xref: /netbsd-src/sys/dev/vnd.c (revision 08c81a9c2dc8c7300e893321eb65c0925d60871c)
1 /*	$NetBSD: vnd.c,v 1.86 2002/09/06 13:18:43 gehenna Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the NetBSD
21  *	Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 /*
40  * Copyright (c) 1988 University of Utah.
41  * Copyright (c) 1990, 1993
42  *	The Regents of the University of California.  All rights reserved.
43  *
44  * This code is derived from software contributed to Berkeley by
45  * the Systems Programming Group of the University of Utah Computer
46  * Science Department.
47  *
48  * Redistribution and use in source and binary forms, with or without
49  * modification, are permitted provided that the following conditions
50  * are met:
51  * 1. Redistributions of source code must retain the above copyright
52  *    notice, this list of conditions and the following disclaimer.
53  * 2. Redistributions in binary form must reproduce the above copyright
54  *    notice, this list of conditions and the following disclaimer in the
55  *    documentation and/or other materials provided with the distribution.
56  * 3. All advertising materials mentioning features or use of this software
57  *    must display the following acknowledgement:
58  *	This product includes software developed by the University of
59  *	California, Berkeley and its contributors.
60  * 4. Neither the name of the University nor the names of its contributors
61  *    may be used to endorse or promote products derived from this software
62  *    without specific prior written permission.
63  *
64  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
65  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
66  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
67  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
68  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
69  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
70  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
71  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
72  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
73  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
74  * SUCH DAMAGE.
75  *
76  * from: Utah $Hdr: vn.c 1.13 94/04/02$
77  *
78  *	@(#)vn.c	8.9 (Berkeley) 5/14/95
79  */
80 
81 /*
82  * Vnode disk driver.
83  *
84  * Block/character interface to a vnode.  Allows one to treat a file
85  * as a disk (e.g. build a filesystem in it, mount it, etc.).
86  *
87  * NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode
88  * instead of a simple VOP_RDWR.  We do this to avoid distorting the
89  * local buffer cache.
90  *
91  * NOTE 2: There is a security issue involved with this driver.
92  * Once mounted all access to the contents of the "mapped" file via
93  * the special file is controlled by the permissions on the special
94  * file, the protection of the mapped file is ignored (effectively,
95  * by using root credentials in all transactions).
96  *
97  * NOTE 3: Doesn't interact with leases, should it?
98  */
99 
100 #include <sys/cdefs.h>
101 __KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.86 2002/09/06 13:18:43 gehenna Exp $");
102 
103 #if defined(_KERNEL_OPT)
104 #include "fs_nfs.h"
105 #endif
106 
107 #include <sys/param.h>
108 #include <sys/systm.h>
109 #include <sys/namei.h>
110 #include <sys/proc.h>
111 #include <sys/errno.h>
112 #include <sys/buf.h>
113 #include <sys/malloc.h>
114 #include <sys/ioctl.h>
115 #include <sys/disklabel.h>
116 #include <sys/device.h>
117 #include <sys/disk.h>
118 #include <sys/stat.h>
119 #include <sys/mount.h>
120 #include <sys/vnode.h>
121 #include <sys/file.h>
122 #include <sys/uio.h>
123 #include <sys/conf.h>
124 
125 #include <miscfs/specfs/specdev.h>
126 
127 #include <dev/vndvar.h>
128 
129 #if defined(VNDDEBUG) && !defined(DEBUG)
130 #define	DEBUG
131 #endif
132 
133 #ifdef DEBUG
134 int dovndcluster = 1;
135 #define	VDB_FOLLOW	0x01
136 #define	VDB_INIT	0x02
137 #define	VDB_IO		0x04
138 #define	VDB_LABEL	0x08
139 int vnddebug = 0x00;
140 #endif
141 
142 #define	vndunit(x)	DISKUNIT(x)
143 
144 struct vndxfer {
145 	struct buf	*vx_bp;		/* Pointer to parent buffer */
146 	int		vx_error;
147 	int		vx_pending;	/* # of pending aux buffers */
148 	int		vx_flags;
149 #define VX_BUSY		1
150 };
151 
152 struct vndbuf {
153 	struct buf	vb_buf;
154 	struct vndxfer	*vb_xfer;
155 };
156 
157 #define	VND_GETXFER(vnd)	pool_get(&(vnd)->sc_vxpool, PR_NOWAIT)
158 #define	VND_PUTXFER(vnd, vx)	pool_put(&(vnd)->sc_vxpool, (vx))
159 
160 #define	VND_GETBUF(vnd)		pool_get(&(vnd)->sc_vbpool, PR_NOWAIT)
