char *add_devices(char *const *, char *);
char *remove_device(const char *, bool);
char *bcache_get_capacity(const char *, const char *, bool);
+char *dev_name(const char *);
+char *device_set_failed(const char *dev_uuid, const char *set_uuid);
#define csum_set(i, type) \
({ \