On Thu, Apr 27, 2023 at 03:45:40PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@xxxxxxxxxx>
>
> I've noticed a fair number of fstests failures when we create a scratch
> device on a RAID device and the test specifies an explicit AG count or
> AG size:
>
> --- /tmp/fstests/tests/xfs/042.out 2022-09-01 15:09:11.484679979 -0700
> +++ /var/tmp/fstests/xfs/042.out.bad 2023-04-25 19:59:04.040000000 -0700
> @@ -1,5 +1,8 @@
> QA output created by 042
> -Make a 96 megabyte filesystem on SCRATCH_DEV and mount... done
> +Make a 96 megabyte filesystem on SCRATCH_DEV and mount... Warning: AG size is a multiple of stripe width. This can cause performance
> +problems by aligning all AGs on the same disk. To avoid this, run mkfs with
> +an AG size that is one stripe unit smaller or larger, for example 8160.
> +done
>
> Emitting this warning on stderr is silly -- nothing has failed, and we
> aren't going to abort the format either. Send the warning to stdout.
I agree with it, looks better printing it out to stdout other than stderr, so,
with one caveat below:
Reviewed-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
I think this might impact user tools monitoring stderr, but for mkfs I don't
think it's a big deal, just wanted to raise this concern.
>
> Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
> ---
> mkfs/xfs_mkfs.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 6dc0f335..2f2995e1 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -3167,11 +3167,12 @@ _("agsize rounded to %lld, sunit = %d\n"),
>
> if (cli_opt_set(&dopts, D_AGCOUNT) ||
> cli_opt_set(&dopts, D_AGSIZE)) {
> - fprintf(stderr, _(
> + 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"),
> (unsigned long long)cfg->agsize - dsunit);
> + fflush(stdout);
> goto validate;
> }
>
--
Carlos Maiolino
