diff options
Diffstat (limited to 'net/ipv4/fib_trie.c')
| -rw-r--r-- | net/ipv4/fib_trie.c | 1960 |
1 files changed, 934 insertions, 1026 deletions
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c index 18bcaf2..3daf022 100644 --- a/net/ipv4/fib_trie.c +++ b/net/ipv4/fib_trie.c @@ -83,28 +83,33 @@ #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 { @@ -115,20 +120,6 @@ 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; @@ -151,19 +142,13 @@ struct trie_stat { }; 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; /* @@ -176,170 +161,101 @@ static const int sync_pages = 128; 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; @@ -357,17 +273,23 @@ static inline void alias_free_mem_rcu(struct fib_alias *fa) 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); @@ -381,56 +303,31 @@ static struct tnode *tnode_alloc(size_t size) 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) +static inline void empty_child_inc(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); + ++n->empty_children ? : ++n->full_children; } -static void tnode_free_flush(void) +static inline void empty_child_dec(struct tnode *n) { - 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; @@ -449,462 +346,530 @@ static struct leaf_info *leaf_info_new(int plen) 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; - - /* compress one level */ + /* setup the parent pointer out of and back into this node */ + NODE_INIT_PARENT(tn, tp); + put_child_root(tp, t, tn->key, tn); - node_set_parent(n, NULL); - tnode_free_safe(tn); - return n; - } - } - return (struct rt_trie_node *) tn; -} + /* update all of the child parent pointers */ + update_children(tn); + /* all pointers should be clean so we are done */ + tnode_free(oldtnode); -static void tnode_clean_free(struct tnode *tn) -{ - int i; - struct tnode *tofree; + /* resize children now that oldtnode is freed */ + for (i = tnode_child_length(tn); i;) { + struct tnode *inode = tnode_get_child(tn, --i); - 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); + + /* link parent to nodes */ + put_child(tn, 2 * i + 1, node1); + put_child(tn, 2 * i, node0); + } + + /* 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; +} + +static int halve(struct trie *t, struct tnode *oldtnode) +{ + struct tnode *tn; + unsigned long i; + + pr_debug("In halve\n"); - left = (struct tnode *) tnode_get_child(tn, 2*i); - put_child(tn, 2*i, NULL); + tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1); + if (!tn) + return -ENOMEM; - BUG_ON(!left); + /* prepare oldtnode to be freed */ + tnode_free_init(oldtnode); - right = (struct tnode *) tnode_get_child(tn, 2*i+1); - put_child(tn, 2*i+1, NULL); + /* 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); - newn = tnode_new(left->key, tn->pos + tn->bits, 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; + } - if (!newn) - goto nomem; + tn->slen = slen; - put_child(tn, i/2, (struct rt_trie_node *)newn); - } + return slen; +} - } +/* 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; - for (i = 0; i < olen; i += 2) { - struct tnode *newBinNode; + /* Keep root node larger */ + threshold *= tp ? inflate_threshold : inflate_threshold_root; + used -= tn->empty_children; + used += tn->full_children; - left = tnode_get_child(oldtnode, i); - right = tnode_get_child(oldtnode, i+1); + /* if bits == KEYLENGTH then pos = 0, and will fail below */ - /* 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 (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; } - if (right == NULL) { - put_child(tn, i/2, left); - continue; + max_work--; + tn = rtnl_dereference(*cptr); + } + + /* 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; } - /* 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)); + max_work--; + tn = rtnl_dereference(*cptr); + } + + /* Only one child remains */ + if (should_collapse(tn)) { + collapse(t, tn); + return; + } + + /* Return if at least one deflate was run */ + if (max_work != MAX_WORK) + return; + + /* push the suffix length to the parent node */ + if (tn->slen > tn->pos) { + unsigned char slen = update_suffix(tn); + + 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; @@ -916,7 +881,7 @@ static struct leaf_info *find_leaf_info(struct leaf *l, int plen) 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); @@ -926,8 +891,51 @@ static inline struct list_head *get_fa_head(struct leaf *l, int 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)) { @@ -944,218 +952,174 @@ static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new) 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 */ + insert_leaf_info(l, li); - node_set_parent((struct rt_trie_node *)l, tp); - - 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; } @@ -1172,7 +1136,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg) u8 tos = cfg->fc_tos; u32 key, mask; int err; - struct leaf *l; + struct tnode *l; if (plen > 32) return -EINVAL; @@ -1329,18 +1293,130 @@ err: 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; + } + + 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]; + } + } - hlist_for_each_entry_rcu(li, hhead, hlist) { +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) { @@ -1355,9 +1431,9 @@ static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l, 