2 * Copyright (c) 1994 The Regents of the University of California.
3 * Copyright (c) 1994 Jan-Simon Pendry.
6 * This code is derived from software donated to Berkeley by
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
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15 * notice, this list of conditions and the following disclaimer in the
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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.
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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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
37 * @(#)union.h 8.9 (Berkeley) 12/10/94
38 * $FreeBSD: src/sys/miscfs/union/union.h,v 1.17 1999/12/29 04:54:48 peter Exp $
39 * $DragonFly: src/sys/vfs/union/union.h,v 1.5 2003/08/27 02:03:23 dillon Exp $
43 char *target; /* Target of loopback */
44 int mntflags; /* Options on the mount */
47 #define UNMNT_ABOVE 0x0001 /* Target appears below mount point */
48 #define UNMNT_BELOW 0x0002 /* Target appears below mount point */
49 #define UNMNT_REPLACE 0x0003 /* Target replaces mount point */
50 #define UNMNT_OPMASK 0x0003
53 struct vnode *um_uppervp; /* UN_ULOCK holds locking state */
54 struct vnode *um_lowervp; /* Left unlocked */
55 struct ucred *um_cred; /* Credentials of user calling mount */
56 int um_cmode; /* cmask from mount process */
57 int um_op; /* Operation mode */
68 #if defined(_KERNEL) || defined(_KERNEL_STRUCTURES)
71 * DEFDIRMODE is the mode bits used to create a shadow directory.
73 #define VRWXMODE (VREAD|VWRITE|VEXEC)
74 #define VRWMODE (VREAD|VWRITE)
75 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
76 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
79 * A cache of vnode references (hangs off v_data)
81 * Placing un_lock as the first elements theoretically allows us to
82 * use the vop_stdlock functions. However, we need to make sure of
83 * certain side effects so we will still punch in our own code.
87 LIST_ENTRY(union_node) un_cache; /* Hash chain */
88 struct vnode *un_vnode; /* Back pointer */
89 struct vnode *un_uppervp; /* overlaying object */
90 struct vnode *un_lowervp; /* underlying object */
91 struct vnode *un_dirvp; /* Parent dir of uppervp */
92 struct vnode *un_pvp; /* Parent vnode */
93 char *un_path; /* saved component name */
94 int un_openl; /* # of opens on lowervp */
95 int un_exclcnt; /* exclusive count */
96 unsigned int un_flags;
97 struct vnode **un_dircache; /* cached union stack */
98 off_t un_uppersz; /* size of upper object */
99 off_t un_lowersz; /* size of lower object */
106 * XXX UN_ULOCK - indicates that the uppervp is locked
108 * UN_CACHED - node is in the union cache
111 /*#define UN_ULOCK 0x04*/ /* Upper node is locked */
112 #define UN_CACHED 0x10 /* In union cache */
115 * Hash table locking flags
118 #define UNVP_WANT 0x01
119 #define UNVP_LOCKED 0x02
121 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
122 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
123 #define UNIONTOV(un) ((un)->un_vnode)
124 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
125 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
126 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
128 #define UDEBUG(x) if (uniondebug) printf x
129 #define UDEBUG_ENABLED 1
135 extern int union_allocvp (struct vnode **, struct mount *,
138 struct componentname *, struct vnode *,
139 struct vnode *, int);
140 extern int union_freevp (struct vnode *);
141 extern struct vnode *union_dircache (struct vnode *, struct thread *);
142 extern int union_copyup (struct union_node *, int, struct ucred *,
144 extern int union_dowhiteout (struct union_node *, struct ucred *,
146 extern int union_mkshadow (struct union_mount *, struct vnode *,
147 struct componentname *, struct vnode **);
148 extern int union_mkwhiteout (struct union_mount *, struct vnode *,
149 struct componentname *, char *);
150 extern int union_cn_close (struct vnode *, int, struct ucred *,
152 extern void union_removed_upper (struct union_node *un);
153 extern struct vnode *union_lowervp (struct vnode *);
154 extern void union_newsize (struct vnode *, off_t, off_t);
155 extern void union_vm_coherency (struct vnode *, struct uio *, int);
157 extern int (*union_dircheckp) (struct thread *, struct vnode **,
160 extern vop_t **union_vnodeop_p;
161 extern struct vfsops union_vfsops;
162 extern int uniondebug;