xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision 3642298923e528d795e3a30ec165d2b469e28b40)
1 /*-
2  * Copyright (c) 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
30  * $FreeBSD$
31  */
32 
33 #include <sys/param.h>
34 #include <sys/systm.h>
35 #include <sys/kernel.h>
36 #include <sys/lock.h>
37 #include <sys/mutex.h>
38 #include <sys/poll.h>
39 #include <sys/vnode.h>
40 
41 /*
42  * Prototypes for dead operations on vnodes.
43  */
44 static vop_bmap_t	dead_bmap;
45 static vop_ioctl_t	dead_ioctl;
46 static vop_lookup_t	dead_lookup;
47 static vop_open_t	dead_open;
48 static vop_poll_t	dead_poll;
49 static vop_read_t	dead_read;
50 static vop_write_t	dead_write;
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 =		dead_bmap,
58 	.vop_create =		VOP_PANIC,
59 	.vop_getattr =		VOP_EBADF,
60 	.vop_inactive =		VOP_NULL,
61 	.vop_ioctl =		dead_ioctl,
62 	.vop_link =		VOP_PANIC,
63 	.vop_lookup =		dead_lookup,
64 	.vop_mkdir =		VOP_PANIC,
65 	.vop_mknod =		VOP_PANIC,
66 	.vop_open =		dead_open,
67 	.vop_pathconf =		VOP_EBADF,	/* per pathconf(2) */
68 	.vop_poll =		dead_poll,
69 	.vop_read =		dead_read,
70 	.vop_readdir =		VOP_EBADF,
71 	.vop_readlink =		VOP_EBADF,
72 	.vop_reclaim =		VOP_NULL,
73 	.vop_remove =		VOP_PANIC,
74 	.vop_rename =		VOP_PANIC,
75 	.vop_rmdir =		VOP_PANIC,
76 	.vop_setattr =		VOP_EBADF,
77 	.vop_symlink =		VOP_PANIC,
78 	.vop_write =		dead_write,
79 };
80 
81 /*
82  * Trivial lookup routine that always fails.
83  */
84 /* ARGSUSED */
85 static int
86 dead_lookup(ap)
87 	struct vop_lookup_args /* {
88 		struct vnode * a_dvp;
89 		struct vnode ** a_vpp;
90 		struct componentname * a_cnp;
91 	} */ *ap;
92 {
93 
94 	*ap->a_vpp = NULL;
95 	return (ENOTDIR);
96 }
97 
98 /*
99  * Open always fails as if device did not exist.
100  */
101 /* ARGSUSED */
102 static int
103 dead_open(ap)
104 	struct vop_open_args /* {
105 		struct vnode *a_vp;
106 		int  a_mode;
107 		struct ucred *a_cred;
108 		struct proc *a_p;
109 	} */ *ap;
110 {
111 
112 	return (ENXIO);
113 }
114 
115 /*
116  * Vnode op for read
117  */
118 /* ARGSUSED */
119 static int
120 dead_read(ap)
121 	struct vop_read_args /* {
122 		struct vnode *a_vp;
123 		struct uio *a_uio;
124 		int  a_ioflag;
125 		struct ucred *a_cred;
126 	} */ *ap;
127 {
128 	/*
129 	 * Return EOF for tty devices, EIO for others
130 	 */
131 	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
132 		return (EIO);
133 	return (0);
134 }
135 
136 /*
137  * Vnode op for write
138  */
139 /* ARGSUSED */
140 static int
141 dead_write(ap)
142 	struct vop_write_args /* {
143 		struct vnode *a_vp;
144 		struct uio *a_uio;
145 		int  a_ioflag;
146 		struct ucred *a_cred;
147 	} */ *ap;
148 {
149 	return (EIO);
150 }
151 
152 /*
153  * Device ioctl operation.
154  */
155 /* ARGSUSED */
156 static int
157 dead_ioctl(ap)
158 	struct vop_ioctl_args /* {
159 		struct vnode *a_vp;
160 		u_long  a_command;
161 		caddr_t  a_data;
162 		int  a_fflag;
163 		struct ucred *a_cred;
164 		struct proc *a_p;
165 	} */ *ap;
166 {
167 	/* XXX: Doesn't this just recurse back here ? */
168 	return (VOP_IOCTL_AP(ap));
169 }
170 
171 /*
172  * Wait until the vnode has finished changing state.
173  */
174 static int
175 dead_bmap(ap)
176 	struct vop_bmap_args /* {
177 		struct vnode *a_vp;
178 		daddr_t  a_bn;
179 		struct bufobj **a_bop;
180 		daddr_t *a_bnp;
181 		int *a_runp;
182 		int *a_runb;
183 	} */ *ap;
184 {
185 
186 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_bop, ap->a_bnp, ap->a_runp, ap->a_runb));
187 }
188 
189 /*
190  * Trivial poll routine that always returns POLLHUP.
191  * This is necessary so that a process which is polling a file
192  * gets notified when that file is revoke()d.
193  */
194 static int
195 dead_poll(ap)
196 	struct vop_poll_args *ap;
197 {
198 	return (POLLHUP);
199 }
200