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; } @@ -1371,241 +1447,48 @@ static int check_leaf(struct fib_table *tb, struct trie *t, struct leaf *l, 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++; + this_cpu_inc(stats->semantic_match_passed); #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; - } - - 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); } /* @@ -1619,7 +1502,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) 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) @@ -1684,7 +1567,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg) tb->tb_num_default--; if (list_empty(fa_head)) { - hlist_del_rcu(&li->hlist); + remove_leaf_info(l, li); free_leaf_info(li); } @@ -1717,12 +1600,13 @@ static int trie_flush_list(struct list_head *head) 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); @@ -1730,8 +1614,14 @@ static int trie_flush_leaf(struct leaf *l) if (list_empty(&li->falh)) { hlist_del_rcu(&li->hlist); free_leaf_info(li); + continue; } + + plen = li->plen; } + + l->slen = KEYLENGTH - plen; + return found; } @@ -1739,63 +1629,57 @@ static int trie_flush_leaf(struct leaf *l) * 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; + unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0; - if (c) - idx = tkey_extract_bits(c->key, p->pos, p->bits) + 1; - else - idx = 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); @@ -1810,19 +1694,28 @@ static struct leaf *trie_leafindex(struct trie *t, int index) 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; @@ -1830,6 +1723,11 @@ int fib_table_flush(struct fib_table *tb) 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); } @@ -1870,7 +1768,7 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah, 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; @@ -1906,7 +1804,7 @@ static int fn_trie_dump_leaf(struct leaf *l, struct fib_table *tb, 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]; @@ -1952,7 +1850,7 @@ void __init fib_trie_init(void) 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); } @@ -1973,7 +1871,14 @@ struct fib_table *fib_trie_table(u32 id) 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; } @@ -1988,10 +1893,10 @@ struct fib_trie_iter { 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 */ @@ -2001,8 +1906,8 @@ static struct rt_trie_node *fib_trie_get_next(struct fib_trie_iter *iter) 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)) { @@ -2010,7 +1915,7 @@ rescan: iter->index = cindex + 1; } else { /* push down one level */ - iter->tnode = (struct tnode *) n; + iter->tnode = n; iter->index = 0; ++iter->depth; } @@ -2021,9 +1926,9 @@ rescan: } /* 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; @@ -2033,10 +1938,10 @@ 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; @@ -2046,7 +1951,7 @@ static struct rt_trie_node *fib_trie_get_first(struct fib_trie_iter *iter, return NULL; if (IS_TNODE(n)) { - iter->tnode = (struct tnode *) n; + iter->tnode = n; iter->index = 0; iter->depth = 1; } else { @@ -2060,7 +1965,7 @@ static struct rt_trie_node *fib_trie_get_first(struct fib_trie_iter *iter, 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)); @@ -2068,7 +1973,6 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s) rcu_read_lock(); for (n = fib_trie_get_first(&iter, t); n; n = fib_trie_get_next(&iter)) { if (IS_LEAF(n)) { - struct leaf *l = (struct leaf *)n; struct leaf_info *li; s->leaves++; @@ -2076,19 +1980,13 @@ static void trie_collect_stats(struct trie *t, struct trie_stat *s) 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(); @@ -2111,7 +2009,7 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 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; @@ -2132,25 +2030,38 @@ static void trie_show_stats(struct seq_file *seq, struct trie_stat *stat) 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 */ @@ -2173,7 +2084,7 @@ static int fib_triestat_seq_show(struct seq_file *seq, void *v) 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]; @@ -2191,7 +2102,7 @@ static int fib_triestat_seq_show(struct seq_file *seq, void *v) 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 } } @@ -2212,7 +2123,7 @@ static const struct file_operations fib_triestat_fops = { .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); @@ -2224,7 +2135,7 @@ static struct rt_trie_node *fib_trie_get_idx(struct seq_file *seq, loff_t pos) 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); @@ -2253,7 +2164,7 @@ static void *fib_trie_seq_next(struct seq_file *seq, void *v, loff_t *pos) 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 */ @@ -2339,29 +2250,26 @@ static inline const char *rtn_type(char *buf, size_t len, unsigned int t) 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) { @@ -2411,9 +2319,9 @@ struct fib_route_iter { 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 */ @@ -2458,7 +2366,7 @@ static void *fib_route_seq_start(struct seq_file *seq, loff_t *pos) 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) { @@ -2504,7 +2412,7 @@ static unsigned int fib_flag_trans(int type, __be32 mask, const struct fib_info */ static int fib_route_seq_show(struct seq_file *seq, void *v) { - struct leaf *l = v; + struct tnode *l = v; struct leaf_info *li; if (v == SEQ_START_TOKEN) { |
