--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Tue, 2 Dec 2014 10:58:21 -0800
+Subject: [PATCH] fib_trie: Fix /proc/net/fib_trie when
+ CONFIG_IP_MULTIPLE_TABLES is not defined
+
+In recent testing I had disabled CONFIG_IP_MULTIPLE_TABLES and as a result
+when I ran "cat /proc/net/fib_trie" the main trie was displayed multiple
+times. I found that the problem line of code was in the function
+fib_trie_seq_next. Specifically the line below caused the indexes to go in
+the opposite direction of our traversal:
+
+ h = tb->tb_id & (FIB_TABLE_HASHSZ - 1);
+
+This issue was that the RT tables are defined such that RT_TABLE_LOCAL is ID
+255, while it is located at TABLE_LOCAL_INDEX of 0, and RT_TABLE_MAIN is 254
+with a TABLE_MAIN_INDEX of 1. This means that the above line will return 1
+for the local table and 0 for main. The result is that fib_trie_seq_next
+will return NULL at the end of the local table, fib_trie_seq_start will
+return the start of the main table, and then fib_trie_seq_next will loop on
+main forever as h will always return 0.
+
+The fix for this is to reverse the ordering of the two tables. It has the
+advantage of making it so that the tables now print in the same order
+regardless of if multiple tables are enabled or not. In order to make the
+definition consistent with the multiple tables case I simply masked the to
+RT_TABLE_XXX values by (FIB_TABLE_HASHSZ - 1). This way the two table
+layouts should always stay consistent.
+
+Fixes: 93456b6 ("[IPV4]: Unify access to the routing tables")
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/include/net/ip_fib.h
++++ b/include/net/ip_fib.h
+@@ -201,8 +201,8 @@ void fib_free_table(struct fib_table *tb
+
+ #ifndef CONFIG_IP_MULTIPLE_TABLES
+
+-#define TABLE_LOCAL_INDEX 0
+-#define TABLE_MAIN_INDEX 1
++#define TABLE_LOCAL_INDEX (RT_TABLE_LOCAL & (FIB_TABLE_HASHSZ - 1))
++#define TABLE_MAIN_INDEX (RT_TABLE_MAIN & (FIB_TABLE_HASHSZ - 1))
+
+ static inline struct fib_table *fib_get_table(struct net *net, u32 id)
+ {
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 10 Dec 2014 21:49:22 -0800
+Subject: [PATCH] fib_trie: Fix trie balancing issue if new node pushes down
+ existing node
+
+This patch addresses an issue with the level compression of the fib_trie.
+Specifically in the case of adding a new leaf that triggers a new node to
+be added that takes the place of the old node. The result is a trie where
+the 1 child tnode is on one side and one leaf is on the other which gives
+you a very deep trie. Below is the script I used to generate a trie on
+dummy0 with a 10.X.X.X family of addresses.
+
+ ip link add type dummy
+ ipval=184549374
+ bit=2
+ for i in `seq 1 23`
+ do
+ ifconfig dummy0:$bit $ipval/8
+ ipval=`expr $ipval - $bit`
+ bit=`expr $bit \* 2`
+ done
+ cat /proc/net/fib_triestat
+
+Running the script before the patch:
+
+ Local:
+ Aver depth: 10.82
+ Max depth: 23
+ Leaves: 29
+ Prefixes: 30
+ Internal nodes: 27
+ 1: 26 2: 1
+ Pointers: 56
+ Null ptrs: 1
+ Total size: 5 kB
+
+After applying the patch and repeating:
+
+ Local:
+ Aver depth: 4.72
+ Max depth: 9
+ Leaves: 29
+ Prefixes: 30
+ Internal nodes: 12
+ 1: 3 2: 2 3: 7
+ Pointers: 70
+ Null ptrs: 30
+ Total size: 4 kB
+
+What this fix does is start the rebalance at the newly created tnode
+instead of at the parent tnode. This way if there is a gap between the
+parent and the new node it doesn't prevent the new tnode from being
+coalesced with any pre-existing nodes that may have been pushed into one
+of the new nodes child branches.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -1143,8 +1143,9 @@ static struct list_head *fib_insert_node
+ put_child(tp, cindex, (struct rt_trie_node *)tn);
+ } else {
+ rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
+- tp = tn;
+ }
++
++ tp = tn;
+ }
+
+ if (tp && tp->pos + tp->bits > 32)
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:55:29 -0800
+Subject: [PATCH] fib_trie: Update usage stats to be percpu instead of
+ global variables
+
+The trie usage stats were currently being shared by all threads that were
+calling fib_table_lookup. As a result when multiple threads were
+performing lookups simultaneously the trie would begin to cache bounce
+between those threads.
+
+In order to prevent this I have updated the usage stats to use a set of
+percpu variables. By doing this we should be able to avoid the cache
+bouncing and still make use of these stats.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_frontend.c
++++ b/net/ipv4/fib_frontend.c
+@@ -67,7 +67,7 @@ static int __net_init fib4_rules_init(st
+ return 0;
+
+ fail:
+- kfree(local_table);
++ fib_free_table(local_table);
+ return -ENOMEM;
+ }
+ #else
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -153,7 +153,7 @@ struct trie_stat {
+ struct trie {
+ struct rt_trie_node __rcu *trie;
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- struct trie_use_stats stats;
++ struct trie_use_stats __percpu *stats;
+ #endif
+ };
+
+@@ -631,7 +631,7 @@ static struct rt_trie_node *resize(struc
+ 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;
+ }
+@@ -658,7 +658,7 @@ static struct rt_trie_node *resize(struc
+ 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;
+ }
+@@ -1357,7 +1357,7 @@ static int check_leaf(struct fib_table *
+ err = fib_props[fa->fa_type].error;
+ if (err) {
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- t->stats.semantic_match_passed++;
++ this_cpu_inc(t->stats->semantic_match_passed);
+ #endif
+ return err;
+ }
+@@ -1372,7 +1372,7 @@ static int check_leaf(struct fib_table *
+ 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;
+@@ -1388,7 +1388,7 @@ static int check_leaf(struct fib_table *
+ }
+
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- t->stats.semantic_match_miss++;
++ this_cpu_inc(t->stats->semantic_match_miss);
+ #endif
+ }
+
+@@ -1399,6 +1399,9 @@ int fib_table_lookup(struct fib_table *t
+ 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
+ int ret;
+ struct rt_trie_node *n;
+ struct tnode *pn;
+@@ -1417,7 +1420,7 @@ int fib_table_lookup(struct fib_table *t
+ goto failed;
+
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- t->stats.gets++;
++ this_cpu_inc(stats->gets);
+ #endif
+
+ /* Just a leaf? */
+@@ -1441,7 +1444,7 @@ int fib_table_lookup(struct fib_table *t
+
+ if (n == NULL) {
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- t->stats.null_node_hit++;
++ this_cpu_inc(stats->null_node_hit);
+ #endif
+ goto backtrace;
+ }
+@@ -1576,7 +1579,7 @@ backtrace:
+ chopped_off = 0;
+
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+- t->stats.backtrack++;
++ this_cpu_inc(stats->backtrack);
+ #endif
+ goto backtrace;
+ }
+@@ -1830,6 +1833,11 @@ 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);
+ }
+
+@@ -1973,7 +1981,14 @@ 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;
+ }
+@@ -2139,18 +2154,31 @@ static void trie_show_stats(struct seq_f
+
+ #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 */
+
+@@ -2191,7 +2219,7 @@ static int fib_triestat_seq_show(struct
+ 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
+ }
+ }
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:55:35 -0800
+Subject: [PATCH] fib_trie: Make leaf and tnode more uniform
+
+This change makes some fundamental changes to the way leaves and tnodes are
+constructed. The big differences are:
+1. Leaves now populate pos and bits indicating their full key size.
+2. Trie nodes now mask out their lower bits to be consistent with the leaf
+3. Both structures have been reordered so that rt_trie_node now consisists
+ of a much larger region including the pos, bits, and rcu portions of
+ the tnode structure.
+
+On 32b systems this will result in the leaf being 4B larger as the pos and
+bits values were added to a hole created by the key as it was only 4B in
+length.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -87,24 +87,38 @@
+
+ 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)
++struct tnode {
++ t_key key;
++ unsigned char bits; /* 2log(KEYLENGTH) bits needed */
++ unsigned char pos; /* 2log(KEYLENGTH) bits needed */
++ struct tnode __rcu *parent;
++ union {
++ struct rcu_head rcu;
++ struct tnode *tnode_free;
++ };
++ unsigned int full_children; /* KEYLENGTH bits needed */
++ unsigned int empty_children; /* KEYLENGTH bits needed */
++ struct rt_trie_node __rcu *child[0];
++};
+
+ struct rt_trie_node {
+- unsigned long parent;
+ t_key key;
++ unsigned char bits;
++ unsigned char pos;
++ struct tnode __rcu *parent;
++ struct rcu_head rcu;
+ };
+
+ struct leaf {
+- unsigned long parent;
+ t_key key;
+- struct hlist_head list;
++ unsigned char bits;
++ unsigned char pos;
++ struct tnode __rcu *parent;
+ struct rcu_head rcu;
++ struct hlist_head list;
+ };
+
+ struct leaf_info {
+@@ -115,20 +129,6 @@ 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;
+@@ -176,38 +176,27 @@ 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;
++/* 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 rt_trie_node *node, struct tnode *ptr)
+ {
+- 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 (node)
++ rcu_assign_pointer(node->parent, ptr);
+ }
+
+-/* 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);
+ }
+
+ /*
+@@ -215,7 +204,7 @@ static inline void node_set_parent(struc
+ */
+ static inline struct rt_trie_node *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]);
+ }
+@@ -225,16 +214,11 @@ static inline struct rt_trie_node *tnode
+ */
+ static inline struct rt_trie_node *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);
+@@ -336,11 +320,6 @@ static inline int tkey_mismatch(t_key a,
+
+ */
+
+-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;
+@@ -426,11 +405,20 @@ static void tnode_free_flush(void)
+ }
+ }
+
+-static struct leaf *leaf_new(void)
++static struct leaf *leaf_new(t_key key)
+ {
+ struct leaf *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;
+@@ -451,12 +439,16 @@ static struct tnode *tnode_new(t_key key
+ {
+ size_t sz = sizeof(struct tnode) + (sizeof(struct rt_trie_node *) << 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;
+ }
+@@ -473,10 +465,7 @@ static struct tnode *tnode_new(t_key key
+
+ static inline int tnode_full(const struct tnode *tn, const struct rt_trie_node *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,
+@@ -514,8 +503,7 @@ static void tnode_put_child_reorg(struct
+ 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);
+ }
+@@ -523,7 +511,7 @@ static void tnode_put_child_reorg(struct
+ #define MAX_WORK 10
+ static struct rt_trie_node *resize(struct trie *t, struct tnode *tn)
+ {
+- int i;
++ struct rt_trie_node *n = NULL;
+ struct tnode *old_tn;
+ int inflate_threshold_use;
+ int halve_threshold_use;
+@@ -536,12 +524,11 @@ static struct rt_trie_node *resize(struc
+ 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
+@@ -607,11 +594,9 @@ static struct rt_trie_node *resize(struc
+ *
+ */
+
+- 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 {
+@@ -637,8 +622,6 @@ static struct rt_trie_node *resize(struc
+ }
+ }
+
+- check_tnode(tn);
+-
+ /* Return if at least one inflate is run */
+ if (max_work != MAX_WORK)
+ return (struct rt_trie_node *) tn;
+@@ -666,21 +649,16 @@ static struct rt_trie_node *resize(struc
+
+
+ /* 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;
+ }
+@@ -760,8 +738,7 @@ static struct tnode *inflate(struct trie
+
+ /* A leaf or an internal node with skipped bits */
+
+- if (IS_LEAF(node) || ((struct tnode *) node)->pos >
+- tn->pos + tn->bits - 1) {
++ if (IS_LEAF(node) || (node->pos > (tn->pos + tn->bits - 1))) {
+ put_child(tn,
+ tkey_extract_bits(node->key, oldtnode->pos, oldtnode->bits + 1),
+ node);
+@@ -958,11 +935,9 @@ fib_find_node(struct trie *t, u32 key)
+ pos = 0;
+ n = rcu_dereference_rtnl(t->trie);
+
+- while (n != NULL && NODE_TYPE(n) == T_TNODE) {
++ while (n && IS_TNODE(n)) {
+ tn = (struct tnode *) n;
+
+- 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,
+@@ -988,7 +963,7 @@ static void trie_rebalance(struct trie *
+
+ 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);
+@@ -996,7 +971,7 @@ static void trie_rebalance(struct trie *
+ tnode_put_child_reorg(tp, cindex,
+ (struct rt_trie_node *)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);
+
+@@ -1048,11 +1023,9 @@ static struct list_head *fib_insert_node
+ * If it doesn't, we need to replace it with a T_TNODE.
+ */
+
+- while (n != NULL && NODE_TYPE(n) == T_TNODE) {
++ while (n && IS_TNODE(n)) {
+ 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;
+@@ -1087,12 +1060,11 @@ static struct list_head *fib_insert_node
+ insert_leaf_info(&l->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) {
+@@ -1569,7 +1541,7 @@ backtrace:
+ if (chopped_off <= pn->bits) {
+ cindex &= ~(1 << (chopped_off-1));
+ } else {
+- struct tnode *parent = node_parent_rcu((struct rt_trie_node *) pn);
++ struct tnode *parent = node_parent_rcu(pn);
+ if (!parent)
+ goto failed;
+
+@@ -1597,7 +1569,7 @@ EXPORT_SYMBOL_GPL(fib_table_lookup);
+ */
+ static void trie_leaf_remove(struct trie *t, struct leaf *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);
+
+@@ -2375,7 +2347,7 @@ static int fib_trie_seq_show(struct seq_
+
+ if (IS_TNODE(n)) {
+ struct tnode *tn = (struct tnode *) n;
+- __be32 prf = htonl(mask_pfx(tn->key, tn->pos));
++ __be32 prf = htonl(tn->key);
+
+ seq_indent(seq, iter->depth-1);
+ seq_printf(seq, " +-- %pI4/%d %d %d %d\n",
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:55:41 -0800
+Subject: [PATCH] fib_trie: Merge tnode_free and leaf_free into node_free
+
+Both the leaf and the tnode had an rcu_head in them, but they had them in
+slightly different places. Since we now have them in the same spot and
+know that any node with bits == 0 is a leaf and the rest are either vmalloc
+or kmalloc tnodes depending on the value of bits it makes it easy to combine
+the functions and reduce overhead.
+
+In addition I have taken advantage of the rcu_head pointer to go ahead and
+put together a simple linked list instead of using the tnode pointer as
+this way we can merge either type of structure for freeing.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -95,15 +95,17 @@ struct tnode {
+ unsigned char bits; /* 2log(KEYLENGTH) bits needed */
+ unsigned char pos; /* 2log(KEYLENGTH) bits needed */
+ struct tnode __rcu *parent;
+- union {
+- struct rcu_head rcu;
+- struct tnode *tnode_free;
+- };
++ struct rcu_head rcu;
++ /* everything above this comment must be the same as rt_trie_node */
+ unsigned int full_children; /* KEYLENGTH bits needed */
+ unsigned int empty_children; /* KEYLENGTH bits needed */
+ struct rt_trie_node __rcu *child[0];
+ };
+
++/* This struct represents the shared bits between tnode and leaf. If any
++ * ordering is changed here is must also be updated in tnode and leaf as
++ * well.
