rhashtable: Allow hashfn to be unset

[mirror_ubuntu-artful-kernel.git] / lib / rhashtable.c

diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index 618a3f00d71281e1021bf608508feaba3e0503c2..798f01d64ab0135e602a518f93801d7be34ab3f7 100644 (file)
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -532,6 +532,11 @@ static size_t rounded_hashtable_size(const struct rhashtable_params *params)
                   (unsigned long)params->min_size);
 }
 
+static u32 rhashtable_jhash2(const void *key, u32 length, u32 seed)
+{
+       return jhash2(key, length, seed);
+}
+
 /**
  * rhashtable_init - initialize a new hash table
  * @ht:                hash table to be initialized
@@ -583,7 +588,7 @@ int rhashtable_init(struct rhashtable *ht,
 
        size = HASH_DEFAULT_SIZE;
 
-       if ((!(params->key_len && params->hashfn) && !params->obj_hashfn) ||
+       if ((!params->key_len && !params->obj_hashfn) ||
            (params->obj_hashfn && !params->obj_cmpfn))
                return -EINVAL;
 
@@ -610,6 +615,16 @@ int rhashtable_init(struct rhashtable *ht,
        else
                ht->p.locks_mul = BUCKET_LOCKS_PER_CPU;
 
+       ht->key_len = ht->p.key_len;
+       if (!params->hashfn) {
+               ht->p.hashfn = jhash;
+
+               if (!(ht->key_len & (sizeof(u32) - 1))) {
+                       ht->key_len /= sizeof(u32);
+                       ht->p.hashfn = rhashtable_jhash2;
+               }
+       }
+
        tbl = bucket_table_alloc(ht, size);
        if (tbl == NULL)
                return -ENOMEM;