[PATCH] Allow raw_notifier callouts to unregister themselves
Since raw_notifier chains don't benefit from any centralized locking
protections, they shouldn't suffer from the associated limitations. Under
some circumstances it might make sense for a raw_notifier callout routine
to unregister itself from the notifier chain. This patch (as678) changes
the notifier core to allow for such things.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/kernel/sys.c b/kernel/sys.c
index 90930b2..7e0927b 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -137,14 +137,15 @@
unsigned long val, void *v)
{
int ret = NOTIFY_DONE;
- struct notifier_block *nb;
+ struct notifier_block *nb, *next_nb;
nb = rcu_dereference(*nl);
while (nb) {
+ next_nb = rcu_dereference(nb->next);
ret = nb->notifier_call(nb, val, v);
if ((ret & NOTIFY_STOP_MASK) == NOTIFY_STOP_MASK)
break;
- nb = rcu_dereference(nb->next);
+ nb = next_nb;
}
return ret;
}