]> git.apps.os.sepia.ceph.com Git - ceph.git/commitdiff
test/librbd: initial unit tests for migration/QCOWFormat
authorJason Dillaman <dillaman@redhat.com>
Mon, 25 Jan 2021 23:15:15 +0000 (18:15 -0500)
committerJason Dillaman <dillaman@redhat.com>
Tue, 26 Jan 2021 16:42:48 +0000 (11:42 -0500)
Signed-off-by: Jason Dillaman <dillaman@redhat.com>
src/test/librbd/CMakeLists.txt
src/test/librbd/migration/test_mock_QCOWFormat.cc [new file with mode: 0644]

index d943c3720a2be29470439db700ee3dcf86cbd3f2..68b1b75dba51daa5cb4eb0a8a043690302ca2528 100644 (file)
@@ -96,6 +96,7 @@ set(unittest_librbd_srcs
   migration/test_mock_HttpStream.cc
   migration/test_mock_RawFormat.cc
   migration/test_mock_RawSnapshot.cc
+  migration/test_mock_QCOWFormat.cc
   migration/test_mock_S3Stream.cc
   migration/test_mock_Utils.cc
   mirror/snapshot/test_mock_CreateNonPrimaryRequest.cc
diff --git a/src/test/librbd/migration/test_mock_QCOWFormat.cc b/src/test/librbd/migration/test_mock_QCOWFormat.cc
new file mode 100644 (file)
index 0000000..3515a0e
--- /dev/null
@@ -0,0 +1,1245 @@
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+
+#include "test/librbd/test_mock_fixture.h"
+#include "test/librbd/test_support.h"
+#include "test/librbd/mock/migration/MockStreamInterface.h"
+#include "include/rbd_types.h"
+#include "common/ceph_mutex.h"
+#include "librbd/migration/QCOWFormat.h"
+#include "librbd/migration/SourceSpecBuilder.h"
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include "json_spirit/json_spirit.h"
+
+namespace librbd {
+namespace {
+
+struct MockTestImageCtx : public MockImageCtx {
+  MockTestImageCtx(ImageCtx &image_ctx) : MockImageCtx(image_ctx) {
+  }
+};
+
+} // anonymous namespace
+
+namespace migration {
+
+template<>
+struct SourceSpecBuilder<librbd::MockTestImageCtx> {
+
+  MOCK_CONST_METHOD2(build_stream, int(const json_spirit::mObject&,
+                                       std::shared_ptr<StreamInterface>*));
+
+};
+
+} // namespace migration
+
+bool operator==(const SnapInfo& lhs, const SnapInfo& rhs) {
+    return (lhs.name == rhs.name &&
+            lhs.size == rhs.size);
+}
+
+} // namespace librbd
+
+#include "librbd/migration/QCOWFormat.cc"
+
+using ::testing::_;
+using ::testing::InSequence;
+using ::testing::Invoke;
+using ::testing::ReturnRef;
+using ::testing::WithArg;
+using ::testing::WithArgs;
+
+namespace librbd {
+namespace migration {
+
+using ::testing::Invoke;
+
+class TestMockMigrationQCOWFormat : public TestMockFixture {
+public:
+  typedef QCOWFormat<MockTestImageCtx> MockQCOWFormat;
+  typedef SourceSpecBuilder<MockTestImageCtx> MockSourceSpecBuilder;
+
+  librbd::ImageCtx *m_image_ctx;
+
+  void SetUp() override {
+    TestMockFixture::SetUp();
+
+    ASSERT_EQ(0, open_image(m_image_name, &m_image_ctx));
+
+    json_spirit::mObject stream_obj;
+    stream_obj["type"] = "file";
+    json_object["stream"] = stream_obj;
+  }
+
+  void expect_build_stream(MockSourceSpecBuilder& mock_source_spec_builder,
+                           MockStreamInterface* mock_stream_interface, int r) {
+    EXPECT_CALL(mock_source_spec_builder, build_stream(_, _))
+      .WillOnce(WithArgs<1>(Invoke([mock_stream_interface, r]
+        (std::shared_ptr<StreamInterface>* ptr) {
+          ptr->reset(mock_stream_interface);
+          return r;
+        })));
+  }
+
+  void expect_stream_open(MockStreamInterface& mock_stream_interface, int r) {
+    EXPECT_CALL(mock_stream_interface, open(_))
+      .WillOnce(Invoke([r](Context* ctx) { ctx->complete(r); }));
+  }
+
+  void expect_stream_close(MockStreamInterface& mock_stream_interface, int r) {
+    EXPECT_CALL(mock_stream_interface, close(_))
+      .WillOnce(Invoke([r](Context* ctx) { ctx->complete(r); }));
+  }
+
+  void expect_stream_read(MockStreamInterface& mock_stream_interface,
+                          const io::Extents& byte_extents,
+                          const bufferlist& bl, int r) {
+    EXPECT_CALL(mock_stream_interface, read(byte_extents, _, _))
+      .WillOnce(WithArgs<1, 2>(Invoke([bl, r]
+        (bufferlist* out_bl, Context* ctx) {
+          *out_bl = bl;
+          ctx->complete(r);
+        })));
+  }
+
+  void expect_probe_header(MockStreamInterface& mock_stream_interface,
