diff --git a/CMake/FindCURL.cmake b/CMake/FindCURL.cmake
index 041bd5e2..2577fbab 100644
--- a/CMake/FindCURL.cmake
+++ b/CMake/FindCURL.cmake
@@ -3,10 +3,9 @@ include(FetchContent)
 if(${BUILD_CURL_FROM_SOURCE})
     message("Add and build standalone libcurl")
     include(FetchContent)
-    FetchContent_Declare(
-        curl_bundle
-        GIT_REPOSITORY https://github.com/curl/curl.git
-        GIT_TAG curl-7_42_1
+    FetchContent_Declare(curl_bundle
+        GIT_REPOSITORY ${DEPENDENCY_CURL_REPOSITORY}
+        GIT_TAG ${DEPENDENCY_CURL_TAG}
         GIT_PROGRESS 1)
 
     FetchContent_GetProperties(curl_bundle)
diff --git a/CMake/FindOpenSSL.cmake b/CMake/FindOpenSSL.cmake
index dbe1d545..0b49b403 100644
--- a/CMake/FindOpenSSL.cmake
+++ b/CMake/FindOpenSSL.cmake
@@ -5,10 +5,9 @@ if(${BUILD_CURL_FROM_SOURCE})
     include(FetchContent)
 
     # make openssl into bundle
-    FetchContent_Declare(
-        openssl102
-        GIT_REPOSITORY https://github.com/openssl/openssl.git
-        GIT_TAG OpenSSL_1_0_2-stable
+    FetchContent_Declare(openssl102
+        GIT_REPOSITORY ${DEPENDENCY_OPENSSL_REPOSITORY}
+        GIT_TAG ${DEPENDENCY_OPENSSL_TAG}
         GIT_PROGRESS 1)
 
     FetchContent_GetProperties(openssl102)
diff --git a/CMake/FindRapidJSON.cmake b/CMake/FindRapidJSON.cmake
index f142f5cf..e411b368 100644
--- a/CMake/FindRapidJSON.cmake
+++ b/CMake/FindRapidJSON.cmake
@@ -1,19 +1,30 @@
-find_package(PkgConfig)
-if (PKG_CONFIG_FOUND)
-    pkg_check_modules(RAPIDJSON RapidJSON)
-endif()
+include(FetchContent)
+include(FindPackageHandleStandardArgs)
 
-if (NOT RAPIDJSON_FOUND)
+if(DEPENDENCY_RAPIDJSON_REPOSITORY)
     if (NOT rapidjson_POPULATED)
-      FetchContent_Populate(
-        rapidjson
-        GIT_REPOSITORY https://github.com/Tencent/rapidjson.git
-        GIT_TAG 80b6d1c83402a5785c486603c5611923159d0894
-        GIT_SUBMODULES ""
-      )
+        # header only, no need to build it
+        FetchContent_Populate(
+            rapidjson
+            GIT_REPOSITORY ${DEPENDENCY_RAPIDJSON_REPOSITORY}
+            GIT_TAG ${DEPENDENCY_RAPIDJSON_TAG}
+            GIT_SUBMODULES ""
+        )
     endif()
     FetchContent_GetProperties(rapidjson)
     set(RAPIDJSON_INCLUDE_DIRS "${rapidjson_SOURCE_DIR}/include")
+    set(RapidJSON_FOUND yes)
+else()
+    find_package(PkgConfig)
+    if (PKG_CONFIG_FOUND)
+        pkg_check_modules(RAPIDJSON RapidJSON)
+    endif()
+
+    if (NOT RAPIDJSON_FOUND)
+        find_path(RAPIDJSON_INCLUDE_DIRS rapidjson/document.h)
+        find_package_handle_standard_args(RapidJSON DEFAULT_MSG
+                                          RAPIDJSON_INCLUDE_DIRS)
+    endif()
 endif()
 
 add_definitions("-DRAPIDJSON_HAS_STDSTRING=1")
diff --git a/CMake/Findaio.cmake b/CMake/Findaio.cmake
index eca99351..3f13ebe9 100644
--- a/CMake/Findaio.cmake
+++ b/CMake/Findaio.cmake
@@ -5,4 +5,13 @@ find_library(AIO_LIBRARIES aio)
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(aio DEFAULT_MSG AIO_LIBRARIES AIO_INCLUDE_DIR)
 
+if(AIO_FOUND AND NOT TARGET AIO::aio)
+  add_library(AIO::aio UNKNOWN IMPORTED)
+  set_target_properties(
+    AIO::aio
+    PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+               IMPORTED_LOCATION "${AIO_LIBRARIES}"
+               INTERFACE_INCLUDE_DIRECTORIES "${AIO_INCLUDE_DIR}")
+endif()
+
 mark_as_advanced(AIO_INCLUDE_DIR AIO_LIBRARIES)
\ No newline at end of file
diff --git a/CMake/Finde2fs.cmake b/CMake/Finde2fs.cmake
index a36f51f3..3bb149e2 100644
--- a/CMake/Finde2fs.cmake
+++ b/CMake/Finde2fs.cmake
@@ -1,16 +1,16 @@
-if(NOT ORIGIN_EXT2FS)
+if(DEPENDENCY_E2FSPROGS_REPOSITORY)
     message("Add and build standalone libext2fs")
     include(FetchContent)
-    FetchContent_Declare(
-        e2fsprogs
-        GIT_REPOSITORY https://github.com/data-accelerator/e2fsprogs.git
-        GIT_TAG 404deb95e6b0ed0ceb0148d289977e65bee7f8d0
+
+    FetchContent_Declare(e2fsprogs
+        GIT_REPOSITORY ${DEPENDENCY_E2FSPROGS_REPOSITORY}
+        GIT_TAG ${DEPENDENCY_E2FSPROGS_TAG}
     )
     FetchContent_GetProperties(e2fsprogs)
 
     if(NOT TARGET libext2fs_build)
         FetchContent_MakeAvailable(e2fsprogs)
-        set(LIBEXT2FS_INSTALL_DIR ${e2fsprogs_SOURCE_DIR}/build/libext2fs CACHE STRING "")
+        set(LIBEXT2FS_INSTALL_DIR ${e2fsprogs_SOURCE_DIR}/build/v1.47.0-opt CACHE STRING "")
         set(E2FS_RESIZE_DIR ${e2fsprogs_SOURCE_DIR}/build/resize CACHE STRING "path to e2fsprogs resize build dir")
         set(E2FS_INSTALL_LIB_DIR ${LIBEXT2FS_INSTALL_DIR}/lib CACHE STRING "path to e2fsprogs install-libs output")
 
@@ -32,20 +32,53 @@ if(NOT ORIGIN_EXT2FS)
     set(E2FS_FOUND yes)
     set(E2FS_LIBRARY ${LIBEXT2FS_INSTALL_DIR}/lib/libext2fs.so)
     set(E2FS_COM_ERR_LIBRARY ${e2fsprogs_SOURCE_DIR}/build/lib/libcom_err.a)
+    # E2FS_LIBRARIES is what photon's own build consumes, overlaybd links the
+    # imported targets below instead.
     set(E2FS_LIBRARIES ${E2FS_LIBRARY} ${E2FS_COM_ERR_LIBRARY})
     set(E2FS_INCLUDE_DIR ${LIBEXT2FS_INSTALL_DIR}/include)
     set(E2FS_INCLUDE_DIRS ${E2FS_INCLUDE_DIR})
 
-    if(NOT TARGET libext2fs)
-        add_library(libext2fs UNKNOWN IMPORTED)
-    endif()
-    add_dependencies(libext2fs libext2fs_build)
-
+    # The libraries and headers only appear once libext2fs_build has run, but
+    # imported targets validate INTERFACE_INCLUDE_DIRECTORIES at configure time.
+    file(MAKE_DIRECTORY ${E2FS_INCLUDE_DIR})
 else()
     find_path(E2FS_INCLUDE_DIRS ext2fs/ext2fs.h)
-    find_library(E2FS_LIBRARIES ext2fs)
+    find_library(E2FS_LIBRARY ext2fs)
+    find_library(E2FS_COM_ERR_LIBRARY com_err)
+    set(E2FS_LIBRARIES ${E2FS_LIBRARY})
+
+    find_package_handle_standard_args(e2fs DEFAULT_MSG E2FS_LIBRARY
+                                      E2FS_INCLUDE_DIRS)
 endif()
 
-find_package_handle_standard_args(e2fs DEFAULT_MSG E2FS_LIBRARIES E2FS_INCLUDE_DIRS)
+if(E2FS_FOUND)
+    if(E2FS_COM_ERR_LIBRARY AND NOT TARGET E2FSPROGS::libcom_err)
+        add_library(E2FSPROGS::libcom_err UNKNOWN IMPORTED)
+        set_target_properties(
+            E2FSPROGS::libcom_err
+            PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                       IMPORTED_LOCATION "${E2FS_COM_ERR_LIBRARY}")
+        if(DEPENDENCY_E2FSPROGS_REPOSITORY)
+            add_dependencies(E2FSPROGS::libcom_err libext2fs_build)
+        endif()
+    endif()
+
+    if(NOT TARGET E2FSPROGS::libext2fs)
+        add_library(E2FSPROGS::libext2fs UNKNOWN IMPORTED)
+        set_target_properties(
+            E2FSPROGS::libext2fs
+            PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                       IMPORTED_LOCATION "${E2FS_LIBRARY}"
+                       INTERFACE_INCLUDE_DIRECTORIES "${E2FS_INCLUDE_DIRS}")
+        # libext2fs calls into com_err, which therefore has to follow it.
+        if(TARGET E2FSPROGS::libcom_err)
+            set_property(TARGET E2FSPROGS::libext2fs PROPERTY
+                         INTERFACE_LINK_LIBRARIES E2FSPROGS::libcom_err)
+        endif()
+        if(DEPENDENCY_E2FSPROGS_REPOSITORY)
+            add_dependencies(E2FSPROGS::libext2fs libext2fs_build)
+        endif()
+    endif()
+endif()
 
-mark_as_advanced(E2FS_INCLUDE_DIRS E2FS_LIBRARIES)
+mark_as_advanced(E2FS_INCLUDE_DIRS E2FS_LIBRARY E2FS_COM_ERR_LIBRARY)
diff --git a/CMake/Finderofsutils.cmake b/CMake/Finderofsutils.cmake
new file mode 100644
index 00000000..ddd77d77
--- /dev/null
+++ b/CMake/Finderofsutils.cmake
@@ -0,0 +1,62 @@
+include(FetchContent)
+include(FindPackageHandleStandardArgs)
+
+if(DEPENDENCY_EROFS_UTILS_REPOSITORY)
+    FetchContent_Declare(erofs-utils
+        GIT_REPOSITORY ${DEPENDENCY_EROFS_UTILS_REPOSITORY}
+        GIT_TAG        ${DEPENDENCY_EROFS_UTILS_TAG}
+    )
+    FetchContent_GetProperties(erofs-utils)
+    if(NOT erofs-utils_POPULATED)
+        FetchContent_Populate(erofs-utils)
+    endif()
+
+    set(EROFS_LIB_INCLUDE_DIR "${erofs-utils_SOURCE_DIR}/include/" CACHE PATH "erofs-utils include path.")
+    set(EROFS_CONFIG_FILE "${erofs-utils_SOURCE_DIR}/config.h" CACHE PATH "erofs-utils config file.")
+    set(EROFS_LIB_STATIC "${erofs-utils_SOURCE_DIR}/lib/.libs/liberofs.a" CACHE PATH "erofs-utils static lib.")
+
+    # liberofs.a and config.h are produced at build time; make sure the include
+    # dir exists at configure time so EROFS::utils' INTERFACE_INCLUDE_DIRECTORIES
+    # passes CMake's imported-target path validation.
+    file(MAKE_DIRECTORY ${EROFS_LIB_INCLUDE_DIR})
+
+    # build erofs-utils with its own autotools at build time (not configure time)
+    if(NOT TARGET liberofs_build)
+        add_custom_command(
+            OUTPUT ${EROFS_LIB_STATIC}
+            WORKING_DIRECTORY ${erofs-utils_SOURCE_DIR}
+            COMMAND ./autogen.sh &&
+                    ./configure --disable-lz4 --disable-lzma --without-libzstd
+                        --without-uuid --disable-multithreading &&
+                    make)
+        add_custom_target(liberofs_build DEPENDS ${EROFS_LIB_STATIC})
+    endif()
+
+    set(erofsutils_FOUND yes)
+    if(NOT TARGET EROFS::utils)
+        add_library(EROFS::utils STATIC IMPORTED)
+    endif()
+    add_dependencies(EROFS::utils liberofs_build)
+else()
+    find_path(EROFS_LIB_INCLUDE_DIR erofs/tar.h)
+    find_library(EROFS_LIB_STATIC erofs)
+    # config.h is generated by erofs-utils' own configure and force-included as
+    # a compile option below, so a local installation has to provide it as well
+    find_file(EROFS_CONFIG_FILE erofs/config.h)
+
+    find_package_handle_standard_args(erofsutils DEFAULT_MSG EROFS_LIB_STATIC
+                                      EROFS_LIB_INCLUDE_DIR EROFS_CONFIG_FILE)
+
+    if(erofsutils_FOUND AND NOT TARGET EROFS::utils)
+        add_library(EROFS::utils STATIC IMPORTED)
+    endif()
+endif()
+
+if(TARGET EROFS::utils)
+    set_target_properties(
+        EROFS::utils
+        PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                   IMPORTED_LOCATION "${EROFS_LIB_STATIC}"
+                   INTERFACE_INCLUDE_DIRECTORIES "${EROFS_LIB_INCLUDE_DIR}"
+                   INTERFACE_COMPILE_OPTIONS "-include${EROFS_CONFIG_FILE}")
+endif()
diff --git a/CMake/Findgflags.cmake b/CMake/Findgflags.cmake
new file mode 100644
index 00000000..8a5497d2
--- /dev/null
+++ b/CMake/Findgflags.cmake
@@ -0,0 +1,16 @@
+find_path(GFLAGS_INCLUDE_DIRS gflags/gflags.h)
+
+find_library(GFLAGS_LIBRARIES gflags)
+
+find_package_handle_standard_args(gflags DEFAULT_MSG GFLAGS_LIBRARIES
+                                  GFLAGS_INCLUDE_DIRS)
+
+if(gflags_FOUND AND NOT TARGET GFLAGS::gflags)
+    add_library(GFLAGS::gflags UNKNOWN IMPORTED)
+    set_target_properties(
+        GFLAGS::gflags
+        PROPERTIES IMPORTED_LOCATION "${GFLAGS_LIBRARIES}"
+                   INTERFACE_INCLUDE_DIRECTORIES "${GFLAGS_INCLUDE_DIRS}")
+endif()
+
+mark_as_advanced(GFLAGS_INCLUDE_DIRS GFLAGS_LIBRARIES)
diff --git a/CMake/Findgtest.cmake b/CMake/Findgtest.cmake
new file mode 100644
index 00000000..28ca56a6
--- /dev/null
+++ b/CMake/Findgtest.cmake
@@ -0,0 +1,16 @@
+find_path(GTEST_INCLUDE_DIRS gtest/gtest.h)
+
+find_library(GTEST_LIBRARIES gtest)
+
+find_package_handle_standard_args(gtest DEFAULT_MSG GTEST_LIBRARIES
+                                  GTEST_INCLUDE_DIRS)
+
+if(gtest_FOUND AND NOT TARGET GTEST::gtest)
+    add_library(GTEST::gtest UNKNOWN IMPORTED)
+    set_target_properties(
+        GTEST::gtest
+        PROPERTIES IMPORTED_LOCATION "${GTEST_LIBRARIES}"
+                   INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIRS}")
+endif()
+
+mark_as_advanced(GTEST_INCLUDE_DIRS GTEST_LIBRARIES)
diff --git a/CMake/Findphoton.cmake b/CMake/Findphoton.cmake
index 1c196f75..113fd889 100644
--- a/CMake/Findphoton.cmake
+++ b/CMake/Findphoton.cmake
@@ -1,5 +1,10 @@
 include(FetchContent)
+include(FindPackageHandleStandardArgs)
 set(FETCHCONTENT_QUIET false)
+
+# PHOTON_ENABLE_RESIZE is also consumed by our own sources, so define it
+# regardless of where photon comes from. A locally installed photon is then
+# expected to provide extfs and resize as well.
 set(PHOTON_ENABLE_EXTFS ON)
 
 if(NOT ORIGIN_EXT2FS)
@@ -7,28 +12,92 @@ if(NOT ORIGIN_EXT2FS)
   add_definitions(-DPHOTON_ENABLE_RESIZE)
 endif()
 
