CA-402901: Update leaked dp to Sr

When add leaked datapath:
1. add leaked datapath to Sr.vdis
2. write to db file
3. log enhance

In XSI-1752/1753, there are storage exceptions rasied when
destroying datapath. Then the procedure fails and the state
of VDI becomes incorrect, which leads to various abnormal
results in subsequent operations.
We can find logs as "Leaked datapath: dp: xxxx". The leaked
datapath is designed to redestory the datapath and refresh
the state before next storage operation via function
remove_datapaths_andthen_nolock. But we don't find logs
about redestorying like "Attempting to destroy datapath".
It seems leaked datapath mechanism doesn't take effect.
This commit is to fix this bug. We should add leaked
datapath to Sr.vdis to make the leaked datapath realy work.
And write to db file to avoid losing the leaked datapath
when xapi restart.

Signed-off-by: Changlei Li <[email protected]>

ocaml/xapi/storage_smapiv1_wrapper.ml

@@ -453,6 +453,9 @@ functor
         List.fold_left perform_one vdi_t ops
 
       let perform_nolock context ~dbg ~dp ~sr ~vdi ~vm this_op =
+        debug "perform_nolock dp=%s, sr=%s, vdi=%s, vm=%s, op=%s" dp
+          (s_of_sr sr) (s_of_vdi vdi) (s_of_vm vm)
+          (Vdi_automaton.string_of_op this_op) ;
         match Host.find sr !Host.host with
         | None ->
             raise (Storage_error (Sr_not_attached (s_of_sr sr)))
@@ -473,6 +476,15 @@ functor
                    						   superstate to superstate'. These may fail: if so we revert the
                    						   datapath+VDI state to the most appropriate value. *)
                 let ops = Vdi_automaton.( - ) superstate superstate' in
+                debug "perform_nolock %s -> %s: %s"
+                  (Vdi_automaton.string_of_state superstate)
+                  (Vdi_automaton.string_of_state superstate')
+                  (String.concat ", "
+                     (List.map
+                        (fun (op, _) -> Vdi_automaton.string_of_op op)
+                        ops
+                     )
+                  ) ;
                 side_effects context dbg dp sr sr_t vdi vdi_t vm ops
               with e ->
                 let e =
@@ -529,7 +541,8 @@ functor
                     )
                 with e ->
                   if not allow_leak then (
-                    ignore (Vdi.add_leaked dp vdi_t) ;
+                    Sr.add_or_replace vdi (Vdi.add_leaked dp vdi_t) sr_t ;
+                    Everything.to_file !host_state_path (Everything.make ()) ;
                     raise e
                   ) else (
                     (* allow_leak means we can forget this dp *)