From 2222bf5eb2e77aca6baa736638b719d0bda8b2bb Mon Sep 17 00:00:00 2001
From: dongdong <tdd21151186@gmail.com>
Date: Wed, 7 Jun 2017 13:41:27 +0800
Subject: [PATCH] Client: signal MDS to flush log when doing a syncfs Fixes:
 http://tracker.ceph.com/issues/20129 Signed-off-by: dongdong tao
 <tdd21151186@gmail.com>

---
 src/client/Client.cc  | 19 +++++++++++++++++++
 src/client/Client.h   |  6 +++++-
 src/include/ceph_fs.h |  3 ++-
 src/mds/Server.cc     |  4 ++++
 4 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/src/client/Client.cc b/src/client/Client.cc
index 0a55e73977e3b..93d348c026b37 100644
--- a/src/client/Client.cc
+++ b/src/client/Client.cc
@@ -5788,6 +5788,24 @@ void Client::_close_sessions()
   }
 }
 
+void Client::flush_mdlog_sync()
+{
+
+  for (map<mds_rank_t,MetaSession*>::iterator p = mds_sessions.begin();
+       p != mds_sessions.end();
+       ++p) {
+    MetaSession *s = p->second;
+    flush_mdlog(s);
+  }
+}
+
+void Client::flush_mdlog(MetaSession *session)
+{
+  MClientSession *m = new MClientSession(CEPH_SESSION_REQUEST_FLUSH_MDLOG);
+  session->con->send_message(m);
+}
+
+
 void Client::unmount()
 {
   Mutex::Locker lock(client_lock);
@@ -5799,6 +5817,7 @@ void Client::unmount()
 
   while (!mds_requests.empty()) {
     ldout(cct, 10) << "waiting on " << mds_requests.size() << " requests" << dendl;
+    flush_mdlog_sync();
     mount_cond.Wait(client_lock);
   }
 
diff --git a/src/client/Client.h b/src/client/Client.h
index da06729e8176d..b6369a29363e1 100644
--- a/src/client/Client.h
+++ b/src/client/Client.h
@@ -724,7 +724,11 @@ protected:
 
   bool use_faked_inos() { return _use_faked_inos; }
   vinodeno_t map_faked_ino(ino_t ino);
-
+ 
+  //notify the mds to flush the mdlog
+  void flush_mdlog_sync();
+  void flush_mdlog(MetaSession *session);
+  
   // ----------------------
   // fs ops.
 private:
diff --git a/src/include/ceph_fs.h b/src/include/ceph_fs.h
index 726ee69d62f21..4188bff8b03fd 100644
--- a/src/include/ceph_fs.h
+++ b/src/include/ceph_fs.h
@@ -305,7 +305,8 @@ enum {
 	CEPH_SESSION_FORCE_RO,
     // A response to REQUEST_OPEN indicating that the client should
     // permanently desist from contacting the MDS
-	CEPH_SESSION_REJECT
+	CEPH_SESSION_REJECT,
+        CEPH_SESSION_REQUEST_FLUSH_MDLOG
 };
 
 extern const char *ceph_session_op_name(int op);
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 43ea584be1b1d..7dab254119281 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -455,6 +455,10 @@ void Server::handle_client_session(MClientSession *m)
     finish_flush_session(session, m->get_seq());
     break;
 
+  case CEPH_SESSION_REQUEST_FLUSH_MDLOG:
+    mdlog->flush();
+    break;
+
   default:
     ceph_abort();
   }
-- 
2.39.5