+                           uint32_t magic, uint32_t version, int r) {
+    magic = htobe32(magic);
+    version = htobe32(version);
+
+    bufferlist probe_bl;
+    probe_bl.append(std::string_view(reinterpret_cast<char*>(&magic), 4));
+    probe_bl.append(std::string_view(reinterpret_cast<char*>(&version), 4));
+    expect_stream_read(mock_stream_interface, {{0, 8}}, probe_bl, r);
+  }
+
+  void expect_read_header(MockStreamInterface& mock_stream_interface,
+                          uint32_t snapshot_count, int r) {
+    QCowHeader qcow_header;
+    memset(&qcow_header, 0, sizeof(qcow_header));
+    qcow_header.magic = htobe32(QCOW_MAGIC);
+    qcow_header.version = htobe32(2);
+    qcow_header.size = htobe64(1<<30);
+    qcow_header.cluster_bits = htobe32(16);
+    qcow_header.l1_size = htobe32(2);
+    qcow_header.l1_table_offset = htobe64(1<<20);
+    if (snapshot_count > 0) {
+      qcow_header.nb_snapshots = htobe32(snapshot_count);
+      qcow_header.snapshots_offset = htobe64(1<<21);
+    }
+
+    bufferlist header_bl;
+    header_bl.append(std::string_view(reinterpret_cast<char*>(&qcow_header),
+                     sizeof(qcow_header)));
+    expect_stream_read(mock_stream_interface, {{0, sizeof(qcow_header)}},
+                       header_bl, r);
+  }
+
+  void expect_read_l1_table(MockStreamInterface& mock_stream_interface,
+                            std::optional<std::vector<uint64_t>>&& l1_table,
+                            int r) {
+    bufferlist l1_table_bl;
+    if (!l1_table) {
+      l1_table.emplace(2);
+    }
+
+    l1_table->resize(2);
+    for (size_t idx = 0; idx < l1_table->size(); ++idx) {
+      (*l1_table)[idx] = htobe64((*l1_table)[idx]);
+    }
+
+    l1_table_bl.append(
+      std::string_view(reinterpret_cast<char*>(l1_table->data()), 16));
+    expect_stream_read(mock_stream_interface, {{1<<20, 16}}, l1_table_bl, r);
+  }
+
+  void expect_read_l2_table(MockStreamInterface& mock_stream_interface,
+                            uint64_t l2_table_offset,
+                            std::optional<std::vector<uint64_t>>&& l2_table,
+                            int r) {
+    size_t l2_table_size = 1<<(16 - 3); // cluster_bit - 3 bits for offset
+    bufferlist l2_table_bl;
+    if (!l2_table) {
+      l2_table.emplace(l2_table_size);
+    }
+
+    l2_table->resize(l2_table_size);
+    for (size_t idx = 0; idx < l2_table->size(); ++idx) {
+      (*l2_table)[idx] = htobe64((*l2_table)[idx]);
+    }
+
+    l2_table_bl.append(
+      std::string_view(reinterpret_cast<char*>(l2_table->data()),
+                       l2_table->size() * sizeof(uint64_t)));
+    expect_stream_read(mock_stream_interface,
+                       {{l2_table_offset, l2_table->size() * sizeof(uint64_t)}},
+                       l2_table_bl, r);
+  }
+
+  void expect_read_cluster(MockStreamInterface& mock_stream_interface,
+                           uint64_t cluster_offset, uint32_t offset,
+                           const bufferlist& bl, int r) {
+    uint32_t cluster_size = 1<<16;
+
+    bufferlist cluster_bl;
+    if (offset > 0) {
+      cluster_size -= offset;
+      cluster_bl.append_zero(offset);
+    }
+
+    cluster_size -= bl.length();
+    cluster_bl.append(bl);
+
+    if (cluster_size > 0) {
+      cluster_bl.append_zero(cluster_size);
+    }
+
+    expect_stream_read(mock_stream_interface,
+                       {{cluster_offset, cluster_bl.length()}}, cluster_bl, r);
+  }
+
+  void expect_open(MockStreamInterface& mock_stream_interface,
+                   std::optional<std::vector<uint64_t>>&& l1_table) {
+    expect_stream_open(mock_stream_interface, 0);
+
+    expect_probe_header(mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+    expect_read_header(mock_stream_interface, 0, 0);
+
+    expect_read_l1_table(mock_stream_interface, std::move(l1_table), 0);
+  }
+
+  void expect_read_snapshot_header(MockStreamInterface& mock_stream_interface,
+                                   const std::string& id,
+                                   const std::string& name,
+                                   uint64_t l1_table_offset,
+                                   uint64_t* snapshot_offset, int r) {
