bsd/miscfs/nullfs/nullfs.h

   1 /*
   2  * Copyright (c) 2016 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_NULL_H
  61 #define FS_NULL_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 NULLFS_DEBUG 0
  82
  83 #define NULLM_CACHE 0x0001
  84 #define NULLM_CASEINSENSITIVE 0x0000000000000002
  85 #define NULLM_UNVEIL 0x1ULL << 2
  86
  87 typedef int (*vop_t)(void *);
  88
  89 struct null_mount {
  90         struct vnode * nullm_rootvp;       /* Reference to root null_node (inode 1) */
  91         struct vnode * nullm_secondvp;     /* Reference to virtual directory vnode to wrap app
  92                                             *  bundles (inode 2) */
  93         struct vnode * nullm_thirdcovervp; /* Reference to vnode that covers
  94                                             *  lowerrootvp  (inode 3) */
  95         struct vnode * nullm_lowerrootvp;  /* reference to the root of the tree we are
  96                                            *  relocating (in the other file system) */
  97         uint32_t nullm_lowerrootvid;       /* store the lower root vid so we can check
  98                                             *  before we build the shadow vnode lazily*/
  99         lck_mtx_t nullm_lock;              /* lock to protect vps above */
 100         uint64_t nullm_flags;
 101         uid_t uid;
 102         gid_t gid;
 103 };
 104
 105 struct null_mount_conf {
 106         uint64_t flags;
 107 };
 108
 109 #ifdef KERNEL
 110
 111 #define NULL_FLAG_HASHED 0x000000001
 112
 113 /*
 114  * A cache of vnode references
 115  */
 116 struct null_node {
 117         LIST_ENTRY(null_node) null_hash; /* Hash list */
 118         struct vnode * null_lowervp;     /* VREFed once */
 119         struct vnode * null_vnode;       /* Back pointer */
 120         uint32_t null_lowervid;          /* vid for lowervp to detect lowervp getting recycled out
 121                                           *  from under us */
 122         uint32_t null_myvid;
 123         uint32_t null_flags;
 124 };
 125
 126 struct vnodeop_desc_fake {
 127         int vdesc_offset;
 128         const char * vdesc_name;
 129         /* other stuff */
 130 };
 131
 132 #define NULLV_NOUNLOCK 0x0001
 133 #define NULLV_DROP 0x0002
 134
 135 #define MOUNTTONULLMOUNT(mp) ((struct null_mount *)(vfs_fsprivate(mp)))
 136 #define VTONULL(vp) ((struct null_node *)vnode_fsnode(vp))
 137 #define NULLTOV(xp) ((xp)->null_vnode)
 138
 139 __BEGIN_DECLS
 140
 141 int nullfs_init(struct vfsconf * vfsp);
 142 int nullfs_init_lck(lck_mtx_t * lck);
 143 int nullfs_destroy_lck(lck_mtx_t * lck);
 144 int nullfs_uninit(void);
 145 int null_nodeget(
 146         struct mount * mp, struct vnode * lowervp, struct vnode * dvp, struct vnode ** vpp, struct componentname * cnp, int root);
 147 int null_hashget(struct mount * mp, struct vnode * lowervp, struct vnode ** vpp);
 148 int null_getnewvnode(
 149         struct mount * mp, struct vnode * lowervp, struct vnode * dvp, struct vnode ** vpp, struct componentname * cnp, int root);
 150 void null_hashrem(struct null_node * xp);
 151
 152 int nullfs_getbackingvnode(vnode_t in_vp, vnode_t* out_vpp);
 153
 154 vfs_context_t nullfs_get_patched_context(struct null_mount * null_mp, vfs_context_t ctx);
 155 void nullfs_cleanup_patched_context(struct null_mount * null_mp, vfs_context_t ctx);
 156
 157 #define NULLVPTOLOWERVP(vp) (VTONULL(vp)->null_lowervp)
 158 #define NULLVPTOLOWERVID(vp) (VTONULL(vp)->null_lowervid)
 159 #define NULLVPTOMYVID(vp) (VTONULL(vp)->null_myvid)
 160
 161 extern const struct vnodeopv_desc nullfs_vnodeop_opv_desc;
 162
 163 extern vop_t * nullfs_vnodeop_p;
 164
 165 __END_DECLS
 166
 167 #ifdef NULLFS_DEBUG
 168 #define NULLFSDEBUG(format, args...) printf(format, ##args)
 169 #else
 170 #define NULLFSDEBUG(format, args...)
 171 #endif /* NULLFS_DEBUG */
 172
 173 #endif /* KERNEL */
 174
 175 #endif