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Commit 418a99ac authored by Priyanka Jain's avatar Priyanka Jain Committed by David S. Miller
Browse files

Replace rwlock on xfrm_policy_afinfo with rcu 



xfrm_policy_afinfo is read mosly data structure.
Write on xfrm_policy_afinfo is done only at the
time of configuration.
So rwlocks can be safely replaced with RCU.

RCUs usage optimizes the performance.

Signed-off-by: default avatarPriyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c12b395a

net/xfrm/xfrm_policy.c

+21 −18
Original line number Diff line number Diff line
@@ -42,13 +42,14 @@ static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock); 
static struct dst_entry *xfrm_policy_sk_bundles;

static DEFINE_RWLOCK(xfrm_policy_lock);



static DEFINE_RWLOCK(xfrm_policy_afinfo_lock);

static struct xfrm_policy_afinfo *xfrm_policy_afinfo[NPROTO];

static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);

static struct xfrm_policy_afinfo __rcu *xfrm_policy_afinfo[NPROTO]

						__read_mostly;



static struct kmem_cache *xfrm_dst_cache __read_mostly;



static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family);

static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);

static inline void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo);

static void xfrm_init_pmtu(struct dst_entry *dst);

static int stale_bundle(struct dst_entry *dst);

static int xfrm_bundle_ok(struct xfrm_dst *xdst);
@@ -2418,7 +2419,7 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo) 
		return -EINVAL;

	if (unlikely(afinfo->family >= NPROTO))

		return -EAFNOSUPPORT;

	write_lock_bh(&xfrm_policy_afinfo_lock);

	spin_lock_bh(&xfrm_policy_afinfo_lock);

	if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))

		err = -ENOBUFS;

	else {
@@ -2439,9 +2440,9 @@ int xfrm_policy_register_afinfo(struct xfrm_policy_afinfo *afinfo) 
			dst_ops->neigh_lookup = xfrm_neigh_lookup;

		if (likely(afinfo->garbage_collect == NULL))

			afinfo->garbage_collect = xfrm_garbage_collect_deferred;

		xfrm_policy_afinfo[afinfo->family] = afinfo;

		rcu_assign_pointer(xfrm_policy_afinfo[afinfo->family], afinfo);

	}

	write_unlock_bh(&xfrm_policy_afinfo_lock);

	spin_unlock_bh(&xfrm_policy_afinfo_lock);



	rtnl_lock();

	for_each_net(net) {
@@ -2474,13 +2475,14 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo) 
		return -EINVAL;

	if (unlikely(afinfo->family >= NPROTO))

		return -EAFNOSUPPORT;

	write_lock_bh(&xfrm_policy_afinfo_lock);

	spin_lock_bh(&xfrm_policy_afinfo_lock);

	if (likely(xfrm_policy_afinfo[afinfo->family] != NULL)) {

		if (unlikely(xfrm_policy_afinfo[afinfo->family] != afinfo))

			err = -EINVAL;

		else {

			struct dst_ops *dst_ops = afinfo->dst_ops;

			xfrm_policy_afinfo[afinfo->family] = NULL;

			rcu_assign_pointer(xfrm_policy_afinfo[afinfo->family],

									NULL);

			dst_ops->kmem_cachep = NULL;

			dst_ops->check = NULL;

			dst_ops->negative_advice = NULL;
@@ -2488,7 +2490,8 @@ int xfrm_policy_unregister_afinfo(struct xfrm_policy_afinfo *afinfo) 
			afinfo->garbage_collect = NULL;

		}

	}

	write_unlock_bh(&xfrm_policy_afinfo_lock);

	spin_unlock_bh(&xfrm_policy_afinfo_lock);

	synchronize_rcu();

	return err;

}

EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
@@ -2497,16 +2500,16 @@ static void __net_init xfrm_dst_ops_init(struct net *net) 
{

	struct xfrm_policy_afinfo *afinfo;



	read_lock_bh(&xfrm_policy_afinfo_lock);

	afinfo = xfrm_policy_afinfo[AF_INET];

	rcu_read_lock_bh();

	afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET]);

	if (afinfo)

		net->xfrm.xfrm4_dst_ops = *afinfo->dst_ops;

#if IS_ENABLED(CONFIG_IPV6)

	afinfo = xfrm_policy_afinfo[AF_INET6];

	afinfo = rcu_dereference(xfrm_policy_afinfo[AF_INET6]);

	if (afinfo)

		net->xfrm.xfrm6_dst_ops = *afinfo->dst_ops;

#endif

	read_unlock_bh(&xfrm_policy_afinfo_lock);

	rcu_read_unlock_bh();

}



static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
@@ -2514,16 +2517,16 @@ static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family) 
	struct xfrm_policy_afinfo *afinfo;

	if (unlikely(family >= NPROTO))

		return NULL;

	read_lock(&xfrm_policy_afinfo_lock);

	afinfo = xfrm_policy_afinfo[family];

	rcu_read_lock();

	afinfo = rcu_dereference(xfrm_policy_afinfo[family]);

	if (unlikely(!afinfo))

		read_unlock(&xfrm_policy_afinfo_lock);

		rcu_read_unlock();

	return afinfo;

}



static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)

static inline void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)

{

	read_unlock(&xfrm_policy_afinfo_lock);

	rcu_read_unlock();

}



static int xfrm_dev_event(struct notifier_block *this, unsigned long event, void *ptr)