1 /* 2 * Copyright (c) 1982, 1986, 1989 Regents of the University of California. 3 * All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)file.h 7.11 (Berkeley) 03/02/92 8 */ 9 10 #include <sys/fcntl.h> 11 #include <sys/unistd.h> 12 13 #ifdef KERNEL 14 struct proc; 15 struct uio; 16 17 /* 18 * Kernel descriptor table. 19 * One entry for each open kernel vnode and socket. 20 */ 21 struct file { 22 struct file *f_filef; /* list of active files */ 23 struct file **f_fileb; /* list of active files */ 24 short f_flag; /* see fcntl.h */ 25 #define DTYPE_VNODE 1 /* file */ 26 #define DTYPE_SOCKET 2 /* communications endpoint */ 27 short f_type; /* descriptor type */ 28 short f_count; /* reference count */ 29 short f_msgcount; /* references from message queue */ 30 struct ucred *f_cred; /* credentials associated with descriptor */ 31 struct fileops { 32 int (*fo_read) __P((struct file *fp, struct uio *uio, 33 struct ucred *cred)); 34 int (*fo_write) __P((struct file *fp, struct uio *uio, 35 struct ucred *cred)); 36 int (*fo_ioctl) __P((struct file *fp, int com, 37 caddr_t data, struct proc *p)); 38 int (*fo_select) __P((struct file *fp, int which, 39 struct proc *p)); 40 int (*fo_close) __P((struct file *fp, struct proc *p)); 41 } *f_ops; 42 off_t f_offset; 43 caddr_t f_data; /* vnode or socket */ 44 }; 45 46 extern struct file *filehead; /* head of list of open files */ 47 extern int maxfiles; /* kernel limit on number of open files */ 48 extern int nfiles; /* actual number of open files */ 49 50 #endif /* KERNEL */ 51