SERVER-14387 Propogate OperationContext through calls requiring document read locks, without doing the locking.

146 files changed, 1398 insertions, 1012 deletions

diff --git a/src/mongo/db/catalog/collection.cpp b/src/mongo/db/catalog/collection.cpp
index f21a00abfc6..37d5ae84104 100644
--- a/src/mongo/db/catalog/collection.cpp
+++ b/src/mongo/db/catalog/collection.cpp
@@ -1,7 +1,7 @@
 // collection.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -122,20 +122,23 @@ namespace mongo {
         return true;
     }
 
-    RecordIterator* Collection::getIterator( const DiskLoc& start, bool tailable,
-                                                     const CollectionScanParams::Direction& dir) const {
+    RecordIterator* Collection::getIterator( OperationContext* txn,
+                                             const DiskLoc& start,
+                                             bool tailable,
+                                             const CollectionScanParams::Direction& dir) const {
         invariant( ok() );
-        return _recordStore->getIterator( start, tailable, dir );
+        return _recordStore->getIterator( txn, start, tailable, dir );
     }
 
-    vector<RecordIterator*> Collection::getManyIterators() const {
-        return _recordStore->getManyIterators();
+    vector<RecordIterator*> Collection::getManyIterators( OperationContext* txn ) const {
+        return _recordStore->getManyIterators(txn);
     }
 
-    int64_t Collection::countTableScan( const MatchExpression* expression ) {
-        scoped_ptr<RecordIterator> iterator( getIterator( DiskLoc(),
-                                                              false,
-                                                              CollectionScanParams::FORWARD ) );
+    int64_t Collection::countTableScan( OperationContext* txn, const MatchExpression* expression ) {
+        scoped_ptr<RecordIterator> iterator( getIterator( txn,
+                                                          DiskLoc(),
+                                                          false,
+                                                          CollectionScanParams::FORWARD ) );
         int64_t count = 0;
         while ( !iterator->isEOF() ) {
             DiskLoc loc = iterator->getNext();
@@ -178,7 +181,7 @@ namespace mongo {
 
         if ( isCapped() ) {
             // TOOD: old god not done
-            Status ret = _indexCatalog.checkNoIndexConflicts( docToInsert );
+            Status ret = _indexCatalog.checkNoIndexConflicts( txn, docToInsert );
             if ( !ret.isOK() )
                 return StatusWith<DiskLoc>( ret );
         }
@@ -332,7 +335,7 @@ namespace mongo {
                 || repl::getGlobalReplicationCoordinator()->shouldIgnoreUniqueIndex(descriptor);
             UpdateTicket* updateTicket = new UpdateTicket();
             updateTickets.mutableMap()[descriptor] = updateTicket;
-            Status ret = iam->validateUpdate(objOld, objNew, oldLocation, options, updateTicket );
+            Status ret = iam->validateUpdate(txn, objOld, objNew, oldLocation, options, updateTicket );
             if ( !ret.isOK() ) {
                 return StatusWith<DiskLoc>( ret );
             }
@@ -527,7 +530,7 @@ namespace mongo {
                     invariant( iam );
 
                     int64_t keys;
-                    iam->validate(&keys);
+                    iam->validate(txn, &keys);
                     indexes.appendNumber(descriptor->indexNamespace(),
                                          static_cast<long long>(keys));
                     idxn++;
diff --git a/src/mongo/db/catalog/collection.h b/src/mongo/db/catalog/collection.h
index 6ddf8bd9cf4..dea27fdc77b 100644
--- a/src/mongo/db/catalog/collection.h
+++ b/src/mongo/db/catalog/collection.h
@@ -1,7 +1,7 @@
 // collection.h
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -137,7 +137,8 @@ namespace mongo {
          * canonical to get all would be
          * getIterator( DiskLoc(), false, CollectionScanParams::FORWARD )
          */
-        RecordIterator* getIterator( const DiskLoc& start = DiskLoc(),
+        RecordIterator* getIterator( OperationContext* txn,
+                                     const DiskLoc& start = DiskLoc(),
                                      bool tailable = false,
                                      const CollectionScanParams::Direction& dir = CollectionScanParams::FORWARD ) const;
 
@@ -146,7 +147,7 @@ namespace mongo {
          * all returned iterators is equivalent to Iterating the full collection.
          * Caller owns all pointers in the vector.
          */
-        std::vector<RecordIterator*> getManyIterators() const;
+        std::vector<RecordIterator*> getManyIterators( OperationContext* txn ) const;
 
 
         /**
@@ -154,7 +155,7 @@ namespace mongo {
          * this should only be used at a very low level
          * does no yielding, indexes, etc...
          */
-        int64_t countTableScan( const MatchExpression* expression );
+        int64_t countTableScan( OperationContext* txn, const MatchExpression* expression );
 
         void deleteDocument( OperationContext* txn,
                              const DiskLoc& loc,
diff --git a/src/mongo/db/catalog/collection_catalog_entry.h b/src/mongo/db/catalog/collection_catalog_entry.h
index 28d2def59ff..1b0175b59c8 100644
--- a/src/mongo/db/catalog/collection_catalog_entry.h
+++ b/src/mongo/db/catalog/collection_catalog_entry.h
@@ -51,7 +51,7 @@ namespace mongo {
 
         // ------- indexes ----------
 
-        virtual CollectionOptions getCollectionOptions() const = 0;
+        virtual CollectionOptions getCollectionOptions( OperationContext* txn ) const = 0;
 
         virtual int getTotalIndexCount() const = 0;
 
diff --git a/src/mongo/db/catalog/database.cpp b/src/mongo/db/catalog/database.cpp
index cbfd70a1502..e9ff8027e50 100644
--- a/src/mongo/db/catalog/database.cpp
+++ b/src/mongo/db/catalog/database.cpp
@@ -1,7 +1,7 @@
 // database.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -172,7 +172,7 @@ namespace mongo {
 
             CollectionCatalogEntry* coll = _dbEntry->getCollectionCatalogEntry( txn, ns );
 
-            CollectionOptions options = coll->getCollectionOptions();
+            CollectionOptions options = coll->getCollectionOptions( txn );
             if ( !options.temp )
                 continue;
 
@@ -267,7 +267,7 @@ namespace mongo {
             size += collection->dataSize();
 
             BSONObjBuilder temp;
-            storageSize += collection->getRecordStore()->storageSize( &temp );
+            storageSize += collection->getRecordStore()->storageSize( opCtx, &temp );
             numExtents += temp.obj()["numExtents"].numberInt(); // XXX
 
             indexes += collection->getIndexCatalog()->numIndexesTotal();
diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index 840d0042872..52df950c274 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -1,7 +1,7 @@
 // index_catalog.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -222,7 +222,8 @@ namespace mongo {
         }
 
         auto_ptr<Runner> runner(
-            InternalPlanner::collectionScan(db->_indexesName,
+            InternalPlanner::collectionScan(txn,
+                                            db->_indexesName,
                                             db->getCollection(txn, db->_indexesName)));
 
         BSONObj index;
@@ -691,7 +692,7 @@ namespace mongo {
                 EqualityMatchExpression expr;
                 BSONObj nsBSON = BSON( "ns" << _collection->ns() );
                 invariant( expr.init( "ns", nsBSON.firstElement() ).isOK() );
-                numSystemIndexesEntries = systemIndexes->countTableScan( &expr );
+                numSystemIndexesEntries = systemIndexes->countTableScan( txn, &expr );
             }
             else {
                 // this is ok, 0 is the right number
@@ -1078,7 +1079,7 @@ namespace mongo {
         }
     }
 
-    Status IndexCatalog::checkNoIndexConflicts( const BSONObj &obj ) {
+    Status IndexCatalog::checkNoIndexConflicts( OperationContext* txn, const BSONObj &obj ) {
         IndexIterator ii = getIndexIterator( true );
         while ( ii.more() ) {
             IndexDescriptor* descriptor = ii.next();
@@ -1096,7 +1097,7 @@ namespace mongo {
             options.dupsAllowed = false;
 
             UpdateTicket ticket;
-            Status ret = iam->validateUpdate(BSONObj(), obj, DiskLoc(), options, &ticket);
+            Status ret = iam->validateUpdate(txn, BSONObj(), obj, DiskLoc(), options, &ticket);
             if ( !ret.isOK() )
                 return ret;
         }
diff --git a/src/mongo/db/catalog/index_catalog.h b/src/mongo/db/catalog/index_catalog.h
index d4f3edcb281..9d509b9ebbe 100644
--- a/src/mongo/db/catalog/index_catalog.h
+++ b/src/mongo/db/catalog/index_catalog.h
@@ -1,7 +1,7 @@
 // index_catalog.h
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -247,7 +247,7 @@ namespace mongo {
          * checks all unique indexes and checks for conflicts
          * should not throw
          */
-        Status checkNoIndexConflicts( const BSONObj& obj );
+        Status checkNoIndexConflicts( OperationContext* txn, const BSONObj& obj );
 
         // ------- temp internal -------
 
diff --git a/src/mongo/db/catalog/index_create.cpp b/src/mongo/db/catalog/index_create.cpp
index 176939669c4..b230121d533 100644
--- a/src/mongo/db/catalog/index_create.cpp
+++ b/src/mongo/db/catalog/index_create.cpp
@@ -1,7 +1,7 @@
 // index_create.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -104,7 +104,7 @@ namespace mongo {
         unsigned long long n = 0;
         unsigned long long numDropped = 0;
 
-        auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns,collection));
+        auto_ptr<Runner> runner(InternalPlanner::collectionScan(txn,ns,collection));
 
         std::string idxName = descriptor->indexName();
 
diff --git a/src/mongo/db/commands/collection_to_capped.cpp b/src/mongo/db/commands/collection_to_capped.cpp
index e7859976de0..d2dbf60e565 100644
--- a/src/mongo/db/commands/collection_to_capped.cpp
+++ b/src/mongo/db/commands/collection_to_capped.cpp
@@ -1,7 +1,7 @@
 // collection_to_capped.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -81,9 +81,10 @@ namespace mongo {
         // datasize and extentSize can't be compared exactly, so add some padding to 'size'
         long long excessSize =
             static_cast<long long>( fromCollection->dataSize() -
-                                    ( toCollection->getRecordStore()->storageSize() * 2 ) );
+                                    ( toCollection->getRecordStore()->storageSize( txn ) * 2 ) );
 
-        scoped_ptr<Runner> runner( InternalPlanner::collectionScan(fromNs,
+        scoped_ptr<Runner> runner( InternalPlanner::collectionScan(txn,
+                                                                   fromNs,
                                                                    fromCollection,
                                                                    InternalPlanner::FORWARD ) );
 
diff --git a/src/mongo/db/commands/count.cpp b/src/mongo/db/commands/count.cpp
index aa43882ea78..9c901e71025 100644
--- a/src/mongo/db/commands/count.cpp
+++ b/src/mongo/db/commands/count.cpp
@@ -98,7 +98,7 @@ namespace mongo {
             limit = -limit;
         }
 
-        uassertStatusOK(getRunnerCount(collection, query, hintObj, &rawRunner));
+        uassertStatusOK(getRunnerCount(txn, collection, query, hintObj, &rawRunner));
         auto_ptr<Runner> runner(rawRunner);
 
         // Store the plan summary string in CurOp.
@@ -177,7 +177,7 @@ namespace mongo {
         // Get an executor for the command and use it to generate the explain output.
         CanonicalQuery* rawCq;
         PlanExecutor* rawExec;
-        Status execStatus = parseCountToExecutor(cmdObj, dbname, ns, collection,
+        Status execStatus = parseCountToExecutor(txn, cmdObj, dbname, ns, collection,
                                                  &rawCq, &rawExec);
         if (!execStatus.isOK()) {
             return execStatus;
@@ -189,7 +189,8 @@ namespace mongo {
         return Explain::explainStages(exec.get(), cq.get(), verbosity, out);
     }
 
-    Status CmdCount::parseCountToExecutor(const BSONObj& cmdObj,
+    Status CmdCount::parseCountToExecutor(OperationContext* txn,
+                                          const BSONObj& cmdObj,
                                           const std::string& dbname,
                                           const std::string& ns,
                                           Collection* collection,
@@ -229,7 +230,7 @@ namespace mongo {
 
         auto_ptr<CanonicalQuery> autoCq(cq);
 
-        Status execStat = getExecutor(collection, cq, execOut,
+        Status execStat = getExecutor(txn, collection, cq, execOut,
                                       QueryPlannerParams::PRIVATE_IS_COUNT);
         if (!execStat.isOK()) {
             return execStat;
diff --git a/src/mongo/db/commands/count.h b/src/mongo/db/commands/count.h
index eeaaac204f1..f6dcc19c535 100644
--- a/src/mongo/db/commands/count.h
+++ b/src/mongo/db/commands/count.h
@@ -98,7 +98,8 @@ namespace mongo {
          * TODO: the regular run() command for count should call this instead of getting
          * a runner.
          */
-        Status parseCountToExecutor(const BSONObj& cmdObj,
+        Status parseCountToExecutor(OperationContext* txn,
+                                    const BSONObj& cmdObj,
                                     const std::string& dbname,
                                     const std::string& ns,
                                     Collection* collection,
diff --git a/src/mongo/db/commands/dbhash.cpp b/src/mongo/db/commands/dbhash.cpp
index 9b4a2a385aa..47405dd9888 100644
--- a/src/mongo/db/commands/dbhash.cpp
+++ b/src/mongo/db/commands/dbhash.cpp
@@ -1,7 +1,7 @@
 // dbhash.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -84,7 +84,8 @@ namespace mongo {
 
         auto_ptr<Runner> runner;
         if ( desc ) {
-            runner.reset(InternalPlanner::indexScan(collection,
+            runner.reset(InternalPlanner::indexScan(opCtx,
+                                                    collection,
                                                     desc,
                                                     BSONObj(),
                                                     BSONObj(),
@@ -93,7 +94,8 @@ namespace mongo {
                                                     InternalPlanner::IXSCAN_FETCH));
         }
         else if ( collection->isCapped() ) {
-            runner.reset(InternalPlanner::collectionScan(fullCollectionName,
+            runner.reset(InternalPlanner::collectionScan(opCtx,
+                                                         fullCollectionName,
                                                          collection));
         }
         else {
diff --git a/src/mongo/db/commands/distinct.cpp b/src/mongo/db/commands/distinct.cpp
index 9e35ef3b0c7..ce582933d7a 100644
--- a/src/mongo/db/commands/distinct.cpp
+++ b/src/mongo/db/commands/distinct.cpp
@@ -1,7 +1,7 @@
 // distinct.cpp
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -115,7 +115,7 @@ namespace mongo {
             }
 
             Runner* rawRunner;
-            Status status = getRunnerDistinct(collection, query, key, &rawRunner);
+            Status status = getRunnerDistinct(txn, collection, query, key, &rawRunner);
             if (!status.isOK()) {
                 uasserted(17216, mongoutils::str::stream() << "Can't get runner for query "
                               << query << ": " << status.toString());
diff --git a/src/mongo/db/commands/find_and_modify.cpp b/src/mongo/db/commands/find_and_modify.cpp
index 125826760a0..f242327f935 100644
--- a/src/mongo/db/commands/find_and_modify.cpp
+++ b/src/mongo/db/commands/find_and_modify.cpp
@@ -1,7 +1,7 @@
 // find_and_modify.cpp
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -153,7 +153,7 @@ namespace mongo {
 
                 Runner* rawRunner;
                 massert(17384, "Could not get runner for query " + queryOriginal.toString(),
-                        getRunner(collection, cq, &rawRunner, QueryPlannerParams::DEFAULT).isOK());
+                        getRunner(txn, collection, cq, &rawRunner, QueryPlannerParams::DEFAULT).isOK());
 
                 auto_ptr<Runner> runner(rawRunner);
 
diff --git a/src/mongo/db/commands/geonear.cpp b/src/mongo/db/commands/geonear.cpp
index bbcc5ab19f5..f994004e2b2 100644
--- a/src/mongo/db/commands/geonear.cpp
+++ b/src/mongo/db/commands/geonear.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -187,7 +187,7 @@ namespace mongo {
             }
 
             Runner* rawRunner;
-            if (!getRunner(collection, cq, &rawRunner, 0).isOK()) {
+            if (!getRunner(txn, collection, cq, &rawRunner, 0).isOK()) {
                 errmsg = "can't get query runner";
                 return false;
             }
diff --git a/src/mongo/db/commands/group.cpp b/src/mongo/db/commands/group.cpp
index b65f4f85fcd..519a5989dd1 100644
--- a/src/mongo/db/commands/group.cpp
+++ b/src/mongo/db/commands/group.cpp
@@ -1,7 +1,7 @@
 // group.cpp
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -147,7 +147,7 @@ namespace mongo {
                 }
 
                 Runner* rawRunner;
-                if (!getRunner(collection, cq, &rawRunner).isOK()) {
+                if (!getRunner(txn,collection, cq, &rawRunner).isOK()) {
                     uasserted(17213, "Can't get runner for query " + query.toString());
                     return 0;
                 }
diff --git a/src/mongo/db/commands/list_collections.cpp b/src/mongo/db/commands/list_collections.cpp
index 46667c1a319..f7c32549627 100644
--- a/src/mongo/db/commands/list_collections.cpp
+++ b/src/mongo/db/commands/list_collections.cpp
@@ -1,7 +1,7 @@
 // list_collections.cpp
 
 /**
-*    Copyright (C) 2014 10gen Inc.
+*    Copyright (C) 2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -83,7 +83,7 @@ namespace mongo {
                 b.append( "name", nsToCollectionSubstring( ns ) );
 
                 CollectionOptions options =
-                    dbEntry->getCollectionCatalogEntry( txn, ns )->getCollectionOptions();
+                    dbEntry->getCollectionCatalogEntry( txn, ns )->getCollectionOptions(txn);
                 b.append( "options", options.toBSON() );
 
                 arr.append( b.obj() );
diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index a55597b58b2..b319dbd9e8a 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -981,7 +981,7 @@ namespace mongo {
                                                 whereCallback).isOK());
 
             Runner* rawRunner;
-            verify(getRunner(ctx->ctx().db()->getCollection(_txn, _config.incLong),
+            verify(getRunner(_txn, ctx->ctx().db()->getCollection(_txn, _config.incLong),
                              cq, &rawRunner, QueryPlannerParams::NO_TABLE_SCAN).isOK());
 
             auto_ptr<Runner> runner(rawRunner);
@@ -1324,7 +1324,7 @@ namespace mongo {
                         }
 
                         Runner* rawRunner;
-                        if (!getRunner(ctx->db()->getCollection(txn, config.ns), cq, &rawRunner).isOK()) {
+                        if (!getRunner(txn, ctx->db()->getCollection(txn, config.ns), cq, &rawRunner).isOK()) {
                             uasserted(17239, "Can't get runner for query " + config.filter.toString());
                             return 0;
                         }
diff --git a/src/mongo/db/commands/parallel_collection_scan.cpp b/src/mongo/db/commands/parallel_collection_scan.cpp
index 4f41daa71f1..c10cf053534 100644
--- a/src/mongo/db/commands/parallel_collection_scan.cpp
+++ b/src/mongo/db/commands/parallel_collection_scan.cpp
@@ -185,7 +185,7 @@ namespace mongo {
                                                     "numCursors has to be between 1 and 10000" <<
                                                     " was: " << numCursors ) );
 
-            OwnedPointerVector<RecordIterator> iterators(collection->getManyIterators());
+            OwnedPointerVector<RecordIterator> iterators(collection->getManyIterators(txn));
 
             if (iterators.size() < numCursors) {
                 numCursors = iterators.size();
diff --git a/src/mongo/db/commands/pipeline_command.cpp b/src/mongo/db/commands/pipeline_command.cpp
index 6e5232d4c12..5033dd05da7 100644
--- a/src/mongo/db/commands/pipeline_command.cpp
+++ b/src/mongo/db/commands/pipeline_command.cpp
@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2011 10gen Inc.
+ * Copyright (c) 2011-2014 MongoDB Inc.
  *
  * This program is free software: you can redistribute it and/or  modify
  * it under the terms of the GNU Affero General Public License, version 3,
@@ -324,7 +324,8 @@ namespace {
 
                 // This does mongod-specific stuff like creating the input Runner and adding to the
                 // front of the pipeline if needed.
-                boost::shared_ptr<Runner> input = PipelineD::prepareCursorSource(collection,
+                boost::shared_ptr<Runner> input = PipelineD::prepareCursorSource(txn,
+                                                                                 collection,
                                                                                  pPipeline,
                                                                                  pCtx);
                 pPipeline->stitch();
diff --git a/src/mongo/db/commands/rename_collection.cpp b/src/mongo/db/commands/rename_collection.cpp
index a878e8222f1..904041aa648 100644
--- a/src/mongo/db/commands/rename_collection.cpp
+++ b/src/mongo/db/commands/rename_collection.cpp
@@ -1,7 +1,7 @@
 // rename_collection.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -181,7 +181,7 @@ namespace mongo {
                     indexesInProg = stopIndexBuilds( txn, srcCtx.db(), cmdObj );
                     capped = sourceColl->isCapped();
                     if ( capped ) {
-                        size = sourceColl->getRecordStore()->storageSize();
+                        size = sourceColl->getRecordStore()->storageSize( txn );
                     }
                 }
             }
@@ -252,7 +252,7 @@ namespace mongo {
             {
                 Client::Context srcCtx(txn, source);
                 sourceColl = srcCtx.db()->getCollection( txn, source );
-                sourceIt.reset( sourceColl->getIterator( DiskLoc(), false, CollectionScanParams::FORWARD ) );
+                sourceIt.reset( sourceColl->getIterator( txn, DiskLoc(), false, CollectionScanParams::FORWARD ) );
             }
 
             Collection* targetColl = NULL;
diff --git a/src/mongo/db/commands/test_commands.cpp b/src/mongo/db/commands/test_commands.cpp
index 8f7e91d04f0..9036445a88b 100644
--- a/src/mongo/db/commands/test_commands.cpp
+++ b/src/mongo/db/commands/test_commands.cpp
@@ -1,7 +1,7 @@
 // test_commands.cpp
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -150,7 +150,8 @@ namespace mongo {
             Collection* collection = ctx.ctx().db()->getCollection( txn, nss.ns() );
             massert( 13417, "captrunc collection not found or empty", collection);
 
-            boost::scoped_ptr<Runner> runner(InternalPlanner::collectionScan(nss.ns(),
+            boost::scoped_ptr<Runner> runner(InternalPlanner::collectionScan(txn,
+                                                                             nss.ns(),
                                                                              collection,
                                                                              InternalPlanner::BACKWARD));
             DiskLoc end;
diff --git a/src/mongo/db/concurrency/SConscript b/src/mongo/db/concurrency/SConscript
index f032e337bd2..97507d58197 100644
--- a/src/mongo/db/concurrency/SConscript
+++ b/src/mongo/db/concurrency/SConscript
@@ -10,7 +10,8 @@ env.Library(
     LIBDEPS=[
         '$BUILD_DIR/mongo/base/base',
         '$BUILD_DIR/third_party/shim_boost',
-        '$BUILD_DIR/mongo/foundation'
+        '$BUILD_DIR/mongo/foundation',
+        '$BUILD_DIR/mongo/server_parameters'
     ],
 )
 
diff --git a/src/mongo/db/concurrency/lock_mgr.cpp b/src/mongo/db/concurrency/lock_mgr.cpp
index c25636dad52..68e161fc0a9 100644
--- a/src/mongo/db/concurrency/lock_mgr.cpp
+++ b/src/mongo/db/concurrency/lock_mgr.cpp
@@ -33,10 +33,11 @@
 #include <boost/thread/locks.hpp>
 #include <sstream>
 
+#include "mongo/base/init.h"
+#include "mongo/db/server_parameters.h"
 #include "mongo/util/assert_util.h"
 #include "mongo/util/log.h"
 #include "mongo/util/timer.h"
-#include "mongo/base/init.h"
 
 using boost::unique_lock;
 
@@ -274,6 +275,11 @@ namespace mongo {
 
     /*---------- LockManager public functions (mutex guarded) ---------*/
 
+
+    // This startup parameter enables experimental document-level locking features
+    // It should be removed once full document-level locking is checked-in.
+    MONGO_EXPORT_STARTUP_SERVER_PARAMETER(useExperimentalDocLocking, bool, false);
+
     static LockManager* _singleton = NULL;
 
     MONGO_INITIALIZER(InstantiateLockManager)(InitializerContext* context) {
@@ -379,7 +385,12 @@ namespace mongo {
     }
 
     void LockManager::acquireLock(LockRequest* lr, Notifier* notifier) {
-        if (NULL == lr) return;
+        if (!useExperimentalDocLocking)  {
+            return;
+        }
+
+        invariant(lr);
+
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown();
@@ -408,6 +419,10 @@ namespace mongo {
                               const LockMode& mode,
                               const ResourceId& resId,
                               Notifier* notifier) {
+        if (kReservedResourceId == resId || !useExperimentalDocLocking) {
+            return;
+        }
+
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown();
@@ -472,7 +487,8 @@ namespace mongo {
     }
 
     LockManager::LockStatus LockManager::releaseLock(LockRequest* lr) {
-        if (NULL == lr) return kLockNotFound;
+        if (!useExperimentalDocLocking) return kLockNotFound;
+        invariant(lr);
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown(lr->requestor);
@@ -485,6 +501,10 @@ namespace mongo {
     LockManager::LockStatus LockManager::release(const Transaction* holder,
                                                  const LockMode& mode,
                                                  const ResourceId& resId) {
+        if (kReservedResourceId == resId || !useExperimentalDocLocking) {
+            return kLockNotFound;
+        }
+
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown(holder);
@@ -529,7 +549,7 @@ namespace mongo {
         return numLocksReleased;
     }
 #endif
-    void LockManager::abort(Transaction* goner) {
+    void LockManager::abort(Transaction* goner) {   
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown(goner);
@@ -619,6 +639,9 @@ namespace mongo {
     bool LockManager::isLocked(const Transaction* holder,
                                const LockMode& mode,
                                const ResourceId& resId) const {
+        if (!useExperimentalDocLocking) {
+            return false;
+        }
         {
             unique_lock<boost::mutex> lk(_mutex);
             _throwIfShuttingDown(holder);
diff --git a/src/mongo/db/concurrency/lock_mgr.h b/src/mongo/db/concurrency/lock_mgr.h
index b19cb528077..9a94bd33799 100644
--- a/src/mongo/db/concurrency/lock_mgr.h
+++ b/src/mongo/db/concurrency/lock_mgr.h
@@ -39,7 +39,6 @@
 #include "mongo/platform/compiler.h"
 #include "mongo/platform/cstdint.h"
 #include "mongo/util/timer.h"
-
 #include "mongo/bson/util/atomic_int.h"
 
 /*
@@ -60,6 +59,9 @@
 
 namespace mongo {
 
+    // Defined in lock_mgr.cpp
+    extern bool useExperimentalDocLocking;
+
     class ResourceId {
     public:
         ResourceId() : _rid(0) { }
@@ -69,7 +71,7 @@ namespace mongo {
         operator size_t() const { return _rid; }
 
     private:
-        size_t _rid;
+        uint64_t _rid;
     };
     static const ResourceId kReservedResourceId = 0;
 
@@ -706,29 +708,29 @@ namespace mongo {
 
     class SharedResourceLock : public ResourceLock {
     public:
-    SharedResourceLock(Transaction* requestor, void* resource)
-        : ResourceLock(LockManager::getSingleton(),
-                       requestor,
-                       kShared,
-                       (size_t)resource) { }
-    SharedResourceLock(Transaction* requestor, size_t resource)
-        : ResourceLock(LockManager::getSingleton(),
-                       requestor,
-                       kShared,
-                       resource) { }
+        SharedResourceLock(Transaction* requestor, void* resource)
+            : ResourceLock(LockManager::getSingleton(),
+                           requestor,
+                           kShared,
+                           (size_t)resource) { }
+        SharedResourceLock(Transaction* requestor, uint64_t resource)
+            : ResourceLock(LockManager::getSingleton(),
+                           requestor,
+                           kShared,
+                           resource) { }
     };
 
     class ExclusiveResourceLock : public ResourceLock {
     public:
-    ExclusiveResourceLock(Transaction* requestor, void* resource)
-        : ResourceLock(LockManager::getSingleton(),
-                       requestor,
-                       kExclusive,
-                       (size_t)resource) { }
-    ExclusiveResourceLock(Transaction* requestor, size_t resource)
-        : ResourceLock(LockManager::getSingleton(),
-                       requestor,
-                       kExclusive,
-                       resource) { }
+        ExclusiveResourceLock(Transaction* requestor, void* resource)
+            : ResourceLock(LockManager::getSingleton(),
+                           requestor,
+                           kExclusive,
+                           (size_t)resource) { }
+        ExclusiveResourceLock(Transaction* requestor, uint64_t resource)
+            : ResourceLock(LockManager::getSingleton(),
+                           requestor,
+                           kExclusive,
+                           resource) { }
     };
 } // namespace mongo
diff --git a/src/mongo/db/d_concurrency.cpp b/src/mongo/db/d_concurrency.cpp
index 530dc4d3879..bccc4d977d0 100644
--- a/src/mongo/db/d_concurrency.cpp
+++ b/src/mongo/db/d_concurrency.cpp
@@ -1,7 +1,7 @@
 // @file d_concurrency.cpp 
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -847,11 +847,4 @@ namespace mongo {
         }
 
     } lockStatsServerStatusSection;
-
-
-    // This startup parameter enables experimental document-level locking features, which work
-    // for update-in-place changes only (i.e., no index updates and no document growth or 
-    // movement). It should be removed once full document-level locking is checked-in.
-    MONGO_EXPORT_STARTUP_SERVER_PARAMETER(useExperimentalDocLocking, bool, false);
-
 }
diff --git a/src/mongo/db/d_concurrency.h b/src/mongo/db/d_concurrency.h
index a11351b5a84..7a93b0936ae 100644
--- a/src/mongo/db/d_concurrency.h
+++ b/src/mongo/db/d_concurrency.h
@@ -1,7 +1,7 @@
 // @file d_concurrency.h
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -250,7 +250,4 @@ namespace mongo {
         ~writelocktry();
         bool got() const { return _got; }
     };
-
-    // Defined in instance.cpp
-    extern bool useExperimentalDocLocking;
 }
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index b3ba3020306..612c1c28d3d 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -1,7 +1,7 @@
 // @file db.cpp : Defines main() for the mongod program.
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -366,7 +366,7 @@ namespace mongo {
 
                 const string systemIndexes = ctx.db()->name() + ".system.indexes";
                 Collection* coll = ctx.db()->getCollection( &txn, systemIndexes );
-                auto_ptr<Runner> runner(InternalPlanner::collectionScan(systemIndexes,coll));
+                auto_ptr<Runner> runner(InternalPlanner::collectionScan(&txn, systemIndexes,coll));
                 BSONObj index;
                 Runner::RunnerState state;
                 while (Runner::RUNNER_ADVANCED == (state = runner->getNext(&index, NULL))) {
diff --git a/src/mongo/db/dbcommands.cpp b/src/mongo/db/dbcommands.cpp
index 96804e2dfc0..e8bfba4218c 100644
--- a/src/mongo/db/dbcommands.cpp
+++ b/src/mongo/db/dbcommands.cpp
@@ -1,7 +1,7 @@
 // dbcommands.cpp
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -674,7 +674,7 @@ namespace mongo {
             }
 
             Runner* rawRunner;
-            if (!getRunner(coll, cq, &rawRunner, QueryPlannerParams::NO_TABLE_SCAN).isOK()) {
+            if (!getRunner(txn, coll, cq, &rawRunner, QueryPlannerParams::NO_TABLE_SCAN).isOK()) {
                 uasserted(17241, "Can't get runner for query " + query.toString());
                 return 0;
             }
@@ -797,7 +797,7 @@ namespace mongo {
                     result.append( "millis" , timer.millis() );
                     return 1;
                 }
-                runner.reset(InternalPlanner::collectionScan(ns,collection));
+                runner.reset(InternalPlanner::collectionScan(txn, ns,collection));
             }
             else if ( min.isEmpty() || max.isEmpty() ) {
                 errmsg = "only one of min or max specified";
@@ -822,7 +822,7 @@ namespace mongo {
                 min = Helpers::toKeyFormat( kp.extendRangeBound( min, false ) );
                 max = Helpers::toKeyFormat( kp.extendRangeBound( max, false ) );
 
-                runner.reset(InternalPlanner::indexScan(collection, idx, min, max, false));
+                runner.reset(InternalPlanner::indexScan(txn, collection, idx, min, max, false));
             }
 
             long long avgObjSize = collection->dataSize() / collection->numRecords();
@@ -925,12 +925,12 @@ namespace mongo {
                 result.append( "avgObjSize" , collection->averageObjectSize() );
 
             result.appendNumber( "storageSize",
-                                 static_cast<long long>(collection->getRecordStore()->storageSize( &result,
+                                 static_cast<long long>(collection->getRecordStore()->storageSize( txn, &result,
                                                                                                    verbose ? 1 : 0 ) ) / 
                                  scale );
             result.append( "nindexes" , collection->getIndexCatalog()->numIndexesReady() );
 
-            collection->getRecordStore()->appendCustomStats( &result, scale );
+            collection->getRecordStore()->appendCustomStats( txn, &result, scale );
 
             BSONObjBuilder indexSizes;
             result.appendNumber( "totalIndexSize" , db->getIndexSizeForCollection(txn,
diff --git a/src/mongo/db/dbhelpers.cpp b/src/mongo/db/dbhelpers.cpp
index f0ac18ca3bc..83b5b0b7ec5 100644
--- a/src/mongo/db/dbhelpers.cpp
+++ b/src/mongo/db/dbhelpers.cpp
@@ -1,7 +1,7 @@
 // dbhelpers.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -114,7 +114,7 @@ namespace mongo {
         Runner* rawRunner;
         size_t options = requireIndex ? QueryPlannerParams::NO_TABLE_SCAN : QueryPlannerParams::DEFAULT;
         massert(17245, "Could not get runner for query " + query.toString(),
-                getRunner(collection, cq, &rawRunner, options).isOK());
+                getRunner(txn, collection, cq, &rawRunner, options).isOK());
 
         auto_ptr<Runner> runner(rawRunner);
         Runner::RunnerState state;
@@ -156,7 +156,7 @@ namespace mongo {
         BtreeBasedAccessMethod* accessMethod =
             static_cast<BtreeBasedAccessMethod*>(catalog->getIndex( desc ));
 
-        DiskLoc loc = accessMethod->findSingle( query["_id"].wrap() );
+        DiskLoc loc = accessMethod->findSingle( txn, query["_id"].wrap() );
         if ( loc.isNull() )
             return false;
         result = collection->docFor( loc );
@@ -173,7 +173,7 @@ namespace mongo {
         // See SERVER-12397.  This may not always be true.
         BtreeBasedAccessMethod* accessMethod =
             static_cast<BtreeBasedAccessMethod*>(catalog->getIndex( desc ));
-        return accessMethod->findSingle( idquery["_id"].wrap() );
+        return accessMethod->findSingle( txn, idquery["_id"].wrap() );
     }
 
     /* Get the first object from a collection.  Generally only useful if the collection
@@ -183,7 +183,8 @@ namespace mongo {
     */
     bool Helpers::getSingleton(OperationContext* txn, const char *ns, BSONObj& result) {
         Client::Context context(txn, ns);
-        auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns,
+        auto_ptr<Runner> runner(InternalPlanner::collectionScan(txn,
+                                                                ns,
                                                                 context.db()->getCollection(txn,
                                                                                             ns)));
         Runner::RunnerState state = runner->getNext(&result, NULL);
@@ -194,7 +195,8 @@ namespace mongo {
     bool Helpers::getLast(OperationContext* txn, const char *ns, BSONObj& result) {
         Client::Context ctx(txn, ns);
         Collection* coll = ctx.db()->getCollection( txn, ns );
-        auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns,
+        auto_ptr<Runner> runner(InternalPlanner::collectionScan(txn,
+                                                                ns,
                                                                 coll,
                                                                 InternalPlanner::BACKWARD));
         Runner::RunnerState state = runner->getNext(&result, NULL);
@@ -359,7 +361,7 @@ namespace mongo {
                 IndexDescriptor* desc =
                     collection->getIndexCatalog()->findIndexByKeyPattern( indexKeyPattern.toBSON() );
 
-                auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, desc, min, max,
+                auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, desc, min, max,
                                                                    maxInclusive,
                                                                    InternalPlanner::FORWARD,
                                                                    InternalPlanner::IXSCAN_FETCH));
@@ -520,7 +522,7 @@ namespace mongo {
         bool isLargeChunk = false;
         long long docCount = 0;
 
-        auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, idx, min, max, false));
+        auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, idx, min, max, false));
         // we can afford to yield here because any change to the base data that we might miss  is
         // already being queued and will be migrated in the 'transferMods' stage
 
diff --git a/src/mongo/db/exec/2dcommon.cpp b/src/mongo/db/exec/2dcommon.cpp
index 7ffc110d8f6..f7c01ac3a25 100644
--- a/src/mongo/db/exec/2dcommon.cpp
+++ b/src/mongo/db/exec/2dcommon.cpp
@@ -231,8 +231,12 @@ namespace twod_exec {
     // The only time these may be equal is when we actually equal the location
     // itself, otherwise our expanding algorithm will fail.
     // static
-    bool BtreeLocation::initial(const IndexDescriptor* descriptor, const TwoDIndexingParams& params,
-            BtreeLocation& min, BtreeLocation& max, GeoHash start) {
+    bool BtreeLocation::initial(OperationContext* txn,
+                                const IndexDescriptor* descriptor,
+                                const TwoDIndexingParams& params,
+                                BtreeLocation& min,
+                                BtreeLocation& max,
+                                GeoHash start) {
         verify(descriptor);
 
         min._eof = false;
@@ -294,10 +298,10 @@ namespace twod_exec {
         verify(maxParams.bounds.isValidFor(descriptor->keyPattern(), 1));
 
         min._ws.reset(new WorkingSet());
-        min._scan.reset(new IndexScan(minParams, min._ws.get(), NULL));
+        min._scan.reset(new IndexScan(txn, minParams, min._ws.get(), NULL));
 
         max._ws.reset(new WorkingSet());
-        max._scan.reset(new IndexScan(maxParams, max._ws.get(), NULL));
+        max._scan.reset(new IndexScan(txn, maxParams, max._ws.get(), NULL));
 
         min.advance();
         max.advance();
@@ -396,7 +400,9 @@ namespace twod_exec {
     // Are we finished getting points?
     bool GeoBrowse::moreToDo() { return _state != DONE; }
 
-    bool GeoBrowse::checkAndAdvance(BtreeLocation* bl, const GeoHash& hash, int& totalFound) {
+    bool GeoBrowse::checkAndAdvance(BtreeLocation* bl,
+                                    const GeoHash& hash,
+                                    int& totalFound) {
         if (bl->eof()) { return false; }
 
         //cout << "looking at " << bl->_loc.obj().toString() << " dl " << bl->_loc.toString() << endl;
@@ -433,7 +439,7 @@ namespace twod_exec {
             if(! isNeighbor)
                 _prefix = expandStartHash();
 
-            if (!BtreeLocation::initial(_descriptor, _params, _min, _max, _prefix)) {
+            if (!BtreeLocation::initial(&_txn, _descriptor, _params, _min, _max, _prefix)) {
                 _state = isNeighbor ? DONE_NEIGHBOR : DONE;
             } else {
                 _state = DOING_EXPAND;
diff --git a/src/mongo/db/exec/2dcommon.h b/src/mongo/db/exec/2dcommon.h
index 9283e327ee0..1d27b610a70 100644
--- a/src/mongo/db/exec/2dcommon.h
+++ b/src/mongo/db/exec/2dcommon.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -32,10 +32,14 @@
 #include "mongo/db/geo/shapes.h"
 
 #include "mongo/db/index/2d_access_method.h"
+#include "mongo/db/operation_context_noop.h"
 
