In order to handle a race condition where the passive side of
a connection can receive data on a QP before the connection established
event has been received, transition the QP to RTS before sending the reply.
This allows a user to send a response to any received message immediately,
rather than waiting until the connection established event has been
processed.
A similar fix was applied to the kernel rdma_cm a while ago.
Simply duplicate the fix in the user space library.
Signed-off-by: Sean Hefty <sean.he...@intel.com>
---
src/cma.c | 27 +++++++++------------------
1 files changed, 9 insertions(+), 18 deletions(-)
diff --git a/src/cma.c b/src/cma.c
index efad6ae..59e89dd 100644
--- a/src/cma.c
+++ b/src/cma.c
@@ -652,7 +652,8 @@ static int ucma_modify_qp_rtr(struct rdma_cm_id *id,
return ibv_modify_qp(id->qp, &qp_attr, qp_attr_mask);
}
-static int ucma_modify_qp_rts(struct rdma_cm_id *id)
+static int ucma_modify_qp_rts(struct rdma_cm_id *id,
+ struct rdma_conn_param *conn_param)
{
struct ibv_qp_attr qp_attr;
int qp_attr_mask, ret;
@@ -662,6 +663,8 @@ static int ucma_modify_qp_rts(struct rdma_cm_id *id)
if (ret)
return ret;
+ if (conn_param)
+ qp_attr.max_rd_atomic = conn_param->initiator_depth;
return ibv_modify_qp(id->qp, &qp_attr, qp_attr_mask);
}
@@ -929,6 +932,10 @@ int rdma_accept(struct rdma_cm_id *id, struct
rdma_conn_param *conn_param)
ret = ucma_modify_qp_rtr(id, conn_param);
if (ret)
return ret;
+
+ ret = ucma_modify_qp_rts(id, conn_param);
+ if (ret)
+ return ret;
}
CMA_CREATE_MSG_CMD(msg, cmd, UCMA_CMD_ACCEPT, size);
@@ -1212,7 +1219,7 @@ static int ucma_process_conn_resp(struct cma_id_private
*id_priv)
if (ret)
goto err;
- ret = ucma_modify_qp_rts(&id_priv->id);
+ ret = ucma_modify_qp_rts(&id_priv->id, NULL);
if (ret)
goto err;
@@ -1231,17 +1238,6 @@ err:
return ret;
}
-static int ucma_process_establish(struct rdma_cm_id *id)
-{
- int ret;
-
- ret = ucma_modify_qp_rts(id);
- if (ret)
- ucma_modify_qp_err(id);
-
- return ret;
-}
-
static int ucma_process_join(struct cma_event *evt)
{
evt->mc->mgid = evt->event.param.ud.ah_attr.grh.dgid;
@@ -1367,11 +1363,6 @@ retry:
}
ucma_copy_conn_event(evt, &resp->param.conn);
- evt->event.status = ucma_process_establish(&evt->id_priv->id);
- if (evt->event.status) {
- evt->event.event = RDMA_CM_EVENT_CONNECT_ERROR;
- evt->id_priv->connect_error = 1;
- }
break;
case RDMA_CM_EVENT_REJECTED:
if (evt->id_priv->connect_error) {
--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
