V7/usr/sys/h/filsys.h
/*
* Structure of the super-block
*/
struct filsys {
unsigned short s_isize; /* size in blocks of i-list */
daddr_t s_fsize; /* size in blocks of entire volume */
short s_nfree; /* number of addresses in s_free */
daddr_t s_free[NICFREE];/* free block list */
short s_ninode; /* number of i-nodes in s_inode */
ino_t s_inode[NICINOD];/* free i-node list */
char s_flock; /* lock during free list manipulation */
char s_ilock; /* lock during i-list manipulation */
char s_fmod; /* super block modified flag */
char s_ronly; /* mounted read-only flag */
time_t s_time; /* last super block update */
/* remainder not maintained by this version of the system */
daddr_t s_tfree; /* total free blocks*/
ino_t s_tinode; /* total free inodes */
short s_m; /* interleave factor */
short s_n; /* " " */
char s_fname[6]; /* file system name */
char s_fpack[6]; /* file system pack name */
};