUint32 clusterListLen=1; |
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245 TInt endCluster=aStartCluster; |
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246 TInt64 endClusterPos=DataPositionInBytes(endCluster); |
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247 while (clusterListLen<aMaxCount) |
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248 { |
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249 TInt oldCluster=endCluster; |
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250 TInt64 oldClusterPos=endClusterPos; |
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251 if (GetNextClusterL(endCluster)==EFalse || (endClusterPos=DataPositionInBytes(endCluster))!=(oldClusterPos+(1<<iOwner->ClusterSizeLog2()))) |
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252 { |
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253 endCluster=oldCluster; |
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254 break; |
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255 } |
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256 clusterListLen++; |
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257 } |
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258 anEndCluster=endCluster; |
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259 return(clusterListLen); |
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260 } |
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261 |
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262 //----------------------------------------------------------------------------- |
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263 |
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264 /** |
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265 Extend a file or directory cluster chain, leaves if there are no free clusters (the disk is full). |
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266 |
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267 @param aNumber amount of clusters to allocate |
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268 @param aCluster FAT entry index to start with. |
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269 |
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270 @leave KErrDiskFull + system wide error codes |
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271 */ |
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272 void CFatTable::ExtendClusterListL(TUint32 aNumber,TInt& aCluster) |
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273 { |
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274 __PRINT2(_L("CFatTable::ExtendClusterListL() num:%d, clust:%d"), aNumber, aCluster); |
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275 __ASSERT_DEBUG(aNumber>0,Fault(EFatBadParameter)); |
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276 |
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277 while(aNumber && GetNextClusterL(aCluster)) |
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278 aNumber--; |
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279 |
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280 if(!aNumber) |
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281 return; |
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282 |
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283 if (iFreeClusters<aNumber) |
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284 { |
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285 __PRINT(_L("CFatTable::ExtendClusterListL - leaving KErrDirFull")); |
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286 User::Leave(KErrDiskFull); |
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287 } |
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288 |
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289 |
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290 TUint32 freeCluster = 0; |
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291 |
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292 //-- note: this can be impoved by trying to fing as long chain of free clusters as possible in FindClosestFreeClusterL() |
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293 for(TUint i=0; i<aNumber; ++i) |
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294 { |
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295 freeCluster = FindClosestFreeClusterL(aCluster); |
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296 WriteFatEntryEofL(freeCluster); // Must write EOF for FindClosestFreeCluster to work again |
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297 WriteL(aCluster,freeCluster); |
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298 aCluster=freeCluster; |
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299 } |
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300 |
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301 //-- decrement number of available clusters |
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302 DecrementFreeClusterCount(aNumber); |
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303 |
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304 //-- update free cluster hint, it isn't required to be a precise value, just a hint where to start the from from |
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305 SetFreeClusterHint(aCluster); |
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306 |
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307 } |
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308 |
