DM_DEV_REMOVE_CMD 1676 drivers/md/dm-ioctl.c 		{DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
DM_DEV_REMOVE_CMD  256 include/uapi/linux/dm-ioctl.h #define DM_DEV_REMOVE    _IOWR(DM_IOCTL, DM_DEV_REMOVE_CMD, struct dm_ioctl)