SERVER-15319 Handle 2.8-style freelist bit in pdfile version

5 files changed, 29 insertions, 13 deletions

diff --git a/src/mongo/db/catalog/index_catalog.cpp b/src/mongo/db/catalog/index_catalog.cpp
index ead9dd9311e..8614c368f91 100644
--- a/src/mongo/db/catalog/index_catalog.cpp
+++ b/src/mongo/db/catalog/index_catalog.cpp
@@ -182,13 +182,8 @@ namespace mongo {
     bool IndexCatalog::_shouldOverridePlugin(const BSONObj& keyPattern) const {
         string pluginName = IndexNames::findPluginName(keyPattern);
         bool known = IndexNames::isKnownName(pluginName);
-
-        int majorVersion;
-        int minorVersion;
-
-        _collection->_database->getFileFormat( &majorVersion, &minorVersion );
             
-        if (minorVersion == PDFILE_VERSION_MINOR_24_AND_NEWER) {
+        if (_collection->_database->getExtentManager().getFile(0)->getHeader()->is24IndexClean()) {
             // RulesFor24
             // This assert will be triggered when downgrading from a future version that
             // supports an index plugin unsupported by this version.
@@ -236,11 +231,11 @@ namespace mongo {
         Database* db = _collection->_database;
 
         DataFileHeader* dfh = db->getExtentManager().getFile(0)->getHeader();
-        if ( dfh->versionMinor == PDFILE_VERSION_MINOR_24_AND_NEWER ) {
+        if ( dfh->is24IndexClean() ) {
             return Status::OK(); // these checks have already been done
         }
 
-        fassert(16737, dfh->versionMinor == PDFILE_VERSION_MINOR_22_AND_OLDER);
+        fassert(16737, dfh->isCurrentVersion());
 
         auto_ptr<Runner> runner( InternalPlanner::collectionScan( db->_indexesName ) );
 
@@ -265,7 +260,7 @@ namespace mongo {
             warning() << "Internal error while reading system.indexes collection";
         }
 
-        getDur().writingInt(dfh->versionMinor) = PDFILE_VERSION_MINOR_24_AND_NEWER;
+        dfh->setIs24IndexClean();
 
         return Status::OK();
     }
diff --git a/src/mongo/db/db.cpp b/src/mongo/db/db.cpp
index 69e0076d0a3..1b28f3004b5 100644
--- a/src/mongo/db/db.cpp
+++ b/src/mongo/db/db.cpp
@@ -420,7 +420,7 @@ namespace mongo {
                     const BSONObj key = index.getObjectField("key");
                     const string plugin = IndexNames::findPluginName(key);
 
-                    if (h->versionMinor == PDFILE_VERSION_MINOR_22_AND_OLDER) {
+                    if (!h->is24IndexClean()) {
                         if (IndexNames::existedBefore24(plugin))
                             continue;
 
diff --git a/src/mongo/db/pdfile_version.h b/src/mongo/db/pdfile_version.h
index a83b24cf493..c285a8b0d6c 100644
--- a/src/mongo/db/pdfile_version.h
+++ b/src/mongo/db/pdfile_version.h
@@ -35,6 +35,9 @@ namespace mongo {
     const int PDFILE_VERSION_MINOR_22_AND_OLDER = 5;
     const int PDFILE_VERSION_MINOR_24_AND_NEWER = 6;
 
+    const int PDFILE_VERSION_MINOR_INDEX_MASK = 0xf;
+    const int PDFILE_VERSION_MINOR_28_FREELIST_MASK = (1 << 4); // SERVER-14081
+
     // 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
diff --git a/src/mongo/db/storage/data_file.cpp b/src/mongo/db/storage/data_file.cpp
index e365ae6bdcd..04cdd4cd095 100644
--- a/src/mongo/db/storage/data_file.cpp
+++ b/src/mongo/db/storage/data_file.cpp
@@ -174,6 +174,16 @@ namespace mongo {
 
     // -------------------------------------------------------------------------------
 
+    bool DataFileHeader::is24IndexClean() const {
+        return (versionMinor & PDFILE_VERSION_MINOR_INDEX_MASK)
+            == PDFILE_VERSION_MINOR_24_AND_NEWER;
+    }
+
+    void DataFileHeader::setIs24IndexClean() {
+        getDur().writingInt(versionMinor) = ((versionMinor & ~PDFILE_VERSION_MINOR_INDEX_MASK)
+                                          | PDFILE_VERSION_MINOR_24_AND_NEWER);
+    }
+
     void DataFileHeader::init(int fileno, int filelength, const char* filename) {
         if ( uninitialized() ) {
             DEV log() << "datafileheader::init initializing " << filename << " n:" << fileno << endl;
diff --git a/src/mongo/db/storage/data_file.h b/src/mongo/db/storage/data_file.h
index 6402c63da05..f09fa1e11ba 100644
--- a/src/mongo/db/storage/data_file.h
+++ b/src/mongo/db/storage/data_file.h
@@ -69,11 +69,19 @@ namespace mongo {
 
         // 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
-                                                );
+            if (version != PDFILE_VERSION)
+               return false;
+
+            // Masking off the 2.8 freelist bit since this version of the code is safe to use with
+            // it. SERVER-15319
+            const int minor = versionMinor & ~PDFILE_VERSION_MINOR_28_FREELIST_MASK;
+            return minor == PDFILE_VERSION_MINOR_22_AND_OLDER
+                || minor == PDFILE_VERSION_MINOR_24_AND_NEWER;
         }
 
+        bool is24IndexClean() const;
+        void setIs24IndexClean();
+
         bool uninitialized() const { return version == 0; }
 
         void init(int fileno, int filelength, const char* filename);