SERVER-16431 Simplify DB profile code

12 files changed, 197 insertions, 225 deletions

diff --git a/src/mongo/db/catalog/database.cpp b/src/mongo/db/catalog/database.cpp
index 24c0ea01821..4d873eca3e2 100644
--- a/src/mongo/db/catalog/database.cpp
+++ b/src/mongo/db/catalog/database.cpp
@@ -249,25 +249,28 @@ namespace mongo {
         }
     }
 
-    bool Database::setProfilingLevel( OperationContext* txn, int newLevel , string& errmsg ) {
-        if ( _profile == newLevel )
-            return true;
-
-        if ( newLevel < 0 || newLevel > 2 ) {
-            errmsg = "profiling level has to be >=0 and <= 2";
-            return false;
+    Status Database::setProfilingLevel(OperationContext* txn, int newLevel) {
+        if (_profile == newLevel) {
+            return Status::OK();
         }
 
-        if ( newLevel == 0 ) {
+        if (newLevel == 0) {
             _profile = 0;
-            return true;
+            return Status::OK();
         }
 
-        if (!getOrCreateProfileCollection(txn, this, true, &errmsg))
-            return false;
+        if (newLevel < 0 || newLevel > 2) {
+            return Status(ErrorCodes::BadValue, "profiling level has to be >=0 and <= 2");
+        }
+
+        Status status = createProfileCollection(txn, this);
+        if (!status.isOK()) {
+            return status;
+        }
 
         _profile = newLevel;
-        return true;
+
+        return Status::OK();
     }
 
     void Database::getStats( OperationContext* opCtx, BSONObjBuilder* output, double scale ) {
diff --git a/src/mongo/db/catalog/database.h b/src/mongo/db/catalog/database.h
index 23354d3e307..ea4c2e80724 100644
--- a/src/mongo/db/catalog/database.h
+++ b/src/mongo/db/catalog/database.h
@@ -69,9 +69,12 @@ namespace mongo {
         void clearTmpCollections(OperationContext* txn);
 
         /**
-         * @return true if success.  false if bad level or error creating profile ns
+         * Sets a new profiling level for the database and returns the outcome.
+         *
+         * @param txn Operation context which to use for creating the profiling collection.
+         * @param newLevel New profiling level to use.
          */
-        bool setProfilingLevel( OperationContext* txn, int newLevel , std::string& errmsg );
+        Status setProfilingLevel(OperationContext* txn, int newLevel);
 
         /**
          * @return true if ns is part of the database
diff --git a/src/mongo/db/catalog/database_holder.cpp b/src/mongo/db/catalog/database_holder.cpp
index c924375ef0a..dc7bd5106c5 100644
--- a/src/mongo/db/catalog/database_holder.cpp
+++ b/src/mongo/db/catalog/database_holder.cpp
@@ -30,13 +30,15 @@
 
 #include "mongo/platform/basic.h"
 
+#include "mongo/db/catalog/database_holder.h"
+
 #include "mongo/db/audit.h"
 #include "mongo/db/auth/auth_index_d.h"
 #include "mongo/db/background.h"
 #include "mongo/db/client.h"
 #include "mongo/db/clientcursor.h"
+#include "mongo/db/catalog/database.h"
 #include "mongo/db/catalog/database_catalog_entry.h"
-#include "mongo/db/catalog/database_holder.h"
 #include "mongo/db/global_environment_experiment.h"
 #include "mongo/db/operation_context.h"
 #include "mongo/db/storage/storage_engine.h"
@@ -44,11 +46,9 @@
 #include "mongo/util/log.h"
 
 namespace mongo {
-
-    static DatabaseHolder _dbHolder;
-
 namespace {
-    static StringData _todb(const StringData& ns) {
+
+    StringData _todb(const StringData& ns) {
         size_t i = ns.find('.');
         if (i == std::string::npos) {
             uassert(13074, "db name can't be empty", ns.size());
@@ -62,12 +62,18 @@ namespace {
 
         return d;
     }
-}
+
+
+    DatabaseHolder _dbHolder;
+
+} // namespace
+
 
     DatabaseHolder& dbHolder() {
         return _dbHolder;
     }
 
+
     Database* DatabaseHolder::get(OperationContext* txn,
                                   const StringData& ns) const {
 
diff --git a/src/mongo/db/catalog/database_holder.h b/src/mongo/db/catalog/database_holder.h
index dd3afdf2470..6ad69c5bef2 100644
--- a/src/mongo/db/catalog/database_holder.h
+++ b/src/mongo/db/catalog/database_holder.h
@@ -28,13 +28,17 @@
 
