xref: /netbsd-src/sys/miscfs/deadfs/dead_vnops.c (revision 06be8101a16cc95f40783b3cb7afd12112103a9a)
1 /*	$NetBSD: dead_vnops.c,v 1.31 2001/11/10 13:33:40 lukem Exp $	*/
2 
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. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)dead_vnops.c	8.2 (Berkeley) 11/21/94
36  */
37 
38 #include <sys/cdefs.h>
39 __KERNEL_RCSID(0, "$NetBSD: dead_vnops.c,v 1.31 2001/11/10 13:33:40 lukem Exp $");
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/time.h>
44 #include <sys/vnode.h>
45 #include <sys/errno.h>
46 #include <sys/namei.h>
47 #include <sys/buf.h>
48 #include <sys/proc.h>
49 
50 #include <miscfs/genfs/genfs.h>
51 
52 /*
53  * Prototypes for dead operations on vnodes.
54  */
55 int	dead_lookup	__P((void *));
56 #define dead_create	genfs_badop
57 #define dead_mknod	genfs_badop
58 int	dead_open	__P((void *));
59 #define dead_close	genfs_nullop
60 #define dead_access	genfs_ebadf
61 #define dead_getattr	genfs_ebadf
62 #define dead_setattr	genfs_ebadf
63 int	dead_read	__P((void *));
64 int	dead_write	__P((void *));
65 #define dead_lease_check genfs_nullop
66 #define dead_fcntl	genfs_nullop
67 int	dead_ioctl	__P((void *));
68 int	dead_poll	__P((void *));
69 #define dead_mmap	genfs_badop
70 #define dead_fsync	genfs_nullop
71 #define dead_seek	genfs_nullop
72 #define dead_remove	genfs_badop
73 #define dead_link	genfs_badop
74 #define dead_rename	genfs_badop
75 #define dead_mkdir	genfs_badop
76 #define dead_rmdir	genfs_badop
77 #define dead_symlink	genfs_badop
78 #define dead_readdir	genfs_ebadf
79 #define dead_readlink	genfs_ebadf
80 #define dead_abortop	genfs_badop
81 #define dead_inactive	genfs_nullop
82 #define dead_reclaim	genfs_nullop
83 int	dead_lock	__P((void *));
84 #define dead_unlock	genfs_nullop
85 int	dead_bmap	__P((void *));
86 int	dead_strategy	__P((void *));
87 int	dead_print	__P((void *));
88 #define dead_islocked	genfs_nullop
89 #define dead_pathconf	genfs_ebadf
90 #define dead_advlock	genfs_ebadf
91 #define dead_blkatoff	genfs_badop
92 #define dead_valloc	genfs_badop
93 #define dead_vfree	genfs_badop
94 #define dead_truncate	genfs_nullop
95 #define dead_update	genfs_nullop
96 #define dead_bwrite	genfs_nullop
97 #define dead_revoke	genfs_nullop
98 
99 int	chkvnlock __P((struct vnode *));
100 
101 int (**dead_vnodeop_p) __P((void *));
102 
103 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
104 	{ &vop_default_desc, vn_default_error },
105 	{ &vop_lookup_desc, dead_lookup },		/* lookup */
106 	{ &vop_create_desc, dead_create },		/* create */
107 	{ &vop_mknod_desc, dead_mknod },		/* mknod */
108 	{ &vop_open_desc, dead_open },			/* open */
109 	{ &vop_close_desc, dead_close },		/* close */
110 	{ &vop_access_desc, dead_access },		/* access */
111 	{ &vop_getattr_desc, dead_getattr },		/* getattr */
112 	{ &vop_setattr_desc, dead_setattr },		/* setattr */
113 	{ &vop_read_desc, dead_read },			/* read */
114 	{ &vop_write_desc, dead_write },		/* write */
115 	{ &vop_lease_desc, dead_lease_check },		/* lease */
116 	{ &vop_fcntl_desc, dead_fcntl },		/* fcntl */
117 	{ &vop_ioctl_desc, dead_ioctl },		/* ioctl */
118 	{ &vop_poll_desc, dead_poll },			/* poll */
