[IPV4]: FIB Trie cleanups.

Below is a patch that cleans up some of this, supposedly without
changing any behaviour:

* Whitespace cleanups
* Introduce DBG()
* BUG_ON() instead of if () { BUG(); }
* Remove some of the deep nesting to make the code flow more
  comprehensible
* Some mask operations were simplified

Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 592 insertions, 645 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 45efd5f4741..6f818cc7efd 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -89,27 +89,27 @@ typedef unsigned int t_key;
 #define T_TNODE 0
 #define T_LEAF  1
 #define NODE_TYPE_MASK	0x1UL
-#define NODE_PARENT(_node) \
-	((struct tnode *)((_node)->_parent & ~NODE_TYPE_MASK))
-#define NODE_SET_PARENT(_node, _ptr) \
-	((_node)->_parent = (((unsigned long)(_ptr)) | \
-                     ((_node)->_parent & NODE_TYPE_MASK)))
-#define NODE_INIT_PARENT(_node, _type) \
-	((_node)->_parent = (_type))
-#define NODE_TYPE(_node) \
-	((_node)->_parent & NODE_TYPE_MASK)
-
-#define IS_TNODE(n) (!(n->_parent & T_LEAF))
-#define IS_LEAF(n) (n->_parent & T_LEAF)
+#define NODE_PARENT(node) \
+	((struct tnode *)((node)->parent & ~NODE_TYPE_MASK))
+#define NODE_SET_PARENT(node, ptr) \
+	((node)->parent = (((unsigned long)(ptr)) | \
+                     ((node)->parent & NODE_TYPE_MASK)))
+#define NODE_INIT_PARENT(node, type) \
+	((node)->parent = (type))
+#define NODE_TYPE(node) \
+	((node)->parent & NODE_TYPE_MASK)
+
+#define IS_TNODE(n) (!(n->parent & T_LEAF))
+#define IS_LEAF(n) (n->parent & T_LEAF)
 
 struct node {
-        t_key key;
-	unsigned long _parent;
+	t_key key;
+	unsigned long parent;
 };
 
 struct leaf {
-        t_key key;
-	unsigned long _parent;
+	t_key key;
+	unsigned long parent;
 	struct hlist_head list;
 };
 
@@ -120,13 +120,13 @@ struct leaf_info {
 };
 
 struct tnode {
-        t_key key;
-	unsigned long _parent;
-        unsigned short pos:5;        /* 2log(KEYLENGTH) bits needed */
-        unsigned short bits:5;       /* 2log(KEYLENGTH) bits needed */
-        unsigned short full_children;  /* KEYLENGTH bits needed */
-        unsigned short empty_children; /* KEYLENGTH bits needed */
-        struct node *child[0];
+	t_key key;
+	unsigned long parent;
+	unsigned short pos:5;		/* 2log(KEYLENGTH) bits needed */
+	unsigned short bits:5;		/* 2log(KEYLENGTH) bits needed */
+	unsigned short full_children;	/* KEYLENGTH bits needed */
+	unsigned short empty_children;	/* KEYLENGTH bits needed */
+	struct node *child[0];
 };
 
 #ifdef CONFIG_IP_FIB_TRIE_STATS
@@ -150,16 +150,18 @@ struct trie_stat {
 };
 
 struct trie {
-        struct node *trie;
+	struct node *trie;
 #ifdef CONFIG_IP_FIB_TRIE_STATS
 	struct trie_use_stats stats;
 #endif
-        int size;
+	int size;
 	unsigned int revision;
 };
 
 static int trie_debug = 0;
 
+#define DBG(x...) do { if (trie_debug) printk(x); } while (0)
+
 static int tnode_full(struct tnode *tn, struct node *n);
 static void put_child(struct trie *t, struct tnode *tn, int i, struct node *n);
 static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int wasfull);
@@ -171,56 +173,31 @@ static void tnode_free(struct tnode *tn);
 static void trie_dump_seq(struct seq_file *seq, struct trie *t);
 extern struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio);
 extern int fib_detect_death(struct fib_info *fi, int order,
-                            struct fib_info **last_resort, int *last_idx, int *dflt);
+			    struct fib_info **last_resort, int *last_idx, int *dflt);
 
 extern void rtmsg_fib(int event, u32 key, struct fib_alias *fa, int z, int tb_id,
-               struct nlmsghdr *n, struct netlink_skb_parms *req);
+		      struct nlmsghdr *n, struct netlink_skb_parms *req);
 
 static kmem_cache_t *fn_alias_kmem;
 static struct trie *trie_local = NULL, *trie_main = NULL;
 
-static void trie_bug(char *err)
-{
-	printk("Trie Bug: %s\n", err);
-	BUG();
-}
-
 static inline struct node *tnode_get_child(struct tnode *tn, int i)
 {
-        if (i >= 1<<tn->bits)
-                trie_bug("tnode_get_child");
+	BUG_ON(i >= 1 << tn->bits);
 
