From 8e1cc88e068fe57e9bbfa1ebbc6bbf89fb62aaac Mon Sep 17 00:00:00 2001
From: Mykola Golub <mgolub@mirantis.com>
Date: Wed, 2 Nov 2016 12:43:45 +0200
Subject: [PATCH] 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>
---
 src/librbd/Operations.cc | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/librbd/Operations.cc b/src/librbd/Operations.cc
index 63dacf9430d..feb99ed4a98 100644
--- a/src/librbd/Operations.cc
+++ b/src/librbd/Operations.cc
@@ -1020,6 +1020,11 @@ 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;