[unix-history] / usr / src / sys.386bsd / kern / dead_vnops.c

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)dead_vnops.c	7.13 (Berkeley) 4/15/91
 */

#include "param.h"
#include "systm.h"
#include "time.h"
#include "vnode.h"
#include "errno.h"
#include "namei.h"
#include "buf.h"

/*
 * Prototypes for dead operations on vnodes.
 */
int	dead_badop(),
	dead_ebadf();
int	dead_lookup __P((
		struct vnode *vp,
		struct nameidata *ndp,
		struct proc *p));
#define dead_create ((int (*) __P(( \
		struct nameidata *ndp, \
		struct vattr *vap, \
		struct proc *p))) dead_badop)
#define dead_mknod ((int (*) __P(( \
		struct nameidata *ndp, \
		struct vattr *vap, \
		struct ucred *cred, \
		struct proc *p))) dead_badop)
int	dead_open __P((
		struct vnode *vp,
		int mode,
		struct ucred *cred,
		struct proc *p));
#define dead_close ((int (*) __P(( \
		struct vnode *vp, \
		int fflag, \
		struct ucred *cred, \
		struct proc *p))) nullop)
#define dead_access ((int (*) __P(( \
		struct vnode *vp, \
		int mode, \
		struct ucred *cred, \
		struct proc *p))) dead_ebadf)
#define dead_getattr ((int (*) __P(( \
		struct vnode *vp, \
		struct vattr *vap, \
		struct ucred *cred, \
		struct proc *p))) dead_ebadf)
#define dead_setattr ((int (*) __P(( \
		struct vnode *vp, \
		struct vattr *vap, \
		struct ucred *cred, \
		struct proc *p))) dead_ebadf)
int	dead_read __P((
		struct vnode *vp,
		struct uio *uio,
		int ioflag,
		struct ucred *cred));
int	dead_write __P((
		struct vnode *vp,
		struct uio *uio,
		int ioflag,
		struct ucred *cred));
int	dead_ioctl __P((
		struct vnode *vp,
		int command,
		caddr_t data,
		int fflag,
		struct ucred *cred,
		struct proc *p));
int	dead_select __P((
		struct vnode *vp,
		int which,
		int fflags,
		struct ucred *cred,
		struct proc *p));
#define dead_mmap ((int (*) __P(( \
		struct vnode *vp, \
		int fflags, \
		struct ucred *cred, \
		struct proc *p))) dead_badop)
#define dead_fsync ((int (*) __P(( \
		struct vnode *vp, \
		int fflags, \
		struct ucred *cred, \
		int waitfor, \
		struct proc *p))) nullop)
#define dead_seek ((int (*) __P(( \
		struct vnode *vp, \
		off_t oldoff, \
		off_t newoff, \
		struct ucred *cred))) nullop)
#define dead_remove ((int (*) __P(( \
		struct nameidata *ndp, \
		struct proc *p))) dead_badop)
#define dead_link ((int (*) __P(( \
		struct vnode *vp, \
		struct nameidata *ndp, \
		struct proc *p))) dead_badop)
#define dead_rename ((int (*) __P(( \
		struct nameidata *fndp, \
		struct nameidata *tdnp, \
		struct proc *p))) dead_badop)
#define dead_mkdir ((int (*) __P(( \
		struct nameidata *ndp, \
		struct vattr *vap, \
		struct proc *p))) dead_badop)
#define dead_rmdir ((int (*) __P(( \
		struct nameidata *ndp, \
		struct proc *p))) dead_badop)
#define dead_symlink ((int (*) __P(( \
		struct nameidata *ndp, \
		struct vattr *vap, \
		char *target, \
		struct proc *p))) dead_badop)
#define dead_readdir ((int (*) __P(( \
		struct vnode *vp, \
		struct uio *uio, \
		struct ucred *cred, \
		int *eofflagp))) dead_ebadf)
#define dead_readlink ((int (*) __P(( \
		struct vnode *vp, \
		struct uio *uio, \
		struct ucred *cred))) dead_ebadf)
#define dead_abortop ((int (*) __P(( \
		struct nameidata *ndp))) dead_badop)
#define dead_inactive ((int (*) __P(( \
		struct vnode *vp, \
		struct proc *p))) nullop)
#define dead_reclaim ((int (*) __P(( \
		struct vnode *vp))) nullop)
int	dead_lock __P((
		struct vnode *vp));
#define dead_unlock ((int (*) __P(( \
		struct vnode *vp))) nullop)
int	dead_bmap __P((
		struct vnode *vp,
		daddr_t bn,
		struct vnode **vpp,
		daddr_t *bnp));
int	dead_strategy __P((
		struct buf *bp));
int	dead_print __P((
		struct vnode *vp));
#define dead_islocked ((int (*) __P(( \
		struct vnode *vp))) nullop)
#define dead_advlock ((int (*) __P(( \
		struct vnode *vp, \
		caddr_t id, \
		int op, \
		struct flock *fl, \
		int flags))) dead_ebadf)