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309 //----------------------------------------------------------------------------- |
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310 |
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311 /** |
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312 Allocate and mark as EOF a single cluster as close as possible to aNearestCluster |
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313 |
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314 @param aNearestCluster Cluster the new cluster should be nearest to |
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315 @leave System wide error codes |
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316 @return The cluster number allocated |
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317 */ |
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318 TUint32 CFatTable::AllocateSingleClusterL(TUint32 aNearestCluster) |
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319 { |
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320 __PRINT1(_L("CFatTable::AllocateSingleCluster() nearest:%d"), aNearestCluster); |
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321 if (iFreeClusters==0) |
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322 User::Leave(KErrDiskFull); |
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323 const TInt freeCluster=FindClosestFreeClusterL(aNearestCluster); |
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324 WriteFatEntryEofL(freeCluster); |
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325 DecrementFreeClusterCount(1); |
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326 |
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327 //-- update free cluster hint, it isn't required to be a precise value, just a hint where to start the from from. |
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328 SetFreeClusterHint(freeCluster); |
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329 |
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330 return(freeCluster); |
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331 } |
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332 |
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333 //----------------------------------------------------------------------------- |
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334 |
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335 /** |
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336 Allocate and link a cluster chain, leaves if there are not enough free clusters. |
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337 Chain starts as close as possible to aNearestCluster, last cluster will be marked as EOF. |
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338 |
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339 @param aNumber Number of clusters to allocate |
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340 @param aNearestCluster Cluster the new chain should be nearest to |
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341 @leave System wide error codes |
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342 @return The first cluster number allocated |
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343 */ |
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344 TUint32 CFatTable::AllocateClusterListL(TUint32 aNumber, TUint32 aNearestCluster) |
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345 { |
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346 __PRINT2(_L("#>> CFatTable::AllocateClusterList() N:%d,NearestCL:%d"),aNumber,aNearestCluster); |
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347 __ASSERT_DEBUG(aNumber>0,Fault(EFatBadParameter)); |
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348 |
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349 if (iFreeClusters<aNumber) |
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350 { |
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351 __PRINT(_L("CFatTable::AllocateClusterListL - leaving KErrDirFull")); |
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352 User::Leave(KErrDiskFull); |
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353 } |
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354 |
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355 TInt firstCluster = aNearestCluster = AllocateSingleClusterL(aNearestCluster); |
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356 if (aNumber>1) |
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357 ExtendClusterListL(aNumber-1, (TInt&)aNearestCluster); |
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358 |
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359 return(firstCluster); |
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360 } |
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361 |
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362 //----------------------------------------------------------------------------- |
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363 |
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364 /** |
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365 Notify the media drive about media areas that shall be treated as "deleted" if this feature is supported. |
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366 @param aFreedClusters array with FAT numbers of clusters that shall be marked as "deleted" |
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367 */ |