 #pragma once
 
 namespace mongo {
+
+    class OperationContext;
+
 namespace twod_exec {
 
     //
@@ -111,7 +115,6 @@ namespace twod_exec {
 
     struct BtreeLocation {
         BtreeLocation() : _eof(false) { }
-
         scoped_ptr<IndexScan> _scan;
         scoped_ptr<WorkingSet> _ws;
         DiskLoc _loc;
@@ -130,8 +133,12 @@ namespace twod_exec {
         // Returns the min and max keys which bound a particular location.
         // The only time these may be equal is when we actually equal the location
         // itself, otherwise our expanding algorithm will fail.
-        static bool initial(const IndexDescriptor* descriptor, const TwoDIndexingParams& params,
-                            BtreeLocation& min, BtreeLocation& max, GeoHash start);
+        static bool initial(OperationContext* txn,
+                            const IndexDescriptor* descriptor,
+                            const TwoDIndexingParams& params,
+                            BtreeLocation& min,
+                            BtreeLocation& max,
+                            GeoHash start);
     };
 
     //
@@ -207,7 +214,9 @@ namespace twod_exec {
 
         // Fills the stack, but only checks a maximum number of maxToCheck points at a time.
         // Further calls to this function will continue the expand/check neighbors algorithm.
-        virtual void fillStack(int maxToCheck, int maxToAdd = -1, bool onlyExpand = false);
+        virtual void fillStack(int maxToCheck,
+                               int maxToAdd = -1,
+                               bool onlyExpand = false);
 
         bool checkAndAdvance(BtreeLocation* bl, const GeoHash& hash, int& totalFound);
 
@@ -273,6 +282,7 @@ namespace twod_exec {
 
     private:
         const Collection* _collection;
+        OperationContextNoop _txn;
     };
 
 }  // namespace twod_exec
diff --git a/src/mongo/db/exec/2dnear.cpp b/src/mongo/db/exec/2dnear.cpp
index d1f276c233a..a42ad52d5de 100644
--- a/src/mongo/db/exec/2dnear.cpp
+++ b/src/mongo/db/exec/2dnear.cpp
@@ -40,8 +40,8 @@ namespace mongo {
     // static
     const char* TwoDNear::kStageType = "GEO_NEAR_2D";
 
-    TwoDNear::TwoDNear(const TwoDNearParams& params, WorkingSet* ws)
-        : _commonStats(kStageType) {
+    TwoDNear::TwoDNear(OperationContext* txn, const TwoDNearParams& params, WorkingSet* ws)
+        : _txn(txn), _commonStats(kStageType) {
         _params = params;
         _workingSet = ws;
         _initted = false;
diff --git a/src/mongo/db/exec/2dnear.h b/src/mongo/db/exec/2dnear.h
index 265f3ff6402..2216f76c41d 100644
--- a/src/mongo/db/exec/2dnear.h
+++ b/src/mongo/db/exec/2dnear.h
@@ -64,7 +64,7 @@ namespace mongo {
 
     class TwoDNear : public PlanStage {
     public:
-        TwoDNear(const TwoDNearParams& params, WorkingSet* ws);
+        TwoDNear(OperationContext* txn, const TwoDNearParams& params, WorkingSet* ws);
         virtual ~TwoDNear();
 
         virtual bool isEOF();
@@ -83,6 +83,10 @@ namespace mongo {
         static const char* kStageType;
 
     private:
+
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         WorkingSet* _workingSet;
 
         // Stats
diff --git a/src/mongo/db/exec/collection_scan.cpp b/src/mongo/db/exec/collection_scan.cpp
index 195ab21e551..d76ce92e19c 100644
--- a/src/mongo/db/exec/collection_scan.cpp
+++ b/src/mongo/db/exec/collection_scan.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -42,10 +42,12 @@ namespace mongo {
     // static
     const char* CollectionScan::kStageType = "COLLSCAN";
 
-    CollectionScan::CollectionScan(const CollectionScanParams& params,
+    CollectionScan::CollectionScan(OperationContext* txn,
+                                   const CollectionScanParams& params,
                                    WorkingSet* workingSet,
                                    const MatchExpression* filter)
-        : _workingSet(workingSet),
+        : _txn(txn),
+          _workingSet(workingSet),
           _filter(filter),
           _params(params),
           _nsDropped(false),
@@ -66,7 +68,8 @@ namespace mongo {
                 return PlanStage::DEAD;
             }
 
-            _iter.reset( _params.collection->getIterator( _params.start,
+            _iter.reset( _params.collection->getIterator( _txn,
+                                                          _params.start,
                                                           _params.tailable,
                                                           _params.direction ) );
 
diff --git a/src/mongo/db/exec/collection_scan.h b/src/mongo/db/exec/collection_scan.h
index f752c69e4c3..fbc47701d84 100644
--- a/src/mongo/db/exec/collection_scan.h
+++ b/src/mongo/db/exec/collection_scan.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -37,6 +37,7 @@ namespace mongo {
 
     class RecordIterator;
     class WorkingSet;
+    class OperationContext;
 
     /**
      * Scans over a collection, starting at the DiskLoc provided in params and continuing until
@@ -46,7 +47,8 @@ namespace mongo {
      */
     class CollectionScan : public PlanStage {
     public:
-        CollectionScan(const CollectionScanParams& params,
+        CollectionScan(OperationContext* txn,
+                       const CollectionScanParams& params,
                        WorkingSet* workingSet,
                        const MatchExpression* filter);
 
@@ -71,6 +73,9 @@ namespace mongo {
          */
         bool diskLocInMemory(DiskLoc loc);
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // WorkingSet is not owned by us.
         WorkingSet* _workingSet;
 
diff --git a/src/mongo/db/exec/count.cpp b/src/mongo/db/exec/count.cpp
index eeb860e9e92..5b5264e0e63 100644
--- a/src/mongo/db/exec/count.cpp
+++ b/src/mongo/db/exec/count.cpp
@@ -36,8 +36,9 @@ namespace mongo {
     // static
     const char* Count::kStageType = "COUNT";
 
-    Count::Count(const CountParams& params, WorkingSet* workingSet)
-        : _workingSet(workingSet),
+    Count::Count(OperationContext* txn, const CountParams& params, WorkingSet* workingSet)
+        : _txn(txn),
+          _workingSet(workingSet),
           _descriptor(params.descriptor),
           _iam(params.descriptor->getIndexCatalog()->getIndex(params.descriptor)),
           _btreeCursor(NULL),
@@ -54,7 +55,7 @@ namespace mongo {
         cursorOptions.direction = CursorOptions::INCREASING;
 
         IndexCursor *cursor;
-        Status s = _iam->newCursor(cursorOptions, &cursor);
+        Status s = _iam->newCursor(_txn, cursorOptions, &cursor);
         verify(s.isOK());
         verify(cursor);
 
@@ -69,7 +70,7 @@ namespace mongo {
 
         // Create the cursor that points at our end position.
         IndexCursor* endCursor;
-        verify(_iam->newCursor(cursorOptions, &endCursor).isOK());
+        verify(_iam->newCursor(_txn, cursorOptions, &endCursor).isOK());
         verify(endCursor);
 
         // Is this assumption always valid?  See SERVER-12397
diff --git a/src/mongo/db/exec/count.h b/src/mongo/db/exec/count.h
index a3a82ab0032..3371587c368 100644
--- a/src/mongo/db/exec/count.h
+++ b/src/mongo/db/exec/count.h
@@ -36,6 +36,7 @@
 #include "mongo/db/index/index_access_method.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/matcher/expression.h"
+#include "mongo/db/operation_context.h"
 #include "mongo/platform/unordered_set.h"
 
 namespace mongo {
@@ -67,7 +68,7 @@ namespace mongo {
      */
     class Count : public PlanStage {
     public:
-        Count(const CountParams& params, WorkingSet* workingSet);
+        Count(OperationContext* txn, const CountParams& params, WorkingSet* workingSet);
         virtual ~Count() { }
 
         virtual StageState work(WorkingSetID* out);
@@ -95,6 +96,9 @@ namespace mongo {
          */
         void checkEnd();
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // The WorkingSet we annotate with results.  Not owned by us.
         WorkingSet* _workingSet;
 
diff --git a/src/mongo/db/exec/distinct_scan.cpp b/src/mongo/db/exec/distinct_scan.cpp
index 3cbd9e84d08..a55ea4e997e 100644
--- a/src/mongo/db/exec/distinct_scan.cpp
+++ b/src/mongo/db/exec/distinct_scan.cpp
@@ -39,8 +39,9 @@ namespace mongo {
     // static
     const char* DistinctScan::kStageType = "DISTINCT";
 
-    DistinctScan::DistinctScan(const DistinctParams& params, WorkingSet* workingSet)
-        : _workingSet(workingSet),
+    DistinctScan::DistinctScan(OperationContext* txn, const DistinctParams& params, WorkingSet* workingSet)
+        : _txn(txn),
+          _workingSet(workingSet),
           _descriptor(params.descriptor),
           _iam(params.descriptor->getIndexCatalog()->getIndex(params.descriptor)),
           _btreeCursor(NULL),
@@ -60,7 +61,7 @@ namespace mongo {
         }
 
         IndexCursor *cursor;
-        Status s = _iam->newCursor(cursorOptions, &cursor);
+        Status s = _iam->newCursor(_txn, cursorOptions, &cursor);
         verify(s.isOK());
         verify(cursor);
         // Is this assumption always valid?  See SERVER-12397
diff --git a/src/mongo/db/exec/distinct_scan.h b/src/mongo/db/exec/distinct_scan.h
index 9e088da5068..d81a936937f 100644
--- a/src/mongo/db/exec/distinct_scan.h
+++ b/src/mongo/db/exec/distinct_scan.h
@@ -79,7 +79,7 @@ namespace mongo {
      */
     class DistinctScan : public PlanStage {
     public:
-        DistinctScan(const DistinctParams& params, WorkingSet* workingSet);
+        DistinctScan(OperationContext* txn, const DistinctParams& params, WorkingSet* workingSet);
         virtual ~DistinctScan() { }
 
         virtual StageState work(WorkingSetID* out);
@@ -105,6 +105,9 @@ namespace mongo {
         /** See if the cursor is pointing at or past _endKey, if _endKey is non-empty. */
         void checkEnd();
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // The WorkingSet we annotate with results.  Not owned by us.
         WorkingSet* _workingSet;
 
diff --git a/src/mongo/db/exec/idhack.cpp b/src/mongo/db/exec/idhack.cpp
index d27f7a34b5b..e577210226f 100644
--- a/src/mongo/db/exec/idhack.cpp
+++ b/src/mongo/db/exec/idhack.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -40,8 +40,10 @@ namespace mongo {
     // static
     const char* IDHackStage::kStageType = "IDHACK";
 
-    IDHackStage::IDHackStage(const Collection* collection, CanonicalQuery* query, WorkingSet* ws)
-        : _collection(collection),
+    IDHackStage::IDHackStage(OperationContext* txn, const Collection* collection,
+                             CanonicalQuery* query, WorkingSet* ws)
+        : _txn(txn),
+          _collection(collection),
           _workingSet(ws),
           _key(query->getQueryObj()["_id"].wrap()),
           _query(query),
@@ -49,8 +51,10 @@ namespace mongo {
           _done(false),
           _commonStats(kStageType) { }
 
-    IDHackStage::IDHackStage(Collection* collection, const BSONObj& key, WorkingSet* ws)
-        : _collection(collection),
+    IDHackStage::IDHackStage(OperationContext* txn, Collection* collection,
+                             const BSONObj& key, WorkingSet* ws)
+        : _txn(txn),
+          _collection(collection),
           _workingSet(ws),
           _key(key),
           _query(NULL),
@@ -88,7 +92,7 @@ namespace mongo {
             static_cast<const BtreeBasedAccessMethod*>(catalog->getIndex(idDesc));
 
         // Look up the key by going directly to the Btree.
-        DiskLoc loc = accessMethod->findSingle( _key );
+        DiskLoc loc = accessMethod->findSingle( _txn, _key );
 
         // Key not found.
         if (loc.isNull()) {
diff --git a/src/mongo/db/exec/idhack.h b/src/mongo/db/exec/idhack.h
index 3f266638d9e..85cdd78abae 100644
--- a/src/mongo/db/exec/idhack.h
+++ b/src/mongo/db/exec/idhack.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -42,9 +42,11 @@ namespace mongo {
     class IDHackStage : public PlanStage {
     public:
         /** Takes ownership of all the arguments -collection. */
-        IDHackStage(const Collection* collection, CanonicalQuery* query, WorkingSet* ws);
+        IDHackStage(OperationContext* txn, const Collection* collection,
+                    CanonicalQuery* query, WorkingSet* ws);
 
-        IDHackStage(Collection* collection, const BSONObj& key, WorkingSet* ws);
+        IDHackStage(OperationContext* txn, Collection* collection,
+                    const BSONObj& key, WorkingSet* ws);
 
         virtual ~IDHackStage();
 
@@ -69,6 +71,9 @@ namespace mongo {
         static const char* kStageType;
 
     private:
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // Not owned here.
         const Collection* _collection;
 
diff --git a/src/mongo/db/exec/index_scan.cpp b/src/mongo/db/exec/index_scan.cpp
index 1982f134b8d..b4ee4706cf0 100644
--- a/src/mongo/db/exec/index_scan.cpp
+++ b/src/mongo/db/exec/index_scan.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -51,9 +51,12 @@ namespace mongo {
     // static
     const char* IndexScan::kStageType = "IXSCAN";
 
-    IndexScan::IndexScan(const IndexScanParams& params, WorkingSet* workingSet,
+    IndexScan::IndexScan(OperationContext* txn,
+                         const IndexScanParams& params,
+                         WorkingSet* workingSet,
                          const MatchExpression* filter)
-        : _workingSet(workingSet),
+        : _txn(txn),
+          _workingSet(workingSet),
           _hitEnd(false),
           _filter(filter), 
           _shouldDedup(true),
@@ -90,7 +93,7 @@ namespace mongo {
         }
 
         IndexCursor *cursor;
-        Status s = _iam->newCursor(cursorOptions, &cursor);
+        Status s = _iam->newCursor(_txn, cursorOptions, &cursor);
         verify(s.isOK());
         _indexCursor.reset(cursor);
 
diff --git a/src/mongo/db/exec/index_scan.h b/src/mongo/db/exec/index_scan.h
index 6b993f387ad..02b14f1e6d8 100644
--- a/src/mongo/db/exec/index_scan.h
+++ b/src/mongo/db/exec/index_scan.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -80,7 +80,9 @@ namespace mongo {
      */
     class IndexScan : public PlanStage {
     public:
-        IndexScan(const IndexScanParams& params, WorkingSet* workingSet,
+        IndexScan(OperationContext* txn,
+                  const IndexScanParams& params,
+                  WorkingSet* workingSet,
                   const MatchExpression* filter);
 
         virtual ~IndexScan() { }
@@ -108,6 +110,9 @@ namespace mongo {
         /** See if the cursor is pointing at or past _endKey, if _endKey is non-empty. */
         void checkEnd();
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // The WorkingSet we annotate with results.  Not owned by us.
         WorkingSet* _workingSet;
 
diff --git a/src/mongo/db/exec/oplogstart.cpp b/src/mongo/db/exec/oplogstart.cpp
index c569bfb8a34..93d4028ed10 100644
--- a/src/mongo/db/exec/oplogstart.cpp
+++ b/src/mongo/db/exec/oplogstart.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -35,8 +35,12 @@
 namespace mongo {
 
     // Does not take ownership.
-    OplogStart::OplogStart(const Collection* collection, MatchExpression* filter, WorkingSet* ws)
-        : _needInit(true),
+    OplogStart::OplogStart(OperationContext* txn,
+                           const Collection* collection,
+                           MatchExpression* filter,
+                           WorkingSet* ws)
+        : _txn(txn),
+          _needInit(true),
           _backwardsScanning(false),
           _extentHopping(false),
           _done(false),
@@ -52,7 +56,7 @@ namespace mongo {
             CollectionScanParams params;
             params.collection = _collection;
             params.direction = CollectionScanParams::BACKWARD;
-            _cs.reset(new CollectionScan(params, _workingSet, NULL));
+            _cs.reset(new CollectionScan(_txn, params, _workingSet, NULL));
             _needInit = false;
             _backwardsScanning = true;
             _timer.reset();
@@ -105,7 +109,7 @@ namespace mongo {
         _cs.reset();
 
         // Set up our extent hopping state.
-        _subIterators = _collection->getManyIterators();
+        _subIterators = _collection->getManyIterators(_txn);
     }
 
     PlanStage::StageState OplogStart::workBackwardsScan(WorkingSetID* out) {
diff --git a/src/mongo/db/exec/oplogstart.h b/src/mongo/db/exec/oplogstart.h
index e10721a9064..5d313368532 100644
--- a/src/mongo/db/exec/oplogstart.h
+++ b/src/mongo/db/exec/oplogstart.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -60,7 +60,10 @@ namespace mongo {
     class OplogStart : public PlanStage {
     public:
         // Does not take ownership.
-        OplogStart(const Collection* collection, MatchExpression* filter, WorkingSet* ws);
+        OplogStart(OperationContext* txn,
+                   const Collection* collection,
+                   MatchExpression* filter,
+                   WorkingSet* ws);
         virtual ~OplogStart();
 
         virtual StageState work(WorkingSetID* out);
@@ -88,6 +91,9 @@ namespace mongo {
 
         StageState workExtentHopping(WorkingSetID* out);
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // If we're backwards scanning we just punt to a collscan.
         scoped_ptr<CollectionScan> _cs;
 
diff --git a/src/mongo/db/exec/s2near.cpp b/src/mongo/db/exec/s2near.cpp
index c7d37111840..66babb6d832 100644
--- a/src/mongo/db/exec/s2near.cpp
+++ b/src/mongo/db/exec/s2near.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 MongoDB Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -43,8 +43,8 @@ namespace mongo {
     // static
     const char* S2NearStage::kStageType = "GEO_NEAR_2DSPHERE";
 
-    S2NearStage::S2NearStage(const S2NearParams& params, WorkingSet* ws)
-        : _commonStats(kStageType) {
+    S2NearStage::S2NearStage(OperationContext* txn, const S2NearParams& params, WorkingSet* ws)
+        : _txn(txn), _commonStats(kStageType) {
         _initted = false;
         _params = params;
         _ws = ws;
@@ -282,7 +282,7 @@ namespace mongo {
         // Owns geo filter.
         _keyGeoFilter.reset(new GeoS2KeyMatchExpression(
             &_annulus, _params.baseBounds.fields[_nearFieldIndex].name));
-        IndexScan* scan = new IndexScan(params, _ws, _keyGeoFilter.get());
+        IndexScan* scan = new IndexScan(_txn, params, _ws, _keyGeoFilter.get());
 
         // Owns 'scan'.
         _child.reset(new FetchStage(_ws, scan, _params.filter, _params.collection));
diff --git a/src/mongo/db/exec/s2near.h b/src/mongo/db/exec/s2near.h
index f273b8bf992..e71f697c23e 100644
--- a/src/mongo/db/exec/s2near.h
+++ b/src/mongo/db/exec/s2near.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 MongoDB Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -43,6 +43,8 @@
 
 namespace mongo {
 
+    class OperationContext;
+
     struct S2NearParams {
         S2NearParams() : collection(NULL) { }
         Collection* collection;
@@ -63,7 +65,7 @@ namespace mongo {
          * Takes: index to scan over, MatchExpression with near point, other MatchExpressions for
          * covered data,
          */
-        S2NearStage(const S2NearParams& params, WorkingSet* ws);
+        S2NearStage(OperationContext* txn, const S2NearParams& params, WorkingSet* ws);
 
         virtual ~S2NearStage();
 
@@ -87,6 +89,9 @@ namespace mongo {
         StageState addResultToQueue(WorkingSetID* out);
         void nextAnnulus();
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         bool _worked;
 
         S2NearParams _params;
diff --git a/src/mongo/db/exec/stagedebug_cmd.cpp b/src/mongo/db/exec/stagedebug_cmd.cpp
index c2f6698414d..346d481d8be 100644
--- a/src/mongo/db/exec/stagedebug_cmd.cpp
+++ b/src/mongo/db/exec/stagedebug_cmd.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -134,7 +134,7 @@ namespace mongo {
             OwnedPointerVector<MatchExpression> exprs;
             auto_ptr<WorkingSet> ws(new WorkingSet());
 
-            PlanStage* userRoot = parseQuery(collection, planObj, ws.get(), &exprs);
+            PlanStage* userRoot = parseQuery(txn, collection, planObj, ws.get(), &exprs);
             uassert(16911, "Couldn't parse plan from " + cmdObj.toString(), NULL != userRoot);
 
             // Add a fetch at the top for the user so we can get obj back for sure.
@@ -153,7 +153,8 @@ namespace mongo {
             return true;
         }
 
-        PlanStage* parseQuery(Collection* collection,
+        PlanStage* parseQuery(OperationContext* txn,
+                              Collection* collection,
                               BSONObj obj,
                               WorkingSet* workingSet,
                               OwnedPointerVector<MatchExpression>* exprs) {
@@ -211,7 +212,7 @@ namespace mongo {
                 params.bounds.endKeyInclusive = nodeArgs["endKeyInclusive"].Bool();
                 params.direction = nodeArgs["direction"].numberInt();
 
-                return new IndexScan(params, workingSet, matcher);
+                return new IndexScan(txn, params, workingSet, matcher);
             }
             else if ("andHash" == nodeName) {
                 uassert(16921, "Nodes argument must be provided to AND",
@@ -226,7 +227,7 @@ namespace mongo {
                     uassert(16922, "node of AND isn't an obj?: " + e.toString(),
                             e.isABSONObj());
 
-                    PlanStage* subNode = parseQuery(collection, e.Obj(), workingSet, exprs);
+                    PlanStage* subNode = parseQuery(txn, collection, e.Obj(), workingSet, exprs);
                     uassert(16923, "Can't parse sub-node of AND: " + e.Obj().toString(),
                             NULL != subNode);
                     // takes ownership
@@ -252,7 +253,7 @@ namespace mongo {
                     uassert(16925, "node of AND isn't an obj?: " + e.toString(),
                             e.isABSONObj());
 
-                    PlanStage* subNode = parseQuery(collection, e.Obj(), workingSet, exprs);
+                    PlanStage* subNode = parseQuery(txn, collection, e.Obj(), workingSet, exprs);
                     uassert(16926, "Can't parse sub-node of AND: " + e.Obj().toString(),
                             NULL != subNode);
                     // takes ownership
@@ -275,7 +276,7 @@ namespace mongo {
                 while (it.more()) {
                     BSONElement e = it.next();
                     if (!e.isABSONObj()) { return NULL; }
-                    PlanStage* subNode = parseQuery(collection, e.Obj(), workingSet, exprs);
+                    PlanStage* subNode = parseQuery(txn, collection, e.Obj(), workingSet, exprs);
                     uassert(16936, "Can't parse sub-node of OR: " + e.Obj().toString(),
                             NULL != subNode);
                     // takes ownership
@@ -287,7 +288,8 @@ namespace mongo {
             else if ("fetch" == nodeName) {
                 uassert(16929, "Node argument must be provided to fetch",
                         nodeArgs["node"].isABSONObj());
-                PlanStage* subNode = parseQuery(collection,
+                PlanStage* subNode = parseQuery(txn,
+                                                collection,
                                                 nodeArgs["node"].Obj(),
                                                 workingSet,
                                                 exprs);
@@ -300,7 +302,8 @@ namespace mongo {
                         nodeArgs["node"].isABSONObj());
                 uassert(16931, "Num argument must be provided to limit",
                         nodeArgs["num"].isNumber());
-                PlanStage* subNode = parseQuery(collection,
+                PlanStage* subNode = parseQuery(txn,
+                                                collection,
                                                 nodeArgs["node"].Obj(),
                                                 workingSet,
                                                 exprs);
@@ -313,7 +316,8 @@ namespace mongo {
                         nodeArgs["node"].isABSONObj());
                 uassert(16933, "Num argument must be provided to skip",
                         nodeArgs["num"].isNumber());
-                PlanStage* subNode = parseQuery(collection,
+                PlanStage* subNode = parseQuery(txn,
+                                                collection,
                                                 nodeArgs["node"].Obj(),
                                                 workingSet,
                                                 exprs);
@@ -333,7 +337,7 @@ namespace mongo {
                     params.direction = CollectionScanParams::BACKWARD;
                 }
 
-                return new CollectionScan(params, workingSet, matcher);
+                return new CollectionScan(txn, params, workingSet, matcher);
             }
             // sort is disabled for now.
 #if 0
@@ -342,7 +346,7 @@ namespace mongo {
                         nodeArgs["node"].isABSONObj());
                 uassert(16970, "Pattern argument must be provided to sort",
                         nodeArgs["pattern"].isABSONObj());
-                PlanStage* subNode = parseQuery(db, nodeArgs["node"].Obj(), workingSet, exprs);
+                PlanStage* subNode = parseQuery(txn, db, nodeArgs["node"].Obj(), workingSet, exprs);
                 SortStageParams params;
                 params.pattern = nodeArgs["pattern"].Obj();
                 return new SortStage(params, workingSet, subNode);
@@ -367,7 +371,7 @@ namespace mongo {
                     uassert(16973, "node of mergeSort isn't an obj?: " + e.toString(),
                             e.isABSONObj());
 
-                    PlanStage* subNode = parseQuery(collection, e.Obj(), workingSet, exprs);
+                    PlanStage* subNode = parseQuery(txn, collection, e.Obj(), workingSet, exprs);
                     uassert(16974, "Can't parse sub-node of mergeSort: " + e.Obj().toString(),
                             NULL != subNode);
                     // takes ownership
@@ -403,7 +407,7 @@ namespace mongo {
                     return NULL;
                 }
 
-                return new TextStage(params, workingSet, matcher);
+                return new TextStage(txn, params, workingSet, matcher);
             }
             else {
                 return NULL;
diff --git a/src/mongo/db/exec/subplan.cpp b/src/mongo/db/exec/subplan.cpp
index 67e631abebd..6875a53f977 100644
--- a/src/mongo/db/exec/subplan.cpp
+++ b/src/mongo/db/exec/subplan.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -46,11 +46,13 @@ namespace mongo {
     // static
     const char* SubplanStage::kStageType = "SUBPLAN";
 
-    SubplanStage::SubplanStage(Collection* collection,
+    SubplanStage::SubplanStage(OperationContext* txn,
+                               Collection* collection,
                                WorkingSet* ws,
                                const QueryPlannerParams& params,
                                CanonicalQuery* cq)
-        : _state(SubplanStage::PLANNING),
+        : _txn(txn),
+          _state(SubplanStage::PLANNING),
           _collection(collection),
           _ws(ws),
           _plannerParams(params),
@@ -75,12 +77,13 @@ namespace mongo {
     }
 
     // static
-    Status SubplanStage::make(Collection* collection,
+    Status SubplanStage::make(OperationContext* txn,
+                              Collection* collection,
                               WorkingSet* ws,
                               const QueryPlannerParams& params,
                               CanonicalQuery* cq,
                               SubplanStage** out) {
-        auto_ptr<SubplanStage> autoStage(new SubplanStage(collection, ws, params, cq));
+        auto_ptr<SubplanStage> autoStage(new SubplanStage(txn, collection, ws, params, cq));
         Status planningStatus = autoStage->planSubqueries();
         if (!planningStatus.isOK()) {
             return planningStatus;
@@ -262,7 +265,8 @@ namespace mongo {
                 // Dump all the solutions into the MPR.
                 for (size_t ix = 0; ix < solutions.size(); ++ix) {
                     PlanStage* nextPlanRoot;
-                    verify(StageBuilder::build(_collection,
+                    verify(StageBuilder::build(_txn,
+                                               _collection,
                                                *solutions[ix],
                                                sharedWorkingSet,
                                                &nextPlanRoot));
@@ -349,7 +353,7 @@ namespace mongo {
         auto_ptr<MultiPlanStage> multiPlanStage(new MultiPlanStage(_collection, _query));
         WorkingSet* ws = new WorkingSet();
         PlanStage* root;
-        verify(StageBuilder::build(_collection, *soln, ws, &root));
+        verify(StageBuilder::build(_txn, _collection, *soln, ws, &root));
         multiPlanStage->addPlan(soln, root, ws); // Takes ownership first two arguments.
 
         multiPlanStage->pickBestPlan();
@@ -402,7 +406,9 @@ namespace mongo {
             else if (!_killed) {
                 // Couldn't run as subplans so we'll just call normal getExecutor.
                 PlanExecutor* exec;
-                Status status = getExecutorAlwaysPlan(_collection, _query, _plannerParams, &exec);
+
+                Status status = getExecutorAlwaysPlan(
+                    _txn, _collection, _query, _plannerParams, &exec);
 
                 if (!status.isOK()) {
                     // We utterly failed.
diff --git a/src/mongo/db/exec/subplan.h b/src/mongo/db/exec/subplan.h
index 1fb6c698523..5e63d82286c 100644
--- a/src/mongo/db/exec/subplan.h
+++ b/src/mongo/db/exec/subplan.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -40,6 +40,8 @@
 
 namespace mongo {
 
+    class OperationContext;
+
     /**
      * The SubplanStage is used for rooted $or queries. It plans each clause of the $or
      * individually, and then creates an overall query plan based on the winning plan from
@@ -55,7 +57,8 @@ namespace mongo {
          *
          * 'out' is valid only if an OK status is returned.
          */
-        static Status make(Collection* collection,
+        static Status make(OperationContext* txn,
+                           Collection* collection,
                            WorkingSet* ws,
                            const QueryPlannerParams& params,
                            CanonicalQuery* cq,
@@ -91,7 +94,8 @@ namespace mongo {
         Status planSubqueries();
 
     private:
-        SubplanStage(Collection* collection,
+        SubplanStage(OperationContext* txn,
+                     Collection* collection,
                      WorkingSet* ws,
                      const QueryPlannerParams& params,
                      CanonicalQuery* cq);
@@ -103,6 +107,9 @@ namespace mongo {
             RUNNING,
         };
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         SubplanningState _state;
 
         Collection* _collection;
diff --git a/src/mongo/db/exec/text.cpp b/src/mongo/db/exec/text.cpp
index 50f7e3f99e4..85ddde49100 100644
--- a/src/mongo/db/exec/text.cpp
+++ b/src/mongo/db/exec/text.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -41,10 +41,12 @@ namespace mongo {
     // static
     const char* TextStage::kStageType = "TEXT";
 
-    TextStage::TextStage(const TextStageParams& params,
+    TextStage::TextStage(OperationContext* txn,
+                         const TextStageParams& params,
                          WorkingSet* ws,
                          const MatchExpression* filter)
-        : _params(params),
+        : _txn(txn),
+          _params(params),
           _ftsMatcher(params.query, params.spec),
           _ws(ws),
           _filter(filter),
@@ -180,7 +182,7 @@ namespace mongo {
             params.bounds.isSimpleRange = true;
             params.descriptor = _params.index;
             params.direction = -1;
-            _scanners.mutableVector().push_back(new IndexScan(params, _ws, NULL));
+            _scanners.mutableVector().push_back(new IndexScan(_txn, params, _ws, NULL));
         }
 
         // If we have no terms we go right to EOF.
diff --git a/src/mongo/db/exec/text.h b/src/mongo/db/exec/text.h
index 851d3cdada7..48f4c595b27 100644
--- a/src/mongo/db/exec/text.h
+++ b/src/mongo/db/exec/text.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -52,6 +52,8 @@ namespace mongo {
     using fts::FTSSpec;
     using fts::MAX_WEIGHT;
 
+    class OperationContext;
+
     struct TextStageParams {
         TextStageParams(const FTSSpec& s) : spec(s) {}
 
@@ -93,7 +95,10 @@ namespace mongo {
             DONE,
         };
 
-        TextStage(const TextStageParams& params, WorkingSet* ws, const MatchExpression* filter);
+        TextStage(OperationContext* txn,
+                  const TextStageParams& params,
+                  WorkingSet* ws,
+                  const MatchExpression* filter);
 
         virtual ~TextStage();
 
@@ -137,6 +142,9 @@ namespace mongo {
          */
         StageState returnResults(WorkingSetID* out);
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // Parameters of this text stage.
         TextStageParams _params;
 
diff --git a/src/mongo/db/fts/fts_command_mongod.cpp b/src/mongo/db/fts/fts_command_mongod.cpp
index 4c0915df8db..a2c4b35e165 100644
--- a/src/mongo/db/fts/fts_command_mongod.cpp
+++ b/src/mongo/db/fts/fts_command_mongod.cpp
@@ -1,7 +1,7 @@
 // fts_command_mongod.h
 
 /**
-*    Copyright (C) 2012 10gen Inc.
+*    Copyright (C) 2012-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -113,7 +113,7 @@ namespace mongo {
             }
 
             Runner* rawRunner;
-            Status getRunnerStatus = getRunner(ctx.ctx().db()->getCollection(txn, ns), cq, &rawRunner);
+            Status getRunnerStatus = getRunner(txn, ctx.ctx().db()->getCollection(txn, ns), cq, &rawRunner);
             if (!getRunnerStatus.isOK()) {
                 errmsg = getRunnerStatus.reason();
                 return false;
diff --git a/src/mongo/db/geo/haystack.cpp b/src/mongo/db/geo/haystack.cpp
index 27cc3cb0633..ad8b06f00eb 100644
--- a/src/mongo/db/geo/haystack.cpp
+++ b/src/mongo/db/geo/haystack.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2008-2013 10gen Inc.
+ *    Copyright (C) 2008-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -110,7 +110,7 @@ namespace mongo {
             IndexDescriptor* desc = idxs[0];
             HaystackAccessMethod* ham =
                 static_cast<HaystackAccessMethod*>( collection->getIndexCatalog()->getIndex(desc) );
-            ham->searchCommand(collection, nearElt.Obj(), maxDistance.numberDouble(), search.Obj(),
+            ham->searchCommand(txn, collection, nearElt.Obj(), maxDistance.numberDouble(), search.Obj(),
                                &result, limit);
             return 1;
         }
diff --git a/src/mongo/db/index/btree_based_access_method.cpp b/src/mongo/db/index/btree_based_access_method.cpp
index 0e09b1cb98a..664aa7de94c 100644
--- a/src/mongo/db/index/btree_based_access_method.cpp
+++ b/src/mongo/db/index/btree_based_access_method.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -143,8 +143,8 @@ namespace mongo {
         return ret;
     }
 
-    Status BtreeBasedAccessMethod::newCursor(const CursorOptions& opts, IndexCursor** out) const {
-        *out = new BtreeIndexCursor(_newInterface->newCursor(opts.direction));
+    Status BtreeBasedAccessMethod::newCursor(OperationContext* txn, const CursorOptions& opts, IndexCursor** out) const {
+        *out = new BtreeIndexCursor(_newInterface->newCursor(txn, opts.direction));
         return Status::OK();
     }
 
@@ -197,11 +197,11 @@ namespace mongo {
         return _newInterface->initAsEmpty(txn);
     }
 
-    Status BtreeBasedAccessMethod::touch(const BSONObj& obj) {
+    Status BtreeBasedAccessMethod::touch(OperationContext* txn, const BSONObj& obj) {
         BSONObjSet keys;
         getKeys(obj, &keys);
 
-        boost::scoped_ptr<BtreeInterface::Cursor> cursor(_newInterface->newCursor(1));
+        boost::scoped_ptr<BtreeInterface::Cursor> cursor(_newInterface->newCursor(txn, 1));
         for (BSONObjSet::const_iterator i = keys.begin(); i != keys.end(); ++i) {
             cursor->locate(*i, DiskLoc());
         }
@@ -214,8 +214,8 @@ namespace mongo {
         return _newInterface->touch(txn);
     }
 
-    DiskLoc BtreeBasedAccessMethod::findSingle(const BSONObj& key) const {
-        boost::scoped_ptr<BtreeInterface::Cursor> cursor(_newInterface->newCursor(1));
+    DiskLoc BtreeBasedAccessMethod::findSingle( OperationContext* txn, const BSONObj& key) const {
+        boost::scoped_ptr<BtreeInterface::Cursor> cursor(_newInterface->newCursor(txn, 1));
         cursor->locate(key, minDiskLoc);
 
         // A null bucket means the key wasn't found (nor was anything found after it).
@@ -233,15 +233,16 @@ namespace mongo {
         return cursor->getDiskLoc();
     }
 
-    Status BtreeBasedAccessMethod::validate(int64_t* numKeys) {
+    Status BtreeBasedAccessMethod::validate(OperationContext* txn, int64_t* numKeys) {
         // XXX: long long vs int64_t
         long long keys;
-        _newInterface->fullValidate(&keys);
+        _newInterface->fullValidate(txn, &keys);
         *numKeys = keys;
         return Status::OK();
     }
 
-    Status BtreeBasedAccessMethod::validateUpdate(const BSONObj &from,
+    Status BtreeBasedAccessMethod::validateUpdate(OperationContext* txn,
+                                                  const BSONObj &from,
                                                   const BSONObj &to,
                                                   const DiskLoc &record,
                                                   const InsertDeleteOptions &options,
@@ -264,7 +265,7 @@ namespace mongo {
 
         if (checkForDups) {
             for (vector<BSONObj*>::iterator i = data->added.begin(); i != data->added.end(); i++) {
-                Status check = _newInterface->dupKeyCheck(**i, record);
+                Status check = _newInterface->dupKeyCheck(txn, **i, record);
                 if (!check.isOK()) {
                     status->_isValid = false;
                     return check;
diff --git a/src/mongo/db/index/btree_based_access_method.h b/src/mongo/db/index/btree_based_access_method.h
index 5b1aa351ae1..710a323b60a 100644
--- a/src/mongo/db/index/btree_based_access_method.h
+++ b/src/mongo/db/index/btree_based_access_method.h
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -74,7 +74,8 @@ namespace mongo {
                               const InsertDeleteOptions& options,
                               int64_t* numDeleted);
 
-        virtual Status validateUpdate(const BSONObj& from,
+        virtual Status validateUpdate(OperationContext* txn,
+                                      const BSONObj& from,
                                       const BSONObj& to,
                                       const DiskLoc& loc,
                                       const InsertDeleteOptions& options,
@@ -84,7 +85,9 @@ namespace mongo {
                               const UpdateTicket& ticket,
                               int64_t* numUpdated);
 
-        virtual Status newCursor(const CursorOptions& opts, IndexCursor** out) const;
+        virtual Status newCursor(OperationContext* txn,
+                                 const CursorOptions& opts,
+                                 IndexCursor** out) const;
 
         virtual Status initializeAsEmpty(OperationContext* txn);
 
@@ -94,14 +97,14 @@ namespace mongo {
                                    bool mayInterrupt,
                                    std::set<DiskLoc>* dups );
 
-        virtual Status touch(const BSONObj& obj);
+        virtual Status touch(OperationContext* txn, const BSONObj& obj);
 
         virtual Status touch(OperationContext* txn) const;
 
-        virtual Status validate(int64_t* numKeys);
+        virtual Status validate(OperationContext* txn, int64_t* numKeys);
 
         // XXX: consider migrating callers to use IndexCursor instead
-        virtual DiskLoc findSingle( const BSONObj& key ) const;
+        virtual DiskLoc findSingle( OperationContext* txn, const BSONObj& key ) const;
 
         /**
          * Invalidates all active cursors, which point at the bucket being deleted.
diff --git a/src/mongo/db/index/btree_based_bulk_access_method.h b/src/mongo/db/index/btree_based_bulk_access_method.h
index 88dad32ea04..0c766aad1ec 100644
--- a/src/mongo/db/index/btree_based_bulk_access_method.h
+++ b/src/mongo/db/index/btree_based_bulk_access_method.h
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -75,7 +75,7 @@ namespace mongo {
             return Status::OK();
         }
 
-        virtual Status touch(const BSONObj& obj) {
+        virtual Status touch(OperationContext* txn, const BSONObj& obj) {
             return _notAllowed();
         }
 
@@ -83,7 +83,7 @@ namespace mongo {
             return _notAllowed();
         }
 
-        virtual Status validate(int64_t* numKeys) {
+        virtual Status validate(OperationContext* txn, int64_t* numKeys) {
             return _notAllowed();
         }
 
@@ -95,7 +95,8 @@ namespace mongo {
             return _notAllowed();
         }
 
-        virtual Status validateUpdate(const BSONObj& from,
+        virtual Status validateUpdate(OperationContext* txn,
+                                      const BSONObj& from,
                                       const BSONObj& to,
                                       const DiskLoc& loc,
                                       const InsertDeleteOptions& options,
@@ -109,7 +110,9 @@ namespace mongo {
             return _notAllowed();
         }
 
