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Commit 0a5c0475 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

fib: add __rcu annotations 



Add __rcu annotations and lockdep checks.

Add const qualifiers

node_parent() and node_parent_rcu() can use
rcu_dereference_index_check()

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ab392d2d

net/ipv4/fib_trie.c

+58 −45
Original line number Diff line number Diff line
@@ -126,7 +126,7 @@ struct tnode { 
		struct work_struct work;

		struct tnode *tnode_free;

	};

	struct rt_trie_node *child[0];

	struct rt_trie_node __rcu *child[0];

};



#ifdef CONFIG_IP_FIB_TRIE_STATS
@@ -151,7 +151,7 @@ struct trie_stat { 
};



struct trie {

	struct rt_trie_node *trie;

	struct rt_trie_node __rcu *trie;

#ifdef CONFIG_IP_FIB_TRIE_STATS

	struct trie_use_stats stats;

#endif
@@ -177,16 +177,29 @@ static const int sync_pages = 128; 
static struct kmem_cache *fn_alias_kmem __read_mostly;

static struct kmem_cache *trie_leaf_kmem __read_mostly;



static inline struct tnode *node_parent(struct rt_trie_node *node)

/*

 * caller must hold RTNL

 */

static inline struct tnode *node_parent(const struct rt_trie_node *node)

{

	return (struct tnode *)(node->parent & ~NODE_TYPE_MASK);

	unsigned long parent;



	parent = rcu_dereference_index_check(node->parent, lockdep_rtnl_is_held());



	return (struct tnode *)(parent & ~NODE_TYPE_MASK);

}



static inline struct tnode *node_parent_rcu(struct rt_trie_node *node)

/*

 * caller must hold RCU read lock or RTNL

 */

static inline struct tnode *node_parent_rcu(const struct rt_trie_node *node)

{

	struct tnode *ret = node_parent(node);

	unsigned long parent;



	parent = rcu_dereference_index_check(node->parent, rcu_read_lock_held() ||

							   lockdep_rtnl_is_held());



	return rcu_dereference_rtnl(ret);

	return (struct tnode *)(parent & ~NODE_TYPE_MASK);

}



/* Same as rcu_assign_pointer
@@ -198,18 +211,24 @@ static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr) 
	node->parent = (unsigned long)ptr | NODE_TYPE(node);

}



static inline struct rt_trie_node *tnode_get_child(struct tnode *tn, unsigned int i)

/*

 * caller must hold RTNL

 */

static inline struct rt_trie_node *tnode_get_child(const struct tnode *tn, unsigned int i)

{

	BUG_ON(i >= 1U << tn->bits);



	return tn->child[i];

	return rtnl_dereference(tn->child[i]);

}



static inline struct rt_trie_node *tnode_get_child_rcu(struct tnode *tn, unsigned int i)

/*

 * caller must hold RCU read lock or RTNL

 */

static inline struct rt_trie_node *tnode_get_child_rcu(const struct tnode *tn, unsigned int i)

{

	struct rt_trie_node *ret = tnode_get_child(tn, i);

	BUG_ON(i >= 1U << tn->bits);



	return rcu_dereference_rtnl(ret);

	return rcu_dereference_rtnl(tn->child[i]);

}



static inline int tnode_child_length(const struct tnode *tn)
@@ -487,7 +506,7 @@ static inline void put_child(struct trie *t, struct tnode *tn, int i, 
static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *n,

				  int wasfull)

{

	struct rt_trie_node *chi = tn->child[i];

	struct rt_trie_node *chi = rtnl_dereference(tn->child[i]);

	int isfull;



	BUG_ON(i >= 1<<tn->bits);
@@ -665,7 +684,7 @@ one_child: 
		for (i = 0; i < tnode_child_length(tn); i++) {

			struct rt_trie_node *n;



			n = tn->child[i];

			n = rtnl_dereference(tn->child[i]);

			if (!n)

				continue;
@@ -679,6 +698,20 @@ one_child: 
	return (struct rt_trie_node *) tn;

}





static void tnode_clean_free(struct tnode *tn)

{

	int i;

	struct tnode *tofree;



	for (i = 0; i < tnode_child_length(tn); i++) {

		tofree = (struct tnode *)rtnl_dereference(tn->child[i]);

		if (tofree)

			tnode_free(tofree);

	}

	tnode_free(tn);

}



static struct tnode *inflate(struct trie *t, struct tnode *tn)

{

	struct tnode *oldtnode = tn;
@@ -755,8 +788,8 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) 
		inode = (struct tnode *) node;



		if (inode->bits == 1) {

			put_child(t, tn, 2*i, inode->child[0]);

			put_child(t, tn, 2*i+1, inode->child[1]);

			put_child(t, tn, 2*i, rtnl_dereference(inode->child[0]));

			put_child(t, tn, 2*i+1, rtnl_dereference(inode->child[1]));



			tnode_free_safe(inode);

			continue;
@@ -797,8 +830,8 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) 


		size = tnode_child_length(left);

		for (j = 0; j < size; j++) {

			put_child(t, left, j, inode->child[j]);

			put_child(t, right, j, inode->child[j + size]);

			put_child(t, left, j, rtnl_dereference(inode->child[j]));

			put_child(t, right, j, rtnl_dereference(inode->child[j + size]));

		}

		put_child(t, tn, 2*i, resize(t, left));

		put_child(t, tn, 2*i+1, resize(t, right));
@@ -808,19 +841,9 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn) 
	tnode_free_safe(oldtnode);

	return tn;

nomem:

	{

		int size = tnode_child_length(tn);

		int j;



		for (j = 0; j < size; j++)

			if (tn->child[j])

				tnode_free((struct tnode *)tn->child[j]);



		tnode_free(tn);



	tnode_clean_free(tn);

	return ERR_PTR(-ENOMEM);

}

}



static struct tnode *halve(struct trie *t, struct tnode *tn)

{
@@ -890,19 +913,9 @@ static struct tnode *halve(struct trie *t, struct tnode *tn) 
	tnode_free_safe(oldtnode);

	return tn;

nomem:

	{

		int size = tnode_child_length(tn);

		int j;



		for (j = 0; j < size; j++)

			if (tn->child[j])

				tnode_free((struct tnode *)tn->child[j]);



		tnode_free(tn);



	tnode_clean_free(tn);

	return ERR_PTR(-ENOMEM);

}

}



/* readside must use rcu_read_lock currently dump routines

 via get_fa_head and dump */
@@ -1033,7 +1046,7 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen) 
	t_key cindex;



	pos = 0;

	n = t->trie;

	n = rtnl_dereference(t->trie);



	/* If we point to NULL, stop. Either the tree is empty and we should

	 * just put a new leaf in if, or we have reached an empty child slot,
@@ -1756,7 +1769,7 @@ static struct leaf *leaf_walk_rcu(struct tnode *p, struct rt_trie_node *c) 
				continue;



			if (IS_LEAF(c)) {

				prefetch(p->child[idx]);

				prefetch(rcu_dereference_rtnl(p->child[idx]));

				return (struct leaf *) c;

			}
@@ -2272,7 +2285,7 @@ static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 


	/* walk rest of this hash chain */

	h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);

	while ( (tb_node = rcu_dereference(tb->tb_hlist.next)) ) {

	while ((tb_node = rcu_dereference(hlist_next_rcu(&tb->tb_hlist)))) {

		tb = hlist_entry(tb_node, struct fib_table, tb_hlist);

		n = fib_trie_get_first(iter, (struct trie *) tb->tb_data);

		if (n)