Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 79e5ad2c authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller
Browse files

fib_trie: Remove leaf_info 



At this point the leaf_info hash is redundant.  By adding the suffix length
to the fib_alias hash list we no longer have need of leaf_info as we can
determine the prefix length from fa_slen.  So we can compress things by
dropping the leaf_info structure from fib_trie and instead directly connect
the leaves to the fib_alias hash list.

Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9b6ebad5

net/ipv4/fib_trie.c

+156 −307
Original line number Diff line number Diff line
@@ -108,17 +108,10 @@ struct tnode { 
			struct tnode __rcu *child[0];

		};

		/* This list pointer if valid if bits == 0 (LEAF) */

		struct hlist_head list;

		struct hlist_head leaf;

	};

};



struct leaf_info {

	struct hlist_node hlist;

	unsigned char slen;

	struct hlist_head falh;

	struct rcu_head rcu;

};



#ifdef CONFIG_IP_FIB_TRIE_STATS

struct trie_use_stats {

	unsigned int gets;
@@ -289,11 +282,6 @@ static void __node_free_rcu(struct rcu_head *head) 


#define node_free(n) call_rcu(&n->rcu, __node_free_rcu)



static inline void free_leaf_info(struct leaf_info *leaf)

{

	kfree_rcu(leaf, rcu);

}



static struct tnode *tnode_alloc(size_t size)

{

	if (size <= PAGE_SIZE)
@@ -327,21 +315,11 @@ static struct tnode *leaf_new(t_key key) 
		/* set bits to 0 indicating we are not a tnode */

		l->bits = 0;



		INIT_HLIST_HEAD(&l->list);

		INIT_HLIST_HEAD(&l->leaf);

	}

	return l;

}



static struct leaf_info *leaf_info_new(int plen)

{

	struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);

	if (li) {

		li->slen = KEYLENGTH - plen;

		INIT_HLIST_HEAD(&li->falh);

	}

	return li;

}



static struct tnode *tnode_new(t_key key, int pos, int bits)

{

	size_t sz = offsetof(struct tnode, child[1ul << bits]);
@@ -864,32 +842,6 @@ static void resize(struct trie *t, struct tnode *tn) 
	}

}



/* readside must use rcu_read_lock currently dump routines

 via get_fa_head and dump */



static struct leaf_info *find_leaf_info(struct tnode *l, int plen)

{

	struct hlist_head *head = &l->list;

	struct leaf_info *li;

	int slen = KEYLENGTH - plen;



	hlist_for_each_entry_rcu(li, head, hlist)

		if (li->slen == slen)

			return li;



	return NULL;

}



static inline struct hlist_head *get_fa_head(struct tnode *l, int plen)

{

	struct leaf_info *li = find_leaf_info(l, plen);



	if (!li)

		return NULL;



	return &li->falh;

}



static void leaf_pull_suffix(struct tnode *l)

{

	struct tnode *tp = node_parent(l);
@@ -914,43 +866,47 @@ static void leaf_push_suffix(struct tnode *l) 
	}

}



static void remove_leaf_info(struct tnode *l, struct leaf_info *old)

static void fib_remove_alias(struct tnode *l, struct fib_alias *old)

{

	/* record the location of the previous list_info entry */

	struct hlist_node **pprev = old->hlist.pprev;

	struct leaf_info *li = hlist_entry(pprev, typeof(*li), hlist.next);

	struct hlist_node **pprev = old->fa_list.pprev;

	struct fib_alias *fa = hlist_entry(pprev, typeof(*fa), fa_list.next);



	/* remove the leaf info from the list */

	hlist_del_rcu(&old->hlist);

	/* remove the fib_alias from the list */

	hlist_del_rcu(&old->fa_list);



	/* only access li if it is pointing at the last valid hlist_node */

	if (hlist_empty(&l->list) || (*pprev))

	/* only access fa if it is pointing at the last valid hlist_node */

	if (hlist_empty(&l->leaf) || (*pprev))

		return;



	/* update the trie with the latest suffix length */

	l->slen = li->slen;

	l->slen = fa->fa_slen;

	leaf_pull_suffix(l);

}



static void insert_leaf_info(struct tnode *l, struct leaf_info *new)

static void fib_insert_alias(struct tnode *l, struct fib_alias *fa,

			     struct fib_alias *new)

