1 /* 2 * Copyright (c) 1982, 1986, 1989, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * %sccs.include.redist.c% 6 * 7 * @(#)file.h 8.2 (Berkeley) 08/20/94 8 */ 9 10 #include <sys/fcntl.h> 11 #include <sys/unistd.h> 12 13 #ifdef KERNEL 14 #include <sys/queue.h> 15 16 struct proc; 17 struct uio; 18 19 /* 20 * Kernel descriptor table. 21 * One entry for each open kernel vnode and socket. 22 */ 23 struct file { 24 LIST_ENTRY(file) f_list;/* list of active files */ 25 short f_flag; /* see fcntl.h */ 26 #define DTYPE_VNODE 1 /* file */ 27 #define DTYPE_SOCKET 2 /* communications endpoint */ 28 short f_type; /* descriptor type */ 29 short f_count; /* reference count */ 30 short f_msgcount; /* references from message queue */ 31 struct ucred *f_cred; /* credentials associated with descriptor */ 32 struct fileops { 33 int (*fo_read) __P((struct file *fp, struct uio *uio, 34 struct ucred *cred)); 35 int (*fo_write) __P((struct file *fp, struct uio *uio, 36 struct ucred *cred)); 37 int (*fo_ioctl) __P((struct file *fp, int com, 38 caddr_t data, struct proc *p)); 39 int (*fo_select) __P((struct file *fp, int which, 40 struct proc *p)); 41 int (*fo_close) __P((struct file *fp, struct proc *p)); 42 } *f_ops; 43 off_t f_offset; 44 caddr_t f_data; /* vnode or socket */ 45 }; 46 47 LIST_HEAD(filelist, file); 48 extern struct filelist filehead; /* head of list of open files */ 49 extern int maxfiles; /* kernel limit on number of open files */ 50 extern int nfiles; /* actual number of open files */ 51 52 #endif /* KERNEL */ 53