From f2fca650993b81e6083a51ae411c272074a82c38 Mon Sep 17 00:00:00 2001
From: Allison Easton <allison.easton@mongodb.com>
Date: Fri, 25 Feb 2022 10:42:47 +0000
Subject: SERVER-63905 ConfigureCollectionBalancing command should refresh
 collection routing info

---
 .../db/s/config/sharding_catalog_manager_collection_operations.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/mongo/db/s/config/sharding_catalog_manager_collection_operations.cpp b/src/mongo/db/s/config/sharding_catalog_manager_collection_operations.cpp
index fb34606a968..aafe803ef45 100644
--- a/src/mongo/db/s/config/sharding_catalog_manager_collection_operations.cpp
+++ b/src/mongo/db/s/config/sharding_catalog_manager_collection_operations.cpp
@@ -609,7 +609,11 @@ void ShardingCatalogManager::configureCollectionBalancing(
         return;
     }
 
-    const auto cm = Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfo(opCtx, nss);
+    // Take _kChunkOpLock in exclusive mode to prevent concurrent chunk splits, merges, and
+    // migrations
+    Lock::ExclusiveLock lk(opCtx, opCtx->lockState(), _kChunkOpLock);
+    const auto cm = uassertStatusOK(
+        Grid::get(opCtx)->catalogCache()->getShardedCollectionRoutingInfoWithRefresh(opCtx, nss));
     const auto uuid = cm.getUUID();
 
     std::set<ShardId> shardsIds;
@@ -639,7 +643,6 @@ void ShardingCatalogManager::configureCollectionBalancing(
             bumpCollectionMinorVersionInTxn(opCtx, nss, txnNumber);
         });
 
-
     const auto executor = Grid::get(opCtx)->getExecutorPool()->getFixedExecutor();
     sharding_util::tellShardsToRefreshCollection(
         opCtx,
-- 
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