3 * - By John Hodge (thePowersGang)
\r
9 #define VERSION VER2(0,90)
\r
10 #include "ext2_common.h"
\r
11 #include <modules.h>
\r
13 #define MIN_BLOCKS_PER_GROUP 2
\r
14 #define MAX_BLOCK_LOG_SIZE 10 // 1024 << 10 = 1MiB
\r
17 extern tVFS_NodeType gExt2_DirType;
\r
19 // === PROTOTYPES ===
\r
20 int Ext2_Install(char **Arguments);
\r
21 int Ext2_Cleanup(void);
\r
22 // - Interface Functions
\r
23 int Ext2_Detect(int FD);
\r
24 tVFS_Node *Ext2_InitDevice(const char *Device, const char **Options);
\r
25 void Ext2_Unmount(tVFS_Node *Node);
\r
26 void Ext2_CloseFile(tVFS_Node *Node);
\r
27 // - Internal Helpers
\r
28 int Ext2_int_GetInode(tVFS_Node *Node, tExt2_Inode *Inode);
\r
29 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum);
\r
30 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent);
\r
31 void Ext2_int_DereferenceInode(tExt2_Disk *Disk, Uint32 Inode);
\r
32 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk);
\r
34 // === SEMI-GLOBALS ===
\r
35 MODULE_DEFINE(0, VERSION, FS_Ext2, Ext2_Install, Ext2_Cleanup);
\r
36 tExt2_Disk gExt2_disks[6];
\r
37 int giExt2_count = 0;
\r
38 tVFS_Driver gExt2_FSInfo = {
\r
40 .Detect = Ext2_Detect,
\r
41 .InitDevice = Ext2_InitDevice,
\r
42 .Unmount = Ext2_Unmount,
\r
43 .GetNodeFromINode = NULL
\r
48 * \fn int Ext2_Install(char **Arguments)
\r
49 * \brief Install the Ext2 Filesystem Driver
\r
51 int Ext2_Install(char **Arguments)
\r
53 VFS_AddDriver( &gExt2_FSInfo );
\r
54 return MODULE_ERR_OK;
\r
58 * \brief Clean up driver state before unload
\r
60 int Ext2_Cleanup(void)
\r
66 * Detect if a volume is Ext2 formatted
\r
68 int Ext2_Detect(int FD)
\r
70 tExt2_SuperBlock sb;
\r
73 len = VFS_ReadAt(FD, 1024, 1024, &sb);
\r
76 Log_Debug("Ext2", "_Detect: Read failed? (0x%x != 1024)", len);
\r
85 Log_Debug("Ext2", "_Detect: s_magic = 0x%x", sb.s_magic);
\r
91 \brief Initializes a device to be read by by the driver
\r
92 \param Device String - Device to read from
\r
93 \param Options NULL Terminated array of option strings
\r
96 tVFS_Node *Ext2_InitDevice(const char *Device, const char **Options)
\r
101 tExt2_SuperBlock sb;
\r
104 ENTER("sDevice pOptions", Device, Options);
\r
107 fd = VFS_Open(Device, VFS_OPENFLAG_READ|VFS_OPENFLAG_WRITE); //Open Device
\r
109 Log_Warning("EXT2", "Unable to open '%s'", Device);
\r
114 // Read Superblock at offset 1024
\r
115 VFS_ReadAt(fd, 1024, 1024, &sb); // Read Superblock
\r
117 // Sanity Check Magic value
\r
118 if(sb.s_magic != 0xEF53) {
\r
119 Log_Warning("EXT2", "Volume '%s' is not an EXT2 volume (0x%x != 0xEF53)",
\r
120 Device, sb.s_magic);
\r
126 if( sb.s_blocks_per_group < MIN_BLOCKS_PER_GROUP ) {
\r
127 Log_Warning("Ext2", "Blocks per group is too small (%i < %i)",
\r
128 sb.s_blocks_per_group, MIN_BLOCKS_PER_GROUP);
\r
133 groupCount = DivUp(sb.s_blocks_count, sb.s_blocks_per_group);
\r
134 LOG("groupCount = %i", groupCount);
\r
136 // Allocate Disk Information
\r
137 disk = malloc(sizeof(tExt2_Disk) + sizeof(tExt2_Group)*groupCount);
\r
139 Log_Warning("EXT2", "Unable to allocate disk structure");
\r
