/include/linux/dcache.h

#define DNAME_INLINE_LEN 16

struct dentry {
	atomic_t d_count;
	unsigned int d_flags;
	struct inode  * d_inode;	/* Where the name belongs to - NULL is negative */
	struct dentry * d_parent;	/* parent directory */
	struct list_head d_hash;	/* lookup hash list */
	struct list_head d_lru;		/* d_count = 0 LRU list */
	struct list_head d_child;	/* child of parent list */
	struct list_head d_subdirs;	/* our children */
	struct list_head d_alias;	/* inode alias list */
	int d_mounted;
	struct qstr d_name;
	unsigned long d_time;		/* used by d_revalidate */
	struct dentry_operations  *d_op;
	struct super_block * d_sb;	/* The root of the dentry tree */
	unsigned long d_vfs_flags;
	void * d_fsdata;		/* fs-specific data */
	unsigned char d_iname[DNAME_INLINE_LEN]; /* small names */
};

struct dentry_operations {
	int (*d_revalidate)(struct dentry *, int);
	int (*d_hash) (struct dentry *, struct qstr *);
	int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
	int (*d_delete)(struct dentry *);
	void (*d_release)(struct dentry *);
	void (*d_iput)(struct dentry *, struct inode *);
};