{

	struct hlist_head *head = &l->list;

	struct leaf_info *li, *last = NULL;

	if (fa) {

		hlist_add_before_rcu(&new->fa_list, &fa->fa_list);

	} else {

		struct fib_alias *last;



	hlist_for_each_entry(li, head, hlist) {

		if (new->slen < li->slen)

		hlist_for_each_entry(last, &l->leaf, fa_list) {

			if (new->fa_slen < last->fa_slen)

				break;

		last = li;

			fa = last;

		}



	if (last)

		hlist_add_behind_rcu(&new->hlist, &last->hlist);

		if (fa)

			hlist_add_behind_rcu(&new->fa_list, &fa->fa_list);

		else

		hlist_add_head_rcu(&new->hlist, head);

			hlist_add_head_rcu(&new->fa_list, &l->leaf);

	}



	/* if we added to the tail node then we need to update slen */

	if (l->slen < new->slen) {

		l->slen = new->slen;

	if (l->slen < new->fa_slen) {

		l->slen = new->fa_slen;

		leaf_push_suffix(l);

	}

}
@@ -989,8 +945,8 @@ static struct tnode *fib_find_node(struct trie *t, u32 key) 
/* Return the first fib alias matching TOS with

 * priority less than or equal to PRIO.

 */

static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 tos,

					u32 prio)

static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 slen,

					u8 tos, u32 prio)

{

	struct fib_alias *fa;
@@ -998,6 +954,10 @@ static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 tos, 
		return NULL;



	hlist_for_each_entry(fa, fah, fa_list) {

		if (fa->fa_slen < slen)

			continue;

		if (fa->fa_slen != slen)

			break;

		if (fa->fa_tos > tos)

			continue;

		if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
@@ -1023,16 +983,9 @@ static void trie_rebalance(struct trie *t, struct tnode *tn) 


/* only used from updater-side */



static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen)

static struct tnode *fib_insert_node(struct trie *t, u32 key, int plen)

{

	struct hlist_head *fa_head = NULL;

	struct tnode *l, *n, *tp = NULL;

	struct leaf_info *li;



	li = leaf_info_new(plen);

	if (!li)

		return NULL;

	fa_head = &li->falh;



	n = rtnl_dereference(t->trie);
@@ -1063,8 +1016,7 @@ static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen) 
		/* we have found a leaf. Prefixes have already been compared */

		if (IS_LEAF(n)) {

			/* Case 1: n is a leaf, and prefixes match*/

			insert_leaf_info(n, li);

			return fa_head;

			return n;

		}



		tp = n;
@@ -1072,12 +1024,8 @@ static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen) 
	}



	l = leaf_new(key);

	if (!l) {

		free_leaf_info(li);

	if (!l)

		return NULL;

	}



	insert_leaf_info(l, li);



	/* Case 2: n is a LEAF or a TNODE and the key doesn't match.

	 *
@@ -1090,7 +1038,6 @@ static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen) 


		tn = tnode_new(key, __fls(key ^ n->key), 1);

		if (!tn) {

			free_leaf_info(li);

			node_free(l);

			return NULL;

		}
@@ -1116,7 +1063,7 @@ static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen) 
		rcu_assign_pointer(t->trie, l);

	}



	return fa_head;

	return l;

}



/*
@@ -1126,9 +1073,9 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
{

	struct trie *t = (struct trie *) tb->tb_data;

	struct fib_alias *fa, *new_fa;

	struct hlist_head *fa_head = NULL;

	struct fib_info *fi;

	int plen = cfg->fc_dst_len;

	u8 plen = cfg->fc_dst_len;

	u8 slen = KEYLENGTH - plen;

	u8 tos = cfg->fc_tos;

	u32 key, mask;

	int err;
@@ -1146,8 +1093,6 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
	if (key & ~mask)

		return -EINVAL;



	key = key & mask;



	fi = fib_create_info(cfg);

	if (IS_ERR(fi)) {

		err = PTR_ERR(fi);
@@ -1155,12 +1100,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
	}



	l = fib_find_node(t, key);

	fa = NULL;



	if (l) {

		fa_head = get_fa_head(l, plen);

		fa = fib_find_alias(fa_head, tos, fi->fib_priority);

	}

	fa = l ? fib_find_alias(&l->leaf, slen, tos, fi->fib_priority) : NULL;



