From 445b290bd3c3470a220049648150eefaec64937a Mon Sep 17 00:00:00 2001 From: "jeff.liu" Date: Mon, 8 Oct 2012 18:57:27 +0000 Subject: RDS: fix rds-ping spinlock recursion [ Upstream commit 5175a5e76bbdf20a614fb47ce7a38f0f39e70226 ] This is the revised patch for fixing rds-ping spinlock recursion according to Venkat's suggestions. RDS ping/pong over TCP feature has been broken for years(2.6.39 to 3.6.0) since we have to set TCP cork and call kernel_sendmsg() between ping/pong which both need to lock "struct sock *sk". However, this lock has already been hold before rds_tcp_data_ready() callback is triggerred. As a result, we always facing spinlock resursion which would resulting in system panic. Given that RDS ping is only used to test the connectivity and not for serious performance measurements, we can queue the pong transmit to rds_wq as a delayed response. Reported-by: Dan Carpenter CC: Venkat Venkatsubra CC: David S. Miller CC: James Morris Signed-off-by: Jie Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/send.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/rds/send.c b/net/rds/send.c index c803341..f6bdfb0 100644 --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1121,7 +1121,7 @@ rds_send_pong(struct rds_connection *conn, __be16 dport) rds_stats_inc(s_send_pong); if (!test_bit(RDS_LL_SEND_FULL, &conn->c_flags)) - rds_send_xmit(conn); + queue_delayed_work(rds_wq, &conn->c_send_w, 0); rds_message_put(rm); return 0; -- cgit v1.1