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368 void CFatTable::DoFreedClustersNotify(RClusterArray &aFreedClusters) |
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369 { |
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370 ASSERT(iMediaAtt & KMediaAttDeleteNotify); |
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371 |
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372 const TUint clusterCount = aFreedClusters.Count(); |
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373 |
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374 if(!clusterCount) |
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375 return; |
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376 |
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377 FlushL(); //-- Commit the FAT changes to disk first to be safe |
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378 |
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379 const TUint bytesPerCluster = 1 << iOwner->ClusterSizeLog2(); |
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380 |
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381 TInt64 byteAddress = 0; |
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382 TUint deleteLen = 0; // zero indicates no clusters accumulated yet |
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383 |
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384 for (TUint i=0; i<clusterCount; ++i) |
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385 { |
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386 const TUint currCluster = aFreedClusters[i]; |
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387 |
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388 if (deleteLen == 0) |
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389 byteAddress = DataPositionInBytes(currCluster); //-- start of the media range |
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390 |
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391 deleteLen += bytesPerCluster; |
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392 |
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393 //-- if this is the last entry in the array or the net cluster number is not consecutive, notify the driver |
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394 if ((i+1) == clusterCount || aFreedClusters[i+1] != (currCluster+1)) |
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395 { |
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396 //__PRINT3(_L("DeleteNotify(%08X:%08X, %u), first cluster %u last cluster #%u"), I64HIGH(byteAddress), I64LOW(byteAddress), deleteLen); |
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397 //__PRINT2(_L(" first cluster %u last cluster #%u"), I64LOW((byteAddress - iOwner->ClusterBasePosition()) >> iOwner->ClusterSizeLog2()) + 2, cluster); |
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398 const TInt r = iOwner->LocalDrive()->DeleteNotify(byteAddress, deleteLen); |
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399 if(r != KErrNone) |
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400 {//-- if DeleteNotify() failed, it means that something terribly wrong happened to the NAND media; |
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401 //-- in normal circumstances it can not happen. One of the reasons: totally worn out media. |
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402 const TBool platSecEnabled = PlatSec::ConfigSetting(PlatSec::EPlatSecEnforcement); |
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403 __PRINT3(_L("CFatTable::DoFreedClustersNotify() DeleteNotify failure! drv:%d err:%d, PlatSec:%d"),iOwner->DriveNumber(), r, platSecEnabled); |
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404 |
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405 if(platSecEnabled) |
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406 { |
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407 //-- if PlatSec is enabled, we can't afford jeopardize the security; without DeleteNotify() |
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408 //-- it's possible to pick up data from deleted files, so, panic the file server. |
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409 Fault(EFatBadLocalDrive); |
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410 } |
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411 else |
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412 { |
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413 //-- if PlatSec is disabled, it's OK to ignore the NAND fault in release mode. |
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414 __ASSERT_DEBUG(0, Fault(EFatBadLocalDrive)); |
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415 } |
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416 } |
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417 |
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418 |
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419 deleteLen = 0; |
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420 } |
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421 |
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422 } |
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423 |
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424 //-- empty the array. |
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425 aFreedClusters.Reset(); |
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426 } |
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427 |
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428 //----------------------------------------------------------------------------- |