+    QCowSnapshotHeader snapshot_header;
+    memset(&snapshot_header, 0, sizeof(snapshot_header));
+    snapshot_header.id_str_size = htobe16(id.size());
+    snapshot_header.name_size = htobe16(name.size());
+    snapshot_header.extra_data_size = htobe32(16);
+    snapshot_header.l1_size = htobe32(1);
+    snapshot_header.l1_table_offset = htobe64(l1_table_offset);
+
+    bufferlist snapshot_header_bl;
+    snapshot_header_bl.append(
+      std::string_view(reinterpret_cast<char*>(&snapshot_header),
+                       sizeof(snapshot_header)));
+    expect_stream_read(mock_stream_interface,
+                       {{*snapshot_offset, sizeof(snapshot_header)}},
+                       snapshot_header_bl, r);
+    *snapshot_offset += sizeof(snapshot_header);
+  }
+
+  void expect_read_snapshot_header_extra(
+      MockStreamInterface& mock_stream_interface,
+      const std::string& id, const std::string& name, uint64_t size,
+      uint64_t* snapshot_offset, int r) {
+    QCowSnapshotExtraData snapshot_header_extra;
+    memset(&snapshot_header_extra, 0, sizeof(snapshot_header_extra));
+    snapshot_header_extra.disk_size = htobe64(size);
+
+    bufferlist snapshot_header_extra_bl;
+    snapshot_header_extra_bl.append(
+      std::string_view(reinterpret_cast<char*>(&snapshot_header_extra), 16));
+    snapshot_header_extra_bl.append(id);
+    snapshot_header_extra_bl.append(name);
+    expect_stream_read(mock_stream_interface,
+                       {{*snapshot_offset, 16 + id.size() + name.size()}},
+                       snapshot_header_extra_bl, r);
+
+    *snapshot_offset += 16 + id.size() + name.size();
+    *snapshot_offset = p2roundup(*snapshot_offset, static_cast<uint64_t>(8));
+  }
+
+  void expect_read_snapshot_l1_table(MockStreamInterface& mock_stream_interface,
+                                     uint64_t l1_table_offset, int r) {
+    uint64_t l2_table_cluster = htobe64(l1_table_offset);
+
+    bufferlist snapshot_l1_table_bl;
+    snapshot_l1_table_bl.append(
+      std::string_view(reinterpret_cast<char*>(&l2_table_cluster), 8));
+    expect_stream_read(mock_stream_interface, {{l1_table_offset, 8}},
+                       snapshot_l1_table_bl, r);
+  }
+
+
+  void expect_read_snapshot(MockStreamInterface& mock_stream_interface,
+                            const std::string& id, const std::string& name,
+                            uint64_t size, uint64_t l1_table_offset,
+                            uint64_t* snapshot_offset) {
+    expect_read_snapshot_header(mock_stream_interface, id, name,
+                                l1_table_offset, snapshot_offset, 0);
+    expect_read_snapshot_header_extra(mock_stream_interface, id, name,
+                                      size, snapshot_offset, 0);
+    expect_read_snapshot_l1_table(mock_stream_interface, l1_table_offset, 0);
+  }
+
+  json_spirit::mObject json_object;
+};
+
+TEST_F(TestMockMigrationQCOWFormat, OpenCloseV1) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  QCowHeaderV1 qcow_header;
+  memset(&qcow_header, 0, sizeof(qcow_header));
+  qcow_header.magic = htobe32(QCOW_MAGIC);
+  qcow_header.version = htobe32(1);
+  qcow_header.size = htobe64(1<<30);
+  qcow_header.l1_table_offset = htobe64(1<<20);
+  qcow_header.cluster_bits = 16;
+  qcow_header.l2_bits = 13;
+
+  bufferlist probe_bl;
+  probe_bl.append(std::string_view(reinterpret_cast<char*>(&qcow_header), 8));
+  expect_stream_read(*mock_stream_interface, {{0, 8}}, probe_bl, 0);
+
+  bufferlist header_bl;
+  header_bl.append(std::string_view(reinterpret_cast<char*>(&qcow_header),
+                                    sizeof(qcow_header)));
+  expect_stream_read(*mock_stream_interface, {{0, sizeof(qcow_header)}},
+                     header_bl, 0);
+
+  bufferlist l1_table_bl;
+  l1_table_bl.append_zero(16);
+  expect_stream_read(*mock_stream_interface, {{1<<20, 16}}, l1_table_bl, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, OpenCloseV2) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {});
