From: Bruno Faccini <bruno.faccini@intel.com>
Date: Mon, 20 Apr 2015 14:25:30 +0000 (+0200)
Subject: LU-6476 lnet: avoid race during acceptor thread termination
X-Git-Tag: 2.7.54~21
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=7574e32e64b77851163d0a8d3141b406d03621be

LU-6476 lnet: avoid race during acceptor thread termination

This patch will avoid potential race, around socket sleepers
wait list, during acceptor thread termination and using
sk_callback_lock RW-Lock protection.

Signed-off-by: Bruno Faccini <bruno.faccini@intel.com>
Change-Id: Ib0a06bd8b3947648cb3ab7e1148b5073f68316fe
Reviewed-on: http://review.whamcloud.com/14503
Reviewed-by: Amir Shehata <amir.shehata@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lnet/lnet/acceptor.c b/lnet/lnet/acceptor.c
index a0c0783..3585d20 100644
--- a/lnet/lnet/acceptor.c
+++ b/lnet/lnet/acceptor.c
@@ -507,11 +507,17 @@ lnet_acceptor_start(void)
 void
 lnet_acceptor_stop(void)
 {
+	struct sock *sk;
+
 	if (lnet_acceptor_state.pta_shutdown) /* not running */
 		return;
 
 	lnet_acceptor_state.pta_shutdown = 1;
-	wake_up_all(sk_sleep(lnet_acceptor_state.pta_sock->sk));
+
+	sk = lnet_acceptor_state.pta_sock->sk;
+
+	/* awake any sleepers using safe method */
+	sk->sk_state_change(sk);
 
 	/* block until acceptor signals exit */
 	wait_for_completion(&lnet_acceptor_state.pta_signal);