Re: [PATCH 3/3] f2fs: support clone_file_range

From: Christoph Hellwig
Date: Mon Jul 18 2016 - 23:48:01 EST

On Sat, Jul 16, 2016 at 11:24:27PM -0700, Jaegeuk Kim wrote:
> This patch implements clone_file_range in f2fs.


> +int f2fs_clone_file_range(struct file *file_in, loff_t pos_in,
> + struct file *file_out, loff_t pos_out, u64 len)
> +{
> + return f2fs_clone_files(file_in, pos_in, file_out, pos_out, len);
> +}
> +

Falling back from copy to clone should be done in the VFS. I look into
implementing the fallback, and the code is trivial, but we don't seem
to have any useful coverage for copy_file_range yet, so I didn't dare
to add it yet. How did you test copy and clone in f2fs? And how did
you handle the difference in corner cases (e.g. the lacking 0 special
case in copy)?