	/* Now fa, if non-NULL, points to the first fib alias

	 * with the same keys [prefix,tos,priority], if such key already
@@ -1187,7 +1127,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
		fa_match = NULL;

		fa_first = fa;

		hlist_for_each_entry_from(fa, fa_list) {

			if (fa->fa_tos != tos)

			if ((fa->fa_slen != slen) || (fa->fa_tos != tos))

				break;

			if (fa->fa_info->fib_priority != fi->fib_priority)

				break;
@@ -1255,12 +1195,12 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
	new_fa->fa_tos = tos;

	new_fa->fa_type = cfg->fc_type;

	new_fa->fa_state = 0;

	new_fa->fa_slen = KEYLENGTH - plen;

	new_fa->fa_slen = slen;



	/* Insert new entry to the list. */

	if (!fa_head) {

		fa_head = fib_insert_node(t, key, plen);

		if (unlikely(!fa_head)) {

	if (!l) {

		l = fib_insert_node(t, key, plen);

		if (unlikely(!l)) {

			err = -ENOMEM;

			goto out_free_new_fa;

		}
@@ -1269,19 +1209,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) 
	if (!plen)

		tb->tb_num_default++;



	if (fa) {

		hlist_add_before_rcu(&new_fa->fa_list, &fa->fa_list);

	} else {

		struct fib_alias *last;



		hlist_for_each_entry(last, fa_head, fa_list)

			fa = last;



		if (fa)

			hlist_add_behind_rcu(&new_fa->fa_list, &fa->fa_list);

		else

			hlist_add_head_rcu(&new_fa->fa_list, fa_head);

	}

	fib_insert_alias(l, fa, new_fa);



	rt_cache_flush(cfg->fc_nlinfo.nl_net);

	rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
@@ -1314,7 +1242,7 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 
#endif

	const t_key key = ntohl(flp->daddr);

	struct tnode *n, *pn;

	struct leaf_info *li;

	struct fib_alias *fa;

	t_key cindex;



	n = rcu_dereference(t->trie);
@@ -1417,16 +1345,12 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 


found:

	/* Step 3: Process the leaf, if that fails fall back to backtracing */

	hlist_for_each_entry_rcu(li, &n->list, hlist) {

		struct fib_alias *fa;



		hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {

	hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {

		struct fib_info *fi = fa->fa_info;

		int nhsel, err;



		if (((key ^ n->key) >= (1ul << fa->fa_slen)) &&

			    ((BITS_PER_LONG > KEYLENGTH) ||

			     (fa->fa_slen != KEYLENGTH)))

		    ((BITS_PER_LONG > KEYLENGTH) || (fa->fa_slen != KEYLENGTH)))

				continue;

		if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)

			continue;
@@ -1461,14 +1385,13 @@ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp, 
			res->scope = fi->fib_scope;

			res->fi = fi;

			res->table = tb;

				res->fa_head = &li->falh;

			res->fa_head = &n->leaf;

#ifdef CONFIG_IP_FIB_TRIE_STATS

			this_cpu_inc(stats->semantic_match_passed);

#endif

			return err;

		}

	}

	}

#ifdef CONFIG_IP_FIB_TRIE_STATS

	this_cpu_inc(stats->semantic_match_miss);

#endif
@@ -1501,15 +1424,14 @@ static void trie_leaf_remove(struct trie *t, struct tnode *l) 
int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)

{

	struct trie *t = (struct trie *) tb->tb_data;

	u32 key, mask;

	int plen = cfg->fc_dst_len;

	u8 tos = cfg->fc_tos;

	struct fib_alias *fa, *fa_to_delete;

	struct hlist_head *fa_head;

	u8 plen = cfg->fc_dst_len;

	u8 tos = cfg->fc_tos;

	u8 slen = KEYLENGTH - plen;

	struct tnode *l;

	struct leaf_info *li;

	u32 key, mask;



	if (plen > 32)

	if (plen > KEYLENGTH)

		return -EINVAL;



	key = ntohl(cfg->fc_dst);
@@ -1518,19 +1440,11 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 
	if (key & ~mask)

		return -EINVAL;



	key = key & mask;

	l = fib_find_node(t, key);



	if (!l)

		return -ESRCH;



	li = find_leaf_info(l, plen);



	if (!li)

		return -ESRCH;



	fa_head = &li->falh;

	fa = fib_find_alias(fa_head, tos, 0);

	fa = fib_find_alias(&l->leaf, slen, tos, 0);



	if (!fa)

		return -ESRCH;
@@ -1541,7 +1455,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 
	hlist_for_each_entry_from(fa, fa_list) {

		struct fib_info *fi = fa->fa_info;



		if (fa->fa_tos != tos)

		if ((fa->fa_slen != slen) || (fa->fa_tos != tos))

			break;



		if ((!cfg->fc_type || fa->fa_type == cfg->fc_type) &&
@@ -1564,17 +1478,12 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 
	rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,