-FetchContent_Declare(
-  photon
-  GIT_REPOSITORY https://github.com/alibaba/PhotonLibOS.git
-  GIT_TAG 0178d14499d8639759a81e32ad58da5226df5e9b
-)
+if(DEPENDENCY_PHOTON_REPOSITORY)
+  FetchContent_Declare(photon
+    GIT_REPOSITORY ${DEPENDENCY_PHOTON_REPOSITORY}
+    GIT_TAG ${DEPENDENCY_PHOTON_TAG}
+  )
+
+  if(BUILD_TESTING)
+    set(BUILD_TESTING 0)
+    FetchContent_MakeAvailable(photon)
+    set(BUILD_TESTING 1)
+  else()
+    FetchContent_MakeAvailable(photon)
+  endif()
+
+  # photon_obj is only defined by photon's own build
+  if (BUILD_CURL_FROM_SOURCE)
+    find_package(OpenSSL REQUIRED)
+    find_package(CURL REQUIRED)
+    add_dependencies(photon_obj CURL::libcurl OpenSSL::SSL OpenSSL::Crypto)
+  endif()
 
-if(BUILD_TESTING)
-  set(BUILD_TESTING 0)
-  FetchContent_MakeAvailable(photon)
-  set(BUILD_TESTING 1)
+  if(NOT ORIGIN_EXT2FS)
+    add_dependencies(photon_obj libext2fs_build)
+  endif()
+
+  # Consume photon as plain archives rather than through its photon_static
+  # target: the latter also propagates photon's own third-party dependencies,
+  # whose declaration (which libraries, in which order) is an implementation
+  # detail that has changed between photon versions. overlaybd brings those
+  # dependencies itself, see the external_lib target in the top-level
+  # CMakeLists.txt.
+  set(PHOTON_INCLUDE_DIR ${photon_SOURCE_DIR}/include/)
+  set(PHOTON_LIBRARY ${photon_BINARY_DIR}/output/libphoton_sole.a)
+  set(PHOTON_EASY_WEAK_LIBRARY ${photon_BINARY_DIR}/output/libeasy_weak.a)
+  set(photon_FOUND yes)
 else()
-  FetchContent_MakeAvailable(photon)
-endif()
+  # A locally installed photon has no photon_BINARY_DIR, look the archives up
+  # instead. photon_sole is photon's own archive and the one paired with the
+  # separate weak-symbol archives; libphoton.a is the merged one, which already
+  # bundles them and is used as a fallback.
+  find_path(PHOTON_INCLUDE_DIR photon/photon.h)
+  find_library(PHOTON_LIBRARY NAMES photon_sole photon)
+  find_library(PHOTON_EASY_WEAK_LIBRARY NAMES easy_weak)
 
-if (BUILD_CURL_FROM_SOURCE)
-  find_package(OpenSSL REQUIRED)
-  find_package(CURL REQUIRED)
-  add_dependencies(photon_obj CURL::libcurl OpenSSL::SSL OpenSSL::Crypto)
+  find_package_handle_standard_args(photon DEFAULT_MSG PHOTON_LIBRARY
+                                    PHOTON_INCLUDE_DIR)
 endif()
 
-if(NOT ORIGIN_EXT2FS)
-  add_dependencies(photon_obj libext2fs)
-endif()
+if(photon_FOUND)
+  if(NOT TARGET PHOTON::photonlib)
+    add_library(PHOTON::photonlib STATIC IMPORTED)
+    set_target_properties(
+      PHOTON::photonlib
+      PROPERTIES IMPORTED_LOCATION "${PHOTON_LIBRARY}"
+                 INTERFACE_INCLUDE_DIRECTORIES "${PHOTON_INCLUDE_DIR}")
+  endif()
+  set(PHOTON_ARCHIVES PHOTON::photonlib)
+
+  # Absent when a locally installed photon only ships the merged libphoton.a.
+  if(PHOTON_EASY_WEAK_LIBRARY)
+    if(NOT TARGET PHOTON::easy_weak)
+      add_library(PHOTON::easy_weak STATIC IMPORTED)
+      set_target_properties(
+        PHOTON::easy_weak
+        PROPERTIES IMPORTED_LOCATION "${PHOTON_EASY_WEAK_LIBRARY}")
+    endif()
+    list(APPEND PHOTON_ARCHIVES PHOTON::easy_weak)
+  endif()
 
-set(PHOTON_INCLUDE_DIR ${photon_SOURCE_DIR}/include/)
+  # The weak overrides have to follow the archive referring to them on the link
+  # line, hence the aggregate rather than a plain list at every call site.
+  if(NOT TARGET PHOTON::photon)
+    add_library(PHOTON::photon INTERFACE IMPORTED)
+    set_target_properties(
+      PHOTON::photon
+      PROPERTIES INTERFACE_LINK_LIBRARIES "${PHOTON_ARCHIVES}"
+                 INTERFACE_INCLUDE_DIRECTORIES "${PHOTON_INCLUDE_DIR}")
+  endif()
+
+  # When photon is built here, the archives above only exist once its own
+  # targets have run. The dependency is followed through the aggregate, so
+  # everything linking PHOTON::photon waits for them.
+  if(DEPENDENCY_PHOTON_REPOSITORY)
+    add_dependencies(PHOTON::photonlib photon_static)
+    if(TARGET PHOTON::easy_weak)
+      add_dependencies(PHOTON::easy_weak easy_weak)
+    endif()
+  endif()
+endif()
diff --git a/CMake/Findtcmu.cmake b/CMake/Findtcmu.cmake
index 92d6ec65..30fe4ec9 100644
--- a/CMake/Findtcmu.cmake
+++ b/CMake/Findtcmu.cmake
@@ -1,17 +1,48 @@
 include(FetchContent)
+include(FindPackageHandleStandardArgs)
 set(FETCHCONTENT_QUIET false)
 
-FetchContent_Declare(
-  tcmu
-  GIT_REPOSITORY https://github.com/data-accelerator/photon-libtcmu.git
-  GIT_TAG 813fd65361bb2f348726b9c41478a44211847614
-)
+if(DEPENDENCY_TCMU_REPOSITORY)
+  FetchContent_Declare(tcmu
+    GIT_REPOSITORY ${DEPENDENCY_TCMU_REPOSITORY}
+    GIT_TAG ${DEPENDENCY_TCMU_TAG}
+  )
 
-if(BUILD_TESTING)
-  set(BUILD_TESTING 0)
-  FetchContent_MakeAvailable(tcmu)
-  set(BUILD_TESTING 1)
+  # tcmu itself links against libnl, which is only available as a shared
+  # library on the target systems. Restore the normal suffix list while it
+  # configures itself and its own dependencies, then switch back.
+  set(_tcmu_suffixes ${CMAKE_FIND_LIBRARY_SUFFIXES})
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ${CMAKE_FIND_LIBRARY_SUFFIXES_SAVE})
+
+  if(BUILD_TESTING)
+    set(BUILD_TESTING 0)
+    FetchContent_MakeAvailable(tcmu)
+    set(BUILD_TESTING 1)
+  else()
+    FetchContent_MakeAvailable(tcmu)
+  endif()
+  set(TCMU_INCLUDE_DIR ${tcmu_SOURCE_DIR}/)
+  set(tcmu_FOUND yes)
+
+  set(CMAKE_FIND_LIBRARY_SUFFIXES ${_tcmu_suffixes})
 else()
-  FetchContent_MakeAvailable(tcmu)
+  find_path(TCMU_INCLUDE_DIR libtcmu.h)
+  find_library(TCMU_LIBRARY tcmu)
+
+  find_package_handle_standard_args(tcmu DEFAULT_MSG TCMU_LIBRARY
+                                    TCMU_INCLUDE_DIR)
+endif()
+
+if(tcmu_FOUND AND NOT TARGET TCMU::tcmu)
+  if(DEPENDENCY_TCMU_REPOSITORY)
+    # tcmu_static is defined by tcmu's own build
+    add_library(TCMU::tcmu ALIAS tcmu_static)
+  else()
+    add_library(TCMU::tcmu STATIC IMPORTED)
+    set_target_properties(
+      TCMU::tcmu
+      PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                 IMPORTED_LOCATION "${TCMU_LIBRARY}"
+                 INTERFACE_INCLUDE_DIRECTORIES "${TCMU_INCLUDE_DIR}")
+  endif()
 endif()
-set(TCMU_INCLUDE_DIR ${tcmu_SOURCE_DIR}/)
diff --git a/CMake/Findyamlcpp.cmake b/CMake/Findyamlcpp.cmake
new file mode 100644
index 00000000..ad1518d4
--- /dev/null
+++ b/CMake/Findyamlcpp.cmake
@@ -0,0 +1,25 @@
+include(FetchContent)
+include(FindPackageHandleStandardArgs)
+
+if(DEPENDENCY_YAML_CPP_REPOSITORY)
+  FetchContent_Declare(yaml-cpp
+    GIT_REPOSITORY ${DEPENDENCY_YAML_CPP_REPOSITORY}
+    GIT_TAG ${DEPENDENCY_YAML_CPP_TAG}
+  )
+  FetchContent_MakeAvailable(yaml-cpp)
+  set(yamlcpp_FOUND yes)
+else()
+  find_path(YAMLCPP_INCLUDE_DIRS yaml-cpp/yaml.h)
+  find_library(YAMLCPP_LIBRARIES yaml-cpp)
+
+  find_package_handle_standard_args(yamlcpp DEFAULT_MSG YAMLCPP_LIBRARIES
+                                    YAMLCPP_INCLUDE_DIRS)
+
+  if(yamlcpp_FOUND AND NOT TARGET yaml-cpp)
+    add_library(yaml-cpp UNKNOWN IMPORTED)
+    set_target_properties(
+      yaml-cpp
+      PROPERTIES INTERFACE_INCLUDE_DIRECTORIES "${YAMLCPP_INCLUDE_DIRS}"
+                 IMPORTED_LOCATION "${YAMLCPP_LIBRARIES}")
+  endif()
+endif()
diff --git a/CMake/Findzstd.cmake b/CMake/Findzstd.cmake
new file mode 100644
index 00000000..5f5ca477
--- /dev/null
+++ b/CMake/Findzstd.cmake
@@ -0,0 +1,17 @@
+find_path(ZSTD_INCLUDE_DIRS zstd.h)
+
+find_library(ZSTD_LIBRARIES zstd)
+
+find_package_handle_standard_args(zstd DEFAULT_MSG ZSTD_LIBRARIES
+                                  ZSTD_INCLUDE_DIRS)
+
+if(zstd_FOUND AND NOT TARGET ZSTD::zstd)
+    add_library(ZSTD::zstd UNKNOWN IMPORTED)
+    set_target_properties(
+        ZSTD::zstd
+        PROPERTIES IMPORTED_LINK_INTERFACE_LANGUAGES "C"
+                   IMPORTED_LOCATION "${ZSTD_LIBRARIES}"
+                   INTERFACE_INCLUDE_DIRECTORIES "${ZSTD_INCLUDE_DIRS}")
+endif()
+
+mark_as_advanced(ZSTD_INCLUDE_DIRS ZSTD_LIBRARIES)
diff --git a/CMakeLists.txt b/CMakeLists.txt
index cf5852a7..ba23a23e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,27 +1,40 @@
 cmake_minimum_required(VERSION 3.14)
 
 project(
-  overlaybd
-  LANGUAGES C CXX
+    overlaybd
+    LANGUAGES C CXX
 )
-enable_language(C)
 
-set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
-set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -DNDEBUG -g")
+#---------------------------------------------------------------------
+# Options
+#---------------------------------------------------------------------
+option(FULL_STATIC "make all binary output depends only libc dynamic libs" on)
+option(BUILD_CURL_FROM_SOURCE "Compile static libcurl" off)
+option(BUILD_STREAM_CONVERTOR "Build the stream convertor" on)
+option(ORIGIN_EXT2FS "Use original libext2fs" off)
+option(ENABLE_OCF_CACHE "Build the OCF cache backend (requires the ocf submodule)" on)
+option(ENABLE_QAT "Build the QAT compression backend" off)
+option(ENABLE_DSA "Build the DSA crc32 backend (requires the DML submodule)" off)
+option(ENABLE_ISAL "Build the ISA-L crc32 backend (requires the isa-l submodule)" off)
 
-if (NOT (CMAKE_SYSTEM_PROCESSOR STREQUAL x86_64) AND NOT (CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64) AND NOT (CMAKE_SYSTEM_PROCESSOR STREQUAL arm64))
-    message(FATAL_ERROR "Unknown CPU architecture ${CMAKE_SYSTEM_PROCESSOR}")
-endif ()
+set(OBD_VER "overlaybd/0.0.0-undefined" CACHE STRING "Overlaybd version")
 
-option(OBD_VER "Overlaybd version" "overlaybd/0.0.0-undefined")
+#---------------------------------------------------------------------
+# Toolchain
+#---------------------------------------------------------------------
+if(NOT CMAKE_SYSTEM_PROCESSOR MATCHES "^(x86_64|aarch64|arm64)$")
+    message(FATAL_ERROR "Unknown CPU architecture ${CMAKE_SYSTEM_PROCESSOR}")
+endif()
 
-set(LIBRARY_OUTPUT_PATH "${CMAKE_SOURCE_DIR}/build/output")
-set(EXECUTABLE_OUTPUT_PATH "${CMAKE_SOURCE_DIR}/build/output")
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED on)
+set(CMAKE_POSITION_INDEPENDENT_CODE on) # -fpic
+set(CMAKE_EXPORT_COMPILE_COMMANDS on)
 
-set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_CURRENT_SOURCE_DIR}/CMake")
+set(CMAKE_CXX_FLAGS_RELEASE "-O2 -DNDEBUG")
+set(CMAKE_CXX_FLAGS_RELWITHDEBINFO "-O2 -DNDEBUG -g")
 
-set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fpic -Wall -Werror=sign-compare")
-set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fpic -Wall -Werror=sign-compare -DOVERLAYBD_VER=${OBD_VER}")
+add_definitions(-DOVERLAYBD_VER=${OBD_VER})
 
 # GCC 13+ (default on Azure Linux 4.0 with GCC 15) no longer transitively
 # includes <cstdint> from other standard headers. Force-include it for every
@@ -30,54 +43,464 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fpic -Wall -Werror=sign-compare -DOVERL
 # without needing to upgrade those pins. C sources (e.g. OCF) are unaffected.
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -include cstdint")
 
-if ((CMAKE_SYSTEM_PROCESSOR STREQUAL aarch64) OR (CMAKE_SYSTEM_PROCESSOR STREQUAL arm64))
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=armv8-a+crc -fsigned-char -fno-stack-protector -fomit-frame-pointer")
-endif ()
+if(CMAKE_SYSTEM_PROCESSOR MATCHES "^(aarch64|arm64)$")
+    # +crc also covers what crc32_lib below needs on this architecture
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=armv8-a+crc -fsigned-char\
+ -fno-stack-protector -fomit-frame-pointer")
+endif()
 
 set(CMAKE_CXX_STANDARD_LIBRARIES "-static-libgcc ${CMAKE_CXX_STANDARD_LIBRARIES}")
-find_library(STATIC_LIBSTDC++ libstdc++.a PATHS /usr/lib/gcc/*/*)
-if(NOT ${STATIC_LIBSTDC++} STREQUAL "STATIC_LIBSTDC++-NOTFOUND")
-  set(CMAKE_CXX_STANDARD_LIBRARIES "-static-libstdc++ ${CMAKE_CXX_STANDARD_LIBRARIES}")
+find_library(STATIC_LIBSTDCXX libstdc++.a PATHS /usr/lib/gcc/*/*)
+if(STATIC_LIBSTDCXX)
+    set(CMAKE_CXX_STANDARD_LIBRARIES "-static-libstdc++ ${CMAKE_CXX_STANDARD_LIBRARIES}")
 endif()
 
