dead_vnops.c revision 1541 
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 */
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/time.h>
39#include <sys/vnode.h>
40#include <sys/errno.h>
41#include <sys/namei.h>
42#include <sys/buf.h>
43
44/*
45 * Prototypes for dead operations on vnodes.
46 */
47int	dead_badop(),
48	dead_ebadf();
49int	dead_lookup __P((struct vop_lookup_args *));
50#define dead_create ((int (*) __P((struct  vop_create_args *)))dead_badop)
51#define dead_mknod ((int (*) __P((struct  vop_mknod_args *)))dead_badop)
52int	dead_open __P((struct vop_open_args *));
53#define dead_close ((int (*) __P((struct  vop_close_args *)))nullop)
54#define dead_access ((int (*) __P((struct  vop_access_args *)))dead_ebadf)
55#define dead_getattr ((int (*) __P((struct  vop_getattr_args *)))dead_ebadf)
56#define dead_setattr ((int (*) __P((struct  vop_setattr_args *)))dead_ebadf)
57int	dead_read __P((struct vop_read_args *));
58int	dead_write __P((struct vop_write_args *));
59int	dead_ioctl __P((struct vop_ioctl_args *));
60int	dead_select __P((struct vop_select_args *));
61#define dead_mmap ((int (*) __P((struct  vop_mmap_args *)))dead_badop)
62#define dead_fsync ((int (*) __P((struct  vop_fsync_args *)))nullop)
63#define dead_seek ((int (*) __P((struct  vop_seek_args *)))nullop)
64#define dead_remove ((int (*) __P((struct  vop_remove_args *)))dead_badop)
65#define dead_link ((int (*) __P((struct  vop_link_args *)))dead_badop)
66#define dead_rename ((int (*) __P((struct  vop_rename_args *)))dead_badop)
67#define dead_mkdir ((int (*) __P((struct  vop_mkdir_args *)))dead_badop)
68#define dead_rmdir ((int (*) __P((struct  vop_rmdir_args *)))dead_badop)
69#define dead_symlink ((int (*) __P((struct  vop_symlink_args *)))dead_badop)
70#define dead_readdir ((int (*) __P((struct  vop_readdir_args *)))dead_ebadf)
71#define dead_readlink ((int (*) __P((struct  vop_readlink_args *)))dead_ebadf)
72#define dead_abortop ((int (*) __P((struct  vop_abortop_args *)))dead_badop)
73#define dead_inactive ((int (*) __P((struct  vop_inactive_args *)))nullop)
74#define dead_reclaim ((int (*) __P((struct  vop_reclaim_args *)))nullop)
75int	dead_lock __P((struct vop_lock_args *));
76#define dead_unlock ((int (*) __P((struct  vop_unlock_args *)))nullop)
77int	dead_bmap __P((struct vop_bmap_args *));
78int	dead_strategy __P((struct vop_strategy_args *));
79int	dead_print __P((struct vop_print_args *));
80#define dead_islocked ((int (*) __P((struct  vop_islocked_args *)))nullop)
81#define dead_pathconf ((int (*) __P((struct  vop_pathconf_args *)))dead_ebadf)
82#define dead_advlock ((int (*) __P((struct  vop_advlock_args *)))dead_ebadf)
83#define dead_blkatoff ((int (*) __P((struct  vop_blkatoff_args *)))dead_badop)
84#define dead_valloc ((int (*) __P((struct  vop_valloc_args *)))dead_badop)
85#define dead_vfree ((int (*) __P((struct  vop_vfree_args *)))dead_badop)
86#define dead_truncate ((int (*) __P((struct  vop_truncate_args *)))nullop)
87#define dead_update ((int (*) __P((struct  vop_update_args *)))nullop)
88#define dead_bwrite ((int (*) __P((struct  vop_bwrite_args *)))nullop)
89
90int (**dead_vnodeop_p)();
91struct vnodeopv_entry_desc dead_vnodeop_entries[] = {
92	{ &vop_default_desc, vn_default_error },
93	{ &vop_lookup_desc, dead_lookup },	/* lookup */
94	{ &vop_create_desc, dead_create },	/* create */
95	{ &vop_mknod_desc, dead_mknod },	/* mknod */
