> diff --git a/include/uapi/linux/fs.h b/include/uapi/linux/fs.h > index b7b56871029c..dff56813f95a 100644 > --- a/include/uapi/linux/fs.h > +++ b/include/uapi/linux/fs.h > @@ -64,6 +64,9 @@ struct fstrim_range { > __u64 minlen; > }; > > +/* maximum copy offload length, this is set to 128MB based on current testing */ > +#define COPY_MAX_BYTES (1 << 27) This should not be in the UAPI. It is a totally arbitrary internal limit.