SERVER-39206 Avoid PBWM lock conflicts for prepared transaction on startup

4 files changed, 9 insertions, 0 deletions

diff --git a/src/mongo/db/repl/apply_ops.cpp b/src/mongo/db/repl/apply_ops.cpp
index 6f90eedf4c1..608e7ce3c64 100644
--- a/src/mongo/db/repl/apply_ops.cpp
+++ b/src/mongo/db/repl/apply_ops.cpp
@@ -455,6 +455,8 @@ Status applyApplyOpsOplogEntry(OperationContext* opCtx,
 }
 
 Status applyRecoveredPrepareTransaction(OperationContext* opCtx, const OplogEntry& entry) {
+    // Snapshot transactions never conflict with the PBWM lock.
+    invariant(!opCtx->lockState()->shouldConflictWithSecondaryBatchApplication());
     UnreplicatedWritesBlock uwb(opCtx);
     return _applyPrepareTransaction(opCtx, entry, OplogApplication::Mode::kRecovering);
 }
diff --git a/src/mongo/db/repl/replication_recovery.cpp b/src/mongo/db/repl/replication_recovery.cpp
index ec6a31a99ac..28b0c28562a 100644
--- a/src/mongo/db/repl/replication_recovery.cpp
+++ b/src/mongo/db/repl/replication_recovery.cpp
@@ -308,6 +308,9 @@ void ReplicationRecoveryImpl::_reconstructPreparedTransactions(OperationContext*
             AlternativeClientRegion acr(newClient);
             const auto newOpCtx = cc().makeOperationContext();
 
+            // Snapshot transaction can never conflict with the PBWM lock.
+            newOpCtx->lockState()->setShouldConflictWithSecondaryBatchApplication(false);
+
             // Checks out the session, applies the operations and prepares the transactions.
             uassertStatusOK(applyRecoveredPrepareTransaction(newOpCtx.get(), prepareOplogEntry));
         }
diff --git a/src/mongo/db/transaction_participant.cpp b/src/mongo/db/transaction_participant.cpp
index 83a9b67aeb4..b484d0fc07c 100644
--- a/src/mongo/db/transaction_participant.cpp
+++ b/src/mongo/db/transaction_participant.cpp
@@ -869,6 +869,9 @@ void TransactionParticipant::refreshLocksForPreparedTransaction(OperationContext
     _txnResourceStash->release(opCtx);
     _txnResourceStash = boost::none;
 
+    // Snapshot transactions don't conflict with PBWM lock on both primary and secondary.
+    invariant(!opCtx->lockState()->shouldConflictWithSecondaryBatchApplication());
+
     // Transfer the txn resource back from the operation context to the stash.
     auto stashStyle =
         yieldLocks ? TxnResources::StashStyle::kSecondary : TxnResources::StashStyle::kPrimary;
diff --git a/src/mongo/db/transaction_participant_test.cpp b/src/mongo/db/transaction_participant_test.cpp
index 0f9713b0598..8cb4808f1f9 100644
--- a/src/mongo/db/transaction_participant_test.cpp
+++ b/src/mongo/db/transaction_participant_test.cpp
@@ -257,6 +257,7 @@ protected:
 
     std::unique_ptr<MongoDOperationContextSession> checkOutSession(
         boost::optional<bool> startNewTxn = true) {
+        opCtx()->lockState()->setShouldConflictWithSecondaryBatchApplication(false);
         auto opCtxSession = std::make_unique<MongoDOperationContextSession>(opCtx());
         auto txnParticipant = TransactionParticipant::get(opCtx());
         txnParticipant->beginOrContinue(*opCtx()->getTxnNumber(), false, startNewTxn);