-        return tn->child[i];
+	return tn->child[i];
 }
 
 static inline int tnode_child_length(struct tnode *tn)
 {
-        return 1<<tn->bits;
+	return 1 << tn->bits;
 }
 
-/*
-  _________________________________________________________________
-  | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
-  ----------------------------------------------------------------
-    0   1   2   3   4   5   6   7   8   9  10  11  12  13  14  15
-
-  _________________________________________________________________
-  | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
-  -----------------------------------------------------------------
-   16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31
-
-  tp->pos = 7
-  tp->bits = 3
-  n->pos = 15
-  n->bits=4
-  KEYLENGTH=32
-*/
-
 static inline t_key tkey_extract_bits(t_key a, int offset, int bits)
 {
-        if (offset < KEYLENGTH)
+	if (offset < KEYLENGTH)
 		return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
-        else
+	else
 		return 0;
 }
 
@@ -233,8 +210,8 @@ static inline int tkey_sub_equals(t_key a, int offset, int bits, t_key b)
 {
 	if (bits == 0 || offset >= KEYLENGTH)
 		return 1;
-        bits = bits > KEYLENGTH ? KEYLENGTH : bits;
-        return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
+	bits = bits > KEYLENGTH ? KEYLENGTH : bits;
+	return ((a ^ b) << offset) >> (KEYLENGTH - bits) == 0;
 }
 
 static inline int tkey_mismatch(t_key a, int offset, t_key b)
@@ -249,7 +226,7 @@ static inline int tkey_mismatch(t_key a, int offset, t_key b)
 	return i;
 }
 
-/* Candiate for fib_semantics */
+/* Candidate for fib_semantics */
 
 static void fn_free_alias(struct fib_alias *fa)
 {
@@ -295,7 +272,7 @@ static void fn_free_alias(struct fib_alias *fa)
   tp->pos = 7
   tp->bits = 3
   n->pos = 15
-  n->bits=4
+  n->bits = 4
 
   First, let's just ignore the bits that come before the parent tp, that is 
   the bits from 0 to (tp->pos-1). They are *known* but at this point we do 
@@ -343,10 +320,13 @@ static struct leaf *leaf_new(void)
 static struct leaf_info *leaf_info_new(int plen)
 {
 	struct leaf_info *li = kmalloc(sizeof(struct leaf_info),  GFP_KERNEL);
-	if (li) {
-		li->plen = plen;
-		INIT_LIST_HEAD(&li->falh);
-	}
+
+	if (!li)
+		return NULL;
+
+	li->plen = plen;
+	INIT_LIST_HEAD(&li->falh);
+
 	return li;
 }
 
@@ -373,7 +353,7 @@ static struct tnode *tnode_alloc(unsigned int size)
 static void __tnode_free(struct tnode *tn)
 {
 	unsigned int size = sizeof(struct tnode) +
-	                    (1<<tn->bits) * sizeof(struct node *);
+				(1 << tn->bits) * sizeof(struct node *);
 
 	if (size <= PAGE_SIZE)
 		kfree(tn);
@@ -387,7 +367,7 @@ static struct tnode* tnode_new(t_key key, int pos, int bits)
 	int sz = sizeof(struct tnode) + nchildren * sizeof(struct node *);
 	struct tnode *tn = tnode_alloc(sz);
 
-	if (tn)  {
+	if (tn) {
 		memset(tn, 0, sz);
 		NODE_INIT_PARENT(tn, T_TNODE);
 		tn->pos = pos;
@@ -397,29 +377,21 @@ static struct tnode* tnode_new(t_key key, int pos, int bits)
 		tn->empty_children = 1<<bits;
 	}
 
-	if (trie_debug > 0)
-		printk("AT %p s=%u %u\n", tn, (unsigned int) sizeof(struct tnode),
-		       (unsigned int) (sizeof(struct node) * 1<<bits));
+	DBG("AT %p s=%u %u\n", tn, (unsigned int) sizeof(struct tnode),
+	       (unsigned int) (sizeof(struct node) * 1<<bits));
 	return tn;
 }
 
 static void tnode_free(struct tnode *tn)
 {
-	if (!tn) {
-		trie_bug("tnode_free\n");
-	}
+	BUG_ON(!tn);
+
 	if (IS_LEAF(tn)) {
 		free_leaf((struct leaf *)tn);
-		if (trie_debug > 0 )
-			printk("FL %p \n", tn);
-	}
-	else if (IS_TNODE(tn)) {
+		DBG("FL %p \n", tn);
+	} else {
 		__tnode_free(tn);
-		if (trie_debug > 0 )
-			printk("FT %p \n", tn);
-	}
-	else {
-		trie_bug("tnode_free\n");
+		DBG("FT %p \n", tn);
 	}
 }
 