145 memcpy(&disk->SuperBlock, &sb, 1024);
\r
146 disk->GroupCount = groupCount;
\r
148 // Get an inode cache handle
\r
149 disk->CacheID = Inode_GetHandle();
\r
152 if( sb.s_log_block_size > MAX_BLOCK_LOG_SIZE ) {
\r
153 Log_Warning("Ext2", "Block size (log2) too large (%i > %i)",
\r
154 sb.s_log_block_size, MAX_BLOCK_LOG_SIZE);
\r
157 disk->BlockSize = 1024 << sb.s_log_block_size;
\r
158 LOG("Disk->BlockSie = 0x%x (1024 << %i)", disk->BlockSize, sb.s_log_block_size);
\r
160 // Read Group Information
\r
161 LOG("sb,s_first_data_block = %x", sb.s_first_data_block);
\r
164 sb.s_first_data_block * disk->BlockSize + 1024,
\r
165 sizeof(tExt2_Group)*groupCount,
\r
169 LOG("Block Group 0");
\r
170 LOG(".bg_block_bitmap = 0x%x", disk->Groups[0].bg_block_bitmap);
\r
171 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[0].bg_inode_bitmap);
\r
172 LOG(".bg_inode_table = 0x%x", disk->Groups[0].bg_inode_table);
\r
173 LOG("Block Group 1");
\r
174 LOG(".bg_block_bitmap = 0x%x", disk->Groups[1].bg_block_bitmap);
\r
175 LOG(".bg_inode_bitmap = 0x%x", disk->Groups[1].bg_inode_bitmap);
\r
176 LOG(".bg_inode_table = 0x%x", disk->Groups[1].bg_inode_table);
\r
179 Ext2_int_ReadInode(disk, 2, &inode);
\r
181 // Create Root Node
\r
182 memset(&disk->RootNode, 0, sizeof(tVFS_Node));
\r
183 disk->RootNode.Inode = 2; // Root inode ID
\r
184 disk->RootNode.ImplPtr = disk; // Save disk pointer
\r
185 disk->RootNode.Size = -1; // Fill in later (on readdir)
\r
186 disk->RootNode.Flags = VFS_FFLAG_DIRECTORY;
\r
188 disk->RootNode.Type = &gExt2_DirType;
\r
190 // Complete root node
\r
191 disk->RootNode.UID = inode.i_uid;
\r
192 disk->RootNode.GID = inode.i_gid;
\r
193 disk->RootNode.NumACLs = 1;
\r
194 disk->RootNode.ACLs = &gVFS_ACL_EveryoneRW;
\r
197 LOG("inode.i_size = 0x%x", inode.i_size);
\r
198 LOG("inode.i_block[0] = 0x%x", inode.i_block[0]);
\r
201 LEAVE('p', &disk->RootNode);
\r
202 return &disk->RootNode;
\r
211 * \fn void Ext2_Unmount(tVFS_Node *Node)
\r
212 * \brief Close a mounted device
\r
214 void Ext2_Unmount(tVFS_Node *Node)
\r
216 tExt2_Disk *disk = Node->ImplPtr;
\r
218 VFS_Close( disk->FD );
\r
219 Inode_ClearCache( disk->CacheID );
\r
220 memset(disk, 0, sizeof(tExt2_Disk)+disk->GroupCount*sizeof(tExt2_Group));
\r
225 * \fn void Ext2_CloseFile(tVFS_Node *Node)
\r
226 * \brief Close a file (Remove it from the cache)
\r
228 void Ext2_CloseFile(tVFS_Node *Node)
\r
230 tExt2_Disk *disk = Node->ImplPtr;
\r
231 ENTER("pNode", Node);
\r
233 if( Mutex_Acquire(&Node->Lock) != 0 )
\r
239 if( Node->Flags & VFS_FFLAG_DIRTY )
\r
242 Log_Warning("Ext2", "TODO: Commit node changes");
\r
245 int was_not_referenced = (Node->ImplInt == 0);
\r
246 tVFS_ACL *acls = Node->ACLs;
\r
247 if( Inode_UncacheNode(disk->CacheID, Node->Inode) == 1 )
\r
249 if( was_not_referenced )
\r
251 LOG("Removng inode");
\r
253 Log_Warning("Ext2", "TODO: Remove inode when not referenced");
\r
255 if( acls != &gVFS_ACL_EveryoneRW ) {
\r
258 LOG("Node cleaned");
\r
261 LOG("Still referenced, releasing lock");
\r
262 Mutex_Release(&Node->Lock);
\r
268 //==================================
