From: Zhi Zhang <willzzhang@tencent.com>
Date: Mon, 27 Jun 2016 05:00:26 +0000 (+0800)
Subject: mds: fix shutting down mds timed-out due to deadlock
X-Git-Tag: v10.2.3~34^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=1d3a816814c6cb87f645f205362de800cc84d484;p=ceph.git

mds: fix shutting down mds timed-out due to deadlock

Signed-off-by: Zhi Zhang <zhangz.david@outlook.com>
(cherry picked from commit ca069149654ecd10778cd5327bf59b9643e23967)
---

diff --git a/src/mds/MDSRank.cc b/src/mds/MDSRank.cc
index 68ea33eb0b3..9c5def15a94 100644
--- a/src/mds/MDSRank.cc
+++ b/src/mds/MDSRank.cc
@@ -237,7 +237,11 @@ void MDSRankDispatcher::shutdown()
   progress_thread.shutdown();
 
   // shut down messenger
+  // release mds_lock first because messenger thread might call 
+  // MDSDaemon::ms_handle_reset which will try to hold mds_lock
+  mds_lock.Unlock();
   messenger->shutdown();
+  mds_lock.Lock();
 
   // Workaround unclean shutdown: HeartbeatMap will assert if
   // worker is not removed (as we do in ~MDS), but ~MDS is not