rbd-mirror: prevent infinite loop when computing replay status

If the image had a non-primary predecessor epoch whose tag tid
duplicates an epoch within its own journal, an infinite loop
would result.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/tools/rbd_mirror/image_replayer/ReplayStatusFormatter.cc b/src/tools/rbd_mirror/image_replayer/ReplayStatusFormatter.cc
index faca72b47d43d2f7d796ff7a6ce90cbd976ab9ba..e86765c2d4f9cede1f642dad978dce8e665351b5 100644 (file)
--- a/src/tools/rbd_mirror/image_replayer/ReplayStatusFormatter.cc
+++ b/src/tools/rbd_mirror/image_replayer/ReplayStatusFormatter.cc
@@ -196,7 +196,13 @@ void ReplayStatusFormatter<I>::handle_update_tag_cache(uint64_t master_tag_tid,
     }
   }
 
-  if (tag_data.predecessor.tag_tid == 0) {
+  if (tag_data.predecessor.mirror_uuid !=
+        librbd::Journal<>::LOCAL_MIRROR_UUID &&
+      tag_data.predecessor.mirror_uuid !=
+        librbd::Journal<>::ORPHAN_MIRROR_UUID) {
+    dout(20) << "hit remote image non-primary epoch" << dendl;
+    tag_data.predecessor.tag_tid = mirror_tag_tid;
+  } else if (tag_data.predecessor.tag_tid == 0) {
     // We failed. Don't consider this fatal, just terminate retrieving.
     dout(20) << "making fake tag" << dendl;
     tag_data.predecessor.tag_tid = mirror_tag_tid;