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_shift(_kv) (KEYLENGTH - (_kv)->pos - (_kv)->bits)
+#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> get_shift(_kv))
-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 */
+ struct tnode __rcu *parent;
struct rcu_head rcu;
+ union {
+ /* The fields in this struct are valid if bits > 0 (TNODE) */
+ struct {
+ unsigned int full_children; /* KEYLENGTH bits needed */
+ unsigned int empty_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,
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n,
int wasfull);
-static struct rt_trie_node *resize(struct trie *t, struct tnode *tn);
+static struct tnode *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 struct callback_head *tnode_free_head;
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;
+/* caller must hold RTNL */
+#define node_parent(n) rtnl_dereference((n)->parent)
- parent = rcu_dereference_index_check(node->parent, lockdep_rtnl_is_held());
+/* caller must hold RCU read lock or RTNL */
+#define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
- return (struct tnode *)(parent & ~NODE_TYPE_MASK);
-}
-
-/*
- * 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 int 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)
+static inline struct tnode *tnode_get_child(const struct tnode *tn, unsigned int i)
{
- BUG_ON(i >= 1U << tn->bits);
+ BUG_ON(i >= tnode_child_length(tn));
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)
+static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn, unsigned int i)
{
- BUG_ON(i >= 1U << tn->bits);
+ BUG_ON(i >= tnode_child_length(tn));
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 void check_tnode(const struct tnode *tn)
-{
- WARN_ON(tn && tn->pos+tn->bits > 32);
-}
-
static const int halve_threshold = 25;
static const int inflate_threshold = 50;
static const int halve_threshold_root = 15;
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)
-{
- if (IS_LEAF(tn))
- free_leaf((struct leaf *) tn);
- else
- call_rcu(&tn->rcu, __tnode_free_rcu);
-}
-
static void tnode_free_safe(struct tnode *tn)
{
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);
+ tn->rcu.next = tnode_free_head;
+ tnode_free_head = &tn->rcu;
}
static void tnode_free_flush(void)
{
- struct tnode *tn;
+ struct callback_head *head;
+
+ while ((head = tnode_free_head)) {
+ struct tnode *tn = container_of(head, struct tnode, rcu);
+
+ tnode_free_head = head->next;
+ tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
- while ((tn = tnode_free_head)) {
- tnode_free_head = tn->tnode_free;
- tn->tnode_free = NULL;
- tnode_free(tn);
+ node_free(tn);
}
if (tnode_free_size >= PAGE_SIZE * sync_pages) {
}
}
-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->pos = KEYLENGTH;
+ /* 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[1 << 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->pos = pos;
tn->bits = bits;
- tn->key = key;
+ tn->key = mask_pfx(key, pos);
tn->full_children = 0;
tn->empty_children = 1<<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;
}
* 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 && IS_TNODE(n) && (n->pos == (tn->pos + tn->bits));
}
static inline void put_child(struct tnode *tn, int i,
- struct rt_trie_node *n)
+ struct tnode *n)
{
tnode_put_child_reorg(tn, i, n, -1);
}
* 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,
+static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n,
int wasfull)
{
- struct rt_trie_node *chi = rtnl_dereference(tn->child[i]);
+ struct tnode *chi = rtnl_dereference(tn->child[i]);
int isfull;
BUG_ON(i >= 1<<tn->bits);
else if (!wasfull && isfull)
tn->full_children++;
- if (n)
- node_set_parent(n, tn);
+ node_set_parent(n, tn);
rcu_assign_pointer(tn->child[i], n);
}