96	{ &vop_open_desc, dead_open },	/* open */
97	{ &vop_close_desc, dead_close },	/* close */
98	{ &vop_access_desc, dead_access },	/* access */
99	{ &vop_getattr_desc, dead_getattr },	/* getattr */
100	{ &vop_setattr_desc, dead_setattr },	/* setattr */
101	{ &vop_read_desc, dead_read },	/* read */
102	{ &vop_write_desc, dead_write },	/* write */
103	{ &vop_ioctl_desc, dead_ioctl },	/* ioctl */
104	{ &vop_select_desc, dead_select },	/* select */
105	{ &vop_mmap_desc, dead_mmap },	/* mmap */
106	{ &vop_fsync_desc, dead_fsync },	/* fsync */
107	{ &vop_seek_desc, dead_seek },	/* seek */
108	{ &vop_remove_desc, dead_remove },	/* remove */
109	{ &vop_link_desc, dead_link },	/* link */
110	{ &vop_rename_desc, dead_rename },	/* rename */
111	{ &vop_mkdir_desc, dead_mkdir },	/* mkdir */
112	{ &vop_rmdir_desc, dead_rmdir },	/* rmdir */
113	{ &vop_symlink_desc, dead_symlink },	/* symlink */
114	{ &vop_readdir_desc, dead_readdir },	/* readdir */
115	{ &vop_readlink_desc, dead_readlink },	/* readlink */
116	{ &vop_abortop_desc, dead_abortop },	/* abortop */
117	{ &vop_inactive_desc, dead_inactive },	/* inactive */
118	{ &vop_reclaim_desc, dead_reclaim },	/* reclaim */
119	{ &vop_lock_desc, dead_lock },	/* lock */
120	{ &vop_unlock_desc, dead_unlock },	/* unlock */
121	{ &vop_bmap_desc, dead_bmap },	/* bmap */
122	{ &vop_strategy_desc, dead_strategy },	/* strategy */
123	{ &vop_print_desc, dead_print },	/* print */
124	{ &vop_islocked_desc, dead_islocked },	/* islocked */
125	{ &vop_pathconf_desc, dead_pathconf },	/* pathconf */
126	{ &vop_advlock_desc, dead_advlock },	/* advlock */
127	{ &vop_blkatoff_desc, dead_blkatoff },	/* blkatoff */
128	{ &vop_valloc_desc, dead_valloc },	/* valloc */
129	{ &vop_vfree_desc, dead_vfree },	/* vfree */
130	{ &vop_truncate_desc, dead_truncate },	/* truncate */
131	{ &vop_update_desc, dead_update },	/* update */
132	{ &vop_bwrite_desc, dead_bwrite },	/* bwrite */
133	{ (struct vnodeop_desc*)NULL, (int(*)())NULL }
134};
135struct vnodeopv_desc dead_vnodeop_opv_desc =
136	{ &dead_vnodeop_p, dead_vnodeop_entries };
137
138/*
139 * Trivial lookup routine that always fails.
140 */
141/* ARGSUSED */
142int
143dead_lookup(ap)
144	struct vop_lookup_args /* {
145		struct vnode * a_dvp;
146		struct vnode ** a_vpp;
147		struct componentname * a_cnp;
148	} */ *ap;
149{
150
151	*ap->a_vpp = NULL;
152	return (ENOTDIR);
153}
154
155/*
156 * Open always fails as if device did not exist.
157 */
158/* ARGSUSED */
159dead_open(ap)
160	struct vop_open_args /* {
161		struct vnode *a_vp;
162		int  a_mode;
163		struct ucred *a_cred;
164		struct proc *a_p;
165	} */ *ap;
166{
167
168	return (ENXIO);
169}
170
171/*
172 * Vnode op for read
173 */
174/* ARGSUSED */
175dead_read(ap)
176	struct vop_read_args /* {
177		struct vnode *a_vp;
178		struct uio *a_uio;
179		int  a_ioflag;
180		struct ucred *a_cred;
181	} */ *ap;
182{
183
184	if (chkvnlock(ap->a_vp))
185		panic("dead_read: lock");
186	/*
187	 * Return EOF for character devices, EIO for others
188	 */
189	if (ap->a_vp->v_type != VCHR)
190		return (EIO);
191	return (0);
192}
193
194/*
195 * Vnode op for write
196 */
197/* ARGSUSED */
198dead_write(ap)
199	struct vop_write_args /* {
200		struct vnode *a_vp;
201		struct uio *a_uio;
202		int  a_ioflag;
203		struct ucred *a_cred;
204	} */ *ap;
205{
206
207	if (chkvnlock(ap->a_vp))
208		panic("dead_write: lock");
209	return (EIO);
210}
211
212/*
213 * Device ioctl operation.
