SERVER-43712 mongos use ReadWriteConcernDefaults for WC

28 files changed, 258 insertions, 99 deletions

diff --git a/src/mongo/db/transaction_validation.cpp b/src/mongo/db/transaction_validation.cpp
index faabf3f766c..3401ceea111 100644
--- a/src/mongo/db/transaction_validation.cpp
+++ b/src/mongo/db/transaction_validation.cpp
@@ -57,12 +57,15 @@ bool isRetryableWriteCommand(StringData cmdName) {
 
 }  // namespace
 
+bool commandSupportsWriteConcernInTransaction(StringData cmdName) {
+    return cmdName == "commitTransaction" || cmdName == "coordinateCommitTransaction" ||
+        cmdName == "abortTransaction" || cmdName == "prepareTransaction";
+}
+
 void validateWriteConcernForTransaction(const WriteConcernOptions& wcResult, StringData cmdName) {
     uassert(ErrorCodes::InvalidOptions,
             "writeConcern is not allowed within a multi-statement transaction",
-            wcResult.usedDefault || cmdName == "commitTransaction" ||
-                cmdName == "coordinateCommitTransaction" || cmdName == "abortTransaction" ||
-                cmdName == "prepareTransaction");
+            wcResult.usedDefault || commandSupportsWriteConcernInTransaction(cmdName));
 }
 
 bool shouldCommandSkipSessionCheckout(StringData cmdName) {
diff --git a/src/mongo/db/transaction_validation.h b/src/mongo/db/transaction_validation.h
index ec22c7f304e..2e57866eeb1 100644
--- a/src/mongo/db/transaction_validation.h
+++ b/src/mongo/db/transaction_validation.h
@@ -35,6 +35,11 @@
 namespace mongo {
 
 /**
+ * Returns true if the given cmd name is allowed to specify write concern in a transaction.
+ */
+bool commandSupportsWriteConcernInTransaction(StringData cmdName);
+
+/**
  * Throws if the given write concern is not allowed in a transaction.
  */
 void validateWriteConcernForTransaction(const WriteConcernOptions& wcResult, StringData cmdName);
diff --git a/src/mongo/s/cluster_commands_helpers.cpp b/src/mongo/s/cluster_commands_helpers.cpp
index a2fd9e350b2..6036dcc31c8 100644
--- a/src/mongo/s/cluster_commands_helpers.cpp
+++ b/src/mongo/s/cluster_commands_helpers.cpp
@@ -267,6 +267,57 @@ BSONObj appendAllowImplicitCreate(BSONObj cmdObj, bool allow) {
     return newCmdBuilder.obj();
 }
 
+BSONObj applyReadWriteConcern(OperationContext* opCtx, bool appendWC, const BSONObj& cmdObj) {
+    // Never apply write concern to ordinary operations inside transactions.  Applying writeConcern
+    // to terminal operations such as abortTransaction and commitTransaction is done directly by the
+    // TransactionRouter.
+    if (TransactionRouter::get(opCtx)) {
+        return cmdObj;
+    }
+
+    // Append all original fields except the readConcern/writeConcern field to the new command.
+    BSONObjBuilder output;
+    bool seenWriteConcern = false;
+    for (const auto& elem : cmdObj) {
+        const auto name = elem.fieldNameStringData();
+        if (appendWC && name == WriteConcernOptions::kWriteConcernField) {
+            seenWriteConcern = true;
+        }
+        if (!output.hasField(name)) {
+            output.append(elem);
+        }
+    }
+
+    // Finally, add the new read/write concern.
+    if (appendWC && !seenWriteConcern) {
+        output.append(WriteConcernOptions::kWriteConcernField, opCtx->getWriteConcern().toBSON());
+    }
+
+    return output.obj();
+}
+
+BSONObj applyReadWriteConcern(OperationContext* opCtx,
+                              CommandInvocation* invocation,
+                              const BSONObj& cmdObj) {
+    return applyReadWriteConcern(opCtx, invocation->supportsWriteConcern(), cmdObj);
+}
+
+BSONObj applyReadWriteConcern(OperationContext* opCtx, BasicCommand* cmd, const BSONObj& cmdObj) {
+    return applyReadWriteConcern(opCtx, cmd->supportsWriteConcern(cmdObj), cmdObj);
+}
+
+BSONObj stripWriteConcern(const BSONObj& cmdObj) {
+    BSONObjBuilder output;
+    for (const auto& elem : cmdObj) {
+        const auto name = elem.fieldNameStringData();
+        if (name == WriteConcernOptions::kWriteConcernField) {
+            continue;
+        }
+        output.append(elem);
+    }
+    return output.obj();
+}
+
 std::vector<AsyncRequestsSender::Response> scatterGatherUnversionedTargetAllShards(
     OperationContext* opCtx,
     StringData dbName,
diff --git a/src/mongo/s/cluster_commands_helpers.h b/src/mongo/s/cluster_commands_helpers.h
index 2a50e01d2a3..f65f39f9607 100644
--- a/src/mongo/s/cluster_commands_helpers.h
+++ b/src/mongo/s/cluster_commands_helpers.h
@@ -36,6 +36,7 @@
 #include "mongo/base/status.h"
 #include "mongo/base/string_data.h"
 #include "mongo/bson/bsonobj.h"
+#include "mongo/db/commands.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/rpc/write_concern_error_detail.h"
 #include "mongo/s/async_requests_sender.h"
@@ -91,6 +92,26 @@ BSONObj appendShardVersion(BSONObj cmdObj, ChunkVersion version);
 BSONObj appendAllowImplicitCreate(BSONObj cmdObj, bool allow);
 