++ */
+ struct rt_trie_node {
+ t_key key;
+ unsigned char bits;
+@@ -118,6 +120,7 @@ struct leaf {
+ unsigned char pos;
+ struct tnode __rcu *parent;
+ struct rcu_head rcu;
++ /* everything above this comment must be the same as rt_trie_node */
+ struct hlist_head list;
+ };
+
+@@ -163,7 +166,7 @@ static struct rt_trie_node *resize(struc
+ 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;
+
+ /*
+@@ -336,17 +339,23 @@ static inline void alias_free_mem_rcu(st
+ 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 rt_trie_node *))
+
+-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 rt_trie_node *n = container_of(head, struct rt_trie_node, 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);
+@@ -360,43 +369,24 @@ static struct tnode *tnode_alloc(size_t
+ 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) {
+@@ -437,7 +427,7 @@ static struct leaf_info *leaf_info_new(i
+
+ 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;
+
+@@ -666,15 +656,15 @@ no_children:
+
+ static void tnode_clean_free(struct tnode *tn)
+ {
++ struct rt_trie_node *tofree;
+ int i;
+- struct tnode *tofree;
+
+ 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)
+@@ -717,7 +707,7 @@ static struct tnode *inflate(struct trie
+ inode->bits - 1);
+
+ if (!right) {
+- tnode_free(left);
++ node_free(left);
+ goto nomem;
+ }
+
+@@ -1068,7 +1058,7 @@ static struct list_head *fib_insert_node
+ li = leaf_info_new(plen);
+
+ if (!li) {
+- free_leaf(l);
++ node_free(l);
+ return NULL;
+ }
+
+@@ -1100,7 +1090,7 @@ static struct list_head *fib_insert_node
+
+ if (!tn) {
+ free_leaf_info(li);
+- free_leaf(l);
++ node_free(l);
+ return NULL;
+ }
+
+@@ -1580,7 +1570,7 @@ static void trie_leaf_remove(struct trie
+ } else
+ RCU_INIT_POINTER(t->trie, NULL);
+
+- free_leaf(l);
++ node_free(l);
+ }
+
+ /*
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:55:47 -0800
+Subject: [PATCH] fib_trie: Merge leaf into tnode
+
+This change makes it so that leaf and tnode are the same struct. As a
+result there is no need for rt_trie_node anymore since everyting can be
+merged into tnode.
+
+On 32b systems this results in the leaf being 4 bytes larger, however I
+don't know if that is really an issue as this and an eariler patch that
+added bits & pos have increased the size from 20 to 28. If I am not
+mistaken slub/slab allocate on power of 2 sizes so 20 was likely being
+rounded up to 32 anyway.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -96,32 +96,16 @@ struct tnode {
+ unsigned char pos; /* 2log(KEYLENGTH) bits needed */
+ struct tnode __rcu *parent;
+ struct rcu_head rcu;
+- /* everything above this comment must be the same as rt_trie_node */
+- unsigned int full_children; /* KEYLENGTH bits needed */
+- unsigned int empty_children; /* KEYLENGTH bits needed */
+- struct rt_trie_node __rcu *child[0];
+-};
+-
+-/* This struct represents the shared bits between tnode and leaf. If any
+- * ordering is changed here is must also be updated in tnode and leaf as
+- * well.
+- */
+-struct rt_trie_node {
+- t_key key;
+- unsigned char bits;
+- unsigned char pos;
+- struct tnode __rcu *parent;
+- struct rcu_head rcu;
+-};
+-
+-struct leaf {
+- t_key key;
+- unsigned char bits;
+- unsigned char pos;
+- struct tnode __rcu *parent;
+- struct rcu_head rcu;
+- /* everything above this comment must be the same as rt_trie_node */
+- struct hlist_head list;
++ 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 {
+@@ -154,15 +138,15 @@ 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 __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 */
+@@ -186,10 +170,10 @@ static struct kmem_cache *trie_leaf_kmem
+ #define node_parent_rcu(n) rcu_dereference_rtnl((n)->parent)
+
+ /* wrapper for rcu_assign_pointer */
+-static inline void node_set_parent(struct rt_trie_node *node, struct tnode *ptr)
++static inline void node_set_parent(struct tnode *n, struct tnode *tp)
+ {
+- if (node)
+- rcu_assign_pointer(node->parent, ptr);
++ if (n)
++ rcu_assign_pointer(n->parent, tp);
+ }
+
+ #define NODE_INIT_PARENT(n, p) RCU_INIT_POINTER((n)->parent, p)
+@@ -205,7 +189,7 @@ static inline int tnode_child_length(con
+ /*
+ * 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 >= tnode_child_length(tn));
+
+@@ -215,7 +199,7 @@ static inline struct rt_trie_node *tnode
+ /*
+ * 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 >= tnode_child_length(tn));
+
+@@ -340,11 +324,11 @@ static inline void alias_free_mem_rcu(st
+ }
+
+ #define TNODE_KMALLOC_MAX \
+- ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct rt_trie_node *))
++ ilog2((PAGE_SIZE - sizeof(struct tnode)) / sizeof(struct tnode *))
+
+ static void __node_free_rcu(struct rcu_head *head)
+ {
+- struct rt_trie_node *n = container_of(head, struct rt_trie_node, rcu);
++ struct tnode *n = container_of(head, struct tnode, rcu);
+
+ if (IS_LEAF(n))
+ kmem_cache_free(trie_leaf_kmem, n);
+@@ -395,9 +379,9 @@ static void tnode_free_flush(void)
+ }
+ }
+
+-static struct leaf *leaf_new(t_key key)
++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 = NULL;
+ /* set key and pos to reflect full key value
+@@ -444,7 +428,7 @@ static struct tnode *tnode_new(t_key key
+ }
+
+ pr_debug("AT %p s=%zu %zu\n", tn, sizeof(struct tnode),
+- sizeof(struct rt_trie_node *) << bits);
++ sizeof(struct tnode *) << bits);
+ return tn;
+ }
+
+@@ -453,13 +437,13 @@ static struct tnode *tnode_new(t_key key
+ * 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)
+ {
+ 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);
+ }
+@@ -469,10 +453,10 @@ static inline void put_child(struct tnod
+ * 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);
+@@ -499,10 +483,9 @@ static void tnode_put_child_reorg(struct
+ }
+
+ #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)
+ {
+- struct rt_trie_node *n = NULL;
+- struct tnode *old_tn;
++ struct tnode *old_tn, *n = NULL;
+ int inflate_threshold_use;
+ int halve_threshold_use;
+ int max_work;
+@@ -614,7 +597,7 @@ static struct rt_trie_node *resize(struc
+
+ /* 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
+@@ -650,13 +633,13 @@ no_children:
+ tnode_free_safe(tn);
+ return n;
+ }
+- return (struct rt_trie_node *) tn;
++ return tn;
+ }
+
+
+ static void tnode_clean_free(struct tnode *tn)
+ {
+- struct rt_trie_node *tofree;
++ struct tnode *tofree;
+ int i;
+
+ for (i = 0; i < tnode_child_length(tn); i++) {
+@@ -667,10 +650,10 @@ static void tnode_clean_free(struct tnod
+ 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");
+@@ -690,11 +673,8 @@ static struct tnode *inflate(struct trie
+ 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;
+
+@@ -711,33 +691,29 @@ static struct tnode *inflate(struct trie
+ 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) || (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]));
+@@ -769,12 +745,12 @@ static struct tnode *inflate(struct trie
+ * 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);
+@@ -796,12 +772,11 @@ nomem:
+ 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");
+
+@@ -830,7 +805,7 @@ static struct tnode *halve(struct trie *
+ if (!newn)
+ goto nomem;
+
+- put_child(tn, i/2, (struct rt_trie_node *)newn);
++ put_child(tn, i/2, newn);
+ }
+
+ }
+@@ -855,7 +830,7 @@ static struct tnode *halve(struct trie *
+ }
+
+ /* 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);
+@@ -871,7 +846,7 @@ nomem:
+ /* 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;
+@@ -883,7 +858,7 @@ static struct leaf_info *find_leaf_info(
+ 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);
+
+@@ -915,32 +890,25 @@ static void insert_leaf_info(struct hlis
+
+ /* 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);
++ struct tnode *n = rcu_dereference_rtnl(t->trie);
++ int pos = 0;
+
+ while (n && IS_TNODE(n)) {
+- tn = (struct tnode *) n;
+-
+- if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+- pos = tn->pos + tn->bits;
+- n = tnode_get_child_rcu(tn,
++ 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;
+ }
+@@ -956,14 +924,13 @@ static void trie_rebalance(struct trie *
+ 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(tn);
+ if (!tp)
+- rcu_assign_pointer(t->trie, (struct rt_trie_node *)tn);
++ rcu_assign_pointer(t->trie, tn);
+
+ tnode_free_flush();
+ if (!tp)
+@@ -973,9 +940,9 @@ static void trie_rebalance(struct trie *
+
+ /* 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();
+ }
+
+@@ -985,8 +952,8 @@ static struct list_head *fib_insert_node
+ {
+ 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;
+@@ -1014,17 +981,15 @@ static struct list_head *fib_insert_node
+ */
+
+ while (n && IS_TNODE(n)) {
+- tn = (struct tnode *) n;
+-
+- if (tkey_sub_equals(tn->key, pos, tn->pos-pos, key)) {
+- tp = tn;
+- pos = tn->pos + tn->bits;
+- n = tnode_get_child(tn,
++ 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;
+ }
+@@ -1040,14 +1005,13 @@ static struct list_head *fib_insert_node
+ /* 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(key);
+@@ -1068,10 +1032,10 @@ static struct list_head *fib_insert_node
+ 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. */
+ /*
+@@ -1094,17 +1058,17 @@ static struct list_head *fib_insert_node
+ 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;
+@@ -1134,7 +1098,7 @@ int fib_table_insert(struct fib_table *t
+ u8 tos = cfg->fc_tos;
+ u32 key, mask;
+ int err;
+- struct leaf *l;
++ struct tnode *l;
+
+ if (plen > 32)
+ return -EINVAL;
+@@ -1292,7 +1256,7 @@ err:
+ }
+
+ /* 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)
+ {
+@@ -1365,7 +1329,7 @@ int fib_table_lookup(struct fib_table *t
+ struct trie_use_stats __percpu *stats = t->stats;
+ #endif
+ int ret;
+- struct rt_trie_node *n;
++ struct tnode *n;
+ struct tnode *pn;
+ unsigned int pos, bits;
+ t_key key = ntohl(flp->daddr);
+@@ -1387,11 +1351,11 @@ int fib_table_lookup(struct fib_table *t
+
+ /* Just a leaf? */
+ if (IS_LEAF(n)) {
+- ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
++ ret = check_leaf(tb, t, n, key, flp, res, fib_flags);
+ goto found;
+ }
+
+- pn = (struct tnode *) n;
++ pn = n;
+ chopped_off = 0;
+
+ while (pn) {
+@@ -1412,13 +1376,13 @@ int fib_table_lookup(struct fib_table *t
+ }
+
+ if (IS_LEAF(n)) {
+- ret = check_leaf(tb, t, (struct leaf *)n, key, flp, res, fib_flags);
++ ret = check_leaf(tb, t, n, key, flp, res, fib_flags);
+ if (ret > 0)
+ goto backtrace;
+ goto found;
+ }
+
+- cn = (struct tnode *)n;
++ cn = n;
+
+ /*
+ * It's a tnode, and we can do some extra checks here if we
+@@ -1506,7 +1470,7 @@ int fib_table_lookup(struct fib_table *t
+ current_prefix_length = mp;
+ }
+
+- pn = (struct tnode *)n; /* Descend */
++ pn = n; /* Descend */
+ chopped_off = 0;
+ continue;
+
+@@ -1557,7 +1521,7 @@ 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(l);
+
+@@ -1584,7 +1548,7 @@ int fib_table_delete(struct fib_table *t
+ 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)
+@@ -1682,7 +1646,7 @@ static int trie_flush_list(struct list_h
+ 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;
+@@ -1704,7 +1668,7 @@ static int trie_flush_leaf(struct leaf *
+ * 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;
+@@ -1720,47 +1684,46 @@ static struct leaf *leaf_walk_rcu(struct
+ 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);
+@@ -1775,7 +1738,7 @@ static struct leaf *trie_leafindex(struc
+ 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)) {
+@@ -1840,7 +1803,7 @@ static int fn_trie_dump_fa(t_key key, in
+ 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;
+@@ -1876,7 +1839,7 @@ static int fn_trie_dump_leaf(struct leaf
+ 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];
+@@ -1922,7 +1885,7 @@ 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);
+ }
+@@ -1965,7 +1928,7 @@ 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)
+ {
+ struct tnode *tn = iter->tnode;
+ unsigned int cindex = iter->index;
+@@ -1979,7 +1942,7 @@ static struct rt_trie_node *fib_trie_get
+ 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)) {
+@@ -1987,7 +1950,7 @@ rescan:
+ iter->index = cindex + 1;
+ } else {
+ /* push down one level */
+- iter->tnode = (struct tnode *) n;
++ iter->tnode = n;
+ iter->index = 0;
+ ++iter->depth;
+ }
+@@ -1998,7 +1961,7 @@ 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;
+ tn = p;
+@@ -2010,10 +1973,10 @@ 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;
+@@ -2023,7 +1986,7 @@ static struct rt_trie_node *fib_trie_get
+ return NULL;
+
+ if (IS_TNODE(n)) {
+- iter->tnode = (struct tnode *) n;
++ iter->tnode = n;
+ iter->index = 0;
+ iter->depth = 1;
+ } else {
+@@ -2037,7 +2000,7 @@ static struct rt_trie_node *fib_trie_get
+
+ 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));
+@@ -2045,7 +2008,6 @@ static void trie_collect_stats(struct tr
+ 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++;
+@@ -2053,18 +2015,17 @@ static void trie_collect_stats(struct tr
+ 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++;
+ }
+ }
+@@ -2088,7 +2049,7 @@ static void trie_show_stats(struct seq_f
+ 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;
+@@ -2109,7 +2070,7 @@ static void trie_show_stats(struct seq_f
+ 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);
+ }
+@@ -2163,7 +2124,7 @@ static int fib_triestat_seq_show(struct
+ 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];
+@@ -2202,7 +2163,7 @@ static const struct file_operations fib_
+ .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);
+@@ -2214,7 +2175,7 @@ static struct rt_trie_node *fib_trie_get
+ 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);
+@@ -2243,7 +2204,7 @@ static void *fib_trie_seq_next(struct se
+ 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 */
+@@ -2330,29 +2291,26 @@ static inline const char *rtn_type(char
+ 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(tn->key);
++ __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) {
+@@ -2402,9 +2360,9 @@ 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 */
+@@ -2449,7 +2407,7 @@ static void *fib_route_seq_start(struct
+ 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) {
+@@ -2495,7 +2453,7 @@ static unsigned int fib_flag_trans(int t
+ */
+ 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) {
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:55:54 -0800
+Subject: [PATCH] fib_trie: Optimize fib_table_lookup to avoid wasting
+ time on loops/variables
+
+This patch is meant to reduce the complexity of fib_table_lookup by reducing
+the number of variables to the bare minimum while still keeping the same if
+not improved functionality versus the original.
