DM_TARGET_IMMUTABLE 1997 drivers/md/dm-mpath.c .features = DM_TARGET_SINGLETON | DM_TARGET_IMMUTABLE | DM_TARGET_IMMUTABLE 4124 drivers/md/dm-thin.c DM_TARGET_IMMUTABLE, DM_TARGET_IMMUTABLE 224 include/linux/device-mapper.h #define dm_target_is_immutable(type) ((type)->features & DM_TARGET_IMMUTABLE)