-find_library(LIBZSTD libzstd.a PATHS /usr/lib/x86_64-linux-gnu/* /usr/lib64/*)
-if(${LIBZSTD} STREQUAL "LIBZSTD-NOTFOUND")
-  message("libzstd.a not found, try to find shared library")
-  find_library(LIBZSTD libzstd.so PATHS /usr/lib/x86_64-linux-gnu/* /usr/lib64/*)
+# Kept under the source tree: the CI jobs and the packaging scripts expect the
+# binaries at build/output regardless of where cmake was invoked from.
+set(CMAKE_ARCHIVE_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/build/output")
+set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/build/output")
+set(CMAKE_RUNTIME_OUTPUT_DIRECTORY "${CMAKE_SOURCE_DIR}/build/output")
+
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake")
+include(FindPackageHandleStandardArgs)
+
+# Prefer static archives for everything we link. Findtcmu.cmake temporarily
+# restores the saved list, as libnl is only shipped as a shared library.
+set(CMAKE_FIND_LIBRARY_SUFFIXES_SAVE ${CMAKE_FIND_LIBRARY_SUFFIXES})
+if(FULL_STATIC)
+    set(CMAKE_FIND_LIBRARY_SUFFIXES ".a")
 endif()
 
-set(CMAKE_CXX_STANDARD 14)
-set(CMAKE_CXX_STANDARD_REQUIRED on)
-set(ENABLE_MIMIC_VDSO off)
+#---------------------------------------------------------------------
+# Sources of the dependencies
+#
+# For each dependency, setting DEPENDENCY_<DEP>_REPOSITORY selects where to
+# fetch and build it from, at DEPENDENCY_<DEP>_TAG. Setting the repository to
+# empty selects the locally installed one instead, which is then looked up with
+# the usual find_path()/find_library() (honoring CMAKE_PREFIX_PATH etc.), e.g.
+#
+#   cmake -DDEPENDENCY_PHOTON_REPOSITORY= -DCMAKE_PREFIX_PATH=/path/to/deps ...
+#
+# Note that a locally installed dependency is used as is: it is the caller's
+# responsibility to make sure it is compatible, since the tag below is then
+# neither used nor checked.
+#---------------------------------------------------------------------
+set(DEPENDENCY_PHOTON_REPOSITORY "https://github.com/alibaba/PhotonLibOS.git"
+    CACHE STRING "repository of photon, empty to use the local installation")
+set(DEPENDENCY_PHOTON_TAG "62244b5a3726775cf70ad5c26a1345e562072094"
+    CACHE STRING "tag/commit of photon")
 
-option(BUILD_CURL_FROM_SOURCE "Compile static libcurl" off)
-option(BUILD_STREAM_CONVERTOR "Build the stream convertor" on)
-option(ORIGIN_EXT2FS "Use original libext2fs" off)
+set(DEPENDENCY_TCMU_REPOSITORY "https://github.com/data-accelerator/photon-libtcmu.git"
+    CACHE STRING "repository of photon-libtcmu, empty to use the local installation")
+set(DEPENDENCY_TCMU_TAG "813fd65361bb2f348726b9c41478a44211847614"
+    CACHE STRING "tag/commit of photon-libtcmu")
+
+set(DEPENDENCY_E2FSPROGS_REPOSITORY "https://github.com/data-accelerator/e2fsprogs.git"
+    CACHE STRING "repository of e2fsprogs, empty to use the local installation")
+set(DEPENDENCY_E2FSPROGS_TAG "404deb95e6b0ed0ceb0148d289977e65bee7f8d0"
+    CACHE STRING "tag/commit of e2fsprogs")
+
+set(DEPENDENCY_EROFS_UTILS_REPOSITORY "https://github.com/erofs/erofs-utils.git"
+    CACHE STRING "repository of erofs-utils, empty to use the local installation")
+set(DEPENDENCY_EROFS_UTILS_TAG "eec6f7a2755dfccc8f655aa37cf6f26db9164e60"
+    CACHE STRING "tag/commit of erofs-utils")
+
+set(DEPENDENCY_RAPIDJSON_REPOSITORY "https://github.com/Tencent/rapidjson.git"
+    CACHE STRING "repository of rapidjson, empty to use the local installation")
+set(DEPENDENCY_RAPIDJSON_TAG "80b6d1c83402a5785c486603c5611923159d0894"
+    CACHE STRING "tag/commit of rapidjson")
+
+# 0.9.0 includes the missing <cstdint> include (PR #1310) required to build with
+# GCC 15 (C23 default), e.g. on Azure Linux 4.0.
+set(DEPENDENCY_YAML_CPP_REPOSITORY "https://github.com/jbeder/yaml-cpp.git"
+    CACHE STRING "repository of yaml-cpp, empty to use the local installation")
+set(DEPENDENCY_YAML_CPP_TAG "yaml-cpp-0.9.0"
+    CACHE STRING "tag/commit of yaml-cpp")
 
-find_package(photon REQUIRED)
-find_package(tcmu REQUIRED)
+# curl and openssl default to the local installation, as building them from
+# source is only needed for fully static binaries. BUILD_CURL_FROM_SOURCE below
+# fills in the repositories known to work for that.
+set(DEPENDENCY_CURL_REPOSITORY ""
+    CACHE STRING "repository of curl, empty to use the local installation")
+set(DEPENDENCY_CURL_TAG "curl-7_42_1"
+    CACHE STRING "tag/commit of curl")
 
+set(DEPENDENCY_OPENSSL_REPOSITORY ""
+    CACHE STRING "repository of openssl, empty to use the local installation")
+set(DEPENDENCY_OPENSSL_TAG "OpenSSL_1_0_2-stable"
+    CACHE STRING "tag/commit of openssl")
+
+# ORIGIN_EXT2FS and BUILD_CURL_FROM_SOURCE predate the variables above and are
+# kept as shortcuts for them. They are also still consumed on their own, so keep
+# both forms in sync.
+if(ORIGIN_EXT2FS)
+    set(DEPENDENCY_E2FSPROGS_REPOSITORY "")
+elseif(NOT DEPENDENCY_E2FSPROGS_REPOSITORY)
+    set(ORIGIN_EXT2FS on)
+endif()
+if(BUILD_CURL_FROM_SOURCE)
+    if(NOT DEPENDENCY_CURL_REPOSITORY)
+        set(DEPENDENCY_CURL_REPOSITORY "https://github.com/curl/curl.git")
+    endif()
+    if(NOT DEPENDENCY_OPENSSL_REPOSITORY)
+        set(DEPENDENCY_OPENSSL_REPOSITORY "https://github.com/openssl/openssl.git")
+    endif()
+elseif(DEPENDENCY_CURL_REPOSITORY OR DEPENDENCY_OPENSSL_REPOSITORY)
+    set(BUILD_CURL_FROM_SOURCE on)
+endif()
+
+#---------------------------------------------------------------------
+# External dependencies
+#---------------------------------------------------------------------
+# e2fs is looked up before photon: photon's own build looks it up as well, and
+# photon_obj is ordered after the libext2fs build declared by this call.
+find_package(e2fs REQUIRED)      # E2FSPROGS::libext2fs E2FSPROGS::libcom_err
+find_package(photon REQUIRED)    # PHOTON::photon
+find_package(tcmu REQUIRED)      # TCMU::tcmu
+find_package(CURL REQUIRED)      # CURL::libcurl
+find_package(OpenSSL REQUIRED)   # OpenSSL::SSL OpenSSL::Crypto
+find_package(ZLIB REQUIRED)      # ZLIB::ZLIB
+find_package(aio REQUIRED)       # AIO::aio
+find_package(zstd REQUIRED)      # ZSTD::zstd
+find_package(erofsutils REQUIRED) # EROFS::utils
+find_package(RapidJSON REQUIRED) # (header only) RAPIDJSON_INCLUDE_DIRS
 if(BUILD_STREAM_CONVERTOR)
-    find_package(yaml-cpp)
-    if (NOT yaml-cpp_FOUND)
-        FetchContent_Declare(
-            yaml-cpp
-            GIT_REPOSITORY https://github.com/jbeder/yaml-cpp.git
-            # 0.9.0 includes the missing <cstdint> include (PR #1310) required
-            # to build with GCC 15 (C23 default), e.g. on Azure Linux 4.0.
-            GIT_TAG yaml-cpp-0.9.0
-        )
-        FetchContent_MakeAvailable(yaml-cpp)
+    find_package(yamlcpp REQUIRED) # yaml-cpp
+endif()
+
+# Everything overlaybd links besides its own libraries, declared once here
+# instead of being spelled out by every target.
+#
+# photon and overlaybd share these: photon references curl, openssl, zlib and
+# libaio, and overlaybd uses openssl and zlib on its own as well. They are all
+# static in the default configuration, so their relative order on the link line
+# matters -- a single list is what keeps that order right, in particular
+# libcurl.a needing openssl and zlib to follow it.
+#
+# Dependencies only some of the binaries need are deliberately not part of this,
+# E2FSPROGS::libext2fs in particular: it is linked by the targets that go
+# through photon's extfs support, so that the ones that do not are not tied to
+# libext2fs.so at runtime.
+add_library(external_lib INTERFACE)
+target_include_directories(external_lib INTERFACE ${RAPIDJSON_INCLUDE_DIRS})
+target_link_libraries(external_lib INTERFACE
+    PHOTON::photon
+    CURL::libcurl
+    OpenSSL::SSL
+    OpenSSL::Crypto
+    ZLIB::ZLIB
+    AIO::aio
+    pthread
+    rt
+    dl
+    resolv
+)
+if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    # photon needs libgcc for the hidden __cpu_model symbol
+    target_link_libraries(external_lib INTERFACE gcc)
+endif()
+
+#---------------------------------------------------------------------
+# overlaybd libraries
+#
+# Warnings are errors for the code that follows, i.e. ours. The call is
+# deliberately placed after the find_package()es above, so that the
+# dependencies they add as subprojects keep their own warning settings.
+#---------------------------------------------------------------------
+add_compile_options(-Wall -Werror)
+
+add_library(checksum_lib STATIC src/tools/sha256file.cpp)
+target_link_libraries(checksum_lib PUBLIC external_lib)
+
+add_library(registryfs_lib STATIC
+    src/overlaybd/registryfs/registryfs.cpp
+    src/overlaybd/registryfs/registryfs_v2.cpp
+)
+target_link_libraries(registryfs_lib PUBLIC external_lib)
+
+add_library(lsmt_lib STATIC
+    src/overlaybd/lsmt/file.cpp
+    src/overlaybd/lsmt/index.cpp
+)
+target_link_libraries(lsmt_lib PUBLIC external_lib)
+
+# crc32c.cpp is the only source built for a specific ISA extension, hence its
+# own library rather than compile options on zfile_lib as a whole.
+add_library(crc32_lib STATIC src/overlaybd/zfile/crc32/crc32c.cpp)
+target_link_libraries(crc32_lib PUBLIC external_lib)
+if(CMAKE_SYSTEM_PROCESSOR STREQUAL x86_64)
+    target_compile_options(crc32_lib PUBLIC -msse4.2 -mcrc32)
+endif()
+
+add_library(zfile_lib STATIC
+    src/overlaybd/zfile/compressor.cpp
+    src/overlaybd/zfile/zfile.cpp
+    src/overlaybd/zfile/lz4/lz4.c
+)
+target_link_libraries(zfile_lib PUBLIC external_lib crc32_lib ZSTD::zstd)
+
+add_library(zstd_lib STATIC src/overlaybd/zstd/zstdfile.cpp)
+target_link_libraries(zstd_lib PUBLIC external_lib ZSTD::zstd)
+
+add_library(gzip_lib STATIC src/overlaybd/gzip/gz.cpp)
+target_link_libraries(gzip_lib PUBLIC external_lib checksum_lib)
+
+add_library(gzindex_lib STATIC
+    src/overlaybd/gzindex/gzfile.cpp
+    src/overlaybd/gzindex/gzip_index_create.cpp
+)
+target_link_libraries(gzindex_lib PUBLIC external_lib)
+
+add_library(cache_lib STATIC
+    src/overlaybd/cache/cache.cpp
+    src/overlaybd/cache/cached_fs.cpp
+    src/overlaybd/cache/store.cpp
+    src/overlaybd/cache/full_file_cache/cache_pool.cpp
+    src/overlaybd/cache/full_file_cache/cache_store.cpp
+    src/overlaybd/cache/download_cache/download_cache.cpp
+    src/overlaybd/cache/gzip_cache/cached_fs.cpp
+)
+target_link_libraries(cache_lib PUBLIC external_lib gzindex_lib)
+
+# EROFS::utils propagates its include dir and the "-include config.h" compile
+# option, and orders erofs_lib after the erofs-utils build
+add_library(erofs_lib STATIC
+    src/overlaybd/tar/erofs/erofs_common.cpp
+    src/overlaybd/tar/erofs/erofs_fs.cpp
+    src/overlaybd/tar/erofs/liberofs.cpp
+)
+target_link_libraries(erofs_lib PUBLIC external_lib PRIVATE EROFS::utils)
+
+add_library(tar_lib STATIC
+    src/overlaybd/tar/header.cpp
+    src/overlaybd/tar/libtar.cpp
+    src/overlaybd/tar/tar_file.cpp
+    src/overlaybd/tar/whiteout.cpp
+)
+target_link_libraries(tar_lib PUBLIC external_lib PRIVATE erofs_lib)
+
+#---------------------------------------------------------------------
+# Optional acceleration backends
+#---------------------------------------------------------------------
+if(ENABLE_QAT)
+    find_path(QAT_INCLUDE_DIR NAMES qat/cpa.h PATHS /usr/include/qat /usr/local/include/qat)
+    find_library(QAT_LIBRARY NAMES qat)
+    find_library(USDM_LIBRARY NAMES usdm)
+    if(NOT (QAT_INCLUDE_DIR AND QAT_LIBRARY AND USDM_LIBRARY))
+        message(FATAL_ERROR "ENABLE_QAT=on but the QAT headers/libraries were not found")
     endif()
+    target_sources(zfile_lib PRIVATE src/overlaybd/zfile/lz4/lz4-qat.cpp)
+    target_compile_definitions(zfile_lib PUBLIC ENABLE_QAT)
+    target_include_directories(zfile_lib PUBLIC ${QAT_INCLUDE_DIR})
+    target_link_libraries(zfile_lib PUBLIC ${QAT_LIBRARY} ${USDM_LIBRARY} pci)
 endif()
 
