From e1bf46c6a53acee31df8088ce0d94541a3e629fb Mon Sep 17 00:00:00 2001
From: Nicola Murino <nicola.murino@gmail.com>
Date: Thu, 27 May 2021 20:14:12 +0200
Subject: [PATCH] local fs rename: if it fails with a cross device error try a
 copy

I don't want to add a new setting for this, at least until we get the
first complain for a slow rename :)

Fixes #440
---
 vfs/fileinfo_windows.go               |  7 -------
 vfs/osfs.go                           | 11 +++++++++--
 vfs/{fileinfo_unix.go => sys_unix.go} |  7 +++++++
 vfs/sys_windows.go                    | 16 ++++++++++++++++
 4 files changed, 32 insertions(+), 9 deletions(-)
 delete mode 100644 vfs/fileinfo_windows.go
 rename vfs/{fileinfo_unix.go => sys_unix.go} (77%)
 create mode 100644 vfs/sys_windows.go

diff --git a/vfs/fileinfo_windows.go b/vfs/fileinfo_windows.go
deleted file mode 100644
index 9947677c..00000000
--- a/vfs/fileinfo_windows.go
+++ /dev/null
@@ -1,7 +0,0 @@
-package vfs
-
-import "syscall"
-
-func (fi FileInfo) getFileInfoSys() interface{} {
-	return syscall.Win32FileAttributeData{}
-}
diff --git a/vfs/osfs.go b/vfs/osfs.go
index d749a9f2..c2c913e2 100644
--- a/vfs/osfs.go
+++ b/vfs/osfs.go
@@ -11,6 +11,7 @@ import (
 	"time"
 
 	"github.com/eikenb/pipeat"
+	fscopy "github.com/otiai10/copy"
 	"github.com/pkg/sftp"
 	"github.com/rs/xid"
 
@@ -98,8 +99,14 @@ func (*OsFs) Create(name string, flag int) (File, *PipeWriter, func(), error) {
 }
 
 // Rename renames (moves) source to target
-func (*OsFs) Rename(source, target string) error {
-	return os.Rename(source, target)
+func (fs *OsFs) Rename(source, target string) error {
+	err := os.Rename(source, target)
+	if err != nil && isCrossDeviceError(err) {
+		fsLog(fs, logger.LevelWarn, "cross device error detected while renaming %#v -> %#v. Trying a copy, this could take a long time",
+			source, target)
+		return fscopy.Copy(source, target)
+	}
+	return err
 }
 
 // Remove removes the named file or (empty) directory.
diff --git a/vfs/fileinfo_unix.go b/vfs/sys_unix.go
similarity index 77%
rename from vfs/fileinfo_unix.go
rename to vfs/sys_unix.go
index a28ed3ea..6c98f0f0 100644
--- a/vfs/fileinfo_unix.go
+++ b/vfs/sys_unix.go
@@ -3,8 +3,11 @@
 package vfs
 
 import (
+	"errors"
 	"os"
 	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 var (
@@ -27,3 +30,7 @@ func (fi FileInfo) getFileInfoSys() interface{} {
 		Uid: uint32(defaultUID),
 		Gid: uint32(defaultGID)}
 }
+
+func isCrossDeviceError(err error) bool {
+	return errors.Is(err, unix.EXDEV)
+}
diff --git a/vfs/sys_windows.go b/vfs/sys_windows.go
new file mode 100644
index 00000000..0521a2e8
--- /dev/null
+++ b/vfs/sys_windows.go
@@ -0,0 +1,16 @@
+package vfs
+
+import (
+	"errors"
+	"syscall"
+
+	"golang.org/x/sys/windows"
+)
+
+func (fi FileInfo) getFileInfoSys() interface{} {
+	return syscall.Win32FileAttributeData{}
+}
+
+func isCrossDeviceError(err error) bool {
+	return errors.Is(err, windows.ERROR_NOT_SAME_DEVICE)
+}