 /**
+ * Returns a copy of 'cmdObj' with the read/writeConcern from the OpCtx appended, unless the
+ * cmdObj explicitly specifies read/writeConcern.
+ */
+BSONObj applyReadWriteConcern(OperationContext* opCtx, bool appendWC, const BSONObj& cmdObj);
+
+/**
+ * Convenience versions of applyReadWriteConcern() for calling from within
+ * CommandInvocation or BasicCommand.
+ */
+BSONObj applyReadWriteConcern(OperationContext* opCtx,
+                              CommandInvocation* invocation,
+                              const BSONObj& cmdObj);
+BSONObj applyReadWriteConcern(OperationContext* opCtx, BasicCommand* cmd, const BSONObj& cmdObj);
+
+/**
+ * Returns a copy of 'cmdObj' with the writeConcern removed.
+ */
+BSONObj stripWriteConcern(const BSONObj& cmdObj);
+
+/**
  * Utility for dispatching unversioned commands to all shards in a cluster.
  *
  * Returns a non-OK status if a failure occurs on *this* node during execution. Otherwise, returns
diff --git a/src/mongo/s/commands/cluster_coll_stats_cmd.cpp b/src/mongo/s/commands/cluster_coll_stats_cmd.cpp
index 8389409d6ba..3d4667879f3 100644
--- a/src/mongo/s/commands/cluster_coll_stats_cmd.cpp
+++ b/src/mongo/s/commands/cluster_coll_stats_cmd.cpp
@@ -88,7 +88,8 @@ public:
             nss.db(),
             nss,
             routingInfo,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent,
             {},
diff --git a/src/mongo/s/commands/cluster_collection_mod_cmd.cpp b/src/mongo/s/commands/cluster_collection_mod_cmd.cpp
index f4091d155c4..247aa8db8aa 100644
--- a/src/mongo/s/commands/cluster_collection_mod_cmd.cpp
+++ b/src/mongo/s/commands/cluster_collection_mod_cmd.cpp
@@ -73,7 +73,8 @@ public:
         auto shardResponses = scatterGatherOnlyVersionIfUnsharded(
             opCtx,
             nss,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kNoRetry);
         return appendRawResponses(
diff --git a/src/mongo/s/commands/cluster_create_indexes_cmd.cpp b/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
index 7ec58e26000..3169b6fe485 100644
--- a/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
+++ b/src/mongo/s/commands/cluster_create_indexes_cmd.cpp
@@ -73,8 +73,8 @@ public:
 
         createShardDatabase(opCtx, dbName);
 
-        auto shardResponses =
-            dispatchCommandAssertCollectionExistsOnAtLeastOneShard(opCtx, nss, cmdObj);
+        auto shardResponses = dispatchCommandAssertCollectionExistsOnAtLeastOneShard(
+            opCtx, nss, applyReadWriteConcern(opCtx, this, cmdObj));
 
