xfrm: state: don't use lock anymore unless acquire operation is needed
push the lock down, after earlier patches we can rely on rcu to
make sure state struct won't go away.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/xfrm/xfrm_state.c b/net/xfrm/xfrm_state.c
index 53e7867..1a15b65 100644
--- a/net/xfrm/xfrm_state.c
+++ b/net/xfrm/xfrm_state.c
@@ -799,7 +799,7 @@
sequence = read_seqcount_begin(&xfrm_state_hash_generation);
- spin_lock_bh(&net->xfrm.xfrm_state_lock);
+ rcu_read_lock();
h = xfrm_dst_hash(net, daddr, saddr, tmpl->reqid, encap_family);
hlist_for_each_entry_rcu(x, net->xfrm.state_bydst + h, bydst) {
if (x->props.family == encap_family &&
@@ -870,6 +870,7 @@
}
if (km_query(x, tmpl, pol) == 0) {
+ spin_lock_bh(&net->xfrm.xfrm_state_lock);
x->km.state = XFRM_STATE_ACQ;
list_add(&x->km.all, &net->xfrm.state_all);
hlist_add_head_rcu(&x->bydst, net->xfrm.state_bydst + h);
@@ -883,6 +884,7 @@
tasklet_hrtimer_start(&x->mtimer, ktime_set(net->xfrm.sysctl_acq_expires, 0), HRTIMER_MODE_REL);
net->xfrm.state_num++;
xfrm_hash_grow_check(net, x->bydst.next != NULL);
+ spin_unlock_bh(&net->xfrm.xfrm_state_lock);
} else {
x->km.state = XFRM_STATE_DEAD;
to_put = x;
@@ -899,7 +901,7 @@
} else {
*err = acquire_in_progress ? -EAGAIN : error;
}
- spin_unlock_bh(&net->xfrm.xfrm_state_lock);
+ rcu_read_unlock();
if (to_put)
xfrm_state_put(to_put);