locking/atomic, kref: Implement kref_put_lock()

Because home-rolling your own is _awesome_, stop doing it. Provide
kref_put_lock(), just like kref_put_mutex() but for a spinlock.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 10 insertions, 5 deletions

diff --git a/net/sunrpc/svcauth.c b/net/sunrpc/svcauth.c
index e112da8005b5..bb8db3cb8032 100644
--- a/net/sunrpc/svcauth.c
+++ b/net/sunrpc/svcauth.c
@@ -126,13 +126,18 @@ EXPORT_SYMBOL_GPL(svc_auth_unregister);
 static struct hlist_head        auth_domain_table[DN_HASHMAX];
 static DEFINE_SPINLOCK(auth_domain_lock);
 
+static void auth_domain_release(struct kref *kref)
+{
+        struct auth_domain *dom = container_of(kref, struct auth_domain, ref);
+
+        hlist_del(&dom->hash);
+        dom->flavour->domain_release(dom);
+        spin_unlock(&auth_domain_lock);
+}
+
 void auth_domain_put(struct auth_domain *dom)
 {
-        if (atomic_dec_and_lock(&dom->ref.refcount, &auth_domain_lock)) {
-                hlist_del(&dom->hash);
-                dom->flavour->domain_release(dom);
-                spin_unlock(&auth_domain_lock);
-        }
+        kref_put_lock(&dom->ref, auth_domain_release, &auth_domain_lock);
 }
 EXPORT_SYMBOL_GPL(auth_domain_put);