X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;ds=sidebyside;f=Modules%2FFilesystems%2FExt2%2Fext2.c;fp=Modules%2FFilesystems%2FExt2%2Fext2.c;h=c2c2df9cd7ee579b4afa59cd51bdf876d07ac506;hb=923a9dc473851ec2bb1c94021bbf139724e7e8a5;hp=0000000000000000000000000000000000000000;hpb=f4646f2b6d64e42d1eec1d97877ae23eac6863f6;p=tpg%2Facess2.git

diff --git a/Modules/Filesystems/Ext2/ext2.c b/Modules/Filesystems/Ext2/ext2.c
new file mode 100644
index 00000000..c2c2df9c
--- /dev/null
+++ b/Modules/Filesystems/Ext2/ext2.c
@@ -0,0 +1,330 @@
+/*
+ * Acess OS
+ * Ext2 Driver Version 1
+ */
+/**
+ * \file fs/ext2.c
+ * \brief Second Extended Filesystem Driver
+ * \todo Implement file full write support
+ */
+#define DEBUG	1
+#define VERBOSE	0
+#include "ext2_common.h"
+#include <modules.h>
+
+// === PROTOTYPES ===
+ int	Ext2_Install(char **Arguments);
+// Interface Functions
+tVFS_Node	*Ext2_InitDevice(char *Device, char **Options);
+void		Ext2_Unmount(tVFS_Node *Node);
+void		Ext2_CloseFile(tVFS_Node *Node);
+// Internal Helpers
+ int		Ext2_int_GetInode(tVFS_Node *Node, tExt2_Inode *Inode);
+Uint64		Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum);
+Uint32		Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent);
+void		Ext2_int_UpdateSuperblock(tExt2_Disk *Disk);
+
+// === SEMI-GLOBALS ===
+MODULE_DEFINE(0, 0x5B /*v0.90*/, FS_Ext2, Ext2_Install, NULL);
+tExt2_Disk	gExt2_disks[6];
+ int	giExt2_count = 0;
+tVFS_Driver	gExt2_FSInfo = {
+	"ext2", 0, Ext2_InitDevice, Ext2_Unmount, NULL
+	};
+
+// === CODE ===
+
+/**
+ * \fn int Ext2_Install(char **Arguments)
+ * \brief Install the Ext2 Filesystem Driver
+ */
+int Ext2_Install(char **Arguments)
+{
+	VFS_AddDriver( &gExt2_FSInfo );
+	return MODULE_ERR_OK;
+}
+
+/**
+ \fn tVFS_Node *Ext2_InitDevice(char *Device, char **Options)
+ \brief Initializes a device to be read by by the driver
+ \param Device	String - Device to read from
+ \param Options	NULL Terminated array of option strings
+ \return Root Node
+*/
+tVFS_Node *Ext2_InitDevice(char *Device, char **Options)
+{
+	tExt2_Disk	*disk;
+	 int	fd;
+	 int	groupCount;
+	tExt2_SuperBlock	sb;
+	tExt2_Inode	inode;
+	
+	ENTER("sDevice pOptions", Device, Options);
+	
+	// Open Disk
+	fd = VFS_Open(Device, VFS_OPENFLAG_READ|VFS_OPENFLAG_WRITE);		//Open Device
+	if(fd == -1) {
+		Warning("[EXT2 ] Unable to open '%s'", Device);
+		LEAVE('n');
+		return NULL;
+	}
+	
+	// Read Superblock at offset 1024
+	VFS_ReadAt(fd, 1024, 1024, &sb);	// Read Superblock
+	
+	// Sanity Check Magic value
+	if(sb.s_magic != 0xEF53) {
+		Warning("[EXT2 ] Volume '%s' is not an EXT2 volume", Device);
+		VFS_Close(fd);
+		LEAVE('n');
+		return NULL;
+	}
+	
+	// Get Group count
+	groupCount = DivUp(sb.s_blocks_count, sb.s_blocks_per_group);
+	LOG("groupCount = %i", groupCount);
+	
+	// Allocate Disk Information
+	disk = malloc(sizeof(tExt2_Disk) + sizeof(tExt2_Group)*groupCount);
+	if(!disk) {
+		Warning("[EXT2 ] Unable to allocate disk structure");
+		VFS_Close(fd);
+		LEAVE('n');
+		return NULL;
+	}
+	disk->FD = fd;
+	memcpy(&disk->SuperBlock, &sb, 1024);
+	disk->GroupCount = groupCount;
+	
+	// Get an inode cache handle
+	disk->CacheID = Inode_GetHandle();
+	
+	// Get Block Size
+	LOG("s_log_block_size = 0x%x", sb.s_log_block_size);
