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  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  23 /*
  24  * Copyright (c) 1994 The Regents of the University of California.
  25  * Copyright (c) 1994 Jan-Simon Pendry.
  26  * All rights reserved.
  27  *
  28  * This code is derived from software donated to Berkeley by
  29  * Jan-Simon Pendry.
  30  *
  31  * Redistribution and use in source and binary forms, with or without
  32  * modification, are permitted provided that the following conditions
  33  * are met:
  34  * 1. Redistributions of source code must retain the above copyright
  35  *    notice, this list of conditions and the following disclaimer.
  36  * 2. Redistributions in binary form must reproduce the above copyright
  37  *    notice, this list of conditions and the following disclaimer in the
  38  *    documentation and/or other materials provided with the distribution.
  39  * 3. All advertising materials mentioning features or use of this software
  40  *    must display the following acknowledgement:
  41  *      This product includes software developed by the University of
  42  *      California, Berkeley and its contributors.
  43  * 4. Neither the name of the University nor the names of its contributors
  44  *    may be used to endorse or promote products derived from this software
  45  *    without specific prior written permission.
  46  *
  47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  57  * SUCH DAMAGE.
  58  *
  59  *      @(#)union.h     8.9 (Berkeley) 12/10/94
  60  */
  61 #ifndef __UNION_UNION_H__
  62 #define __UNION_UNION_H__
  63
  64 #include  <sys/appleapiopts.h>
  65
  66 #ifdef __APPLE_API_PRIVATE
  67 struct union_args {
  68         char            *target;        /* Target of loopback  */
  69         int             mntflags;       /* Options on the mount */
  70 };
  71
  72 #define UNMNT_ABOVE     0x0001          /* Target appears below mount point */
  73 #define UNMNT_BELOW     0x0002          /* Target appears below mount point */
  74 #define UNMNT_REPLACE   0x0003          /* Target replaces mount point */
  75 #define UNMNT_OPMASK    0x0003
  76
  77 struct union_mount {
  78         struct vnode    *um_uppervp;
  79         struct vnode    *um_lowervp;
  80         struct ucred    *um_cred;       /* Credentials of user calling mount */
  81         int             um_cmode;       /* cmask from mount process */
  82         int             um_op;          /* Operation mode */
  83 };
  84
  85 #ifdef KERNEL
  86
  87 /*
  88  * DEFDIRMODE is the mode bits used to create a shadow directory.
  89  */
  90 #define VRWXMODE (VREAD|VWRITE|VEXEC)
  91 #define VRWMODE (VREAD|VWRITE)
  92 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
  93 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
  94
  95 /*
  96  * A cache of vnode references
  97  */
  98 struct union_node {
  99         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 100         struct vnode            *un_vnode;      /* Back pointer */
 101         struct vnode            *un_uppervp;    /* overlaying object */
 102         struct vnode            *un_lowervp;    /* underlying object */
 103         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 104         struct vnode            *un_pvp;        /* Parent vnode */
 105         char                    *un_path;       /* saved component name */
 106         int                     un_hash;        /* saved un_path hash value */
 107         int                     un_openl;       /* # of opens on lowervp */
 108         unsigned int            un_flags;
 109         struct vnode            **un_dircache;  /* cached union stack */
 110         off_t                   un_uppersz;     /* size of upper object */
 111         off_t                   un_lowersz;     /* size of lower object */
 112 #if DIAGNOSTIC
 113         pid_t                   un_pid;
 114 #endif
 115 };
 116
 117 #define UN_WANT         0x01
 118 #define UN_LOCKED       0x02
 119 #define UN_ULOCK        0x04            /* Upper node is locked */
 120 #define UN_KLOCK        0x08            /* Keep upper node locked on vput */
 121 #define UN_CACHED       0x10            /* In union cache */
 122
 123 extern int union_allocvp __P((struct vnode **, struct mount *,
 124                                 struct vnode *, struct vnode *,
 125                                 struct componentname *, struct vnode *,
 126                                 struct vnode *, int));
 127 extern int union_copyfile __P((struct vnode *, struct vnode *,
 128                                         struct ucred *, struct proc *));
 129 extern int union_copyup __P((struct union_node *, int, struct ucred *,
 130                                 struct proc *));
 131 extern int union_dowhiteout __P((struct union_node *, struct ucred *,
 132                                         struct proc *));
 133 extern int union_mkshadow __P((struct union_mount *, struct vnode *,
 134                                 struct componentname *, struct vnode **));
 135 extern int union_mkwhiteout __P((struct union_mount *, struct vnode *,
 136                                 struct componentname *, char *));
 137 extern int union_vn_create __P((struct vnode **, struct union_node *,
 138                                 struct proc *));
 139 extern int union_cn_close __P((struct vnode *, int, struct ucred *,
 140                                 struct proc *));
 141 extern void union_removed_upper __P((struct union_node *un));
 142 extern struct vnode *union_lowervp __P((struct vnode *));
 143 extern void union_newlower __P((struct union_node *, struct vnode *));
 144 extern void union_newupper __P((struct union_node *, struct vnode *));
 145 extern void union_newsize __P((struct vnode *, off_t, off_t));
 146
 147 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 148 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 149 #define UNIONTOV(un) ((un)->un_vnode)
 150 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 151 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 152 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 153
 154 extern int (**union_vnodeop_p)(void *);
 155 extern struct vfsops union_vfsops;
 156 #endif /* KERNEL */
 157
 158 #endif /* __APPLE_API_PRIVATE */
 159 #endif /* __UNION_UNION_H__ */