[PATCH 09/15] rbd: count pending object requests in-line

[Hannes Reinecke <hare@xxxxxxx>]

Instead of having a counter for outstanding object requests
check the state and count only those which are not in the final
state.

Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
 drivers/block/rbd.c | 41 ++++++++++++++++++++++++++++++-----------
 1 file changed, 30 insertions(+), 11 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index b708f5ecda07..a6c95b6e9c0c 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -350,7 +350,7 @@ struct rbd_img_request {
 	struct mutex		object_mutex;
 
 	struct mutex		state_mutex;
-	struct pending_result	pending;
+	int			pending_result;
 	struct work_struct	work;
 	int			work_result;
 	struct kref		kref;
@@ -3602,11 +3602,12 @@ static int rbd_img_exclusive_lock(struct rbd_img_request *img_req)
 	return 0;
 }
 
-static void rbd_img_object_requests(struct rbd_img_request *img_req)
+static int rbd_img_object_requests(struct rbd_img_request *img_req)
 {
 	struct rbd_obj_request *obj_req;
+	int num_pending = 0;
 
-	rbd_assert(!img_req->pending.result && !img_req->pending.num_pending);
+	rbd_assert(!img_req->pending_result);
 
 	mutex_lock(&img_req->object_mutex);
 	for_each_obj_request(img_req, obj_req) {
@@ -3617,15 +3618,33 @@ static void rbd_img_object_requests(struct rbd_img_request *img_req)
 			     __func__, obj_req, obj_req->img_request,
 			     img_req, result);
 			if (result) {
-				img_req->pending.result = result;
-				mutex_unlock(&img_req->object_mutex);
-				return;
+				img_req->pending_result = result;
+				break;
 			}
 		} else {
-			img_req->pending.num_pending++;
+			num_pending++;
 		}
 	}
 	mutex_unlock(&img_req->object_mutex);
+	return num_pending;
+}
+
+static int rbd_img_object_requests_pending(struct rbd_img_request *img_req)
+{
+	struct rbd_obj_request *obj_req;
+	int num_pending = 0;
+
+	mutex_lock(&img_req->object_mutex);
+	for_each_obj_request(img_req, obj_req) {
+		if (obj_req->obj_state > 1)
+			num_pending++;
+		else if (WARN_ON(obj_req->obj_state == 1))
+			num_pending++;
+		else if (WARN_ON(obj_req->pending.num_pending))
+			num_pending++;
+	}
+	mutex_unlock(&img_req->object_mutex);
+	return num_pending;
 }
 
 static bool rbd_img_advance(struct rbd_img_request *img_req, int *result)
@@ -3658,16 +3677,16 @@ static bool rbd_img_advance(struct rbd_img_request *img_req, int *result)
 			   __rbd_is_lock_owner(rbd_dev));
 
 		img_req->state = RBD_IMG_OBJECT_REQUESTS;
-		rbd_img_object_requests(img_req);
-		if (!img_req->pending.num_pending) {
-			*result = img_req->pending.result;
+		if (!rbd_img_object_requests(img_req)) {
+			*result = img_req->pending_result;
 			img_req->state = RBD_IMG_DONE;
 			return true;
 		}
 		return false;
 	case RBD_IMG_OBJECT_REQUESTS:
-		if (!pending_result_dec(&img_req->pending, result))
+		if (rbd_img_object_requests_pending(img_req))
 			return false;
+		*result = img_req->pending_result;
 		img_req->state = RBD_IMG_DONE;
 		/* fall through */
 	case RBD_IMG_DONE:
-- 
2.16.4