119 	{ &vop_revoke_desc, dead_revoke },		/* revoke */
120 	{ &vop_mmap_desc, dead_mmap },			/* mmap */
121 	{ &vop_fsync_desc, dead_fsync },		/* fsync */
122 	{ &vop_seek_desc, dead_seek },			/* seek */
123 	{ &vop_remove_desc, dead_remove },		/* remove */
124 	{ &vop_link_desc, dead_link },			/* link */
125 	{ &vop_rename_desc, dead_rename },		/* rename */
126 	{ &vop_mkdir_desc, dead_mkdir },		/* mkdir */
127 	{ &vop_rmdir_desc, dead_rmdir },		/* rmdir */
128 	{ &vop_symlink_desc, dead_symlink },		/* symlink */
129 	{ &vop_readdir_desc, dead_readdir },		/* readdir */
130 	{ &vop_readlink_desc, dead_readlink },		/* readlink */
131 	{ &vop_abortop_desc, dead_abortop },		/* abortop */
132 	{ &vop_inactive_desc, dead_inactive },		/* inactive */
133 	{ &vop_reclaim_desc, dead_reclaim },		/* reclaim */
134 	{ &vop_lock_desc, dead_lock },			/* lock */
135 	{ &vop_unlock_desc, dead_unlock },		/* unlock */
136 	{ &vop_bmap_desc, dead_bmap },			/* bmap */
137 	{ &vop_strategy_desc, dead_strategy },		/* strategy */
138 	{ &vop_print_desc, dead_print },		/* print */
139 	{ &vop_islocked_desc, dead_islocked },		/* islocked */
140 	{ &vop_pathconf_desc, dead_pathconf },		/* pathconf */
141 	{ &vop_advlock_desc, dead_advlock },		/* advlock */
142 	{ &vop_blkatoff_desc, dead_blkatoff },		/* blkatoff */
143 	{ &vop_valloc_desc, dead_valloc },		/* valloc */
144 	{ &vop_vfree_desc, dead_vfree },		/* vfree */
145 	{ &vop_truncate_desc, dead_truncate },		/* truncate */
146 	{ &vop_update_desc, dead_update },		/* update */
147 	{ &vop_bwrite_desc, dead_bwrite },		/* bwrite */
148 	{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
149 };
150 const struct vnodeopv_desc dead_vnodeop_opv_desc =
151 	{ &dead_vnodeop_p, dead_vnodeop_entries };
152 
153 /*
154  * Trivial lookup routine that always fails.
155  */
156 /* ARGSUSED */
157 int
158 dead_lookup(v)
159 	void *v;
160 {
161 	struct vop_lookup_args /* {
162 		struct vnode * a_dvp;
163 		struct vnode ** a_vpp;
164 		struct componentname * a_cnp;
165 	} */ *ap = v;
166 
167 	*ap->a_vpp = NULL;
168 	return (ENOTDIR);
169 }
170 
171 /*
172  * Open always fails as if device did not exist.
173  */
174 /* ARGSUSED */
175 int
176 dead_open(v)
177 	void *v;
178 {
179 
180 	return (ENXIO);
181 }
182 
183 /*
184  * Vnode op for read
185  */
186 /* ARGSUSED */
187 int
188 dead_read(v)
189 	void *v;
190 {
191 	struct vop_read_args /* {
192 		struct vnode *a_vp;
193 		struct uio *a_uio;
194 		int  a_ioflag;
195 		struct ucred *a_cred;
196 	} */ *ap = v;
197 
198 	if (chkvnlock(ap->a_vp))
199 		panic("dead_read: lock");
200 	/*
201 	 * Return EOF for tty devices, EIO for others
202 	 */
203 	if ((ap->a_vp->v_flag & VISTTY) == 0)
204 		return (EIO);
205 	return (0);
206 }
207 
208 /*
209  * Vnode op for write
210  */
211 /* ARGSUSED */
212 int
213 dead_write(v)
214 	void *v;
215 {
216 	struct vop_write_args /* {
217 		struct vnode *a_vp;
218 		struct uio *a_uio;
219 		int  a_ioflag;
220 		struct ucred *a_cred;
221 	} */ *ap = v;
222 
223 	if (chkvnlock(ap->a_vp))
224 		panic("dead_write: lock");
225 	return (EIO);
226 }
227 
228 /*
229  * Device ioctl operation.
