#define MAX_STAT_DEPTH 32
-#define KEYLENGTH (8*sizeof(t_key))
+#define KEYLENGTH (8*sizeof(t_key))
+#define KEY_MAX ((t_key)~0)
typedef unsigned int t_key;
-#define T_TNODE 0
-#define T_LEAF 1
-#define NODE_TYPE_MASK 0x1UL
-#define NODE_TYPE(node) ((node)->parent & NODE_TYPE_MASK)
+#define IS_TNODE(n) ((n)->bits)
+#define IS_LEAF(n) (!(n)->bits)
-#define IS_TNODE(n) (!(n->parent & T_LEAF))
-#define IS_LEAF(n) (n->parent & T_LEAF)
+#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> (_kv)->pos)
-struct rt_trie_node {
- unsigned long parent;
- t_key key;
-};
-
-struct leaf {
- unsigned long parent;
+struct tnode {
t_key key;
- struct hlist_head list;
+ unsigned char bits; /* 2log(KEYLENGTH) bits needed */
+ unsigned char pos; /* 2log(KEYLENGTH) bits needed */
+ unsigned char slen;
+ struct tnode __rcu *parent;
struct rcu_head rcu;
+ union {
+ /* The fields in this struct are valid if bits > 0 (TNODE) */
+ struct {
+ t_key empty_children; /* KEYLENGTH bits needed */
+ t_key full_children; /* KEYLENGTH bits needed */
+ struct tnode __rcu *child[0];
+ };
+ /* This list pointer if valid if bits == 0 (LEAF) */
+ struct hlist_head list;
+ };
};
struct leaf_info {
struct rcu_head rcu;
};
-struct tnode {
- unsigned long parent;
- t_key key;
- unsigned char pos; /* 2log(KEYLENGTH) bits needed */
- unsigned char bits; /* 2log(KEYLENGTH) bits needed */
- unsigned int full_children; /* KEYLENGTH bits needed */
- unsigned int empty_children; /* KEYLENGTH bits needed */
- union {
- struct rcu_head rcu;
- struct tnode *tnode_free;
- };
- struct rt_trie_node __rcu *child[0];
-};
-
#ifdef CONFIG_IP_FIB_TRIE_STATS
struct trie_use_stats {
unsigned int gets;
};
struct trie {
- struct rt_trie_node __rcu *trie;
+ struct tnode __rcu *trie;
#ifdef CONFIG_IP_FIB_TRIE_STATS
- struct trie_use_stats stats;
+ struct trie_use_stats __percpu *stats;
#endif
};
-static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *n,
- int wasfull);
-static struct rt_trie_node *resize(struct trie *t, struct tnode *tn);
-static struct tnode *inflate(struct trie *t, struct tnode *tn);
-static struct tnode *halve(struct trie *t, struct tnode *tn);
-/* tnodes to free after resize(); protected by RTNL */
-static struct tnode *tnode_free_head;
+static void resize(struct trie *t, struct tnode *tn);
static size_t tnode_free_size;
/*
static struct kmem_cache *fn_alias_kmem __read_mostly;
static struct kmem_cache *trie_leaf_kmem __read_mostly;
-/*
- * caller must hold RTNL
- */
-static inline struct tnode *node_parent(const struct rt_trie_node *node)
-{
- unsigned long parent;
-
- parent = rcu_dereference_index_check(node->parent, lockdep_rtnl_is_held());
+/* caller must hold RTNL */
+#define node_parent(n) rtnl_dereference((n)->parent)
- return (struct tnode *)(parent & ~NODE_TYPE_MASK);
-}
+/* caller must hold RCU read lock or RTNL */
+#define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
-/*
- * caller must hold RCU read lock or RTNL
- */
-static inline struct tnode *node_parent_rcu(const struct rt_trie_node *node)
+/* wrapper for rcu_assign_pointer */
+static inline void node_set_parent(struct tnode *n, struct tnode *tp)
{
- unsigned long parent;
-
- parent = rcu_dereference_index_check(node->parent, rcu_read_lock_held() ||
- lockdep_rtnl_is_held());
-
- return (struct tnode *)(parent & ~NODE_TYPE_MASK);
+ if (n)
+ rcu_assign_pointer(n->parent, tp);
}
-/* Same as rcu_assign_pointer
- * but that macro() assumes that value is a pointer.
+#define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER((n)->parent, p)
+
+/* This provides us with the number of children in this node, in the case of a
+ * leaf this will return 0 meaning none of the children are accessible.
*/
-static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr)
+static inline unsigned long tnode_child_length(const struct tnode *tn)
{
- smp_wmb();
- node->parent = (unsigned long)ptr | NODE_TYPE(node);
+ return (1ul << tn->bits) & ~(1ul);
}
-/*
- * caller must hold RTNL
- */
-static inline struct rt_trie_node *tnode_get_child(const struct tnode *tn, unsigned int i)
+/* caller must hold RTNL */
+static inline struct tnode *tnode_get_child(const struct tnode *tn,
+ unsigned long i)
{
- BUG_ON(i >= 1U << tn->bits);
-
return rtnl_dereference(tn->child[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)
+/* caller must hold RCU read lock or RTNL */
+static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
+ unsigned long i)
{
- BUG_ON(i >= 1U << tn->bits);
-
return rcu_dereference_rtnl(tn->child[i]);
}
-static inline int tnode_child_length(const struct tnode *tn)
-{
- return 1 << tn->bits;
-}
-
-static inline t_key mask_pfx(t_key k, unsigned int l)
-{
- return (l == 0) ? 0 : k >> (KEYLENGTH-l) << (KEYLENGTH-l);
-}
-
-static inline t_key tkey_extract_bits(t_key a, unsigned int offset, unsigned int bits)
-{
- if (offset < KEYLENGTH)
- return ((t_key)(a << offset)) >> (KEYLENGTH - bits);
- else
- return 0;
-}
-
-static inline int tkey_equals(t_key a, t_key b)
-{
- return a == b;
-}
-
-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;
-}
-
-static inline int tkey_mismatch(t_key a, int offset, t_key b)
-{
- t_key diff = a ^ b;
- int i = offset;
-
- if (!diff)
- return 0;
- while ((diff << i) >> (KEYLENGTH-1) == 0)
- i++;
- return i;
-}
-
-/*
- To understand this stuff, an understanding of keys and all their bits is
- necessary. Every node in the trie has a key associated with it, but not
- all of the bits in that key are significant.
-
- Consider a node 'n' and its parent 'tp'.
-
- If n is a leaf, every bit in its key is significant. Its presence is
- necessitated by path compression, since during a tree traversal (when
- searching for a leaf - unless we are doing an insertion) we will completely
- ignore all skipped bits we encounter. Thus we need to verify, at the end of
- a potentially successful search, that we have indeed been walking the
- correct key path.
-
- Note that we can never "miss" the correct key in the tree if present by
- following the wrong path. Path compression ensures that segments of the key
- that are the same for all keys with a given prefix are skipped, but the
- skipped part *is* identical for each node in the subtrie below the skipped
- bit! trie_insert() in this implementation takes care of that - note the
- call to tkey_sub_equals() in trie_insert().
-
- if n is an internal node - a 'tnode' here, the various parts of its key
- have many different meanings.
-
- Example:
- _________________________________________________________________
- | 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
-
- 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
- not use them for anything.
-
- The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
- index into the parent's child array. That is, they will be used to find
- 'n' among tp's children.
-
- The bits from (tp->pos + tp->bits) to (n->pos - 1) - "S" - are skipped bits
- for the node n.
-
- All the bits we have seen so far are significant to the node n. The rest
- of the bits are really not needed or indeed known in n->key.
-
- The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
- n's child array, and will of course be different for each child.
-
-
- The rest of the bits, from (n->pos + n->bits) onward, are completely unknown
- at this point.
-
-*/
-
-static inline void check_tnode(const struct tnode *tn)
-{
- WARN_ON(tn && tn->pos+tn->bits > 32);
-}
+/* To understand this stuff, an understanding of keys and all their bits is
+ * necessary. Every node in the trie has a key associated with it, but not
+ * all of the bits in that key are significant.
+ *
+ * Consider a node 'n' and its parent 'tp'.
+ *
+ * If n is a leaf, every bit in its key is significant. Its presence is
+ * necessitated by path compression, since during a tree traversal (when
+ * searching for a leaf - unless we are doing an insertion) we will completely
+ * ignore all skipped bits we encounter. Thus we need to verify, at the end of
+ * a potentially successful search, that we have indeed been walking the
+ * correct key path.
+ *
+ * Note that we can never "miss" the correct key in the tree if present by
+ * following the wrong path. Path compression ensures that segments of the key
+ * that are the same for all keys with a given prefix are skipped, but the
+ * skipped part *is* identical for each node in the subtrie below the skipped
+ * bit! trie_insert() in this implementation takes care of that.
+ *
+ * if n is an internal node - a 'tnode' here, the various parts of its key
+ * have many different meanings.
