3 * Ext2 Driver Version 1
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7 * \brief Second Extended Filesystem Driver
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8 * \todo Implement file full write support
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12 #include "ext2_common.h"
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13 #include <modules.h>
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15 // === PROTOTYPES ===
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16 int Ext2_Install(char **Arguments);
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17 // Interface Functions
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18 tVFS_Node *Ext2_InitDevice(char *Device, char **Options);
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19 void Ext2_Unmount(tVFS_Node *Node);
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20 void Ext2_CloseFile(tVFS_Node *Node);
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22 int Ext2_int_GetInode(tVFS_Node *Node, tExt2_Inode *Inode);
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23 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum);
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24 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent);
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25 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk);
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27 // === SEMI-GLOBALS ===
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28 MODULE_DEFINE(0, 0x5B /*v0.90*/, FS_Ext2, Ext2_Install, NULL);
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29 tExt2_Disk gExt2_disks[6];
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30 int giExt2_count = 0;
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31 tVFS_Driver gExt2_FSInfo = {
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32 "ext2", 0, Ext2_InitDevice, Ext2_Unmount, NULL
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38 * \fn int Ext2_Install(char **Arguments)
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39 * \brief Install the Ext2 Filesystem Driver
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41 int Ext2_Install(char **Arguments)
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43 VFS_AddDriver( &gExt2_FSInfo );
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44 return MODULE_ERR_OK;
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48 \fn tVFS_Node *Ext2_InitDevice(char *Device, char **Options)
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49 \brief Initializes a device to be read by by the driver
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50 \param Device String - Device to read from
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51 \param Options NULL Terminated array of option strings
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54 tVFS_Node *Ext2_InitDevice(char *Device, char **Options)
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59 tExt2_SuperBlock sb;
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62 ENTER("sDevice pOptions", Device, Options);
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65 fd = VFS_Open(Device, VFS_OPENFLAG_READ|VFS_OPENFLAG_WRITE); //Open Device
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67 Warning("[EXT2 ] Unable to open '%s'", Device);
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72 // Read Superblock at offset 1024
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73 VFS_ReadAt(fd, 1024, 1024, &sb); // Read Superblock
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75 // Sanity Check Magic value
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76 if(sb.s_magic != 0xEF53) {
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77 Warning("[EXT2 ] Volume '%s' is not an EXT2 volume", Device);
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84 groupCount = DivUp(sb.s_blocks_count, sb.s_blocks_per_group);
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85 LOG("groupCount = %i", groupCount);
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87 // Allocate Disk Information
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88 disk = malloc(sizeof(tExt2_Disk) + sizeof(tExt2_Group)*groupCount);
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90 Warning("[EXT2 ] Unable to allocate disk structure");
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96 memcpy(&disk->SuperBlock, &sb, 1024);
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97 disk->GroupCount = groupCount;
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99 // Get an inode cache handle
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100 disk->CacheID = Inode_GetHandle();
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103 LOG("s_log_block_size = 0x%x", sb.s_log_block_size);
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104 disk->BlockSize = 1024 << sb.s_log_block_size;
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106 // Read Group Information
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109 sb.s_first_data_block * disk->BlockSize + 1024,
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110 sizeof(tExt2_Group)*groupCount,
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115 LOG("Block Group 0");
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116 LOG(".bg_block_bitmap = 0x%x", disk->Groups[0].bg_block_bitmap);
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117 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[0].bg_inode_bitmap);
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118 LOG(".bg_inode_table = 0x%x", disk->Groups[0].bg_inode_table);
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119 LOG("Block Group 1");
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120 LOG(".bg_block_bitmap = 0x%x", disk->Groups[1].bg_block_bitmap);
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121 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[1].bg_inode_bitmap);
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122 LOG(".bg_inode_table = 0x%x", disk->Groups[1].bg_inode_table);
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126 Ext2_int_ReadInode(disk, 2, &inode);
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128 // Create Root Node
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129 memset(&disk->RootNode, 0, sizeof(tVFS_Node));
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130 disk->RootNode.Inode = 2; // Root inode ID
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131 disk->RootNode.ImplPtr = disk; // Save disk pointer
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132 disk->RootNode.Size = -1; // Fill in later (on readdir)
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133 disk->RootNode.Flags = VFS_FFLAG_DIRECTORY;
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135 disk->RootNode.ReadDir = Ext2_ReadDir;
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136 disk->RootNode.FindDir = Ext2_FindDir;
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137 //disk->RootNode.Relink = Ext2_Relink;
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139 // Complete root node
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140 disk->RootNode.UID = inode.i_uid;
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141 disk->RootNode.GID = inode.i_gid;
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142 disk->RootNode.NumACLs = 1;
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143 disk->RootNode.ACLs = &gVFS_ACL_EveryoneRW;
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146 LOG("inode.i_size = 0x%x", inode.i_size);
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147 LOG("inode.i_block[0] = 0x%x", inode.i_block[0]);
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150 LEAVE('p', &disk->RootNode);
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151 return &disk->RootNode;
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155 * \fn void Ext2_Unmount(tVFS_Node *Node)
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156 * \brief Close a mounted device
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158 void Ext2_Unmount(tVFS_Node *Node)
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160 tExt2_Disk *disk = Node->ImplPtr;
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162 VFS_Close( disk->FD );
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163 Inode_ClearCache( disk->CacheID );
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164 memset(disk, 0, sizeof(tExt2_Disk)+disk->GroupCount*sizeof(tExt2_Group));
