Method GetInodeBlock

Kernel/src/fs/ext2.cpp:152–198

    }

    uint32_t Ext2Volume::GetInodeBlock(uint32_t index, ext2_inode_t& ino){
        uint32_t blocksPerPointer = blocksize / sizeof(uint32_t); // Amount of blocks in a indirect block table
        uint32_t singlyIndirectStart = EXT2_DIRECT_BLOCK_COUNT;
        uint32_t doublyIndirectStart = singlyIndirectStart + blocksPerPointer;
        uint32_t triplyIndirectStart = doublyIndirectStart + blocksPerPointer * blocksPerPointer;

        assert(index < triplyIndirectStart + blocksPerPointer * blocksPerPointer * blocksPerPointer); // Make sure that an invalid index was not passed

        if(index < EXT2_DIRECT_BLOCK_COUNT){
            // Index lies within the direct blocklist
            return ino.blocks[index];
        } else if(index < doublyIndirectStart){
            // Index lies within the singly indirect blocklist
            uint32_t buffer[blocksize / sizeof(uint32_t)];

            if(int e = ReadBlockCached(ino.blocks[EXT2_SINGLY_INDIRECT_INDEX], buffer)){
                (void)e;
                error = DiskReadError;
                return 0;
            }

            return buffer[index - singlyIndirectStart];
        } else if(index < triplyIndirectStart){
            // Index lies within the doubly indirect blocklist
            uint32_t blockPointers[blocksize / sizeof(uint32_t)];
            uint32_t buffer[blocksize / sizeof(uint32_t)];

            if(int e = ReadBlockCached(ino.blocks[EXT2_DOUBLY_INDIRECT_INDEX], blockPointers)){
                (void)e;
                error = DiskReadError;
                return 0;
            }

            uint32_t blockPointer = blockPointers[(index - doublyIndirectStart) / blocksPerPointer];

            if(int e = ReadBlockCached(blockPointer, buffer)){
                (void)e;
                error = DiskReadError;
                return 0;
            }

            return buffer[(index - doublyIndirectStart) % blocksPerPointer];
        } else {
            assert(!"Yet to support triply indirect");
            return 0;
        }
    }

    Vector<uint32_t> Ext2Volume::GetInodeBlocks(uint32_t index, uint32_t count, ext2_inode_t& ino){
        uint32_t blocksPerPointer = blocksize / sizeof(uint32_t); // Amount of blocks in a indirect block table