rhashtable: Do hashing inside of rhashtable_lookup_compare()

Hash the key inside of rhashtable_lookup_compare() like
rhashtable_lookup() does. This allows to simplify the hashing
functions and keep them private.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Cc: netfilter-devel@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 30 insertions, 61 deletions

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 6c3c723e902b..1ee0eb636ca3 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -42,69 +42,39 @@ static void *rht_obj(const struct rhashtable *ht, const struct rhash_head *he)
         return (void *) he - ht->p.head_offset;
 }
 
-static u32 __hashfn(const struct rhashtable *ht, const void *key,
-                      u32 len, u32 hsize)
+static u32 rht_bucket_index(const struct bucket_table *tbl, u32 hash)
 {
-        u32 h;
-
-        h = ht->p.hashfn(key, len, ht->p.hash_rnd);
-
-        return h & (hsize - 1);
-}
-
-/**
- * rhashtable_hashfn - compute hash for key of given length
- * @ht:         hash table to compute for
- * @key:        pointer to key
- * @len:        length of key
- *
- * Computes the hash value using the hash function provided in the 'hashfn'
- * of struct rhashtable_params. The returned value is guaranteed to be
- * smaller than the number of buckets in the hash table.
- */
-u32 rhashtable_hashfn(const struct rhashtable *ht, const void *key, u32 len)
-{
-        struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
-
-        return __hashfn(ht, key, len, tbl->size);
+        return hash & (tbl->size - 1);
 }
-EXPORT_SYMBOL_GPL(rhashtable_hashfn);
 
-static u32 obj_hashfn(const struct rhashtable *ht, const void *ptr, u32 hsize)
+static u32 obj_raw_hashfn(const struct rhashtable *ht, const void *ptr)
 {
-        if (unlikely(!ht->p.key_len)) {
-                u32 h;
-
-                h = ht->p.obj_hashfn(ptr, ht->p.hash_rnd);
+        u32 hash;
 
-                return h & (hsize - 1);
-        }
+        if (unlikely(!ht->p.key_len))
+                hash = ht->p.obj_hashfn(ptr, ht->p.hash_rnd);
+        else
+                hash = ht->p.hashfn(ptr + ht->p.key_offset, ht->p.key_len,
+                                    ht->p.hash_rnd);
 
-        return __hashfn(ht, ptr + ht->p.key_offset, ht->p.key_len, hsize);
+        return hash;
 }
 
-/**
- * rhashtable_obj_hashfn - compute hash for hashed object
- * @ht:         hash table to compute for
- * @ptr:        pointer to hashed object
- *
- * Computes the hash value using the hash function `hashfn` respectively
- * 'obj_hashfn' depending on whether the hash table is set up to work with
- * a fixed length key. The returned value is guaranteed to be smaller than
- * the number of buckets in the hash table.
- */
-u32 rhashtable_obj_hashfn(const struct rhashtable *ht, void *ptr)
+static u32 key_hashfn(const struct rhashtable *ht, const void *key, u32 len)
 {
         struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
+        u32 hash;
+
+        hash = ht->p.hashfn(key, len, ht->p.hash_rnd);
 
-        return obj_hashfn(ht, ptr, tbl->size);
+        return rht_bucket_index(tbl, hash);
 }
-EXPORT_SYMBOL_GPL(rhashtable_obj_hashfn);
 
 static u32 head_hashfn(const struct rhashtable *ht,
-                       const struct rhash_head *he, u32 hsize)
+                       const struct bucket_table *tbl,
+                       const struct rhash_head *he)
 {
-        return obj_hashfn(ht, rht_obj(ht, he), hsize);
+        return rht_bucket_index(tbl, obj_raw_hashfn(ht, rht_obj(ht, he)));
 }
 