-if(BUILD_TESTING)
-  enable_testing()
-  include(CTest)
+# DML and isa-l bring their own autotools/cmake builds, driven here at build
+# time and consumed from the output directory they are told to install into.
+if(ENABLE_DSA OR ENABLE_ISAL)
+    set(THIRDPARTY_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/overlaybd/zfile/thirdparty")
+    add_custom_target(thirdparty_lib)
+    target_link_directories(crc32_lib PUBLIC ${CMAKE_LIBRARY_OUTPUT_DIRECTORY})
+    target_include_directories(crc32_lib PUBLIC ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/include)
+    add_dependencies(crc32_lib thirdparty_lib)
+endif()
+if(ENABLE_DSA)
+    add_custom_command(TARGET thirdparty_lib
+        WORKING_DIRECTORY ${THIRDPARTY_DIR}/DML
+        COMMAND git checkout 5a2956362d7b1c65d8aee753938ae9bf5cf0b7fd
+        COMMAND rm -rf build && mkdir build
+        COMMAND cd build && cmake -DCMAKE_INSTALL_PREFIX=dmldir .. && cmake --build . --target install
+        COMMAND cd build/dmldir && find ./ -name "libdml*.a" | xargs -i cp {} ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/
+        COMMAND cp -r build/dmldir/include ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/
+    )
+    target_compile_definitions(crc32_lib PUBLIC ENABLE_DSA)
+    target_link_libraries(crc32_lib PUBLIC pci dmlhl)
+endif()
+if(ENABLE_ISAL)
+    add_custom_command(TARGET thirdparty_lib
+        WORKING_DIRECTORY ${THIRDPARTY_DIR}/isa-l
+        COMMAND git checkout ad8dce15c6d3f0c7f3d1b486d9c649ed39223b45
+        COMMAND ./autogen.sh && ./configure && make
+        COMMAND cp .libs/libisal.a ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/
+        COMMAND mkdir -p ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/include
+        COMMAND cp include/crc.h ${CMAKE_LIBRARY_OUTPUT_DIRECTORY}/include/
+    )
+    target_compile_definitions(crc32_lib PUBLIC ENABLE_ISAL)
+    target_compile_options(crc32_lib PUBLIC -mavx512f)
+    target_link_libraries(crc32_lib PUBLIC isal)
+endif()
+
+if(ENABLE_OCF_CACHE)
+    if(NOT EXISTS "${CMAKE_CURRENT_SOURCE_DIR}/src/overlaybd/cache/ocf_cache/ocf/src")
+        message(FATAL_ERROR "the ocf submodule is missing, please run "
+            "'git submodule update --init' first, or configure with "
+            "-DENABLE_OCF_CACHE=off to disable the OCF cache backend")
+    endif()
+    set(OCF_DIR "${CMAKE_CURRENT_SOURCE_DIR}/src/overlaybd/cache/ocf_cache")
+
+    add_library(ocf_env_lib STATIC
+        ${OCF_DIR}/ease_bindings/env/ocf_env.cpp
+        ${OCF_DIR}/ease_bindings/env/utils_mpool.cpp
+    )
+    target_include_directories(ocf_env_lib PUBLIC ${OCF_DIR}/include)
+    target_link_libraries(ocf_env_lib PUBLIC external_lib)
+
+    # the vendored OCF sources are globbed: they are not ours to enumerate
+    file(GLOB_RECURSE src_ocf ${OCF_DIR}/ocf/src/*.c)
+    add_library(ocf_lib STATIC ${src_ocf})
+    target_include_directories(ocf_lib PUBLIC ${OCF_DIR}/include ${OCF_DIR}/ease_bindings/env)
+    target_link_libraries(ocf_lib PUBLIC ocf_env_lib ZLIB::ZLIB)
+    # vendored code, don't let its warnings break our build
+    target_compile_options(ocf_lib PRIVATE -Wno-error -Wno-sign-compare)
+
+    add_library(ocf_cache_lib STATIC
+        ${OCF_DIR}/ocf_cache.cpp
+        ${OCF_DIR}/ocf_namespace.cpp
+        ${OCF_DIR}/ease_bindings/ctx.cpp
+        ${OCF_DIR}/ease_bindings/provider.cpp
+        ${OCF_DIR}/ease_bindings/queue.cpp
+        ${OCF_DIR}/ease_bindings/volume.cpp
+    )
+    target_include_directories(ocf_cache_lib PUBLIC ${OCF_DIR}/ease_bindings/env)
+    target_link_libraries(ocf_cache_lib PUBLIC external_lib ocf_lib)
+
+    target_link_libraries(cache_lib PUBLIC ocf_cache_lib)
+endif()
+
+# overlaybd_lib - the aggregate every binary links against
+add_library(overlaybd_lib INTERFACE)
+target_link_libraries(overlaybd_lib INTERFACE
+    external_lib
+    registryfs_lib
+    lsmt_lib
+    zfile_lib
+    zstd_lib
+    cache_lib
+    tar_lib
+    gzip_lib
+    gzindex_lib
+)
+
+add_library(overlaybd_image_lib STATIC
+    src/image_file.cpp
+    src/image_service.cpp
+    src/switch_file.cpp
+    src/bk_download.cpp
+    src/prefetch.cpp
+    src/api_server.cpp
+    src/tools/comm_func.cpp
+)
+target_link_libraries(overlaybd_image_lib PUBLIC
+    overlaybd_lib
+    checksum_lib
+    # image_file.cpp, prefetch.cpp and comm_func.cpp go through photon's extfs
+    E2FSPROGS::libext2fs
+)
+if(ENABLE_OCF_CACHE)
+    target_compile_definitions(overlaybd_image_lib PRIVATE ENABLE_OCF_CACHE)
+endif()
+
+# Propagate the resize .o files to all consumers of overlaybd_image_lib. These
+# provide the resize_fs() symbol needed by photon's resize_extfs().
+if(NOT ORIGIN_EXT2FS)
+    set_source_files_properties(
+        ${E2FS_RESIZE_DIR}/resize2fs.o
+        ${E2FS_RESIZE_DIR}/extent.o
+        ${E2FS_RESIZE_DIR}/resource_track.o
+        PROPERTIES GENERATED TRUE EXTERNAL_OBJECT TRUE)
+    target_link_libraries(overlaybd_image_lib PUBLIC
+        ${E2FS_RESIZE_DIR}/resize2fs.o
+        ${E2FS_RESIZE_DIR}/extent.o
+        ${E2FS_RESIZE_DIR}/resource_track.o
+    )
+    add_dependencies(overlaybd_image_lib libext2fs_build)
 endif()
 
-add_subdirectory(src)
+#---------------------------------------------------------------------
+# Executables
+#---------------------------------------------------------------------
+add_executable(overlaybd-tcmu src/main.cpp)
+target_include_directories(overlaybd-tcmu PRIVATE ${TCMU_INCLUDE_DIR})
+target_link_libraries(overlaybd-tcmu overlaybd_image_lib TCMU::tcmu)
+
+add_executable(overlaybd-commit src/tools/overlaybd-commit.cpp)
+target_link_libraries(overlaybd-commit overlaybd_image_lib)
+
+add_executable(overlaybd-merge src/tools/overlaybd-merge.cpp)
+target_link_libraries(overlaybd-merge overlaybd_image_lib)
+
+# overlaybd-create.cpp goes through photon's extfs, the other tools reach it
+# through overlaybd_image_lib
+add_executable(overlaybd-create src/tools/overlaybd-create.cpp)
+target_link_libraries(overlaybd-create overlaybd_lib E2FSPROGS::libext2fs)
 
-add_subdirectory(baselayers)
+add_executable(overlaybd-zfile src/tools/overlaybd-zfile.cpp)
+target_link_libraries(overlaybd-zfile overlaybd_lib)
+
+add_executable(overlaybd-apply src/tools/overlaybd-apply.cpp src/tools/qcow2converter.cpp)
+target_link_libraries(overlaybd-apply overlaybd_image_lib)
+
+add_executable(turboOCI-apply src/tools/turboOCI-apply.cpp)
+target_link_libraries(turboOCI-apply overlaybd_image_lib)
+
+set(OVERLAYBD_TOOLS
+    overlaybd-commit
+    overlaybd-merge
+    overlaybd-create
+    overlaybd-zfile
+    overlaybd-apply
+    turboOCI-apply
+)
+
+# overlaybd-resize: userspace ext4 resize for overlaybd images, only available
+# with the libext2fs built here
+if(NOT ORIGIN_EXT2FS)
+    add_executable(overlaybd-resize src/tools/overlaybd-resize.cpp)
+    target_link_libraries(overlaybd-resize overlaybd_image_lib)
+    list(APPEND OVERLAYBD_TOOLS overlaybd-resize)
+endif()
 
-include(CMake/pack.cmake)
+if(BUILD_STREAM_CONVERTOR)
+    add_executable(overlaybd-streamConv src/overlaybd/stream_convertor/stream_conv.cpp)
+    target_link_libraries(overlaybd-streamConv
+        external_lib tar_lib gzip_lib gzindex_lib yaml-cpp)
+endif()
+
+# The tools are installed next to the libraries they may load at runtime.
+set_target_properties(${OVERLAYBD_TOOLS} PROPERTIES
+    INSTALL_RPATH "$ORIGIN/../lib:$ORIGIN/../lib64")
+
+#---------------------------------------------------------------------
+# baselayer - the empty ext4 image the tools start from
+#---------------------------------------------------------------------
+add_custom_command(
+    OUTPUT ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/ext4_64
+    COMMAND tar -zxvf ${CMAKE_CURRENT_SOURCE_DIR}/baselayers/ext4_64.tar.gz
+                -C ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}
+    VERBATIM
+)
+add_custom_target(baselayer ALL DEPENDS ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/ext4_64)
+
+#---------------------------------------------------------------------
+# Install
+#---------------------------------------------------------------------
+install(TARGETS overlaybd-tcmu DESTINATION /opt/overlaybd/bin)
+install(TARGETS ${OVERLAYBD_TOOLS} DESTINATION /opt/overlaybd/bin)
+install(FILES src/example_config/overlaybd-tcmu.service DESTINATION /opt/overlaybd/)
+install(FILES src/example_config/cred.json DESTINATION /opt/overlaybd/)
+install(FILES src/example_config/overlaybd.json DESTINATION /etc/overlaybd/)
+install(FILES ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/ext4_64 DESTINATION /opt/overlaybd/baselayers)
+if(NOT ORIGIN_EXT2FS)
+    install(DIRECTORY ${LIBEXT2FS_INSTALL_DIR}/lib DESTINATION /opt/overlaybd/ USE_SOURCE_PERMISSIONS)
+endif()
+
+include(pack)
+
+#---------------------------------------------------------------------
+# Unit tests
+#---------------------------------------------------------------------
+if(BUILD_TESTING)
+    enable_testing()
+    include(CTest)
+    add_subdirectory(test)
+endif()
diff --git a/baselayers/CMakeLists.txt b/baselayers/CMakeLists.txt
deleted file mode 100644
index 7e7d7f54..00000000
--- a/baselayers/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-add_custom_command(
-    OUTPUT ${EXECUTABLE_OUTPUT_PATH}/ext4_64
-    COMMAND tar -zxvf ${CMAKE_CURRENT_LIST_DIR}/ext4_64.tar.gz -C ${EXECUTABLE_OUTPUT_PATH}
-    VERBATIM
-)
-
-add_custom_target(baselayer ALL DEPENDS ${EXECUTABLE_OUTPUT_PATH}/ext4_64)
-
-install(FILES ${EXECUTABLE_OUTPUT_PATH}/ext4_64 DESTINATION /opt/overlaybd/baselayers)
\ No newline at end of file
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
deleted file mode 100644
index 44b0030c..00000000
--- a/src/CMakeLists.txt
+++ /dev/null
@@ -1,80 +0,0 @@
-find_package(CURL REQUIRED)
-find_package(OpenSSL REQUIRED)
-find_package(aio REQUIRED)
-find_package(RapidJSON REQUIRED MODULE)
-
-link_libraries(rt pthread resolv)
-
-add_subdirectory(overlaybd)
-
-add_library(overlaybd_image_lib
-  image_file.cpp
-  image_service.cpp
-  switch_file.cpp
-  bk_download.cpp
-  prefetch.cpp
-  tools/sha256file.cpp
-  tools/comm_func.cpp
-  api_server.cpp
-)
-target_include_directories(overlaybd_image_lib PUBLIC
-  ${CURL_INCLUDE_DIRS}
-  ${OPENSSL_INCLUDE_DIR}
-  ${RAPIDJSON_INCLUDE_DIRS}
-  ${PHOTON_INCLUDE_DIR}
-)
-
-target_link_libraries(overlaybd_image_lib
-  photon_static
-  overlaybd_lib
-  ${CURL_LIBRARIES}
-  ${OPENSSL_SSL_LIBRARY}
-  ${OPENSSL_CRYPTO_LIBRARY}
-  ${AIO_LIBRARIES}
-)
-
-# Propagate resize .o files to all consumers of overlaybd_image_lib.
-# These provide the resize_fs() symbol needed by photon's resize_extfs().
-if (NOT ORIGIN_EXT2FS)
-    target_link_libraries(overlaybd_image_lib
-        ${E2FS_RESIZE_DIR}/resize2fs.o
-        ${E2FS_RESIZE_DIR}/extent.o
-        ${E2FS_RESIZE_DIR}/resource_track.o
-        ${E2FS_LIBRARIES}
-    )
-    add_dependencies(overlaybd_image_lib libext2fs_build)
-endif()
-
-add_executable(overlaybd-tcmu
-  main.cpp
-)
-target_include_directories(overlaybd-tcmu PUBLIC
-  ${TCMU_INCLUDE_DIR}
-  ${CURL_INCLUDE_DIRS}
-  ${OPENSSL_INCLUDE_DIR}
-  ${RAPIDJSON_INCLUDE_DIRS}
-  ${PHOTON_INCLUDE_DIR}
-)
-target_link_libraries(overlaybd-tcmu
-  photon_static
-  overlaybd_lib
-  overlaybd_image_lib
-  tcmu_static
-  ${CURL_LIBRARIES}
-  ${OPENSSL_SSL_LIBRARY}
-  ${OPENSSL_CRYPTO_LIBRARY}
-  ${AIO_LIBRARIES}
-)
-
-install(TARGETS overlaybd-tcmu DESTINATION /opt/overlaybd/bin)
-install(FILES example_config/overlaybd-tcmu.service DESTINATION /opt/overlaybd/)
-install(FILES example_config/overlaybd.json DESTINATION /etc/overlaybd/)
-install(FILES example_config/cred.json DESTINATION /opt/overlaybd/)
-if (NOT ORIGIN_EXT2FS)
-    install(DIRECTORY ${LIBEXT2FS_INSTALL_DIR}/lib DESTINATION /opt/overlaybd/ USE_SOURCE_PERMISSIONS)
-endif()
-
-add_subdirectory(tools)
-if (BUILD_TESTING)
-    add_subdirectory(test)
-endif ()
diff --git a/src/api_server.cpp b/src/api_server.cpp
index 37aaa8d6..1e585350 100644
--- a/src/api_server.cpp
+++ b/src/api_server.cpp
@@ -152,7 +152,7 @@ struct ApiServer {
             host.resize(pos);
         }
         tcpserver = photon::net::new_tcp_socket_server();
-        tcpserver->setsockopt(SOL_SOCKET, SO_REUSEPORT, 1);
+        tcpserver->setsockopt<int>(SOL_SOCKET, SO_REUSEPORT, 1);
         if(tcpserver->bind(url.port(), photon::net::IPAddr(host.c_str())) < 0)
             LOG_ERRNO_RETURN(0, -1, "Failed to bind api server port `", url.port());
         if(tcpserver->listen() < 0)
diff --git a/src/exporter_server.h b/src/exporter_server.h
index 80d0b6e1..d657c881 100644
--- a/src/exporter_server.h
+++ b/src/exporter_server.h
@@ -53,7 +53,7 @@ struct ExporterServer {
     ExporterServer(ImageConfigNS::GlobalConfig &config,
                    OverlayBDMetric *metrics) {
         tcpserver = photon::net::new_tcp_socket_server();
-        tcpserver->setsockopt(SOL_SOCKET, SO_REUSEPORT, 1);
+        tcpserver->setsockopt<int>(SOL_SOCKET, SO_REUSEPORT, 1);
         if (tcpserver->bind(config.exporterConfig().port()) < 0)
             LOG_ERRNO_RETURN(0, , "Failed to bind exporter port `",
                              config.exporterConfig().port());
diff --git a/src/image_file.h b/src/image_file.h
index d391ac78..851699ea 100644
--- a/src/image_file.h
+++ b/src/image_file.h
@@ -43,7 +43,7 @@ static std::string LEGACY_COMMIT_FILE_NAME = ".commit";
 class ImageFile : public photon::fs::ForwardFile {
 public:
     ImageFile(ImageConfigNS::ImageConfig &_conf, ImageService &is, const std::string &dev_id, const char *_config_path)
-        : ForwardFile(nullptr), image_service(is), m_lower_file(nullptr), config_path(_config_path) {
+        : ForwardFile(nullptr), config_path(_config_path), image_service(is), m_lower_file(nullptr) {
         conf.CopyFrom(_conf, conf.GetAllocator());
         m_exception = "";
         if(image_service.register_image_file(dev_id, this) != 0) { // register itself
diff --git a/src/image_service.cpp b/src/image_service.cpp
index 43c3b9f4..761dfb6e 100644
--- a/src/image_service.cpp
+++ b/src/image_service.cpp
@@ -403,7 +403,7 @@ int ImageService::init() {
     }
 
     std::string cache_type, cache_dir;
-    uint32_t cache_size_GB, refill_size, block_size;
+    uint32_t cache_size_GB, refill_size;
     if (global_conf.cacheConfig().cacheType().empty()) {
         cache_type = global_conf.cacheType();
         cache_dir = global_conf.registryCacheDir();
@@ -414,11 +414,15 @@ int ImageService::init() {
         cache_size_GB = global_conf.cacheConfig().cacheSizeGB();
     }
     refill_size = global_conf.cacheConfig().refillSize();
-    block_size = global_conf.cacheConfig().blockSize();
 
     if (cache_type != "file" && cache_type != "ocf" && cache_type != "download") {
         LOG_ERROR_RETURN(0, -1, "unknown cache type: `", cache_type);
     }
+#ifndef ENABLE_OCF_CACHE
+    if (cache_type == "ocf") {
+        LOG_ERROR_RETURN(0, -1, "'ocf' cache is disabled in this build (ENABLE_OCF_CACHE=off)");
+    }
+#endif
     LOG_INFO("cache config: ", VALUE(cache_type), VALUE(cache_dir),
                                VALUE(cache_size_GB), VALUE(refill_size));
 
