dm_sm_get_nr_blocks
r = dm_sm_get_nr_blocks(cmd->metadata_sm, result);
r = dm_sm_get_nr_blocks(cmd->sm, result);
r = dm_sm_get_nr_blocks(md->sm, &nr_total);
r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
r = dm_sm_get_nr_blocks(pmd->data_sm, result);
r = dm_sm_get_nr_blocks(sm, &old_count);
r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total);