         return appendRawResponses(opCtx,
                                   &errmsg,
diff --git a/src/mongo/s/commands/cluster_data_size_cmd.cpp b/src/mongo/s/commands/cluster_data_size_cmd.cpp
index c8d410e1634..3b172589ffb 100644
--- a/src/mongo/s/commands/cluster_data_size_cmd.cpp
+++ b/src/mongo/s/commands/cluster_data_size_cmd.cpp
@@ -107,7 +107,8 @@ public:
             nss.db(),
             nss,
             routingInfo,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent,
             {},
diff --git a/src/mongo/s/commands/cluster_db_stats_cmd.cpp b/src/mongo/s/commands/cluster_db_stats_cmd.cpp
index d7d31e5fd55..3408419de95 100644
--- a/src/mongo/s/commands/cluster_db_stats_cmd.cpp
+++ b/src/mongo/s/commands/cluster_db_stats_cmd.cpp
@@ -124,7 +124,8 @@ public:
         auto shardResponses = scatterGatherUnversionedTargetAllShards(
             opCtx,
             dbName,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent);
         if (!appendRawResponses(opCtx, &errmsg, &output, shardResponses)) {
diff --git a/src/mongo/s/commands/cluster_distinct_cmd.cpp b/src/mongo/s/commands/cluster_distinct_cmd.cpp
index 3c9c667678d..0009fc6f89a 100644
--- a/src/mongo/s/commands/cluster_distinct_cmd.cpp
+++ b/src/mongo/s/commands/cluster_distinct_cmd.cpp
@@ -186,7 +186,8 @@ public:
                 nss.db(),
                 nss,
                 routingInfo,
-                CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+                applyReadWriteConcern(
+                    opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
                 ReadPreferenceSetting::get(opCtx),
                 Shard::RetryPolicy::kIdempotent,
                 query,
diff --git a/src/mongo/s/commands/cluster_drop_indexes_cmd.cpp b/src/mongo/s/commands/cluster_drop_indexes_cmd.cpp
index 9dca911b224..90db76876da 100644
--- a/src/mongo/s/commands/cluster_drop_indexes_cmd.cpp
+++ b/src/mongo/s/commands/cluster_drop_indexes_cmd.cpp
@@ -80,7 +80,8 @@ public:
         auto shardResponses = scatterGatherOnlyVersionIfUnsharded(
             opCtx,
             nss,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kNotIdempotent);
         return appendRawResponses(opCtx,
diff --git a/src/mongo/s/commands/cluster_filemd5_cmd.cpp b/src/mongo/s/commands/cluster_filemd5_cmd.cpp
index 8b3d1385864..e17534b8618 100644
--- a/src/mongo/s/commands/cluster_filemd5_cmd.cpp
+++ b/src/mongo/s/commands/cluster_filemd5_cmd.cpp
@@ -118,8 +118,10 @@ public:
             SimpleBSONObjComparator::kInstance.evaluate(
                 routingInfo.cm()->getShardKeyPattern().toBSON() == BSON("files_id" << 1))) {
             CommandHelpers::filterCommandReplyForPassthrough(
-                callShardFn(CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
-                            BSON("files_id" << cmdObj.firstElement())),
+                callShardFn(
+                    applyReadWriteConcern(
+                        opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+                    BSON("files_id" << cmdObj.firstElement())),
                 &result);
             return true;
         }
@@ -149,7 +151,8 @@ public:
         while (true) {
             const auto res = callShardFn(
                 [&] {
-                    BSONObjBuilder bb(CommandHelpers::filterCommandRequestForPassthrough(cmdObj));
+                    BSONObjBuilder bb(applyReadWriteConcern(
+                        opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)));
                     bb.append("partialOk", true);
                     bb.append("startAt", numGridFSChunksProcessed);
                     if (!lastResult.isEmpty()) {
diff --git a/src/mongo/s/commands/cluster_find_and_modify_cmd.cpp b/src/mongo/s/commands/cluster_find_and_modify_cmd.cpp
index 90442a2b4c2..7169f2be79a 100644
--- a/src/mongo/s/commands/cluster_find_and_modify_cmd.cpp
+++ b/src/mongo/s/commands/cluster_find_and_modify_cmd.cpp
@@ -207,7 +207,7 @@ public:
                         chunkMgr->getVersion(shard->getId()),
                         boost::none,
                         nss,
-                        explainCmd,
+                        applyReadWriteConcern(opCtx, false, explainCmd),
                         &bob);
         } else {
             _runCommand(opCtx,
@@ -215,7 +215,7 @@ public:
                         ChunkVersion::UNSHARDED(),
                         routingInfo.db().databaseVersion(),
                         nss,
-                        explainCmd,
+                        applyReadWriteConcern(opCtx, false, explainCmd),
                         &bob);
         }
 
@@ -254,7 +254,7 @@ public:
                         ChunkVersion::UNSHARDED(),
                         routingInfo.db().databaseVersion(),
                         nss,
-                        cmdObjForShard,
+                        applyReadWriteConcern(opCtx, this, cmdObjForShard),
                         &result);
             return true;
         }
@@ -271,7 +271,7 @@ public:
                     chunkMgr->getVersion(chunk.getShardId()),
                     boost::none,
                     nss,
-                    cmdObjForShard,
+                    applyReadWriteConcern(opCtx, this, cmdObjForShard),
                     &result);
 
