3 * - By John Hodge (thePowersGang)
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9 #define VERSION VER2(0,90)
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10 #include "ext2_common.h"
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11 #include <modules.h>
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13 #define MIN_BLOCKS_PER_GROUP 2
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14 #define MAX_BLOCK_LOG_SIZE 10 // 1024 << 10 = 1MiB
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16 // === PROTOTYPES ===
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17 int Ext2_Install(char **Arguments);
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18 int Ext2_Cleanup(void);
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19 // - Interface Functions
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20 int Ext2_Detect(int FD);
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21 tVFS_Node *Ext2_InitDevice(const char *Device, const char **Options);
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22 void Ext2_Unmount(tVFS_Node *Node);
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23 void Ext2_CloseFile(tVFS_Node *Node);
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24 // - Internal Helpers
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25 int Ext2_int_GetInode(tVFS_Node *Node, tExt2_Inode *Inode);
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26 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum);
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27 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent);
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28 void Ext2_int_DereferenceInode(tExt2_Disk *Disk, Uint32 Inode);
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29 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk);
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31 // === SEMI-GLOBALS ===
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32 MODULE_DEFINE(0, VERSION, FS_Ext2, Ext2_Install, Ext2_Cleanup);
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33 tExt2_Disk gExt2_disks[6];
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34 int giExt2_count = 0;
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35 tVFS_Driver gExt2_FSInfo = {
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37 .Detect = Ext2_Detect,
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38 .InitDevice = Ext2_InitDevice,
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39 .Unmount = Ext2_Unmount,
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40 .GetNodeFromINode = NULL
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45 * \fn int Ext2_Install(char **Arguments)
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46 * \brief Install the Ext2 Filesystem Driver
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48 int Ext2_Install(char **Arguments)
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50 VFS_AddDriver( &gExt2_FSInfo );
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51 return MODULE_ERR_OK;
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55 * \brief Clean up driver state before unload
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57 int Ext2_Cleanup(void)
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63 * Detect if a volume is Ext2 formatted
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65 int Ext2_Detect(int FD)
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67 tExt2_SuperBlock sb;
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70 len = VFS_ReadAt(FD, 1024, 1024, &sb);
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73 Log_Debug("Ext2", "_Detect: Read failed? (0x%x != 1024)", len);
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82 Log_Debug("Ext2", "_Detect: s_magic = 0x%x", sb.s_magic);
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88 \brief Initializes a device to be read by by the driver
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89 \param Device String - Device to read from
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90 \param Options NULL Terminated array of option strings
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93 tVFS_Node *Ext2_InitDevice(const char *Device, const char **Options)
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95 tExt2_Disk *disk = NULL;
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98 tExt2_SuperBlock sb;
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101 ENTER("sDevice pOptions", Device, Options);
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104 fd = VFS_Open(Device, VFS_OPENFLAG_READ|VFS_OPENFLAG_WRITE); //Open Device
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106 Log_Warning("EXT2", "Unable to open '%s'", Device);
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111 // Read Superblock at offset 1024
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112 VFS_ReadAt(fd, 1024, 1024, &sb); // Read Superblock
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114 // Sanity Check Magic value
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115 if(sb.s_magic != 0xEF53) {
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116 Log_Warning("EXT2", "Volume '%s' is not an EXT2 volume (0x%x != 0xEF53)",
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117 Device, sb.s_magic);
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121 if( sb.s_blocks_per_group < MIN_BLOCKS_PER_GROUP ) {
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122 Log_Warning("Ext2", "Blocks per group is too small (%i < %i)",
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123 sb.s_blocks_per_group, MIN_BLOCKS_PER_GROUP);
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128 groupCount = DivUp(sb.s_blocks_count, sb.s_blocks_per_group);
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129 LOG("groupCount = %i", groupCount);
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131 // Allocate Disk Information
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132 disk = malloc(sizeof(tExt2_Disk) + sizeof(tExt2_Group)*groupCount);
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134 Log_Warning("EXT2", "Unable to allocate disk structure");
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138 memcpy(&disk->SuperBlock, &sb, 1024);
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139 disk->GroupCount = groupCount;
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141 // Get an inode cache handle
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142 disk->CacheID = Inode_GetHandle();
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145 if( sb.s_log_block_size > MAX_BLOCK_LOG_SIZE ) {
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146 Log_Warning("Ext2", "Block size (log2) too large (%i > %i)",
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147 sb.s_log_block_size, MAX_BLOCK_LOG_SIZE);
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150 disk->BlockSize = 1024 << sb.s_log_block_size;
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151 LOG("Disk->BlockSie = 0x%x (1024 << %i)", disk->BlockSize, sb.s_log_block_size);
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153 // Read Group Information
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154 LOG("sb,s_first_data_block = %x", sb.s_first_data_block);
