[PATCH 35/40] staging: lustre: avoid race during lnet acceptor thread termination

From: James Simmons
Date: Fri Nov 20 2015 - 18:39:28 EST


From: Bruno Faccini <bruno.faccini@xxxxxxxxx>

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@xxxxxxxxx>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-6476
Reviewed-on: http://review.whamcloud.com/14503
Reviewed-by: Amir Shehata <amir.shehata@xxxxxxxxx>
Reviewed-by: John L. Hammond <john.hammond@xxxxxxxxx>
Reviewed-by: Oleg Drokin <oleg.drokin@xxxxxxxxx>
---
drivers/staging/lustre/lnet/lnet/acceptor.c | 8 +++++++-
1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/drivers/staging/lustre/lnet/lnet/acceptor.c b/drivers/staging/lustre/lnet/lnet/acceptor.c
index ffa2b19..61806ce 100644
--- a/drivers/staging/lustre/lnet/lnet/acceptor.c
+++ b/drivers/staging/lustre/lnet/lnet/acceptor.c
@@ -485,11 +485,17 @@ 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);
--
1.7.1

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