V8/usr/sys/h/inode.h

/*
 * The I node is the focus of all
 * file activity in unix. There is a unique
 * inode allocated for each active file,
 * each current directory, each mounted-on
 * file, text file, and the root. An inode is 'named'
 * by its dev/inumber pair. (iget/iget.c)
 * Data, from mode on, is read in
 * from permanent inode on volume.
 */

#define	NADDR	13

struct	inode
{
	short	i_flag;
	u_char	i_count;	/* reference count */
	char	i_fstyp;	/* type of its filesystem */
	dev_t	i_dev;		/* device where inode resides */
	long	i_number;	/* i number, 1-to-1 with device address */
	unsigned short i_mode;
	short	i_nlink;	/* directory entries */
	short	i_uid;		/* owner */
	short	i_gid;		/* group of owner */
	off_t	i_size;		/* size of file */
	struct	stdata *i_sptr;	/* stream associated with this inode */
	union {
		struct {
			daddr_t	I_addr[NADDR];	/* if normal file/directory */
			daddr_t	I_lastr;	/* last read (for read-ahead) */
		} i_f;
#define	i_addr	i_f.I_addr
#define	i_lastr	i_f.I_lastr
		struct {
			daddr_t	I_rdev;		/* i_addr[0] */
			long	I_key;		/* see istread */
		} i_d;
#define	i_rdev	i_d.I_rdev
#define i_key	i_d.I_key
		struct {
			long I_tag;
			struct inode *I_cip;	/* communications */
		} i_a;		/* when i_fstyp != 0 */
#define i_tag	i_a.I_tag
#define i_cip	i_a.I_cip
		struct {
			struct proc *I_proc;	/* sanity checking */
			int	    I_sigmask;	/* signal trace mask */
		} i_p;
#define i_proc	i_p.I_proc
#define i_sigmask	i_p.I_sigmask
	} i_un;
	short	i_hlink;	/* link in hash chain (iget/iput/ifind) */
};

#ifdef KERNEL
struct	inode *inode, *inodeNINODE;
int	ninode;

struct	inode *rootdir;		/* pointer to inode of root directory */

struct	inode *ialloc();
struct	inode *ifind();
struct	inode *iget();
struct	inode *owner();
struct	inode *maknode();
struct	inode *namei();
struct	inode *openi();
#endif

/* flags */
#define	ILOCK	01		/* inode is locked */
#define	IUPD	02		/* file has been modified */
#define	IACC	04		/* inode access time to be updated */
#define	IMOUNT	010		/* inode is mounted on */
#define	IWANT	020		/* some process waiting on lock */
#define	ITEXT	040		/* inode is pure text prototype */
#define	ICHG	0100		/* inode has been changed */
#define	IPIPE	0200		/* inode is a pipe */
#define IDEAD	0400		/* only iput and iget */
#define	IALOCK	01000		/* advisory lock has been set */

/* modes */
#define	IFMT	0170000		/* type of file */
#define		IFDIR	0040000	/* directory */
#define		IFCHR	0020000	/* character special */
#define		IFBLK	0060000	/* block special */
#define		IFREG	0100000	/* regular */
#define		IFLNK	0120000 /* symbolic link to another file */
#define	ISUID	04000		/* set user id on execution */
#define	ISGID	02000		/* set group id on execution */
#define	ISVTX	01000		/* save swapped text even after use */
#define	IREAD	0400		/* read, write, execute permissions */
#define	IWRITE	0200
#define	IEXEC	0100

struct argnamei {	/* namei's flag argument */
	short flag;	/* type of request */
	ino_t ino;	/* ino and dev for linking */
	dev_t idev;
	short mode;	/* mode for creating */
};
#define NI_DEL	1	/* unlink this file */
#define NI_CREAT 2	/* create it if it doesn't exits */
#define NI_NXCREAT 3	/* create it, error if it already exists */
#define NI_LINK	4	/* make a link */
#define NI_MKDIR 5	/* make a directory */
#define NI_RMDIR 6	/* remove a directory */
struct nx {	/* arg to real nami */
	struct inode *dp;
	char *cp;
	struct buf *nbp;
	int nlink;
};