+
+Most of this change was started off by the desire to rid the function of
+chopped_off and current_prefix_length as they actually added very little to
+the function since they only applied when computing the cindex. I was able
+to replace them mostly with just a check for the prefix match. As long as
+the prefix between the key and the node being tested was the same we know
+we can search the tnode fully versus just testing cindex 0.
+
+The second portion of the change ended up being a massive reordering.
+Originally the calls to check_leaf were up near the start of the loop, and
+the backtracing and descending into lower levels of tnodes was later. This
+didn't make much sense as the structure of the tree means the leaves are
+always the last thing to be tested. As such I reordered things so that we
+instead have a loop that will delve into the tree and only exit when we
+have either found a leaf or we have exhausted the tree. The advantage of
+rearranging things like this is that we can fully inline check_leaf since
+there is now only one reference to it in the function.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -90,6 +90,9 @@ typedef unsigned int t_key;
+ #define IS_TNODE(n) ((n)->bits)
+ #define IS_LEAF(n) (!(n)->bits)
+
++#define get_shift(_kv) (KEYLENGTH - (_kv)->pos - (_kv)->bits)
++#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> get_shift(_kv))
++
+ struct tnode {
+ t_key key;
+ unsigned char bits; /* 2log(KEYLENGTH) bits needed */
+@@ -1281,7 +1284,7 @@ static int check_leaf(struct fib_table *
+ continue;
+ fib_alias_accessed(fa);
+ err = fib_props[fa->fa_type].error;
+- if (err) {
++ if (unlikely(err < 0)) {
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(t->stats->semantic_match_passed);
+ #endif
+@@ -1303,7 +1306,7 @@ static int check_leaf(struct fib_table *
+ 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;
+@@ -1321,23 +1324,24 @@ static int check_leaf(struct fib_table *
+ 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;
++ struct trie *t = (struct trie *)tb->tb_data;
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+ struct trie_use_stats __percpu *stats = t->stats;
+ #endif
+- int ret;
+- struct tnode *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;
++ const t_key key = ntohl(flp->daddr);
++ struct tnode *n, *pn;
++ t_key cindex;
++ int ret = 1;
+
+ rcu_read_lock();
+
+@@ -1349,170 +1353,102 @@ int fib_table_lookup(struct fib_table *t
+ this_cpu_inc(stats->gets);
+ #endif
+
+- /* Just a leaf? */
+- if (IS_LEAF(n)) {
+- ret = check_leaf(tb, t, n, key, flp, res, fib_flags);
+- goto found;
+- }
+-
+ pn = n;
+- chopped_off = 0;
+-
+- while (pn) {
+- pos = pn->pos;
+- bits = pn->bits;
++ cindex = 0;
+
+- 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
+- this_cpu_inc(stats->null_node_hit);
+-#endif
+- goto backtrace;
+- }
++ /* 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, 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 = 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.
+- */
+-
+- /* 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.
+- */
++ n = rcu_dereference(n->child[index]);
++ if (unlikely(!n))
++ goto backtrace;
++ }
+
+- /*
+- * Note: We aren't very concerned about the piece of
+- * the key that precede pn->pos+pn->bits, since these
+- * have already been checked. The bits after cn->pos
+- * aren't checked since these are by definition
+- * "unknown" at this point. Thus, what we want to see
+- * is if we are about to enter the "prefix matching"
+- * state, and in that case verify that the skipped
+- * bits that will prevail throughout this subtree are
+- * zero, as they have to be if we are to find a
+- * matching prefix.
++ /* 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)))
++ 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 = 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(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
+- this_cpu_inc(stats->backtrack);
++ if (!n)
++ this_cpu_inc(stats->null_node_hit);
+ #endif
+- goto backtrace;
++ /* 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
++ /* 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;
+ }
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:00 -0800
+Subject: [PATCH] fib_trie: Optimize fib_find_node
+
+This patch makes use of the same features I made use of for
+fib_table_lookup to streamline fib_find_node. The resultant code should be
+smaller and run faster than the original.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -892,28 +892,34 @@ static void insert_leaf_info(struct hlis
+ }
+
+ /* 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);
+- int pos = 0;
+
+- 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,
+- n->pos,
+- n->bits));
+- } 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 cindex. 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 cindex
++ * else
++ * we have a mismatch in skip bits and failed
++ */
++ if (index >> n->bits)
++ return NULL;
++
++ /* we have found a leaf. Prefixes have already been compared */
++ if (IS_LEAF(n))
+ break;
+- }
+- /* Case we have found a leaf. Compare prefixes */
+
+- if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key))
+- return n;
++ n = rcu_dereference_rtnl(n->child[index]);
++ }
+
+- return NULL;
++ return n;
+ }
+
+ static void trie_rebalance(struct trie *t, struct tnode *tn)
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:06 -0800
+Subject: [PATCH] fib_trie: Optimize fib_table_insert
+
+This patch updates the fib_table_insert function to take advantage of the
+changes made to improve the performance of fib_table_lookup. As a result
+the code should be smaller and run faster then the original.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -222,31 +222,6 @@ static inline t_key tkey_extract_bits(t_
+ 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
+@@ -485,6 +460,15 @@ static void tnode_put_child_reorg(struct
+ rcu_assign_pointer(tn->child[i], n);
+ }
+
++static 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);
++}
++
+ #define MAX_WORK 10
+ static struct tnode *resize(struct trie *t, struct tnode *tn)
+ {
+@@ -959,138 +943,100 @@ static void trie_rebalance(struct trie *
+
+ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
+ {
+- int pos, newpos;
+- struct tnode *tp = NULL, *tn = NULL;
+- struct tnode *n;
+- struct tnode *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) {
++ unsigned long index = get_index(key, n);
+
+- 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,
+- n->pos,
+- n->bits));
+-
+- BUG_ON(n && node_parent(n) != tp);
+- } else
++ /* 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)) {
+- 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->list, li);
++ return fa_head;
++ }
+
+- fa_head = &li->falh;
+- insert_leaf_info(&n->list, li);
+- goto done;
++ tp = n;
++ n = rcu_dereference_rtnl(n->child[index]);
+ }
+- l = leaf_new(key);
+-
+- if (!l)
+- return NULL;
+-
+- li = leaf_info_new(plen);
+
+- if (!li) {
+- node_free(l);
++ l = leaf_new(key);
++ if (!l) {
++ free_leaf_info(li);
+ return NULL;
+ }
+
+- fa_head = &li->falh;
+ insert_leaf_info(&l->list, li);
+
+- if (t->trie && n == NULL) {
+- /* Case 2: n is NULL, and will just insert a new leaf */
+-
+- node_set_parent(l, tp);
+-
+- cindex = tkey_extract_bits(key, tp->pos, tp->bits);
+- put_child(tp, cindex, 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
+- */
++ /* 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;
++ int newpos;
+
+- 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 */
+- }
++ newpos = KEYLENGTH - __fls(n->key ^ key) - 1;
+
++ tn = tnode_new(key, newpos, 1);
+ if (!tn) {
+ free_leaf_info(li);
+ node_free(l);
+ return NULL;
+ }
+
+- node_set_parent(tn, tp);
+-
+- missbit = tkey_extract_bits(key, newpos, 1);
+- 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, tn);
+- } else {
+- rcu_assign_pointer(t->trie, tn);
+- }
++ /* initialize routes out of node */
++ NODE_INIT_PARENT(tn, tp);
++ put_child(tn, get_index(key, tn) ^ 1, n);
++
++ /* 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;
+ }
+
+@@ -1470,11 +1416,11 @@ static void trie_leaf_remove(struct trie
+ 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);
++ }
+
+ node_free(l);
+ }
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:12 -0800
+Subject: [PATCH] fib_trie: Update meaning of pos to represent unchecked
+ bits
+
+This change moves the pos value to the other side of the "bits" field. By
+doing this it actually simplifies a significant amount of code in the trie.
+
+For example when halving a tree we know that the bit lost exists at
+oldnode->pos, and if we inflate the tree the new bit being add is at
+tn->pos. Previously to find those bits you would have to subtract pos and
+bits from the keylength or start with a value of (1 << 31) and then shift
+that.
+
+There are a number of spots throughout the code that benefit from this. In
+the case of the hot-path searches the main advantage is that we can drop 2
+or more operations from the search path as we no longer need to compute the
+value for the index to be shifted by and can instead just use the raw pos
+value.
+
+In addition the tkey_extract_bits is now defunct and can be replaced by
+get_index since the two operations were doing the same thing, but now
+get_index does it much more quickly as it is only an xor and shift versus a
+pair of shifts and a subtraction.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -90,8 +90,7 @@ typedef unsigned int t_key;
+ #define IS_TNODE(n) ((n)->bits)
+ #define IS_LEAF(n) (!(n)->bits)
+
+-#define get_shift(_kv) (KEYLENGTH - (_kv)->pos - (_kv)->bits)
+-#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> get_shift(_kv))
++#define get_index(_key, _kv) (((_key) ^ (_kv)->key) >> (_kv)->pos)
+
+ struct tnode {
+ t_key key;
+@@ -209,81 +208,64 @@ static inline struct tnode *tnode_get_ch
+ return rcu_dereference_rtnl(tn->child[i]);
+ }
+
+-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;
+-}
+-
+-/*
+- 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.
+-
+-*/
++/* 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;
+@@ -367,7 +349,7 @@ static struct tnode *leaf_new(t_key key)
+ * as the nodes are searched
+ */
+ l->key = key;
+- l->pos = KEYLENGTH;
++ l->pos = 0;
+ /* set bits to 0 indicating we are not a tnode */
+ l->bits = 0;
+
+@@ -400,7 +382,7 @@ static struct tnode *tnode_new(t_key key
+ tn->parent = NULL;
+ tn->pos = pos;
+ tn->bits = bits;
+- tn->key = mask_pfx(key, pos);
++ tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
+ tn->full_children = 0;
+ tn->empty_children = 1<<bits;
+ }
+@@ -410,14 +392,12 @@ static struct tnode *tnode_new(t_key key
+ 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 tnode *n)
+ {
+- return n && IS_TNODE(n) && (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,
+@@ -641,11 +621,12 @@ static struct tnode *inflate(struct trie
+ {
+ int olen = tnode_child_length(oldtnode);
+ struct tnode *tn;
++ t_key m;
+ int i;
+
+ 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);
+@@ -656,21 +637,18 @@ static struct tnode *inflate(struct trie
+ * fails. In case of failure we return the oldnode and inflate
+ * of tnode is ignored.
+ */
++ for (i = 0, m = 1u << tn->pos; i < olen; i++) {
++ struct tnode *inode = tnode_get_child(oldtnode, i);
+
+- for (i = 0; i < olen; i++) {
+- struct tnode *inode;
+-
+- inode = tnode_get_child(oldtnode, i);
+- if (tnode_full(oldtnode, inode) && inode->bits > 1) {
++ if (tnode_full(oldtnode, inode) && (inode->bits > 1)) {
+ struct tnode *left, *right;
+- t_key m = ~0U << (KEYLENGTH - 1) >> inode->pos;
+
+- left = tnode_new(inode->key&(~m), inode->pos + 1,
++ left = tnode_new(inode->key & ~m, inode->pos,
+ inode->bits - 1);
+ if (!left)
+ goto nomem;
+
+- right = tnode_new(inode->key|m, inode->pos + 1,
++ right = tnode_new(inode->key | m, inode->pos,
+ inode->bits - 1);
+
+ if (!right) {
+@@ -694,9 +672,7 @@ static struct tnode *inflate(struct trie
+
+ /* A leaf or an internal node with skipped bits */
+ if (!tnode_full(oldtnode, inode)) {
+- put_child(tn,
+- tkey_extract_bits(inode->key, tn->pos, tn->bits),
+- inode);
++ put_child(tn, get_index(inode->key, tn), inode);
+ continue;
+ }
+
+@@ -767,7 +743,7 @@ static struct tnode *halve(struct trie *
+
+ pr_debug("In halve\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);
+@@ -787,7 +763,7 @@ static struct tnode *halve(struct trie *
+ if (left && right) {
+ struct tnode *newn;
+
+- newn = tnode_new(left->key, tn->pos + tn->bits, 1);
++ newn = tnode_new(left->key, oldtnode->pos, 1);
+
+ if (!newn)
+ goto nomem;
+@@ -915,7 +891,7 @@ static void trie_rebalance(struct trie *
+ key = tn->key;
+
+ while (tn != NULL && (tp = node_parent(tn)) != NULL) {
+- cindex = tkey_extract_bits(key, tp->pos, tp->bits);
++ cindex = get_index(key, tp);
+ wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
+ tn = resize(t, tn);
+
+@@ -1005,11 +981,8 @@ static struct list_head *fib_insert_node
+ */
+ if (n) {
+ struct tnode *tn;
+- int newpos;
+-
+- newpos = KEYLENGTH - __fls(n->key ^ key) - 1;
+
+- tn = tnode_new(key, newpos, 1);
++ tn = tnode_new(key, __fls(key ^ n->key), 1);
+ if (!tn) {
+ free_leaf_info(li);
+ node_free(l);
+@@ -1559,12 +1532,7 @@ static int trie_flush_leaf(struct tnode
+ static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
+ {
+ do {
+- t_key idx;
+-
+- if (c)
+- idx = tkey_extract_bits(c->key, p->pos, p->bits) + 1;
+- else
+- idx = 0;
++ t_key idx = c ? idx = get_index(c->key, p) + 1 : 0;
+
+ while (idx < 1u << p->bits) {
+ c = tnode_get_child_rcu(p, idx++);
+@@ -1851,7 +1819,7 @@ rescan:
+ /* Current node exhausted, pop back up */
+ 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;
+@@ -2187,10 +2155,10 @@ static int fib_trie_seq_show(struct seq_
+ if (IS_TNODE(n)) {
+ __be32 prf = htonl(n->key);
+
+- seq_indent(seq, iter->depth - 1);
+- seq_printf(seq, " +-- %pI4/%d %d %d %d\n",
+- &prf, n->pos, n->bits, n->full_children,
+- n->empty_children);
++ seq_indent(seq, iter->depth-1);
++ 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_info *li;
+ __be32 val = htonl(n->key);
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:18 -0800
+Subject: [PATCH] fib_trie: Use unsigned long for anything dealing with a
+ shift by bits
+
+This change makes it so that anything that can be shifted by, or compared
+to a value shifted by bits is updated to be an unsigned long. This is
+mostly a precaution against an insanely huge address space that somehow
+starts coming close to the 2^32 root node size which would require
+something like 1.5 billion addresses.