+ *
+ * Example:
+ * _________________________________________________________________
+ * | i | i | i | i | i | i | i | N | N | N | S | S | S | S | S | C |
+ * -----------------------------------------------------------------
+ * 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
+ *
+ * _________________________________________________________________
+ * | C | C | C | u | u | u | u | u | u | u | u | u | u | u | u | u |
+ * -----------------------------------------------------------------
+ * 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
+ *
+ * tp->pos = 22
+ * tp->bits = 3
+ * n->pos = 13
+ * n->bits = 4
+ *
+ * First, let's just ignore the bits that come before the parent tp, that is
+ * the bits from (tp->pos + tp->bits) to 31. They are *known* but at this
+ * point we do not use them for anything.
+ *
+ * The bits from (tp->pos) to (tp->pos + tp->bits - 1) - "N", above - are the
+ * index into the parent's child array. That is, they will be used to find
+ * 'n' among tp's children.
+ *
+ * The bits from (n->pos + n->bits) to (tn->pos - 1) - "S" - are skipped bits
+ * for the node n.
+ *
+ * All the bits we have seen so far are significant to the node n. The rest
+ * of the bits are really not needed or indeed known in n->key.
+ *
+ * The bits from (n->pos) to (n->pos + n->bits - 1) - "C" - are the index into
+ * n's child array, and will of course be different for each child.
+ *
+ * The rest of the bits, from 0 to (n->pos + n->bits), are completely unknown
+ * at this point.
+ */
static const int halve_threshold = 25;
static const int inflate_threshold = 50;
call_rcu(&fa->rcu, __alias_free_mem);
}
-static void __leaf_free_rcu(struct rcu_head *head)
-{
- struct leaf *l = container_of(head, struct leaf, rcu);
- kmem_cache_free(trie_leaf_kmem, l);
-}
+#define TNODE_KMALLOC_MAX \
+ ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct tnode *))
-static inline void free_leaf(struct leaf *l)
+static void __node_free_rcu(struct rcu_head *head)
{
- call_rcu(&l->rcu, __leaf_free_rcu);
+ struct tnode *n = container_of(head, struct tnode, rcu);
+
+ if (IS_LEAF(n))
+ kmem_cache_free(trie_leaf_kmem, n);
+ else if (n->bits <= TNODE_KMALLOC_MAX)
+ kfree(n);
+ else
+ vfree(n);
}
+#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);
return vzalloc(size);
}
-static void __tnode_free_rcu(struct rcu_head *head)
-{
- struct tnode *tn = container_of(head, struct tnode, rcu);
- size_t size = sizeof(struct tnode) +
- (sizeof(struct rt_trie_node *) << tn->bits);
-
- if (size <= PAGE_SIZE)
- kfree(tn);
- else
- vfree(tn);
-}
-
-static inline void tnode_free(struct tnode *tn)
+static inline void empty_child_inc(struct tnode *n)
{
- if (IS_LEAF(tn))
- free_leaf((struct leaf *) tn);
- else
- call_rcu(&tn->rcu, __tnode_free_rcu);
+ ++n->empty_children ? : ++n->full_children;
}
-static void tnode_free_safe(struct tnode *tn)
+static inline void empty_child_dec(struct tnode *n)
{
- BUG_ON(IS_LEAF(tn));
- tn->tnode_free = tnode_free_head;
- tnode_free_head = tn;
- tnode_free_size += sizeof(struct tnode) +
- (sizeof(struct rt_trie_node *) << tn->bits);
-}
-
-static void tnode_free_flush(void)
-{
- struct tnode *tn;
-
- while ((tn = tnode_free_head)) {
- tnode_free_head = tn->tnode_free;
- tn->tnode_free = NULL;
- tnode_free(tn);
- }
-
- if (tnode_free_size >= PAGE_SIZE * sync_pages) {
- tnode_free_size = 0;
- synchronize_rcu();
- }
+ n->empty_children-- ? : n->full_children--;
}
-static struct leaf *leaf_new(void)
+static struct tnode *leaf_new(t_key key)
{
- struct leaf *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+ struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
if (l) {
- l->parent = T_LEAF;
+ l->parent = NULL;
+ /* set key and pos to reflect full key value
+ * any trailing zeros in the key should be ignored
+ * as the nodes are searched
+ */
+ l->key = key;
+ l->slen = 0;
+ l->pos = 0;
+ /* set bits to 0 indicating we are not a tnode */
+ l->bits = 0;
+
INIT_HLIST_HEAD(&l->list);
}
return l;
static struct tnode *tnode_new(t_key key, int pos, int bits)
{
- size_t sz = sizeof(struct tnode) + (sizeof(struct rt_trie_node *) << bits);
+ size_t sz = offsetof(struct tnode, child[1ul << bits]);
struct tnode *tn = tnode_alloc(sz);
+ unsigned int shift = pos + bits;
+
+ /* verify bits and pos their msb bits clear and values are valid */
+ BUG_ON(!bits || (shift > KEYLENGTH));
if (tn) {
- tn->parent = T_TNODE;
+ tn->parent = NULL;
+ tn->slen = pos;
tn->pos = pos;
tn->bits = bits;
- tn->key = key;
- tn->full_children = 0;
- tn->empty_children = 1<<bits;
+ tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
+ if (bits == KEYLENGTH)
+ tn->full_children = 1;
+ else
+ tn->empty_children = 1ul << bits;
}
pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
- sizeof(struct rt_trie_node *) << bits);
+ sizeof(struct tnode *) << bits);
return tn;
}
-/*
- * Check whether a tnode 'n' is "full", i.e. it is an internal node
+/* Check whether a tnode 'n' is "full", i.e. it is an internal node
* and no bits are skipped. See discussion in dyntree paper p. 6
*/
-
-static inline int tnode_full(const struct tnode *tn, const struct rt_trie_node *n)
+static inline int tnode_full(const struct tnode *tn, const struct tnode *n)
{
- if (n == NULL || IS_LEAF(n))
- return 0;
-
- return ((struct tnode *) n)->pos == tn->pos + tn->bits;
+ return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
}
-static inline void put_child(struct tnode *tn, int i,
- struct rt_trie_node *n)
-{
- tnode_put_child_reorg(tn, i, n, -1);
-}
-
- /*
- * Add a child at position i overwriting the old value.
- * Update the value of full_children and empty_children.
- */
-
-static void tnode_put_child_reorg(struct tnode *tn, int i, struct rt_trie_node *n,
- int wasfull)
+/* Add a child at position i overwriting the old value.
+ * Update the value of full_children and empty_children.
+ */
+static void put_child(struct tnode *tn, unsigned long i, struct tnode *n)
{
- struct rt_trie_node *chi = rtnl_dereference(tn->child[i]);
- int isfull;
+ struct tnode *chi = tnode_get_child(tn, i);
+ int isfull, wasfull;
- BUG_ON(i >= 1<<tn->bits);
+ BUG_ON(i >= tnode_child_length(tn));
- /* update emptyChildren */
+ /* update emptyChildren, overflow into fullChildren */
if (n == NULL && chi != NULL)
- tn->empty_children++;
- else if (n != NULL && chi == NULL)
- tn->empty_children--;
+ empty_child_inc(tn);
+ if (n != NULL && chi == NULL)
+ empty_child_dec(tn);
/* update fullChildren */
- if (wasfull == -1)
- wasfull = tnode_full(tn, chi);
-
+ 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);
+ if (n && (tn->slen < n->slen))
+ tn->slen = n->slen;
rcu_assign_pointer(tn->child[i], n);
}
-#define MAX_WORK 10
-static struct rt_trie_node *resize(struct trie *t, struct tnode *tn)
+static void update_children(struct tnode *tn)
{
- int i;
- struct tnode *old_tn;
- int inflate_threshold_use;
- int halve_threshold_use;
- int max_work;
+ unsigned long i;
- if (!tn)
- return NULL;
+ /* update all of the child parent pointers */
+ for (i = tnode_child_length(tn); i;) {
+ struct tnode *inode = tnode_get_child(tn, --i);
- pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
- tn, inflate_threshold, halve_threshold);
+ if (!inode)
+ continue;
- /* No children */
- if (tn->empty_children == tnode_child_length(tn)) {
- tnode_free_safe(tn);
- return NULL;
+ /* Either update the children of a tnode that
+ * already belongs to us or update the child
+ * to point to ourselves.
+ */
+ if (node_parent(inode) == tn)
+ update_children(inode);
+ else
+ node_set_parent(inode, tn);
}
- /* One child */
- if (tn->empty_children == tnode_child_length(tn) - 1)
- goto one_child;
- /*
- * Double as long as the resulting node has a number of
- * nonempty nodes that are above the threshold.
- */
-
- /*
- * From "Implementing a dynamic compressed trie" by Stefan Nilsson of
- * the Helsinki University of Technology and Matti Tikkanen of Nokia
- * Telecommunications, page 6:
- * "A node is doubled if the ratio of non-empty children to all
- * children in the *doubled* node is at least 'high'."
- *
- * 'high' in this instance is the variable 'inflate_threshold'. It
- * is expressed as a percentage, so we multiply it with
- * tnode_child_length() and instead of multiplying by 2 (since the
- * child array will be doubled by inflate()) and multiplying
- * the left-hand side by 100 (to handle the percentage thing) we
- * multiply the left-hand side by 50.
