proc->thread stage 4: rework the VFS and DEVICE subsystems to take thread
[dragonfly.git] / sys / sys / filedesc.h
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1/*
2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93
34 * $FreeBSD: src/sys/sys/filedesc.h,v 1.19.2.5 2003/06/06 20:21:32 tegge Exp $
dadab5e9 35 * $DragonFly: src/sys/sys/filedesc.h,v 1.4 2003/06/25 03:56:10 dillon Exp $
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36 */
37
38#ifndef _SYS_FILEDESC_H_
39#define _SYS_FILEDESC_H_
40
41#include <sys/queue.h>
42
43/*
44 * This structure is used for the management of descriptors. It may be
45 * shared by multiple processes.
46 *
47 * A process is initially started out with NDFILE descriptors stored within
48 * this structure, selected to be enough for typical applications based on
49 * the historical limit of 20 open files (and the usage of descriptors by
50 * shells). If these descriptors are exhausted, a larger descriptor table
51 * may be allocated, up to a process' resource limit; the internal arrays
52 * are then unused. The initial expansion is set to NDEXTENT; each time
53 * it runs out, it is doubled until the resource limit is reached. NDEXTENT
54 * should be selected to be the biggest multiple of OFILESIZE (see below)
55 * that will fit in a power-of-two sized piece of memory.
56 */
57#define NDFILE 20
58#define NDEXTENT 50 /* 250 bytes in 256-byte alloc. */
59
60struct klist;
61
62struct filedesc {
63 struct file **fd_ofiles; /* file structures for open files */
64 char *fd_ofileflags; /* per-process open file flags */
65 struct vnode *fd_cdir; /* current directory */
66 struct vnode *fd_rdir; /* root directory */
67 struct vnode *fd_jdir; /* jail root directory */
68 int fd_nfiles; /* number of open files allocated */
69 u_short fd_lastfile; /* high-water mark of fd_ofiles */
70 u_short fd_freefile; /* approx. next free file */
71 u_short fd_cmask; /* mask for file creation */
72 u_short fd_refcnt; /* reference count */
73
74 int fd_knlistsize; /* size of knlist */
75 struct klist *fd_knlist; /* list of attached knotes */
76 u_long fd_knhashmask; /* size of knhash */
77 struct klist *fd_knhash; /* hash table for attached knotes */
78 int fd_holdleaderscount; /* block fdfree() for shared close() */
79 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
80};
81
82/*
83 * Basic allocation of descriptors:
84 * one of the above, plus arrays for NDFILE descriptors.
85 */
86struct filedesc0 {
87 struct filedesc fd_fd;
88 /*
89 * These arrays are used when the number of open files is
90 * <= NDFILE, and are then pointed to by the pointers above.
91 */
92 struct file *fd_dfiles[NDFILE];
93 char fd_dfileflags[NDFILE];
94};
95
96
97
98/*
99 * Structure to keep track of (process leader, struct fildedesc) tuples.
100 * Each process has a pointer to such a structure when detailed tracking
101 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor
102 * table to be shared by processes having different "p_leader" pointers
103 * and thus distinct POSIX style locks.
104 */
105struct filedesc_to_leader {
106 int fdl_refcount; /* references from struct proc */
107 int fdl_holdcount; /* temporary hold during closef */
108 int fdl_wakeup; /* fdfree() waits on closef() */
109 struct proc *fdl_leader; /* owner of POSIX locks */
110 /* Circular list */
111 struct filedesc_to_leader *fdl_prev;
112 struct filedesc_to_leader *fdl_next;
113};
114
115/*
116 * Per-process open flags.
117 */
118#define UF_EXCLOSE 0x01 /* auto-close on exec */
119#if 0
120#define UF_MAPPED 0x02 /* mapped from device */
121#endif
122
123/*
124 * Storage required per open file descriptor.
125 */
126#define OFILESIZE (sizeof(struct file *) + sizeof(char))
127
128/*
129 * This structure that holds the information needed to send a SIGIO or
130 * a SIGURG signal to a process or process group when new data arrives
131 * on a device or socket. The structure is placed on an SLIST belonging
132 * to the proc or pgrp so that the entire list may be revoked when the
133 * process exits or the process group disappears.
134 */
135struct sigio {
136 union {
137 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */
138 struct pgrp *siu_pgrp; /* process group to receive ... */
139 } sio_u;
140 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */
141 struct sigio **sio_myref; /* location of the pointer that holds
142 * the reference to this structure */
143 struct ucred *sio_ucred; /* current credentials */
144 uid_t sio_ruid; /* real user id */
145 pid_t sio_pgid; /* pgid for signals */
146};
147#define sio_proc sio_u.siu_proc
148#define sio_pgrp sio_u.siu_pgrp
149
150SLIST_HEAD(sigiolst, sigio);
151
152#ifdef _KERNEL
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153
154struct thread;
155struct proc;
156
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157/*
158 * Kernel global variables and routines.
159 */
41c20dac 160int dupfdopen __P((struct filedesc *, int, int, int, int));
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161int fdalloc __P((struct proc *p, int want, int *result));
162int fdavail __P((struct proc *p, int n));
163int falloc __P((struct proc *p, struct file **resultfp, int *resultfd));
164void ffree __P((struct file *));
165struct filedesc *fdinit __P((struct proc *p));
166struct filedesc *fdshare __P((struct proc *p));
167struct filedesc *fdcopy __P((struct proc *p));
168void fdfree __P((struct proc *p));
dadab5e9 169int closef __P((struct file *fp, struct thread *td));
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170void fdcloseexec __P((struct proc *p));
171int fdcheckstd __P((struct proc *p));
dadab5e9 172struct file *holdfp __P((struct filedesc *fdp, int fd, int flag));
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173int getvnode __P((struct filedesc *fdp, int fd, struct file **fpp));
174int fdissequential __P((struct file *));
175void fdsequential __P((struct file *, int));
176pid_t fgetown __P((struct sigio *));
177int fsetown __P((pid_t, struct sigio **));
178void funsetown __P((struct sigio *));
179void funsetownlst __P((struct sigiolst *));
180void setugidsafety __P((struct proc *p));
181
182struct filedesc_to_leader *
183filedesc_to_leader_alloc(struct filedesc_to_leader *old,
184 struct proc *leader);
185
186#endif
187
188#endif