xfrm: Namespacify xfrm state/policy locks

By semantics, xfrm layer is fully name space aware,
so will the locks, e.g. xfrm_state/pocliy_lock.
Ensure exclusive access into state/policy link list
for different name space with one global lock is not
right in terms of semantics aspect at first place,
as they are indeed mutually independent with each
other, but also more seriously causes scalability
problem.

One practical scenario is on a Open Network Stack,
more than hundreds of lxc tenants acts as routers
within one host, a global xfrm_state/policy_lock
becomes the bottleneck. But onces those locks are
decoupled in a per-namespace fashion, locks contend
is just with in specific name space scope, without
causing additional SPD/SAD access delay for other
name space.

Also this patch improve scalability while as without
changing original xfrm behavior.

Signed-off-by: Fan Du <fan.du@windriver.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 55 insertions, 49 deletions

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 907fd2fa70bc..73b04d3df44e 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -39,12 +39,7 @@
 #define XFRM_QUEUE_TMO_MAX ((unsigned)(60*HZ))
 #define XFRM_MAX_QUEUE_LEN	100
 
-DEFINE_MUTEX(xfrm_cfg_mutex);
-EXPORT_SYMBOL(xfrm_cfg_mutex);
-
-static DEFINE_SPINLOCK(xfrm_policy_sk_bundle_lock);
 static struct dst_entry *xfrm_policy_sk_bundles;
-static DEFINE_RWLOCK(xfrm_policy_lock);
 
 static DEFINE_SPINLOCK(xfrm_policy_afinfo_lock);
 static struct xfrm_policy_afinfo __rcu *xfrm_policy_afinfo[NPROTO]
@@ -438,7 +433,7 @@ static void xfrm_bydst_resize(struct net *net, int dir)
 	if (!ndst)
 		return;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	for (i = hmask; i >= 0; i--)
 		xfrm_dst_hash_transfer(odst + i, ndst, nhashmask);
@@ -446,7 +441,7 @@ static void xfrm_bydst_resize(struct net *net, int dir)
 	net->xfrm.policy_bydst[dir].table = ndst;
 	net->xfrm.policy_bydst[dir].hmask = nhashmask;
 
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	xfrm_hash_free(odst, (hmask + 1) * sizeof(struct hlist_head));
 }
@@ -463,7 +458,7 @@ static void xfrm_byidx_resize(struct net *net, int total)
 	if (!nidx)
 		return;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	for (i = hmask; i >= 0; i--)
 		xfrm_idx_hash_transfer(oidx + i, nidx, nhashmask);
@@ -471,7 +466,7 @@ static void xfrm_byidx_resize(struct net *net, int total)
 	net->xfrm.policy_byidx = nidx;
 	net->xfrm.policy_idx_hmask = nhashmask;
 
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	xfrm_hash_free(oidx, (hmask + 1) * sizeof(struct hlist_head));
 }
@@ -504,7 +499,7 @@ static inline int xfrm_byidx_should_resize(struct net *net, int total)
 
 void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 {
-	read_lock_bh(&xfrm_policy_lock);
+	read_lock_bh(&net->xfrm.xfrm_policy_lock);
 	si->incnt = net->xfrm.policy_count[XFRM_POLICY_IN];
 	si->outcnt = net->xfrm.policy_count[XFRM_POLICY_OUT];
 	si->fwdcnt = net->xfrm.policy_count[XFRM_POLICY_FWD];
@@ -513,7 +508,7 @@ void xfrm_spd_getinfo(struct net *net, struct xfrmk_spdinfo *si)
 	si->fwdscnt = net->xfrm.policy_count[XFRM_POLICY_FWD+XFRM_POLICY_MAX];
 	si->spdhcnt = net->xfrm.policy_idx_hmask;
 	si->spdhmcnt = xfrm_policy_hashmax;
-	read_unlock_bh(&xfrm_policy_lock);
+	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 }
 EXPORT_SYMBOL(xfrm_spd_getinfo);
 
