From d0104b9f9bd96e008fe3fbe8e5658cae605525b1 Mon Sep 17 00:00:00 2001
From: Alex Auvolat <lx@deuxfleurs.fr>
Date: Fri, 14 Feb 2025 16:14:59 +0100
Subject: [PATCH] block manager: write blocks only to currently active layout
 version (fix #815)

avoid wastefully writing blocks to nodes that will discard them as soon
as the layout migration is finished
---
 src/block/manager.rs     | 4 ++--
 src/rpc/layout/helper.rs | 5 +++++
 2 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/block/manager.rs b/src/block/manager.rs
index 537e1fc1..572bdadd 100644
--- a/src/block/manager.rs
+++ b/src/block/manager.rs
@@ -370,7 +370,7 @@ impl BlockManager {
 		prevent_compression: bool,
 		order_tag: Option<OrderTag>,
 	) -> Result<(), Error> {
-		let who = self.replication.write_sets(&hash);
+		let who = self.system.cluster_layout().current_storage_nodes_of(&hash);
 
 		let compression_level = self.compression_level.filter(|_| !prevent_compression);
 		let (header, bytes) = DataBlock::from_buffer(data, compression_level)
@@ -396,7 +396,7 @@ impl BlockManager {
 			.rpc_helper()
 			.try_write_many_sets(
 				&self.endpoint,
-				who.as_ref(),
+				&[who],
 				put_block_rpc,
 				RequestStrategy::with_priority(PRIO_NORMAL | PRIO_SECONDARY)
 					.with_drop_on_completion(permit)
diff --git a/src/rpc/layout/helper.rs b/src/rpc/layout/helper.rs
index 44c826f9..c08a5629 100644
--- a/src/rpc/layout/helper.rs
+++ b/src/rpc/layout/helper.rs
@@ -219,6 +219,11 @@ impl LayoutHelper {
 		ret
 	}
 
+	pub fn current_storage_nodes_of(&self, position: &Hash) -> Vec<Uuid> {
+		let ver = self.current();
+		ver.nodes_of(position, ver.replication_factor).collect()
+	}
+
 	pub fn trackers_hash(&self) -> Hash {
 		self.trackers_hash
 	}