From 09ce099c2f184924e1b9be0617d4a9ce6de4481c Mon Sep 17 00:00:00 2001
From: Joe Thornber <ejt@redhat.com>
Date: Wed, 17 Feb 2016 10:42:42 +0000
Subject: [PATCH] [thin_delta] set nr_data_blocks to zero if there are no space
 maps.

ie. a metadata_snap is being used.
---
 thin-provisioning/thin_delta.cc | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/thin-provisioning/thin_delta.cc b/thin-provisioning/thin_delta.cc
index 3ec71c8..3b33c73 100644
--- a/thin-provisioning/thin_delta.cc
+++ b/thin-provisioning/thin_delta.cc
@@ -527,7 +527,7 @@ namespace local {
 		mapping_recorder mr2;
 		damage_visitor damage_v;
 		superblock_detail::superblock sb;
-		checked_space_map::ptr data_sm;
+		block_address nr_data_blocks = 0ull;
 
 		{
 			block_manager<>::ptr bm = open_bm(*fs.dev, block_manager<>::READ_ONLY, !fs.use_metadata_snap);
@@ -562,13 +562,16 @@ namespace local {
 
 			btree_visit_values(snap2, mr2, damage_v);
 			mr2.complete();
+
+			if (md->data_sm_)
+				nr_data_blocks = md->data_sm_->get_nr_blocks();
 		}
 
 		indented_stream is(cout);
 		begin_superblock(is, "", sb.time_,
 				 sb.trans_id_,
 				 sb.data_block_size_,
-				 data_sm->get_nr_blocks(),
+				 nr_data_blocks,
 				 sb.metadata_snap_ ?
 				 boost::optional<block_address>(sb.metadata_snap_) :
 				 boost::optional<block_address>());