         return true;
@@ -331,9 +331,18 @@ private:
                     // Re-run the findAndModify command that will change the shard key value in a
                     // transaction. We call _runCommand recursively, and this second time through
                     // since it will be run as a transaction it will take the other code path to
-                    // updateShardKeyValueOnWouldChangeOwningShardError.
+                    // updateShardKeyValueOnWouldChangeOwningShardError.  We ensure the retried
+                    // operation does not include WC inside the transaction by stripping it from the
+                    // cmdObj.  The transaction commit will still use the WC, because it uses the WC
+                    // from the opCtx (which has been set previously in Strategy).
                     documentShardKeyUpdateUtil::startTransactionForShardKeyUpdate(opCtx);
-                    _runCommand(opCtx, shardId, shardVersion, dbVersion, nss, cmdObj, result);
+                    _runCommand(opCtx,
+                                shardId,
+                                shardVersion,
+                                dbVersion,
+                                nss,
+                                stripWriteConcern(cmdObj),
+                                result);
                     uassertStatusOK(getStatusFromCommandResult(result->asTempObj()));
                     auto commitResponse =
                         documentShardKeyUpdateUtil::commitShardKeyUpdateTransaction(opCtx);
diff --git a/src/mongo/s/commands/cluster_get_last_error_cmd.cpp b/src/mongo/s/commands/cluster_get_last_error_cmd.cpp
index aabd696f845..3d941e1ad3b 100644
--- a/src/mongo/s/commands/cluster_get_last_error_cmd.cpp
+++ b/src/mongo/s/commands/cluster_get_last_error_cmd.cpp
@@ -39,6 +39,7 @@
 #include "mongo/db/lasterror.h"
 #include "mongo/executor/task_executor_pool.h"
 #include "mongo/s/client/shard_registry.h"
+#include "mongo/s/cluster_commands_helpers.h"
 #include "mongo/s/cluster_last_error_info.h"
 #include "mongo/s/grid.h"
 #include "mongo/s/multi_statement_transaction_requests_sender.h"
@@ -251,12 +252,13 @@ public:
         const HostOpTimeMap hostOpTimes(ClusterLastErrorInfo::get(cc())->getPrevHostOpTimes());
 
         std::vector<LegacyWCResponse> wcResponses;
-        auto status =
-            enforceLegacyWriteConcern(opCtx,
-                                      dbname,
-                                      CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
-                                      hostOpTimes,
-                                      &wcResponses);
+        auto status = enforceLegacyWriteConcern(
+            opCtx,
+            dbname,
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+            hostOpTimes,
+            &wcResponses);
 
         // Don't forget about our last hosts, reset the client info
         ClusterLastErrorInfo::get(cc())->disableForCommand();
diff --git a/src/mongo/s/commands/cluster_index_filter_cmd.cpp b/src/mongo/s/commands/cluster_index_filter_cmd.cpp
index dc517eccd4e..f6c5bd37777 100644
--- a/src/mongo/s/commands/cluster_index_filter_cmd.cpp
+++ b/src/mongo/s/commands/cluster_index_filter_cmd.cpp
@@ -99,7 +99,8 @@ public:
             nss.db(),
             nss,
             routingInfo,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent,
             query,
diff --git a/src/mongo/s/commands/cluster_list_databases_cmd.cpp b/src/mongo/s/commands/cluster_list_databases_cmd.cpp
index 9ba0e23bd34..fb5e9ab261a 100644
--- a/src/mongo/s/commands/cluster_list_databases_cmd.cpp
+++ b/src/mongo/s/commands/cluster_list_databases_cmd.cpp
@@ -40,6 +40,7 @@
 #include "mongo/db/commands/list_databases_gen.h"
 #include "mongo/s/client/shard.h"
 #include "mongo/s/client/shard_registry.h"
+#include "mongo/s/cluster_commands_helpers.h"
 #include "mongo/s/commands/strategy.h"
 #include "mongo/s/grid.h"
 
@@ -118,7 +119,8 @@ public:
         shardIds.emplace_back(ShardRegistry::kConfigServerShardId);
 
         // { filter: matchExpression }.
-        auto filteredCmd = CommandHelpers::filterCommandRequestForPassthrough(cmdObj);
+        auto filteredCmd = applyReadWriteConcern(
+            opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj));
 
         for (const ShardId& shardId : shardIds) {
             const auto shardStatus = shardRegistry->getShard(opCtx, shardId);
diff --git a/src/mongo/s/commands/cluster_map_reduce_cmd.cpp b/src/mongo/s/commands/cluster_map_reduce_cmd.cpp
index c0abf8efd87..6656c0d8f25 100644
--- a/src/mongo/s/commands/cluster_map_reduce_cmd.cpp
+++ b/src/mongo/s/commands/cluster_map_reduce_cmd.cpp
@@ -35,6 +35,7 @@
 #include "mongo/db/commands/map_reduce_command_base.h"
 #include "mongo/db/commands/test_commands_enabled.h"
 #include "mongo/db/query/query_knobs_gen.h"
+#include "mongo/s/cluster_commands_helpers.h"
 #include "mongo/s/commands/cluster_map_reduce.h"
 #include "mongo/s/commands/cluster_map_reduce_agg.h"
 
