SERVER-47569: Allow readConcern snapshot outside of transactions (mongod)

1 files changed, 12 insertions, 7 deletions

diff --git a/src/mongo/db/read_concern_mongod.cpp b/src/mongo/db/read_concern_mongod.cpp
index e6b90951325..205506b9f2f 100644
--- a/src/mongo/db/read_concern_mongod.cpp
+++ b/src/mongo/db/read_concern_mongod.cpp
@@ -300,6 +300,18 @@ Status waitForReadConcernImpl(OperationContext* opCtx,
         }
     }
 
+    if (readConcernArgs.getLevel() == repl::ReadConcernLevel::kSnapshotReadConcern) {
+        if (replCoord->getReplicationMode() != repl::ReplicationCoordinator::modeReplSet) {
+            return {ErrorCodes::NotAReplicaSet,
+                    "node needs to be a replica set member to use readConcern: snapshot"};
+        }
+        if (!opCtx->inMultiDocumentTransaction() && !serverGlobalParams.enableMajorityReadConcern) {
+            return {ErrorCodes::ReadConcernMajorityNotEnabled,
+                    "read concern level snapshot is not supported when "
+                    "enableMajorityReadConcern=false"};
+        }
+    }
+
     auto afterClusterTime = readConcernArgs.getArgsAfterClusterTime();
     auto atClusterTime = readConcernArgs.getArgsAtClusterTime();
 
@@ -349,13 +361,6 @@ Status waitForReadConcernImpl(OperationContext* opCtx,
         }
     }
 
-    if (readConcernArgs.getLevel() == repl::ReadConcernLevel::kSnapshotReadConcern) {
-        if (replCoord->getReplicationMode() != repl::ReplicationCoordinator::modeReplSet) {
-            return {ErrorCodes::NotAReplicaSet,
-                    "node needs to be a replica set member to use readConcern: snapshot"};
-        }
-    }
-
     if (atClusterTime) {
         opCtx->recoveryUnit()->setTimestampReadSource(RecoveryUnit::ReadSource::kProvided,
                                                       atClusterTime->asTimestamp());