230  */
231 /* ARGSUSED */
232 int
233 dead_ioctl(v)
234 	void *v;
235 {
236 	struct vop_ioctl_args /* {
237 		struct vnode *a_vp;
238 		u_long a_command;
239 		caddr_t  a_data;
240 		int  a_fflag;
241 		struct ucred *a_cred;
242 		struct proc *a_p;
243 	} */ *ap = v;
244 
245 	if (!chkvnlock(ap->a_vp))
246 		return (EBADF);
247 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
248 }
249 
250 /* ARGSUSED */
251 int
252 dead_poll(v)
253 	void *v;
254 {
255 	struct vop_poll_args /* {
256 		struct vnode *a_vp;
257 		int a_events;
258 		struct proc *a_p;
259 	} */ *ap = v;
260 
261 	/*
262 	 * Let the user find out that the descriptor is gone.
263 	 */
264 	return (ap->a_events);
265 }
266 
267 /*
268  * Just call the device strategy routine
269  */
270 int
271 dead_strategy(v)
272 	void *v;
273 {
274 
275 	struct vop_strategy_args /* {
276 		struct buf *a_bp;
277 	} */ *ap = v;
278 	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
279 		ap->a_bp->b_flags |= B_ERROR;
280 		biodone(ap->a_bp);
281 		return (EIO);
282 	}
283 	return (VOP_STRATEGY(ap->a_bp));
284 }
285 
286 /*
287  * Wait until the vnode has finished changing state.
288  */
289 int
290 dead_lock(v)
291 	void *v;
292 {
293 	struct vop_lock_args /* {
294 		struct vnode *a_vp;
295 		int a_flags;
296 		struct proc *a_p;
297 	} */ *ap = v;
298 
299 	if (ap->a_flags & LK_INTERLOCK) {
300 		simple_unlock(&ap->a_vp->v_interlock);
301 		ap->a_flags &= ~LK_INTERLOCK;
302 	}
303 	if (!chkvnlock(ap->a_vp))
304 		return (0);
305 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
306 }
307 
308 /*
309  * Wait until the vnode has finished changing state.
310  */
311 int
312 dead_bmap(v)
313 	void *v;
314 {
315 	struct vop_bmap_args /* {
316 		struct vnode *a_vp;
317 		daddr_t  a_bn;
318 		struct vnode **a_vpp;
319 		daddr_t *a_bnp;
320 		int *a_runp;
321 	} */ *ap = v;
322 
323 	if (!chkvnlock(ap->a_vp))
324 		return (EIO);
325 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
326 }
327 
328 /*
329  * Print out the contents of a dead vnode.
330  */
331 /* ARGSUSED */
332 int
333 dead_print(v)
334 	void *v;
335 {
336 	printf("tag VT_NON, dead vnode\n");
337 	return 0;
338 }
339 
340 /*
341  * We have to wait during times when the vnode is
342  * in a state of change.
343  */
344 int
345 chkvnlock(vp)
346 	struct vnode *vp;
347 {
348 	int locked = 0;
349 
350 	while (vp->v_flag & VXLOCK) {
351 		vp->v_flag |= VXWANT;
352 		(void) tsleep(vp, PINOD, "deadchk", 0);
353 		locked = 1;
354 	}
355 	return (locked);
356 }
357