Allow duplicate extents in SMB3 not just SMB3.1.1

Enable duplicate extents (cp --reflink) ioctl for SMB3.0 not just
SMB3.1.1 since have verified that this works to Windows 2016
(REFS) and additional testing done at recent plugfest with
SMB3.0 not just SMB3.1.1  This will also make it easier
for Samba.

Signed-off-by: Steve French <steve.french@primarydata.com>
Reviewed-by: David Disseldorp <ddiss@suse.de>
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 18da19f..2f169eb 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -810,7 +810,6 @@
 			    cfile->fid.volatile_fid, cfile->pid, &eof, false);
 }
 
-#ifdef CONFIG_CIFS_SMB311
 static int
 smb2_duplicate_extents(const unsigned int xid,
 			struct cifsFileInfo *srcfile,
@@ -854,8 +853,6 @@
 duplicate_extents_out:
 	return rc;
 }
-#endif /* CONFIG_CIFS_SMB311 */
-
 
 static int
 smb2_set_compression(const unsigned int xid, struct cifs_tcon *tcon,
@@ -1703,6 +1700,7 @@
 	.create_lease_buf = smb3_create_lease_buf,
 	.parse_lease_buf = smb3_parse_lease_buf,
 	.clone_range = smb2_clone_range,
+	.duplicate_extents = smb2_duplicate_extents,
 	.validate_negotiate = smb3_validate_negotiate,
 	.wp_retry_size = smb2_wp_retry_size,
 	.dir_needs_close = smb2_dir_needs_close,