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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>
This commit is contained in:
Antonio Quartulli 2011-07-10 00:36:36 +02:00 committed by Marek Lindner
parent 322a8b0340
commit 1a1f37d925
3 changed files with 22 additions and 9 deletions

View File

@ -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

View File

@ -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;

View File

@ -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);