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ProbeInvalidMagic) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, 0, 2, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EINVAL, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ProbeInvalidVersion) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 0, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EINVAL, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ProbeError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, -EIO);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EIO, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadHeaderV1Error) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 1, 0);
+
+  QCowHeaderV1 qcow_header;
+  memset(&qcow_header, 0, sizeof(qcow_header));
+  qcow_header.magic = htobe32(QCOW_MAGIC);
+  qcow_header.version = htobe32(1);
+  qcow_header.size = htobe64(1<<30);
+  qcow_header.l1_table_offset = htobe64(1<<20);
+  qcow_header.cluster_bits = 16;
+  qcow_header.l2_bits = 13;
+
+  bufferlist header_bl;
+  header_bl.append(std::string_view(reinterpret_cast<char*>(&qcow_header),
+                                    sizeof(qcow_header)));
+  expect_stream_read(*mock_stream_interface, {{0, sizeof(qcow_header)}},
+                     header_bl, -EPERM);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EPERM, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadHeaderV2Error) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 0, -EIO);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EIO, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadL1TableError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 0, 0);
+
+  expect_read_l1_table(*mock_stream_interface, {}, -EPERM);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EPERM, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, Snapshots) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 2, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot(*mock_stream_interface, "1", "snap1", 1<<29, 1<<22,
+                       &snapshot_offset);
+  expect_read_snapshot(*mock_stream_interface, "2", "snap2", 1<<29, 1<<22,
+                       &snapshot_offset);
+
+  expect_read_l1_table(*mock_stream_interface, {}, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  FormatInterface::SnapInfos snap_infos;
+  C_SaferCond ctx2;
+  mock_qcow_format.get_snapshots(&snap_infos, &ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+
+  FormatInterface::SnapInfos expected_snap_infos{
+    {1, {"snap1", cls::rbd::UserSnapshotNamespace{}, 1<<29, {}, 0, 0, {}}},
+    {2, {"snap2", cls::rbd::UserSnapshotNamespace{}, 1<<29, {}, 0, 0, {}}}};
+  ASSERT_EQ(expected_snap_infos, snap_infos);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, SnapshotHeaderError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 2, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot_header(*mock_stream_interface, "1", "snap1",
+                              1<<22, &snapshot_offset, -EINVAL);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EINVAL, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, SnapshotExtraError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 2, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot_header(*mock_stream_interface, "1", "snap1",
+                              1<<22, &snapshot_offset, 0);
+  expect_read_snapshot_header_extra(*mock_stream_interface, "1", "snap1",
+                                    1<<29, &snapshot_offset, -EINVAL);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EINVAL, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, SnapshotL1TableError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 2, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot_header(*mock_stream_interface, "1", "snap1",
+                              1<<22, &snapshot_offset, 0);
+  expect_read_snapshot_header_extra(*mock_stream_interface, "1", "snap1",
+                                    1<<29, &snapshot_offset, 0);
+  expect_read_snapshot_l1_table(*mock_stream_interface, 1<<22, -EINVAL);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(-EINVAL, ctx1.wait());
+
+  C_SaferCond ctx2;
+  mock_qcow_format.close(&ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, GetImageSize) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {});
