xref: /xnu-11215/bsd/miscfs/bindfs/bindfs.h (revision e6231be0)
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
161