bsd/miscfs/union/union.h

   1 /*
   2  * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
   7  *
   8  * This file contains Original Code and/or Modifications of Original Code
   9  * as defined in and that are subject to the Apple Public Source License
  10  * Version 2.0 (the 'License'). You may not use this file except in
  11  * compliance with the License. Please obtain a copy of the License at
  12  * http://www.opensource.apple.com/apsl/ and read it before using this
  13  * file.
  14  *
  15  * The Original Code and all software distributed under the License are
  16  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  17  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  18  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  19  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  20  * Please see the License for the specific language governing rights and
  21  * limitations under the License.
  22  *
  23  * @APPLE_LICENSE_HEADER_END@
  24  */
  25 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  26 /*
  27  * Copyright (c) 1994 The Regents of the University of California.
  28  * Copyright (c) 1994 Jan-Simon Pendry.
  29  * All rights reserved.
  30  *
  31  * This code is derived from software donated to Berkeley by
  32  * Jan-Simon Pendry.
  33  *
  34  * Redistribution and use in source and binary forms, with or without
  35  * modification, are permitted provided that the following conditions
  36  * are met:
  37  * 1. Redistributions of source code must retain the above copyright
  38  *    notice, this list of conditions and the following disclaimer.
  39  * 2. Redistributions in binary form must reproduce the above copyright
  40  *    notice, this list of conditions and the following disclaimer in the
  41  *    documentation and/or other materials provided with the distribution.
  42  * 3. All advertising materials mentioning features or use of this software
  43  *    must display the following acknowledgement:
  44  *      This product includes software developed by the University of
  45  *      California, Berkeley and its contributors.
  46  * 4. Neither the name of the University nor the names of its contributors
  47  *    may be used to endorse or promote products derived from this software
  48  *    without specific prior written permission.
  49  *
  50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  60  * SUCH DAMAGE.
  61  *
  62  *      @(#)union.h     8.9 (Berkeley) 12/10/94
  63  */
  64 #ifndef __UNION_UNION_H__
  65 #define __UNION_UNION_H__
  66
  67 #include  <sys/appleapiopts.h>
  68
  69 #ifdef __APPLE_API_PRIVATE
  70 struct union_args {
  71         char            *target;        /* Target of loopback  */
  72         int             mntflags;       /* Options on the mount */
  73 };
  74
  75 #define UNMNT_ABOVE     0x0001          /* Target appears below mount point */
  76 #define UNMNT_BELOW     0x0002          /* Target appears below mount point */
  77 #define UNMNT_REPLACE   0x0003          /* Target replaces mount point */
  78 #define UNMNT_OPMASK    0x0003
  79
  80 struct union_mount {
  81         struct vnode    *um_uppervp;
  82         struct vnode    *um_lowervp;
  83         struct ucred    *um_cred;       /* Credentials of user calling mount */
  84         int             um_cmode;       /* cmask from mount process */
  85         int             um_op;          /* Operation mode */
  86 };
  87
  88 #ifdef KERNEL
  89
  90 /*
  91  * DEFDIRMODE is the mode bits used to create a shadow directory.
  92  */
  93 #define VRWXMODE (VREAD|VWRITE|VEXEC)
  94 #define VRWMODE (VREAD|VWRITE)
  95 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
  96 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
  97
  98 /*
  99  * A cache of vnode references
 100  */
 101 struct union_node {
 102         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 103         struct vnode            *un_vnode;      /* Back pointer */
 104         struct vnode            *un_uppervp;    /* overlaying object */
 105         struct vnode            *un_lowervp;    /* underlying object */
 106         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 107         struct vnode            *un_pvp;        /* Parent vnode */
 108         char                    *un_path;       /* saved component name */
 109         int                     un_hash;        /* saved un_path hash value */
 110         int                     un_openl;       /* # of opens on lowervp */
 111         unsigned int            un_flags;
 112         struct vnode            **un_dircache;  /* cached union stack */
 113         off_t                   un_uppersz;     /* size of upper object */
 114         off_t                   un_lowersz;     /* size of lower object */
 115 #if DIAGNOSTIC
 116         pid_t                   un_pid;
 117 #endif
 118 };
 119
 120 #define UN_WANT         0x01
 121 #define UN_LOCKED       0x02
 122 #define UN_ULOCK        0x04            /* Upper node is locked */
 123 #define UN_KLOCK        0x08            /* Keep upper node locked on vput */
 124 #define UN_CACHED       0x10            /* In union cache */
 125
 126 extern int union_allocvp __P((struct vnode **, struct mount *,
 127                                 struct vnode *, struct vnode *,
 128                                 struct componentname *, struct vnode *,
 129                                 struct vnode *, int));
 130 extern int union_copyfile __P((struct vnode *, struct vnode *,
 131                                         struct ucred *, struct proc *));
 132 extern int union_copyup __P((struct union_node *, int, struct ucred *,
 133                                 struct proc *));
 134 extern int union_dowhiteout __P((struct union_node *, struct ucred *,
 135                                         struct proc *));
 136 extern int union_mkshadow __P((struct union_mount *, struct vnode *,
 137                                 struct componentname *, struct vnode **));
 138 extern int union_mkwhiteout __P((struct union_mount *, struct vnode *,
 139                                 struct componentname *, char *));
 140 extern int union_vn_create __P((struct vnode **, struct union_node *,
 141                                 struct proc *));
 142 extern int union_cn_close __P((struct vnode *, int, struct ucred *,
 143                                 struct proc *));
 144 extern void union_removed_upper __P((struct union_node *un));
 145 extern struct vnode *union_lowervp __P((struct vnode *));
 146 extern void union_newlower __P((struct union_node *, struct vnode *));
 147 extern void union_newupper __P((struct union_node *, struct vnode *));
 148 extern void union_newsize __P((struct vnode *, off_t, off_t));
 149
 150 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 151 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 152 #define UNIONTOV(un) ((un)->un_vnode)
 153 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 154 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 155 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 156
 157 extern int (**union_vnodeop_p)(void *);
 158 extern struct vfsops union_vfsops;
 159 #endif /* KERNEL */
 160
 161 #endif /* __APPLE_API_PRIVATE */
 162 #endif /* __UNION_UNION_H__ */