dm_sysfs_attr
struct dm_sysfs_attr dm_attr_##_name = \
struct dm_sysfs_attr *dm_attr;
dm_attr = container_of(attr, struct dm_sysfs_attr, attr);
struct dm_sysfs_attr dm_attr_##_name = \
struct dm_sysfs_attr *dm_attr;
dm_attr = container_of(attr, struct dm_sysfs_attr, attr);