struct vnodeops dead_vnodeops = {
	dead_lookup,	/* lookup */
	dead_create,	/* create */
	dead_mknod,	/* mknod */
	dead_open,	/* open */
	dead_close,	/* close */
	dead_access,	/* access */
	dead_getattr,	/* getattr */
	dead_setattr,	/* setattr */
	dead_read,	/* read */
	dead_write,	/* write */
	dead_ioctl,	/* ioctl */
	dead_select,	/* select */
	dead_mmap,	/* mmap */
	dead_fsync,	/* fsync */
	dead_seek,	/* seek */
	dead_remove,	/* remove */
	dead_link,	/* link */
	dead_rename,	/* rename */
	dead_mkdir,	/* mkdir */
	dead_rmdir,	/* rmdir */
	dead_symlink,	/* symlink */
	dead_readdir,	/* readdir */
	dead_readlink,	/* readlink */
	dead_abortop,	/* abortop */
	dead_inactive,	/* inactive */
	dead_reclaim,	/* reclaim */
	dead_lock,	/* lock */
	dead_unlock,	/* unlock */
	dead_bmap,	/* bmap */
	dead_strategy,	/* strategy */
	dead_print,	/* print */
	dead_islocked,	/* islocked */
	dead_advlock,	/* advlock */
};

/*
 * Trivial lookup routine that always fails.
 */
/* ARGSUSED */
dead_lookup(vp, ndp, p)
	struct vnode *vp;
	struct nameidata *ndp;
	struct proc *p;
{

	ndp->ni_dvp = vp;
	ndp->ni_vp = NULL;
	return (ENOTDIR);
}

/*
 * Open always fails as if device did not exist.
 */
/* ARGSUSED */
dead_open(vp, mode, cred, p)
	struct vnode *vp;
	int mode;
	struct ucred *cred;
	struct proc *p;
{

	return (ENXIO);
}

/*
 * Vnode op for read
 */
/* ARGSUSED */
dead_read(vp, uio, ioflag, cred)
	struct vnode *vp;
	struct uio *uio;
	int ioflag;
	struct ucred *cred;
{

	if (chkvnlock(vp))
		panic("dead_read: lock");
	/*
	 * Return EOF for character devices, EIO for others
	 */
	if (vp->v_type != VCHR)
		return (EIO);
	return (0);
}

/*
 * Vnode op for write
 */
/* ARGSUSED */
dead_write(vp, uio, ioflag, cred)
	register struct vnode *vp;
	struct uio *uio;
	int ioflag;
	struct ucred *cred;
{

	if (chkvnlock(vp))
		panic("dead_write: lock");
	return (EIO);
}

/*
 * Device ioctl operation.
 */
/* ARGSUSED */
dead_ioctl(vp, com, data, fflag, cred, p)
	struct vnode *vp;
	register int com;
	caddr_t data;
	int fflag;
	struct ucred *cred;
	struct proc *p;
{

	if (!chkvnlock(vp))
		return (EBADF);
	return (VOP_IOCTL(vp, com, data, fflag, cred, p));
}

/* ARGSUSED */
dead_select(vp, which, fflags, cred, p)
	struct vnode *vp;
	int which, fflags;
	struct ucred *cred;
	struct proc *p;
{

	/*
	 * Let the user find out that the descriptor is gone.
	 */
	return (1);
}

/*
 * Just call the device strategy routine
 */
dead_strategy(bp)
	register struct buf *bp;
{

	if (bp->b_vp == NULL || !chkvnlock(bp->b_vp)) {
		bp->b_flags |= B_ERROR;
		biodone(bp);
		return (EIO);
	}
	return (VOP_STRATEGY(bp));
}