@@ -453,7 +425,7 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w
 
 	if (i >= 1<<tn->bits) {
 		printk("bits=%d, i=%d\n", tn->bits, i);
-		trie_bug("tnode_put_child_reorg bits");
+		BUG();
 	}
 	write_lock_bh(&fib_lock);
 	chi = tn->child[i];
@@ -465,15 +437,15 @@ static void tnode_put_child_reorg(struct tnode *tn, int i, struct node *n, int w
 		tn->empty_children--;
 
 	/* update fullChildren */
-        if (wasfull == -1)
+	if (wasfull == -1)
 		wasfull = tnode_full(tn, chi);
 
 	isfull = tnode_full(tn, n);
 	if (wasfull && !isfull)
 		tn->full_children--;
-
 	else if (!wasfull && isfull)
 		tn->full_children++;
+
 	if (n)
 		NODE_SET_PARENT(n, tn);
 
@@ -489,9 +461,8 @@ static struct node *resize(struct trie *t, struct tnode *tn)
  	if (!tn)
 		return NULL;
 
-	if (trie_debug)
-		printk("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
-		      tn, inflate_threshold, halve_threshold);
+	DBG("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+	      tn, inflate_threshold, halve_threshold);
 
 	/* No children */
 	if (tn->empty_children == tnode_child_length(tn)) {
@@ -501,20 +472,21 @@ static struct node *resize(struct trie *t, struct tnode *tn)
 	/* One child */
 	if (tn->empty_children == tnode_child_length(tn) - 1)
 		for (i = 0; i < tnode_child_length(tn); i++) {
+			struct node *n;
 
 			write_lock_bh(&fib_lock);
-			if (tn->child[i] != NULL) {
-
-				/* compress one level */
-				struct node *n = tn->child[i];
-				if (n)
-					NODE_INIT_PARENT(n, NODE_TYPE(n));
-
+			n = tn->child[i];
+			if (!n) {
 				write_unlock_bh(&fib_lock);
-				tnode_free(tn);
-				return n;
+				continue;
 			}
+
+			/* compress one level */
+			NODE_INIT_PARENT(n, NODE_TYPE(n));
+
 			write_unlock_bh(&fib_lock);
+			tnode_free(tn);
+			return n;
 		}
 	/*
 	 * Double as long as the resulting node has a number of
@@ -566,16 +538,16 @@ static struct node *resize(struct trie *t, struct tnode *tn)
 	 *
 	 * expand not_to_be_doubled and to_be_doubled, and shorten:
 	 * 100 * (tnode_child_length(tn) - tn->empty_children +
-	 *    tn->full_children ) >= inflate_threshold * new_child_length
+	 *    tn->full_children) >= inflate_threshold * new_child_length
 	 *
 	 * expand new_child_length:
 	 * 100 * (tnode_child_length(tn) - tn->empty_children +
-	 *    tn->full_children ) >=
+	 *    tn->full_children) >=
 	 *      inflate_threshold * tnode_child_length(tn) * 2
 	 *
 	 * shorten again:
 	 * 50 * (tn->full_children + tnode_child_length(tn) -
-	 *    tn->empty_children ) >= inflate_threshold *
+	 *    tn->empty_children) >= inflate_threshold *
 	 *    tnode_child_length(tn)
 	 *
 	 */
@@ -624,20 +596,23 @@ static struct node *resize(struct trie *t, struct tnode *tn)
 
 	if (tn->empty_children == tnode_child_length(tn) - 1)
 		for (i = 0; i < tnode_child_length(tn); i++) {
-		
-			write_lock_bh(&fib_lock);
-			if (tn->child[i] != NULL) {
-				/* compress one level */
-				struct node *n = tn->child[i];
+			struct node *n;
 
-				if (n)
-					NODE_INIT_PARENT(n, NODE_TYPE(n));
+			write_lock_bh(&fib_lock);
 
+			n = tn->child[i];
+			if (!n) {
 				write_unlock_bh(&fib_lock);
-				tnode_free(tn);
-				return n;
+				continue;
 			}
+
+			/* compress one level */
+
+			NODE_INIT_PARENT(n, NODE_TYPE(n));
+
 			write_unlock_bh(&fib_lock);
+			tnode_free(tn);
+			return n;
 		}
 
 	return (struct node *) tn;
@@ -650,8 +625,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 	int olen = tnode_child_length(tn);
 	int i;
 
-  	if (trie_debug)
-		printk("In inflate\n");
+	DBG("In inflate\n");
 