214 */
215/* ARGSUSED */
216dead_ioctl(ap)
217	struct vop_ioctl_args /* {
218		struct vnode *a_vp;
219		int  a_command;
220		caddr_t  a_data;
221		int  a_fflag;
222		struct ucred *a_cred;
223		struct proc *a_p;
224	} */ *ap;
225{
226
227	if (!chkvnlock(ap->a_vp))
228		return (EBADF);
229	return (VCALL(ap->a_vp, VOFFSET(vop_ioctl), ap));
230}
231
232/* ARGSUSED */
233dead_select(ap)
234	struct vop_select_args /* {
235		struct vnode *a_vp;
236		int  a_which;
237		int  a_fflags;
238		struct ucred *a_cred;
239		struct proc *a_p;
240	} */ *ap;
241{
242
243	/*
244	 * Let the user find out that the descriptor is gone.
245	 */
246	return (1);
247}
248
249/*
250 * Just call the device strategy routine
251 */
252dead_strategy(ap)
253	struct vop_strategy_args /* {
254		struct buf *a_bp;
255	} */ *ap;
256{
257
258	if (ap->a_bp->b_vp == NULL || !chkvnlock(ap->a_bp->b_vp)) {
259		ap->a_bp->b_flags |= B_ERROR;
260		biodone(ap->a_bp);
261		return (EIO);
262	}
263	return (VOP_STRATEGY(ap->a_bp));
264}
265
266/*
267 * Wait until the vnode has finished changing state.
268 */
269dead_lock(ap)
270	struct vop_lock_args /* {
271		struct vnode *a_vp;
272	} */ *ap;
273{
274
275	if (!chkvnlock(ap->a_vp))
276		return (0);
277	return (VCALL(ap->a_vp, VOFFSET(vop_lock), ap));
278}
279
280/*
281 * Wait until the vnode has finished changing state.
282 */
283dead_bmap(ap)
284	struct vop_bmap_args /* {
285		struct vnode *a_vp;
286		daddr_t  a_bn;
287		struct vnode **a_vpp;
288		daddr_t *a_bnp;
289		int *a_runp;
290	} */ *ap;
291{
292
293	if (!chkvnlock(ap->a_vp))
294		return (EIO);
295	return (VOP_BMAP(ap->a_vp, ap->a_bn, ap->a_vpp, ap->a_bnp, ap->a_runp));
296}
297
298/*
299 * Print out the contents of a dead vnode.
300 */
301/* ARGSUSED */
302dead_print(ap)
303	struct vop_print_args /* {
304		struct vnode *a_vp;
305	} */ *ap;
306{
307
308	printf("tag VT_NON, dead vnode\n");
309}
310
311/*
312 * Empty vnode failed operation
313 */
314dead_ebadf()
315{
316
317	return (EBADF);
318}
319
320/*
321 * Empty vnode bad operation
322 */
323dead_badop()
324{
325
326	panic("dead_badop called");
327	/* NOTREACHED */
328}
329
330/*
331 * Empty vnode null operation
332 */
333dead_nullop()
334{
335
336	return (0);
337}
338
339/*
340 * We have to wait during times when the vnode is
341 * in a state of change.
342 */
343chkvnlock(vp)
344	register struct vnode *vp;
345{
346	int locked = 0;
347
348	while (vp->v_flag & VXLOCK) {
349		vp->v_flag |= VXWANT;
350		sleep((caddr_t)vp, PINOD);
351		locked = 1;
352	}
353	return (locked);
354}
355