Function dnode_sync

freebsd/contrib/openzfs/module/zfs/dnode_sync.c:623–858

* Write out the dnode's dirty buffers. */

 * Write out the dnode's dirty buffers.
 */
void
dnode_sync(dnode_t *dn, dmu_tx_t *tx)
{
	objset_t *os = dn->dn_objset;
	dnode_phys_t *dnp = dn->dn_phys;
	int txgoff = tx->tx_txg & TXG_MASK;
	list_t *list = &dn->dn_dirty_records[txgoff];
	static const dnode_phys_t zerodn __maybe_unused = { 0 };
	boolean_t kill_spill = B_FALSE;

	ASSERT(dmu_tx_is_syncing(tx));
	ASSERT(dnp->dn_type != DMU_OT_NONE || dn->dn_allocated_txg);
	ASSERT(dnp->dn_type != DMU_OT_NONE ||
	    bcmp(dnp, &zerodn, DNODE_MIN_SIZE) == 0);
	DNODE_VERIFY(dn);

	ASSERT(dn->dn_dbuf == NULL || arc_released(dn->dn_dbuf->db_buf));

	/*
	 * Do user accounting if it is enabled and this is not
	 * an encrypted receive.
	 */
	if (dmu_objset_userused_enabled(os) &&
	    !DMU_OBJECT_IS_SPECIAL(dn->dn_object) &&
	    (!os->os_encrypted || !dmu_objset_is_receiving(os))) {
		mutex_enter(&dn->dn_mtx);
		dn->dn_oldused = DN_USED_BYTES(dn->dn_phys);
		dn->dn_oldflags = dn->dn_phys->dn_flags;
		dn->dn_phys->dn_flags |= DNODE_FLAG_USERUSED_ACCOUNTED;
		if (dmu_objset_userobjused_enabled(dn->dn_objset))
			dn->dn_phys->dn_flags |=
			    DNODE_FLAG_USEROBJUSED_ACCOUNTED;
		mutex_exit(&dn->dn_mtx);
		dmu_objset_userquota_get_ids(dn, B_FALSE, tx);
	} else {
		/* Once we account for it, we should always account for it */
		ASSERT(!(dn->dn_phys->dn_flags &
		    DNODE_FLAG_USERUSED_ACCOUNTED));
		ASSERT(!(dn->dn_phys->dn_flags &
		    DNODE_FLAG_USEROBJUSED_ACCOUNTED));
	}

	mutex_enter(&dn->dn_mtx);
	if (dn->dn_allocated_txg == tx->tx_txg) {
		/* The dnode is newly allocated or reallocated */
		if (dnp->dn_type == DMU_OT_NONE) {
			/* this is a first alloc, not a realloc */
			dnp->dn_nlevels = 1;
			dnp->dn_nblkptr = dn->dn_nblkptr;
		}

		dnp->dn_type = dn->dn_type;
		dnp->dn_bonustype = dn->dn_bonustype;
		dnp->dn_bonuslen = dn->dn_bonuslen;
	}

	dnp->dn_extra_slots = dn->dn_num_slots - 1;