[LU-12695] A client panics if a request succeeded from Server but the following processing on the client failed.

• Type: Bug
• Resolution: Unresolved
• Priority: Major
• Affects Version/s: Lustre 2.12.2
• Severity: 3
• Assignee: Tatsushi Takamura
• Reporter: Tatsushi Takamura

Description

A client panics if a request succeeded but the following processing failed.
The flow is below.

mdc_enqueue_base
 ldlm_cli_enqueue 
　 ptlrpc_queue_wait      // succeeded, that is, req->rq_transno != 0
  ldlm_cli_enqueue_fini  // failed, that is, rc != 0
   ldlm_lock_change_resource // error ex. ENOMEM
 mdc_clear_replay_flag
  LBUG // <-

There are serveral ways that ldlm_cli_enqueue() may fail even if ldlm_cli_enqueue() succeeded. LBUG should be removed.