+
+I chose unsigned long instead of unsigned long long since I do not believe
+it is possible to allocate a 32 bit tnode on a 32 bit system as the memory
+consumed would be 16GB + 28B which exceeds the addressible space for any
+one process.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -146,8 +146,8 @@ struct trie {
+ #endif
+ };
+
+-static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n,
+- int wasfull);
++static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
++ struct tnode *n, int wasfull);
+ 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);
+@@ -183,25 +183,23 @@ static inline void node_set_parent(struc
+ /* 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 int tnode_child_length(const struct tnode *tn)
++static inline unsigned long tnode_child_length(const struct tnode *tn)
+ {
+ return (1ul << tn->bits) & ~(1ul);
+ }
+
+-/*
+- * caller must hold RTNL
+- */
+-static inline struct tnode *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 >= tnode_child_length(tn));
+
+ return rtnl_dereference(tn->child[i]);
+ }
+
+-/*
+- * caller must hold RCU read lock or RTNL
+- */
+-static inline struct tnode *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 >= tnode_child_length(tn));
+
+@@ -400,7 +398,7 @@ static inline int tnode_full(const struc
+ return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
+ }
+
+-static inline void put_child(struct tnode *tn, int i,
++static inline void put_child(struct tnode *tn, unsigned long i,
+ struct tnode *n)
+ {
+ tnode_put_child_reorg(tn, i, n, -1);
+@@ -411,13 +409,13 @@ static inline void put_child(struct tnod
+ * Update the value of full_children and empty_children.
+ */
+
+-static void tnode_put_child_reorg(struct tnode *tn, int i, struct tnode *n,
+- int wasfull)
++static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
++ struct tnode *n, int wasfull)
+ {
+ struct tnode *chi = rtnl_dereference(tn->child[i]);
+ int isfull;
+
+- BUG_ON(i >= 1<<tn->bits);
++ BUG_ON(i >= tnode_child_length(tn));
+
+ /* update emptyChildren */
+ if (n == NULL && chi != NULL)
+@@ -607,10 +605,10 @@ no_children:
+ static void tnode_clean_free(struct tnode *tn)
+ {
+ struct tnode *tofree;
+- int i;
++ unsigned long i;
+
+ for (i = 0; i < tnode_child_length(tn); i++) {
+- tofree = rtnl_dereference(tn->child[i]);
++ tofree = tnode_get_child(tn, i);
+ if (tofree)
+ node_free(tofree);
+ }
+@@ -619,10 +617,10 @@ static void tnode_clean_free(struct tnod
+
+ static struct tnode *inflate(struct trie *t, struct tnode *oldtnode)
+ {
+- int olen = tnode_child_length(oldtnode);
++ unsigned long olen = tnode_child_length(oldtnode);
+ struct tnode *tn;
++ unsigned long i;
+ t_key m;
+- int i;
+
+ pr_debug("In inflate\n");
+
+@@ -664,7 +662,7 @@ static struct tnode *inflate(struct trie
+ for (i = 0; i < olen; i++) {
+ struct tnode *inode = tnode_get_child(oldtnode, i);
+ struct tnode *left, *right;
+- int size, j;
++ unsigned long size, j;
+
+ /* An empty child */
+ if (inode == NULL)
+@@ -737,7 +735,7 @@ nomem:
+
+ static struct tnode *halve(struct trie *t, struct tnode *oldtnode)
+ {
+- int olen = tnode_child_length(oldtnode);
++ unsigned long olen = tnode_child_length(oldtnode);
+ struct tnode *tn, *left, *right;
+ int i;
+
+@@ -1532,9 +1530,9 @@ static int trie_flush_leaf(struct tnode
+ static struct tnode *leaf_walk_rcu(struct tnode *p, struct tnode *c)
+ {
+ do {
+- t_key idx = c ? idx = get_index(c->key, p) + 1 : 0;
++ unsigned long idx = c ? idx = get_index(c->key, p) + 1 : 0;
+
+- while (idx < 1u << p->bits) {
++ while (idx < tnode_child_length(p)) {
+ c = tnode_get_child_rcu(p, idx++);
+ if (!c)
+ continue;
+@@ -1786,8 +1784,8 @@ struct fib_trie_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 */
+@@ -1797,7 +1795,7 @@ static struct tnode *fib_trie_get_next(s
+ pr_debug("get_next iter={node=%p index=%d depth=%d}\n",
+ iter->tnode, iter->index, iter->depth);
+ rescan:
+- while (cindex < (1<<tn->bits)) {
++ while (cindex < tnode_child_length(tn)) {
+ struct tnode *n = tnode_get_child_rcu(tn, cindex);
+
+ if (n) {
+@@ -1874,15 +1872,16 @@ static void trie_collect_stats(struct tr
+ hlist_for_each_entry_rcu(li, &n->list, hlist)
+ ++s->prefixes;
+ } else {
+- int i;
++ unsigned long i;
+
+ s->tnodes++;
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
+
+- for (i = 0; i < tnode_child_length(n); i++)
++ for (i = 0; i < tnode_child_length(n); i++) {
+ if (!rcu_access_pointer(n->child[i]))
+ s->nullpointers++;
++ }
+ }
+ }
+ rcu_read_unlock();
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:24 -0800
+Subject: [PATCH] fib_trie: Push rcu_read_lock/unlock to callers
+
+This change is to start cleaning up some of the rcu_read_lock/unlock
+handling. I realized while reviewing the code there are several spots that
+I don't believe are being handled correctly or are masking warnings by
+locally calling rcu_read_lock/unlock instead of calling them at the correct
+level.
+
+A common example is a call to fib_get_table followed by fib_table_lookup.
+The rcu_read_lock/unlock ought to wrap both but there are several spots where
+they were not wrapped.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/include/net/ip_fib.h
++++ b/include/net/ip_fib.h
+@@ -222,16 +222,19 @@ static inline struct fib_table *fib_new_
+ static inline int fib_lookup(struct net *net, const struct flowi4 *flp,
+ struct fib_result *res)
+ {
+- struct fib_table *table;
++ int err = -ENETUNREACH;
+
+- table = fib_get_table(net, RT_TABLE_LOCAL);
+- if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
+- return 0;
+-
+- table = fib_get_table(net, RT_TABLE_MAIN);
+- if (!fib_table_lookup(table, flp, res, FIB_LOOKUP_NOREF))
+- return 0;
+- return -ENETUNREACH;
++ rcu_read_lock();
++
++ if (!fib_table_lookup(fib_get_table(net, RT_TABLE_LOCAL), flp, res,
++ FIB_LOOKUP_NOREF) ||
++ !fib_table_lookup(fib_get_table(net, RT_TABLE_MAIN), flp, res,
++ FIB_LOOKUP_NOREF))
++ err = 0;
++
++ rcu_read_unlock();
++
++ return err;
+ }
+
+ #else /* CONFIG_IP_MULTIPLE_TABLES */
+@@ -247,20 +250,25 @@ static inline int fib_lookup(struct net
+ struct fib_result *res)
+ {
+ if (!net->ipv4.fib_has_custom_rules) {
++ int err = -ENETUNREACH;
++
++ rcu_read_lock();
++
+ res->tclassid = 0;
+- if (net->ipv4.fib_local &&
+- !fib_table_lookup(net->ipv4.fib_local, flp, res,
+- FIB_LOOKUP_NOREF))
+- return 0;
+- if (net->ipv4.fib_main &&
+- !fib_table_lookup(net->ipv4.fib_main, flp, res,
+- FIB_LOOKUP_NOREF))
+- return 0;
+- if (net->ipv4.fib_default &&
+- !fib_table_lookup(net->ipv4.fib_default, flp, res,
+- FIB_LOOKUP_NOREF))
+- return 0;
+- return -ENETUNREACH;
++ if ((net->ipv4.fib_local &&
++ !fib_table_lookup(net->ipv4.fib_local, flp, res,
++ FIB_LOOKUP_NOREF)) ||
++ (net->ipv4.fib_main &&
++ !fib_table_lookup(net->ipv4.fib_main, flp, res,
++ FIB_LOOKUP_NOREF)) ||
++ (net->ipv4.fib_default &&
++ !fib_table_lookup(net->ipv4.fib_default, flp, res,
++ FIB_LOOKUP_NOREF)))
++ err = 0;
++
++ rcu_read_unlock();
++
++ return err;
+ }
+ return __fib_lookup(net, flp, res);
+ }
+--- a/net/ipv4/fib_frontend.c
++++ b/net/ipv4/fib_frontend.c
+@@ -109,6 +109,7 @@ struct fib_table *fib_new_table(struct n
+ return tb;
+ }
+
++/* caller must hold either rtnl or rcu read lock */
+ struct fib_table *fib_get_table(struct net *net, u32 id)
+ {
+ struct fib_table *tb;
+@@ -119,15 +120,11 @@ struct fib_table *fib_get_table(struct n
+ id = RT_TABLE_MAIN;
+ h = id & (FIB_TABLE_HASHSZ - 1);
+
+- rcu_read_lock();
+ head = &net->ipv4.fib_table_hash[h];
+ hlist_for_each_entry_rcu(tb, head, tb_hlist) {
+- if (tb->tb_id == id) {
+- rcu_read_unlock();
++ if (tb->tb_id == id)
+ return tb;
+- }
+ }
+- rcu_read_unlock();
+ return NULL;
+ }
+ #endif /* CONFIG_IP_MULTIPLE_TABLES */
+@@ -167,16 +164,18 @@ static inline unsigned int __inet_dev_ad
+ if (ipv4_is_multicast(addr))
+ return RTN_MULTICAST;
+
++ rcu_read_lock();
++
+ local_table = fib_get_table(net, RT_TABLE_LOCAL);
+ if (local_table) {
+ ret = RTN_UNICAST;
+- rcu_read_lock();
+ if (!fib_table_lookup(local_table, &fl4, &res, FIB_LOOKUP_NOREF)) {
+ if (!dev || dev == res.fi->fib_dev)
+ ret = res.type;
+ }
+- rcu_read_unlock();
+ }
++
++ rcu_read_unlock();
+ return ret;
+ }
+
+@@ -919,7 +918,7 @@ void fib_del_ifaddr(struct in_ifaddr *if
+ #undef BRD1_OK
+ }
+
+-static void nl_fib_lookup(struct fib_result_nl *frn, struct fib_table *tb)
++static void nl_fib_lookup(struct net *net, struct fib_result_nl *frn)
+ {
+
+ struct fib_result res;
+@@ -929,6 +928,11 @@ static void nl_fib_lookup(struct fib_res
+ .flowi4_tos = frn->fl_tos,
+ .flowi4_scope = frn->fl_scope,
+ };
++ struct fib_table *tb;
++
++ rcu_read_lock();
++
++ tb = fib_get_table(net, frn->tb_id_in);
+
+ frn->err = -ENOENT;
+ if (tb) {
+@@ -945,6 +949,8 @@ static void nl_fib_lookup(struct fib_res
+ }
+ local_bh_enable();
+ }
++
++ rcu_read_unlock();
+ }
+
+ static void nl_fib_input(struct sk_buff *skb)
+@@ -952,7 +958,6 @@ static void nl_fib_input(struct sk_buff
+ struct net *net;
+ struct fib_result_nl *frn;
+ struct nlmsghdr *nlh;
+- struct fib_table *tb;
+ u32 portid;
+
+ net = sock_net(skb->sk);
+@@ -967,9 +972,7 @@ static void nl_fib_input(struct sk_buff
+ nlh = nlmsg_hdr(skb);
+
+ frn = (struct fib_result_nl *) nlmsg_data(nlh);
+- tb = fib_get_table(net, frn->tb_id_in);
+-
+- nl_fib_lookup(frn, tb);
++ nl_fib_lookup(net, frn);
+
+ portid = NETLINK_CB(skb).portid; /* netlink portid */
+ NETLINK_CB(skb).portid = 0; /* from kernel */
+--- a/net/ipv4/fib_rules.c
++++ b/net/ipv4/fib_rules.c
+@@ -81,27 +81,25 @@ static int fib4_rule_action(struct fib_r
+ break;
+
+ case FR_ACT_UNREACHABLE:
+- err = -ENETUNREACH;
+- goto errout;
++ return -ENETUNREACH;
+
+ case FR_ACT_PROHIBIT:
+- err = -EACCES;
+- goto errout;
++ return -EACCES;
+
+ case FR_ACT_BLACKHOLE:
+ default:
+- err = -EINVAL;
+- goto errout;
++ return -EINVAL;
+ }
+
++ rcu_read_lock();
++
+ tbl = fib_get_table(rule->fr_net, rule->table);
+- if (!tbl)
+- goto errout;
++ if (tbl)
++ err = fib_table_lookup(tbl, &flp->u.ip4,
++ (struct fib_result *)arg->result,
++ arg->flags);
+
+- err = fib_table_lookup(tbl, &flp->u.ip4, (struct fib_result *) arg->result, arg->flags);
+- if (err > 0)
+- err = -EAGAIN;
+-errout:
++ rcu_read_unlock();
+ return err;
+ }
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -1181,72 +1181,6 @@ err:
+ return err;
+ }
+
+-/* should be called with rcu_read_lock */
+-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)
+-{
+- struct leaf_info *li;
+- struct hlist_head *hhead = &l->list;
+-
+- hlist_for_each_entry_rcu(li, hhead, hlist) {
+- struct fib_alias *fa;
+-
+- if (l->key != (key & li->mask_plen))
+- continue;
+-
+- list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+- struct fib_info *fi = fa->fa_info;
+- int nhsel, err;
+-
+- if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
+- continue;
+- if (fi->fib_dead)
+- continue;
+- if (fa->fa_info->fib_scope < flp->flowi4_scope)
+- continue;
+- fib_alias_accessed(fa);
+- err = fib_props[fa->fa_type].error;
+- if (unlikely(err < 0)) {
+-#ifdef CONFIG_IP_FIB_TRIE_STATS
+- this_cpu_inc(t->stats->semantic_match_passed);
+-#endif
+- return err;
+- }
+- if (fi->fib_flags & RTNH_F_DEAD)
+- continue;
+- for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
+- const struct fib_nh *nh = &fi->fib_nh[nhsel];
+-
+- if (nh->nh_flags & RTNH_F_DEAD)
+- continue;
+- if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
+- continue;
+-
+-#ifdef CONFIG_IP_FIB_TRIE_STATS
+- this_cpu_inc(t->stats->semantic_match_passed);
+-#endif
+- res->prefixlen = li->plen;
+- res->nh_sel = nhsel;
+- res->type = fa->fa_type;
+- 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
+- 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;
+@@ -1254,6 +1188,7 @@ static inline t_key prefix_mismatch(t_ke
+ return (key ^ prefix) & (prefix | -prefix);
+ }
+
++/* should be called with rcu_read_lock */
+ int fib_table_lookup(struct fib_table *tb, const struct flowi4 *flp,
+ struct fib_result *res, int fib_flags)
+ {
+@@ -1263,14 +1198,12 @@ int fib_table_lookup(struct fib_table *t
+ #endif
+ const t_key key = ntohl(flp->daddr);
+ struct tnode *n, *pn;
++ struct leaf_info *li;
+ t_key cindex;
+- int ret = 1;
+-
+- rcu_read_lock();
+
+ n = rcu_dereference(t->trie);
+ if (!n)
+- goto failed;
++ return -EAGAIN;
+
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->gets);
+@@ -1350,7 +1283,7 @@ backtrace:
+
+ pn = node_parent_rcu(pn);
+ if (unlikely(!pn))
+- goto failed;
++ return -EAGAIN;
+ #ifdef CONFIG_IP_FIB_TRIE_STATS
+ this_cpu_inc(stats->backtrack);
+ #endif
+@@ -1368,12 +1301,62 @@ backtrace:
+
+ 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;
++ hlist_for_each_entry_rcu(li, &n->list, hlist) {
++ struct fib_alias *fa;
++
++ if ((key ^ n->key) & li->mask_plen)
++ continue;
++
++ list_for_each_entry_rcu(fa, &li->falh, fa_list) {
++ struct fib_info *fi = fa->fa_info;
++ int nhsel, err;
++
++ if (fa->fa_tos && fa->fa_tos != flp->flowi4_tos)
++ continue;
++ if (fi->fib_dead)
++ continue;
++ if (fa->fa_info->fib_scope < flp->flowi4_scope)
++ continue;
++ fib_alias_accessed(fa);
++ err = fib_props[fa->fa_type].error;
++ if (unlikely(err < 0)) {
++#ifdef CONFIG_IP_FIB_TRIE_STATS