- *
- * The left-hand side may look a bit weird: tnode_child_length(tn)
- * - tn->empty_children is of course the number of non-null children
- * in the current node. tn->full_children is the number of "full"
- * children, that is non-null tnodes with a skip value of 0.
- * All of those will be doubled in the resulting inflated tnode, so
- * we just count them one extra time here.
- *
- * A clearer way to write this would be:
- *
- * to_be_doubled = tn->full_children;
- * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
- * tn->full_children;
- *
- * new_child_length = tnode_child_length(tn) * 2;
- *
- * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
- * new_child_length;
- * if (new_fill_factor >= inflate_threshold)
- *
- * ...and so on, tho it would mess up the while () loop.
- *
- * anyway,
- * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
- * inflate_threshold
- *
- * avoid a division:
- * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
- * inflate_threshold * new_child_length
- *
- * 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
- *
- * expand new_child_length:
- * 100 * (tnode_child_length(tn) - tn->empty_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 *
- * tnode_child_length(tn)
- *
- */
+}
- check_tnode(tn);
+static inline void put_child_root(struct tnode *tp, struct trie *t,
+ t_key key, struct tnode *n)
+{
+ if (tp)
+ put_child(tp, get_index(key, tp), n);
+ else
+ rcu_assign_pointer(t->trie, n);
+}
- /* Keep root node larger */
+static inline void tnode_free_init(struct tnode *tn)
+{
+ tn->rcu.next = NULL;
+}
- if (!node_parent((struct rt_trie_node *)tn)) {
- inflate_threshold_use = inflate_threshold_root;
- halve_threshold_use = halve_threshold_root;
- } else {
- inflate_threshold_use = inflate_threshold;
- halve_threshold_use = halve_threshold;
- }
+static inline void tnode_free_append(struct tnode *tn, struct tnode *n)
+{
+ n->rcu.next = tn->rcu.next;
+ tn->rcu.next = &n->rcu;
+}
- max_work = MAX_WORK;
- while ((tn->full_children > 0 && max_work-- &&
- 50 * (tn->full_children + tnode_child_length(tn)
- - tn->empty_children)
- >= inflate_threshold_use * tnode_child_length(tn))) {
+static void tnode_free(struct tnode *tn)
+{
+ struct callback_head *head = &tn->rcu;
- old_tn = tn;
- tn = inflate(t, tn);
+ while (head) {
+ head = head->next;
+ tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
+ node_free(tn);
- if (IS_ERR(tn)) {
- tn = old_tn;
-#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.resize_node_skipped++;
-#endif
- break;
- }
+ tn = container_of(head, struct tnode, rcu);
}
- check_tnode(tn);
-
- /* Return if at least one inflate is run */
- if (max_work != MAX_WORK)
- return (struct rt_trie_node *) tn;
-
- /*
- * Halve as long as the number of empty children in this
- * node is above threshold.
- */
-
- max_work = MAX_WORK;
- while (tn->bits > 1 && max_work-- &&
- 100 * (tnode_child_length(tn) - tn->empty_children) <
- halve_threshold_use * tnode_child_length(tn)) {
-
- old_tn = tn;
- tn = halve(t, tn);
- if (IS_ERR(tn)) {
- tn = old_tn;
-#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.resize_node_skipped++;
-#endif
- break;
- }
+ if (tnode_free_size >= PAGE_SIZE * sync_pages) {
+ tnode_free_size = 0;
+ synchronize_rcu();
}
+}
+static void replace(struct trie *t, struct tnode *oldtnode, struct tnode *tn)
+{
+ struct tnode *tp = node_parent(oldtnode);
+ unsigned long i;
- /* Only one child remains */
- if (tn->empty_children == tnode_child_length(tn) - 1) {
-one_child:
- for (i = 0; i < tnode_child_length(tn); i++) {
- struct rt_trie_node *n;
-
- n = rtnl_dereference(tn->child[i]);
- if (!n)
- continue;
+ /* setup the parent pointer out of and back into this node */
+ NODE_INIT_PARENT(tn, tp);
+ put_child_root(tp, t, tn->key, tn);
- /* compress one level */
+ /* update all of the child parent pointers */
+ update_children(tn);
- node_set_parent(n, NULL);
- tnode_free_safe(tn);
- return n;
- }
- }
- return (struct rt_trie_node *) tn;
-}
+ /* all pointers should be clean so we are done */
+ tnode_free(oldtnode);
+ /* resize children now that oldtnode is freed */
+ for (i = tnode_child_length(tn); i;) {
+ struct tnode *inode = tnode_get_child(tn, --i);
-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);
+ /* resize child node */
+ if (tnode_full(tn, inode))
+ resize(t, inode);
}
- tnode_free(tn);
}
-static struct tnode *inflate(struct trie *t, struct tnode *tn)
+static int inflate(struct trie *t, struct tnode *oldtnode)
{
- struct tnode *oldtnode = tn;
- int olen = tnode_child_length(tn);
- int i;
+ struct tnode *tn;
+ unsigned long i;
+ t_key m;
pr_debug("In inflate\n");
- tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits + 1);
-
+ tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
if (!tn)
- return ERR_PTR(-ENOMEM);
-
- /*
- * Preallocate and store tnodes before the actual work so we
- * don't get into an inconsistent state if memory allocation
- * fails. In case of failure we return the oldnode and inflate
- * of tnode is ignored.
- */
-
- for (i = 0; i < olen; i++) {
- struct tnode *inode;
-
- inode = (struct tnode *) tnode_get_child(oldtnode, i);
- if (inode &&
- IS_TNODE(inode) &&
- inode->pos == oldtnode->pos + oldtnode->bits &&
- inode->bits > 1) {
- struct tnode *left, *right;
- t_key m = ~0U << (KEYLENGTH - 1) >> inode->pos;
-
- left = tnode_new(inode->key&(~m), inode->pos + 1,
- inode->bits - 1);
- if (!left)
- goto nomem;
-
- right = tnode_new(inode->key|m, inode->pos + 1,
- inode->bits - 1);
-
- if (!right) {
- tnode_free(left);
- goto nomem;
- }
+ return -ENOMEM;
- put_child(tn, 2*i, (struct rt_trie_node *) left);
- put_child(tn, 2*i+1, (struct rt_trie_node *) right);
- }
- }
+ /* prepare oldtnode to be freed */
+ tnode_free_init(oldtnode);
- for (i = 0; i < olen; i++) {
- struct tnode *inode;
- struct rt_trie_node *node = tnode_get_child(oldtnode, i);
- struct tnode *left, *right;
- int size, j;
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = tnode_child_length(oldtnode), m = 1u << tn->pos; i;) {
+ struct tnode *inode = tnode_get_child(oldtnode, --i);
+ struct tnode *node0, *node1;
+ unsigned long j, k;
/* An empty child */
- if (node == NULL)
+ if (inode == NULL)
continue;
/* A leaf or an internal node with skipped bits */
-
- if (IS_LEAF(node) || ((struct tnode *) node)->pos >
- tn->pos + tn->bits - 1) {
- put_child(tn,
- tkey_extract_bits(node->key, oldtnode->pos, oldtnode->bits + 1),
- node);
+ if (!tnode_full(oldtnode, inode)) {
+ put_child(tn, get_index(inode->key, tn), inode);
continue;
}
- /* An internal node with two children */
- inode = (struct tnode *) node;
+ /* drop the node in the old tnode free list */
+ tnode_free_append(oldtnode, inode);
+ /* An internal node with two children */
if (inode->bits == 1) {
- put_child(tn, 2*i, rtnl_dereference(inode->child[0]));
- put_child(tn, 2*i+1, rtnl_dereference(inode->child[1]));
-
- tnode_free_safe(inode);
+ put_child(tn, 2 * i + 1, tnode_get_child(inode, 1));
+ put_child(tn, 2 * i, tnode_get_child(inode, 0));
continue;
}
- /* 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
+ * ones, 'node0' and 'node1', 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
+ * node0's key and "1" in node1'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)
+ * (tn->pos) - is the one that will differ between
+ * node0 and node1. So... we synthesize that bit in the
+ * two new keys.
*/
+ node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
+ if (!node1)
+ goto nomem;
+ node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
+
+ tnode_free_append(tn, node1);
+ if (!node0)
+ goto nomem;
+ tnode_free_append(tn, node0);
+
+ /* populate child pointers in new nodes */
+ for (k = tnode_child_length(inode), j = k / 2; j;) {
+ put_child(node1, --j, tnode_get_child(inode, --k));
+ put_child(node0, j, tnode_get_child(inode, j));
+ put_child(node1, --j, tnode_get_child(inode, --k));
+ put_child(node0, j, tnode_get_child(inode, j));
+ }
- /* Use the old key, but set the new significant
- * bit to zero.