\r
269 //= INTERNAL FUNCTIONS =
\r
270 //==================================
\r
272 * \fn int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint InodeId, tExt2_Inode *Inode)
\r
273 * \brief Read an inode into memory
\r
275 int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
\r
279 ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
\r
281 if(InodeId == 0) return 0;
\r
283 InodeId --; // Inodes are numbered starting at 1
\r
285 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
\r
286 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
\r
288 LOG("group=%i, subId = %i", group, subId);
\r
291 VFS_ReadAt(Disk->FD,
\r
292 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
\r
293 sizeof(tExt2_Inode),
\r
301 * \brief Write a modified inode out to disk
\r
303 int Ext2_int_WriteInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
\r
306 ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
\r
313 InodeId --; // Inodes are numbered starting at 1
\r
315 group = InodeId / Disk->SuperBlock.s_inodes_per_group;
\r
316 subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
\r
318 LOG("group=%i, subId = %i", group, subId);
\r
321 VFS_WriteAt(Disk->FD,
\r
322 Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
\r
323 sizeof(tExt2_Inode),
\r
332 * \fn Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
\r
333 * \brief Get the address of a block from an inode's list
\r
334 * \param Disk Disk information structure
\r
335 * \param Blocks Pointer to an inode's block list
\r
336 * \param BlockNum Block index in list
\r
338 Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
\r
341 int dwPerBlock = Disk->BlockSize / 4;
\r
345 return (Uint64)Blocks[BlockNum] * Disk->BlockSize;
\r
347 // Single Indirect Blocks
\r
348 iBlocks = malloc( Disk->BlockSize );
\r
349 VFS_ReadAt(Disk->FD, (Uint64)Blocks[12]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
352 if(BlockNum < dwPerBlock)
\r
354 BlockNum = iBlocks[BlockNum];
\r
356 return (Uint64)BlockNum * Disk->BlockSize;
\r
359 BlockNum -= dwPerBlock;
\r
360 // Double Indirect Blocks
\r
361 if(BlockNum < dwPerBlock*dwPerBlock)
\r
363 VFS_ReadAt(Disk->FD, (Uint64)Blocks[13]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
364 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
365 BlockNum = iBlocks[BlockNum%dwPerBlock];
\r
367 return (Uint64)BlockNum * Disk->BlockSize;
\r
370 BlockNum -= dwPerBlock*dwPerBlock;
\r
371 // Triple Indirect Blocks
\r
372 VFS_ReadAt(Disk->FD, (Uint64)Blocks[14]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
373 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/(dwPerBlock*dwPerBlock)]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
374 VFS_ReadAt(Disk->FD, (Uint64)iBlocks[(BlockNum/dwPerBlock)%dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
\r
375 BlockNum = iBlocks[BlockNum%dwPerBlock];
\r
377 return (Uint64)BlockNum * Disk->BlockSize;
\r
381 * \fn Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
\r
382 * \brief Allocate an inode (from the current group preferably)
\r