 static struct bucket_table *bucket_table_alloc(size_t nbuckets)
@@ -170,9 +140,9 @@ static void hashtable_chain_unzip(const struct rhashtable *ht,
          * reaches a node that doesn't hash to the same bucket as the
          * previous node p. Call the previous node p;
          */
-        h = head_hashfn(ht, p, new_tbl->size);
+        h = head_hashfn(ht, new_tbl, p);
         rht_for_each(he, p->next, ht) {
-                if (head_hashfn(ht, he, new_tbl->size) != h)
+                if (head_hashfn(ht, new_tbl, he) != h)
                         break;
                 p = he;
         }
@@ -184,7 +154,7 @@ static void hashtable_chain_unzip(const struct rhashtable *ht,
         next = NULL;
         if (he) {
                 rht_for_each(he, he->next, ht) {
-                        if (head_hashfn(ht, he, new_tbl->size) == h) {
+                        if (head_hashfn(ht, new_tbl, he) == h) {
                                 next = he;
                                 break;
                         }
@@ -237,9 +207,9 @@ int rhashtable_expand(struct rhashtable *ht)
          * single imprecise chain.
          */
         for (i = 0; i < new_tbl->size; i++) {
-                h = i & (old_tbl->size - 1);
+                h = rht_bucket_index(old_tbl, i);
                 rht_for_each(he, old_tbl->buckets[h], ht) {
-                        if (head_hashfn(ht, he, new_tbl->size) == i) {
+                        if (head_hashfn(ht, new_tbl, he) == i) {
                                 RCU_INIT_POINTER(new_tbl->buckets[i], he);
                                 break;
                         }
@@ -353,7 +323,7 @@ void rhashtable_insert(struct rhashtable *ht, struct rhash_head *obj)
 
         ASSERT_RHT_MUTEX(ht);
 
-        hash = head_hashfn(ht, obj, tbl->size);
+        hash = head_hashfn(ht, tbl, obj);
         RCU_INIT_POINTER(obj->next, tbl->buckets[hash]);
         rcu_assign_pointer(tbl->buckets[hash], obj);
         ht->nelems++;
@@ -413,7 +383,7 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj)
 
         ASSERT_RHT_MUTEX(ht);
 
-        h = head_hashfn(ht, obj, tbl->size);
+        h = head_hashfn(ht, tbl, obj);
 
         pprev = &tbl->buckets[h];
         rht_for_each(he, tbl->buckets[h], ht) {
@@ -452,7 +422,7 @@ void *rhashtable_lookup(const struct rhashtable *ht, const void *key)
 
         BUG_ON(!ht->p.key_len);
 
-        h = __hashfn(ht, key, ht->p.key_len, tbl->size);
+        h = key_hashfn(ht, key, ht->p.key_len);
         rht_for_each_rcu(he, tbl->buckets[h], ht) {
                 if (memcmp(rht_obj(ht, he) + ht->p.key_offset, key,
                            ht->p.key_len))
@@ -467,7 +437,7 @@ EXPORT_SYMBOL_GPL(rhashtable_lookup);
 /**
  * rhashtable_lookup_compare - search hash table with compare function
  * @ht:         hash table
- * @hash:       hash value of desired entry
+ * @key:        the pointer to the key
  * @compare:    compare function, must return true on match
  * @arg:        argument passed on to compare function
  *
@@ -479,15 +449,14 @@ EXPORT_SYMBOL_GPL(rhashtable_lookup);
  *
  * Returns the first entry on which the compare function returned true.
  */
-void *rhashtable_lookup_compare(const struct rhashtable *ht, u32 hash,
+void *rhashtable_lookup_compare(const struct rhashtable *ht, const void *key,
                                 bool (*compare)(void *, void *), void *arg)
 {
         const struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
         struct rhash_head *he;
+        u32 hash;
 
-        if (unlikely(hash >= tbl->size))
-                return NULL;
-
+        hash = key_hashfn(ht, key, ht->p.key_len);
         rht_for_each_rcu(he, tbl->buckets[hash], ht) {
                 if (!compare(rht_obj(ht, he), arg))
                         continue;