161 #define	VND_PUTBUF(vnd, vb)	pool_put(&(vnd)->sc_vbpool, (vb))
162 
163 struct vnd_softc *vnd_softc;
164 int numvnd = 0;
165 
166 #define	VNDLABELDEV(dev) \
167 	(MAKEDISKDEV(major((dev)), vndunit((dev)), RAW_PART))
168 
169 /* called by main() at boot time */
170 void	vndattach __P((int));
171 void	vnddetach __P((void));
172 
173 void	vndclear __P((struct vnd_softc *));
174 void	vndstart __P((struct vnd_softc *));
175 int	vndsetcred __P((struct vnd_softc *, struct ucred *));
176 void	vndthrottle __P((struct vnd_softc *, struct vnode *));
177 void	vndiodone __P((struct buf *));
178 void	vndshutdown __P((void));
179 
180 void	vndgetdefaultlabel __P((struct vnd_softc *, struct disklabel *));
181 void	vndgetdisklabel __P((dev_t));
182 
183 static	int vndlock __P((struct vnd_softc *));
184 static	void vndunlock __P((struct vnd_softc *));
185 
186 dev_type_open(vndopen);
187 dev_type_close(vndclose);
188 dev_type_read(vndread);
189 dev_type_write(vndwrite);
190 dev_type_ioctl(vndioctl);
191 dev_type_strategy(vndstrategy);
192 dev_type_dump(vnddump);
193 dev_type_size(vndsize);
194 
195 const struct bdevsw vnd_bdevsw = {
196 	vndopen, vndclose, vndstrategy, vndioctl, vnddump, vndsize, D_DISK
197 };
198 
199 const struct cdevsw vnd_cdevsw = {
200 	vndopen, vndclose, vndread, vndwrite, vndioctl,
201 	nostop, notty, nopoll, nommap, D_DISK
202 };
203 
204 void
205 vndattach(num)
206 	int num;
207 {
208 	int i;
209 	char *mem;
210 
211 	if (num <= 0)
212 		return;
213 	i = num * sizeof(struct vnd_softc);
214 	mem = malloc(i, M_DEVBUF, M_NOWAIT|M_ZERO);
215 	if (mem == NULL) {
216 		printf("WARNING: no memory for vnode disks\n");
217 		return;
218 	}
219 	vnd_softc = (struct vnd_softc *)mem;
220 	numvnd = num;
221 
222 	for (i = 0; i < numvnd; i++)
223 		bufq_alloc(&vnd_softc[i].sc_tab,
224 		    BUFQ_DISKSORT|BUFQ_SORT_RAWBLOCK);
225 }
226 
227 void
228 vnddetach()
229 {
230 	int i;
231 
232 	for (i = 0; i < numvnd; i++)
233 		bufq_free(&vnd_softc[i].sc_tab);
234 
235 	free(vnd_softc, M_DEVBUF);
236 }
237 
238 int
239 vndopen(dev, flags, mode, p)
240 	dev_t dev;
241 	int flags, mode;
242 	struct proc *p;
243 {
244 	int unit = vndunit(dev);
245 	struct vnd_softc *sc;
246 	int error = 0, part, pmask;
247 	struct disklabel *lp;
248 
249 #ifdef DEBUG
250 	if (vnddebug & VDB_FOLLOW)
251 		printf("vndopen(0x%x, 0x%x, 0x%x, %p)\n", dev, flags, mode, p);
252 #endif
253 	if (unit >= numvnd)
254 		return (ENXIO);
255 	sc = &vnd_softc[unit];
256 
257 	if ((error = vndlock(sc)) != 0)
258 		return (error);
259 
260 	lp = sc->sc_dkdev.dk_label;
261 
262 	part = DISKPART(dev);
263 	pmask = (1 << part);
264 
265 	/*
266 	 * If we're initialized, check to see if there are any other
267 	 * open partitions.  If not, then it's safe to update the
268 	 * in-core disklabel.
269 	 */
270 	if ((sc->sc_flags & VNF_INITED) && (sc->sc_dkdev.dk_openmask == 0))
271 		vndgetdisklabel(dev);
272 
273 	/* Check that the partitions exists. */
274 	if (part != RAW_PART) {
275 		if (((sc->sc_flags & VNF_INITED) == 0) ||
276 		    ((part >= lp->d_npartitions) ||
277 		     (lp->d_partitions[part].p_fstype == FS_UNUSED))) {
278 			error = ENXIO;
279 			goto done;
280 		}
281 	}
282 
283 	/* Prevent our unit from being unconfigured while open. */
284 	switch (mode) {
285 	case S_IFCHR:
286 		sc->sc_dkdev.dk_copenmask |= pmask;
287 		break;
288 
289 	case S_IFBLK:
290 		sc->sc_dkdev.dk_bopenmask |= pmask;
291 		break;
292 	}
293 	sc->sc_dkdev.dk_openmask =
294 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
295 
296  done:
297 	vndunlock(sc);
298 	return (error);
299 }
300 
301 int
302 vndclose(dev, flags, mode, p)
303 	dev_t dev;
304 	int flags, mode;
305 	struct proc *p;
306 {
307 	int unit = vndunit(dev);
308 	struct vnd_softc *sc;
309 	int error = 0, part;
310 
311 #ifdef DEBUG
312 	if (vnddebug & VDB_FOLLOW)
313 		printf("vndclose(0x%x, 0x%x, 0x%x, %p)\n", dev, flags, mode, p);
314 #endif
315 
316 	if (unit >= numvnd)
317 		return (ENXIO);
318 	sc = &vnd_softc[unit];
319 
320 	if ((error = vndlock(sc)) != 0)
321 		return (error);
322 
323 	part = DISKPART(dev);
324 
325 	/* ...that much closer to allowing unconfiguration... */
326 	switch (mode) {
327 	case S_IFCHR:
328 		sc->sc_dkdev.dk_copenmask &= ~(1 << part);
329 		break;
330 
331 	case S_IFBLK:
332 		sc->sc_dkdev.dk_bopenmask &= ~(1 << part);
333 		break;
334 	}
335 	sc->sc_dkdev.dk_openmask =
336 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
337 
338 	vndunlock(sc);
339 	return (0);
340 }
341 
342 /*
343  * Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY.
