Re: [PATCH 02/11] IB/ipoib: Return IPoIB devices matching connection parameters

Jason Gunthorpe
2015-06-15T17:22:10Z

On Mon, Jun 15, 2015 at 11:47:07AM +0300, Haggai Eran wrote:

> +/* Called with an RCU read lock taken */

Add _rcu to the name? That is the standard convention.

> +/* returns an IPoIB netdev on top a given ipoib device matching a pkey_index
> + * and address, if one exists. */
> +static struct net_device *ipoib_match_gid_pkey_addr(struct ipoib_dev_priv *priv,
> + const union ib_gid *gid,
> + u16 pkey_index,
> + const struct sockaddr *addr)
> +{
> + struct ipoib_dev_priv *child_priv;
> + struct net_device *net_dev = NULL;
> +
> + if (priv->pkey_index == pkey_index &&
> + (!gid || !memcmp(gid, &priv->local_gid, sizeof(*gid)))) {
> + net_dev = ipoib_get_net_dev_match_addr(addr, priv->dev);
> + if (net_dev)
> + return net_dev;

As I said already, this should not even look at the sockaddr unless
there are multiple possible hits on the other parameters, and there
should be a comment explaining the sockaddr is only a hack to make up
for having an incomplete LLADDR.

That way people not using same guid children do not get incorrect
functionality..

> +static struct net_device *ipoib_get_net_dev_by_params(
> + struct ib_device *dev, u8 port, u16 pkey,
> + const union ib_gid *gid, const struct sockaddr *addr)

[..]

> + ret = ib_find_cached_pkey(dev, port, pkey, &pkey_index);
> + if (ret)
> + return NULL;
> +
> + if (!rdma_protocol_ib(dev, port))
> + return NULL;

This if should be first I'd think.

> + dev_list = ib_get_client_data(dev, &ipoib_client);
> + if (!dev_list)
> + return NULL;

Is the locking OK here? This access protected by lists_rwsem -
but for instance ib_unregister_device holds only the device_mutex when
calling client->remove, which kfree's dev_list. Looks wrong to me.

Jason