bsd/miscfs/union/union.h

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