1 files changed, 31 insertions, 40 deletions

diff --git a/drivers/dma-buf/reservation.c b/drivers/dma-buf/reservation.c
index 723d8af988e5..ba3e25dab95b 100644
--- a/drivers/dma-buf/reservation.c
+++ b/drivers/dma-buf/reservation.c
@@ -280,18 +280,24 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
 				      unsigned *pshared_count,
 				      struct fence ***pshared)
 {
-	unsigned shared_count = 0;
-	unsigned retry = 1;
-	struct fence **shared = NULL, *fence_excl = NULL;
-	int ret = 0;
+	struct fence **shared = NULL;
+	struct fence *fence_excl;
+	unsigned int shared_count;
+	int ret = 1;
 
-	while (retry) {
+	do {
 		struct reservation_object_list *fobj;
 		unsigned seq;
+		unsigned int i;
 
-		seq = read_seqcount_begin(&obj->seq);
+		shared_count = i = 0;
 
 		rcu_read_lock();
+		seq = read_seqcount_begin(&obj->seq);
+
+		fence_excl = rcu_dereference(obj->fence_excl);
+		if (fence_excl && !fence_get_rcu(fence_excl))
+			goto unlock;
 
 		fobj = rcu_dereference(obj->fence);
 		if (fobj) {
@@ -309,52 +315,37 @@ int reservation_object_get_fences_rcu(struct reservation_object *obj,
 				}
 
 				ret = -ENOMEM;
-				shared_count = 0;
 				break;
 			}
 			shared = nshared;
-			memcpy(shared, fobj->shared, sz);
 			shared_count = fobj->shared_count;
-		} else
-			shared_count = 0;
-		fence_excl = rcu_dereference(obj->fence_excl);
-
-		retry = read_seqcount_retry(&obj->seq, seq);
-		if (retry)
-			goto unlock;
-
-		if (!fence_excl || fence_get_rcu(fence_excl)) {
-			unsigned i;
 
 			for (i = 0; i < shared_count; ++i) {
-				if (fence_get_rcu(shared[i]))
-					continue;
-
-				/* uh oh, refcount failed, abort and retry */
-				while (i--)
-					fence_put(shared[i]);
-
-				if (fence_excl) {
-					fence_put(fence_excl);
-					fence_excl = NULL;
-				}
-
-				retry = 1;
-				break;
+				shared[i] = rcu_dereference(fobj->shared[i]);
+				if (!fence_get_rcu(shared[i]))
+					break;
 			}
-		} else
-			retry = 1;
+		}
+
+		if (i != shared_count || read_seqcount_retry(&obj->seq, seq)) {
+			while (i--)
+				fence_put(shared[i]);
+			fence_put(fence_excl);
+			goto unlock;
+		}
 
+		ret = 0;
 unlock:
 		rcu_read_unlock();
-	}
-	*pshared_count = shared_count;
-	if (shared_count)
-		*pshared = shared;
-	else {
-		*pshared = NULL;
+	} while (ret);
+
+	if (!shared_count) {
 		kfree(shared);
+		shared = NULL;
 	}
+
+	*pshared_count = shared_count;
+	*pshared = shared;
 	*pfence_excl = fence_excl;
 
 	return ret;