xref: /freebsd/sys/fs/deadfs/dead_vnops.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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_write =		dead_write,
82 };
83 
84 /* ARGSUSED */
85 static int
86 dead_getwritemount(ap)
87 	struct vop_getwritemount_args /* {
88 		struct vnode *a_vp;
89 		struct mount **a_mpp;
90 	} */ *ap;
91 {
92 	*(ap->a_mpp) = NULL;
93 	return (0);
94 }
95 
96 /*
97  * Trivial lookup routine that always fails.
98  */
99 /* ARGSUSED */
100 static int
101 dead_lookup(ap)
102 	struct vop_lookup_args /* {
103 		struct vnode * a_dvp;
104 		struct vnode ** a_vpp;
105 		struct componentname * a_cnp;
106 	} */ *ap;
107 {
108 
109 	*ap->a_vpp = NULL;
110 	return (ENOTDIR);
111 }
112 
113 /*
114  * Open always fails as if device did not exist.
115  */
116 /* ARGSUSED */
117 static int
118 dead_open(ap)
119 	struct vop_open_args /* {
120 		struct vnode *a_vp;
121 		int  a_mode;
122 		struct ucred *a_cred;
123 		struct proc *a_p;
124 	} */ *ap;
125 {
126 
127 	return (ENXIO);
128 }
129 
130 /*
131  * Vnode op for read
132  */
133 /* ARGSUSED */
134 static int
135 dead_read(ap)
136 	struct vop_read_args /* {
137 		struct vnode *a_vp;
138 		struct uio *a_uio;
139 		int  a_ioflag;
140 		struct ucred *a_cred;
141 	} */ *ap;
142 {
143 	/*
144 	 * Return EOF for tty devices, EIO for others
145 	 */
146 	if ((ap->a_vp->v_vflag & VV_ISTTY) == 0)
147 		return (EIO);
148 	return (0);
149 }
150 
151 /*
152  * Vnode op for write
153  */
154 /* ARGSUSED */
155 static int
156 dead_write(ap)
157 	struct vop_write_args /* {
158 		struct vnode *a_vp;
159 		struct uio *a_uio;
160 		int  a_ioflag;
161 		struct ucred *a_cred;
162 	} */ *ap;
163 {
164 	return (EIO);
165 }
166 
167 /*
168  * Device ioctl operation.
169  */
170 /* ARGSUSED */
171 static int
172 dead_ioctl(ap)
173 	struct vop_ioctl_args /* {
174 		struct vnode *a_vp;
175 		u_long  a_command;
176 		caddr_t  a_data;
177 		int  a_fflag;
178 		struct ucred *a_cred;
179 		struct proc *a_p;
180 	} */ *ap;
181 {
182 	/* XXX: Doesn't this just recurse back here ? */
183 	return (VOP_IOCTL_AP(ap));
184 }
185 
186 /*
187  * Wait until the vnode has finished changing state.
188  */
189 static int
190 dead_bmap(ap)
191 	struct vop_bmap_args /* {
192 		struct vnode *a_vp;
193 		daddr_t  a_bn;
194 		struct bufobj **a_bop;
195 		daddr_t *a_bnp;
196 		int *a_runp;
197 		int *a_runb;
198 	} */ *ap;
199 {
200 
201 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_bop, ap->a_bnp, ap->a_runp, ap->a_runb));
202 }
203 
204 /*
205  * Trivial poll routine that always returns POLLHUP.
206  * This is necessary so that a process which is polling a file
207  * gets notified when that file is revoke()d.
208  */
209 static int
210 dead_poll(ap)
211 	struct vop_poll_args *ap;
212 {
213 	return (POLLHUP);
214 }
215 
216 static int
217 dead_rename(ap)
218 	struct vop_rename_args  /* {
219 		struct vnode *a_fdvp;
220 		struct vnode *a_fvp;
221 		struct componentname *a_fcnp;
222 		struct vnode *a_tdvp;
223 		struct vnode *a_tvp;
224 		struct componentname *a_tcnp;
225 	} */ *ap;
226 {
227 	if (ap->a_tvp)
228 		vput(ap->a_tvp);
229 	if (ap->a_tdvp == ap->a_tvp)
230 		vrele(ap->a_tdvp);
231 	else
232 		vput(ap->a_tdvp);
233 	vrele(ap->a_fdvp);
234 	vrele(ap->a_fvp);
235 	return (EXDEV);
236 }
237