xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision 3110d4ebd6c0848cf5e25890d01791bb407e2a9b)
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_getwritemount_t dead_getwritemount;
49 static vop_rename_t	dead_rename;
50 static vop_unset_text_t	dead_unset_text;
51 
52 struct vop_vector dead_vnodeops = {
53 	.vop_default =		&default_vnodeops,
54 
55 	.vop_access =		VOP_EBADF,
56 	.vop_advlock =		VOP_EBADF,
57 	.vop_bmap =		VOP_EBADF,
58 	.vop_create =		VOP_PANIC,
59 	.vop_getattr =		VOP_EBADF,
60 	.vop_getwritemount =	dead_getwritemount,
61 	.vop_inactive =		VOP_NULL,
62 	.vop_ioctl =		VOP_EBADF,
63 	.vop_link =		VOP_PANIC,
64 	.vop_lookup =		dead_lookup,
65 	.vop_mkdir =		VOP_PANIC,
66 	.vop_mknod =		VOP_PANIC,
67 	.vop_open =		dead_open,
68 	.vop_pathconf =		VOP_EBADF,	/* per pathconf(2) */
69 	.vop_poll =		dead_poll,
70 	.vop_read =		dead_read,
71 	.vop_readdir =		VOP_EBADF,
72 	.vop_readlink =		VOP_EBADF,
73 	.vop_reclaim =		VOP_NULL,
74 	.vop_remove =		VOP_PANIC,
75 	.vop_rename =		dead_rename,
76 	.vop_rmdir =		VOP_PANIC,
77 	.vop_setattr =		VOP_EBADF,
78 	.vop_symlink =		VOP_PANIC,
79 	.vop_vptocnp =		VOP_EBADF,
80 	.vop_unset_text =	dead_unset_text,
81 	.vop_write =		dead_write,
82 	.vop_fplookup_vexec =	VOP_EOPNOTSUPP,
83 	.vop_fplookup_symlink =	VOP_EAGAIN,
84 };
85 VFS_VOP_VECTOR_REGISTER(dead_vnodeops);
86 
87 static int
88 dead_getwritemount(struct vop_getwritemount_args *ap)
89 {
90 
91 	*(ap->a_mpp) = NULL;
92 	return (0);
93 }
94 
95 /*
96  * Trivial lookup routine that always fails.
97  */
98 static int
99 dead_lookup(struct vop_lookup_args *ap)
100 {
101 
102 	*ap->a_vpp = NULL;
103 	return (ENOTDIR);
104 }
105 
106 /*
107  * Open always fails as if device did not exist.
108  */
109 static int
110 dead_open(struct vop_open_args *ap)
111 {
112 
113 	return (ENXIO);
114 }
115 
116 int
117 dead_read(struct vop_read_args *ap)
118 {
119 
120 	/*
121 	 * Return EOF for tty devices, EIO for others
122 	 */
123 	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
124 		return (EIO);
125 	return (0);
126 }
127 
128 int
129 dead_write(struct vop_write_args *ap)
130 {
131 
132 	return (EIO);
133 }
134 
135 int
136 dead_poll(struct vop_poll_args *ap)
137 {
138 
139 	if (ap->a_events & ~POLLSTANDARD)
140 		return (POLLNVAL);
141 
142 	/*
143 	 * Let the user find out that the descriptor is gone.
144 	 */
145 	return (POLLHUP | ((POLLIN | POLLRDNORM) & ap->a_events));
146 
147 }
148 
149 static int
150 dead_rename(struct vop_rename_args *ap)
151 {
152 
153 	vop_rename_fail(ap);
154 	return (EXDEV);
155 }
156 
157 static int
158 dead_unset_text(struct vop_unset_text_args *ap)
159 {
160 
161 	return (0);
162 }
163