/*
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)filedesc.h 8.1 (Berkeley) 6/2/93
* $FreeBSD$
*/
#ifndef _SYS_FILEDESC_H_
#define _SYS_FILEDESC_H_
#include <sys/queue.h>
#include <sys/event.h>
#include <sys/priority.h>
#include <sys/_lock.h>
#include <sys/_mutex.h>
#include <machine/_limits.h>
/*
* This structure is used for the management of descriptors. It may be
* shared by multiple processes.
*/
#define NDSLOTTYPE u_long
struct filedesc {
struct file **fd_ofiles; /* file structures for open files */
char *fd_ofileflags; /* per-process open file flags */
struct vnode *fd_cdir; /* current directory */
struct vnode *fd_rdir; /* root directory */
struct vnode *fd_jdir; /* jail root directory */
int fd_nfiles; /* number of open files allocated */
NDSLOTTYPE *fd_map; /* bitmap of free fds */
int fd_lastfile; /* high-water mark of fd_ofiles */
int fd_freefile; /* approx. next free file */
u_short fd_cmask; /* mask for file creation */
u_short fd_refcnt; /* thread reference count */
u_short fd_holdcnt; /* hold count on structure + mutex */
struct mtx fd_mtx; /* protects members of this struct */
int fd_locked; /* long lock flag */
int fd_wanted; /* "" */
struct kqlist fd_kqlist; /* list of kqueues on this filedesc */
int fd_holdleaderscount; /* block fdfree() for shared close() */
int fd_holdleaderswakeup; /* fdfree() needs wakeup */
};
/*
* Structure to keep track of (process leader, struct fildedesc) tuples.
* Each process has a pointer to such a structure when detailed tracking
* is needed, e.g., when rfork(RFPROC | RFMEM) causes a file descriptor
* table to be shared by processes having different "p_leader" pointers
* and thus distinct POSIX style locks.
*
* fdl_refcount and fdl_holdcount are protected by struct filedesc mtx.
*/
struct filedesc_to_leader {
int fdl_refcount; /* references from struct proc */
int fdl_holdcount; /* temporary hold during closef */
int fdl_wakeup; /* fdfree() waits on closef() */
struct proc *fdl_leader; /* owner of POSIX locks */
/* Circular list: */
struct filedesc_to_leader *fdl_prev;
struct filedesc_to_leader *fdl_next;
};
/*
* Per-process open flags.
*/
#define UF_EXCLOSE 0x01 /* auto-close on exec */
#ifdef _KERNEL
/* Lock a file descriptor table. */
#define FILEDESC_LOCK(fd) \
do { \
mtx_lock(&(fd)->fd_mtx); \
(fd)->fd_wanted++; \
while ((fd)->fd_locked) \
msleep(&(fd)->fd_locked, &(fd)->fd_mtx, PLOCK, "fdesc", 0); \
(fd)->fd_locked = 2; \
(fd)->fd_wanted--; \
mtx_unlock(&(fd)->fd_mtx); \
} while (0);
#define FILEDESC_UNLOCK(fd) \
do { \
mtx_lock(&(fd)->fd_mtx); \
KASSERT((fd)->fd_locked == 2, \
("fdesc locking mistake %d should be %d", (fd)->fd_locked, 2)); \
(fd)->fd_locked = 0; \
if ((fd)->fd_wanted) \
wakeup(&(fd)->fd_locked); \
mtx_unlock(&(fd)->fd_mtx); \
} while (0);
#define FILEDESC_LOCK_FAST(fd) \
do { \
mtx_lock(&(fd)->fd_mtx); \
(fd)->fd_wanted++; \
while ((fd)->fd_locked) \
msleep(&(fd)->fd_locked, &(fd)->fd_mtx, PLOCK, "fdesc", 0); \
(fd)->fd_locked = 1; \
(fd)->fd_wanted--; \
} while (0);
#define FILEDESC_UNLOCK_FAST(fd) \
do { \
KASSERT((fd)->fd_locked == 1, \
("fdesc locking mistake %d should be %d", (fd)->fd_locked, 1)); \
(fd)->fd_locked = 0; \
if ((fd)->fd_wanted) \
wakeup(&(fd)->fd_locked); \
mtx_unlock(&(fd)->fd_mtx); \
} while (0);
#ifdef INVARIANT_SUPPORT
#define FILEDESC_LOCK_ASSERT(fd, arg) \
do { \
if ((arg) == MA_OWNED) \
KASSERT((fd)->fd_locked != 0, ("fdesc locking mistake")); \
else \
KASSERT((fd)->fd_locked == 0, ("fdesc locking mistake")); \
} while (0);
#else
#define FILEDESC_LOCK_ASSERT(fd, arg)
#endif
#define FILEDESC_LOCK_DESC "filedesc structure"
struct thread;
int closef(struct file *fp, struct thread *td);
int dupfdopen(struct thread *td, struct filedesc *fdp, int indx, int dfd,
int mode, int error);
int falloc(struct thread *td, struct file **resultfp, int *resultfd);
int fdalloc(struct thread *td, int minfd, int *result);
int fdavail(struct thread *td, int n);
int fdcheckstd(struct thread *td);
void fdclose(struct filedesc *fdp, struct file *fp, int idx, struct thread *td);
void fdcloseexec(struct thread *td);
struct filedesc *fdcopy(struct filedesc *fdp);
void fdunshare(struct proc *p, struct thread *td);
void fdfree(struct thread *td);
struct filedesc *fdinit(struct filedesc *fdp);
struct filedesc *fdshare(struct filedesc *fdp);
void fdused(struct filedesc *fdp, int fd);
struct filedesc_to_leader *
filedesc_to_leader_alloc(struct filedesc_to_leader *old,
struct filedesc *fdp, struct proc *leader);
int getvnode(struct filedesc *fdp, int fd, struct file **fpp);
void mountcheckdirs(struct vnode *olddp, struct vnode *newdp);
void setugidsafety(struct thread *td);
static __inline struct file *
fget_locked(struct filedesc *fdp, int fd)
{
return (fd < 0 || fd >= fdp->fd_nfiles ? NULL : fdp->fd_ofiles[fd]);
}
#endif /* _KERNEL */
#endif /* !_SYS_FILEDESC_H_ */