- */
+ /* link new nodes to parent */
+ NODE_INIT_PARENT(node1, tn);
+ NODE_INIT_PARENT(node0, tn);
- left = (struct tnode *) tnode_get_child(tn, 2*i);
- put_child(tn, 2*i, NULL);
+ /* link parent to nodes */
+ put_child(tn, 2 * i + 1, node1);
+ put_child(tn, 2 * i, node0);
+ }
- BUG_ON(!left);
+ /* setup the parent pointers into and out of this node */
+ replace(t, oldtnode, tn);
+
+ return 0;
+nomem:
+ /* all pointers should be clean so we are done */
+ tnode_free(tn);
+ return -ENOMEM;
+}
- right = (struct tnode *) tnode_get_child(tn, 2*i+1);
- put_child(tn, 2*i+1, NULL);
+static int halve(struct trie *t, struct tnode *oldtnode)
+{
+ struct tnode *tn;
+ unsigned long i;
+
+ pr_debug("In halve\n");
+
+ tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
+ if (!tn)
+ return -ENOMEM;
+
+ /* prepare oldtnode to be freed */
+ tnode_free_init(oldtnode);
+
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = tnode_child_length(oldtnode); i;) {
+ struct tnode *node1 = tnode_get_child(oldtnode, --i);
+ struct tnode *node0 = tnode_get_child(oldtnode, --i);
+ struct tnode *inode;
- BUG_ON(!right);
+ /* At least one of the children is empty */
+ if (!node1 || !node0) {
+ put_child(tn, i / 2, node1 ? : node0);
+ continue;
+ }
- size = tnode_child_length(left);
- for (j = 0; j < size; j++) {
- put_child(left, j, rtnl_dereference(inode->child[j]));
- put_child(right, j, rtnl_dereference(inode->child[j + size]));
+ /* Two nonempty children */
+ inode = tnode_new(node0->key, oldtnode->pos, 1);
+ if (!inode) {
+ tnode_free(tn);
+ return -ENOMEM;
}
- put_child(tn, 2*i, resize(t, left));
- put_child(tn, 2*i+1, resize(t, right));
+ tnode_free_append(tn, inode);
+
+ /* initialize pointers out of node */
+ put_child(inode, 1, node1);
+ put_child(inode, 0, node0);
+ NODE_INIT_PARENT(inode, tn);
- tnode_free_safe(inode);
+ /* link parent to node */
+ put_child(tn, i / 2, inode);
}
- tnode_free_safe(oldtnode);
- return tn;
-nomem:
- tnode_clean_free(tn);
- return ERR_PTR(-ENOMEM);
+
+ /* setup the parent pointers into and out of this node */
+ replace(t, oldtnode, tn);
+
+ return 0;
}
-static struct tnode *halve(struct trie *t, struct tnode *tn)
+static void collapse(struct trie *t, struct tnode *oldtnode)
{
- struct tnode *oldtnode = tn;
- struct rt_trie_node *left, *right;
- int i;
- int olen = tnode_child_length(tn);
+ struct tnode *n, *tp;
+ unsigned long i;
- pr_debug("In halve\n");
+ /* scan the tnode looking for that one child that might still exist */
+ for (n = NULL, i = tnode_child_length(oldtnode); !n && i;)
+ n = tnode_get_child(oldtnode, --i);
- tn = tnode_new(oldtnode->key, oldtnode->pos, oldtnode->bits - 1);
+ /* compress one level */
+ tp = node_parent(oldtnode);
+ put_child_root(tp, t, oldtnode->key, n);
+ node_set_parent(n, tp);
- if (!tn)
- return ERR_PTR(-ENOMEM);
+ /* drop dead node */
+ node_free(oldtnode);
+}
- /*
- * Preallocate and store tnodes before the actual work so we
- * don't get into an inconsistent state if memory allocation
- * fails. In case of failure we return the oldnode and halve
- * of tnode is ignored.
+static unsigned char update_suffix(struct tnode *tn)
+{
+ unsigned char slen = tn->pos;
+ unsigned long stride, i;
+
+ /* search though the list of children looking for nodes that might
+ * have a suffix greater than the one we currently have. This is
+ * why we start with a stride of 2 since a stride of 1 would
+ * represent the nodes with suffix length equal to tn->pos
*/
+ for (i = 0, stride = 0x2ul ; i < tnode_child_length(tn); i += stride) {
+ struct tnode *n = tnode_get_child(tn, i);
- for (i = 0; i < olen; i += 2) {
- left = tnode_get_child(oldtnode, i);
- right = tnode_get_child(oldtnode, i+1);
+ if (!n || (n->slen <= slen))
+ continue;
- /* Two nonempty children */
- if (left && right) {
- struct tnode *newn;
+ /* update stride and slen based on new value */
+ stride <<= (n->slen - slen);
+ slen = n->slen;
+ i &= ~(stride - 1);
+
+ /* if slen covers all but the last bit we can stop here
+ * there will be nothing longer than that since only node
+ * 0 and 1 << (bits - 1) could have that as their suffix
+ * length.
+ */
+ if ((slen + 1) >= (tn->pos + tn->bits))
+ break;
+ }
+
+ tn->slen = slen;
+
+ return slen;
+}
- newn = tnode_new(left->key, tn->pos + tn->bits, 1);
+/* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+ * the Helsinki University of Technology and Matti Tikkanen of Nokia
+ * Telecommunications, page 6:
+ * "A node is doubled if the ratio of non-empty children to all
+ * children in the *doubled* node is at least 'high'."
+ *
+ * 'high' in this instance is the variable 'inflate_threshold'. It
+ * is expressed as a percentage, so we multiply it with
+ * tnode_child_length() and instead of multiplying by 2 (since the
+ * child array will be doubled by inflate()) and multiplying
+ * the left-hand side by 100 (to handle the percentage thing) we
+ * multiply the left-hand side by 50.
+ *
+ * The left-hand side may look a bit weird: tnode_child_length(tn)
+ * - tn->empty_children is of course the number of non-null children
+ * in the current node. tn->full_children is the number of "full"
+ * children, that is non-null tnodes with a skip value of 0.
+ * All of those will be doubled in the resulting inflated tnode, so
+ * we just count them one extra time here.
+ *
+ * A clearer way to write this would be:
+ *
+ * to_be_doubled = tn->full_children;
+ * not_to_be_doubled = tnode_child_length(tn) - tn->empty_children -
+ * tn->full_children;
+ *
+ * new_child_length = tnode_child_length(tn) * 2;
+ *
+ * new_fill_factor = 100 * (not_to_be_doubled + 2*to_be_doubled) /
+ * new_child_length;
+ * if (new_fill_factor >= inflate_threshold)
+ *
+ * ...and so on, tho it would mess up the while () loop.
+ *
+ * anyway,
+ * 100 * (not_to_be_doubled + 2*to_be_doubled) / new_child_length >=
+ * inflate_threshold
+ *
+ * avoid a division:
+ * 100 * (not_to_be_doubled + 2*to_be_doubled) >=
+ * inflate_threshold * new_child_length
+ *
+ * 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
+ *
+ * expand new_child_length:
+ * 100 * (tnode_child_length(tn) - tn->empty_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 *
+ * tnode_child_length(tn)
+ *
+ */
+static bool should_inflate(const struct tnode *tp, const struct tnode *tn)
+{
+ unsigned long used = tnode_child_length(tn);
+ unsigned long threshold = used;
- if (!newn)
- goto nomem;
+ /* Keep root node larger */
+ threshold *= tp ? inflate_threshold : inflate_threshold_root;
+ used -= tn->empty_children;
+ used += tn->full_children;
- put_child(tn, i/2, (struct rt_trie_node *)newn);
+ /* if bits == KEYLENGTH then pos = 0, and will fail below */
+
+ return (used > 1) && tn->pos && ((50 * used) >= threshold);
+}
+
+static bool should_halve(const struct tnode *tp, const struct tnode *tn)
+{
+ unsigned long used = tnode_child_length(tn);
+ unsigned long threshold = used;
+
+ /* Keep root node larger */
+ threshold *= tp ? halve_threshold : halve_threshold_root;
+ used -= tn->empty_children;
+
+ /* if bits == KEYLENGTH then used = 100% on wrap, and will fail below */
+
+ return (used > 1) && (tn->bits > 1) && ((100 * used) < threshold);
+}
+
+static bool should_collapse(const struct tnode *tn)
+{
+ unsigned long used = tnode_child_length(tn);
+
+ used -= tn->empty_children;
+
+ /* account for bits == KEYLENGTH case */
+ if ((tn->bits == KEYLENGTH) && tn->full_children)
+ used -= KEY_MAX;
+
+ /* One child or none, time to drop us from the trie */
+ return used < 2;
+}
+
+#define MAX_WORK 10
+static void resize(struct trie *t, struct tnode *tn)
+{
+ struct tnode *tp = node_parent(tn);
+ struct tnode __rcu **cptr;
+ int max_work = MAX_WORK;
+
+ pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+ tn, inflate_threshold, halve_threshold);
+
+ /* track the tnode via the pointer from the parent instead of
+ * doing it ourselves. This way we can let RCU fully do its
+ * thing without us interfering
+ */
+ cptr = tp ? &tp->child[get_index(tn->key, tp)] : &t->trie;
+ BUG_ON(tn != rtnl_dereference(*cptr));
+
+ /* Double as long as the resulting node has a number of
+ * nonempty nodes that are above the threshold.
