[thin_generate_damage] Introduce tools to generate metadata damage

thin-provisioning/damage_generator.cc

@@ -0,0 +1,66 @@
+#include "damage_generator.h"
+
+using namespace thin_provisioning;
+
+//----------------------------------------------------------------
+
+namespace {
+	void find_blocks(space_map::ptr sm,
+			 block_address nr_blocks,
+			 ref_t expected,
+			 std::set<block_address> &found) {
+		block_address sm_size = sm->get_nr_blocks();
+		base::run_set<block_address> visited;
+		block_address nr_visited = 0;
+
+		srand(time(NULL));
+		while (nr_blocks) {
+			if (nr_visited == sm_size)
+				break;
+
+			block_address b = rand() % sm_size;
+			if (visited.member(b))
+				continue;
+
+			ref_t c = sm->get_count(b);
+			if (c == expected) {
+				found.insert(b);
+				--nr_blocks;
+			}
+
+			visited.add(b);
+			++nr_visited;
+		}
+
+		if (nr_blocks) {
+			ostringstream out;
+			out << "cannot find " << (nr_blocks + found.size())
+			    << " blocks of ref-count " << expected;
+			throw runtime_error(out.str());
+		}
+	}
+}
+
+//----------------------------------------------------------------
+
+damage_generator::damage_generator(block_manager::ptr bm)
+{
+	md_ = metadata::ptr(new metadata(bm, true));
+}
+
+void damage_generator::commit()
+{
+	md_->commit();
+}
+
+void damage_generator::create_metadata_leaks(block_address nr_leaks,
+					     ref_t expected, ref_t actual)
+{
+	std::set<block_address> leaks;
+	find_blocks(md_->metadata_sm_, nr_leaks, expected, leaks);
+
+	for (auto const &b : leaks)
+		md_->metadata_sm_->set_count(b, actual);
+}
+
+//----------------------------------------------------------------