@@ -473,6 +477,7 @@ int ImageService::init() {
                 (uint64_t)1048576 * 1024, global_fs.io_alloc, 0, {nullptr, &cache_fn_trans_sha256});
 
         } else if (cache_type == "ocf") {
+#ifdef ENABLE_OCF_CACHE
             auto namespace_dir = std::string(cache_dir + "/namespace");
             if (::access(namespace_dir.c_str(), F_OK) != 0 && ::mkdir(namespace_dir.c_str(), 0755) != 0) {
                 LOG_ERRNO_RETURN(0, -1, "failed to create namespace_dir");
@@ -498,8 +503,10 @@ int ImageService::init() {
             }
             global_fs.media_file = media_file;
 
-            global_fs.cached_fs = FileSystem::new_ocf_cached_fs(global_fs.srcfs, namespace_fs, block_size, refill_size,
+            global_fs.cached_fs = FileSystem::new_ocf_cached_fs(global_fs.srcfs, namespace_fs,
+                                                                global_conf.cacheConfig().blockSize(), refill_size,
                                                                 media_file, reload_media, global_fs.io_alloc);
+#endif
         } else if (cache_type == "download") {
             global_fs.cached_fs = FileSystem::new_download_cached_fs(global_fs.srcfs, 4096, refill_size, global_fs.io_alloc);
         } else {
diff --git a/src/main.cpp b/src/main.cpp
index e151dd38..d98c53ca 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -38,6 +38,12 @@
 #include <linux/netlink.h>
 #include <string>
 
+// glibc did not export SOL_NETLINK until 2.24, while the value is a fixed part
+// of the kernel ABI. Define it for the older toolchains, e.g. on CentOS 7.
+#ifndef SOL_NETLINK
+#define SOL_NETLINK 270
+#endif
+
 class TCMUDevLoop;
 
 #define MAX_OPEN_FD 1048576
diff --git a/src/overlaybd/CMakeLists.txt b/src/overlaybd/CMakeLists.txt
deleted file mode 100644
index af095b79..00000000
--- a/src/overlaybd/CMakeLists.txt
+++ /dev/null
@@ -1,28 +0,0 @@
-add_subdirectory(registryfs)
-add_subdirectory(lsmt)
-add_subdirectory(zfile)
-add_subdirectory(zstd)
-add_subdirectory(cache)
-add_subdirectory(tar)
-add_subdirectory(gzip)
-add_subdirectory(gzindex)
-
-if(BUILD_STREAM_CONVERTOR)
-    add_subdirectory(stream_convertor)
-endif()
-
-add_library(overlaybd_lib INTERFACE)
-target_include_directories(overlaybd_lib INTERFACE
-    ${PHOTON_INCLUDE_DIR}
-)
-target_link_libraries(overlaybd_lib INTERFACE
-    photon_static
-    registryfs_lib
-    lsmt_lib
-    zfile_lib
-    zstd_lib
-    cache_lib
-    tar_lib
-    gzip_lib
-    gzindex_lib
-)
diff --git a/src/overlaybd/cache/CMakeLists.txt b/src/overlaybd/cache/CMakeLists.txt
deleted file mode 100644
index 760567be..00000000
--- a/src/overlaybd/cache/CMakeLists.txt
+++ /dev/null
@@ -1,22 +0,0 @@
-add_subdirectory(full_file_cache)
-add_subdirectory(ocf_cache)
-add_subdirectory(download_cache)
-add_subdirectory(gzip_cache)
-
-file(GLOB SRC_CACHE "*.cpp")
-
-add_library(cache_lib STATIC ${SRC_CACHE})
-target_link_libraries(cache_lib
-    photon_static
-    full_file_cache_lib
-    ocf_cache_lib
-    download_cache_lib
-    gzip_cache_lib
-)
-target_include_directories(cache_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
diff --git a/src/overlaybd/cache/cache.cpp b/src/overlaybd/cache/cache.cpp
index 46c2ba09..287790e8 100644
--- a/src/overlaybd/cache/cache.cpp
+++ b/src/overlaybd/cache/cache.cpp
@@ -107,7 +107,7 @@ void ICachePool::set_trans_func(CacheFnTransFunc fn_trans_func) {
     this->fn_trans_func = fn_trans_func;
 }
 
-int ICachePool::store_release(ICacheStore *store) {
-    return cast(m_stores)->release(store->get_store_key());
+void ICachePool::store_release(ICacheStore *store) {
+    cast(m_stores)->release(store->get_store_key());
 }
 } // namespace FileSystem
diff --git a/src/overlaybd/cache/download_cache/CMakeLists.txt b/src/overlaybd/cache/download_cache/CMakeLists.txt
deleted file mode 100644
index 40fcd3f0..00000000
--- a/src/overlaybd/cache/download_cache/CMakeLists.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-file(GLOB SRC_DOWNLOADCACHE "*.cpp")
-
-add_library(download_cache_lib STATIC ${SRC_DOWNLOADCACHE})
-target_include_directories(download_cache_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
diff --git a/src/overlaybd/cache/download_cache/download_cache.cpp b/src/overlaybd/cache/download_cache/download_cache.cpp
index ab800379..37e38cda 100644
--- a/src/overlaybd/cache/download_cache/download_cache.cpp
+++ b/src/overlaybd/cache/download_cache/download_cache.cpp
@@ -110,8 +110,8 @@ class DownloadCacheFile : public VirtualFile {
 class DownloadCacheFs : public IFileSystem {
 public:
     DownloadCacheFs(IFileSystem *fs, size_t bs, size_t rs, IOAlloc *io_alloc)
-        : m_src_fs(fs), block_size(bs), refill_size(rs), io_alloc(io_alloc),
-          m_file_pool(1 * 1000 * 1000) {
+        : block_size(bs), refill_size(rs), io_alloc(io_alloc),
+          m_file_pool(1 * 1000 * 1000), m_src_fs(fs) {
         LOG_INFO("new DownloadCacheFs");
     }
     ~DownloadCacheFs() {
diff --git a/src/overlaybd/cache/full_file_cache/CMakeLists.txt b/src/overlaybd/cache/full_file_cache/CMakeLists.txt
deleted file mode 100644
index 8eacb764..00000000
--- a/src/overlaybd/cache/full_file_cache/CMakeLists.txt
+++ /dev/null
@@ -1,6 +0,0 @@
-file(GLOB SRC_FULLFILECACHE "*.cpp")
-
-add_library(full_file_cache_lib STATIC ${SRC_FULLFILECACHE})
-target_include_directories(full_file_cache_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
diff --git a/src/overlaybd/cache/gzip_cache/CMakeLists.txt b/src/overlaybd/cache/gzip_cache/CMakeLists.txt
deleted file mode 100644
index 2e844bab..00000000
--- a/src/overlaybd/cache/gzip_cache/CMakeLists.txt
+++ /dev/null
@@ -1,7 +0,0 @@
-file(GLOB SRC_FRONTEND "*.cpp")
-
-add_library(gzip_cache_lib STATIC ${SRC_FRONTEND})
-target_link_libraries(gzip_cache_lib gzindex_lib)
-target_include_directories(gzip_cache_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
\ No newline at end of file
diff --git a/src/overlaybd/cache/gzip_cache/cached_fs.cpp b/src/overlaybd/cache/gzip_cache/cached_fs.cpp
index d28de2ae..3ae16ebb 100644
--- a/src/overlaybd/cache/gzip_cache/cached_fs.cpp
+++ b/src/overlaybd/cache/gzip_cache/cached_fs.cpp
@@ -16,6 +16,7 @@
 #include "cached_fs.h"
 #include "../full_file_cache/cache_pool.h"
 #include "../cache.h"
+#include <photon/common/alog.h>
 #include <photon/common/estring.h>
 
 namespace Cache {
diff --git a/src/overlaybd/cache/ocf_cache/CMakeLists.txt b/src/overlaybd/cache/ocf_cache/CMakeLists.txt
deleted file mode 100644
index 9bdca075..00000000
--- a/src/overlaybd/cache/ocf_cache/CMakeLists.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
-
-# ocf_env_lib
-file(GLOB_RECURSE src_ocf_env ease_bindings/env/*.cpp)
-add_library(ocf_env_lib STATIC ${src_ocf_env})
-target_include_directories(ocf_env_lib PUBLIC include/ ${PHOTON_INCLUDE_DIR})
-
-# ocf_lib
-file(GLOB_RECURSE src_ocf ocf/src/*.c)
-add_library(ocf_lib STATIC ${src_ocf})
-target_include_directories(ocf_lib PUBLIC include/ ease_bindings/env/)
-target_link_libraries(ocf_lib ocf_env_lib z)
-target_compile_options(ocf_lib PRIVATE -Wno-sign-compare)
-
-# ocf_cache_lib
-file(GLOB src_ocf_cache ocf_cache.cpp ocf_namespace.cpp ease_bindings/*.cpp)
-add_library(ocf_cache_lib STATIC ${src_ocf_cache})
-target_include_directories(ocf_cache_lib PUBLIC include/ ease_bindings/env/ ${PHOTON_INCLUDE_DIR})
-target_link_libraries(ocf_cache_lib ocf_lib photon_static)
\ No newline at end of file
diff --git a/src/overlaybd/cache/ocf_cache/test/CMakeLists.txt b/src/overlaybd/cache/ocf_cache/test/CMakeLists.txt
deleted file mode 100644
index 9476e116..00000000
--- a/src/overlaybd/cache/ocf_cache/test/CMakeLists.txt
+++ /dev/null
@@ -1,21 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-find_package(CURL REQUIRED)
-
-add_executable(ocf_perf_test ocf_perf_test.cpp)
-target_include_directories(
-        ocf_perf_test PUBLIC
-        ${CURL_INCLUDE_DIRS}
-        ${PHOTON_INCLUDE_DIR}
-)
-target_link_libraries(
-        ocf_perf_test
-        gflags pthread ${CURL_LIBRARIES}
-        photon_static overlaybd_lib
-)
-
-add_test(
-        NAME ocf_perf_test
-        COMMAND ${EXECUTABLE_OUTPUT_PATH}/ocf_perf_test --ut_pass=true
-)
diff --git a/src/overlaybd/cache/pool_store.h b/src/overlaybd/cache/pool_store.h
index 3aea97e8..1ad04ea7 100644
--- a/src/overlaybd/cache/pool_store.h
+++ b/src/overlaybd/cache/pool_store.h
@@ -93,7 +93,7 @@ class ICachePool : public Object {
     // available space meet other requirements as well
     virtual int evict(size_t size = 0) = 0;
 
-    int store_release(ICacheStore *store);
+    void store_release(ICacheStore *store);
 
     void stores_clear();
 
diff --git a/src/overlaybd/cache/test/CMakeLists.txt b/src/overlaybd/cache/test/CMakeLists.txt
deleted file mode 100644
index 768642e4..00000000
--- a/src/overlaybd/cache/test/CMakeLists.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(cache_test cache_test.cpp)
-target_include_directories(cache_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(cache_test gtest gtest_main gflags pthread photon_static overlaybd_lib)
-
-add_test(
-  NAME cache_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/cache_test
-)
\ No newline at end of file
diff --git a/src/overlaybd/config_util.h b/src/overlaybd/config_util.h
index 4b2b4191..dbfdd3e5 100644
--- a/src/overlaybd/config_util.h
+++ b/src/overlaybd/config_util.h
@@ -137,9 +137,9 @@ GetResult(Document *j, const char (&path)[N]) {
     Value *val = GetValueByPointer(*j, path);
     Document ret;
     if (!val)
-        return std::move(ret);
+        return ret;
     ret.CopyFrom(*val, ret.GetAllocator());
-    return std::move(ret);
+    return ret;
 }
 
 template <typename T, size_t N>
diff --git a/src/overlaybd/gzindex/CMakeLists.txt b/src/overlaybd/gzindex/CMakeLists.txt
deleted file mode 100644
index 0ccd496f..00000000
--- a/src/overlaybd/gzindex/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-file(GLOB SOURCE_TAR "*.cpp")
-add_library(gzindex_lib STATIC ${SOURCE_TAR})
-
-target_include_directories(gzindex_lib PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(gzindex_lib photon_static)
-
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
diff --git a/src/overlaybd/gzindex/gzip_index_create.cpp b/src/overlaybd/gzindex/gzip_index_create.cpp
index 8bec915f..192e97f2 100644
--- a/src/overlaybd/gzindex/gzip_index_create.cpp
+++ b/src/overlaybd/gzindex/gzip_index_create.cpp
@@ -41,7 +41,7 @@ class IndexFilterRecorder {
     explicit IndexFilterRecorder(IndexFileHeader* h, INDEX *index,
         photon::fs::IFile* index_file):h_(h),index_(index),index_file_(index_file) {
         buf_ = new unsigned char[DEFLATE_BLOCK_UNCOMPRESS_MAX_SIZE];
-        memset(&last_, 0, sizeof(last_));
+        last_ = {};
     }
     virtual ~IndexFilterRecorder(){
         delete []buf_;
diff --git a/src/overlaybd/gzindex/test/CMakeLists.txt b/src/overlaybd/gzindex/test/CMakeLists.txt
deleted file mode 100644
index 9decda13..00000000
--- a/src/overlaybd/gzindex/test/CMakeLists.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(gzindex_test test.cpp)
-target_include_directories(gzindex_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(gzindex_test gtest gtest_main gflags pthread photon_static
-     gzindex_lib gzip_lib cache_lib checksum_lib)
-
-add_test(
-    NAME gzindex_test
-    COMMAND ${EXECUTABLE_OUTPUT_PATH}/gzindex_test
-)
diff --git a/src/overlaybd/gzip/CMakeLists.txt b/src/overlaybd/gzip/CMakeLists.txt
deleted file mode 100644
index b5555c87..00000000
--- a/src/overlaybd/gzip/CMakeLists.txt
+++ /dev/null
@@ -1,11 +0,0 @@
-file(GLOB SOURCE_GZIP "*.cpp")
-
-add_library(gzip_lib STATIC ${SOURCE_GZIP})
-target_include_directories(gzip_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-target_link_libraries(gzip_lib photon_static checksum_lib)
-
-# if(BUILD_TESTING)
-#   add_subdirectory(test)
-# endif()
diff --git a/src/overlaybd/lsmt/CMakeLists.txt b/src/overlaybd/lsmt/CMakeLists.txt
deleted file mode 100644
index 24d5e5b1..00000000
--- a/src/overlaybd/lsmt/CMakeLists.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-file(GLOB SOURCE_LSMT "*.cpp")
-
-add_library(lsmt_lib STATIC ${SOURCE_LSMT})
-target_include_directories(lsmt_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
diff --git a/src/overlaybd/lsmt/test/CMakeLists.txt b/src/overlaybd/lsmt/test/CMakeLists.txt
deleted file mode 100644
index 8e28ef6b..00000000
--- a/src/overlaybd/lsmt/test/CMakeLists.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(lsmt_test test.cpp)
-target_include_directories(lsmt_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(lsmt_test gtest gtest_main gflags pthread photon_static overlaybd_lib)
-
-add_test(
-  NAME lsmt_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/lsmt_test
-)
-
diff --git a/src/overlaybd/lsmt/test/lsmt-filetest.h b/src/overlaybd/lsmt/test/lsmt-filetest.h
index 384b9b5b..03512edc 100644
--- a/src/overlaybd/lsmt/test/lsmt-filetest.h
+++ b/src/overlaybd/lsmt/test/lsmt-filetest.h
@@ -456,7 +456,6 @@ class FileTest3 : public FileTest2 {
     IFile *create_commit_layer(int i = 0, int io_engine = 0, bool compress = false,
                                bool verify = false, bool sparse = false) {
         auto file = create_a_layer(sparse);
-        IFile *as = nullptr;
         IFile *dst = nullptr;
         auto dst_filename = layer_name.back();
         if (compress) {
diff --git a/src/overlaybd/lsmt/test/test.cpp b/src/overlaybd/lsmt/test/test.cpp
index d08f273a..0b2e4921 100644
--- a/src/overlaybd/lsmt/test/test.cpp
+++ b/src/overlaybd/lsmt/test/test.cpp
@@ -616,9 +616,7 @@ TEST_F(FileTest2, commit_zfile) {
     reset_verify_file();
 