 	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
 
@@ -666,8 +640,8 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 	 * fails. In case of failure we return the oldnode and  inflate
 	 * of tnode is ignored.
 	 */
-		
-	for(i = 0; i < olen; i++) {
+
+	for (i = 0; i < olen; i++) {
 		struct tnode *inode = (struct tnode *) tnode_get_child(oldtnode, i);
 
 		if (inode &&
@@ -675,7 +649,6 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 		    inode->pos == oldtnode->pos + oldtnode->bits &&
 		    inode->bits > 1) {
 			struct tnode *left, *right;
-
 			t_key m = TKEY_GET_MASK(inode->pos, 1);
 
 			left = tnode_new(inode->key&(~m), inode->pos + 1,
@@ -685,7 +658,7 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 				*err = -ENOMEM;
 				break;
 			}
-		
+
 			right = tnode_new(inode->key|m, inode->pos + 1,
 					  inode->bits - 1);
 
@@ -703,18 +676,20 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 		int size = tnode_child_length(tn);
 		int j;
 
-		for(j = 0; j < size; j++)
+		for (j = 0; j < size; j++)
 			if (tn->child[j])
 				tnode_free((struct tnode *)tn->child[j]);
 
 		tnode_free(tn);
-	
+
 		*err = -ENOMEM;
 		return oldtnode;
 	}
 
-	for(i = 0; i < olen; i++) {
+	for (i = 0; i < olen; i++) {
 		struct node *node = tnode_get_child(oldtnode, i);
+		struct tnode *left, *right;
+		int size, j;
 
 		/* An empty child */
 		if (node == NULL)
@@ -740,56 +715,51 @@ static struct tnode *inflate(struct trie *t, struct tnode *tn, int *err)
 			put_child(t, tn, 2*i+1, inode->child[1]);
 
 			tnode_free(inode);
+			continue;
 		}
 
-			/* An internal node with more than two children */
-		else {
-			struct tnode *left, *right;
-			int size, j;
-
-			/* We will replace this node 'inode' with two new
-			 * ones, 'left' and 'right', each with half of the
-			 * original children. The two new nodes will have
-			 * a position one bit further down the key and this
-			 * means that the "significant" part of their keys
-			 * (see the discussion near the top of this file)
-			 * will differ by one bit, which will be "0" in
-			 * left's key and "1" in right's key. Since we are
-			 * moving the key position by one step, the bit that
-			 * we are moving away from - the bit at position
-			 * (inode->pos) - is the one that will differ between
-			 * left and right. So... we synthesize that bit in the
-			 * two  new keys.
-			 * The mask 'm' below will be a single "one" bit at
-			 * the position (inode->pos)
-			 */
-
-			/* Use the old key, but set the new significant
-			 *   bit to zero.
-			 */
+		/* An internal node with more than two children */
+
+		/* We will replace this node 'inode' with two new
+		 * ones, 'left' and 'right', each with half of the
+		 * original children. The two new nodes will have
+		 * a position one bit further down the key and this
+		 * means that the "significant" part of their keys
+		 * (see the discussion near the top of this file)
+		 * will differ by one bit, which will be "0" in
+		 * left's key and "1" in right's key. Since we are
+		 * moving the key position by one step, the bit that
+		 * we are moving away from - the bit at position
+		 * (inode->pos) - is the one that will differ between
+		 * left and right. So... we synthesize that bit in the
+		 * two  new keys.
+		 * The mask 'm' below will be a single "one" bit at
+		 * the position (inode->pos)
+		 */
 
-			left = (struct tnode *) tnode_get_child(tn, 2*i);
-			put_child(t, tn, 2*i, NULL);
+		/* Use the old key, but set the new significant
+		 *   bit to zero.
+		 */
 
-			if (!left)
-				BUG();
+		left = (struct tnode *) tnode_get_child(tn, 2*i);
+		put_child(t, tn, 2*i, NULL);
 
-			right = (struct tnode *) tnode_get_child(tn, 2*i+1);
-			put_child(t, tn, 2*i+1, NULL);
+		BUG_ON(!left);
 
-			if (!right)
-				BUG();
+		right = (struct tnode *) tnode_get_child(tn, 2*i+1);
+		put_child(t, tn, 2*i+1, NULL);
 
-			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, tn, 2*i, resize(t, left));
-			put_child(t, tn, 2*i+1, resize(t, right));
+		BUG_ON(!right);
 
-			tnode_free(inode);
+		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, tn, 2*i, resize(t, left));
+		put_child(t, tn, 2*i+1, resize(t, right));
+
+		tnode_free(inode);
 	}
 	tnode_free(oldtnode);
 	return tn;
@@ -802,7 +772,7 @@ static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
 	int i;
 	int olen = tnode_child_length(tn);
 
-	if (trie_debug) printk("In halve\n");
+	DBG("In halve\n");
 
 	tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
 
@@ -818,7 +788,7 @@ static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
 	 * of tnode is ignored.
 	 */
 
