From: Jason Dillaman <dillaman@redhat.com>
Date: Fri, 22 Feb 2019 15:59:26 +0000 (-0500)
Subject: rbd-mirror: complete pool watcher initialization if object missing
X-Git-Tag: v13.2.7~300^2~3
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=b7dd40c15dfe3d6372da3c1e026ed3fb52bdda26;p=ceph.git

rbd-mirror: complete pool watcher initialization if object missing

If the mirroring object is missing, complete the initialization and
continue to retry in the background. This is useful for cases where
the remote doesn't (yet) have mirroring enabled but the remote
pool watcher initialization is delaying the leader watcher promotion
to the point where the leader is blacklisted by its peers.

Signed-off-by: Jason Dillaman <dillaman@redhat.com>
(cherry picked from commit 80954cd914c86e11ffb6a8cbfcb21202cb8131b5)
---

diff --git a/src/test/rbd_mirror/test_mock_PoolWatcher.cc b/src/test/rbd_mirror/test_mock_PoolWatcher.cc
index 07f9a4d62f8..6e8b67908a8 100644
--- a/src/test/rbd_mirror/test_mock_PoolWatcher.cc
+++ b/src/test/rbd_mirror/test_mock_PoolWatcher.cc
@@ -498,7 +498,7 @@ TEST_F(TestMockPoolWatcher, RegisterWatcherMissing) {
                                     mock_listener);
   C_SaferCond ctx;
   mock_pool_watcher.init(&ctx);
-  ASSERT_EQ(0, ctx.wait());
+  ASSERT_EQ(-ENOENT, ctx.wait());
 
   ASSERT_TRUE(wait_for_update(1));
   expect_mirroring_watcher_unregister(mock_mirroring_watcher, 0);
diff --git a/src/tools/rbd_mirror/PoolReplayer.cc b/src/tools/rbd_mirror/PoolReplayer.cc
index ea28a27c70c..049461e890c 100644
--- a/src/tools/rbd_mirror/PoolReplayer.cc
+++ b/src/tools/rbd_mirror/PoolReplayer.cc
@@ -818,7 +818,13 @@ template <typename I>
 void PoolReplayer<I>::handle_init_remote_pool_watcher(
     int r, Context *on_finish) {
   dout(10) << "r=" << r << dendl;
-  if (r < 0) {
+  if (r == -ENOENT) {
+    // Technically nothing to do since the other side doesn't
+    // have mirroring enabled. Eventually the remote pool watcher will
+    // detect images (if mirroring is enabled), so no point propagating
+    // an error which would just busy-spin the state machines.
+    dout(0) << "remote peer does not have mirroring configured" << dendl;
+  } else if (r < 0) {
     derr << "failed to retrieve remote images: " << cpp_strerror(r) << dendl;
     on_finish = new FunctionContext([this, on_finish, r](int) {
         on_finish->complete(r);
diff --git a/src/tools/rbd_mirror/PoolWatcher.cc b/src/tools/rbd_mirror/PoolWatcher.cc
index 9056a615ddd..d73c59d3895 100644
--- a/src/tools/rbd_mirror/PoolWatcher.cc
+++ b/src/tools/rbd_mirror/PoolWatcher.cc
@@ -174,6 +174,9 @@ void PoolWatcher<I>::handle_register_watcher(int r) {
   } else if (r == -ENOENT) {
     dout(5) << "mirroring directory does not exist" << dendl;
     schedule_refresh_images(30);
+
+    Mutex::Locker locker(m_lock);
+    std::swap(on_init_finish, m_on_init_finish);
   } else {
     derr << "unexpected error registering mirroring directory watch: "
          << cpp_strerror(r) << dendl;