#define MAX_WORK 10
-static struct rt_trie_node *resize(struct trie *t, struct tnode *tn)
+static struct tnode *resize(struct trie *t, struct tnode *tn)
{
- int i;
- struct tnode *old_tn;
+ struct tnode *old_tn, *n = NULL;
int inflate_threshold_use;
int halve_threshold_use;
int max_work;
tn, inflate_threshold, halve_threshold);
/* No children */
- if (tn->empty_children == tnode_child_length(tn)) {
- tnode_free_safe(tn);
- return NULL;
- }
+ if (tn->empty_children > (tnode_child_length(tn) - 1))
+ goto no_children;
+
/* One child */
- if (tn->empty_children == tnode_child_length(tn) - 1)
+ if (tn->empty_children == (tnode_child_length(tn) - 1))
goto one_child;
/*
* Double as long as the resulting node has a number of
*
*/
- check_tnode(tn);
-
/* Keep root node larger */
- if (!node_parent((struct rt_trie_node *)tn)) {
+ if (!node_parent(tn)) {
inflate_threshold_use = inflate_threshold_root;
halve_threshold_use = halve_threshold_root;
} else {
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.resize_node_skipped++;
+ this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
}
- check_tnode(tn);
-
/* Return if at least one inflate is run */
if (max_work != MAX_WORK)
- return (struct rt_trie_node *) tn;
+ return tn;
/*
* Halve as long as the number of empty children in this
if (IS_ERR(tn)) {
tn = old_tn;
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.resize_node_skipped++;
+ this_cpu_inc(t->stats->resize_node_skipped);
#endif
break;
}
/* Only one child remains */
- if (tn->empty_children == tnode_child_length(tn) - 1) {
+ if (tn->empty_children == (tnode_child_length(tn) - 1)) {
+ unsigned long i;
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;
-
- /* compress one level */
-
- node_set_parent(n, NULL);
- tnode_free_safe(tn);
- return n;
- }
+ for (i = tnode_child_length(tn); !n && i;)
+ n = tnode_get_child(tn, --i);
+no_children:
+ /* compress one level */
+ node_set_parent(n, NULL);
+ tnode_free_safe(tn);
+ return n;
}
- return (struct rt_trie_node *) tn;
+ return tn;
}
static void tnode_clean_free(struct tnode *tn)
{
- int i;
struct tnode *tofree;
+ int i;
for (i = 0; i < tnode_child_length(tn); i++) {
- tofree = (struct tnode *)rtnl_dereference(tn->child[i]);
+ tofree = rtnl_dereference(tn->child[i]);
if (tofree)
- tnode_free(tofree);
+ node_free(tofree);
}
- tnode_free(tn);
+ node_free(tn);
}
-static struct tnode *inflate(struct trie *t, struct tnode *tn)
+static struct tnode *inflate(struct trie *t, struct tnode *oldtnode)
{
- struct tnode *oldtnode = tn;
- int olen = tnode_child_length(tn);
+ int olen = tnode_child_length(oldtnode);
+ struct tnode *tn;
int i;
pr_debug("In inflate\n");
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) {
+ inode = tnode_get_child(oldtnode, i);
+ if (tnode_full(oldtnode, inode) && inode->bits > 1) {
struct tnode *left, *right;
t_key m = ~0U << (KEYLENGTH - 1) >> inode->pos;
inode->bits - 1);
if (!right) {
- tnode_free(left);
+ node_free(left);
goto nomem;
}
- put_child(tn, 2*i, (struct rt_trie_node *) left);
- put_child(tn, 2*i+1, (struct rt_trie_node *) right);
+ put_child(tn, 2*i, left);
+ put_child(tn, 2*i+1, right);
}
}
for (i = 0; i < olen; i++) {
- struct tnode *inode;
- struct rt_trie_node *node = tnode_get_child(oldtnode, i);
+ struct tnode *inode = tnode_get_child(oldtnode, i);
struct tnode *left, *right;
int size, j;
/* 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) {
+ if (!tnode_full(oldtnode, inode)) {
put_child(tn,
- tkey_extract_bits(node->key, oldtnode->pos, oldtnode->bits + 1),
- node);
+ tkey_extract_bits(inode->key, tn->pos, tn->bits),
+ inode);
continue;
}
/* An internal node with two children */
- inode = (struct tnode *) node;
-
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]));
* bit to zero.
