SERVER-43941: Add "errorLabels" field to failCommand failpoint

7 files changed, 56 insertions, 11 deletions

diff --git a/src/mongo/db/SConscript b/src/mongo/db/SConscript
index 3375d49d295..8c051a3916a 100644
--- a/src/mongo/db/SConscript
+++ b/src/mongo/db/SConscript
@@ -1335,6 +1335,7 @@ env.Library(
         'error_labels.cpp',
     ],
     LIBDEPS=[
+        'commands',
         'logical_session_id',
     ],
 )
diff --git a/src/mongo/db/commands.cpp b/src/mongo/db/commands.cpp
index fd6c28d145c..0345bd31680 100644
--- a/src/mongo/db/commands.cpp
+++ b/src/mongo/db/commands.cpp
@@ -50,6 +50,7 @@
 #include "mongo/db/command_generic_argument.h"
 #include "mongo/db/commands/test_commands_enabled.h"
 #include "mongo/db/curop.h"
+#include "mongo/db/error_labels.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/namespace_string.h"
 #include "mongo/db/read_write_concern_defaults.h"
@@ -471,6 +472,11 @@ constexpr StringData CommandHelpers::kHelpFieldName;
 MONGO_FAIL_POINT_DEFINE(failCommand);
 MONGO_FAIL_POINT_DEFINE(waitInCommandMarkKillOnClientDisconnect);
 
+// A decoration representing error labels specified in a failCommand failpoint that has affected a
+// command in this OperationContext.
+const OperationContext::Decoration<boost::optional<BSONArray>> errorLabelsOverride =
+    OperationContext::declareDecoration<boost::optional<BSONArray>>();
+
 bool CommandHelpers::shouldActivateFailCommandFailPoint(const BSONObj& data,
                                                         StringData cmdName,
                                                         Client* client,
@@ -515,7 +521,16 @@ void CommandHelpers::evaluateFailCommandFailPoint(OperationContext* opCtx,
     bool hasErrorCode;
     long long errorCode;
     failCommand.executeIf(
-        [&](const BSONObj&) {
+        [&](const BSONObj& data) {
+            if (data.hasField(kErrorLabelsFieldName) &&
+                data[kErrorLabelsFieldName].type() == Array) {
+                // Propagate error labels specified in the failCommand failpoint to the
+                // OperationContext decoration to override getErrorLabels() behaviors.
+                invariant(!errorLabelsOverride(opCtx));
+                errorLabelsOverride(opCtx).emplace(
+                    data.getObjectField(kErrorLabelsFieldName).getOwned());
+            }
+
             if (closeConnection) {
                 opCtx->getClient()->session()->end();
                 log() << "Failing command '" << commandName
diff --git a/src/mongo/db/commands.h b/src/mongo/db/commands.h
index 6f174a40dfa..ea62ac51fc0 100644
--- a/src/mongo/db/commands.h
+++ b/src/mongo/db/commands.h
@@ -56,6 +56,7 @@ namespace mongo {
 
 extern FailPoint failCommand;
 extern FailPoint waitInCommandMarkKillOnClientDisconnect;
+extern const OperationContext::Decoration<boost::optional<BSONArray>> errorLabelsOverride;
 
 class Command;
 class CommandInvocation;
diff --git a/src/mongo/db/error_labels.cpp b/src/mongo/db/error_labels.cpp
index d56ba6dd82d..383f4f77551 100644
--- a/src/mongo/db/error_labels.cpp
+++ b/src/mongo/db/error_labels.cpp
@@ -28,6 +28,7 @@
  */
 
 #include "mongo/db/error_labels.h"
+#include "mongo/db/commands.h"
 
 namespace mongo {
 
@@ -94,17 +95,28 @@ bool ErrorLabelBuilder::_isCommitOrAbort() const {
         _commandName == "abortTransaction";
 }
 
-BSONObj getErrorLabels(const OperationSessionInfoFromClient& sessionOptions,
+BSONObj getErrorLabels(OperationContext* opCtx,
+                       const OperationSessionInfoFromClient& sessionOptions,
                        const std::string& commandName,
                        boost::optional<ErrorCodes::Error> code,
                        boost::optional<ErrorCodes::Error> wcCode,
                        bool isInternalClient) {
-    BSONArrayBuilder labelArray;
+    if (MONGO_unlikely(errorLabelsOverride(opCtx))) {
+        // This command was failed by a failCommand failpoint. Thus, we return the errorLabels
+        // specified in the failpoint to supress any other error labels that would otherwise be
+        // returned by the ErrorLabelBuilder.
+        if (errorLabelsOverride(opCtx).get().isEmpty()) {
+            return BSONObj();
+        } else {
+            return BSON(kErrorLabelsFieldName << errorLabelsOverride(opCtx).get());
+        }
+    }
 
+    BSONArrayBuilder labelArray;
     ErrorLabelBuilder labelBuilder(sessionOptions, commandName, code, wcCode, isInternalClient);
     labelBuilder.build(labelArray);
 
