From 8806dfe4f4201a46d00e4c5657486b3be44bfc8d Mon Sep 17 00:00:00 2001
From: Ming-Hung Tsai <mtsai@redhat.com>
Date: Mon, 25 Oct 2021 15:33:18 +0800
Subject: [PATCH] [cache_writeback] Fix space map commits

Fix github issue #138
---
 caching/cache_writeback.cc |  2 +-
 caching/metadata.cc        | 11 ++++++++---
 caching/metadata.h         |  4 ++--
 3 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/caching/cache_writeback.cc b/caching/cache_writeback.cc
index 24a2385..cc2a9c9 100644
--- a/caching/cache_writeback.cc
+++ b/caching/cache_writeback.cc
@@ -301,7 +301,7 @@ namespace {
 
 	int writeback_(flags const &f) {
 		block_manager::ptr bm = open_bm(*f.metadata_dev, block_manager::READ_WRITE);
-		metadata md(bm);
+		metadata md(bm, true);
 
 		// FIXME: we're going to have to copy runs to get the through put with small block sizes
 		unsigned max_ios = f.cache_size / (md.sb_.data_block_size << SECTOR_SHIFT);
diff --git a/caching/metadata.cc b/caching/metadata.cc
index 9646bff..0cf304f 100644
--- a/caching/metadata.cc
+++ b/caching/metadata.cc
@@ -45,9 +45,9 @@ metadata::metadata(block_manager::ptr bm, open_type ot, unsigned metadata_versio
 	}
 }
 
-metadata::metadata(block_manager::ptr bm)
+metadata::metadata(block_manager::ptr bm, bool read_space_map)
 {
-	open_metadata(bm);
+	open_metadata(bm, read_space_map);
 }
 
 void
@@ -90,11 +90,16 @@ metadata::create_metadata(block_manager::ptr bm, unsigned metadata_version)
 }
 
 void
-metadata::open_metadata(block_manager::ptr bm)
+metadata::open_metadata(block_manager::ptr bm, bool read_space_map)
 {
 	tm_ = open_tm(bm);
 	sb_ = read_superblock(tm_->get_bm());
 
+	if (read_space_map) {
+		metadata_sm_ = open_metadata_sm(*tm_, &sb_.metadata_space_map_root);
+		tm_->set_sm(metadata_sm_);
+	}
+
 	mappings_ = mapping_array::ptr(
 		new mapping_array(*tm_,
 				  mapping_array::ref_counter(),
diff --git a/caching/metadata.h b/caching/metadata.h
index 949139c..10454a8 100644
--- a/caching/metadata.h
+++ b/caching/metadata.h
@@ -27,7 +27,7 @@ namespace caching {
 		typedef std::shared_ptr<metadata> ptr;
 
 		metadata(block_manager::ptr bm, open_type ot, unsigned metadata_version = 2); // Create only
-		metadata(block_manager::ptr bm);
+		metadata(block_manager::ptr bm, bool read_space_map = false);
 
 		void commit(bool clean_shutdown = true);
 		void setup_hint_array(size_t width);
@@ -46,7 +46,7 @@ namespace caching {
 		void init_superblock();
 
 		void create_metadata(block_manager::ptr bm, unsigned metadata_version);
-		void open_metadata(block_manager::ptr bm);
+		void open_metadata(block_manager::ptr bm, bool read_space_map);
 
 		void commit_space_map();
 		void commit_mappings();