+ */
+ while (should_inflate(tp, tn) && max_work) {
+ if (inflate(t, tn)) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(t->stats->resize_node_skipped);
+#endif
+ break;
}
+ max_work--;
+ tn = rtnl_dereference(*cptr);
}
- for (i = 0; i < olen; i += 2) {
- struct tnode *newBinNode;
+ /* Return if at least one inflate is run */
+ if (max_work != MAX_WORK)
+ return;
+
+ /* Halve as long as the number of empty children in this
+ * node is above threshold.
+ */
+ while (should_halve(tp, tn) && max_work) {
+ if (halve(t, tn)) {
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(t->stats->resize_node_skipped);
+#endif
+ break;
+ }
+
+ max_work--;
+ tn = rtnl_dereference(*cptr);
+ }
- left = tnode_get_child(oldtnode, i);
- right = tnode_get_child(oldtnode, i+1);
+ /* Only one child remains */
+ if (should_collapse(tn)) {
+ collapse(t, tn);
+ return;
+ }
- /* At least one of the children is empty */
- if (left == NULL) {
- if (right == NULL) /* Both are empty */
- continue;
- put_child(tn, i/2, right);
- continue;
- }
+ /* Return if at least one deflate was run */
+ if (max_work != MAX_WORK)
+ return;
- if (right == NULL) {
- put_child(tn, i/2, left);
- continue;
- }
+ /* push the suffix length to the parent node */
+ if (tn->slen > tn->pos) {
+ unsigned char slen = update_suffix(tn);
- /* Two nonempty children */
- newBinNode = (struct tnode *) tnode_get_child(tn, i/2);
- put_child(tn, i/2, NULL);
- put_child(newBinNode, 0, left);
- put_child(newBinNode, 1, right);
- put_child(tn, i/2, resize(t, newBinNode));
+ if (tp && (slen > tp->slen))
+ tp->slen = slen;
}
- tnode_free_safe(oldtnode);
- return tn;
-nomem:
- tnode_clean_free(tn);
- return ERR_PTR(-ENOMEM);
}
/* readside must use rcu_read_lock currently dump routines
via get_fa_head and dump */
-static struct leaf_info *find_leaf_info(struct leaf *l, int plen)
+static struct leaf_info *find_leaf_info(struct tnode *l, int plen)
{
struct hlist_head *head = &l->list;
struct leaf_info *li;
return NULL;
}
-static inline struct list_head *get_fa_head(struct leaf *l, int plen)
+static inline struct list_head *get_fa_head(struct tnode *l, int plen)
{
struct leaf_info *li = find_leaf_info(l, plen);
return &li->falh;
}
-static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
+static void leaf_pull_suffix(struct tnode *l)
+{
+ struct tnode *tp = node_parent(l);
+
+ while (tp && (tp->slen > tp->pos) && (tp->slen > l->slen)) {
+ if (update_suffix(tp) > l->slen)
+ break;
+ tp = node_parent(tp);
+ }
+}
+
+static void leaf_push_suffix(struct tnode *l)
+{
+ struct tnode *tn = node_parent(l);
+
+ /* if this is a new leaf then tn will be NULL and we can sort
+ * out parent suffix lengths as a part of trie_rebalance
+ */
+ while (tn && (tn->slen < l->slen)) {
+ tn->slen = l->slen;
+ tn = node_parent(tn);
+ }
+}
+
+static void remove_leaf_info(struct tnode *l, struct leaf_info *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);
+
+ /* remove the leaf info from the list */
+ hlist_del_rcu(&old->hlist);
+
+ /* only access li if it is pointing at the last valid hlist_node */
+ if (hlist_empty(&l->list) || (*pprev))
+ return;
+
+ /* update the trie with the latest suffix length */
+ l->slen = KEYLENGTH - li->plen;
+ leaf_pull_suffix(l);
+}
+
+static void insert_leaf_info(struct tnode *l, struct leaf_info *new)
+{
+ struct hlist_head *head = &l->list;
struct leaf_info *li = NULL, *last = NULL;
if (hlist_empty(head)) {
else
hlist_add_before_rcu(&new->hlist, &li->hlist);
}
+
+ /* if we added to the tail node then we need to update slen */
+ if (l->slen < (KEYLENGTH - new->plen)) {
+ l->slen = KEYLENGTH - new->plen;
+ leaf_push_suffix(l);
+ }
}
/* rcu_read_lock needs to be hold by caller from readside */
+static struct tnode *fib_find_node(struct trie *t, u32 key)
+{
+ struct tnode *n = rcu_dereference_rtnl(t->trie);
+
+ while (n) {
+ unsigned long index = get_index(key, n);
+
+ /* This bit of code is a bit tricky but it combines multiple
+ * checks into a single check. The prefix consists of the
+ * prefix plus zeros for the bits in the cindex. The index
+ * is the difference between the key and this value. From
+ * this we can actually derive several pieces of data.
+ * if (index & (~0ul << bits))
+ * we have a mismatch in skip bits and failed
+ * else
+ * we know the value is cindex
+ */
+ if (index & (~0ul << n->bits))
+ return NULL;
-static struct leaf *
-fib_find_node(struct trie *t, u32 key)
-{
- int pos;
- struct tnode *tn;
- struct rt_trie_node *n;
+ /* we have found a leaf. Prefixes have already been compared */
+ if (IS_LEAF(n))
+ break;
- pos = 0;
- n = rcu_dereference_rtnl(t->trie);
+ n = tnode_get_child_rcu(n, index);
+ }
- while (n != NULL && NODE_TYPE(n) == T_TNODE) {
- tn = (struct tnode *) n;
+ return n;
+}
- check_tnode(tn);
+/* Return the first fib alias matching TOS with
+ * priority less than or equal to PRIO.
+ */
+static struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
+{
+ struct fib_alias *fa;
- if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
- pos = tn->pos + tn->bits;
- n = tnode_get_child_rcu(tn,
- tkey_extract_bits(key,
- tn->pos,
- tn->bits));
- } else
- break;
- }
- /* Case we have found a leaf. Compare prefixes */
+ if (!fah)
+ return NULL;
- if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
- return (struct leaf *)n;
+ list_for_each_entry(fa, fah, fa_list) {
+ if (fa->fa_tos > tos)
+ continue;
+ if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
+ return fa;
+ }
return NULL;
}
static void trie_rebalance(struct trie *t, struct tnode *tn)
{
- int wasfull;
- t_key cindex, key;
struct tnode *tp;
- key = tn->key;
-
- while (tn != NULL && (tp = node_parent((struct rt_trie_node *)tn)) != NULL) {
- cindex = tkey_extract_bits(key, tp->pos, tp->bits);
- wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
- tn = (struct tnode *)resize(t, tn);
-
- tnode_put_child_reorg(tp, cindex,
- (struct rt_trie_node *)tn, wasfull);
-
- tp = node_parent((struct rt_trie_node *) tn);
- if (!tp)
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
-
- tnode_free_flush();
- if (!tp)
- break;
+ while ((tp = node_parent(tn)) != NULL) {
+ resize(t, tn);
tn = tp;
}
/* Handle last (top) tnode */
if (IS_TNODE(tn))
- tn = (struct tnode *)resize(t, tn);
-
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
- tnode_free_flush();
+ resize(t, tn);
}
/* only used from updater-side */
static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
{
- int pos, newpos;
- struct tnode *tp = NULL, *tn = NULL;
- struct rt_trie_node *n;
- struct leaf *l;
- int missbit;
struct list_head *fa_head = NULL;
+ struct tnode *l, *n, *tp = NULL;
struct leaf_info *li;
- t_key cindex;
- pos = 0;
+ li = leaf_info_new(plen);
+ if (!li)
+ return NULL;
+ fa_head = &li->falh;
+
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,
* and we should just put our new leaf in that.
- * If we point to a T_TNODE, check if it matches our key. Note that
- * a T_TNODE might be skipping any number of bits - its 'pos' need
- * not be the parent's 'pos'+'bits'!
- *
- * If it does match the current key, get pos/bits from it, extract
- * the index from our key, push the T_TNODE and walk the tree.
*
- * If it doesn't, we have to replace it with a new T_TNODE.
- *
- * If we point to a T_LEAF, it might or might not have the same key
- * as we do. If it does, just change the value, update the T_LEAF's
- * value, and return it.
- * If it doesn't, we need to replace it with a T_TNODE.
+ * If we hit a node with a key that does't match then we should stop
+ * and create a new tnode to replace that node and insert ourselves
+ * and the other node into the new tnode.
*/
-
- 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;
- n = tnode_get_child(tn,
- tkey_extract_bits(key,
- tn->pos,
- tn->bits));
-
- BUG_ON(n && node_parent(n) != tn);
- } else
+ while (n) {
+ unsigned long index = get_index(key, n);
+
+ /* This bit of code is a bit tricky but it combines multiple
+ * checks into a single check. The prefix consists of the
+ * prefix plus zeros for the "bits" in the prefix. The index
+ * is the difference between the key and this value. From
+ * this we can actually derive several pieces of data.
