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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 04/17] net: sched: protect block->chain0 with block->lock
Date: Mon, 11 Feb 2019 10:55:35 +0200
Message-ID: <20190211085548.7190-5-vladbu@mellanox.com> (raw)
In-Reply-To: <20190211085548.7190-1-vladbu@mellanox.com>

In order to remove dependency on rtnl lock, use block->lock to protect
chain0 struct from concurrent modification. Rearrange code in chain0
callback add and del functions to only access chain0 when block->lock is
held.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
---
 net/sched/cls_api.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index b5db0f79db14..869ae44d7631 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -244,8 +244,11 @@ static void tcf_chain0_head_change(struct tcf_chain *chain,
 
 	if (chain->index)
 		return;
+
+	mutex_lock(&block->lock);
 	list_for_each_entry(item, &block->chain0.filter_chain_list, list)
 		tcf_chain_head_change_item(item, tp_head);
+	mutex_unlock(&block->lock);
 }
 
 /* Returns true if block can be safely freed. */
@@ -756,8 +759,8 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
 			      struct tcf_block_ext_info *ei,
 			      struct netlink_ext_ack *extack)
 {
-	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
+	struct tcf_chain *chain0;
 
 	item = kmalloc(sizeof(*item), GFP_KERNEL);
 	if (!item) {
@@ -766,9 +769,14 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
 	}
 	item->chain_head_change = ei->chain_head_change;
 	item->chain_head_change_priv = ei->chain_head_change_priv;
+
+	mutex_lock(&block->lock);
+	chain0 = block->chain0.chain;
 	if (chain0 && chain0->filter_chain)
 		tcf_chain_head_change_item(item, chain0->filter_chain);
 	list_add(&item->list, &block->chain0.filter_chain_list);
+	mutex_unlock(&block->lock);
+
 	return 0;
 }
 
@@ -776,20 +784,23 @@ static void
 tcf_chain0_head_change_cb_del(struct tcf_block *block,
 			      struct tcf_block_ext_info *ei)
 {
-	struct tcf_chain *chain0 = block->chain0.chain;
 	struct tcf_filter_chain_list_item *item;
 
+	mutex_lock(&block->lock);
 	list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
 		if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
 		    (item->chain_head_change == ei->chain_head_change &&
 		     item->chain_head_change_priv == ei->chain_head_change_priv)) {
-			if (chain0)
+			if (block->chain0.chain)
 				tcf_chain_head_change_item(item, NULL);
 			list_del(&item->list);
+			mutex_unlock(&block->lock);
+
 			kfree(item);
 			return;
 		}
 	}
+	mutex_unlock(&block->lock);
 	WARN_ON(1);
 }
 
-- 
2.13.6


  parent reply index

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 ` Vlad Buslov [this message]
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 ` [PATCH net-next v4 09/17] net: sched: traverse classifiers in chain with tcf_get_next_proto() Vlad Buslov
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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