FreeBSD/Linux Kernel Cross Reference
sys/fs/unionfs/union.h
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: releng/5.0/sys/fs/unionfs/union.h 105077 2002-10-14 03:20:36Z mckusick $
39 */
40
41 #define UNMNT_ABOVE 0x0001 /* Target appears above mount point */
42 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */
43 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */
44
45 struct union_mount {
46 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */
47 struct vnode *um_lowervp; /* Left unlocked */
48 struct ucred *um_cred; /* Credentials of user calling mount */
49 int um_cmode; /* cmask from mount process */
50 int um_op; /* Operation mode */
51 };
52
53 #ifdef _KERNEL
54
55 #ifndef DIAGNOSTIC
56 #define DIAGNOSTIC
57 #endif
58
59 /*
60 * DEFDIRMODE is the mode bits used to create a shadow directory.
61 */
62 #define VRWXMODE (VREAD|VWRITE|VEXEC)
63 #define VRWMODE (VREAD|VWRITE)
64 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
65 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
66
67 /*
68 * A cache of vnode references (hangs off v_data)
69 */
70 struct union_node {
71 LIST_ENTRY(union_node) un_cache; /* Hash chain */
72 struct vnode *un_vnode; /* Back pointer */
73 struct vnode *un_uppervp; /* overlaying object */
74 struct vnode *un_lowervp; /* underlying object */
75 struct vnode *un_dirvp; /* Parent dir of uppervp */
76 struct vnode *un_pvp; /* Parent vnode */
77 char *un_path; /* saved component name */
78 int un_openl; /* # of opens on lowervp */
79 int un_exclcnt; /* exclusive count */
80 unsigned int un_flags;
81 struct vnode **un_dircache; /* cached union stack */
82 off_t un_uppersz; /* size of upper object */
83 off_t un_lowersz; /* size of lower object */
84 #ifdef DIAGNOSTIC
85 pid_t un_pid;
86 #endif
87 };
88
89 /*
90 * XXX UN_ULOCK - indicates that the uppervp is locked
91 *
92 * UN_CACHED - node is in the union cache
93 */
94
95 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */
96 #define UN_CACHED 0x10 /* In union cache */
97
98 /*
99 * Hash table locking flags
100 */
101
102 #define UNVP_WANT 0x01
103 #define UNVP_LOCKED 0x02
104
105 extern int union_allocvp(struct vnode **, struct mount *,
106 struct vnode *,
107 struct vnode *,
108 struct componentname *, struct vnode *,
109 struct vnode *, int);
110 extern int union_freevp(struct vnode *);
111 extern struct vnode *union_dircache(struct vnode *, struct thread *);
112 extern int union_copyup(struct union_node *, int, struct ucred *,
113 struct thread *);
114 extern int union_dowhiteout(struct union_node *, struct ucred *,
115 struct thread *);
116 extern int union_mkshadow(struct union_mount *, struct vnode *,
117 struct componentname *, struct vnode **);
118 extern int union_mkwhiteout(struct union_mount *, struct vnode *,
119 struct componentname *, char *);
120 extern int union_cn_close(struct vnode *, int, struct ucred *,
121 struct thread *);
122 extern void union_removed_upper(struct union_node *un);
123 extern struct vnode *union_lowervp(struct vnode *);
124 extern void union_newsize(struct vnode *, off_t, off_t);
125
126 extern int (*union_dircheckp)(struct thread *, struct vnode **,
127 struct file *);
128
129 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
130 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
131 #define UNIONTOV(un) ((un)->un_vnode)
132 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
133 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
134 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
135
136 #define UDEBUG(x) if (uniondebug) printf x
137 #define UDEBUG_ENABLED 1
138
139 extern vop_t **union_vnodeop_p;
140 extern struct vfsops union_vfsops;
141 extern int uniondebug;
142
143 #endif /* _KERNEL */
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