+	disk->BlockSize = 1024 << sb.s_log_block_size;
+	
+	// Read Group Information
+	VFS_ReadAt(
+		disk->FD,
+		sb.s_first_data_block * disk->BlockSize + 1024,
+		sizeof(tExt2_Group)*groupCount,
+		disk->Groups
+		);
+	
+	#if VERBOSE
+	LOG("Block Group 0");
+	LOG(".bg_block_bitmap = 0x%x", disk->Groups[0].bg_block_bitmap);
+	LOG(".bg_inode_bitmap = 0x%x", disk->Groups[0].bg_inode_bitmap);
+	LOG(".bg_inode_table = 0x%x", disk->Groups[0].bg_inode_table);
+	LOG("Block Group 1");
+	LOG(".bg_block_bitmap = 0x%x", disk->Groups[1].bg_block_bitmap);
+	LOG(".bg_inode_bitmap = 0x%x", disk->Groups[1].bg_inode_bitmap);
+	LOG(".bg_inode_table = 0x%x", disk->Groups[1].bg_inode_table);
+	#endif
+	
+	// Get root Inode
+	Ext2_int_ReadInode(disk, 2, &inode);
+	
+	// Create Root Node
+	memset(&disk->RootNode, 0, sizeof(tVFS_Node));
+	disk->RootNode.Inode = 2;	// Root inode ID
+	disk->RootNode.ImplPtr = disk;	// Save disk pointer
+	disk->RootNode.Size = -1;	// Fill in later (on readdir)
+	disk->RootNode.Flags = VFS_FFLAG_DIRECTORY;
+	
+	disk->RootNode.ReadDir = Ext2_ReadDir;
+	disk->RootNode.FindDir = Ext2_FindDir;
+	//disk->RootNode.Relink = Ext2_Relink;
+	
+	// Complete root node
+	disk->RootNode.UID = inode.i_uid;
+	disk->RootNode.GID = inode.i_gid;
+	disk->RootNode.NumACLs = 1;
+	disk->RootNode.ACLs = &gVFS_ACL_EveryoneRW;
+	
+	#if DEBUG
+	LOG("inode.i_size = 0x%x", inode.i_size);
+	LOG("inode.i_block[0] = 0x%x", inode.i_block[0]);
+	#endif
+	
+	LEAVE('p', &disk->RootNode);
+	return &disk->RootNode;
+}
+
+/**
+ * \fn void Ext2_Unmount(tVFS_Node *Node)
+ * \brief Close a mounted device
+ */
+void Ext2_Unmount(tVFS_Node *Node)
+{
+	tExt2_Disk	*disk = Node->ImplPtr;
+	
+	VFS_Close( disk->FD );
+	Inode_ClearCache( disk->CacheID );
+	memset(disk, 0, sizeof(tExt2_Disk)+disk->GroupCount*sizeof(tExt2_Group));
+	free(disk);
+}
+
+/**
+ * \fn void Ext2_CloseFile(tVFS_Node *Node)
+ * \brief Close a file (Remove it from the cache)
+ */
+void Ext2_CloseFile(tVFS_Node *Node)
+{
+	tExt2_Disk	*disk = Node->ImplPtr;
+	Inode_UncacheNode(disk->CacheID, Node->Inode);
+	return ;
+}
+
+//==================================
+//=       INTERNAL FUNCTIONS       =
+//==================================
+/**
+ * \fn int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint InodeId, tExt2_Inode *Inode)
+ * \brief Read an inode into memory
+ */
+int Ext2_int_ReadInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
+{
+	 int	group, subId;
+	
+	//ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
+	
+	if(InodeId == 0)	return 0;
+	
+	InodeId --;	// Inodes are numbered starting at 1
+	
+	group = InodeId / Disk->SuperBlock.s_inodes_per_group;
+	subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
+	
+	//LOG("group=%i, subId = %i", group, subId);
+	
+	// Read Inode
+	VFS_ReadAt(Disk->FD,
+		Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
+		sizeof(tExt2_Inode),
+		Inode);
+	
+	//LEAVE('i', 1);
+	return 1;
+}
+
+/**
+ * \brief Write a modified inode out to disk
+ */
+int Ext2_int_WriteInode(tExt2_Disk *Disk, Uint32 InodeId, tExt2_Inode *Inode)
+{
+	 int	group, subId;
+	ENTER("pDisk iInodeId pInode", Disk, InodeId, Inode);
+	
+	if(InodeId == 0)	return 0;
+	
+	InodeId --;	// Inodes are numbered starting at 1
+	
+	group = InodeId / Disk->SuperBlock.s_inodes_per_group;