 #pragma once
 
+#include <set>
+
 #include "mongo/base/string_data.h"
-#include "mongo/db/catalog/database.h"
 #include "mongo/db/namespace_string.h"
+#include "mongo/util/concurrency/mutex.h"
 #include "mongo/util/string_map.h"
 
 namespace mongo {
 
+    class Database;
+
     /**
      * Registry of opened databases.
      */
diff --git a/src/mongo/db/client.h b/src/mongo/db/client.h
index 3703d555ff2..2296fd58c9b 100644
--- a/src/mongo/db/client.h
+++ b/src/mongo/db/client.h
@@ -55,7 +55,6 @@ namespace mongo {
     class AuthenticationInfo;
     class Database;
     class CurOp;
-    class Client;
     class Collection;
     class AbstractMessagingPort;
     class Locker;
diff --git a/src/mongo/db/commands/write_commands/batch_executor.cpp b/src/mongo/db/commands/write_commands/batch_executor.cpp
index 956f17a9c0b..31a5923ef3a 100644
--- a/src/mongo/db/commands/write_commands/batch_executor.cpp
+++ b/src/mongo/db/commands/write_commands/batch_executor.cpp
@@ -638,8 +638,8 @@ namespace mongo {
             LOG(0) << currentOp->debug().report( *currentOp ) << endl;
         }
 
-        if ( currentOp->shouldDBProfile( executionTime ) ) {
-            profile( txn, *txn->getClient(), currentOp->getOp(), *currentOp );
+        if (currentOp->shouldDBProfile(executionTime)) {
+            profile(txn, txn->getCurOp()->getOp());
         }
     }
 
diff --git a/src/mongo/db/dbcommands.cpp b/src/mongo/db/dbcommands.cpp
index 19958e19d21..90d38d20e00 100644
--- a/src/mongo/db/dbcommands.cpp
+++ b/src/mongo/db/dbcommands.cpp
@@ -341,10 +341,16 @@ namespace mongo {
 
         }
 
-        bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl) {
+        bool run(OperationContext* txn,
+                 const string& dbname,
+                 BSONObj& cmdObj,
+                 int options,
+                 string& errmsg,
+                 BSONObjBuilder& result,
+                 bool fromRepl) {
+
             // Needs to be locked exclusively, because creates the system.profile collection
             // in the local database.
-            //
             ScopedTransaction transaction(txn, MODE_IX);
             Lock::DBLock dbXLock(txn->lockState(), dbname, MODE_X);
             Client::Context ctx(txn, dbname);
@@ -354,21 +360,26 @@ namespace mongo {
             result.append("slowms", serverGlobalParams.slowMS);
 
             int p = (int) e.number();
-            bool ok = false;
+            Status status = Status::OK();
 
-            if ( p == -1 )
-                ok = true;
+            if (p == -1)
+                status = Status::OK();
             else if ( p >= 0 && p <= 2 ) {
-                ok = ctx.db()->setProfilingLevel( txn, p , errmsg );
+                status = ctx.db()->setProfilingLevel(txn, p);
             }
 
-            BSONElement slow = cmdObj["slowms"];
+            const BSONElement slow = cmdObj["slowms"];
             if (slow.isNumber()) {
                 serverGlobalParams.slowMS = slow.numberInt();
             }
 
