SERVER-27892 Don't call canAcceptWritesFor in mapReduce until after grabing locks

1 files changed, 10 insertions, 9 deletions

diff --git a/src/mongo/db/commands/mr.cpp b/src/mongo/db/commands/mr.cpp
index ffeecffaca5..50e6edc44a5 100644
--- a/src/mongo/db/commands/mr.cpp
+++ b/src/mongo/db/commands/mr.cpp
@@ -1436,15 +1436,6 @@ public:
                 Status(ErrorCodes::NamespaceNotFound,
                        str::stream() << "namespace does not exist: " << config.nss.ns()));
         }
-        if (state.isOnDisk()) {
-            // this means that it will be doing a write operation, make sure we are on Master
-            // ideally this check should be in slaveOk(), but at that point config is not known
-            if (!repl::getGlobalReplicationCoordinator()->canAcceptWritesFor_UNSAFE(opCtx,
-                                                                                    config.nss)) {
-                errmsg = "not master";
-                return false;
-            }
-        }
 
         try {
             state.init();
@@ -1485,6 +1476,16 @@ public:
                 // Need lock and context to use it
                 unique_ptr<AutoGetDb> scopedAutoDb(new AutoGetDb(opCtx, config.nss.db(), MODE_S));
 
+                if (state.isOnDisk()) {
+                    // this means that it will be doing a write operation, make sure it is safe to
+                    // do so.
+                    if (!repl::getGlobalReplicationCoordinator()->canAcceptWritesFor(opCtx,
+                                                                                     config.nss)) {
+                        uasserted(ErrorCodes::NotMaster, "not master");
+                        return false;
+                    }
+                }
+
                 auto qr = stdx::make_unique<QueryRequest>(config.nss);
                 qr->setFilter(config.filter);
                 qr->setSort(config.sort);