Function vdev_space_update

freebsd/contrib/openzfs/module/zfs/vdev.c:4522–4561

* Update the in-core space usage stats for this vdev, its metaslab class, * and the root vdev. */

 * and the root vdev.
 */
void
vdev_space_update(vdev_t *vd, int64_t alloc_delta, int64_t defer_delta,
    int64_t space_delta)
{
	int64_t dspace_delta;
	spa_t *spa = vd->vdev_spa;
	vdev_t *rvd = spa->spa_root_vdev;

	ASSERT(vd == vd->vdev_top);

	/*
	 * Apply the inverse of the psize-to-asize (ie. RAID-Z) space-expansion
	 * factor.  We must calculate this here and not at the root vdev
	 * because the root vdev's psize-to-asize is simply the max of its
	 * children's, thus not accurate enough for us.
	 */
	dspace_delta = vdev_deflated_space(vd, space_delta);

	mutex_enter(&vd->vdev_stat_lock);
	/* ensure we won't underflow */
	if (alloc_delta < 0) {
		ASSERT3U(vd->vdev_stat.vs_alloc, >=, -alloc_delta);
	}

	vd->vdev_stat.vs_alloc += alloc_delta;
	vd->vdev_stat.vs_space += space_delta;
	vd->vdev_stat.vs_dspace += dspace_delta;
	mutex_exit(&vd->vdev_stat_lock);

	/* every class but log contributes to root space stats */
	if (vd->vdev_mg != NULL && !vd->vdev_islog) {
		ASSERT(!vd->vdev_isl2cache);
		mutex_enter(&rvd->vdev_stat_lock);
		rvd->vdev_stat.vs_alloc += alloc_delta;
		rvd->vdev_stat.vs_space += space_delta;
		rvd->vdev_stat.vs_dspace += dspace_delta;
		mutex_exit(&rvd->vdev_stat_lock);
	}
	/* Note: metaslab_class_space_update moved to metaslab_space_update */
}

/*
 * Mark a top-level vdev's config as dirty, placing it on the dirty list