fib_trie: Convert fib_alias to hlist from list

There isn't any advantage to having it as a list and by making it an hlist
we make the fib_alias more compatible with the list_info in terms of the
type of list used.

Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

4 files changed, 48 insertions, 40 deletions

diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index 5bd120e4bc0a..cba4b7c32935 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -136,7 +136,7 @@ struct fib_result {
         u32             tclassid;
         struct fib_info *fi;
         struct fib_table *table;
-        struct list_head *fa_head;
+        struct hlist_head *fa_head;
 };
 
 struct fib_result_nl {
diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h
index 825981b1049a..3cd444f4e0f6 100644
--- a/net/ipv4/fib_lookup.h
+++ b/net/ipv4/fib_lookup.h
@@ -6,7 +6,7 @@
 #include <net/ip_fib.h>
 
 struct fib_alias {
-        struct list_head        fa_list;
+        struct hlist_node       fa_list;
         struct fib_info         *fa_info;
         u8                      fa_tos;
         u8                      fa_type;
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 1e2090ea663e..c6d267442dac 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -1163,12 +1163,12 @@ int fib_sync_down_dev(struct net_device *dev, int force)
 void fib_select_default(struct fib_result *res)
 {
         struct fib_info *fi = NULL, *last_resort = NULL;
-        struct list_head *fa_head = res->fa_head;
+        struct hlist_head *fa_head = res->fa_head;
         struct fib_table *tb = res->table;
         int order = -1, last_idx = -1;
         struct fib_alias *fa;
 
-        list_for_each_entry_rcu(fa, fa_head, fa_list) {
+        hlist_for_each_entry_rcu(fa, fa_head, fa_list) {
                 struct fib_info *next_fi = fa->fa_info;
 
                 if (next_fi->fib_scope != res->scope ||
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 3daf0224ff2e..f17e2239b7b9 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -116,7 +116,7 @@ struct leaf_info {
         struct hlist_node hlist;
         int plen;
         u32 mask_plen; /* ntohl(inet_make_mask(plen)) */
-        struct list_head falh;
+        struct hlist_head falh;
         struct rcu_head rcu;
 };
 
@@ -339,7 +339,7 @@ static struct leaf_info *leaf_info_new(int plen)
         if (li) {
                 li->plen = plen;
                 li->mask_plen = ntohl(inet_make_mask(plen));
-                INIT_LIST_HEAD(&li->falh);
+                INIT_HLIST_HEAD(&li->falh);
         }
         return li;
 }
@@ -881,7 +881,7 @@ static struct leaf_info *find_leaf_info(struct tnode *l, int plen)
         return NULL;
 }
 
-static inline struct list_head *get_fa_head(struct tnode *l, int plen)
+static inline struct hlist_head *get_fa_head(struct tnode *l, int plen)
 {
         struct leaf_info *li = find_leaf_info(l, plen);
 
@@ -994,14 +994,15 @@ static struct tnode *fib_find_node(struct trie *t, u32 key)
 /* 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)
+static struct fib_alias *fib_find_alias(struct hlist_head *fah, u8 tos,
+                                        u32 prio)
 {
         struct fib_alias *fa;
 
         if (!fah)
                 return NULL;
 
-        list_for_each_entry(fa, fah, fa_list) {
+        hlist_for_each_entry(fa, fah, fa_list) {
                 if (fa->fa_tos > tos)
                         continue;
                 if (fa->fa_info->fib_priority >= prio || fa->fa_tos < tos)
@@ -1027,9 +1028,9 @@ static void trie_rebalance(struct trie *t, struct tnode *tn)
 
 /* only used from updater-side */
 
-static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
+static struct hlist_head *fib_insert_node(struct trie *t, u32 key, int plen)
 {
-        struct list_head *fa_head = NULL;
+        struct hlist_head *fa_head = NULL;
         struct tnode *l, *n, *tp = NULL;
         struct leaf_info *li;
 
