xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision b3e7694832e81d7a904a10f525f8797b753bf0d3)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
32  * $FreeBSD$
33  */
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
38 #include <sys/lock.h>
39 #include <sys/mutex.h>
40 #include <sys/poll.h>
41 #include <sys/vnode.h>
42 
43 /*
44  * Prototypes for dead operations on vnodes.
45  */
46 static vop_lookup_t	dead_lookup;
47 static vop_open_t	dead_open;
48 static vop_close_t	dead_close;
49 static vop_getwritemount_t dead_getwritemount;
50 static vop_rename_t	dead_rename;
51 static vop_unset_text_t	dead_unset_text;
52 
53 struct vop_vector dead_vnodeops = {
54 	.vop_default =		&default_vnodeops,
55 
56 	.vop_access =		VOP_EBADF,
57 	.vop_advlock =		VOP_EBADF,
58 	.vop_bmap =		VOP_EBADF,
59 	.vop_close =		dead_close,
60 	.vop_create =		VOP_PANIC,
61 	.vop_getattr =		VOP_EBADF,
62 	.vop_getwritemount =	dead_getwritemount,
63 	.vop_inactive =		VOP_NULL,
64 	.vop_ioctl =		VOP_EBADF,
65 	.vop_link =		VOP_PANIC,
66 	.vop_lookup =		dead_lookup,
67 	.vop_mkdir =		VOP_PANIC,
68 	.vop_mknod =		VOP_PANIC,
69 	.vop_open =		dead_open,
70 	.vop_pathconf =		VOP_EBADF,	/* per pathconf(2) */
71 	.vop_poll =		dead_poll,
72 	.vop_read =		dead_read,
73 	.vop_readdir =		VOP_EBADF,
74 	.vop_readlink =		VOP_EBADF,
75 	.vop_reclaim =		VOP_NULL,
76 	.vop_remove =		VOP_PANIC,
77 	.vop_rename =		dead_rename,
78 	.vop_rmdir =		VOP_PANIC,
79 	.vop_setattr =		VOP_EBADF,
80 	.vop_symlink =		VOP_PANIC,
81 	.vop_vptocnp =		VOP_EBADF,
82 	.vop_unset_text =	dead_unset_text,
83 	.vop_write =		dead_write,
84 	.vop_fplookup_vexec =	VOP_EOPNOTSUPP,
85 	.vop_fplookup_symlink =	VOP_EOPNOTSUPP,
86 };
87 VFS_VOP_VECTOR_REGISTER(dead_vnodeops);
88 
89 static int
90 dead_getwritemount(struct vop_getwritemount_args *ap)
91 {
92 
93 	*(ap->a_mpp) = NULL;
94 	return (0);
95 }
96 
97 /*
98  * Trivial lookup routine that always fails.
99  */
100 static int
101 dead_lookup(struct vop_lookup_args *ap)
102 {
103 
104 	*ap->a_vpp = NULL;
105 	return (ENOTDIR);
106 }
107 
108 /*
109  * Silently succeed open and close.
110  */
111 static int
112 dead_open(struct vop_open_args *ap)
113 {
114 	return (0);
115 }
116 
117 static int
118 dead_close(struct vop_close_args *ap)
119 {
120 	return (0);
121 }
122 
123 int
124 dead_read(struct vop_read_args *ap)
125 {
126 
127 	/*
128 	 * Return EOF for tty devices, EIO for others
129 	 */
130 	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
131 		return (EIO);
132 	return (0);
133 }
134 
135 int
136 dead_write(struct vop_write_args *ap)
137 {
138 
139 	return (EIO);
140 }
141 
142 int
143 dead_poll(struct vop_poll_args *ap)
144 {
145 
146 	if (ap->a_events & ~POLLSTANDARD)
147 		return (POLLNVAL);
148 
149 	/*
150 	 * Let the user find out that the descriptor is gone.
151 	 */
152 	return (POLLHUP | ((POLLIN | POLLRDNORM) & ap->a_events));
153 
154 }
155 
156 static int
157 dead_rename(struct vop_rename_args *ap)
158 {
159 
160 	vop_rename_fail(ap);
161 	return (EXDEV);
162 }
163 
164 static int
165 dead_unset_text(struct vop_unset_text_args *ap)
166 {
167 
168 	return (0);
169 }
170