-	for(i = 0; i < olen; i += 2) {
+	for (i = 0; i < olen; i += 2) {
 		left = tnode_get_child(oldtnode, i);
 		right = tnode_get_child(oldtnode, i+1);
 
@@ -839,17 +809,19 @@ static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
 		int size = tnode_child_length(tn);
 		int j;
 
-		for(j = 0; j < size; j++)
+		for (j = 0; j < size; j++)
 			if (tn->child[j])
 				tnode_free((struct tnode *)tn->child[j]);
 
 		tnode_free(tn);
-	
+
 		*err = -ENOMEM;
 		return oldtnode;
 	}
 
-	for(i = 0; i < olen; i += 2) {
+	for (i = 0; i < olen; i += 2) {
+		struct tnode *newBinNode;
+
 		left = tnode_get_child(oldtnode, i);
 		right = tnode_get_child(oldtnode, i+1);
 
@@ -858,38 +830,39 @@ static struct tnode *halve(struct trie *t, struct tnode *tn, int *err)
 			if (right == NULL)    /* Both are empty */
 				continue;
 			put_child(t, tn, i/2, right);
-		} else if (right == NULL)
+			continue;
+		} 
+
+		if (right == NULL) {
 			put_child(t, tn, i/2, left);
+			continue;
+		}
 
 		/* Two nonempty children */
-		else {
-			struct tnode *newBinNode =
-				(struct tnode *) tnode_get_child(tn, i/2);
-			put_child(t, tn, i/2, NULL);
+		newBinNode = (struct tnode *) tnode_get_child(tn, i/2);
+		put_child(t, tn, i/2, NULL);
 
-			if (!newBinNode)
-				BUG();
+		BUG_ON(!newBinNode);
 
-			put_child(t, newBinNode, 0, left);
-			put_child(t, newBinNode, 1, right);
-			put_child(t, tn, i/2, resize(t, newBinNode));
-		}
+		put_child(t, newBinNode, 0, left);
+		put_child(t, newBinNode, 1, right);
+		put_child(t, tn, i/2, resize(t, newBinNode));
 	}
 	tnode_free(oldtnode);
 	return tn;
 }
 
-static void *trie_init(struct trie *t)
+static void trie_init(struct trie *t)
 {
-	if (t) {
-		t->size = 0;
-		t->trie = NULL;
-		t->revision = 0;
+	if (!t)
+		return;
+
+	t->size = 0;
+	t->trie = NULL;
+	t->revision = 0;
 #ifdef CONFIG_IP_FIB_TRIE_STATS
-       		memset(&t->stats, 0, sizeof(struct trie_use_stats));
+	memset(&t->stats, 0, sizeof(struct trie_use_stats));
 #endif
-	}
-	return t;
 }
 
 static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen)
@@ -897,39 +870,37 @@ static struct leaf_info *find_leaf_info(struct hlist_head *head, int plen)
 	struct hlist_node *node;
 	struct leaf_info *li;
 
-	hlist_for_each_entry(li, node, head, hlist) {
+	hlist_for_each_entry(li, node, head, hlist)
 		if (li->plen == plen)
 			return li;
-	}
+
 	return NULL;
 }
 
 static inline struct list_head * get_fa_head(struct leaf *l, int plen)
 {
-	struct list_head *fa_head = NULL;
 	struct leaf_info *li = find_leaf_info(&l->list, plen);
 
-	if (li)
-		fa_head = &li->falh;
+	if (!li)
+		return NULL;
 
-	return fa_head;
+	return &li->falh;
 }
 
 static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
 {
 	struct leaf_info *li = NULL, *last = NULL;
-	struct hlist_node *node, *tmp;
+	struct hlist_node *node;
 
 	write_lock_bh(&fib_lock);
 
-	if (hlist_empty(head))
+	if (hlist_empty(head)) {
 		hlist_add_head(&new->hlist, head);
-	else {
-		hlist_for_each_entry_safe(li, node, tmp, head, hlist) {
-		
+	} else {
+		hlist_for_each_entry(li, node, head, hlist) {
 			if (new->plen > li->plen)
 				break;
-		
+
 			last = li;
 		}
 		if (last)
@@ -952,49 +923,47 @@ fib_find_node(struct trie *t, u32 key)
 
 	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
 		tn = (struct tnode *) n;
-		
+
 		check_tnode(tn);
-		
+
 		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
-			pos=tn->pos + tn->bits;
+			pos = tn->pos + tn->bits;
 			n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));
-		}
-		else
+		} else
 			break;
 	}
 	/* Case we have found a leaf. Compare prefixes */
 
-	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
-		struct leaf *l = (struct leaf *) n;
-		return l;
-	}
+	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
+		return (struct leaf *)n;
+
 	return NULL;
 }
 
 static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
 {
-	int i = 0;
+	int i;
 	int wasfull;
 	t_key cindex, key;
 	struct tnode *tp = NULL;
 