+	subId = InodeId % Disk->SuperBlock.s_inodes_per_group;
+	
+	LOG("group=%i, subId = %i", group, subId);
+	
+	// Write Inode
+	VFS_WriteAt(Disk->FD,
+		Disk->Groups[group].bg_inode_table * Disk->BlockSize + sizeof(tExt2_Inode)*subId,
+		sizeof(tExt2_Inode),
+		Inode);
+	
+	LEAVE('i', 1);
+	return 1;
+}
+
+/**
+ * \fn Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
+ * \brief Get the address of a block from an inode's list
+ * \param Disk	Disk information structure
+ * \param Blocks	Pointer to an inode's block list
+ * \param BlockNum	Block index in list
+ */
+Uint64 Ext2_int_GetBlockAddr(tExt2_Disk *Disk, Uint32 *Blocks, int BlockNum)
+{
+	Uint32	*iBlocks;
+	 int	dwPerBlock = Disk->BlockSize / 4;
+	
+	// Direct Blocks
+	if(BlockNum < 12)
+		return (Uint64)Blocks[BlockNum] * Disk->BlockSize;
+	
+	// Single Indirect Blocks
+	iBlocks = malloc( Disk->BlockSize );
+	VFS_ReadAt(Disk->FD, (Uint64)Blocks[12]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+	
+	BlockNum -= 12;
+	if(BlockNum < dwPerBlock)
+	{
+		BlockNum = iBlocks[BlockNum];
+		free(iBlocks);
+		return (Uint64)BlockNum * Disk->BlockSize;
+	}
+	
+	BlockNum -= dwPerBlock;
+	// Double Indirect Blocks
+	if(BlockNum < dwPerBlock*dwPerBlock)
+	{
+		VFS_ReadAt(Disk->FD, (Uint64)Blocks[13]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+		VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+		BlockNum = iBlocks[BlockNum%dwPerBlock];
+		free(iBlocks);
+		return (Uint64)BlockNum * Disk->BlockSize;
+	}
+	
+	BlockNum -= dwPerBlock*dwPerBlock;
+	// Triple Indirect Blocks
+	VFS_ReadAt(Disk->FD, (Uint64)Blocks[14]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+	VFS_ReadAt(Disk->FD, (Uint64)iBlocks[BlockNum/(dwPerBlock*dwPerBlock)]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+	VFS_ReadAt(Disk->FD, (Uint64)iBlocks[(BlockNum/dwPerBlock)%dwPerBlock]*Disk->BlockSize, Disk->BlockSize, iBlocks);
+	BlockNum = iBlocks[BlockNum%dwPerBlock];
+	free(iBlocks);
+	return (Uint64)BlockNum * Disk->BlockSize;
+}
+
+/**
+ * \fn Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
+ * \brief Allocate an inode (from the current group preferably)
+ * \param Disk	EXT2 Disk Information Structure
+ * \param Parent	Inode ID of the parent (used to locate the child nearby)
+ */
+Uint32 Ext2_int_AllocateInode(tExt2_Disk *Disk, Uint32 Parent)
+{
+//	Uint	block = (Parent - 1) / Disk->SuperBlock.s_inodes_per_group;
+	return 0;
+}
+
+/**
+ * \fn void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
+ * \brief Updates the superblock
+ */
+void Ext2_int_UpdateSuperblock(tExt2_Disk *Disk)
+{
+	 int	bpg = Disk->SuperBlock.s_blocks_per_group;
+	 int	ngrp = Disk->SuperBlock.s_blocks_count / bpg;
+	 int	i;
+	 
+	// Update Primary
+	VFS_WriteAt(Disk->FD, 1024, 1024, &Disk->SuperBlock);
+	
+	// Secondaries
+	// at Block Group 1, 3^n, 5^n, 7^n
+	
+	// 1
+	if(ngrp <= 1)	return;
+	VFS_WriteAt(Disk->FD, 1*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
+	
+	// Powers of 3
+	for( i = 3; i < ngrp; i *= 3 )
+		VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
+	
+	// Powers of 5
+	for( i = 5; i < ngrp; i *= 5 )
+		VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
+	
+	// Powers of 7
+	for( i = 7; i < ngrp; i *= 7 )
+		VFS_WriteAt(Disk->FD, i*bpg*Disk->BlockSize, 1024, &Disk->SuperBlock);
+}