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file.h
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file.h
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/* $NetBSD: file.h,v 1.56.12.1 2009/04/10 20:32:04 snj 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. 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/mallocvar.h>
#include <sys/queue.h>
#include <sys/lock.h>
MALLOC_DECLARE(M_FILE);
MALLOC_DECLARE(M_IOCTLOPS);
struct proc;
struct lwp;
struct uio;
struct iovec;
struct stat;
struct knote;
/*
* 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 */
int f_iflags; /* internal flags; FIF_* */
int f_advice; /* access pattern hint; UVM_ADV_* */
#define DTYPE_VNODE 1 /* file */
#define DTYPE_SOCKET 2 /* communications endpoint */
#define DTYPE_PIPE 3 /* pipe */
#define DTYPE_KQUEUE 4 /* event queue */
#define DTYPE_MISC 5 /* misc file descriptor type */
#define DTYPE_CRYPTO 6 /* crypto */
#define DTYPE_NAMES \
"0", "file", "socket", "pipe", "kqueue", "misc", "crypto"
int f_type; /* descriptor type */
u_int f_count; /* reference count */
u_int f_msgcount; /* references from message queue */
int f_usecount; /* number active users */
kauth_cred_t f_cred; /* creds associated with descriptor */
const struct fileops {
int (*fo_read) (struct file *, off_t *, struct uio *,
kauth_cred_t, int);
int (*fo_write) (struct file *, off_t *, struct uio *,
kauth_cred_t, int);
int (*fo_ioctl) (struct file *, u_long, void *,
struct lwp *);
int (*fo_fcntl) (struct file *, u_int, void *,
struct lwp *);
int (*fo_poll) (struct file *, int, struct lwp *);
int (*fo_stat) (struct file *, struct stat *,
struct lwp *);
int (*fo_close) (struct file *, struct lwp *);
int (*fo_kqfilter) (struct file *, struct knote *);
} *f_ops;
off_t f_offset;
void *f_data; /* descriptor data, e.g. vnode/socket */
struct simplelock f_slock;
};
#define FIF_WANTCLOSE 0x01 /* a close is waiting for usecount */
#define FIF_LARVAL 0x02 /* not fully constructed; don't use */
#define FIF_DISCARDED 0x04 /* file is discarded, pending close */
#define FILE_IS_USABLE(fp) (((fp)->f_iflags & \
(FIF_WANTCLOSE|FIF_LARVAL|FIF_DISCARDED)) == 0)
#define FILE_SET_MATURE(fp) \
do { \
(fp)->f_iflags &= ~FIF_LARVAL; \
} while (/*CONSTCOND*/0)
#ifdef DIAGNOSTIC
#define FILE_USE_CHECK(fp, str) \
do { \
if ((fp)->f_usecount < 0) \
panic(str); \
} while (/* CONSTCOND */ 0)
#else
#define FILE_USE_CHECK(fp, str) /* nothing */
#endif
/*
* FILE_USE() must be called with the file lock held.
* (Typical usage is: `fp = fd_getfile(..); FILE_USE(fp);'
* and fd_getfile() returns the file locked)
*/
#define FILE_USE(fp) \
do { \
(fp)->f_usecount++; \
FILE_USE_CHECK((fp), "f_usecount overflow"); \
simple_unlock(&(fp)->f_slock); \
} while (/* CONSTCOND */ 0)
#define FILE_UNUSE_WLOCK(fp, l, havelock) \
do { \
if (!(havelock)) \
simple_lock(&(fp)->f_slock); \
if ((fp)->f_iflags & FIF_WANTCLOSE) { \
simple_unlock(&(fp)->f_slock); \
/* Will drop usecount */ \
(void) closef((fp), (l)); \
break; \
} else { \
(fp)->f_usecount--; \
FILE_USE_CHECK((fp), "f_usecount underflow"); \
} \
simple_unlock(&(fp)->f_slock); \
} while (/* CONSTCOND */ 0)
#define FILE_UNUSE(fp, l) FILE_UNUSE_WLOCK(fp, l, 0)
#define FILE_UNUSE_HAVELOCK(fp, l) FILE_UNUSE_WLOCK(fp, l, 1)
/*
* 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 # of open files */
extern int nfiles; /* actual number of open files */
extern const struct fileops vnops; /* vnode operations for files */
int dofileread(struct lwp *, int, struct file *, void *, size_t,
off_t *, int, register_t *);
int dofilewrite(struct lwp *, int, struct file *, const void *,
size_t, off_t *, int, register_t *);
int dofilereadv(struct lwp *, int, struct file *,
const struct iovec *, int, off_t *, int, register_t *);
int dofilewritev(struct lwp *, int, struct file *,
const struct iovec *, int, off_t *, int, register_t *);
int fsetown(struct proc *, pid_t *, int, const void *);
int fgetown(struct proc *, pid_t, int, void *);
void fownsignal(pid_t, int, int, int, void *);
int fdclone(struct lwp *, struct file *, int, int, const struct fileops *,
void *);
/* Commonly used fileops */
int fnullop_fcntl(struct file *, u_int, void *, struct lwp *);
int fnullop_poll(struct file *, int, struct lwp *);
int fnullop_kqfilter(struct file *, struct knote *);
int fbadop_stat(struct file *, struct stat *, struct lwp *);
#endif /* _KERNEL */
#endif /* _SYS_FILE_H_ */