Re: [PATCH v4 03/10] fs: Introduce ->corrupted_range() for superblock

[Dan Williams <dan.j.williams@intel.com>]

[ drop old linux-nvdimm@lists.01.org, add nvdimm@lists.linux.dev ]

On Thu, Jun 3, 2021 at 6:19 PM Shiyang Ruan <ruansy.fnst@fujitsu.com> wrote:
>
> Memory failure occurs in fsdax mode will finally be handled in
> filesystem.  We introduce this interface to find out files or metadata
> affected by the corrupted range, and try to recover the corrupted data
> if possiable.
>
> Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
> ---
>  include/linux/fs.h | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index c3c88fdb9b2a..92af36c4225f 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -2176,6 +2176,8 @@ struct super_operations {
>                                   struct shrink_control *);
>         long (*free_cached_objects)(struct super_block *,
>                                     struct shrink_control *);
> +       int (*corrupted_range)(struct super_block *sb, struct block_device *bdev,
> +                              loff_t offset, size_t len, void *data);

Why does the superblock need a new operation? Wouldn't whatever
function is specified here just be specified to the dax_dev as the
->notify_failure() holder callback?