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Commit f71e0ca4 authored by Jiri Pirko's avatar Jiri Pirko Committed by David S. Miller
Browse files

net: sched: Avoid implicit chain 0 creation 



Currently, chain 0 is implicitly created during block creation. However
that does not align with chain object exposure, creation and destruction
api introduced later on. So make the chain 0 behave the same way as any
other chain and only create it when it is needed. Since chain 0 is
somehow special as the qdiscs need to hold pointer to the first chain
tp, this requires to move the chain head change callback infra to the
block structure.

Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent f34e8bff

include/net/sch_generic.h

+4 −1
Original line number Diff line number Diff line
@@ -300,7 +300,6 @@ typedef void tcf_chain_head_change_t(struct tcf_proto *tp_head, void *priv); 


struct tcf_chain {

	struct tcf_proto __rcu *filter_chain;

	struct list_head filter_chain_list;

	struct list_head list;

	struct tcf_block *block;

	u32 index; /* chain index */
@@ -318,6 +317,10 @@ struct tcf_block { 
	bool keep_dst;

	unsigned int offloadcnt; /* Number of oddloaded filters */

	unsigned int nooffloaddevcnt; /* Number of devs unable to do offload */

	struct {

		struct tcf_chain *chain;

		struct list_head filter_chain_list;

	} chain0;

};



static inline void tcf_block_offload_inc(struct tcf_block *block, u32 *flags)

net/sched/cls_api.c

+39 −47
Original line number Diff line number Diff line
@@ -204,11 +204,12 @@ static struct tcf_chain *tcf_chain_create(struct tcf_block *block, 
	chain = kzalloc(sizeof(*chain), GFP_KERNEL);

	if (!chain)

		return NULL;

	INIT_LIST_HEAD(&chain->filter_chain_list);

	list_add_tail(&chain->list, &block->chain_list);

	chain->block = block;

	chain->index = chain_index;

	chain->refcnt = 1;

	if (!chain->index)

		block->chain0.chain = chain;

	return chain;

}
@@ -218,12 +219,16 @@ static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item, 
	if (item->chain_head_change)

		item->chain_head_change(tp_head, item->chain_head_change_priv);

}

static void tcf_chain_head_change(struct tcf_chain *chain,



static void tcf_chain0_head_change(struct tcf_chain *chain,

				   struct tcf_proto *tp_head)

{

	struct tcf_filter_chain_list_item *item;

	struct tcf_block *block = chain->block;



	list_for_each_entry(item, &chain->filter_chain_list, list)

	if (chain->index)

		return;

	list_for_each_entry(item, &block->chain0.filter_chain_list, list)

		tcf_chain_head_change_item(item, tp_head);

}
@@ -231,7 +236,7 @@ static void tcf_chain_flush(struct tcf_chain *chain) 
{

	struct tcf_proto *tp = rtnl_dereference(chain->filter_chain);



	tcf_chain_head_change(chain, NULL);

	tcf_chain0_head_change(chain, NULL);

	while (tp) {

		RCU_INIT_POINTER(chain->filter_chain, tp->next);

		tcf_proto_destroy(tp, NULL);
@@ -245,8 +250,10 @@ static void tcf_chain_destroy(struct tcf_chain *chain) 
	struct tcf_block *block = chain->block;



	list_del(&chain->list);

	if (!chain->index)

		block->chain0.chain = NULL;

	kfree(chain);

	if (list_empty(&block->chain_list))

	if (list_empty(&block->chain_list) && block->refcnt == 0)

		kfree(block);

}
@@ -346,10 +353,11 @@ static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q, 
}



static int

tcf_chain_head_change_cb_add(struct tcf_chain *chain,

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;



	item = kmalloc(sizeof(*item), GFP_KERNEL);
@@ -359,22 +367,24 @@ tcf_chain_head_change_cb_add(struct tcf_chain *chain, 
	}

	item->chain_head_change = ei->chain_head_change;

	item->chain_head_change_priv = ei->chain_head_change_priv;

	if (chain->filter_chain)

		tcf_chain_head_change_item(item, chain->filter_chain);

	list_add(&item->list, &chain->filter_chain_list);

	if (chain0 && chain0->filter_chain)

		tcf_chain_head_change_item(item, chain0->filter_chain);

	list_add(&item->list, &block->chain0.filter_chain_list);

	return 0;

