On Wed, Apr 09, 2025 at 09:55:34AM +0200, Christoph Hellwig wrote:
> When size is specified for zoned file systems, calculate the required
> over provisioning to back the requested capacity.
>
> Signed-off-by: Hans Holmberg <hans.holmberg@xxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
> mkfs/xfs_mkfs.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 46 insertions(+)
>
> diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
> index 133ede8d8483..6b5eb9eb140a 100644
> --- a/mkfs/xfs_mkfs.c
> +++ b/mkfs/xfs_mkfs.c
> @@ -4413,6 +4413,49 @@ _("rgsize (%s) not a multiple of fs blk size (%d)\n"),
> NBBY * (cfg->blocksize - sizeof(struct xfs_rtbuf_blkinfo)));
> }
>
> +/*
> + * If we're creating a zoned filesystem and the user specified a size, add
> + * enough over-provisioning to be able to back the requested amount of
> + * writable space.
> + */
> +static void
> +adjust_nr_zones(
> + struct mkfs_params *cfg,
> + struct cli_params *cli,
> + struct libxfs_init *xi,
> + struct zone_topology *zt)
> +{
> + uint64_t new_rtblocks, slack;
> + unsigned int max_zones;
> +
> + if (zt->rt.nr_zones)
> + max_zones = zt->rt.nr_zones;
> + else
> + max_zones = DTOBT(xi->rt.size, cfg->blocklog) / cfg->rgsize;
> +
> + if (!cli->rgcount)
> + cfg->rgcount += XFS_RESERVED_ZONES;
> + if (cfg->rgcount > max_zones) {
> + cfg->rgcount = max_zones;
> + fprintf(stderr,
> +_("Warning: not enough zones for backing requested rt size due to\n"
> + "over-provisioning needs, writeable size will be less than %s\n"),
Nit: "writable", not "writeable"
With that fixed,
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
--D
> + cli->rtsize);
> + }
> + new_rtblocks = (cfg->rgcount * cfg->rgsize);
> + slack = (new_rtblocks - cfg->rtblocks) % cfg->rgsize;
> +
> + cfg->rtblocks = new_rtblocks;
> + cfg->rtextents = cfg->rtblocks / cfg->rtextblocks;
> +
> + /*
> + * Add the slack to the end of the last zone to the reserved blocks.
> + * This ensures the visible user capacity is exactly the one that the
> + * user asked for.
> + */
> + cfg->rtreserved += (slack * cfg->blocksize);
> +}
> +
> static void
> calculate_zone_geometry(
> struct mkfs_params *cfg,
> @@ -4485,6 +4528,9 @@ _("rgsize (%s) not a multiple of fs blk size (%d)\n"),
> }
> }
>
> + if (cli->rtsize || cli->rgcount)
> + adjust_nr_zones(cfg, cli, xi, zt);
> +
> if (cfg->rgcount < XFS_MIN_ZONES) {
> fprintf(stderr,
> _("realtime group count (%llu) must be greater than the minimum zone count (%u)\n"),
> --
> 2.47.2
>
>
