futex: Cleanup the goto confusion in requeue_pi()

out_unlock: does not only drop the locks, it also drops the refcount
on the pi_state. Really intuitive.

Move the label after the put_pi_state() call and use 'break' in the
error handling path of the requeue loop.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <darren@dvhart.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Bhuvanesh_Surachari@mentor.com
Cc: Andy Lowe <Andy_Lowe@mentor.com>
Link: http://lkml.kernel.org/r/20151219200607.526665141@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

diff --git a/kernel/futex.c b/kernel/futex.c
index dcec018..461d438 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1839,20 +1839,25 @@ retry_private:
                                 */
                                this->pi_state = NULL;
                                put_pi_state(pi_state);
-                               goto out_unlock;
+                               /*
+                                * We stop queueing more waiters and let user
+                                * space deal with the mess.
+                                */
+                               break;
                        }
                }
                requeue_futex(this, hb1, hb2, &key2);
                drop_count++;
        }
 
-out_unlock:
        /*
         * We took an extra initial reference to the pi_state either
         * in futex_proxy_trylock_atomic() or in lookup_pi_state(). We
         * need to drop it here again.
         */
        put_pi_state(pi_state);
+
+out_unlock:
        double_unlock_hb(hb1, hb2);
        wake_up_q(&wake_q);
        hb_waiters_dec(hb2);