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Commit 165f0135 authored by Vlad Buslov's avatar Vlad Buslov Committed by David S. Miller
Browse files

net: sched: protect block->chain0 with block->lock 



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: default avatarVlad Buslov <vladbu@mellanox.com>
Acked-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2cbfab07

net/sched/cls_api.c

+14 −3
Original line number Diff line number Diff line
@@ -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);

}