/* $NetBSD: union.h,v 1.29.10.1 2020/08/27 09:08:39 martin Exp $ */
/*
* Copyright (c) 1994 The Regents of the University of California.
* 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
*/
/*
* 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
*/
#ifndef _MISCFS_UNION_H_
#define _MISCFS_UNION_H_
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\0"
#ifdef _KERNEL
struct union_mount {
struct vnode *um_uppervp;
struct vnode *um_lowervp;
kauth_cred_t um_cred; /* Credentials of user calling mount */
int um_cmode; /* cmask from mount process */
int um_op; /* Operation mode */
};
/*
* 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.
* Lock requirements are:
*
* : stable
* c unheadlock[hash]
* l un_lock
* m un_lock or vnode lock to read, un_lock and
* exclusive vnode lock to write
* v vnode lock to read, exclusive vnode lock to write
*
* Lock order is vnode then un_lock.
*/
struct union_node {
kmutex_t un_lock;
LIST_ENTRY(union_node) un_cache; /* c: Hash chain */
int un_refs; /* c: Reference counter */
struct mount *un_mount; /* c: union mount */
struct vnode *un_vnode; /* :: Back pointer */
struct vnode *un_uppervp; /* m: overlaying object */
struct vnode *un_lowervp; /* v: underlying object */
struct vnode *un_dirvp; /* v: Parent dir of uppervp */
struct vnode *un_pvp; /* v: Parent vnode */
char *un_path; /* v: saved component name */
int un_openl; /* v: # of opens on lowervp */
unsigned int un_cflags; /* c: cache flags */
bool un_hooknode; /* :: from union_readdirhook */
struct vnode **un_dircache; /* v: cached union stack */
off_t un_uppersz; /* l: size of upper object */
off_t un_lowersz; /* l: size of lower object */
};
#define UN_CACHED 0x10 /* In union cache */
extern int union_allocvp(struct vnode **, struct mount *,
struct vnode *, struct vnode *,
struct componentname *, struct vnode *,
struct vnode *, int);
extern int union_check_rmdir(struct union_node *, kauth_cred_t);
extern int union_copyfile(struct vnode *, struct vnode *, kauth_cred_t,
struct lwp *);
extern int union_copyup(struct union_node *, int, kauth_cred_t,
struct lwp *);
extern void union_diruncache(struct union_node *);
extern int union_dowhiteout(struct union_node *, kauth_cred_t);
extern int union_mkshadow(struct union_mount *, struct vnode *,
struct componentname *, struct vnode **);
extern int union_mkwhiteout(struct union_mount *, struct vnode *,
struct componentname *, struct union_node *);
extern int union_vn_create(struct vnode **, struct union_node *,
struct lwp *);
extern int union_cn_close(struct vnode *, int, kauth_cred_t,
struct lwp *);
extern void union_removed_upper(struct union_node *un);
extern struct vnode *union_lowervp(struct vnode *);
extern void union_newsize(struct vnode *, off_t, off_t);
int union_readdirhook(struct vnode **, struct file *, struct lwp *);
VFS_PROTOS(union);
#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 LOCKVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : (vp))
extern int (**union_vnodeop_p)(void *);
void union_init(void);
void union_reinit(void);
void union_done(void);
int union_freevp(struct vnode *);
#endif /* _KERNEL */
#endif /* _MISCFS_UNION_H_ */