From f2caab6119b37d16340142208a76e51ddc9e8e6b Mon Sep 17 00:00:00 2001
From: ed <s@ocv.me>
Date: Sat, 11 Oct 2025 23:43:09 +0000
Subject: [PATCH] dedup: explicit reflink/ficlone on python<3.14

---
 copyparty/authsrv.py |  2 --
 copyparty/up2k.py    | 28 +++++++++++++++++++++++-----
 copyparty/util.py    |  2 ++
 3 files changed, 25 insertions(+), 7 deletions(-)

diff --git a/copyparty/authsrv.py b/copyparty/authsrv.py
index 3e6b92e2..979fd042 100644
--- a/copyparty/authsrv.py
+++ b/copyparty/authsrv.py
@@ -2868,8 +2868,6 @@ class AuthSrv(object):
 
         if have_reflink:
             t = "WARNING: Reflink-based dedup was requested, but %s. This will not work; files will be full copies instead."
-            if sys.version_info < (3, 14):
-                self.log(t % "your python version is not new enough", 1)
             if not sys.platform.startswith("linux"):
                 self.log(t % "your OS is not Linux", 1)
 
diff --git a/copyparty/up2k.py b/copyparty/up2k.py
index b6032f1e..58bfb445 100644
--- a/copyparty/up2k.py
+++ b/copyparty/up2k.py
@@ -10,6 +10,7 @@ import re
 import shutil
 import stat
 import subprocess as sp
+import sys
 import tempfile
 import threading
 import time
@@ -27,6 +28,7 @@ from .mtag import MParser, MTag
 from .util import (
     E_FS_CRIT,
     E_FS_MEH,
+    HAVE_FICLONE,
     HAVE_SQLITE3,
     SYMTIME,
     VF_CAREFUL,
@@ -88,6 +90,10 @@ if True:  # pylint: disable=using-constant-test
 if TYPE_CHECKING:
     from .svchub import SvcHub
 
+USE_FICLONE = HAVE_FICLONE and sys.version_info < (3, 14)
+if USE_FICLONE:
+    import fcntl
+
 zsg = "avif,avifs,bmp,gif,heic,heics,heif,heifs,ico,j2p,j2k,jp2,jpeg,jpg,jpx,png,tga,tif,tiff,webp"
 ICV_EXTS = set(zsg.split(","))
 
@@ -3530,11 +3536,26 @@ class Up2k(object):
 
         linked = False
         try:
-            if "reflink" in flags:
-                raise Exception("reflink")
+            if rm and bos.path.exists(dst):
+                wunlink(self.log, dst, flags)
+
             if not is_mv and not flags.get("dedup"):
                 raise Exception("dedup is disabled in config")
 
+            if "reflink" in flags:
+                if not USE_FICLONE:
+                    raise Exception("reflink")  # python 3.14 or newer; no need
+                try:
+                    with open(fsenc(src), "rb") as fi, open(fsenc(dst), "wb") as fo:
+                        fcntl.ioctl(fo.fileno(), fcntl.FICLONE, fi.fileno())
+                except:
+                    if bos.path.exists(dst):
+                        wunlink(self.log, dst, flags)
+                    raise
+                if lmod:
+                    bos.utime_c(self.log, dst, int(lmod), False)
+                return
+
             lsrc = src
             ldst = dst
             fs1 = bos.stat(os.path.dirname(src)).st_dev
@@ -3561,9 +3582,6 @@ class Up2k(object):
                 lsrc = lsrc.replace("/", "\\")
                 ldst = ldst.replace("/", "\\")
 
-            if rm and bos.path.exists(dst):
-                wunlink(self.log, dst, flags)
-
             try:
                 if "hardlink" in flags:
                     os.link(fsenc(absreal(src)), fsenc(dst))
diff --git a/copyparty/util.py b/copyparty/util.py
index d8011ddf..4f026a56 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -129,8 +129,10 @@ try:
     import fcntl
 
     HAVE_FCNTL = True
+    HAVE_FICLONE = hasattr(fcntl, "FICLONE")
 except:
     HAVE_FCNTL = False
+    HAVE_FICLONE = False
 
 try:
     import ctypes