xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision 9a14aa017b21c292740c00ee098195cd46642730)
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 static vop_getwritemount_t dead_getwritemount;
52 static vop_rename_t	dead_rename;
53 
54 struct vop_vector dead_vnodeops = {
55 	.vop_default =		&default_vnodeops,
56 
57 	.vop_access =		VOP_EBADF,
58 	.vop_advlock =		VOP_EBADF,
59 	.vop_bmap =		dead_bmap,
60 	.vop_create =		VOP_PANIC,
61 	.vop_getattr =		VOP_EBADF,
62 	.vop_getwritemount =	dead_getwritemount,
63 	.vop_inactive =		VOP_NULL,
64 	.vop_ioctl =		dead_ioctl,
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_write =		dead_write,
83 };
84 
85 /* ARGSUSED */
86 static int
87 dead_getwritemount(ap)
88 	struct vop_getwritemount_args /* {
89 		struct vnode *a_vp;
90 		struct mount **a_mpp;
91 	} */ *ap;
92 {
93 	*(ap->a_mpp) = NULL;
94 	return (0);
95 }
96 
97 /*
98  * Trivial lookup routine that always fails.
99  */
100 /* ARGSUSED */
101 static int
102 dead_lookup(ap)
103 	struct vop_lookup_args /* {
104 		struct vnode * a_dvp;
105 		struct vnode ** a_vpp;
106 		struct componentname * a_cnp;
107 	} */ *ap;
108 {
109 
110 	*ap->a_vpp = NULL;
111 	return (ENOTDIR);
112 }
113 
114 /*
115  * Open always fails as if device did not exist.
116  */
117 /* ARGSUSED */
118 static int
119 dead_open(ap)
120 	struct vop_open_args /* {
121 		struct vnode *a_vp;
122 		int  a_mode;
123 		struct ucred *a_cred;
124 		struct proc *a_p;
125 	} */ *ap;
126 {
127 
128 	return (ENXIO);
129 }
130 
131 /*
132  * Vnode op for read
133  */
134 /* ARGSUSED */
135 static int
136 dead_read(ap)
137 	struct vop_read_args /* {
138 		struct vnode *a_vp;
139 		struct uio *a_uio;
140 		int  a_ioflag;
141 		struct ucred *a_cred;
142 	} */ *ap;
143 {
144 	/*
145 	 * Return EOF for tty devices, EIO for others
146 	 */
147 	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
148 		return (EIO);
149 	return (0);
150 }
151 
152 /*
153  * Vnode op for write
154  */
155 /* ARGSUSED */
156 static int
157 dead_write(ap)
158 	struct vop_write_args /* {
159 		struct vnode *a_vp;
160 		struct uio *a_uio;
161 		int  a_ioflag;
162 		struct ucred *a_cred;
163 	} */ *ap;
164 {
165 	return (EIO);
166 }
167 
168 /*
169  * Device ioctl operation.
170  */
171 /* ARGSUSED */
172 static int
173 dead_ioctl(ap)
174 	struct vop_ioctl_args /* {
175 		struct vnode *a_vp;
176 		u_long  a_command;
177 		caddr_t  a_data;
178 		int  a_fflag;
179 		struct ucred *a_cred;
180 		struct proc *a_p;
181 	} */ *ap;
182 {
183 	/* XXX: Doesn't this just recurse back here ? */
184 	return (VOP_IOCTL_AP(ap));
185 }
186 
187 /*
188  * Wait until the vnode has finished changing state.
189  */
190 static int
191 dead_bmap(ap)
192 	struct vop_bmap_args /* {
193 		struct vnode *a_vp;
194 		daddr_t  a_bn;
195 		struct bufobj **a_bop;
196 		daddr_t *a_bnp;
197 		int *a_runp;
198 		int *a_runb;
199 	} */ *ap;
200 {
201 
202 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_bop, ap->a_bnp, ap->a_runp, ap->a_runb));
203 }
204 
205 /*
206  * Trivial poll routine that always returns POLLHUP.
207  * This is necessary so that a process which is polling a file
208  * gets notified when that file is revoke()d.
209  */
210 static int
211 dead_poll(ap)
212 	struct vop_poll_args *ap;
213 {
214 	return (POLLHUP);
215 }
216 
217 static int
218 dead_rename(ap)
219 	struct vop_rename_args  /* {
220 		struct vnode *a_fdvp;
221 		struct vnode *a_fvp;
222 		struct componentname *a_fcnp;
223 		struct vnode *a_tdvp;
224 		struct vnode *a_tvp;
225 		struct componentname *a_tcnp;
226 	} */ *ap;
227 {
228 
229 	vop_rename_fail(ap);
230 	return (EXDEV);
231 }
232