@@ -636,7 +631,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 	struct hlist_head *chain;
 	struct hlist_node *newpos;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_bysel(net, &policy->selector, policy->family, dir);
 	delpol = NULL;
 	newpos = NULL;
@@ -647,7 +642,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 		    xfrm_sec_ctx_match(pol->security, policy->security) &&
 		    !WARN_ON(delpol)) {
 			if (excl) {
-				write_unlock_bh(&xfrm_policy_lock);
+				write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 				return -EEXIST;
 			}
 			delpol = pol;
@@ -685,7 +680,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl)
 	if (!mod_timer(&policy->timer, jiffies + HZ))
 		xfrm_pol_hold(policy);
 	list_add(&policy->walk.all, &net->xfrm.policy_all);
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (delpol)
 		xfrm_policy_kill(delpol);
@@ -705,7 +700,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 	struct hlist_head *chain;
 
 	*err = 0;
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_bysel(net, sel, sel->family, dir);
 	ret = NULL;
 	hlist_for_each_entry(pol, chain, bydst) {
@@ -718,7 +713,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 				*err = security_xfrm_policy_delete(
 								pol->security);
 				if (*err) {
-					write_unlock_bh(&xfrm_policy_lock);
+					write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 					return pol;
 				}
 				__xfrm_policy_unlink(pol, dir);
@@ -727,7 +722,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u8 type,
 			break;
 		}
 	}
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (ret && delete)
 		xfrm_policy_kill(ret);
@@ -746,7 +741,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 		return NULL;
 
 	*err = 0;
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = net->xfrm.policy_byidx + idx_hash(net, id);
 	ret = NULL;
 	hlist_for_each_entry(pol, chain, byidx) {
@@ -757,7 +752,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 				*err = security_xfrm_policy_delete(
 								pol->security);
 				if (*err) {
-					write_unlock_bh(&xfrm_policy_lock);
+					write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 					return pol;
 				}
 				__xfrm_policy_unlink(pol, dir);
@@ -766,7 +761,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u8 type,
 			break;
 		}
 	}
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (ret && delete)
 		xfrm_policy_kill(ret);
@@ -829,7 +824,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 {
 	int dir, err = 0, cnt = 0;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 
 	err = xfrm_policy_flush_secctx_check(net, type, audit_info);
 	if (err)
@@ -845,7 +840,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 			if (pol->type != type)
 				continue;
 			__xfrm_policy_unlink(pol, dir);
-			write_unlock_bh(&xfrm_policy_lock);
+			write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 			cnt++;
 
 			xfrm_audit_policy_delete(pol, 1, audit_info->loginuid,
@@ -854,7 +849,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 
 			xfrm_policy_kill(pol);
 
-			write_lock_bh(&xfrm_policy_lock);
+			write_lock_bh(&net->xfrm.xfrm_policy_lock);
 			goto again1;
 		}
 
@@ -866,7 +861,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 				if (pol->type != type)
 					continue;
 				__xfrm_policy_unlink(pol, dir);
-				write_unlock_bh(&xfrm_policy_lock);
+				write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 				cnt++;
 
 				xfrm_audit_policy_delete(pol, 1,
@@ -875,7 +870,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 							 audit_info->secid);
 				xfrm_policy_kill(pol);
 
-				write_lock_bh(&xfrm_policy_lock);
+				write_lock_bh(&net->xfrm.xfrm_policy_lock);
 				goto again2;
 			}
 		}
@@ -884,7 +879,7 @@ int xfrm_policy_flush(struct net *net, u8 type, struct xfrm_audit *audit_info)
 	if (!cnt)
 		err = -ESRCH;
 out:
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return err;
 }
 EXPORT_SYMBOL(xfrm_policy_flush);
@@ -904,7 +899,7 @@ int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 	if (list_empty(&walk->walk.all) && walk->seq != 0)
 		return 0;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	if (list_empty(&walk->walk.all))
 		x = list_first_entry(&net->xfrm.policy_all, struct xfrm_policy_walk_entry, all);
 	else
@@ -930,7 +925,7 @@ int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk,
 	}
 	list_del_init(&walk->walk.all);
 out:
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return error;
 }
 EXPORT_SYMBOL(xfrm_policy_walk);
@@ -944,14 +939,14 @@ void xfrm_policy_walk_init(struct xfrm_policy_walk *walk, u8 type)
 }
 EXPORT_SYMBOL(xfrm_policy_walk_init);
 
