set_opt
#define set_opt(opt, option) ((opt)->mount_opt |= EROFS_MOUNT_##option)
#define set_opt(o, opt) o |= EXT2_MOUNT_##opt
#define set_opt(sb, opt) EXT4_SB(sb)->s_mount_opt |= \
#define set_opt(sbi, option) \
#define set_opt(o, opt) (o |= (QNX6_MOUNT_##opt))