On Wed, Oct 24, 2018 at 10:59 PM Olga Kornievskaia
<olga.kornievskaia@xxxxxxxxx> wrote:
>
> From: Olga Kornievskaia <kolga@xxxxxxxxxx>
>
> VFS copy_file_range was relaxed to allow for cross-device copy.
> Add a check for now, to disallow cross-device copy offload until
> appropriate support is added.
>
> Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
> `
> ---
> fs/overlayfs/file.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
> index aeaefd2..5282853 100644
> --- a/fs/overlayfs/file.c
> +++ b/fs/overlayfs/file.c
> @@ -483,6 +483,9 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
> struct file *file_out, loff_t pos_out,
> size_t len, unsigned int flags)
> {
> + if (file_in->f_inode->i_sb != file_out->f_inode->i_sb)
> + return -EXDEV;
>
Note that this could be relaxed later on to same fs type
allowing for cross container copy_file_range() to be performced
as clone_file_range() when upper is a shared fs with clone support.
Don't worry about it though, I can make this change later after testing
the use case.
As long as this patch comes in the series *before* relaxing the VFS check,
You may add:
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Thanks,
Amir.