++ this_cpu_inc(stats->semantic_match_passed);
++#endif
++ return err;
++ }
++ if (fi->fib_flags & RTNH_F_DEAD)
++ continue;
++ for (nhsel = 0; nhsel < fi->fib_nhs; nhsel++) {
++ const struct fib_nh *nh = &fi->fib_nh[nhsel];
++
++ if (nh->nh_flags & RTNH_F_DEAD)
++ continue;
++ if (flp->flowi4_oif && flp->flowi4_oif != nh->nh_oif)
++ continue;
++
++ 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 = fi->fib_scope;
++ res->fi = fi;
++ res->table = tb;
++ res->fa_head = &li->falh;
++#ifdef CONFIG_IP_FIB_TRIE_STATS
++ this_cpu_inc(stats->semantic_match_passed);
++#endif
++ return err;
++ }
++ }
++
++#ifdef CONFIG_IP_FIB_TRIE_STATS
++ this_cpu_inc(stats->semantic_match_miss);
++#endif
++ }
++ goto backtrace;
+ }
+ EXPORT_SYMBOL_GPL(fib_table_lookup);
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:31 -0800
+Subject: [PATCH] fib_trie: Move resize to after inflate/halve
+
+This change consists of a cut/paste of resize to behind inflate and halve
+so that I could remove the two function prototypes.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -149,8 +149,6 @@ struct trie {
+ static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
+ struct tnode *n, int wasfull);
+ 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 callback_head *tnode_free_head;
+ static size_t tnode_free_size;
+@@ -447,161 +445,6 @@ static void put_child_root(struct tnode
+ rcu_assign_pointer(t->trie, n);
+ }
+
+-#define MAX_WORK 10
+-static struct tnode *resize(struct trie *t, struct tnode *tn)
+-{
+- struct tnode *old_tn, *n = NULL;
+- int inflate_threshold_use;
+- int halve_threshold_use;
+- int max_work;
+-
+- if (!tn)
+- return NULL;
+-
+- pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+- tn, inflate_threshold, halve_threshold);
+-
+- /* No children */
+- if (tn->empty_children > (tnode_child_length(tn) - 1))
+- goto no_children;
+-
+- /* 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)
+- *
+- */
+-
+- /* Keep root node larger */
+-
+- if (!node_parent(tn)) {
+- inflate_threshold_use = inflate_threshold_root;
+- halve_threshold_use = halve_threshold_root;
+- } else {
+- inflate_threshold_use = inflate_threshold;
+- halve_threshold_use = halve_threshold;
+- }
+-
+- 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))) {
+-
+- old_tn = tn;
+- tn = inflate(t, tn);
+-
+- if (IS_ERR(tn)) {
+- tn = old_tn;
+-#ifdef CONFIG_IP_FIB_TRIE_STATS
+- this_cpu_inc(t->stats->resize_node_skipped);
+-#endif
+- break;
+- }
+- }
+-
+- /* Return if at least one inflate is run */
+- if (max_work != MAX_WORK)
+- return 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
+- this_cpu_inc(t->stats->resize_node_skipped);
+-#endif
+- break;
+- }
+- }
+-
+-
+- /* Only one child remains */
+- if (tn->empty_children == (tnode_child_length(tn) - 1)) {
+- unsigned long i;
+-one_child:
+- 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 tn;
+-}
+-
+-
+ static void tnode_clean_free(struct tnode *tn)
+ {
+ struct tnode *tofree;
+@@ -804,6 +647,160 @@ nomem:
+ return ERR_PTR(-ENOMEM);
+ }
+
++#define MAX_WORK 10
++static struct tnode *resize(struct trie *t, struct tnode *tn)
++{
++ struct tnode *old_tn, *n = NULL;
++ int inflate_threshold_use;
++ int halve_threshold_use;
++ int max_work;
++
++ if (!tn)
++ return NULL;
++
++ pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
++ tn, inflate_threshold, halve_threshold);
++
++ /* No children */
++ if (tn->empty_children > (tnode_child_length(tn) - 1))
++ goto no_children;
++
++ /* 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)
++ *
++ */
++
++ /* Keep root node larger */
++
++ if (!node_parent(tn)) {
++ inflate_threshold_use = inflate_threshold_root;
++ halve_threshold_use = halve_threshold_root;
++ } else {
++ inflate_threshold_use = inflate_threshold;
++ halve_threshold_use = halve_threshold;
++ }
++
++ 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))) {
++
++ old_tn = tn;
++ tn = inflate(t, tn);
++
++ if (IS_ERR(tn)) {
++ tn = old_tn;
++#ifdef CONFIG_IP_FIB_TRIE_STATS
++ this_cpu_inc(t->stats->resize_node_skipped);
++#endif
++ break;
++ }
++ }
++
++ /* Return if at least one inflate is run */
++ if (max_work != MAX_WORK)
++ return 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
++ this_cpu_inc(t->stats->resize_node_skipped);
++#endif
++ break;
++ }
++ }
++
++
++ /* Only one child remains */
++ if (tn->empty_children == (tnode_child_length(tn) - 1)) {
++ unsigned long i;
++one_child:
++ 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 tn;
++}
++
+ /* readside must use rcu_read_lock currently dump routines
+ via get_fa_head and dump */
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:37 -0800
+Subject: [PATCH] fib_trie: Add functions should_inflate and should_halve
+
+This change pulls the logic for if we should inflate/halve the nodes out
+into separate functions. It also addresses what I believe is a bug where 1
+full node is all that is needed to keep a node from ever being halved.
+
+Simple script to reproduce the issue:
+ modprobe dummy; ifconfig dummy0 up
+ for i in `seq 0 255`; do ifconfig dummy0:$i 10.0.${i}.1/24 up; done
+ ifconfig dummy0:256 10.0.255.33/16 up
+ for i in `seq 0 254`; do ifconfig dummy0:$i down; done
+
+Results from /proc/net/fib_triestat
+Before:
+ Local:
+ Aver depth: 3.00
+ Max depth: 4
+ Leaves: 17
+ Prefixes: 18
+ Internal nodes: 11
+ 1: 8 2: 2 10: 1
+ Pointers: 1048
+ Null ptrs: 1021
+ Total size: 11 kB
+After:
+ Local:
+ Aver depth: 3.41
+ Max depth: 5
+ Leaves: 17
+ Prefixes: 18
+ Internal nodes: 12
+ 1: 8 2: 3 3: 1
+ Pointers: 36
+ Null ptrs: 8
+ Total size: 3 kB
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -647,12 +647,94 @@ nomem:
+ return ERR_PTR(-ENOMEM);
+ }
+
++/* 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 *tn)
++{
++ unsigned long used = tnode_child_length(tn);
++ unsigned long threshold = used;
++
++ /* Keep root node larger */
++ threshold *= node_parent(tn) ? inflate_threshold :
++ inflate_threshold_root;
++ used += tn->full_children;
++ used -= tn->empty_children;
++
++ return tn->pos && ((50 * used) >= threshold);
++}
++
++static bool should_halve(const struct tnode *tn)
++{
++ unsigned long used = tnode_child_length(tn);
++ unsigned long threshold = used;
++
++ /* Keep root node larger */
++ threshold *= node_parent(tn) ? halve_threshold :
++ halve_threshold_root;
++ used -= tn->empty_children;
++
++ return (tn->bits > 1) && ((100 * used) < threshold);
++}
++
+ #define MAX_WORK 10
+ static struct tnode *resize(struct trie *t, struct tnode *tn)
+ {
+ struct tnode *old_tn, *n = NULL;
+- int inflate_threshold_use;
+- int halve_threshold_use;
+ int max_work;
+
+ if (!tn)
+@@ -668,86 +750,12 @@ static struct tnode *resize(struct trie
+ /* 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)
+- *
++ /* Double as long as the resulting node has a number of
++ * nonempty nodes that are above the threshold.
+ */
+-
+- /* Keep root node larger */
+-
+- if (!node_parent(tn)) {
+- inflate_threshold_use = inflate_threshold_root;
+- halve_threshold_use = halve_threshold_root;
+- } else {
+- inflate_threshold_use = inflate_threshold;
+- halve_threshold_use = halve_threshold;
+- }
+-
+ 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))) {
+-
++ while (should_inflate(tn) && max_work--) {
+ old_tn = tn;
+ tn = inflate(t, tn);
+
+@@ -764,16 +772,11 @@ static struct tnode *resize(struct trie
+ if (max_work != MAX_WORK)
+ return tn;
+
+- /*
+- * Halve as long as the number of empty children in this
++ /* 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)) {
+-
++ while (should_halve(tn) && max_work--) {
+ old_tn = tn;
+ tn = halve(t, tn);
+ if (IS_ERR(tn)) {
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:43 -0800
+Subject: [PATCH] fib_trie: Push assignment of child to parent down into
+ inflate/halve
+
+This change makes it so that the assignment of the tnode to the parent is
+handled directly within whatever function is currently handling the node be
+it inflate, halve, or resize. By doing this we can avoid some of the need
+to set NULL pointers in the tree while we are resizing the subnodes.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -146,9 +146,7 @@ struct trie {
+ #endif
+ };
+
+-static void tnode_put_child_reorg(struct tnode *tn, unsigned long i,
+- struct tnode *n, int wasfull);
+-static struct tnode *resize(struct trie *t, struct tnode *tn);
++static void resize(struct trie *t, struct tnode *tn);
+ /* tnodes to free after resize(); protected by RTNL */
+ static struct callback_head *tnode_free_head;
+ static size_t tnode_free_size;
+@@ -396,22 +394,13 @@ static inline int tnode_full(const struc
+ return n && ((n->pos + n->bits) == tn->pos) && IS_TNODE(n);
+ }
+
+-static inline void put_child(struct tnode *tn, unsigned long i,
+- struct tnode *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, unsigned long i,
+- struct tnode *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 tnode *chi = rtnl_dereference(tn->child[i]);
+- int isfull;
++ int isfull, wasfull;
+
+ BUG_ON(i >= tnode_child_length(tn));
+
+@@ -422,10 +411,9 @@ static void tnode_put_child_reorg(struct
+ tn->empty_children--;
+
+ /* 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)
+@@ -458,9 +446,10 @@ static void tnode_clean_free(struct tnod
+ node_free(tn);
+ }
+
+-static struct tnode *inflate(struct trie *t, struct tnode *oldtnode)
++static int inflate(struct trie *t, struct tnode *oldtnode)
+ {
+ unsigned long olen = tnode_child_length(oldtnode);
++ struct tnode *tp = node_parent(oldtnode);
+ struct tnode *tn;
+ unsigned long i;
+ t_key m;
+@@ -468,9 +457,8 @@ static struct tnode *inflate(struct trie
+ pr_debug("In inflate\n");
+
+ tn = tnode_new(oldtnode->key, oldtnode->pos - 1, oldtnode->bits + 1);
+-
+ if (!tn)
+- return ERR_PTR(-ENOMEM);
++ return -ENOMEM;
+
+ /*
+ * Preallocate and store tnodes before the actual work so we
+@@ -564,30 +552,36 @@ static struct tnode *inflate(struct trie
+ put_child(left, j, rtnl_dereference(inode->child[j]));
+ put_child(right, j, rtnl_dereference(inode->child[j + size]));
+ }
+- put_child(tn, 2*i, resize(t, left));
+- put_child(tn, 2*i+1, resize(t, right));
++
++ put_child(tn, 2 * i, left);
++ put_child(tn, 2 * i + 1, right);
+
+ tnode_free_safe(inode);
++
++ resize(t, left);
++ resize(t, right);
+ }
++
++ put_child_root(tp, t, tn->key, tn);
+ tnode_free_safe(oldtnode);
+- return tn;
++ return 0;
+ nomem:
+ tnode_clean_free(tn);
+- return ERR_PTR(-ENOMEM);
++ return -ENOMEM;
+ }
+
+-static struct tnode *halve(struct trie *t, struct tnode *oldtnode)
++static int halve(struct trie *t, struct tnode *oldtnode)
+ {
+ unsigned long olen = tnode_child_length(oldtnode);
++ struct tnode *tp = node_parent(oldtnode);
+ struct tnode *tn, *left, *right;
+ int i;
+
+ pr_debug("In halve\n");
+
+ tn = tnode_new(oldtnode->key, oldtnode->pos + 1, oldtnode->bits - 1);
+-
+ if (!tn)
+- return ERR_PTR(-ENOMEM);
++ return -ENOMEM;
+
+ /*
+ * Preallocate and store tnodes before the actual work so we
+@@ -606,8 +600,10 @@ static struct tnode *halve(struct trie *
+
+ newn = tnode_new(left->key, oldtnode->pos, 1);
+
+- if (!newn)
+- goto nomem;
++ if (!newn) {
++ tnode_clean_free(tn);
++ return -ENOMEM;
++ }
+
+ put_child(tn, i/2, newn);
+ }
+@@ -635,16 +631,18 @@ static struct tnode *halve(struct trie *
+
+ /* Two nonempty children */
+ newBinNode = 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));
++
++ put_child(tn, i / 2, newBinNode);
++
++ resize(t, newBinNode);
+ }
++
++ put_child_root(tp, t, tn->key, tn);
+ tnode_free_safe(oldtnode);
+- return tn;
+-nomem:
+- tnode_clean_free(tn);
+- return ERR_PTR(-ENOMEM);
++
++ return 0;
+ }
+
+ /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+@@ -704,45 +702,48 @@ nomem:
+ * tnode_child_length(tn)
+ *
+ */
+-static bool should_inflate(const struct tnode *tn)
++static bool should_inflate(const struct tnode *tp, const struct tnode *tn)
+ {
+ unsigned long used = tnode_child_length(tn);
+ unsigned long threshold = used;
+
+ /* Keep root node larger */
+- threshold *= node_parent(tn) ? inflate_threshold :
+- inflate_threshold_root;
++ threshold *= tp ? inflate_threshold : inflate_threshold_root;
+ used += tn->full_children;
+ used -= tn->empty_children;
+
+ return tn->pos && ((50 * used) >= threshold);
+ }
+
+-static bool should_halve(const struct tnode *tn)
++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 *= node_parent(tn) ? halve_threshold :
+- halve_threshold_root;
++ threshold *= tp ? halve_threshold : halve_threshold_root;
+ used -= tn->empty_children;
+
+ return (tn->bits > 1) && ((100 * used) < threshold);
+ }
+
+ #define MAX_WORK 10
+-static struct tnode *resize(struct trie *t, struct tnode *tn)
++static void resize(struct trie *t, struct tnode *tn)
+ {
+- struct tnode *old_tn, *n = NULL;
++ struct tnode *tp = node_parent(tn), *n = NULL;
++ struct tnode __rcu **cptr;
+ int max_work;
+
+- if (!tn)
+- return NULL;
+-
+ 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));
++
+ /* No children */
+ if (tn->empty_children > (tnode_child_length(tn) - 1))
+ goto no_children;
+@@ -755,39 +756,35 @@ static struct tnode *resize(struct trie
+ * nonempty nodes that are above the threshold.
