xref: /netbsd-src/sys/miscfs/deadfs/dead_vnops.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: dead_vnops.c,v 1.38 2005/12/11 12:24:50 christos 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 1.38 2005/12/11 12:24:50 christos 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(void *);
52 #define dead_create	genfs_badop
53 #define dead_mknod	genfs_badop
54 int	dead_open(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(void *);
60 int	dead_write(void *);
61 #define dead_lease_check genfs_nullop
62 #define dead_fcntl	genfs_nullop
63 int	dead_ioctl(void *);
64 int	dead_poll(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(void *);
80 #define dead_unlock	genfs_nullop
81 int	dead_bmap(void *);
82 int	dead_strategy(void *);
83 int	dead_print(void *);
84 #define dead_islocked	genfs_nullop
85 #define dead_pathconf	genfs_ebadf
86 #define dead_advlock	genfs_ebadf
87 #define dead_bwrite	genfs_nullop
88 #define dead_revoke	genfs_nullop
89 #define dead_putpages	genfs_null_putpages
90 
91 int	chkvnlock(struct vnode *);
92 
93 int (**dead_vnodeop_p)(void *);
94 
95 const struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
96 	{ &vop_default_desc, vn_default_error },
97 	{ &vop_lookup_desc, dead_lookup },		/* lookup */
98 	{ &vop_create_desc, dead_create },		/* create */
99 	{ &vop_mknod_desc, dead_mknod },		/* mknod */
100 	{ &vop_open_desc, dead_open },			/* open */
101 	{ &vop_close_desc, dead_close },		/* close */
102 	{ &vop_access_desc, dead_access },		/* access */
103 	{ &vop_getattr_desc, dead_getattr },		/* getattr */
104 	{ &vop_setattr_desc, dead_setattr },		/* setattr */
105 	{ &vop_read_desc, dead_read },			/* read */
106 	{ &vop_write_desc, dead_write },		/* write */
107 	{ &vop_lease_desc, dead_lease_check },		/* lease */
108 	{ &vop_fcntl_desc, dead_fcntl },		/* fcntl */
109 	{ &vop_ioctl_desc, dead_ioctl },		/* ioctl */
110 	{ &vop_poll_desc, dead_poll },			/* poll */
111 	{ &vop_revoke_desc, dead_revoke },		/* revoke */
112 	{ &vop_mmap_desc, dead_mmap },			/* mmap */
113 	{ &vop_fsync_desc, dead_fsync },		/* fsync */
114 	{ &vop_seek_desc, dead_seek },			/* seek */
115 	{ &vop_remove_desc, dead_remove },		/* remove */
116 	{ &vop_link_desc, dead_link },			/* link */
117 	{ &vop_rename_desc, dead_rename },		/* rename */
118 	{ &vop_mkdir_desc, dead_mkdir },		/* mkdir */
119 	{ &vop_rmdir_desc, dead_rmdir },		/* rmdir */
120 	{ &vop_symlink_desc, dead_symlink },		/* symlink */
121 	{ &vop_readdir_desc, dead_readdir },		/* readdir */
122 	{ &vop_readlink_desc, dead_readlink },		/* readlink */
123 	{ &vop_abortop_desc, dead_abortop },		/* abortop */
124 	{ &vop_inactive_desc, dead_inactive },		/* inactive */
125 	{ &vop_reclaim_desc, dead_reclaim },		/* reclaim */
126 	{ &vop_lock_desc, dead_lock },			/* lock */
127 	{ &vop_unlock_desc, dead_unlock },		/* unlock */
128 	{ &vop_bmap_desc, dead_bmap },			/* bmap */
129 	{ &vop_strategy_desc, dead_strategy },		/* strategy */
130 	{ &vop_print_desc, dead_print },		/* print */
131 	{ &vop_islocked_desc, dead_islocked },		/* islocked */
132 	{ &vop_pathconf_desc, dead_pathconf },		/* pathconf */
133 	{ &vop_advlock_desc, dead_advlock },		/* advlock */
134 	{ &vop_bwrite_desc, dead_bwrite },		/* bwrite */
135 	{ &vop_putpages_desc, dead_putpages },		/* putpages */
136 	{ NULL, NULL }
137 };
138 const struct vnodeopv_desc dead_vnodeop_opv_desc =
139 	{ &dead_vnodeop_p, dead_vnodeop_entries };
140 
141 /*
142  * Trivial lookup routine that always fails.
143  */
144 /* ARGSUSED */
145 int
146 dead_lookup(v)
147 	void *v;
148 {
149 	struct vop_lookup_args /* {
150 		struct vnode * a_dvp;
151 		struct vnode ** a_vpp;
152 		struct componentname * a_cnp;
153 	} */ *ap = v;
154 
155 	*ap->a_vpp = NULL;
156 	return (ENOTDIR);
157 }
158 
159 /*
160  * Open always fails as if device did not exist.