-	if (!tn)
-		BUG();
+	BUG_ON(!tn);
 
 	key = tn->key;
 	i = 0;
 
 	while (tn != NULL && NODE_PARENT(tn) != NULL) {
-
 		if (i > 10) {
 			printk("Rebalance tn=%p \n", tn);
-			if (tn) 		printk("tn->parent=%p \n", NODE_PARENT(tn));
-		
+			if (tn)
+				printk("tn->parent=%p \n", NODE_PARENT(tn));
+
 			printk("Rebalance tp=%p \n", tp);
-			if (tp) 		printk("tp->parent=%p \n", NODE_PARENT(tp));
+			if (tp)
+				printk("tp->parent=%p \n", NODE_PARENT(tp));
 		}
 
-		if (i > 12) BUG();
+		BUG_ON(i > 12); /* Why is this a bug? -ojn */
 		i++;
 
 		tp = NODE_PARENT(tn);
@@ -1002,7 +971,7 @@ static struct node *trie_rebalance(struct trie *t, struct tnode *tn)
 		wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
 		tn = (struct tnode *) resize (t, (struct tnode *)tn);
 		tnode_put_child_reorg((struct tnode *)tp, cindex,(struct node*)tn, wasfull);
-	
+
 		if (!NODE_PARENT(tn))
 			break;
 
@@ -1050,20 +1019,19 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
 
 	while (n != NULL &&  NODE_TYPE(n) == T_TNODE) {
 		tn = (struct tnode *) n;
-		
+
 		check_tnode(tn);
-	
+
 		if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
 			tp = tn;
-			pos=tn->pos + tn->bits;
+			pos = tn->pos + tn->bits;
 			n = tnode_get_child(tn, tkey_extract_bits(key, tn->pos, tn->bits));
 
 			if (n && NODE_PARENT(n) != tn) {
 				printk("BUG tn=%p, n->parent=%p\n", tn, NODE_PARENT(n));
 				BUG();
 			}
-		}
-		else
+		} else
 			break;
 	}
 
@@ -1073,17 +1041,15 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
 	 * tp is n's (parent) ----> NULL or TNODE
 	 */
 
-	if (tp && IS_LEAF(tp))
-		BUG();
-
+	BUG_ON(tp && IS_LEAF(tp));
 
 	/* Case 1: n is a leaf. Compare prefixes */
 
 	if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) {
-		struct leaf *l = ( struct leaf *)  n;
-	
+		struct leaf *l = (struct leaf *) n;
+
 		li = leaf_info_new(plen);
-	
+
 		if (!li) {
 			*err = -ENOMEM;
 			goto err;
@@ -1113,35 +1079,31 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
 	fa_head = &li->falh;
 	insert_leaf_info(&l->list, li);
 
-	/* Case 2: n is NULL, and will just insert a new leaf */
 	if (t->trie && n == NULL) {
+		/* Case 2: n is NULL, and will just insert a new leaf */
 
 		NODE_SET_PARENT(l, tp);
-	
-		if (!tp)
-			BUG();
 
-		else {
-			cindex = tkey_extract_bits(key, tp->pos, tp->bits);
-			put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
-		}
-	}
-	/* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
-	else {
+		BUG_ON(!tp);
+
+		cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+		put_child(t, (struct tnode *)tp, cindex, (struct node *)l);
+	} else {
+		/* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
 		/*
 		 *  Add a new tnode here
 		 *  first tnode need some special handling
 		 */
 
 		if (tp)
-			pos=tp->pos+tp->bits;
+			pos = tp->pos+tp->bits;
 		else
-			pos=0;
+			pos = 0;
+
 		if (n) {
 			newpos = tkey_mismatch(key, pos, n->key);
 			tn = tnode_new(n->key, newpos, 1);
-		}
-		else {
+		} else {
 			newpos = 0;
 			tn = tnode_new(key, newpos, 1); /* First tnode */
 		}
@@ -1151,32 +1113,32 @@ fib_insert_node(struct trie *t, int *err, u32 key, int plen)
 			tnode_free((struct tnode *) l);
 			*err = -ENOMEM;
 			goto err;
-		}		
-		
+		}
+
 		NODE_SET_PARENT(tn, tp);
 
-		missbit=tkey_extract_bits(key, newpos, 1);
+		missbit = tkey_extract_bits(key, newpos, 1);
 		put_child(t, tn, missbit, (struct node *)l);
 		put_child(t, tn, 1-missbit, n);
 
 		if (tp) {
 			cindex = tkey_extract_bits(key, tp->pos, tp->bits);
 			put_child(t, (struct tnode *)tp, cindex, (struct node *)tn);
-		}
-		else {
+		} else {
 			t->trie = (struct node*) tn; /* First tnode */
 			tp = tn;
 		}
 	}
-	if (tp && tp->pos+tp->bits > 32) {
+
+	if (tp && tp->pos + tp->bits > 32)
 		printk("ERROR tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
 		       tp, tp->pos, tp->bits, key, plen);
-	}
+
 	/* Rebalance the trie */
 	t->trie = trie_rebalance(t, tp);
 done:
 	t->revision++;
-err:;
+err:
 	return fa_head;
 }
 
