From 69b92b5b7419846e2a0d61a097b11b17a089e046 Mon Sep 17 00:00:00 2001 From: Sowmini Varadhan Date: Wed, 21 Jun 2017 13:40:12 -0700 Subject: [PATCH] rds: tcp: send handshake ping-probe from passive endpoint The RDS handshake ping probe added by commit 5916e2c1554f ("RDS: TCP: Enable multipath RDS for TCP") is sent from rds_sendmsg() before the first data packet is sent to a peer. If the conversation is not bidirectional (i.e., one side is always passive and never invokes rds_sendmsg()) and the passive side restarts its rds_tcp module, a new HS ping probe needs to be sent, so that the number of paths can be re-established. This patch achieves that by sending a HS ping probe from rds_tcp_accept_one() when c_npaths is 0 (i.e., we have not done a handshake probe with this peer yet). Signed-off-by: Sowmini Varadhan Tested-by: Jenny Xu Signed-off-by: David S. Miller --- net/rds/rds.h | 1 + net/rds/recv.c | 6 +++--- net/rds/send.c | 14 ++++++-------- net/rds/tcp_listen.c | 2 ++ 4 files changed, 12 insertions(+), 11 deletions(-) diff --git a/net/rds/rds.h b/net/rds/rds.h index d6a04a05eb79..aa696b361e20 100644 --- a/net/rds/rds.h +++ b/net/rds/rds.h @@ -827,6 +827,7 @@ void rds_send_drop_acked(struct rds_connection *conn, u64 ack, is_acked_func is_acked); void rds_send_path_drop_acked(struct rds_conn_path *cp, u64 ack, is_acked_func is_acked); +void rds_send_ping(struct rds_connection *conn, int cp_index); int rds_send_pong(struct rds_conn_path *cp, __be16 dport); /* rdma.c */ diff --git a/net/rds/recv.c b/net/rds/recv.c index 49493dbc43a1..373a6aa1d976 100644 --- a/net/rds/recv.c +++ b/net/rds/recv.c @@ -227,6 +227,7 @@ 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); + conn->c_ping_triggered = 0; rds_conn_peer_gen_update(conn, new_peer_gen_num); } @@ -244,8 +245,7 @@ static void rds_recv_hs_exthdrs(struct rds_header *hdr, * called after reception of the probe-pong on all mprds_paths. * Otherwise (sender of probe-ping is not the smaller ip addr): just call * rds_conn_path_connect_if_down on the hashed path. (see rule 4) - * 4. when cp_index > 0, rds_connect_worker must only trigger - * a connection if laddr < faddr. + * 4. rds_connect_worker must only trigger a connection if laddr < faddr. * 5. sender may end up queuing the packet on the cp. will get sent out later. * when connection is completed. */ @@ -256,7 +256,7 @@ static void rds_start_mprds(struct rds_connection *conn) if (conn->c_npaths > 1 && IS_CANONICAL(conn->c_laddr, conn->c_faddr)) { - for (i = 1; i < conn->c_npaths; i++) { + for (i = 0; i < conn->c_npaths; i++) { cp = &conn->c_path[i]; rds_conn_path_connect_if_down(cp); } diff --git a/net/rds/send.c b/net/rds/send.c index 3652a50397c7..e81aa176f4e2 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -971,8 +971,6 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm, return ret; } -static void rds_send_ping(struct rds_connection *conn); - static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) { int hash; @@ -982,7 +980,7 @@ static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) else hash = RDS_MPATH_HASH(rs, conn->c_npaths); if (conn->c_npaths == 0 && hash != 0) { - rds_send_ping(conn); + rds_send_ping(conn, 0); if (conn->c_npaths == 0) { wait_event_interruptible(conn->c_hs_waitq, @@ -1282,11 +1280,11 @@ rds_send_pong(struct rds_conn_path *cp, __be16 dport) return rds_send_probe(cp, 0, dport, 0); } -static void -rds_send_ping(struct rds_connection *conn) +void +rds_send_ping(struct rds_connection *conn, int cp_index) { unsigned long flags; - struct rds_conn_path *cp = &conn->c_path[0]; + struct rds_conn_path *cp = &conn->c_path[cp_index]; spin_lock_irqsave(&cp->cp_lock, flags); if (conn->c_ping_triggered) { @@ -1295,6 +1293,6 @@ rds_send_ping(struct rds_connection *conn) } conn->c_ping_triggered = 1; spin_unlock_irqrestore(&cp->cp_lock, flags); - rds_send_probe(&conn->c_path[0], cpu_to_be16(RDS_FLAG_PROBE_PORT), - 0, 0); + rds_send_probe(cp, cpu_to_be16(RDS_FLAG_PROBE_PORT), 0, 0); } +EXPORT_SYMBOL_GPL(rds_send_ping); diff --git a/net/rds/tcp_listen.c b/net/rds/tcp_listen.c index df291ac245d6..6089e9a8e00a 100644 --- a/net/rds/tcp_listen.c +++ b/net/rds/tcp_listen.c @@ -192,6 +192,8 @@ int rds_tcp_accept_one(struct socket *sock) } new_sock = NULL; ret = 0; + if (conn->c_npaths == 0) + rds_send_ping(cp->cp_conn, cp->cp_index); goto out; rst_nsk: /* reset the newly returned accept sock and bail. -- 2.39.5