Re: [PATCH] mkfs: warn out the V4 format

["Darrick J. Wong" <djwong@kernel.org>]

On Wed, Apr 21, 2021 at 04:57:16PM +0800, Gao Xiang wrote:
> Kernel commit b96cb835e37c ("xfs: deprecate the V4 format") started
> the process of retiring the old format to close off attack surfaces
> and to encourage users to migrate onto V5.
> 
> This also prints warning to users when mkfs as well.
> 
> Suggested-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Gao Xiang <hsiangkao@redhat.com>

Looks fine to me; but does this cause any golden output failures in
fstests?

--D

> ---
>  mkfs/xfs_mkfs.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 0eac5336..ef09f8b3 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -4022,6 +4022,10 @@ main(
>  	validate_extsize_hint(mp, &cli);
>  	validate_cowextsize_hint(mp, &cli);
>  
> +	if (!cli.sb_feat.crcs_enabled)
> +		fprintf(stderr,
> +_("Deprecated V4 format (-mcrc=0) will not be supported after September 2030.\n"));
> +
>  	/* Print the intended geometry of the fs. */
>  	if (!quiet || dry_run) {
>  		struct xfs_fsop_geom	geo;
> -- 
> 2.27.0
>