-void xfrm_policy_walk_done(struct xfrm_policy_walk *walk)
+void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net)
 {
 	if (list_empty(&walk->walk.all))
 		return;
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME where is net? */
 	list_del(&walk->walk.all);
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 }
 EXPORT_SYMBOL(xfrm_policy_walk_done);
 
@@ -996,7 +991,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 	if (unlikely(!daddr || !saddr))
 		return NULL;
 
-	read_lock_bh(&xfrm_policy_lock);
+	read_lock_bh(&net->xfrm.xfrm_policy_lock);
 	chain = policy_hash_direct(net, daddr, saddr, family, dir);
 	ret = NULL;
 	hlist_for_each_entry(pol, chain, bydst) {
@@ -1032,7 +1027,7 @@ static struct xfrm_policy *xfrm_policy_lookup_bytype(struct net *net, u8 type,
 	if (ret)
 		xfrm_pol_hold(ret);
 fail:
-	read_unlock_bh(&xfrm_policy_lock);
+	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	return ret;
 }
@@ -1109,8 +1104,9 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir,
 						 const struct flowi *fl)
 {
 	struct xfrm_policy *pol;
+	struct net *net = sock_net(sk);
 
-	read_lock_bh(&xfrm_policy_lock);
+	read_lock_bh(&net->xfrm.xfrm_policy_lock);
 	if ((pol = sk->sk_policy[dir]) != NULL) {
 		bool match = xfrm_selector_match(&pol->selector, fl,
 						 sk->sk_family);
@@ -1134,7 +1130,7 @@ static struct xfrm_policy *xfrm_sk_policy_lookup(struct sock *sk, int dir,
 			pol = NULL;
 	}
 out:
-	read_unlock_bh(&xfrm_policy_lock);
+	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	return pol;
 }
 
@@ -1172,9 +1168,11 @@ static struct xfrm_policy *__xfrm_policy_unlink(struct xfrm_policy *pol,
 
 int xfrm_policy_delete(struct xfrm_policy *pol, int dir)
 {
-	write_lock_bh(&xfrm_policy_lock);
+	struct net *net = xp_net(pol);
+
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	pol = __xfrm_policy_unlink(pol, dir);
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 	if (pol) {
 		xfrm_policy_kill(pol);
 		return 0;
@@ -1193,7 +1191,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 		return -EINVAL;
 #endif
 
-	write_lock_bh(&xfrm_policy_lock);
+	write_lock_bh(&net->xfrm.xfrm_policy_lock);
 	old_pol = sk->sk_policy[dir];
 	sk->sk_policy[dir] = pol;
 	if (pol) {
@@ -1210,7 +1208,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 		 */
 		__xfrm_policy_unlink(old_pol, XFRM_POLICY_MAX+dir);
 	}
-	write_unlock_bh(&xfrm_policy_lock);
+	write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	if (old_pol) {
 		xfrm_policy_kill(old_pol);
@@ -1221,6 +1219,7 @@ int xfrm_sk_policy_insert(struct sock *sk, int dir, struct xfrm_policy *pol)
 static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
 {
 	struct xfrm_policy *newp = xfrm_policy_alloc(xp_net(old), GFP_ATOMIC);
+	struct net *net = xp_net(old);
 
 	if (newp) {
 		newp->selector = old->selector;
@@ -1239,9 +1238,9 @@ static struct xfrm_policy *clone_policy(const struct xfrm_policy *old, int dir)
 		newp->type = old->type;
 		memcpy(newp->xfrm_vec, old->xfrm_vec,
 		       newp->xfrm_nr*sizeof(struct xfrm_tmpl));
-		write_lock_bh(&xfrm_policy_lock);
+		write_lock_bh(&net->xfrm.xfrm_policy_lock);
 		__xfrm_policy_link(newp, XFRM_POLICY_MAX+dir);
-		write_unlock_bh(&xfrm_policy_lock);
+		write_unlock_bh(&net->xfrm.xfrm_policy_lock);
 		xfrm_pol_put(newp);
 	}
 	return newp;
@@ -2112,10 +2111,10 @@ restart:
 
 			dst_hold(&xdst->u.dst);
 