-        virtual Status newCursor(const CursorOptions& opts, IndexCursor** out) const {
+        virtual Status newCursor(OperationContext*txn,
+                                 const CursorOptions& opts,
+                                 IndexCursor** out) const {
             return _notAllowed();
         }
 
diff --git a/src/mongo/db/index/haystack_access_method.cpp b/src/mongo/db/index/haystack_access_method.cpp
index 44492bc87a2..a2fbe010a3f 100644
--- a/src/mongo/db/index/haystack_access_method.cpp
+++ b/src/mongo/db/index/haystack_access_method.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -61,7 +61,7 @@ namespace mongo {
         ExpressionKeysPrivate::getHaystackKeys(obj, _geoField, _otherFields, _bucketSize, keys);
     }
 
-    void HaystackAccessMethod::searchCommand(Collection* collection,
+    void HaystackAccessMethod::searchCommand(OperationContext* txn, Collection* collection,
                                              const BSONObj& nearObj, double maxDistance,
                                              const BSONObj& search, BSONObjBuilder* result,
                                              unsigned limit) {
@@ -100,7 +100,7 @@ namespace mongo {
                 unordered_set<DiskLoc, DiskLoc::Hasher> thisPass;
 
 
-                scoped_ptr<Runner> runner(InternalPlanner::indexScan(collection,
+                scoped_ptr<Runner> runner(InternalPlanner::indexScan(txn,  collection,
                                                                      _descriptor, key, key, true));
                 Runner::RunnerState state;
                 DiskLoc loc;
diff --git a/src/mongo/db/index/haystack_access_method.h b/src/mongo/db/index/haystack_access_method.h
index 5ce9d787450..ebab7177a59 100644
--- a/src/mongo/db/index/haystack_access_method.h
+++ b/src/mongo/db/index/haystack_access_method.h
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -36,6 +36,7 @@
 namespace mongo {
 
     class Collection;
+    class OperationContext;
 
     /**
      * Maps (lat, lng) to the bucketSize-sided square bucket that contains it.
@@ -62,7 +63,7 @@ namespace mongo {
 
     protected:
         friend class GeoHaystackSearchCommand;
-        void searchCommand(Collection* collection,
+        void searchCommand(OperationContext* txn, Collection* collection,
                            const BSONObj& nearObj, double maxDistance, const BSONObj& search,
                            BSONObjBuilder* result, unsigned limit);
 
diff --git a/src/mongo/db/index/index_access_method.h b/src/mongo/db/index/index_access_method.h
index 90bed6811d1..8cef5a5ef29 100644
--- a/src/mongo/db/index/index_access_method.h
+++ b/src/mongo/db/index/index_access_method.h
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -91,7 +91,8 @@ namespace mongo {
          *
          * There is no obligation to perform the update after performing validation.
          */
-        virtual Status validateUpdate(const BSONObj& from,
+        virtual Status validateUpdate(OperationContext* txn,
+                                      const BSONObj& from,
                                       const BSONObj& to,
                                       const DiskLoc& loc,
                                       const InsertDeleteOptions& options,
@@ -113,7 +114,7 @@ namespace mongo {
          * Fills in '*out' with an IndexCursor.  Return a status indicating success or reason of
          * failure. If the latter, '*out' contains NULL.  See index_cursor.h for IndexCursor usage.
          */
-        virtual Status newCursor(const CursorOptions& opts, IndexCursor** out) const = 0;
+        virtual Status newCursor(OperationContext* txn, const CursorOptions& opts, IndexCursor** out) const = 0;
 
         // ------ index level operations ------
 
@@ -131,12 +132,12 @@ namespace mongo {
          * appropriate pages are not swapped out.
          * See prefetch.cpp.
          */
-        virtual Status touch(const BSONObj& obj) = 0;
+        virtual Status touch(OperationContext* txn, const BSONObj& obj) = 0;
 
         /**
          * this pages in the entire index
          */
-        virtual Status touch( OperationContext* txn ) const = 0;
+        virtual Status touch(OperationContext* txn) const = 0;
 
         /**
          * Walk the entire index, checking the internal structure for consistency.
@@ -147,7 +148,7 @@ namespace mongo {
          * Currently wasserts that the index is invalid.  This could/should be changed in
          * the future to return a Status.
          */
-        virtual Status validate(int64_t* numKeys) = 0;
+        virtual Status validate(OperationContext* txn, int64_t* numKeys) = 0;
 
         //
         // Bulk operations support
diff --git a/src/mongo/db/ops/delete_executor.cpp b/src/mongo/db/ops/delete_executor.cpp
index 2d776984236..e7eb2a9546c 100644
--- a/src/mongo/db/ops/delete_executor.cpp
+++ b/src/mongo/db/ops/delete_executor.cpp
@@ -118,11 +118,12 @@ namespace mongo {
 
         Runner* rawRunner;
         if (_canonicalQuery.get()) {
-            uassertStatusOK(getRunner(collection, _canonicalQuery.release(), &rawRunner));
+            uassertStatusOK(getRunner(txn, collection, _canonicalQuery.release(), &rawRunner));
         }
         else {
             CanonicalQuery* ignored;
-            uassertStatusOK(getRunner(collection,
+            uassertStatusOK(getRunner(txn,
+                                      collection,
                                       ns.ns(),
                                       _request->getQuery(),
                                       &rawRunner,
diff --git a/src/mongo/db/ops/update.cpp b/src/mongo/db/ops/update.cpp
index b39008a1bef..e675fd142ac 100644
--- a/src/mongo/db/ops/update.cpp
+++ b/src/mongo/db/ops/update.cpp
@@ -1,7 +1,7 @@
 //@file update.cpp
 
 /**
- *    Copyright (C) 2008 10gen Inc.
+ *    Copyright (C) 2008-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -457,8 +457,8 @@ namespace mongo {
 
         Runner* rawRunner;
         Status status = cq ?
-            getRunner(collection, cqHolder.release(), &rawRunner) :
-            getRunner(collection, nsString.ns(), request.getQuery(), &rawRunner, &cq);
+            getRunner(txn, collection, cqHolder.release(), &rawRunner) :
+            getRunner(txn, collection, nsString.ns(), request.getQuery(), &rawRunner, &cq);
         uassert(17243,
                 "could not get runner " + request.getQuery().toString() + "; " + causedBy(status),
                 status.isOK());
diff --git a/src/mongo/db/pipeline/pipeline_d.cpp b/src/mongo/db/pipeline/pipeline_d.cpp
index 6f62767f999..1f6f93f1274 100644
--- a/src/mongo/db/pipeline/pipeline_d.cpp
+++ b/src/mongo/db/pipeline/pipeline_d.cpp
@@ -1,5 +1,5 @@
 /**
- * Copyright (c) 2012 10gen Inc.
+ * Copyright (c) 2012-2014 MongoDB Inc.
  *
  * This program is free software: you can redistribute it and/or  modify
  * it under the terms of the GNU Affero General Public License, version 3,
@@ -75,6 +75,7 @@ namespace {
 }
 
     boost::shared_ptr<Runner> PipelineD::prepareCursorSource(
+            OperationContext* txn,
             Collection* collection,
             const intrusive_ptr<Pipeline>& pPipeline,
             const intrusive_ptr<ExpressionContext>& pExpCtx) {
@@ -178,7 +179,7 @@ namespace {
                                              &cq,
                                              whereCallback);
             Runner* rawRunner;
-            if (status.isOK() && getRunner(collection, cq, &rawRunner, runnerOptions).isOK()) {
+            if (status.isOK() && getRunner(txn, collection, cq, &rawRunner, runnerOptions).isOK()) {
                 // success: The Runner will handle sorting for us using an index.
                 runner.reset(rawRunner);
                 sortInRunner = true;
@@ -203,7 +204,7 @@ namespace {
                                              whereCallback));
 
             Runner* rawRunner;
-            uassertStatusOK(getRunner(collection, cq, &rawRunner, runnerOptions));
+            uassertStatusOK(getRunner(txn, collection, cq, &rawRunner, runnerOptions));
             runner.reset(rawRunner);
         }
 
diff --git a/src/mongo/db/pipeline/pipeline_d.h b/src/mongo/db/pipeline/pipeline_d.h
index b6b34e6f378..b9d85a69dbb 100644
--- a/src/mongo/db/pipeline/pipeline_d.h
+++ b/src/mongo/db/pipeline/pipeline_d.h
@@ -1,5 +1,5 @@
 /**
- * Copyright 2012 (c) 10gen Inc.
+ * Copyright (C) 2012-2014 MongoDB Inc.
  *
  * This program is free software: you can redistribute it and/or  modify
  * it under the terms of the GNU Affero General Public License, version 3,
@@ -34,6 +34,7 @@ namespace mongo {
     class Collection;
     class DocumentSourceCursor;
     struct ExpressionContext;
+    class OperationContext;
     class Pipeline;
     class Runner;
 
@@ -71,6 +72,7 @@ namespace mongo {
          * @param pExpCtx the expression context for this pipeline
          */
         static boost::shared_ptr<Runner> prepareCursorSource(
+            OperationContext* txn,
             Collection* collection,
             const intrusive_ptr<Pipeline> &pPipeline,
             const intrusive_ptr<ExpressionContext> &pExpCtx);
diff --git a/src/mongo/db/prefetch.cpp b/src/mongo/db/prefetch.cpp
index 88ba08716e7..fe2500f4b16 100644
--- a/src/mongo/db/prefetch.cpp
+++ b/src/mongo/db/prefetch.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -58,7 +58,8 @@ namespace mongo {
                                                     "repl.preload.docs",
                                                     &prefetchDocStats );
 
-    void prefetchIndexPages(Collection* collection,
+    void prefetchIndexPages(OperationContext* txn,
+                            Collection* collection,
                             const repl::ReplSetImpl::IndexPrefetchConfig& prefetchConfig,
                             const BSONObj& obj);
 
@@ -111,7 +112,7 @@ namespace mongo {
         // a way to achieve that would be to prefetch the record first, and then afterwards do 
         // this part.
         //
-        prefetchIndexPages(collection, prefetchConfig, obj);
+        prefetchIndexPages(txn, collection, prefetchConfig, obj);
 
         // do not prefetch the data for inserts; it doesn't exist yet
         // 
@@ -128,7 +129,8 @@ namespace mongo {
     }
 
     // page in pages needed for all index lookups on a given object
-    void prefetchIndexPages(Collection* collection,
+    void prefetchIndexPages(OperationContext* txn,
+                            Collection* collection,
                             const repl::ReplSetImpl::IndexPrefetchConfig& prefetchConfig,
                             const BSONObj& obj) {
         DiskLoc unusedDl; // unused
@@ -151,7 +153,7 @@ namespace mongo {
                     return;
                 IndexAccessMethod* iam = collection->getIndexCatalog()->getIndex( desc );
                 verify( iam );
-                iam->touch(obj);
+                iam->touch(txn, obj);
             }
             catch (const DBException& e) {
                 LOG(2) << "ignoring exception in prefetchIndexPages(): " << e.what() << endl;
@@ -170,7 +172,7 @@ namespace mongo {
                     IndexDescriptor* desc = ii.next();
                     IndexAccessMethod* iam = collection->getIndexCatalog()->getIndex( desc );
                     verify( iam );
-                    iam->touch(obj);
+                    iam->touch(txn, obj);
                 }
                 catch (const DBException& e) {
                     LOG(2) << "ignoring exception in prefetchIndexPages(): " << e.what() << endl;
diff --git a/src/mongo/db/query/explain.h b/src/mongo/db/query/explain.h
index 32d144466f5..bf4b5b4742c 100644
--- a/src/mongo/db/query/explain.h
+++ b/src/mongo/db/query/explain.h
@@ -38,6 +38,7 @@
 namespace mongo {
 
     class Collection;
+    class OperationContext;
 
     // Temporarily hide the new explain implementation behind a setParameter.
     // TODO: take this out, and make the new implementation the default.
@@ -131,7 +132,6 @@ namespace mongo {
          * are no stages, this requires a special explain format.
          */
         static void explainCountEmptyQuery(BSONObjBuilder* out);
-
     };
 
 } // namespace
diff --git a/src/mongo/db/query/get_executor.cpp b/src/mongo/db/query/get_executor.cpp
index 74ec3f62f38..2a547a465c9 100644
--- a/src/mongo/db/query/get_executor.cpp
+++ b/src/mongo/db/query/get_executor.cpp
@@ -162,7 +162,8 @@ namespace mongo {
         plannerParams->options |= QueryPlannerParams::SPLIT_LIMITED_SORT;
     }
 
-    Status getExecutorIDHack(Collection* collection,
+    Status getExecutorIDHack(OperationContext* txn,
+                             Collection* collection,
                              CanonicalQuery* query,
                              const QueryPlannerParams& plannerParams,
                              PlanExecutor** out) {
@@ -170,7 +171,7 @@ namespace mongo {
 
         LOG(2) << "Using idhack: " << query->toStringShort();
         WorkingSet* ws = new WorkingSet();
-        PlanStage* root = new IDHackStage(collection, query, ws);
+        PlanStage* root = new IDHackStage(txn, collection, query, ws);
 
         // Might have to filter out orphaned docs.
         if (plannerParams.options & QueryPlannerParams::INCLUDE_SHARD_FILTER) {
@@ -201,7 +202,8 @@ namespace mongo {
         return Status::OK();
     }
 
-    Status getExecutor(Collection* collection,
+    Status getExecutor(OperationContext* txn,
+                      Collection* collection,
                       CanonicalQuery* canonicalQuery,
                       PlanExecutor** out,
                       size_t plannerOptions) {
@@ -226,7 +228,7 @@ namespace mongo {
         // If we have an _id index we can use the idhack runner.
         if (IDHackStage::supportsQuery(*canonicalQuery) &&
             collection->getIndexCatalog()->findIdIndex()) {
-            return getExecutorIDHack(collection, canonicalQuery, plannerParams, out);
+            return getExecutorIDHack(txn, collection, canonicalQuery, plannerParams, out);
         }
 
         // Tailable: If the query requests tailable the collection must be capped.
@@ -267,7 +269,7 @@ namespace mongo {
                 WorkingSet* sharedWs = new WorkingSet();
 
                 PlanStage *root, *backupRoot=NULL;
-                verify(StageBuilder::build(collection, *qs, sharedWs, &root));
+                verify(StageBuilder::build(txn, collection, *qs, sharedWs, &root));
                 if ((plannerParams.options & QueryPlannerParams::PRIVATE_IS_COUNT)
                     && turnIxscanIntoCount(qs)) {
                     LOG(2) << "Using fast count: " << canonicalQuery->toStringShort()
@@ -278,7 +280,7 @@ namespace mongo {
                     }
                 }
                 else if (NULL != backupQs) {
-                    verify(StageBuilder::build(collection, *backupQs, sharedWs, &backupRoot));
+                    verify(StageBuilder::build(txn, collection, *backupQs, sharedWs, &backupRoot));
                 }
 
                 // add a CachedPlanStage on top of the previous root
@@ -298,7 +300,7 @@ namespace mongo {
             auto_ptr<WorkingSet> ws(new WorkingSet());
 
             SubplanStage* subplan;
-            Status runnerStatus = SubplanStage::make(collection, ws.get(), plannerParams,
+            Status runnerStatus = SubplanStage::make(txn, collection, ws.get(), plannerParams,
                                                      canonicalQuery, &subplan);
             if (!runnerStatus.isOK()) {
                 return runnerStatus;
@@ -308,10 +310,11 @@ namespace mongo {
             return Status::OK();
         }
 
-        return getExecutorAlwaysPlan(collection, canonicalQuery, plannerParams, out);
+        return getExecutorAlwaysPlan(txn, collection, canonicalQuery, plannerParams, out);
     }
 
-    Status getExecutorAlwaysPlan(Collection* collection,
+    Status getExecutorAlwaysPlan(OperationContext* txn,
+                                 Collection* collection,
                                  CanonicalQuery* canonicalQuery,
                                  const QueryPlannerParams& plannerParams,
                                  PlanExecutor** execOut) {
@@ -355,7 +358,8 @@ namespace mongo {
                     // We're not going to cache anything that's fast count.
                     WorkingSet* ws = new WorkingSet();
                     PlanStage* root;
-                    verify(StageBuilder::build(collection, *solutions[i], ws, &root));
+
+                    verify(StageBuilder::build(txn, collection, *solutions[i], ws, &root));
 
                     *execOut = new PlanExecutor(ws, root, solutions[i], collection);
                     return Status::OK();
@@ -371,7 +375,8 @@ namespace mongo {
             // Only one possible plan.  Run it.  Build the stages from the solution.
             WorkingSet* ws = new WorkingSet();
             PlanStage* root;
-            verify(StageBuilder::build(collection, *solutions[0], ws, &root));
+
+            verify(StageBuilder::build(txn, collection, *solutions[0], ws, &root));
 
             *execOut = new PlanExecutor(ws, root, solutions[0], collection);
             return Status::OK();
@@ -391,7 +396,7 @@ namespace mongo {
 
                 // version of StageBuild::build when WorkingSet is shared
                 PlanStage* nextPlanRoot;
-                verify(StageBuilder::build(collection, *solutions[ix],
+                verify(StageBuilder::build(txn, collection, *solutions[ix],
                                            sharedWorkingSet, &nextPlanRoot));
 
                 // Owns none of the arguments
@@ -581,7 +586,8 @@ namespace mongo {
 
     }  // namespace
 
-    Status getExecutorCount(Collection* collection,
+    Status getExecutorCount(OperationContext* txn,
+                            Collection* collection,
                             const BSONObj& query,
                             const BSONObj& hintObj,
                             PlanExecutor** execOut) {
@@ -602,7 +608,7 @@ namespace mongo {
 
         scoped_ptr<CanonicalQuery> cleanupCq(cq);
 
-        return getExecutor(collection, cq, execOut, QueryPlannerParams::PRIVATE_IS_COUNT);
+        return getExecutor(txn, collection, cq, execOut, QueryPlannerParams::PRIVATE_IS_COUNT);
     }
 
     //
@@ -658,7 +664,8 @@ namespace mongo {
         return false;
     }
 
-    Status getExecutorDistinct(Collection* collection,
+    Status getExecutorDistinct(OperationContext* txn,
+                               Collection* collection,
                                const BSONObj& query,
                                const std::string& field,
                                PlanExecutor** out) {
@@ -709,7 +716,7 @@ namespace mongo {
             scoped_ptr<CanonicalQuery> cleanupCq(cq);
 
             // Does not take ownership of its args.
-            return getExecutor(collection, cq, out);
+            return getExecutor(txn, collection, cq, out);
         }
 
         //
@@ -758,7 +765,7 @@ namespace mongo {
 
             WorkingSet* ws = new WorkingSet();
             PlanStage* root;
-            verify(StageBuilder::build(collection, *soln, ws, &root));
+            verify(StageBuilder::build(txn, collection, *soln, ws, &root));
             // Takes ownership of 'ws', 'root', and 'soln'.
             *out = new PlanExecutor(ws, root, soln, collection);
             return Status::OK();
@@ -768,7 +775,7 @@ namespace mongo {
         vector<QuerySolution*> solutions;
         status = QueryPlanner::plan(*cq, plannerParams, &solutions);
         if (!status.isOK()) {
-            return getExecutor(collection, cq, out);
+            return getExecutor(txn, collection, cq, out);
         }
 
         // We look for a solution that has an ixscan we can turn into a distinctixscan
@@ -787,7 +794,7 @@ namespace mongo {
                 // Build and return the SSR over solutions[i].
                 WorkingSet* ws = new WorkingSet();
                 PlanStage* root;
-                verify(StageBuilder::build(collection, *solutions[i], ws, &root));
+                verify(StageBuilder::build(txn, collection, *solutions[i], ws, &root));
                 // Takes ownership of 'ws', 'root', and 'solutions[i]'.
                 *out = new PlanExecutor(ws, root, solutions[i], collection);
                 return Status::OK();
@@ -810,7 +817,7 @@ namespace mongo {
         cleanupCq.reset(cq);
 
         // Does not take ownership.
-        return getExecutor(collection, cq, out);
+        return getExecutor(txn, collection, cq, out);
     }
 
 }  // namespace mongo
diff --git a/src/mongo/db/query/get_executor.h b/src/mongo/db/query/get_executor.h
index fc78e302709..f1eb40db2db 100644
--- a/src/mongo/db/query/get_executor.h
+++ b/src/mongo/db/query/get_executor.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -62,7 +62,8 @@ namespace mongo {
      * If the query cannot be executed, returns a Status indicating why.  Deletes
      * rawCanonicalQuery.
      */
-    Status getExecutor(Collection* collection,
+    Status getExecutor(OperationContext* txn,
+                       Collection* collection,
                        CanonicalQuery* canonicalQuery,
                        PlanExecutor** out,
                        size_t plannerOptions = 0);
@@ -94,7 +95,8 @@ namespace mongo {
      * possible values of a certain field.  As such, we can skip lots of data in certain cases (see
      * body of method for detail).
      */
-    Status getExecutorDistinct(Collection* collection,
+    Status getExecutorDistinct(OperationContext* txn,
+                               Collection* collection,
                                const BSONObj& query,
                                const std::string& field,
                                PlanExecutor** out);
@@ -106,7 +108,8 @@ namespace mongo {
      * As such, with certain covered queries, we can skip the overhead of fetching etc. when
      * executing a count.
      */
-    Status getExecutorCount(Collection* collection,
+    Status getExecutorCount(OperationContext* txn,
+                            Collection* collection,
                             const BSONObj& query,
                             const BSONObj& hintObj,
                             PlanExecutor** execOut);
@@ -119,7 +122,8 @@ namespace mongo {
      * Returns the resulting executor through 'execOut'. The caller must delete 'execOut',
      * if an OK status is returned.
      */
-    Status getExecutorAlwaysPlan(Collection* collection,
+    Status getExecutorAlwaysPlan(OperationContext* txn,
+                                 Collection* collection,
                                  CanonicalQuery* canonicalQuery,
                                  const QueryPlannerParams& plannerParams,
                                  PlanExecutor** execOut);
diff --git a/src/mongo/db/query/get_runner.cpp b/src/mongo/db/query/get_runner.cpp
index 3e027d60cff..429cbc15d33 100644
--- a/src/mongo/db/query/get_runner.cpp
+++ b/src/mongo/db/query/get_runner.cpp
@@ -69,7 +69,8 @@ namespace mongo {
 
     MONGO_LOG_DEFAULT_COMPONENT_FILE(::mongo::logger::LogComponent::kQuery);
 
-    Status getRunner(Collection* collection,
+    Status getRunner(OperationContext* txn,
+                     Collection* collection,
                      const std::string& ns,
                      const BSONObj& unparsedQuery,
                      Runner** outRunner,
@@ -92,13 +93,13 @@ namespace mongo {
                         collection->ns(), unparsedQuery, outCanonicalQuery, whereCallback);
             if (!status.isOK())
                 return status;
-            return getRunner(collection, *outCanonicalQuery, outRunner, plannerOptions);
+            return getRunner(txn, collection, *outCanonicalQuery, outRunner, plannerOptions);
         }
 
         LOG(2) << "Using idhack: " << unparsedQuery.toString();
 
         *outCanonicalQuery = NULL;
-        *outRunner = new IDHackRunner(collection, unparsedQuery["_id"].wrap());
+        *outRunner = new IDHackRunner(txn, collection, unparsedQuery["_id"].wrap());
         return Status::OK();
     }
 
@@ -111,7 +112,8 @@ namespace mongo {
     /**
      * For a given query, get a runner.
      */
-    Status getRunner(Collection* collection,
+    Status getRunner(OperationContext* txn,
+                     Collection* collection,
                      CanonicalQuery* rawCanonicalQuery,
                      Runner** out,
                      size_t plannerOptions) {
@@ -132,7 +134,7 @@ namespace mongo {
         if (IDHackStage::supportsQuery(*canonicalQuery) &&
             collection->getIndexCatalog()->findIdIndex()) {
             LOG(2) << "Using idhack: " << canonicalQuery->toStringShort();
-            *out = new IDHackRunner(collection, canonicalQuery.release());
+            *out = new IDHackRunner(txn, collection, canonicalQuery.release());
             return Status::OK();
         }
 
@@ -179,7 +181,7 @@ namespace mongo {
                 WorkingSet* sharedWs = new WorkingSet();
 
                 PlanStage *root, *backupRoot=NULL;
-                verify(StageBuilder::build(collection, *qs, sharedWs, &root));
+                verify(StageBuilder::build(txn, collection, *qs, sharedWs, &root));
                 if ((plannerParams.options & QueryPlannerParams::PRIVATE_IS_COUNT)
                     && turnIxscanIntoCount(qs)) {
                     LOG(2) << "Using fast count: " << canonicalQuery->toStringShort()
@@ -190,7 +192,7 @@ namespace mongo {
                     }
                 }
                 else if (NULL != backupQs) {
-                    verify(StageBuilder::build(collection, *backupQs, sharedWs, &backupRoot));
+                    verify(StageBuilder::build(txn, collection, *backupQs, sharedWs, &backupRoot));
                 }
 
                 // add a CachedPlanStage on top of the previous root
@@ -210,7 +212,7 @@ namespace mongo {
             LOG(2) << "Running query as sub-queries: " << canonicalQuery->toStringShort();
 
             SubplanRunner* runner;
-            Status runnerStatus = SubplanRunner::make(collection, plannerParams,
+            Status runnerStatus = SubplanRunner::make(txn, collection, plannerParams,
                                                       canonicalQuery.release(), &runner);
             if (!runnerStatus.isOK()) {
                 return runnerStatus;
@@ -220,10 +222,11 @@ namespace mongo {
             return Status::OK();
         }
 
-        return getRunnerAlwaysPlan(collection, canonicalQuery.release(), plannerParams, out);
+        return getRunnerAlwaysPlan(txn, collection, canonicalQuery.release(), plannerParams, out);
     }
 
-    Status getRunnerAlwaysPlan(Collection* collection,
+    Status getRunnerAlwaysPlan(OperationContext* txn,
+                               Collection* collection,
                                CanonicalQuery* rawCanonicalQuery,
                                const QueryPlannerParams& plannerParams,
                                Runner** out) {
@@ -266,7 +269,7 @@ namespace mongo {
                     // We're not going to cache anything that's fast count.
                     WorkingSet* ws = new WorkingSet();
                     PlanStage* root;
-                    verify(StageBuilder::build(collection, *solutions[i], ws, &root));
+                    verify(StageBuilder::build(txn, collection, *solutions[i], ws, &root));
                     *out = new SingleSolutionRunner(collection,
                                                     canonicalQuery.release(),
                                                     solutions[i],
@@ -285,7 +288,7 @@ namespace mongo {
             // Only one possible plan.  Run it.  Build the stages from the solution.
             WorkingSet* ws = new WorkingSet();
             PlanStage* root;
-            verify(StageBuilder::build(collection, *solutions[0], ws, &root));
+            verify(StageBuilder::build(txn, collection, *solutions[0], ws, &root));
 
             // And, run the plan.
             *out = new SingleSolutionRunner(collection,
@@ -310,7 +313,7 @@ namespace mongo {
 
                 // version of StageBuild::build when WorkingSet is shared
                 PlanStage* nextPlanRoot;
-                verify(StageBuilder::build(collection, *solutions[ix],
+                verify(StageBuilder::build(txn, collection, *solutions[ix],
                                            sharedWorkingSet, &nextPlanRoot));
 
                 // Owns none of the arguments
@@ -506,7 +509,8 @@ namespace mongo {
 
     }  // namespace
 
-    Status getRunnerCount(Collection* collection,
+    Status getRunnerCount(OperationContext* txn,
+                          Collection* collection,
                           const BSONObj& query,
                           const BSONObj& hintObj,
                           Runner** out) {
@@ -525,14 +529,15 @@ namespace mongo {
                                                      &cq,
                                                      whereCallback));
 
-        return getRunner(collection, cq, out, QueryPlannerParams::PRIVATE_IS_COUNT);
+        return getRunner(txn, collection, cq, out, QueryPlannerParams::PRIVATE_IS_COUNT);
     }
 
     //
     // Distinct hack
     //
 
-    Status getRunnerDistinct(Collection* collection,
+    Status getRunnerDistinct(OperationContext* txn,
+                             Collection* collection,
                              const BSONObj& query,
                              const string& field,
                              Runner** out) {
@@ -581,7 +586,7 @@ namespace mongo {
             }
 
             // Takes ownership of cq.
-            return getRunner(collection, cq, out);
+            return getRunner(txn, collection, cq, out);
         }
 
         //
@@ -628,7 +633,7 @@ namespace mongo {
 
             WorkingSet* ws = new WorkingSet();
             PlanStage* root;
-            verify(StageBuilder::build(collection, *soln, ws, &root));
+            verify(StageBuilder::build(txn, collection, *soln, ws, &root));
             *out = new SingleSolutionRunner(collection, cq, soln, root, ws);
             return Status::OK();
         }
@@ -637,7 +642,7 @@ namespace mongo {
         vector<QuerySolution*> solutions;
         status = QueryPlanner::plan(*cq, plannerParams, &solutions);
         if (!status.isOK()) {
-            return getRunner(collection, cq, out);
+            return getRunner(txn, collection, cq, out);
         }
 
         // We look for a solution that has an ixscan we can turn into a distinctixscan
@@ -656,7 +661,7 @@ namespace mongo {
                 // Build and return the SSR over solutions[i].
                 WorkingSet* ws = new WorkingSet();
                 PlanStage* root;
-                verify(StageBuilder::build(collection, *solutions[i], ws, &root));
+                verify(StageBuilder::build(txn, collection, *solutions[i], ws, &root));
                 *out = new SingleSolutionRunner(collection, cq, solutions[i], root, ws);
                 return Status::OK();
             }
@@ -677,7 +682,7 @@ namespace mongo {
         }
 
         // Takes ownership of cq.
-        return getRunner(collection, cq, out);
+        return getRunner(txn, collection, cq, out);
     }
 
     ScopedRunnerRegistration::ScopedRunnerRegistration(Runner* runner)
diff --git a/src/mongo/db/query/get_runner.h b/src/mongo/db/query/get_runner.h
index eabc78d3bdd..2d9dd75c88e 100644
--- a/src/mongo/db/query/get_runner.h
+++ b/src/mongo/db/query/get_runner.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -37,6 +37,7 @@
 namespace mongo {
 
     class Collection;
+    class OperationContext;
 
     /**
      * Get a runner for a query.  Takes ownership of rawCanonicalQuery.
@@ -47,7 +48,8 @@ namespace mongo {
      * If the query cannot be executed, returns a Status indicating why.  Deletes
      * rawCanonicalQuery.
      */
-    Status getRunner(Collection* collection,
+    Status getRunner(OperationContext* txn,
+                     Collection* collection,
                      CanonicalQuery* rawCanonicalQuery,
                      Runner** out,
                      size_t plannerOptions = 0);
@@ -63,7 +65,8 @@ namespace mongo {
      * the returned runner.  On failure, returns other status values, and '*outRunner' and
      * '*outCanonicalQuery' have unspecified values.
      */
-    Status getRunner(Collection* collection,
+    Status getRunner(OperationContext* txn,
+                     Collection* collection,
                      const std::string& ns,
                      const BSONObj& unparsedQuery,
                      Runner** outRunner,
@@ -76,7 +79,8 @@ namespace mongo {
      * possible values of a certain field.  As such, we can skip lots of data in certain cases (see
      * body of method for detail).
      */
-    Status getRunnerDistinct(Collection* collection,
+    Status getRunnerDistinct(OperationContext* txn,
+                             Collection* collection,
                              const BSONObj& query,
                              const std::string& field,
                              Runner** out);
@@ -88,7 +92,8 @@ namespace mongo {
      * As such, with certain covered queries, we can skip the overhead of fetching etc. when
      * executing a count.
      */
-    Status getRunnerCount(Collection* collection,
+    Status getRunnerCount(OperationContext* txn,
+                          Collection* collection,
                           const BSONObj& query,
                           const BSONObj& hintObj,
                           Runner** out);
@@ -96,7 +101,8 @@ namespace mongo {
     /**
      * Get a runner for a query.  Ignores the cache and always plans the full query.
      */
-    Status getRunnerAlwaysPlan(Collection* collection,
+    Status getRunnerAlwaysPlan(OperationContext* txn,
+                               Collection* collection,
                                CanonicalQuery* rawCanonicalQuery,
                                const QueryPlannerParams& plannerParams,
                                Runner** out);
diff --git a/src/mongo/db/query/idhack_runner.cpp b/src/mongo/db/query/idhack_runner.cpp
index b9c0da6f82b..5382a4e4bfa 100644
--- a/src/mongo/db/query/idhack_runner.cpp
+++ b/src/mongo/db/query/idhack_runner.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright 2013 MongoDB Inc.
+ *    Copyright 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -43,8 +43,11 @@
 
 namespace mongo {
 
-    IDHackRunner::IDHackRunner(const Collection* collection, CanonicalQuery* query)
-        : _collection(collection),
+    IDHackRunner::IDHackRunner(OperationContext* txn,
+                               const Collection* collection,
+                               CanonicalQuery* query)
+        : _txn(txn),
+          _collection(collection),
           _key(query->getQueryObj()["_id"].wrap()),
           _query(query),
           _killed(false),
@@ -52,8 +55,9 @@ namespace mongo {
           _nscanned(0),
           _nscannedObjects(0) { }
 
-    IDHackRunner::IDHackRunner(Collection* collection, const BSONObj& key)
-        : _collection(collection),
+    IDHackRunner::IDHackRunner(OperationContext* txn, Collection* collection, const BSONObj& key)
+        : _txn(txn),
+          _collection(collection),
           _key(key),
           _query(NULL),
           _killed(false),
@@ -80,7 +84,7 @@ namespace mongo {
             static_cast<const BtreeBasedAccessMethod*>(catalog->getIndex(idDesc));
 
         // Look up the key by going directly to the Btree.
-        DiskLoc loc = accessMethod->findSingle( _key );
+        DiskLoc loc = accessMethod->findSingle(_txn,  _key );
 
         // Key not found.
         if (loc.isNull()) {
diff --git a/src/mongo/db/query/idhack_runner.h b/src/mongo/db/query/idhack_runner.h
index 23e2d02691c..a6747a6d83b 100644
--- a/src/mongo/db/query/idhack_runner.h
+++ b/src/mongo/db/query/idhack_runner.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -50,10 +50,14 @@ namespace mongo {
     class IDHackRunner : public Runner {
     public:
 
-        /** Takes ownership of all the arguments -collection. */
-        IDHackRunner(const Collection* collection, CanonicalQuery* query);
+        /** Takes ownership of all the arguments -txn, -collection. */
+        IDHackRunner(OperationContext* txn,
+                     const Collection* collection,
+                     CanonicalQuery* query);
 
-        IDHackRunner(Collection* collection, const BSONObj& key);
+        IDHackRunner(OperationContext* txn,
+                     Collection* collection,
+                     const BSONObj& key);
 
         virtual ~IDHackRunner();
 
@@ -88,6 +92,9 @@ namespace mongo {
          */
         BSONObj applyProjection(const BSONObj& docObj) const;
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // Not owned here.
         const Collection* _collection;
 
diff --git a/src/mongo/db/query/internal_plans.h b/src/mongo/db/query/internal_plans.h
index c6a576d80f9..dae7af1c521 100644
--- a/src/mongo/db/query/internal_plans.h
+++ b/src/mongo/db/query/internal_plans.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -38,6 +38,8 @@
 
 namespace mongo {
 
+    class OperationContext;
+
     /**
      * The internal planner is a one-stop shop for "off-the-shelf" plans.  Most internal procedures
      * that do not require advanced queries could be served by plans already in here.
@@ -62,7 +64,8 @@ namespace mongo {
         /**
          * Return a collection scan.  Caller owns pointer.
          */
-        static Runner* collectionScan(const StringData& ns,
+        static Runner* collectionScan(OperationContext* txn,
+                                      const StringData& ns,
                                       Collection* collection,
                                       const Direction direction = FORWARD,
                                       const DiskLoc startLoc = DiskLoc()) {
@@ -84,14 +87,15 @@ namespace mongo {
             }
 
             WorkingSet* ws = new WorkingSet();
-            CollectionScan* cs = new CollectionScan(params, ws, NULL);
+            CollectionScan* cs = new CollectionScan(txn, params, ws, NULL);
             return new InternalRunner(collection, cs, ws);
         }
 
         /**
          * Return an index scan.  Caller owns returned pointer.
          */
-        static Runner* indexScan(const Collection* collection,
+        static Runner* indexScan(OperationContext* txn,
+                                 const Collection* collection,
                                  const IndexDescriptor* descriptor,
                                  const BSONObj& startKey, const BSONObj& endKey,
                                  bool endKeyInclusive, Direction direction = FORWARD,
@@ -108,11 +112,11 @@ namespace mongo {
             params.bounds.endKeyInclusive = endKeyInclusive;
 
             WorkingSet* ws = new WorkingSet();
-            IndexScan* ix = new IndexScan(params, ws, NULL);
+            IndexScan* ix = new IndexScan(txn, params, ws, NULL);
 
             if (IXSCAN_FETCH & options) {
                 return new InternalRunner(
-                                collection, new FetchStage(ws, ix, NULL, collection), ws);
+                    collection, new FetchStage(ws, ix, NULL, collection), ws);
             }
             else {
                 return new InternalRunner(collection, ix, ws);
diff --git a/src/mongo/db/query/internal_runner.h b/src/mongo/db/query/internal_runner.h
index d6af5e43db2..d01a39606f6 100644
--- a/src/mongo/db/query/internal_runner.h
+++ b/src/mongo/db/query/internal_runner.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -39,11 +39,12 @@ namespace mongo {
     class BSONObj;
     class CanonicalQuery;
     class DiskLoc;
+    class OperationContext;
     class PlanExecutor;
+    struct PlanInfo;
     class PlanStage;
     struct QuerySolution;
     class TypeExplain;
-    struct PlanInfo;
     class WorkingSet;
 
     /**
diff --git a/src/mongo/db/query/new_find.cpp b/src/mongo/db/query/new_find.cpp
index ac4e4d1766b..db2afd847fb 100644
--- a/src/mongo/db/query/new_find.cpp
+++ b/src/mongo/db/query/new_find.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -365,7 +365,10 @@ namespace mongo {
         return qr;
     }
 
-    Status getOplogStartHack(Collection* collection, CanonicalQuery* cq, Runner** runnerOut) {
+    Status getOplogStartHack(OperationContext* txn,
+                             Collection* collection,
+                             CanonicalQuery* cq,
+                             Runner** runnerOut) {
         if ( collection == NULL )
             return Status(ErrorCodes::InternalError,
                           "getOplogStartHack called with a NULL collection" );
@@ -398,7 +401,7 @@ namespace mongo {
 
         // Make an oplog start finding stage.
         WorkingSet* oplogws = new WorkingSet();
-        OplogStart* stage = new OplogStart(collection, tsExpr, oplogws);
+        OplogStart* stage = new OplogStart(txn, collection, tsExpr, oplogws);
 
         // Takes ownership of ws and stage.
         auto_ptr<InternalRunner> runner(new InternalRunner(collection, stage, oplogws));
@@ -408,7 +411,7 @@ namespace mongo {
         Runner::RunnerState state = runner->getNext(NULL, &startLoc);
 
         // This is normal.  The start of the oplog is the beginning of the collection.
-        if (Runner::RUNNER_EOF == state) { return getRunner(collection, cq, runnerOut); }
+        if (Runner::RUNNER_EOF == state) { return getRunner(txn, collection, cq, runnerOut); }
 
         // This is not normal.  An error was encountered.
         if (Runner::RUNNER_ADVANCED != state) {
@@ -426,7 +429,7 @@ namespace mongo {
         params.tailable = cq->getParsed().hasOption(QueryOption_CursorTailable);
 
         WorkingSet* ws = new WorkingSet();
-        CollectionScan* cs = new CollectionScan(params, ws, cq->root());
+        CollectionScan* cs = new CollectionScan(txn, params, ws, cq->root());
         // Takes ownership of cq, cs, ws.
         *runnerOut = new SingleSolutionRunner(collection, cq, NULL, cs, ws);
         return Status::OK();
@@ -528,7 +531,7 @@ namespace mongo {
             bb.skip(sizeof(QueryResult));
 
