bsd/miscfs/union/union.h

   1 /*
   2  * Copyright (c) 2000-2006 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 above mount point */
  80 #define UNMNT_BELOW     0x0002          /* Target appears below mount point */
  81 #define UNMNT_REPLACE   0x0003          /* Target replaces mount point */
  82 #ifdef FAULTFS
  83 #define UNMNT_FAULTIN   0x0004          /* get the files to TOT on lookup */
  84 #define UNMNT_OPMASK    0x0007
  85 #else
  86 #define UNMNT_OPMASK    0x0003
  87 #endif
  88
  89 #ifdef BSD_KERNEL_PRIVATE
  90
  91 struct union_mount {
  92         struct vnode    *um_uppervp;    /* */
  93         int             um_uppervid;    /* vid of upper vnode */
  94         struct vnode    *um_lowervp;    /* Left unlocked */
  95         int             um_lowervid;    /* vid of lower vnode */
  96         kauth_cred_t    um_cred;        /* Credentials of user calling mount */
  97         int             um_cmode;       /* cmask from mount process */
  98         int             um_op;          /* Operation mode */
  99         dev_t           um_upperdev;    /* Upper root node fsid[0]*/
 100 };
 101
 102
 103 #define  UNION_ABOVE(x) (x->um_op == UNMNT_ABOVE)
 104 #define  UNION_LOWER(x) (x->um_op == UNMNT_BELOW)
 105 #define  UNION_REPLACE(x) (x->um_op == UNMNT_REPLACE)
 106 #ifdef FAULTFS
 107 #define  UNION_FAULTIN(x) (x->um_op == UNMNT_FAULTIN)
 108 #else
 109 #define  UNION_FAULTIN(x) (0)
 110
 111 #endif
 112
 113 /* LP64 version of union_args.  all pointers
 114  * grow when we're dealing with a 64-bit process.
 115  * WARNING - keep in sync with union_args
 116  */
 117
 118 struct user_union_args {
 119         user_addr_t     target;         /* Target of loopback  */
 120         int                     mntflags;       /* Options on the mount */
 121         char            _pad[4];
 122 };
 123
 124 /*
 125  * DEFDIRMODE is the mode bits used to create a shadow directory.
 126  */
 127 #define VRWXMODE (VREAD|VWRITE|VEXEC)
 128 #define VRWMODE (VREAD|VWRITE)
 129 #define UN_DIRMODE ((VRWXMODE)|(VRWXMODE>>3)|(VRWXMODE>>6))
 130 #define UN_FILEMODE ((VRWMODE)|(VRWMODE>>3)|(VRWMODE>>6))
 131
 132 /*
 133  * A cache of vnode references
 134  */
 135 struct union_node {
 136         LIST_ENTRY(union_node)  un_cache;       /* Hash chain */
 137         struct vnode            *un_vnode;      /* Back pointer */
 138
 139         struct vnode            *un_uppervp;    /* overlaying object */
 140         int                     un_uppervid;    /* vid of upper vnode */
 141         off_t                   un_uppersz;     /* size of upper object */
 142
 143         struct vnode            *un_lowervp;    /* underlying object */
 144         int                     un_lowervid;    /* vid of upper vnode */
 145         off_t                   un_lowersz;     /* size of lower object */
 146
 147         struct vnode            *un_dirvp;      /* Parent dir of uppervp */
 148         struct vnode            *un_pvp;        /* Parent vnode */
 149
 150         char                    *un_path;       /* saved component name */
 151         int                     un_hash;        /* saved un_path hash value */
 152         int                     un_openl;       /* # of opens on lowervp */
 153         int                     un_exclcnt;     /* exclusive count */
 154         unsigned int            un_flags;
 155         mount_t                 un_mount;
 156         struct vnode            **un_dircache;  /* cached union stack */
 157 };
 158
 159 #define UN_WANT         0x01            /* union node is needed */
 160 #define UN_LOCKED       0x02            /* union node is locked */
 161 #define UN_CACHED       0x04            /* In union cache */
 162 #define UN_TRANSIT      0x08            /* The union node is in creation */
 163 #define UN_DELETED      0x10            /* The union node is deleted  */
 164 #ifdef FAULTFS
 165 #define UN_FAULTFS      0x80            /* The union node is for faultfs */
 166 #endif
 167 #define UN_DIRENVN      0x100           /* The union node is created for dir enumeration */
 168
 169
 170 #ifdef FAULTFS
 171 #define  UNNODE_FAULTIN(x) ((x->un_flags & UN_FAULTFS)== UN_FAULTFS)
 172 #else
 173 #define  UNNODE_FAULTIN(x) (0)
 174 #endif
 175 /*
 176  * Hash table locking flags
 177  */
 178
 179 #define UNVP_WANT       0x01
 180 #define UNVP_LOCKED     0x02
 181
 182 #define MOUNTTOUNIONMOUNT(mp) ((struct union_mount *)((mp)->mnt_data))
 183 #define VTOUNION(vp) ((struct union_node *)(vp)->v_data)
 184 #define UNIONTOV(un) ((un)->un_vnode)
 185 #define LOWERVP(vp) (VTOUNION(vp)->un_lowervp)
 186 #define UPPERVP(vp) (VTOUNION(vp)->un_uppervp)
 187 #define OTHERVP(vp) (UPPERVP(vp) ? UPPERVP(vp) : LOWERVP(vp))
 188
 189
 190 extern int union_allocvp(struct vnode **, struct mount *,
 191                                 struct vnode *, struct vnode *,
 192                                 struct componentname *, struct vnode *,
 193                                 struct vnode *, int);
 194 extern int union_freevp(struct vnode *);
 195 extern struct vnode * union_dircache(struct vnode *, vfs_context_t);
 196 extern int union_copyfile(struct vnode *, struct vnode *,vfs_context_t );
 197 extern int union_copyup(struct union_node *, int, vfs_context_t );
 198 extern int union_dowhiteout(struct union_node *, vfs_context_t);
 199 extern int union_mkshadow(struct union_mount *, struct vnode *,
 200                                 struct componentname *, struct vnode **);
 201 extern int union_mkwhiteout(struct union_mount *, struct vnode *,
 202                                 struct componentname *, char *);
 203 extern int union_vn_create(struct vnode **, struct union_node *, mode_t  mode, vfs_context_t context);
 204 extern int union_cn_close(struct vnode *, int, vfs_context_t context);
 205 extern void union_removed_upper(struct union_node *un);
 206 extern struct vnode *union_lowervp(struct vnode *);
 207 extern void union_newsize(struct vnode *, off_t, off_t);
 208 extern int union_init(struct vfsconf *);
 209 extern void union_updatevp(struct union_node *, struct vnode *, struct vnode *);
 210 extern void union_dircache_free(struct union_node *);
 211 extern int (*union_dircheckp)(struct vnode **, struct fileproc *, vfs_context_t);
 212 extern int union_faultin_copyup(struct vnode ** uvpp, vnode_t udvp, vnode_t lvp, struct componentname * cnp, vfs_context_t context);
 213 extern int (**union_vnodeop_p)(void *);
 214 extern struct vfsops union_vfsops;
 215 void union_lock(void);
 216 void union_unlock(void);
 217
 218 #endif /* BSD_KERNEL_PRIVATE */
 219
 220 #endif /* __APPLE_API_PRIVATE */
 221
 222 #endif /* __UNION_UNION_H__ */