SB_SUBMOUNT      1012 fs/namespace.c 	return vfs_kern_mount(type, SB_SUBMOUNT, name, data);
SB_SUBMOUNT       591 fs/super.c     	if (flags & SB_SUBMOUNT)
SB_SUBMOUNT       613 fs/super.c     		s = alloc_super(type, (flags & ~SB_SUBMOUNT), user_ns);