SERVER-15319 Bump file versions for 2.8-style freelist

8 files changed, 97 insertions, 98 deletions

diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index f2c64765098..2f82a287043 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -65,7 +65,6 @@
 #include "mongo/db/log_process_details.h"
 #include "mongo/db/mongod_options.h"
 #include "mongo/db/operation_context_impl.h"
-#include "mongo/db/pdfile_version.h"
 #include "mongo/db/query/internal_plans.h"
 #include "mongo/db/range_deleter_service.h"
 #include "mongo/db/repl/repl_coordinator_global.h"
diff --git a/src/mongo/db/index_names.h b/src/mongo/db/index_names.h
index 658ddd8459b..728906ed701 100644
--- a/src/mongo/db/index_names.h
+++ b/src/mongo/db/index_names.h
@@ -71,8 +71,8 @@ namespace mongo {
 
         /**
          * True if is a regular (non-plugin) index or uses a plugin that existed before 2.4.
-         * These plugins are grandfathered in and allowed to exist in DBs with
-         * PDFILE_MINOR_VERSION_22_AND_OLDER
+         * These plugins are grandfathered in and allowed to exist in DBs where
+         * DataFileVersion::is24IndexClean() returns false.
          */
         static bool existedBefore24(const std::string& name);
 
diff --git a/src/mongo/db/pdfile_version.h b/src/mongo/db/pdfile_version.h
deleted file mode 100644
index a83b24cf493..00000000000
--- a/src/mongo/db/pdfile_version.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/**
-*    Copyright (C) 2013 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.
-*/
-
-#pragma once
-
-namespace mongo {
-
-    // pdfile versions
-    const int PDFILE_VERSION = 4;
-    const int PDFILE_VERSION_MINOR_22_AND_OLDER = 5;
-    const int PDFILE_VERSION_MINOR_24_AND_NEWER = 6;
-
-    // For backward compatibility with versions before 2.4.0 all new DBs start
-    // with PDFILE_VERSION_MINOR_22_AND_OLDER and are converted when the first
-    // index using a new plugin is created. See the logic in
-    // IndexCatalog::_upgradeDatabaseMinorVersionIfNeeded for details
-
-} // namespace mongo
diff --git a/src/mongo/db/storage/mmap_v1/data_file.cpp b/src/mongo/db/storage/mmap_v1/data_file.cpp
index c08f00ece21..d8941c341fe 100644
--- a/src/mongo/db/storage/mmap_v1/data_file.cpp
+++ b/src/mongo/db/storage/mmap_v1/data_file.cpp
@@ -202,8 +202,7 @@ namespace mongo {
             verify( HeaderSize == 8192 );
             DataFileHeader *h = getDur().writing(this);
             h->fileLength = filelength;
-            h->version = PDFILE_VERSION;
-            h->versionMinor = PDFILE_VERSION_MINOR_22_AND_OLDER; // All dbs start like this
+            h->version = DataFileVersion::defaultForNewFiles();
             h->unused.set( fileno, HeaderSize );
             verify( (data-(char*)this) == HeaderSize );
             h->unusedLength = fileLength - HeaderSize - 16;
diff --git a/src/mongo/db/storage/mmap_v1/data_file.h b/src/mongo/db/storage/mmap_v1/data_file.h
index b8aa7f4f379..ce5f0b34549 100644
--- a/src/mongo/db/storage/mmap_v1/data_file.h
+++ b/src/mongo/db/storage/mmap_v1/data_file.h
@@ -31,7 +31,6 @@
 #pragma once
 
 #include "mongo/db/diskloc.h"
-#include "mongo/db/pdfile_version.h"
 #include "mongo/db/storage/mmap_v1/durable_mapped_file.h"
 
 namespace mongo {
@@ -39,6 +38,67 @@ namespace mongo {
     class ExtentManager;
     class OperationContext;
 