-			spin_lock_bh(&xfrm_policy_sk_bundle_lock);
+			spin_lock_bh(&net->xfrm.xfrm_policy_sk_bundle_lock);
 			xdst->u.dst.next = xfrm_policy_sk_bundles;
 			xfrm_policy_sk_bundles = &xdst->u.dst;
-			spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
+			spin_unlock_bh(&net->xfrm.xfrm_policy_sk_bundle_lock);
 
 			route = xdst->route;
 		}
@@ -2440,7 +2439,7 @@ int __xfrm_policy_check(struct sock *sk, int dir, struct sk_buff *skb,
 		}
 		xfrm_nr = ti;
 		if (npols > 1) {
-			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family);
+			xfrm_tmpl_sort(stp, tpp, xfrm_nr, family, net);
 			tpp = stp;
 		}
 
@@ -2569,10 +2568,10 @@ static void __xfrm_garbage_collect(struct net *net)
 {
 	struct dst_entry *head, *next;
 
-	spin_lock_bh(&xfrm_policy_sk_bundle_lock);
+	spin_lock_bh(&net->xfrm.xfrm_policy_sk_bundle_lock);
 	head = xfrm_policy_sk_bundles;
 	xfrm_policy_sk_bundles = NULL;
-	spin_unlock_bh(&xfrm_policy_sk_bundle_lock);
+	spin_unlock_bh(&net->xfrm.xfrm_policy_sk_bundle_lock);
 
 	while (head) {
 		next = head->next;
@@ -2956,6 +2955,13 @@ static int __net_init xfrm_net_init(struct net *net)
 	rv = xfrm_sysctl_init(net);
 	if (rv < 0)
 		goto out_sysctl;
+
+	/* Initialize the per-net locks here */
+	spin_lock_init(&net->xfrm.xfrm_state_lock);
+	rwlock_init(&net->xfrm.xfrm_policy_lock);
+	spin_lock_init(&net->xfrm.xfrm_policy_sk_bundle_lock);
+	mutex_init(&net->xfrm.xfrm_cfg_mutex);
+
 	return 0;
 
 out_sysctl:
@@ -3082,7 +3088,7 @@ static struct xfrm_policy * xfrm_migrate_policy_find(const struct xfrm_selector
 	struct hlist_head *chain;
 	u32 priority = ~0U;
 
-	read_lock_bh(&xfrm_policy_lock);
+	read_lock_bh(&net->xfrm.xfrm_policy_lock); /*FIXME*/
 	chain = policy_hash_direct(net, &sel->daddr, &sel->saddr, sel->family, dir);
 	hlist_for_each_entry(pol, chain, bydst) {
 		if (xfrm_migrate_selector_match(sel, &pol->selector) &&
@@ -3105,7 +3111,7 @@ static struct xfrm_policy * xfrm_migrate_policy_find(const struct xfrm_selector
 	if (ret)
 		xfrm_pol_hold(ret);
 
-	read_unlock_bh(&xfrm_policy_lock);
+	read_unlock_bh(&net->xfrm.xfrm_policy_lock);
 
 	return ret;
 }
@@ -3236,7 +3242,7 @@ int xfrm_migrate(const struct xfrm_selector *sel, u8 dir, u8 type,
 
 	/* Stage 2 - find and update state(s) */
 	for (i = 0, mp = m; i < num_migrate; i++, mp++) {
-		if ((x = xfrm_migrate_state_find(mp))) {
+		if ((x = xfrm_migrate_state_find(mp, net))) {
 			x_cur[nx_cur] = x;
 			nx_cur++;
 			if ((xc = xfrm_state_migrate(x, mp))) {