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429 /** |
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430 Mark a chain of clusters as free in the FAT. |
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431 |
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432 @param aCluster Start cluster of cluster chain to free |
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433 @leave System wide error codes |
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434 */ |
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435 void CFatTable::FreeClusterListL(TUint32 aCluster) |
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436 { |
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437 __PRINT1(_L("CFatTable::FreeClusterListL startCluster=%d"),aCluster); |
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438 if (aCluster == KSpareCluster) |
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439 return; |
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440 |
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441 //-- here we can store array of freed cluster numbers in order to |
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442 //-- notify media drive about the media addresses marked as "invalid" |
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443 RClusterArray deletedClusters; |
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444 CleanupClosePushL(deletedClusters); |
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445 |
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446 //-- if ETrue, we need to notify media driver about invalidated media addressses |
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447 const TBool bFreeClustersNotify = iMediaAtt & KMediaAttDeleteNotify; |
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448 |
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449 //-- this is a maximal number of FAT entries in the deletedClusters array. |
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450 //-- as soon as we collect this number of entries in the array, FAT cache will be flushed |
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451 //-- and driver notified. The array will be emptied. Used to avoid huge array when deleting |
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452 //-- large files on NAND media |
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453 const TUint KSubListLen = 4096; |
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454 ASSERT(IsPowerOf2(KSubListLen)); |
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455 |
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456 TUint32 lastKnownFreeCluster = FreeClusterHint(); |
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457 TUint32 cntFreedClusters = 0; |
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458 |
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459 TUint32 currCluster = aCluster; |
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460 TInt nextCluster = aCluster; |
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461 |
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462 for(;;) |
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463 { |
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464 const TBool bEOF = !GetNextClusterL(nextCluster); |
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465 WriteL(currCluster, KSpareCluster); |
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466 |
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467 lastKnownFreeCluster = Min(currCluster, lastKnownFreeCluster); |
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468 |
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469 // Keep a record of the deleted clusters so that we can subsequently notify the media driver. This is only safe |
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470 // to do once the FAT changes have been written to disk. |
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471 if(bFreeClustersNotify) |
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472 deletedClusters.Append(currCluster); |
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473 |
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474 ++cntFreedClusters; |
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475 currCluster = nextCluster; |
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476 |
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477 if (bEOF || aCluster == KSpareCluster) |
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478 break; |
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479 |
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480 if(bFreeClustersNotify && cntFreedClusters && (cntFreedClusters & (KSubListLen-1))==0) |
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481 {//-- reached a limit of the entries in the array. Flush FAT cache, notify the driver and empty the array. |
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482 IncrementFreeClusterCount(cntFreedClusters); |
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483 cntFreedClusters = 0; |
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484 |
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485 SetFreeClusterHint(lastKnownFreeCluster); |
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486 DoFreedClustersNotify(deletedClusters); |
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487 } |
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488 |
