bsd/miscfs/bindfs/bindfs.h

   1 /*
   2  * Copyright (c) 2019 Apple 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
  24 /*-
  25  * Portions Copyright (c) 1992, 1993
  26  *  The Regents of the University of California.  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  * 4. Neither the name of the University nor the names of its contributors
  40  *    may be used to endorse or promote products derived from this software
  41  *    without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  53  * SUCH DAMAGE.
  54  *
  55  *  @(#)null.h  8.3 (Berkeley) 8/20/94
  56  *
  57  * $FreeBSD$
  58  */
  59
  60 #ifndef FS_BIND_H
  61 #define FS_BIND_H
  62
  63 #include <sys/appleapiopts.h>
  64 #include <libkern/libkern.h>
  65 #include <sys/vnode.h>
  66 #include <sys/vnode_if.h>
  67 #include <sys/ubc.h>
  68 #include <vfs/vfs_support.h>
  69 #include <sys/lock.h>
  70
  71 #include <sys/cdefs.h>
  72 #include <sys/types.h>
  73 #include <sys/syslimits.h>
  74
  75 #if KERNEL
  76 #include <libkern/tree.h>
  77 #else
  78 #include <System/libkern/tree.h>
  79 #endif
  80
  81 //#define BINDFS_DEBUG 0
  82
  83 #define BINDM_CACHE 0x0001
  84 #define BINDM_CASEINSENSITIVE 0x0000000000000002
  85
  86 typedef int (*vop_t)(void *);
  87
  88 struct bind_mount {
  89         struct vnode * bindm_rootvp;       /* Reference to root bind_node (inode 1) */
  90         struct vnode * bindm_lowerrootvp;  /* reference to the root of the tree we are
  91                                             * relocating (in the other file system) */
  92         uint32_t bindm_lowerrootvid;       /* store the lower root vid so we can check
  93                                             * before we build the shadow vnode lazily */
  94         uint64_t bindm_flags;
  95 };
  96
  97 #ifdef KERNEL
  98
  99 #define BIND_FLAG_HASHED 0x000000001
 100
 101 /*
 102  * A cache of vnode references
 103  */
 104 struct bind_node {
 105         LIST_ENTRY(bind_node) bind_hash; /* Hash list */
 106         struct vnode * bind_lowervp;     /* VREFed once */
 107         struct vnode * bind_vnode;       /* Back pointer */
 108         uint32_t bind_lowervid;          /* vid for lowervp to detect lowervp getting recycled out
 109                                           *  from under us */
 110         uint32_t bind_myvid;
 111         uint32_t bind_flags;
 112 };
 113
 114 struct vnodeop_desc_fake {
 115         int vdesc_offset;
 116         const char * vdesc_name;
 117         /* other stuff */
 118 };
 119
 120 #define BINDV_NOUNLOCK 0x0001
 121 #define BINDV_DROP 0x0002
 122
 123 #define MOUNTTOBINDMOUNT(mp) ((struct bind_mount *)(vfs_fsprivate(mp)))
 124 #define VTOBIND(vp) ((struct bind_node *)vnode_fsnode(vp))
 125 #define BINDTOV(xp) ((xp)->bind_vnode)
 126
 127 __BEGIN_DECLS
 128
 129 int bindfs_init(struct vfsconf * vfsp);
 130 int bindfs_destroy(void);
 131 int bind_nodeget(
 132         struct mount * mp, struct vnode * lowervp, struct vnode * dvp, struct vnode ** vpp, struct componentname * cnp, int root);
 133 int bind_hashget(struct mount * mp, struct vnode * lowervp, struct vnode ** vpp);
 134 int bind_getnewvnode(
 135         struct mount * mp, struct vnode * lowervp, struct vnode * dvp, struct vnode ** vpp, struct componentname * cnp, int root);
 136 void bind_hashrem(struct bind_node * xp);
 137
 138 int bindfs_getbackingvnode(vnode_t in_vp, vnode_t* out_vpp);
 139
 140 #define BINDVPTOLOWERVP(vp) (VTOBIND(vp)->bind_lowervp)
 141 #define BINDVPTOLOWERVID(vp) (VTOBIND(vp)->bind_lowervid)
 142 #define BINDVPTOMYVID(vp) (VTOBIND(vp)->bind_myvid)
 143
 144 extern const struct vnodeopv_desc bindfs_vnodeop_opv_desc;
 145
 146 extern vop_t * bindfs_vnodeop_p;
 147
 148 __END_DECLS
 149
 150 #ifdef BINDFS_DEBUG
 151 #define BINDFSDEBUG(format, args...) printf("DEBUG: BindFS %s: " format, __FUNCTION__, ##args)
 152 #else
 153 #define BINDFSDEBUG(format, args...)
 154 #endif /* BINDFS_DEBUG */
 155
 156 #define BINDFSERROR(format, args...) printf("ERROR: BindFS %s: " format, __FUNCTION__, ##args)
 157
 158 #endif /* KERNEL */
 159
 160 #endif