batman-adv: hash_add() has to discriminate on the return value
hash_add() returns 0 on success while returns -1 either on error and on
entry already present. The caller could use such information to select
its behaviour. For this reason it is useful that hash_add() returns -1
in case on error and returns 1 in case of entry already present.
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
diff --git a/net/batman-adv/hash.h b/net/batman-adv/hash.h
index dd5c9fd..d20aa71 100644
--- a/net/batman-adv/hash.h
+++ b/net/batman-adv/hash.h
@@ -76,19 +76,30 @@
hash_destroy(hash);
}
-/* adds data to the hashtable. returns 0 on success, -1 on error */
+/**
+ * hash_add - adds data to the hashtable
+ * @hash: storage hash table
+ * @compare: callback to determine if 2 hash elements are identical
+ * @choose: callback calculating the hash index
+ * @data: data passed to the aforementioned callbacks as argument
+ * @data_node: to be added element
+ *
+ * Returns 0 on success, 1 if the element already is in the hash
+ * and -1 on error.
+ */
+
static inline int hash_add(struct hashtable_t *hash,
hashdata_compare_cb compare,
hashdata_choose_cb choose,
const void *data, struct hlist_node *data_node)
{
- int index;
+ int index, ret = -1;
struct hlist_head *head;
struct hlist_node *node;
spinlock_t *list_lock; /* spinlock to protect write access */
if (!hash)
- goto err;
+ goto out;
index = choose(data, hash->size);
head = &hash->table[index];
@@ -99,6 +110,7 @@
if (!compare(node, data))
continue;
+ ret = 1;
goto err_unlock;
}
rcu_read_unlock();
@@ -108,12 +120,13 @@
hlist_add_head_rcu(data_node, head);
spin_unlock_bh(list_lock);
- return 0;
+ ret = 0;
+ goto out;
err_unlock:
rcu_read_unlock();
-err:
- return -1;
+out:
+ return ret;
}
/* removes data from hash, if found. returns pointer do data on success, so you
