Re: [PATCH v5 11/18] btrfs: new inline ref storing owning subvol of data extents

Josef Bacik
2023-08-21T18:07:53Z

On Thu, Jul 27, 2023 at 03:12:58PM -0700, Boris Burkov wrote:
> In order to implement simple quota groups, we need to be able to
> associate a data extent with the subvolume that created it. Once you
> account for reflink, this information cannot be recovered without
> explicitly storing it. Options for storing it are:
> - a new key/item
> - a new extent inline ref item
>
> The former is backwards compatible, but wastes space, the latter is
> incompat, but is efficient in space and reuses the existing inline ref
> machinery, while only abusing it a tiny amount -- specifically, the new
> item is not a ref, per-se.
>
> Signed-off-by: Boris Burkov <boris@bur.io>

Reviewed-by: Josef Bacik <josef@toxicpanda.com>

Thanks,

Josef