@@ -1204,17 +1166,18 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 
 	key = ntohl(key);
 
-	if (trie_debug)
-		printk("Insert table=%d %08x/%d\n", tb->tb_id, key, plen);
+	DBG("Insert table=%d %08x/%d\n", tb->tb_id, key, plen);
 
-	mask = ntohl( inet_make_mask(plen) );
+	mask = ntohl(inet_make_mask(plen));
 
 	if (key & ~mask)
 		return -EINVAL;
 
 	key = key & mask;
 
-	if  ((fi = fib_create_info(r, rta, nlhdr, &err)) == NULL)
+	fi = fib_create_info(r, rta, nlhdr, &err);
+
+	if (!fi)
 		goto err;
 
 	l = fib_find_node(t, key);
@@ -1236,8 +1199,7 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 	 * and we need to allocate a new one of those as well.
 	 */
 
-	if (fa &&
-	    fa->fa_info->fib_priority == fi->fib_priority) {
+	if (fa && fa->fa_info->fib_priority == fi->fib_priority) {
 		struct fib_alias *fa_orig;
 
 		err = -EEXIST;
@@ -1261,9 +1223,9 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 
 			fib_release_info(fi_drop);
 			if (state & FA_S_ACCESSED)
-			  rt_cache_flush(-1);
+				rt_cache_flush(-1);
 
-			    goto succeeded;
+			goto succeeded;
 		}
 		/* Error if we find a perfect match which
 		 * uses the same scope, type, and nexthop
@@ -1285,7 +1247,7 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 			fa = fa_orig;
 	}
 	err = -ENOENT;
-	if (!(nlhdr->nlmsg_flags&NLM_F_CREATE))
+	if (!(nlhdr->nlmsg_flags & NLM_F_CREATE))
 		goto out;
 
 	err = -ENOBUFS;
@@ -1298,9 +1260,6 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 	new_fa->fa_type = type;
 	new_fa->fa_scope = r->rtm_scope;
 	new_fa->fa_state = 0;
-#if 0
-	new_fa->dst = NULL;
-#endif
 	/*
 	 * Insert new entry to the list.
 	 */
@@ -1314,8 +1273,7 @@ fn_trie_insert(struct fib_table *tb, struct rtmsg *r, struct kern_rta *rta,
 
 	write_lock_bh(&fib_lock);
 
-	list_add_tail(&new_fa->fa_list,
-		 (fa ? &fa->fa_list : fa_head));
+	list_add_tail(&new_fa->fa_list, (fa ? &fa->fa_list : fa_head));
 
 	write_unlock_bh(&fib_lock);
 
@@ -1328,7 +1286,7 @@ out_free_new_fa:
 	kmem_cache_free(fn_alias_kmem, new_fa);
 out:
 	fib_release_info(fi);
-err:;
+err:
 	return err;
 }
 
@@ -1342,7 +1300,6 @@ static inline int check_leaf(struct trie *t, struct leaf *l,  t_key key, int *pl
 	struct hlist_node *node;
 
 	hlist_for_each_entry(li, node, hhead, hlist) {
-
 		i = li->plen;
 		mask = ntohl(inet_make_mask(i));
 		if (l->key != (key & mask))
@@ -1370,13 +1327,18 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
 	struct node *n;
 	struct tnode *pn;
 	int pos, bits;
-	t_key key=ntohl(flp->fl4_dst);
+	t_key key = ntohl(flp->fl4_dst);
 	int chopped_off;
 	t_key cindex = 0;
 	int current_prefix_length = KEYLENGTH;
+	struct tnode *cn;
+	t_key node_prefix, key_prefix, pref_mismatch;
+	int mp;
+
 	n = t->trie;
 
 	read_lock(&fib_lock);
+
 	if (!n)
 		goto failed;
 
@@ -1393,8 +1355,7 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
 	pn = (struct tnode *) n;
 	chopped_off = 0;
 
-        while (pn) {
-
+	while (pn) {
 		pos = pn->pos;
 		bits = pn->bits;
 
@@ -1410,130 +1371,129 @@ fn_trie_lookup(struct fib_table *tb, const struct flowi *flp, struct fib_result
 			goto backtrace;
 		}
 