344  */
345 void
346 vndstrategy(bp)
347 	struct buf *bp;
348 {
349 	int unit = vndunit(bp->b_dev);
350 	struct vnd_softc *vnd = &vnd_softc[unit];
351 	struct vndxfer *vnx;
352 	int s, bsize, resid;
353 	off_t bn;
354 	caddr_t addr;
355 	int sz, flags, error, wlabel;
356 	struct disklabel *lp;
357 	struct partition *pp;
358 
359 #ifdef DEBUG
360 	if (vnddebug & VDB_FOLLOW)
361 		printf("vndstrategy(%p): unit %d\n", bp, unit);
362 #endif
363 	if ((vnd->sc_flags & VNF_INITED) == 0) {
364 		bp->b_error = ENXIO;
365 		bp->b_flags |= B_ERROR;
366 		goto done;
367 	}
368 
369 	/* If it's a nil transfer, wake up the top half now. */
370 	if (bp->b_bcount == 0)
371 		goto done;
372 
373 	lp = vnd->sc_dkdev.dk_label;
374 
375 	/*
376 	 * The transfer must be a whole number of blocks.
377 	 */
378 	if ((bp->b_bcount % lp->d_secsize) != 0) {
379 		bp->b_error = EINVAL;
380 		bp->b_flags |= B_ERROR;
381 		goto done;
382 	}
383 
384 	/*
385 	 * Do bounds checking and adjust transfer.  If there's an error,
386 	 * the bounds check will flag that for us.
387 	 */
388 	wlabel = vnd->sc_flags & (VNF_WLABEL|VNF_LABELLING);
389 	if (DISKPART(bp->b_dev) != RAW_PART)
390 		if (bounds_check_with_label(bp, lp, wlabel) <= 0)
391 			goto done;
392 
393 	bp->b_resid = bp->b_bcount;
394 
395 	/*
396 	 * Put the block number in terms of the logical blocksize
397 	 * of the "device".
398 	 */
399 	bn = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
400 
401 	/*
402 	 * Translate the partition-relative block number to an absolute.
403 	 */
404 	if (DISKPART(bp->b_dev) != RAW_PART) {
405 		pp = &vnd->sc_dkdev.dk_label->d_partitions[DISKPART(bp->b_dev)];
406 		bn += pp->p_offset;
407 	}
408 
409 	/* ...and convert to a byte offset within the file. */
410 	bn *= lp->d_secsize;
411 
412 	if (vnd->sc_vp->v_mount == NULL) {
413 		bp->b_error = ENXIO;
414 		bp->b_flags |= B_ERROR;
415 		goto done;
416 	}
417  	bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize;
418 	addr = bp->b_data;
419 	flags = (bp->b_flags & (B_READ|B_ASYNC)) | B_CALL;
420 
421 	/* Allocate a header for this transfer and link it to the buffer */
422 	s = splbio();
423 	vnx = VND_GETXFER(vnd);
424 	splx(s);
425 	vnx->vx_flags = VX_BUSY;
426 	vnx->vx_error = 0;
427 	vnx->vx_pending = 0;
428 	vnx->vx_bp = bp;
429 
430 	for (resid = bp->b_resid; resid; resid -= sz) {
431 		struct vndbuf *nbp;
432 		struct vnode *vp;
433 		daddr_t nbn;
434 		int off, nra;
435 
436 		nra = 0;
437 		vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY | LK_CANRECURSE);
438 		error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra);
439 		VOP_UNLOCK(vnd->sc_vp, 0);
440 
441 		if (error == 0 && (long)nbn == -1)
442 			error = EIO;
443 
444 		/*
445 		 * If there was an error or a hole in the file...punt.
446 		 * Note that we may have to wait for any operations
447 		 * that we have already fired off before releasing
448 		 * the buffer.
449 		 *
450 		 * XXX we could deal with holes here but it would be
451 		 * a hassle (in the write case).
452 		 */
453 		if (error) {
454 			s = splbio();
455 			vnx->vx_error = error;
456 			goto out;
457 		}
458 
459 #ifdef DEBUG
460 		if (!dovndcluster)
461 			nra = 0;
462 #endif
463 
464 		if ((off = bn % bsize) != 0)
465 			sz = bsize - off;
466 		else
467 			sz = (1 + nra) * bsize;
468 		if (resid < sz)
469 			sz = resid;
470 #ifdef DEBUG
471 		if (vnddebug & VDB_IO)
472 			printf("vndstrategy: vp %p/%p bn 0x%qx/0x%x sz 0x%x\n",
473 			    vnd->sc_vp, vp, (long long)bn, nbn, sz);
474 #endif
475 
476 		s = splbio();
477 		nbp = VND_GETBUF(vnd);
478 		splx(s);
479 		nbp->vb_buf.b_flags = flags;
480 		nbp->vb_buf.b_bcount = sz;
481 		nbp->vb_buf.b_bufsize = round_page((ulong)addr + sz)
482 		    - trunc_page((ulong) addr);
483 		nbp->vb_buf.b_error = 0;
484 		nbp->vb_buf.b_data = addr;
485 		nbp->vb_buf.b_blkno = nbp->vb_buf.b_rawblkno = nbn + btodb(off);
486 		nbp->vb_buf.b_proc = bp->b_proc;
487 		nbp->vb_buf.b_iodone = vndiodone;
488 		nbp->vb_buf.b_vp = NULLVP;
489 		LIST_INIT(&nbp->vb_buf.b_dep);
490 
491 		nbp->vb_xfer = vnx;
492 
493 		/*
494 		 * Just sort by block number
495 		 */
496 		s = splbio();
497 		if (vnx->vx_error != 0) {
498 			VND_PUTBUF(vnd, nbp);
499 			goto out;
500 		}
501 		vnx->vx_pending++;
502 		bgetvp(vp, &nbp->vb_buf);
503 		BUFQ_PUT(&vnd->sc_tab, &nbp->vb_buf);
504 		vndstart(vnd);
505 		splx(s);
506 		bn += sz;
507 		addr += sz;
508 	}
509 
510 	s = splbio();
511 
512 out: /* Arrive here at splbio */
513 	vnx->vx_flags &= ~VX_BUSY;
514 	if (vnx->vx_pending == 0) {
515 		if (vnx->vx_error != 0) {
516 			bp->b_error = vnx->vx_error;
517 			bp->b_flags |= B_ERROR;
518 		}
519 		VND_PUTXFER(vnd, vnx);
520 		biodone(bp);
521 	}
522 	splx(s);
523 	return;
524 
525  done:
526 	biodone(bp);
527 }
528 
529 /*
530  * Feed requests sequentially.
