dm_lock_for_deletion
r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
dm_lock_for_deletion(md, !!(flags & DM_REMOVE_MARK_DEFERRED), !!(flags & DM_REMOVE_ONLY_DEFERRED))) {
int dm_lock_for_deletion(struct mapped_device *md, bool mark_deferred, bool only_deferred);