From 148de7ac6cf010d62a15f8a72881a21102b13429 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Mon, 16 Mar 2026 15:41:33 -0700
Subject: [PATCH] Honor keepLocalDatFile in tier upload shortcut

---
 seaweed-volume/src/server/grpc_server.rs | 28 +++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/seaweed-volume/src/server/grpc_server.rs b/seaweed-volume/src/server/grpc_server.rs
index f6a99d807..14c115292 100644
--- a/seaweed-volume/src/server/grpc_server.rs
+++ b/seaweed-volume/src/server/grpc_server.rs
@@ -24,6 +24,10 @@ use super::volume_server::VolumeServerState;
 
 type BoxStream<T> = Pin<Box<dyn Stream<Item = Result<T, Status>> + Send + 'static>>;
 
+fn volume_is_remote_only(dat_path: &str, has_remote_file: bool) -> bool {
+    has_remote_file && !std::path::Path::new(dat_path).exists()
+}
+
 struct WriteThrottler {
     bytes_per_second: i64,
     last_size_counter: i64,
@@ -2401,8 +2405,11 @@ impl VolumeServer for VolumeGrpcService {
                 )));
             }
 
-            // Check if already on remote
-            if vol.has_remote_file {
+            let dat_path = vol.dat_path();
+
+            // Match Go's DiskFile check: if the .dat file is still local, we can
+            // keep tiering it even when remote file entries already exist.
+            if volume_is_remote_only(&dat_path, vol.has_remote_file) {
                 // Already on remote -- return empty stream (matches Go: returns nil)
                 let stream = tokio_stream::empty();
                 return Ok(Response::new(
@@ -2424,7 +2431,7 @@ impl VolumeServer for VolumeGrpcService {
                 }
             }
 
-            vol.dat_path()
+            dat_path
         };
 
         // Look up the S3 tier backend
@@ -3668,4 +3675,19 @@ mod tests {
     fn test_parse_grpc_address_invalid() {
         assert!(parse_grpc_address("no-colon").is_err());
     }
+
+    #[test]
+    fn test_volume_is_remote_only_requires_missing_local_dat_file() {
+        let temp_dir = tempfile::tempdir().unwrap();
+        let dat_path = temp_dir.path().join("1.dat");
+        std::fs::write(&dat_path, b"dat").unwrap();
+
+        assert!(!volume_is_remote_only(dat_path.to_str().unwrap(), true));
+        assert!(!volume_is_remote_only(dat_path.to_str().unwrap(), false));
+
+        std::fs::remove_file(&dat_path).unwrap();
+
+        assert!(volume_is_remote_only(dat_path.to_str().unwrap(), true));
+        assert!(!volume_is_remote_only(dat_path.to_str().unwrap(), false));
+    }
 }