+ */
+ max_work = MAX_WORK;
+- while (should_inflate(tn) && max_work--) {
+- old_tn = tn;
+- tn = inflate(t, tn);
+-
+- if (IS_ERR(tn)) {
+- tn = old_tn;
++ 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;
+ }
++
++ tn = rtnl_dereference(*cptr);
+ }
+
+ /* Return if at least one inflate is run */
+ if (max_work != MAX_WORK)
+- return tn;
++ return;
+
+ /* Halve as long as the number of empty children in this
+ * node is above threshold.
+ */
+ max_work = MAX_WORK;
+- while (should_halve(tn) && max_work--) {
+- old_tn = tn;
+- tn = halve(t, tn);
+- if (IS_ERR(tn)) {
+- tn = old_tn;
++ 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;
+ }
+- }
+
++ tn = rtnl_dereference(*cptr);
++ }
+
+ /* Only one child remains */
+ if (tn->empty_children == (tnode_child_length(tn) - 1)) {
+@@ -797,11 +794,12 @@ one_child:
+ n = tnode_get_child(tn, --i);
+ no_children:
+ /* compress one level */
+- node_set_parent(n, NULL);
++ put_child_root(tp, t, tn->key, n);
++ node_set_parent(n, tp);
++
++ /* drop dead node */
+ tnode_free_safe(tn);
+- return n;
+ }
+- return tn;
+ }
+
+ /* readside must use rcu_read_lock currently dump routines
+@@ -882,34 +880,19 @@ static struct tnode *fib_find_node(struc
+
+ 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(tn)) != NULL) {
+- cindex = get_index(key, tp);
+- wasfull = tnode_full(tp, tnode_get_child(tp, cindex));
+- tn = resize(t, tn);
+-
+- tnode_put_child_reorg(tp, cindex, tn, wasfull);
+-
+- tp = node_parent(tn);
+- if (!tp)
+- rcu_assign_pointer(t->trie, tn);
++ while ((tp = node_parent(tn)) != NULL) {
++ resize(t, tn);
+
+ tnode_free_flush();
+- if (!tp)
+- break;
+ tn = tp;
+ }
+
+ /* Handle last (top) tnode */
+ if (IS_TNODE(tn))
+- tn = resize(t, tn);
++ resize(t, tn);
+
+- rcu_assign_pointer(t->trie, tn);
+ tnode_free_flush();
+ }
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:49 -0800
+Subject: [PATCH] fib_trie: Push tnode flushing down to inflate/halve
+
+This change pushes the tnode freeing down into the inflate and halve
+functions. It makes more sense here as we have a better grasp of what is
+going on and when a given cluster of nodes is ready to be freed.
+
+I believe this may address a bug in the freeing logic as well. For some
+reason if the freelist got to a certain size we would call
+synchronize_rcu(). I'm assuming that what they meant to do is call
+synchronize_rcu() after they had handed off that much memory via
+call_rcu(). As such that is what I have updated the behavior to be.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -147,8 +147,6 @@ struct trie {
+ };
+
+ static void resize(struct trie *t, struct tnode *tn);
+-/* tnodes to free after resize(); protected by RTNL */
+-static struct callback_head *tnode_free_head;
+ static size_t tnode_free_size;
+
+ /*
+@@ -307,32 +305,6 @@ static struct tnode *tnode_alloc(size_t
+ return vzalloc(size);
+ }
+
+-static void tnode_free_safe(struct tnode *tn)
+-{
+- BUG_ON(IS_LEAF(tn));
+- tn->rcu.next = tnode_free_head;
+- tnode_free_head = &tn->rcu;
+-}
+-
+-static void tnode_free_flush(void)
+-{
+- 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]);
+-
+- node_free(tn);
+- }
+-
+- if (tnode_free_size >= PAGE_SIZE * sync_pages) {
+- tnode_free_size = 0;
+- synchronize_rcu();
+- }
+-}
+-
+ static struct tnode *leaf_new(t_key key)
+ {
+ struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+@@ -433,17 +405,33 @@ static void put_child_root(struct tnode
+ rcu_assign_pointer(t->trie, n);
+ }
+
+-static void tnode_clean_free(struct tnode *tn)
++static inline void tnode_free_init(struct tnode *tn)
+ {
+- struct tnode *tofree;
+- unsigned long i;
++ tn->rcu.next = NULL;
++}
++
++static inline void tnode_free_append(struct tnode *tn, struct tnode *n)
++{
++ n->rcu.next = tn->rcu.next;
++ tn->rcu.next = &n->rcu;
++}
+
+- for (i = 0; i < tnode_child_length(tn); i++) {
+- tofree = tnode_get_child(tn, i);
+- if (tofree)
+- node_free(tofree);
++static void tnode_free(struct tnode *tn)
++{
++ struct callback_head *head = &tn->rcu;
++
++ while (head) {
++ head = head->next;
++ tnode_free_size += offsetof(struct tnode, child[1 << tn->bits]);
++ node_free(tn);
++
++ tn = container_of(head, struct tnode, rcu);
++ }
++
++ if (tnode_free_size >= PAGE_SIZE * sync_pages) {
++ tnode_free_size = 0;
++ synchronize_rcu();
+ }
+- node_free(tn);
+ }
+
+ static int inflate(struct trie *t, struct tnode *oldtnode)
+@@ -476,20 +464,23 @@ static int inflate(struct trie *t, struc
+ inode->bits - 1);
+ if (!left)
+ goto nomem;
++ tnode_free_append(tn, left);
+
+ right = tnode_new(inode->key | m, inode->pos,
+ inode->bits - 1);
+
+- if (!right) {
+- node_free(left);
++ if (!right)
+ goto nomem;
+- }
++ tnode_free_append(tn, right);
+
+ put_child(tn, 2*i, left);
+ put_child(tn, 2*i+1, right);
+ }
+ }
+
++ /* prepare oldtnode to be freed */
++ tnode_free_init(oldtnode);
++
+ for (i = 0; i < olen; i++) {
+ struct tnode *inode = tnode_get_child(oldtnode, i);
+ struct tnode *left, *right;
+@@ -505,12 +496,13 @@ static int inflate(struct trie *t, struc
+ continue;
+ }
+
++ /* 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);
+ continue;
+ }
+
+@@ -556,17 +548,19 @@ static int inflate(struct trie *t, struc
+ put_child(tn, 2 * i, left);
+ put_child(tn, 2 * i + 1, right);
+
+- tnode_free_safe(inode);
+-
++ /* resize child nodes */
+ resize(t, left);
+ resize(t, right);
+ }
+
+ put_child_root(tp, t, tn->key, tn);
+- tnode_free_safe(oldtnode);
++
++ /* we completed without error, prepare to free old node */
++ tnode_free(oldtnode);
+ return 0;
+ nomem:
+- tnode_clean_free(tn);
++ /* all pointers should be clean so we are done */
++ tnode_free(tn);
+ return -ENOMEM;
+ }
+
+@@ -599,17 +593,20 @@ static int halve(struct trie *t, struct
+ struct tnode *newn;
+
+ newn = tnode_new(left->key, oldtnode->pos, 1);
+-
+ if (!newn) {
+- tnode_clean_free(tn);
++ tnode_free(tn);
+ return -ENOMEM;
+ }
++ tnode_free_append(tn, newn);
+
+ put_child(tn, i/2, newn);
+ }
+
+ }
+
++ /* prepare oldtnode to be freed */
++ tnode_free_init(oldtnode);
++
+ for (i = 0; i < olen; i += 2) {
+ struct tnode *newBinNode;
+
+@@ -636,11 +633,14 @@ static int halve(struct trie *t, struct
+
+ put_child(tn, i / 2, newBinNode);
+
++ /* resize child node */
+ resize(t, newBinNode);
+ }
+
+ put_child_root(tp, t, tn->key, tn);
+- tnode_free_safe(oldtnode);
++
++ /* all pointers should be clean so we are done */
++ tnode_free(oldtnode);
+
+ return 0;
+ }
+@@ -798,7 +798,8 @@ no_children:
+ node_set_parent(n, tp);
+
+ /* drop dead node */
+- tnode_free_safe(tn);
++ tnode_free_init(tn);
++ tnode_free(tn);
+ }
+ }
+
+@@ -884,16 +885,12 @@ static void trie_rebalance(struct trie *
+
+ while ((tp = node_parent(tn)) != NULL) {
+ resize(t, tn);
+-
+- tnode_free_flush();
+ tn = tp;
+ }
+
+ /* Handle last (top) tnode */
+ if (IS_TNODE(tn))
+ resize(t, tn);
+-
+- tnode_free_flush();
+ }
+
+ /* only used from updater-side */
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:56:55 -0800
+Subject: [PATCH] fib_trie: inflate/halve nodes in a more RCU friendly
+ way
+
+This change pulls the node_set_parent functionality out of put_child_reorg
+and instead leaves that to the function to take care of as well. By doing
+this we can fully construct the new cluster of tnodes and all of the
+pointers out of it before we start routing pointers into it.
+
+I am suspecting this will likely fix some concurency issues though I don't
+have a good test to show as such.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -391,8 +391,6 @@ static void put_child(struct tnode *tn,
+ else if (!wasfull && isfull)
+ tn->full_children++;
+
+- node_set_parent(n, tn);
+-
+ rcu_assign_pointer(tn->child[i], n);
+ }
+
+@@ -436,10 +434,8 @@ static void tnode_free(struct tnode *tn)
+
+ static int inflate(struct trie *t, struct tnode *oldtnode)
+ {
+- unsigned long olen = tnode_child_length(oldtnode);
+- struct tnode *tp = node_parent(oldtnode);
+- struct tnode *tn;
+- unsigned long i;
++ struct tnode *inode, *node0, *node1, *tn, *tp;
++ unsigned long i, j, k;
+ t_key m;
+
+ pr_debug("In inflate\n");
+@@ -448,43 +444,13 @@ static int inflate(struct trie *t, struc
+ if (!tn)
+ return -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.
++ /* 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 = 0, m = 1u << tn->pos; i < olen; i++) {
+- struct tnode *inode = tnode_get_child(oldtnode, i);
+-
+- if (tnode_full(oldtnode, inode) && (inode->bits > 1)) {
+- struct tnode *left, *right;
+-
+- left = tnode_new(inode->key & ~m, inode->pos,
+- inode->bits - 1);
+- if (!left)
+- goto nomem;
+- tnode_free_append(tn, left);
+-
+- right = tnode_new(inode->key | m, inode->pos,
+- inode->bits - 1);
+-
+- if (!right)
+- goto nomem;
+- tnode_free_append(tn, right);
+-
+- put_child(tn, 2*i, left);
+- put_child(tn, 2*i+1, right);
+- }
+- }
+-
+- /* prepare oldtnode to be freed */
+- tnode_free_init(oldtnode);
+-
+- for (i = 0; i < olen; i++) {
+- struct tnode *inode = tnode_get_child(oldtnode, i);
+- struct tnode *left, *right;
+- unsigned long size, j;
++ for (i = tnode_child_length(oldtnode), m = 1u << tn->pos; i;) {
++ inode = tnode_get_child(oldtnode, --i);
+
+ /* An empty child */
+ if (inode == NULL)
+@@ -496,65 +462,99 @@ static int inflate(struct trie *t, struc
+ continue;
+ }
+
+- /* 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]));
++ 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;
++ tnode_free_append(tn, node1);
++
++ node0 = tnode_new(inode->key & ~m, inode->pos, inode->bits - 1);
++ 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));
++ }
++
++ /* 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 pointer into and out of this node */
++ tp = node_parent(oldtnode);
++ NODE_INIT_PARENT(tn, tp);
++ put_child_root(tp, t, tn->key, tn);
+
+- /* Use the old key, but set the new significant
+- * bit to zero.
+- */
++ /* prepare oldtnode to be freed */
++ tnode_free_init(oldtnode);
+
+- left = tnode_get_child(tn, 2*i);
+- put_child(tn, 2*i, NULL);
++ /* update all child nodes parent pointers to route to us */
++ for (i = tnode_child_length(oldtnode); i;) {
++ inode = tnode_get_child(oldtnode, --i);
+
+- BUG_ON(!left);
++ /* A leaf or an internal node with skipped bits */
++ if (!tnode_full(oldtnode, inode)) {
++ node_set_parent(inode, tn);
++ continue;
++ }
+
+- right = tnode_get_child(tn, 2*i+1);
+- put_child(tn, 2*i+1, NULL);
++ /* drop the node in the old tnode free list */
++ tnode_free_append(oldtnode, inode);
+
+- BUG_ON(!right);
++ /* fetch new nodes */
++ node1 = tnode_get_child(tn, 2 * i + 1);
++ node0 = tnode_get_child(tn, 2 * i);
+
+- 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]));
++ /* bits == 1 then node0 and node1 represent inode's children */
++ if (inode->bits == 1) {
++ node_set_parent(node1, tn);
++ node_set_parent(node0, tn);
++ continue;
+ }
+
+- put_child(tn, 2 * i, left);
+- put_child(tn, 2 * i + 1, right);
++ /* update parent pointers in child node's children */
++ for (k = tnode_child_length(inode), j = k / 2; j;) {
++ node_set_parent(tnode_get_child(inode, --k), node1);
++ node_set_parent(tnode_get_child(inode, --j), node0);
++ node_set_parent(tnode_get_child(inode, --k), node1);
++ node_set_parent(tnode_get_child(inode, --j), node0);
++ }
+
+ /* resize child nodes */
+- resize(t, left);
+- resize(t, right);
++ resize(t, node1);
++ resize(t, node0);
+ }
+
+- put_child_root(tp, t, tn->key, tn);
+-
+ /* we completed without error, prepare to free old node */
+ tnode_free(oldtnode);
+ return 0;
+@@ -566,10 +566,8 @@ nomem:
+
+ static int halve(struct trie *t, struct tnode *oldtnode)
+ {
+- unsigned long olen = tnode_child_length(oldtnode);
+- struct tnode *tp = node_parent(oldtnode);
+- struct tnode *tn, *left, *right;
+- int i;
++ struct tnode *tn, *tp, *inode, *node0, *node1;
++ unsigned long i;
+
+ pr_debug("In halve\n");
+
+@@ -577,68 +575,64 @@ static int halve(struct trie *t, struct
+ if (!tn)
+ return -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 halve
+- * of tnode is ignored.