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489 } |
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490 |
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491 //-- increase the number of free clusters and notify the driver if required. |
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492 IncrementFreeClusterCount(cntFreedClusters); |
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493 SetFreeClusterHint(lastKnownFreeCluster); |
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494 |
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495 if(bFreeClustersNotify) |
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496 DoFreedClustersNotify(deletedClusters); |
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497 |
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498 CleanupStack::PopAndDestroy(&deletedClusters); |
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499 } |
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500 |
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501 //----------------------------------------------------------------------------- |
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502 |
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503 /** |
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504 Find a free cluster nearest to aCluster, Always checks to the right of aCluster first |
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505 but checks in both directions in the Fat. |
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506 |
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507 @param aCluster Cluster to find nearest free cluster to. |
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508 @leave KErrDiskFull + system wide error codes |
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509 @return cluster number found |
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510 */ |
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511 TUint32 CFatTable::FindClosestFreeClusterL(TUint32 aCluster) |
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512 { |
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513 __PRINT2(_L("CFatTable::FindClosestFreeClusterL() drv:%d cl:%d"),iOwner->DriveNumber(),aCluster); |
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514 |
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515 if(!ClusterNumberValid(aCluster)) |
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516 { |
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517 ASSERT(0); |
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518 User::Leave(KErrCorrupt); |
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519 } |
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520 |
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521 |
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522 if(iFreeClusters==0) |
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523 {//-- there is no at least 1 free cluster available |
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524 __PRINT(_L("CFatTable::FindClosestFreeClusterL() leaving KErrDiskFull #1")); |
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525 User::Leave(KErrDiskFull); |
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526 } |
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527 |
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528 //-- 1. look if the given index contains a free entry |
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529 if(ReadL(aCluster) != KSpareCluster) |
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530 {//-- no, it doesn't... |
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531 |
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532 //-- 2. look in both directions starting from the aCluster, looking in the right direction first |
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533 |
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534 const TUint32 maxEntries = MaxEntries(); |
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535 const TUint32 MinIdx = KFatFirstSearchCluster; |
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536 const TUint32 MaxIdx = maxEntries-1; |
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537 |
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538 TBool canGoRight = ETrue; |
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539 TBool canGoLeft = ETrue; |
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540 |
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541 TUint32 rightIdx = aCluster; |
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542 TUint32 leftIdx = aCluster; |
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543 |
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544 for(TUint i=0; i<maxEntries; ++i) |
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545 { |
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546 if(canGoRight) |
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547 { |
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548 if(rightIdx < MaxIdx) |
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549 ++rightIdx; |
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550 else |
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551 canGoRight = EFalse; |
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552 } |
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553 |
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554 if(canGoLeft) |
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555 { |
