Function l2arc_untransform

freebsd/contrib/openzfs/module/zfs/arc.c:8371–8460

}

static int
l2arc_untransform(zio_t *zio, l2arc_read_callback_t *cb)
{
	int ret;
	spa_t *spa = zio->io_spa;
	arc_buf_hdr_t *hdr = cb->l2rcb_hdr;
	blkptr_t *bp = zio->io_bp;
	uint8_t salt[ZIO_DATA_SALT_LEN];
	uint8_t iv[ZIO_DATA_IV_LEN];
	uint8_t mac[ZIO_DATA_MAC_LEN];
	boolean_t no_crypt = B_FALSE;

	/*
	 * ZIL data is never be written to the L2ARC, so we don't need
	 * special handling for its unique MAC storage.
	 */
	ASSERT3U(BP_GET_TYPE(bp), !=, DMU_OT_INTENT_LOG);
	ASSERT(MUTEX_HELD(HDR_LOCK(hdr)));
	ASSERT3P(hdr->b_l1hdr.b_pabd, !=, NULL);

	/*
	 * If the data was encrypted, decrypt it now. Note that
	 * we must check the bp here and not the hdr, since the
	 * hdr does not have its encryption parameters updated
	 * until arc_read_done().
	 */
	if (BP_IS_ENCRYPTED(bp)) {
		abd_t *eabd = arc_get_data_abd(hdr, arc_hdr_size(hdr), hdr,
		    B_TRUE);

		zio_crypt_decode_params_bp(bp, salt, iv);
		zio_crypt_decode_mac_bp(bp, mac);

		ret = spa_do_crypt_abd(B_FALSE, spa, &cb->l2rcb_zb,
		    BP_GET_TYPE(bp), BP_GET_DEDUP(bp), BP_SHOULD_BYTESWAP(bp),
		    salt, iv, mac, HDR_GET_PSIZE(hdr), eabd,
		    hdr->b_l1hdr.b_pabd, &no_crypt);
		if (ret != 0) {
			arc_free_data_abd(hdr, eabd, arc_hdr_size(hdr), hdr);
			goto error;
		}

		/*
		 * If we actually performed decryption, replace b_pabd
		 * with the decrypted data. Otherwise we can just throw
		 * our decryption buffer away.
		 */
		if (!no_crypt) {
			arc_free_data_abd(hdr, hdr->b_l1hdr.b_pabd,
			    arc_hdr_size(hdr), hdr);
			hdr->b_l1hdr.b_pabd = eabd;
			zio->io_abd = eabd;
		} else {
			arc_free_data_abd(hdr, eabd, arc_hdr_size(hdr), hdr);
		}
	}

	/*