161  */
162 /* ARGSUSED */
163 int
164 dead_open(v)
165 	void *v;
166 {
167 
168 	return (ENXIO);
169 }
170 
171 /*
172  * Vnode op for read
173  */
174 /* ARGSUSED */
175 int
176 dead_read(v)
177 	void *v;
178 {
179 	struct vop_read_args /* {
180 		struct vnode *a_vp;
181 		struct uio *a_uio;
182 		int  a_ioflag;
183 		struct ucred *a_cred;
184 	} */ *ap = v;
185 
186 	if (chkvnlock(ap->a_vp))
187 		panic("dead_read: lock");
188 	/*
189 	 * Return EOF for tty devices, EIO for others
190 	 */
191 	if ((ap->a_vp->v_flag & VISTTY) == 0)
192 		return (EIO);
193 	return (0);
194 }
195 
196 /*
197  * Vnode op for write
198  */
199 /* ARGSUSED */
200 int
201 dead_write(v)
202 	void *v;
203 {
204 	struct vop_write_args /* {
205 		struct vnode *a_vp;
206 		struct uio *a_uio;
207 		int  a_ioflag;
208 		struct ucred *a_cred;
209 	} */ *ap = v;
210 
211 	if (chkvnlock(ap->a_vp))
212 		panic("dead_write: lock");
213 	return (EIO);
214 }
215 
216 /*
217  * Device ioctl operation.
218  */
219 /* ARGSUSED */
220 int
221 dead_ioctl(v)
222 	void *v;
223 {
224 	struct vop_ioctl_args /* {
225 		struct vnode *a_vp;
226 		u_long a_command;
227 		void *a_data;
228 		int  a_fflag;
229 		struct ucred *a_cred;
230 		struct lwp *a_l;
231 	} */ *ap = v;
232 
233 	if (!chkvnlock(ap->a_vp))
234 		return (EBADF);
235 	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
236 }
237 
238 /* ARGSUSED */
239 int
240 dead_poll(v)
241 	void *v;
242 {
243 	struct vop_poll_args /* {
244 		struct vnode *a_vp;
245 		int a_events;
246 		struct lwp *a_l;
247 	} */ *ap = v;
248 
249 	/*
250 	 * Let the user find out that the descriptor is gone.
251 	 */
252 	return (ap->a_events);
253 }
254 
255 /*
256  * Just call the device strategy routine
257  */
258 int
259 dead_strategy(v)
260 	void *v;
261 {
262 
263 	struct vop_strategy_args /* {
264 		struct vnode *a_vp;
265 		struct buf *a_bp;
266 	} */ *ap = v;
267 	if (ap->a_vp == NULL || !chkvnlock(ap->a_vp)) {
268 		ap->a_bp->b_flags |= B_ERROR;
269 		biodone(ap->a_bp);
270 		return (EIO);
271 	}
272 	return (VOP_STRATEGY(ap->a_vp, ap->a_bp));
273 }
274 
275 /*
276  * Wait until the vnode has finished changing state.
277  */
278 int
279 dead_lock(v)
280 	void *v;
281 {
282 	struct vop_lock_args /* {
283 		struct vnode *a_vp;
284 		int a_flags;
285 		struct proc *a_p;
286 	} */ *ap = v;
287 
288 	if (ap->a_flags & LK_INTERLOCK) {
289 		simple_unlock(&ap->a_vp->v_interlock);
290 		ap->a_flags &= ~LK_INTERLOCK;
291 	}
292 	if (!chkvnlock(ap->a_vp))
293 		return (0);
294 	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
295 }
296 
297 /*
298  * Wait until the vnode has finished changing state.
299  */
300 int
301 dead_bmap(v)
302 	void *v;
303 {
304 	struct vop_bmap_args /* {
305 		struct vnode *a_vp;
306 		daddr_t  a_bn;
307 		struct vnode **a_vpp;
308 		daddr_t *a_bnp;
309 		int *a_runp;
310 	} */ *ap = v;
311 
312 	if (!chkvnlock(ap->a_vp))
313 		return (EIO);
314 	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
315 }
316 
317 /*
318  * Print out the contents of a dead vnode.
319  */
320 /* ARGSUSED */
321 int
322 dead_print(v)
323 	void *v;
324 {
325 	printf("tag VT_NON, dead vnode\n");
326 	return 0;
327 }
328 
329 /*
330  * We have to wait during times when the vnode is
331  * in a state of change.
332  */
333 int
334 chkvnlock(vp)
335 	struct vnode *vp;
336 {
337 	int locked = 0;
338 
339 	while (vp->v_flag & VXLOCK) {
340 		vp->v_flag |= VXWANT;
341 		(void) tsleep(vp, PINOD, "deadchk", 0);
342 		locked = 1;
343 	}
344 	return (locked);
345 }
346