@@ -57,7 +58,7 @@ public:
         if (getTestCommandsEnabled() && internalQueryUseAggMapReduce.load()) {
             return runAggregationMapReduce(opCtx, dbname, cmd, errmsg, result);
         }
-        return runMapReduce(opCtx, dbname, cmd, errmsg, result);
+        return runMapReduce(opCtx, dbname, applyReadWriteConcern(opCtx, this, cmd), errmsg, result);
     }
 } clusterMapReduceCommand;
 
diff --git a/src/mongo/s/commands/cluster_plan_cache_cmd.cpp b/src/mongo/s/commands/cluster_plan_cache_cmd.cpp
index b0854622b20..192c5f9300a 100644
--- a/src/mongo/s/commands/cluster_plan_cache_cmd.cpp
+++ b/src/mongo/s/commands/cluster_plan_cache_cmd.cpp
@@ -122,7 +122,8 @@ bool ClusterPlanCacheCmd::run(OperationContext* opCtx,
         nss.db(),
         nss,
         routingInfo,
-        CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+        applyReadWriteConcern(
+            opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
         ReadPreferenceSetting::get(opCtx),
         Shard::RetryPolicy::kIdempotent,
         query,
diff --git a/src/mongo/s/commands/cluster_reset_error_cmd.cpp b/src/mongo/s/commands/cluster_reset_error_cmd.cpp
index 1a37a591b05..21dca8edbf3 100644
--- a/src/mongo/s/commands/cluster_reset_error_cmd.cpp
+++ b/src/mongo/s/commands/cluster_reset_error_cmd.cpp
@@ -36,6 +36,7 @@
 #include "mongo/db/commands.h"
 #include "mongo/db/lasterror.h"
 #include "mongo/s/client/shard_connection.h"
+#include "mongo/s/cluster_commands_helpers.h"
 #include "mongo/s/cluster_last_error_info.h"
 
 namespace mongo {
@@ -77,7 +78,10 @@ public:
 
             // Don't care about result from shards.
             conn->runCommand(
-                dbname, CommandHelpers::filterCommandRequestForPassthrough(cmdObj), res);
+                dbname,
+                applyReadWriteConcern(
+                    opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+                res);
             conn.done();
         }
 
diff --git a/src/mongo/s/commands/cluster_restart_catalog_command.cpp b/src/mongo/s/commands/cluster_restart_catalog_command.cpp
index 5bcc6686ca5..4f3af29908c 100644
--- a/src/mongo/s/commands/cluster_restart_catalog_command.cpp
+++ b/src/mongo/s/commands/cluster_restart_catalog_command.cpp
@@ -79,7 +79,8 @@ public:
         auto shardResponses = scatterGatherUnversionedTargetAllShards(
             opCtx,
             db,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent);
 
diff --git a/src/mongo/s/commands/cluster_set_index_commit_quorum_cmd.cpp b/src/mongo/s/commands/cluster_set_index_commit_quorum_cmd.cpp
index a19fb187524..5074b7da454 100644
--- a/src/mongo/s/commands/cluster_set_index_commit_quorum_cmd.cpp
+++ b/src/mongo/s/commands/cluster_set_index_commit_quorum_cmd.cpp
@@ -91,7 +91,8 @@ public:
             scatterGatherOnlyVersionIfUnsharded(
                 opCtx,
                 request().getNamespace(),
-                CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+                applyReadWriteConcern(
+                    opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
                 ReadPreferenceSetting::get(opCtx),
                 Shard::RetryPolicy::kNotIdempotent);
         }
diff --git a/src/mongo/s/commands/cluster_user_management_commands.cpp b/src/mongo/s/commands/cluster_user_management_commands.cpp
index 607114dda40..58384e84755 100644
--- a/src/mongo/s/commands/cluster_user_management_commands.cpp
+++ b/src/mongo/s/commands/cluster_user_management_commands.cpp
@@ -90,7 +90,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
     }
 
@@ -134,7 +135,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -183,7 +185,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -223,7 +226,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -270,7 +274,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -317,7 +322,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -354,7 +360,11 @@ public:
              const BSONObj& cmdObj,
              BSONObjBuilder& result) {
         return Grid::get(opCtx)->catalogClient()->runUserManagementReadCommand(
-            opCtx, dbname, CommandHelpers::filterCommandRequestForPassthrough(cmdObj), &result);
+            opCtx,
+            dbname,
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+            &result);
     }
 
 } cmdUsersInfo;
@@ -389,7 +399,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
     }
 
@@ -425,7 +436,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -466,7 +478,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -506,7 +519,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -546,7 +560,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -586,7 +601,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -629,7 +645,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -674,7 +691,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
 
         const auto authzManager = AuthorizationManager::get(opCtx->getServiceContext());
@@ -711,7 +729,11 @@ public:
              const BSONObj& cmdObj,
              BSONObjBuilder& result) {
         return Grid::get(opCtx)->catalogClient()->runUserManagementReadCommand(
-            opCtx, dbname, CommandHelpers::filterCommandRequestForPassthrough(cmdObj), &result);
+            opCtx,
+            dbname,
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+            &result);
     }
 
