rbd-mirror: do not attempt to unlink from more recent snapshots

The snapshot-based mirroring replayer should only attempt to unlink
from any snapshots that are older than the end remote snapshot id to
prevent the remote side from incorrectly deleted the snapshot.

Fixes: https://tracker.ceph.com/issues/48527
Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/src/test/rbd_mirror/image_replayer/snapshot/test_mock_Replayer.cc b/src/test/rbd_mirror/image_replayer/snapshot/test_mock_Replayer.cc
index f9550dcb5b4213b15ce9165e2fac1e62b3a6d3c6..50a155d241826a782ebe5561fcd9230833b2b528 100644 (file)
--- a/src/test/rbd_mirror/image_replayer/snapshot/test_mock_Replayer.cc
+++ b/src/test/rbd_mirror/image_replayer/snapshot/test_mock_Replayer.cc
@@ -783,7 +783,24 @@ TEST_F(TestMockImageReplayerSnapshotReplayer, SyncSnapshot) {
          1, true, 0, {{1, CEPH_NOSNAP}}},
        0, {}, 0, 0, {}}},
     }, 0);
-  expect_is_refresh_required(mock_remote_image_ctx, false);
+  expect_is_refresh_required(mock_remote_image_ctx, true);
+  expect_refresh(
+    mock_remote_image_ctx, {
+      {2U, librbd::SnapInfo{"snap2", cls::rbd::UserSnapshotNamespace{},
+       0, {}, 0, 0, {}}},
+      {3U, librbd::SnapInfo{"snap3", cls::rbd::MirrorSnapshotNamespace{
+         cls::rbd::MIRROR_SNAPSHOT_STATE_PRIMARY, {""},
+         "", CEPH_NOSNAP, true, 0, {}},
+       0, {}, 0, 0, {}}},
+      {4U, librbd::SnapInfo{"snap4", cls::rbd::MirrorSnapshotNamespace{
+         cls::rbd::MIRROR_SNAPSHOT_STATE_PRIMARY, {"remote mirror peer uuid"},
+         "", CEPH_NOSNAP, true, 0, {}},
+       0, {}, 0, 0, {}}},
+      {5U, librbd::SnapInfo{"snap5", cls::rbd::MirrorSnapshotNamespace{
+         cls::rbd::MIRROR_SNAPSHOT_STATE_PRIMARY, {"remote mirror peer uuid"},
+         "", CEPH_NOSNAP, true, 0, {}},
+       0, {}, 0, 0, {}}}
+    }, 0);
   expect_snapshot_copy(mock_snapshot_copy_request, 1, 4, 11,
                        {{1, 11}, {2, 12}, {4, CEPH_NOSNAP}}, 0);
   expect_get_image_state(mock_get_image_state_request, 4, 0);

diff --git a/src/tools/rbd_mirror/image_replayer/snapshot/Replayer.cc b/src/tools/rbd_mirror/image_replayer/snapshot/Replayer.cc
index d2c8ee27278e7c08ab2657cab916171b8f9bf311..1b9d08f0b48d0e81f369401e2ac6fbad037484a1 100644 (file)
--- a/src/tools/rbd_mirror/image_replayer/snapshot/Replayer.cc
+++ b/src/tools/rbd_mirror/image_replayer/snapshot/Replayer.cc
@@ -552,7 +552,10 @@ void Replayer<I>::scan_remote_mirror_snapshots(
         ceph_assert(m_local_mirror_snap_ns.primary_mirror_uuid ==
                       m_state_builder->remote_mirror_uuid);
 
-        unlink_snap_ids.insert(remote_snap_id);
+        if (m_remote_snap_id_end == CEPH_NOSNAP) {
+          // haven't found the end snap so treat this as a candidate for unlink
+          unlink_snap_ids.insert(remote_snap_id);
+        }
         if (m_local_mirror_snap_ns.complete &&
             m_local_mirror_snap_ns.primary_snap_id >= remote_snap_id) {
           // skip past completed remote snapshot