From: Vlad Buslov <vladbu@mellanox.com>
To: netdev@vger.kernel.org
Cc: jhs@mojatatu.com, xiyou.wangcong@gmail.com, jiri@resnulli.us,
davem@davemloft.net, ast@kernel.org, daniel@iogearbox.net,
Vlad Buslov <vladbu@mellanox.com>
Subject: [PATCH net-next v4 09/17] net: sched: traverse classifiers in chain with tcf_get_next_proto()
Date: Mon, 11 Feb 2019 10:55:40 +0200 [thread overview]
Message-ID: <20190211085548.7190-10-vladbu@mellanox.com> (raw)
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>
All users of chain->filters_chain rely on rtnl lock and assume that no new
classifier instances are added when traversing the list. Use
tcf_get_next_proto() to traverse filters list without relying on rtnl
mutex. This function iterates over classifiers by taking reference to
current iterator classifier only and doesn't assume external
synchronization of filters list.
Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
include/net/pkt_cls.h | 2 ++
net/sched/cls_api.c | 70 +++++++++++++++++++++++++++++++++++++++++++--------
net/sched/sch_api.c | 4 +--
3 files changed, 64 insertions(+), 12 deletions(-)
diff --git a/include/net/pkt_cls.h b/include/net/pkt_cls.h
index 38bee7dd21d1..e5dafa5ee1b2 100644
--- a/include/net/pkt_cls.h
+++ b/include/net/pkt_cls.h
@@ -46,6 +46,8 @@ struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block,
void tcf_chain_put_by_act(struct tcf_chain *chain);
struct tcf_chain *tcf_get_next_chain(struct tcf_block *block,
struct tcf_chain *chain);
+struct tcf_proto *tcf_get_next_proto(struct tcf_chain *chain,
+ struct tcf_proto *tp);
void tcf_block_netif_keep_dst(struct tcf_block *block);
int tcf_block_get(struct tcf_block **p_block,
struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 37c05b96898f..dca8a3bee9c2 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -980,6 +980,45 @@ tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
}
EXPORT_SYMBOL(tcf_get_next_chain);
+static struct tcf_proto *
+__tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+{
+ ASSERT_RTNL();
+ mutex_lock(&chain->filter_chain_lock);
+
+ if (!tp)
+ tp = tcf_chain_dereference(chain->filter_chain, chain);
+ else
+ tp = tcf_chain_dereference(tp->next, chain);
+
+ if (tp)
+ tcf_proto_get(tp);
+
+ mutex_unlock(&chain->filter_chain_lock);
+
+ return tp;
+}
+
+/* Function to be used by all clients that want to iterate over all tp's on
+ * chain. Users of this function must be tolerant to concurrent tp
+ * insertion/deletion or ensure that no concurrent chain modification is
+ * possible. Note that all netlink dump callbacks cannot guarantee to provide
+ * consistent dump because rtnl lock is released each time skb is filled with
+ * data and sent to user-space.
+ */
+
+struct tcf_proto *
+tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
+{
+ struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
+
+ if (tp)
+ tcf_proto_put(tp, NULL);
+
+ return tp_next;
+}
+EXPORT_SYMBOL(tcf_get_next_proto);
+
static void tcf_block_flush_all_chains(struct tcf_block *block)
{
struct tcf_chain *chain;
@@ -1352,7 +1391,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
struct netlink_ext_ack *extack)
{
struct tcf_chain *chain, *chain_prev;
- struct tcf_proto *tp;
+ struct tcf_proto *tp, *tp_prev;
int err;
for (chain = __tcf_get_next_chain(block, NULL);
@@ -1360,8 +1399,10 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
chain_prev = chain,
chain = __tcf_get_next_chain(block, chain),
tcf_chain_put(chain_prev)) {
- for (tp = rtnl_dereference(chain->filter_chain); tp;
- tp = rtnl_dereference(tp->next)) {
+ for (tp = __tcf_get_next_proto(chain, NULL); tp;
+ tp_prev = tp,
+ tp = __tcf_get_next_proto(chain, tp),
+ tcf_proto_put(tp_prev, NULL)) {
if (tp->ops->reoffload) {
err = tp->ops->reoffload(tp, add, cb, cb_priv,
extack);
@@ -1378,6 +1419,7 @@ tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
return 0;
err_playback_remove:
+ tcf_proto_put(tp, NULL);
tcf_chain_put(chain);
tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
extack);
@@ -1677,8 +1719,8 @@ static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
{
struct tcf_proto *tp;
- for (tp = rtnl_dereference(chain->filter_chain);
- tp; tp = rtnl_dereference(tp->next))
+ for (tp = tcf_get_next_proto(chain, NULL);
+ tp; tp = tcf_get_next_proto(chain, tp))
tfilter_notify(net, oskb, n, tp, block,
q, parent, NULL, event, false);
}
@@ -2104,11 +2146,15 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
struct net *net = sock_net(skb->sk);
struct tcf_block *block = chain->block;
struct tcmsg *tcm = nlmsg_data(cb->nlh);
+ struct tcf_proto *tp, *tp_prev;
struct tcf_dump_args arg;
- struct tcf_proto *tp;
- for (tp = rtnl_dereference(chain->filter_chain);
- tp; tp = rtnl_dereference(tp->next), (*p_index)++) {
