1/*
2 * Copyright (c) 1994 The Regents of the University of California.
3 * Copyright (c) 1994 Jan-Simon Pendry.
4 * All rights reserved.
5 *
6 * This code is derived from software donated to Berkeley by
7 * Jan-Simon Pendry.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 * 3. All advertising materials mentioning features or use of this software
18 * must display the following acknowledgement:
19 * This product includes software developed by the University of
20 * California, Berkeley and its contributors.
21 * 4. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 * @(#)union.h 8.9 (Berkeley) 12/10/94
38 * $FreeBSD: head/sys/fs/unionfs/union.h 51688 1999-09-26 20:52:41Z dillon $
39 */
40
41struct union_args {
42 char *target; /* Target of loopback */
43 int mntflags; /* Options on the mount */
44};
45
46#define UNMNT_ABOVE 0x0001 /* Target appears below mount point */
47#define UNMNT_BELOW 0x0002 /* Target appears below mount point */
48#define UNMNT_REPLACE 0x0003 /* Target replaces mount point */
49#define UNMNT_OPMASK 0x0003
50
51struct union_mount {
52 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */
53 struct vnode *um_lowervp; /* Left unlocked */
54 struct ucred *um_cred; /* Credentials of user calling mount */
55 int um_cmode; /* cmask from mount process */
56 int um_op; /* Operation mode */
57};
58
59#ifdef KERNEL
60
61#ifndef DIAGNOSTIC
62#define DIAGNOSTIC
63#endif
64
65/*
66 * DEFDIRMODE is the mode bits used to create a shadow directory.
67 */
68#define VRWXMODE (VREAD|VWRITE|VEXEC)
69#define VRWMODE (VREAD|VWRITE)
70#define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
71#define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
72
73/*
74 * A cache of vnode references (hangs off v_data)
75 *
76 * Placing un_lock as the first elements theoretically allows us to
77 * use the vop_stdlock functions. However, we need to make sure of
78 * certain side effects so we will still punch in our own code.
79 */
80struct union_node {
81 struct lock un_lock;
82 LIST_ENTRY(union_node) un_cache; /* Hash chain */
83 struct vnode *un_vnode; /* Back pointer */
84 struct vnode *un_uppervp; /* overlaying object */
85 struct vnode *un_lowervp; /* underlying object */
86 struct vnode *un_dirvp; /* Parent dir of uppervp */
87 struct vnode *un_pvp; /* Parent vnode */
88 char *un_path; /* saved component name */
89 int un_hash; /* saved un_path hash value */
90 int un_openl; /* # of opens on lowervp */
91 int un_exclcnt; /* exclusive count */
92 unsigned int un_flags;
93 struct vnode **un_dircache; /* cached union stack */
94 off_t un_uppersz; /* size of upper object */
95 off_t un_lowersz; /* size of lower object */
96#ifdef DIAGNOSTIC
97 pid_t un_pid;
98#endif
99};
100
101/*
102 * XXX UN_ULOCK - indicates that the uppervp is locked
103 *
104 * UN_CACHED - node is in the union cache
105 */
106
107/*#define UN_ULOCK 0x04*/ /* Upper node is locked */
108#define UN_CACHED 0x10 /* In union cache */
109
110/*
111 * Hash table locking flags
112 */
113
114#define UNVP_WANT 0x01
115#define UNVP_LOCKED 0x02
116
117extern int union_allocvp __P((struct vnode **, struct mount *,
118 struct vnode *,
119 struct vnode *,
120 struct componentname *, struct vnode *,
121 struct vnode *, int));
122extern int union_freevp __P((struct vnode *));
123extern struct vnode *union_dircache __P((struct vnode *, struct proc *));
124extern int union_copyup __P((struct union_node *, int, struct ucred *,
125 struct proc *));
126extern int union_dowhiteout __P((struct union_node *, struct ucred *,
127 struct proc *));
128extern int union_mkshadow __P((struct union_mount *, struct vnode *,
129 struct componentname *, struct vnode **));
130extern int union_mkwhiteout __P((struct union_mount *, struct vnode *,
131 struct componentname *, char *));
132extern int union_cn_close __P((struct vnode *, int, struct ucred *,
133 struct proc *));
134extern void union_removed_upper __P((struct union_node *un));
135extern struct vnode *union_lowervp __P((struct vnode *));
136extern void union_newsize __P((struct vnode *, off_t, off_t));
137extern void union_vm_coherency __P((struct vnode *, struct uio *, int));
138
139extern int (*union_dircheckp) __P((struct proc *, struct vnode **,
140 struct file *));
141
142#define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
143#define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
144#define UNIONTOV(un) ((un)->un_vnode)
145#define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
146#define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
147#define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
148
149#define UDEBUG(x) if (uniondebug) printf x
150#define UDEBUG_ENABLED 1
151
152extern vop_t **union_vnodeop_p;
153extern struct vfsops union_vfsops;
154extern int uniondebug;
155
156#endif /* KERNEL */