383 * \param Disk EXT2 Disk Information Structure
\r
384 * \param Parent Inode ID of the parent (used to locate the child nearby)
\r
386 Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
\r
388 Uint start_group = (Parent - 1) / Disk->SuperBlock.s_inodes_per_group;
\r
389 Uint group = start_group;
\r
391 if( Disk->SuperBlock.s_free_inodes_count == 0 )
\r
393 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes on %p", Disk);
\r
397 while( group < Disk->GroupCount && Disk->Groups[group].bg_free_inodes_count == 0 )
\r
399 if( group == Disk->GroupCount )
\r
402 while( group < start_group && Disk->Groups[group].bg_free_inodes_count == 0 )
\r
406 if( Disk->Groups[group].bg_free_inodes_count == 0 )
\r
408 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes on %p, but superblock says some free", Disk);
\r
412 // Load bitmap for group
\r
413 // (s_inodes_per_group / 8) bytes worth
\r
414 // - Allocate a buffer the size of a sector/block
\r
415 // - Read in part of the bitmap
\r
416 // - Search for a free inode
\r
417 tExt2_Group *bg = &Disk->Groups[group];
\r
420 const int sector_size = 512;
\r
421 Uint8 buf[sector_size];
\r
422 VFS_ReadAt(Disk->FD, Disk->BlockSize*bg->bg_inode_bitmap+ofs, sector_size, buf);
\r
425 for( byte = 0; byte < sector_size && buf[byte] != 0xFF; byte ++ )
\r
427 if( byte < sector_size )
\r
429 for( bit = 0; bit < 8 && buf[byte] & (1 << bit); bit ++)
\r
432 buf[byte] |= 1 << bit;
\r
433 VFS_WriteAt(Disk->FD, Disk->BlockSize*bg->bg_inode_bitmap+ofs, sector_size, buf);
\r
435 bg->bg_free_inodes_count --;
\r
436 Disk->SuperBlock.s_free_inodes_count --;
\r
438 Uint32 ret = group * Disk->SuperBlock.s_inodes_per_group + byte * 8 + bit + 1;
\r
439 Log_Debug("Ext2", "Ext2_int_AllocateInode - Allocated 0x%x", ret);
\r
443 ofs += sector_size;
\r
444 } while(ofs < Disk->SuperBlock.s_inodes_per_group / 8);
\r
446 Log_Notice("Ext2", "Ext2_int_AllocateInode - Out of inodes in group %p:%i but header reported free",
\r
453 * \brief Reduce the reference count on an inode
\r
455 void Ext2_int_DereferenceInode(tExt2_Disk *Disk, Uint32 Inode)
\r
457 Log_Warning("Ext2", "TODO: Impliment Ext2_int_DereferenceInode");
\r
461 * \fn void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
\r
462 * \brief Updates the superblock
\r
464 void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
\r
466 int bpg = Disk->SuperBlock.s_blocks_per_group;
\r
467 int ngrp = Disk->SuperBlock.s_blocks_count / bpg;
\r
471 VFS_WriteAt(Disk->FD, 1024, 1024, &Disk->SuperBlock);
\r
474 // at Block Group 1, 3^n, 5^n, 7^n
\r
477 if(ngrp <= 1) return;
\r
478 VFS_WriteAt(Disk->FD, 1*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
\r
480 #define INT_MAX (((long long int)1<<(sizeof(int)*8))-1)
\r
483 for( i = 3; i < ngrp && i < INT_MAX/3; i *= 3 )
\r
484 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
\r
487 for( i = 5; i < ngrp && i < INT_MAX/5; i *= 5 )
\r
488 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
\r
491 for( i = 7; i < ngrp && i < INT_MAX/7; i *= 7 )
\r
492 VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
\r