rbd-mirror: snap protect of non-layered image results in split-brain

Fixes: http://tracker.ceph.com/issues/16962
Signed-off-by: Mykola Golub <mgolub@mirantis.com>
(cherry picked from commit 8e1cc88e068fe57e9bbfa1ebbc6bbf89fb62aaac)

diff --git a/src/librbd/Operations.cc b/src/librbd/Operations.cc
index f3e92a7671593bd067a81e8104364d1a9227ef81..31a503f4d4f166b2d5a5e17f5d6e628812214b3e 100644 (file)
--- a/src/librbd/Operations.cc
+++ b/src/librbd/Operations.cc
@@ -951,6 +951,11 @@ int Operations<I>::snap_protect(const char *snap_name) {
     return -EROFS;
   }
 
+  if (!m_image_ctx.test_features(RBD_FEATURE_LAYERING)) {
+    lderr(cct) << "image must support layering" << dendl;
+    return -ENOSYS;
+  }
+
   int r = m_image_ctx.state->refresh_if_required();
   if (r < 0) {
     return r;