*/
- left = (struct tnode *) tnode_get_child(tn, 2*i);
+ left = tnode_get_child(tn, 2*i);
put_child(tn, 2*i, NULL);
BUG_ON(!left);
- right = (struct tnode *) tnode_get_child(tn, 2*i+1);
+ right = tnode_get_child(tn, 2*i+1);
put_child(tn, 2*i+1, NULL);
BUG_ON(!right);
return ERR_PTR(-ENOMEM);
}
-static struct tnode *halve(struct trie *t, struct tnode *tn)
+static struct tnode *halve(struct trie *t, struct tnode *oldtnode)
{
- struct tnode *oldtnode = tn;
- struct rt_trie_node *left, *right;
+ int olen = tnode_child_length(oldtnode);
+ struct tnode *tn, *left, *right;
int i;
- int olen = tnode_child_length(tn);
pr_debug("In halve\n");
if (!newn)
goto nomem;
- put_child(tn, i/2, (struct rt_trie_node *)newn);
+ put_child(tn, i/2, newn);
}
}
}
/* Two nonempty children */
- newBinNode = (struct tnode *) tnode_get_child(tn, i/2);
+ newBinNode = tnode_get_child(tn, i/2);
put_child(tn, i/2, NULL);
put_child(newBinNode, 0, left);
put_child(newBinNode, 1, right);
/* 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);
/* rcu_read_lock needs to be hold by caller from readside */
-static struct leaf *
-fib_find_node(struct trie *t, u32 key)
+static struct tnode *fib_find_node(struct trie *t, u32 key)
{
- int pos;
- struct tnode *tn;
- struct rt_trie_node *n;
-
- pos = 0;
- n = rcu_dereference_rtnl(t->trie);
-
- while (n != NULL && NODE_TYPE(n) == T_TNODE) {
- tn = (struct tnode *) n;
+ struct tnode *n = rcu_dereference_rtnl(t->trie);
+ int pos = 0;
- check_tnode(tn);
-
- if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
- pos = tn->pos + tn->bits;
- n = tnode_get_child_rcu(tn,
+ while (n && IS_TNODE(n)) {
+ if (tkey_sub_equals(n->key, pos, n->pos-pos, key)) {
+ pos = n->pos + n->bits;
+ n = tnode_get_child_rcu(n,
tkey_extract_bits(key,
- tn->pos,
- tn->bits));
+ n->pos,
+ n->bits));
} else
break;
}
/* Case we have found a leaf. Compare prefixes */
if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
- return (struct leaf *)n;
+ return n;
return NULL;
}
key = tn->key;
- while (tn != NULL && (tp = node_parent((struct rt_trie_node *)tn)) != NULL) {
+ while (tn != NULL && (tp = node_parent(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);
+ tn = resize(t, tn);
- tnode_put_child_reorg(tp, cindex,
- (struct rt_trie_node *)tn, wasfull);
+ tnode_put_child_reorg(tp, cindex, tn, wasfull);
- tp = node_parent((struct rt_trie_node *) tn);
+ tp = node_parent(tn);
if (!tp)
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+ rcu_assign_pointer(t->trie, tn);
tnode_free_flush();
if (!tp)
/* Handle last (top) tnode */
if (IS_TNODE(tn))
- tn = (struct tnode *)resize(t, tn);
+ tn = resize(t, tn);
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+ rcu_assign_pointer(t->trie, tn);
tnode_free_flush();
}
{
int pos, newpos;
struct tnode *tp = NULL, *tn = NULL;
- struct rt_trie_node *n;
- struct leaf *l;
+ struct tnode *n;
+ struct tnode *l;
int missbit;
struct list_head *fa_head = NULL;
struct leaf_info *li;
* If it doesn't, we need to replace it with a T_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,
+ while (n && IS_TNODE(n)) {
+ if (tkey_sub_equals(n->key, pos, n->pos-pos, key)) {
+ tp = n;
+ pos = n->pos + n->bits;
+ n = tnode_get_child(n,
tkey_extract_bits(key,
- tn->pos,
- tn->bits));
+ n->pos,
+ n->bits));
- BUG_ON(n && node_parent(n) != tn);
+ BUG_ON(n && node_parent(n) != tp);
} else
break;
}
/* 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;
fa_head = &li->falh;
- insert_leaf_info(&l->list, li);
+ insert_leaf_info(&n->list, li);
goto done;
}
- l = leaf_new();
+ l = leaf_new(key);
if (!l)
return NULL;
- l->key = key;
li = leaf_info_new(plen);
if (!li) {
- free_leaf(l);
+ node_free(l);
return NULL;
}
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);
+ node_set_parent(l, tp);
cindex = tkey_extract_bits(key, tp->pos, tp->bits);
- put_child(tp, cindex, (struct rt_trie_node *)l);
+ put_child(tp, cindex, l);
} else {
/* Case 3: n is a LEAF or a TNODE and the key doesn't match. */
/*
if (!tn) {
free_leaf_info(li);
- free_leaf(l);
+ node_free(l);
return NULL;
}
- node_set_parent((struct rt_trie_node *)tn, tp);
+ node_set_parent(tn, tp);
missbit = tkey_extract_bits(key, newpos, 1);
- put_child(tn, missbit, (struct rt_trie_node *)l);
+ put_child(tn, missbit, 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);
+ put_child(tp, cindex, tn);
} else {
- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+ rcu_assign_pointer(t->trie, tn);
}
tp = tn;
u8 tos = cfg->fc_tos;
u32 key, mask;
int err;
