Function ddt_sync_entry

freebsd/contrib/openzfs/module/zfs/ddt.c:1004–1071

}

static void
ddt_sync_entry(ddt_t *ddt, ddt_entry_t *dde, dmu_tx_t *tx, uint64_t txg)
{
	dsl_pool_t *dp = ddt->ddt_spa->spa_dsl_pool;
	ddt_phys_t *ddp = dde->dde_phys;
	ddt_key_t *ddk = &dde->dde_key;
	enum ddt_type otype = dde->dde_type;
	enum ddt_type ntype = DDT_TYPE_CURRENT;
	enum ddt_class oclass = dde->dde_class;
	enum ddt_class nclass;
	uint64_t total_refcnt = 0;

	ASSERT(dde->dde_loaded);
	ASSERT(!dde->dde_loading);

	for (int p = 0; p < DDT_PHYS_TYPES; p++, ddp++) {
		ASSERT(dde->dde_lead_zio[p] == NULL);
		if (ddp->ddp_phys_birth == 0) {
			ASSERT(ddp->ddp_refcnt == 0);
			continue;
		}
		if (p == DDT_PHYS_DITTO) {
			/*
			 * Note, we no longer create DDT-DITTO blocks, but we
			 * don't want to leak any written by older software.
			 */
			ddt_phys_free(ddt, ddk, ddp, txg);
			continue;
		}
		if (ddp->ddp_refcnt == 0)
			ddt_phys_free(ddt, ddk, ddp, txg);
		total_refcnt += ddp->ddp_refcnt;
	}

	/* We do not create new DDT-DITTO blocks. */
	ASSERT0(dde->dde_phys[DDT_PHYS_DITTO].ddp_phys_birth);
	if (total_refcnt > 1)
		nclass = DDT_CLASS_DUPLICATE;
	else
		nclass = DDT_CLASS_UNIQUE;

	if (otype != DDT_TYPES &&
	    (otype != ntype || oclass != nclass || total_refcnt == 0)) {
		VERIFY(ddt_object_remove(ddt, otype, oclass, dde, tx) == 0);
		ASSERT(ddt_object_lookup(ddt, otype, oclass, dde) == ENOENT);
	}

	if (total_refcnt != 0) {
		dde->dde_type = ntype;
		dde->dde_class = nclass;
		ddt_stat_update(ddt, dde, 0);
		if (!ddt_object_exists(ddt, ntype, nclass))
			ddt_object_create(ddt, ntype, nclass, tx);
		VERIFY(ddt_object_update(ddt, ntype, nclass, dde, tx) == 0);

		/*
		 * If the class changes, the order that we scan this bp
		 * changes.  If it decreases, we could miss it, so