     auto *file = create_file();
-    auto fn_c0 = "commit0";
     auto fn_c1 = "commit1";
-    auto fcommit0 = lfs->open(fn_c0, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU);
     auto fcommit1 = lfs->open(fn_c1, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU);
     CompressOptions opt;
     opt.verify = 1;
@@ -632,7 +630,6 @@ TEST_F(FileTest2, commit_zfile) {
     fstream_zfile->close();
     file->close();
     LOG_INFO("verify commit file from StreamingZFile");
-    // zfile_compress(fcommit1, fcommit0, &zfile_args);
     auto zfile = ZFile::zfile_open_ro(fcommit1);
     file = (IFileRW *)::open_file_ro(zfile);
     // file = (IFileRW*)open_file_ro(fn_c1);
diff --git a/src/overlaybd/registryfs/CMakeLists.txt b/src/overlaybd/registryfs/CMakeLists.txt
deleted file mode 100644
index a7f59e16..00000000
--- a/src/overlaybd/registryfs/CMakeLists.txt
+++ /dev/null
@@ -1,10 +0,0 @@
-file(GLOB SOURCE_REGISTRYFS "*.cpp")
-
-find_package(CURL REQUIRED)
-
-add_library(registryfs_lib STATIC ${SOURCE_REGISTRYFS})
-target_include_directories(registryfs_lib PUBLIC
-    ${CURL_INCLUDE_DIRS}
-    ${RAPIDJSON_INCLUDE_DIRS}
-    ${PHOTON_INCLUDE_DIR}
-)
diff --git a/src/overlaybd/registryfs/registryfs.cpp b/src/overlaybd/registryfs/registryfs.cpp
index 27b52954..8625278a 100644
--- a/src/overlaybd/registryfs/registryfs.cpp
+++ b/src/overlaybd/registryfs/registryfs.cpp
@@ -117,7 +117,7 @@ class RegistryFSImpl : public RegistryFS {
 
     long GET(const char *url, photon::net::HeaderMap *headers, off_t offset, size_t count,
              photon::net::IOVWriter *writer, uint64_t timeout) {
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         long ret = 0;
         UrlInfo *actual_info = m_url_info.acquire(url, [&]() -> UrlInfo * {
             return getActualUrl(url, tmo.timeout(), ret);
@@ -197,7 +197,7 @@ class RegistryFSImpl : public RegistryFS {
             uint64_t elapsed = 1000000UL * (end.tv_sec - start.tv_sec) + end.tv_usec - start.tv_usec;
             LOG_INFO("getActualUrl for: `, time used: ` ms", url, elapsed / 1000);
         });
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         auto curl = get_cURL();
         DEFER({ release_cURL(curl); });
         photon::net::HeaderMap headers;
@@ -297,7 +297,7 @@ class RegistryFSImpl : public RegistryFS {
 
     int getScopeAuth(const char *url, estring *authurl, estring *scope, uint64_t timeout) {
         // need authorize;
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         auto curl = get_cURL();
         DEFER({ release_cURL(curl); });
         photon::net::HeaderMap headers;
@@ -339,7 +339,7 @@ class RegistryFSImpl : public RegistryFS {
             uint64_t elapsed = 1000000UL * (end.tv_sec - start.tv_sec) + end.tv_usec - start.tv_usec;
             LOG_INFO("authenticate for: `, time used: ` ms", auth_url, elapsed / 1000);
         });
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         photon::net::cURL *req = get_cURL();
         DEFER({ release_cURL(req); });
         photon::net::StringWriter writer;
@@ -411,7 +411,7 @@ class RegistryFileImpl : public photon::fs::VirtualReadOnlyFile {
         }
         auto filesize = m_filesize;
         int retry = 3;
-        Timeout timeout(m_timeout);
+        photon::Timeout tmo(m_timeout);
 
     again:
         photon::net::IOVWriter container(iov, iovcnt);
@@ -422,11 +422,11 @@ class RegistryFileImpl : public photon::fs::VirtualReadOnlyFile {
 
         photon::net::HeaderMap headers;
         long code =
-            m_fs->GET(m_url.c_str(), &headers, offset, count, &container, timeout.timeout());
+            m_fs->GET(m_url.c_str(), &headers, offset, count, &container, tmo.timeout());
 
         if (code != 200 && code != 206) {
             ERRNO eno;
-            if (timeout.expire() < photon::now) {
+            if (tmo.expired()) {
                 LOG_ERROR_RETURN(ETIMEDOUT, -1, "timed out in preadv ", VALUE(m_url),
                                  VALUE(offset));
             }
@@ -459,12 +459,12 @@ class RegistryFileImpl : public photon::fs::VirtualReadOnlyFile {
      */
     int64_t getMetaLength(uint64_t timeout = -1) {
         photon::net::HeaderMap headers;
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         int retry = 3;
     again:
         auto code = m_fs->GET(m_url.c_str(), &headers, -1, -1, nullptr, tmo.timeout());
         if (code != 200 && code != 206) {
-            if (tmo.expire() < photon::now)
+            if (tmo.expired())
                 LOG_ERROR_RETURN(ETIMEDOUT, -1, "Get meta timedout");
             if (retry--)
                 goto again;
diff --git a/src/overlaybd/registryfs/registryfs_v2.cpp b/src/overlaybd/registryfs/registryfs_v2.cpp
index 92416bc3..86a4d091 100644
--- a/src/overlaybd/registryfs/registryfs_v2.cpp
+++ b/src/overlaybd/registryfs/registryfs_v2.cpp
@@ -147,7 +147,7 @@ class RegistryFSImpl_v2 : public RegistryFS {
     }
 
     long get_data(const estring &url, off_t offset, size_t count, uint64_t timeout, HTTP_OP &op) {
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         long ret = 0;
         UrlInfo *actual_info = m_url_info.acquire(url, [&]() -> UrlInfo * {
             return get_actual_url(url, tmo.timeout(), ret);
@@ -210,7 +210,7 @@ class RegistryFSImpl_v2 : public RegistryFS {
 
     UrlInfo* get_actual_url(const estring &url, uint64_t timeout, long &code) {
 
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         estring authurl, scope;
         estring *token = nullptr;
 
@@ -300,7 +300,7 @@ class RegistryFSImpl_v2 : public RegistryFS {
 
     int refresh_token(const estring &url, estring &token) {
         estring authurl, scope;
-        Timeout tmo(m_timeout);
+        photon::Timeout tmo(m_timeout);
         auto authtype = get_scope_auth(url, &authurl, &scope, tmo.timeout(), true);
         if (authtype == AuthType::Unknown)
             return -1;
@@ -329,7 +329,7 @@ class RegistryFSImpl_v2 : public RegistryFS {
 
     AuthType get_scope_auth(const estring &url, estring *authurl, estring *scope, uint64_t timeout,
                        bool push = false) {
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         auto verb = push ? Verb::POST : Verb::GET;
         HTTP_OP op(m_client, verb, url);
         op.follow = 0;
@@ -403,7 +403,7 @@ class RegistryFSImpl_v2 : public RegistryFS {
 
     bool authenticate(const estring &authurl, std::string &username, std::string &password,
                       estring *token, uint64_t timeout) {
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         estring userpwd_b64;
         photon::net::Base64Encode(estring().appends(username, ":", password), userpwd_b64);
         HTTP_OP op(m_client, Verb::GET, authurl);
@@ -455,7 +455,7 @@ class RegistryFileImpl_v2 : public photon::fs::VirtualReadOnlyFile {
         }
         auto filesize = m_filesize;
         int retry = 3;
-        Timeout tmo(m_timeout);
+        photon::Timeout tmo(m_timeout);
 
     again:
         iovector_view view((struct iovec*)iov, iovcnt);
@@ -468,7 +468,7 @@ class RegistryFileImpl_v2 : public photon::fs::VirtualReadOnlyFile {
         auto code = m_fs->get_data(m_url, offset, count, tmo.timeout(), op);
         if (code != 200 && code != 206) {
             ERRNO eno;
-            if (tmo.expire() < photon::now) {
+            if (tmo.expired()) {
                 LOG_ERROR_RETURN(ETIMEDOUT, -1, "timed out in preadv ", VALUE(m_url), VALUE(offset));
             }
             if (retry--) {
@@ -485,13 +485,13 @@ class RegistryFileImpl_v2 : public photon::fs::VirtualReadOnlyFile {
     }
 
     int64_t get_length(uint64_t timeout = -1) {
-        Timeout tmo(timeout);
+        photon::Timeout tmo(timeout);
         int retry = 3;
     again:
         HTTP_OP op;
         auto code = m_fs->get_data(m_url, 0, 1, tmo.timeout(), op);
         if (code != 200 && code != 206) {
-            if (tmo.expire() < photon::now)
+            if (tmo.expired())
                 LOG_ERROR_RETURN(ETIMEDOUT, -1, "get meta timedout");
             if (retry--)
                     goto again;
@@ -652,7 +652,7 @@ class RegistryUploader : public VirtualFile {
     // non-empty digest means complete request
     off_t upload_chunk(off_t offset, size_t count, std::string_view digest) {
         LOG_INFO("upload chunk ", VALUE(offset), VALUE(count), VALUE(digest));
-        Timeout tmo(m_timeout);
+        photon::Timeout tmo(m_timeout);
         auto verb = Verb::PATCH;
         estring url = m_upload_url;
         if (!digest.empty()) {
@@ -812,7 +812,7 @@ class RegistryUploader : public VirtualFile {
             return -1;
         }
 
-        Timeout tmo(m_timeout);
+        photon::Timeout tmo(m_timeout);
         HTTP_OP op(m_upload_fs->get_client(), Verb::POST, m_upload_url);
         op.req.headers.insert("Content-Type", "application/octet-stream");
         op.req.headers.insert(kAuthHeaderKey, "Bearer ");
diff --git a/src/overlaybd/stream_convertor/CMakeLists.txt b/src/overlaybd/stream_convertor/CMakeLists.txt
deleted file mode 100644
index 19f1acd1..00000000
--- a/src/overlaybd/stream_convertor/CMakeLists.txt
+++ /dev/null
@@ -1,18 +0,0 @@
-file(GLOB SOURCE_SERV "*.cpp")
-
-add_executable(overlaybd-streamConv ${SOURCE_SERV})
-target_include_directories(overlaybd-streamConv PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-)
-target_link_libraries(overlaybd-streamConv
-    photon_static
-    gzip_lib
-    gzindex_lib
-    tar_lib
-    yaml-cpp
-)
-
-# if(BUILD_TESTING)
-#   add_subdirectory(test)
-# endif()
diff --git a/src/overlaybd/stream_convertor/stream_conv.cpp b/src/overlaybd/stream_convertor/stream_conv.cpp
index 58722ee7..30817a6c 100644
--- a/src/overlaybd/stream_convertor/stream_conv.cpp
+++ b/src/overlaybd/stream_convertor/stream_conv.cpp
@@ -143,7 +143,7 @@ class StreamConvertor {
         m_tcp_serv = new_tcp_socket_server();
         m_tcp_serv->timeout(1000UL*1000);
         if ( gconfig.globalConfig().reusePort() ){
-            m_tcp_serv->setsockopt(SOL_SOCKET, SO_REUSEPORT, 1);
+            m_tcp_serv->setsockopt<int>(SOL_SOCKET, SO_REUSEPORT, 1);
         }
         if (m_tcp_serv->bind(gconfig.globalConfig().httpPort(), IPAddr(httpAddr.c_str())) != 0) {
             LOG_ERRNO_RETURN(0, -1, "Failed to bind to port ",
diff --git a/src/overlaybd/tar/CMakeLists.txt b/src/overlaybd/tar/CMakeLists.txt
deleted file mode 100644
index a3eb8ed0..00000000
--- a/src/overlaybd/tar/CMakeLists.txt
+++ /dev/null
@@ -1,13 +0,0 @@
-file(GLOB SOURCE_TAR "*.cpp")
-
-add_library(tar_lib STATIC ${SOURCE_TAR})
-target_include_directories(tar_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
-
-add_subdirectory(erofs)
-target_link_libraries(tar_lib PRIVATE erofs_lib)
\ No newline at end of file
diff --git a/src/overlaybd/tar/erofs/CMakeLists.txt b/src/overlaybd/tar/erofs/CMakeLists.txt
deleted file mode 100644
index 57d5b762..00000000
--- a/src/overlaybd/tar/erofs/CMakeLists.txt
+++ /dev/null
@@ -1,45 +0,0 @@
-include(FetchContent)
-
-FetchContent_Declare(
-    erofs-utils
-    GIT_REPOSITORY https://github.com/erofs/erofs-utils.git
-    GIT_TAG        eec6f7a2755dfccc8f655aa37cf6f26db9164e60
-)
-
-FetchContent_MakeAvailable(erofs-utils)
-
-execute_process(
-    COMMAND ./autogen.sh
-    WORKING_DIRECTORY ${erofs-utils_SOURCE_DIR}
-)
-execute_process(
-    COMMAND ./configure --disable-lz4 --disable-lzma --without-libzstd --without-uuid --disable-multithreading
-    WORKING_DIRECTORY ${erofs-utils_SOURCE_DIR}
-)
-execute_process(
-    COMMAND make
-    WORKING_DIRECTORY ${erofs-utils_SOURCE_DIR}
-)
-
-set(EROFS_LIB_INCLUDE_DIR "${erofs-utils_SOURCE_DIR}/include/" CACHE PATH "erofs-utils include path.")
-set(EROFS_CONFIG_FILE "${erofs-utils_SOURCE_DIR}/config.h" CACHE PATH "erofs-utils config file.")
-set(EROFS_LIB_STATIC "${erofs-utils_SOURCE_DIR}/lib/.libs/liberofs.a" CACHE PATH "erofs-utils static lib.")
-
-file(GLOB EROFS_SOURCE "*.cpp")
-
-add_library(erofs_lib STATIC ${EROFS_SOURCE})
-
-target_include_directories(erofs_lib PRIVATE
-    ${PHOTON_INCLUDE_DIR}
-)
-
-target_include_directories(erofs_lib PRIVATE
-    ${EROFS_LIB_INCLUDE_DIR}
-)
-
-target_compile_options(erofs_lib PRIVATE "-include${EROFS_CONFIG_FILE}")
-target_link_libraries(erofs_lib PRIVATE ${EROFS_LIB_STATIC})
-
-if(BUILD_TESTING)
-  add_subdirectory(test)
-endif()
diff --git a/src/overlaybd/tar/erofs/test/CMakeLists.txt b/src/overlaybd/tar/erofs/test/CMakeLists.txt
deleted file mode 100644
index 0c10f34d..00000000
--- a/src/overlaybd/tar/erofs/test/CMakeLists.txt
+++ /dev/null
@@ -1,37 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-# erofs simple test
-add_executable(erofs_simple_test erofs_simple.cpp)
-target_include_directories(erofs_simple_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(erofs_simple_test gtest gtest_main pthread photon_static
-  tar_lib lsmt_lib gzip_lib gzindex_lib checksum_lib overlaybd_image_lib)
-
-target_include_directories(erofs_simple_test PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-)
-
-add_test(
-  NAME erofs_simple_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/erofs_simple_test
-)
-
-# erofs stress test
-add_executable(erofs_stress_test erofs_stress.cpp erofs_stress_base.cpp)
-target_include_directories(erofs_stress_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(erofs_stress_test gtest gtest_main pthread photon_static
-  tar_lib lsmt_lib gzip_lib gzindex_lib checksum_lib overlaybd_image_lib)
-
-target_include_directories(erofs_stress_test PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-)
-
-add_test(
-  NAME erofs_stress_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/erofs_stress_test
-)
diff --git a/src/overlaybd/tar/libtar.h b/src/overlaybd/tar/libtar.h
index 705c511e..998d712e 100644
--- a/src/overlaybd/tar/libtar.h
+++ b/src/overlaybd/tar/libtar.h
@@ -52,10 +52,11 @@ static size_t oct_to_size(char *oct) {
     size_t i;
     return sscanf(oct, "%zo", &i) == 1 ? i : 0;
 }
-#define int_to_oct(num, oct, octlen)                                                               \
+
+#define int_to_oct(num, oct, octlen) \
     snprintf((oct), (octlen), "%*lo ", (octlen)-2, (unsigned long)(num))
 