             PlanExecutor* rawExec;
-            Status execStatus = getExecutor(collection, cq, &rawExec, options);
+            Status execStatus = getExecutor(txn, collection, cq, &rawExec, options);
             if (!execStatus.isOK()) {
                 uasserted(17510, "Explain error: " + execStatus.reason());
             }
@@ -581,7 +584,7 @@ namespace mongo {
             rawRunner = new EOFRunner(cq, cq->ns());
         }
         else if (pq.hasOption(QueryOption_OplogReplay)) {
-            status = getOplogStartHack(collection, cq, &rawRunner);
+            status = getOplogStartHack(txn, collection, cq, &rawRunner);
         }
         else {
             // Takes ownership of cq.
@@ -589,7 +592,7 @@ namespace mongo {
             if (shardingState.needCollectionMetadata(pq.ns())) {
                 options |= QueryPlannerParams::INCLUDE_SHARD_FILTER;
             }
-            status = getRunner(collection, cq, &rawRunner, options);
+            status = getRunner(txn, collection, cq, &rawRunner, options);
         }
 
         if (!status.isOK()) {
diff --git a/src/mongo/db/query/stage_builder.cpp b/src/mongo/db/query/stage_builder.cpp
index a332088c1b2..5e29d472dfb 100644
--- a/src/mongo/db/query/stage_builder.cpp
+++ b/src/mongo/db/query/stage_builder.cpp
@@ -53,7 +53,8 @@
 
 namespace mongo {
 
-    PlanStage* buildStages(Collection* collection,
+    PlanStage* buildStages(OperationContext* txn,
+                           Collection* collection,
                            const QuerySolution& qsol,
                            const QuerySolutionNode* root,
                            WorkingSet* ws) {
@@ -65,7 +66,7 @@ namespace mongo {
             params.direction = (csn->direction == 1) ? CollectionScanParams::FORWARD
                                                      : CollectionScanParams::BACKWARD;
             params.maxScan = csn->maxScan;
-            return new CollectionScan(params, ws, csn->filter.get());
+            return new CollectionScan(txn, params, ws, csn->filter.get());
         }
         else if (STAGE_IXSCAN == root->getType()) {
             const IndexScanNode* ixn = static_cast<const IndexScanNode*>(root);
@@ -89,17 +90,17 @@ namespace mongo {
             params.direction = ixn->direction;
             params.maxScan = ixn->maxScan;
             params.addKeyMetadata = ixn->addKeyMetadata;
-            return new IndexScan(params, ws, ixn->filter.get());
+            return new IndexScan(txn, params, ws, ixn->filter.get());
         }
         else if (STAGE_FETCH == root->getType()) {
             const FetchNode* fn = static_cast<const FetchNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, fn->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, fn->children[0], ws);
             if (NULL == childStage) { return NULL; }
             return new FetchStage(ws, childStage, fn->filter.get(), collection);
         }
         else if (STAGE_SORT == root->getType()) {
             const SortNode* sn = static_cast<const SortNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, sn->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, sn->children[0], ws);
             if (NULL == childStage) { return NULL; }
             SortStageParams params;
             params.collection = collection;
@@ -110,7 +111,7 @@ namespace mongo {
         }
         else if (STAGE_PROJECTION == root->getType()) {
             const ProjectionNode* pn = static_cast<const ProjectionNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, pn->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, pn->children[0], ws);
             if (NULL == childStage) { return NULL; }
 
             ProjectionStageParams params(WhereCallbackReal(collection->ns().db()));
@@ -135,13 +136,13 @@ namespace mongo {
         }
         else if (STAGE_LIMIT == root->getType()) {
             const LimitNode* ln = static_cast<const LimitNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, ln->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, ln->children[0], ws);
             if (NULL == childStage) { return NULL; }
             return new LimitStage(ln->limit, ws, childStage);
         }
         else if (STAGE_SKIP == root->getType()) {
             const SkipNode* sn = static_cast<const SkipNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, sn->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, sn->children[0], ws);
             if (NULL == childStage) { return NULL; }
             return new SkipStage(sn->skip, ws, childStage);
         }
@@ -149,7 +150,7 @@ namespace mongo {
             const AndHashNode* ahn = static_cast<const AndHashNode*>(root);
             auto_ptr<AndHashStage> ret(new AndHashStage(ws, ahn->filter.get(), collection));
             for (size_t i = 0; i < ahn->children.size(); ++i) {
-                PlanStage* childStage = buildStages(collection, qsol, ahn->children[i], ws);
+                PlanStage* childStage = buildStages(txn, collection, qsol, ahn->children[i], ws);
                 if (NULL == childStage) { return NULL; }
                 ret->addChild(childStage);
             }
@@ -159,7 +160,7 @@ namespace mongo {
             const OrNode * orn = static_cast<const OrNode*>(root);
             auto_ptr<OrStage> ret(new OrStage(ws, orn->dedup, orn->filter.get()));
             for (size_t i = 0; i < orn->children.size(); ++i) {
-                PlanStage* childStage = buildStages(collection, qsol, orn->children[i], ws);
+                PlanStage* childStage = buildStages(txn, collection, qsol, orn->children[i], ws);
                 if (NULL == childStage) { return NULL; }
                 ret->addChild(childStage);
             }
@@ -169,7 +170,7 @@ namespace mongo {
             const AndSortedNode* asn = static_cast<const AndSortedNode*>(root);
             auto_ptr<AndSortedStage> ret(new AndSortedStage(ws, asn->filter.get(), collection));
             for (size_t i = 0; i < asn->children.size(); ++i) {
-                PlanStage* childStage = buildStages(collection, qsol, asn->children[i], ws);
+                PlanStage* childStage = buildStages(txn, collection, qsol, asn->children[i], ws);
                 if (NULL == childStage) { return NULL; }
                 ret->addChild(childStage);
             }
@@ -182,7 +183,7 @@ namespace mongo {
             params.pattern = msn->sort;
             auto_ptr<MergeSortStage> ret(new MergeSortStage(params, ws, collection));
             for (size_t i = 0; i < msn->children.size(); ++i) {
-                PlanStage* childStage = buildStages(collection, qsol, msn->children[i], ws);
+                PlanStage* childStage = buildStages(txn, collection, qsol, msn->children[i], ws);
                 if (NULL == childStage) { return NULL; }
                 ret->addChild(childStage);
             }
@@ -198,7 +199,7 @@ namespace mongo {
             params.numWanted = node->numWanted;
             params.addPointMeta = node->addPointMeta;
             params.addDistMeta = node->addDistMeta;
-            return new TwoDNear(params, ws);
+            return new TwoDNear(txn, params, ws);
         }
         else if (STAGE_GEO_NEAR_2DSPHERE == root->getType()) {
             const GeoNear2DSphereNode* node = static_cast<const GeoNear2DSphereNode*>(root);
@@ -210,7 +211,7 @@ namespace mongo {
             params.filter = node->filter.get();
             params.addPointMeta = node->addPointMeta;
             params.addDistMeta = node->addDistMeta;
-            return new S2NearStage(params, ws);
+            return new S2NearStage(txn, params, ws);
         }
         else if (STAGE_TEXT == root->getType()) {
             const TextNode* node = static_cast<const TextNode*>(root);
@@ -245,18 +246,18 @@ namespace mongo {
                 return NULL;
             }
 
-            return new TextStage(params, ws, node->filter.get());
+            return new TextStage(txn, params, ws, node->filter.get());
         }
         else if (STAGE_SHARDING_FILTER == root->getType()) {
             const ShardingFilterNode* fn = static_cast<const ShardingFilterNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, fn->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, fn->children[0], ws);
             if (NULL == childStage) { return NULL; }
             return new ShardFilterStage(shardingState.getCollectionMetadata(collection->ns()),
                                         ws, childStage);
         }
         else if (STAGE_KEEP_MUTATIONS == root->getType()) {
             const KeepMutationsNode* km = static_cast<const KeepMutationsNode*>(root);
-            PlanStage* childStage = buildStages(collection, qsol, km->children[0], ws);
+            PlanStage* childStage = buildStages(txn, collection, qsol, km->children[0], ws);
             if (NULL == childStage) { return NULL; }
             return new KeepMutationsStage(km->filter.get(), ws, childStage);
         }
@@ -275,7 +276,7 @@ namespace mongo {
             params.direction = dn->direction;
             params.bounds = dn->bounds;
             params.fieldNo = dn->fieldNo;
-            return new DistinctScan(params, ws);
+            return new DistinctScan(txn, params, ws);
         }
         else if (STAGE_COUNT == root->getType()) {
             const CountNode* cn = static_cast<const CountNode*>(root);
@@ -294,7 +295,7 @@ namespace mongo {
             params.endKey = cn->endKey;
             params.endKeyInclusive = cn->endKeyInclusive;
 
-            return new Count(params, ws);
+            return new Count(txn, params, ws);
         }
         else {
             mongoutils::str::stream ss;
@@ -306,14 +307,15 @@ namespace mongo {
     }
 
     // static (this one is used for Cached and MultiPlanStage)
-    bool StageBuilder::build(Collection* collection,
+    bool StageBuilder::build(OperationContext* txn,
+                             Collection* collection,
                              const QuerySolution& solution,
                              WorkingSet* wsIn,
                              PlanStage** rootOut) {
         if (NULL == wsIn || NULL == rootOut) { return false; }
         QuerySolutionNode* solutionNode = solution.root.get();
         if (NULL == solutionNode) { return false; }
-        return NULL != (*rootOut = buildStages(collection, solution, solutionNode, wsIn));
+        return NULL != (*rootOut = buildStages(txn, collection, solution, solutionNode, wsIn));
     }
 
 }  // namespace mongo
diff --git a/src/mongo/db/query/stage_builder.h b/src/mongo/db/query/stage_builder.h
index 9f3c9f20d60..c9c88e800bd 100644
--- a/src/mongo/db/query/stage_builder.h
+++ b/src/mongo/db/query/stage_builder.h
@@ -34,6 +34,8 @@
 
 namespace mongo {
 
+    class OperationContext;
+
     /**
      * The StageBuilder converts a QuerySolution to an executable tree of PlanStage(s).
      */
@@ -47,7 +49,8 @@ namespace mongo {
          *
          * Returns false otherwise.  *rootOut and *wsOut are invalid.
          */
-        static bool build(Collection* collection,
+        static bool build(OperationContext* txn,
+                          Collection* collection,
                           const QuerySolution& solution,
                           WorkingSet* wsIn,
                           PlanStage** rootOut);
diff --git a/src/mongo/db/query/subplan_runner.cpp b/src/mongo/db/query/subplan_runner.cpp
index 765bd236a90..c107f829c77 100644
--- a/src/mongo/db/query/subplan_runner.cpp
+++ b/src/mongo/db/query/subplan_runner.cpp
@@ -93,11 +93,12 @@ namespace mongo {
     }
 
     // static
-    Status SubplanRunner::make(Collection* collection,
+    Status SubplanRunner::make(OperationContext* txn,
+                               Collection* collection,
                                const QueryPlannerParams& params,
                                CanonicalQuery* cq,
                                SubplanRunner** out) {
-        auto_ptr<SubplanRunner> autoRunner(new SubplanRunner(collection, params, cq));
+        auto_ptr<SubplanRunner> autoRunner(new SubplanRunner(txn, collection, params, cq));
         Status planningStatus = autoRunner->planSubqueries();
         if (!planningStatus.isOK()) {
             return planningStatus;
@@ -107,10 +108,12 @@ namespace mongo {
         return Status::OK();
     }
 
-    SubplanRunner::SubplanRunner(Collection* collection,
+    SubplanRunner::SubplanRunner(OperationContext* txn,
+                                 Collection* collection,
                                  const QueryPlannerParams& params,
                                  CanonicalQuery* cq)
-        : _state(SubplanRunner::PLANNING),
+        : _txn(txn),
+          _state(SubplanRunner::PLANNING),
           _collection(collection),
           _plannerParams(params),
           _query(cq),
@@ -150,7 +153,8 @@ namespace mongo {
 
                 Runner* runner;
                 Status status = getRunnerAlwaysPlan(
-                    _collection, _query.release(), _plannerParams, &runner);
+                    _txn, _collection, _query.release(), _plannerParams, &runner
+                );
 
                 if (!status.isOK()) {
                     // We utterly failed.
@@ -315,7 +319,8 @@ namespace mongo {
                 // Dump all the solutions into the MPR.
                 for (size_t ix = 0; ix < solutions.size(); ++ix) {
                     PlanStage* nextPlanRoot;
-                    verify(StageBuilder::build(_collection,
+                    verify(StageBuilder::build(_txn,
+                                               _collection,
                                                *solutions[ix],
                                                sharedWorkingSet,
                                                &nextPlanRoot));
@@ -404,7 +409,7 @@ namespace mongo {
         MultiPlanStage* multiPlanStage = new MultiPlanStage(_collection, _query.get());
         WorkingSet* ws = new WorkingSet();
         PlanStage* root;
-        verify(StageBuilder::build(_collection, *soln, ws, &root));
+        verify(StageBuilder::build(_txn, _collection, *soln, ws, &root));
         multiPlanStage->addPlan(soln, root, ws); // Takes ownership first two arguments.
 
         multiPlanStage->pickBestPlan();
diff --git a/src/mongo/db/query/subplan_runner.h b/src/mongo/db/query/subplan_runner.h
index 907fe719363..896772450ad 100644
--- a/src/mongo/db/query/subplan_runner.h
+++ b/src/mongo/db/query/subplan_runner.h
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -42,6 +42,7 @@ namespace mongo {
     class BSONObj;
     class CanonicalQuery;
     class DiskLoc;
+    class OperationContext;
     class TypeExplain;
     struct PlanInfo;
 
@@ -53,7 +54,8 @@ namespace mongo {
          *
          * 'out' is valid only if an OK status is returned.
          */
-        static Status make(Collection* collection,
+        static Status make(OperationContext* txn,
+                           Collection* collection,
                            const QueryPlannerParams& params,
                            CanonicalQuery* cq,
                            SubplanRunner** out);
@@ -94,7 +96,8 @@ namespace mongo {
         Status planSubqueries();
 
     private:
-        SubplanRunner(Collection* collection,
+        SubplanRunner(OperationContext* txn,
+                      Collection* collection,
                       const QueryPlannerParams& params,
                       CanonicalQuery* cq);
 
@@ -105,6 +108,9 @@ namespace mongo {
             RUNNING,
         };
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         SubplanRunnerState _state;
 
         Collection* _collection;
diff --git a/src/mongo/db/repl/master_slave.cpp b/src/mongo/db/repl/master_slave.cpp
index 54afae7e969..00c7e40d86f 100644
--- a/src/mongo/db/repl/master_slave.cpp
+++ b/src/mongo/db/repl/master_slave.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -252,7 +252,8 @@ namespace repl {
             // add if missing
             int n = 0;
             auto_ptr<Runner> runner(
-                InternalPlanner::collectionScan(localSources,
+                InternalPlanner::collectionScan(txn,
+                                                localSources,
                                                 ctx.db()->getCollection(txn, localSources)));
             BSONObj obj;
             Runner::RunnerState state;
@@ -296,7 +297,8 @@ namespace repl {
         }
 
         auto_ptr<Runner> runner(
-            InternalPlanner::collectionScan(localSources,
+            InternalPlanner::collectionScan(txn,
+                                            localSources,
                                             ctx.db()->getCollection(txn, localSources)));
         BSONObj obj;
         Runner::RunnerState state;
diff --git a/src/mongo/db/repl/oplog.cpp b/src/mongo/db/repl/oplog.cpp
index dbe5fd62b79..f8414766eea 100644
--- a/src/mongo/db/repl/oplog.cpp
+++ b/src/mongo/db/repl/oplog.cpp
@@ -1,7 +1,7 @@
 // @file oplog.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -473,7 +473,7 @@ namespace repl {
         if ( collection ) {
 
             if (replSettings.oplogSize != 0) {
-                int o = (int)(collection->getRecordStore()->storageSize() / ( 1024 * 1024 ) );
+                int o = (int)(collection->getRecordStore()->storageSize(&txn) / ( 1024 * 1024 ) );
                 int n = (int)(replSettings.oplogSize / (1024 * 1024));
                 if ( n != o ) {
                     stringstream ss;
diff --git a/src/mongo/db/repl/repl_info.cpp b/src/mongo/db/repl/repl_info.cpp
index 17f5b893cd5..740cc8f044a 100644
--- a/src/mongo/db/repl/repl_info.cpp
+++ b/src/mongo/db/repl/repl_info.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -83,7 +83,8 @@ namespace repl {
                 const char* localSources = "local.sources";
                 Client::ReadContext ctx(txn, localSources);
                 auto_ptr<Runner> runner(
-                    InternalPlanner::collectionScan(localSources,
+                    InternalPlanner::collectionScan(txn,
+                                                    localSources,
                                                     ctx.ctx().db()->getCollection(txn,
                                                                                   localSources)));
                 BSONObj obj;
diff --git a/src/mongo/db/repl/rs_rollback.cpp b/src/mongo/db/repl/rs_rollback.cpp
index 321885f60d7..32093b02374 100644
--- a/src/mongo/db/repl/rs_rollback.cpp
+++ b/src/mongo/db/repl/rs_rollback.cpp
@@ -1,6 +1,6 @@
 /* @file rs_rollback.cpp
 *
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -237,7 +237,8 @@ namespace repl {
         Client::Context ctx(txn, rsoplog);
 
         boost::scoped_ptr<Runner> runner(
-                InternalPlanner::collectionScan(rsoplog,
+                InternalPlanner::collectionScan(txn,
+                                                rsoplog,
                                                 ctx.db()->getCollection(txn, rsoplog),
                                                 InternalPlanner::BACKWARD));
 
diff --git a/src/mongo/db/storage/heap1/heap1_btree_impl.cpp b/src/mongo/db/storage/heap1/heap1_btree_impl.cpp
index 25695ccef65..2d5ae2fc63b 100644
--- a/src/mongo/db/storage/heap1/heap1_btree_impl.cpp
+++ b/src/mongo/db/storage/heap1/heap1_btree_impl.cpp
@@ -279,12 +279,12 @@ namespace {
             
         }
 
-        virtual void fullValidate(long long *numKeysOut) {
+        virtual void fullValidate(OperationContext* txn, long long *numKeysOut) {
             // TODO check invariants?
             *numKeysOut = _data->size();
         }
 
-        virtual Status dupKeyCheck(const BSONObj& key, const DiskLoc& loc) {
+        virtual Status dupKeyCheck(OperationContext* txn, const BSONObj& key, const DiskLoc& loc) {
             invariant(!hasFieldNames(key));
             if (isDup(*_data, key, loc))
                 return dupKeyError(key);
@@ -302,8 +302,9 @@ namespace {
 
         class ForwardCursor : public BtreeInterface::Cursor {
         public:
-            ForwardCursor(const IndexSet& data)
-                : _data(data),
+            ForwardCursor(const IndexSet& data, OperationContext* txn)
+                : _txn(txn),
+                  _data(data),
                   _it(data.end())
             {}
 
@@ -387,6 +388,7 @@ namespace {
             }
 
         private:
+            OperationContext* _txn; // not owned
             const IndexSet& _data;
             IndexSet::const_iterator _it;
 
@@ -399,8 +401,9 @@ namespace {
         // TODO see if this can share any code with ForwardIterator
         class ReverseCursor : public BtreeInterface::Cursor {
         public:
-            ReverseCursor(const IndexSet& data)
-                : _data(data),
+            ReverseCursor(const IndexSet& data, OperationContext* txn)
+                : _txn(txn),
+                  _data(data),
                   _it(data.rend())
             {}
 
@@ -499,6 +502,7 @@ namespace {
                 return IndexSet::const_reverse_iterator(it);
             }
 
+            OperationContext* _txn; // not owned
             const IndexSet& _data;
             IndexSet::const_reverse_iterator _it;
 
@@ -508,12 +512,12 @@ namespace {
             DiskLoc _savedLoc;
         };
 
-        virtual BtreeInterface::Cursor* newCursor(int direction) const {
+        virtual BtreeInterface::Cursor* newCursor(OperationContext* txn, int direction) const {
             if (direction == 1)
-                return new ForwardCursor(*_data);
+                return new ForwardCursor(*_data, txn);
 
             invariant(direction == -1);
-            return new ReverseCursor(*_data);
+            return new ReverseCursor(*_data, txn);
         }
 
         virtual Status initAsEmpty(OperationContext* txn) {
diff --git a/src/mongo/db/storage/heap1/heap1_database_catalog_entry.h b/src/mongo/db/storage/heap1/heap1_database_catalog_entry.h
index 825477c5ffb..1268d26ff3e 100644
--- a/src/mongo/db/storage/heap1/heap1_database_catalog_entry.h
+++ b/src/mongo/db/storage/heap1/heap1_database_catalog_entry.h
@@ -150,7 +150,7 @@ namespace mongo {
                                    const StringData& idxName,
                                    long long newExpireSeconds );
 
-            CollectionOptions getCollectionOptions() const { return options; }
+            CollectionOptions getCollectionOptions(OperationContext* txn) const { return options; }
 
             CollectionOptions options;
             scoped_ptr<HeapRecordStore> rs;
diff --git a/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.cpp b/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.cpp
index cf1d805900d..a9ed7d8650f 100644
--- a/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.cpp
+++ b/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.cpp
@@ -180,7 +180,7 @@ namespace mongo {
         invariant( details );
 
         RecordStoreV1Base* systemIndexRecordStore = _getIndexRecordStore();
-        scoped_ptr<RecordIterator> it( systemIndexRecordStore->getIterator() );
+        scoped_ptr<RecordIterator> it( systemIndexRecordStore->getIterator(txn) );
 
         while ( !it->isEOF() ) {
             DiskLoc loc = it->getNext();
@@ -289,7 +289,7 @@ namespace mongo {
             BSONObj oldSpec;
             {
                 RecordStoreV1Base* rs = _getNamespaceRecordStore();
-                scoped_ptr<RecordIterator> it( rs->getIterator() );
+                scoped_ptr<RecordIterator> it( rs->getIterator(txn) );
                 while ( !it->isEOF() ) {
                     DiskLoc loc = it->getNext();
                     BSONObj entry = it->dataFor( loc ).toBson();
@@ -481,7 +481,7 @@ namespace mongo {
                                                                  &_extentManager,
                                                                  false ) );
 
-            if ( nsEntry->recordStore->storageSize() == 0 )
+            if ( nsEntry->recordStore->storageSize( txn ) == 0 )
                 nsEntry->recordStore->increaseStorageSize( txn, _extentManager.initialSize( 128 ), -1 );
         }
 
@@ -497,7 +497,7 @@ namespace mongo {
                                                                     &_extentManager,
                                                                     true ) );
 
-            if ( indexEntry->recordStore->storageSize() == 0 )
+            if ( indexEntry->recordStore->storageSize( txn ) == 0 )
                 indexEntry->recordStore->increaseStorageSize( txn, _extentManager.initialSize( 128 ), -1 );
         }
 
@@ -581,10 +581,10 @@ namespace mongo {
                     // Must do this at least once, otherwise we leave the collection with no
                     // extents, which is invalid.
                     int sz = _massageExtentSize( &_extentManager,
-                                                 options.cappedSize - rs->storageSize() );
+                                                 options.cappedSize - rs->storageSize(txn) );
                     sz &= 0xffffff00;
                     rs->increaseStorageSize( txn, sz, -1 );
-                } while( rs->storageSize() < options.cappedSize );
+                } while( rs->storageSize(txn) < options.cappedSize );
             }
             else {
                 rs->increaseStorageSize( txn, _extentManager.initialSize( 128 ), -1 );
@@ -773,7 +773,7 @@ namespace mongo {
         RecordStoreV1Base* rs = _getNamespaceRecordStore();
         invariant( rs );
 
-        scoped_ptr<RecordIterator> it( rs->getIterator() );
+        scoped_ptr<RecordIterator> it( rs->getIterator(txn) );
         while ( !it->isEOF() ) {
             DiskLoc loc = it->getNext();
             BSONObj entry = it->dataFor( loc ).toBson();
@@ -785,7 +785,8 @@ namespace mongo {
         }
     }
 
-    CollectionOptions MMAPV1DatabaseCatalogEntry::getCollectionOptions( const StringData& ns ) const {
+    CollectionOptions MMAPV1DatabaseCatalogEntry::getCollectionOptions( OperationContext* txn,
+                                                                        const StringData& ns ) const {
         if ( nsToCollectionSubstring( ns ) == "system.namespaces" ) {
             return CollectionOptions();
         }
@@ -793,7 +794,7 @@ namespace mongo {
         RecordStoreV1Base* rs = _getNamespaceRecordStore();
         invariant( rs );
 
-        scoped_ptr<RecordIterator> it( rs->getIterator() );
+        scoped_ptr<RecordIterator> it( rs->getIterator(txn) );
         while ( !it->isEOF() ) {
             DiskLoc loc = it->getNext();
             BSONObj entry = it->dataFor( loc ).toBson();
diff --git a/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.h b/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.h
index 9215ef37d93..16a88b84ede 100644
--- a/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.h
+++ b/src/mongo/db/storage/mmap_v1/mmap_v1_database_catalog_entry.h
@@ -101,7 +101,8 @@ namespace mongo {
         const MmapV1ExtentManager* getExtentManager() const { return &_extentManager; }
         MmapV1ExtentManager* getExtentManager() { return &_extentManager; }
 
-        CollectionOptions getCollectionOptions( const StringData& ns ) const;
+        CollectionOptions getCollectionOptions( OperationContext* txn,
+                                                const StringData& ns ) const;
 
     private:
 
diff --git a/src/mongo/db/storage/mmap_v1/repair_database.cpp b/src/mongo/db/storage/mmap_v1/repair_database.cpp
index 836827a0ee6..8fb06a5eae6 100644
--- a/src/mongo/db/storage/mmap_v1/repair_database.cpp
+++ b/src/mongo/db/storage/mmap_v1/repair_database.cpp
@@ -345,9 +345,10 @@ namespace mongo {
                 Client::Context ctx(txn,  ns );
                 Collection* coll = originalDatabase->getCollection( txn, ns );
                 if ( coll ) {
-                    scoped_ptr<RecordIterator> it( coll->getIterator( DiskLoc(),
-                                                                          false,
-                                                                          CollectionScanParams::FORWARD ) );
+                    scoped_ptr<RecordIterator> it( coll->getIterator( txn,
+                                                                      DiskLoc(),
+                                                                      false,
+                                                                      CollectionScanParams::FORWARD ) );
                     while ( !it->isEOF() ) {
                         DiskLoc loc = it->getNext();
                         BSONObj obj = coll->docFor( loc );
@@ -411,9 +412,9 @@ namespace mongo {
 
                 }
 
-                scoped_ptr<RecordIterator> iterator( originalCollection->getIterator( DiskLoc(),
-                                                                                          false,
-                                                                                          CollectionScanParams::FORWARD ) );
+                scoped_ptr<RecordIterator> iterator(
+                    originalCollection->getIterator( txn, DiskLoc(), false,
+                                                     CollectionScanParams::FORWARD ));
                 while ( !iterator->isEOF() ) {
                     DiskLoc loc = iterator->getNext();
                     invariant( !loc.isNull() );
diff --git a/src/mongo/db/storage/rocks/rocks_btree_impl.cpp b/src/mongo/db/storage/rocks/rocks_btree_impl.cpp
index 385081bbf2d..00cbbf1c580 100644
--- a/src/mongo/db/storage/rocks/rocks_btree_impl.cpp
+++ b/src/mongo/db/storage/rocks/rocks_btree_impl.cpp
@@ -202,6 +202,7 @@ namespace mongo {
             }
 
             scoped_ptr<rocksdb::Iterator> _iterator;
+            OperationContext* _txn; // not owned
             bool _direction;
 
             mutable bool _cached;
@@ -231,7 +232,7 @@ namespace mongo {
 
         if ( !dupsAllowed ) {
             // XXX: this is slow
-            Status status = dupKeyCheck( key, loc );
+            Status status = dupKeyCheck( txn, key, loc );
             if ( !status.isOK() )
                 return status;
         }
@@ -263,12 +264,12 @@ namespace mongo {
         return 1; // XXX: fix? does it matter since its so slow to check?
     }
 
-    Status RocksBtreeImpl::dupKeyCheck(const BSONObj& key, const DiskLoc& loc) {
+    Status RocksBtreeImpl::dupKeyCheck(OperationContext* txn, const BSONObj& key, const DiskLoc& loc) {
         // XXX: not done yet!
         return Status::OK();
     }
 
-    void RocksBtreeImpl::fullValidate(long long* numKeysOut) {
+    void RocksBtreeImpl::fullValidate(OperationContext* txn, long long* numKeysOut) {
         // XXX: no key counts
         if ( numKeysOut )
             numKeysOut[0] = -1;
@@ -284,9 +285,11 @@ namespace mongo {
         return Status::OK();
     }
 
-    BtreeInterface::Cursor* RocksBtreeImpl::newCursor(int direction) const {
+    BtreeInterface::Cursor* RocksBtreeImpl::newCursor(OperationContext* txn,
+                                                      int direction) const {
         return new RocksCursor( _db->NewIterator( rocksdb::ReadOptions(),
                                                   _columnFamily ),
+                                txn,
                                 direction );
     }
 
diff --git a/src/mongo/db/storage/rocks/rocks_btree_impl.h b/src/mongo/db/storage/rocks/rocks_btree_impl.h
index 5bb419f1d55..2a15e46aad5 100644
--- a/src/mongo/db/storage/rocks/rocks_btree_impl.h
+++ b/src/mongo/db/storage/rocks/rocks_btree_impl.h
@@ -64,15 +64,17 @@ namespace mongo {
                              const BSONObj& key,
                              const DiskLoc& loc);
 
-        virtual Status dupKeyCheck(const BSONObj& key, const DiskLoc& loc);
+        virtual Status dupKeyCheck(OperationContext* txn,
+                                   const BSONObj& key,
+                                   const DiskLoc& loc);
 
-        virtual void fullValidate(long long* numKeysOut);
+        virtual void fullValidate(OperationContext* txn, long long* numKeysOut);
 
         virtual bool isEmpty();
 
         virtual Status touch(OperationContext* txn) const;
 
-        virtual Cursor* newCursor(int direction) const;
+        virtual Cursor* newCursor(OperationContext* int direction) const;
 
         virtual Status initAsEmpty(OperationContext* txn);
 
diff --git a/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.cpp b/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.cpp
index 5b45242a9ec..fdbae7d4442 100644
--- a/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.cpp
+++ b/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.cpp
@@ -53,7 +53,7 @@ namespace mongo {
         _metaDataKey = string("metadata-") + ns.toString();
     }
 
-    CollectionOptions RocksCollectionCatalogEntry::getCollectionOptions() const {
+    CollectionOptions RocksCollectionCatalogEntry::getCollectionOptions( OperationContext* txn ) const {
         // todo: put more options in here?
         return CollectionOptions();
     }
diff --git a/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.h b/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.h
index a32387a2da7..6a9a71804bf 100644
--- a/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.h
+++ b/src/mongo/db/storage/rocks/rocks_collection_catalog_entry.h
@@ -42,7 +42,7 @@ namespace mongo {
 
         virtual ~RocksCollectionCatalogEntry(){}
 
-        virtual CollectionOptions getCollectionOptions() const;
+        virtual CollectionOptions getCollectionOptions(OperationContext* txn) const;
 
         // ------- indexes ----------
 
diff --git a/src/mongo/db/storage/rocks/rocks_record_store.cpp b/src/mongo/db/storage/rocks/rocks_record_store.cpp
index 06ae8bf6242..664e643b760 100644
--- a/src/mongo/db/storage/rocks/rocks_record_store.cpp
+++ b/src/mongo/db/storage/rocks/rocks_record_store.cpp
@@ -180,7 +180,8 @@ namespace mongo {
         return Status::OK();
     }
 
-    RecordIterator* RocksRecordStore::getIterator( const DiskLoc& start,
+    RecordIterator* RocksRecordStore::getIterator( OperationContext* txn,
+                                                   const DiskLoc& start,
                                                    bool tailable,
                                                    const CollectionScanParams::Direction& dir
                                                    ) const {
@@ -191,11 +192,11 @@ namespace mongo {
     }
 
 
-    RecordIterator* RocksRecordStore::getIteratorForRepair() const {
-        return getIterator();
+    RecordIterator* RocksRecordStore::getIteratorForRepair(OperationContext* txn) const {
+        return getIterator(txn);
     }
 
-    std::vector<RecordIterator*> RocksRecordStore::getManyIterators() const {
+    std::vector<RecordIterator*> RocksRecordStore::getManyIterators(OperationContext* txn) const {
         invariant( false );
     }
 
@@ -218,7 +219,9 @@ namespace mongo {
         return Status::OK();
     }
 
-    void RocksRecordStore::appendCustomStats( BSONObjBuilder* result, double scale ) const {
+    void RocksRecordStore::appendCustomStats( OperationContext* txn,
+                                              BSONObjBuilder* result,
+                                              double scale ) const {
         string statsString;
         bool valid = _db->GetProperty( _columnFamily, "rocksdb.stats", &statsString );
         invariant( valid );
diff --git a/src/mongo/db/storage/rocks/rocks_record_store.h b/src/mongo/db/storage/rocks/rocks_record_store.h
index 492e8079fc6..eeaf8df9882 100644
--- a/src/mongo/db/storage/rocks/rocks_record_store.h
+++ b/src/mongo/db/storage/rocks/rocks_record_store.h
@@ -90,15 +90,16 @@ namespace mongo {
                                           const char* damangeSource,
                                           const mutablebson::DamageVector& damages );
 
-        virtual RecordIterator* getIterator( const DiskLoc& start = DiskLoc(),
+        virtual RecordIterator* getIterator( OperationContext* txn,
+                                             const DiskLoc& start = DiskLoc(),
                                              bool tailable = false,
                                              const CollectionScanParams::Direction& dir =
                                              CollectionScanParams::FORWARD
                                              ) const;
 
-        virtual RecordIterator* getIteratorForRepair() const;
+        virtual RecordIterator* getIteratorForRepair( OperationContext* txn ) const;
 
-        virtual std::vector<RecordIterator*> getManyIterators() const;
+        virtual std::vector<RecordIterator*> getManyIterators( OperationContext* txn ) const;
 
         virtual Status truncate( OperationContext* txn );
 
@@ -114,7 +115,9 @@ namespace mongo {
                                  ValidateAdaptor* adaptor,
                                  ValidateResults* results, BSONObjBuilder* output ) const;
 
-        virtual void appendCustomStats( BSONObjBuilder* result, double scale ) const;
+        virtual void appendCustomStats( OperationContext* txn,
+                                        BSONObjBuilder* result,
+                                        double scale ) const;
 
         virtual Status touch( OperationContext* txn, BSONObjBuilder* output ) const;
 
diff --git a/src/mongo/db/storage/rocks/rocks_record_store_test.cpp b/src/mongo/db/storage/rocks/rocks_record_store_test.cpp
index 119aacb565e..4c003da75f9 100644
--- a/src/mongo/db/storage/rocks/rocks_record_store_test.cpp
+++ b/src/mongo/db/storage/rocks/rocks_record_store_test.cpp
@@ -330,8 +330,9 @@ namespace mongo {
         }
 
         {
+            MyOperationContext opCtx( db.get() );
             BSONObjBuilder b;
-            rs.appendCustomStats( &b, 1 );
+            rs.appendCustomStats( &opCtx, &b, 1 );
             BSONObj obj = b.obj();
             ASSERT( obj["stats"].String().find( "WAL" ) != string::npos );
         }
diff --git a/src/mongo/db/structure/SConscript b/src/mongo/db/structure/SConscript
index 360876db22a..f6163c4aaf4 100644
--- a/src/mongo/db/structure/SConscript
+++ b/src/mongo/db/structure/SConscript
@@ -10,6 +10,7 @@ env.Library(
     LIBDEPS= [
         '$BUILD_DIR/mongo/bson',
         '$BUILD_DIR/mongo/db/commands/server_status_core',
+        '$BUILD_DIR/mongo/db/concurrency/lock_mgr',
         '$BUILD_DIR/mongo/foundation',
         '$BUILD_DIR/mongo/mongocommon',
         ]
diff --git a/src/mongo/db/structure/btree/btree_interface.cpp b/src/mongo/db/structure/btree/btree_interface.cpp
index 46e3997f84f..ef5efccf832 100644
--- a/src/mongo/db/structure/btree/btree_interface.cpp
+++ b/src/mongo/db/structure/btree/btree_interface.cpp
@@ -98,12 +98,14 @@ namespace mongo {
             return _btree->unindex(txn, key, loc);
         }
 
-        virtual void fullValidate(long long *numKeysOut) {
-            *numKeysOut = _btree->fullValidate(NULL, false, false, 0);
+        virtual void fullValidate(OperationContext* txn, long long *numKeysOut) {
+            *numKeysOut = _btree->fullValidate(txn, NULL, false, false, 0);
         }
 
-        virtual Status dupKeyCheck(const BSONObj& key, const DiskLoc& loc) {
-            return _btree->dupKeyCheck(key, loc);
+        virtual Status dupKeyCheck(OperationContext* txn,
+                                   const BSONObj& key,
+                                   const DiskLoc& loc) {
+            return _btree->dupKeyCheck(txn, key, loc);
         }
 
         virtual bool isEmpty() {
@@ -116,8 +118,11 @@ namespace mongo {
 
         class Cursor : public BtreeInterface::Cursor {
         public:
-            Cursor(const BtreeLogic<OnDiskFormat>* btree, int direction)
-                : _btree(btree),
+            Cursor(OperationContext* txn,
+                   const BtreeLogic<OnDiskFormat>* btree,
+                   int direction)
+                : _txn(txn),
+                  _btree(btree),
                   _direction(direction),
                   _bucket(btree->getHead()), // XXX this shouldn't be nessisary, but is.
                   _ofs(0) {
@@ -142,7 +147,7 @@ namespace mongo {
             }
 
             virtual bool locate(const BSONObj& key, const DiskLoc& loc) {
-                return _btree->locate(key, loc, _direction, &_ofs, &_bucket);
+                return _btree->locate(_txn, key, loc, _direction, &_ofs, &_bucket);
             }
 
             virtual void customLocate(const BSONObj& keyBegin,
@@ -151,7 +156,8 @@ namespace mongo {
                                       const vector<const BSONElement*>& keyEnd,
                                       const vector<bool>& keyEndInclusive) {
 
-                _btree->customLocate(&_bucket,
+                _btree->customLocate(_txn,
+                                     &_bucket,
                                      &_ofs,
                                      keyBegin,
                                      keyBeginLen,
@@ -167,7 +173,8 @@ namespace mongo {
                            const vector<const BSONElement*>& keyEnd,
                            const vector<bool>& keyEndInclusive) {
 
-                _btree->advanceTo(&_bucket,
+                _btree->advanceTo(_txn,
+                                  &_bucket,
                                   &_ofs,
                                   keyBegin,
                                   keyBeginLen,
@@ -186,7 +193,7 @@ namespace mongo {
             }
 
             virtual void advance() {
-                _btree->advance(&_bucket, &_ofs, _direction);
+                _btree->advance(_txn, &_bucket, &_ofs, _direction);
             }
 
             virtual void savePosition() {
@@ -198,7 +205,8 @@ namespace mongo {
 
             virtual void restorePosition() {
                 if (!_bucket.isNull()) {
-                    _btree->restorePosition(_savedKey,
+                    _btree->restorePosition(_txn,
+                                            _savedKey,
                                             _savedLoc,
                                             _direction,
                                             &_bucket,
@@ -207,6 +215,7 @@ namespace mongo {
             }
 
         private:
+            OperationContext* _txn; // not owned
             const BtreeLogic<OnDiskFormat>* const _btree;
             const int _direction;
 
@@ -218,8 +227,8 @@ namespace mongo {
             DiskLoc _savedLoc;
         };
 
-        virtual Cursor* newCursor(int direction) const {
-            return new Cursor(_btree.get(), direction);
+        virtual Cursor* newCursor(OperationContext* txn, int direction) const {
+            return new Cursor(txn, _btree.get(), direction);
         }
 
         virtual Status initAsEmpty(OperationContext* txn) {
diff --git a/src/mongo/db/structure/btree/btree_interface.h b/src/mongo/db/structure/btree/btree_interface.h
index 92339c1fe63..845a02d467a 100644
--- a/src/mongo/db/structure/btree/btree_interface.h
+++ b/src/mongo/db/structure/btree/btree_interface.h
@@ -107,14 +107,16 @@ namespace mongo {
                              const DiskLoc& loc) = 0;
 
         // TODO: Hide this by exposing an update method?
-        virtual Status dupKeyCheck(const BSONObj& key, const DiskLoc& loc) = 0;
+        virtual Status dupKeyCheck(OperationContext* txn,
+                                   const BSONObj& key,
+                                   const DiskLoc& loc) = 0;
 
