1 files changed, 34 insertions, 16 deletions

diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c
index 221180384fd7..78ef2c5e130b 100644
--- a/net/sched/cls_cgroup.c
+++ b/net/sched/cls_cgroup.c
@@ -16,14 +16,11 @@
 #include <linux/errno.h>
 #include <linux/skbuff.h>
 #include <linux/cgroup.h>
+#include <linux/rcupdate.h>
 #include <net/rtnetlink.h>
 #include <net/pkt_cls.h>
-
-struct cgroup_cls_state
-{
-        struct cgroup_subsys_state css;
-        u32 classid;
-};
+#include <net/sock.h>
+#include <net/cls_cgroup.h>
 
 static struct cgroup_subsys_state *cgrp_create(struct cgroup_subsys *ss,
                                                struct cgroup *cgrp);
@@ -112,6 +109,10 @@ static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
         struct cls_cgroup_head *head = tp->root;
         u32 classid;
 
+        rcu_read_lock();
+        classid = task_cls_state(current)->classid;
+        rcu_read_unlock();
+
         /*
          * Due to the nature of the classifier it is required to ignore all
          * packets originating from softirq context as accessing `current'
@@ -122,12 +123,12 @@ static int cls_cgroup_classify(struct sk_buff *skb, struct tcf_proto *tp,
          * calls by looking at the number of nested bh disable calls because
          * softirqs always disables bh.
          */
-        if (softirq_count() != SOFTIRQ_OFFSET)
-                return -1;
-
-        rcu_read_lock();
-        classid = task_cls_state(current)->classid;
-        rcu_read_unlock();
+        if (softirq_count() != SOFTIRQ_OFFSET) {
+                /* If there is an sk_classid we'll use that. */
+                if (!skb->sk)
+                        return -1;
+                classid = skb->sk->sk_classid;
+        }
 
         if (!classid)
                 return -1;
@@ -289,18 +290,35 @@ static struct tcf_proto_ops cls_cgroup_ops __read_mostly = {
 
 static int __init init_cgroup_cls(void)
 {
-        int ret = register_tcf_proto_ops(&cls_cgroup_ops);
-        if (ret)
-                return ret;
+        int ret;
+
         ret = cgroup_load_subsys(&net_cls_subsys);
         if (ret)
-                unregister_tcf_proto_ops(&cls_cgroup_ops);
+                goto out;
+
+#ifndef CONFIG_NET_CLS_CGROUP
+        /* We can't use rcu_assign_pointer because this is an int. */
+        smp_wmb();
+        net_cls_subsys_id = net_cls_subsys.subsys_id;
+#endif
+
+        ret = register_tcf_proto_ops(&cls_cgroup_ops);
+        if (ret)
+                cgroup_unload_subsys(&net_cls_subsys);
+
+out:
         return ret;
 }
 
 static void __exit exit_cgroup_cls(void)
 {
         unregister_tcf_proto_ops(&cls_cgroup_ops);
+
+#ifndef CONFIG_NET_CLS_CGROUP
+        net_cls_subsys_id = -1;
+        synchronize_rcu();
+#endif
+
         cgroup_unload_subsys(&net_cls_subsys);
 }