DAOS-13540 object: handle RESTART for TX convert with condition

dc_tx_convert_post() may be triggered by the callback for related
(existence) condition check. It is relative rare but valid, should
not assert.

Signed-off-by: Fan Yong <fan.yong@intel.com>

src/object/obj_tx.c

@@ -83,6 +83,7 @@ struct dc_tx {
  tx_for_convert:1,
  tx_has_cond:1,
  tx_renew:1,
+ tx_closed:1,
  tx_reintegrating:1;
  /** Transaction status (OPEN, COMMITTED, etc.), see dc_tx_status. */
  enum dc_tx_status tx_status;
@@ -2463,6 +2464,9 @@ dc_tx_open_snap(tse_task_t *task)
 static void
 dc_tx_close_internal(struct dc_tx *tx)
 {
+ D_ASSERT(tx->tx_closed == 0);
+
+ tx->tx_closed = 1;
  dc_tx_cleanup(tx);
  dc_tx_hdl_unlink(tx);
  dc_tx_decref(tx);
@@ -3575,9 +3579,6 @@ dc_tx_convert_restart(struct dc_tx *tx, struct dc_object *obj, enum obj_rpc_opc
  goto again;
 
 out:
- if (rc != 0 && tx->tx_has_cond)
- dc_tx_close_internal(tx);
-
  return rc;
 }
 
@@ -3590,7 +3591,6 @@ dc_tx_convert_cb(tse_task_t *task, void *data)
  enum obj_rpc_opc opc = conv->conv_opc;
  uint32_t backoff = 0;
  int rc = task->dt_result;
- bool tx_need_close = true;
 
  D_DEBUG(DB_IO, "Convert task %p/%p with DTX " DF_DTI ", pm_ver %u: %d\n", task,
  tx->tx_orig_task, DP_DTI(&tx->tx_id), tx->tx_pm_ver, rc);
@@ -3602,15 +3602,11 @@ dc_tx_convert_cb(tse_task_t *task, void *data)
  * dc_tx_convert_post().
  */
  task->dt_result = 0;
- tx_need_close = false;
 
- rc = dc_tx_convert_restart(tx, obj, opc, &backoff);
- if (!tx->tx_has_cond)
- rc = dc_tx_convert_post(tx, obj, opc, rc, backoff);
- }
-
- if (tx_need_close)
+ rc = dc_tx_convert_post(tx, obj, opc, rc, backoff);
+ } else {
  dc_tx_close_internal(tx);
+ }
 
  /* Drop object reference held via dc_tx_convert_post(). */
  obj_decref(obj);
@@ -3630,7 +3626,14 @@ dc_tx_convert_post(struct dc_tx *tx, struct dc_object *obj, enum obj_rpc_opc opc
  int rc = 0;
  bool tx_need_close = true;
 
- D_ASSERT(result != -DER_TX_RESTART);
+ if (unlikely(result == -DER_TX_RESTART)) {
+ result = dc_tx_convert_restart(tx, obj, opc, &backoff);
+ /* For condition case, dc_tx_convert_post() will be triggered by dc_tx_post() some
+ * time later after being re-attached.
+ */
+ if (result == 0 && tx->tx_has_cond)
+ return 0;
+ }
 
  if (result != 0)
  D_GOTO(out, rc = result);
@@ -3687,7 +3690,6 @@ dc_tx_convert(struct dc_object *obj, enum obj_rpc_opc opc, tse_task_t *task)
 {
  struct dc_tx *tx = NULL;
  int rc = 0;
- uint32_t backoff = 0;
  daos_handle_t coh;
 
  D_ASSERT(obj != NULL);
@@ -3709,15 +3711,13 @@ dc_tx_convert(struct dc_object *obj, enum obj_rpc_opc opc, tse_task_t *task)
  tx->tx_for_convert = 1;
  tx->tx_orig_task = task;
  rc = dc_tx_attach(dc_tx_ptr2hdl(tx), obj, opc, task, 0, false);
- if (unlikely(rc == -DER_TX_RESTART))
- rc = dc_tx_convert_restart(tx, obj, opc, &backoff);
 
  /* The 'task' will be completed via dc_tx_convert_post(). For condition case,
  * dc_tx_convert_post() will be triggered via condition callback; otherwise,
  * call dc_tx_convert_post() directly.
  */
- if (!tx->tx_has_cond)
- rc = dc_tx_convert_post(tx, obj, opc, rc, backoff);
+ if (!tx->tx_has_cond || rc != 0)
+ rc = dc_tx_convert_post(tx, obj, opc, rc, 0);
 
 out:
  if (tx != NULL)