-static void int_to_oct_nonull(int num, char *oct, size_t octlen) {
+static inline void int_to_oct_nonull(int num, char *oct, size_t octlen) {
     snprintf(oct, octlen, "%*lo", (int)(octlen - 1), (unsigned long)num);
     oct[octlen - 1] = ' ';
 }
@@ -82,8 +83,8 @@ class TarHeader {
     char devminor[8];
     char prefix[155];
     char padding[12];
-    char *gnu_longname = nullptr;
-    char *gnu_longlink = nullptr;
+    char *gnu_longname;
+    char *gnu_longlink;
 
     mode_t get_mode();
     gid_t get_gid();
@@ -151,6 +152,7 @@ class TarCore {
     TarCore(photon::fs::IFile *file, int options, uint64_t fs_blocksize = FS_BLOCKSIZE)
         : file(file), options(options), fs_blocksize(fs_blocksize) {
         fs_blockmask = ~(fs_blocksize - 1);
+        memset(&header, 0, sizeof(header));
     }
     virtual ~TarCore() {
         if (th_pathname != nullptr)
diff --git a/src/overlaybd/tar/tar_file.cpp b/src/overlaybd/tar/tar_file.cpp
index b027b2a1..6863d730 100644
--- a/src/overlaybd/tar/tar_file.cpp
+++ b/src/overlaybd/tar/tar_file.cpp
@@ -191,8 +191,8 @@ class TarFile : public ForwardFile_Ownership {
         auto record = format_pax_record("size", to_string(size));
         LOG_DEBUG(VALUE(record.c_str()), VALUE(record.size()));
         int_to_oct_nonull(record.size(), th_buf->size, 12);             // size
-        strncpy(th_buf->version, TVERSION, TVERSLEN);                   // version
-        strncpy(th_buf->magic, TMAGIC, TMAGLEN);                        // magic
+        memcpy(th_buf->version, TVERSION, TVERSLEN);                    // version
+        memcpy(th_buf->magic, TMAGIC, TMAGLEN);                         // magic
         int_to_oct(th_buf->crc_calc(), th_buf->chksum, 8);              // checksum
         memcpy(buf + T_BLOCKSIZE, record.c_str(), record.size());
         // tar header, 1 block
@@ -208,7 +208,7 @@ class TarFile : public ForwardFile_Ownership {
         if (gr != NULL)
             strlcpy(th_buf->gname, gr->gr_name, sizeof(th_buf->gname)); // gname
         int_to_oct(0, th_buf->gid, 8);                                  // gid
-        int_to_oct(s.st_mode, th_buf->mode, 8);                         // mode
+        int_to_oct(s.st_mode&0777777, th_buf->mode, 8);                         // mode
 #ifndef NO_TIMESTAMP
         int_to_oct_nonull(s.st_mtime, th_buf->mtime, 12);               // mtime
 #else
@@ -216,8 +216,8 @@ class TarFile : public ForwardFile_Ownership {
 #endif
         int_to_oct_nonull(0, th_buf->size, 12);                         // size
         snprintf(th_buf->name, 100, "%.100s", "overlaybd.commit");      // name
-        strncpy(th_buf->version, TVERSION, TVERSLEN);                   // version
-        strncpy(th_buf->magic, TMAGIC, TMAGLEN);                        // magic
+        memcpy(th_buf->version, TVERSION, TVERSLEN);                    // version
+        memcpy(th_buf->magic, TMAGIC, TMAGLEN);                         // magic
         int_to_oct(th_buf->crc_calc(), th_buf->chksum, 8);              // checksum
         // write header
         m_file->pwrite(buf, 3 * T_BLOCKSIZE, 0);
@@ -245,8 +245,8 @@ class TarFile : public ForwardFile_Ownership {
         // tar header, 1 block
         th_buf = (TarHeader *)(buf + 2 * T_BLOCKSIZE);
         snprintf(th_buf->name, 100, "%.100s", "overlaybd.new"); // name
-        strncpy(th_buf->version, TVERSION_EMPTY, TVERSLEN);     // version
-        strncpy(th_buf->magic, TMAGIC_EMPTY, TMAGLEN);          // magic
+        memcpy(th_buf->version, TVERSION_EMPTY, TVERSLEN);      // version
+        memcpy(th_buf->magic, TMAGIC_EMPTY, TMAGLEN);           // magic
         int_to_oct_nonull(0, th_buf->size, 12);                 // size
         // write header
         return (m_file->pwrite(buf, 3 * T_BLOCKSIZE, 0) == 3 * T_BLOCKSIZE);
diff --git a/src/overlaybd/tar/test/CMakeLists.txt b/src/overlaybd/tar/test/CMakeLists.txt
deleted file mode 100644
index 21499419..00000000
--- a/src/overlaybd/tar/test/CMakeLists.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(untar_test test.cpp)
-target_include_directories(untar_test PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(untar_test gtest gtest_main pthread photon_static
-  tar_lib lsmt_lib gzip_lib gzindex_lib checksum_lib)
-
-add_test(
-  NAME untar_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/untar_test
-)
diff --git a/src/overlaybd/zfile/CMakeLists.txt b/src/overlaybd/zfile/CMakeLists.txt
deleted file mode 100644
index 7422d5c2..00000000
--- a/src/overlaybd/zfile/CMakeLists.txt
+++ /dev/null
@@ -1,72 +0,0 @@
-file(GLOB SOURCE_ZFILE "*.cpp")
-file(GLOB SOURCE_LZ4 "lz4/*.c" "lz4/*.cpp")
-file(GLOB SOURCE_CRC32 "crc32/crc32c.cpp")
-
-set (CMAKE_CXX_STANDARD 17)
-add_library(crc32_lib STATIC ${SOURCE_CRC32})
-target_include_directories(crc32_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-
-if (CMAKE_SYSTEM_PROCESSOR STREQUAL x86_64)
-    target_compile_options(crc32_lib PUBLIC -msse4.2 -mcrc32)
-else()
-    if (NOT CMAKE_CXX_FLAGS MATCHES "-march=|-mcpu=")
-        check_cxx_compiler_flag(-mcpu=native COMPILER_HAS_NATIVE_FLAG)
-        if (COMPILER_HAS_NATIVE_FLAG)
-            target_compile_options(crc32_lib PRIVATE -mcpu=native)
-        else ()
-            target_compile_options(crc32_lib PRIVATE -mcpu=generic+crc)
-        endif ()
-    endif ()
-endif()
-
-if(ENABLE_DSA OR ENABLE_ISAL)
-    add_subdirectory(thirdparty)
-    add_dependencies(crc32_lib thirdparty_lib)
-    target_link_directories(crc32_lib PUBLIC ${LIBRARY_OUTPUT_PATH})
-    target_include_directories(crc32_lib PUBLIC ${LIBRARY_OUTPUT_PATH}/include)
-    if(ENABLE_DSA)
-        target_link_libraries(crc32_lib -lpci -ldmlhl -ldl)
-        target_compile_definitions(crc32_lib PUBLIC -DENABLE_DSA)
-    endif()
-    if(ENABLE_ISAL)
-        target_compile_options(crc32_lib PUBLIC -mavx512f)
-        target_compile_definitions(crc32_lib PUBLIC -DENABLE_ISAL)
-        target_link_libraries(crc32_lib -lisal)
-    endif()
-endif()
-set (CMAKE_CXX_STANDARD 14)
-
-# ---- QAT auto-detection ----
-if (ENABLE_QAT)
-    find_path(QAT_INCLUDE_DIR NAMES qat/cpa.h
-              PATHS /usr/include/qat /usr/local/include/qat)
-    find_library(QAT_LIBRARY NAMES qat)
-    find_library(USDM_LIBRARY NAMES usdm)
-    if (QAT_INCLUDE_DIR AND QAT_LIBRARY AND USDM_LIBRARY)
-        message(STATUS "QAT acceleration: ENABLED (include=${QAT_INCLUDE_DIR})")
-    else()
-        message(WARNING "ENABLE_QAT=ON but QAT headers/libs not found; disabling QAT")
-        set(ENABLE_QAT OFF)
-    endif()
-endif()
-if (NOT ENABLE_QAT)
-    # When QAT is off, exclude lz4-qat.cpp so we don't need QAT headers at all
-    list(REMOVE_ITEM SOURCE_LZ4 "${CMAKE_CURRENT_SOURCE_DIR}/lz4/lz4-qat.cpp")
-    message(STATUS "QAT acceleration: DISABLED")
-endif()
-# --------------------------------
-
-add_library(zfile_lib STATIC ${SOURCE_ZFILE} ${SOURCE_LZ4})
-target_link_libraries(zfile_lib photon_static crc32_lib ${LIBZSTD})
-
-if (ENABLE_QAT)
-    target_compile_definitions(zfile_lib PUBLIC -DENABLE_QAT)
-    target_include_directories(zfile_lib PUBLIC ${QAT_INCLUDE_DIR})
-    target_link_libraries(zfile_lib ${QAT_LIBRARY} ${USDM_LIBRARY} -lpci -lpthread)
-endif()
-
-if (BUILD_TESTING)
-    add_subdirectory(test)
-endif ()
diff --git a/src/overlaybd/zfile/test/CMakeLists.txt b/src/overlaybd/zfile/test/CMakeLists.txt
deleted file mode 100644
index 4303a6d8..00000000
--- a/src/overlaybd/zfile/test/CMakeLists.txt
+++ /dev/null
@@ -1,15 +0,0 @@
-
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(zfile_test ./test.cpp)
-
-target_link_libraries(zfile_test gtest gtest_main gflags pthread photon_static overlaybd_lib)
-target_include_directories(zfile_test PUBLIC ${PHOTON_INCLUDE_DIR})
-add_test(
-  NAME zfile_test
-  COMMAND ${EXECUTABLE_OUTPUT_PATH}/zfile_test
-)
\ No newline at end of file
diff --git a/src/overlaybd/zfile/thirdparty/CMakeLists.txt b/src/overlaybd/zfile/thirdparty/CMakeLists.txt
deleted file mode 100644
index 4dec6f2a..00000000
--- a/src/overlaybd/zfile/thirdparty/CMakeLists.txt
+++ /dev/null
@@ -1,23 +0,0 @@
-add_custom_target(thirdparty_lib)
-set(THIRDPARTY_PATH "${CMAKE_SOURCE_DIR}/src/overlaybd/zfile/thirdparty")
-
-if(ENABLE_DSA)
-    add_custom_command(TARGET thirdparty_lib
-        COMMAND cd ${THIRDPARTY_PATH}/DML && git checkout 5a2956362d7b1c65d8aee753938ae9bf5cf0b7fd
-        COMMAND cd ${THIRDPARTY_PATH}/DML && rm -rf build && mkdir build && cd build && cmake -DCMAKE_INSTALL_PREFIX=dmldir ..
-        COMMAND cd ${THIRDPARTY_PATH}/DML/build && cmake --build . --target install
-        COMMAND cd ${THIRDPARTY_PATH}/DML/build/dmldir && find ./ -name "libdml*.a" | xargs -i cp {} ${LIBRARY_OUTPUT_PATH}/;
-        COMMAND cp -r ${THIRDPARTY_PATH}/DML/build/dmldir/include ${LIBRARY_OUTPUT_PATH}/
-    )
-endif()
-
-if(ENABLE_ISAL)
-    add_custom_command(TARGET thirdparty_lib
-        COMMAND cd ${THIRDPARTY_PATH}/isa-l && git checkout ad8dce15c6d3f0c7f3d1b486d9c649ed39223b45
-        COMMAND cd ${THIRDPARTY_PATH}/isa-l && ./autogen.sh
-        COMMAND cd ${THIRDPARTY_PATH}/isa-l && ./configure
-        COMMAND cd ${THIRDPARTY_PATH}/isa-l && make
-        COMMAND cp -r ${THIRDPARTY_PATH}/isa-l/.libs/libisal.a ${LIBRARY_OUTPUT_PATH}/
-        COMMAND mkdir -p ${LIBRARY_OUTPUT_PATH}/include && cp ${THIRDPARTY_PATH}/isa-l/include/crc.h ${LIBRARY_OUTPUT_PATH}/include/
-    )
-endif()
\ No newline at end of file
diff --git a/src/overlaybd/zfile/zfile.cpp b/src/overlaybd/zfile/zfile.cpp
index e250d079..687a08c7 100644
--- a/src/overlaybd/zfile/zfile.cpp
+++ b/src/overlaybd/zfile/zfile.cpp
@@ -1011,11 +1011,11 @@ class ZFileBuilderMP : public ZFileBuilderBase {
 