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556 if(leftIdx > MinIdx) |
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557 --leftIdx; |
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558 else |
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559 canGoLeft = EFalse; |
|
560 } |
|
561 |
|
562 if(!canGoRight && !canGoLeft) |
|
563 { |
|
564 __PRINT(_L("CFatTable::FindClosestFreeClusterL() leaving KErrDiskFull #2")); |
|
565 User::Leave(KErrDiskFull); |
|
566 } |
|
567 |
|
568 if (canGoRight && ReadL(rightIdx) == KSpareCluster) |
|
569 { |
|
570 aCluster = rightIdx; |
|
571 break; |
|
572 } |
|
573 |
|
574 if (canGoLeft && ReadL(leftIdx) == KSpareCluster) |
|
575 { |
|
576 aCluster = leftIdx; |
|
577 break; |
|
578 } |
|
579 }//for(..) |
|
580 |
|
581 }//if(ReadL(aCluster) != KSpareCluster) |
|
582 |
|
583 |
|
584 //-- note: do not update free cluster hint here by calling SetFreeClusterHint(). This is going to be |
|
585 //-- expensive especially if overridden methods with synchronisation are called. Instead, set the number of |
|
586 //-- the last known free cluster in the caller of this internal method. |
|
587 |
|
588 // __PRINT1(_L("CFatTable::FindClosestFreeClusterL found:%d"),aCluster); |
|
589 |
|
590 return aCluster; |
|
591 } |
|
592 |
|
593 //----------------------------------------------------------------------------- |
|
594 |
|
595 /** |
|
596 Converts a cluster number to byte offset in the FAT |
|
597 |
|
598 @param aFatIndex Cluster number |
|
599 @return Number of bytes from the beginning of the FAT |
|
600 */ |
|
601 TUint32 CFatTable::PosInBytes(TUint32 aFatIndex) const |
|
602 { |
|
603 switch(FatType()) |
|
604 { |
|
605 case EFat12: |
|
606 return (((aFatIndex>>1)<<1) + (aFatIndex>>1)); //-- 1.5 bytes per FAT entry |
|
607 |
|
608 case EFat16: |
|
609 return aFatIndex<<1; //-- 2 bytes per FAT entry |
|
610 |
|
611 default: |
|
612 ASSERT(0); |
|
613 return 0;//-- get rid of warning |
|
614 }; |
|
615 |
|
616 } |
|
617 |
|
618 //----------------------------------------------------------------------------- |
|
619 |
|
620 /** |
|
621 Checks if we have at least aClustersRequired clusters free in the FAT. |
|
622 This is, actually a dummy implementation. |
|
623 |
|
624 @param aClustersRequired number of free clusters required |
|
625 @return ETrue if there is at least aClustersRequired free clusters available, EFalse otherwise. |
|
626 */ |
|
627 TBool CFatTable::RequestFreeClusters(TUint32 aClustersRequired) const |
|
628 { |
|
629 //ASSERT(aClustersRequired >0 && aClustersRequired <= iOwner->UsableClusters()); |
|
630 ASSERT(aClustersRequired >0); |
|
631 return (NumberOfFreeClusters() >= aClustersRequired); |
|
632 } |
|
633 |
|
634 //----------------------------------------------------------------------------- |
|
635 /** |
|
636 @return ETrue if the cluster number aClusterNo is valid, i.e. belongs to the FAT table |
|
637 */ |
|
638 TBool CFatTable::ClusterNumberValid(TUint32 aClusterNo) const |
|
639 { |
|
640 return (aClusterNo >= KFatFirstSearchCluster) && (aClusterNo < iMaxEntries); |
|
641 } |
|
642 |
|
643 |
|
644 |
|
645 //####################################################################################################################################### |
|
646 //# CAtaFatTable class implementation |
|
647 //####################################################################################################################################### |
|
648 |
|
649 /** |
|
650 Constructor |
|
651 */ |
|
652 CAtaFatTable::CAtaFatTable(CFatMountCB& aOwner) |
|
653 :CFatTable(aOwner) |
|
654 { |
|
655 } |
|
656 |
|
657 |
|
658 /** factory method */ |
|
659 CAtaFatTable* CAtaFatTable::NewL(CFatMountCB& aOwner) |
|
660 { |
|
661 __PRINT1(_L("CAtaFatTable::NewL() drv:%d"),aOwner.DriveNumber()); |
|
662 CAtaFatTable* pSelf = new (ELeave) CAtaFatTable(aOwner); |
|
663 |
|
664 CleanupStack::PushL(pSelf); |
|
665 pSelf->InitializeL(); |
|
666 CleanupStack::Pop(); |
|
667 |
|
668 return pSelf; |
|
669 } |
|
670 |
|
671 |
|
672 //--------------------------------------------------------------------------------------------------------------------------------------- |
|
673 |
|
674 /** |
|
675 CAtaFatTable's FAT cache factory method. |
|
676 Creates fixed cache for FAT12 or FAT16 |
|
677 */ |
|
678 void CAtaFatTable::CreateCacheL() |
|
679 { |
|
680 ASSERT(iOwner); |
|
681 const TUint32 fatSize=iOwner->FatSizeInBytes(); |
|
682 __PRINT3(_L("CAtaFatTable::CreateCacheL drv:%d, FAT:%d, FAT Size:%d"), iOwner->DriveNumber(), FatType(), fatSize); |
|
683 |
|
684 |
|
685 //-- according to FAT specs: |
|
686 //-- FAT12 max size is 4084 entries or 6126 bytes => create fixed cache for whole FAT |
|
687 //-- FAT16 min size is 4085 entries or 8170 bytes, max size is 65525 entries or 131048 bytes => create fixed cache for whole FAT |
|
688 |
|
689 ASSERT(!iCache); |
|
690 |
|
691 //-- this is used for chaches granularity sanity check |
|
692 const TUint32 KMaxGranularityLog2 = 18; //-- 256K is a maximal allowed granularity |
|
693 const TUint32 KMinGranularityLog2 = KDefSectorSzLog2; //-- 512 bytes is a minimal allowed granularity |
|
694 |
|
695 switch(FatType()) |
|
696 { |
|
697 case EFat12: //-- create fixed FAT12 cache |
|
698 iCache = CFat12Cache::NewL(iOwner, fatSize); |
|
699 break; |
|
700 |
|
701 case EFat16: //-- create fixed FAT16 cache |
|
702 { |
|
703 TUint32 fat16_ReadGranularity_Log2; //-- FAT16 cache read granularity Log2 |
|
704 TUint32 fat16_WriteGranularity_Log2;//-- FAT16 cache write granularity Log2 |
|
705 |
|
706 iOwner->FatConfig().Fat16FixedCacheParams(fat16_ReadGranularity_Log2, fat16_WriteGranularity_Log2); |
