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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 1.11 2005/06/22 01:33:22 dillon Exp $
38 #ifndef _SYS_FILEDESC_H_
39 #define _SYS_FILEDESC_H_
41 #include <sys/queue.h>
44 * This structure is used for the management of descriptors. It may be
45 * shared by multiple processes.
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) and the constraint of being one less than a power of 2.
51 * If these descriptors are exhausted, a larger descriptor table
52 * may be allocated, up to a process' resource limit; the internal arrays
53 * are then unused. Each time the file table runs out, it is doubled until
54 * the resource limit is reached.
56 #define NDFILE 15 /* must be of the form 2^n - 1 */
72 struct fdnode *fd_files; /* file structures for open files */
73 struct vnode *fd_cdir; /* current directory (phaseout) */
74 struct vnode *fd_rdir; /* root directory (phaseout) */
75 struct vnode *fd_jdir; /* jail root directory (phaseout) */
76 struct namecache *fd_ncdir; /* current directory */
77 struct namecache *fd_nrdir; /* root directory */
78 struct namecache *fd_njdir; /* jail directory */
79 int fd_nfiles; /* number of open files allocated */
80 int fd_lastfile; /* high-water mark of fd_files */
81 int fd_freefile; /* approx. next free file */
82 int fd_cmask; /* mask for file creation */
83 int fd_refcnt; /* reference count */
85 int fd_knlistsize; /* size of knlist */
86 struct klist *fd_knlist; /* list of attached knotes */
87 u_long fd_knhashmask; /* size of knhash */
88 struct klist *fd_knhash; /* hash table for attached knotes */
89 int fd_holdleaderscount; /* block fdfree() for shared close() */
90 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
91 struct fdnode fd_builtin_files[NDFILE];
95 * Structure to keep track of (process leader, struct fildedesc) tuples.
96 * Each process has a pointer to such a structure when detailed tracking
97 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor
98 * table to be shared by processes having different "p_leader" pointers
99 * and thus distinct POSIX style locks.
101 struct filedesc_to_leader {
102 int fdl_refcount; /* references from struct proc */
103 int fdl_holdcount; /* temporary hold during closef */
104 int fdl_wakeup; /* fdfree() waits on closef() */
105 struct proc *fdl_leader; /* owner of POSIX locks */
107 struct filedesc_to_leader *fdl_prev;
108 struct filedesc_to_leader *fdl_next;
112 * Per-process open flags.
114 #define UF_EXCLOSE 0x01 /* auto-close on exec */
116 #define UF_MAPPED 0x02 /* mapped from device */
120 * This structure that holds the information needed to send a SIGIO or
121 * a SIGURG signal to a process or process group when new data arrives
122 * on a device or socket. The structure is placed on an SLIST belonging
123 * to the proc or pgrp so that the entire list may be revoked when the
124 * process exits or the process group disappears.
128 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */
129 struct pgrp *siu_pgrp; /* process group to receive ... */
131 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */
132 struct sigio **sio_myref; /* location of the pointer that holds
133 * the reference to this structure */
134 struct ucred *sio_ucred; /* current credentials */
135 uid_t sio_ruid; /* real user id */
136 pid_t sio_pgid; /* pgid for signals */
138 #define sio_proc sio_u.siu_proc
139 #define sio_pgrp sio_u.siu_pgrp
141 SLIST_HEAD(sigiolst, sigio);
149 * Kernel global variables and routines.
151 int dupfdopen (struct filedesc *, int, int, int, int);
152 int fdalloc (struct proc *p, int want, int *result);
153 int fdavail (struct proc *p, int n);
154 void fdreserve (struct filedesc *fdp, int fd0, int incr);
155 int falloc (struct proc *p, struct file **resultfp, int *resultfd);
156 int fsetfd (struct proc *p, struct file *fp, int *resultfd);
157 void funsetfd (struct filedesc *fdp, int fd);
158 void fsetcred (struct file *fp, struct ucred *cr);
159 void ffree (struct file *);
160 struct filedesc *fdinit (struct proc *p);
161 struct filedesc *fdshare (struct proc *p);
162 struct filedesc *fdcopy (struct proc *p);
163 void fdfree (struct proc *p);
164 int closef (struct file *fp, struct thread *td);
165 void fdcloseexec (struct proc *p);
166 int fdcheckstd (struct proc *p);
167 struct file *holdfp (struct filedesc *fdp, int fd, int flag);
168 int getvnode (struct filedesc *fdp, int fd, struct file **fpp);
169 int fdissequential (struct file *);
170 void fdsequential (struct file *, int);
171 pid_t fgetown (struct sigio *);
172 int fsetown (pid_t, struct sigio **);
173 void funsetown (struct sigio *);
174 void funsetownlst (struct sigiolst *);
175 void setugidsafety (struct proc *p);
177 struct filedesc_to_leader *
178 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
179 struct proc *leader);