 } cmdRolesInfo;
@@ -798,7 +820,8 @@ public:
             opCtx,
             getName(),
             dbname,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             &result);
     }
 
diff --git a/src/mongo/s/commands/cluster_validate_cmd.cpp b/src/mongo/s/commands/cluster_validate_cmd.cpp
index 510b299ac35..f56261282e4 100644
--- a/src/mongo/s/commands/cluster_validate_cmd.cpp
+++ b/src/mongo/s/commands/cluster_validate_cmd.cpp
@@ -80,7 +80,8 @@ public:
             nss.db(),
             nss,
             routingInfo,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             ReadPreferenceSetting::get(opCtx),
             Shard::RetryPolicy::kIdempotent,
             {},
diff --git a/src/mongo/s/commands/cluster_write_cmd.cpp b/src/mongo/s/commands/cluster_write_cmd.cpp
index e1b8a7a41e2..5732d1243d3 100644
--- a/src/mongo/s/commands/cluster_write_cmd.cpp
+++ b/src/mongo/s/commands/cluster_write_cmd.cpp
@@ -190,14 +190,14 @@ boost::optional<WouldChangeOwningShardInfo> getWouldChangeOwningShardErrorInfo(
  * inserts the new one. Returns whether or not we actually complete the delete and insert.
  */
 bool handleWouldChangeOwningShardError(OperationContext* opCtx,
-                                       const BatchedCommandRequest& request,
+                                       BatchedCommandRequest* request,
                                        BatchedCommandResponse* response,
                                        BatchWriteExecStats stats) {
     auto txnRouter = TransactionRouter::get(opCtx);
     bool isRetryableWrite = opCtx->getTxnNumber() && !txnRouter;
 
     auto wouldChangeOwningShardErrorInfo =
-        getWouldChangeOwningShardErrorInfo(opCtx, request, response, !isRetryableWrite);
+        getWouldChangeOwningShardErrorInfo(opCtx, *request, response, !isRetryableWrite);
     if (!wouldChangeOwningShardErrorInfo)
         return false;
 
@@ -214,12 +214,17 @@ bool handleWouldChangeOwningShardError(OperationContext* opCtx,
             auto& readConcernArgs = repl::ReadConcernArgs::get(opCtx);
             readConcernArgs = repl::ReadConcernArgs(repl::ReadConcernLevel::kLocalReadConcern);
 
+            // Ensure the retried operation does not include WC inside the transaction.  The
+            // transaction commit will still use the WC, because it uses the WC from the opCtx
+            // (which has been set previously in Strategy).
+            request->unsetWriteConcern();
+
             documentShardKeyUpdateUtil::startTransactionForShardKeyUpdate(opCtx);
             // Clear the error details from the response object before sending the write again
             response->unsetErrDetails();
-            ClusterWriter::write(opCtx, request, &stats, response);
+            ClusterWriter::write(opCtx, *request, &stats, response);
             wouldChangeOwningShardErrorInfo =
-                getWouldChangeOwningShardErrorInfo(opCtx, request, response, !isRetryableWrite);
+                getWouldChangeOwningShardErrorInfo(opCtx, *request, response, !isRetryableWrite);
             if (!wouldChangeOwningShardErrorInfo)
                 uassertStatusOK(response->toStatus());
 
@@ -228,7 +233,7 @@ bool handleWouldChangeOwningShardError(OperationContext* opCtx,
             // new one.
             updatedShardKey = wouldChangeOwningShardErrorInfo &&
                 documentShardKeyUpdateUtil::updateShardKeyForDocument(
-                                  opCtx, request.getNS(), wouldChangeOwningShardErrorInfo.get());
+                                  opCtx, request->getNS(), wouldChangeOwningShardErrorInfo.get());
 
             // If the operation was an upsert, record the _id of the new document.
             if (updatedShardKey && wouldChangeOwningShardErrorInfo->getShouldUpsert()) {
@@ -272,7 +277,7 @@ bool handleWouldChangeOwningShardError(OperationContext* opCtx,
         try {
             // Delete the original document and insert the new one
             updatedShardKey = documentShardKeyUpdateUtil::updateShardKeyForDocument(
-                opCtx, request.getNS(), wouldChangeOwningShardErrorInfo.get());
+                opCtx, request->getNS(), wouldChangeOwningShardErrorInfo.get());
 
             // If the operation was an upsert, record the _id of the new document.
             if (updatedShardKey && wouldChangeOwningShardErrorInfo->getShouldUpsert()) {
@@ -441,7 +446,7 @@ private:
         bool updatedShardKey = false;
         if (_batchedRequest.getBatchType() == BatchedCommandRequest::BatchType_Update) {
             updatedShardKey =
-                handleWouldChangeOwningShardError(opCtx, batchedRequest, &response, stats);
+                handleWouldChangeOwningShardError(opCtx, &batchedRequest, &response, stats);
         }
 
