# \[PATCH v4 9/9\] btrfs: btrfs\_copy\_file\_range() only supports reflinks

- From: Anna Schumaker \<hidden\>
- Date: 2015-09-29 18:05:36 
- List: linux-api
- Page: https://ratatoskr.run/linux-api/2015/09/100059
- Thread: https://ratatoskr.run/linux-nfs/2015/09/100062/t.md

```text
Reject copies that don't have the COPY_FR_REFLINK flag set.

Signed-off-by: Anna Schumaker <redacted>
Reviewed-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/ioctl.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4311554..2e14b91 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -44,6 +44,7 @@
 #include <linux/uuid.h>
 #include <linux/btrfs.h>
 #include <linux/uaccess.h>
+#include <linux/copy.h>
 #include "ctree.h"
 #include "disk-io.h"
 #include "transaction.h"
@@ -3848,6 +3849,9 @@ ssize_t btrfs_copy_file_range(struct file *file_in, loff_t pos_in,
 {
 	ssize_t ret;
 
+	if (!(flags & COPY_FR_REFLINK))
+		return -EOPNOTSUPP;
+
 	ret = btrfs_clone_files(file_out, file_in, pos_in, len, pos_out);
 	if (ret == 0)
 		ret = len;
-- 
2.5.3

```