[PATCH net] rds: RDS (tcp) hangs on sendto() to unresponding address
From: Ka-Cheong Poon <hidden>
Date: 2018-10-08 23:29:50
Subsystem:
networking [general], rds - reliable datagram sockets, the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Allison Henderson, Linus Torvalds
In rds_send_mprds_hash(), if the calculated hash value is non-zero and the MPRDS connections are not yet up, it will wait. But it should not wait if the send is non-blocking. In this case, it should just use the base c_path for sending the message. Signed-off-by: Ka-Cheong Poon <redacted> --- net/rds/send.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/net/rds/send.c b/net/rds/send.c
index 57b3d5a..fe785ee 100644
--- a/net/rds/send.c
+++ b/net/rds/send.c@@ -1007,7 +1007,8 @@ static int rds_cmsg_send(struct rds_sock *rs, struct rds_message *rm, return ret; } -static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) +static int rds_send_mprds_hash(struct rds_sock *rs, + struct rds_connection *conn, int nonblock) { int hash;
@@ -1023,10 +1024,16 @@ static int rds_send_mprds_hash(struct rds_sock *rs, struct rds_connection *conn) * used. But if we are interrupted, we have to use the zero * c_path in case the connection ends up being non-MP capable. */ - if (conn->c_npaths == 0) + if (conn->c_npaths == 0) { + /* Cannot wait for the connection be made, so just use + * the base c_path. + */ + if (nonblock) + return 0; if (wait_event_interruptible(conn->c_hs_waitq, conn->c_npaths != 0)) hash = 0; + } if (conn->c_npaths == 1) hash = 0; }
@@ -1256,7 +1263,7 @@ int rds_sendmsg(struct socket *sock, struct msghdr *msg, size_t payload_len) } if (conn->c_trans->t_mp_capable) - cpath = &conn->c_path[rds_send_mprds_hash(rs, conn)]; + cpath = &conn->c_path[rds_send_mprds_hash(rs, conn, nonblock)]; else cpath = &conn->c_path[0];
--
1.8.3.1