From: Yan, Zheng <zyan@redhat.com>
Date: Fri, 28 Nov 2014 13:11:05 +0000 (+0800)
Subject: mds: notify clients when MDS goes to readonly
X-Git-Tag: v0.91~52^2~14^2~6
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=f716903858bee8d7dfbf9e8aba0f4873b12a711b;p=ceph.git

mds: notify clients when MDS goes to readonly

notice clients that MDS goes to readonly and MDS won't issue write
caps any more.

Signed-off-by: Yan, Zheng <zyan@redhat.com>
---

diff --git a/src/include/ceph_fs.h b/src/include/ceph_fs.h
index 70a3958c7e55..c4776ea6bbd3 100644
--- a/src/include/ceph_fs.h
+++ b/src/include/ceph_fs.h
@@ -285,6 +285,7 @@ enum {
 	CEPH_SESSION_RECALL_STATE,
 	CEPH_SESSION_FLUSHMSG,
 	CEPH_SESSION_FLUSHMSG_ACK,
+	CEPH_SESSION_FORCE_RO,
 };
 
 extern const char *ceph_session_op_name(int op);
diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index 6488870bf857..ca3656e9b960 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -11284,6 +11284,8 @@ void MDCache::force_readonly()
 
   set_readonly();
 
+  mds->server->force_clients_readonly();
+
   // revoke write caps
   for (ceph::unordered_map<vinodeno_t,CInode*>::iterator p = inode_map.begin();
        p != inode_map.end();
diff --git a/src/mds/Server.cc b/src/mds/Server.cc
index 01e6cdc45882..3c36ff94575b 100644
--- a/src/mds/Server.cc
+++ b/src/mds/Server.cc
@@ -344,6 +344,8 @@ void Server::_session_logged(Session *session, uint64_t state_seq, bool open, ve
     mds->sessionmap.touch_session(session);
     assert(session->connection != NULL);
     session->connection->send_message(new MClientSession(CEPH_SESSION_OPEN));
+    if (mdcache->is_readonly())
+      session->connection->send_message(new MClientSession(CEPH_SESSION_FORCE_RO));
   } else if (session->is_closing() ||
 	     session->is_killing()) {
     // kill any lingering capabilities, leases, requests
@@ -448,11 +450,9 @@ void Server::finish_force_open_sessions(map<client_t,entity_inst_t>& cm,
 	dout(10) << "force_open_sessions opened " << session->info.inst << dendl;
 	mds->sessionmap.set_state(session, Session::STATE_OPEN);
 	mds->sessionmap.touch_session(session);
-	Message *m = new MClientSession(CEPH_SESSION_OPEN);
-	if (session->connection)
-	  session->connection->send_message(m);
-	else
-	  session->preopen_out_queue.push_back(m);
+	mds->send_message_client(new MClientSession(CEPH_SESSION_OPEN), session);
+	if (mdcache->is_readonly())
+	  mds->send_message_client(new MClientSession(CEPH_SESSION_FORCE_RO), session);
       }
     } else {
       dout(10) << "force_open_sessions skipping already-open " << session->info.inst << dendl;
@@ -841,6 +841,21 @@ void Server::recall_client_state(float ratio)
   }
 }
 
+void Server::force_clients_readonly()
+{
+  dout(10) << "force_clients_readonly" << dendl;
+  set<Session*> sessions;
+  mds->sessionmap.get_client_session_set(sessions);
+  for (set<Session*>::const_iterator p = sessions.begin();
+      p != sessions.end();
+      ++p) {
+    Session *session = *p;
+    if (!session->info.inst.name.is_client() ||
+	!(session->is_open() || session->is_stale()))
+      continue;
+    mds->send_message_client(new MClientSession(CEPH_SESSION_FORCE_RO), session);
+  }
+}
 
 /*******
  * some generic stuff for finishing off requests
diff --git a/src/mds/Server.h b/src/mds/Server.h
index 0cc95f145307..5a90d1394c9f 100644
--- a/src/mds/Server.h
+++ b/src/mds/Server.h
@@ -102,6 +102,7 @@ public:
   void recover_filelocks(CInode *in, bufferlist locks, int64_t client);
 
   void recall_client_state(float ratio);
+  void force_clients_readonly();
 
   // -- requests --
   void handle_client_request(MClientRequest *m);