- struct leaf *l;
+ struct tnode *l;
if (plen > 32)
return -EINVAL;
}
/* should be called with rcu_read_lock */
-static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l,
+static int check_leaf(struct fib_table *tb, struct trie *t, struct tnode *l,
t_key key, const struct flowi4 *flp,
struct fib_result *res, int fib_flags)
{
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(t->stats->semantic_match_passed);
#endif
return err;
}
continue;
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.semantic_match_passed++;
+ this_cpu_inc(t->stats->semantic_match_passed);
#endif
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;
}
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.semantic_match_miss++;
+ this_cpu_inc(t->stats->semantic_match_miss);
#endif
}
return 1;
}
+static inline t_key prefix_mismatch(t_key key, struct tnode *n)
+{
+ t_key prefix = n->key;
+
+ return (key ^ prefix) & (prefix | -prefix);
+}
+
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;
+ 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;
+ t_key cindex;
+ int ret = 1;
rcu_read_lock();
goto failed;
#ifdef CONFIG_IP_FIB_TRIE_STATS
- t->stats.gets++;
+ this_cpu_inc(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++;
-#endif
- goto backtrace;
- }
+ 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 >> bits)
+ * we know the value is child index
+ * else
+ * we have a mismatch in skip bits and failed
+ */
+ if (index >> n->bits)
+ break;
- if (IS_LEAF(n)) {
- ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
- if (ret > 0)
- goto backtrace;
+ /* we have found a leaf. Prefixes have already been compared */
+ if (IS_LEAF(n))
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.
+ /* only record pn and cindex if we are going to be chopping
+ * bits later. Otherwise we are just wasting cycles.
*/
-
- /* 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 (index) {
+ pn = n;
+ cindex = index;
}
- /*
- * 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.
- */
+ n = rcu_dereference(n->child[index]);
+ if (unlikely(!n))
+ goto backtrace;
+ }
- /* 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.
- */
+ /* 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;
- /*
- * 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.
+ /* 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)))
+ goto backtrace;
- pref_mismatch = mask_pfx(cn->key ^ key, cn->pos);
+ /* exit out and process leaf */
+ if (unlikely(IS_LEAF(n)))
+ break;
- /*
- * In short: If skipped bits in this node do not match
- * the search key, enter the "prefix matching"
- * state.directly.
+ /* 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
*/
- 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;
- }
-
- pn = (struct tnode *)n; /* Descend */
- chopped_off = 0;
- continue;
+ while ((n = rcu_dereference(*cptr)) == NULL) {
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++;
+ 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))
+ goto failed;
+#ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->backtrack);
#endif
- goto backtrace;
+ /* 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];
}
}
-failed:
- ret = 1;
+
found:
+ /* Step 3: Process the leaf, if that fails fall back to backtracing */
+ ret = check_leaf(tb, t, n, key, flp, res, fib_flags);
+ if (unlikely(ret > 0))
+ goto backtrace;
+failed:
rcu_read_unlock();
return ret;
}
/*
* 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);
} 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)
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;
* 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;
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)) {
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)
{
struct tnode *tn = iter->tnode;
unsigned int cindex = iter->index;
iter->tnode, iter->index, iter->depth);
rescan:
while (cindex < (1<<tn->bits)) {
- struct rt_trie_node *n = tnode_get_child_rcu(tn, cindex);
+ 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;
tn = p;
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]++;
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
- for (i = 0; i < (1<<tn->bits); i++)
- if (!tn->child[i])
+ for (i = 0; i < tnode_child_length(n); i++)
+ if (!rcu_access_pointer(n->child[i]))
s->nullpointers++;
}
}
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_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);
-
+ &prf, n->pos, 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) {
projects / cascardo / linux.git / blobdiff