NetBSD/sys/sys/file.h

142 lines
4.8 KiB
C

/* $NetBSD: file.h,v 1.22 2000/02/01 01:22:45 assar Exp $ */
/*
* Copyright (c) 1982, 1986, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)file.h 8.3 (Berkeley) 1/9/95
*/
#ifndef _SYS_FILE_H_
#define _SYS_FILE_H_
#include <sys/fcntl.h>
#include <sys/unistd.h>
#ifdef _KERNEL
#include <sys/queue.h>
struct proc;
struct uio;
struct iovec;
/*
* Kernel descriptor table.
* One entry for each open kernel vnode and socket.
*/
struct file {
LIST_ENTRY(file) f_list;/* list of active files */
int f_flag; /* see fcntl.h */
#define DTYPE_VNODE 1 /* file */
#define DTYPE_SOCKET 2 /* communications endpoint */
short f_type; /* descriptor type */
short f_count; /* reference count */
short f_msgcount; /* references from message queue */
short f_pad0; /* spare */
struct ucred *f_cred; /* credentials associated with descriptor */
struct fileops {
int (*fo_read) __P((struct file *fp, off_t *offset,
struct uio *uio,
struct ucred *cred, int flags));
int (*fo_write) __P((struct file *fp, off_t *offset,
struct uio *uio,
struct ucred *cred, int flags));
int (*fo_ioctl) __P((struct file *fp, u_long com,
caddr_t data, struct proc *p));
int (*fo_fcntl) __P((struct file *fp, u_int com,
caddr_t data, struct proc *p));
int (*fo_poll) __P((struct file *fp, int events,
struct proc *p));
int (*fo_close) __P((struct file *fp, struct proc *p));
} *f_ops;
off_t f_offset;
caddr_t f_data; /* vnode or socket */
int f_iflags; /* internal flags */
int f_usecount; /* number active users */
};
#define FIF_WANTCLOSE 0x01 /* a close is waiting for usecount */
#ifdef DIAGNOSTIC
#define FILE_USE_CHECK(fp, str) \
do { \
if ((fp)->f_usecount < 0) \
panic(str); \
} while (0)
#else
#define FILE_USE_CHECK(fp, str) /* nothing */
#endif
#define FILE_USE(fp) \
do { \
(fp)->f_usecount++; \
FILE_USE_CHECK((fp), "f_usecount overflow"); \
} while (0)
#define FILE_UNUSE(fp, p) \
do { \
if ((fp)->f_iflags & FIF_WANTCLOSE) { \
/* Will drop usecount. */ \
(void) closef((fp), (p)); \
} else { \
(fp)->f_usecount--; \
FILE_USE_CHECK((fp), "f_usecount underflow"); \
} \
} while (0)
/*
* Flags for fo_read and fo_write.
*/
#define FOF_UPDATE_OFFSET 0x01 /* update the file offset */
LIST_HEAD(filelist, file);
extern struct filelist filehead; /* head of list of open files */
extern int maxfiles; /* kernel limit on number of open files */
extern int nfiles; /* actual number of open files */
extern struct fileops vnops; /* vnode operations for files */
int dofileread __P((struct proc *, int, struct file *, void *, size_t,
off_t *, int, register_t *));
int dofilewrite __P((struct proc *, int, struct file *, const void *,
size_t, off_t *, int, register_t *));
int dofilereadv __P((struct proc *, int, struct file *,
const struct iovec *, int, off_t *, int, register_t *));
int dofilewritev __P((struct proc *, int, struct file *,
const struct iovec *, int, off_t *, int, register_t *));
void finit __P((void));
#endif /* _KERNEL */
#endif /* _SYS_FILE_H_ */