diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h index 22bfc3a13c254f704c5d305ee05fec61737804e5..ef727f71336e7e5f89d92000194bcfab4bacc5a8 100644 --- a/include/net/pkt_cls.h +++ b/include/net/pkt_cls.h @@ -40,11 +40,8 @@ struct tcf_block_cb; bool tcf_queue_work(struct rcu_work *rwork, work_func_t func); #ifdef CONFIG_NET_CLS -struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, - bool create); struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index); -void tcf_chain_put(struct tcf_chain *chain); void tcf_chain_put_by_act(struct tcf_chain *chain); void tcf_block_netif_keep_dst(struct tcf_block *block); int tcf_block_get(struct tcf_block **p_block, diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index e20aad1987b8b77fa03ef94614b47670959e16b4..e8b0bbd0883f3b427f9ff406346d504d545c60a3 100644 --- a/net/sched/cls_api.c +++ b/net/sched/cls_api.c @@ -232,19 +232,6 @@ static void tcf_chain0_head_change(struct tcf_chain *chain, tcf_chain_head_change_item(item, tp_head); } -static void tcf_chain_flush(struct tcf_chain *chain) -{ - struct tcf_proto *tp = rtnl_dereference(chain->filter_chain); - - tcf_chain0_head_change(chain, NULL); - while (tp) { - RCU_INIT_POINTER(chain->filter_chain, tp->next); - tcf_proto_destroy(tp, NULL); - tp = rtnl_dereference(chain->filter_chain); - tcf_chain_put(chain); - } -} - static void tcf_chain_destroy(struct tcf_chain *chain) { struct tcf_block *block = chain->block; @@ -262,21 +249,10 @@ static void tcf_chain_hold(struct tcf_chain *chain) ++chain->refcnt; } -static void tcf_chain_hold_by_act(struct tcf_chain *chain) -{ - ++chain->action_refcnt; -} - -static void tcf_chain_release_by_act(struct tcf_chain *chain) -{ - --chain->action_refcnt; -} - -static bool tcf_chain_is_zombie(struct tcf_chain *chain) +static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain) { /* In case all the references are action references, this - * chain is a zombie and should not be listed in the chain - * dump list. + * chain should not be shown to the user. */ return chain->refcnt == chain->action_refcnt; } @@ -296,52 +272,75 @@ static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block, static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb, u32 seq, u16 flags, int event, bool unicast); -struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, - bool create) +static struct tcf_chain *__tcf_chain_get(struct tcf_block *block, + u32 chain_index, bool create, + bool by_act) { struct tcf_chain *chain = tcf_chain_lookup(block, chain_index); if (chain) { tcf_chain_hold(chain); - return chain; + } else { + if (!create) + return NULL; + chain = tcf_chain_create(block, chain_index); + if (!chain) + return NULL; } - if (!create) - return NULL; - chain = tcf_chain_create(block, chain_index); - if (!chain) - return NULL; - tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL, - RTM_NEWCHAIN, false); + if (by_act) + ++chain->action_refcnt; + + /* Send notification only in case we got the first + * non-action reference. Until then, the chain acts only as + * a placeholder for actions pointing to it and user ought + * not know about them. + */ + if (chain->refcnt - chain->action_refcnt == 1 && !by_act) + tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL, + RTM_NEWCHAIN, false); + return chain; } -EXPORT_SYMBOL(tcf_chain_get); -struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index) +static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index, + bool create) { - struct tcf_chain *chain = tcf_chain_get(block, chain_index, true); + return __tcf_chain_get(block, chain_index, create, false); +} - tcf_chain_hold_by_act(chain); - return chain; +struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index) +{ + return __tcf_chain_get(block, chain_index, true, true); } EXPORT_SYMBOL(tcf_chain_get_by_act); static void tc_chain_tmplt_del(struct tcf_chain *chain); -void tcf_chain_put(struct tcf_chain *chain) +static void __tcf_chain_put(struct tcf_chain *chain, bool by_act) { - if (--chain->refcnt == 0) { + if (by_act) + chain->action_refcnt--; + chain->refcnt--; + + /* The last dropped non-action reference will trigger notification. */ + if (chain->refcnt - chain->action_refcnt == 0 && !by_act) tc_chain_notify(chain, NULL, 0, 0, RTM_DELCHAIN, false); + + if (chain->refcnt == 0) { tc_chain_tmplt_del(chain); tcf_chain_destroy(chain); } } -EXPORT_SYMBOL(tcf_chain_put); + +static void tcf_chain_put(struct tcf_chain *chain) +{ + __tcf_chain_put(chain, false); +} void tcf_chain_put_by_act(struct tcf_chain *chain) { - tcf_chain_release_by_act(chain); - tcf_chain_put(chain); + __tcf_chain_put(chain, true); } EXPORT_SYMBOL(tcf_chain_put_by_act); @@ -351,6 +350,19 @@ static void tcf_chain_put_explicitly_created(struct tcf_chain *chain) tcf_chain_put(chain); } +static void tcf_chain_flush(struct tcf_chain *chain) +{ + struct tcf_proto *tp = rtnl_dereference(chain->filter_chain); + + tcf_chain0_head_change(chain, NULL); + while (tp) { + RCU_INIT_POINTER(chain->filter_chain, tp->next); + tcf_proto_destroy(tp, NULL); + tp = rtnl_dereference(chain->filter_chain); + tcf_chain_put(chain); + } +} + static bool tcf_block_offload_in_use(struct tcf_block *block) { return block->offloadcnt; @@ -1838,10 +1850,9 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n, chain = tcf_chain_lookup(block, chain_index); if (n->nlmsg_type == RTM_NEWCHAIN) { if (chain) { - if (tcf_chain_is_zombie(chain)) { + if (tcf_chain_held_by_acts_only(chain)) { /* The chain exists only because there is - * some action referencing it, meaning it - * is a zombie. + * some action referencing it. */ tcf_chain_hold(chain); } else { @@ -1860,7 +1871,7 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n, } } } else { - if (!chain || tcf_chain_is_zombie(chain)) { + if (!chain || tcf_chain_held_by_acts_only(chain)) { NL_SET_ERR_MSG(extack, "Cannot find specified filter chain"); return -EINVAL; } @@ -1988,7 +1999,7 @@ static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb) index++; continue; } - if (tcf_chain_is_zombie(chain)) + if (tcf_chain_held_by_acts_only(chain)) continue; err = tc_chain_fill_node(chain, net, skb, block, NETLINK_CB(cb->skb).portid,