1 /* $OpenBSD: dead_vnops.c,v 1.15 2003/09/23 16:51:12 millert Exp $ */
2 /* $NetBSD: dead_vnops.c,v 1.16 1996/02/13 13:12:48 mycroft Exp $ */
3
4 /*
5 * Copyright (c) 1989, 1993
6 * The Regents of the University of California. All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the University nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 *
32 * @(#)dead_vnops.c 8.2 (Berkeley) 11/21/94
33 */
34
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/time.h>
38 #include <sys/vnode.h>
39 #include <sys/errno.h>
40 #include <sys/namei.h>
41 #include <sys/buf.h>
42 #include <sys/proc.h>
43 #include <sys/poll.h>
44
45 /*
46 * Prototypes for dead operations on vnodes.
47 */
48 int dead_badop(void *);
49 int dead_ebadf(void *);
50
51 int dead_lookup(void *);
52 #define dead_create dead_badop
53 #define dead_mknod dead_badop
54 int dead_open(void *);
55 #define dead_close nullop
56 #define dead_access dead_ebadf
57 #define dead_getattr dead_ebadf
58 #define dead_setattr dead_ebadf
59 int dead_read(void *);
60 int dead_write(void *);
61 int dead_ioctl(void *);
62 int dead_poll(void *);
63 #define dead_fsync nullop
64 #define dead_remove dead_badop
65 #define dead_link dead_badop
66 #define dead_rename dead_badop
67 #define dead_mkdir dead_badop
68 #define dead_rmdir dead_badop
69 #define dead_symlink dead_badop
70 #define dead_readdir dead_ebadf
71 #define dead_readlink dead_ebadf
72 #define dead_abortop dead_badop
73 #define dead_inactive nullop
74 #define dead_reclaim nullop
75 int dead_lock(void *);
76 #define dead_unlock vop_generic_unlock
77 int dead_bmap(void *);
78 int dead_strategy(void *);
79 int dead_print(void *);
80 #define dead_islocked vop_generic_islocked
81 #define dead_pathconf dead_ebadf
82 #define dead_advlock dead_ebadf
83 #define dead_bwrite nullop
84
85 int chkvnlock(struct vnode *);
86
87 int (**dead_vnodeop_p)(void *);
88
89 struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
90 { &vop_default_desc, vn_default_error },
91 { &vop_lookup_desc, dead_lookup }, /* lookup */
92 { &vop_create_desc, dead_create }, /* create */
93 { &vop_mknod_desc, dead_mknod }, /* mknod */
94 { &vop_open_desc, dead_open }, /* open */
95 { &vop_close_desc, dead_close }, /* close */
96 { &vop_access_desc, dead_access }, /* access */
97 { &vop_getattr_desc, dead_getattr }, /* getattr */
98 { &vop_setattr_desc, dead_setattr }, /* setattr */
99 { &vop_read_desc, dead_read }, /* read */
100 { &vop_write_desc, dead_write }, /* write */
101 { &vop_ioctl_desc, dead_ioctl }, /* ioctl */
102 { &vop_poll_desc, dead_poll }, /* poll */
103 { &vop_fsync_desc, dead_fsync }, /* fsync */
104 { &vop_remove_desc, dead_remove }, /* remove */
105 { &vop_link_desc, dead_link }, /* link */
106 { &vop_rename_desc, dead_rename }, /* rename */
107 { &vop_mkdir_desc, dead_mkdir }, /* mkdir */
108 { &vop_rmdir_desc, dead_rmdir }, /* rmdir */
109 { &vop_symlink_desc, dead_symlink }, /* symlink */
110 { &vop_readdir_desc, dead_readdir }, /* readdir */
111 { &vop_readlink_desc, dead_readlink }, /* readlink */
112 { &vop_abortop_desc, dead_abortop }, /* abortop */
113 { &vop_inactive_desc, dead_inactive }, /* inactive */
114 { &vop_reclaim_desc, dead_reclaim }, /* reclaim */
115 { &vop_lock_desc, dead_lock }, /* lock */
116 { &vop_unlock_desc, dead_unlock }, /* unlock */
117 { &vop_bmap_desc, dead_bmap }, /* bmap */
118 { &vop_strategy_desc, dead_strategy }, /* strategy */
119 { &vop_print_desc, dead_print }, /* print */
120 { &vop_islocked_desc, dead_islocked }, /* islocked */
121 { &vop_pathconf_desc, dead_pathconf }, /* pathconf */
122 { &vop_advlock_desc, dead_advlock }, /* advlock */
123 { &vop_bwrite_desc, dead_bwrite }, /* bwrite */
124 { (struct vnodeop_desc*)NULL, (int(*)(void *))NULL }
125 };
126 struct vnodeopv_desc dead_vnodeop_opv_desc =
127 { &dead_vnodeop_p, dead_vnodeop_entries };
128
129 /*
130 * Trivial lookup routine that always fails.
131 */
132 /* ARGSUSED */
133 int
dead_lookup(v)134 dead_lookup(v)
135 void *v;
136 {
137 struct vop_lookup_args /* {
138 struct vnode * a_dvp;
139 struct vnode ** a_vpp;
140 struct componentname * a_cnp;
141 } */ *ap = v;
142
143 *ap->a_vpp = NULL;
144 return (ENOTDIR);
145 }
146
147 /*
148 * Open always fails as if device did not exist.
