IB/cma: Add support for network namespaces

Add support for network namespaces in the ib_cma module. This is
accomplished by:

1. Adding network namespace parameter for rdma_create_id. This parameter is
   used to populate the network namespace field in rdma_id_private.
   rdma_create_id keeps a reference on the network namespace.
2. Using the network namespace from the rdma_id instead of init_net inside
   of ib_cma, when listening on an ID and when looking for an ID for an
   incoming request.
3. Decrementing the reference count for the appropriate network namespace
   when calling rdma_destroy_id.

In order to preserve the current behavior init_net is passed when calling
from other modules.

Signed-off-by: Guy Shapiro <guysh@mellanox.com>
Signed-off-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Yotam Kenneth <yotamke@mellanox.com>
Signed-off-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index c92522c192d2..463ec0ccbe51 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -160,13 +160,17 @@ struct rdma_cm_id {
 /**
  * rdma_create_id - Create an RDMA identifier.
  *
+ * @net: The network namespace in which to create the new id.
  * @event_handler: User callback invoked to report events associated with the
  *   returned rdma_id.
  * @context: User specified context associated with the id.
  * @ps: RDMA port space.
  * @qp_type: type of queue pair associated with the id.
+ *
+ * The id holds a reference on the network namespace until it is destroyed.
  */
-struct rdma_cm_id *rdma_create_id(rdma_cm_event_handler event_handler,
+struct rdma_cm_id *rdma_create_id(struct net *net,
+                                  rdma_cm_event_handler event_handler,
                                   void *context, enum rdma_port_space ps,
                                   enum ib_qp_type qp_type);