-            return ok;
+            if (!status.isOK()) {
+                errmsg = status.reason();
+            }
+
+            return status.isOK();
         }
+
     } cmdProfile;
 
     class CmdDiagLogging : public Command {
diff --git a/src/mongo/db/dbeval.cpp b/src/mongo/db/dbeval.cpp
index 72d7ebcd977..b873b64b760 100644
--- a/src/mongo/db/dbeval.cpp
+++ b/src/mongo/db/dbeval.cpp
@@ -32,16 +32,16 @@
 
 #include "mongo/platform/basic.h"
 
-#include <time.h>
-
 #include "mongo/bson/util/builder.h"
 #include "mongo/db/auth/authorization_manager.h"
 #include "mongo/db/auth/authorization_manager_global.h"
 #include "mongo/db/auth/authorization_session.h"
+#include "mongo/db/client.h"
 #include "mongo/db/commands.h"
 #include "mongo/db/introspect.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/json.h"
+#include "mongo/db/operation_context.h"
 #include "mongo/scripting/engine.h"
 #include "mongo/util/log.h"
 
@@ -153,6 +153,7 @@ namespace mongo {
 
             ScopedTransaction transaction(txn, MODE_X);
             Lock::GlobalWrite lk(txn->lockState());
+
             // No WriteUnitOfWork necessary, as dbEval will create its own, see "nolock" case above
             Client::Context ctx(txn,  dbname );
 
diff --git a/src/mongo/db/instance.cpp b/src/mongo/db/instance.cpp
index aad9da30096..ccc949ed6f0 100644
--- a/src/mongo/db/instance.cpp
+++ b/src/mongo/db/instance.cpp
@@ -489,17 +489,12 @@ namespace {
         }
 
         if ( currentOp.shouldDBProfile( debug.executionTime ) ) {
-            // performance profiling is on
-            if (txn->lockState()->isReadLocked()) {
-                MONGO_LOG_COMPONENT(1, logComponentForOp(op))
-                        << "note: not profiling because recursive read lock" << endl;
-            }
-            else if ( lockedForWriting() ) {
+            if (lockedForWriting()) {
                 MONGO_LOG_COMPONENT(1, logComponentForOp(op))
                         << "note: not profiling because doing fsync+lock" << endl;
             }
             else {
-                profile(txn, c, op, currentOp);
+                profile(txn, op);
             }
         }
 
diff --git a/src/mongo/db/introspect.cpp b/src/mongo/db/introspect.cpp
index 6dd6c323a99..65a5bee8c86 100644
--- a/src/mongo/db/introspect.cpp
+++ b/src/mongo/db/introspect.cpp
@@ -1,53 +1,49 @@
-// introspect.cpp
-
 /**
-*    Copyright (C) 2008 10gen 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,
-*    as published by the Free Software Foundation.
-*
-*    This program is distributed in the hope that it will be useful,
-*    but WITHOUT ANY WARRANTY; without even the implied warranty of
-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-*    GNU Affero General Public License for more details.
-*
-*    You should have received a copy of the GNU Affero General Public License
-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*
-*    As a special exception, the copyright holders give permission to link the
-*    code of portions of this program with the OpenSSL library under certain
-*    conditions as described in each individual source file and distribute
-*    linked combinations including the program with the OpenSSL library. You
-*    must comply with the GNU Affero General Public License in all respects for
-*    all of the code used other than as permitted herein. If you modify file(s)
-*    with this exception, you may extend this exception to your version of the
-*    file(s), but you are not obligated to do so. If you do not wish to do so,
-*    delete this exception statement from your version. If you delete this
-*    exception statement from all source files in the program, then also delete
-*    it in the license file.
-*/
+ *    Copyright (C) 2008 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,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
 
 #define MONGO_LOG_DEFAULT_COMPONENT ::mongo::logger::LogComponent::kDefault
 
-#include "mongo/pch.h"
+#include "mongo/platform/basic.h"
+
+#include "mongo/db/introspect.h"
 