+#pragma pack(1)
+    class DataFileVersion {
+    public:
+        DataFileVersion(uint32_t major, uint32_t minor) :_major(major), _minor(minor) {}
+
+        static DataFileVersion defaultForNewFiles() {
+            return DataFileVersion(kCurrentMajor, kIndexes24AndNewer
+                                                | kMayHave28Freelist
+                                                );
+        }
+
+        bool isCompatibleWithCurrentCode() const {
+            if (_major != kCurrentMajor)
+                return false;
+
+            if (_minor & ~kUsedMinorFlagsMask)
+                return false;
+
+            const uint32_t indexCleanliness = _minor & kIndexPluginMask;
+            if (indexCleanliness != kIndexes24AndNewer && indexCleanliness != kIndexes22AndOlder)
+                return false;
+
+            // We are compatible with either setting of kMayHave28Freelist.
+
+            return true;
+        }
+
+        bool is24IndexClean() const { return (_minor & kIndexPluginMask) == kIndexes24AndNewer; }
+        void setIs24IndexClean() { _minor = ((_minor & ~kIndexPluginMask) | kIndexes24AndNewer); }
+
+        bool mayHave28Freelist() const { return _minor & kMayHave28Freelist; }
+        void setMayHave28Freelist() { _minor |= kMayHave28Freelist; }
+
+        uint32_t major() const { return _major; }
+        uint32_t minorRaw() const { return _minor; }
+
+    private:
+        static const uint32_t kCurrentMajor = 4;
+
+        // minor layout:
+        // first 4 bits - index plugin cleanliness.
+        //    see IndexCatalog::_upgradeDatabaseMinorVersionIfNeeded for details
+        // 5th bit - 1 if started with 2.8-style freelist implementation (SERVER-14081)
+        // 6th through 31st bit - reserved and must be set to 0.
+        static const uint32_t kIndexPluginMask = 0xf;
+        static const uint32_t kIndexes22AndOlder = 5;
+        static const uint32_t kIndexes24AndNewer = 6;
+
+        static const uint32_t kMayHave28Freelist = (1 << 4);
+
+        // All set bits we know about are covered by this mask.
+        static const uint32_t kUsedMinorFlagsMask = 0x1f;
+
+        uint32_t _major;
+        uint32_t _minor;
+    };
+
+    // Note: Intentionally not defining relational operators for DataFileVersion as there is no
+    // total ordering of all versions now that '_minor' is used as a bit vector.
+#pragma pack()
+
     /*  a datafile - i.e. the "dbname.<#>" files :
 
           ----------------------
@@ -55,8 +115,7 @@ namespace mongo {
 #pragma pack(1)
     class DataFileHeader {
     public:
-        int version;
-        int versionMinor;
+        DataFileVersion version;
         int fileLength;
         DiskLoc unused; /* unused is the portion of the file that doesn't belong to any allocated extents. -1 = no more */
         int unusedLength;
@@ -68,14 +127,7 @@ namespace mongo {
 
         enum { HeaderSize = 8192 };
 
-        // all of this should move up to the database level
-        bool isCurrentVersion() const {
-            return version == PDFILE_VERSION && ( versionMinor == PDFILE_VERSION_MINOR_22_AND_OLDER
-                                               || versionMinor == PDFILE_VERSION_MINOR_24_AND_NEWER
-                                                );
-        }
-
-        bool uninitialized() const { return version == 0; }
+        bool uninitialized() const { return version.major() == 0; }
 
         void init(OperationContext* txn, int fileno, int filelength, const char* filename);
 
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 e219c5cf765..d9872b170b2 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
@@ -43,12 +43,12 @@
 #include "mongo/db/index/hash_access_method.h"
 #include "mongo/db/index/haystack_access_method.h"
 #include "mongo/db/index/s2_access_method.h"
-#include "mongo/db/pdfile_version.h"
 #include "mongo/db/server_parameters.h"
 #include "mongo/db/storage/mmap_v1/btree/btree_interface.h"
 #include "mongo/db/storage/mmap_v1/catalog/namespace_details.h"
 #include "mongo/db/storage/mmap_v1/catalog/namespace_details_collection_entry.h"
 #include "mongo/db/storage/mmap_v1/catalog/namespace_details_rsv1_metadata.h"
+#include "mongo/db/storage/mmap_v1/dur.h"
 #include "mongo/db/storage/mmap_v1/data_file.h"
 #include "mongo/db/storage/mmap_v1/dur_recovery_unit.h"
 #include "mongo/db/storage/mmap_v1/record_store_v1_capped.h"
@@ -170,6 +170,13 @@ namespace mongo {
                         }
                     }
                 }
+
+                DataFileVersion version = _extentManager.getFileFormat(txn);
+                if (version.isCompatibleWithCurrentCode() && !version.mayHave28Freelist()) {
+                    // Any DB that can be opened and written to gets this flag set.
+                    version.setMayHave28Freelist();
+                    _extentManager.setFileFormat(txn, version);
+                }
             }
 
             wunit.commit();
@@ -435,13 +442,11 @@ namespace mongo {
 
             {
 
-                int major = 0;
-                int minor = 0;
-                _extentManager.getFileFormat( opCtx, &major, &minor );
+                const DataFileVersion version = _extentManager.getFileFormat(opCtx);
 
                 BSONObjBuilder dataFileVersion( output->subobjStart( "dataFileVersion" ) );
-                dataFileVersion.append( "major", major );
-                dataFileVersion.append( "minor", minor );
+                dataFileVersion.append( "major", version.major() );
+                dataFileVersion.append( "minor", version.minorRaw() );
                 dataFileVersion.done();
             }
         }
@@ -452,40 +457,33 @@ namespace mongo {
         if ( _extentManager.numFiles() == 0 )
             return false;
 