149 */
150 /* ARGSUSED */
151 int
dead_open(v)152 dead_open(v)
153 void *v;
154 {
155
156 return (ENXIO);
157 }
158
159 /*
160 * Vnode op for read
161 */
162 /* ARGSUSED */
163 int
dead_read(v)164 dead_read(v)
165 void *v;
166 {
167 struct vop_read_args /* {
168 struct vnode *a_vp;
169 struct uio *a_uio;
170 int a_ioflag;
171 struct ucred *a_cred;
172 } */ *ap = v;
173
174 if (chkvnlock(ap->a_vp))
175 panic("dead_read: lock");
176 /*
177 * Return EOF for tty devices, EIO for others
178 */
179 if ((ap->a_vp->v_flag & VISTTY) == 0)
180 return (EIO);
181 return (0);
182 }
183
184 /*
185 * Vnode op for write
186 */
187 /* ARGSUSED */
188 int
dead_write(v)189 dead_write(v)
190 void *v;
191 {
192 struct vop_write_args /* {
193 struct vnode *a_vp;
194 struct uio *a_uio;
195 int a_ioflag;
196 struct ucred *a_cred;
197 } */ *ap = v;
198
199 if (chkvnlock(ap->a_vp))
200 panic("dead_write: lock");
201 return (EIO);
202 }
203
204 /*
205 * Device ioctl operation.
206 */
207 /* ARGSUSED */
208 int
dead_ioctl(v)209 dead_ioctl(v)
210 void *v;
211 {
212 struct vop_ioctl_args /* {
213 struct vnode *a_vp;
214 u_long a_command;
215 caddr_t a_data;
216 int a_fflag;
217 struct ucred *a_cred;
218 struct proc *a_p;
219 } */ *ap = v;
220
221 if (!chkvnlock(ap->a_vp))
222 return (EBADF);
223 return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
224 }
225
226 /* ARGSUSED */
227 int
dead_poll(v)228 dead_poll(v)
229 void *v;
230 {
231 #if 0
232 struct vop_poll_args /* {
233 struct vnode *a_vp;
234 int a_events;
235 struct proc *a_p;
236 } */ *ap = v;
237 #endif
238
239 /*
240 * Let the user find out that the descriptor is gone.
241 */
242 return (POLLHUP);
243 }
244
245 /*
246 * Just call the device strategy routine
247 */
248 int
dead_strategy(v)249 dead_strategy(v)
250 void *v;
251 {
252
253 struct vop_strategy_args /* {
254 struct buf *a_bp;
255 } */ *ap = v;
256 int s;
257
258 if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
259 ap->a_bp->b_flags |= B_ERROR;
260 s = splbio();
261 biodone(ap->a_bp);
262 splx(s);
263 return (EIO);
264 }
265 return (VOP_STRATEGY(ap->a_bp));
266 }
267
268 /*
269 * Wait until the vnode has finished changing state.
270 */
271 int
dead_lock(v)272 dead_lock(v)
273 void *v;
274 {
275 struct vop_lock_args /* {
276 struct vnode *a_vp;
277 int a_flags;
278 struct proc *a_p;
279 } */ *ap = v;
280 struct vnode *vp = ap->a_vp;
281
282 /*
283 * Since we are not using the lock manager, we must clear
284 * the interlock here.
285 */
286 if (ap->a_flags & LK_INTERLOCK) {
287 simple_unlock(&vp->v_interlock);
288 ap->a_flags &= ~LK_INTERLOCK;
289 }
290 if (ap->a_flags & LK_DRAIN || !chkvnlock(vp))
291 return (0);
292
293 return (VCALL(vp, VOFFSET(vop_lock), ap));
294 }
295
296 /*
297 * Wait until the vnode has finished changing state.
298 */
299 int
dead_bmap(v)300 dead_bmap(v)
301 void *v;
302 {
303 struct vop_bmap_args /* {
304 struct vnode *a_vp;
305 daddr_t a_bn;
306 struct vnode **a_vpp;
307 daddr_t *a_bnp;
308 int *a_runp;
309 } */ *ap = v;
310
311 if (!chkvnlock(ap->a_vp))
312 return (EIO);
313 return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
314 }
315
316 /*
317 * Print out the contents of a dead vnode.
318 */
319 /* ARGSUSED */
320 int
dead_print(v)321 dead_print(v)
322 void *v;
323 {
324 printf("tag VT_NON, dead vnode\n");
325 return 0;
326 }
327
328 /*
329 * Empty vnode failed operation
330 */
331 /*ARGSUSED*/
332 int
dead_ebadf(v)333 dead_ebadf(v)
334 void *v;
335 {
336
337 return (EBADF);
338 }
339
340 /*
341 * Empty vnode bad operation
342 */
343 /*ARGSUSED*/
344 int
dead_badop(v)345 dead_badop(v)
346 void *v;
347 {
348
349 panic("dead_badop called");
350 /* NOTREACHED */
351 }
352
353 /*
354 * We have to wait during times when the vnode is
355 * in a state of change.
356 */
357 int
chkvnlock(vp)358 chkvnlock(vp)
359 register struct vnode *vp;
360 {
361 int locked = 0;
362
363 while (vp->v_flag & VXLOCK) {
364 vp->v_flag |= VXWANT;
365 tsleep(vp, PINOD, "chkvnlock", 0);
366 locked = 1;
367 }
368 return (locked);
369 }
370