diff options
| -rw-r--r-- | net/sched/cls_cgroup.c | 63 |
1 files changed, 39 insertions, 24 deletions
diff --git a/net/sched/cls_cgroup.c b/net/sched/cls_cgroup.c index cacf01bd04f0..3b7548759998 100644 --- a/net/sched/cls_cgroup.c +++ b/net/sched/cls_cgroup.c @@ -22,17 +22,17 @@ struct cls_cgroup_head { u32 handle; struct tcf_exts exts; struct tcf_ematch_tree ematches; + struct tcf_proto *tp; + struct rcu_head rcu; }; static int cls_cgroup_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res) { - struct cls_cgroup_head *head = tp->root; + struct cls_cgroup_head *head = rcu_dereference_bh(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 @@ -80,13 +80,25 @@ static const struct nla_policy cgroup_policy[TCA_CGROUP_MAX + 1] = { [TCA_CGROUP_EMATCHES] = { .type = NLA_NESTED }, }; +static void cls_cgroup_destroy_rcu(struct rcu_head *root) +{ + struct cls_cgroup_head *head = container_of(root, + struct cls_cgroup_head, + rcu); + + tcf_exts_destroy(head->tp, &head->exts); + tcf_em_tree_destroy(head->tp, &head->ematches); + kfree(head); +} + static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, struct tcf_proto *tp, unsigned long base, u32 handle, struct nlattr **tca, unsigned long *arg, bool ovr) { struct nlattr *tb[TCA_CGROUP_MAX + 1]; - struct cls_cgroup_head *head = tp->root; + struct cls_cgroup_head *head = rtnl_dereference(tp->root); + struct cls_cgroup_head *new; struct tcf_ematch_tree t; struct tcf_exts e; int err; @@ -94,25 +106,24 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, if (!tca[TCA_OPTIONS]) return -EINVAL; - if (head == NULL) { - if (!handle) - return -EINVAL; + if (!head && !handle) + return -EINVAL; - head = kzalloc(sizeof(*head), GFP_KERNEL); - if (head == NULL) - return -ENOBUFS; + if (head && handle != head->handle) + return -ENOENT; - tcf_exts_init(&head->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); - head->handle = handle; + new = kzalloc(sizeof(*head), GFP_KERNEL); + if (!new) + return -ENOBUFS; - tcf_tree_lock(tp); - tp->root = head; - tcf_tree_unlock(tp); + if (head) { + new->handle = head->handle; + } else { + tcf_exts_init(&new->exts, TCA_CGROUP_ACT, TCA_CGROUP_POLICE); + new->handle = handle; } - if (handle != head->handle) - return -ENOENT; - + new->tp = tp; err = nla_parse_nested(tb, TCA_CGROUP_MAX, tca[TCA_OPTIONS], cgroup_policy); if (err < 0) @@ -127,20 +138,24 @@ static int cls_cgroup_change(struct net *net, struct sk_buff *in_skb, if (err < 0) return err; - tcf_exts_change(tp, &head->exts, &e); - tcf_em_tree_change(tp, &head->ematches, &t); + tcf_exts_change(tp, &new->exts, &e); + tcf_em_tree_change(tp, &new->ematches, &t); + rcu_assign_pointer(tp->root, new); + if (head) + call_rcu(&head->rcu, cls_cgroup_destroy_rcu); return 0; } static void cls_cgroup_destroy(struct tcf_proto *tp) { - struct cls_cgroup_head *head = tp->root; + struct cls_cgroup_head *head = rtnl_dereference(tp->root); if (head) { tcf_exts_destroy(tp, &head->exts); tcf_em_tree_destroy(tp, &head->ematches); - kfree(head); + RCU_INIT_POINTER(tp->root, NULL); + kfree_rcu(head, rcu); } } @@ -151,7 +166,7 @@ static int cls_cgroup_delete(struct tcf_proto *tp, unsigned long arg) static void cls_cgroup_walk(struct tcf_proto *tp, struct tcf_walker *arg) { - struct cls_cgroup_head *head = tp->root; + struct cls_cgroup_head *head = rtnl_dereference(tp->root); if (arg->count < arg->skip) goto skip; @@ -167,7 +182,7 @@ skip: static int cls_cgroup_dump(struct net *net, struct tcf_proto *tp, unsigned long fh, struct sk_buff *skb, struct tcmsg *t) { - struct cls_cgroup_head *head = tp->root; + struct cls_cgroup_head *head = rtnl_dereference(tp->root); unsigned char *b = skb_tail_pointer(skb); struct nlattr *nest; |