From: Antonio Quartulli ordex@autistici.org
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 --- net/batman-adv/hash.h | 25 +++++++++++++++++++------ net/batman-adv/originator.c | 2 +- net/batman-adv/vis.c | 4 ++-- 3 files changed, 22 insertions(+), 9 deletions(-)
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 @@ static inline void hash_delete(struct hashtable_t *hash, 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 @@ static inline int hash_add(struct hashtable_t *hash, if (!compare(node, data)) continue;
+ ret = 1; goto err_unlock; } rcu_read_unlock(); @@ -108,12 +120,13 @@ static inline int hash_add(struct hashtable_t *hash, 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 diff --git a/net/batman-adv/originator.c b/net/batman-adv/originator.c index f3c3f62..d448018 100644 --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -252,7 +252,7 @@ struct orig_node *get_orig_node(struct bat_priv *bat_priv, const uint8_t *addr)
hash_added = hash_add(bat_priv->orig_hash, compare_orig, choose_orig, orig_node, &orig_node->hash_entry); - if (hash_added < 0) + if (hash_added != 0) goto free_bcast_own_sum;
return orig_node; diff --git a/net/batman-adv/vis.c b/net/batman-adv/vis.c index 8a1b985..8b75cc5 100644 --- a/net/batman-adv/vis.c +++ b/net/batman-adv/vis.c @@ -465,7 +465,7 @@ static struct vis_info *add_packet(struct bat_priv *bat_priv, /* try to add it */ hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose, info, &info->hash_entry); - if (hash_added < 0) { + if (hash_added != 0) { /* did not work (for some reason) */ kref_put(&info->refcount, free_info); info = NULL; @@ -920,7 +920,7 @@ int vis_init(struct bat_priv *bat_priv) hash_added = hash_add(bat_priv->vis_hash, vis_info_cmp, vis_info_choose, bat_priv->my_vis_info, &bat_priv->my_vis_info->hash_entry); - if (hash_added < 0) { + if (hash_added != 0) { pr_err("Can't add own vis packet into hash\n"); /* not in hash, need to remove it manually. */ kref_put(&bat_priv->my_vis_info->refcount, free_info);