BH_Delay
1 << BH_Delay | 1 << BH_Unwritten)
#define EXT4_MAP_DELAYED BIT(BH_Delay)
#define BH_FLAGS (BIT(BH_Unwritten) | BIT(BH_Delay))
BIT(BH_Delay));
BIT(BH_Delay));
BIT(BH_Delay) | BIT(BH_NILFS_Volatile) |