Function open_objset

freebsd/contrib/openzfs/cmd/zdb/zdb.c:2924–2966

static sa_attr_type_t *sa_attr_table = NULL;

static int
open_objset(const char *path, void *tag, objset_t **osp)
{
	int err;
	uint64_t sa_attrs = 0;
	uint64_t version = 0;

	VERIFY3P(sa_os, ==, NULL);
	/*
	 * We can't own an objset if it's redacted.  Therefore, we do this
	 * dance: hold the objset, then acquire a long hold on its dataset, then
	 * release the pool (which is held as part of holding the objset).
	 */
	err = dmu_objset_hold(path, tag, osp);
	if (err != 0) {
		(void) fprintf(stderr, "failed to hold dataset '%s': %s\n",
		    path, strerror(err));
		return (err);
	}
	dsl_dataset_long_hold(dmu_objset_ds(*osp), tag);
	dsl_pool_rele(dmu_objset_pool(*osp), tag);

	if (dmu_objset_type(*osp) == DMU_OST_ZFS && !(*osp)->os_encrypted) {
		(void) zap_lookup(*osp, MASTER_NODE_OBJ, ZPL_VERSION_STR,
		    8, 1, &version);
		if (version >= ZPL_VERSION_SA) {
			(void) zap_lookup(*osp, MASTER_NODE_OBJ, ZFS_SA_ATTRS,
			    8, 1, &sa_attrs);
		}
		err = sa_setup(*osp, sa_attrs, zfs_attr_table, ZPL_END,
		    &sa_attr_table);
		if (err != 0) {
			(void) fprintf(stderr, "sa_setup failed: %s\n",
			    strerror(err));
			dsl_dataset_long_rele(dmu_objset_ds(*osp), tag);
			dsl_dataset_rele(dmu_objset_ds(*osp), tag);
			*osp = NULL;
		}
	}
	sa_os = *osp;

	return (0);
}

static void
close_objset(objset_t *os, void *tag)