 #include "mongo/bson/util/builder.h"
 #include "mongo/db/auth/authorization_manager.h"
 #include "mongo/db/auth/authorization_session.h"
 #include "mongo/db/auth/user_set.h"
 #include "mongo/db/curop.h"
-#include "mongo/db/catalog/database_holder.h"
-#include "mongo/db/introspect.h"
 #include "mongo/db/jsobj.h"
-#include "mongo/db/storage_options.h"
 #include "mongo/db/catalog/collection.h"
-#include "mongo/util/goodies.h"
 #include "mongo/util/log.h"
 
 namespace mongo {
-
 namespace {
+
     void _appendUserInfo(const CurOp& c,
                          BSONObjBuilder& builder,
                          AuthorizationSession* authSession) {
@@ -75,141 +71,110 @@ namespace {
         builder.append("user", bestUser.getUser().empty() ? "" : bestUser.getFullName());
 
     }
+
 } // namespace
 
-    /**
-     * @return if collection existed or was created
-     */
-    static bool _profile(OperationContext* txn,
-                         const Client& c,
-                         Database* db,
-                         CurOp& currentOp,
-                         BufBuilder& profileBufBuilder) {
-        dassert( db );
-
-        // build object
+
+    void profile(OperationContext* txn, int op) {
+        // initialize with 1kb to start, to avoid realloc later
+        BufBuilder profileBufBuilder(1024);
+
         BSONObjBuilder b(profileBufBuilder);
 
-        currentOp.debug().append(currentOp, b);
+        txn->getCurOp()->debug().append(*txn->getCurOp(), b);
 
         b.appendDate("ts", jsTime());
-        b.append("client", c.clientAddress());
+        b.append("client", txn->getClient()->clientAddress());
 
-        AuthorizationSession * authSession = c.getAuthorizationSession();
-        _appendUserInfo(currentOp, b, authSession);
+        AuthorizationSession * authSession = txn->getClient()->getAuthorizationSession();
+        _appendUserInfo(*txn->getCurOp(), b, authSession);
 
         BSONObj p = b.done();
 
-        WriteUnitOfWork wunit(txn);
+        const string dbName(nsToDatabase(txn->getCurOp()->getNS()));
 
-        // write: not replicated
-        // get or create the profiling collection
-        Collection* profileCollection = getOrCreateProfileCollection(txn, db);
-        if ( !profileCollection ) {
-            return false;
-        }
-        profileCollection->insertDocument( txn, p, false );
-        wunit.commit();
-        return true;
-    }
+        try {
+            bool acquireDbXLock = false;
+            while (true) {
+                ScopedTransaction scopedXact(txn, MODE_IX);
 
