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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 1.15 2006/05/20 02:42:13 dillon Exp $
38 #ifndef _SYS_FILEDESC_H_
39 #define _SYS_FILEDESC_H_
42 #include <sys/types.h>
46 #include <sys/queue.h>
50 * This structure is used for the management of descriptors. It may be
51 * shared by multiple processes.
53 * A process is initially started out with NDFILE descriptors stored within
54 * this structure, selected to be enough for typical applications based on
55 * the historical limit of 20 open files (and the usage of descriptors by
56 * shells) and the constraint of being one less than a power of 2.
57 * If these descriptors are exhausted, a larger descriptor table
58 * may be allocated, up to a process' resource limit; the internal arrays
59 * are then unused. Each time the file table runs out, it is doubled until
60 * the resource limit is reached.
62 #define NDFILE 15 /* must be of the form 2^n - 1 */
78 struct fdnode *fd_files; /* file structures for open files */
79 struct vnode *fd_cdir; /* current directory (phaseout) */
80 struct vnode *fd_rdir; /* root directory (phaseout) */
81 struct vnode *fd_jdir; /* jail root directory (phaseout) */
82 struct namecache *fd_ncdir; /* current directory */
83 struct namecache *fd_nrdir; /* root directory */
84 struct namecache *fd_njdir; /* jail directory */
85 int fd_nfiles; /* number of open files allocated */
86 int fd_lastfile; /* high-water mark of fd_files */
87 int fd_freefile; /* approx. next free file */
88 int fd_cmask; /* mask for file creation */
89 int fd_refcnt; /* reference count */
91 int fd_knlistsize; /* size of knlist */
92 struct klist *fd_knlist; /* list of attached knotes */
93 u_long fd_knhashmask; /* size of knhash */
94 struct klist *fd_knhash; /* hash table for attached knotes */
95 int fd_holdleaderscount; /* block fdfree() for shared close() */
96 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
97 struct fdnode fd_builtin_files[NDFILE];
101 * Structure to keep track of (process leader, struct fildedesc) tuples.
102 * Each process has a pointer to such a structure when detailed tracking
103 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor
104 * table to be shared by processes having different "p_leader" pointers
105 * and thus distinct POSIX style locks.
107 struct filedesc_to_leader {
108 int fdl_refcount; /* references from struct proc */
109 int fdl_holdcount; /* temporary hold during closef */
110 int fdl_wakeup; /* fdfree() waits on closef() */
111 struct proc *fdl_leader; /* owner of POSIX locks */
113 struct filedesc_to_leader *fdl_prev;
114 struct filedesc_to_leader *fdl_next;
118 * Per-process open flags.
120 #define UF_EXCLOSE 0x01 /* auto-close on exec */
123 * This structure that holds the information needed to send a SIGIO or
124 * a SIGURG signal to a process or process group when new data arrives
125 * on a device or socket. The structure is placed on an SLIST belonging
126 * to the proc or pgrp so that the entire list may be revoked when the
127 * process exits or the process group disappears.
131 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */
132 struct pgrp *siu_pgrp; /* process group to receive ... */
134 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */
135 struct sigio **sio_myref; /* location of the pointer that holds
136 * the reference to this structure */
137 struct ucred *sio_ucred; /* current credentials */
138 uid_t sio_ruid; /* real user id */
139 pid_t sio_pgid; /* pgid for signals */
141 #define sio_proc sio_u.siu_proc
142 #define sio_pgrp sio_u.siu_pgrp
144 SLIST_HEAD(sigiolst, sigio);
152 * Kernel global variables and routines.
154 int dupfdopen (struct filedesc *, int, int, int, int);
155 int fdalloc (struct proc *p, int want, int *result);
156 int fdavail (struct proc *p, int n);
157 int falloc (struct proc *p, struct file **resultfp, int *resultfd);
158 int fdealloc (struct proc *p, struct file *fp, int fd);
159 int fsetfd (struct proc *p, struct file *fp, int *resultfd);
160 int fsetfdflags(struct filedesc *fdp, int fd, int add_flags);
161 int fclrfdflags(struct filedesc *fdp, int fd, int rem_flags);
162 void fsetcred (struct file *fp, struct ucred *cr);
163 void ffree (struct file *);
164 void fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask);
165 struct filedesc *fdinit (struct proc *p);
166 struct filedesc *fdshare (struct proc *p);
167 struct filedesc *fdcopy (struct proc *p);
168 void fdfree (struct proc *p);
169 int closef (struct file *fp, struct thread *td);
170 void fdcloseexec (struct proc *p);
171 int fdcheckstd (struct proc *p);
172 struct file *holdfp (struct filedesc *fdp, int fd, int flag);
173 int holdsock (struct filedesc *fdp, int fdes, struct file **fpp);
174 int getvnode (struct filedesc *fdp, int fd, struct file **fpp);
175 int fdissequential (struct file *);
176 void fdsequential (struct file *, int);
177 pid_t fgetown (struct sigio *);
178 int fsetown (pid_t, struct sigio **);
179 void funsetown (struct sigio *);
180 void funsetownlst (struct sigiolst *);
181 void setugidsafety (struct proc *p);
183 struct filedesc_to_leader *
184 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
185 struct proc *leader);