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>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 6c3c723..1ee0eb6 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -42,69 +42,39 @@
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);
+ return hash & (tbl->size - 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)
+static u32 obj_raw_hashfn(const struct rhashtable *ht, const void *ptr)
+{
+ u32 hash;
+
+ 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 hash;
+}
+
+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;
- return __hashfn(ht, key, len, tbl->size);
+ hash = ht->p.hashfn(key, len, ht->p.hash_rnd);
+
+ return rht_bucket_index(tbl, hash);
}
-EXPORT_SYMBOL_GPL(rhashtable_hashfn);
-
-static u32 obj_hashfn(const struct rhashtable *ht, const void *ptr, u32 hsize)
-{
- if (unlikely(!ht->p.key_len)) {
- u32 h;
-
- h = ht->p.obj_hashfn(ptr, ht->p.hash_rnd);
-
- return h & (hsize - 1);
- }
-
- return __hashfn(ht, ptr + ht->p.key_offset, ht->p.key_len, hsize);
-}
-
-/**
- * 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)
-{
- struct bucket_table *tbl = rht_dereference_rcu(ht->tbl, ht);
-
- return obj_hashfn(ht, ptr, tbl->size);
-}
-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 @@
* 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 @@
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 @@
* 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 @@
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 @@
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 @@
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 @@
/**
* 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 @@
*
* 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;