Revert "net/rds: determine active/passive connection with IP addresses"

This reverts commit 1f2ea7a ("net/rds: determine active/passive
connection with IP addresses"). The plan is to use the original, well
tested one-sided reconnection that was reverted in "812c02791: RDS: restore
the exponential back-off scheme".

Orabug: 26497333

Signed-off-by: Wei Lin Guay <[email protected]>
Reviewed-by: Håkon Bugge <[email protected]>
Reviewed-by: Avinash Repaka <[email protected]>
Reviewed-by: Ajaykumar Hotchandani <[email protected]>

Author: Wei Lin Guay

net/rds/ib_cm.c

@@ -922,14 +922,6 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 	 * see the comment above rds_queue_reconnect()
 	 */
 	mutex_lock(&conn->c_cm_lock);
-	if (rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_DOWN) &&
-	    (conn->c_laddr < conn->c_faddr)) {
-		rds_rtd(RDS_RTD_CM_EXT_P,
-			"incoming passive connection is trying to connect %p\n",
-			conn);
-		rds_conn_drop(conn, DR_IB_CONN_DROP_RACE);
-		goto out;
-	}
 	if (!rds_conn_transition(conn, RDS_CONN_DOWN, RDS_CONN_CONNECTING)) {
 		/*
 		 * in both of the cases below, the conn is half setup.
@@ -960,39 +952,10 @@ int rds_ib_cm_handle_connect(struct rdma_cm_id *cm_id,
 					NIPQUAD(conn->c_laddr),
 					NIPQUAD(conn->c_faddr),
 					conn->c_tos);
-				rds_rtd(RDS_RTD_CM, "RDS/IB: connection "
-					" id %p conn %p "
-					"<%u.%u.%u.%u,%u.%u.%u.%u,%d> "
-					"racing for 15s, forcing reset\n",
-					cm_id, conn,
-					NIPQUAD(conn->c_laddr),
-					NIPQUAD(conn->c_faddr),
-					conn->c_tos);
 				rds_conn_drop(conn, DR_IB_REQ_WHILE_CONNECTING);
 				rds_ib_stats_inc(s_ib_listen_closed_stale);
 			} else {
 				/* Wait and see - our connect may still be succeeding */
-				rds_rtd(RDS_RTD_CM, "RDS/IB: connection "
-					" id %p conn %p "
-					"<%u.%u.%u.%u,%u.%u.%u.%u,%d> "
-					" will be rejected\n",
-					cm_id, conn,
-					NIPQUAD(conn->c_laddr),
-					NIPQUAD(conn->c_faddr),
-					conn->c_tos);
-				if (test_and_clear_bit(RDS_INITIAL_RECONNECT, &conn->c_flags) ||
-				    (conn->c_laddr > conn->c_faddr) ||
-				    rds_conn_self_loopback_passive(conn)) {
-					rds_rtd(RDS_RTD_CM, "RDS/IB: connection "
-						" id %p conn %p "
-						"<%u.%u.%u.%u,%u.%u.%u.%u,%d> "
-						" will be rejected as passive conn\n",
-						cm_id, conn,
-						NIPQUAD(conn->c_laddr),
-						NIPQUAD(conn->c_faddr),
-						conn->c_tos);
-					rds_conn_drop(conn, DR_IB_CONN_DROP_RACE);
-				}
 				rds_ib_stats_inc(s_ib_connect_raced);
 			}
 		}

net/rds/rds.h

@@ -137,7 +137,6 @@ enum {
 #define RDS_IN_XMIT		2
 #define RDS_RECV_REFILL		3
 #define RDS_DESTROY_PENDING	4
-#define RDS_INITIAL_RECONNECT	5
 
 #define RDS_RDMA_RESOLVE_TO_MAX_INDEX   5
 #define RDS_ADDR_RES_TM_INDEX_MAX 5

net/rds/threads.c

@@ -132,7 +132,6 @@ EXPORT_SYMBOL_GPL(rds_connect_complete);
  */
 void rds_queue_reconnect(struct rds_conn_path *cp, int reason)
 {
-	unsigned long delay = 0;
 	unsigned long rand;
 	struct rds_connection *conn = cp->cp_conn;
 	bool is_tcp = conn->c_trans->t_type == RDS_TRANS_TCP;
@@ -146,31 +145,22 @@ void rds_queue_reconnect(struct rds_conn_path *cp, int reason)
 	if (is_tcp && !IS_CANONICAL(conn->c_laddr, conn->c_faddr))
 		return;
 
-	if (reason == DR_IB_BASE_CONN_DOWN) {
-		cp->cp_reconnect_jiffies = 0;
-		delay = msecs_to_jiffies(500);
-	}
-
 	set_bit(RDS_RECONNECT_PENDING, &cp->cp_flags);
 	if (cp->cp_reconnect_jiffies == 0) {
-		set_bit(RDS_INITIAL_RECONNECT, &cp->cp_flags);
-		get_random_bytes(&rand, sizeof(rand));
 		cp->cp_reconnect_jiffies = rds_sysctl_reconnect_min_jiffies;
-		queue_delayed_work(cp->cp_wq, &cp->cp_conn_w,
-				   delay + (rand % cp->cp_reconnect_jiffies));
+		queue_delayed_work(cp->cp_wq, &cp->cp_conn_w, 0);
 		return;
 	}
 
-	clear_bit(RDS_INITIAL_RECONNECT, &cp->cp_flags);
-	if ((conn->c_laddr > conn->c_faddr) ||
-	    rds_conn_self_loopback_passive(conn))
-		delay = msecs_to_jiffies(15000);
+	get_random_bytes(&rand, sizeof(rand));
 	rds_rtd(RDS_RTD_CM_EXT,
 		"%lu delay %lu ceil conn %p for %pI4 -> %pI4 tos %d\n",
-		delay, cp->cp_reconnect_jiffies,
+		rand % cp->cp_reconnect_jiffies, cp->cp_reconnect_jiffies,
 		conn, &conn->c_laddr, &conn->c_faddr, conn->c_tos);
 
-	queue_delayed_work(cp->cp_wq, &cp->cp_conn_w, delay);
+	queue_delayed_work(cp->cp_wq, &cp->cp_conn_w,
+			   rand % cp->cp_reconnect_jiffies);
+
 	cp->cp_reconnect_jiffies = min(cp->cp_reconnect_jiffies * 2,
 					rds_sysctl_reconnect_max_jiffies);
 }