xref: /netbsd-src/sys/miscfs/deadfs/dead_vnops.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: dead_vnops.c,v 1.30 2001/01/22 12:17:37 jdolecek 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/param.h>
39 #include <sys/systm.h>
40 #include <sys/time.h>
41 #include <sys/vnode.h>
42 #include <sys/errno.h>
43 #include <sys/namei.h>
44 #include <sys/buf.h>
45 #include <sys/proc.h>
46 
47 #include <miscfs/genfs/genfs.h>
48 
49 /*
50  * Prototypes for dead operations on vnodes.
51  */
52 int	dead_lookup	__P((void *));
53 #define dead_create	genfs_badop
54 #define dead_mknod	genfs_badop
55 int	dead_open	__P((void *));
56 #define dead_close	genfs_nullop
57 #define dead_access	genfs_ebadf
58 #define dead_getattr	genfs_ebadf
59 #define dead_setattr	genfs_ebadf
60 int	dead_read	__P((void *));
61 int	dead_write	__P((void *));
62 #define dead_lease_check genfs_nullop
63 #define dead_fcntl	genfs_nullop
64 int	dead_ioctl	__P((void *));
65 int	dead_poll	__P((void *));
66 #define dead_mmap	genfs_badop
67 #define dead_fsync	genfs_nullop
68 #define dead_seek	genfs_nullop
69 #define dead_remove	genfs_badop
70 #define dead_link	genfs_badop
71 #define dead_rename	genfs_badop
72 #define dead_mkdir	genfs_badop
73 #define dead_rmdir	genfs_badop
74 #define dead_symlink	genfs_badop
75 #define dead_readdir	genfs_ebadf
76 #define dead_readlink	genfs_ebadf
77 #define dead_abortop	genfs_badop
78 #define dead_inactive	genfs_nullop
79 #define dead_reclaim	genfs_nullop
80 int	dead_lock	__P((void *));
81 #define dead_unlock	genfs_nullop
82 int	dead_bmap	__P((void *));
83 int	dead_strategy	__P((void *));
84 int	dead_print	__P((void *));
85 #define dead_islocked	genfs_nullop
86 #define dead_pathconf	genfs_ebadf
87 #define dead_advlock	genfs_ebadf
88 #define dead_blkatoff	genfs_badop
89 #define dead_valloc	genfs_badop
90 #define dead_vfree	genfs_badop
91 #define dead_truncate	genfs_nullop
92 #define dead_update	genfs_nullop
93 #define dead_bwrite	genfs_nullop
94 #define dead_revoke	genfs_nullop
95 
96 int	chkvnlock __P((struct vnode *));
97 
98 int (**dead_vnodeop_p) __P((void *));
99 
100 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
101 	{ &vop_default_desc, vn_default_error },
102 	{ &vop_lookup_desc, dead_lookup },		/* lookup */
103 	{ &vop_create_desc, dead_create },		/* create */
104 	{ &vop_mknod_desc, dead_mknod },		/* mknod */
105 	{ &vop_open_desc, dead_open },			/* open */
106 	{ &vop_close_desc, dead_close },		/* close */
107 	{ &vop_access_desc, dead_access },		/* access */
108 	{ &vop_getattr_desc, dead_getattr },		/* getattr */
109 	{ &vop_setattr_desc, dead_setattr },		/* setattr */
110 	{ &vop_read_desc, dead_read },			/* read */
111 	{ &vop_write_desc, dead_write },		/* write */
112 	{ &vop_lease_desc, dead_lease_check },		/* lease */
113 	{ &vop_fcntl_desc, dead_fcntl },		/* fcntl */
114 	{ &vop_ioctl_desc, dead_ioctl },		/* ioctl */
115 	{ &vop_poll_desc, dead_poll },			/* poll */
116 	{ &vop_revoke_desc, dead_revoke },		/* revoke */
117 	{ &vop_mmap_desc, dead_mmap },			/* mmap */
118 	{ &vop_fsync_desc, dead_fsync },		/* fsync */
119 	{ &vop_seek_desc, dead_seek },			/* seek */
120 	{ &vop_remove_desc, dead_remove },		/* remove */
121 	{ &vop_link_desc, dead_link },			/* link */
122 	{ &vop_rename_desc, dead_rename },		/* rename */
123 	{ &vop_mkdir_desc, dead_mkdir },		/* mkdir */
124 	{ &vop_rmdir_desc, dead_rmdir },		/* rmdir */
125 	{ &vop_symlink_desc, dead_symlink },		/* symlink */
126 	{ &vop_readdir_desc, dead_readdir },		/* readdir */
127 	{ &vop_readlink_desc, dead_readlink },		/* readlink */
128 	{ &vop_abortop_desc, dead_abortop },		/* abortop */
129 	{ &vop_inactive_desc, dead_inactive },		/* inactive */
130 	{ &vop_reclaim_desc, dead_reclaim },		/* reclaim */
131 	{ &vop_lock_desc, dead_lock },			/* lock */
132 	{ &vop_unlock_desc, dead_unlock },		/* unlock */
133 	{ &vop_bmap_desc, dead_bmap },			/* bmap */
134 	{ &vop_strategy_desc, dead_strategy },		/* strategy */
135 	{ &vop_print_desc, dead_print },		/* print */
136 	{ &vop_islocked_desc, dead_islocked },		/* islocked */
137 	{ &vop_pathconf_desc, dead_pathconf },		/* pathconf */
138 	{ &vop_advlock_desc, dead_advlock },		/* advlock */
139 	{ &vop_blkatoff_desc, dead_blkatoff },		/* blkatoff */
140 	{ &vop_valloc_desc, dead_valloc },		/* valloc */
141 	{ &vop_vfree_desc, dead_vfree },		/* vfree */
142 	{ &vop_truncate_desc, dead_truncate },		/* truncate */
143 	{ &vop_update_desc, dead_update },		/* update */
144 	{ &vop_bwrite_desc, dead_bwrite },		/* bwrite */
145 	{ (struct vnodeop_desc*)NULL, (int(*) __P((void *)))NULL }
146 };
147 const struct vnodeopv_desc dead_vnodeop_opv_desc =
148 	{ &dead_vnodeop_p, dead_vnodeop_entries };
149 
150 /*
151  * Trivial lookup routine that always fails.