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157 sb.s_first_data_block * disk->BlockSize + 1024,
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158 sizeof(tExt2_Group)*groupCount,
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162 LOG("Block Group 0");
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163 LOG(".bg_block_bitmap = 0x%x", disk->Groups[0].bg_block_bitmap);
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164 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[0].bg_inode_bitmap);
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165 LOG(".bg_inode_table = 0x%x", disk->Groups[0].bg_inode_table);
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166 LOG("Block Group 1");
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167 LOG(".bg_block_bitmap = 0x%x", disk->Groups[1].bg_block_bitmap);
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168 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[1].bg_inode_bitmap);
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169 LOG(".bg_inode_table = 0x%x", disk->Groups[1].bg_inode_table);
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172 Ext2_int_ReadInode(disk, 2, &inode);
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174 // Create Root Node
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175 memset(&disk->RootNode, 0, sizeof(tVFS_Node));
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176 disk->RootNode.Inode = 2; // Root inode ID
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177 disk->RootNode.ImplPtr = disk; // Save disk pointer
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178 disk->RootNode.Size = -1; // Fill in later (on readdir)
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179 disk->RootNode.Flags = VFS_FFLAG_DIRECTORY;
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181 disk->RootNode.Type = &gExt2_DirType;
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183 // Complete root node
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184 disk->RootNode.UID = inode.i_uid;
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185 disk->RootNode.GID = inode.i_gid;
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186 disk->RootNode.NumACLs = 1;
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187 disk->RootNode.ACLs = &gVFS_ACL_EveryoneRW;
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190 LOG("inode.i_size = 0x%x", inode.i_size);
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191 LOG("inode.i_block[0] = 0x%x", inode.i_block[0]);
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194 LEAVE('p', &disk->RootNode);
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195 return &disk->RootNode;
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205 * \fn void Ext2_Unmount(tVFS_Node *Node)
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206 * \brief Close a mounted device
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208 void Ext2_Unmount(tVFS_Node *Node)
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210 tExt2_Disk *disk = Node->ImplPtr;
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212 VFS_Close( disk->FD );
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213 Inode_ClearCache( disk->CacheID );
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214 memset(disk, 0, sizeof(tExt2_Disk)+disk->GroupCount*sizeof(tExt2_Group));
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219 * \fn void Ext2_CloseFile(tVFS_Node *Node)
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220 * \brief Close a file (Remove it from the cache)
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222 void Ext2_CloseFile(tVFS_Node *Node)
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224 tExt2_Disk *disk = Node->ImplPtr;
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225 ENTER("pNode", Node);
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227 if( Mutex_Acquire(&Node->Lock) != 0 )
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233 if( Node->Flags & VFS_FFLAG_DIRTY )
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236 Ext2_int_WritebackNode(disk, Node);
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237 Node->Flags &= ~VFS_FFLAG_DIRTY;
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240 int was_not_referenced = (Node->ImplInt == 0);
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241 tVFS_ACL *acls = Node->ACLs;
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242 if( Inode_UncacheNode(disk->CacheID, Node->Inode) == 1 )
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244 if( was_not_referenced )
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246 LOG("Removng inode");
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248 Log_Warning("Ext2", "TODO: Remove inode when not referenced (%x)", (Uint32)Node->Inode);
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250 if( acls != &gVFS_ACL_EveryoneRW ) {
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253 LOG("Node cleaned");
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256 LOG("Still referenced, releasing lock");
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257 Mutex_Release(&Node->Lock);
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263 //==================================
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264 //= INTERNAL FUNCTIONS =
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265 //==================================
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267 * \fn int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint InodeId, tExt2_Inode *Inode)
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268 * \brief Read an inode into memory
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270 int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
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274 ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
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276 if(InodeId == 0) return 0;
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278 InodeId --; // Inodes are numbered starting at 1
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280 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
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281 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
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283 LOG("group=%i, subId = %i", group, subId);
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286 VFS_ReadAt(Disk->FD,
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287 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
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288 sizeof(tExt2_Inode),
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296 * \brief Write a modified inode out to disk
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298 int Ext2_int_WriteInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
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301 ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
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308 InodeId --; // Inodes are numbered starting at 1
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310 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
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311 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