531  * We do it this way to keep from flooding NFS servers if we are connected
532  * to an NFS file.  This places the burden on the client rather than the
533  * server.
534  */
535 void
536 vndstart(vnd)
537 	struct vnd_softc *vnd;
538 {
539 	struct buf	*bp;
540 
541 	/*
542 	 * Dequeue now since lower level strategy routine might
543 	 * queue using same links
544 	 */
545 
546 	if ((vnd->sc_flags & VNF_BUSY) != 0)
547 		return;
548 
549 	vnd->sc_flags |= VNF_BUSY;
550 
551 	while (vnd->sc_active < vnd->sc_maxactive) {
552 		bp = BUFQ_GET(&vnd->sc_tab);
553 		if (bp == NULL)
554 			break;
555 		vnd->sc_active++;
556 #ifdef DEBUG
557 		if (vnddebug & VDB_IO)
558 			printf("vndstart(%ld): bp %p vp %p blkno 0x%x"
559 				" flags %lx addr %p cnt 0x%lx\n",
560 			    (long) (vnd-vnd_softc), bp, bp->b_vp, bp->b_blkno,
561 			    bp->b_flags, bp->b_data, bp->b_bcount);
562 #endif
563 
564 		/* Instrumentation. */
565 		disk_busy(&vnd->sc_dkdev);
566 
567 		if ((bp->b_flags & B_READ) == 0)
568 			bp->b_vp->v_numoutput++;
569 		VOP_STRATEGY(bp);
570 	}
571 	vnd->sc_flags &= ~VNF_BUSY;
572 }
573 
574 void
575 vndiodone(bp)
576 	struct buf *bp;
577 {
578 	struct vndbuf *vbp = (struct vndbuf *) bp;
579 	struct vndxfer *vnx = (struct vndxfer *)vbp->vb_xfer;
580 	struct buf *pbp = vnx->vx_bp;
581 	struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)];
582 	int s, resid;
583 
584 	s = splbio();
585 #ifdef DEBUG
586 	if (vnddebug & VDB_IO)
587 		printf("vndiodone(%ld): vbp %p vp %p blkno 0x%x addr %p cnt 0x%lx\n",
588 		    (long) (vnd-vnd_softc), vbp, vbp->vb_buf.b_vp,
589 		    vbp->vb_buf.b_blkno, vbp->vb_buf.b_data,
590 		    vbp->vb_buf.b_bcount);
591 #endif
592 
593 	resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid;
594 	pbp->b_resid -= resid;
595 	disk_unbusy(&vnd->sc_dkdev, resid);
596 	vnx->vx_pending--;
597 
598 	if (vbp->vb_buf.b_error) {
599 #ifdef DEBUG
600 		if (vnddebug & VDB_IO)
601 			printf("vndiodone: vbp %p error %d\n", vbp,
602 			    vbp->vb_buf.b_error);
603 #endif
604 		vnx->vx_error = vbp->vb_buf.b_error;
605 	}
606 
607 	if (vbp->vb_buf.b_vp != NULLVP)
608 		brelvp(&vbp->vb_buf);
609 
610 	VND_PUTBUF(vnd, vbp);
611 
612 	/*
613 	 * Wrap up this transaction if it has run to completion or, in
614 	 * case of an error, when all auxiliary buffers have returned.