/*
 * Wait until the vnode has finished changing state.
 */
dead_lock(vp)
	struct vnode *vp;
{

	if (!chkvnlock(vp))
		return (0);
	return (VOP_LOCK(vp));
}

/*
 * Wait until the vnode has finished changing state.
 */
dead_bmap(vp, bn, vpp, bnp)
	struct vnode *vp;
	daddr_t bn;
	struct vnode **vpp;
	daddr_t *bnp;
{

	if (!chkvnlock(vp))
		return (EIO);
	return (VOP_BMAP(vp, bn, vpp, bnp));
}

/*
 * Print out the contents of a dead vnode.
 */
/* ARGSUSED */
dead_print(vp)
	struct vnode *vp;
{

	printf("tag VT_NON, dead vnode\n");
}

/*
 * Empty vnode failed operation
 */
dead_ebadf()
{

	return (EBADF);
}

/*
 * Empty vnode bad operation
 */
dead_badop()
{

	panic("dead_badop called");
	/* NOTREACHED */
}

/*
 * Empty vnode null operation
 */
dead_nullop()
{

	return (0);
}

/*
 * We have to wait during times when the vnode is
 * in a state of change.
 */
chkvnlock(vp)
	register struct vnode *vp;
{
	int locked = 0;

	while (vp->v_flag & VXLOCK) {
		vp->v_flag |= VXWANT;
		sleep((caddr_t)vp, PINOD);
		locked = 1;
	}
	return (locked);
}
Commit	Line	Data
b688fc87 WJ	1	/*
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* 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 7.13 (Berkeley) 4/15/91
	34	*/
	35
	36	#include "param.h"
	37	#include "systm.h"
	38	#include "time.h"
	39	#include "vnode.h"
	40	#include "errno.h"
	41	#include "namei.h"
	42	#include "buf.h"
	43
	44	/*
	45	* Prototypes for dead operations on vnodes.
	46	*/
	47	int dead_badop(),
	48	dead_ebadf();
	49	int dead_lookup __P((
	50	struct vnode *vp,
	51	struct nameidata *ndp,
	52	struct proc *p));
	53	#define dead_create ((int (*) __P(( \
	54	struct nameidata *ndp, \
	55	struct vattr *vap, \
	56	struct proc *p))) dead_badop)
	57	#define dead_mknod ((int (*) __P(( \
	58	struct nameidata *ndp, \
	59	struct vattr *vap, \
	60	struct ucred *cred, \
	61	struct proc *p))) dead_badop)
	62	int dead_open __P((
	63	struct vnode *vp,
	64	int mode,
65	struct ucred *cred,
66	struct proc *p));
67	#define dead_close ((int (*) __P(( \
68	struct vnode *vp, \
69	int fflag, \
70	struct ucred *cred, \
71	struct proc *p))) nullop)
72	#define dead_access ((int (*) __P(( \
73	struct vnode *vp, \
74	int mode, \
75	struct ucred *cred, \
76	struct proc *p))) dead_ebadf)
77	#define dead_getattr ((int (*) __P(( \
78	struct vnode *vp, \
79	struct vattr *vap, \
80	struct ucred *cred, \
81	struct proc *p))) dead_ebadf)
82	#define dead_setattr ((int (*) __P(( \
83	struct vnode *vp, \
84	struct vattr *vap, \
85	struct ucred *cred, \
86	struct proc *p))) dead_ebadf)
87	int dead_read __P((
88	struct vnode *vp,
89	struct uio *uio,
90	int ioflag,
91	struct ucred *cred));
92	int dead_write __P((
93	struct vnode *vp,
94	struct uio *uio,
95	int ioflag,
96	struct ucred *cred));
97	int dead_ioctl __P((
98	struct vnode *vp,
99	int command,
100	caddr_t data,
101	int fflag,
102	struct ucred *cred,
103	struct proc *p));
104	int dead_select __P((
105	struct vnode *vp,
106	int which,
107	int fflags,
108	struct ucred *cred,
109	struct proc *p));
110	#define dead_mmap ((int (*) __P(( \
111	struct vnode *vp, \
112	int fflags, \
113	struct ucred *cred, \
114	struct proc *p))) dead_badop)
115	#define dead_fsync ((int (*) __P(( \
116	struct vnode *vp, \
117	int fflags, \