+ * if !(index >> bits)
+ * we know the value is child index
+ * else
+ * we have a mismatch in skip bits and failed
+ */
+ if (index >> n->bits)
break;
- }
-
- /*
- * n ----> NULL, LEAF or TNODE
- *
- * tp is n's (parent) ----> NULL or TNODE
- */
-
- 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)) {
- l = (struct leaf *) n;
- li = leaf_info_new(plen);
- if (!li)
- return NULL;
+ /* 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;
+ }
- fa_head = &li->falh;
- insert_leaf_info(&l->list, li);
- goto done;
+ tp = n;
+ n = tnode_get_child_rcu(n, index);
}
- l = leaf_new();
-
- if (!l)
- return NULL;
-
- l->key = key;
- li = leaf_info_new(plen);
- if (!li) {
- free_leaf(l);
+ l = leaf_new(key);
+ if (!l) {
+ free_leaf_info(li);
return NULL;
}
- fa_head = &li->falh;
- insert_leaf_info(&l->list, li);
-
- if (t->trie && n == NULL) {
- /* Case 2: n is NULL, and will just insert a new leaf */
-
- node_set_parent((struct rt_trie_node *)l, tp);
+ insert_leaf_info(l, li);
- cindex = tkey_extract_bits(key, tp->pos, tp->bits);
- put_child(tp, cindex, (struct rt_trie_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 (n) {
- pos = tp ? tp->pos+tp->bits : 0;
- newpos = tkey_mismatch(key, pos, n->key);
- tn = tnode_new(n->key, newpos, 1);
- } else {
- newpos = 0;
- tn = tnode_new(key, newpos, 1); /* First tnode */
- }
+ /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
+ *
+ * Add a new tnode here
+ * first tnode need some special handling
+ * leaves us in position for handling as case 3
+ */
+ if (n) {
+ struct tnode *tn;
+ tn = tnode_new(key, __fls(key ^ n->key), 1);
if (!tn) {
free_leaf_info(li);
- free_leaf(l);
+ node_free(l);
return NULL;
}
- node_set_parent((struct rt_trie_node *)tn, tp);
+ /* initialize routes out of node */
+ NODE_INIT_PARENT(tn, tp);
+ put_child(tn, get_index(key, tn) ^ 1, n);
- missbit = tkey_extract_bits(key, newpos, 1);
- put_child(tn, missbit, (struct rt_trie_node *)l);
- put_child(tn, 1-missbit, n);
-
- if (tp) {
- cindex = tkey_extract_bits(key, tp->pos, tp->bits);
- put_child(tp, cindex, (struct rt_trie_node *)tn);
- } else {
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
- }
+ /* start adding routes into the node */
+ put_child_root(tp, t, key, tn);
+ node_set_parent(n, tn);
+ /* parent now has a NULL spot where the leaf can go */
tp = tn;
}
- if (tp && tp->pos + tp->bits > 32)
- pr_warn("fib_trie tp=%p pos=%d, bits=%d, key=%0x plen=%d\n",
- tp, tp->pos, tp->bits, key, plen);
-
- /* Rebalance the trie */
+ /* Case 3: n is NULL, and will just insert a new leaf */
+ if (tp) {
+ NODE_INIT_PARENT(l, tp);
+ put_child(tp, get_index(key, tp), l);
+ trie_rebalance(t, tp);
+ } else {
+ rcu_assign_pointer(t->trie, l);
+ }
- trie_rebalance(t, tp);
-done:
return fa_head;
}
u8 tos = cfg->fc_tos;
u32 key, mask;
int err;
- struct leaf *l;
+ struct tnode *l;
if (plen > 32)
return -EINVAL;
return err;
}
+static inline t_key prefix_mismatch(t_key key, struct tnode *n)
+{
+ t_key prefix = n->key;
+
+ return (key ^ prefix) & (prefix | -prefix);
+}
+
/* should be called with rcu_read_lock */
-static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l,
- t_key key, const struct flowi4 *flp,
- struct fib_result *res, int fib_flags)
+int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
+ struct fib_result *res, int fib_flags)
{
+ struct trie *t = (struct trie *)tb->tb_data;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie_use_stats __percpu *stats = t->stats;
+#endif
+ const t_key key = ntohl(flp->daddr);
+ struct tnode *n, *pn;
struct leaf_info *li;
- struct hlist_head *hhead = &l->list;
+ t_key cindex;
+
+ n = rcu_dereference(t->trie);
+ if (!n)
+ return -EAGAIN;
+
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->gets);
+#endif
+
+ pn = n;
+ cindex = 0;
+
+ /* Step 1: Travel to the longest prefix match in the trie */
+ for (;;) {
+ unsigned long index = get_index(key, n);
+
+ /* This bit of code is a bit tricky but it combines multiple
+ * checks into a single check. The prefix consists of the
+ * prefix plus zeros for the "bits" in the prefix. The index
+ * is the difference between the key and this value. From
+ * this we can actually derive several pieces of data.
+ * if (index & (~0ul << bits))
+ * we have a mismatch in skip bits and failed
+ * else
+ * we know the value is cindex
+ */
+ if (index & (~0ul << n->bits))
+ break;
+
+ /* we have found a leaf. Prefixes have already been compared */
+ if (IS_LEAF(n))
+ goto found;
+
+ /* only record pn and cindex if we are going to be chopping
+ * bits later. Otherwise we are just wasting cycles.
+ */
+ if (n->slen > n->pos) {
+ pn = n;
+ cindex = index;
+ }
- hlist_for_each_entry_rcu(li, hhead, hlist) {
+ n = tnode_get_child_rcu(n, index);
+ if (unlikely(!n))
+ goto backtrace;
+ }
+
+ /* Step 2: Sort out leaves and begin backtracing for longest prefix */
+ for (;;) {
+ /* record the pointer where our next node pointer is stored */
+ struct tnode __rcu **cptr = n->child;
+
+ /* This test verifies that none of the bits that differ
+ * between the key and the prefix exist in the region of
+ * the lsb and higher in the prefix.
+ */
+ if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
+ goto backtrace;
+
+ /* exit out and process leaf */
+ if (unlikely(IS_LEAF(n)))
+ break;
+
+ /* Don't bother recording parent info. Since we are in
+ * prefix match mode we will have to come back to wherever
+ * we started this traversal anyway
+ */
+
+ while ((n = rcu_dereference(*cptr)) == NULL) {
+backtrace:
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ if (!n)
+ this_cpu_inc(stats->null_node_hit);
+#endif
+ /* If we are at cindex 0 there are no more bits for
+ * us to strip at this level so we must ascend back
+ * up one level to see if there are any more bits to
+ * be stripped there.
+ */
+ while (!cindex) {
+ t_key pkey = pn->key;
+
+ pn = node_parent_rcu(pn);
+ if (unlikely(!pn))
+ return -EAGAIN;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->backtrack);
+#endif
+ /* Get Child's index */
+ cindex = get_index(pkey, pn);
+ }
+
+ /* strip the least significant bit from the cindex */
+ cindex &= cindex - 1;
+
+ /* grab pointer for next child node */
+ cptr = &pn->child[cindex];
+ }
+ }
+
+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;
- if (l->key != (key & li->mask_plen))
+ if ((key ^ n->key) & li->mask_plen)
continue;
list_for_each_entry_rcu(fa, &li->falh, fa_list) {
continue;
fib_alias_accessed(fa);
err = fib_props[fa->fa_type].error;
- if (err) {
+ if (unlikely(err < 0)) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.semantic_match_passed++;
+ this_cpu_inc(stats->semantic_match_passed);
#endif
return err;
}
if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
continue;
-#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.semantic_match_passed++;
-#endif
+ if (!(fib_flags & FIB_LOOKUP_NOREF))
+ atomic_inc(&fi->fib_clntref);
+
res->prefixlen = li->plen;
res->nh_sel = nhsel;
res->type = fa->fa_type;
- res->scope = fa->fa_info->fib_scope;
+ res->scope = fi->fib_scope;
res->fi = fi;
res->table = tb;
res->fa_head = &li->falh;
- if (!(fib_flags & FIB_LOOKUP_NOREF))
- atomic_inc(&fi->fib_clntref);
- return 0;
- }
- }
-
-#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.semantic_match_miss++;
-#endif
- }
-
- return 1;
-}
-
-int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
- struct fib_result *res, int fib_flags)
-{
- struct trie *t = (struct trie *) tb->tb_data;
- int ret;
- struct rt_trie_node *n;
- struct tnode *pn;
- unsigned int pos, bits;
- t_key key = ntohl(flp->daddr);
- unsigned int chopped_off;
- t_key cindex = 0;
- unsigned int current_prefix_length = KEYLENGTH;
- struct tnode *cn;
- t_key pref_mismatch;
-
- rcu_read_lock();
-
- n = rcu_dereference(t->trie);
- if (!n)
- goto failed;
-
-#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.gets++;
-#endif
-
- /* Just a leaf? */
- if (IS_LEAF(n)) {
- ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
- goto found;
- }
-
- pn = (struct tnode *) n;
- chopped_off = 0;
-
- while (pn) {
- pos = pn->pos;
- bits = pn->bits;
-
- if (!chopped_off)
- cindex = tkey_extract_bits(mask_pfx(key, current_prefix_length),
- pos, bits);
-
- n = tnode_get_child_rcu(pn, cindex);
-
- if (n == NULL) {
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.null_node_hit++;
+ this_cpu_inc(stats->semantic_match_passed);
#endif
- goto backtrace;
- }
-
- if (IS_LEAF(n)) {
- ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
- if (ret > 0)
- goto backtrace;
- goto found;
- }
-
- 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.