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169 * \fn void Ext2_CloseFile(tVFS_Node *Node)
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170 * \brief Close a file (Remove it from the cache)
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172 void Ext2_CloseFile(tVFS_Node *Node)
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174 tExt2_Disk *disk = Node->ImplPtr;
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175 Inode_UncacheNode(disk->CacheID, Node->Inode);
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179 //==================================
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180 //= INTERNAL FUNCTIONS =
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181 //==================================
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183 * \fn int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint InodeId, tExt2_Inode *Inode)
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184 * \brief Read an inode into memory
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186 int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
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190 //ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
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192 if(InodeId == 0) return 0;
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194 InodeId --; // Inodes are numbered starting at 1
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196 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
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197 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
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199 //LOG("group=%i, subId = %i", group, subId);
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202 VFS_ReadAt(Disk->FD,
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203 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
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204 sizeof(tExt2_Inode),
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212 * \brief Write a modified inode out to disk
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214 int Ext2_int_WriteInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
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217 ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
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219 if(InodeId == 0) return 0;
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221 InodeId --; // Inodes are numbered starting at 1
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223 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
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224 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
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226 LOG("group=%i, subId = %i", group, subId);
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229 VFS_WriteAt(Disk->FD,
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230 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
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231 sizeof(tExt2_Inode),
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239 * \fn Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
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240 * \brief Get the address of a block from an inode's list
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241 * \param Disk Disk information structure
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242 * \param Blocks Pointer to an inode's block list
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243 * \param BlockNum Block index in list
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245 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
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248 int dwPerBlock = Disk->BlockSize / 4;
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252 return (Uint64)Blocks[BlockNum] * Disk->BlockSize;
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254 // Single Indirect Blocks
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255 iBlocks = malloc( Disk->BlockSize );
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256 VFS_ReadAt(Disk->FD, (Uint64)Blocks[12]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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259 if(BlockNum < dwPerBlock)
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261 BlockNum = iBlocks[BlockNum];
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263 return (Uint64)BlockNum * Disk->BlockSize;
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266 BlockNum -= dwPerBlock;
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267 // Double Indirect Blocks
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268 if(BlockNum < dwPerBlock*dwPerBlock)
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270 VFS_ReadAt(Disk->FD, (Uint64)Blocks[13]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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271 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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272 BlockNum = iBlocks[BlockNum%dwPerBlock];
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274 return (Uint64)BlockNum * Disk->BlockSize;
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277 BlockNum -= dwPerBlock*dwPerBlock;
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278 // Triple Indirect Blocks
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279 VFS_ReadAt(Disk->FD, (Uint64)Blocks[14]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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280 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/(dwPerBlock*dwPerBlock)]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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281 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[(BlockNum/dwPerBlock)%dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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282 BlockNum = iBlocks[BlockNum%dwPerBlock];
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284 return (Uint64)BlockNum * Disk->BlockSize;
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288 * \fn Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
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289 * \brief Allocate an inode (from the current group preferably)
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290 * \param Disk EXT2 Disk Information Structure
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291 * \param Parent Inode ID of the parent (used to locate the child nearby)
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293 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
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295 // Uint block = (Parent - 1) / Disk->SuperBlock.s_inodes_per_group;
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300 * \fn void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
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301 * \brief Updates the superblock
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303 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
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305 int bpg = Disk->SuperBlock.s_blocks_per_group;
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306 int ngrp = Disk->SuperBlock.s_blocks_count / bpg;
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310 VFS_WriteAt(Disk->FD, 1024, 1024, &Disk->SuperBlock);
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313 // at Block Group 1, 3^n, 5^n, 7^n
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316 if(ngrp <= 1) return;
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317 VFS_WriteAt(Disk->FD, 1*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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320 for( i = 3; i < ngrp; i *= 3 )
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321 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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324 for( i = 5; i < ngrp; i *= 5 )
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325 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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328 for( i = 7; i < ngrp; i *= 7 )
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329 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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