-        int major = 0;
-        int minor = 0;
-
-        _extentManager.getFileFormat( opCtx, &major, &minor );
+        const DataFileVersion version = _extentManager.getFileFormat(opCtx);
 
-        invariant( major == PDFILE_VERSION );
+        invariant(version.isCompatibleWithCurrentCode());
 
-        return minor == PDFILE_VERSION_MINOR_22_AND_OLDER;
+        return !version.is24IndexClean();
     }
 
     void MMAPV1DatabaseCatalogEntry::markIndexSafe24AndUp( OperationContext* opCtx ) {
         if ( _extentManager.numFiles() == 0 )
             return;
 
-        int major = 0;
-        int minor = 0;
+        DataFileVersion version = _extentManager.getFileFormat(opCtx);
 
-        _extentManager.getFileFormat( opCtx, &major, &minor );
-
-        invariant( major == PDFILE_VERSION );
-
-        if ( minor == PDFILE_VERSION_MINOR_24_AND_NEWER )
-            return;
+        invariant(version.isCompatibleWithCurrentCode());
 
-        invariant( minor == PDFILE_VERSION_MINOR_22_AND_OLDER );
+        if (version.is24IndexClean())
+            return; // nothing to do
 
-        _extentManager.setFileFormat(opCtx, major, PDFILE_VERSION_MINOR_24_AND_NEWER);
+        version.setIs24IndexClean();
+        _extentManager.setFileFormat(opCtx, version);
     }
 
     bool MMAPV1DatabaseCatalogEntry::currentFilesCompatible( OperationContext* opCtx ) const {
         if ( _extentManager.numFiles() == 0 )
             return true;
 
-        return _extentManager.getOpenFile( 0 )->getHeader()->isCurrentVersion();
+        return _extentManager.getOpenFile( 0 )->getHeader()->version.isCompatibleWithCurrentCode();
     }
 
     void MMAPV1DatabaseCatalogEntry::getCollectionNamespaces( std::list<std::string>* tofill ) const {
diff --git a/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.cpp b/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.cpp
index f6d18f3090d..ccf903cf035 100644
--- a/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.cpp
+++ b/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.cpp
@@ -563,27 +563,20 @@ namespace mongo {
         _size.store(n + 1);
     }
 
-    void MmapV1ExtentManager::getFileFormat( OperationContext* txn, int* major, int* minor ) const {
+    DataFileVersion MmapV1ExtentManager::getFileFormat(OperationContext* txn) const {
         if ( numFiles() == 0 )
-            return;
-        const DataFile* df = _getOpenFile( 0 );
-        *major = df->getHeader()->version;
-        *minor = df->getHeader()->versionMinor;
-
-        if ( *major <= 0 || *major >= 100 ||
-             *minor <= 0 || *minor >= 100 ) {
-            error() << "corrupt pdfile version? major: " << *major << " minor: " << *minor;
-            fassertFailed( 14026 );
-        }
+            return DataFileVersion(0, 0);
+
+        // We explicitly only look at the first file.
+        return _getOpenFile(0)->getHeader()->version;
     }
 
-    void MmapV1ExtentManager::setFileFormat(OperationContext* txn, int major, int minor) {
+    void MmapV1ExtentManager::setFileFormat(OperationContext* txn, DataFileVersion newVersion) {
         invariant(numFiles() > 0);
 
         DataFile* df = _getOpenFile(0);
         invariant(df);
 
-        txn->recoveryUnit()->writingInt(df->getHeader()->version) = major;
-        txn->recoveryUnit()->writingInt(df->getHeader()->versionMinor) = minor;
+        *txn->recoveryUnit()->writing(&df->getHeader()->version) = newVersion;
     }
 }
diff --git a/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.h b/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.h
index e1857db726c..61d2f1cfcb7 100644
--- a/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.h
+++ b/src/mongo/db/storage/mmap_v1/mmap_v1_extent_manager.h
@@ -45,6 +45,7 @@
 namespace mongo {
 
     class DataFile;
+    class DataFileVersion;
     class Record;
     class OperationContext;
 
@@ -142,8 +143,8 @@ namespace mongo {
         /**
          * Not thread safe, requires a database exclusive lock
          */
-        void getFileFormat(OperationContext* txn, int* major, int* minor) const;
-        void setFileFormat(OperationContext* txn, int major, int minor);
+        DataFileVersion getFileFormat(OperationContext* txn) const;
+        void setFileFormat(OperationContext* txn, DataFileVersion newVersion);
 
         const DataFile* getOpenFile( int n ) const { return _getOpenFile( n ); }