[ofa-general] [PATCH 11/11] mlx4: XRC receive-only QPs

[Roland Dreier]

 > +int mlx4_ib_modify_xrc_rcv_qp(struct ib_xrcd *ibxrcd, u32 qp_num,
 > +			      struct ib_qp_attr *attr, int attr_mask)
 > +{
 > +	struct mlx4_ib_dev *dev = to_mdev(ibxrcd->device);
 > +	struct mlx4_ib_xrcd *xrcd = to_mxrcd(ibxrcd);
 > +	struct mlx4_qp *mqp;
 > +	int err;
 > +
 > +	if (!(dev->dev->caps.flags & MLX4_DEV_CAP_FLAG_XRC))
 > +		return -ENOSYS;
 > +
 > +	mqp = __mlx4_qp_lookup(dev->dev, qp_num);
 > +	if (unlikely(!mqp)) {
 > +		printk(KERN_WARNING "mlx4_ib_reg_xrc_rcv_qp: unknown QPN %06x\n",
 > +		       qp_num);
 > +		return -EINVAL;
 > +	}

I don't see any locking here... what protects against the QP from being
destroyed out from under you in another thread?

 - R.