RDS: avoid duplicate connection drop for self loopback

For self-IB loopback is special mode and the c_passive conn is just a
place holder to stick the the second QP.

Orabug: 22347191

Tested-by: Michael Nowak <[email protected]>
Tested-by: Rafael Alejandro Peralez <[email protected]>
Tested-by: Liwen Huang <[email protected]>
Tested-by: Hong Liu <[email protected]>
Reviewed-by: Mukesh Kacker <[email protected]>
Signed-off-by: Santosh Shilimkar <[email protected]>

Author: SantoshShilimkar

net/rds/rdma_transport.c

@@ -309,7 +309,8 @@ int rds_rdma_cm_event_handler(struct rdma_cm_id *cm_id,
 				"ADDR_CHANGE: calling rds_conn_drop <%u.%u.%u.%u,%u.%u.%u.%u,%d>\n",
 				NIPQUAD(conn->c_laddr),	NIPQUAD(conn->c_faddr),
 				conn->c_tos);
-			rds_conn_drop(conn, DR_IB_ADDR_CHANGE);
+			if (!rds_conn_self_loopback_passive(conn))
+				rds_conn_drop(conn, DR_IB_ADDR_CHANGE);
 		}
 		break;
 

net/rds/rds.h

@@ -887,6 +887,15 @@ rds_conn_connecting(struct rds_connection *conn)
 	return atomic_read(&conn->c_state) == RDS_CONN_CONNECTING;
 }
 
+static inline bool
+rds_conn_self_loopback_passive(struct rds_connection *conn)
+{
+	if (conn->c_laddr == conn->c_faddr && !conn->c_passive)
+		return true;
+	else
+		return false;
+}
+
 /* message.c */
 struct rds_message *rds_message_alloc(unsigned int nents, gfp_t gfp);
 struct scatterlist *rds_message_alloc_sgs(struct rds_message *rm, int nents);