xref: /netbsd-src/sys/miscfs/deadfs/dead_vnops.c (revision 23c8222edbfb0f0932d88a8351d3a0cf817dfb9e)
1 /*	$NetBSD: dead_vnops.c,v 1.35 2004/04/27 17:37:31 jrf 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)dead_vnops.c	8.2 (Berkeley) 11/21/94
32  */
33 
34 #include <sys/cdefs.h>
35 __KERNEL_RCSID(0, "$NetBSD: dead_vnops.c,v 1.35 2004/04/27 17:37:31 jrf Exp $");
36 
37 #include <sys/param.h>
38 #include <sys/systm.h>
39 #include <sys/time.h>
40 #include <sys/vnode.h>
41 #include <sys/errno.h>
42 #include <sys/namei.h>
43 #include <sys/buf.h>
44 #include <sys/proc.h>
45 
46 #include <miscfs/genfs/genfs.h>
47 
48 /*
49  * Prototypes for dead operations on vnodes.
50  */
51 int	dead_lookup	__P((void *));
52 #define dead_create	genfs_badop
53 #define dead_mknod	genfs_badop
54 int	dead_open	__P((void *));
55 #define dead_close	genfs_nullop
56 #define dead_access	genfs_ebadf
57 #define dead_getattr	genfs_ebadf
58 #define dead_setattr	genfs_ebadf
59 int	dead_read	__P((void *));
60 int	dead_write	__P((void *));
61 #define dead_lease_check genfs_nullop
62 #define dead_fcntl	genfs_nullop
63 int	dead_ioctl	__P((void *));
64 int	dead_poll	__P((void *));
65 #define dead_mmap	genfs_badop
66 #define dead_fsync	genfs_nullop
67 #define dead_seek	genfs_nullop
68 #define dead_remove	genfs_badop
69 #define dead_link	genfs_badop
70 #define dead_rename	genfs_badop
71 #define dead_mkdir	genfs_badop
72 #define dead_rmdir	genfs_badop
73 #define dead_symlink	genfs_badop
74 #define dead_readdir	genfs_ebadf
75 #define dead_readlink	genfs_ebadf
76 #define dead_abortop	genfs_badop
77 #define dead_inactive	genfs_nullop
78 #define dead_reclaim	genfs_nullop
79 int	dead_lock	__P((void *));
80 #define dead_unlock	genfs_nullop
81 int	dead_bmap	__P((void *));
82 int	dead_strategy	__P((void *));
83 int	dead_print	__P((void *));
84 #define dead_islocked	genfs_nullop
85 #define dead_pathconf	genfs_ebadf
86 #define dead_advlock	genfs_ebadf
87 #define dead_blkatoff	genfs_badop
88 #define dead_valloc	genfs_badop
89 #define dead_vfree	genfs_badop
90 #define dead_truncate	genfs_nullop
91 #define dead_update	genfs_nullop
92 #define dead_bwrite	genfs_nullop
93 #define dead_revoke	genfs_nullop
94 #define dead_putpages	genfs_null_putpages
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 	{ &vop_putpages_desc, dead_putpages },		/* putpages */
146 	{ NULL, NULL }
147 };
148 const struct vnodeopv_desc dead_vnodeop_opv_desc =
149 	{ &dead_vnodeop_p, dead_vnodeop_entries };
150 
151 /*
152  * Trivial lookup routine that always fails.
153  */
154 /* ARGSUSED */
155 int
156 dead_lookup(v)
157 	void *v;
158 {
159 	struct vop_lookup_args /* {
160 		struct vnode * a_dvp;
161 		struct vnode ** a_vpp;
162 		struct componentname * a_cnp;
163 	} */ *ap = v;
164 
165 	*ap->a_vpp = NULL;
166 	return (ENOTDIR);
167 }
168 
169 /*
170  * Open always fails as if device did not exist.
