ocfs2/dlm: return in progress if master can not clear the refmap bit right now

Master returns in-progress to non-master node when it can not clear the
refmap bit right now.  And non-master node will not purge the lock
resource until receiving deref done message.

Signed-off-by: xuejiufei <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 8913e7d..87e2254 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -2278,7 +2278,7 @@
 		dlm_print_one_lock_resource(res);
 		BUG();
 	}
-	return ret;
+	return ret ? ret : r;
 }
 
 int dlm_deref_lockres_handler(struct o2net_msg *msg, u32 len, void *data,
@@ -2345,7 +2345,7 @@
 		     	res->lockname.len, res->lockname.name, node);
 			dlm_print_one_lock_resource(res);
 		}
-		ret = 0;
+		ret = DLM_DEREF_RESPONSE_DONE;
 		goto done;
 	}
 
@@ -2365,7 +2365,7 @@
 	spin_unlock(&dlm->work_lock);
 
 	queue_work(dlm->dlm_worker, &dlm->dispatched_work);
-	return 0;
+	return DLM_DEREF_RESPONSE_INPROG;
 
 done:
 	if (res)
@@ -2511,6 +2511,8 @@
 	}
 	spin_unlock(&res->spinlock);
 
+	dlm_drop_lockres_ref_done(dlm, res, node);
+
 	if (cleared) {
 		mlog(0, "%s:%.*s node %u ref dropped in dispatch\n",
 		     dlm->name, res->lockname.len, res->lockname.name, node);