6 files changed, 57 insertions, 3 deletions

diff --git a/net/rds/af_rds.c b/net/rds/af_rds.c
index 6beaeb1138f3..2ac1e6194be3 100644
--- a/net/rds/af_rds.c
+++ b/net/rds/af_rds.c
@@ -605,10 +605,14 @@ static void rds_exit(void)
 }
 module_exit(rds_exit);
 
+u32 rds_gen_num;
+
 static int rds_init(void)
 {
 	int ret;
 
+	net_get_random_once(&rds_gen_num, sizeof(rds_gen_num));
+
 	ret = rds_bind_lock_init();
 	if (ret)
 		goto out;
diff --git a/net/rds/connection.c b/net/rds/connection.c
index 13f459dad4ef..b86e188bde32 100644
--- a/net/rds/connection.c
+++ b/net/rds/connection.c
@@ -269,6 +269,8 @@ static struct rds_connection *__rds_conn_create(struct net *net,
 			kmem_cache_free(rds_conn_slab, conn);
 			conn = found;
 		} else {
+			conn->c_my_gen_num = rds_gen_num;
+			conn->c_peer_gen_num = 0;
 			hlist_add_head_rcu(&conn->c_hash_node, head);
 			rds_cong_add_conn(conn);
 			rds_conn_count++;
diff --git a/net/rds/message.c b/net/rds/message.c
index 6cb91061556a..49bfb512d808 100644
--- a/net/rds/message.c
+++ b/net/rds/message.c
@@ -42,6 +42,7 @@ static unsigned int	rds_exthdr_size[__RDS_EXTHDR_MAX] = {
 [RDS_EXTHDR_RDMA]	= sizeof(struct rds_ext_header_rdma),
 [RDS_EXTHDR_RDMA_DEST]	= sizeof(struct rds_ext_header_rdma_dest),
 [RDS_EXTHDR_NPATHS]	= sizeof(u16),
+[RDS_EXTHDR_GEN_NUM]	= sizeof(u32),
 };
 
 
diff --git a/net/rds/rds.h b/net/rds/rds.h
index 4121e1862444..ebbf909b87ec 100644
--- a/net/rds/rds.h
+++ b/net/rds/rds.h
@@ -151,6 +151,9 @@ struct rds_connection {
 
 	struct rds_conn_path	c_path[RDS_MPATH_WORKERS];
 	wait_queue_head_t	c_hs_waitq; /* handshake waitq */
+
+	u32			c_my_gen_num;
+	u32			c_peer_gen_num;
 };
 
 static inline
@@ -243,7 +246,8 @@ struct rds_ext_header_rdma_dest {
 /* Extension header announcing number of paths.
  * Implicit length = 2 bytes.
  */
-#define RDS_EXTHDR_NPATHS	4
+#define RDS_EXTHDR_NPATHS	5
+#define RDS_EXTHDR_GEN_NUM	6
 
 #define __RDS_EXTHDR_MAX	16 /* for now */
 
@@ -338,6 +342,7 @@ static inline u32 rds_rdma_cookie_offset(rds_rdma_cookie_t cookie)
 #define RDS_MSG_RETRANSMITTED	5
 #define RDS_MSG_MAPPED		6
 #define RDS_MSG_PAGEVEC		7
+#define RDS_MSG_FLUSH		8
 
 struct rds_message {
 	atomic_t		m_refcount;
@@ -664,6 +669,7 @@ void rds_cong_exit(void);
 struct rds_message *rds_cong_update_alloc(struct rds_connection *conn);
 
 /* conn.c */
+extern u32 rds_gen_num;
 int rds_conn_init(void);
 void rds_conn_exit(void);
 struct rds_connection *rds_conn_create(struct net *net,
diff --git a/net/rds/recv.c b/net/rds/recv.c
index cbfabdf3ff48..9d0666e5fe35 100644
--- a/net/rds/recv.c
+++ b/net/rds/recv.c
@@ -120,6 +120,36 @@ static void rds_recv_rcvbuf_delta(struct rds_sock *rs, struct sock *sk,
 	/* do nothing if no change in cong state */
 }
 