-    void profile(OperationContext* txn, const Client& c, int op, CurOp& currentOp) {
-        bool tryAgain = false;
-        while ( 1 ) {
-            try {
-                // initialize with 1kb to start, to avoid realloc later
-                // doing this outside the dblock to improve performance
-                BufBuilder profileBufBuilder(1024);
-
-                // NOTE: It's kind of weird that we lock the op's namespace, but have to for now
-                // since we're sometimes inside the lock already
-                const string dbname(nsToDatabase(currentOp.getNS()));
-                scoped_ptr<Lock::DBLock> lk;
-
-                // todo: this can be slow, perhaps can re-work
-                if ( !txn->lockState()->isDbLockedForMode( dbname, MODE_IX ) ) {
-                    lk.reset( new Lock::DBLock( txn->lockState(),
-                                                dbname,
-                                                tryAgain ? MODE_X : MODE_IX) );
-                }
-                Database* db = dbHolder().get(txn, dbname);
-                if (db != NULL) {
-                    Lock::CollectionLock clk(txn->lockState(), db->getProfilingNS(), MODE_X);
-                    Client::Context cx(txn, currentOp.getNS(), false);
-                    if ( !_profile(txn, c, cx.db(), currentOp, profileBufBuilder ) && lk.get() ) {
-                        if ( tryAgain ) {
-                            // we couldn't profile, but that's ok, we should have logged already
-                            break;
-                        }
-                        // we took an IX lock, so now we try again with an X lock
-                        tryAgain = true;
-                        continue;
+                boost::scoped_ptr<AutoGetDb> autoGetDb;
+                if (acquireDbXLock) {
+                    autoGetDb.reset(new AutoGetDb(txn, dbName, MODE_X));
+                    if (autoGetDb->getDb()) {
+                        createProfileCollection(txn, autoGetDb->getDb());
                     }
                 }
                 else {
-                    mongo::log() << "note: not profiling because db went away - "
-                                 << "probably a close on: " << currentOp.getNS();
+                    autoGetDb.reset(new AutoGetDb(txn, dbName, MODE_IX));
+                }
+
+                Database* const db = autoGetDb->getDb();
+                if (!db) {
+                    // Database disappeared
+                    log() << "note: not profiling because db went away for "
+                          << txn->getCurOp()->getNS();
+                    break;
+                }
+
+                Lock::CollectionLock collLock(txn->lockState(), db->getProfilingNS(), MODE_IX);
+
+                Collection* const coll = db->getCollection(txn, db->getProfilingNS());
+                if (coll) {
+                    WriteUnitOfWork wuow(txn);
+                    coll->insertDocument(txn, p, false);
+                    wuow.commit();
+
+                    break;
+                }
+                else if (!acquireDbXLock && !txn->lockState()->isLocked()) {
+                    // Try to create the collection only if we are not under lock, in order to
+                    // avoid deadlocks due to lock conversion. This would only be hit if someone
+                    // deletes the profiler collection after setting profile level.
+                    acquireDbXLock = true;
+                }
+                else {
+                    // Cannot write the profile information
+                    break;
                 }
-                return;
-            }
-            catch (const AssertionException& assertionEx) {
-                warning() << "Caught Assertion while trying to profile " << opToString(op)
-                          << " against " << currentOp.getNS()
-                          << ": " << assertionEx.toString() << endl;
-                return;
             }
         }
+        catch (const AssertionException& assertionEx) {
+            warning() << "Caught Assertion while trying to profile "
+                      << opToString(op)
+                      << " against " << txn->getCurOp()->getNS()
+                      << ": " << assertionEx.toString() << endl;
+        }
     }
 
-    Collection* getOrCreateProfileCollection(OperationContext* txn,
-                                             Database *db,
-                                             bool force,
-                                             string* errmsg ) {
-        fassert(16372, db);
-        const char* profileName = db->getProfilingNS();
-        Collection* collection = db->getCollection( txn, profileName );
-
-        if ( collection ) {
-            if ( !collection->isCapped() ) {
-                string myerrmsg = str::stream() << profileName << " exists but isn't capped";
-                log() << myerrmsg << endl;
-                if ( errmsg )
-                    *errmsg = myerrmsg;
-                return NULL;
-            }
-            return collection;
-        }
 
-        // does not exist!
+    Status createProfileCollection(OperationContext* txn, Database *db) {
+        invariant(txn->lockState()->isDbLockedForMode(db->name(), MODE_X));
+
+        const std::string dbProfilingNS(db->getProfilingNS());
 
-        if ( force == false && serverGlobalParams.defaultProfile == false ) {
-            // we don't want it, so why are we here?
-            static time_t last = time(0) - 10;  // warn the first time
-            if( time(0) > last+10 ) {
-                log() << "profile: warning ns " << profileName << " does not exist" << endl;
-                last = time(0);
+        Collection* const collection = db->getCollection(txn, dbProfilingNS);
+        if (collection) {
+            if (!collection->isCapped()) {
+                return Status(ErrorCodes::NamespaceExists,
+                              str::stream() << dbProfilingNS << " exists but isn't capped");
             }
-            return NULL;
-        }
 
-        if ( !txn->lockState()->isDbLockedForMode( db->name(), MODE_X ) ) {
-            // can't create here
-            return NULL;
+            return Status::OK();
         }
 
         // system.profile namespace doesn't exist; create it
-        log() << "creating profile collection: " << profileName << endl;
+        log() << "Creating profile collection: " << dbProfilingNS << endl;
 
         CollectionOptions collectionOptions;
         collectionOptions.capped = true;
         collectionOptions.cappedSize = 1024 * 1024;
 
