From 4287d7e651307fe10a7bfaa2c81ca5ac81dbb64e Mon Sep 17 00:00:00 2001
From: Ilya Dryomov <idryomov@gmail.com>
Date: Sat, 18 Jun 2022 12:35:51 +0200
Subject: [PATCH] rbd-mirror: strengthen is_local_primary() and is_linked()

Initialize local_promotion_state and remote_promotion_state to UNKNOWN
instead of counterintuitive PRIMARY and NON_PRIMARY -- half the time the
final values are flipped.  Then is_local_primary() and is_linked() can
be strengthened as a non-existent image should stay in UNKNOWN.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
(cherry picked from commit c60f1d5813c7fe248593731bbffb43d12cdd3b62)
---
 .../rbd_mirror/image_replayer/StateBuilder.cc   | 17 +++++++++++------
 .../rbd_mirror/image_replayer/StateBuilder.h    |  4 ++--
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/src/tools/rbd_mirror/image_replayer/StateBuilder.cc b/src/tools/rbd_mirror/image_replayer/StateBuilder.cc
index 3c7274ec56e56..c8649ab2fa83e 100644
--- a/src/tools/rbd_mirror/image_replayer/StateBuilder.cc
+++ b/src/tools/rbd_mirror/image_replayer/StateBuilder.cc
@@ -36,16 +36,21 @@ StateBuilder<I>::~StateBuilder() {
 }
 
 template <typename I>
-bool StateBuilder<I>::is_local_primary() const  {
-  return (!local_image_id.empty() &&
-          local_promotion_state == librbd::mirror::PROMOTION_STATE_PRIMARY);
+bool StateBuilder<I>::is_local_primary() const {
+  if (local_promotion_state == librbd::mirror::PROMOTION_STATE_PRIMARY) {
+    ceph_assert(!local_image_id.empty());
+    return true;
+  }
+  return false;
 }
 
 template <typename I>
 bool StateBuilder<I>::is_linked() const {
-  return ((local_promotion_state ==
-             librbd::mirror::PROMOTION_STATE_NON_PRIMARY) &&
-          is_linked_impl());
+  if (local_promotion_state == librbd::mirror::PROMOTION_STATE_NON_PRIMARY) {
+    ceph_assert(!local_image_id.empty());
+    return is_linked_impl();
+  }
+  return false;
 }
 
 template <typename I>
diff --git a/src/tools/rbd_mirror/image_replayer/StateBuilder.h b/src/tools/rbd_mirror/image_replayer/StateBuilder.h
index 99007ba5e21a8..4c839a3efcee2 100644
--- a/src/tools/rbd_mirror/image_replayer/StateBuilder.h
+++ b/src/tools/rbd_mirror/image_replayer/StateBuilder.h
@@ -81,13 +81,13 @@ public:
 
   std::string local_image_id;
   librbd::mirror::PromotionState local_promotion_state =
-    librbd::mirror::PROMOTION_STATE_PRIMARY;
+    librbd::mirror::PROMOTION_STATE_UNKNOWN;
   ImageCtxT* local_image_ctx = nullptr;
 
   std::string remote_mirror_uuid;
   std::string remote_image_id;
   librbd::mirror::PromotionState remote_promotion_state =
-    librbd::mirror::PROMOTION_STATE_NON_PRIMARY;
+    librbd::mirror::PROMOTION_STATE_UNKNOWN;
   ImageCtxT* remote_image_ctx = nullptr;
 
 protected:
-- 
2.39.5