         //
         // Information about the tree
         //
 
         // TODO: expose full set of args for testing?
-        virtual void fullValidate(long long* numKeysOut) = 0;
+        virtual void fullValidate(OperationContext* txn, long long* numKeysOut) = 0;
 
         virtual bool isEmpty() = 0;
         
@@ -187,7 +189,7 @@ namespace mongo {
         /**
          * Caller takes ownership. BtreeInterface must outlive all Cursors it produces.
          */
-        virtual Cursor* newCursor(int direction) const = 0;
+        virtual Cursor* newCursor(OperationContext* txn, int direction) const = 0;
 
         //
         // Index creation
diff --git a/src/mongo/db/structure/btree/btree_logic.cpp b/src/mongo/db/structure/btree/btree_logic.cpp
index 88b6f32b8f4..8d05a65ab0c 100644
--- a/src/mongo/db/structure/btree/btree_logic.cpp
+++ b/src/mongo/db/structure/btree/btree_logic.cpp
@@ -566,10 +566,8 @@ namespace mongo {
         memcpy(bucket->data + ofs, temp + ofs, dataUsed);
 
         bucket->emptySize = tdz - dataUsed - bucket->n * sizeof(KeyHeaderType);
-        {
-            int foo = bucket->emptySize;
-            invariant( foo >= 0 );
-        }
+        int foo = bucket->emptySize;
+        invariant( foo >= 0 );
         setPacked(bucket);
         assertValid(_indexName, bucket, _ordering);
     }
@@ -667,7 +665,8 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::customLocate(DiskLoc* locInOut,
+    void BtreeLogic<BtreeLayout>::customLocate(OperationContext* txn,
+                                               DiskLoc* locInOut,
                                                int* keyOfsInOut,
                                                const BSONObj& keyBegin,
                                                int keyBeginLen,
@@ -677,7 +676,8 @@ namespace mongo {
                                                int direction) const {
         pair<DiskLoc, int> unused;
 
-        customLocate(locInOut,
+        customLocate(txn,
+                     locInOut,
                      keyOfsInOut,
                      keyBegin,
                      keyBeginLen,
@@ -687,27 +687,32 @@ namespace mongo {
                      direction,
                      unused);
 
-        skipUnusedKeys(locInOut, keyOfsInOut, direction);
+        skipUnusedKeys(txn, locInOut, keyOfsInOut, direction);
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::advance(DiskLoc* bucketLocInOut,
+    void BtreeLogic<BtreeLayout>::advance(OperationContext* txn,
+                                          DiskLoc* bucketLocInOut,
                                           int* posInOut,
                                           int direction) const {
 
-        *bucketLocInOut = advance(*bucketLocInOut, posInOut, direction);
-        skipUnusedKeys(bucketLocInOut, posInOut, direction);
+        *bucketLocInOut = advance(txn, *bucketLocInOut, posInOut, direction);
+        skipUnusedKeys(txn, bucketLocInOut, posInOut, direction);
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::skipUnusedKeys(DiskLoc* loc, int* pos, int direction) const {
+    void BtreeLogic<BtreeLayout>::skipUnusedKeys(OperationContext* txn,
+                                                 DiskLoc* loc,
+                                                 int* pos,
+                                                 int direction) const {
         while (!loc->isNull() && !keyIsUsed(*loc, *pos)) {
-            *loc = advance(*loc, pos, direction);
+            *loc = advance(txn, *loc, pos, direction);
         }
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::advanceTo(DiskLoc* thisLocInOut,
+    void BtreeLogic<BtreeLayout>::advanceTo(OperationContext* txn,
+                                            DiskLoc* thisLocInOut,
                                             int* keyOfsInOut,
                                             const BSONObj &keyBegin,
                                             int keyBeginLen,
@@ -716,7 +721,8 @@ namespace mongo {
                                             const vector<bool>& keyEndInclusive,
                                             int direction) const {
 
-        advanceToImpl(thisLocInOut,
+        advanceToImpl(txn,
+                      thisLocInOut,
                       keyOfsInOut,
                       keyBegin,
                       keyBeginLen,
@@ -725,7 +731,7 @@ namespace mongo {
                       keyEndInclusive,
                       direction);
 
-        skipUnusedKeys(thisLocInOut, keyOfsInOut, direction);
+        skipUnusedKeys(txn, thisLocInOut, keyOfsInOut, direction);
     }
 
     /**
@@ -738,7 +744,8 @@ namespace mongo {
      * and reverse implementations would be more efficient
      */
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::advanceToImpl(DiskLoc* thisLocInOut,
+    void BtreeLogic<BtreeLayout>::advanceToImpl(OperationContext* txn,
+                                                DiskLoc* thisLocInOut,
                                                 int* keyOfsInOut,
                                                 const BSONObj &keyBegin,
                                                 int keyBeginLen,
@@ -831,7 +838,8 @@ namespace mongo {
             }
         }
 
-        customLocate(thisLocInOut,
+        customLocate(txn,
+                     thisLocInOut,
                      keyOfsInOut,
                      keyBegin,
                      keyBeginLen,
@@ -843,7 +851,8 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::customLocate(DiskLoc* locInOut,
+    void BtreeLogic<BtreeLayout>::customLocate(OperationContext* txn,
+                                               DiskLoc* locInOut,
                                                int* keyOfsInOut,
                                                const BSONObj& keyBegin,
                                                int keyBeginLen,
@@ -1071,28 +1080,31 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    bool BtreeLogic<BtreeLayout>::exists(const KeyDataType& key) const {
+    bool BtreeLogic<BtreeLayout>::exists(OperationContext* txn, const KeyDataType& key) const {
         int position = 0;
 
         // Find the DiskLoc 
         bool found;
-        DiskLoc bucket = _locate(getRootLoc(), key, &position, &found, minDiskLoc, 1);
+
+        DiskLoc bucket = _locate(txn, getRootLoc(), key, &position, &found, minDiskLoc, 1);
 
         while (!bucket.isNull()) {
             FullKey fullKey = getFullKey(getBucket(bucket), position);
             if (fullKey.header.isUsed()) {
                 return fullKey.data.woEqual(key);
             }
-            bucket = advance(bucket, &position, 1);
+            bucket = advance(txn, bucket, &position, 1);
         }
 
         return false;
     }
 
     template <class BtreeLayout>
-    Status BtreeLogic<BtreeLayout>::dupKeyCheck(const BSONObj& key, const DiskLoc& loc) const {
+    Status BtreeLogic<BtreeLayout>::dupKeyCheck(OperationContext* txn,
+                                                const BSONObj& key,
+                                                const DiskLoc& loc) const {
         KeyDataOwnedType theKey(key);
-        if (!wouldCreateDup(theKey, loc)) {
+        if (!wouldCreateDup(txn, theKey, loc)) {
             return Status::OK();
         }
 
@@ -1100,11 +1112,13 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    bool BtreeLogic<BtreeLayout>::wouldCreateDup(const KeyDataType& key,
+    bool BtreeLogic<BtreeLayout>::wouldCreateDup(OperationContext* txn,
+                                                 const KeyDataType& key,
                                                  const DiskLoc self) const {
         int position;
         bool found;
-        DiskLoc posLoc = _locate(getRootLoc(), key, &position, &found, minDiskLoc, 1);
+
+        DiskLoc posLoc = _locate(txn, getRootLoc(), key, &position, &found, minDiskLoc, 1);
 
         while (!posLoc.isNull()) {
             FullKey fullKey = getFullKey(getBucket(posLoc), position);
@@ -1117,7 +1131,7 @@ namespace mongo {
                 break;
             }
 
-            posLoc = advance(posLoc, &position, 1);
+            posLoc = advance(txn, posLoc, &position, 1);
         }
         return false;
     }
@@ -1146,7 +1160,8 @@ namespace mongo {
      * note result might be an Unused location!
      */
     template <class BtreeLayout>
-    Status BtreeLogic<BtreeLayout>::_find(BucketType* bucket,
+    Status BtreeLogic<BtreeLayout>::_find(OperationContext* txn,
+                                          BucketType* bucket,
                                           const KeyDataType& key,
                                           const DiskLoc& recordLoc,
                                           bool errorIfDup,
@@ -1180,8 +1195,8 @@ namespace mongo {
                             // This is expensive and we only want to do it once(? -- when would
                             // it happen twice).
                             dupsChecked = true;
-                            if (exists(key)) {
-                                if (wouldCreateDup(key, genericRecordLoc)) {
+                            if (exists(txn, key)) {
+                                if (wouldCreateDup(txn, key, genericRecordLoc)) {
                                     return Status(ErrorCodes::DuplicateKey, dupKeyError(key), 11000);
                                 }
                                 else {
@@ -1259,7 +1274,7 @@ namespace mongo {
         _bucketDeletion->aboutToDeleteBucket(bucketLoc);
 
         BucketType* p = getBucket(bucket->parent);
-        int parentIdx = indexInParent(bucket, bucketLoc);
+        int parentIdx = indexInParent(txn, bucket, bucketLoc);
         *txn->recoveryUnit()->writing(&childLocForPos(p, parentIdx)) = DiskLoc();
         deallocBucket(txn, bucket, bucketLoc);
     }
@@ -1274,7 +1289,8 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    void BtreeLogic<BtreeLayout>::restorePosition(const BSONObj& savedKey,
+    void BtreeLogic<BtreeLayout>::restorePosition(OperationContext* txn,
+                                                  const BSONObj& savedKey,
                                                   const DiskLoc& savedLoc,
                                                   int direction,
                                                   DiskLoc* bucketLocInOut,
@@ -1285,7 +1301,7 @@ namespace mongo {
         // thing should be kept BTree-internal.  This'll go away with finer grained locking: we
         // can hold on to a bucket for as long as we need it.
         if (-1 == *keyOffsetInOut) {
-            locate(savedKey, savedLoc, direction, keyOffsetInOut, bucketLocInOut);
+            locate(txn, savedKey, savedLoc, direction, keyOffsetInOut, bucketLocInOut);
             return;
         }
 
@@ -1296,19 +1312,19 @@ namespace mongo {
         invariant(BtreeLayout::INVALID_N_SENTINEL != bucket->n);
 
         if (_keyIsAt(savedKey, savedLoc, bucket, *keyOffsetInOut)) {
-            skipUnusedKeys(bucketLocInOut, keyOffsetInOut, direction);
+            skipUnusedKeys(txn, bucketLocInOut, keyOffsetInOut, direction);
             return;
         }
 
         if (*keyOffsetInOut > 0) {
             (*keyOffsetInOut)--;
             if (_keyIsAt(savedKey, savedLoc, bucket, *keyOffsetInOut)) {
-                skipUnusedKeys(bucketLocInOut, keyOffsetInOut, direction);
+                skipUnusedKeys(txn, bucketLocInOut, keyOffsetInOut, direction);
                 return;
             }
         }
 
-        locate(savedKey, savedLoc, direction, keyOffsetInOut, bucketLocInOut);
+        locate(txn, savedKey, savedLoc, direction, keyOffsetInOut, bucketLocInOut);
     }
 
     template <class BtreeLayout>
@@ -1337,7 +1353,6 @@ namespace mongo {
                                               int p) {
         invariant(bucket->n > 0);
         DiskLoc left = childLocForPos(bucket, p);
-
         if (bucket->n == 1) {
             if (left.isNull() && bucket->nextChild.isNull()) {
                 _delKeyAtPos(bucket, p);
@@ -1400,7 +1415,7 @@ namespace mongo {
         invariant(!lchild.isNull() || !rchild.isNull());
         int advanceDirection = lchild.isNull() ? 1 : -1;
         int advanceKeyOfs = keypos;
-        DiskLoc advanceLoc = advance(bucketLoc, &advanceKeyOfs, advanceDirection);
+        DiskLoc advanceLoc = advance(txn, bucketLoc, &advanceKeyOfs, advanceDirection);
         // advanceLoc must be a descentant of thisLoc, because thisLoc has a
         // child in the proper direction and all descendants of thisLoc must be
         // nonempty because they are not the root.
@@ -1435,7 +1450,7 @@ namespace mongo {
         }
         else {
             BucketType* parentBucket = getBucket(bucket->parent);
-            int bucketIndexInParent = indexInParent(bucket, bucketLoc);
+            int bucketIndexInParent = indexInParent(txn, bucket, bucketLoc);
             *txn->recoveryUnit()->writing(&childLocForPos(parentBucket, bucketIndexInParent)) =
                 bucket->nextChild;
         }
@@ -1446,9 +1461,10 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    bool BtreeLogic<BtreeLayout>::canMergeChildren(BucketType* bucket,
-                                                    const DiskLoc bucketLoc,
-                                                    const int leftIndex) {
+    bool BtreeLogic<BtreeLayout>::canMergeChildren(OperationContext* txn,
+                                                   BucketType* bucket,
+                                                   const DiskLoc bucketLoc,
+                                                   const int leftIndex) {
         invariant(leftIndex >= 0 && leftIndex < bucket->n);
 
         DiskLoc leftNodeLoc = childLocForPos(bucket, leftIndex);
@@ -1477,9 +1493,12 @@ namespace mongo {
      * splitPos().
      */
     template <class BtreeLayout>
-    int BtreeLogic<BtreeLayout>::_rebalancedSeparatorPos(BucketType* bucket, int leftIndex) {
+    int BtreeLogic<BtreeLayout>::_rebalancedSeparatorPos(OperationContext* txn,
+                                                         BucketType* bucket,
+                                                         int leftIndex) {
         int split = -1;
         int rightSize = 0;
+
         const BucketType* l = childForPos(bucket, leftIndex);
         const BucketType* r = childForPos(bucket, leftIndex + 1);
 
@@ -1539,6 +1558,7 @@ namespace mongo {
 
         DiskLoc leftNodeLoc = childLocForPos(bucket, leftIndex);
         DiskLoc rightNodeLoc = childLocForPos(bucket, leftIndex + 1);
+
         BucketType* l = btreemod(txn, getBucket(leftNodeLoc));
         BucketType* r = btreemod(txn, getBucket(rightNodeLoc));
 
@@ -1578,8 +1598,9 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    int BtreeLogic<BtreeLayout>::indexInParent(BucketType* bucket,
-                                                const DiskLoc bucketLoc) const {
+    int BtreeLogic<BtreeLayout>::indexInParent(OperationContext* txn,
+                                               BucketType* bucket,
+                                               const DiskLoc bucketLoc) const {
         invariant(!bucket->parent.isNull());
         const BucketType* p = getBucket(bucket->parent);
         if (p->nextChild == bucketLoc) {
@@ -1609,7 +1630,7 @@ namespace mongo {
 
         // If we can merge, then we must merge rather than balance to preserve bucket utilization
         // constraints.
-        if (canMergeChildren(bucket, bucketLoc, leftIndex)) {
+        if (canMergeChildren(txn, bucket, bucketLoc, leftIndex)) {
             return false;
         }
 
@@ -1718,7 +1739,7 @@ namespace mongo {
         BucketType* r = btreemod(txn, getBucket(rchild));
         _packReadyForMod(r, zeropos);
 
-        int split = _rebalancedSeparatorPos(bucket, leftIndex);
+        int split = _rebalancedSeparatorPos(txn, bucket, leftIndex);
 
         // By definition, if we are below the low water mark and cannot merge
         // then we must actively balance.
@@ -1744,7 +1765,7 @@ namespace mongo {
         }
 
         BucketType* p = getBucket(bucket->parent);
-        int parentIdx = indexInParent(bucket, bucketLoc);
+        int parentIdx = indexInParent(txn, bucket, bucketLoc);
 
         // TODO will missing neighbor case be possible long term?  Should we try to merge/balance
         // somehow in that case if so?
@@ -1782,7 +1803,8 @@ namespace mongo {
         int pos;
         bool found = false;
         KeyDataOwnedType ownedKey(key);
-        DiskLoc loc = _locate(getRootLoc(), ownedKey, &pos, &found, recordLoc, 1);
+
+        DiskLoc loc = _locate(txn, getRootLoc(), ownedKey, &pos, &found, recordLoc, 1);
         if (found) {
             BucketType* bucket = btreemod(txn, getBucket(loc));
             delKeyAtPos(txn, bucket, loc, pos);
@@ -1997,6 +2019,8 @@ namespace mongo {
         StatusWith<DiskLoc> loc = _recordStore->insertRecord(txn, &docWriter, false);
         // XXX: remove this(?) or turn into massert or sanely bubble it back up.
         uassertStatusOK(loc.getStatus());
+
+        // this is a new bucket, not referenced by anyone, probably don't need this lock
         BucketType* b = btreemod(txn, getBucket(loc.getValue()));
         init(b);
         return loc.getValue();
@@ -2059,15 +2083,17 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    long long BtreeLogic<BtreeLayout>::fullValidate(long long *unusedCount,
-                                                     bool strict,
-                                                     bool dumpBuckets,
-                                                     unsigned depth) {
-        return _fullValidate(getRootLoc(), unusedCount, strict, dumpBuckets, depth);
+    long long BtreeLogic<BtreeLayout>::fullValidate(OperationContext* txn,
+                                                    long long *unusedCount,
+                                                    bool strict,
+                                                    bool dumpBuckets,
+                                                    unsigned depth) {
+        return _fullValidate(txn, getRootLoc(), unusedCount, strict, dumpBuckets, depth);
     }
 
     template <class BtreeLayout>
-    long long BtreeLogic<BtreeLayout>::_fullValidate(const DiskLoc bucketLoc,
+    long long BtreeLogic<BtreeLayout>::_fullValidate(OperationContext* txn,
+                                                     const DiskLoc bucketLoc,
                                                      long long *unusedCount,
                                                      bool strict,
                                                      bool dumpBuckets,
@@ -2103,7 +2129,7 @@ namespace mongo {
                     wassert(b->parent == bucketLoc);
                 }
 
-                keyCount += _fullValidate(left, unusedCount, strict, dumpBuckets, depth + 1);
+                keyCount += _fullValidate(txn, left, unusedCount, strict, dumpBuckets, depth + 1);
             }
         }
 
@@ -2116,7 +2142,7 @@ namespace mongo {
                 wassert(b->parent == bucketLoc);
             }
 
-            keyCount += _fullValidate(bucket->nextChild, unusedCount, strict, dumpBuckets, depth + 1);
+            keyCount += _fullValidate(txn, bucket->nextChild, unusedCount, strict, dumpBuckets, depth + 1);
         }
 
         return keyCount;
@@ -2230,7 +2256,7 @@ namespace mongo {
 
         int pos;
         bool found;
-        Status findStatus = _find(bucket, key, recordLoc, !dupsAllowed, &pos, &found);
+        Status findStatus = _find(txn, bucket, key, recordLoc, !dupsAllowed, &pos, &found);
         if (!findStatus.isOK()) {
             return findStatus;
         }
@@ -2269,9 +2295,10 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    DiskLoc BtreeLogic<BtreeLayout>::advance(const DiskLoc& bucketLoc,
-                                              int* posInOut,
-                                              int direction) const {
+    DiskLoc BtreeLogic<BtreeLayout>::advance(OperationContext* txn,
+                                             const DiskLoc& bucketLoc,
+                                             int* posInOut,
+                                             int direction) const {
         BucketType* bucket = getBucket(bucketLoc);
 
         if (*posInOut < 0 || *posInOut >= bucket->n ) {
@@ -2343,7 +2370,8 @@ namespace mongo {
     }
 
     template <class BtreeLayout>
-    bool BtreeLogic<BtreeLayout>::locate(const BSONObj& key,
+    bool BtreeLogic<BtreeLayout>::locate(OperationContext* txn,
+                                         const BSONObj& key,
                                          const DiskLoc& recordLoc,
                                          const int direction,
                                          int* posOut,
@@ -2355,28 +2383,33 @@ namespace mongo {
         bool found = false;
         KeyDataOwnedType owned(key);
 
-        *bucketLocOut = _locate(getRootLoc(), owned, posOut, &found, recordLoc, direction);
+        *bucketLocOut = _locate(txn, getRootLoc(), owned, posOut, &found, recordLoc, direction);
 
         if (!found) {
             return false;
         }
 
-        skipUnusedKeys(bucketLocOut, posOut, direction);
+        skipUnusedKeys(txn, bucketLocOut, posOut, direction);
 
         return found;
     }
 
+    /**
+     * Recursively walk down the btree, looking for a match of key and recordLoc.
+     * Caller should have acquired lock on bucketLoc.
+     */
     template <class BtreeLayout>
-    DiskLoc BtreeLogic<BtreeLayout>::_locate(const DiskLoc& bucketLoc,
-                                            const KeyDataType& key,
-                                            int* posOut,
-                                            bool* foundOut,
-                                            const DiskLoc& recordLoc,
-                                            const int direction) const {
+    DiskLoc BtreeLogic<BtreeLayout>::_locate(OperationContext* txn,
+                                             const DiskLoc& bucketLoc,
+                                             const KeyDataType& key,
+                                             int* posOut,
+                                             bool* foundOut,
+                                             const DiskLoc& recordLoc,
+                                             const int direction) const {
         int position;
         BucketType* bucket = getBucket(bucketLoc);
         // XXX: owned to not owned conversion(?)
-        _find(bucket, key, recordLoc, false, &position, foundOut);
+        _find(txn, bucket, key, recordLoc, false, &position, foundOut);
 
         // Look in our current bucket.
         if (*foundOut) {
@@ -2388,7 +2421,7 @@ namespace mongo {
         DiskLoc childLoc = childLocForPos(bucket, position);
 
         if (!childLoc.isNull()) {
-            DiskLoc inChild = _locate(childLoc, key, posOut, foundOut, recordLoc, direction);
+            DiskLoc inChild = _locate(txn, childLoc, key, posOut, foundOut, recordLoc, direction);
             if (!inChild.isNull()) {
                 return inChild;
             }
@@ -2455,7 +2488,8 @@ namespace mongo {
     template <class BtreeLayout>
     typename BtreeLogic<BtreeLayout>::BucketType*
     BtreeLogic<BtreeLayout>::childForPos(BucketType* bucket, int pos) const {
-        return getBucket(childLocForPos(bucket, pos));
+        DiskLoc loc = childLocForPos(bucket, pos);
+        return getBucket(loc);
     }
 
     template <class BtreeLayout>
diff --git a/src/mongo/db/structure/btree/btree_logic.h b/src/mongo/db/structure/btree/btree_logic.h
index 157040e4891..b7a31f80f52 100644
--- a/src/mongo/db/structure/btree/btree_logic.h
+++ b/src/mongo/db/structure/btree/btree_logic.h
@@ -137,7 +137,9 @@ namespace mongo {
          */
         Builder* newBuilder(OperationContext* txn, bool dupsAllowed);
 
-        Status dupKeyCheck(const BSONObj& key, const DiskLoc& loc) const;
+        Status dupKeyCheck(OperationContext* txn,
+                           const BSONObj& key,
+                           const DiskLoc& loc) const;
 
         Status insert(OperationContext* txn,
                       const BSONObj& rawKey,
@@ -152,15 +154,19 @@ namespace mongo {
          *      bucketLocOut would contain the bucket containing key which is before or after the
          *      searched one (dependent on the direction).
          */
-        bool locate(const BSONObj& key,
+        bool locate(OperationContext* txn,
+                    const BSONObj& key,
                     const DiskLoc& recordLoc,
                     const int direction,
                     int* posOut,
                     DiskLoc* bucketLocOut) const;
 
-        void advance(DiskLoc* bucketLocInOut, int* posInOut, int direction) const;
+        void advance(OperationContext* txn,
+                     DiskLoc* bucketLocInOut,
+                     int* posInOut,
+                     int direction) const;
 
-        bool exists(const KeyDataType& key) const;
+        bool exists(OperationContext* txn, const KeyDataType& key) const;
 
         bool unindex(OperationContext* txn,
                      const BSONObj& key,
@@ -168,7 +174,8 @@ namespace mongo {
 
         bool isEmpty() const;
 
-        long long fullValidate(long long *unusedCount,
+        long long fullValidate(OperationContext*,
+                               long long *unusedCount,
                                bool strict,
                                bool dumpBuckets,
                                unsigned depth);
@@ -185,7 +192,8 @@ namespace mongo {
         // Composite key navigation methods
         //
 
-        void customLocate(DiskLoc* locInOut,
+        void customLocate(OperationContext* txn,
+                          DiskLoc* locInOut,
                           int* keyOfsInOut,
                           const BSONObj& keyBegin,
                           int keyBeginLen,
@@ -194,7 +202,8 @@ namespace mongo {
                           const vector<bool>& keyEndInclusive,
                           int direction) const;
 
-        void advanceTo(DiskLoc* thisLocInOut,
+        void advanceTo(OperationContext*,
+                       DiskLoc* thisLocInOut,
                        int* keyOfsInOut,
                        const BSONObj &keyBegin,
                        int keyBeginLen,
@@ -203,7 +212,8 @@ namespace mongo {
                        const vector<bool>& keyEndInclusive,
                        int direction) const;
 
-        void restorePosition(const BSONObj& savedKey,
+        void restorePosition(OperationContext* txn,
+                             const BSONObj& savedKey,
                              const DiskLoc& savedLoc,
                              int direction,
                              DiskLoc* bucketInOut,
@@ -330,7 +340,8 @@ namespace mongo {
 
         void _pack(OperationContext* txn, BucketType* bucket, const DiskLoc thisLoc, int &refPos);
 
-        void customLocate(DiskLoc* locInOut,
+        void customLocate(OperationContext* txn,
+                          DiskLoc* locInOut,
                           int* keyOfsInOut,
                           const BSONObj& keyBegin,
                           int keyBeginLen,
@@ -340,12 +351,13 @@ namespace mongo {
                           int direction,
                           pair<DiskLoc, int>& bestParent) const;
 
-        Status _find(BucketType* bucket,
-                    const KeyDataType& key,
-                    const DiskLoc& recordLoc,
-                    bool errorIfDup,
-                    int* keyPositionOut,
-                    bool* foundOut) const;
+        Status _find(OperationContext* txn,
+                     BucketType* bucket,
+                     const KeyDataType& key,
+                     const DiskLoc& recordLoc,
+                     bool errorIfDup,
+                     int* keyPositionOut,
+                     bool* foundOut) const;
 
         bool customFind(int low,
                         int high,
@@ -360,7 +372,8 @@ namespace mongo {
                         int* keyOfsInOut,
                         pair<DiskLoc, int>& bestParent) const;
 
-        void advanceToImpl(DiskLoc* thisLocInOut,
+        void advanceToImpl(OperationContext* txn,
+                           DiskLoc* thisLocInOut,
                            int* keyOfsInOut,
                            const BSONObj &keyBegin,
                            int keyBeginLen,
@@ -369,35 +382,48 @@ namespace mongo {
                            const vector<bool>& keyEndInclusive,
                            int direction) const;
 
-        bool wouldCreateDup(const KeyDataType& key, const DiskLoc self) const;
+        bool wouldCreateDup(OperationContext* txn,
+                            const KeyDataType& key,
+                            const DiskLoc self) const;
 
         bool keyIsUsed(const DiskLoc& loc, const int& pos) const;
 
-        void skipUnusedKeys(DiskLoc* loc, int* pos, int direction) const;
+        void skipUnusedKeys(OperationContext* txn,
+                            DiskLoc* loc,
+                            int* pos,
+                            int direction) const;
 
-        DiskLoc advance(const DiskLoc& bucketLoc, int* posInOut, int direction) const;
+        DiskLoc advance(OperationContext* txn,
+                        const DiskLoc& bucketLoc,
+                        int* posInOut,
+                        int direction) const;
 
-        DiskLoc _locate(const DiskLoc& bucketLoc,
-                       const KeyDataType& key,
-                       int* posOut,
-                       bool* foundOut,
-                       const DiskLoc& recordLoc,
-                       const int direction) const;
+        DiskLoc _locate(OperationContext* txn,
+                        const DiskLoc& bucketLoc,
+                        const KeyDataType& key,
+                        int* posOut,
+                        bool* foundOut,
+                        const DiskLoc& recordLoc,
+                        const int direction) const;
 
-        long long _fullValidate(const DiskLoc bucketLoc,
-                               long long *unusedCount,
-                               bool strict,
-                               bool dumpBuckets,
-                               unsigned depth);
+        long long _fullValidate(OperationContext* txn,
+                                const DiskLoc bucketLoc,
+                                long long *unusedCount,
+                                bool strict,
+                                bool dumpBuckets,
+                                unsigned depth);
 
         DiskLoc _addBucket(OperationContext* txn);
 
-        bool canMergeChildren(BucketType* bucket,
+        bool canMergeChildren(OperationContext* txn,
+                              BucketType* bucket,
                               const DiskLoc bucketLoc,
                               const int leftIndex);
 
         // has to look in children of 'bucket' and requires record store
-        int _rebalancedSeparatorPos(BucketType* bucket, int leftIndex);
+        int _rebalancedSeparatorPos(OperationContext* txn,
+                                    BucketType* bucket,
+                                    int leftIndex);
 
         void _packReadyForMod(BucketType* bucket, int &refPos);
 
@@ -466,7 +492,7 @@ namespace mongo {
 
         void doBalanceRightToLeft(OperationContext* txn,
                                   BucketType* bucket,
-                                  const DiskLoc bucketLoc,
+                                  const DiskLoc thisLoc,
                                   int leftIndex,
                                   int split,
                                   BucketType* l,
@@ -479,7 +505,9 @@ namespace mongo {
                                 const DiskLoc bucketLoc,
                                 int leftIndex);
 
-        int indexInParent(BucketType* bucket, const DiskLoc bucketLoc) const;
+        int indexInParent(OperationContext* txn,
+                          BucketType* bucket,
+                          const DiskLoc bucketLoc) const;
 
         void doMergeChildren(OperationContext* txn,
                              BucketType* bucket,
diff --git a/src/mongo/db/structure/btree/btree_logic_test.cpp b/src/mongo/db/structure/btree/btree_logic_test.cpp
index deabd340184..3cfa48a3a25 100644
--- a/src/mongo/db/structure/btree/btree_logic_test.cpp
+++ b/src/mongo/db/structure/btree/btree_logic_test.cpp
@@ -63,7 +63,8 @@ namespace mongo {
 
     protected:
         void checkValidNumKeys(int nKeys) {
-            ASSERT_EQUALS(nKeys, _helper.btree.fullValidate(NULL, true, true, 0));
+            OperationContextNoop txn;
+            ASSERT_EQUALS(nKeys, _helper.btree.fullValidate(&txn, NULL, true, true, 0));
         }
 
         void insert(const BSONObj &key, const DiskLoc dl) {
@@ -83,8 +84,9 @@ namespace mongo {
                     int direction) {
             int pos;
             DiskLoc loc;
+            OperationContextNoop txn;
             ASSERT_EQUALS(expectedFound,
-                          _helper.btree.locate(key, _helper.dummyDiskLoc, direction, &pos, &loc));
+                          _helper.btree.locate(&txn, key, _helper.dummyDiskLoc, direction, &pos, &loc));
             ASSERT_EQUALS(expectedLocation, loc);
             ASSERT_EQUALS(expectedPos, pos);
         }
@@ -128,8 +130,8 @@ namespace mongo {
 
         int bucketRebalancedSeparatorPos(const DiskLoc bucketLoc, int leftIndex) {
             BucketType* bucket = _helper.btree.getBucket(bucketLoc);
-
-            return _helper.btree._rebalancedSeparatorPos(bucket, leftIndex);
+            OperationContextNoop txn;
+            return _helper.btree._rebalancedSeparatorPos(&txn, bucket, leftIndex);
         }
 
         FullKey getKey(const DiskLoc bucketLoc, int pos) const {
@@ -328,21 +330,21 @@ namespace mongo {
 
             // 'E' is the split point and should be in the head the rest should be ~50/50
             const BSONObj splitPoint = simpleKey('E', 800);
-            this->_helper.btree.locate(splitPoint, this->_helper.dummyDiskLoc, 1, &pos, &loc);
+            this->_helper.btree.locate(&txn, splitPoint, this->_helper.dummyDiskLoc, 1, &pos, &loc);
             ASSERT_EQUALS(this->_helper.headManager.getHead(), loc);
             ASSERT_EQUALS(0, pos);
 
             // Find the one before 'E'
             int largePos;
             DiskLoc largeLoc;
-            this->_helper.btree.locate(splitPoint, this->_helper.dummyDiskLoc, 1, &largePos, &largeLoc);
-            this->_helper.btree.advance(&largeLoc, &largePos, -1);
+            this->_helper.btree.locate(&txn, splitPoint, this->_helper.dummyDiskLoc, 1, &largePos, &largeLoc);
+            this->_helper.btree.advance(&txn, &largeLoc, &largePos, -1);
 
             // Find the one after 'E'
             int smallPos;
             DiskLoc smallLoc;
-            this->_helper.btree.locate(splitPoint, this->_helper.dummyDiskLoc, 1, &smallPos, &smallLoc);
-            this->_helper.btree.advance(&smallLoc, &smallPos, 1);
+            this->_helper.btree.locate(&txn, splitPoint, this->_helper.dummyDiskLoc, 1, &smallPos, &smallLoc);
+            this->_helper.btree.advance(&txn, &smallLoc, &smallPos, 1);
 
             ASSERT_NOT_EQUALS(smallLoc, largeLoc);
             ASSERT_NOT_EQUALS(smallLoc, loc);
@@ -378,23 +380,23 @@ namespace mongo {
 
             // 'H' is the maximum 'large' interval key, 90% should be < 'H' and 10% larger
             const BSONObj splitPoint = simpleKey('H', 800);
-            this->_helper.btree.locate(splitPoint, this->_helper.dummyDiskLoc, 1, &pos, &loc);
+            this->_helper.btree.locate(&txn, splitPoint, this->_helper.dummyDiskLoc, 1, &pos, &loc);
             ASSERT_EQUALS(this->_helper.headManager.getHead(), loc);
             ASSERT_EQUALS(0, pos);
 
             // Find the one before 'H'
             int largePos;
             DiskLoc largeLoc;
-            this->_helper.btree.locate(
+            this->_helper.btree.locate(&txn,
                                 splitPoint, this->_helper.dummyDiskLoc, 1, &largePos, &largeLoc);
-            this->_helper.btree.advance(&largeLoc, &largePos, -1);
+            this->_helper.btree.advance(&txn, &largeLoc, &largePos, -1);
 
             // Find the one after 'H'
             int smallPos;
             DiskLoc smallLoc;
-            this->_helper.btree.locate(
+            this->_helper.btree.locate(&txn, 
                                 splitPoint, this->_helper.dummyDiskLoc, 1, &smallPos, &smallLoc);
-            this->_helper.btree.advance(&smallLoc, &smallPos, 1);
+            this->_helper.btree.advance(&txn, &smallLoc, &smallPos, 1);
 
             ASSERT_NOT_EQUALS(smallLoc, largeLoc);
             ASSERT_NOT_EQUALS(smallLoc, loc);
@@ -441,7 +443,7 @@ namespace mongo {
             ASSERT_EQUALS(1, this->_helper.recordStore.numRecords() - 1);
 
             long long unusedCount = 0;
-            ASSERT_EQUALS(expectedCount, this->_helper.btree.fullValidate(&unusedCount, true, true, 0));
+            ASSERT_EQUALS(expectedCount, this->_helper.btree.fullValidate(&txn, &unusedCount, true, true, 0));
             ASSERT_EQUALS(0, unusedCount);
         }
 
@@ -497,7 +499,7 @@ namespace mongo {
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords() - 1);
 
             long long unusedCount = 0;
-            ASSERT_EQUALS(17, this->_helper.btree.fullValidate(&unusedCount, true, true, 0));
+            ASSERT_EQUALS(17, this->_helper.btree.fullValidate(&txn, &unusedCount, true, true, 0));
             ASSERT_EQUALS(0, unusedCount);
         }
     };
@@ -510,7 +512,7 @@ namespace mongo {
             ArtificialTreeBuilder<OnDiskFormat> builder(&txn, &this->_helper);
 
             builder.makeTree("{d:{b:{a:null},bb:null,_:{c:null}},_:{f:{e:null},_:{g:null}}}");
-            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -518,7 +520,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "bb");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -535,7 +537,7 @@ namespace mongo {
             ArtificialTreeBuilder<OnDiskFormat> builder(&txn, &this->_helper);
 
             builder.makeTree("{d:{b:{a:null},bb:null,cc:{c:null}},_:{f:{e:null},h:{g:null}}}");
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -543,7 +545,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "bb");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -564,7 +566,7 @@ namespace mongo {
 
             builder.makeTree("{d:{b:{a:null},c:null}}");
 
-            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -572,7 +574,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "c");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -590,7 +592,7 @@ namespace mongo {
 
             builder.makeTree("{d:{b:{a:null},bb:null,cc:{c:null}},i:{f:{e:null},h:{g:null}}}");
 
-            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -598,7 +600,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "bb");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // Child does not currently replace parent in this case. Also, the tree 
             // has 6 buckets + 1 for the this->_helper.dummyDiskLoc.
@@ -617,7 +619,7 @@ namespace mongo {
 
             builder.makeTree("{d:{b:{a:null},cc:{c:null}},i:{f:{e:null},ff:null,h:{g:null}}}");
 
-            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -625,7 +627,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "ff");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // Child does not currently replace parent in this case. Also, the tree 
             // has 6 buckets + 1 for the this->_helper.dummyDiskLoc.
@@ -646,7 +648,7 @@ namespace mongo {
                              "dd:null,"
                              "_:{f:{e:null},h:{g:null}}}");
 
-            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -654,7 +656,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "bb");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -674,7 +676,7 @@ namespace mongo {
 
             builder.makeTree("{c:{b:{a:null}},d:null,_:{f:{e:null},g:null}}");
 
-            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -682,7 +684,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "g");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(6, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(6, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -700,7 +702,7 @@ namespace mongo {
 
             builder.makeTree("{c:{b:{a:null}},f:{e:{d:null},ee:null},_:{h:{g:null}}}");
 
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -708,7 +710,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "ee");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -726,7 +728,7 @@ namespace mongo {
 
             builder.makeTree("{c:{b:{a:null}},f:{e:{d:null},ee:null},ff:null,_:{h:{g:null}}}");
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -734,7 +736,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "ee");
             verify(this->unindex(k));
             
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -752,7 +754,7 @@ namespace mongo {
 
             builder.makeTree("{c:{b:{a:null}},cc:null,f:{e:{d:null},ee:null},_:{h:{g:null}}}");
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 7 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(8, this->_helper.recordStore.numRecords());
@@ -760,7 +762,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "ee");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -778,7 +780,7 @@ namespace mongo {
 
             builder.makeTree("{h:{e:{b:{a:null},c:null,d:null},g:{f:null}},j:{i:null}}");
 
-            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(10, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -786,7 +788,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "c");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -805,7 +807,7 @@ namespace mongo {
 
             builder.makeTree("{h:{e:{b:{a:null},c:null,d:null},g:{f:null}},_:{i:null}}");
 
-            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(9, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -813,7 +815,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "c");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -831,7 +833,7 @@ namespace mongo {
 
             builder.makeTree("{h:{e:{b:{a:null},c:null,d:null},_:{f:null}},_:{i:null}}");
 
-            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(8, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -839,7 +841,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "c");
             verify(this->unindex(k));
 
-            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -897,7 +899,7 @@ namespace mongo {
             const char *keys = delKeys();
             for (const char *i = keys; *i; ++i) {
                 long long unused = 0;
-                ASSERT_EQUALS(_count, this->_helper.btree.fullValidate(&unused, true, true, 0));
+                ASSERT_EQUALS(_count, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
                 ASSERT_EQUALS(0, unused);
 
                 // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
@@ -910,7 +912,7 @@ namespace mongo {
             }
 
             long long unused = 0;
-            ASSERT_EQUALS(_count, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(_count, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
             ASSERT_EQUALS(0, unused);
 
             validate();
@@ -1136,7 +1138,7 @@ namespace mongo {
                                 "b:{$20:null,$30:null,$40:null,$50:null,a:null},"
                                 "_:{c:null}}");
 
-            ASSERT_EQUALS(14, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(14, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1144,7 +1146,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x40, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1166,7 +1168,7 @@ namespace mongo {
                                 "b:{$20:null,$30:null,$40:null,$50:null,$60:null,$70:null},"
                                 "_:{c:null}}");
 
