dead_vnops.c revision 1817 
1/*
2 * Copyright (c) 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)dead_vnops.c	8.1 (Berkeley) 6/10/93
34 * $Id$
35 */
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
45/*
46 * Prototypes for dead operations on vnodes.
47 */
48int	dead_badop(),
49	dead_ebadf();
50int	dead_lookup __P((struct vop_lookup_args *));
51#define dead_create ((int (*) __P((struct  vop_create_args *)))dead_badop)
52#define dead_mknod ((int (*) __P((struct  vop_mknod_args *)))dead_badop)
53int	dead_open __P((struct vop_open_args *));
54#define dead_close ((int (*) __P((struct  vop_close_args *)))nullop)
55#define dead_access ((int (*) __P((struct  vop_access_args *)))dead_ebadf)
56#define dead_getattr ((int (*) __P((struct  vop_getattr_args *)))dead_ebadf)
57#define dead_setattr ((int (*) __P((struct  vop_setattr_args *)))dead_ebadf)
58int	dead_read __P((struct vop_read_args *));
59int	dead_write __P((struct vop_write_args *));
60int	dead_ioctl __P((struct vop_ioctl_args *));
61int	dead_select __P((struct vop_select_args *));
62#define dead_mmap ((int (*) __P((struct  vop_mmap_args *)))dead_badop)
63#define dead_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
64#define dead_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
65#define dead_remove ((int (*) __P((struct  vop_remove_args *)))dead_badop)
66#define dead_link ((int (*) __P((struct  vop_link_args *)))dead_badop)
67#define dead_rename ((int (*) __P((struct  vop_rename_args *)))dead_badop)
68#define dead_mkdir ((int (*) __P((struct  vop_mkdir_args *)))dead_badop)
69#define dead_rmdir ((int (*) __P((struct  vop_rmdir_args *)))dead_badop)
70#define dead_symlink ((int (*) __P((struct  vop_symlink_args *)))dead_badop)
71#define dead_readdir ((int (*) __P((struct  vop_readdir_args *)))dead_ebadf)
72#define dead_readlink ((int (*) __P((struct  vop_readlink_args *)))dead_ebadf)
73#define dead_abortop ((int (*) __P((struct  vop_abortop_args *)))dead_badop)
74#define dead_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
75#define dead_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
76int	dead_lock __P((struct vop_lock_args *));
77#define dead_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
78int	dead_bmap __P((struct vop_bmap_args *));
79int	dead_strategy __P((struct vop_strategy_args *));
80int	dead_print __P((struct vop_print_args *));
81#define dead_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
82#define dead_pathconf ((int (*) __P((struct  vop_pathconf_args *)))dead_ebadf)
83#define dead_advlock ((int (*) __P((struct  vop_advlock_args *)))dead_ebadf)
84#define dead_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))dead_badop)
85#define dead_valloc ((int (*) __P((struct  vop_valloc_args *)))dead_badop)
86#define dead_vfree ((int (*) __P((struct  vop_vfree_args *)))dead_badop)
87#define dead_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
88#define dead_update ((int (*) __P((struct  vop_update_args *)))nullop)
89#define dead_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
90
91int (**dead_vnodeop_p)();
92struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
93	{ &vop_default_desc, vn_default_error },
94	{ &vop_lookup_desc, dead_lookup },	/* lookup */
95	{ &vop_create_desc, dead_create },	/* create */
96	{ &vop_mknod_desc, dead_mknod },	/* mknod */
97	{ &vop_open_desc, dead_open },	/* open */
98	{ &vop_close_desc, dead_close },	/* close */
99	{ &vop_access_desc, dead_access },	/* access */
100	{ &vop_getattr_desc, dead_getattr },	/* getattr */
101	{ &vop_setattr_desc, dead_setattr },	/* setattr */
102	{ &vop_read_desc, dead_read },	/* read */
103	{ &vop_write_desc, dead_write },	/* write */
104	{ &vop_ioctl_desc, dead_ioctl },	/* ioctl */
105	{ &vop_select_desc, dead_select },	/* select */
106	{ &vop_mmap_desc, dead_mmap },	/* mmap */
107	{ &vop_fsync_desc, dead_fsync },	/* fsync */
108	{ &vop_seek_desc, dead_seek },	/* seek */
109	{ &vop_remove_desc, dead_remove },	/* remove */
110	{ &vop_link_desc, dead_link },	/* link */
111	{ &vop_rename_desc, dead_rename },	/* rename */
112	{ &vop_mkdir_desc, dead_mkdir },	/* mkdir */
113	{ &vop_rmdir_desc, dead_rmdir },	/* rmdir */
114	{ &vop_symlink_desc, dead_symlink },	/* symlink */
115	{ &vop_readdir_desc, dead_readdir },	/* readdir */
116	{ &vop_readlink_desc, dead_readlink },	/* readlink */
117	{ &vop_abortop_desc, dead_abortop },	/* abortop */
118	{ &vop_inactive_desc, dead_inactive },	/* inactive */
119	{ &vop_reclaim_desc, dead_reclaim },	/* reclaim */
120	{ &vop_lock_desc, dead_lock },	/* lock */
121	{ &vop_unlock_desc, dead_unlock },	/* unlock */
122	{ &vop_bmap_desc, dead_bmap },	/* bmap */
123	{ &vop_strategy_desc, dead_strategy },	/* strategy */
124	{ &vop_print_desc, dead_print },	/* print */
125	{ &vop_islocked_desc, dead_islocked },	/* islocked */
126	{ &vop_pathconf_desc, dead_pathconf },	/* pathconf */
127	{ &vop_advlock_desc, dead_advlock },	/* advlock */
128	{ &vop_blkatoff_desc, dead_blkatoff },	/* blkatoff */
129	{ &vop_valloc_desc, dead_valloc },	/* valloc */
130	{ &vop_vfree_desc, dead_vfree },	/* vfree */
131	{ &vop_truncate_desc, dead_truncate },	/* truncate */
132	{ &vop_update_desc, dead_update },	/* update */
133	{ &vop_bwrite_desc, dead_bwrite },	/* bwrite */
134	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
135};
136struct vnodeopv_desc dead_vnodeop_opv_desc =
137	{ &dead_vnodeop_p, dead_vnodeop_entries };
138
139/*
140 * Trivial lookup routine that always fails.
