SERVER-39310: Call checkCanServeReadsFor() in 'getMore'

- added call to checkCanServeReadsFor() in getmore_cmd.cpp after getting readlocks
- introduced two fail points: 1. pause 'getMore' before readlocks 2. pause rollback after state transition
- added testcase read_operations_during_rollback.js

1 files changed, 3 insertions, 0 deletions

diff --git a/src/mongo/db/repl/roll_back_local_operations.h b/src/mongo/db/repl/roll_back_local_operations.h
index 7d21b2feb74..57780fb755a 100644
--- a/src/mongo/db/repl/roll_back_local_operations.h
+++ b/src/mongo/db/repl/roll_back_local_operations.h
@@ -50,6 +50,9 @@ namespace repl {
 MONGO_FAIL_POINT_DECLARE(rollbackHangBeforeFinish);
 MONGO_FAIL_POINT_DECLARE(rollbackHangThenFailAfterWritingMinValid);
 
+// This is needed by rs_rollback and rollback_impl.
+MONGO_FAIL_POINT_DECLARE(rollbackHangAfterTransitionToRollback);
+
 class RollBackLocalOperations {
     RollBackLocalOperations(const RollBackLocalOperations&) = delete;
     RollBackLocalOperations& operator=(const RollBackLocalOperations&) = delete;