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1174,7 +1176,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x3, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1197,7 +1199,7 @@ namespace mongo {
                                 "b:{$30:null,$40:{$35:null},$50:{$45:null}},"
                                 "_:{c:null}}");
 
-            ASSERT_EQUALS(23, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(23, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 14 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(15, this->_helper.recordStore.numRecords());
@@ -1205,7 +1207,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x30, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(22, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(22, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 14 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(15, this->_helper.recordStore.numRecords());
@@ -1231,7 +1233,7 @@ namespace mongo {
                                         "$90:{$85:null},$100:{$95:null}},"
                                 "_:{c:null}}");
 
-            ASSERT_EQUALS(25, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(25, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 15 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(16, this->_helper.recordStore.numRecords());
@@ -1239,7 +1241,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x5, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(24, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(24, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 15 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(16, this->_helper.recordStore.numRecords());
@@ -1262,7 +1264,7 @@ namespace mongo {
             builder.makeTree("{$10:{$1:null,$2:null,$3:null,$4:null,$5:null,$6:null},"
                                 "_:{$20:null,$30:null,$40:null,$50:null,a:null}}");
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1270,7 +1272,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x40, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1342,7 +1344,7 @@ namespace mongo {
             builder.makeTree("{$10:{$1:null,$2:null,$3:null,$4:null,$5:null,$6:null},"
                                 "_:{$20:null,$30:null,$40:null,$50:null,a:null}}");
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1353,7 +1355,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x40, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(11, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1376,7 +1378,7 @@ namespace mongo {
                    "$200:null,$300:null,$400:null,$500:null,$600:null,"
                    "$700:null,$800:null,$900:null,_:{c:null}}");
 
-            ASSERT_EQUALS(22, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(22, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1384,7 +1386,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x3, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(21, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(21, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 6 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(7, this->_helper.recordStore.numRecords());
@@ -1559,7 +1561,7 @@ namespace mongo {
                               "$20:{$11:null,$12:null,$13:null,$14:null},"
                                 "_:{$30:null}}");
 
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1567,7 +1569,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x12, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1589,7 +1591,7 @@ namespace mongo {
                               "$20:{$11:null,$12:null,$13:null,$14:null},"
                                 "_:{$31:null,$32:null,$33:null,$34:null,$35:null,$36:null}}");
 
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1597,7 +1599,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x12, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1619,7 +1621,7 @@ namespace mongo {
                                 "_:{$20:null,$30:null,$40:null,$50:null,"
                                     "$60:null,$70:null,$80:null,$90:null}}");
 
-            ASSERT_EQUALS(15, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(15, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -1627,7 +1629,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x7, 800));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(14, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(14, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1647,7 +1649,7 @@ namespace mongo {
 
             builder.makeTree("{b:{a:null}}");
 
-            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1655,7 +1657,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "a");
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(1, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(1, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 1 bucket + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(2, this->_helper.recordStore.numRecords());
@@ -1673,7 +1675,7 @@ namespace mongo {
 
             builder.makeTree("{a:null,c:{b:null},d:null}");
 
-            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1681,7 +1683,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "b");
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(NULL, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, NULL, true, true, 0));
 
             // The tree has 1 bucket + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(2, this->_helper.recordStore.numRecords());
@@ -1700,7 +1702,7 @@ namespace mongo {
             builder.makeTree("{a:null,c:{b:null},d:null}");
 
             long long unused = 0;
-            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1709,7 +1711,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "c");
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 1 bucket + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(2, this->_helper.recordStore.numRecords());
@@ -1733,7 +1735,7 @@ namespace mongo {
             this->markKeyUnused(prevChildBucket, 0);
 
             long long unused = 0;
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1743,7 +1745,7 @@ namespace mongo {
             ASSERT(this->unindex(k));
 
             unused = 0;
-            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 1 bucket + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(2, this->_helper.recordStore.numRecords());
@@ -1764,7 +1766,7 @@ namespace mongo {
             builder.makeTree("{a:null,_:{b:null}}");
 
             long long unused = 0;
-            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1774,7 +1776,7 @@ namespace mongo {
             ASSERT(this->unindex(k));
 
             unused = 0;
-            ASSERT_EQUALS(1, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(1, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 1 bucket + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(2, this->_helper.recordStore.numRecords());
@@ -1794,7 +1796,7 @@ namespace mongo {
             builder.makeTree("{a:null,y:{d:{c:{b:null}},_:{e:null}},z:null}");
 
             long long unused = 0;
-            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(7, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 5 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(6, this->_helper.recordStore.numRecords());
@@ -1804,7 +1806,7 @@ namespace mongo {
             ASSERT(this->unindex(k));
 
             unused = 0;
-            ASSERT_EQUALS(6, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(6, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1824,7 +1826,7 @@ namespace mongo {
             builder.makeTree("{a:null,_:{e:{c:null},_:{f:null}}}");
 
             long long unused = 0;
-            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1834,7 +1836,7 @@ namespace mongo {
             ASSERT(this->unindex(k));
 
             unused = 0;
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 2 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(3, this->_helper.recordStore.numRecords());
@@ -1854,7 +1856,7 @@ namespace mongo {
             builder.makeTree("{a:null,d:{c:{b:null}},e:null}");
 
             long long unused = 0;
-            ASSERT_EQUALS(5, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(5, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1863,7 +1865,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "d");
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(4, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1886,7 +1888,7 @@ namespace mongo {
             builder.makeTree("{a:null,_:{c:null,_:{d:null}}}");
 
             long long unused = 0;
-            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(3, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1895,7 +1897,7 @@ namespace mongo {
             const BSONObj k = BSON("" << "a");
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(2, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 3 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(4, this->_helper.recordStore.numRecords());
@@ -1919,7 +1921,7 @@ namespace mongo {
                               "$40:null,$50:null,$60:null,$70:null,$80:null,$90:null,$100:null}");
 
             long long unused = 0;
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1928,7 +1930,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x30, 0x10));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1951,7 +1953,7 @@ namespace mongo {
                               "$80:null,$90:null,$100$10:{$95:{$93:null},_:{$97:null}}}");
 
             long long unused = 0;
-            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(13, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -1960,7 +1962,7 @@ namespace mongo {
             const BSONObj k = BSON("" << bigNumString(0x100, 0x10));
             ASSERT(this->unindex(k));
 
-            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&unused, true, true, 0));
+            ASSERT_EQUALS(12, this->_helper.btree.fullValidate(&txn, &unused, true, true, 0));
 
             // The tree has 4 buckets + 1 for the this->_helper.dummyDiskLoc
             ASSERT_EQUALS(5, this->_helper.recordStore.numRecords());
@@ -2044,14 +2046,14 @@ namespace mongo {
             }
 
             long long unused = 0;
-            ASSERT_EQUALS( 0, bt()->fullValidate( dl(), order(), &unused, true ) );
+            ASSERT_EQUALS( 0, bt()->fullValidate(&txn,  dl(), order(), &unused, true ) );
 
             for ( long long i = 50000; i < 50100; ++i ) {
                 insert( i );
             }
 
             long long unused2 = 0;
-            ASSERT_EQUALS( 100, bt()->fullValidate( dl(), order(), &unused2, true ) );
+            ASSERT_EQUALS( 100, bt()->fullValidate(&txn,  dl(), order(), &unused2, true ) );
 
 //            log() << "old unused: " << unused << ", new unused: " << unused2 << endl;
 //
diff --git a/src/mongo/db/structure/btree/btree_test_help.cpp b/src/mongo/db/structure/btree/btree_test_help.cpp
index deaca1285ab..a2deff60d27 100644
--- a/src/mongo/db/structure/btree/btree_test_help.cpp
+++ b/src/mongo/db/structure/btree/btree_test_help.cpp
@@ -174,7 +174,8 @@ namespace mongo {
     bool ArtificialTreeBuilder<OnDiskFormat>::isPresent(const BSONObj &key, int direction) const {
         int pos;
         DiskLoc loc;
-        return _helper->btree.locate(key, _helper->dummyDiskLoc, direction, &pos, &loc);
+        OperationContextNoop txn;
+        return _helper->btree.locate(&txn, key, _helper->dummyDiskLoc, direction, &pos, &loc);
     }
 
     // Static
diff --git a/src/mongo/db/structure/catalog/namespace_details_collection_entry.cpp b/src/mongo/db/structure/catalog/namespace_details_collection_entry.cpp
index 018d6a735c3..16bfb2cc5cc 100644
--- a/src/mongo/db/structure/catalog/namespace_details_collection_entry.cpp
+++ b/src/mongo/db/structure/catalog/namespace_details_collection_entry.cpp
@@ -47,8 +47,8 @@ namespace mongo {
           _db( db ) {
     }
 
-    CollectionOptions NamespaceDetailsCollectionCatalogEntry::getCollectionOptions() const {
-        return _db->getCollectionOptions( ns().ns() );
+    CollectionOptions NamespaceDetailsCollectionCatalogEntry::getCollectionOptions(OperationContext* txn) const {
+        return _db->getCollectionOptions( txn, ns().ns() );
     }
 
     int NamespaceDetailsCollectionCatalogEntry::getTotalIndexCount() const {
diff --git a/src/mongo/db/structure/catalog/namespace_details_collection_entry.h b/src/mongo/db/structure/catalog/namespace_details_collection_entry.h
index e034abf047a..78a5b96f181 100644
--- a/src/mongo/db/structure/catalog/namespace_details_collection_entry.h
+++ b/src/mongo/db/structure/catalog/namespace_details_collection_entry.h
@@ -52,7 +52,7 @@ namespace mongo {
 
         virtual ~NamespaceDetailsCollectionCatalogEntry(){}
 
-        virtual CollectionOptions getCollectionOptions() const;
+        virtual CollectionOptions getCollectionOptions(OperationContext* txn) const;
 
         virtual int getTotalIndexCount() const;
 
diff --git a/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.cpp b/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.cpp
index 88625f0104b..4b03af168c8 100644
--- a/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.cpp
+++ b/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.cpp
@@ -101,7 +101,7 @@ namespace mongo {
         }
     }
 
-    const DiskLoc& NamespaceDetailsRSV1MetaData::firstExtent() const {
+    const DiskLoc& NamespaceDetailsRSV1MetaData::firstExtent( OperationContext* txn ) const {
         return _details->firstExtent;
     }
 
@@ -109,7 +109,7 @@ namespace mongo {
         *txn->recoveryUnit()->writing( &_details->firstExtent ) = loc;
     }
 
-    const DiskLoc& NamespaceDetailsRSV1MetaData::lastExtent() const {
+    const DiskLoc& NamespaceDetailsRSV1MetaData::lastExtent( OperationContext* txn ) const {
         return _details->lastExtent;
     }
 
@@ -156,7 +156,7 @@ namespace mongo {
         return true;
     }
 
-    int NamespaceDetailsRSV1MetaData::lastExtentSize() const {
+    int NamespaceDetailsRSV1MetaData::lastExtentSize( OperationContext* txn ) const {
         return _details->lastExtentSize;
     }
 
@@ -191,7 +191,8 @@ namespace mongo {
         if ( !_namespaceRecordStore )
             return;
 
-        scoped_ptr<RecordIterator> iterator( _namespaceRecordStore->getIterator( DiskLoc(),
+        scoped_ptr<RecordIterator> iterator( _namespaceRecordStore->getIterator( txn,
+                                                                                 DiskLoc(),
                                                                                  false,
                                                                                  CollectionScanParams::FORWARD ) );
         while ( !iterator->isEOF() ) {
diff --git a/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.h b/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.h
index d4460de8bf2..7e8ab9af7a7 100644
--- a/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.h
+++ b/src/mongo/db/structure/catalog/namespace_details_rsv1_metadata.h
@@ -77,10 +77,10 @@ namespace mongo {
                                           const DiskLoc& loc );
         virtual void orphanDeletedList(OperationContext* txn);
 
-        virtual const DiskLoc& firstExtent() const;
+        virtual const DiskLoc& firstExtent( OperationContext* txn ) const;
         virtual void setFirstExtent( OperationContext* txn, const DiskLoc& loc );
 
-        virtual const DiskLoc& lastExtent() const;
+        virtual const DiskLoc& lastExtent( OperationContext* txn ) const;
         virtual void setLastExtent( OperationContext* txn, const DiskLoc& loc );
 
         virtual bool isCapped() const;
@@ -91,7 +91,7 @@ namespace mongo {
         virtual bool clearUserFlag( OperationContext* txn, int flag );
         virtual bool replaceUserFlags( OperationContext* txn, int flags );
 
-        virtual int lastExtentSize() const;
+        virtual int lastExtentSize( OperationContext* txn ) const;
         virtual void setLastExtentSize( OperationContext* txn, int newMax );
 
         virtual long long maxCappedDocs() const;
diff --git a/src/mongo/db/structure/record_store.h b/src/mongo/db/structure/record_store.h
index c3805976959..1d6ca0098b0 100644
--- a/src/mongo/db/structure/record_store.h
+++ b/src/mongo/db/structure/record_store.h
@@ -46,6 +46,7 @@ namespace mongo {
     class MAdvise;
     class NamespaceDetails;
     class OperationContext;
+    class Record;
 
     class RecordStoreCompactAdaptor;
     class RecordStore;
@@ -133,7 +134,9 @@ namespace mongo {
          * @param extraInfo - optional more debug info
          * @param level - optional, level of debug info to put in (higher is more)
          */
-        virtual int64_t storageSize( BSONObjBuilder* extraInfo = NULL, int infoLevel = 0 ) const = 0;
+        virtual int64_t storageSize( OperationContext* txn,
+                                     BSONObjBuilder* extraInfo = NULL,
+                                     int infoLevel = 0 ) const = 0;
 
         // CRUD related
 
@@ -170,9 +173,10 @@ namespace mongo {
         /**
          * returned iterator owned by caller
          * canonical to get all would be
-         * getIterator( DiskLoc(), false, CollectionScanParams::FORWARD )
+         * getIterator( txn, DiskLoc(), false, CollectionScanParams::FORWARD )
          */
-        virtual RecordIterator* getIterator( const DiskLoc& start = DiskLoc(),
+        virtual RecordIterator* getIterator( OperationContext* txn,
+                                             const DiskLoc& start = DiskLoc(),
                                              bool tailable = false,
                                              const CollectionScanParams::Direction& dir =
                                              CollectionScanParams::FORWARD
@@ -183,13 +187,13 @@ namespace mongo {
          * damaged records. The iterator might return every record in the store if all of them 
          * are reachable and not corrupted.
          */
-        virtual RecordIterator* getIteratorForRepair() const = 0;
+        virtual RecordIterator* getIteratorForRepair( OperationContext* txn ) const = 0;
 
         /**
          * Returns many iterators that partition the RecordStore into many disjoint sets. Iterating
          * all returned iterators is equivalent to Iterating the full store.
          */
-        virtual std::vector<RecordIterator*> getManyIterators() const = 0;
+        virtual std::vector<RecordIterator*> getManyIterators( OperationContext* txn ) const = 0;
 
         // higher level
 
@@ -233,7 +237,9 @@ namespace mongo {
          * @param scaleSize - amount by which to scale size metrics
          * appends any custom stats from the RecordStore or other unique stats
          */
-        virtual void appendCustomStats( BSONObjBuilder* result, double scale ) const = 0;
+        virtual void appendCustomStats( OperationContext* txn,
+                                        BSONObjBuilder* result,
+                                        double scale ) const = 0;
 
         /**
          * Load all data into cache.
diff --git a/src/mongo/db/structure/record_store_heap.cpp b/src/mongo/db/structure/record_store_heap.cpp
index bbaa86ebea1..789b8e2fedd 100644
--- a/src/mongo/db/structure/record_store_heap.cpp
+++ b/src/mongo/db/structure/record_store_heap.cpp
@@ -29,6 +29,7 @@
 *    it in the license file.
 */
 
+#include "mongo/db/operation_context_noop.h"
 #include "mongo/db/structure/record_store_heap.h"
 
 namespace mongo {
@@ -217,29 +218,30 @@ namespace mongo {
         return Status::OK();
     }
 
-    RecordIterator* HeapRecordStore::getIterator(const DiskLoc& start,
+    RecordIterator* HeapRecordStore::getIterator(OperationContext* txn,
+                                                 const DiskLoc& start,
                                                  bool tailable,
                                                  const CollectionScanParams::Direction& dir) const {
         if (tailable)
             invariant(_isCapped && dir == CollectionScanParams::FORWARD);
 
         if (dir == CollectionScanParams::FORWARD) {
-            return new HeapRecordIterator(_records, *this, start, tailable);
+            return new HeapRecordIterator(txn, _records, *this, start, tailable);
         }
         else {
-            return new HeapRecordIterator(_records, *this, start);
+            return new HeapRecordIterator(txn, _records, *this, start);
         }
     }
 
-    RecordIterator* HeapRecordStore::getIteratorForRepair() const {
+    RecordIterator* HeapRecordStore::getIteratorForRepair(OperationContext* txn) const {
         // TODO maybe make different from HeapRecordIterator
-        return new HeapRecordIterator(_records, *this);
+        return new HeapRecordIterator(txn, _records, *this);
     }
 
-    std::vector<RecordIterator*> HeapRecordStore::getManyIterators() const {
+    std::vector<RecordIterator*> HeapRecordStore::getManyIterators(OperationContext* txn) const {
         std::vector<RecordIterator*> out;
         // TODO maybe find a way to return multiple iterators.
-        out.push_back(new HeapRecordIterator(_records, *this));
+        out.push_back(new HeapRecordIterator(txn, _records, *this));
         return out;
     }
 
@@ -297,7 +299,9 @@ namespace mongo {
 
     }
     
-    void HeapRecordStore::appendCustomStats( BSONObjBuilder* result, double scale ) const {
+    void HeapRecordStore::appendCustomStats( OperationContext* txn,
+                                             BSONObjBuilder* result,
+                                             double scale ) const {
         result->append( "note", "HeapRecordStore has no cusom stats yet" );
     }
 
@@ -319,7 +323,9 @@ namespace mongo {
         invariant(!"increaseStorageSize not yet implemented");
     }
 
-    int64_t HeapRecordStore::storageSize(BSONObjBuilder* extraInfo, int infoLevel) const {
+    int64_t HeapRecordStore::storageSize(OperationContext* txn,
+                                         BSONObjBuilder* extraInfo,
+                                         int infoLevel) const {
         // Note: not making use of extraInfo or infoLevel since we don't have extents
         const int64_t recordOverhead = numRecords() * HeapRecord::HeaderSize;
         return _dataSize + recordOverhead;
@@ -337,11 +343,13 @@ namespace mongo {
     // Forward Iterator
     //
 
-    HeapRecordIterator::HeapRecordIterator(const HeapRecordStore::Records& records,
+    HeapRecordIterator::HeapRecordIterator(OperationContext* txn,
+                                           const HeapRecordStore::Records& records,
                                            const HeapRecordStore& rs,
                                            DiskLoc start,
                                            bool tailable)
-            : _tailable(tailable),
+            : _txn(txn),
+              _tailable(tailable),
               _lastLoc(minDiskLoc),
               _killedByInvalidate(false),
               _records(records),
@@ -425,10 +433,12 @@ namespace mongo {
     // Reverse Iterator
     //
 
-    HeapRecordReverseIterator::HeapRecordReverseIterator(const HeapRecordStore::Records& records,
+    HeapRecordReverseIterator::HeapRecordReverseIterator(OperationContext* txn,
+                                                         const HeapRecordStore::Records& records,
                                                          const HeapRecordStore& rs,
                                                          DiskLoc start)
-            : _killedByInvalidate(false),
+            : _txn(txn),
+              _killedByInvalidate(false),
               _records(records),
               _rs(rs) {
         if (start.isNull()) {
diff --git a/src/mongo/db/structure/record_store_heap.h b/src/mongo/db/structure/record_store_heap.h
index 0ea43cc8d76..59959c4c968 100644
--- a/src/mongo/db/structure/record_store_heap.h
+++ b/src/mongo/db/structure/record_store_heap.h
@@ -79,12 +79,14 @@ namespace mongo {
                                           const char* damangeSource,
                                           const mutablebson::DamageVector& damages );
 
-        virtual RecordIterator* getIterator( const DiskLoc& start, bool tailable,
+        virtual RecordIterator* getIterator( OperationContext* txn,
+                                             const DiskLoc& start,
+                                             bool tailable,
                                              const CollectionScanParams::Direction& dir) const;
 
-        virtual RecordIterator* getIteratorForRepair() const;
+        virtual RecordIterator* getIteratorForRepair( OperationContext* txn ) const;
 
-        virtual std::vector<RecordIterator*> getManyIterators() const;
+        virtual std::vector<RecordIterator*> getManyIterators( OperationContext* txn ) const;
 
         virtual Status truncate( OperationContext* txn );
 
@@ -102,7 +104,9 @@ namespace mongo {
                                  ValidateAdaptor* adaptor,
                                  ValidateResults* results, BSONObjBuilder* output ) const;
                                  
-        virtual void appendCustomStats( BSONObjBuilder* result, double scale ) const;
+        virtual void appendCustomStats( OperationContext* txn,
+                                        BSONObjBuilder* result,
+                                        double scale ) const;
 
         virtual Status touch( OperationContext* txn, BSONObjBuilder* output ) const;
         
@@ -112,7 +116,9 @@ namespace mongo {
 
         virtual void increaseStorageSize( OperationContext* txn,  int size, bool enforceQuota );
 
-        virtual int64_t storageSize(BSONObjBuilder* extraInfo = NULL, int infoLevel = 0) const;
+        virtual int64_t storageSize( OperationContext* txn,
+                                     BSONObjBuilder* extraInfo = NULL,
+                                     int infoLevel = 0) const;
 
         virtual long long dataSize() const { return _dataSize; }
 
@@ -170,7 +176,8 @@ namespace mongo {
 
     class HeapRecordIterator : public RecordIterator {
     public:
-        HeapRecordIterator(const HeapRecordStore::Records& records,
+        HeapRecordIterator(OperationContext* txn,
+                           const HeapRecordStore::Records& records,
                            const HeapRecordStore& rs,
                            DiskLoc start = DiskLoc(),
                            bool tailable = false);
@@ -190,6 +197,7 @@ namespace mongo {
         virtual RecordData dataFor( const DiskLoc& loc ) const;
 
     private:
+        OperationContext* _txn; // not owned
         HeapRecordStore::Records::const_iterator _it;
         bool _tailable;
         DiskLoc _lastLoc; // only for restarting tailable
@@ -201,7 +209,8 @@ namespace mongo {
 
     class HeapRecordReverseIterator : public RecordIterator {
     public:
-        HeapRecordReverseIterator(const HeapRecordStore::Records& records,
+        HeapRecordReverseIterator(OperationContext* txn,
+                                  const HeapRecordStore::Records& records,
                                   const HeapRecordStore& rs,
                                   DiskLoc start = DiskLoc());
 
@@ -220,6 +229,7 @@ namespace mongo {
         virtual RecordData dataFor( const DiskLoc& loc ) const;
 
     private:
+        OperationContext* _txn; // not owned
         HeapRecordStore::Records::const_reverse_iterator _it;
         bool _killedByInvalidate;
 
diff --git a/src/mongo/db/structure/record_store_v1_base.cpp b/src/mongo/db/structure/record_store_v1_base.cpp
index f929b0ef984..784a391e204 100644
--- a/src/mongo/db/structure/record_store_v1_base.cpp
+++ b/src/mongo/db/structure/record_store_v1_base.cpp
@@ -1,7 +1,7 @@
 // record_store_v1_base.cpp
 
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -31,6 +31,7 @@
 #include "mongo/db/structure/record_store_v1_base.h"
 
 #include "mongo/db/catalog/collection.h"
+#include "mongo/db/concurrency/lock_mgr.h"
 #include "mongo/db/operation_context.h"
 #include "mongo/db/storage/mmap_v1/extent.h"
 #include "mongo/db/storage/mmap_v1/extent_manager.h"
@@ -71,13 +72,16 @@ namespace mongo {
     }
 
 
-    int64_t RecordStoreV1Base::storageSize( BSONObjBuilder* extraInfo, int level ) const {
+    int64_t RecordStoreV1Base::storageSize( OperationContext* txn,
+                                            BSONObjBuilder* extraInfo,
+                                            int level ) const {
         BSONArrayBuilder extentInfo;
 
         int64_t total = 0;
         int n = 0;
 
-        DiskLoc cur = _details->firstExtent();
+        DiskLoc cur = _details->firstExtent(txn);
+
         while ( !cur.isNull() ) {
             Extent* e = _extentManager->getExtent( cur );
 
@@ -87,8 +91,7 @@ namespace mongo {
             if ( extraInfo && level > 0 ) {
                 extentInfo.append( BSON( "len" << e->length << "loc: " << e->myLoc.toBSONObj() ) );
             }
-
-            cur = e->xnext;
+            cur = e->xnext;            
         }
 
         if ( extraInfo ) {
@@ -118,27 +121,28 @@ namespace mongo {
         return reinterpret_cast<DeletedRecord*>( recordFor( loc ) );
     }
 
-    Extent* RecordStoreV1Base::_getExtent( const DiskLoc& loc ) const {
+    Extent* RecordStoreV1Base::_getExtent( OperationContext* txn, const DiskLoc& loc ) const {
         return _extentManager->getExtent( loc );
     }
 
-    DiskLoc RecordStoreV1Base::_getExtentLocForRecord( const DiskLoc& loc ) const {
+    DiskLoc RecordStoreV1Base::_getExtentLocForRecord( OperationContext* txn, const DiskLoc& loc ) const {
         return _extentManager->extentLocForV1( loc );
     }
 
 
-    DiskLoc RecordStoreV1Base::getNextRecord( const DiskLoc& loc ) const {
-        DiskLoc next = getNextRecordInExtent( loc );
-        if ( !next.isNull() )
+    DiskLoc RecordStoreV1Base::getNextRecord( OperationContext* txn, const DiskLoc& loc ) const {
+        DiskLoc next = getNextRecordInExtent( txn, loc );
+        if ( !next.isNull() ) {
             return next;
+        }
 
         // now traverse extents
 
-        Extent* e = _getExtent( _getExtentLocForRecord(loc) );
+        Extent* e = _getExtent( txn, _getExtentLocForRecord(txn, loc) );
         while ( 1 ) {
             if ( e->xnext.isNull() )
                 return DiskLoc(); // end of collection
-            e = _getExtent( e->xnext );
+            e = _getExtent( txn, e->xnext );
             if ( !e->firstRecord.isNull() )
                 break;
             // entire extent could be empty, keep looking
@@ -146,18 +150,19 @@ namespace mongo {
         return e->firstRecord;
     }
 
-    DiskLoc RecordStoreV1Base::getPrevRecord( const DiskLoc& loc ) const {
-        DiskLoc prev = getPrevRecordInExtent( loc );
-        if ( !prev.isNull() )
+    DiskLoc RecordStoreV1Base::getPrevRecord( OperationContext* txn, const DiskLoc& loc ) const {
+        DiskLoc prev = getPrevRecordInExtent( txn, loc );
+        if ( !prev.isNull() ) {
             return prev;
+        }
 
         // now traverse extents
 
-        Extent *e = _getExtent(_getExtentLocForRecord(loc));
+        Extent *e = _getExtent(txn, _getExtentLocForRecord(txn, loc));
         while ( 1 ) {
             if ( e->xprev.isNull() )
                 return DiskLoc(); // end of collection
-            e = _getExtent( e->xprev );
+            e = _getExtent( txn, e->xprev );
             if ( !e->firstRecord.isNull() )
                 break;
             // entire extent could be empty, keep looking
@@ -167,7 +172,8 @@ namespace mongo {
     }
 
     DiskLoc RecordStoreV1Base::_findFirstSpot( OperationContext* txn,
-                                               const DiskLoc& extDiskLoc, Extent* e ) {
+                                               const DiskLoc& extDiskLoc,
+                                               Extent* e ) {
         DiskLoc emptyLoc = extDiskLoc;
         emptyLoc.inc( Extent::HeaderSize() );
         int delRecLength = e->length - Extent::HeaderSize();
@@ -188,25 +194,26 @@ namespace mongo {
 
     }
 
-    DiskLoc RecordStoreV1Base::getNextRecordInExtent( const DiskLoc& loc ) const {
+    DiskLoc RecordStoreV1Base::getNextRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const {
         int nextOffset = recordFor( loc )->nextOfs();
 
         if ( nextOffset == DiskLoc::NullOfs )
             return DiskLoc();
 
         fassert( 17441, abs(nextOffset) >= 8 ); // defensive
-        return DiskLoc( loc.a(), nextOffset );
+        DiskLoc result( loc.a(), nextOffset );
+        return result;
     }
 
-    DiskLoc RecordStoreV1Base::getPrevRecordInExtent( const DiskLoc& loc ) const {
+    DiskLoc RecordStoreV1Base::getPrevRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const {
         int prevOffset = recordFor( loc )->prevOfs();
 
         if ( prevOffset == DiskLoc::NullOfs )
             return DiskLoc();
 
         fassert( 17442, abs(prevOffset) >= 8 ); // defensive
-        return DiskLoc( loc.a(), prevOffset );
-
+        DiskLoc result( loc.a(), prevOffset );
+        return result;
     }
 
 
@@ -356,13 +363,13 @@ namespace mongo {
         /* remove ourself from the record next/prev chain */
         {
             if ( todelete->prevOfs() != DiskLoc::NullOfs ) {
-                DiskLoc prev = getPrevRecordInExtent( dl );
+                DiskLoc prev = getPrevRecordInExtent( txn, dl );
                 Record* prevRecord = recordFor( prev );
                 txn->recoveryUnit()->writingInt( prevRecord->nextOfs() ) = todelete->nextOfs();
             }
 
             if ( todelete->nextOfs() != DiskLoc::NullOfs ) {
-                DiskLoc next = getNextRecord( dl );
+                DiskLoc next = getNextRecord( txn, dl );
                 Record* nextRecord = recordFor( next );
                 txn->recoveryUnit()->writingInt( nextRecord->prevOfs() ) = todelete->prevOfs();
             }
@@ -370,7 +377,8 @@ namespace mongo {
 
         /* remove ourself from extent pointers */
         {
-            Extent *e =  _getExtent( todelete->myExtentLoc(dl) );
+            DiskLoc extentLoc = todelete->myExtentLoc(dl);
+            Extent *e =  _getExtent( txn, extentLoc );
             if ( e->firstRecord == dl ) {
                 txn->recoveryUnit()->writing(&e->firstRecord);
                 if ( todelete->nextOfs() == DiskLoc::NullOfs )
@@ -410,15 +418,16 @@ namespace mongo {
 
     }
 
-    RecordIterator* RecordStoreV1Base::getIteratorForRepair() const {
-        return new RecordStoreV1RepairIterator(this);
+    RecordIterator* RecordStoreV1Base::getIteratorForRepair(OperationContext* txn) const {
+        return new RecordStoreV1RepairIterator(txn, this);
     }
 
     void RecordStoreV1Base::_addRecordToRecListInExtent(OperationContext* txn,
                                                         Record *r,
                                                         DiskLoc loc) {
         dassert( recordFor(loc) == r );
-        Extent *e = _getExtent( _getExtentLocForRecord( loc ) );
+        DiskLoc extentLoc = _getExtentLocForRecord( txn, loc );
+        Extent *e = _getExtent( txn, extentLoc );
         if ( e->lastRecord.isNull() ) {
             *txn->recoveryUnit()->writing(&e->firstRecord) = loc;
             *txn->recoveryUnit()->writing(&e->lastRecord) = loc;
@@ -440,7 +449,6 @@ namespace mongo {
                                                        isCapped(),
                                                        size,
                                                        enforceQuota );
-
         Extent *e = _extentManager->getExtent( eloc );
         invariant( e );
 
@@ -453,8 +461,8 @@ namespace mongo {
 
         DiskLoc emptyLoc = _findFirstSpot( txn, eloc, e );
 
-        if ( _details->lastExtent().isNull() ) {
-            invariant( _details->firstExtent().isNull() );
+        if ( _details->lastExtent(txn).isNull() ) {
+            invariant( _details->firstExtent(txn).isNull() );
             _details->setFirstExtent( txn, eloc );
             _details->setLastExtent( txn, eloc );
             _details->setCapExtent( txn, eloc );
@@ -462,9 +470,9 @@ namespace mongo {
             invariant( e->xnext.isNull() );
         }
         else {
-            invariant( !_details->firstExtent().isNull() );
-            *txn->recoveryUnit()->writing(&e->xprev) = _details->lastExtent();
-            *txn->recoveryUnit()->writing(&_extentManager->getExtent(_details->lastExtent())->xnext) = eloc;
+            invariant( !_details->firstExtent(txn).isNull() );
+            *txn->recoveryUnit()->writing(&e->xprev) = _details->lastExtent(txn);
+            *txn->recoveryUnit()->writing(&_extentManager->getExtent(_details->lastExtent(txn))->xnext) = eloc;
             _details->setLastExtent( txn, eloc );
         }
 
@@ -494,36 +502,37 @@ namespace mongo {
 
         output->appendNumber("datasize", _details->dataSize());
         output->appendNumber("nrecords", _details->numRecords());
-        output->appendNumber("lastExtentSize", _details->lastExtentSize());
+        output->appendNumber("lastExtentSize", _details->lastExtentSize(txn));
         output->appendNumber("padding", _details->paddingFactor());
 
-        if ( _details->firstExtent().isNull() )
+        if ( _details->firstExtent(txn).isNull() )
             output->append( "firstExtent", "null" );
         else
             output->append( "firstExtent",
-                            str::stream() << _details->firstExtent().toString()
+                            str::stream() << _details->firstExtent(txn).toString()
                             << " ns:"
-                            << _getExtent( _details->firstExtent() )->nsDiagnostic.toString());
-        if ( _details->lastExtent().isNull() )
+                            << _getExtent( txn, _details->firstExtent(txn) )->nsDiagnostic.toString());
+        if ( _details->lastExtent(txn).isNull() )
             output->append( "lastExtent", "null" );
         else
-            output->append( "lastExtent", str::stream() << _details->lastExtent().toString()
+            output->append( "lastExtent", str::stream() << _details->lastExtent(txn).toString()
                             << " ns:"
-                            << _getExtent( _details->lastExtent() )->nsDiagnostic.toString());
+                            << _getExtent( txn, _details->lastExtent(txn) )->nsDiagnostic.toString());
 
         // 22222222222222222222222222
         { // validate extent basics
             BSONArrayBuilder extentData;
             int extentCount = 0;
+            DiskLoc extentDiskLoc;
             try {
-                if ( !_details->firstExtent().isNull() ) {
-                    _getExtent( _details->firstExtent() )->assertOk();
-                    _getExtent( _details->lastExtent() )->assertOk();
+                if ( !_details->firstExtent(txn).isNull() ) {
+                    _getExtent( txn, _details->firstExtent(txn) )->assertOk();
+                    _getExtent( txn, _details->lastExtent(txn) )->assertOk();
                 }
 
-                DiskLoc extentDiskLoc = _details->firstExtent();
+                extentDiskLoc = _details->firstExtent(txn);
                 while (!extentDiskLoc.isNull()) {
-                    Extent* thisExtent = _getExtent( extentDiskLoc );
+                    Extent* thisExtent = _getExtent( txn, extentDiskLoc );
                     if (full) {
                         extentData << thisExtent->dump();
                     }
@@ -531,18 +540,19 @@ namespace mongo {
                         results->valid = false;
                     }
                     DiskLoc nextDiskLoc = thisExtent->xnext;
+                    
                     if (extentCount > 0 && !nextDiskLoc.isNull()
-                        &&  _getExtent( nextDiskLoc )->xprev != extentDiskLoc) {
+                        &&  _getExtent( txn, nextDiskLoc )->xprev != extentDiskLoc) {
                         StringBuilder sb;
-                        sb << "'xprev' pointer " << _getExtent( nextDiskLoc )->xprev.toString()
+                        sb << "'xprev' pointer " << _getExtent( txn, nextDiskLoc )->xprev.toString()
                            << " in extent " << nextDiskLoc.toString()
                            << " does not point to extent " << extentDiskLoc.toString();
                         results->errors.push_back( sb.str() );
                         results->valid = false;
                     }
-                    if (nextDiskLoc.isNull() && extentDiskLoc != _details->lastExtent()) {
+                    if (nextDiskLoc.isNull() && extentDiskLoc != _details->lastExtent(txn)) {
                         StringBuilder sb;
-                        sb << "'lastExtent' pointer " << _details->lastExtent().toString()
+                        sb << "'lastExtent' pointer " << _details->lastExtent(txn).toString()
                            << " does not point to last extent in list " << extentDiskLoc.toString();
                         results->errors.push_back( sb.str() );
                         results->valid = false;
@@ -571,31 +581,33 @@ namespace mongo {
             // 333333333333333333333333333
             bool testingLastExtent = false;
             try {
-                if (_details->firstExtent().isNull()) {
+                DiskLoc firstExtentLoc = _details->firstExtent(txn);
+                if (firstExtentLoc.isNull()) {
                     // this is ok
                 }
                 else {
-                    output->append("firstExtentDetails", _getExtent(_details->firstExtent())->dump());
-                    if (!_getExtent(_details->firstExtent())->xprev.isNull()) {
+                    output->append("firstExtentDetails", _getExtent(txn, firstExtentLoc)->dump());
+                    if (!_getExtent(txn, firstExtentLoc)->xprev.isNull()) {
                         StringBuilder sb;
-                        sb << "'xprev' pointer in 'firstExtent' " << _details->firstExtent().toString()
-                           << " is " << _getExtent(_details->firstExtent())->xprev.toString()
+                        sb << "'xprev' pointer in 'firstExtent' " << _details->firstExtent(txn).toString()
+                           << " is " << _getExtent(txn, firstExtentLoc)->xprev.toString()
                            << ", should be null";
                         results->errors.push_back( sb.str() );
                         results->valid = false;
                     }
                 }
                 testingLastExtent = true;
-                if (_details->lastExtent().isNull()) {
+                DiskLoc lastExtentLoc = _details->lastExtent(txn);
+                if (lastExtentLoc.isNull()) {
                     // this is ok
                 }
                 else {
-                    if (_details->firstExtent() != _details->lastExtent()) {
-                        output->append("lastExtentDetails", _getExtent(_details->lastExtent())->dump());
-                        if (!_getExtent(_details->lastExtent())->xnext.isNull()) {
+                    if (firstExtentLoc != lastExtentLoc) {
+                        output->append("lastExtentDetails", _getExtent(txn, lastExtentLoc)->dump());
+                        if (!_getExtent(txn, lastExtentLoc)->xnext.isNull()) {
                             StringBuilder sb;
-                            sb << "'xnext' pointer in 'lastExtent' " << _details->lastExtent().toString()
-                               << " is " << _getExtent(_details->lastExtent())->xnext.toString()
+                            sb << "'xnext' pointer in 'lastExtent' " << lastExtentLoc.toString()
+                               << " is " << _getExtent(txn, lastExtentLoc)->xnext.toString()
                                << ", should be null";
                             results->errors.push_back( sb.str() );
                             results->valid = false;
@@ -626,7 +638,8 @@ namespace mongo {
                 int outOfOrder = 0;
                 DiskLoc cl_last;
 
-                scoped_ptr<RecordIterator> iterator( getIterator( DiskLoc(),
+                scoped_ptr<RecordIterator> iterator( getIterator( txn,
+                                                                  DiskLoc(),
                                                                   false,
                                                                   CollectionScanParams::FORWARD ) );
                 DiskLoc cl;
@@ -771,8 +784,10 @@ namespace mongo {
         return Status::OK();
     }
 
-    void RecordStoreV1Base::appendCustomStats( BSONObjBuilder* result, double scale ) const {
-        result->append( "lastExtentSize", _details->lastExtentSize() / scale );
+    void RecordStoreV1Base::appendCustomStats( OperationContext* txn,
+                                               BSONObjBuilder* result,
+                                               double scale ) const {
+        result->append( "lastExtentSize", _details->lastExtentSize(txn) / scale );
         result->append( "paddingFactor", _details->paddingFactor() );
         result->append( "userFlags", _details->userFlags() );
 
@@ -793,21 +808,21 @@ namespace mongo {
     Status RecordStoreV1Base::touch( OperationContext* txn, BSONObjBuilder* output ) const {
         Timer t;
 