         for (off_t i = 0; i < (ssize_t)count; i += m_opt.block_size) {
             if (i + m_opt.block_size > (ssize_t)count) {
-                copy(ctx, buf+i, count-i, 0);
+                copy(ctx, (const char *)buf + i, count-i, 0);
                 reserved_size = count - i;
                 break;
             }
-            copy(ctx, buf+i, m_opt.block_size, 0);
+            copy(ctx, (const char *)buf + i, m_opt.block_size, 0);
             ctx->start_compress(m_opt.block_size);
             cur_id = (cur_id+1)%m_workers;
             ctx = workers[cur_id];
diff --git a/src/overlaybd/zstd/CMakeLists.txt b/src/overlaybd/zstd/CMakeLists.txt
deleted file mode 100644
index 68535cd4..00000000
--- a/src/overlaybd/zstd/CMakeLists.txt
+++ /dev/null
@@ -1,9 +0,0 @@
-file(GLOB SOURCE_ZSTD "*.cpp")
-
-add_library(zstd_lib STATIC ${SOURCE_ZSTD})
-
-target_include_directories(zstd_lib PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-)
-
-target_link_libraries(zstd_lib photon_static ${LIBZSTD})
diff --git a/src/test/CMakeLists.txt b/src/test/CMakeLists.txt
deleted file mode 100644
index 7fa107e5..00000000
--- a/src/test/CMakeLists.txt
+++ /dev/null
@@ -1,76 +0,0 @@
-include_directories($ENV{GFLAGS}/include)
-link_directories($ENV{GFLAGS}/lib)
-
-include_directories($ENV{GTEST}/googletest/include)
-link_directories($ENV{GTEST}/lib)
-
-add_executable(image_service_test image_service_test.cpp)
-target_include_directories(image_service_test PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-)
-target_link_libraries(image_service_test gtest gtest_main gflags pthread photon_static overlaybd_lib overlaybd_image_lib)
-
-add_test(
-    NAME image_service_test
-    COMMAND ${EXECUTABLE_OUTPUT_PATH}/image_service_test
-)
-
-
-add_executable(simple_credsrv_test simple_credsrv_test.cpp)
-add_test(
-    NAME simple_credsrv_test
-    COMMAND ${EXECUTABLE_OUTPUT_PATH}/simple_credsrv_test
-)
-target_link_libraries(simple_credsrv_test
-overlaybd_image_lib
-photon_static
-rt
-resolv
-aio
-pthread
-gtest
-)
-
-target_include_directories(simple_credsrv_test PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-    $ENV{GTEST}/googletest/include
-)
-
-add_executable(trace_test trace_test.cpp ../tools/comm_func.cpp)
-target_include_directories(trace_test PUBLIC
-    ${PHOTON_INCLUDE_DIR}
-    ${RAPIDJSON_INCLUDE_DIRS}
-)
-target_link_libraries(trace_test gtest gtest_main gflags pthread photon_static overlaybd_lib overlaybd_image_lib)
-
-add_test(
-    NAME trace_test
-    COMMAND ${EXECUTABLE_OUTPUT_PATH}/trace_test
-)
-
-if (NOT ORIGIN_EXT2FS)
-    set_source_files_properties(
-        ${E2FS_RESIZE_DIR}/resize2fs.o
-        ${E2FS_RESIZE_DIR}/extent.o
-        ${E2FS_RESIZE_DIR}/resource_track.o
-        PROPERTIES GENERATED TRUE EXTERNAL_OBJECT TRUE)
-    add_executable(resize_test
-        resize_test.cpp
-        ${E2FS_RESIZE_DIR}/resize2fs.o
-        ${E2FS_RESIZE_DIR}/extent.o
-        ${E2FS_RESIZE_DIR}/resource_track.o
-    )
-    target_include_directories(resize_test PUBLIC
-        ${PHOTON_INCLUDE_DIR}
-        ${E2FS_INCLUDE_DIRS}
-        ${E2FS_RESIZE_DIR}
-    )
-    target_link_libraries(resize_test gtest pthread photon_static ${E2FS_LIBRARIES})
-    add_dependencies(resize_test libext2fs_build)
-    add_test(
-        NAME resize_test
-        COMMAND ${EXECUTABLE_OUTPUT_PATH}/resize_test
-    )
-endif()
diff --git a/src/test/image_service_test.cpp b/src/test/image_service_test.cpp
index ae1a8a5f..152df7dc 100644
--- a/src/test/image_service_test.cpp
+++ b/src/test/image_service_test.cpp
@@ -37,12 +37,12 @@
 #include "../tools/comm_func.h"
 #include "../overlaybd/lsmt/file.h"
 
-char *test_ua = nullptr;
+const char *test_ua = nullptr;
 
 photon::net::ISocketServer *new_server(std::string ip, uint16_t port) {
     auto server = photon::net::new_tcp_socket_server();
     server->timeout(1000UL*1000);
-    server->setsockopt(SOL_SOCKET, SO_REUSEPORT, 1);
+    server->setsockopt<int>(SOL_SOCKET, SO_REUSEPORT, 1);
     server->bind(port, photon::net::IPAddr(ip.c_str()));
     server->listen();
     server->set_handler(nullptr);
@@ -154,7 +154,7 @@ TEST(http_client, user_agent) {
     client->set_user_agent(test_ua);
     DEFER(delete client);
     auto op = client->new_operation(photon::net::http::Verb::GET, target_get);
-    DEFER(delete op);
+    DEFER(client->destroy_operation(op));
     op->req.headers.content_length(0);
     client->call(op);
     EXPECT_EQ(op->status_code, 200);
@@ -291,7 +291,7 @@ class HTTPServerTest : public DevIDRegisterTest {
         auto client = photon::net::http::new_http_client();
         DEFER(delete client);
         auto op = client->new_operation(photon::net::http::Verb::GET, request_url);
-        DEFER(delete op);
+        DEFER(client->destroy_operation(op));
         op->req.headers.content_length(0);
         // std::cout << "op->req.target(): " << op->req.target() << " op->req.query(): " << op->req.query() << std::endl;
         client->call(op);
@@ -319,12 +319,12 @@ TEST_F(HTTPServerTest, http_server) {
 }
 
 #define PREADV_SINGLE(file, buf, count, offset) ({ \
-    struct iovec iov = { .iov_base = (void *)buf, .iov_len = count }; \
+    struct iovec iov = { .iov_base = (void *)buf, .iov_len = (size_t)(count) }; \
     (file)->preadv(&iov, 1, offset); \
 })
 
 #define PWRITEV_SINGLE(file, buf, count, offset) ({ \
-    struct iovec iov = { .iov_base = (void *)buf, .iov_len = count }; \
+    struct iovec iov = { .iov_base = (void *)buf, .iov_len = (size_t)(count) }; \
     (file)->pwritev(&iov, 1, offset); \
 })
 
@@ -367,7 +367,7 @@ class CreateSnapshotTest : public DevIDRegisterTest {
         srand(154574045);
     }
 
-    void create_file_rw(char *data_name, char *index_name, bool sparse = false) {
+    void create_file_rw(const char *data_name, const char *index_name, bool sparse = false) {
         auto fdata = photon::fs::open_localfile_adaptor(data_name, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU);
         auto findex = photon::fs::open_localfile_adaptor(index_name, O_RDWR | O_CREAT | O_TRUNC, S_IRWXU);
         LSMT::LayerInfo args(fdata, findex);
@@ -432,8 +432,9 @@ TEST_F(CreateSnapshotTest, create_snapshot) {
     EXPECT_EQ(ret, len);
     for(auto i = 0; i < len; i++) {
         EXPECT_EQ(buf0[i], buf1[i]);
-        if(i >= len / 4 && i < len / 2 + len / 4)
+        if (i >= len / 4 && i < len / 2 + len / 4) {
             EXPECT_EQ(buf0[i], buf[i - len / 4]);
+        }
     }
 
     delete imgfile0;
@@ -491,8 +492,9 @@ TEST_F(CreateSnapshotTest, create_snapshot_sparse) {
     EXPECT_EQ(ret, len);
     for(auto i = 0; i < len; i++) {
         EXPECT_EQ(buf0[i], buf1[i]);
-        if(i >= len / 4 && i < len / 2 + len / 4)
+        if (i >= len / 4 && i < len / 2 + len / 4) {
             EXPECT_EQ(buf0[i], buf[i - len / 4]);
+        }
     }
 
     delete imgfile0;
diff --git a/src/test/simple_credsrv_test.cpp b/src/test/simple_credsrv_test.cpp
index 169c47df..eaeda14b 100644
--- a/src/test/simple_credsrv_test.cpp
+++ b/src/test/simple_credsrv_test.cpp
@@ -78,7 +78,7 @@ class SimpleAuthHandler : public HTTPHandler {
 TEST(auth, http_server) {
     auto tcpserver = photon::net::new_tcp_socket_server();
     tcpserver->timeout(1000UL*1000);
-    tcpserver->setsockopt(SOL_SOCKET, SO_REUSEPORT, 1);
+    tcpserver->setsockopt<int>(SOL_SOCKET, SO_REUSEPORT, 1);
     tcpserver->bind(19876, IPAddr("127.0.0.1"));
     tcpserver->listen();
     DEFER(delete tcpserver);
diff --git a/src/tools/CMakeLists.txt b/src/tools/CMakeLists.txt
deleted file mode 100644
index 43c13733..00000000
--- a/src/tools/CMakeLists.txt
+++ /dev/null
@@ -1,54 +0,0 @@
-add_executable(overlaybd-commit overlaybd-commit.cpp)
-target_include_directories(overlaybd-commit PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(overlaybd-commit photon_static overlaybd_image_lib)
-
-add_executable(overlaybd-merge overlaybd-merge.cpp)
-target_include_directories(overlaybd-merge PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(overlaybd-merge photon_static overlaybd_image_lib)
-
-
-add_executable(overlaybd-create overlaybd-create.cpp)
-target_include_directories(overlaybd-create PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(overlaybd-create photon_static overlaybd_lib)
-set_target_properties(overlaybd-create PROPERTIES INSTALL_RPATH "/opt/overlaybd/lib")
-
-add_executable(overlaybd-zfile overlaybd-zfile.cpp)
-target_include_directories(overlaybd-zfile PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(overlaybd-zfile photon_static overlaybd_lib)
-
-add_executable(overlaybd-apply overlaybd-apply.cpp qcow2converter.cpp)
-target_include_directories(overlaybd-apply PUBLIC ${PHOTON_INCLUDE_DIR} ${RAPIDJSON_INCLUDE_DIRS})
-target_link_libraries(overlaybd-apply photon_static overlaybd_lib overlaybd_image_lib checksum_lib z)
-set_target_properties(overlaybd-apply PROPERTIES INSTALL_RPATH "/opt/overlaybd/lib")
-
-add_executable(turboOCI-apply turboOCI-apply.cpp)
-target_include_directories(turboOCI-apply PUBLIC ${PHOTON_INCLUDE_DIR} ${RAPIDJSON_INCLUDE_DIRS})
-target_link_libraries(turboOCI-apply photon_static overlaybd_lib overlaybd_image_lib)
-set_target_properties(turboOCI-apply PROPERTIES INSTALL_RPATH "/opt/overlaybd/lib")
-
-add_library(checksum_lib sha256file.cpp)
-target_include_directories(checksum_lib PUBLIC ${PHOTON_INCLUDE_DIR})
-target_link_libraries(checksum_lib photon_static)
-
-# overlaybd-resize: userspace ext4 resize for overlaybd images
-if (NOT ORIGIN_EXT2FS)
-    add_executable(overlaybd-resize overlaybd-resize.cpp)
-    target_include_directories(overlaybd-resize PUBLIC ${PHOTON_INCLUDE_DIR})
-    target_link_libraries(overlaybd-resize photon_static overlaybd_image_lib)
-    set_target_properties(overlaybd-resize PROPERTIES INSTALL_RPATH "/opt/overlaybd/lib")
-endif()
-
-install(TARGETS
-    overlaybd-commit
-    overlaybd-create
-    overlaybd-zfile
-    overlaybd-apply
-    overlaybd-merge
-
-    turboOCI-apply
-    DESTINATION /opt/overlaybd/bin
-)
-
-if (NOT ORIGIN_EXT2FS)
-    install(TARGETS overlaybd-resize DESTINATION /opt/overlaybd/bin)
-endif()
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
new file mode 100644
index 00000000..1f310e12
--- /dev/null
+++ b/test/CMakeLists.txt
@@ -0,0 +1,75 @@
+find_package(gtest REQUIRED)  # GTEST::gtest
+find_package(gflags REQUIRED) # GFLAGS::gflags
+
+set(SRC_DIR ${PROJECT_SOURCE_DIR}/src)
+
+# Every test brings its own main(), gtest_main is deliberately not linked.
+function(overlaybd_add_test name)
+    add_executable(${name} ${ARGN})
+    target_link_libraries(${name} PRIVATE GTEST::gtest)
+    add_test(NAME ${name} COMMAND ${name})
+endfunction()
+
+overlaybd_add_test(lsmt_test ${SRC_DIR}/overlaybd/lsmt/test/test.cpp)
+target_link_libraries(lsmt_test PRIVATE overlaybd_lib GFLAGS::gflags)
+
+overlaybd_add_test(zfile_test ${SRC_DIR}/overlaybd/zfile/test/test.cpp)
+target_link_libraries(zfile_test PRIVATE overlaybd_lib GFLAGS::gflags)
+
+overlaybd_add_test(cache_test ${SRC_DIR}/overlaybd/cache/test/cache_test.cpp)
+target_link_libraries(cache_test PRIVATE overlaybd_lib)
+
+overlaybd_add_test(gzindex_test ${SRC_DIR}/overlaybd/gzindex/test/test.cpp)
+target_link_libraries(gzindex_test PRIVATE gzindex_lib gzip_lib cache_lib checksum_lib)
+
+# test.cpp goes through photon's extfs
+overlaybd_add_test(untar_test ${SRC_DIR}/overlaybd/tar/test/test.cpp)
+target_link_libraries(untar_test PRIVATE
+    tar_lib lsmt_lib gzip_lib gzindex_lib checksum_lib E2FSPROGS::libext2fs)
+
+overlaybd_add_test(erofs_simple_test ${SRC_DIR}/overlaybd/tar/erofs/test/erofs_simple.cpp)
+target_link_libraries(erofs_simple_test PRIVATE overlaybd_image_lib)
+
+overlaybd_add_test(erofs_stress_test
+    ${SRC_DIR}/overlaybd/tar/erofs/test/erofs_stress.cpp
+    ${SRC_DIR}/overlaybd/tar/erofs/test/erofs_stress_base.cpp)
+target_link_libraries(erofs_stress_test PRIVATE overlaybd_image_lib)
+
+overlaybd_add_test(image_service_test ${SRC_DIR}/test/image_service_test.cpp)
+target_link_libraries(image_service_test PRIVATE overlaybd_image_lib)
+
+overlaybd_add_test(simple_credsrv_test ${SRC_DIR}/test/simple_credsrv_test.cpp)
+target_link_libraries(simple_credsrv_test PRIVATE overlaybd_image_lib)
+
+overlaybd_add_test(trace_test ${SRC_DIR}/test/trace_test.cpp)
+target_link_libraries(trace_test PRIVATE overlaybd_image_lib)
+
+# resize_test drives resize2fs directly, so it needs the objects that
+# overlaybd_image_lib only re-exports for photon's resize_extfs()
+if(NOT ORIGIN_EXT2FS)
+    # These .o files are produced by the libext2fs_build step, so they are
+    # absent at configure time. The GENERATED/EXTERNAL_OBJECT properties are
+    # directory-scoped, hence set again here rather than inherited from the
+    # top-level CMakeLists.txt.
+    set_source_files_properties(
+        ${E2FS_RESIZE_DIR}/resize2fs.o
+        ${E2FS_RESIZE_DIR}/extent.o
+        ${E2FS_RESIZE_DIR}/resource_track.o
+        PROPERTIES GENERATED TRUE EXTERNAL_OBJECT TRUE)
+    overlaybd_add_test(resize_test
+        ${SRC_DIR}/test/resize_test.cpp
+        ${E2FS_RESIZE_DIR}/resize2fs.o
+        ${E2FS_RESIZE_DIR}/extent.o
+        ${E2FS_RESIZE_DIR}/resource_track.o)
+    target_include_directories(resize_test PRIVATE ${E2FS_INCLUDE_DIRS} ${E2FS_RESIZE_DIR})
+    target_link_libraries(resize_test PRIVATE external_lib E2FSPROGS::libext2fs)
+    add_dependencies(resize_test libext2fs_build)
+endif()
+
+# ocf_perf_test is a benchmark rather than a unit test, --ut_pass makes it
+# report success without running the workload
+if(ENABLE_OCF_CACHE)
+    add_executable(ocf_perf_test ${SRC_DIR}/overlaybd/cache/ocf_cache/test/ocf_perf_test.cpp)
+    target_link_libraries(ocf_perf_test PRIVATE overlaybd_lib GTEST::gtest GFLAGS::gflags)
+    add_test(NAME ocf_perf_test COMMAND ocf_perf_test --ut_pass=true)
+endif()