From be1115a72248eb3bc22242ebfb0a5f706e69a933 Mon Sep 17 00:00:00 2001
From: oech3 <79379754+oech3@users.noreply.github.com>
Date: Tue, 23 Jun 2026 19:19:26 +0900
Subject: [PATCH] mv: use copy_stream for fast cross-device move

---
 src/uu/mv/Cargo.toml | 1 +
 src/uu/mv/src/mv.rs  | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/uu/mv/Cargo.toml b/src/uu/mv/Cargo.toml
index c252bb3a36b..b7b42cee7d2 100644
--- a/src/uu/mv/Cargo.toml
+++ b/src/uu/mv/Cargo.toml
@@ -28,6 +28,7 @@ rustc-hash = { workspace = true }
 thiserror = { workspace = true }
 uucore = { workspace = true, features = [
   "backup-control",
+  "buf-copy",
   "fs",
   "fsxattr",
   "perms",
diff --git a/src/uu/mv/src/mv.rs b/src/uu/mv/src/mv.rs
index 0e6cbaa3657..719a7409ad9 100644
--- a/src/uu/mv/src/mv.rs
+++ b/src/uu/mv/src/mv.rs
@@ -1310,7 +1310,8 @@ fn rename_file_fallback(
             & 0o7777;
         let mut dst_file = create_dest_restrictive(to, /* nofollow */ true)
             .map_err(|err| io::Error::new(err.kind(), translate!("mv-error-permission-denied")))?;
-        io::copy(&mut &src_file, &mut dst_file)
+        // copy_stream has fast-path for Linux
+        uucore::buf_copy::copy_stream(&mut &src_file, &mut dst_file)
             .map_err(|err| io::Error::new(err.kind(), translate!("mv-error-permission-denied")))?;
 
         #[cfg(not(any(target_os = "macos", target_os = "redox")))]