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313 LOG("group=%i, subId = %i", group, subId);
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316 VFS_WriteAt(Disk->FD,
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317 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
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318 sizeof(tExt2_Inode),
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327 * \fn vfs_node *Ext2_int_CreateNode(tExt2_Disk *Disk, Uint InodeID)
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328 * \brief Create a new VFS Node
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330 tVFS_Node *Ext2_int_CreateNode(tExt2_Disk *Disk, Uint InodeID)
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334 tVFS_Node *tmpNode;
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336 if( !Ext2_int_ReadInode(Disk, InodeID, &inode) )
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339 if( (tmpNode = Inode_GetCache(Disk->CacheID, InodeID)) )
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342 memset(&retNode, 0, sizeof(retNode));
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345 retNode.Inode = InodeID;
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346 retNode.ImplPtr = Disk;
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347 retNode.ImplInt = inode.i_links_count;
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348 if( inode.i_links_count == 0 ) {
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349 Log_Notice("Ext2", "Inode %p:%x is not referenced, bug?", Disk, InodeID);
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353 retNode.Size = inode.i_size;
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355 // Set Access Permissions
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356 retNode.UID = inode.i_uid;
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357 retNode.GID = inode.i_gid;
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358 retNode.NumACLs = 3;
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359 retNode.ACLs = VFS_UnixToAcessACL(inode.i_mode & 0777, inode.i_uid, inode.i_gid);
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361 // Set Function Pointers
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362 retNode.Type = &gExt2_FileType;
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364 switch(inode.i_mode & EXT2_S_IFMT)
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368 retNode.Flags = VFS_FFLAG_SYMLINK;
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373 retNode.Size |= (Uint64)inode.i_dir_acl << 32;
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377 retNode.Type = &gExt2_DirType;
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378 retNode.Flags = VFS_FFLAG_DIRECTORY;
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379 retNode.Data = calloc( sizeof(Uint16), DivUp(retNode.Size, Disk->BlockSize) );
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381 // Unknown, Write protect it to be safe
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383 retNode.Flags = VFS_FFLAG_READONLY;
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388 retNode.ATime = inode.i_atime * 1000;
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389 retNode.MTime = inode.i_mtime * 1000;
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390 retNode.CTime = inode.i_ctime * 1000;
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392 // Save in node cache and return saved node
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393 return Inode_CacheNode(Disk->CacheID, &retNode);
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396 int Ext2_int_WritebackNode(tExt2_Disk *Disk, tVFS_Node *Node)
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400 if( Disk != Node->ImplPtr ) {
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401 Log_Error("Ext2", "Ext2_int_WritebackNode - Disk != Node->ImplPtr");
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405 if( Node->Flags & VFS_FFLAG_SYMLINK ) {
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406 inode.i_mode = EXT2_S_IFLNK;
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408 else if( Node->Flags & VFS_FFLAG_DIRECTORY ) {
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409 inode.i_mode = EXT2_S_IFDIR;
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411 else if( Node->Flags & VFS_FFLAG_READONLY ) {
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412 Log_Notice("Ext2", "Not writing back readonly inode %p:%x", Disk, Node->Inode);
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416 inode.i_mode = EXT2_S_IFREG;
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417 inode.i_dir_acl = Node->Size >> 32;
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420 inode.i_size = Node->Size & 0xFFFFFFFF;
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421 inode.i_links_count = Node->ImplInt;
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423 inode.i_uid = Node->UID;
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424 inode.i_gid = Node->GID;
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426 inode.i_atime = Node->ATime / 1000;
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427 inode.i_mtime = Node->MTime / 1000;
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428 inode.i_ctime = Node->CTime / 1000;
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430 // TODO: Compact ACLs into unix mode
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431 Log_Warning("Ext2", "TODO: Support converting Acess ACLs into unix modes");
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433 Ext2_int_WriteInode(Disk, Node->Inode, &inode);
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439 * \fn Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
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440 * \brief Get the address of a block from an inode's list
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441 * \param Disk Disk information structure
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442 * \param Blocks Pointer to an inode's block list
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443 * \param BlockNum Block index in list
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445 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
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448 int dwPerBlock = Disk->BlockSize / 4;
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452 return (Uint64)Blocks[BlockNum] * Disk->BlockSize;
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454 // Single Indirect Blocks
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455 iBlocks = malloc( Disk->BlockSize );
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456 VFS_ReadAt(Disk->FD, (Uint64)Blocks[12]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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459 if(BlockNum < dwPerBlock)
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461 BlockNum = iBlocks[BlockNum];
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463 return (Uint64)BlockNum * Disk->BlockSize;
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466 BlockNum -= dwPerBlock;
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467 // Double Indirect Blocks
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468 if(BlockNum < dwPerBlock*dwPerBlock)
