[PATCH net-next v2] rhashtable: Warn if min_size or max_size are not a power of two

[Thomas Graf <tgraf@suug.ch>]

The current code correctly limits table size to the next power of two.
This check is solely to catch programming errors.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
---
v2: use is_power_of_2() instead of roundup_pow_of_two()

 lib/rhashtable.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 5f8fe3e..5474507 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -933,6 +933,9 @@ int rhashtable_init(struct rhashtable *ht, struct rhashtable_params *params)
 	if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT))
 		return -EINVAL;
 
+	WARN_ON(params->min_size && !is_power_of_2(params->min_size));
+	WARN_ON(params->max_size && !is_power_of_2(params->max_size));
+
 	params->min_size = max(params->min_size, HASH_MIN_SIZE);
 
 	if (params->nelem_hint)
-- 
1.9.3