-        // Note: when this class has document level locking, we'll need a lock to get extents
-        // and then ideally only hold the collection lock from above while doing actual touching.
-
         std::vector<touch_location> ranges;
         {
-            Extent* ext = _getExtent( _details->firstExtent() );
+            DiskLoc nextLoc = _details->firstExtent(txn);
+            Extent* ext = _getExtent( txn, nextLoc );
             while ( ext ) {
                 touch_location tl;
                 tl.root = reinterpret_cast<const char*>(ext);
                 tl.length = ext->length;
                 ranges.push_back(tl);
-                if ( ext->xnext.isNull() )
+
+                nextLoc = ext->xnext;
+                if ( nextLoc.isNull() )
                     ext = NULL;
                 else
-                    ext = _getExtent( ext->xnext );
+                    ext = _getExtent( txn, nextLoc );
             }
         }
 
@@ -859,8 +874,9 @@ namespace mongo {
     }
 
     void RecordStoreV1Base::IntraExtentIterator::invalidate(const DiskLoc& dl) {
-        if (dl == _curr)
+        if (dl == _curr) {
             getNext();
+        }
     }
 
     /* @return the size for an allocated record quantized to 1/16th of the BucketSize
diff --git a/src/mongo/db/structure/record_store_v1_base.h b/src/mongo/db/structure/record_store_v1_base.h
index 3d393e355ee..7265528762a 100644
--- a/src/mongo/db/structure/record_store_v1_base.h
+++ b/src/mongo/db/structure/record_store_v1_base.h
@@ -1,7 +1,7 @@
 // record_store_v1_base.h
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -72,10 +72,10 @@ namespace mongo {
                                           const DiskLoc& loc ) = 0;
         virtual void orphanDeletedList(OperationContext* txn) = 0;
 
-        virtual const DiskLoc& firstExtent() const = 0;
+        virtual const DiskLoc& firstExtent( OperationContext* txn ) const = 0;
         virtual void setFirstExtent( OperationContext* txn, const DiskLoc& loc ) = 0;
 
-        virtual const DiskLoc& lastExtent() const = 0;
+        virtual const DiskLoc& lastExtent( OperationContext* txn ) const = 0;
         virtual void setLastExtent( OperationContext* txn, const DiskLoc& loc ) = 0;
 
         virtual bool isCapped() const = 0;
@@ -86,7 +86,7 @@ namespace mongo {
         virtual bool clearUserFlag( OperationContext* txn, int flag ) = 0;
         virtual bool replaceUserFlags( OperationContext* txn, int flags ) = 0;
 
-        virtual int lastExtentSize() const = 0;
+        virtual int lastExtentSize( OperationContext* txn) const = 0;
         virtual void setLastExtentSize( OperationContext* txn, int newMax ) = 0;
 
         virtual long long maxCappedDocs() const = 0;
@@ -127,7 +127,9 @@ namespace mongo {
         virtual long long dataSize() const { return _details->dataSize(); }
         virtual long long numRecords() const { return _details->numRecords(); }
 
-        virtual int64_t storageSize( BSONObjBuilder* extraInfo = NULL, int level = 0 ) const;
+        virtual int64_t storageSize( OperationContext* txn,
+                                     BSONObjBuilder* extraInfo = NULL,
+                                     int level = 0 ) const;
 
         virtual RecordData dataFor( const DiskLoc& loc ) const;
 
@@ -155,7 +157,7 @@ namespace mongo {
                                           const char* damangeSource,
                                           const mutablebson::DamageVector& damages );
 
-        virtual RecordIterator* getIteratorForRepair() const;
+        virtual RecordIterator* getIteratorForRepair( OperationContext* txn ) const;
 
         void increaseStorageSize( OperationContext* txn, int size, bool enforceQuota );
 
@@ -164,7 +166,9 @@ namespace mongo {
                                  ValidateAdaptor* adaptor,
                                  ValidateResults* results, BSONObjBuilder* output ) const;
 
-        virtual void appendCustomStats( BSONObjBuilder* result, double scale ) const;
+        virtual void appendCustomStats( OperationContext* txn,
+                                        BSONObjBuilder* result,
+                                        double scale ) const;
 
         virtual Status touch( OperationContext* txn, BSONObjBuilder* output ) const;
 
@@ -177,13 +181,13 @@ namespace mongo {
          */
         int getRecordAllocationSize( int minRecordSize ) const;
 
-        DiskLoc getExtentLocForRecord( const DiskLoc& loc ) const;
+        DiskLoc getExtentLocForRecord( OperationContext* txn, const DiskLoc& loc ) const;
 
-        DiskLoc getNextRecord( const DiskLoc& loc ) const;
-        DiskLoc getPrevRecord( const DiskLoc& loc ) const;
+        DiskLoc getNextRecord( OperationContext* txn, const DiskLoc& loc ) const;
+        DiskLoc getPrevRecord( OperationContext* txn, const DiskLoc& loc ) const;
 
-        DiskLoc getNextRecordInExtent( const DiskLoc& loc ) const;
-        DiskLoc getPrevRecordInExtent( const DiskLoc& loc ) const;
+        DiskLoc getNextRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const;
+        DiskLoc getPrevRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const;
 
         /* @return the size for an allocated record quantized to 1/16th of the BucketSize.
            @param allocSize    requested size to allocate
@@ -221,15 +225,15 @@ namespace mongo {
         virtual DeletedRecord* drec( const DiskLoc& loc ) const;
 
         // just a wrapper for _extentManager->getExtent( loc );
-        Extent* _getExtent( const DiskLoc& loc ) const;
+        Extent* _getExtent( OperationContext* txn, const DiskLoc& loc ) const;
 
-        DiskLoc _getExtentLocForRecord( const DiskLoc& loc ) const;
+        DiskLoc _getExtentLocForRecord( OperationContext* txn, const DiskLoc& loc ) const;
 
-        DiskLoc _getNextRecord( const DiskLoc& loc ) const;
-        DiskLoc _getPrevRecord( const DiskLoc& loc ) const;
+        DiskLoc _getNextRecord( OperationContext* txn, const DiskLoc& loc ) const;
+        DiskLoc _getPrevRecord( OperationContext* txn, const DiskLoc& loc ) const;
 
-        DiskLoc _getNextRecordInExtent( const DiskLoc& loc ) const;
-        DiskLoc _getPrevRecordInExtent( const DiskLoc& loc ) const;
+        DiskLoc _getNextRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const;
+        DiskLoc _getPrevRecordInExtent( OperationContext* txn, const DiskLoc& loc ) const;
 
         /**
          * finds the first suitable DiskLoc for data
@@ -268,14 +272,17 @@ namespace mongo {
      */
     class RecordStoreV1Base::IntraExtentIterator : public RecordIterator {
     public:
-        IntraExtentIterator(DiskLoc start, const RecordStoreV1Base* rs, bool forward = true)
-            : _curr(start), _rs(rs), _forward(forward) {}
+        IntraExtentIterator(OperationContext* txn,
+                            DiskLoc start,
+                            const RecordStoreV1Base* rs,
+                            bool forward = true)
+            : _txn(txn), _curr(start), _rs(rs), _forward(forward) {}
 
         virtual bool isEOF() { return _curr.isNull(); }
 
         virtual DiskLoc curr() { return _curr; }
 
-        virtual DiskLoc getNext();
+        virtual DiskLoc getNext( );
 
         virtual void invalidate(const DiskLoc& dl);
 
@@ -287,6 +294,7 @@ namespace mongo {
 
     private:
         virtual const Record* recordFor( const DiskLoc& loc ) const { return _rs->recordFor(loc); }
+        OperationContext* _txn;
         DiskLoc _curr;
         const RecordStoreV1Base* _rs;
         bool _forward;
diff --git a/src/mongo/db/structure/record_store_v1_capped.cpp b/src/mongo/db/structure/record_store_v1_capped.cpp
index 57657a1f3b2..fbc6c2e8186 100644
--- a/src/mongo/db/structure/record_store_v1_capped.cpp
+++ b/src/mongo/db/structure/record_store_v1_capped.cpp
@@ -67,7 +67,7 @@ namespace mongo {
         : RecordStoreV1Base( ns, details, em, isSystemIndexes ),
           _deleteCallback( collection ) {
 
-        DiskLoc extentLoc = details->firstExtent();
+        DiskLoc extentLoc = details->firstExtent(txn);
         while ( !extentLoc.isNull() ) {
             _extentAdvice.push_back( _extentManager->cacheHint( extentLoc,
                                                                 ExtentManager::Sequential ) );
@@ -94,11 +94,11 @@ namespace mongo {
             // the extent check is a way to try and improve performance
             // since we have to iterate all the extents (for now) to get
             // storage size
-            if ( lenToAlloc > storageSize() ) {
+            if ( lenToAlloc > storageSize(txn) ) {
                 return StatusWith<DiskLoc>( ErrorCodes::BadValue,
                                             mongoutils::str::stream()
                                             << "document is larger than capped size "
-                                            << lenToAlloc << " > " << storageSize(),
+                                            << lenToAlloc << " > " << storageSize(txn),
                                             16328 );
             }
 
@@ -136,7 +136,7 @@ namespace mongo {
                 if ( !_details->capFirstNewRecord().isValid() ) {
                     advanceCapExtent( txn, _ns );
 
-                    if ( _details->capExtent() != _details->firstExtent() )
+                    if ( _details->capExtent() != _details->firstExtent(txn) )
                         _details->setCapFirstNewRecord( txn, DiskLoc().setInvalid() );
                     // else signal done with first iteration through extents.
                     continue;
@@ -155,7 +155,7 @@ namespace mongo {
                         firstEmptyExtent = _details->capExtent();
                     advanceCapExtent( txn, _ns );
                     if ( firstEmptyExtent == _details->capExtent() ) {
-                        _maybeComplain( lenToAlloc );
+                        _maybeComplain( txn, lenToAlloc );
                         return StatusWith<DiskLoc>( ErrorCodes::InternalError,
                                                     "no space in capped collection" );
                     }
@@ -220,7 +220,7 @@ namespace mongo {
         setListOfAllDeletedRecords( txn, DiskLoc() );
 
         // preserve firstExtent/lastExtent
-        _details->setCapExtent( txn, _details->firstExtent() );
+        _details->setCapExtent( txn, _details->firstExtent(txn) );
         _details->setStats( txn, 0, 0 );
         // preserve lastExtentSize
         // nIndexes preserve 0
@@ -234,7 +234,7 @@ namespace mongo {
 
         // Reset all existing extents and recreate the deleted list.
         Extent* ext;
-        for( DiskLoc extLoc = _details->firstExtent();
+        for( DiskLoc extLoc = _details->firstExtent(txn);
              !extLoc.isNull();
              extLoc = ext->xnext ) {
             ext = _extentManager->getExtent(extLoc);
@@ -340,7 +340,7 @@ namespace mongo {
             // NOTE cappedLastDelRecLastExtent() set to DiskLoc() in above
 
             // Last, in case we're killed before getting here
-            _details->setCapExtent( txn, _details->firstExtent() );
+            _details->setCapExtent( txn, _details->firstExtent(txn) );
         }
     }
 
@@ -369,7 +369,7 @@ namespace mongo {
     void CappedRecordStoreV1::advanceCapExtent( OperationContext* txn, const StringData& ns ) {
         // We want cappedLastDelRecLastExtent() to be the last DeletedRecord of the prev cap extent
         // (or DiskLoc() if new capExtent == firstExtent)
-        if ( _details->capExtent() == _details->lastExtent() )
+        if ( _details->capExtent() == _details->lastExtent(txn) )
             setLastDelRecLastExtent( txn, DiskLoc() );
         else {
             DiskLoc i = cappedFirstDeletedInCurExtent();
@@ -378,7 +378,7 @@ namespace mongo {
         }
 
         _details->setCapExtent( txn,
-                                theCapExtent()->xnext.isNull() ?  _details->firstExtent()
+                                theCapExtent()->xnext.isNull() ?  _details->firstExtent(txn)
                                                                : theCapExtent()->xnext );
 
         /* this isn't true if a collection has been renamed...that is ok just used for diagnostics */
@@ -415,7 +415,7 @@ namespace mongo {
     }
 
     void CappedRecordStoreV1::cappedTruncateLastDelUpdate(OperationContext* txn) {
-        if ( _details->capExtent() == _details->firstExtent() ) {
+        if ( _details->capExtent() == _details->firstExtent(txn) ) {
             // Only one extent of the collection is in use, so there
             // is no deleted record in a previous extent, so nullify
             // cappedLastDelRecLastExtent().
@@ -522,8 +522,8 @@ namespace mongo {
                 DiskLoc newCapExtent = _details->capExtent();
                 do {
                     // Find the previous extent, looping if necessary.
-                    newCapExtent = ( newCapExtent == _details->firstExtent() ) ?
-                        _details->lastExtent() :
+                    newCapExtent = ( newCapExtent == _details->firstExtent(txn) ) ?
+                        _details->lastExtent(txn) :
                         _extentManager->getExtent(newCapExtent)->xprev;
                     _extentManager->getExtent(newCapExtent)->assertOk();
                 }
@@ -586,23 +586,26 @@ namespace mongo {
         }
     }
 
-    RecordIterator* CappedRecordStoreV1::getIterator( const DiskLoc& start, bool tailable,
+    RecordIterator* CappedRecordStoreV1::getIterator( OperationContext* txn,
+                                                      const DiskLoc& start,
+                                                      bool tailable,
                                                       const CollectionScanParams::Direction& dir) const {
-        return new CappedRecordStoreV1Iterator( this, start, tailable, dir );
+        return new CappedRecordStoreV1Iterator( txn, this, start, tailable, dir );
     }
 
-    vector<RecordIterator*> CappedRecordStoreV1::getManyIterators() const {
+    vector<RecordIterator*> CappedRecordStoreV1::getManyIterators( OperationContext* txn ) const {
         OwnedPointerVector<RecordIterator> iterators;
 
         if (!_details->capLooped()) {
             // if we haven't looped yet, just spit out all extents (same as non-capped impl)
             const Extent* ext;
-            for (DiskLoc extLoc = details()->firstExtent(); !extLoc.isNull(); extLoc = ext->xnext) {
-                ext = _getExtent(extLoc);
+            for (DiskLoc extLoc = details()->firstExtent(txn); !extLoc.isNull(); extLoc = ext->xnext) {
+                ext = _getExtent(txn, extLoc);
                 if (ext->firstRecord.isNull())
                     continue;
 
-                iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(ext->firstRecord,
+                iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(txn,
+                                                                               ext->firstRecord,
                                                                                this));
             }
         }
@@ -616,28 +619,32 @@ namespace mongo {
             // First do the "old" portion of capExtent if there is any
             DiskLoc extLoc = capExtent;
             {
-                const Extent* ext = _getExtent(extLoc);
+                const Extent* ext = _getExtent(txn, extLoc);
                 if (ext->firstRecord != details()->capFirstNewRecord()) {
                     // this means there is old data in capExtent
-                    iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(ext->firstRecord,
+                    iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(txn,
+                                                                                   ext->firstRecord,
                                                                                    this));
                 }
 
-                extLoc = ext->xnext.isNull() ? details()->firstExtent() : ext->xnext;
+                extLoc = ext->xnext.isNull() ? details()->firstExtent(txn) : ext->xnext;
             }
 
             // Next handle all the other extents
             while (extLoc != capExtent) {
-                const Extent* ext = _getExtent(extLoc);
-                iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(ext->firstRecord,
+                const Extent* ext = _getExtent(txn, extLoc);
+                iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(txn,
+                                                                               ext->firstRecord,
                                                                                this));
 
-                extLoc = ext->xnext.isNull() ? details()->firstExtent() : ext->xnext;
+                extLoc = ext->xnext.isNull() ? details()->firstExtent(txn) : ext->xnext;
             }
 
             // Finally handle the "new" data in the capExtent
             iterators.push_back(
-                new RecordStoreV1Base::IntraExtentIterator(details()->capFirstNewRecord(), this));
+                new RecordStoreV1Base::IntraExtentIterator(txn,
+                                                           details()->capFirstNewRecord(),
+                                                           this));
         }
 
         return iterators.release();
@@ -650,13 +657,13 @@ namespace mongo {
         invariant(false);
     }
 
-    void CappedRecordStoreV1::_maybeComplain( int len ) const {
+    void CappedRecordStoreV1::_maybeComplain( OperationContext* txn, int len ) const {
         RARELY {
             std::stringstream buf;
             buf << "couldn't make room for record len: " << len << " in capped ns " << _ns << '\n';
             buf << "numRecords: " << numRecords() << '\n';
             int i = 0;
-            for ( DiskLoc e = _details->firstExtent();
+            for ( DiskLoc e = _details->firstExtent(txn);
                   !e.isNull();
                   e = _extentManager->getExtent( e )->xnext, ++i ) {
                 buf << "  Extent " << i;
@@ -676,12 +683,13 @@ namespace mongo {
             warning() << buf.str();
 
             // assume it is unusually large record; if not, something is broken
-            fassert( 17438, len * 5 > _details->lastExtentSize() );
+            fassert( 17438, len * 5 > _details->lastExtentSize(txn) );
         }
     }
 
-    DiskLoc CappedRecordStoreV1::firstRecord( const DiskLoc &startExtent ) const {
-        for (DiskLoc i = startExtent.isNull() ? _details->firstExtent() : startExtent;
+    DiskLoc CappedRecordStoreV1::firstRecord( OperationContext* txn,
+                                              const DiskLoc &startExtent ) const {
+        for (DiskLoc i = startExtent.isNull() ? _details->firstExtent(txn) : startExtent;
                 !i.isNull();
              i = _extentManager->getExtent( i )->xnext ) {
 
@@ -693,8 +701,9 @@ namespace mongo {
         return DiskLoc();
     }
 
-    DiskLoc CappedRecordStoreV1::lastRecord( const DiskLoc &startExtent ) const {
-        for (DiskLoc i = startExtent.isNull() ? _details->lastExtent() : startExtent;
+    DiskLoc CappedRecordStoreV1::lastRecord( OperationContext* txn,
+                                             const DiskLoc &startExtent ) const {
+        for (DiskLoc i = startExtent.isNull() ? _details->lastExtent(txn) : startExtent;
                 !i.isNull();
              i = _extentManager->getExtent( i )->xprev ) {
 
diff --git a/src/mongo/db/structure/record_store_v1_capped.h b/src/mongo/db/structure/record_store_v1_capped.h
index dcc19cf0c08..02f28727f30 100644
--- a/src/mongo/db/structure/record_store_v1_capped.h
+++ b/src/mongo/db/structure/record_store_v1_capped.h
@@ -62,10 +62,11 @@ namespace mongo {
          */
         virtual void temp_cappedTruncateAfter( OperationContext* txn, DiskLoc end, bool inclusive );
 
-        virtual RecordIterator* getIterator( const DiskLoc& start, bool tailable,
+        virtual RecordIterator* getIterator( OperationContext* txn,
+                                             const DiskLoc& start, bool tailable,
                                              const CollectionScanParams::Direction& dir) const;
 
-        virtual std::vector<RecordIterator*> getManyIterators() const;
+        virtual std::vector<RecordIterator*> getManyIterators( OperationContext* txn ) const;
 
         virtual bool compactSupported() const { return false; }
 
@@ -75,9 +76,11 @@ namespace mongo {
                                 CompactStats* stats );
 
         // Start from firstExtent by default.
-        DiskLoc firstRecord( const DiskLoc &startExtent = DiskLoc() ) const;
+        DiskLoc firstRecord( OperationContext* txn,
+                             const DiskLoc &startExtent = DiskLoc() ) const;
         // Start from lastExtent by default.
-        DiskLoc lastRecord( const DiskLoc &startExtent = DiskLoc() ) const;
+        DiskLoc lastRecord( OperationContext* txn,
+                            const DiskLoc &startExtent = DiskLoc() ) const;
 
     protected:
 
@@ -121,7 +124,7 @@ namespace mongo {
                                  DiskLoc end,
                                  bool inclusive);
 
-        void _maybeComplain( int len ) const;
+        void _maybeComplain( OperationContext* txn, int len ) const;
 
         // -- end copy from cap.cpp --
 
diff --git a/src/mongo/db/structure/record_store_v1_capped_iterator.cpp b/src/mongo/db/structure/record_store_v1_capped_iterator.cpp
index 12e6f945f20..c10557d6547 100644
--- a/src/mongo/db/structure/record_store_v1_capped_iterator.cpp
+++ b/src/mongo/db/structure/record_store_v1_capped_iterator.cpp
@@ -39,10 +39,11 @@ namespace mongo {
     //
     // Capped collection traversal
     //
-    CappedRecordStoreV1Iterator::CappedRecordStoreV1Iterator( const CappedRecordStoreV1* collection,
+    CappedRecordStoreV1Iterator::CappedRecordStoreV1Iterator( OperationContext* txn,
+                                                              const CappedRecordStoreV1* collection,
                                                               const DiskLoc& start, bool tailable,
                                                               const CollectionScanParams::Direction& dir)
-        : _recordStore(collection), _curr(start), _tailable(tailable),
+        : _txn(txn), _recordStore(collection), _curr(start), _tailable(tailable),
           _direction(dir), _killedByInvalidate(false) {
 
         if (_curr.isNull()) {
@@ -55,7 +56,7 @@ namespace mongo {
                 // Going forwards.
                 if (!nsd->capLooped()) {
                     // If our capped collection doesn't loop around, the first record is easy.
-                    _curr = collection->firstRecord();
+                    _curr = collection->firstRecord(_txn);
                 }
                 else {
                     // Our capped collection has "looped' around.
@@ -72,7 +73,7 @@ namespace mongo {
                 // Going backwards
                 if (!nsd->capLooped()) {
                     // Start at the end.
-                    _curr = collection->lastRecord();
+                    _curr = collection->lastRecord(_txn);
                 }
                 else {
                     _curr = _getExtent( nsd->capExtent() )->lastRecord;
@@ -205,7 +206,7 @@ namespace mongo {
         if (!next.isNull()) {
             return next;
         }
-        return _recordStore->firstRecord();
+        return _recordStore->firstRecord(_txn);
     }
 
     DiskLoc CappedRecordStoreV1Iterator::prevLoop(const DiskLoc& curr) {
@@ -214,7 +215,7 @@ namespace mongo {
         if (!prev.isNull()) {
             return prev;
         }
-        return _recordStore->lastRecord();
+        return _recordStore->lastRecord(_txn);
     }
 
     RecordData CappedRecordStoreV1Iterator::dataFor( const DiskLoc& loc ) const {
@@ -226,11 +227,11 @@ namespace mongo {
     }
 
     DiskLoc CappedRecordStoreV1Iterator::_getNextRecord( const DiskLoc& loc ) {
-        return _recordStore->getNextRecord( loc );
+        return _recordStore->getNextRecord( _txn, loc );
     }
 
     DiskLoc CappedRecordStoreV1Iterator::_getPrevRecord( const DiskLoc& loc ) {
-        return _recordStore->getPrevRecord( loc );
+        return _recordStore->getPrevRecord( _txn, loc );
     }
 
 }  // namespace mongo
diff --git a/src/mongo/db/structure/record_store_v1_capped_iterator.h b/src/mongo/db/structure/record_store_v1_capped_iterator.h
index 041aef81c05..c63d265ec2e 100644
--- a/src/mongo/db/structure/record_store_v1_capped_iterator.h
+++ b/src/mongo/db/structure/record_store_v1_capped_iterator.h
@@ -47,7 +47,8 @@ namespace mongo {
      */
     class CappedRecordStoreV1Iterator : public RecordIterator {
     public:
-        CappedRecordStoreV1Iterator( const CappedRecordStoreV1* collection,
+        CappedRecordStoreV1Iterator( OperationContext* txn,
+                                     const CappedRecordStoreV1* collection,
                                      const DiskLoc& start,
                                      bool tailable,
                                      const CollectionScanParams::Direction& dir );
@@ -76,6 +77,9 @@ namespace mongo {
         DiskLoc _getNextRecord( const DiskLoc& loc );
         DiskLoc _getPrevRecord( const DiskLoc& loc );
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // The collection we're iterating over.
         const CappedRecordStoreV1* _recordStore;
 
diff --git a/src/mongo/db/structure/record_store_v1_capped_test.cpp b/src/mongo/db/structure/record_store_v1_capped_test.cpp
index 1ab2c5fae07..6ec414ff87d 100644
--- a/src/mongo/db/structure/record_store_v1_capped_test.cpp
+++ b/src/mongo/db/structure/record_store_v1_capped_test.cpp
@@ -70,7 +70,7 @@ namespace {
 
         {
             BSONObjBuilder b;
-            int64_t storageSize = rs.storageSize( &b );
+            int64_t storageSize = rs.storageSize( &txn, &b );
             BSONObj obj = b.obj();
             ASSERT_EQUALS( 1, obj["numExtents"].numberInt() );
             ASSERT_EQUALS( storageSize, em.quantizeExtentSize( 1024 ) );
@@ -127,7 +127,7 @@ namespace {
                 {DiskLoc(0, 1100), 900},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc().setInvalid()); // unlooped
         }
@@ -173,7 +173,7 @@ namespace {
                 {DiskLoc(0, 1500), 50}, // gap at end of extent
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
@@ -219,7 +219,7 @@ namespace {
                 {DiskLoc(0, 1500), 50}, // gap at end of extent
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
@@ -268,7 +268,7 @@ namespace {
                 {DiskLoc(0, 1500), 123}, // gap at end of extent
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
@@ -315,7 +315,7 @@ namespace {
                 {DiskLoc(0, 1600), 24}, // gap at end of extent
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
@@ -362,7 +362,7 @@ namespace {
                 {DiskLoc(1, 1100), 900},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(1, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc().setInvalid()); // unlooped
         }
@@ -413,7 +413,7 @@ namespace {
                 {DiskLoc(1, 1900), 100},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(1, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(1, 1000));
         }
@@ -468,7 +468,7 @@ namespace {
                 {DiskLoc(0, 1920), 80},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
@@ -550,7 +550,7 @@ namespace {
                 {DiskLoc(0, 1628), 84},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
             ASSERT_EQUALS(md->capExtent(), DiskLoc(0, 0));
             ASSERT_EQUALS(md->capFirstNewRecord(), DiskLoc(0, 1000));
         }
diff --git a/src/mongo/db/structure/record_store_v1_repair_iterator.cpp b/src/mongo/db/structure/record_store_v1_repair_iterator.cpp
index 373f8760bf7..aaa96fa2db8 100644
--- a/src/mongo/db/structure/record_store_v1_repair_iterator.cpp
+++ b/src/mongo/db/structure/record_store_v1_repair_iterator.cpp
@@ -35,8 +35,9 @@
 
 namespace mongo {
 
-    RecordStoreV1RepairIterator::RecordStoreV1RepairIterator(const RecordStoreV1Base* recordStore)
-        : _recordStore(recordStore), _stage(FORWARD_SCAN) {
+    RecordStoreV1RepairIterator::RecordStoreV1RepairIterator(OperationContext* txn,
+                                                             const RecordStoreV1Base* recordStore)
+        : _txn(txn), _recordStore(recordStore), _stage(FORWARD_SCAN) {
         
         // Position the iterator at the first record
         //
@@ -73,10 +74,10 @@ namespace mongo {
             else {
                 switch (_stage) {
                 case FORWARD_SCAN:
-                    _currRecord = _recordStore->getNextRecordInExtent(_currRecord);
+                    _currRecord = _recordStore->getNextRecordInExtent(_txn, _currRecord);
                     break;
                 case BACKWARD_SCAN:
-                    _currRecord = _recordStore->getPrevRecordInExtent(_currRecord);
+                    _currRecord = _recordStore->getPrevRecordInExtent(_txn, _currRecord);
                     break;
                 default:
                     invariant(!"This should never be reached.");
@@ -113,10 +114,10 @@ namespace mongo {
             if (_currExtent.isNull()) {
                 switch (_stage) {
                 case FORWARD_SCAN:
-                    _currExtent = _recordStore->details()->firstExtent();
+                    _currExtent = _recordStore->details()->firstExtent(_txn);
                     break;
                 case BACKWARD_SCAN:
-                    _currExtent = _recordStore->details()->lastExtent();
+                    _currExtent = _recordStore->details()->lastExtent(_txn);
                     break;
                 default:
                     invariant(DONE == _stage);
diff --git a/src/mongo/db/structure/record_store_v1_repair_iterator.h b/src/mongo/db/structure/record_store_v1_repair_iterator.h
index 01170617b78..a0319982fda 100644
--- a/src/mongo/db/structure/record_store_v1_repair_iterator.h
+++ b/src/mongo/db/structure/record_store_v1_repair_iterator.h
@@ -42,7 +42,8 @@ namespace mongo {
      */
     class RecordStoreV1RepairIterator : public RecordIterator {
     public:
-        RecordStoreV1RepairIterator(const RecordStoreV1Base* recordStore);
+        RecordStoreV1RepairIterator(OperationContext* txn,
+                                    const RecordStoreV1Base* recordStore);
         virtual ~RecordStoreV1RepairIterator() { }
 
         virtual bool isEOF();
@@ -68,6 +69,9 @@ namespace mongo {
          */
         bool _advanceToNextValidExtent();
 
+        // transactional context for read locks. Not owned by us
+        OperationContext* _txn;
+
         // Reference to the owning RecordStore. The store must not be deleted while there are 
         // active iterators on it.
         //
diff --git a/src/mongo/db/structure/record_store_v1_simple.cpp b/src/mongo/db/structure/record_store_v1_simple.cpp
index 7e99a1b7640..21dd0d7363e 100644
--- a/src/mongo/db/structure/record_store_v1_simple.cpp
+++ b/src/mongo/db/structure/record_store_v1_simple.cpp
@@ -1,7 +1,7 @@
 // record_store_v1_simple.cpp
 
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -96,6 +96,7 @@ namespace mongo {
             int bestmatchlen = INT_MAX; // sentinel meaning we haven't found a record big enough
             int b = bucket(lenToAlloc);
             DiskLoc cur = _details->deletedListEntry(b);
+            
             int extra = 5; // look for a better fit, a little.
             int chain = 0;
             while ( 1 ) {
@@ -220,9 +221,7 @@ namespace mongo {
         newDelW->nextDeleted().Null();
 
         addDeletedRec( txn, newDelLoc );
-
         return loc;
-
     }
 
     StatusWith<DiskLoc> SimpleRecordStoreV1::allocRecord( OperationContext* txn,
@@ -236,7 +235,7 @@ namespace mongo {
 
         increaseStorageSize( txn,
                              _extentManager->followupSize( lengthWithHeaders,
-                                                           _details->lastExtentSize()),
+                                                           _details->lastExtentSize(txn)),
                              enforceQuota );
 
         loc = _allocFromExistingExtents( txn, lengthWithHeaders );
@@ -247,14 +246,14 @@ namespace mongo {
 
         log() << "warning: alloc() failed after allocating new extent. "
               << "lengthWithHeaders: " << lengthWithHeaders << " last extent size:"
-              << _details->lastExtentSize() << "; trying again";
+              << _details->lastExtentSize(txn) << "; trying again";
 
-        for ( int z = 0; z < 10 && lengthWithHeaders > _details->lastExtentSize(); z++ ) {
+        for ( int z = 0; z < 10 && lengthWithHeaders > _details->lastExtentSize(txn); z++ ) {
             log() << "try #" << z << endl;
 
             increaseStorageSize( txn,
                                  _extentManager->followupSize( lengthWithHeaders,
-                                                               _details->lastExtentSize()),
+                                                               _details->lastExtentSize(txn)),
                                  enforceQuota );
 
             loc = _allocFromExistingExtents( txn, lengthWithHeaders );
@@ -280,20 +279,22 @@ namespace mongo {
         _details->setDeletedListEntry(txn, b, dloc);
     }
 
-    RecordIterator* SimpleRecordStoreV1::getIterator( const DiskLoc& start, bool tailable,
+    RecordIterator* SimpleRecordStoreV1::getIterator( OperationContext* txn,
+                                                      const DiskLoc& start,
+                                                      bool tailable,
                                                       const CollectionScanParams::Direction& dir) const {
-        return new SimpleRecordStoreV1Iterator( this, start, dir );
+        return new SimpleRecordStoreV1Iterator( txn, this, start, dir );
     }
 
-    vector<RecordIterator*> SimpleRecordStoreV1::getManyIterators() const {
+    vector<RecordIterator*> SimpleRecordStoreV1::getManyIterators( OperationContext* txn ) const {
         OwnedPointerVector<RecordIterator> iterators;
         const Extent* ext;
-        for (DiskLoc extLoc = details()->firstExtent(); !extLoc.isNull(); extLoc = ext->xnext) {
-            ext = _getExtent(extLoc);
+        for (DiskLoc extLoc = details()->firstExtent(txn); !extLoc.isNull(); extLoc = ext->xnext) {
+            ext = _getExtent(txn, extLoc);
             if (ext->firstRecord.isNull())
                 continue;
-
-            iterators.push_back(new RecordStoreV1Base::IntraExtentIterator(ext->firstRecord, this));
+            iterators.push_back(
+                new RecordStoreV1Base::IntraExtentIterator(txn, ext->firstRecord, this));
         }
 
         return iterators.release();
@@ -370,7 +371,7 @@ namespace mongo {
                 while( 1 ) {
                     Record *recOld = recordFor(L);
                     RecordData oldData = recOld->toRecordData();
-                    L = getNextRecordInExtent(L);
+                    L = getNextRecordInExtent(txn, L);
 
                     if ( compactOptions->validateDocuments && !adaptor->isDataValid( oldData ) ) {
                         // object is corrupt!
@@ -432,8 +433,8 @@ namespace mongo {
                 }
             } // if !L.isNull()
 
-            invariant( _details->firstExtent() == diskloc );
-            invariant( _details->lastExtent() != diskloc );
+            invariant( _details->firstExtent(txn) == diskloc );
+            invariant( _details->lastExtent(txn) != diskloc );
             DiskLoc newFirst = e->xnext;
             _details->setFirstExtent( txn, newFirst );
             *txn->recoveryUnit()->writing(&_extentManager->getExtent( newFirst )->xprev) = DiskLoc();
@@ -462,7 +463,7 @@ namespace mongo {
         txn->recoveryUnit()->commitIfNeeded();
 
         list<DiskLoc> extents;
-        for( DiskLoc extLocation = _details->firstExtent();
+        for( DiskLoc extLocation = _details->firstExtent(txn);
              !extLocation.isNull();
              extLocation = _extentManager->getExtent( extLocation )->xnext ) {
             extents.push_back( extLocation );
@@ -476,7 +477,7 @@ namespace mongo {
         _details->setLastExtentSize( txn, 0 );
 
         // create a new extent so new records go there
-        increaseStorageSize( txn, _details->lastExtentSize(), true );
+        increaseStorageSize( txn, _details->lastExtentSize(txn), true );
 
         // reset data size and record counts to 0 for this namespace
         // as we're about to tally them up again for each new extent
@@ -492,8 +493,8 @@ namespace mongo {
             pm.hit();
         }
 
-        invariant( _extentManager->getExtent( _details->firstExtent() )->xprev.isNull() );
-        invariant( _extentManager->getExtent( _details->lastExtent() )->xnext.isNull() );
+        invariant( _extentManager->getExtent( _details->firstExtent(txn) )->xprev.isNull() );
+        invariant( _extentManager->getExtent( _details->lastExtent(txn) )->xnext.isNull() );
 
         // indexes will do their own progress meter
         pm.finished();
diff --git a/src/mongo/db/structure/record_store_v1_simple.h b/src/mongo/db/structure/record_store_v1_simple.h
index b6b11c9366d..786be3c8056 100644
--- a/src/mongo/db/structure/record_store_v1_simple.h
+++ b/src/mongo/db/structure/record_store_v1_simple.h
@@ -1,7 +1,7 @@
 // record_store_v1_simple.h
 
 /**
-*    Copyright (C) 2013 10gen Inc.
+*    Copyright (C) 2013-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -50,10 +50,10 @@ namespace mongo {
 
         const char* name() const { return "SimpleRecordStoreV1"; }
 
-        virtual RecordIterator* getIterator( const DiskLoc& start, bool tailable,
+        virtual RecordIterator* getIterator( OperationContext* txn, const DiskLoc& start, bool tailable,
                                              const CollectionScanParams::Direction& dir) const;
 
-        virtual std::vector<RecordIterator*> getManyIterators() const;
+        virtual std::vector<RecordIterator*> getManyIterators(OperationContext* txn) const;
 
         virtual Status truncate(OperationContext* txn);
 
diff --git a/src/mongo/db/structure/record_store_v1_simple_iterator.cpp b/src/mongo/db/structure/record_store_v1_simple_iterator.cpp
index 19163be6aeb..675042d3948 100644
--- a/src/mongo/db/structure/record_store_v1_simple_iterator.cpp
+++ b/src/mongo/db/structure/record_store_v1_simple_iterator.cpp
@@ -39,23 +39,24 @@ namespace mongo {
     // Regular / non-capped collection traversal
     //
 
-    SimpleRecordStoreV1Iterator::SimpleRecordStoreV1Iterator(const SimpleRecordStoreV1* collection,
+    SimpleRecordStoreV1Iterator::SimpleRecordStoreV1Iterator(OperationContext* txn,
+                                                             const SimpleRecordStoreV1* collection,
                                                              const DiskLoc& start,
                                                              const CollectionScanParams::Direction& dir)
-        : _curr(start), _recordStore(collection), _direction(dir) {
+        : _txn(txn), _curr(start), _recordStore(collection), _direction(dir) {
 
         if (_curr.isNull()) {
 
             const ExtentManager* em = _recordStore->_extentManager;
 
-            if ( _recordStore->details()->firstExtent().isNull() ) {
+            if ( _recordStore->details()->firstExtent(txn).isNull() ) {
                 // nothing in the collection
-                verify( _recordStore->details()->lastExtent().isNull() );
+                verify( _recordStore->details()->lastExtent(txn).isNull() );
             }
             else if (CollectionScanParams::FORWARD == _direction) {
 
                 // Find a non-empty extent and start with the first record in it.
-                Extent* e = em->getExtent( _recordStore->details()->firstExtent() );
+                Extent* e = em->getExtent( _recordStore->details()->firstExtent(txn) );
 
                 while (e->firstRecord.isNull() && !e->xnext.isNull()) {
                     e = em->getExtent( e->xnext );
@@ -68,7 +69,7 @@ namespace mongo {
             else {
                 // Walk backwards, skipping empty extents, and use the last record in the first
                 // non-empty extent we see.
-                Extent* e = em->getExtent( _recordStore->details()->lastExtent() );
+                Extent* e = em->getExtent( _recordStore->details()->lastExtent(txn) );
 
                 // TODO ELABORATE
                 // Does one of e->lastRecord.isNull(), e.firstRecord.isNull() imply the other?
@@ -95,10 +96,10 @@ namespace mongo {
         // Move to the next thing.
         if (!isEOF()) {
             if (CollectionScanParams::FORWARD == _direction) {
-                _curr = _recordStore->getNextRecord( _curr );
+                _curr = _recordStore->getNextRecord( _txn, _curr );
             }
             else {
-                _curr = _recordStore->getPrevRecord( _curr );
+                _curr = _recordStore->getPrevRecord( _txn, _curr );
             }
         }
 
diff --git a/src/mongo/db/structure/record_store_v1_simple_iterator.h b/src/mongo/db/structure/record_store_v1_simple_iterator.h
index 33746f7e655..7688b15be85 100644
--- a/src/mongo/db/structure/record_store_v1_simple_iterator.h
+++ b/src/mongo/db/structure/record_store_v1_simple_iterator.h
@@ -42,7 +42,8 @@ namespace mongo {
      */
     class SimpleRecordStoreV1Iterator : public RecordIterator {
     public:
-        SimpleRecordStoreV1Iterator( const SimpleRecordStoreV1* records,
+        SimpleRecordStoreV1Iterator( OperationContext* txn,
+                                     const SimpleRecordStoreV1* records,
                                      const DiskLoc& start,
                                      const CollectionScanParams::Direction& dir );
         virtual ~SimpleRecordStoreV1Iterator() { }
@@ -58,6 +59,9 @@ namespace mongo {
         virtual RecordData dataFor( const DiskLoc& loc ) const;
 
     private:
+         // for getNext, not owned
+        OperationContext* _txn;
+
         // The result returned on the next call to getNext().
         DiskLoc _curr;
 
diff --git a/src/mongo/db/structure/record_store_v1_simple_test.cpp b/src/mongo/db/structure/record_store_v1_simple_test.cpp
index 31659f89030..4788e46b1cf 100644
--- a/src/mongo/db/structure/record_store_v1_simple_test.cpp
+++ b/src/mongo/db/structure/record_store_v1_simple_test.cpp
@@ -231,7 +231,7 @@ namespace {
             LocAndSize drecs[] = {
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -262,7 +262,7 @@ namespace {
             LocAndSize drecs[] = {
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -296,7 +296,7 @@ namespace {
             LocAndSize drecs[] = {
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -334,7 +334,7 @@ namespace {
                 {DiskLoc(0, 1320), 24},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -372,7 +372,7 @@ namespace {
             LocAndSize drecs[] = {
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -497,7 +497,7 @@ namespace {
                 {DiskLoc(1, 1000), 1000},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -550,7 +550,7 @@ namespace {
                 {DiskLoc(0, 1700), 999},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -657,7 +657,7 @@ namespace {
                 {DiskLoc(0, 4100),  75},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 
@@ -769,7 +769,7 @@ namespace {
                 {DiskLoc(0, 9000), 140},
                 {}
             };
-            assertStateV1RS(recs, drecs, &em, md);
+            assertStateV1RS(&txn, recs, drecs, &em, md);
         }
     }
 }
diff --git a/src/mongo/db/structure/record_store_v1_test_help.cpp b/src/mongo/db/structure/record_store_v1_test_help.cpp
index 3b4767e9dad..fb25786d54d 100644
--- a/src/mongo/db/structure/record_store_v1_test_help.cpp
+++ b/src/mongo/db/structure/record_store_v1_test_help.cpp
@@ -121,7 +121,7 @@ namespace mongo {
         invariant( false );
     }
 
-    const DiskLoc& DummyRecordStoreV1MetaData::firstExtent() const {
+    const DiskLoc& DummyRecordStoreV1MetaData::firstExtent(OperationContext* txn) const {
         return _firstExtent;
     }
 
@@ -130,7 +130,7 @@ namespace mongo {
         _firstExtent = loc;
     }
 
-    const DiskLoc& DummyRecordStoreV1MetaData::lastExtent() const {
+    const DiskLoc& DummyRecordStoreV1MetaData::lastExtent(OperationContext* txn) const {
         return _lastExtent;
     }
 
@@ -171,7 +171,7 @@ namespace mongo {
     }
 
 
-    int DummyRecordStoreV1MetaData::lastExtentSize() const {
+    int DummyRecordStoreV1MetaData::lastExtentSize(OperationContext* txn) const {
         return _lastExtentSize;
     }
 
@@ -302,9 +302,11 @@ namespace {
         }
     }
 
-    void printRecList(const ExtentManager* em, const RecordStoreV1MetaData* md) {
+    void printRecList(OperationContext* txn,
+                      const ExtentManager* em,
+                      const RecordStoreV1MetaData* md) {
         log() << " *** BEGIN ACTUAL RECORD LIST *** ";
-        DiskLoc extLoc = md->firstExtent();
+        DiskLoc extLoc = md->firstExtent(txn);
         std::set<DiskLoc> seenLocs;
         while (!extLoc.isNull()) {
             Extent* ext = em->getExtent(extLoc, true);
@@ -371,7 +373,7 @@ namespace {
         
         // Need to start with a blank slate
         invariant(em->numFiles() == 0);
-        invariant(md->firstExtent().isNull());
+        invariant(md->firstExtent(txn).isNull());
 
         // pre-allocate extents (even extents that aren't part of this RS)
         {
@@ -410,7 +412,7 @@ namespace {
 
         if (records && !records[0].loc.isNull()) {
             int recIdx = 0;
-            DiskLoc extLoc = md->firstExtent();
+            DiskLoc extLoc = md->firstExtent(txn);
             while (!extLoc.isNull()) {
                 Extent* ext = em->getExtent(extLoc);
                 int prevOfs = DiskLoc::NullOfs;
@@ -492,10 +494,11 @@ namespace {
         }
 
         // Make sure we set everything up as requested.
-        assertStateV1RS(records, drecs, em, md);
+        assertStateV1RS(txn, records, drecs, em, md);
     }
 
-    void assertStateV1RS(const LocAndSize* records,
+    void assertStateV1RS(OperationContext* txn,
+                         const LocAndSize* records,
                          const LocAndSize* drecs,
                          const ExtentManager* em,
                          const DummyRecordStoreV1MetaData* md) {
@@ -508,7 +511,7 @@ namespace {
 
                 int recIdx = 0;
 
-                DiskLoc extLoc = md->firstExtent();
+                DiskLoc extLoc = md->firstExtent(txn);
                 while (!extLoc.isNull()) { // for each Extent
                     Extent* ext = em->getExtent(extLoc, true);
                     int expectedPrevOfs = DiskLoc::NullOfs;
@@ -534,7 +537,7 @@ namespace {
                     }
 
                     if (ext->xnext.isNull()) {
-                        ASSERT_EQUALS(md->lastExtent(), extLoc);
+                        ASSERT_EQUALS(md->lastExtent(txn), extLoc);
                     }
 
                     extLoc = ext->xnext;
@@ -557,7 +560,7 @@ namespace {
                         // the first drec in the capExtent. If the capExtent is the first Extent,
                         // it should be Null.
 
