Commit 4780c195 authored Mar 03, 2009 by Ralph Campbell Committed by Roland Dreier Mar 03, 2009

IB/mad: Fix ib_post_send_mad() returning 0 with no generate send comp



If ib_post_send_mad() returns 0, the API guarantees that there will be
a callback to send_buf->mad_agent->send_handler() so that the sender
can call ib_free_send_mad().  Otherwise, the ib_mad_send_buf will be
leaked and the mad_agent reference count will never go to zero and the
IB device module cannot be unloaded.  The above can happen without
this patch if process_mad() returns (IB_MAD_RESULT_SUCCESS |
IB_MAD_RESULT_CONSUMED).

If process_mad() returns IB_MAD_RESULT_SUCCESS and there is no agent
registered to receive the mad being sent, handle_outgoing_dr_smp()
returns zero which causes a MAD packet which is at the end of the
directed route to be incorrectly sent on the wire but doesn't cause a
hang since the HCA generates a send completion.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

parent d9620a4c

drivers/infiniband/core/mad.c

+6 −6

Original line number	Diff line number	Diff line
		@@ -742,9 +742,7 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
		break;
		case IB_MAD_RESULT_SUCCESS \| IB_MAD_RESULT_CONSUMED:
		kmem_cache_free(ib_mad_cache, mad_priv);
		kfree(local);
		ret = 1;
		goto out;
		break;
		case IB_MAD_RESULT_SUCCESS:
		/* Treat like an incoming receive MAD */
		port_priv = ib_get_mad_port(mad_agent_priv->agent.device,
		@@ -755,10 +753,12 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
		&mad_priv->mad.mad);
		}
		if (!port_priv \|\| !recv_mad_agent) {
		/*
		* No receiving agent so drop packet and
		* generate send completion.
		*/
		kmem_cache_free(ib_mad_cache, mad_priv);
		kfree(local);
		ret = 0;
		goto out;
		break;
		}
		local->mad_priv = mad_priv;
		local->recv_mad_agent = recv_mad_agent;