+static void rds_conn_peer_gen_update(struct rds_connection *conn,
+				     u32 peer_gen_num)
+{
+	int i;
+	struct rds_message *rm, *tmp;
+	unsigned long flags;
+
+	WARN_ON(conn->c_trans->t_type != RDS_TRANS_TCP);
+	if (peer_gen_num != 0) {
+		if (conn->c_peer_gen_num != 0 &&
+		    peer_gen_num != conn->c_peer_gen_num) {
+			for (i = 0; i < RDS_MPATH_WORKERS; i++) {
+				struct rds_conn_path *cp;
+
+				cp = &conn->c_path[i];
+				spin_lock_irqsave(&cp->cp_lock, flags);
+				cp->cp_next_tx_seq = 1;
+				cp->cp_next_rx_seq = 0;
+				list_for_each_entry_safe(rm, tmp,
+							 &cp->cp_retrans,
+							 m_conn_item) {
+					set_bit(RDS_MSG_FLUSH, &rm->m_flags);
+				}
+				spin_unlock_irqrestore(&cp->cp_lock, flags);
+			}
+		}
+		conn->c_peer_gen_num = peer_gen_num;
+	}
+}
+
 /*
  * Process all extension headers that come with this message.
  */
@@ -163,7 +193,9 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr,
 	union {
 		struct rds_ext_header_version version;
 		u16 rds_npaths;
+		u32 rds_gen_num;
 	} buffer;
+	u32 new_peer_gen_num = 0;
 
 	while (1) {
 		len = sizeof(buffer);
@@ -176,6 +208,9 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr,
 			conn->c_npaths = min_t(int, RDS_MPATH_WORKERS,
 					       buffer.rds_npaths);
 			break;
+		case RDS_EXTHDR_GEN_NUM:
+			new_peer_gen_num = buffer.rds_gen_num;
+			break;
 		default:
 			pr_warn_ratelimited("ignoring unknown exthdr type "
 					     "0x%x\n", type);
@@ -183,6 +218,7 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr,
 	}
 	/* if RDS_EXTHDR_NPATHS was not found, default to a single-path */
 	conn->c_npaths = max_t(int, conn->c_npaths, 1);
+	rds_conn_peer_gen_update(conn, new_peer_gen_num);
 }
 
 /* rds_start_mprds() will synchronously start multiple paths when appropriate.
diff --git a/net/rds/send.c b/net/rds/send.c
index 896626b9a0ef..77c8c6e613ad 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c
@@ -259,8 +259,9 @@ restart:
 			 * connection.
 			 * Therefore, we never retransmit messages with RDMA ops.
 			 */
-			if (rm->rdma.op_active &&
-			    test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags)) {
+			if (test_bit(RDS_MSG_FLUSH, &rm->m_flags) ||
+			    (rm->rdma.op_active &&
+			    test_bit(RDS_MSG_RETRANSMITTED, &rm->m_flags))) {
 				spin_lock_irqsave(&cp->cp_lock, flags);
 				if (test_and_clear_bit(RDS_MSG_ON_CONN, &rm->m_flags))
 					list_move(&rm->m_conn_item, &to_be_dropped);
@@ -1209,6 +1210,10 @@ rds_send_probe(struct rds_conn_path *cp, __be16 sport,
 		rds_message_add_extension(&rm->m_inc.i_hdr,
 					  RDS_EXTHDR_NPATHS, &npaths,
 					  sizeof(npaths));
+		rds_message_add_extension(&rm->m_inc.i_hdr,
+					  RDS_EXTHDR_GEN_NUM,
+					  &cp->cp_conn->c_my_gen_num,
+					  sizeof(u32));
 	}
 	spin_unlock_irqrestore(&cp->cp_lock, flags);