dm_get_stats
if ((drive_stats = dm_get_stats(drive_descr, DM_DRV_STAT_TEMPERATURE,
*dev_stats = dm_get_stats(devp, DM_SLICE_STAT_USE, errp);
nvlist_t *dm_get_stats(dm_descriptor_t desc, int stat_type,
nvlist_t *stats = dm_get_stats(slice, DM_SLICE_STAT_USE, error);