rem: struct vnode *v;
add: struct vnode *vnode;
context: create_new_vnode(void){	struct vnode *v;	v = (struct vnode *)kmalloc(sizeof(struct vnode));	if (v == NULL)		return NULL;	memset(v, 0, sizeof(struct vnode));//max_commit - old_store_commitment + commitment(v);	return v;}