bsd/miscfs/union/union.h

   1 /*
   2  * Copyright (c) 2000-2005 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  29 /*
  30  * Copyright (c) 1994 The Regents of the University of California.
  31  * Copyright (c) 1994 Jan-Simon Pendry.
  32  * All rights reserved.
  33  *
  34  * This code is derived from software donated to Berkeley by
  35  * Jan-Simon Pendry.
  36  *
  37  * Redistribution and use in source and binary forms, with or without
  38  * modification, are permitted provided that the following conditions
  39  * are met:
  40  * 1. Redistributions of source code must retain the above copyright
  41  *    notice, this list of conditions and the following disclaimer.
  42  * 2. Redistributions in binary form must reproduce the above copyright
  43  *    notice, this list of conditions and the following disclaimer in the
  44  *    documentation and/or other materials provided with the distribution.
  45  * 3. All advertising materials mentioning features or use of this software
  46  *    must display the following acknowledgement:
  47  *      This product includes software developed by the University of
  48  *      California, Berkeley and its contributors.
  49  * 4. Neither the name of the University nor the names of its contributors
  50  *    may be used to endorse or promote products derived from this software
  51  *    without specific prior written permission.
  52  *
  53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  63  * SUCH DAMAGE.
  64  *
  65  *      @(#)union.h     8.9 (Berkeley) 12/10/94
  66  */
  67 #ifndef __UNION_UNION_H__
  68 #define __UNION_UNION_H__
  69
  70 #include  <sys/appleapiopts.h>
  71 #include  <sys/cdefs.h>
  72
  73 #ifdef __APPLE_API_PRIVATE
  74 struct union_args {
  75         char            *target;        /* Target of loopback  */
  76         int             mntflags;       /* Options on the mount */
  77 };
  78
  79 #define UNMNT_ABOVE     0x0001          /* Target appears below mount point */
  80 #define UNMNT_BELOW     0x0002          /* Target appears below mount point */
  81 #define UNMNT_REPLACE   0x0003          /* Target replaces mount point */
  82 #define UNMNT_OPMASK    0x0003
  83
  84 struct union_mount {
  85         struct vnode    *um_uppervp;
  86         struct vnode    *um_lowervp;
  87         struct ucred    *um_cred;       /* Credentials of user calling mount */
  88         int             um_cmode;       /* cmask from mount process */
  89         int             um_op;          /* Operation mode */
  90 };
  91
  92 #ifdef KERNEL
  93 /* LP64 version of union_args.  all pointers
  94  * grow when we're dealing with a 64-bit process.
  95  * WARNING - keep in sync with union_args
  96  */
  97 /* LP64todo - should this move? */
  98
  99 #if __DARWIN_ALIGN_NATURAL
 100 #pragma options align=natural
 101 #endif
 102
 103 struct user_union_args {
 104         user_addr_t     target;         /* Target of loopback  */
 105         int                     mntflags;       /* Options on the mount */
 106 };
 107
 108 #if __DARWIN_ALIGN_NATURAL
 109 #pragma options align=reset
 110 #endif
 111
 112 /*
 113  * DEFDIRMODE is the mode bits used to create a shadow directory.
 114  */
 115 #define VRWXMODE (VREAD|VWRITE|VEXEC)
 116 #define VRWMODE (VREAD|VWRITE)
 117 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
 118 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
 119
 120 /*
 121  * A cache of vnode references
 122  */
 123 struct union_node {
 124         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 125         struct vnode            *un_vnode;      /* Back pointer */
 126         struct vnode            *un_uppervp;    /* overlaying object */
 127         struct vnode            *un_lowervp;    /* underlying object */
 128         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 129         struct vnode            *un_pvp;        /* Parent vnode */
 130         char                    *un_path;       /* saved component name */
 131         int                     un_hash;        /* saved un_path hash value */
 132         int                     un_openl;       /* # of opens on lowervp */
 133         unsigned int            un_flags;
 134         struct vnode            **un_dircache;  /* cached union stack */
 135         off_t                   un_uppersz;     /* size of upper object */
 136         off_t                   un_lowersz;     /* size of lower object */
 137 #if DIAGNOSTIC
 138         pid_t                   un_pid;
 139 #endif
 140 };
 141
 142 #define UN_WANT         0x01
 143 #define UN_LOCKED       0x02
 144 #define UN_ULOCK        0x04            /* Upper node is locked */
 145 #define UN_KLOCK        0x08            /* Keep upper node locked on vput */
 146 #define UN_CACHED       0x10            /* In union cache */
 147
 148 extern int union_allocvp(struct vnode **, struct mount *,
 149                                 struct vnode *, struct vnode *,
 150                                 struct componentname *, struct vnode *,
 151                                 struct vnode *, int);
 152 extern int union_copyfile(struct vnode *, struct vnode *,
 153                                         struct ucred *, struct proc *);
 154 extern int union_copyup(struct union_node *, int, struct ucred *,
 155                                 struct proc *);
 156 extern int union_dowhiteout(struct union_node *, vfs_context_t);
 157 extern int union_mkshadow(struct union_mount *, struct vnode *,
 158                                 struct componentname *, struct vnode **);
 159 extern int union_mkwhiteout(struct union_mount *, struct vnode *,
 160                                 struct componentname *, char *);
 161 extern int union_vn_create(struct vnode **, struct union_node *, struct proc *);
 162 extern int union_cn_close(struct vnode *, int, struct ucred *, struct proc *);
 163 extern void union_removed_upper(struct union_node *un);
 164 extern struct vnode *union_lowervp(struct vnode *);
 165 extern void union_newlower(struct union_node *, struct vnode *);
 166 extern void union_newupper(struct union_node *, struct vnode *);
 167 extern void union_newsize(struct vnode *, off_t, off_t);
 168
 169 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 170 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 171 #define UNIONTOV(un) ((un)->un_vnode)
 172 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 173 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 174 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 175
 176 extern int (**union_vnodeop_p)(void *);
 177 extern struct vfsops union_vfsops;
 178 #endif /* KERNEL */
 179
 180 #endif /* __APPLE_API_PRIVATE */
 181 #endif /* __UNION_UNION_H__ */