useful functions: set_blocksize(dev, size); brelse(bh); bforget(bh); bread(dev,block,size); breada(dev,block,size,pos,filesize); create_buffer(page,size); -> set_bit(bh_lock,&bh->b_state); mark_buffer_dirty(bh,value); mark_buffer_uptodate(bh,value); mark_buffer_clean(bh,value);