615 	 */
616 	if (vnx->vx_error != 0) {
617 		pbp->b_flags |= B_ERROR;
618 		pbp->b_error = vnx->vx_error;
619 		if ((vnx->vx_flags & VX_BUSY) == 0 && vnx->vx_pending == 0) {
620 
621 #ifdef DEBUG
622 			if (vnddebug & VDB_IO)
623 				printf("vndiodone: pbp %p iodone: error %d\n",
624 					pbp, vnx->vx_error);
625 #endif
626 			VND_PUTXFER(vnd, vnx);
627 			biodone(pbp);
628 		}
629 	} else if (pbp->b_resid == 0) {
630 
631 #ifdef DIAGNOSTIC
632 		if (vnx->vx_pending != 0)
633 			panic("vndiodone: vnx pending: %d", vnx->vx_pending);
634 #endif
635 
636 		if ((vnx->vx_flags & VX_BUSY) == 0) {
637 #ifdef DEBUG
638 			if (vnddebug & VDB_IO)
639 				printf("vndiodone: pbp %p iodone\n", pbp);
640 #endif
641 			VND_PUTXFER(vnd, vnx);
642 			biodone(pbp);
643 		}
644 	}
645 
646 	vnd->sc_active--;
647 	vndstart(vnd);
648 	splx(s);
649 }
650 
651 /* ARGSUSED */
652 int
653 vndread(dev, uio, flags)
654 	dev_t dev;
655 	struct uio *uio;
656 	int flags;
657 {
658 	int unit = vndunit(dev);
659 	struct vnd_softc *sc;
660 
661 #ifdef DEBUG
662 	if (vnddebug & VDB_FOLLOW)
663 		printf("vndread(0x%x, %p)\n", dev, uio);
664 #endif
665 
666 	if (unit >= numvnd)
667 		return (ENXIO);
668 	sc = &vnd_softc[unit];
669 
670 	if ((sc->sc_flags & VNF_INITED) == 0)
671 		return (ENXIO);
672 
673 	return (physio(vndstrategy, NULL, dev, B_READ, minphys, uio));
674 }
675 
676 /* ARGSUSED */
677 int
678 vndwrite(dev, uio, flags)
679 	dev_t dev;
680 	struct uio *uio;
681 	int flags;
682 {
683 	int unit = vndunit(dev);
684 	struct vnd_softc *sc;
685 
686 #ifdef DEBUG
687 	if (vnddebug & VDB_FOLLOW)
688 		printf("vndwrite(0x%x, %p)\n", dev, uio);
689 #endif
690 
691 	if (unit >= numvnd)
692 		return (ENXIO);
693 	sc = &vnd_softc[unit];
694 
695 	if ((sc->sc_flags & VNF_INITED) == 0)
696 		return (ENXIO);
697 
698 	return (physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio));
699 }
700 
701 /* ARGSUSED */
702 int
703 vndioctl(dev, cmd, data, flag, p)
704 	dev_t dev;
705 	u_long cmd;
706 	caddr_t data;
707 	int flag;
708 	struct proc *p;
709 {
710 	int unit = vndunit(dev);
711 	struct vnd_softc *vnd;
712 	struct vnd_ioctl *vio;
713 	struct vattr vattr;
714 	struct nameidata nd;
715 	int error, part, pmask;
716 	size_t geomsize;
717 #ifdef __HAVE_OLD_DISKLABEL
718 	struct disklabel newlabel;
719 #endif
720 
721 #ifdef DEBUG
722 	if (vnddebug & VDB_FOLLOW)
723 		printf("vndioctl(0x%x, 0x%lx, %p, 0x%x, %p): unit %d\n",
724 		    dev, cmd, data, flag, p, unit);
725 #endif
726 	error = suser(p->p_ucred, &p->p_acflag);
727 	if (error)
728 		return (error);
729 	if (unit >= numvnd)
730 		return (ENXIO);
731 
732 	vnd = &vnd_softc[unit];
733 	vio = (struct vnd_ioctl *)data;
734 
735 	/* Must be open for writes for these commands... */
736 	switch (cmd) {
737 	case VNDIOCSET:
738 	case VNDIOCCLR:
739 	case DIOCSDINFO:
740 	case DIOCWDINFO:
741 #ifdef __HAVE_OLD_DISKLABEL
742 	case ODIOCSDINFO:
743 	case ODIOCWDINFO:
744 #endif
745 	case DIOCWLABEL:
746 		if ((flag & FWRITE) == 0)
747 			return (EBADF);
748 	}
749 
750 	/* Must be initialized for these... */
751 	switch (cmd) {
752 	case VNDIOCCLR:
753 	case DIOCGDINFO:
754 	case DIOCSDINFO:
755 	case DIOCWDINFO:
756 	case DIOCGPART:
757 	case DIOCWLABEL:
758 	case DIOCGDEFLABEL:
759 #ifdef __HAVE_OLD_DISKLABEL
760 	case ODIOCGDINFO:
761 	case ODIOCSDINFO:
762 	case ODIOCWDINFO:
763 	case ODIOCGDEFLABEL:
764 #endif
765 		if ((vnd->sc_flags & VNF_INITED) == 0)
766 			return (ENXIO);
767 	}
768 
769 	switch (cmd) {
770 	case VNDIOCSET:
771 		if (vnd->sc_flags & VNF_INITED)
772 			return (EBUSY);
773 
774 		if ((error = vndlock(vnd)) != 0)
775 			return (error);
776 
777 		/*
778 		 * Always open for read and write.
779 		 * This is probably bogus, but it lets vn_open()
780 		 * weed out directories, sockets, etc. so we don't
781 		 * have to worry about them.
782 		 */
783 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vnd_file, p);
784 		if ((error = vn_open(&nd, FREAD|FWRITE, 0)) != 0)
785 			goto unlock_and_exit;
786 		error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p);
787 		VOP_UNLOCK(nd.ni_vp, 0);
788 		if (error)
789 			goto close_and_exit;
790 		vnd->sc_vp = nd.ni_vp;
791 		vnd->sc_size = btodb(vattr.va_size);	/* note truncation */
792 
793 		/*
794 		 * Use pseudo-geometry specified.  If none was provided,
795 		 * use "standard" Adaptec fictitious geometry.
796 		 */
797 		if (vio->vnd_flags & VNDIOF_HASGEOM) {
798 
799 			memcpy(&vnd->sc_geom, &vio->vnd_geom,
800 			    sizeof(vio->vnd_geom));
801 
802 			/*
803 			 * Sanity-check the sector size.
804 			 * XXX Don't allow secsize < DEV_BSIZE.  Should
805 			 * XXX we?
806 			 */
807 			if (vnd->sc_geom.vng_secsize < DEV_BSIZE ||
808 			    (vnd->sc_geom.vng_secsize % DEV_BSIZE) != 0) {
809 				error = EINVAL;
810 				goto close_and_exit;
811 			}
812 
813 			/*
814 			 * Compute the size (in DEV_BSIZE blocks) specified
815 			 * by the geometry.
