bsd/miscfs/union/union.h

   1 /*
   2  * Copyright (c) 2006 Apple Computer, Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_OSREFERENCE_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
  10  * License may not be used to create, or enable the creation or
  11  * redistribution of, unlawful or unlicensed copies of an Apple operating
  12  * system, or to circumvent, violate, or enable the circumvention or
  13  * violation of, any terms of an Apple operating system software license
  14  * agreement.
  15  *
  16  * Please obtain a copy of the License at
  17  * http://www.opensource.apple.com/apsl/ and read it before using this
  18  * file.
  19  *
  20  * The Original Code and all software distributed under the License are
  21  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  22  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  23  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  24  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  25  * Please see the License for the specific language governing rights and
  26  * limitations under the License.
  27  *
  28  * @APPLE_LICENSE_OSREFERENCE_HEADER_END@
  29  */
  30 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
  31 /*
  32  * Copyright (c) 1994 The Regents of the University of California.
  33  * Copyright (c) 1994 Jan-Simon Pendry.
  34  * All rights reserved.
  35  *
  36  * This code is derived from software donated to Berkeley by
  37  * Jan-Simon Pendry.
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  * 3. All advertising materials mentioning features or use of this software
  48  *    must display the following acknowledgement:
  49  *      This product includes software developed by the University of
  50  *      California, Berkeley and its contributors.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  *
  67  *      @(#)union.h     8.9 (Berkeley) 12/10/94
  68  */
  69 #ifndef __UNION_UNION_H__
  70 #define __UNION_UNION_H__
  71
  72 #include  <sys/appleapiopts.h>
  73 #include  <sys/cdefs.h>
  74
  75 #ifdef __APPLE_API_PRIVATE
  76 struct union_args {
  77         char            *target;        /* Target of loopback  */
  78         int             mntflags;       /* Options on the mount */
  79 };
  80
  81 #define UNMNT_ABOVE     0x0001          /* Target appears below mount point */
  82 #define UNMNT_BELOW     0x0002          /* Target appears below mount point */
  83 #define UNMNT_REPLACE   0x0003          /* Target replaces mount point */
  84 #define UNMNT_OPMASK    0x0003
  85
  86 struct union_mount {
  87         struct vnode    *um_uppervp;
  88         struct vnode    *um_lowervp;
  89         struct ucred    *um_cred;       /* Credentials of user calling mount */
  90         int             um_cmode;       /* cmask from mount process */
  91         int             um_op;          /* Operation mode */
  92 };
  93
  94 #ifdef KERNEL
  95 /* LP64 version of union_args.  all pointers
  96  * grow when we're dealing with a 64-bit process.
  97  * WARNING - keep in sync with union_args
  98  */
  99 /* LP64todo - should this move? */
 100
 101 #if __DARWIN_ALIGN_NATURAL
 102 #pragma options align=natural
 103 #endif
 104
 105 struct user_union_args {
 106         user_addr_t     target;         /* Target of loopback  */
 107         int                     mntflags;       /* Options on the mount */
 108 };
 109
 110 #if __DARWIN_ALIGN_NATURAL
 111 #pragma options align=reset
 112 #endif
 113
 114 /*
 115  * DEFDIRMODE is the mode bits used to create a shadow directory.
 116  */
 117 #define VRWXMODE (VREAD|VWRITE|VEXEC)
 118 #define VRWMODE (VREAD|VWRITE)
 119 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
 120 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
 121
 122 /*
 123  * A cache of vnode references
 124  */
 125 struct union_node {
 126         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 127         struct vnode            *un_vnode;      /* Back pointer */
 128         struct vnode            *un_uppervp;    /* overlaying object */
 129         struct vnode            *un_lowervp;    /* underlying object */
 130         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 131         struct vnode            *un_pvp;        /* Parent vnode */
 132         char                    *un_path;       /* saved component name */
 133         int                     un_hash;        /* saved un_path hash value */
 134         int                     un_openl;       /* # of opens on lowervp */
 135         unsigned int            un_flags;
 136         struct vnode            **un_dircache;  /* cached union stack */
 137         off_t                   un_uppersz;     /* size of upper object */
 138         off_t                   un_lowersz;     /* size of lower object */
 139 #if DIAGNOSTIC
 140         pid_t                   un_pid;
 141 #endif
 142 };
 143
 144 #define UN_WANT         0x01
 145 #define UN_LOCKED       0x02
 146 #define UN_ULOCK        0x04            /* Upper node is locked */
 147 #define UN_KLOCK        0x08            /* Keep upper node locked on vput */
 148 #define UN_CACHED       0x10            /* In union cache */
 149
 150 extern int union_allocvp(struct vnode **, struct mount *,
 151                                 struct vnode *, struct vnode *,
 152                                 struct componentname *, struct vnode *,
 153                                 struct vnode *, int);
 154 extern int union_copyfile(struct vnode *, struct vnode *,
 155                                         struct ucred *, struct proc *);
 156 extern int union_copyup(struct union_node *, int, struct ucred *,
 157                                 struct proc *);
 158 extern int union_dowhiteout(struct union_node *, vfs_context_t);
 159 extern int union_mkshadow(struct union_mount *, struct vnode *,
 160                                 struct componentname *, struct vnode **);
 161 extern int union_mkwhiteout(struct union_mount *, struct vnode *,
 162                                 struct componentname *, char *);
 163 extern int union_vn_create(struct vnode **, struct union_node *, struct proc *);
 164 extern int union_cn_close(struct vnode *, int, struct ucred *, struct proc *);
 165 extern void union_removed_upper(struct union_node *un);
 166 extern struct vnode *union_lowervp(struct vnode *);
 167 extern void union_newlower(struct union_node *, struct vnode *);
 168 extern void union_newupper(struct union_node *, struct vnode *);
 169 extern void union_newsize(struct vnode *, off_t, off_t);
 170
 171 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 172 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 173 #define UNIONTOV(un) ((un)->un_vnode)
 174 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 175 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 176 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 177
 178 extern int (**union_vnodeop_p)(void *);
 179 extern struct vfsops union_vfsops;
 180 #endif /* KERNEL */
 181
 182 #endif /* __APPLE_API_PRIVATE */
 183 #endif /* __UNION_UNION_H__ */