++ /* 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;) {
++ node1 = tnode_get_child(oldtnode, --i);
++ node0 = tnode_get_child(oldtnode, --i);
+
+- for (i = 0; i < olen; i += 2) {
+- left = tnode_get_child(oldtnode, i);
+- right = tnode_get_child(oldtnode, i+1);
++ /* At least one of the children is empty */
++ if (!node1 || !node0) {
++ put_child(tn, i / 2, node1 ? : node0);
++ continue;
++ }
+
+ /* Two nonempty children */
+- if (left && right) {
+- struct tnode *newn;
+-
+- newn = tnode_new(left->key, oldtnode->pos, 1);
+- if (!newn) {
+- tnode_free(tn);
+- return -ENOMEM;
+- }
+- tnode_free_append(tn, newn);
+-
+- put_child(tn, i/2, newn);
++ inode = tnode_new(node0->key, oldtnode->pos, 1);
++ if (!inode) {
++ tnode_free(tn);
++ return -ENOMEM;
+ }
++ 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);
++
++ /* link parent to node */
++ put_child(tn, i / 2, inode);
+ }
+
++ /* setup the parent pointer out of and back into this node */
++ tp = node_parent(oldtnode);
++ NODE_INIT_PARENT(tn, tp);
++ put_child_root(tp, t, tn->key, tn);
++
+ /* prepare oldtnode to be freed */
+ tnode_free_init(oldtnode);
+
+- for (i = 0; i < olen; i += 2) {
+- struct tnode *newBinNode;
+-
+- left = tnode_get_child(oldtnode, i);
+- right = tnode_get_child(oldtnode, i+1);
+-
+- /* 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;
+- }
+-
+- if (right == NULL) {
+- put_child(tn, i/2, left);
++ /* update all of the child parent pointers */
++ for (i = tnode_child_length(tn); i;) {
++ inode = tnode_get_child(tn, --i);
++
++ /* only new tnodes will be considered "full" nodes */
++ if (!tnode_full(tn, inode)) {
++ node_set_parent(inode, tn);
+ continue;
+ }
+
+ /* Two nonempty children */
+- newBinNode = tnode_get_child(tn, i/2);
+- put_child(newBinNode, 0, left);
+- put_child(newBinNode, 1, right);
+-
+- put_child(tn, i / 2, newBinNode);
++ node_set_parent(tnode_get_child(inode, 1), inode);
++ node_set_parent(tnode_get_child(inode, 0), inode);
+
+ /* resize child node */
+- resize(t, newBinNode);
++ resize(t, inode);
+ }
+
+- put_child_root(tp, t, tn->key, tn);
+-
+ /* all pointers should be clean so we are done */
+ tnode_free(oldtnode);
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:57:02 -0800
+Subject: [PATCH] fib_trie: Remove checks for index >= tnode_child_length
+ from tnode_get_child
+
+For some reason the compiler doesn't seem to understand that when we are in
+a loop that runs from tnode_child_length - 1 to 0 we don't expect the value
+of tn->bits to change. As such every call to tnode_get_child was rerunning
+tnode_chile_length which ended up consuming quite a bit of space in the
+resultant assembly code.
+
+I have gone though and verified that in all cases where tnode_get_child
+is used we are either winding though a fixed loop from tnode_child_length -
+1 to 0, or are in a fastpath case where we are verifying the value by
+either checking for any remaining bits after shifting index by bits and
+testing for leaf, or by using tnode_child_length.
+
+size net/ipv4/fib_trie.o
+Before:
+ text data bss dec hex filename
+ 15506 376 8 15890 3e12 net/ipv4/fib_trie.o
+
+After:
+ text data bss dec hex filename
+ 14827 376 8 15211 3b6b net/ipv4/fib_trie.o
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -186,8 +186,6 @@ static inline unsigned long tnode_child_
+ static inline struct tnode *tnode_get_child(const struct tnode *tn,
+ unsigned long i)
+ {
+- BUG_ON(i >= tnode_child_length(tn));
+-
+ return rtnl_dereference(tn->child[i]);
+ }
+
+@@ -195,8 +193,6 @@ static inline struct tnode *tnode_get_ch
+ static inline struct tnode *tnode_get_child_rcu(const struct tnode *tn,
+ unsigned long i)
+ {
+- BUG_ON(i >= tnode_child_length(tn));
+-
+ return rcu_dereference_rtnl(tn->child[i]);
+ }
+
+@@ -371,7 +367,7 @@ static inline int tnode_full(const struc
+ */
+ static void put_child(struct tnode *tn, unsigned long i, struct tnode *n)
+ {
+- struct tnode *chi = rtnl_dereference(tn->child[i]);
++ struct tnode *chi = tnode_get_child(tn, i);
+ int isfull, wasfull;
+
+ BUG_ON(i >= tnode_child_length(tn));
+@@ -867,7 +863,7 @@ static struct tnode *fib_find_node(struc
+ if (IS_LEAF(n))
+ break;
+
+- n = rcu_dereference_rtnl(n->child[index]);
++ n = tnode_get_child_rcu(n, index);
+ }
+
+ return n;
+@@ -934,7 +930,7 @@ static struct list_head *fib_insert_node
+ }
+
+ tp = n;
+- n = rcu_dereference_rtnl(n->child[index]);
++ n = tnode_get_child_rcu(n, index);
+ }
+
+ l = leaf_new(key);
+@@ -1215,7 +1211,7 @@ int fib_table_lookup(struct fib_table *t
+ cindex = index;
+ }
+
+- n = rcu_dereference(n->child[index]);
++ n = tnode_get_child_rcu(n, index);
+ if (unlikely(!n))
+ goto backtrace;
+ }
+@@ -1835,7 +1831,7 @@ static void trie_collect_stats(struct tr
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
+
+- for (i = 0; i < tnode_child_length(n); i++) {
++ for (i = tnode_child_length(n); i--;) {
+ if (!rcu_access_pointer(n->child[i]))
+ s->nullpointers++;
+ }
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Wed, 31 Dec 2014 10:57:08 -0800
+Subject: [PATCH] fib_trie: Add tracking value for suffix length
+
+This change adds a tracking value for the maximum suffix length of all
+prefixes stored in any given tnode. With this value we can determine if we
+need to backtrace or not based on if the suffix is greater than the pos
+value.
+
+By doing this we can reduce the CPU overhead for lookups in the local table
+as many of the prefixes there are 32b long and have a suffix length of 0
+meaning we can immediately backtrace to the root node without needing to
+test any of the nodes between it and where we ended up.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -96,6 +96,7 @@ struct tnode {
+ t_key key;
+ 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 {
+@@ -311,6 +312,7 @@ static struct tnode *leaf_new(t_key key)
+ * 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;
+@@ -342,6 +344,7 @@ static struct tnode *tnode_new(t_key key
+
+ if (tn) {
+ tn->parent = NULL;
++ tn->slen = pos;
+ tn->pos = pos;
+ tn->bits = bits;
+ tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
+@@ -387,6 +390,9 @@ static void put_child(struct tnode *tn,
+ else if (!wasfull && isfull)
+ tn->full_children++;
+
++ if (n && (tn->slen < n->slen))
++ tn->slen = n->slen;
++
+ rcu_assign_pointer(tn->child[i], n);
+ }
+
+@@ -635,6 +641,41 @@ static int halve(struct trie *t, struct
+ return 0;
+ }
+
++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);
++
++ if (!n || (n->slen <= slen))
++ continue;
++
++ /* update stride and slen based on new value */
++ stride <<= (n->slen - slen);
++ slen = n->slen;
++ i &= ~(stride - 1);
++
++ /* if slen covers all but the last bit we can stop here
++ * there will be nothing longer than that since only node
++ * 0 and 1 << (bits - 1) could have that as their suffix
++ * length.
++ */
++ if ((slen + 1) >= (tn->pos + tn->bits))
++ break;
++ }
++
++ tn->slen = slen;
++
++ return slen;
++}
++
+ /* From "Implementing a dynamic compressed trie" by Stefan Nilsson of
+ * the Helsinki University of Technology and Matti Tikkanen of Nokia
+ * Telecommunications, page 6:
+@@ -790,6 +831,19 @@ no_children:
+ /* drop dead node */
+ tnode_free_init(tn);
+ tnode_free(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;
+ }
+ }
+
+@@ -818,8 +872,58 @@ static inline struct list_head *get_fa_h
+ 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)
++{
++ struct hlist_node *prev;
++
++ /* record the location of the pointer to this object */
++ prev = rtnl_dereference(hlist_pprev_rcu(&old->hlist));
++
++ /* remove the leaf info from the list */
++ hlist_del_rcu(&old->hlist);
++
++ /* if we emptied the list this leaf will be freed and we can sort
++ * out parent suffix lengths as a part of trie_rebalance
++ */
++ if (hlist_empty(&l->list))
++ return;
++
++ /* if we removed the tail then we need to update slen */
++ if (!rcu_access_pointer(hlist_next_rcu(prev))) {
++ struct leaf_info *li = hlist_entry(prev, typeof(*li), hlist);
++
++ 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)) {
+@@ -836,6 +940,12 @@ static void insert_leaf_info(struct hlis
+ else
+ hlist_add_before_rcu(&new->hlist, &li->hlist);
+ }
++
++ /* if we added to the tail node then we need to update slen */
++ if (!rcu_access_pointer(hlist_next_rcu(&new->hlist))) {
++ l->slen = KEYLENGTH - new->plen;
++ leaf_push_suffix(l);
++ }
+ }
+
+ /* rcu_read_lock needs to be hold by caller from readside */
+@@ -925,7 +1035,7 @@ static struct list_head *fib_insert_node
+ /* 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->list, li);
++ insert_leaf_info(n, li);
+ return fa_head;
+ }
+
+@@ -939,7 +1049,7 @@ static struct list_head *fib_insert_node
+ return NULL;
+ }
+
+- insert_leaf_info(&l->list, li);
++ insert_leaf_info(l, li);
+
+ /* Case 2: n is a LEAF or a TNODE and the key doesn't match.
+ *
+@@ -1206,7 +1316,7 @@ int fib_table_lookup(struct fib_table *t
+ /* only record pn and cindex if we are going to be chopping
+ * bits later. Otherwise we are just wasting cycles.
+ */
+- if (index) {
++ if (n->slen > n->pos) {
+ pn = n;
+ cindex = index;
+ }
+@@ -1225,7 +1335,7 @@ int fib_table_lookup(struct fib_table *t
+ * between the key and the prefix exist in the region of
+ * the lsb and higher in the prefix.
+ */
+- if (unlikely(prefix_mismatch(key, n)))
++ if (unlikely(prefix_mismatch(key, n)) || (n->slen == n->pos))
+ goto backtrace;
+
+ /* exit out and process leaf */
+@@ -1425,7 +1535,7 @@ int fib_table_delete(struct fib_table *t
+ tb->tb_num_default--;
+
+ if (list_empty(fa_head)) {
+- hlist_del_rcu(&li->hlist);
++ remove_leaf_info(l, li);
+ free_leaf_info(li);
+ }
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:14 -0800
+Subject: [PATCH] fib_trie: Fix RCU bug and merge similar bits of inflate/halve
+
+This patch addresses two issues.
+
+The first issue is the fact that I believe I had the RCU freeing sequence
+slightly out of order. As a result we could get into an issue if a caller
+went into a child of a child of the new node, then backtraced into the to be
+freed parent, and then attempted to access a child of a child that may have
+been consumed in a resize of one of the new nodes children. To resolve this I
+have moved the resize after we have freed the oldtnode. The only side effect
+of this is that we will now be calling resize on more nodes in the case of
+inflate due to the fact that we don't have a good way to test to see if a
+full_tnode on the new node was there before or after the allocation. This
+should have minimal impact however since the node should already be
+correctly size so it is just the cost of calling should_inflate that we
+will be taking on the node which is only a couple of cycles.
+
+The second issue is the fact that inflate and halve were essentially doing
+the same thing after the new node was added to the trie replacing the old
+one. As such it wasn't really necessary to keep the code in both functions
+so I have split it out into two other functions, called replace and
+update_children.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -396,8 +396,30 @@ static void put_child(struct tnode *tn,
+ rcu_assign_pointer(tn->child[i], n);
+ }
+
+-static void put_child_root(struct tnode *tp, struct trie *t,
+- t_key key, struct tnode *n)
++static void update_children(struct tnode *tn)
++{
++ unsigned long i;
++
++ /* update all of the child parent pointers */
++ for (i = tnode_child_length(tn); i;) {
++ struct tnode *inode = tnode_get_child(tn, --i);
++
++ if (!inode)
++ continue;
++
++ /* 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);
++ }
++}
++
++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);
+@@ -434,10 +456,35 @@ static void tnode_free(struct tnode *tn)
+ }
+ }
+
++static void replace(struct trie *t, struct tnode *oldtnode, struct tnode *tn)
++{
++ struct tnode *tp = node_parent(oldtnode);
++ unsigned long i;
++
++ /* setup the parent pointer out of and back into this node */
++ NODE_INIT_PARENT(tn, tp);
++ put_child_root(tp, t, tn->key, tn);
++
++ /* update all of the child parent pointers */
++ update_children(tn);
++
++ /* all pointers should be clean so we are done */
++ tnode_free(oldtnode);
++
++ /* resize children now that oldtnode is freed */
++ for (i = tnode_child_length(tn); i;) {
++ struct tnode *inode = tnode_get_child(tn, --i);
++
++ /* resize child node */
++ if (tnode_full(tn, inode))
++ resize(t, inode);
++ }
++}
++
+ static int inflate(struct trie *t, struct tnode *oldtnode)
+ {
+- struct tnode *inode, *node0, *node1, *tn, *tp;
+- unsigned long i, j, k;
++ struct tnode *tn;
++ unsigned long i;
+ t_key m;
+
+ pr_debug("In inflate\n");
+@@ -446,13 +493,18 @@ static int inflate(struct trie *t, struc
+ if (!tn)
+ return -ENOMEM;
+
++ /* prepare oldtnode to be freed */
++ tnode_free_init(oldtnode);
++
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = tnode_child_length(oldtnode), m = 1u << tn->pos; i;) {
+- inode = tnode_get_child(oldtnode, --i);
++ struct tnode *inode = tnode_get_child(oldtnode, --i);
++ struct tnode *node0, *node1;
++ unsigned long j, k;
+
+ /* An empty child */
+ if (inode == NULL)
+@@ -464,6 +516,9 @@ static int inflate(struct trie *t, struc
+ continue;
+ }
+
++ /* 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 + 1, tnode_get_child(inode, 1));
+@@ -488,9 +543,9 @@ static int inflate(struct trie *t, struc
+ node1 = tnode_new(inode->key | m, inode->pos, inode->bits - 1);
+ if (!node1)
+ goto nomem;
+- tnode_free_append(tn, node1);
++ node0 = tnode_new(inode->key, inode->pos, inode->bits - 1);
+
+- node0 = tnode_new(inode->key & ~m, inode->pos, inode->bits - 1);
++ tnode_free_append(tn, node1);
+ if (!node0)
+ goto nomem;
+ tnode_free_append(tn, node0);
+@@ -512,53 +567,9 @@ static int inflate(struct trie *t, struc
+ put_child(tn, 2 * i, node0);
+ }
+
+- /* setup the parent pointer into and out of this node */
+- tp = node_parent(oldtnode);
+- NODE_INIT_PARENT(tn, tp);
+- put_child_root(tp, t, tn->key, tn);
+-
+- /* prepare oldtnode to be freed */
+- tnode_free_init(oldtnode);
+-
+- /* update all child nodes parent pointers to route to us */
+- for (i = tnode_child_length(oldtnode); i;) {
+- inode = tnode_get_child(oldtnode, --i);
+-
+- /* A leaf or an internal node with skipped bits */
+- if (!tnode_full(oldtnode, inode)) {
+- node_set_parent(inode, tn);
+- continue;
+- }
+-
+- /* drop the node in the old tnode free list */
+- tnode_free_append(oldtnode, inode);
+-
+- /* fetch new nodes */
+- node1 = tnode_get_child(tn, 2 * i + 1);
+- node0 = tnode_get_child(tn, 2 * i);
++ /* setup the parent pointers into and out of this node */
++ replace(t, oldtnode, tn);
+
+- /* bits == 1 then node0 and node1 represent inode's children */
+- if (inode->bits == 1) {
+- node_set_parent(node1, tn);
+- node_set_parent(node0, tn);
+- continue;
+- }
+-
+- /* update parent pointers in child node's children */
+- for (k = tnode_child_length(inode), j = k / 2; j;) {
+- node_set_parent(tnode_get_child(inode, --k), node1);
+- node_set_parent(tnode_get_child(inode, --j), node0);
+- node_set_parent(tnode_get_child(inode, --k), node1);
+- node_set_parent(tnode_get_child(inode, --j), node0);
+- }
+-
+- /* resize child nodes */
+- resize(t, node1);
+- resize(t, node0);
+- }
+-
+- /* we completed without error, prepare to free old node */
+- tnode_free(oldtnode);
+ return 0;
+ nomem:
+ /* all pointers should be clean so we are done */
+@@ -568,7 +579,7 @@ nomem:
+
+ static int halve(struct trie *t, struct tnode *oldtnode)
+ {
+- struct tnode *tn, *tp, *inode, *node0, *node1;
++ struct tnode *tn;
+ unsigned long i;
+
+ pr_debug("In halve\n");
+@@ -577,14 +588,18 @@ static int halve(struct trie *t, struct
+ if (!tn)
+ return -ENOMEM;
+
++ /* prepare oldtnode to be freed */
++ tnode_free_init(oldtnode);
++
+ /* Assemble all of the pointers in our cluster, in this case that
+ * represents all of the pointers out of our allocated nodes that
+ * point to existing tnodes and the links between our allocated
+ * nodes.
