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 <sowmini.varad...@oracle.com>
Tested-by: Jenny Xu <jenny.x...@oracle.com>
---
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 d6a04a0..aa696b3 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 49493db..373a6aa 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 3652a50..e81aa17 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 @@ int rds_sendmsg(struct socket *sock, struct msghdr
*msg, size_t payload_len)
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 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg,
size_t payload_len)
}
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 df291ac..6089e9a 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.
--
1.7.1
