Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

[karo-tx-linux.git] / net / xfrm / xfrm_policy.c

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 46550997548c2e2d9cce0db8024a7bd168fb09cd..41eabc46f110d9cb607cb24f8af68054b91bcccd 100644 (file)
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -42,13 +42,12 @@ 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 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);
@@ -95,6 +94,24 @@ bool xfrm_selector_match(const struct xfrm_selector *sel, const struct flowi *fl
        return false;
 }
 
+static struct xfrm_policy_afinfo *xfrm_policy_get_afinfo(unsigned short family)
+{
+       struct xfrm_policy_afinfo *afinfo;
+
+       if (unlikely(family >= NPROTO))
+               return NULL;
+       rcu_read_lock();
+       afinfo = rcu_dereference(xfrm_policy_afinfo[family]);
+       if (unlikely(!afinfo))
+               rcu_read_unlock();
+       return afinfo;
+}
+
+static void xfrm_policy_put_afinfo(struct xfrm_policy_afinfo *afinfo)
+{
+       rcu_read_unlock();
+}
+
 static inline struct dst_entry *__xfrm_dst_lookup(struct net *net, int tos,
                                                  const xfrm_address_t *saddr,
                                                  const xfrm_address_t *daddr,
@@ -2421,7 +2438,7 @@ 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(&xfrm_policy_afinfo_lock);
        if (unlikely(xfrm_policy_afinfo[afinfo->family] != NULL))
                err = -ENOBUFS;
        else {
@@ -2442,9 +2459,9 @@ 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(&xfrm_policy_afinfo_lock);
 
        rtnl_lock();
        for_each_net(net) {
@@ -2477,21 +2494,26 @@ 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(&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;
-                       dst_ops->kmem_cachep = NULL;
-                       dst_ops->check = NULL;
-                       dst_ops->negative_advice = NULL;
-                       dst_ops->link_failure = NULL;
-                       afinfo->garbage_collect = NULL;
-               }
+               else
+                       RCU_INIT_POINTER(xfrm_policy_afinfo[afinfo->family],
+                                        NULL);
+       }
+       spin_unlock(&xfrm_policy_afinfo_lock);
+       if (!err) {
+               struct dst_ops *dst_ops = afinfo->dst_ops;
+
+               synchronize_rcu();
+
+               dst_ops->kmem_cachep = NULL;
+               dst_ops->check = NULL;
+               dst_ops->negative_advice = NULL;
+               dst_ops->link_failure = NULL;
+               afinfo->garbage_collect = NULL;
        }
-       write_unlock_bh(&xfrm_policy_afinfo_lock);
        return err;
 }
 EXPORT_SYMBOL(xfrm_policy_unregister_afinfo);
@@ -2500,33 +2522,16 @@ 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();
+       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);
-}
-
-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];
-       if (unlikely(!afinfo))
-               read_unlock(&xfrm_policy_afinfo_lock);
-       return afinfo;
-}
-
-static 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)