-                        if (md->capExtent() == md->firstExtent()) {
+                        if (md->capExtent() == md->firstExtent(txn)) {
                             ASSERT_EQUALS(actualLoc, DiskLoc());
                         }
                         else {
@@ -597,7 +600,7 @@ namespace {
         }
         catch (...) {
             // If a test fails, provide extra info to make debugging easier
-            printRecList(em, md);
+            printRecList(txn, em, md);
             printDRecList(em, md);
             throw;
         }
diff --git a/src/mongo/db/structure/record_store_v1_test_help.h b/src/mongo/db/structure/record_store_v1_test_help.h
index ed65e3d0a40..75c62205b72 100644
--- a/src/mongo/db/structure/record_store_v1_test_help.h
+++ b/src/mongo/db/structure/record_store_v1_test_help.h
@@ -65,10 +65,10 @@ namespace mongo {
                                           const DiskLoc& loc );
         virtual void orphanDeletedList(OperationContext* txn);
 
-        virtual const DiskLoc& firstExtent() const;
+        virtual const DiskLoc& firstExtent( OperationContext* txn ) const;
         virtual void setFirstExtent( OperationContext* txn, const DiskLoc& loc );
 
-        virtual const DiskLoc& lastExtent() const;
+        virtual const DiskLoc& lastExtent( OperationContext* txn ) const;
         virtual void setLastExtent( OperationContext* txn, const DiskLoc& loc );
 
         virtual bool isCapped() const;
@@ -80,7 +80,7 @@ namespace mongo {
         virtual bool replaceUserFlags( OperationContext* txn, int flags );
 
 
-        virtual int lastExtentSize() const;
+        virtual int lastExtentSize( OperationContext* txn ) const;
         virtual void setLastExtentSize( OperationContext* txn, int newMax );
 
         virtual long long maxCappedDocs() const;
@@ -189,7 +189,8 @@ namespace mongo {
      * List of LocAndSize are terminated by a Null DiskLoc. Passing a NULL pointer means don't check
      * that list.
      */
-    void assertStateV1RS(const LocAndSize* records,
+    void assertStateV1RS(OperationContext* txn,
+                         const LocAndSize* records,
                          const LocAndSize* drecs,
                          const ExtentManager* em,
                          const DummyRecordStoreV1MetaData* md);
diff --git a/src/mongo/dbtests/documentsourcetests.cpp b/src/mongo/dbtests/documentsourcetests.cpp
index 6972e8d7262..1c37fa6db4c 100644
--- a/src/mongo/dbtests/documentsourcetests.cpp
+++ b/src/mongo/dbtests/documentsourcetests.cpp
@@ -1,7 +1,7 @@
 // documentsourcetests.cpp : Unit tests for DocumentSource classes.
 
 /**
- *    Copyright (C) 2012 10gen Inc.
+ *    Copyright (C) 2012-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -178,7 +178,7 @@ namespace DocumentSourceTests {
                 CanonicalQuery* cq;
                 uassertStatusOK(CanonicalQuery::canonicalize(ns, /*query=*/BSONObj(), &cq));
                 Runner* runnerBare;
-                uassertStatusOK(getRunner(ctx.ctx().db()->getCollection(&_opCtx, ns), cq, &runnerBare));
+                uassertStatusOK(getRunner(&_opCtx, ctx.ctx().db()->getCollection(&_opCtx, ns), cq, &runnerBare));
 
                 _runner.reset(runnerBare);
                 _runner->saveState();
diff --git a/src/mongo/dbtests/jstests.cpp b/src/mongo/dbtests/jstests.cpp
index a5f8ff997b6..605e171e2c9 100644
--- a/src/mongo/dbtests/jstests.cpp
+++ b/src/mongo/dbtests/jstests.cpp
@@ -2,7 +2,7 @@
 //
 
 /**
- *    Copyright (C) 2009 10gen Inc.
+ *    Copyright (C) 2009-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -2010,7 +2010,6 @@ namespace JSTests {
 
             OperationContextImpl txn;
             DBDirectClient client(&txn);
-
             client.update( "test.system.js" , query.obj() , update.obj() , true /* upsert */ );
 
             scoped_ptr<Scope> s( globalScriptEngine->newScope() );
diff --git a/src/mongo/dbtests/namespacetests.cpp b/src/mongo/dbtests/namespacetests.cpp
index 4309b9c2356..698678be8ec 100644
--- a/src/mongo/dbtests/namespacetests.cpp
+++ b/src/mongo/dbtests/namespacetests.cpp
@@ -2,7 +2,7 @@
 //
 
 /**
- *    Copyright (C) 2008 10gen Inc.
+ *    Copyright (C) 2008-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -363,14 +363,16 @@ namespace NamespaceTests {
 
                 DiskLoc last, first;
                 {
-                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns(),
+                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(&txn,
+                                                                            ns(),
                                                                             collection(),
                                                                             InternalPlanner::BACKWARD));
                     runner->getNext(NULL, &last);
                     ASSERT( !last.isNull() );
                 }
                 {
-                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns(),
+                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(&txn,
+                                                                            ns(),
                                                                             collection(),
                                                                             InternalPlanner::FORWARD));
                     runner->getNext(NULL, &first);
@@ -383,14 +385,16 @@ namespace NamespaceTests {
 
                 {
                     DiskLoc loc;
-                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns(),
+                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(&txn,
+                                                                            ns(),
                                                                             collection(),
                                                                             InternalPlanner::FORWARD));
                     runner->getNext(NULL, &loc);
                     ASSERT( first == loc);
                 }
                 {
-                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(ns(),
+                    auto_ptr<Runner> runner(InternalPlanner::collectionScan(&txn,
+                                                                            ns(),
                                                                             collection(),
                                                                             InternalPlanner::BACKWARD));
                     DiskLoc loc;
diff --git a/src/mongo/dbtests/oplogstarttests.cpp b/src/mongo/dbtests/oplogstarttests.cpp
index 4f4f88c1ccc..0c6b5c0f20b 100644
--- a/src/mongo/dbtests/oplogstarttests.cpp
+++ b/src/mongo/dbtests/oplogstarttests.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 MongoDB Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -77,7 +77,7 @@ namespace OplogStartTests {
             ASSERT(s.isOK());
             _cq.reset(cq);
             _oplogws.reset(new WorkingSet());
-            _stage.reset(new OplogStart(collection(), _cq->root(), _oplogws.get()));
+            _stage.reset(new OplogStart(&_txn, collection(), _cq->root(), _oplogws.get()));
         }
 
         void assertWorkingSetMemberHasId(WorkingSetID id, int expectedId) {
diff --git a/src/mongo/dbtests/plan_ranking.cpp b/src/mongo/dbtests/plan_ranking.cpp
index 7b8f01add03..4908eb180ef 100644
--- a/src/mongo/dbtests/plan_ranking.cpp
+++ b/src/mongo/dbtests/plan_ranking.cpp
@@ -114,7 +114,7 @@ namespace PlanRankingTests {
             // Put each solution from the planner into the MPR.
             for (size_t i = 0; i < solutions.size(); ++i) {
                 PlanStage* root;
-                ASSERT(StageBuilder::build(collection, *solutions[i], ws, &root));
+                ASSERT(StageBuilder::build(&_txn, collection, *solutions[i], ws, &root));
                 // Takes ownership of all arguments.
                 _mps->addPlan(solutions[i], root, ws);
             }
diff --git a/src/mongo/dbtests/query_multi_plan_runner.cpp b/src/mongo/dbtests/query_multi_plan_runner.cpp
index 81982df6768..e9256246757 100644
--- a/src/mongo/dbtests/query_multi_plan_runner.cpp
+++ b/src/mongo/dbtests/query_multi_plan_runner.cpp
@@ -118,7 +118,7 @@ namespace QueryMultiPlanRunner {
             const Collection* coll = ctx.ctx().db()->getCollection(&_txn, ns());
 
             auto_ptr<WorkingSet> sharedWs(new WorkingSet());
-            IndexScan* ix = new IndexScan(ixparams, sharedWs.get(), NULL);
+            IndexScan* ix = new IndexScan(&_txn, ixparams, sharedWs.get(), NULL);
             auto_ptr<PlanStage> firstRoot(new FetchStage(sharedWs.get(), ix, NULL, coll));
 
             // Plan 1: CollScan with matcher.
@@ -132,7 +132,7 @@ namespace QueryMultiPlanRunner {
             verify(swme.isOK());
             auto_ptr<MatchExpression> filter(swme.getValue());
             // Make the stage.
-            auto_ptr<PlanStage> secondRoot(new CollectionScan(csparams, sharedWs.get(),
+            auto_ptr<PlanStage> secondRoot(new CollectionScan(&_txn, csparams, sharedWs.get(),
                                                               filter.get()));
 
             // Hand the plans off to the runner.
diff --git a/src/mongo/dbtests/query_single_solution_runner.cpp b/src/mongo/dbtests/query_single_solution_runner.cpp
index 91596c5cf49..4f4ddd09570 100644
--- a/src/mongo/dbtests/query_single_solution_runner.cpp
+++ b/src/mongo/dbtests/query_single_solution_runner.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 MongoDB Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -91,7 +91,7 @@ namespace QuerySingleSolutionRunner {
             verify(swme.isOK());
             auto_ptr<MatchExpression> filter(swme.getValue());
             // Make the stage.
-            auto_ptr<PlanStage> root(new CollectionScan(csparams, ws.get(), filter.release()));
+            auto_ptr<PlanStage> root(new CollectionScan(&_txn, csparams, ws.get(), filter.release()));
 
             CanonicalQuery* cq;
             verify(CanonicalQuery::canonicalize(ns(), filterObj, &cq).isOK());
@@ -133,7 +133,7 @@ namespace QuerySingleSolutionRunner {
             const Collection* coll = context.db()->getCollection(&_txn, ns());
 
             auto_ptr<WorkingSet> ws(new WorkingSet());
-            IndexScan* ix = new IndexScan(ixparams, ws.get(), NULL);
+            IndexScan* ix = new IndexScan(&_txn, ixparams, ws.get(), NULL);
             auto_ptr<PlanStage> root(new FetchStage(ws.get(), ix, NULL, coll));
 
             CanonicalQuery* cq;
diff --git a/src/mongo/dbtests/query_stage_and.cpp b/src/mongo/dbtests/query_stage_and.cpp
index 75b144c7e45..a7b77876237 100644
--- a/src/mongo/dbtests/query_stage_and.cpp
+++ b/src/mongo/dbtests/query_stage_and.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -72,8 +72,8 @@ namespace QueryStageAnd {
         }
 
         void getLocs(set<DiskLoc>* out, Collection* coll) {
-            RecordIterator* it = coll->getIterator(DiskLoc(), false,
-                                                       CollectionScanParams::FORWARD);
+            RecordIterator* it = coll->getIterator(&_txn, DiskLoc(), false,
+                                                   CollectionScanParams::FORWARD);
             while (!it->isEOF()) {
                 DiskLoc nextLoc = it->getNext();
                 out->insert(nextLoc);
@@ -154,7 +154,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -162,7 +162,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // ah reads the first child into its hash table.
             // ah should read foo=20, foo=19, ..., foo=0 in that order.
@@ -258,12 +258,12 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar <= 19 (descending)
             params.descriptor = getIndex(BSON("bar" << 1), coll);
             params.bounds.startKey = BSON("" << 19);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // First call to work reads the first result from the children.
             // The first result is for the first scan over foo is {foo: 20, bar: 20, baz: 20}.
@@ -344,7 +344,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -352,7 +352,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // foo == bar == baz, and foo<=20, bar>=10, so our values are:
@@ -399,7 +399,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -407,7 +407,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // Stage execution should fail.
@@ -452,7 +452,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1 << "big" << 1), coll);
@@ -460,7 +460,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // foo == bar == baz, and foo<=20, bar>=10, so our values are:
@@ -500,7 +500,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -508,7 +508,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // 5 <= baz <= 15
             params.descriptor = getIndex(BSON("baz" << 1), coll);
@@ -516,7 +516,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 15);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // foo == bar == baz, and foo<=20, bar>=10, 5<=baz<=15, so our values are:
@@ -567,7 +567,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 10
             params.descriptor = getIndex(BSON("bar" << 1 << "big" << 1), coll);
@@ -575,7 +575,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // 5 <= baz <= 15
             params.descriptor = getIndex(BSON("baz" << 1), coll);
@@ -583,7 +583,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 15);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // Stage execution should fail.
@@ -621,7 +621,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar == 5.  Index scan should be eof.
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -629,7 +629,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 5);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             int count = 0;
             int works = 0;
@@ -682,7 +682,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar <= 100
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -693,7 +693,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << "");
             params.bounds.endKeyInclusive = false;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             ASSERT_EQUALS(0, countResults(ah.get()));
@@ -734,7 +734,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = -1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar >= 95
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -742,7 +742,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSONObj();
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // Bar == 97
@@ -787,11 +787,11 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Scan over bar == 1
             params.descriptor = getIndex(BSON("bar" << 1), coll);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Get the set of disklocs in our collection to use later.
             set<DiskLoc> data;
@@ -914,15 +914,15 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // bar == 1
             params.descriptor = getIndex(BSON("bar" << 1), coll);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // baz == 1
             params.descriptor = getIndex(BSON("baz" << 1), coll);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             ASSERT_EQUALS(50, countResults(ah.get()));
@@ -960,7 +960,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 7);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Bar == 20, not EOF.
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -968,7 +968,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 20);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             ASSERT_EQUALS(0, countResults(ah.get()));
@@ -1009,7 +1009,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 7);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // bar == 20.
             params.descriptor = getIndex(BSON("bar" << 1), coll);
@@ -1017,7 +1017,7 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 20);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             ASSERT_EQUALS(0, countResults(ah.get()));
@@ -1058,11 +1058,11 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // bar == 1
             params.descriptor = getIndex(BSON("bar" << 1), coll);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
             ctx.commit();
 
             // Filter drops everything.
@@ -1100,13 +1100,13 @@ namespace QueryStageAnd {
             params.bounds.endKey = BSON("" << 1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             // Intersect with 7 <= bar < 10000
             params.descriptor = getIndex(BSON("bar" << 1), coll);
             params.bounds.startKey = BSON("" << 7);
             params.bounds.endKey = BSON("" << 10000);
-            ah->addChild(new IndexScan(params, &ws, NULL));
+            ah->addChild(new IndexScan(&_txn, params, &ws, NULL));
 
             WorkingSetID lastId = WorkingSet::INVALID_ID;
 
diff --git a/src/mongo/dbtests/query_stage_collscan.cpp b/src/mongo/dbtests/query_stage_collscan.cpp
index 06088bf425a..415a651babc 100644
--- a/src/mongo/dbtests/query_stage_collscan.cpp
+++ b/src/mongo/dbtests/query_stage_collscan.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -352,7 +352,7 @@ namespace QueryStageCollectionScan {
 
             // Make a scan and have the runner own it.
             WorkingSet* ws = new WorkingSet();
-            PlanStage* ps = new CollectionScan(params, ws, filterExpr.get());
+            PlanStage* ps = new CollectionScan(&_txn, params, ws, filterExpr.get());
             PlanExecutor runner(ws, ps, params.collection);
 
             // Use the runner to count the number of objects scanned.
@@ -371,7 +371,7 @@ namespace QueryStageCollectionScan {
             params.direction = direction;
             params.tailable = false;
 
-            scoped_ptr<CollectionScan> scan(new CollectionScan(params, &ws, NULL));
+            scoped_ptr<CollectionScan> scan(new CollectionScan(&_txn, params, &ws, NULL));
             while (!scan->isEOF()) {
                 WorkingSetID id = WorkingSet::INVALID_ID;
                 PlanStage::StageState state = scan->work(&id);
@@ -457,7 +457,7 @@ namespace QueryStageCollectionScan {
 
             // Make a scan and have the runner own it.
             WorkingSet* ws = new WorkingSet();
-            PlanStage* ps = new CollectionScan(params, ws, NULL);
+            PlanStage* ps = new CollectionScan(&_txn, params, ws, NULL);
             PlanExecutor runner(ws, ps, params.collection);
 
             int count = 0;
@@ -486,7 +486,7 @@ namespace QueryStageCollectionScan {
             params.tailable = false;
 
             WorkingSet* ws = new WorkingSet();
-            PlanStage* ps = new CollectionScan(params, ws, NULL);
+            PlanStage* ps = new CollectionScan(&_txn, params, ws, NULL);
             PlanExecutor runner(ws, ps, params.collection);
 
             int count = 0;
@@ -522,7 +522,7 @@ namespace QueryStageCollectionScan {
             params.tailable = false;
 
             WorkingSet ws;
-            scoped_ptr<CollectionScan> scan(new CollectionScan(params, &ws, NULL));
+            scoped_ptr<CollectionScan> scan(new CollectionScan(&_txn, params, &ws, NULL));
 
             int count = 0;
             while (count < 10) {
@@ -584,7 +584,7 @@ namespace QueryStageCollectionScan {
             params.tailable = false;
 
             WorkingSet ws;
-            scoped_ptr<CollectionScan> scan(new CollectionScan(params, &ws, NULL));
+            scoped_ptr<CollectionScan> scan(new CollectionScan(&_txn, params, &ws, NULL));
 
             int count = 0;
             while (count < 10) {
diff --git a/src/mongo/dbtests/query_stage_count.cpp b/src/mongo/dbtests/query_stage_count.cpp
index b4a86309568..6a7a039008e 100644
--- a/src/mongo/dbtests/query_stage_count.cpp
+++ b/src/mongo/dbtests/query_stage_count.cpp
@@ -129,7 +129,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
 
             int numCounted = runCount(&count);
             ASSERT_EQUALS(2, numCounted);
@@ -162,7 +162,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
 
             int numCounted = runCount(&count);
             ASSERT_EQUALS(5, numCounted);
@@ -195,7 +195,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = false;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
 
             int numCounted = runCount(&count);
             ASSERT_EQUALS(3, numCounted);
@@ -224,7 +224,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = false;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             
             int numCounted = runCount(&count);
             ASSERT_EQUALS(0, numCounted);
@@ -254,7 +254,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = false;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             
             int numCounted = runCount(&count);
             ASSERT_EQUALS(0, numCounted);
@@ -285,7 +285,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             
             int numCounted = runCount(&count);
             ASSERT_EQUALS(0, numCounted);
@@ -317,7 +317,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             WorkingSetID wsid;
 
             int numCounted = 0;
@@ -369,7 +369,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             WorkingSetID wsid;
 
             int numCounted = 0;
@@ -424,7 +424,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             WorkingSetID wsid;
 
             int numCounted = 0;
@@ -482,7 +482,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             WorkingSetID wsid;
 
             int numCounted = 0;
@@ -541,7 +541,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
 
             int numCounted = runCount(&count);
             ASSERT_EQUALS(7, numCounted);
@@ -575,7 +575,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true; // yes?
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
 
             int numCounted = runCount(&count);
             ASSERT_EQUALS(9, numCounted);
@@ -606,7 +606,7 @@ namespace QueryStageCount {
             params.endKeyInclusive = true;
 
             WorkingSet ws;
-            Count count(params, &ws);
+            Count count(&_txn, params, &ws);
             WorkingSetID wsid;
 
             int numCounted = 0;
diff --git a/src/mongo/dbtests/query_stage_distinct.cpp b/src/mongo/dbtests/query_stage_distinct.cpp
index ac61fc55fce..ccf03b58bf3 100644
--- a/src/mongo/dbtests/query_stage_distinct.cpp
+++ b/src/mongo/dbtests/query_stage_distinct.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -145,7 +145,7 @@ namespace QueryStageDistinct {
             params.bounds.fields.push_back(oil);
 
             WorkingSet ws;
-            DistinctScan* distinct = new DistinctScan(params, &ws);
+            DistinctScan* distinct = new DistinctScan(&_txn, params, &ws);
 
             WorkingSetID wsid;
             // Get our first result.
@@ -210,7 +210,7 @@ namespace QueryStageDistinct {
             params.bounds.fields.push_back(oil);
 
             WorkingSet ws;
-            DistinctScan* distinct = new DistinctScan(params, &ws);
+            DistinctScan* distinct = new DistinctScan(&_txn, params, &ws);
 
             // We should see each number in the range [1, 6] exactly once.
             std::set<int> seen;
diff --git a/src/mongo/dbtests/query_stage_fetch.cpp b/src/mongo/dbtests/query_stage_fetch.cpp
index bc95554164a..e758afe8518 100644
--- a/src/mongo/dbtests/query_stage_fetch.cpp
+++ b/src/mongo/dbtests/query_stage_fetch.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -57,8 +57,8 @@ namespace QueryStageFetch {
         }
 
         void getLocs(set<DiskLoc>* out, Collection* coll) {
-            RecordIterator* it = coll->getIterator(DiskLoc(), false,
-                                                       CollectionScanParams::FORWARD);
+            RecordIterator* it = coll->getIterator(&_txn, DiskLoc(), false,
+                                                   CollectionScanParams::FORWARD);
             while (!it->isEOF()) {
                 DiskLoc nextLoc = it->getNext();
                 out->insert(nextLoc);
diff --git a/src/mongo/dbtests/query_stage_keep.cpp b/src/mongo/dbtests/query_stage_keep.cpp
index eca675d6966..9eced015261 100644
--- a/src/mongo/dbtests/query_stage_keep.cpp
+++ b/src/mongo/dbtests/query_stage_keep.cpp
@@ -61,8 +61,8 @@ namespace QueryStageKeep {
         }
 
         void getLocs(set<DiskLoc>* out, Collection* coll) {
-            RecordIterator* it = coll->getIterator(DiskLoc(), false,
-                                                       CollectionScanParams::FORWARD);
+            RecordIterator* it = coll->getIterator(&_txn, DiskLoc(), false,
+                                                   CollectionScanParams::FORWARD);
             while (!it->isEOF()) {
                 DiskLoc nextLoc = it->getNext();
                 out->insert(nextLoc);
@@ -135,7 +135,7 @@ namespace QueryStageKeep {
             params.direction = CollectionScanParams::FORWARD;
             params.tailable = false;
             params.start = DiskLoc();
-            CollectionScan* cs = new CollectionScan(params, &ws, NULL);
+            CollectionScan* cs = new CollectionScan(&_txn, params, &ws, NULL);
 
             // Create a KeepMutations stage to merge in the 10 flagged objects.
             // Takes ownership of 'cs'
diff --git a/src/mongo/dbtests/query_stage_merge_sort.cpp b/src/mongo/dbtests/query_stage_merge_sort.cpp
index 2aa83912515..0a1492c4b0d 100644
--- a/src/mongo/dbtests/query_stage_merge_sort.cpp
+++ b/src/mongo/dbtests/query_stage_merge_sort.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -74,8 +74,10 @@ namespace QueryStageMergeSortTests {
         }
 
         void getLocs(set<DiskLoc>* out, Collection* coll) {
-            RecordIterator* it = coll->getIterator(DiskLoc(), false,
-                                                       CollectionScanParams::FORWARD);
+            RecordIterator* it = coll->getIterator(&_txn,
+                                                   DiskLoc(),
+                                                   false,
+                                                   CollectionScanParams::FORWARD);
             while (!it->isEOF()) {
                 DiskLoc nextLoc = it->getNext();
                 out->insert(nextLoc);
@@ -145,11 +147,11 @@ namespace QueryStageMergeSortTests {
             params.bounds.endKey = objWithMaxKey(1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
 
             // b:1
             params.descriptor = getIndex(secondIndex, coll);
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             ctx.commit();
 
             // Must fetch if we want to easily pull out an obj.
@@ -209,11 +211,11 @@ namespace QueryStageMergeSortTests {
             params.bounds.endKey = objWithMaxKey(1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
 
             // b:1
             params.descriptor = getIndex(secondIndex, coll);
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             ctx.commit();
 
             PlanExecutor runner(ws, new FetchStage(ws, ms, NULL, coll), coll);
@@ -272,11 +274,11 @@ namespace QueryStageMergeSortTests {
             params.bounds.endKey = objWithMaxKey(1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
 
             // b:1
             params.descriptor = getIndex(secondIndex, coll);
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             ctx.commit();
 
             PlanExecutor runner(ws, new FetchStage(ws, ms, NULL, coll), coll);
@@ -338,11 +340,11 @@ namespace QueryStageMergeSortTests {
             params.bounds.endKeyInclusive = true;
             // This is the direction along the index.
             params.direction = 1;
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
 
             // b:1
             params.descriptor = getIndex(secondIndex, coll);
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             ctx.commit();
 
             PlanExecutor runner(ws, new FetchStage(ws, ms, NULL, coll), coll);
@@ -401,13 +403,13 @@ namespace QueryStageMergeSortTests {
             params.bounds.endKey = objWithMaxKey(1);
             params.bounds.endKeyInclusive = true;
             params.direction = 1;
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
 
             // b:51 (EOF)
             params.descriptor = getIndex(secondIndex, coll);
             params.bounds.startKey = BSON("" << 51 << "" << MinKey);
             params.bounds.endKey = BSON("" << 51 << "" << MaxKey);
-            ms->addChild(new IndexScan(params, ws, NULL));
+            ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             ctx.commit();
 
             PlanExecutor runner(ws, new FetchStage(ws, ms, NULL, coll), coll);
@@ -459,7 +461,7 @@ namespace QueryStageMergeSortTests {
                 BSONObj indexSpec = BSON(index << 1 << "foo" << 1);
                 addIndex(indexSpec);
                 params.descriptor = getIndex(indexSpec, coll);
-                ms->addChild(new IndexScan(params, ws, NULL));
+                ms->addChild(new IndexScan(&_txn, params, ws, NULL));
             }
             ctx.commit();
 
@@ -514,7 +516,7 @@ namespace QueryStageMergeSortTests {
                 BSONObj indexSpec = BSON(index << 1 << "foo" << 1);
                 addIndex(indexSpec);
                 params.descriptor = getIndex(indexSpec, coll);
-                ms->addChild(new IndexScan(params, &ws, NULL));
+                ms->addChild(new IndexScan(&_txn, params, &ws, NULL));
             }
 
             set<DiskLoc> locs;
diff --git a/src/mongo/dbtests/query_stage_sort.cpp b/src/mongo/dbtests/query_stage_sort.cpp
index 60838f5df77..81e500cb238 100644
--- a/src/mongo/dbtests/query_stage_sort.cpp
+++ b/src/mongo/dbtests/query_stage_sort.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -66,8 +66,8 @@ namespace QueryStageSortTests {
         }
 
         void getLocs(set<DiskLoc>* out, Collection* coll) {
-            RecordIterator* it = coll->getIterator(DiskLoc(), false,
-                                                       CollectionScanParams::FORWARD);
+            RecordIterator* it = coll->getIterator(&_txn, DiskLoc(), false,
+                                                   CollectionScanParams::FORWARD);
             while (!it->isEOF()) {
                 DiskLoc nextLoc = it->getNext();
                 out->insert(nextLoc);
diff --git a/src/mongo/dbtests/query_stage_tests.cpp b/src/mongo/dbtests/query_stage_tests.cpp
index 91640817f74..24b0ef3db1e 100644
--- a/src/mongo/dbtests/query_stage_tests.cpp
+++ b/src/mongo/dbtests/query_stage_tests.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -83,7 +83,7 @@ namespace QueryStageTests {
 
             WorkingSet* ws = new WorkingSet();
             PlanExecutor runner(ws, 
-                                new IndexScan(params, ws, filterExpr.get()), 
+                                new IndexScan(&_txn, params, ws, filterExpr.get()), 
                                 ctx.ctx().db()->getCollection(&_txn, ns()));
 
             int count = 0;
diff --git a/src/mongo/dbtests/repltests.cpp b/src/mongo/dbtests/repltests.cpp
index 4694c942f73..4580b5682d2 100644
--- a/src/mongo/dbtests/repltests.cpp
+++ b/src/mongo/dbtests/repltests.cpp
@@ -2,7 +2,7 @@
 //
 
 /**
- *    Copyright (C) 2009 10gen Inc.
+ *    Copyright (C) 2009-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -133,8 +133,8 @@ namespace ReplTests {
             }
 
             int count = 0;
-            RecordIterator* it = coll->getIterator( DiskLoc(), false,
-                                                        CollectionScanParams::FORWARD );
+            RecordIterator* it = coll->getIterator( &_txn, DiskLoc(), false,
+                                                    CollectionScanParams::FORWARD );
             for ( ; !it->isEOF(); it->getNext() ) {
                 ++count;
             }
@@ -154,8 +154,8 @@ namespace ReplTests {
             }
 
             int count = 0;
-            RecordIterator* it = coll->getIterator( DiskLoc(), false,
-                                                        CollectionScanParams::FORWARD );
+            RecordIterator* it = coll->getIterator( &txn, DiskLoc(), false,
+                                                    CollectionScanParams::FORWARD );
             for ( ; !it->isEOF(); it->getNext() ) {
                 ++count;
             }
@@ -173,8 +173,8 @@ namespace ReplTests {
                 Database* db = ctx.db();
                 Collection* coll = db->getCollection( &txn, cllNS() );
 
-                RecordIterator* it = coll->getIterator( DiskLoc(), false,
-                                                            CollectionScanParams::FORWARD );
+                RecordIterator* it = coll->getIterator( &txn, DiskLoc(), false,
+                                                        CollectionScanParams::FORWARD );
                 while ( !it->isEOF() ) {
                     DiskLoc currLoc = it->getNext();
                     ops.push_back(coll->docFor(currLoc));
@@ -208,8 +208,8 @@ namespace ReplTests {
                 coll = db->createCollection( &txn, ns );
             }
 
-            RecordIterator* it = coll->getIterator( DiskLoc(), false,
-                                                        CollectionScanParams::FORWARD );
+            RecordIterator* it = coll->getIterator( &txn, DiskLoc(), false,
+                                                    CollectionScanParams::FORWARD );
             ::mongo::log() << "all for " << ns << endl;
             while ( !it->isEOF() ) {
                 DiskLoc currLoc = it->getNext();
@@ -231,8 +231,8 @@ namespace ReplTests {
             }
 
             vector< DiskLoc > toDelete;
-            RecordIterator* it = coll->getIterator( DiskLoc(), false,
-                                                        CollectionScanParams::FORWARD );
+            RecordIterator* it = coll->getIterator( &txn, DiskLoc(), false,
+                                                    CollectionScanParams::FORWARD );
             while ( !it->isEOF() ) {
                 toDelete.push_back( it->getNext() );
             }
diff --git a/src/mongo/dbtests/runner_registry.cpp b/src/mongo/dbtests/runner_registry.cpp
index a6c2b4dfac6..970027d9450 100644
--- a/src/mongo/dbtests/runner_registry.cpp
+++ b/src/mongo/dbtests/runner_registry.cpp
@@ -1,5 +1,5 @@
 /**
- *    Copyright (C) 2013 10gen Inc.
+ *    Copyright (C) 2013-2014 MongoDB Inc.
  *
  *    This program is free software: you can redistribute it and/or  modify
  *    it under the terms of the GNU Affero General Public License, version 3,
@@ -75,7 +75,7 @@ namespace RunnerRegistry {
             params.collection = collection();
             params.direction = CollectionScanParams::FORWARD;
             params.tailable = false;
-            auto_ptr<CollectionScan> scan(new CollectionScan(params, ws.get(), NULL));
+            auto_ptr<CollectionScan> scan(new CollectionScan(&_opCtx, params, ws.get(), NULL));
 
             // Create a runner to hold it
             CanonicalQuery* cq;
diff --git a/src/mongo/s/d_migrate.cpp b/src/mongo/s/d_migrate.cpp
index 2d4cc1eacca..2fb6aa8be8f 100644
--- a/src/mongo/s/d_migrate.cpp
+++ b/src/mongo/s/d_migrate.cpp
@@ -1,7 +1,7 @@
 // d_migrate.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -417,7 +417,7 @@ namespace mongo {
             BSONObj min = Helpers::toKeyFormat( kp.extendRangeBound( _min, false ) );
             BSONObj max = Helpers::toKeyFormat( kp.extendRangeBound( _max, false ) );
 
-            auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, idx, min, max, false));
+            auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, idx, min, max, false));
 
             // use the average object size to estimate how many objects a full chunk would carry
             // do that while traversing the chunk's range using the sharding index, below
diff --git a/src/mongo/s/d_split.cpp b/src/mongo/s/d_split.cpp
index 7dde165002c..3233cfefd88 100644
--- a/src/mongo/s/d_split.cpp
+++ b/src/mongo/s/d_split.cpp
@@ -1,7 +1,7 @@
 // @file  d_split.cpp
 
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -146,7 +146,7 @@ namespace mongo {
                 max = Helpers::toKeyFormat( kp.extendRangeBound( max, false ) );
             }
 
-            auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, idx, min, max,
+            auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, idx, min, max,
                                                                false, InternalPlanner::FORWARD));
 
             // Find the 'missingField' value used to represent a missing document field in a key of
@@ -377,7 +377,7 @@ namespace mongo {
                 long long currCount = 0;
                 long long numChunks = 0;
                 
-                auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, idx, min, max,
+                auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, idx, min, max,
                     false, InternalPlanner::FORWARD));
 
                 BSONObj currKey;
@@ -435,7 +435,7 @@ namespace mongo {
                     currCount = 0;
                     log() << "splitVector doing another cycle because of force, keyCount now: " << keyCount << endl;
 
-                    runner.reset(InternalPlanner::indexScan(collection, idx, min, max,
+                    runner.reset(InternalPlanner::indexScan(txn, collection, idx, min, max,
                                                             false, InternalPlanner::FORWARD));
 
                     state = runner->getNext(&currKey, NULL);
@@ -879,7 +879,7 @@ namespace mongo {
                     BSONObj newmin = Helpers::toKeyFormat( kp.extendRangeBound( chunk.min, false) );
                     BSONObj newmax = Helpers::toKeyFormat( kp.extendRangeBound( chunk.max, false) );
 
-                    auto_ptr<Runner> runner(InternalPlanner::indexScan(collection, idx,
+                    auto_ptr<Runner> runner(InternalPlanner::indexScan(txn, collection, idx,
                                                                        newmin, newmax, false));
 
                     // check if exactly one document found
diff --git a/src/mongo/tools/dump.cpp b/src/mongo/tools/dump.cpp
index ba3ff655092..0b6eafb2e58 100644
--- a/src/mongo/tools/dump.cpp
+++ b/src/mongo/tools/dump.cpp
@@ -1,5 +1,5 @@
 /**
-*    Copyright (C) 2008 10gen Inc.
+*    Copyright (C) 2008-2014 MongoDB Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
@@ -292,8 +292,8 @@ public:
         return _repairByName(toolGlobalParams.db);
     }
     
-    void _repairExtents(Collection* coll, Writer& writer) {
-        scoped_ptr<RecordIterator> iter(coll->getRecordStore()->getIteratorForRepair());
+    void _repairExtents(OperationContext* opCtx, Collection* coll, Writer& writer) {
+        scoped_ptr<RecordIterator> iter(coll->getRecordStore()->getIteratorForRepair(opCtx));
 
         for (DiskLoc currLoc = iter->getNext(); !currLoc.isNull(); currLoc = iter->getNext()) {
             if (logger::globalLogDomain()->shouldLog(logger::LogSeverity::Debug(1))) {
@@ -359,7 +359,7 @@ public:
         Writer w( f , &m );
 
         try {
-            _repairExtents(collection, w);
+            _repairExtents(opCtx, collection, w);
         }
         catch ( DBException& e ){
             toolError() << "Repair scan failed: " << e.toString() << std::endl;