From b5a9cad2bf250090c6ef15f1a92f17a3de679a0f Mon Sep 17 00:00:00 2001
From: Lucas Jeub <lucas.jeub@pometry.com>
Date: Fri, 18 Sep 2026 10:54:05 +0200
Subject: [PATCH] quick fix for the subgraph creation deadlock with reproducing
 test

---
 raphtory-graphql/src/lib.rs       | 16 ++++++++++++++++
 raphtory-graphql/src/model/mod.rs |  6 +++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/raphtory-graphql/src/lib.rs b/raphtory-graphql/src/lib.rs
index 93ea5e743a..2627ea1b6e 100644
--- a/raphtory-graphql/src/lib.rs
+++ b/raphtory-graphql/src/lib.rs
@@ -3671,4 +3671,20 @@ mod graphql_test {
             } } } })
         );
     }
+
+    #[tokio::test]
+    async fn test_subgraph_on_uncached() {
+        let tmp_dir = TempDir::new().unwrap();
+        let g = Graph::new();
+        g.add_node(0, 1, NO_PROPS, None, None).unwrap();
+        setup_with_graphs(&[("g", g.into())], tmp_dir.path()).await; // write to folder and drop the cache
+        let setup = setup_with_graphs(&[], tmp_dir.path()).await; // new data pointing at the folder with the graph unloaded
+
+        let query = r#"
+            mutation {
+                createSubgraph(newPath: "sg", parentPath: "g", nodes: [1], overwrite: false)
+            }"#;
+        let res = run_mutation(&setup.schema, query).await;
+        assert_eq!(res.errors, vec![], "{:?}", res.errors);
+    }
 }
diff --git a/raphtory-graphql/src/model/mod.rs b/raphtory-graphql/src/model/mod.rs
index 0d07327893..57a888e7a4 100644
--- a/raphtory-graphql/src/model/mod.rs
+++ b/raphtory-graphql/src/model/mod.rs
@@ -728,13 +728,13 @@ impl Mut {
         let data = ctx.data_unchecked::<Data>();
         let dst_ns = parent_namespace(&new_path);
         require_namespace_write(ctx, &data.auth_policy, dst_ns, &new_path, "create")?;
+        let (_, parent_graph) = data
+            .get_graph_requiring_read(ctx, parent_path, None)
+            .await?;
         let folder = data
             .work_dir_write()
             .await
             .validate_path_for_insert(&new_path, overwrite)?;
-        let (_, parent_graph) = data
-            .get_graph_requiring_read(ctx, parent_path, None)
-            .await?;
         let folder_clone = folder.clone();
         let new_subgraph = blocking_compute(move || {
             let subgraph = parent_graph.subgraph(nodes);