From e506bd990d6ac567b3ce7fd32d5ce950f899df72 Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Tue, 13 Aug 2013 18:37:45 +0000
Subject: [PATCH] fcst: Fix a race condition

git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@4961 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 fcst/ft_sess.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/fcst/ft_sess.c b/fcst/ft_sess.c
index a943a5b60..ed1687a7a 100644
--- a/fcst/ft_sess.c
+++ b/fcst/ft_sess.c
@@ -216,7 +216,8 @@ static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 	hlist_for_each_entry_rcu(sess, head, hash) {
 #endif
 		if (sess->port_id == port_id) {
-			kref_get(&sess->kref);
+			if (!kref_get_unless_zero(&sess->kref))
+				sess = NULL;
 			rcu_read_unlock();
 			FT_SESS_DBG("port_id %x found %p\n", port_id, sess);
 			return sess;