         WriteUnitOfWork wunit(txn);
-        collection = db->createCollection( txn, profileName, collectionOptions );
-        invariant( collection );
+        invariant(db->createCollection(txn, dbProfilingNS, collectionOptions));
         wunit.commit();
 
-        return collection;
+        return Status::OK();
     }
 
 } // namespace mongo
diff --git a/src/mongo/db/introspect.h b/src/mongo/db/introspect.h
index 07af4ba6653..2a6ec2a477f 100644
--- a/src/mongo/db/introspect.h
+++ b/src/mongo/db/introspect.h
@@ -1,63 +1,48 @@
-// introspect.h
-// system management stuff.
-
 /**
-*    Copyright (C) 2008 10gen 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,
-*    as published by the Free Software Foundation.
-*
-*    This program is distributed in the hope that it will be useful,
-*    but WITHOUT ANY WARRANTY; without even the implied warranty of
-*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-*    GNU Affero General Public License for more details.
-*
-*    You should have received a copy of the GNU Affero General Public License
-*    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*
-*    As a special exception, the copyright holders give permission to link the
-*    code of portions of this program with the OpenSSL library under certain
-*    conditions as described in each individual source file and distribute
-*    linked combinations including the program with the OpenSSL library. You
-*    must comply with the GNU Affero General Public License in all respects for
-*    all of the code used other than as permitted herein. If you modify file(s)
-*    with this exception, you may extend this exception to your version of the
-*    file(s), but you are not obligated to do so. If you do not wish to do so,
-*    delete this exception statement from your version. If you delete this
-*    exception statement from all source files in the program, then also delete
-*    it in the license file.
-*/
+ *    Copyright (C) 2008 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,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects for
+ *    all of the code used other than as permitted herein. If you modify file(s)
+ *    with this exception, you may extend this exception to your version of the
+ *    file(s), but you are not obligated to do so. If you do not wish to do so,
+ *    delete this exception statement from your version. If you delete this
+ *    exception statement from all source files in the program, then also delete
+ *    it in the license file.
+ */
 
 #pragma once
 
-#include <string>
-
-#include "mongo/db/curop.h"
-#include "mongo/db/jsobj.h"
+#include "mongo/base/status.h"
 
 namespace mongo {
 
-    class Collection;
     class Database;
     class OperationContext;
 
-    /* --- profiling --------------------------------------------
-       do when database->profile is set
-    */
-
-    void profile(OperationContext* txn, const Client& c, int op, CurOp& currentOp);
+    /**
+     * Invoked when database profile is enabled.
+     */
+    void profile(OperationContext* txn, int op);
 
     /**
-     * Get (or create) the profile collection
-     *
-     * @param   db      Database in which to create the profile collection
-     * @param   force   Always create the collection if it does not exist
-     * @return  Collection for the newly created collection, or NULL on error
-    **/
-    Collection* getOrCreateProfileCollection(OperationContext* txn,
-                                             Database *db,
-                                             bool force = false,
-                                             std::string* errmsg = NULL);
+     * Pre-creates the profile collection for the specified database.
+     */
+    Status createProfileCollection(OperationContext* txn, Database *db);
 
 } // namespace mongo
diff --git a/src/mongo/db/operation_context.h b/src/mongo/db/operation_context.h
index 59c190733f8..036e2be83b9 100644
--- a/src/mongo/db/operation_context.h
+++ b/src/mongo/db/operation_context.h
@@ -30,7 +30,6 @@
 
 #include "mongo/base/disallow_copying.h"
 #include "mongo/base/status.h"
-#include "mongo/base/string_data.h"
 #include "mongo/db/storage/recovery_unit.h"
 #include "mongo/db/concurrency/locker.h"
 #include "mongo/db/concurrency/d_concurrency.h"
@@ -40,6 +39,7 @@ namespace mongo {
     class Client;
     class CurOp;
     class ProgressMeter;
+    class StringData;
 
     /**
      * This class encompasses the state required by an operation.