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>

1 files changed, 7 insertions, 2 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index dcec01856cf3..461d438f4816 100644
--- 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);