rhashtable: Make rhashtable_init params argument const

This patch marks the rhashtable_init params argument const as
there is no reason to modify it since we will always make a copy
of it in the rhashtable.

This patch also fixes a bug where we don't actually round up the
value of min_size unless it is less than HASH_MIN_SIZE.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/rhashtable.h

@@ -181,7 +181,8 @@ static inline int lockdep_rht_bucket_is_held(const struct bucket_table *tbl,
 }
 #endif /* CONFIG_PROVE_LOCKING */
 
-int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params);
+int rhashtable_init(struct rhashtable *ht,
+		    const struct rhashtable_params *params);
 
 void rhashtable_insert(struct rhashtable *ht, struct rhash_head *node);
 bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *node);

lib/rhashtable.c

@@ -870,7 +870,7 @@ void rhashtable_walk_stop(struct rhashtable_iter *iter)
 }
 EXPORT_SYMBOL_GPL(rhashtable_walk_stop);
 
-static size_t rounded_hashtable_size(struct rhashtable_params *params)
+static size_t rounded_hashtable_size(const struct rhashtable_params *params)
 {
 	return max(roundup_pow_of_two(params->nelem_hint * 4 / 3),
 		   (unsigned long)params->min_size);
@@ -919,7 +919,8 @@ static size_t rounded_hashtable_size(struct rhashtable_params *params)
  *	.obj_hashfn = my_hash_fn,
  * };
  */
-int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
+int rhashtable_init(struct rhashtable *ht,
+		    const struct rhashtable_params *params)
 {
 	struct bucket_table *tbl;
 	size_t size;
@@ -946,7 +947,7 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
 	if (params->max_size)
 		ht->p.max_size = rounddown_pow_of_two(params->max_size);
 
-	ht->p.min_size = max(params->min_size, HASH_MIN_SIZE);
+	ht->p.min_size = max(ht->p.min_size, HASH_MIN_SIZE);
 
 	if (params->locks_mul)
 		ht->p.locks_mul = roundup_pow_of_two(params->locks_mul);