|
707 |
|
708 //-- check if granularity values look sensible |
|
709 const TBool bParamsValid = fat16_ReadGranularity_Log2 >= KMinGranularityLog2 && fat16_ReadGranularity_Log2 <= KMaxGranularityLog2 && |
|
710 fat16_WriteGranularity_Log2 >= KMinGranularityLog2 && fat16_WriteGranularity_Log2 <= KMaxGranularityLog2; |
|
711 |
|
712 __ASSERT_ALWAYS(bParamsValid, Fault(EFatCache_BadGranularity)); |
|
713 |
|
714 |
|
715 iCache = CFat16FixedCache::NewL(iOwner, fatSize, fat16_ReadGranularity_Log2, fat16_WriteGranularity_Log2); |
|
716 } |
|
717 break; |
|
718 |
|
719 default: |
|
720 ASSERT(0); |
|
721 User::Leave(KErrCorrupt); |
|
722 break; |
|
723 }; |
|
724 |
|
725 ASSERT(iCache); |
|
726 } |
|
727 |
|
728 //--------------------------------------------------------------------------------------------------------------------------------------- |
|
729 |
|
730 |
|
731 /** |
|
732 Flush the FAT cache on disk |
|
733 @leave System wide error codes |
|
734 */ |
|
735 void CAtaFatTable::FlushL() |
|
736 { |
|
737 //-- the data can't be written if the mount is inconsistent |
|
738 iOwner->CheckStateConsistentL(); |
|
739 |
|
740 if (iCache) |
|
741 iCache->FlushL(); |
|
742 } |
|
743 |
|
744 /** |
|
745 Clear any cached data |
|
746 @param aDiscardDirtyData if ETrue, non-flushed data in the cache will be discarded. |
|
747 */ |
|
748 void CAtaFatTable::Dismount(TBool aDiscardDirtyData) |
|
749 { |
|
750 if (iCache) |
|
751 { |
|
752 //-- cache's Close() can check if the cache is clean. |
|
753 //-- ignore dirty data in cache if the mount is not in consistent state (it's impossible to flush cache data) |
|
754 //-- or if we are asked to do so. |
|
755 const TBool bIgnoreDirtyData = aDiscardDirtyData || !iOwner->ConsistentState(); |
|
756 iCache->Close(bIgnoreDirtyData); |
|
757 |
|
758 delete iCache; |
|
759 iCache=NULL; |
|
760 } |
|
761 |
|
762 } |
|
763 |
|
764 //--------------------------------------------------------------------------------------------------------------------------------------- |
|
765 |
|
766 /** |
|
767 Invalidate whole FAT cache. |
|
768 Depending of cache type this may just mark cache invalid with reading on demand or re-read whole cache from the media |
|
769 */ |
|
770 void CAtaFatTable::InvalidateCacheL() |
|
771 { |
|
772 __PRINT1(_L("CAtaFatTable::InvalidateCache(), drv:%d"), iOwner->DriveNumber()); |
|
773 |
|
774 //-- if we have a cache, invalidate it entirely |
|
775 if(iCache) |
|
776 { |
|
777 User::LeaveIfError(iCache->Invalidate()); |
|
778 } |
|
779 } |
|
780 |
|
781 |
|
782 //--------------------------------------------------------------------------------------------------------------------------------------- |
|
783 |
|
784 /** |
|
785 Invalidate specified region of the FAT cache |
|
786 Depending of cache type this may just mark part of the cache invalid with reading on demand later |
|
787 or re-read whole cache from the media. |
|
788 |
|
789 @param aPos absolute media position where the region being invalidated starts. |
|
790 @param aLength length in bytes of region to invalidate / refresh |
|
791 */ |
|
792 void CAtaFatTable::InvalidateCacheL(TInt64 aPos, TUint32 aLength) |
|
793 { |
|
794 __PRINT3(_L("CAtaFatTable::InvalidateCacheL() drv:%d, pos:%LU, len:%u,"), iOwner->DriveNumber(), aPos, aLength); |
|
795 |
|
796 if(I64HIGH(aPos) || !aLength || I64HIGH(aPos+aLength)) |
|
797 return; //-- FAT tables can't span over 4G |
|
798 |
|
799 const TUint32 mediaPos32 = I64LOW(aPos); |
|
800 |
|
801 //-- we do not use other copies of FAT, so trach changes only in FAT1 |
|
802 const TUint32 fat1StartPos = iOwner->StartOfFatInBytes(); |
|
803 const TUint32 fat1EndPos = fat1StartPos + iOwner->FatSizeInBytes(); |
|
804 |
|
805 TUint32 invRegionPosStart = 0; //-- media pos where the invalidated region starts |
|
806 TUint32 invRegionLen = 0; //-- size of the invalidated region, bytes |
|
807 |
|
808 //-- calculate the FAT1 region being invalidated |
|
809 if(mediaPos32 < fat1StartPos) |
|
810 { |
|
811 if((mediaPos32 + aLength) <= fat1StartPos) |
|
812 return; |
|
813 |
|
814 invRegionPosStart = fat1StartPos; |
|
815 invRegionLen = aLength - (fat1StartPos-mediaPos32); |
|
816 } |
|
817 else //if(mediaPos32 < fat1StartPos) |
|
818 {//-- mediaPos32 >= fat1StartPos) |
|
819 if(mediaPos32 >= fat1EndPos) |
|
820 return; |
|
821 |
|
822 invRegionPosStart = mediaPos32; |
|
823 |
|
824 if((mediaPos32 + aLength) <= fat1EndPos) |
|
825 { |
|
826 invRegionLen = aLength; |
|
827 } |
|
828 else |
|
829 { |
|
830 invRegionLen = mediaPos32+aLength-fat1EndPos; |
|
831 } |
|
832 } |
|
833 |
|
834 //-- convert the media pos of the region into FAT entries basis, depending on the FAT type |
|
835 ASSERT(invRegionPosStart >= fat1StartPos && invRegionLen <= (TUint)iOwner->FatSizeInBytes()); |
|
836 |
|
837 TUint32 startFatEntry=0; |
|
838 TUint32 numEntries = 0; |
|
839 |
|
840 switch(FatType()) |
|
841 { |
|
842 case EFat12: |
|
843 //-- invalidate whole cache; it is not worth making calculations for such small memory region. |
|
844 User::LeaveIfError(iCache->Invalidate()); |
|
845 return; |
|
846 |
|
847 case EFat16: |
|
848 startFatEntry = (invRegionPosStart-fat1StartPos) >> KFat16EntrySzLog2; |
|
849 numEntries = (invRegionLen + (sizeof(TFat16Entry)-1)) >> KFat16EntrySzLog2; |
|
850 break; |
|
851 |
|
852 default: |
|
853 ASSERT(0); |
|
854 return; |
|
855 }; |
|
856 |
|
857 if(startFatEntry < KFatFirstSearchCluster) |
|
858 {//-- FAT[0] and FAT[1] can't be legally accessed, they are reserved entries. We need to adjust region being refreshed. |
