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Commit 91052fa1 authored by Vlad Buslov's avatar Vlad Buslov Committed by David S. Miller
Browse files

net: sched: protect chain->explicitly_created with block->lock 



In order to remove dependency on rtnl lock, protect
tcf_chain->explicitly_created flag with block->lock. Consolidate code that
checks and resets 'explicitly_created' flag into __tcf_chain_put() to
execute it atomically with rest of code that puts chain reference.

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 c266f64d

net/sched/cls_api.c

+13 −6
Original line number Diff line number Diff line
@@ -370,13 +370,22 @@ EXPORT_SYMBOL(tcf_chain_get_by_act); 


static void tc_chain_tmplt_del(struct tcf_chain *chain);



static void __tcf_chain_put(struct tcf_chain *chain, bool by_act)

static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,

			    bool explicitly_created)

{

	struct tcf_block *block = chain->block;

	bool is_last, free_block = false;

	unsigned int refcnt;



	mutex_lock(&block->lock);

	if (explicitly_created) {

		if (!chain->explicitly_created) {

			mutex_unlock(&block->lock);

			return;

		}

		chain->explicitly_created = false;

	}



	if (by_act)

		chain->action_refcnt--;
@@ -402,19 +411,18 @@ static void __tcf_chain_put(struct tcf_chain *chain, bool by_act) 


static void tcf_chain_put(struct tcf_chain *chain)

{

	__tcf_chain_put(chain, false);

	__tcf_chain_put(chain, false, false);

}



void tcf_chain_put_by_act(struct tcf_chain *chain)

{

	__tcf_chain_put(chain, true);

	__tcf_chain_put(chain, true, false);

}

EXPORT_SYMBOL(tcf_chain_put_by_act);



static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)

{

	if (chain->explicitly_created)

		tcf_chain_put(chain);

	__tcf_chain_put(chain, false, true);

}



static void tcf_chain_flush(struct tcf_chain *chain)
@@ -2305,7 +2313,6 @@ static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n, 
		 * to the chain previously taken during addition.

		 */

		tcf_chain_put_explicitly_created(chain);

		chain->explicitly_created = false;

		break;

	case RTM_GETCHAIN:

		err = tc_chain_notify(chain, skb, n->nlmsg_seq,