From 0c205a51acd16a770d92556479eee4dfa1154488 Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Mon, 25 May 2009 11:12:06 -0700
Subject: [PATCH] osd: only register the ObjectContext if we go on to write

We only need it to be registered if we are carrying state over some period
of time, which isn't the case for reads.
---
 src/messages/MOSDOp.h   |  3 ++-
 src/osd/ReplicatedPG.cc | 33 +++++++++++++++++++++------------
 src/osd/ReplicatedPG.h  |  8 +++++++-
 3 files changed, 30 insertions(+), 14 deletions(-)

diff --git a/src/messages/MOSDOp.h b/src/messages/MOSDOp.h
index 7736419a5ebae..a70365f273622 100644
--- a/src/messages/MOSDOp.h
+++ b/src/messages/MOSDOp.h
@@ -180,7 +180,8 @@ public:
       out << "r";
     if (may_write())
       out << "w";
-    else
+
+    if (head.snapid != CEPH_NOSNAP)
       out << "@" << snapid_t((__u64)head.snapid);
 
     out << " " << ops;
diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index c491e744cacbc..a0789994870cc 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -1838,11 +1838,12 @@ void ReplicatedPG::repop_ack(RepGather *repop, int result, int ack_type,
 
 ReplicatedPG::ObjectContext *ReplicatedPG::get_object_context(const sobject_t& soid, bool can_create)
 {
-  map<sobject_t, ObjectContext>::iterator p = object_contexts.find(soid);
+  map<sobject_t, ObjectContext*>::iterator p = object_contexts.find(soid);
   ObjectContext *obc;
   if (p != object_contexts.end()) {
-    obc = &p->second;
-    dout(10) << "get_object_context " << soid << " " << obc->ref << " -> " << (obc->ref+1) << dendl;
+    obc = p->second;
+    dout(10) << "get_object_context " << soid << " " << obc->ref
+	     << " -> " << (obc->ref+1) << dendl;
   } else {
     // check disk
     struct stat st;
@@ -1850,7 +1851,7 @@ ReplicatedPG::ObjectContext *ReplicatedPG::get_object_context(const sobject_t& s
     if (r < 0 && !can_create)
       return 0;   // -ENOENT!
 
-    obc = &object_contexts[soid];
+    obc = new ObjectContext;
     obc->soid = soid;
 
     if (r == 0) {
@@ -1953,7 +1954,10 @@ void ReplicatedPG::put_object_context(ObjectContext *obc)
   if (obc->ref == 0) {
     assert(obc->waiting.empty());
 
-    object_contexts.erase(obc->soid);
+    if (obc->registered)
+      object_contexts.erase(obc->soid);
+    delete obc;
+
     if (object_contexts.empty())
       kick();
   }
@@ -2078,8 +2082,6 @@ void ReplicatedPG::op_modify(MOSDOp *op, ObjectContext *obc)
     noop = true;
   }
 
-  ctx->mtime = op->get_mtime();
-
   // version
   ctx->at_version = log.top;
   if (!noop) {
@@ -2089,12 +2091,16 @@ void ReplicatedPG::op_modify(MOSDOp *op, ObjectContext *obc)
     assert(ctx->at_version > log.top);
   }
 
-  // snap
-  ctx->snapc.seq = op->get_snap_seq();
-  ctx->snapc.snaps = op->get_snaps();
+  if (op->may_write()) {
+    ctx->mtime = op->get_mtime();
+    
+    // snap
+    ctx->snapc.seq = op->get_snap_seq();
+    ctx->snapc.snaps = op->get_snaps();
 
-  // set version in op, for benefit of client and our eventual reply
-  op->set_version(ctx->at_version);
+    // set version in op, for benefit of client and our eventual reply
+    op->set_version(ctx->at_version);
+  }
 
   dout(10) << "op_modify " << soid << " " << ctx->ops
            << " ov " << obc->oi.version << " av " << ctx->at_version 
@@ -2144,6 +2150,9 @@ void ReplicatedPG::op_modify(MOSDOp *op, ObjectContext *obc)
 
     log_op(ctx);
   }
+  
+  // continuing on to write path, make sure object context is registered
+  register_object_context(obc);
 
   if (ctx->indata.length()) {
     osd->logger->inc(l_osd_c_wr);
diff --git a/src/osd/ReplicatedPG.h b/src/osd/ReplicatedPG.h
index 211145ee14dc3..c8f61cdd8233e 100644
--- a/src/osd/ReplicatedPG.h
+++ b/src/osd/ReplicatedPG.h
@@ -327,9 +327,15 @@ protected:
 
 
   // projected object info
-  map<sobject_t, ObjectContext> object_contexts;
+  map<sobject_t, ObjectContext*> object_contexts;
 
   ObjectContext *get_object_context(const sobject_t& soid, bool can_create=true);
+  void register_object_context(ObjectContext *obc) {
+    if (!obc->registered) {
+      obc->registered = true;
+      object_contexts[obc->soid] = obc;
+    }
+  }
   void put_object_context(ObjectContext *obc);
   int find_object_context(object_t oid, snapid_t snapid, ObjectContext **pobc, bool can_create);
 
-- 
2.39.5