Minix1.5/fs/inode.h

/* Inode table.  This table holds inodes that are currently in use.  In some
 * cases they have been opened by an open() or creat() system call, in other
 * cases the file system itself needs the inode for one reason or another,
 * such as to search a directory for a path name.
 * The first part of the struct holds fields that are present on the
 * disk; the second part holds fields not present on the disk.
 * The disk inode part is also declared in "type.h" as 'd_inode'.
 */

EXTERN struct inode {
  unshort i_mode;		/* file type, protection, etc. */
  uid_t i_uid;			/* user id of the file's owner */
  off_t i_size;			/* current file size in bytes */
  time_t i_mtime;		/* when was file data last changed */
  gid_t i_gid;			/* group number */
  nlink_t i_nlinks;		/* how many links to this file */
  zone_nr i_zone[NR_ZONE_NUMS];	/* zone numbers for direct, ind, and dbl ind */

  /* The following items are not present on the disk. */
  time_t i_atime;		/* time of last access */
  time_t i_ctime;		/* time of last change to the inode's status */
  dev_t i_dev;			/* which device is the inode on */
  ino_t i_num;			/* inode number on its (minor) device */
  short int i_count;		/* # times inode used; 0 means slot is free */
  char i_dirt;			/* CLEAN or DIRTY */
  char i_pipe;			/* set to I_PIPE if pipe */
  char i_mount;			/* this bit is set if file mounted on */
  char i_seek;			/* set on LSEEK, cleared on READ/WRITE */
  char i_update;		/* the ATIME, CTIME, and MTIME bits are here */
} inode[NR_INODES];


#define NIL_INODE (struct inode *) 0	/* indicates absence of inode slot */

/* Field values.  Note that CLEAN and DIRTY are defined in "const.h" */
#define NO_PIPE            0	/* i_pipe is NO_PIPE if inode is not a pipe */
#define I_PIPE             1	/* i_pipe is I_PIPE if inode is a pipe */
#define NO_MOUNT           0	/* i_mount is NO_MOUNT if file not mounted on */
#define I_MOUNT            1	/* i_mount is I_MOUNT if file mounted on */
#define NO_SEEK            0	/* i_seek = NO_SEEK if last op was not SEEK */
#define ISEEK              1	/* i_seek = ISEEK if last op was SEEK */