Re: [PATCH 1/2] btrfs: add helper function find_fsid_by_disk

[David Sterba <dsterba@suse.cz>]

On Thu, Sep 28, 2023 at 09:09:46AM +0800, Anand Jain wrote:
> In preparation for adding support to mount multiple single-disk
> btrfs filesystems with the same FSID, wrap find_fsid() into
> find_fsid_by_disk().
> 
> Signed-off-by: Anand Jain <anand.jain@oracle.com>
> ---
>  fs/btrfs/volumes.c | 19 +++++++++++++++----
>  1 file changed, 15 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
> index 298e5885ed06..39b5bc2521fb 100644
> --- a/fs/btrfs/volumes.c
> +++ b/fs/btrfs/volumes.c
> @@ -553,6 +553,20 @@ static int btrfs_free_stale_devices(dev_t devt, struct btrfs_device *skip_device
>  	return ret;
>  }
>  
> +static struct btrfs_fs_devices *find_fsid_by_disk(

A minor thing here, I think we don't want to use "disk" in the
identifiers, it's been converted to 'device' where possible but there
are still some references that could be related to on-disk structures so
these can't be changed. In new API I'd prefer 'device'.