-		if (IS_TNODE(n)) {
+		if (IS_LEAF(n)) {
+			if ((ret = check_leaf(t, (struct leaf *)n, key, &plen, flp, res)) <= 0)
+				goto found;
+			else
+				goto backtrace;
+		}
+
 #define HL_OPTIMIZE
 #ifdef HL_OPTIMIZE
-			struct tnode *cn = (struct tnode *)n;
-			t_key node_prefix, key_prefix, pref_mismatch;
-			int mp;
+		cn = (struct tnode *)n;
 
-			/*
-			 * It's a tnode, and we can do some extra checks here if we
-			 * like, to avoid descending into a dead-end branch.
-			 * This tnode is in the parent's child array at index
-			 * key[p_pos..p_pos+p_bits] but potentially with some bits
-			 * chopped off, so in reality the index may be just a
-			 * subprefix, padded with zero at the end.
-			 * We can also take a look at any skipped bits in this
-			 * tnode - everything up to p_pos is supposed to be ok,
-			 * and the non-chopped bits of the index (se previous
-			 * paragraph) are also guaranteed ok, but the rest is
-			 * considered unknown.
-			 *
-			 * The skipped bits are key[pos+bits..cn->pos].
-			 */
-		
-			/* If current_prefix_length < pos+bits, we are already doing
-			 * actual prefix  matching, which means everything from
-			 * pos+(bits-chopped_off) onward must be zero along some
-			 * branch of this subtree - otherwise there is *no* valid
-			 * prefix present. Here we can only check the skipped
-			 * bits. Remember, since we have already indexed into the
-			 * parent's child array, we know that the bits we chopped of
-			 * *are* zero.
-			 */
+		/*
+		 * It's a tnode, and we can do some extra checks here if we
+		 * like, to avoid descending into a dead-end branch.
+		 * This tnode is in the parent's child array at index
+		 * key[p_pos..p_pos+p_bits] but potentially with some bits
+		 * chopped off, so in reality the index may be just a
+		 * subprefix, padded with zero at the end.
+		 * We can also take a look at any skipped bits in this
+		 * tnode - everything up to p_pos is supposed to be ok,
+		 * and the non-chopped bits of the index (se previous
+		 * paragraph) are also guaranteed ok, but the rest is
+		 * considered unknown.
+		 *
+		 * The skipped bits are key[pos+bits..cn->pos].
+		 */
 
-			/* NOTA BENE: CHECKING ONLY SKIPPED BITS FOR THE NEW NODE HERE */
-		
-			if (current_prefix_length < pos+bits) {
-				if (tkey_extract_bits(cn->key, current_prefix_length,
-						      cn->pos - current_prefix_length) != 0 ||
-				    !(cn->child[0]))
-					goto backtrace;
-			}
+		/* If current_prefix_length < pos+bits, we are already doing
+		 * actual prefix  matching, which means everything from
+		 * pos+(bits-chopped_off) onward must be zero along some
+		 * branch of this subtree - otherwise there is *no* valid
+		 * prefix present. Here we can only check the skipped
+		 * bits. Remember, since we have already indexed into the
+		 * parent's child array, we know that the bits we chopped of
+		 * *are* zero.
+		 */
 
-			/*
-			 * If chopped_off=0, the index is fully validated and we
-			 * only need to look at the skipped bits for this, the new,
-			 * tnode. What we actually want to do is to find out if
-			 * these skipped bits match our key perfectly, or if we will
-			 * have to count on finding a matching prefix further down,
-			 * because if we do, we would like to have some way of
-			 * verifying the existence of such a prefix at this point.
-			 */
+		/* NOTA BENE: CHECKING ONLY SKIPPED BITS FOR THE NEW NODE HERE */
 
-			/* The only thing we can do at this point is to verify that
-			 * any such matching prefix can indeed be a prefix to our
-			 * key, and if the bits in the node we are inspecting that
-			 * do not match our key are not ZERO, this cannot be true.
-			 * Thus, find out where there is a mismatch (before cn->pos)
-			 * and verify that all the mismatching bits are zero in the
-			 * new tnode's key.
-			 */
+		if (current_prefix_length < pos+bits) {
+			if (tkey_extract_bits(cn->key, current_prefix_length,
+						cn->pos - current_prefix_length) != 0 ||
+			    !(cn->child[0]))
+				goto backtrace;
+		}
 
-			/* Note: We aren't very concerned about the piece of the key
-			 * that precede pn->pos+pn->bits, since these have already been
-			 * checked. The bits after cn->pos aren't checked since these are
-			 * by definition "unknown" at this point. Thus, what we want to
-			 * see is if we are about to enter the "prefix matching" state,
-			 * and in that case verify that the skipped bits that will prevail
-			 * throughout this subtree are zero, as they have to be if we are
-			 * to find a matching prefix.
-			 */
+		/*
+		 * If chopped_off=0, the index is fully validated and we
+		 * only need to look at the skipped bits for this, the new,
+		 * tnode. What we actually want to do is to find out if
+		 * these skipped bits match our key perfectly, or i