useful constants: struct qstr for ".."

fs/dcache.c

fs/ext2/namei.c

fs/ext4/namei.c

fs/f2fs/dir.c

fs/f2fs/namei.c

fs/fuse/inode.c

fs/nilfs2/namei.c

fs/udf/namei.c

fs/ufs/super.c

include/linux/dcache.h