|
859 if(numEntries <= KFatFirstSearchCluster) |
|
860 return; //-- nothing to refresh |
|
861 |
|
862 startFatEntry += KFatFirstSearchCluster; |
|
863 numEntries -= KFatFirstSearchCluster; |
|
864 } |
|
865 |
|
866 User::LeaveIfError(iCache->InvalidateRegion(startFatEntry, numEntries)); |
|
867 } |
|
868 |
|
869 |
|
870 //----------------------------------------------------------------------------- |
|
871 /** |
|
872 Initialize the object, create FAT cache if required |
|
873 @leave KErrNoMemory |
|
874 */ |
|
875 void CAtaFatTable::InitializeL() |
|
876 { |
|
877 __PRINT1(_L("CAtaFatTable::InitializeL() drv:%d"), iOwner->DriveNumber()); |
|
878 CFatTable::InitializeL(); |
|
879 |
|
880 //-- create the FAT cache. |
|
881 ASSERT(!iCache); |
|
882 CreateCacheL(); |
|
883 } |
|
884 |
|
885 |
|
886 //----------------------------------------------------------------------------- |
|
887 /** |
|
888 Remount the FAT table. This method call means that the media parameters wasn't changed, |
|
889 otherwise CFatMountCB::DoReMountL() would reject it. |
|
890 Just do some re-initialisation work. |
|
891 */ |
|
892 void CAtaFatTable::ReMountL() |
|
893 { |
|
894 __PRINT1(_L("CAtaFatTable::ReMountL() drv:%d"), iOwner->DriveNumber()); |
|
895 |
|
896 if(iCache) |
|
897 { |
|
898 iCache->Invalidate(); |
|
899 } |
|
900 else |
|
901 { |
|
902 //-- this situation can happen when someone called CAtaFatTable::Dismount() that deletes the cache object |
|
903 //-- and then ReMount happens. We need to re-initialise this object. |
|
904 InitializeL(); |
|
905 } |
|
906 } |
|
907 |
|
908 |
|
909 //----------------------------------------------------------------------------- |
|
910 /** |
|
911 Read an entry from the FAT table |
|
912 |
|
913 @param aFatIndex FAT entry number to read |
|
914 @return FAT entry value |
|
915 */ |
|
916 TUint32 CAtaFatTable::ReadL(TUint32 aFatIndex) const |
|
917 { |
|
918 if(!ClusterNumberValid(aFatIndex)) |
|
919 { |
|
920 //ASSERT(0); //-- for some silly reason some callers pass 0 here and expect it to leave |
|
921 User::Leave(KErrCorrupt); |
|
922 } |
|
923 |
|
924 |
|
925 const TUint entry = iCache->ReadEntryL(aFatIndex); |
|
926 return entry; |
|
927 } |
|
928 |
|
929 |
|
930 //----------------------------------------------------------------------------- |
|
931 /** |
|
932 Write an entry to the FAT table |
|
933 |
|
934 @param aFatIndex aFatIndex FAT entry number to write |
|
935 @param aValue FAT entry to write |
|
936 @leave |
|
937 */ |
|
938 void CAtaFatTable::WriteL(TUint32 aFatIndex, TUint32 aValue) |
|
939 { |
|
940 const TUint32 KFat16EntryMask = 0x0FFFF; |
|
941 |
|
942 __PRINT2(_L("CAtaFatTable::WriteL() entry:%d, val:0x%x"), aFatIndex, aValue); |
|
943 |
|
944 if(!ClusterNumberValid(aFatIndex)) |
|
945 { |
|
946 ASSERT(0); |
|
947 User::Leave(KErrCorrupt); |
|
948 } |
|
949 |
|
950 if(aValue != KSpareCluster && (aValue < KFatFirstSearchCluster || aValue > KFat16EntryMask)) |
|
951 { |
|
952 ASSERT(0); |
|
953 User::Leave(KErrCorrupt); |
|
954 } |
|
955 iCache->WriteEntryL(aFatIndex, aValue); |
|
956 } |
|
957 |
|
958 |
|
959 /** |
|
960 Get the next cluster in the chain from the FAT |
|
961 |
|
962 @param aCluster number to read, contains next cluster upon return |
|
963 @leave |
|
964 @return False if end of cluster chain |
|
965 */ |
|
966 TBool CFatTable::GetNextClusterL(TInt& aCluster) const |
|
967 { |
|
968 __PRINT1(_L("CAtaFatTable::GetNextClusterL(%d)"), aCluster); |
|
969 |
|
970 const TInt nextCluster = ReadL(aCluster); |
|
971 TBool ret = EFalse; |
|
972 |
|
973 switch(FatType()) |
|
974 { |
|
975 case EFat12: |
|
976 ret=!IsEof12Bit(nextCluster); |
|
977 break; |
|
978 |
|
979 case EFat16: |
|
980 ret=!IsEof16Bit(nextCluster); |
|
981 break; |
|
982 |
|
983 default: |
|
984 ASSERT(0); |
|
985 return EFalse;//-- get rid of warning |
|
986 }; |
|
987 |
|
988 if (ret) |
|
989 { |
|
990 aCluster=nextCluster; |
|
991 } |
|
992 |
|
993 return ret; |
|
994 |
|
995 } |
|
996 |
|
997 /** |
|
998 Write EOF to aFatIndex |
|
999 @param aFatIndex index in FAT (cluster number) to be written |
|
1000 */ |
|
1001 void CFatTable::WriteFatEntryEofL(TUint32 aFatIndex) |
|
1002 { |
|
1003 __PRINT1(_L("CAtaFatTable::WriteFatEntryEofL(%d)"), aFatIndex); |
|
1004 |
|
1005 //-- use EOF_16Bit (0x0ffff) for all types of FAT, FAT cache will mask it appropriately |
|
1006 WriteL(aFatIndex, EOF_16Bit); |
|
1007 } |
|
1008 |
|
1009 |
|
1010 |
|
1011 /** |
|
1012 Mark cluster number aFatIndex in FAT as bad |
|
1013 @param aFatIndex index in FAT (cluster number) to be written |
|
1014 */ |
|
1015 void CFatTable::MarkAsBadClusterL(TUint32 aFatIndex) |
|
1016 { |
|
1017 __PRINT1(_L("CAtaFatTable::MarkAsBadClusterL(%d)"),aFatIndex); |
|
1018 |
|
1019 //-- use KBad_16Bit (0x0fff7) for all types of FAT, FAT cache will mask it appropriately |
|
1020 WriteL(aFatIndex, KBad_16Bit); |
|
1021 |
|
1022 FlushL(); |
|
1023 } |
|
1024 |
|
1025 |
|
1026 /** |
|
1027 Return the location of a Cluster in the data section of the media |
|
1028 |
|
1029 @param aCluster to find location of |
|
1030 @return Byte offset of the cluster data |
|
1031 */ |
|
1032 TInt64 CAtaFatTable::DataPositionInBytes(TUint32 aCluster) const |
|
1033 { |
|
1034 __ASSERT_DEBUG(ClusterNumberValid(aCluster), Fault(EFatTable_InvalidIndex)); |
|
1035 |
|
1036 const TInt clusterBasePosition=iOwner->ClusterBasePosition(); |
|
1037 return(((TInt64(aCluster)-KFatFirstSearchCluster) << iOwner->ClusterSizeLog2()) + clusterBasePosition); |
|
1038 } |
|
1039 |
|
1040 |
|
1041 |
|
1042 |
|
1043 |
|
1044 |