		  &cfg->fc_nlinfo, 0);



	hlist_del_rcu(&fa->fa_list);

	fib_remove_alias(l, fa);



	if (!plen)

		tb->tb_num_default--;



	if (hlist_empty(fa_head)) {

		remove_leaf_info(l, li);

		free_leaf_info(li);

	}



	if (hlist_empty(&l->list))

	if (hlist_empty(&l->leaf))

		trie_leaf_remove(t, l);



	if (fa->fa_state & FA_S_ACCESSED)
@@ -1585,13 +1494,14 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 
	return 0;

}



static int trie_flush_list(struct hlist_head *head)

static int trie_flush_leaf(struct tnode *l)

{

	struct hlist_node *tmp;

	unsigned char slen = 0;

	struct fib_alias *fa;

	int found = 0;



	hlist_for_each_entry_safe(fa, tmp, head, fa_list) {

	hlist_for_each_entry_safe(fa, tmp, &l->leaf, fa_list) {

		struct fib_info *fi = fa->fa_info;



		if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
@@ -1599,28 +1509,11 @@ static int trie_flush_list(struct hlist_head *head) 
			fib_release_info(fa->fa_info);

			alias_free_mem_rcu(fa);

			found++;

		}

	}

	return found;

}



static int trie_flush_leaf(struct tnode *l)

{

	int found = 0;

	struct hlist_node *tmp;

	struct leaf_info *li;

	unsigned char slen = 0;



	hlist_for_each_entry_safe(li, tmp, &l->list, hlist) {

		found += trie_flush_list(&li->falh);



		if (hlist_empty(&li->falh)) {

			hlist_del_rcu(&li->hlist);

			free_leaf_info(li);

			continue;

		}



		slen = li->slen;

		slen = fa->fa_slen;

	}



	l->slen = slen;
@@ -1628,8 +1521,7 @@ static int trie_flush_leaf(struct tnode *l) 
	return found;

}



/*

 * Scan for the next right leaf starting at node p->child[idx]

/* Scan for the next right leaf starting at node p->child[idx]

 * Since we have back pointer, no recursion necessary.

 */

static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
@@ -1704,7 +1596,7 @@ int fib_table_flush(struct fib_table *tb) 
		found += trie_flush_leaf(l);



		if (ll) {

			if (hlist_empty(&ll->list))

			if (hlist_empty(&ll->leaf))

				trie_leaf_remove(t, ll);

			else

				leaf_pull_suffix(ll);
@@ -1714,7 +1606,7 @@ int fib_table_flush(struct fib_table *tb) 
	}



	if (ll) {

		if (hlist_empty(&ll->list))

		if (hlist_empty(&ll->leaf))

			trie_leaf_remove(t, ll);

		else

			leaf_pull_suffix(ll);
@@ -1734,20 +1626,18 @@ void fib_free_table(struct fib_table *tb) 
	kfree(tb);

}



static int fn_trie_dump_fa(t_key key, struct hlist_head *fah,

			   struct fib_table *tb,

static int fn_trie_dump_leaf(struct tnode *l, struct fib_table *tb,

			     struct sk_buff *skb, struct netlink_callback *cb)

{

	int i, s_i;

	__be32 xkey = htonl(l->key);

	struct fib_alias *fa;

	__be32 xkey = htonl(key);

	int i, s_i;



	s_i = cb->args[5];

	s_i = cb->args[4];

	i = 0;



	/* rcu_read_lock is hold by caller */



	hlist_for_each_entry_rcu(fa, fah, fa_list) {

	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {

		if (i < s_i) {

			i++;

			continue;
@@ -1762,38 +1652,6 @@ static int fn_trie_dump_fa(t_key key, struct hlist_head *fah, 
				  KEYLENGTH - fa->fa_slen,

				  fa->fa_tos,

				  fa->fa_info, NLM_F_MULTI) < 0) {

			cb->args[5] = i;

			return -1;

