SERVER-32517 Parse readConcern snapshot and atClusterTime

1 files changed, 18 insertions, 6 deletions

diff --git a/src/mongo/db/read_concern.cpp b/src/mongo/db/read_concern.cpp
index 44196c98dcf..57ae829011c 100644
--- a/src/mongo/db/read_concern.cpp
+++ b/src/mongo/db/read_concern.cpp
@@ -233,7 +233,19 @@ Status waitForReadConcern(OperationContext* opCtx,
         }
     }
 
-    auto afterClusterTime = readConcernArgs.getArgsClusterTime();
+    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 (!replCoord->isV1ElectionProtocol()) {
+            return {ErrorCodes::IncompatibleElectionProtocol,
+                    "Replica sets running protocol version 0 do not support readConcern: snapshot"};
+        }
+    }
+
+    auto afterClusterTime = readConcernArgs.getArgsAfterClusterTime();
     if (afterClusterTime) {
         if (!allowAfterClusterTime) {
             return {ErrorCodes::InvalidOptions, "afterClusterTime is not allowed for this command"};
@@ -246,11 +258,6 @@ Status waitForReadConcern(OperationContext* opCtx,
         }
     }
 
-    auto pointInTime = readConcernArgs.getArgsPointInTime();
-    if (pointInTime) {
-        fassertStatusOK(39345, opCtx->recoveryUnit()->selectSnapshot(pointInTime->asTimestamp()));
-    }
-
     if (!readConcernArgs.isEmpty()) {
         if (replCoord->isReplEnabled() && afterClusterTime) {
             auto status = makeNoopWriteIfNeeded(opCtx, *afterClusterTime);
@@ -268,6 +275,11 @@ Status waitForReadConcern(OperationContext* opCtx,
         }
     }
 
+    auto pointInTime = readConcernArgs.getArgsAtClusterTime();
+    if (pointInTime) {
+        fassertStatusOK(39345, opCtx->recoveryUnit()->selectSnapshot(pointInTime->asTimestamp()));
+    }
+
     if (readConcernArgs.getLevel() == repl::ReadConcernLevel::kMajorityReadConcern &&
         replCoord->getReplicationMode() == repl::ReplicationCoordinator::Mode::modeReplSet) {
         // ReadConcern Majority is not supported in ProtocolVersion 0.