cmake/os: remove WITH_ZFS option

when enabled and found, the os_zfs_objs target would reference a missing
file filestore/ZFSFileStoreBackend.cc and cmake would fail to configure

i take this to mean that WITH_ZFS was accidentally left over from
filestore's removal. drop all references to WITH_ZFS, along with the
corresponding Findzfs.cmake script

Signed-off-by: Casey Bodley <[email protected]>

Author: cbodley

CMakeLists.txt

@@ -242,12 +242,6 @@ if(WITH_XFS)
   set(HAVE_LIBXFS ${XFS_FOUND})
 endif()
 
-option(WITH_ZFS "enable LibZFS if found" OFF)
-if(WITH_ZFS)
-  find_package(zfs)
-  set(HAVE_LIBZFS ${ZFS_FOUND})
-endif()
-
 option(WITH_BLUESTORE "Bluestore OSD backend" ON)
 if(WITH_BLUESTORE)
   if(LINUX)

cmake/modules/Findzfs.cmake

@@ -37,15 +37,6 @@ if(HAVE_LIBXFS)
     fs/XFS.cc)
 endif()
 
-if(HAVE_LIBZFS)
-  add_library(os_zfs_objs OBJECT
-    filestore/ZFSFileStoreBackend.cc
-    fs/ZFS.cc)
-  target_include_directories(os_zfs_objs SYSTEM PRIVATE
-    ${ZFS_INCLUDE_DIRS})
-  list(APPEND libos_srcs $<TARGET_OBJECTS:os_zfs_objs>)
-endif()
-
 add_library(os STATIC ${libos_srcs})
 target_link_libraries(os
   legacy-option-headers
@@ -66,10 +57,6 @@ if(WITH_FUSE)
   target_link_libraries(os FUSE::FUSE)
 endif()
 
-if(HAVE_LIBZFS)
-  target_link_libraries(os ${ZFS_LIBRARIES})
-endif()
-
 if(WITH_LTTNG)
   add_dependencies(os objectstore-tp)
   add_dependencies(os bluestore-tp)