Commit d737a580 authored by Florian Westphal's avatar Florian Westphal Committed by Steffen Klassert
Browse files

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: default avatarFlorian Westphal <fw@strlen.de>
Signed-off-by: default avatarSteffen Klassert <steffen.klassert@secunet.com>
parent c8406998

include/net/netns/xfrm.h

+3 −3
Original line number Diff line number Diff line
@@ -38,9 +38,9 @@ struct netns_xfrm { 
	 * mode. Also, it can be used by ah/esp icmp error handler to find

	 * offending SA.

	 */

	struct hlist_head	*state_bydst;

	struct hlist_head	*state_bysrc;

	struct hlist_head	*state_byspi;

	struct hlist_head	__rcu *state_bydst;

	struct hlist_head	__rcu *state_bysrc;

	struct hlist_head	__rcu *state_byspi;

	unsigned int		state_hmask;

	unsigned int		state_num;

	struct work_struct	state_hash_work;

net/xfrm/xfrm_state.c

+4 −2
Original line number Diff line number Diff line
@@ -799,7 +799,7 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, 


	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 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, 
		}



		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 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, 
			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 @@ xfrm_state_find(const xfrm_address_t *daddr, const xfrm_address_t *saddr, 
	} 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);