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  uint64_t size = 0;
+  C_SaferCond ctx2;
+  mock_qcow_format.get_image_size(CEPH_NOSNAP, &size, &ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+  ASSERT_EQ(1<<30, size);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, GetImageSizeSnap) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 1, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot(*mock_stream_interface, "1", "snap1", 1<<29, 1<<22,
+                       &snapshot_offset);
+
+  expect_read_l1_table(*mock_stream_interface, {}, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  uint64_t size = 0;
+  C_SaferCond ctx2;
+  mock_qcow_format.get_image_size(1U, &size, &ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+  ASSERT_EQ(1<<29, size);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, GetImageSizeSnapDNE) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {});
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  uint64_t size = 0;
+  C_SaferCond ctx2;
+  mock_qcow_format.get_image_size(1U, &size, &ctx2);
+  ASSERT_EQ(-ENOENT, ctx2.wait());
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, Read) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, 1ULL<<32}}, 0);
+
+  bufferlist expect_bl;
+  expect_bl.append(std::string(123, '1'));
+  expect_read_cluster(*mock_stream_interface, 1ULL<<32, 123, expect_bl, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  ASSERT_EQ(expect_bl, bl);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadL1DNE) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {});
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{234, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  bufferlist expect_bl;
+  expect_bl.append_zero(123);
+  ASSERT_EQ(expect_bl, bl);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadL2DNE) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, 1ULL<<32}}, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{234, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  bufferlist expect_bl;
+  expect_bl.append_zero(123);
+  ASSERT_EQ(expect_bl, bl);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadZero) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, QCOW_OFLAG_ZERO}}, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  bufferlist expect_bl;
+  expect_bl.append_zero(123);
+  ASSERT_EQ(expect_bl, bl);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadSnap) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 1, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot(*mock_stream_interface, "1", "snap1", 1<<29, 1<<22,
+                       &snapshot_offset);
+
+  expect_read_l1_table(*mock_stream_interface, {}, 0);
+
+  expect_read_l2_table(*mock_stream_interface, 1<<22,
+                       {{0, 1ULL<<32}}, 0);
+
+  bufferlist expect_bl;
+  expect_bl.append(std::string(123, '1'));
+  expect_read_cluster(*mock_stream_interface, 1ULL<<32, 123, expect_bl, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, 1, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  ASSERT_EQ(expect_bl, bl);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadSnapDNE) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, 1, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(-ENOENT, ctx2.wait());
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadClusterCacheHit) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, 1ULL<<32}}, 0);
+
+  bufferlist expect_bl1;
+  expect_bl1.append(std::string(123, '1'));
+
+  bufferlist expect_bl2;
+  expect_bl2.append(std::string(234, '2'));
+
+  bufferlist cluster_bl;
+  cluster_bl.append_zero(123);
+  cluster_bl.append(expect_bl1);
+  cluster_bl.append_zero(234);
+  cluster_bl.append(expect_bl2);
+
+  expect_read_cluster(*mock_stream_interface, 1ULL<<32, 0, cluster_bl, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp1 = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl1;
+  io::ReadResult read_result1{&bl1};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp1, CEPH_NOSNAP, {{65659, 123}},
+                                    std::move(read_result1), 0, 0, {}));
+  ASSERT_EQ(123, ctx2.wait());
+  ASSERT_EQ(expect_bl1, bl1);
+
+  C_SaferCond ctx3;
+  auto aio_comp2 = io::AioCompletion::create_and_start(