- */
-
- /* 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)
- || !(cn->child[0]))
- goto backtrace;
- }
-
- /*
- * 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.
- */
-
- /* 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.
- */
-
- /*
- * 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.
- */
-
- pref_mismatch = mask_pfx(cn->key ^ key, cn->pos);
-
- /*
- * In short: If skipped bits in this node do not match
- * the search key, enter the "prefix matching"
- * state.directly.
- */
- if (pref_mismatch) {
- /* fls(x) = __fls(x) + 1 */
- int mp = KEYLENGTH - __fls(pref_mismatch) - 1;
-
- if (tkey_extract_bits(cn->key, mp, cn->pos - mp) != 0)
- goto backtrace;
-
- if (current_prefix_length >= cn->pos)
- current_prefix_length = mp;
+ return err;
+ }
}
- pn = (struct tnode *)n; /* Descend */
- chopped_off = 0;
- continue;
-
-backtrace:
- chopped_off++;
-
- /* As zero don't change the child key (cindex) */
- while ((chopped_off <= pn->bits)
- && !(cindex & (1<<(chopped_off-1))))
- chopped_off++;
-
- /* Decrease current_... with bits chopped off */
- if (current_prefix_length > pn->pos + pn->bits - chopped_off)
- current_prefix_length = pn->pos + pn->bits
- - chopped_off;
-
- /*
- * Either we do the actual chop off according or if we have
- * chopped off all bits in this tnode walk up to our parent.
- */
-
- if (chopped_off <= pn->bits) {
- cindex &= ~(1 << (chopped_off-1));
- } else {
- struct tnode *parent = node_parent_rcu((struct rt_trie_node *) pn);
- if (!parent)
- goto failed;
-
- /* Get Child's index */
- cindex = tkey_extract_bits(pn->key, parent->pos, parent->bits);
- pn = parent;
- chopped_off = 0;
-
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.backtrack++;
+ this_cpu_inc(stats->semantic_match_miss);
#endif
- goto backtrace;
- }
}
-failed:
- ret = 1;
-found:
- rcu_read_unlock();
- return ret;
+ goto backtrace;
}
EXPORT_SYMBOL_GPL(fib_table_lookup);
/*
* Remove the leaf and return parent.
*/
-static void trie_leaf_remove(struct trie *t, struct leaf *l)
+static void trie_leaf_remove(struct trie *t, struct tnode *l)
{
- struct tnode *tp = node_parent((struct rt_trie_node *) l);
+ struct tnode *tp = node_parent(l);
pr_debug("entering trie_leaf_remove(%p)\n", l);
if (tp) {
- t_key cindex = tkey_extract_bits(l->key, tp->pos, tp->bits);
- put_child(tp, cindex, NULL);
+ put_child(tp, get_index(l->key, tp), NULL);
trie_rebalance(t, tp);
- } else
+ } else {
RCU_INIT_POINTER(t->trie, NULL);
+ }
- free_leaf(l);
+ node_free(l);
}
/*
u8 tos = cfg->fc_tos;
struct fib_alias *fa, *fa_to_delete;
struct list_head *fa_head;
- struct leaf *l;
+ struct tnode *l;
struct leaf_info *li;
if (plen > 32)
tb->tb_num_default--;
if (list_empty(fa_head)) {
- hlist_del_rcu(&li->hlist);
+ remove_leaf_info(l, li);
free_leaf_info(li);
}
return found;
}
-static int trie_flush_leaf(struct leaf *l)
+static int trie_flush_leaf(struct tnode *l)
{
int found = 0;
struct hlist_head *lih = &l->list;
struct hlist_node *tmp;
struct leaf_info *li = NULL;
+ unsigned char plen = KEYLENGTH;
hlist_for_each_entry_safe(li, tmp, lih, hlist) {
found += trie_flush_list(&li->falh);
if (list_empty(&li->falh)) {
hlist_del_rcu(&li->hlist);
free_leaf_info(li);
+ continue;
}
+
+ plen = li->plen;
}
+
+ l->slen = KEYLENGTH - plen;
+
return found;
}
* Scan for the next right leaf starting at node p->child[idx]
* Since we have back pointer, no recursion necessary.
*/
-static struct leaf *leaf_walk_rcu(struct tnode *p, struct rt_trie_node *c)
+static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
{
do {
- t_key idx;
-
- if (c)
- idx = tkey_extract_bits(c->key, p->pos, p->bits) + 1;
- else
- idx = 0;
+ unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0;
- while (idx < 1u << p->bits) {
+ while (idx < tnode_child_length(p)) {
c = tnode_get_child_rcu(p, idx++);
if (!c)
continue;
if (IS_LEAF(c))
- return (struct leaf *) c;
+ return c;
/* Rescan start scanning in new node */
- p = (struct tnode *) c;
+ p = c;
idx = 0;
}
/* Node empty, walk back up to parent */
- c = (struct rt_trie_node *) p;
+ c = p;
} while ((p = node_parent_rcu(c)) != NULL);
return NULL; /* Root of trie */
}
-static struct leaf *trie_firstleaf(struct trie *t)
+static struct tnode *trie_firstleaf(struct trie *t)
{
- struct tnode *n = (struct tnode *)rcu_dereference_rtnl(t->trie);
+ struct tnode *n = rcu_dereference_rtnl(t->trie);
if (!n)
return NULL;
if (IS_LEAF(n)) /* trie is just a leaf */
- return (struct leaf *) n;
+ return n;
return leaf_walk_rcu(n, NULL);
}
-static struct leaf *trie_nextleaf(struct leaf *l)
+static struct tnode *trie_nextleaf(struct tnode *l)
{
- struct rt_trie_node *c = (struct rt_trie_node *) l;
- struct tnode *p = node_parent_rcu(c);
+ struct tnode *p = node_parent_rcu(l);
if (!p)
return NULL; /* trie with just one leaf */
- return leaf_walk_rcu(p, c);
+ return leaf_walk_rcu(p, l);
}
-static struct leaf *trie_leafindex(struct trie *t, int index)
+static struct tnode *trie_leafindex(struct trie *t, int index)
{
- struct leaf *l = trie_firstleaf(t);
+ struct tnode *l = trie_firstleaf(t);
while (l && index-- > 0)
l = trie_nextleaf(l);
int fib_table_flush(struct fib_table *tb)
{
struct trie *t = (struct trie *) tb->tb_data;
- struct leaf *l, *ll = NULL;
+ struct tnode *l, *ll = NULL;
int found = 0;
for (l = trie_firstleaf(t); l; l = trie_nextleaf(l)) {
found += trie_flush_leaf(l);
- if (ll && hlist_empty(&ll->list))
- trie_leaf_remove(t, ll);
+ if (ll) {
+ if (hlist_empty(&ll->list))
+ trie_leaf_remove(t, ll);
+ else
+ leaf_pull_suffix(ll);
+ }
+
ll = l;
}
- if (ll && hlist_empty(&ll->list))
- trie_leaf_remove(t, ll);
+ if (ll) {
+ if (hlist_empty(&ll->list))
+ trie_leaf_remove(t, ll);
+ else
+ leaf_pull_suffix(ll);
+ }
pr_debug("trie_flush found=%d\n", found);
return found;
void fib_free_table(struct fib_table *tb)
{
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie *t = (struct trie *)tb->tb_data;
+
+ free_percpu(t->stats);
+#endif /* CONFIG_IP_FIB_TRIE_STATS */
kfree(tb);
}
return skb->len;
}
-static int fn_trie_dump_leaf(struct leaf *l, 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)
{
struct leaf_info *li;
int fib_table_dump(struct fib_table *tb, struct sk_buff *skb,
struct netlink_callback *cb)
{
- struct leaf *l;
+ struct tnode *l;
struct trie *t = (struct trie *) tb->tb_data;
t_key key = cb->args[2];
int count = cb->args[3];
0, SLAB_PANIC, NULL);
trie_leaf_kmem = kmem_cache_create("ip_fib_trie",
- max(sizeof(struct leaf),
+ max(sizeof(struct tnode),
sizeof(struct leaf_info)),
0, SLAB_PANIC, NULL);
}
tb->tb_num_default = 0;
t = (struct trie *) tb->tb_data;
- memset(t, 0, sizeof(*t));
+ RCU_INIT_POINTER(t->trie, NULL);
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ t->stats = alloc_percpu(struct trie_use_stats);
+ if (!t->stats) {
+ kfree(tb);
+ tb = NULL;
+ }
+#endif
return tb;
}
unsigned int depth;
};
-static struct rt_trie_node *fib_trie_get_next(struct fib_trie_iter *iter)
