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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 1.19 2006/05/26 02:26:26 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>
52 * This structure is used for the management of descriptors. It may be
53 * shared by multiple processes.
55 * A process is initially started out with NDFILE descriptors stored within
56 * this structure, selected to be enough for typical applications based on
57 * the historical limit of 20 open files (and the usage of descriptors by
58 * shells) and the constraint of being one less than a power of 2.
59 * If these descriptors are exhausted, a larger descriptor table
60 * may be allocated, up to a process' resource limit; the internal arrays
61 * are then unused. Each time the file table runs out, it is doubled until
62 * the resource limit is reached.
64 #define NDFILE 15 /* must be of the form 2^n - 1 */
75 char reserved; /* descriptor has been reserved */
76 int allocated; /* subtree allocation count */
80 struct fdnode *fd_files; /* file structures for open files */
81 struct vnode *fd_cdir; /* current directory (phaseout) */
82 struct vnode *fd_rdir; /* root directory (phaseout) */
83 struct vnode *fd_jdir; /* jail root directory (phaseout) */
84 struct namecache *fd_ncdir; /* current directory */
85 struct namecache *fd_nrdir; /* root directory */
86 struct namecache *fd_njdir; /* jail directory */
87 int fd_nfiles; /* number of open files allocated */
88 int fd_lastfile; /* high-water mark of fd_files */
89 int fd_freefile; /* approx. next free file */
90 int fd_cmask; /* mask for file creation */
91 int fd_refcnt; /* reference count */
93 int fd_knlistsize; /* size of knlist */
94 struct klist *fd_knlist; /* list of attached knotes */
95 u_long fd_knhashmask; /* size of knhash */
96 struct klist *fd_knhash; /* hash table for attached knotes */
97 int fd_holdleaderscount; /* block fdfree() for shared close() */
98 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
99 struct spinlock fd_spin;
100 struct fdnode fd_builtin_files[NDFILE];
104 * Structure to keep track of (process leader, struct fildedesc) tuples.
105 * Each process has a pointer to such a structure when detailed tracking
106 * is needed. e.g. when rfork(RFPROC | RFMEM) causes a file descriptor
107 * table to be shared by processes having different "p_leader" pointers
108 * and thus distinct POSIX style locks.
110 struct filedesc_to_leader {
111 int fdl_refcount; /* references from struct proc */
112 int fdl_holdcount; /* temporary hold during closef */
113 int fdl_wakeup; /* fdfree() waits on closef() */
114 struct proc *fdl_leader; /* owner of POSIX locks */
116 struct filedesc_to_leader *fdl_prev;
117 struct filedesc_to_leader *fdl_next;
121 * Per-process open flags.
123 #define UF_EXCLOSE 0x01 /* auto-close on exec */
126 * This structure that holds the information needed to send a SIGIO or
127 * a SIGURG signal to a process or process group when new data arrives
128 * on a device or socket. The structure is placed on an SLIST belonging
129 * to the proc or pgrp so that the entire list may be revoked when the
130 * process exits or the process group disappears.
134 struct proc *siu_proc; /* process to receive SIGIO/SIGURG */
135 struct pgrp *siu_pgrp; /* process group to receive ... */
137 SLIST_ENTRY(sigio) sio_pgsigio; /* sigio's for process or group */
138 struct sigio **sio_myref; /* location of the pointer that holds
139 * the reference to this structure */
140 struct ucred *sio_ucred; /* current credentials */
141 uid_t sio_ruid; /* real user id */
142 pid_t sio_pgid; /* pgid for signals */
144 #define sio_proc sio_u.siu_proc
145 #define sio_pgrp sio_u.siu_pgrp
147 SLIST_HEAD(sigiolst, sigio);
155 * Kernel global variables and routines.
157 int dupfdopen (struct proc *, int, int, int, int);
158 int fdalloc (struct proc *p, int want, int *result);
159 int fdavail (struct proc *p, int n);
160 int falloc (struct proc *p, struct file **resultfp, int *resultfd);
161 void fsetfd (struct proc *p, struct file *fp, int fd);
162 int fgetfdflags(struct filedesc *fdp, int fd, int *flagsp);
163 int fsetfdflags(struct filedesc *fdp, int fd, int add_flags);
164 int fclrfdflags(struct filedesc *fdp, int fd, int rem_flags);
165 void fsetcred (struct file *fp, struct ucred *cr);
166 void fdinit_bootstrap(struct proc *p0, struct filedesc *fdp0, int cmask);
167 struct filedesc *fdinit (struct proc *p);
168 struct filedesc *fdshare (struct proc *p);
169 struct filedesc *fdcopy (struct proc *p);
170 void fdfree (struct proc *p);
171 int closef (struct file *fp, struct thread *td);
172 void fdcloseexec (struct proc *p);
173 int fdcheckstd (struct proc *p);
174 struct file *holdfp (struct filedesc *fdp, int fd, int flag);
175 int holdsock (struct filedesc *fdp, int fdes, struct file **fpp);
176 int holdvnode (struct filedesc *fdp, int fd, struct file **fpp);
177 int fdissequential (struct file *);
178 void fdsequential (struct file *, int);
179 pid_t fgetown (struct sigio *);
180 int fsetown (pid_t, struct sigio **);
181 void funsetown (struct sigio *);
182 void funsetownlst (struct sigiolst *);
183 void setugidsafety (struct proc *p);
184 void allfiles_scan_exclusive(int (*callback)(struct file *, void *), void *data);
186 struct filedesc_to_leader *
187 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
188 struct proc *leader);