		}

		i++;

	}

	cb->args[5] = i;

	return skb->len;

}



static int fn_trie_dump_leaf(struct tnode *l, struct fib_table *tb,

			struct sk_buff *skb, struct netlink_callback *cb)

{

	struct leaf_info *li;

	int i, s_i;



	s_i = cb->args[4];

	i = 0;



	/* rcu_read_lock is hold by caller */

	hlist_for_each_entry_rcu(li, &l->list, hlist) {

		if (i < s_i) {

			i++;

			continue;

		}



		if (i > s_i)

			cb->args[5] = 0;



		if (hlist_empty(&li->falh))

			continue;



		if (fn_trie_dump_fa(l->key, &li->falh, tb, skb, cb) < 0) {

			cb->args[4] = i;

			return -1;

		}
@@ -1853,8 +1711,7 @@ void __init fib_trie_init(void) 
					  0, SLAB_PANIC, NULL);



	trie_leaf_kmem = kmem_cache_create("ip_fib_trie",

					   max(sizeof(struct tnode),

					       sizeof(struct leaf_info)),

					   sizeof(struct tnode),

					   0, SLAB_PANIC, NULL);

}
@@ -1976,14 +1833,14 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s) 
	rcu_read_lock();

	for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) {

		if (IS_LEAF(n)) {

			struct leaf_info *li;

			struct fib_alias *fa;



			s->leaves++;

			s->totdepth += iter.depth;

			if (iter.depth > s->maxdepth)

				s->maxdepth = iter.depth;



			hlist_for_each_entry_rcu(li, &n->list, hlist)

			hlist_for_each_entry_rcu(fa, &n->leaf, fa_list)

				++s->prefixes;

		} else {

			s->tnodes++;
@@ -2015,7 +1872,7 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 
	bytes = sizeof(struct tnode) * stat->leaves;



	seq_printf(seq, "\tPrefixes:       %u\n", stat->prefixes);

	bytes += sizeof(struct leaf_info) * stat->prefixes;

	bytes += sizeof(struct fib_alias) * stat->prefixes;



	seq_printf(seq, "\tInternal nodes: %u\n\t", stat->tnodes);

	bytes += sizeof(struct tnode) * stat->tnodes;
@@ -2266,16 +2123,13 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v) 
			   &prf, KEYLENGTH - n->pos - n->bits, n->bits,

			   n->full_children, n->empty_children);

	} else {

		struct leaf_info *li;

		__be32 val = htonl(n->key);

		struct fib_alias *fa;



		seq_indent(seq, iter->depth);

		seq_printf(seq, "  |-- %pI4\n", &val);



		hlist_for_each_entry_rcu(li, &n->list, hlist) {

			struct fib_alias *fa;



			hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {

		hlist_for_each_entry_rcu(fa, &n->leaf, fa_list) {

			char buf1[32], buf2[32];



			seq_indent(seq, iter->depth + 1);
@@ -2290,7 +2144,6 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v) 
			seq_putc(seq, '\n');

		}

	}

	}



	return 0;

}
@@ -2416,8 +2269,8 @@ static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info 
 */

static int fib_route_seq_show(struct seq_file *seq, void *v)

{

	struct fib_alias *fa;

	struct tnode *l = v;

	struct leaf_info *li;

	__be32 prefix;



	if (v == SEQ_START_TOKEN) {
@@ -2429,16 +2282,13 @@ static int fib_route_seq_show(struct seq_file *seq, void *v) 


	prefix = htonl(l->key);



	hlist_for_each_entry_rcu(li, &l->list, hlist) {

		struct fib_alias *fa;



		hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {

	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {

		const struct fib_info *fi = fa->fa_info;

		__be32 mask = inet_make_mask(KEYLENGTH - fa->fa_slen);

		unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);



			if (fa->fa_type == RTN_BROADCAST

			    || fa->fa_type == RTN_MULTICAST)

		if ((fa->fa_type == RTN_BROADCAST) ||

		    (fa->fa_type == RTN_MULTICAST))

			continue;



		seq_setwidth(seq, 127);
@@ -2465,7 +2315,6 @@ static int fib_route_seq_show(struct seq_file *seq, void *v) 


		seq_pad(seq, '\n');

	}

	}



	return 0;

}