816 			 */
817 			geomsize = (vnd->sc_geom.vng_nsectors *
818 			    vnd->sc_geom.vng_ntracks *
819 			    vnd->sc_geom.vng_ncylinders) *
820 			    (vnd->sc_geom.vng_secsize / DEV_BSIZE);
821 
822 			/*
823 			 * Sanity-check the size against the specified
824 			 * geometry.
825 			 */
826 			if (vnd->sc_size < geomsize) {
827 				error = EINVAL;
828 				goto close_and_exit;
829 			}
830 		} else {
831 			/*
832 			 * Size must be at least 2048 DEV_BSIZE blocks
833 			 * (1M) in order to use this geometry.
834 			 */
835 			if (vnd->sc_size < (32 * 64)) {
836 				error = EINVAL;
837 				goto close_and_exit;
838 			}
839 
840 			vnd->sc_geom.vng_secsize = DEV_BSIZE;
841 			vnd->sc_geom.vng_nsectors = 32;
842 			vnd->sc_geom.vng_ntracks = 64;
843 			vnd->sc_geom.vng_ncylinders = vnd->sc_size / (64 * 32);
844 		}
845 
846 		if ((error = vndsetcred(vnd, p->p_ucred)) != 0)
847 			goto close_and_exit;
848 		vndthrottle(vnd, vnd->sc_vp);
849 		vio->vnd_size = dbtob(vnd->sc_size);
850 		vnd->sc_flags |= VNF_INITED;
851 #ifdef DEBUG
852 		if (vnddebug & VDB_INIT)
853 			printf("vndioctl: SET vp %p size 0x%lx %d/%d/%d/%d\n",
854 			    vnd->sc_vp, (unsigned long) vnd->sc_size,
855 			    vnd->sc_geom.vng_secsize,
856 			    vnd->sc_geom.vng_nsectors,
857 			    vnd->sc_geom.vng_ntracks,
858 			    vnd->sc_geom.vng_ncylinders);
859 #endif
860 
861 		/* Attach the disk. */
862 		memset(vnd->sc_xname, 0, sizeof(vnd->sc_xname)); /* XXX */
863 		sprintf(vnd->sc_xname, "vnd%d", unit);		/* XXX */
864 		vnd->sc_dkdev.dk_name = vnd->sc_xname;
865 		disk_attach(&vnd->sc_dkdev);
866 
867 		/* Initialize the xfer and buffer pools. */
868 		pool_init(&vnd->sc_vxpool, sizeof(struct vndxfer), 0,
869 		    0, 0, "vndxpl", NULL);
870 		pool_init(&vnd->sc_vbpool, sizeof(struct vndbuf), 0,
871 		    0, 0, "vndbpl", NULL);
872 
873 		/* Try and read the disklabel. */
874 		vndgetdisklabel(dev);
875 
876 		vndunlock(vnd);
877 
878 		break;
879 
880 close_and_exit:
881 		(void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p);
882 unlock_and_exit:
883 		vndunlock(vnd);
884 		return (error);
885 
886 	case VNDIOCCLR:
887 		if ((error = vndlock(vnd)) != 0)
888 			return (error);
889 
890 		/*
891 		 * Don't unconfigure if any other partitions are open
892 		 * or if both the character and block flavors of this
893 		 * partition are open.
894 		 */
895 		part = DISKPART(dev);
896 		pmask = (1 << part);
897 		if ((vnd->sc_dkdev.dk_openmask & ~pmask) ||
898 		    ((vnd->sc_dkdev.dk_bopenmask & pmask) &&
899 		    (vnd->sc_dkdev.dk_copenmask & pmask))) {
900 			vndunlock(vnd);
901 			return (EBUSY);
902 		}
903 
904 		vndclear(vnd);
905 #ifdef DEBUG
906 		if (vnddebug & VDB_INIT)
907 			printf("vndioctl: CLRed\n");
908 #endif
909 
910 		/* Destroy the xfer and buffer pools. */
911 		pool_destroy(&vnd->sc_vxpool);
912 		pool_destroy(&vnd->sc_vbpool);
913 
914 		/* Detatch the disk. */
915 		disk_detach(&vnd->sc_dkdev);
916 
917 		vndunlock(vnd);
918 
919 		break;
920 
921 	case VNDIOCGET: {
922 		struct vnd_user *vnu;
923 		struct vattr va;
924 
925 		vnu = (struct vnd_user *)data;
926 
927 		if (vnu->vnu_unit == -1)
928 			vnu->vnu_unit = unit;
929 		if (vnu->vnu_unit >= numvnd)
930 			return (ENXIO);
931 		if (vnu->vnu_unit < 0)
932 			return (EINVAL);
933 
934 		vnd = &vnd_softc[vnu->vnu_unit];
935 
936 		if (vnd->sc_flags & VNF_INITED) {
937 			error = VOP_GETATTR(vnd->sc_vp, &va, p->p_ucred, p);
938 			if (error)
939 				return (error);
940 			vnu->vnu_dev = va.va_fsid;
941 			vnu->vnu_ino = va.va_fileid;
942 		}
943 		else {
944 			/* unused is not an error */
945 			vnu->vnu_dev = 0;
946 			vnu->vnu_ino = 0;
947 		}
948 
949 		break;
950 	}
951 
952 	case DIOCGDINFO:
