From: Mark Rustad <mark.d.rustad@intel.com>
Date: Tue, 26 Jun 2012 22:57:30 +0000 (-0700)
Subject: tcm_fc: Resolve suspicious RCU usage warnings
X-Git-Tag: firefly_0821_release~3680^2~2438^2~4
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=863555be0c81558b1af277addcf68acb8f778860;p=firefly-linux-kernel-4.4.55.git

tcm_fc: Resolve suspicious RCU usage warnings

Use rcu_dereference_protected to tell rcu that the ft_lport_lock
is held during ft_lport_create. This resolved "suspicious RCU usage"
warnings when debugging options are turned on.

Signed-off-by: Mark Rustad <mark.d.rustad@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---

diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c
index cb99da920068..87901fa74dd7 100644
--- a/drivers/target/tcm_fc/tfc_sess.c
+++ b/drivers/target/tcm_fc/tfc_sess.c
@@ -58,7 +58,8 @@ static struct ft_tport *ft_tport_create(struct fc_lport *lport)
 	struct ft_tport *tport;
 	int i;
 
-	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
+	tport = rcu_dereference_protected(lport->prov[FC_TYPE_FCP],
+					  lockdep_is_held(&ft_lport_lock));
 	if (tport && tport->tpg)
 		return tport;