}



static void

tcf_chain_head_change_cb_del(struct tcf_chain *chain,

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;



	list_for_each_entry(item, &chain->filter_chain_list, list) {

	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)

				tcf_chain_head_change_item(item, NULL);

			list_del(&item->list);

			kfree(item);
@@ -411,8 +421,6 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q, 
					  struct netlink_ext_ack *extack)

{

	struct tcf_block *block;

	struct tcf_chain *chain;

	int err;



	block = kzalloc(sizeof(*block), GFP_KERNEL);

	if (!block) {
@@ -422,14 +430,8 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q, 
	INIT_LIST_HEAD(&block->chain_list);

	INIT_LIST_HEAD(&block->cb_list);

	INIT_LIST_HEAD(&block->owner_list);

	INIT_LIST_HEAD(&block->chain0.filter_chain_list);



	/* Create chain 0 by default, it has to be always present. */

	chain = tcf_chain_create(block, 0);

	if (!chain) {

		NL_SET_ERR_MSG(extack, "Failed to create new tcf chain");

		err = -ENOMEM;

		goto err_chain_create;

	}

	block->refcnt = 1;

	block->net = net;

	block->index = block_index;
@@ -438,10 +440,6 @@ static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q, 
	if (!tcf_block_shared(block))

		block->q = q;

	return block;



err_chain_create:

	kfree(block);

	return ERR_PTR(err);

}



static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
@@ -523,11 +521,6 @@ static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q, 
	return block;

}



static struct tcf_chain *tcf_block_chain_zero(struct tcf_block *block)

{

	return list_first_entry(&block->chain_list, struct tcf_chain, list);

}



struct tcf_block_owner_item {

	struct list_head list;

	struct Qdisc *q;
@@ -621,10 +614,9 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q, 


	tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);



	err = tcf_chain_head_change_cb_add(tcf_block_chain_zero(block),

					   ei, extack);

	err = tcf_chain0_head_change_cb_add(block, ei, extack);

	if (err)

		goto err_chain_head_change_cb_add;

		goto err_chain0_head_change_cb_add;



	err = tcf_block_offload_bind(block, q, ei, extack);

	if (err)
@@ -634,15 +626,14 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q, 
	return 0;



err_block_offload_bind:

	tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);

err_chain_head_change_cb_add:

	tcf_chain0_head_change_cb_del(block, ei);

err_chain0_head_change_cb_add:

	tcf_block_owner_del(block, q, ei->binder_type);

err_block_owner_add:

	if (created) {

		if (tcf_block_shared(block))

			tcf_block_remove(block, net);

err_block_insert:

		kfree(tcf_block_chain_zero(block));

		kfree(block);

	} else {

		block->refcnt--;
@@ -682,10 +673,10 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q, 


	if (!block)

		return;

	tcf_chain_head_change_cb_del(tcf_block_chain_zero(block), ei);

	tcf_chain0_head_change_cb_del(block, ei);

	tcf_block_owner_del(block, q, ei->binder_type);



	if (--block->refcnt == 0) {

	if (block->refcnt == 1) {

		if (tcf_block_shared(block))

			tcf_block_remove(block, block->net);
@@ -701,13 +692,14 @@ void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q, 


	tcf_block_offload_unbind(block, q, ei);



	if (block->refcnt == 0) {

	if (block->refcnt == 1) {

		/* At this point, all the chains should have refcnt >= 1. */

		list_for_each_entry_safe(chain, tmp, &block->chain_list, list)

			tcf_chain_put(chain);



		/* Finally, put chain 0 and allow block to be freed. */

		tcf_chain_put(tcf_block_chain_zero(block));

		block->refcnt--;

		if (list_empty(&block->chain_list))

			kfree(block);

	}

}

EXPORT_SYMBOL(tcf_block_put_ext);
@@ -947,7 +939,7 @@ static void tcf_chain_tp_insert(struct tcf_chain *chain, 
				struct tcf_proto *tp)

{

	if (*chain_info->pprev == chain->filter_chain)

		tcf_chain_head_change(chain, tp);

		tcf_chain0_head_change(chain, tp);

	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain_info));

	rcu_assign_pointer(*chain_info->pprev, tp);

	tcf_chain_hold(chain);
@@ -960,7 +952,7 @@ static void tcf_chain_tp_remove(struct tcf_chain *chain, 
	struct tcf_proto *next = rtnl_dereference(chain_info->next);



	if (tp == chain->filter_chain)

		tcf_chain_head_change(chain, next);

		tcf_chain0_head_change(chain, next);

	RCU_INIT_POINTER(*chain_info->pprev, next);

	tcf_chain_put(chain);

}