The following commit has been merged in the master branch: commit 75c5a2e788ab02f67931442e8dcbc854ae7252d1 Author: Matthias Schiffer mschiffer@universe-factory.net Date: Tue May 8 22:31:57 2012 +0200

batman-adv: fix locking in hash_add()

To ensure an entry isn't added twice all comparisons have to be protected by the hash line write spinlock. This doesn't really hurt as the case that it is tried to add an element already present to the hash shouldn't occur very often, so in most cases the lock would have have to be taken anyways.

Signed-off-by: Matthias Schiffer mschiffer@universe-factory.net Acked-by: Sven Eckelmann sven@narfation.org Signed-off-by: Sven Eckelmann sven@narfation.org

diff --git a/net/batman-adv/hash.h b/net/batman-adv/hash.h index 93b3c71..3d67ce4 100644 --- a/net/batman-adv/hash.h +++ b/net/batman-adv/hash.h @@ -110,26 +110,23 @@ static inline int hash_add(struct hashtable_t *hash, head = &hash->table[index]; list_lock = &hash->list_locks[index];

- rcu_read_lock(); - __hlist_for_each_rcu(node, head) { + spin_lock_bh(list_lock); + + hlist_for_each(node, head) { if (!compare(node, data)) continue;

ret = 1; - goto err_unlock; + goto unlock; } - rcu_read_unlock();

/* no duplicate found in list, add new element */ - spin_lock_bh(list_lock); hlist_add_head_rcu(data_node, head); - spin_unlock_bh(list_lock);

ret = 0; - goto out;

-err_unlock: - rcu_read_unlock(); +unlock: + spin_unlock_bh(list_lock); out: return ret; }