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/* $OpenBSD: union.h,v 1.10 2003/08/14 07:46:40 mickey Exp $ */
/* $NetBSD: union.h,v 1.13 2002/09/21 18:09:31 christos Exp $ */
/*
* 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. 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
*/
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
#define UNMNT_BITS "\177\20" \
"b\00above\0b\01below\0b\02replace"
struct union_mount {
struct vnode *um_uppervp;
struct vnode *um_lowervp;
struct ucred *um_cred; /* Credentials of user calling mount */
int um_cmode; /* cmask from mount process */
int um_op; /* Operation mode */
};
#ifdef _KERNEL
/*
* DEFDIRMODE is the mode bits used to create a shadow directory.
*/
#define UN_DIRMODE (S_IRWXU|S_IRWXG|S_IRWXO)
#define UN_FILEMODE (S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
/*
* A cache of vnode references
*/
struct union_node {
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_hash; /* saved un_path hash value */
int un_openl; /* # of opens on lowervp */
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
};
#define UN_WANTED 0x01
#define UN_LOCKED 0x02
#define UN_ULOCK 0x04 /* Upper node is locked */
#define UN_KLOCK 0x08 /* Keep upper node locked on vput */
#define UN_CACHED 0x10 /* In union cache */
#define UN_DRAINING 0x20 /* upper node lock is draining */
#define UN_DRAINED 0x40 /* upper node lock is drained */
extern int union_allocvp(struct vnode **, struct mount *,
struct vnode *, struct vnode *,
struct componentname *, struct vnode *,
struct vnode *, int);
extern int union_copyfile(struct vnode *, struct vnode *,
struct ucred *, struct proc *);
extern int union_copyup(struct union_node *, int, struct ucred *,
struct proc *);
extern void union_diruncache(struct union_node *);
extern int union_dowhiteout(struct union_node *, struct ucred *,
struct proc *);
extern int union_mkshadow(struct union_mount *, struct vnode *,
struct componentname *, struct vnode **);
extern int union_mkwhiteout(struct union_mount *, struct vnode *,
struct componentname *, char *);
extern int union_vn_create(struct vnode **, struct union_node *,
struct proc *);
extern int union_cn_close(struct vnode *, int, struct ucred *,
struct proc *);
extern void union_removed_upper(struct union_node *un);
extern struct vnode *union_lowervp(struct vnode *);
extern void union_newlower(struct union_node *, struct vnode *);
extern void union_newupper(struct union_node *, struct vnode *);
extern void union_newsize(struct vnode *, off_t, off_t);
#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))
extern int (**union_vnodeop_p)(void *);
extern const struct vfsops union_vfsops;
int union_init(struct vfsconf *);
int union_freevp(struct vnode *);
#endif /* _KERNEL */
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