@@ -1130,7 +1131,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
 {
         struct trie *t = (struct trie *) tb->tb_data;
         struct fib_alias *fa, *new_fa;
-        struct list_head *fa_head = NULL;
+        struct hlist_head *fa_head = NULL;
         struct fib_info *fi;
         int plen = cfg->fc_dst_len;
         u8 tos = cfg->fc_tos;
@@ -1171,10 +1172,8 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
          * exists or to the node before which we will insert new one.
          *
          * If fa is NULL, we will need to allocate a new one and
-         * insert to the head of f.
-         *
-         * If f is NULL, no fib node matched the destination key
-         * and we need to allocate a new one of those as well.
+         * insert to the tail of the section matching the suffix length
+         * of the new alias.
          */
 
         if (fa && fa->fa_tos == tos &&
@@ -1192,8 +1191,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
                  */
                 fa_match = NULL;
                 fa_first = fa;
-                fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
-                list_for_each_entry_continue(fa, fa_head, fa_list) {
+                hlist_for_each_entry_from(fa, fa_list) {
                         if (fa->fa_tos != tos)
                                 break;
                         if (fa->fa_info->fib_priority != fi->fib_priority)
@@ -1227,7 +1225,7 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
                         state = fa->fa_state;
                         new_fa->fa_state = state & ~FA_S_ACCESSED;
 
-                        list_replace_rcu(&fa->fa_list, &new_fa->fa_list);
+                        hlist_replace_rcu(&fa->fa_list, &new_fa->fa_list);
                         alias_free_mem_rcu(fa);
 
                         fib_release_info(fi_drop);
@@ -1276,8 +1274,19 @@ int fib_table_insert(struct fib_table *tb, struct fib_config *cfg)
         if (!plen)
                 tb->tb_num_default++;
 
-        list_add_tail_rcu(&new_fa->fa_list,
-                          (fa ? &fa->fa_list : fa_head));
+        if (fa) {
+                hlist_add_before_rcu(&new_fa->fa_list, &fa->fa_list);
+        } else {
+                struct fib_alias *last;
+
+                hlist_for_each_entry(last, fa_head, fa_list)
+                        fa = last;
+
+                if (fa)
+                        hlist_add_behind_rcu(&new_fa->fa_list, &fa->fa_list);
+                else
+                        hlist_add_head_rcu(&new_fa->fa_list, fa_head);
+        }
 
         rt_cache_flush(cfg->fc_nlinfo.nl_net);
         rtmsg_fib(RTM_NEWROUTE, htonl(key), new_fa, plen, tb->tb_id,
@@ -1419,7 +1428,7 @@ found:
                 if ((key ^ n->key) & li->mask_plen)
                         continue;
 
-                list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+                hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {
                         struct fib_info *fi = fa->fa_info;
                         int nhsel, err;
 
@@ -1501,7 +1510,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
         int plen = cfg->fc_dst_len;
         u8 tos = cfg->fc_tos;
         struct fib_alias *fa, *fa_to_delete;
-        struct list_head *fa_head;
+        struct hlist_head *fa_head;
         struct tnode *l;
         struct leaf_info *li;
 
@@ -1534,8 +1543,7 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
         pr_debug("Deleting %08x/%d tos=%d t=%p\n", key, plen, tos, t);
 
         fa_to_delete = NULL;
-        fa = list_entry(fa->fa_list.prev, struct fib_alias, fa_list);
-        list_for_each_entry_continue(fa, fa_head, fa_list) {
+        hlist_for_each_entry_from(fa, fa_list) {
                 struct fib_info *fi = fa->fa_info;
 
                 if (fa->fa_tos != tos)
@@ -1561,12 +1569,12 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
         rtmsg_fib(RTM_DELROUTE, htonl(key), fa, plen, tb->tb_id,
                   &cfg->fc_nlinfo, 0);
 
-        list_del_rcu(&fa->fa_list);
+        hlist_del_rcu(&fa->fa_list);
 
         if (!plen)
                 tb->tb_num_default--;
 
