BLK_TC_NOTIFY
ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_TN_MESSAGE (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
{ BLK_TC_NOTIFY, "notify" },
if (!(bt->act_mask & BLK_TC_NOTIFY))