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470 VFS_ReadAt(Disk->FD, (Uint64)Blocks[13]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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471 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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472 BlockNum = iBlocks[BlockNum%dwPerBlock];
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474 return (Uint64)BlockNum * Disk->BlockSize;
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477 BlockNum -= dwPerBlock*dwPerBlock;
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478 // Triple Indirect Blocks
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479 VFS_ReadAt(Disk->FD, (Uint64)Blocks[14]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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480 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/(dwPerBlock*dwPerBlock)]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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481 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[(BlockNum/dwPerBlock)%dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
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482 BlockNum = iBlocks[BlockNum%dwPerBlock];
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484 return (Uint64)BlockNum * Disk->BlockSize;
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488 * \fn Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
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489 * \brief Allocate an inode (from the current group preferably)
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490 * \param Disk EXT2 Disk Information Structure
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491 * \param Parent Inode ID of the parent (used to locate the child nearby)
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493 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
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495 Uint start_group = (Parent - 1) / Disk->SuperBlock.s_inodes_per_group;
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496 Uint group = start_group;
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498 if( Disk->SuperBlock.s_free_inodes_count == 0 )
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500 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes on %p", Disk);
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504 while( group < Disk->GroupCount && Disk->Groups[group].bg_free_inodes_count == 0 )
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506 if( group == Disk->GroupCount )
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509 while( group < start_group && Disk->Groups[group].bg_free_inodes_count == 0 )
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513 if( Disk->Groups[group].bg_free_inodes_count == 0 )
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515 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes on %p, but superblock says some free", Disk);
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519 // Load bitmap for group
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520 // (s_inodes_per_group / 8) bytes worth
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521 // - Allocate a buffer the size of a sector/block
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522 // - Read in part of the bitmap
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523 // - Search for a free inode
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524 tExt2_Group *bg = &Disk->Groups[group];
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527 const int sector_size = 512;
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528 Uint8 buf[sector_size];
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529 VFS_ReadAt(Disk->FD, Disk->BlockSize*bg->bg_inode_bitmap+ofs, sector_size, buf);
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532 for( byte = 0; byte < sector_size && buf[byte] != 0xFF; byte ++ )
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534 if( byte < sector_size )
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536 for( bit = 0; bit < 8 && buf[byte] & (1 << bit); bit ++)
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539 buf[byte] |= 1 << bit;
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540 VFS_WriteAt(Disk->FD, Disk->BlockSize*bg->bg_inode_bitmap+ofs, sector_size, buf);
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542 bg->bg_free_inodes_count --;
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543 Disk->SuperBlock.s_free_inodes_count --;
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545 Uint32 ret = group * Disk->SuperBlock.s_inodes_per_group + byte * 8 + bit + 1;
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546 Log_Debug("Ext2", "Ext2_int_AllocateInode - Allocated 0x%x", ret);
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550 ofs += sector_size;
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551 } while(ofs < Disk->SuperBlock.s_inodes_per_group / 8);
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553 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes in group %p:%i but header reported free",
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560 * \brief Reduce the reference count on an inode
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562 void Ext2_int_DereferenceInode(tExt2_Disk *Disk, Uint32 Inode)
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564 Log_Warning("Ext2", "TODO: Impliment Ext2_int_DereferenceInode");
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568 * \fn void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
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569 * \brief Updates the superblock
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571 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
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573 int bpg = Disk->SuperBlock.s_blocks_per_group;
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574 int ngrp = Disk->SuperBlock.s_blocks_count / bpg;
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578 VFS_WriteAt(Disk->FD, 1024, 1024, &Disk->SuperBlock);
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581 // at Block Group 1, 3^n, 5^n, 7^n
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584 if(ngrp <= 1) return;
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585 VFS_WriteAt(Disk->FD, 1*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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587 #define INT_MAX (((long long int)1<<(sizeof(int)*8))-1)
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590 for( i = 3; i < ngrp && i < INT_MAX/3; i *= 3 )
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591 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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594 for( i = 5; i < ngrp && i < INT_MAX/5; i *= 5 )
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595 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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598 for( i = 7; i < ngrp && i < INT_MAX/7; i *= 7 )
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599 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
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