         // Populate the lastError object based on the write response
diff --git a/src/mongo/s/commands/commands_public.cpp b/src/mongo/s/commands/commands_public.cpp
index 1c20246854e..ad038b48066 100644
--- a/src/mongo/s/commands/commands_public.cpp
+++ b/src/mongo/s/commands/commands_public.cpp
@@ -144,7 +144,8 @@ protected:
 
         // Here, we first filter the command before appending an UNSHARDED shardVersion, because
         // "shardVersion" is one of the fields that gets filtered out.
-        BSONObj filteredCmdObj(CommandHelpers::filterCommandRequestForPassthrough(cmdObj));
+        BSONObj filteredCmdObj(applyReadWriteConcern(
+            opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)));
         BSONObj filteredCmdObjWithVersion(
             appendShardVersion(filteredCmdObj, ChunkVersion::UNSHARDED()));
 
@@ -235,8 +236,8 @@ public:
                 opCtx,
                 ReadPreferenceSetting(ReadPreference::PrimaryOnly),
                 "admin",
-                configsvrRenameCollectionRequest.toBSON(
-                    CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+                configsvrRenameCollectionRequest.toBSON(applyReadWriteConcern(
+                    opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj))),
                 Shard::RetryPolicy::kIdempotent));
 
             uassertStatusOK(cmdResponse.commandStatus);
@@ -260,8 +261,10 @@ public:
             NamespaceString::kAdminDb,
             fromNss,
             fromRoutingInfo,
-            appendAllowImplicitCreate(CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
-                                      true),
+            appendAllowImplicitCreate(
+                applyReadWriteConcern(
+                    opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
+                true),
             Shard::RetryPolicy::kNoRetry,
             &result);
     }
@@ -310,7 +313,8 @@ public:
             dbName,
             nss,
             routingInfo,
-            CommandHelpers::filterCommandRequestForPassthrough(cmdObj),
+            applyReadWriteConcern(
+                opCtx, this, CommandHelpers::filterCommandRequestForPassthrough(cmdObj)),
             Shard::RetryPolicy::kIdempotent,
             &result);
     }
@@ -494,7 +498,7 @@ public:
             opCtx,
             dbName,
             dbInfoStatus.getValue(),
-            newCmd,
+            applyReadWriteConcern(opCtx, this, newCmd),
             nss,
             &result,
             uassertStatusOK(AuthorizationSession::get(opCtx->getClient())
@@ -554,7 +558,7 @@ public:
             opCtx,
             nss.db(),
             routingInfo.db(),
-            cmdObj,
+            applyReadWriteConcern(opCtx, this, cmdObj),
             nss,
             &result,
             {Privilege(ResourcePattern::forExactNamespace(nss), ActionType::listIndexes)});
diff --git a/src/mongo/s/commands/strategy.cpp b/src/mongo/s/commands/strategy.cpp
index 3bcb77f840c..631438a95bf 100644
--- a/src/mongo/s/commands/strategy.cpp
+++ b/src/mongo/s/commands/strategy.cpp
@@ -57,6 +57,7 @@
 #include "mongo/db/query/find_common.h"
 #include "mongo/db/query/getmore_request.h"
 #include "mongo/db/query/query_request.h"
+#include "mongo/db/read_write_concern_defaults.h"
 #include "mongo/db/stats/counters.h"
 #include "mongo/db/transaction_validation.h"
 #include "mongo/db/views/resolved_view.h"
@@ -243,23 +244,6 @@ void execCommandClient(OperationContext* opCtx,
         globalOpCounters.gotCommand();
     }
 
-    auto wcResult = uassertStatusOK(WriteConcernOptions::extractWCFromCommand(request.body));
-
-    bool supportsWriteConcern = invocation->supportsWriteConcern();
-    if (!supportsWriteConcern && !wcResult.usedDefault) {
-        // This command doesn't do writes so it should not be passed a writeConcern.
-        // If we did not use the default writeConcern, one was provided when it shouldn't have
-        // been by the user.
-        auto body = result->getBodyBuilder();
-        CommandHelpers::appendCommandStatusNoThrow(
-            body, Status(ErrorCodes::InvalidOptions, "Command does not support writeConcern"));
-        return;
-    }
-
-    if (TransactionRouter::get(opCtx)) {
-        validateWriteConcernForTransaction(wcResult, c->getName());
-    }
-
     auto& readConcernArgs = repl::ReadConcernArgs::get(opCtx);
     if (readConcernArgs.getLevel() == repl::ReadConcernLevel::kSnapshotReadConcern) {
         uassert(ErrorCodes::InvalidOptions,
@@ -280,24 +264,13 @@ void execCommandClient(OperationContext* opCtx,
     }
 