171  */
172 /* ARGSUSED */
173 int
174 dead_open(v)
175 	void *v;
176 {
177 
178 	return (ENXIO);
179 }
180 
181 /*
182  * Vnode op for read
183  */
184 /* ARGSUSED */
185 int
186 dead_read(v)
187 	void *v;
188 {
189 	struct vop_read_args /* {
190 		struct vnode *a_vp;
191 		struct uio *a_uio;
192 		int  a_ioflag;
193 		struct ucred *a_cred;
194 	} */ *ap = v;
195 
196 	if (chkvnlock(ap->a_vp))
197 		panic("dead_read: lock");
198 	/*
199 	 * Return EOF for tty devices, EIO for others
200 	 */
201 	if ((ap->a_vp->v_flag & VISTTY) == 0)
202 		return (EIO);
203 	return (0);
204 }
205 
206 /*
207  * Vnode op for write
208  */
209 /* ARGSUSED */
210 int
211 dead_write(v)
212 	void *v;
213 {
214 	struct vop_write_args /* {
215 		struct vnode *a_vp;
216 		struct uio *a_uio;
217 		int  a_ioflag;
218 		struct ucred *a_cred;
219 	} */ *ap = v;
220 
221 	if (chkvnlock(ap->a_vp))
222 		panic("dead_write: lock");
223 	return (EIO);
224 }
225 
226 /*
227  * Device ioctl operation.
228  */
229 /* ARGSUSED */
230 int
231 dead_ioctl(v)
232 	void *v;
233 {
234 	struct vop_ioctl_args /* {
235 		struct vnode *a_vp;
236 		u_long a_command;
237 		void *a_data;
238 		int  a_fflag;
239 		struct ucred *a_cred;
240 		struct proc *a_p;
241 	} */ *ap = v;
242 
243 	if (!chkvnlock(ap->a_vp))
244 		return (EBADF);
245 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
246 }
247 
248 /* ARGSUSED */
249 int
250 dead_poll(v)
251 	void *v;
252 {
253 	struct vop_poll_args /* {
254 		struct vnode *a_vp;
255 		int a_events;
256 		struct proc *a_p;
257 	} */ *ap = v;
258 
259 	/*
260 	 * Let the user find out that the descriptor is gone.
261 	 */
262 	return (ap->a_events);
263 }
264 
265 /*
266  * Just call the device strategy routine
267  */
268 int
269 dead_strategy(v)
270 	void *v;
271 {
272 
273 	struct vop_strategy_args /* {
274 		struct vnode *a_vp;
275 		struct buf *a_bp;
276 	} */ *ap = v;
277 	if (ap->a_vp == NULL || !chkvnlock(ap->a_vp)) {
278 		ap->a_bp->b_flags |= B_ERROR;
279 		biodone(ap->a_bp);
280 		return (EIO);
281 	}
282 	return (VOP_STRATEGY(ap->a_vp, ap->a_bp));
283 }
284 
285 /*
286  * Wait until the vnode has finished changing state.
287  */
288 int
289 dead_lock(v)
290 	void *v;
291 {
292 	struct vop_lock_args /* {
293 		struct vnode *a_vp;
294 		int a_flags;
295 		struct proc *a_p;
296 	} */ *ap = v;
297 
298 	if (ap->a_flags & LK_INTERLOCK) {
299 		simple_unlock(&ap->a_vp->v_interlock);
300 		ap->a_flags &= ~LK_INTERLOCK;
301 	}
302 	if (!chkvnlock(ap->a_vp))
303 		return (0);
304 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
305 }
306 
307 /*
308  * Wait until the vnode has finished changing state.
309  */
310 int
311 dead_bmap(v)
312 	void *v;
313 {
314 	struct vop_bmap_args /* {
315 		struct vnode *a_vp;
316 		daddr_t  a_bn;
317 		struct vnode **a_vpp;
318 		daddr_t *a_bnp;
319 		int *a_runp;
320 	} */ *ap = v;
321 
322 	if (!chkvnlock(ap->a_vp))
323 		return (EIO);
324 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
325 }
326 
327 /*
328  * Print out the contents of a dead vnode.
329  */
330 /* ARGSUSED */
331 int
332 dead_print(v)
333 	void *v;
334 {
335 	printf("tag VT_NON, dead vnode\n");
336 	return 0;
337 }
338 
339 /*
340  * We have to wait during times when the vnode is
341  * in a state of change.
342  */
343 int
344 chkvnlock(vp)
345 	struct vnode *vp;
346 {
347 	int locked = 0;
348 
349 	while (vp->v_flag & VXLOCK) {
350 		vp->v_flag |= VXWANT;
351 		(void) tsleep(vp, PINOD, "deadchk", 0);
352 		locked = 1;
353 	}
354 	return (locked);
355 }
356