953 		*(struct disklabel *)data = *(vnd->sc_dkdev.dk_label);
954 		break;
955 
956 #ifdef __HAVE_OLD_DISKLABEL
957 	case ODIOCGDINFO:
958 		newlabel = *(vnd->sc_dkdev.dk_label);
959 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
960 			return ENOTTY;
961 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
962 		break;
963 #endif
964 
965 	case DIOCGPART:
966 		((struct partinfo *)data)->disklab = vnd->sc_dkdev.dk_label;
967 		((struct partinfo *)data)->part =
968 		    &vnd->sc_dkdev.dk_label->d_partitions[DISKPART(dev)];
969 		break;
970 
971 	case DIOCWDINFO:
972 	case DIOCSDINFO:
973 #ifdef __HAVE_OLD_DISKLABEL
974 	case ODIOCWDINFO:
975 	case ODIOCSDINFO:
976 #endif
977 	{
978 		struct disklabel *lp;
979 
980 		if ((error = vndlock(vnd)) != 0)
981 			return (error);
982 
983 		vnd->sc_flags |= VNF_LABELLING;
984 
985 #ifdef __HAVE_OLD_DISKLABEL
986 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
987 			memset(&newlabel, 0, sizeof newlabel);
988 			memcpy(&newlabel, data, sizeof (struct olddisklabel));
989 			lp = &newlabel;
990 		} else
991 #endif
992 		lp = (struct disklabel *)data;
993 
994 		error = setdisklabel(vnd->sc_dkdev.dk_label,
995 		    lp, 0, vnd->sc_dkdev.dk_cpulabel);
996 		if (error == 0) {
997 			if (cmd == DIOCWDINFO
998 #ifdef __HAVE_OLD_DISKLABEL
999 			    || cmd == ODIOCWDINFO
1000 #endif
1001 			   )
1002 				error = writedisklabel(VNDLABELDEV(dev),
1003 				    vndstrategy, vnd->sc_dkdev.dk_label,
1004 				    vnd->sc_dkdev.dk_cpulabel);
1005 		}
1006 
1007 		vnd->sc_flags &= ~VNF_LABELLING;
1008 
1009 		vndunlock(vnd);
1010 
1011 		if (error)
1012 			return (error);
1013 		break;
1014 	}
1015 
1016 	case DIOCWLABEL:
1017 		if (*(int *)data != 0)
1018 			vnd->sc_flags |= VNF_WLABEL;
1019 		else
1020 			vnd->sc_flags &= ~VNF_WLABEL;
1021 		break;
1022 
1023 	case DIOCGDEFLABEL:
1024 		vndgetdefaultlabel(vnd, (struct disklabel *)data);
1025 		break;
1026 
1027 #ifdef __HAVE_OLD_DISKLABEL
1028 	case ODIOCGDEFLABEL:
1029 		vndgetdefaultlabel(vnd, &newlabel);
1030 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
1031 			return ENOTTY;
1032 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
1033 		break;
1034 #endif
1035 
1036 	default:
1037 		return (ENOTTY);
1038 	}
1039 
1040 	return (0);
1041 }
1042 
1043 /*
1044  * Duplicate the current processes' credentials.  Since we are called only
1045  * as the result of a SET ioctl and only root can do that, any future access
1046  * to this "disk" is essentially as root.  Note that credentials may change
1047  * if some other uid can write directly to the mapped file (NFS).
1048  */
1049 int
1050 vndsetcred(vnd, cred)
1051 	struct vnd_softc *vnd;
1052 	struct ucred *cred;
1053 {
1054 	struct uio auio;
1055 	struct iovec aiov;
1056 	char *tmpbuf;
1057 	int error;
1058 
1059 	vnd->sc_cred = crdup(cred);
1060 	tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK);
1061 
1062 	/* XXX: Horrible kludge to establish credentials for NFS */
1063 	aiov.iov_base = tmpbuf;
1064 	aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size));
1065 	auio.uio_iov = &aiov;
1066 	auio.uio_iovcnt = 1;
1067 	auio.uio_offset = 0;
1068 	auio.uio_rw = UIO_READ;
1069 	auio.uio_segflg = UIO_SYSSPACE;
1070 	auio.uio_resid = aiov.iov_len;
1071 	vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1072 	error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred);
1073 	if (error == 0) {
1074 		/*
1075 		 * Because vnd does all IO directly through the vnode
1076 		 * we need to flush (at least) the buffer from the above
1077 		 * VOP_READ from the buffer cache to prevent cache
1078 		 * incoherencies.  Also, be careful to write dirty
1079 		 * buffers back to stable storage.