+static struct tnode *fib_trie_get_next(struct fib_trie_iter *iter)
{
+ unsigned long cindex = iter->index;
struct tnode *tn = iter->tnode;
- unsigned int cindex = iter->index;
struct tnode *p;
/* A single entry routing table */
pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
iter->tnode, iter->index, iter->depth);
rescan:
- while (cindex < (1<<tn->bits)) {
- struct rt_trie_node *n = tnode_get_child_rcu(tn, cindex);
+ while (cindex < tnode_child_length(tn)) {
+ struct tnode *n = tnode_get_child_rcu(tn, cindex);
if (n) {
if (IS_LEAF(n)) {
iter->index = cindex + 1;
} else {
/* push down one level */
- iter->tnode = (struct tnode *) n;
+ iter->tnode = n;
iter->index = 0;
++iter->depth;
}
}
/* Current node exhausted, pop back up */
- p = node_parent_rcu((struct rt_trie_node *)tn);
+ p = node_parent_rcu(tn);
if (p) {
- cindex = tkey_extract_bits(tn->key, p->pos, p->bits)+1;
+ cindex = get_index(tn->key, p) + 1;
tn = p;
--iter->depth;
goto rescan;
return NULL;
}
-static struct rt_trie_node *fib_trie_get_first(struct fib_trie_iter *iter,
+static struct tnode *fib_trie_get_first(struct fib_trie_iter *iter,
struct trie *t)
{
- struct rt_trie_node *n;
+ struct tnode *n;
if (!t)
return NULL;
return NULL;
if (IS_TNODE(n)) {
- iter->tnode = (struct tnode *) n;
+ iter->tnode = n;
iter->index = 0;
iter->depth = 1;
} else {
static void trie_collect_stats(struct trie *t, struct trie_stat *s)
{
- struct rt_trie_node *n;
+ struct tnode *n;
struct fib_trie_iter iter;
memset(s, 0, sizeof(*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 *l = (struct leaf *)n;
struct leaf_info *li;
s->leaves++;
if (iter.depth > s->maxdepth)
s->maxdepth = iter.depth;
- hlist_for_each_entry_rcu(li, &l->list, hlist)
+ hlist_for_each_entry_rcu(li, &n->list, hlist)
++s->prefixes;
} else {
- const struct tnode *tn = (const struct tnode *) n;
- int i;
-
s->tnodes++;
- if (tn->bits < MAX_STAT_DEPTH)
- s->nodesizes[tn->bits]++;
-
- for (i = 0; i < (1<<tn->bits); i++)
- if (!tn->child[i])
- s->nullpointers++;
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
+ s->nullpointers += n->empty_children;
}
}
rcu_read_unlock();
seq_printf(seq, "\tMax depth: %u\n", stat->maxdepth);
seq_printf(seq, "\tLeaves: %u\n", stat->leaves);
- bytes = sizeof(struct leaf) * stat->leaves;
+ bytes = sizeof(struct tnode) * stat->leaves;
seq_printf(seq, "\tPrefixes: %u\n", stat->prefixes);
bytes += sizeof(struct leaf_info) * stat->prefixes;
seq_putc(seq, '\n');
seq_printf(seq, "\tPointers: %u\n", pointers);
- bytes += sizeof(struct rt_trie_node *) * pointers;
+ bytes += sizeof(struct tnode *) * pointers;
seq_printf(seq, "Null ptrs: %u\n", stat->nullpointers);
seq_printf(seq, "Total size: %u kB\n", (bytes + 1023) / 1024);
}
#ifdef CONFIG_IP_FIB_TRIE_STATS
static void trie_show_usage(struct seq_file *seq,
- const struct trie_use_stats *stats)
+ const struct trie_use_stats __percpu *stats)
{
+ struct trie_use_stats s = { 0 };
+ int cpu;
+
+ /* loop through all of the CPUs and gather up the stats */
+ for_each_possible_cpu(cpu) {
+ const struct trie_use_stats *pcpu = per_cpu_ptr(stats, cpu);
+
+ s.gets += pcpu->gets;
+ s.backtrack += pcpu->backtrack;
+ s.semantic_match_passed += pcpu->semantic_match_passed;
+ s.semantic_match_miss += pcpu->semantic_match_miss;
+ s.null_node_hit += pcpu->null_node_hit;
+ s.resize_node_skipped += pcpu->resize_node_skipped;
+ }
+
seq_printf(seq, "\nCounters:\n---------\n");
- seq_printf(seq, "gets = %u\n", stats->gets);
- seq_printf(seq, "backtracks = %u\n", stats->backtrack);
+ seq_printf(seq, "gets = %u\n", s.gets);
+ seq_printf(seq, "backtracks = %u\n", s.backtrack);
seq_printf(seq, "semantic match passed = %u\n",
- stats->semantic_match_passed);
- seq_printf(seq, "semantic match miss = %u\n",
- stats->semantic_match_miss);
- seq_printf(seq, "null node hit= %u\n", stats->null_node_hit);
- seq_printf(seq, "skipped node resize = %u\n\n",
- stats->resize_node_skipped);
+ s.semantic_match_passed);
+ seq_printf(seq, "semantic match miss = %u\n", s.semantic_match_miss);
+ seq_printf(seq, "null node hit= %u\n", s.null_node_hit);
+ seq_printf(seq, "skipped node resize = %u\n\n", s.resize_node_skipped);
}
#endif /* CONFIG_IP_FIB_TRIE_STATS */
seq_printf(seq,
"Basic info: size of leaf:"
" %Zd bytes, size of tnode: %Zd bytes.\n",
- sizeof(struct leaf), sizeof(struct tnode));
+ sizeof(struct tnode), sizeof(struct tnode));
for (h = 0; h < FIB_TABLE_HASHSZ; h++) {
struct hlist_head *head = &net->ipv4.fib_table_hash[h];
trie_collect_stats(t, &stat);
trie_show_stats(seq, &stat);
#ifdef CONFIG_IP_FIB_TRIE_STATS
- trie_show_usage(seq, &t->stats);
+ trie_show_usage(seq, t->stats);
#endif
}
}
.release = single_release_net,
};
-static struct rt_trie_node *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
+static struct tnode *fib_trie_get_idx(struct seq_file *seq, loff_t pos)
{
struct fib_trie_iter *iter = seq->private;
struct net *net = seq_file_net(seq);
struct fib_table *tb;
hlist_for_each_entry_rcu(tb, head, tb_hlist) {
- struct rt_trie_node *n;
+ struct tnode *n;
for (n = fib_trie_get_first(iter,
(struct trie *) tb->tb_data);
struct fib_table *tb = iter->tb;
struct hlist_node *tb_node;
unsigned int h;
- struct rt_trie_node *n;
+ struct tnode *n;
++*pos;
/* next node in same table */
static int fib_trie_seq_show(struct seq_file *seq, void *v)
{
const struct fib_trie_iter *iter = seq->private;
- struct rt_trie_node *n = v;
+ struct tnode *n = v;
if (!node_parent_rcu(n))
fib_table_print(seq, iter->tb);
if (IS_TNODE(n)) {
- struct tnode *tn = (struct tnode *) n;
- __be32 prf = htonl(mask_pfx(tn->key, tn->pos));
+ __be32 prf = htonl(n->key);
seq_indent(seq, iter->depth-1);
- seq_printf(seq, " +-- %pI4/%d %d %d %d\n",
- &prf, tn->pos, tn->bits, tn->full_children,
- tn->empty_children);
-
+ seq_printf(seq, " +-- %pI4/%zu %u %u %u\n",
+ &prf, KEYLENGTH - n->pos - n->bits, n->bits,
+ n->full_children, n->empty_children);
} else {
- struct leaf *l = (struct leaf *) n;
struct leaf_info *li;
- __be32 val = htonl(l->key);
+ __be32 val = htonl(n->key);
seq_indent(seq, iter->depth);
seq_printf(seq, " |-- %pI4\n", &val);
- hlist_for_each_entry_rcu(li, &l->list, hlist) {
+ hlist_for_each_entry_rcu(li, &n->list, hlist) {
struct fib_alias *fa;
list_for_each_entry_rcu(fa, &li->falh, fa_list) {
t_key key;
};
-static struct leaf *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
+static struct tnode *fib_route_get_idx(struct fib_route_iter *iter, loff_t pos)
{
- struct leaf *l = NULL;
+ struct tnode *l = NULL;
struct trie *t = iter->main_trie;
/* use cache location of last found key */
static void *fib_route_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
struct fib_route_iter *iter = seq->private;
- struct leaf *l = v;
+ struct tnode *l = v;
++*pos;
if (v == SEQ_START_TOKEN) {
*/
static int fib_route_seq_show(struct seq_file *seq, void *v)
{
- struct leaf *l = v;
+ struct tnode *l = v;
struct leaf_info *li;
if (v == SEQ_START_TOKEN) {