+ for (tp = __tcf_get_next_proto(chain, NULL);
+ tp;
+ tp_prev = tp,
+ tp = __tcf_get_next_proto(chain, tp),
+ tcf_proto_put(tp_prev, NULL),
+ (*p_index)++) {
if (*p_index < index_start)
continue;
if (TC_H_MAJ(tcm->tcm_info) &&
@@ -2125,7 +2171,7 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
NETLINK_CB(cb->skb).portid,
cb->nlh->nlmsg_seq, NLM_F_MULTI,
RTM_NEWTFILTER) <= 0)
- return false;
+ goto errout;
cb->args[1] = 1;
}
@@ -2145,9 +2191,13 @@ static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
cb->args[2] = arg.w.cookie;
cb->args[1] = arg.w.count + 1;
if (arg.w.stop)
- return false;
+ goto errout;
}
return true;
+
+errout:
+ tcf_proto_put(tp, NULL);
+ return false;
}
/* called with RTNL */
diff --git a/net/sched/sch_api.c b/net/sched/sch_api.c
index 80058abc729f..9a530cad2759 100644
--- a/net/sched/sch_api.c
+++ b/net/sched/sch_api.c
@@ -1914,8 +1914,8 @@ static void tc_bind_tclass(struct Qdisc *q, u32 portid, u32 clid,
chain = tcf_get_next_chain(block, chain)) {
struct tcf_proto *tp;
- for (tp = rtnl_dereference(chain->filter_chain);
- tp; tp = rtnl_dereference(tp->next)) {
+ for (tp = tcf_get_next_proto(chain, NULL);
+ tp; tp = tcf_get_next_proto(chain, tp)) {
struct tcf_bind_args arg = {};
arg.w.fn = tcf_node_bind;
--
2.13.6
next prev parent reply other threads:[~2019-02-11 8:57 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-11 8:55 [PATCH net-next v4 00/17] Refactor classifier API to work with chain/classifiers without rtnl lock Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 01/17] net: sched: protect block state with mutex Vlad Buslov
2019-02-11 14:15 ` Jiri Pirko
2019-02-11 8:55 ` [PATCH net-next v4 02/17] net: sched: protect chain->explicitly_created with block->lock Vlad Buslov
2019-02-11 14:15 ` Jiri Pirko
2019-02-11 8:55 ` [PATCH net-next v4 03/17] net: sched: refactor tc_ctl_chain() to use block->lock Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 04/17] net: sched: protect block->chain0 with block->lock Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 05/17] net: sched: traverse chains in block with tcf_get_next_chain() Vlad Buslov
2019-02-15 22:21 ` Cong Wang
2019-02-18 10:07 ` Vlad Buslov
2019-02-18 18:26 ` Cong Wang
2019-02-19 16:04 ` Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 06/17] net: sched: protect chain template accesses with block lock Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 07/17] net: sched: protect filter_chain list with filter_chain_lock mutex Vlad Buslov
2019-02-14 18:24 ` Ido Schimmel
2019-02-15 10:02 ` Vlad Buslov
2019-02-15 11:30 ` Ido Schimmel
2019-02-15 12:11 ` [PATCH] net: sched: matchall: verify that filter is not NULL in mall_walk() Vlad Buslov
2019-02-15 13:47 ` Ido Schimmel
2019-02-16 0:24 ` Cong Wang
2019-02-18 12:00 ` Vlad Buslov
2019-02-17 21:27 ` David Miller
2019-02-15 12:15 ` [PATCH net-next v4 07/17] net: sched: protect filter_chain list with filter_chain_lock mutex Vlad Buslov
2019-02-15 15:35 ` Vlad Buslov
2019-02-19 5:26 ` Cong Wang
2019-02-19 12:31 ` Vlad Buslov
2019-02-20 22:43 ` Cong Wang
2019-02-21 15:49 ` Vlad Buslov
2019-02-19 5:08 ` Cong Wang
2019-02-19 15:20 ` Vlad Buslov
2019-02-20 23:00 ` Cong Wang
2019-02-21 17:11 ` Vlad Buslov
2019-02-15 22:35 ` Cong Wang
2019-02-18 11:06 ` Vlad Buslov
2019-02-18 18:31 ` Cong Wang
2019-02-11 8:55 ` [PATCH net-next v4 08/17] net: sched: introduce reference counting for tcf_proto Vlad Buslov
2019-02-11 8:55 ` Vlad Buslov [this message]
2019-02-11 8:55 ` [PATCH net-next v4 10/17] net: sched: refactor tp insert/delete for concurrent execution Vlad Buslov
2019-02-15 23:17 ` Cong Wang
2019-02-18 11:19 ` Vlad Buslov
2019-02-18 19:55 ` Cong Wang
2019-02-19 10:25 ` Vlad Buslov
2019-02-18 19:53 ` Cong Wang
2019-02-11 8:55 ` [PATCH net-next v4 11/17] net: sched: prevent insertion of new classifiers during chain flush Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 12/17] net: sched: track rtnl lock status when validating extensions Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 13/17] net: sched: extend proto ops with 'put' callback Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 14/17] net: sched: extend proto ops to support unlocked classifiers Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 15/17] net: sched: add flags to Qdisc class ops struct Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 16/17] net: sched: refactor tcf_block_find() into standalone functions Vlad Buslov
2019-02-11 8:55 ` [PATCH net-next v4 17/17] net: sched: unlock rules update API Vlad Buslov
2019-02-18 18:56 ` Cong Wang
2019-02-12 18:42 ` [PATCH net-next v4 00/17] Refactor classifier API to work with chain/classifiers without rtnl lock David Miller
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