118	struct ucred *cred, \
119	int waitfor, \
120	struct proc *p))) nullop)
121	#define dead_seek ((int (*) __P(( \
122	struct vnode *vp, \
123	off_t oldoff, \
124	off_t newoff, \
125	struct ucred *cred))) nullop)
126	#define dead_remove ((int (*) __P(( \
127	struct nameidata *ndp, \
128	struct proc *p))) dead_badop)
129	#define dead_link ((int (*) __P(( \
130	struct vnode *vp, \
131	struct nameidata *ndp, \
132	struct proc *p))) dead_badop)
133	#define dead_rename ((int (*) __P(( \
134	struct nameidata *fndp, \
135	struct nameidata *tdnp, \
136	struct proc *p))) dead_badop)
137	#define dead_mkdir ((int (*) __P(( \
138	struct nameidata *ndp, \
139	struct vattr *vap, \
140	struct proc *p))) dead_badop)
141	#define dead_rmdir ((int (*) __P(( \
142	struct nameidata *ndp, \
143	struct proc *p))) dead_badop)
144	#define dead_symlink ((int (*) __P(( \
145	struct nameidata *ndp, \
146	struct vattr *vap, \
147	char *target, \
148	struct proc *p))) dead_badop)
149	#define dead_readdir ((int (*) __P(( \
150	struct vnode *vp, \
151	struct uio *uio, \
152	struct ucred *cred, \
153	int *eofflagp))) dead_ebadf)
154	#define dead_readlink ((int (*) __P(( \
155	struct vnode *vp, \
156	struct uio *uio, \
157	struct ucred *cred))) dead_ebadf)
158	#define dead_abortop ((int (*) __P(( \
159	struct nameidata *ndp))) dead_badop)
160	#define dead_inactive ((int (*) __P(( \
161	struct vnode *vp, \
162	struct proc *p))) nullop)
163	#define dead_reclaim ((int (*) __P(( \
164	struct vnode *vp))) nullop)
165	int dead_lock __P((
166	struct vnode *vp));
167	#define dead_unlock ((int (*) __P(( \
168	struct vnode *vp))) nullop)
169	int dead_bmap __P((
170	struct vnode *vp,
171	daddr_t bn,
172	struct vnode **vpp,
173	daddr_t *bnp));
174	int dead_strategy __P((
175	struct buf *bp));
176	int dead_print __P((
177	struct vnode *vp));
178	#define dead_islocked ((int (*) __P(( \
179	struct vnode *vp))) nullop)
180	#define dead_advlock ((int (*) __P(( \
181	struct vnode *vp, \
182	caddr_t id, \
183	int op, \
184	struct flock *fl, \
185	int flags))) dead_ebadf)
186
187	struct vnodeops dead_vnodeops = {
188	dead_lookup, /* lookup */
189	dead_create, /* create */
190	dead_mknod, /* mknod */
191	dead_open, /* open */
192	dead_close, /* close */
193	dead_access, /* access */
194	dead_getattr, /* getattr */
195	dead_setattr, /* setattr */
196	dead_read, /* read */
197	dead_write, /* write */
198	dead_ioctl, /* ioctl */
199	dead_select, /* select */
200	dead_mmap, /* mmap */
201	dead_fsync, /* fsync */
202	dead_seek, /* seek */
203	dead_remove, /* remove */
204	dead_link, /* link */
205	dead_rename, /* rename */
206	dead_mkdir, /* mkdir */
207	dead_rmdir, /* rmdir */
208	dead_symlink, /* symlink */
209	dead_readdir, /* readdir */
210	dead_readlink, /* readlink */
211	dead_abortop, /* abortop */
212	dead_inactive, /* inactive */
213	dead_reclaim, /* reclaim */
214	dead_lock, /* lock */
215	dead_unlock, /* unlock */
216	dead_bmap, /* bmap */
217	dead_strategy, /* strategy */
218	dead_print, /* print */
219	dead_islocked, /* islocked */
220	dead_advlock, /* advlock */
221	};
222
223	/*
224	* Trivial lookup routine that always fails.
225	*/
226	/* ARGSUSED */
227	dead_lookup(vp, ndp, p)
228	struct vnode *vp;
