From 0eacee9576265a9fa6a2ccb9db95a05436009487 Mon Sep 17 00:00:00 2001
From: "Yan, Zheng" <zyan@redhat.com>
Date: Sun, 22 Apr 2018 18:27:52 +0800
Subject: [PATCH] mds: combine MDCache::{cap_exports,cap_export_targets}

this change saves a map lookup

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
(cherry picked from commit ea72863b2b8ab5c387b70687300f6f7cff2019db)
---
 src/mds/MDCache.cc | 21 ++++++++++-----------
 src/mds/MDCache.h  |  8 ++++----
 2 files changed, 14 insertions(+), 15 deletions(-)

diff --git a/src/mds/MDCache.cc b/src/mds/MDCache.cc
index c10cc2fe4f8d5..f801dff71b787 100644
--- a/src/mds/MDCache.cc
+++ b/src/mds/MDCache.cc
@@ -3955,12 +3955,11 @@ void MDCache::rejoin_send_rejoins()
   if (mds->is_rejoin()) {
     map<client_t, set<mds_rank_t> > client_exports;
     for (auto p = cap_exports.begin(); p != cap_exports.end(); ++p) {
-      assert(cap_export_targets.count(p->first));
-      mds_rank_t target = cap_export_targets[p->first];
+      mds_rank_t target = p->second.first;
       if (rejoins.count(target) == 0)
 	continue;
-      rejoins[target]->cap_exports[p->first] = p->second;
-      for (auto q = p->second.begin(); q != p->second.end(); ++q)
+      rejoins[target]->cap_exports[p->first] = p->second.second;
+      for (auto q = p->second.second.begin(); q != p->second.second.end(); ++q)
 	client_exports[q->first].insert(target);
     }
     for (map<client_t, set<mds_rank_t> >::iterator p = client_exports.begin();
@@ -5062,13 +5061,13 @@ void MDCache::handle_cache_rejoin_ack(MMDSCacheRejoin *ack)
   for (map<inodeno_t,map<client_t,Capability::Import> >::iterator p = peer_imported.begin();
        p != peer_imported.end();
        ++p) {
-    assert(cap_exports.count(p->first));
-    assert(cap_export_targets.count(p->first));
-    assert(cap_export_targets[p->first] == from);
+    auto& ex = cap_exports.at(p->first);
+    assert(ex.first == from);
     for (map<client_t,Capability::Import>::iterator q = p->second.begin();
 	 q != p->second.end();
 	 ++q) {
-      assert(cap_exports[p->first].count(q->first));
+      auto r = ex.second.find(q->first);
+      assert(r != ex.second.end());
 
       dout(10) << " exporting caps for client." << q->first << " ino " << p->first << dendl;
       Session *session = mds->sessionmap.get_session(entity_name_t::CLIENT(q->first.v));
@@ -5076,15 +5075,15 @@ void MDCache::handle_cache_rejoin_ack(MMDSCacheRejoin *ack)
 
       // mark client caps stale.
       MClientCaps *m = new MClientCaps(CEPH_CAP_OP_EXPORT, p->first, 0,
-				       cap_exports[p->first][q->first].capinfo.cap_id, 0,
+				       r->second.capinfo.cap_id, 0,
                                        mds->get_osd_epoch_barrier());
       m->set_cap_peer(q->second.cap_id, q->second.issue_seq, q->second.mseq,
 		      (q->second.cap_id > 0 ? from : -1), 0);
       mds->send_message_client_counted(m, session);
 
-      cap_exports[p->first].erase(q->first);
+      ex.second.erase(r);
     }
-    assert(cap_exports[p->first].empty());
+    assert(ex.second.empty());
   }
 
   // done?
diff --git a/src/mds/MDCache.h b/src/mds/MDCache.h
index 3d3f9686414b3..c40c2452e65c6 100644
--- a/src/mds/MDCache.h
+++ b/src/mds/MDCache.h
@@ -548,8 +548,7 @@ protected:
   map<inodeno_t,pair<mds_rank_t,map<client_t,Capability::Export> > > rejoin_slave_exports;
   map<client_t,entity_inst_t> rejoin_client_map;
 
-  map<inodeno_t,map<client_t,cap_reconnect_t> > cap_exports; // ino -> client -> capex
-  map<inodeno_t,mds_rank_t> cap_export_targets; // ino -> auth mds
+  map<inodeno_t,pair<mds_rank_t,map<client_t,cap_reconnect_t> > > cap_exports; // ino -> target, client -> capex
 
   map<inodeno_t,map<client_t,map<mds_rank_t,cap_reconnect_t> > > cap_imports;  // ino -> client -> frommds -> capex
   set<inodeno_t> cap_imports_missing;
@@ -589,8 +588,9 @@ public:
   void rejoin_send_rejoins();
   void rejoin_export_caps(inodeno_t ino, client_t client, const cap_reconnect_t& icr,
 			  int target=-1) {
-    cap_exports[ino][client] = icr;
-    cap_export_targets[ino] = target;
+    auto& ex = cap_exports[ino];
+    ex.first = target;
+    ex.second[client] = icr;
   }
   void rejoin_recovered_caps(inodeno_t ino, client_t client, const cap_reconnect_t& icr, 
 			     mds_rank_t frommds=MDS_RANK_NONE) {
-- 
2.39.5