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/*
* Copyright (c) 1994 The Regents of the University of California.
* Copyright (c) 1994 Jan-Simon Pendry.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
* @(#)union.h 8.9 (Berkeley) 12/10/94
* $FreeBSD$
*/
struct union_args {
char *target; /* Target of loopback */
int mntflags; /* Options on the mount */
};
#define UNMNT_ABOVE 0x0001 /* Target appears below mount point */
#define UNMNT_BELOW 0x0002 /* Target appears below mount point */
#define UNMNT_REPLACE 0x0003 /* Target replaces mount point */
#define UNMNT_OPMASK 0x0003
struct union_mount {
struct vnode *um_uppervp; /* UN_ULOCK holds locking state */
struct vnode *um_lowervp; /* Left unlocked */
struct ucred *um_cred; /* Credentials of user calling mount */
int um_cmode; /* cmask from mount process */
int um_op; /* Operation mode */
};
#ifdef _KERNEL
#ifndef DIAGNOSTIC
#define DIAGNOSTIC
#endif
/*
* DEFDIRMODE is the mode bits used to create a shadow directory.
*/
#define VRWXMODE (VREAD|VWRITE|VEXEC)
#define VRWMODE (VREAD|VWRITE)
#define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
#define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
/*
* A cache of vnode references (hangs off v_data)
*
* Placing un_lock as the first elements theoretically allows us to
* use the vop_stdlock functions. However, we need to make sure of
* certain side effects so we will still punch in our own code.
*/
struct union_node {
struct lock un_lock;
LIST_ENTRY(union_node) un_cache; /* Hash chain */
struct vnode *un_vnode; /* Back pointer */
struct vnode *un_uppervp; /* overlaying object */
struct vnode *un_lowervp; /* underlying object */
struct vnode *un_dirvp; /* Parent dir of uppervp */
struct vnode *un_pvp; /* Parent vnode */
char *un_path; /* saved component name */
int un_openl; /* # of opens on lowervp */
int un_exclcnt; /* exclusive count */
unsigned int un_flags;
struct vnode **un_dircache; /* cached union stack */
off_t un_uppersz; /* size of upper object */
off_t un_lowersz; /* size of lower object */
#ifdef DIAGNOSTIC
pid_t un_pid;
#endif
};
/*
* XXX UN_ULOCK - indicates that the uppervp is locked
*
* UN_CACHED - node is in the union cache
*/
/*#define UN_ULOCK 0x04*/ /* Upper node is locked */
#define UN_CACHED 0x10 /* In union cache */
/*
* Hash table locking flags
*/
#define UNVP_WANT 0x01
#define UNVP_LOCKED 0x02
extern int union_allocvp __P((struct vnode **, struct mount *,
struct vnode *,
struct vnode *,
struct componentname *, struct vnode *,
struct vnode *, int));
extern int union_freevp __P((struct vnode *));
extern struct vnode *union_dircache __P((struct vnode *, struct proc *));
extern int union_copyup __P((struct union_node *, int, struct ucred *,
struct proc *));
extern int union_dowhiteout __P((struct union_node *, struct ucred *,
struct proc *));
extern int union_mkshadow __P((struct union_mount *, struct vnode *,
struct componentname *, struct vnode **));
extern int union_mkwhiteout __P((struct union_mount *, struct vnode *,
struct componentname *, char *));
extern int union_cn_close __P((struct vnode *, int, struct ucred *,
struct proc *));
extern void union_removed_upper __P((struct union_node *un));
extern struct vnode *union_lowervp __P((struct vnode *));
extern void union_newsize __P((struct vnode *, off_t, off_t));
extern void union_vm_coherency __P((struct vnode *, struct uio *, int));
extern int (*union_dircheckp) __P((struct proc *, struct vnode **,
struct file *));
#define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
#define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
#define UNIONTOV(un) ((un)->un_vnode)
#define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
#define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
#define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
#define UDEBUG(x) if (uniondebug) printf x
#define UDEBUG_ENABLED 1
extern vop_t **union_vnodeop_p;
extern struct vfsops union_vfsops;
extern int uniondebug;
#endif /* _KERNEL */
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