public FileSystem (SuperBlock superBlock)
{
this.superBlock = superBlock;
///////////////////////////////////////////////////////////////////////
this.blockSize = (uint) (1024 << (int) this.superBlock.BlockSize);
if (this.superBlock.FragmentSize < 0)
this.fragmentSize = (uint) (1024 >> -superBlock.FragmentSize);
else
this.fragmentSize = (uint) (1024 << superBlock.FragmentSize);
if (superBlock.INodesPerGroup == 0)
throw new Exception ("Not a valid SuperBlock.");
this.groupsCount = (uint) (superBlock.INodesCount / superBlock.INodesPerGroup);
this.fragmentsPerBlock = (uint) (this.blockSize / this.fragmentSize);
this.groupDescriptorsPerBlock = (uint) (this.blockSize / GroupDescriptor.GroupDescriptorSize); //Marshal.SizeOf (typeof (GroupDescriptor)));
this.indirectCount = this.blockSize >> 2;
if (this.superBlock.RevisionLevel == 1)
this.inodeSize = this.superBlock.INodeSize;
else
this.inodeSize = 128;
this.inodesPerBlock = (uint) (this.blockSize / this.inodeSize);
this.inodeTableBlocksCount = (uint) Math.Ceiling ((double) (this.superBlock.INodesPerGroup * this.inodeSize) / (double) this.blockSize);
///////////////////////////////////////////////////////////////////////
uint bitmapSize = (uint) Math.Ceiling (this.superBlock.BlocksPerGroup / 8.0f);
this.blockBitmapBlocksCount = (uint) Math.Ceiling ((double) bitmapSize / (double) this.blockSize);
this.groupDescriptors = new GroupDescriptor [this.groupsCount];
}
public FileSystem(SuperBlock superBlock)
{
this.superBlock = superBlock;
///////////////////////////////////////////////////////////////////////
this.blockSize = (uint)(1024 << (int)this.superBlock.BlockSize);
if (this.superBlock.FragmentSize < 0)
{
this.fragmentSize = (uint)(1024 >> -superBlock.FragmentSize);
}
else
{
this.fragmentSize = (uint)(1024 << superBlock.FragmentSize);
}
if (superBlock.INodesPerGroup == 0)
{
throw new Exception("Not a valid SuperBlock.");
}
this.groupsCount = (uint)(superBlock.INodesCount / superBlock.INodesPerGroup);
this.fragmentsPerBlock = (uint)(this.blockSize / this.fragmentSize);
this.groupDescriptorsPerBlock = (uint)(this.blockSize / GroupDescriptor.GroupDescriptorSize); //Marshal.SizeOf (typeof (GroupDescriptor)));
this.indirectCount = this.blockSize >> 2;
if (this.superBlock.RevisionLevel == 1)
{
this.inodeSize = this.superBlock.INodeSize;
}
else
{
this.inodeSize = 128;
}
this.inodesPerBlock = (uint)(this.blockSize / this.inodeSize);
this.inodeTableBlocksCount = (uint)Math.Ceiling((double)(this.superBlock.INodesPerGroup * this.inodeSize) / (double)this.blockSize);
///////////////////////////////////////////////////////////////////////
uint bitmapSize = (uint)Math.Ceiling(this.superBlock.BlocksPerGroup / 8.0f);
this.blockBitmapBlocksCount = (uint)Math.Ceiling((double)bitmapSize / (double)this.blockSize);
this.groupDescriptors = new GroupDescriptor [this.groupsCount];
}
private void ReadSuperBlock(bool hasMBR)
{
if (hasMBR)
{
byte [] mbr = binaryReader.ReadBytes(512);
if (mbr [510] != 55 && mbr [511] != 0xaa)
{
throw new Exception("Invalid MBR Signature.");
}
bool found = false;
for (int i = 446; i < 510; i += 16)
{
if ((mbr [i] & 0x80) != 0)
{
found = true;
if (mbr [i + 4] != 0x83)
{
throw new Exception("The bootable partition is not of type Ext2.");
}
startOffset = mbr [i + 8];
startOffset += (uint)(mbr [i + 9] << 8);
startOffset += (uint)(mbr [i + 10] << 16);
startOffset += (uint)(mbr [i + 11] << 24);
startOffset *= 512;
break;
}
}
if (!found)
{
throw new Exception("No bootable partition found.");
}
}
binaryReader.BaseStream.Seek(startOffset + 1024, SeekOrigin.Begin);
byte [] buffer = binaryReader.ReadBytes(1024);
Block block = new Block(1024, buffer);
SuperBlock superBlock = new SuperBlock(block);
this.fileSystem = new FileSystem(superBlock);
if (this.fileSystem.SuperBlock.Magic != SuperBlock.EXT2_MAGIC)
{
throw new Exception("Not an Ext2 partition.");
}
if (this.fileSystem.SuperBlock.Errors != SuperBlock.EXT2_ERRORS_CONTINUE)
{
throw new Exception("Invalid Ext2 SuperBlock state.");
}
if (this.fileSystem.SuperBlock.AlgorithmsBitmap != 0)
{
throw new Exception("Unsupported Bitmap Compression Algorithm.");
}
}