+    &ctx3, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl2;
+  io::ReadResult read_result2{&bl2};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp2, CEPH_NOSNAP, {{66016, 234}},
+                                    std::move(read_result2), 0, 0, {}));
+  ASSERT_EQ(234, ctx3.wait());
+  ASSERT_EQ(expect_bl2, bl2);
+
+  C_SaferCond ctx4;
+  mock_qcow_format.close(&ctx4);
+  ASSERT_EQ(0, ctx4.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadClusterError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, 1ULL<<32}}, 0);
+
+  bufferlist expect_bl;
+  expect_bl.append(std::string(123, '1'));
+  expect_read_cluster(*mock_stream_interface, 1ULL<<32, 123, expect_bl, -EIO);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(-EIO, ctx2.wait());
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ReadL2TableError) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_open(*mock_stream_interface, {{1ULL<<40}});
+
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<40,
+                       {{0, 1ULL<<32}}, -EIO);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                  &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  auto aio_comp = io::AioCompletion::create_and_start(
+    &ctx2, m_image_ctx, io::AIO_TYPE_READ);
+  bufferlist bl;
+  io::ReadResult read_result{&bl};
+  ASSERT_TRUE(mock_qcow_format.read(aio_comp, CEPH_NOSNAP, {{65659, 123}},
+                                    std::move(read_result), 0, 0, {}));
+  ASSERT_EQ(-EIO, ctx2.wait());
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+TEST_F(TestMockMigrationQCOWFormat, ListSnaps) {
+  MockTestImageCtx mock_image_ctx(*m_image_ctx);
+
+  InSequence seq;
+  MockSourceSpecBuilder mock_source_spec_builder;
+
+  auto mock_stream_interface = new MockStreamInterface();
+  expect_build_stream(mock_source_spec_builder, mock_stream_interface, 0);
+
+  expect_stream_open(*mock_stream_interface, 0);
+
+  expect_probe_header(*mock_stream_interface, QCOW_MAGIC, 2, 0);
+
+  expect_read_header(*mock_stream_interface, 2, 0);
+
+  uint64_t snapshot_offset = 1<<21;
+  expect_read_snapshot(*mock_stream_interface, "1", "snap1", 1<<29, 1<<22,
+                       &snapshot_offset);
+  expect_read_snapshot(*mock_stream_interface, "2", "snap2", 1<<29, 1<<23,
+                       &snapshot_offset);
+
+  expect_read_l1_table(*mock_stream_interface, {{1ULL<<28}}, 0);
+
+  io::SparseExtents sparse_extents_1;
+  sparse_extents_1.insert(0, 196608, {io::SPARSE_EXTENT_STATE_DATA, 196608});
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<22,
+                       {{1ULL<<23, 1ULL<<24, 1ULL<<25}}, 0);
+
+  io::SparseExtents sparse_extents_2;
+  sparse_extents_2.insert(0, 65536, {io::SPARSE_EXTENT_STATE_DATA, 65536});
+  sparse_extents_2.insert(65536, 65536,
+                         {io::SPARSE_EXTENT_STATE_ZEROED, 65536});
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<23,
+                       {{1ULL<<26, QCOW_OFLAG_ZERO, 1ULL<<25}}, 0);
+
+  io::SparseExtents sparse_extents_head;
+  sparse_extents_head.insert(131072, 65536,
+                             {io::SPARSE_EXTENT_STATE_DATA, 65536});
+  expect_read_l2_table(*mock_stream_interface, 1ULL<<28,
+                       {{1ULL<<26, QCOW_OFLAG_ZERO, 1ULL<<27}}, 0);
+
+  expect_stream_close(*mock_stream_interface, 0);
+
+  MockQCOWFormat mock_qcow_format(&mock_image_ctx, json_object,
+                                 &mock_source_spec_builder);
+
+  C_SaferCond ctx1;
+  mock_qcow_format.open(&ctx1);
+  ASSERT_EQ(0, ctx1.wait());
+
+  C_SaferCond ctx2;
+  io::SnapshotDelta snapshot_delta;
+  mock_qcow_format.list_snaps({{0, 196608}}, {1, CEPH_NOSNAP}, 0,
+                              &snapshot_delta, {}, &ctx2);
+  ASSERT_EQ(0, ctx2.wait());
+
+  io::SnapshotDelta expected_snapshot_delta;
+  expected_snapshot_delta[{1, 1}] = sparse_extents_1;
+  expected_snapshot_delta[{CEPH_NOSNAP, 2}] = sparse_extents_2;
+  expected_snapshot_delta[{CEPH_NOSNAP, CEPH_NOSNAP}] = sparse_extents_head;
+  ASSERT_EQ(expected_snapshot_delta, snapshot_delta);
+
+  C_SaferCond ctx3;
+  mock_qcow_format.close(&ctx3);
+  ASSERT_EQ(0, ctx3.wait());
+}
+
+} // namespace migration
+} // namespace librbd