From 75cda62d9ca2cd3fab0412d438fcd1bfa0580b3d Mon Sep 17 00:00:00 2001
From: Florian Westphal <fw@strlen.de>
Date: Mon, 9 Jan 2017 14:20:49 +0100
Subject: [PATCH] xfrm: state: simplify rcu_read_unlock handling in two spots
Instead of:
if (foo) {
unlock();
return bar();
}
unlock();
do:
unlock();
if (foo)
return bar();
This is ok because rcu protected structure is only dereferenced before
the conditional.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
---
net/xfrm/xfrm_state.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index b5dad899fb0e4..a62097e640b56 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -231,17 +231,18 @@ retry:
return NULL;
typemap = afinfo->type_map;
- type = typemap[proto];
+ type = READ_ONCE(typemap[proto]);
if (unlikely(type && !try_module_get(type->owner)))
type = NULL;
+
+ rcu_read_unlock();
+
if (!type && !modload_attempted) {
- rcu_read_unlock();
request_module("xfrm-type-%d-%d", family, proto);
modload_attempted = 1;
goto retry;
}
- rcu_read_unlock();
return type;
}
@@ -327,17 +328,17 @@ retry:
if (unlikely(afinfo == NULL))
return NULL;
- mode = afinfo->mode_map[encap];
+ mode = READ_ONCE(afinfo->mode_map[encap]);
if (unlikely(mode && !try_module_get(mode->owner)))
mode = NULL;
+
+ rcu_read_unlock();
if (!mode && !modload_attempted) {
- rcu_read_unlock();
request_module("xfrm-mode-%d-%d", family, encap);
modload_attempted = 1;
goto retry;
}
- rcu_read_unlock();
return mode;
}
--
2.30.2