2 * Copyright (c) 1990, 1993
3 * The Regents of the University of California. All rights reserved.
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6 * modification, are permitted provided that the following conditions
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14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
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18 * may be used to endorse or promote products derived from this software
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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 $
35 * $DragonFly: src/sys/sys/filedesc.h,v 1.20 2006/10/27 04:56:33 dillon Exp $
38 #ifndef _SYS_FILEDESC_H_
39 #define _SYS_FILEDESC_H_
42 #include <sys/types.h>
45 #include <sys/queue.h>
47 #ifndef _SYS_SPINLOCK_H_
48 #include <sys/spinlock.h>
50 #ifndef _SYS_NAMECACHE_H_
51 #include <sys/namecache.h>
55 * This structure is used for the management of descriptors. It may be
56 * shared by multiple processes.
58 * A process is initially started out with NDFILE descriptors stored within
59 * this structure, selected to be enough for typical applications based on
60 * the historical limit of 20 open files (and the usage of descriptors by
61 * shells) and the constraint of being one less than a power of 2.
62 * If these descriptors are exhausted, a larger descriptor table
63 * may be allocated, up to a process' resource limit; the internal arrays
64 * are then unused. Each time the file table runs out, it is doubled until
65 * the resource limit is reached.
67 #define NDFILE 15 /* must be of the form 2^n - 1 */
77 char reserved
; /* descriptor has been reserved */
78 int allocated
; /* subtree allocation count */
82 struct fdnode
*fd_files
; /* file structures for open files */
83 struct vnode
*fd_cdir
; /* current directory (phaseout) */
84 struct vnode
*fd_rdir
; /* root directory (phaseout) */
85 struct vnode
*fd_jdir
; /* jail root directory (phaseout) */
86 struct nchandle fd_ncdir
; /* current directory */
87 struct nchandle fd_nrdir
; /* root directory */
88 struct nchandle fd_njdir
; /* jail directory */
89 int fd_nfiles
; /* number of open files allocated */
90 int fd_lastfile
; /* high-water mark of fd_files */
91 int fd_freefile
; /* approx. next free file */
92 int fd_cmask
; /* mask for file creation */
93 int fd_refcnt
; /* reference count */
95 int fd_knlistsize
; /* size of knlist */
96 struct klist
*fd_knlist
; /* list of attached knotes */
97 u_long fd_knhashmask
; /* size of knhash */
98 struct klist
*fd_knhash
; /* hash table for attached knotes */
99 int fd_holdleaderscount
; /* block fdfree() for shared close() */
100 int fd_holdleaderswakeup
; /* fdfree() needs wakeup */
101 struct spinlock fd_spin
;
102 struct fdnode fd_builtin_files
[NDFILE
];
106 * Structure to keep track of (process leader, struct fildedesc) tuples.
107 * Each process has a pointer to such a structure when detailed tracking
108 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor
109 * table to be shared by processes having different "p_leader" pointers
110 * and thus distinct POSIX style locks.
112 struct filedesc_to_leader
{
113 int fdl_refcount
; /* references from struct proc */
114 int fdl_holdcount
; /* temporary hold during closef */
115 int fdl_wakeup
; /* fdfree() waits on closef() */
116 struct proc
*fdl_leader
; /* owner of POSIX locks */
118 struct filedesc_to_leader
*fdl_prev
;
119 struct filedesc_to_leader
*fdl_next
;
123 * Per-process open flags.
125 #define UF_EXCLOSE 0x01 /* auto-close on exec */
128 * This structure that holds the information needed to send a SIGIO or
129 * a SIGURG signal to a process or process group when new data arrives
130 * on a device or socket. The structure is placed on an SLIST belonging
131 * to the proc or pgrp so that the entire list may be revoked when the
132 * process exits or the process group disappears.
136 struct proc
*siu_proc
; /* process to receive SIGIO/SIGURG */
137 struct pgrp
*siu_pgrp
; /* process group to receive ... */
139 SLIST_ENTRY(sigio
) sio_pgsigio
; /* sigio's for process or group */
140 struct sigio
**sio_myref
; /* location of the pointer that holds
141 * the reference to this structure */
142 struct ucred
*sio_ucred
; /* current credentials */
143 uid_t sio_ruid
; /* real user id */
144 pid_t sio_pgid
; /* pgid for signals */
146 #define sio_proc sio_u.siu_proc
147 #define sio_pgrp sio_u.siu_pgrp
149 SLIST_HEAD(sigiolst
, sigio
);
157 * Kernel global variables and routines.
159 int dupfdopen (struct proc
*, int, int, int, int);
160 int fdalloc (struct proc
*p
, int want
, int *result
);
161 int fdavail (struct proc
*p
, int n
);
162 int falloc (struct proc
*p
, struct file
**resultfp
, int *resultfd
);
163 void fsetfd (struct proc
*p
, struct file
*fp
, int fd
);
164 int fgetfdflags(struct filedesc
*fdp
, int fd
, int *flagsp
);
165 int fsetfdflags(struct filedesc
*fdp
, int fd
, int add_flags
);
166 int fclrfdflags(struct filedesc
*fdp
, int fd
, int rem_flags
);
167 void fsetcred (struct file
*fp
, struct ucred
*cr
);
168 void fdinit_bootstrap(struct proc
*p0
, struct filedesc
*fdp0
, int cmask
);
169 struct filedesc
*fdinit (struct proc
*p
);
170 struct filedesc
*fdshare (struct proc
*p
);
171 struct filedesc
*fdcopy (struct proc
*p
);
172 void fdfree (struct proc
*p
);
173 int closef (struct file
*fp
, struct thread
*td
);
174 void fdcloseexec (struct proc
*p
);
175 int fdcheckstd (struct proc
*p
);
176 struct file
*holdfp (struct filedesc
*fdp
, int fd
, int flag
);
177 int holdsock (struct filedesc
*fdp
, int fdes
, struct file
**fpp
);
178 int holdvnode (struct filedesc
*fdp
, int fd
, struct file
**fpp
);
179 int fdissequential (struct file
*);
180 void fdsequential (struct file
*, int);
181 pid_t
fgetown (struct sigio
*);
182 int fsetown (pid_t
, struct sigio
**);
183 void funsetown (struct sigio
*);
184 void funsetownlst (struct sigiolst
*);
185 void setugidsafety (struct proc
*p
);
186 void allfiles_scan_exclusive(int (*callback
)(struct file
*, void *), void *data
);
188 struct filedesc_to_leader
*
189 filedesc_to_leader_alloc(struct filedesc_to_leader
*old
,
190 struct proc
*leader
);