+ */
+ for (i = tnode_child_length(oldtnode); i;) {
+- node1 = tnode_get_child(oldtnode, --i);
+- node0 = tnode_get_child(oldtnode, --i);
++ struct tnode *node1 = tnode_get_child(oldtnode, --i);
++ struct tnode *node0 = tnode_get_child(oldtnode, --i);
++ struct tnode *inode;
+
+ /* At least one of the children is empty */
+ if (!node1 || !node0) {
+@@ -609,34 +624,8 @@ static int halve(struct trie *t, struct
+ put_child(tn, i / 2, inode);
+ }
+
+- /* setup the parent pointer out of and back into this node */
+- tp = node_parent(oldtnode);
+- NODE_INIT_PARENT(tn, tp);
+- put_child_root(tp, t, tn->key, tn);
+-
+- /* prepare oldtnode to be freed */
+- tnode_free_init(oldtnode);
+-
+- /* update all of the child parent pointers */
+- for (i = tnode_child_length(tn); i;) {
+- inode = tnode_get_child(tn, --i);
+-
+- /* only new tnodes will be considered "full" nodes */
+- if (!tnode_full(tn, inode)) {
+- node_set_parent(inode, tn);
+- continue;
+- }
+-
+- /* Two nonempty children */
+- node_set_parent(tnode_get_child(inode, 1), inode);
+- node_set_parent(tnode_get_child(inode, 0), inode);
+-
+- /* resize child node */
+- resize(t, inode);
+- }
+-
+- /* all pointers should be clean so we are done */
+- tnode_free(oldtnode);
++ /* setup the parent pointers into and out of this node */
++ replace(t, oldtnode, tn);
+
+ return 0;
+ }
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:20 -0800
+Subject: [PATCH] fib_trie: Fall back to slen update on inflate/halve failure
+
+This change corrects an issue where if inflate or halve fails we were
+exiting the resize function without at least updating the slen for the
+node. To correct this I have moved the update of max_size into the while
+loop so that it is only decremented on a successful call to either inflate
+or halve.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -752,7 +752,7 @@ static void resize(struct trie *t, struc
+ {
+ struct tnode *tp = node_parent(tn), *n = NULL;
+ struct tnode __rcu **cptr;
+- int max_work;
++ int max_work = MAX_WORK;
+
+ pr_debug("In tnode_resize %p inflate_threshold=%d threshold=%d\n",
+ tn, inflate_threshold, halve_threshold);
+@@ -775,8 +775,7 @@ static void resize(struct trie *t, struc
+ /* Double as long as the resulting node has a number of
+ * nonempty nodes that are above the threshold.
+ */
+- max_work = MAX_WORK;
+- while (should_inflate(tp, tn) && max_work--) {
++ 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);
+@@ -784,6 +783,7 @@ static void resize(struct trie *t, struc
+ break;
+ }
+
++ max_work--;
+ tn = rtnl_dereference(*cptr);
+ }
+
+@@ -794,8 +794,7 @@ static void resize(struct trie *t, struc
+ /* Halve as long as the number of empty children in this
+ * node is above threshold.
+ */
+- max_work = MAX_WORK;
+- while (should_halve(tp, tn) && max_work--) {
++ 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);
+@@ -803,6 +802,7 @@ static void resize(struct trie *t, struc
+ break;
+ }
+
++ max_work--;
+ tn = rtnl_dereference(*cptr);
+ }
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:26 -0800
+Subject: [PATCH] fib_trie: Add collapse() and should_collapse() to resize
+
+This patch really does two things.
+
+First it pulls the logic for determining if we should collapse one node out
+of the tree and the actual code doing the collapse into a separate pair of
+functions. This helps to make the changes to these areas more readable.
+
+Second it encodes the upper 32b of the empty_children value onto the
+full_children value in the case of bits == KEYLENGTH. By doing this we are
+able to handle the case of a 32b node where empty_children would appear to
+be 0 when it was actually 1ul << 32.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -83,7 +83,8 @@
+
+ #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;
+
+@@ -102,8 +103,8 @@ struct tnode {
+ 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 */
++ 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) */
+@@ -302,6 +303,16 @@ static struct tnode *tnode_alloc(size_t
+ return vzalloc(size);
+ }
+
++static inline void empty_child_inc(struct tnode *n)
++{
++ ++n->empty_children ? : ++n->full_children;
++}
++
++static inline void empty_child_dec(struct tnode *n)
++{
++ n->empty_children-- ? : n->full_children--;
++}
++
+ static struct tnode *leaf_new(t_key key)
+ {
+ struct tnode *l = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
+@@ -335,7 +346,7 @@ static struct leaf_info *leaf_info_new(i
+
+ static struct tnode *tnode_new(t_key key, int pos, int bits)
+ {
+- size_t sz = offsetof(struct tnode, child[1 << bits]);
++ size_t sz = offsetof(struct tnode, child[1ul << bits]);
+ struct tnode *tn = tnode_alloc(sz);
+ unsigned int shift = pos + bits;
+
+@@ -348,8 +359,10 @@ static struct tnode *tnode_new(t_key key
+ tn->pos = pos;
+ tn->bits = bits;
+ tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
+- tn->full_children = 0;
+- tn->empty_children = 1<<bits;
++ 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),
+@@ -375,11 +388,11 @@ static void put_child(struct tnode *tn,
+
+ 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 */
+ wasfull = tnode_full(tn, chi);
+@@ -630,6 +643,24 @@ static int halve(struct trie *t, struct
+ return 0;
+ }
+
++static void collapse(struct trie *t, struct tnode *oldtnode)
++{
++ struct tnode *n, *tp;
++ unsigned long i;
++
++ /* 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);
++
++ /* compress one level */
++ tp = node_parent(oldtnode);
++ put_child_root(tp, t, oldtnode->key, n);
++ node_set_parent(n, tp);
++
++ /* drop dead node */
++ node_free(oldtnode);
++}
++
+ static unsigned char update_suffix(struct tnode *tn)
+ {
+ unsigned char slen = tn->pos;
+@@ -729,10 +760,12 @@ static bool should_inflate(const struct
+
+ /* Keep root node larger */
+ threshold *= tp ? inflate_threshold : inflate_threshold_root;
+- used += tn->full_children;
+ used -= tn->empty_children;
++ used += tn->full_children;
+
+- return tn->pos && ((50 * used) >= threshold);
++ /* if bits == KEYLENGTH then pos = 0, and will fail below */
++
++ return (used > 1) && tn->pos && ((50 * used) >= threshold);
+ }
+
+ static bool should_halve(const struct tnode *tp, const struct tnode *tn)
+@@ -744,13 +777,29 @@ static bool should_halve(const struct tn
+ threshold *= tp ? halve_threshold : halve_threshold_root;
+ used -= tn->empty_children;
+
+- return (tn->bits > 1) && ((100 * used) < threshold);
++ /* 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), *n = NULL;
++ struct tnode *tp = node_parent(tn);
+ struct tnode __rcu **cptr;
+ int max_work = MAX_WORK;
+
+@@ -764,14 +813,6 @@ static void resize(struct trie *t, struc
+ cptr = tp ? &tp->child[get_index(tn->key, tp)] : &t->trie;
+ BUG_ON(tn != rtnl_dereference(*cptr));
+
+- /* No children */
+- if (tn->empty_children > (tnode_child_length(tn) - 1))
+- goto no_children;
+-
+- /* 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.
+ */
+@@ -807,19 +848,8 @@ static void resize(struct trie *t, struc
+ }
+
+ /* Only one child remains */
+- if (tn->empty_children == (tnode_child_length(tn) - 1)) {
+- unsigned long i;
+-one_child:
+- for (i = tnode_child_length(tn); !n && i;)
+- n = tnode_get_child(tn, --i);
+-no_children:
+- /* compress one level */
+- put_child_root(tp, t, tn->key, n);
+- node_set_parent(n, tp);
+-
+- /* drop dead node */
+- tnode_free_init(tn);
+- tnode_free(tn);
++ if (should_collapse(tn)) {
++ collapse(t, tn);
+ return;
+ }
+
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:33 -0800
+Subject: [PATCH] fib_trie: Use empty_children instead of counting empty nodes
+ in stats collection
+
+It doesn't make much sense to count the pointers ourselves when
+empty_children already has a count for the number of NULL pointers stored
+in the tnode. As such save ourselves the cycles and just use
+empty_children.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -1954,16 +1954,10 @@ static void trie_collect_stats(struct tr
+ hlist_for_each_entry_rcu(li, &n->list, hlist)
+ ++s->prefixes;
+ } else {
+- unsigned long i;
+-
+ s->tnodes++;
+ if (n->bits < MAX_STAT_DEPTH)
+ s->nodesizes[n->bits]++;
+-
+- for (i = tnode_child_length(n); i--;) {
+- if (!rcu_access_pointer(n->child[i]))
+- s->nullpointers++;
+- }
++ s->nullpointers += n->empty_children;
+ }
+ }
+ rcu_read_unlock();
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:39 -0800
+Subject: [PATCH] fib_trie: Move fib_find_alias to file where it is used
+
+The function fib_find_alias is only accessed by functions in fib_trie.c as
+such it makes sense to relocate it and cast it as static so that the
+compiler can take advantage of optimizations it can do to it as a local
+function.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_lookup.h
++++ b/net/ipv4/fib_lookup.h
+@@ -32,7 +32,6 @@ int fib_dump_info(struct sk_buff *skb, u
+ unsigned int);
+ void rtmsg_fib(int event, __be32 key, struct fib_alias *fa, int dst_len,
+ u32 tb_id, const struct nl_info *info, unsigned int nlm_flags);
+-struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio);
+
+ static inline void fib_result_assign(struct fib_result *res,
+ struct fib_info *fi)
+--- a/net/ipv4/fib_semantics.c
++++ b/net/ipv4/fib_semantics.c
+@@ -414,24 +414,6 @@ errout:
+ rtnl_set_sk_err(info->nl_net, RTNLGRP_IPV4_ROUTE, err);
+ }
+
+-/* Return the first fib alias matching TOS with
+- * priority less than or equal to PRIO.
+- */
+-struct fib_alias *fib_find_alias(struct list_head *fah, u8 tos, u32 prio)
+-{
+- if (fah) {
+- struct fib_alias *fa;
+- 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 int fib_detect_death(struct fib_info *fi, int order,
+ struct fib_info **last_resort, int *last_idx,
+ int dflt)
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -998,6 +998,26 @@ static struct tnode *fib_find_node(struc
+ return n;
+ }
+
++/* 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 (!fah)
++ return NULL;
++
++ 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)
+ {
+ struct tnode *tp;
--- /dev/null
+From: Alexander Duyck <alexander.h.duyck@redhat.com>
+Date: Thu, 22 Jan 2015 15:51:45 -0800
+Subject: [PATCH] fib_trie: Various clean-ups for handling slen
+
+While doing further work on the fib_trie I noted a few items.
+
+First I was using calls that were far more complicated than they needed to
+be for determining when to push/pull the suffix length. I have updated the
+code to reflect the simplier logic.
+
+The second issue is that I realised we weren't necessarily handling the
+case of a leaf_info struct surviving a flush. I have updated the logic so
+that now we will call pull_suffix in the event of having a leaf info value
+left in the leaf after flushing it.
+
+Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
+Signed-off-by: David S. Miller <davem@davemloft.net>
+---
+
+--- a/net/ipv4/fib_trie.c
++++ b/net/ipv4/fib_trie.c
+@@ -917,27 +917,20 @@ static void leaf_push_suffix(struct tnod
+
+ static void remove_leaf_info(struct tnode *l, struct leaf_info *old)
+ {
+- struct hlist_node *prev;
+-
+- /* record the location of the pointer to this object */
+- prev = rtnl_dereference(hlist_pprev_rcu(&old->hlist));
++ /* 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);
+
+- /* if we emptied the list this leaf will be freed and we can sort
+- * out parent suffix lengths as a part of trie_rebalance
+- */
+- if (hlist_empty(&l->list))
++ /* only access li if it is pointing at the last valid hlist_node */
++ if (hlist_empty(&l->list) || (*pprev))
+ return;
+
+- /* if we removed the tail then we need to update slen */
+- if (!rcu_access_pointer(hlist_next_rcu(prev))) {
+- struct leaf_info *li = hlist_entry(prev, typeof(*li), hlist);
+-
+- l->slen = KEYLENGTH - li->plen;
+- leaf_pull_suffix(l);
+- }
++ /* 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)
+@@ -961,7 +954,7 @@ static void insert_leaf_info(struct tnod
+ }
+
+ /* if we added to the tail node then we need to update slen */
+- if (!rcu_access_pointer(hlist_next_rcu(&new->hlist))) {
++ if (l->slen < (KEYLENGTH - new->plen)) {
+ l->slen = KEYLENGTH - new->plen;
+ leaf_push_suffix(l);
+ }
+@@ -1613,6 +1606,7 @@ static int trie_flush_leaf(struct tnode
+ 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);
+@@ -1620,8 +1614,14 @@ static int trie_flush_leaf(struct tnode
+ if (list_empty(&li->falh)) {
+ hlist_del_rcu(&li->hlist);
+ free_leaf_info(li);
++ continue;
+ }
++
++ plen = li->plen;
+ }
++
++ l->slen = KEYLENGTH - plen;
++
+ return found;
+ }
+
+@@ -1700,13 +1700,22 @@ int fib_table_flush(struct fib_table *tb
+ 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;
projects / openwrt / staging / chunkeey.git / commitdiff