152  */
153 /* ARGSUSED */
154 int
155 dead_lookup(v)
156 	void *v;
157 {
158 	struct vop_lookup_args /* {
159 		struct vnode * a_dvp;
160 		struct vnode ** a_vpp;
161 		struct componentname * a_cnp;
162 	} */ *ap = v;
163 
164 	*ap->a_vpp = NULL;
165 	return (ENOTDIR);
166 }
167 
168 /*
169  * Open always fails as if device did not exist.
170  */
171 /* ARGSUSED */
172 int
173 dead_open(v)
174 	void *v;
175 {
176 
177 	return (ENXIO);
178 }
179 
180 /*
181  * Vnode op for read
182  */
183 /* ARGSUSED */
184 int
185 dead_read(v)
186 	void *v;
187 {
188 	struct vop_read_args /* {
189 		struct vnode *a_vp;
190 		struct uio *a_uio;
191 		int  a_ioflag;
192 		struct ucred *a_cred;
193 	} */ *ap = v;
194 
195 	if (chkvnlock(ap->a_vp))
196 		panic("dead_read: lock");
197 	/*
198 	 * Return EOF for tty devices, EIO for others
199 	 */
200 	if ((ap->a_vp->v_flag & VISTTY) == 0)
201 		return (EIO);
202 	return (0);
203 }
204 
205 /*
206  * Vnode op for write
207  */
208 /* ARGSUSED */
209 int
210 dead_write(v)
211 	void *v;
212 {
213 	struct vop_write_args /* {
214 		struct vnode *a_vp;
215 		struct uio *a_uio;
216 		int  a_ioflag;
217 		struct ucred *a_cred;
218 	} */ *ap = v;
219 
220 	if (chkvnlock(ap->a_vp))
221 		panic("dead_write: lock");
222 	return (EIO);
223 }
224 
225 /*
226  * Device ioctl operation.
227  */
228 /* ARGSUSED */
229 int
230 dead_ioctl(v)
231 	void *v;
232 {
233 	struct vop_ioctl_args /* {
234 		struct vnode *a_vp;
235 		u_long a_command;
236 		caddr_t  a_data;
237 		int  a_fflag;
238 		struct ucred *a_cred;
239 		struct proc *a_p;
240 	} */ *ap = v;
241 
242 	if (!chkvnlock(ap->a_vp))
243 		return (EBADF);
244 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
245 }
246 
247 /* ARGSUSED */
248 int
249 dead_poll(v)
250 	void *v;
251 {
252 	struct vop_poll_args /* {
253 		struct vnode *a_vp;
254 		int a_events;
255 		struct proc *a_p;
256 	} */ *ap = v;
257 
258 	/*
259 	 * Let the user find out that the descriptor is gone.
260 	 */
261 	return (ap->a_events);
262 }
263 
264 /*
265  * Just call the device strategy routine
266  */
267 int
268 dead_strategy(v)
269 	void *v;
270 {
271 
272 	struct vop_strategy_args /* {
273 		struct buf *a_bp;
274 	} */ *ap = v;
275 	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
276 		ap->a_bp->b_flags |= B_ERROR;
277 		biodone(ap->a_bp);
278 		return (EIO);
279 	}
280 	return (VOP_STRATEGY(ap->a_bp));
281 }
282 
283 /*
284  * Wait until the vnode has finished changing state.
285  */
286 int
287 dead_lock(v)
288 	void *v;
289 {
290 	struct vop_lock_args /* {
291 		struct vnode *a_vp;
292 		int a_flags;
293 		struct proc *a_p;
294 	} */ *ap = v;
295 
296 	if (ap->a_flags & LK_INTERLOCK) {
297 		simple_unlock(&ap->a_vp->v_interlock);
298 		ap->a_flags &= ~LK_INTERLOCK;
299 	}
300 	if (!chkvnlock(ap->a_vp))
301 		return (0);
302 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
303 }
304 
305 /*
306  * Wait until the vnode has finished changing state.
307  */
308 int
309 dead_bmap(v)
310 	void *v;
311 {
312 	struct vop_bmap_args /* {
313 		struct vnode *a_vp;
314 		daddr_t  a_bn;
315 		struct vnode **a_vpp;
316 		daddr_t *a_bnp;
317 		int *a_runp;
318 	} */ *ap = v;
319 
320 	if (!chkvnlock(ap->a_vp))
321 		return (EIO);
322 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
323 }
324 
325 /*
326  * Print out the contents of a dead vnode.
327  */
328 /* ARGSUSED */
329 int
330 dead_print(v)
331 	void *v;
332 {
333 	printf("tag VT_NON, dead vnode\n");
334 	return 0;
335 }
336 
337 /*
338  * We have to wait during times when the vnode is
339  * in a state of change.
340  */
341 int
342 chkvnlock(vp)
343 	struct vnode *vp;
344 {
345 	int locked = 0;
346 
347 	while (vp->v_flag & VXLOCK) {
348 		vp->v_flag |= VXWANT;
349 		(void) tsleep(vp, PINOD, "deadchk", 0);
350 		locked = 1;
351 	}
352 	return (locked);
353 }
354