Re: [PATCH] mkfs: Improve warning when AG size is a multiple of stripe width

[Bill O'Donnell <bodonnel@redhat.com>]

On Thu, Sep 14, 2023 at 02:36:40PM +0200, cem@kernel.org wrote:
> From: Carlos Maiolino <cmaiolino@redhat.com>
> 
> The current output message prints out a suggestion of an AG size to be
> used in lieu of the user-defined one.
> The problem is this suggestion is printed in filesystem blocks, while
> agsize= option receives a size in bytes (or m, g).
> 
> This patch tries to make user's life easier by outputing the suggesting
> in bytes directly.
> 
> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>

Reviewed-by: Bill O'Donnell <bodonnel@redhat.com>

> ---
>  mkfs/xfs_mkfs.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index d3a15cf44..827d5b656 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -3179,9 +3179,11 @@ _("agsize rounded to %lld, sunit = %d\n"),
>  		if (cli_opt_set(&dopts, D_AGCOUNT) ||
>  		    cli_opt_set(&dopts, D_AGSIZE)) {
>  			printf(_(
> -"Warning: AG size is a multiple of stripe width.  This can cause performance\n\
> -problems by aligning all AGs on the same disk.  To avoid this, run mkfs with\n\
> -an AG size that is one stripe unit smaller or larger, for example %llu.\n"),
> +"Warning: AG size is a multiple of stripe width. This can cause performance\n\
> +problems by aligning all AGs on the same disk. To avoid this, run mkfs with\n\
> +an AG size that is one stripe unit smaller or larger,\n\
> +for example: agsize=%llu (%llu blks).\n"),
> +				(unsigned long long)((cfg->agsize - dsunit) * cfg->blocksize),
>  				(unsigned long long)cfg->agsize - dsunit);
>  			fflush(stdout);
>  			goto validate;
> -- 
> 2.39.2
>