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29 * @(#)filedesc.h 8.1 (Berkeley) 6/2/93
33 #ifndef _SYS_FILEDESC_H_
34 #define _SYS_FILEDESC_H_
36 #include <sys/queue.h>
37 #include <sys/event.h>
39 #include <sys/priority.h>
42 #include <machine/_limits.h>
45 * This structure is used for the management of descriptors. It may be
46 * shared by multiple processes.
48 #define NDSLOTTYPE u_long
51 struct file **fd_ofiles; /* file structures for open files */
52 char *fd_ofileflags; /* per-process open file flags */
53 struct vnode *fd_cdir; /* current directory */
54 struct vnode *fd_rdir; /* root directory */
55 struct vnode *fd_jdir; /* jail root directory */
56 int fd_nfiles; /* number of open files allocated */
57 NDSLOTTYPE *fd_map; /* bitmap of free fds */
58 int fd_lastfile; /* high-water mark of fd_ofiles */
59 int fd_freefile; /* approx. next free file */
60 u_short fd_cmask; /* mask for file creation */
61 u_short fd_refcnt; /* thread reference count */
62 u_short fd_holdcnt; /* hold count on structure + mutex */
63 struct sx fd_sx; /* protects members of this struct */
64 struct kqlist fd_kqlist; /* list of kqueues on this filedesc */
65 int fd_holdleaderscount; /* block fdfree() for shared close() */
66 int fd_holdleaderswakeup; /* fdfree() needs wakeup */
70 * Structure to keep track of (process leader, struct fildedesc) tuples.
71 * Each process has a pointer to such a structure when detailed tracking
72 * is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor
73 * table to be shared by processes having different "p_leader" pointers
74 * and thus distinct POSIX style locks.
76 * fdl_refcount and fdl_holdcount are protected by struct filedesc mtx.
78 struct filedesc_to_leader {
79 int fdl_refcount; /* references from struct proc */
80 int fdl_holdcount; /* temporary hold during closef */
81 int fdl_wakeup; /* fdfree() waits on closef() */
82 struct proc *fdl_leader; /* owner of POSIX locks */
84 struct filedesc_to_leader *fdl_prev;
85 struct filedesc_to_leader *fdl_next;
89 * Per-process open flags.
91 #define UF_EXCLOSE 0x01 /* auto-close on exec */
95 /* Lock a file descriptor table. */
96 #define FILEDESC_LOCK_INIT(fdp) sx_init(&(fdp)->fd_sx, "filedesc structure")
97 #define FILEDESC_LOCK_DESTROY(fdp) sx_destroy(&(fdp)->fd_sx)
98 #define FILEDESC_LOCK(fdp) (&(fdp)->fd_sx)
99 #define FILEDESC_XLOCK(fdp) sx_xlock(&(fdp)->fd_sx)
100 #define FILEDESC_XUNLOCK(fdp) sx_xunlock(&(fdp)->fd_sx)
101 #define FILEDESC_SLOCK(fdp) sx_slock(&(fdp)->fd_sx)
102 #define FILEDESC_SUNLOCK(fdp) sx_sunlock(&(fdp)->fd_sx)
104 #define FILEDESC_LOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_LOCKED | \
106 #define FILEDESC_XLOCK_ASSERT(fdp) sx_assert(&(fdp)->fd_sx, SX_XLOCKED | \
111 int closef(struct file *fp, struct thread *td);
112 int dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd,
113 int mode, int error);
114 int falloc(struct thread *td, struct file **resultfp, int *resultfd);
115 int fdalloc(struct thread *td, int minfd, int *result);
116 int fdavail(struct thread *td, int n);
117 int fdcheckstd(struct thread *td);
118 void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td);
119 void fdcloseexec(struct thread *td);
120 struct filedesc *fdcopy(struct filedesc *fdp);
121 void fdunshare(struct proc *p, struct thread *td);
122 void fdfree(struct thread *td);
123 struct filedesc *fdinit(struct filedesc *fdp);
124 struct filedesc *fdshare(struct filedesc *fdp);
125 struct filedesc_to_leader *
126 filedesc_to_leader_alloc(struct filedesc_to_leader *old,
127 struct filedesc *fdp, struct proc *leader);
128 int getvnode(struct filedesc *fdp, int fd, struct file **fpp);
129 void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
130 void setugidsafety(struct thread *td);
132 /* Return a referenced file from an unlocked descriptor. */
133 struct file *fget_unlocked(struct filedesc *fdp, int fd);
135 /* Requires a FILEDESC_{S,X}LOCK held and returns without a ref. */
136 static __inline struct file *
137 fget_locked(struct filedesc *fdp, int fd)
140 return (fd < 0 || fd >= fdp->fd_nfiles ? NULL : fdp->fd_ofiles[fd]);
145 #endif /* !_SYS_FILEDESC_H_ */