Function ztest_get_data

freebsd/contrib/openzfs/cmd/ztest/ztest.c:2274–2359

}

static int
ztest_get_data(void *arg, lr_write_t *lr, char *buf, struct lwb *lwb,
    zio_t *zio)
{
	ztest_ds_t *zd = arg;
	objset_t *os = zd->zd_os;
	uint64_t object = lr->lr_foid;
	uint64_t offset = lr->lr_offset;
	uint64_t size = lr->lr_length;
	uint64_t txg = lr->lr_common.lrc_txg;
	uint64_t crtxg;
	dmu_object_info_t doi;
	dmu_buf_t *db;
	zgd_t *zgd;
	int error;

	ASSERT3P(lwb, !=, NULL);
	ASSERT3P(zio, !=, NULL);
	ASSERT3U(size, !=, 0);

	ztest_object_lock(zd, object, RL_READER);
	error = dmu_bonus_hold(os, object, FTAG, &db);
	if (error) {
		ztest_object_unlock(zd, object);
		return (error);
	}

	crtxg = ztest_bt_bonus(db)->bt_crtxg;

	if (crtxg == 0 || crtxg > txg) {
		dmu_buf_rele(db, FTAG);
		ztest_object_unlock(zd, object);
		return (ENOENT);
	}

	dmu_object_info_from_db(db, &doi);
	dmu_buf_rele(db, FTAG);
	db = NULL;

	zgd = umem_zalloc(sizeof (*zgd), UMEM_NOFAIL);
	zgd->zgd_lwb = lwb;
	zgd->zgd_private = zd;

	if (buf != NULL) {	/* immediate write */
		zgd->zgd_lr = (struct zfs_locked_range *)ztest_range_lock(zd,
		    object, offset, size, RL_READER);

		error = dmu_read(os, object, offset, size, buf,
		    DMU_READ_NO_PREFETCH);
		ASSERT(error == 0);
	} else {
		size = doi.doi_data_block_size;
		if (ISP2(size)) {
			offset = P2ALIGN(offset, size);
		} else {
			ASSERT(offset < size);
			offset = 0;
		}