futex: distangle futex_requeue()

futex_requeue() is getting a bit long-winded, and will be getting more
so after the requeue_pi patch. Factor out the actual requeueing into a
nicely contained inline function to reduce function length and improve
legibility.

Signed-off-by: Darren Hart <dvhltc@us.ibm.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 29 insertions, 14 deletions

diff --git a/kernel/futex.c b/kernel/futex.c
index 6b597cf33b02..e76942e2a79f 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -940,6 +940,34 @@ out:
         return ret;
 }
 
+/**
+ * requeue_futex() - Requeue a futex_q from one hb to another
+ * @q:          the futex_q to requeue
+ * @hb1:        the source hash_bucket
+ * @hb2:        the target hash_bucket
+ * @key2:       the new key for the requeued futex_q
+ */
+static inline
+void requeue_futex(struct futex_q *q, struct futex_hash_bucket *hb1,
+                   struct futex_hash_bucket *hb2, union futex_key *key2)
+{
+
+        /*
+         * If key1 and key2 hash to the same bucket, no need to
+         * requeue.
+         */
+        if (likely(&hb1->chain != &hb2->chain)) {
+                plist_del(&q->list, &hb1->chain);
+                plist_add(&q->list, &hb2->chain);
+                q->lock_ptr = &hb2->lock;
+#ifdef CONFIG_DEBUG_PI_LIST
+                q->list.plist.lock = &hb2->lock;
+#endif
+        }
+        get_futex_key_refs(key2);
+        q->key = *key2;
+}
+
 /*
  * Requeue all waiters hashed on one physical page to another
  * physical page.
@@ -999,20 +1027,7 @@ retry_private:
                 if (++ret <= nr_wake) {
                         wake_futex(this);
                 } else {
-                        /*
-                         * If key1 and key2 hash to the same bucket, no need to
-                         * requeue.
-                         */
-                        if (likely(head1 != &hb2->chain)) {
-                                plist_del(&this->list, &hb1->chain);
-                                plist_add(&this->list, &hb2->chain);
-                                this->lock_ptr = &hb2->lock;
-#ifdef CONFIG_DEBUG_PI_LIST
-                                this->list.plist.lock = &hb2->lock;
-#endif
-                        }
-                        this->key = key2;
-                        get_futex_key_refs(&key2);
+                        requeue_futex(this, hb1, hb2, &key2);
                         drop_count++;
 
                         if (ret - nr_wake >= nr_requeue)