-        if (list_empty(fa_head)) {
+        if (hlist_empty(fa_head)) {
                 remove_leaf_info(l, li);
                 free_leaf_info(li);
         }
@@ -1582,16 +1590,17 @@ int fib_table_delete(struct fib_table *tb, struct fib_config *cfg)
         return 0;
 }
 
-static int trie_flush_list(struct list_head *head)
+static int trie_flush_list(struct hlist_head *head)
 {
-        struct fib_alias *fa, *fa_node;
+        struct hlist_node *tmp;
+        struct fib_alias *fa;
         int found = 0;
 
-        list_for_each_entry_safe(fa, fa_node, head, fa_list) {
+        hlist_for_each_entry_safe(fa, tmp, head, fa_list) {
                 struct fib_info *fi = fa->fa_info;
 
                 if (fi && (fi->fib_flags & RTNH_F_DEAD)) {
-                        list_del_rcu(&fa->fa_list);
+                        hlist_del_rcu(&fa->fa_list);
                         fib_release_info(fa->fa_info);
                         alias_free_mem_rcu(fa);
                         found++;
@@ -1603,15 +1612,14 @@ static int trie_flush_list(struct list_head *head)
 static int trie_flush_leaf(struct tnode *l)
 {
         int found = 0;
-        struct hlist_head *lih = &l->list;
         struct hlist_node *tmp;
-        struct leaf_info *li = NULL;
+        struct leaf_info *li;
         unsigned char plen = KEYLENGTH;
 
-        hlist_for_each_entry_safe(li, tmp, lih, hlist) {
+        hlist_for_each_entry_safe(li, tmp, &l->list, hlist) {
                 found += trie_flush_list(&li->falh);
 
-                if (list_empty(&li->falh)) {
+                if (hlist_empty(&li->falh)) {
                         hlist_del_rcu(&li->hlist);
                         free_leaf_info(li);
                         continue;
@@ -1731,7 +1739,7 @@ void fib_free_table(struct fib_table *tb)
         kfree(tb);
 }
 
-static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
+static int fn_trie_dump_fa(t_key key, int plen, struct hlist_head *fah,
                            struct fib_table *tb,
                            struct sk_buff *skb, struct netlink_callback *cb)
 {
@@ -1744,7 +1752,7 @@ static int fn_trie_dump_fa(t_key key, int plen, struct list_head *fah,
 
         /* rcu_read_lock is hold by caller */
 
-        list_for_each_entry_rcu(fa, fah, fa_list) {
+        hlist_for_each_entry_rcu(fa, fah, fa_list) {
                 if (i < s_i) {
                         i++;
                         continue;
@@ -1787,7 +1795,7 @@ static int fn_trie_dump_leaf(struct tnode *l, struct fib_table *tb,
                 if (i > s_i)
                         cb->args[5] = 0;
 
-                if (list_empty(&li->falh))
+                if (hlist_empty(&li->falh))
                         continue;
 
                 if (fn_trie_dump_fa(l->key, li->plen, &li->falh, tb, skb, cb) < 0) {
@@ -2272,7 +2280,7 @@ static int fib_trie_seq_show(struct seq_file *seq, void *v)
                 hlist_for_each_entry_rcu(li, &n->list, hlist) {
                         struct fib_alias *fa;
 
-                        list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+                        hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {
                                 char buf1[32], buf2[32];
 
                                 seq_indent(seq, iter->depth+1);
@@ -2429,7 +2437,7 @@ static int fib_route_seq_show(struct seq_file *seq, void *v)
                 mask = inet_make_mask(li->plen);
                 prefix = htonl(l->key);
 
-                list_for_each_entry_rcu(fa, &li->falh, fa_list) {
+                hlist_for_each_entry_rcu(fa, &li->falh, fa_list) {
                         const struct fib_info *fi = fa->fa_info;
                         unsigned int flags = fib_flag_trans(fa->fa_type, mask, fi);