     auto txnRouter = TransactionRouter::get(opCtx);
-    if (!supportsWriteConcern) {
-        if (txnRouter) {
-            invokeInTransactionRouter(opCtx, invocation, result);
-        } else {
-            invocation->run(opCtx, result);
-        }
+    if (txnRouter) {
+        invokeInTransactionRouter(opCtx, invocation, result);
     } else {
-        // Change the write concern while running the command.
-        const auto oldWC = opCtx->getWriteConcern();
-        ON_BLOCK_EXIT([&] { opCtx->setWriteConcern(oldWC); });
-        opCtx->setWriteConcern(wcResult);
-
-        if (txnRouter) {
-            invokeInTransactionRouter(opCtx, invocation, result);
-        } else {
-            invocation->run(opCtx, result);
-        }
+        invocation->run(opCtx, result);
+    }
 
+    if (invocation->supportsWriteConcern()) {
         failCommand.executeIf(
             [&](const BSONObj& data) {
                 result->getBodyBuilder().append(data["writeConcernError"]);
@@ -393,6 +366,8 @@ void runCommand(OperationContext* opCtx,
     auto allowTransactionsOnConfigDatabase = false;
     validateSessionOptions(osi, command->getName(), nss, allowTransactionsOnConfigDatabase);
 
+    auto wc = uassertStatusOK(WriteConcernOptions::extractWCFromCommand(request.body));
+
     auto& readConcernArgs = repl::ReadConcernArgs::get(opCtx);
     auto readConcernParseStatus = [&]() {
         // We must obtain the client lock to set the ReadConcernArgs on the operation
@@ -440,6 +415,39 @@ void runCommand(OperationContext* opCtx,
             txnRouter.beginOrContinueTxn(opCtx, *txnNumber, transactionAction);
         }
 
+        bool supportsWriteConcern = invocation->supportsWriteConcern();
+        if (!supportsWriteConcern && !wc.usedDefault) {
+            // This command doesn't do writes so it should not be passed a writeConcern.
+            // If we did not use the default writeConcern, one was provided when it shouldn't have
+            // been by the user.
+            auto responseBuilder = replyBuilder->getBodyBuilder();
+            CommandHelpers::appendCommandStatusNoThrow(
+                responseBuilder,
+                Status(ErrorCodes::InvalidOptions, "Command does not support writeConcern"));
+            return;
+        }
+
+        if (supportsWriteConcern && wc.usedDefault &&
+            (!TransactionRouter::get(opCtx) ||
+             commandSupportsWriteConcernInTransaction(commandName))) {
+            // This command supports WC, but wasn't given one - so apply the default, if there is
+            // one.
+            if (const auto wcDefault = ReadWriteConcernDefaults::get(opCtx->getServiceContext())
+                                           .getDefaultWriteConcern()) {
+                wc = *wcDefault;
+                LOG(2) << "Applying default writeConcern on " << request.getCommandName() << " of "
+                       << wcDefault->toBSON();
+            }
+        }
+
+        if (TransactionRouter::get(opCtx)) {
+            validateWriteConcernForTransaction(wc, commandName);
+        }
+
+        if (supportsWriteConcern) {
+            opCtx->setWriteConcern(wc);
+        }
+
         for (int tries = 0;; ++tries) {
             // Try kMaxNumStaleVersionRetries times. On the last try, exceptions are rethrown.
             bool canRetry = tries < kMaxNumStaleVersionRetries - 1;
diff --git a/src/mongo/s/write_ops/batch_write_op.cpp b/src/mongo/s/write_ops/batch_write_op.cpp
index bba83f7ad6e..309d3f4f83e 100644
--- a/src/mongo/s/write_ops/batch_write_op.cpp
+++ b/src/mongo/s/write_ops/batch_write_op.cpp
@@ -542,6 +542,9 @@ BatchedCommandRequest BatchWriteOp::buildBatchRequest(
             // writeErrors
             request.setWriteConcern(upgradeWriteConcern(_clientRequest.getWriteConcern()));
         }
+    } else if (!TransactionRouter::get(_opCtx)) {
+        // Apply the WC from the opCtx (except if in a transaction).
+        request.setWriteConcern(_opCtx->getWriteConcern().toBSON());
     }
 
     request.setAllowImplicitCreate(_clientRequest.isImplicitCreateAllowed());
diff --git a/src/mongo/s/write_ops/batched_command_request.h b/src/mongo/s/write_ops/batched_command_request.h
index eb0d3439e9e..540f2c5f34d 100644
--- a/src/mongo/s/write_ops/batched_command_request.h
+++ b/src/mongo/s/write_ops/batched_command_request.h
@@ -92,6 +92,10 @@ public:
         _writeConcern = writeConcern.getOwned();
     }
 
+    void unsetWriteConcern() {
+        _writeConcern = boost::none;
+    }
+
     bool hasWriteConcern() const {
         return _writeConcern.is_initialized();
     }