On 27/10/2021 08:51, Damien Le Moal wrote:

quoted

static ssize_t btrfs_stripe_size_show(struct kobject *kobj,
				struct kobj_attribute *a, char *buf)

{
	struct btrfs_space_info *sinfo = to_space_info(kobj);
	struct btrfs_fs_info *fs_info = to_fs_info(get_btrfs_kobj(kobj));
	u64 max_stripe_size;

	spin_lock(&sinfo->lock);
	if (btrfs_is_zoned(fs_info))
		max_stripe_size = fs_info->zone_size;
	else
		max_stripe_size = sinfo->max_stripe_size;
	spin_unlock(&sinfo->lock);

This will not work once we have stripped zoned volume though, won't it ?
Why is not max_stripe_size set to zone size for a simple zoned btrfs volume ?

The other possibility would be to have compute_stripe_size() fan out into
compute_stripe_size_regular() or compute_stripe_size_zoned() which will do
the right thing for each.