-    return (labelArray.arrSize() > 0) ? BSON("errorLabels" << labelArray.arr()) : BSONObj();
+    return (labelArray.arrSize() > 0) ? BSON(kErrorLabelsFieldName << labelArray.arr()) : BSONObj();
 }
 
 bool isTransientTransactionError(ErrorCodes::Error code,
diff --git a/src/mongo/db/error_labels.h b/src/mongo/db/error_labels.h
index 7490d862372..6066963fa98 100644
--- a/src/mongo/db/error_labels.h
+++ b/src/mongo/db/error_labels.h
@@ -32,7 +32,7 @@
 #include "mongo/db/logical_session_id.h"
 
 namespace mongo {
-
+static constexpr StringData kErrorLabelsFieldName = "errorLabels"_sd;
 namespace ErrorLabel {
 // PLEASE CONSULT DRIVERS BEFORE ADDING NEW ERROR LABELS.
 static constexpr StringData kTransientTransaction = "TransientTransactionError"_sd;
@@ -71,7 +71,8 @@ private:
 /**
  * Returns the error labels for the given error.
  */
-BSONObj getErrorLabels(const OperationSessionInfoFromClient& sessionOptions,
+BSONObj getErrorLabels(OperationContext* opCtx,
+                       const OperationSessionInfoFromClient& sessionOptions,
                        const std::string& commandName,
                        boost::optional<ErrorCodes::Error> code,
                        boost::optional<ErrorCodes::Error> wcCode,
diff --git a/src/mongo/db/service_entry_point_common.cpp b/src/mongo/db/service_entry_point_common.cpp
index c64241e5bff..4a42657c92a 100644
--- a/src/mongo/db/service_entry_point_common.cpp
+++ b/src/mongo/db/service_entry_point_common.cpp
@@ -628,6 +628,14 @@ bool runCommandImpl(OperationContext* opCtx,
                 [&](const BSONObj& data) {
                     bb.append(data["writeConcernError"]);
                     reallyWait = false;
+                    if (data.hasField(kErrorLabelsFieldName) &&
+                        data[kErrorLabelsFieldName].type() == Array) {
+                        // Propagate error labels specified in the failCommand failpoint to the
+                        // OperationContext decoration to override getErrorLabels() behaviors.
+                        invariant(!errorLabelsOverride(opCtx));
+                        errorLabelsOverride(opCtx).emplace(
+                            data.getObjectField(kErrorLabelsFieldName).getOwned());
+                    }
                 },
                 [&](const BSONObj& data) {
                     return CommandHelpers::shouldActivateFailCommandFailPoint(
@@ -719,8 +727,8 @@ bool runCommandImpl(OperationContext* opCtx,
         }
         auto isInternalClient = opCtx->getClient()->session() &&
             (opCtx->getClient()->session()->getTags() & transport::Session::kInternalClient);
-        auto errorLabels =
-            getErrorLabels(sessionOptions, command->getName(), code, wcCode, isInternalClient);
+        auto errorLabels = getErrorLabels(
+            opCtx, sessionOptions, command->getName(), code, wcCode, isInternalClient);
         replyBuilder->getBodyBuilder().appendElements(errorLabels);
     }
 
@@ -1024,8 +1032,8 @@ void execCommandDatabase(OperationContext* opCtx,
         }
         auto isInternalClient = opCtx->getClient()->session() &&
             (opCtx->getClient()->session()->getTags() & transport::Session::kInternalClient);
-        auto errorLabels =
-            getErrorLabels(sessionOptions, command->getName(), e.code(), wcCode, isInternalClient);
+        auto errorLabels = getErrorLabels(
+            opCtx, sessionOptions, command->getName(), e.code(), wcCode, isInternalClient);
         extraFieldsBuilder.appendElements(errorLabels);
 
         BSONObjBuilder metadataBob;
diff --git a/src/mongo/s/commands/strategy.cpp b/src/mongo/s/commands/strategy.cpp
index 6a4e5f6da85..2f734c11654 100644
--- a/src/mongo/s/commands/strategy.cpp
+++ b/src/mongo/s/commands/strategy.cpp
@@ -274,6 +274,13 @@ void execCommandClient(OperationContext* opCtx,
         failCommand.executeIf(
             [&](const BSONObj& data) {
                 result->getBodyBuilder().append(data["writeConcernError"]);
+                if (data.hasField(kErrorLabelsFieldName) &&
+                    data[kErrorLabelsFieldName].type() == Array) {
+                    auto labels = data.getObjectField(kErrorLabelsFieldName).getOwned();
+                    if (!labels.isEmpty()) {
+                        result->getBodyBuilder().append(kErrorLabelsFieldName, BSONArray(labels));
+                    }
+                }
             },
             [&](const BSONObj& data) {
                 return CommandHelpers::shouldActivateFailCommandFailPoint(
@@ -629,7 +636,7 @@ void runCommand(OperationContext* opCtx,
         // isInternalClient is set to true to suppress mongos from returning the RetryableWriteError
         // label.
         auto errorLabels = getErrorLabels(
-            osi, command->getName(), e.code(), boost::none, true /* isInternalClient */);
+            opCtx, osi, command->getName(), e.code(), boost::none, true /* isInternalClient */);
         errorBuilder->appendElements(errorLabels);
         throw;
     }