SERVER-31254 Fail initial sync if fCV targetVersion is set or if there is no fCV document

1 files changed, 14 insertions, 0 deletions

diff --git a/src/mongo/db/repl/initial_syncer.h b/src/mongo/db/repl/initial_syncer.h
index 63095486232..157ffcc7249 100644
--- a/src/mongo/db/repl/initial_syncer.h
+++ b/src/mongo/db/repl/initial_syncer.h
@@ -289,6 +289,10 @@ private:
      *    _lastOplogEntryFetcherCallbackForBeginTimestamp()
      *         |
      *         |
+     *         V
+     *    _fcvFetcherCallback()
+     *         |
+     *         |
      *         +------------------------------+
      *         |                              |
      *         |                              |
@@ -389,6 +393,15 @@ private:
         const StatusWith<Fetcher::QueryResponse>& result,
         std::shared_ptr<OnCompletionGuard> onCompletionGuard);
 
+
+    /**
+     * Callback for the '_fCVFetcher'. A successful response lets us check if the remote node
+     * is in a currently acceptable fCV and if it has a 'targetVersion' set.
+     */
+    void _fcvFetcherCallback(const StatusWith<Fetcher::QueryResponse>& result,
+                             std::shared_ptr<OnCompletionGuard> onCompletionGuard,
+                             const OpTimeWithHash& lastOpTimeWithHash);
+
     /**
      * Callback for oplog fetcher.
      */
@@ -592,6 +605,7 @@ private:
     std::unique_ptr<InitialSyncState> _initialSyncState;  // (M)
     std::unique_ptr<OplogFetcher> _oplogFetcher;          // (S)
     std::unique_ptr<Fetcher> _lastOplogEntryFetcher;      // (S)
+    std::unique_ptr<Fetcher> _fCVFetcher;                 // (S)
     std::unique_ptr<MultiApplier> _applier;               // (M)
     HostAndPort _syncSource;                              // (M)
     OpTimeWithHash _lastFetched;                          // (MX)