struct notifier_block *n)
{
while ((*nl) != NULL) {
- WARN_ONCE(((*nl) == n), "double register detected");
- if (n->priority > (*nl)->priority)
- break;
- nl = &((*nl)->next);
- }
- n->next = *nl;
- rcu_assign_pointer(*nl, n);
- return 0;
-}
-
-static int notifier_chain_cond_register(struct notifier_block **nl,
- struct notifier_block *n)
-{
- while ((*nl) != NULL) {
- if ((*nl) == n)
+ if (unlikely((*nl) == n)) {
+ WARN(1, "double register detected");
return 0;
+ }
if (n->priority > (*nl)->priority)
break;
nl = &((*nl)->next);
}
EXPORT_SYMBOL_GPL(blocking_notifier_chain_register);
-/**
- * blocking_notifier_chain_cond_register - Cond add notifier to a blocking notifier chain
- * @nh: Pointer to head of the blocking notifier chain
- * @n: New entry in notifier chain
- *
- * Adds a notifier to a blocking notifier chain, only if not already
- * present in the chain.
- * Must be called in process context.
- *
- * Currently always returns zero.
- */
-int blocking_notifier_chain_cond_register(struct blocking_notifier_head *nh,
- struct notifier_block *n)
-{
- int ret;
-
- down_write(&nh->rwsem);
- ret = notifier_chain_cond_register(&nh->head, n);
- up_write(&nh->rwsem);
- return ret;
-}
-EXPORT_SYMBOL_GPL(blocking_notifier_chain_cond_register);
-
/**
* blocking_notifier_chain_unregister - Remove notifier from a blocking notifier chain
* @nh: Pointer to head of the blocking notifier chain