[ 47/48] tcm_fc: Resolve suspicious RCU usage warnings

From: Ben Hutchings
Date: Mon Jul 09 2012 - 10:46:23 EST


3.2-stable review patch. If anyone has any objections, please let me know.

------------------

From: Mark Rustad <mark.d.rustad@xxxxxxxxx>

commit 863555be0c81558b1af277addcf68acb8f778860 upstream.

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@xxxxxxxxx>
Tested-by: Ross Brattain <ross.b.brattain@xxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/target/tcm_fc/tfc_sess.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/target/tcm_fc/tfc_sess.c b/drivers/target/tcm_fc/tfc_sess.c
index cb99da9..87901fa 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;



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/