141 */
142/* ARGSUSED */
143int
144dead_lookup(ap)
145	struct vop_lookup_args /* {
146		struct vnode * a_dvp;
147		struct vnode ** a_vpp;
148		struct componentname * a_cnp;
149	} */ *ap;
150{
151
152	*ap->a_vpp = NULL;
153	return (ENOTDIR);
154}
155
156/*
157 * Open always fails as if device did not exist.
158 */
159/* ARGSUSED */
160int
161dead_open(ap)
162	struct vop_open_args /* {
163		struct vnode *a_vp;
164		int  a_mode;
165		struct ucred *a_cred;
166		struct proc *a_p;
167	} */ *ap;
168{
169
170	return (ENXIO);
171}
172
173/*
174 * Vnode op for read
175 */
176/* ARGSUSED */
177int
178dead_read(ap)
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;
185{
186
187	if (chkvnlock(ap->a_vp))
188		panic("dead_read: lock");
189	/*
190	 * Return EOF for character devices, EIO for others
191	 */
192	if (ap->a_vp->v_type != VCHR)
193		return (EIO);
194	return (0);
195}
196
197/*
198 * Vnode op for write
199 */
200/* ARGSUSED */
201int
202dead_write(ap)
203	struct vop_write_args /* {
204		struct vnode *a_vp;
205		struct uio *a_uio;
206		int  a_ioflag;
207		struct ucred *a_cred;
208	} */ *ap;
209{
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 */
220int
221dead_ioctl(ap)
222	struct vop_ioctl_args /* {
223		struct vnode *a_vp;
224		int  a_command;
225		caddr_t  a_data;
226		int  a_fflag;
227		struct ucred *a_cred;
228		struct proc *a_p;
229	} */ *ap;
230{
231
232	if (!chkvnlock(ap->a_vp))
233		return (EBADF);
234	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
235}
236
237/* ARGSUSED */
238int
239dead_select(ap)
240	struct vop_select_args /* {
241		struct vnode *a_vp;
242		int  a_which;
243		int  a_fflags;
244		struct ucred *a_cred;
245		struct proc *a_p;
246	} */ *ap;
247{
248
249	/*
250	 * Let the user find out that the descriptor is gone.
251	 */
252	return (1);
253}
254
255/*
256 * Just call the device strategy routine
257 */
258int
259dead_strategy(ap)
260	struct vop_strategy_args /* {
261		struct buf *a_bp;
262	} */ *ap;
263{
264
265	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
266		ap->a_bp->b_flags |= B_ERROR;
267		biodone(ap->a_bp);
268		return (EIO);
269	}
270	return (VOP_STRATEGY(ap->a_bp));
271}
272
273/*
274 * Wait until the vnode has finished changing state.
275 */
276int
277dead_lock(ap)
278	struct vop_lock_args /* {
279		struct vnode *a_vp;
280	} */ *ap;
281{
282
283	if (!chkvnlock(ap->a_vp))
284		return (0);
285	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
286}
287
288/*
289 * Wait until the vnode has finished changing state.
290 */
291int
292dead_bmap(ap)
293	struct vop_bmap_args /* {
294		struct vnode *a_vp;
295		daddr_t  a_bn;
296		struct vnode **a_vpp;
297		daddr_t *a_bnp;
298		int *a_runp;
299	} */ *ap;
300{
301
302	if (!chkvnlock(ap->a_vp))
303		return (EIO);
304	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
305}
306
307/*
308 * Print out the contents of a dead vnode.
309 */
310/* ARGSUSED */
311int
312dead_print(ap)
313	struct vop_print_args /* {
314		struct vnode *a_vp;
315	} */ *ap;
316{
317
318	printf("tag VT_NON, dead vnode\n");
319	return (0);
320}
321
322/*
323 * Empty vnode failed operation
324 */
325int
326dead_ebadf()
327{
328
329	return (EBADF);
330}
331
332/*
333 * Empty vnode bad operation
334 */
335int
336dead_badop()
337{
338
339	panic("dead_badop called");
340	/* NOTREACHED */
341}
342
343/*
344 * Empty vnode null operation
345 */
346int
347dead_nullop()
348{
349
350	return (0);
351}
352
353/*
354 * We have to wait during times when the vnode is
355 * in a state of change.
356 */
357int
358chkvnlock(vp)
359	register struct vnode *vp;
360{
361	int locked = 0;
362
363	while (vp->v_flag & VXLOCK) {
364		vp->v_flag |= VXWANT;
365		sleep((caddr_t)vp, PINOD);
366		locked = 1;
367	}
368	return (locked);
369}
370