229	struct nameidata *ndp;
230	struct proc *p;
231	{
232
233	ndp->ni_dvp = vp;
234	ndp->ni_vp = NULL;
235	return (ENOTDIR);
236	}
237
238	/*
239	* Open always fails as if device did not exist.
240	*/
241	/* ARGSUSED */
242	dead_open(vp, mode, cred, p)
243	struct vnode *vp;
244	int mode;
245	struct ucred *cred;
246	struct proc *p;
247	{
248
249	return (ENXIO);
250	}
251
252	/*
253	* Vnode op for read
254	*/
255	/* ARGSUSED */
256	dead_read(vp, uio, ioflag, cred)
257	struct vnode *vp;
258	struct uio *uio;
259	int ioflag;
260	struct ucred *cred;
261	{
262
263	if (chkvnlock(vp))
264	panic("dead_read: lock");
265	/*
266	* Return EOF for character devices, EIO for others
267	*/
268	if (vp->v_type != VCHR)
269	return (EIO);
270	return (0);
271	}
272
273	/*
274	* Vnode op for write
275	*/
276	/* ARGSUSED */
277	dead_write(vp, uio, ioflag, cred)
278	register struct vnode *vp;
279	struct uio *uio;
280	int ioflag;
281	struct ucred *cred;
282	{
283
284	if (chkvnlock(vp))
285	panic("dead_write: lock");
286	return (EIO);
287	}
288
289	/*
290	* Device ioctl operation.
291	*/
292	/* ARGSUSED */
293	dead_ioctl(vp, com, data, fflag, cred, p)
294	struct vnode *vp;
295	register int com;
296	caddr_t data;
297	int fflag;
298	struct ucred *cred;
299	struct proc *p;
300	{
301
302	if (!chkvnlock(vp))
303	return (EBADF);
304	return (VOP_IOCTL(vp, com, data, fflag, cred, p));
305	}
306
307	/* ARGSUSED */
308	dead_select(vp, which, fflags, cred, p)
309	struct vnode *vp;
310	int which, fflags;
311	struct ucred *cred;
312	struct proc *p;
313	{
314
315	/*
316	* Let the user find out that the descriptor is gone.
317	*/
318	return (1);
319	}
320
321	/*
322	* Just call the device strategy routine
323	*/
324	dead_strategy(bp)
325	register struct buf *bp;
326	{
327
328	if (bp->b_vp == NULL \|\| !chkvnlock(bp->b_vp)) {
329	bp->b_flags \|= B_ERROR;
330	biodone(bp);
331	return (EIO);
332	}
333	return (VOP_STRATEGY(bp));
334	}
335
336	/*
337	* Wait until the vnode has finished changing state.
338	*/
339	dead_lock(vp)
340	struct vnode *vp;
341	{
342
343	if (!chkvnlock(vp))
344	return (0);
345	return (VOP_LOCK(vp));
346	}
347
348	/*
349	* Wait until the vnode has finished changing state.
350	*/
351	dead_bmap(vp, bn, vpp, bnp)
352	struct vnode *vp;
353	daddr_t bn;
354	struct vnode **vpp;
355	daddr_t *bnp;
356	{
357
358	if (!chkvnlock(vp))
359	return (EIO);
360	return (VOP_BMAP(vp, bn, vpp, bnp));
361	}
362
363	/*
364	* Print out the contents of a dead vnode.
365	*/
366	/* ARGSUSED */
367	dead_print(vp)
368	struct vnode *vp;
369	{
370
371	printf("tag VT_NON, dead vnode\n");
372	}
373
374	/*
375	* Empty vnode failed operation
376	*/
377	dead_ebadf()
378	{
379
380	return (EBADF);
381	}
382
383	/*
384	* Empty vnode bad operation
385	*/
386	dead_badop()
387	{
388
389	panic("dead_badop called");
390	/* NOTREACHED */
391	}
392
393	/*
394	* Empty vnode null operation
395	*/
396	dead_nullop()
397	{
398
399	return (0);
400	}
401
402	/*
403	* We have to wait during times when the vnode is
404	* in a state of change.
405	*/
406	chkvnlock(vp)
407	register struct vnode *vp;
408	{
409	int locked = 0;
410
411	while (vp->v_flag & VXLOCK) {
412	vp->v_flag \|= VXWANT;
413	sleep((caddr_t)vp, PINOD);
414	locked = 1;
415	}
416	return (locked);
417	}