CA-405628: unmount/detach PVS cache VDI before destroying

ocaml/xapi/pvs_cache_vdi.ml

@@ -79,11 +79,22 @@ let get_or_recreate_vdi ~__context ~self =
           vdi
   )
 
+let ensure_vdi_is_closed ~__context vdi =
+  (* The pvsproxy daemon normally unmounts and removes the locally attached VBD
+     for the cache VDI. Here we do it as well, just in case pvsproxy did not
+     manage to, for whatever reason. *)
+  try
+    let uuid = Db.VDI.get_uuid ~__context ~self:vdi in
+    let _ = Helpers.call_script !Xapi_globs.pvsproxy_close_cache_vdi [uuid] in
+    ()
+  with _ -> () (* call_script will log anything interesting already *)
+
 let destroy_vdi ~__context ~self =
   match get_vdi ~__context ~self with
   | None ->
       () (* The VDI doesn't exist anymore; nothing to do. *)
   | Some vdi ->
+      ensure_vdi_is_closed ~__context vdi ;
       Helpers.call_api_functions ~__context (fun rpc session_id ->
           Client.Client.VDI.destroy ~rpc ~session_id ~self:vdi
       )

ocaml/xapi/xapi_globs.ml

@@ -939,6 +939,8 @@ let dracut = ref "/usr/bin/dracut"
 
 let udevadm = ref "/usr/sbin/udevadm"
 
+let pvsproxy_close_cache_vdi = ref "/opt/citrix/pvsproxy/close-cache-vdi.sh"
+
 let yum_repos_config_dir = ref "/etc/yum.repos.d"
 
 let remote_repository_prefix = ref "remote"
@@ -1805,6 +1807,10 @@ module Resources = struct
     ; ("depmod", depmod, "Path to depmod command")
     ; ("dracut", dracut, "Path to dracut command")
     ; ("udevadm", udevadm, "Path to udevadm command")
+    ; ( "pvsproxy_close_cache_vdi"
+      , pvsproxy_close_cache_vdi
+      , "Path to close-cache-vdi.sh"
+      )
     ]
 
   let nonessential_executables =