1080 		 */
1081 		error = vinvalbuf(vnd->sc_vp, V_SAVE, vnd->sc_cred,
1082 			    curproc, 0, 0);
1083 	}
1084 	VOP_UNLOCK(vnd->sc_vp, 0);
1085 
1086 	free(tmpbuf, M_TEMP);
1087 	return (error);
1088 }
1089 
1090 /*
1091  * Set maxactive based on FS type
1092  */
1093 void
1094 vndthrottle(vnd, vp)
1095 	struct vnd_softc *vnd;
1096 	struct vnode *vp;
1097 {
1098 #ifdef NFS
1099 	extern int (**nfsv2_vnodeop_p) __P((void *));
1100 
1101 	if (vp->v_op == nfsv2_vnodeop_p)
1102 		vnd->sc_maxactive = 2;
1103 	else
1104 #endif
1105 		vnd->sc_maxactive = 8;
1106 
1107 	if (vnd->sc_maxactive < 1)
1108 		vnd->sc_maxactive = 1;
1109 }
1110 
1111 void
1112 vndshutdown()
1113 {
1114 	struct vnd_softc *vnd;
1115 
1116 	for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++)
1117 		if (vnd->sc_flags & VNF_INITED)
1118 			vndclear(vnd);
1119 }
1120 
1121 void
1122 vndclear(vnd)
1123 	struct vnd_softc *vnd;
1124 {
1125 	struct vnode *vp = vnd->sc_vp;
1126 	struct proc *p = curproc;		/* XXX */
1127 
1128 #ifdef DEBUG
1129 	if (vnddebug & VDB_FOLLOW)
1130 		printf("vndclear(%p): vp %p\n", vnd, vp);
1131 #endif
1132 	vnd->sc_flags &= ~VNF_INITED;
1133 	if (vp == (struct vnode *)0)
1134 		panic("vndioctl: null vp");
1135 	(void) vn_close(vp, FREAD|FWRITE, vnd->sc_cred, p);
1136 	crfree(vnd->sc_cred);
1137 	vnd->sc_vp = (struct vnode *)0;
1138 	vnd->sc_cred = (struct ucred *)0;
1139 	vnd->sc_size = 0;
1140 }
1141 
1142 int
1143 vndsize(dev)
1144 	dev_t dev;
1145 {
1146 	struct vnd_softc *sc;
1147 	struct disklabel *lp;
1148 	int part, unit, omask;
1149 	int size;
1150 
1151 	unit = vndunit(dev);
1152 	if (unit >= numvnd)
1153 		return (-1);
1154 	sc = &vnd_softc[unit];
1155 
1156 	if ((sc->sc_flags & VNF_INITED) == 0)
1157 		return (-1);
1158 
1159 	part = DISKPART(dev);
1160 	omask = sc->sc_dkdev.dk_openmask & (1 << part);
1161 	lp = sc->sc_dkdev.dk_label;
1162 
1163 	if (omask == 0 && vndopen(dev, 0, S_IFBLK, curproc))
1164 		return (-1);
1165 
1166 	if (lp->d_partitions[part].p_fstype != FS_SWAP)
1167 		size = -1;
1168 	else
1169 		size = lp->d_partitions[part].p_size *
1170 		    (lp->d_secsize / DEV_BSIZE);
1171 
1172 	if (omask == 0 && vndclose(dev, 0, S_IFBLK, curproc))
1173 		return (-1);
1174 
1175 	return (size);
1176 }
1177 
1178 int
1179 vnddump(dev, blkno, va, size)
1180 	dev_t dev;
1181 	daddr_t blkno;
1182 	caddr_t va;
1183 	size_t size;
1184 {
1185 
1186 	/* Not implemented. */
1187 	return ENXIO;
1188 }
1189 
1190 void
1191 vndgetdefaultlabel(sc, lp)
1192 	struct vnd_softc *sc;
1193 	struct disklabel *lp;
1194 {
1195 	struct vndgeom *vng = &sc->sc_geom;
1196 	struct partition *pp;
1197 
1198 	memset(lp, 0, sizeof(*lp));
1199 
1200 	lp->d_secperunit = sc->sc_size / (vng->vng_secsize / DEV_BSIZE);
1201 	lp->d_secsize = vng->vng_secsize;
1202 	lp->d_nsectors = vng->vng_nsectors;
1203 	lp->d_ntracks = vng->vng_ntracks;
1204 	lp->d_ncylinders = vng->vng_ncylinders;
1205 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
1206 
1207 	strncpy(lp->d_typename, "vnd", sizeof(lp->d_typename));
1208 	lp->d_type = DTYPE_VND;
1209 	strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
1210 	lp->d_rpm = 3600;
1211 	lp->d_interleave = 1;
1212 	lp->d_flags = 0;
1213 
1214 	pp = &lp->d_partitions[RAW_PART];
1215 	pp->p_offset = 0;
1216 	pp->p_size = lp->d_secperunit;
1217 	pp->p_fstype = FS_UNUSED;
1218 	lp->d_npartitions = RAW_PART + 1;
1219 
1220 	lp->d_magic = DISKMAGIC;
1221 	lp->d_magic2 = DISKMAGIC;
1222 	lp->d_checksum = dkcksum(lp);
1223 }
1224 
1225 /*
1226  * Read the disklabel from a vnd.  If one is not present, create a fake one.
1227  */
1228 void
1229 vndgetdisklabel(dev)
1230 	dev_t dev;
1231 {
1232 	struct vnd_softc *sc = &vnd_softc[vndunit(dev)];
1233 	char *errstring;
1234 	struct disklabel *lp = sc->sc_dkdev.dk_label;
1235 	struct cpu_disklabel *clp = sc->sc_dkdev.dk_cpulabel;
1236 	int i;
1237 
1238 	memset(clp, 0, sizeof(*clp));
1239 
1240 	vndgetdefaultlabel(sc, lp);
1241 
1242 	/*
1243 	 * Call the generic disklabel extraction routine.
1244 	 */
1245 	errstring = readdisklabel(VNDLABELDEV(dev), vndstrategy, lp, clp);
1246 	if (errstring) {
1247 		/*
1248 		 * Lack of disklabel is common, but we print the warning
1249 		 * anyway, since it might contain other useful information.
1250 		 */
1251 		printf("%s: %s\n", sc->sc_xname, errstring);
1252 
1253 		/*
1254 		 * For historical reasons, if there's no disklabel
1255 		 * present, all partitions must be FS_BSDFFS and
1256 		 * occupy the entire disk.
1257 		 */
1258 		for (i = 0; i < MAXPARTITIONS; i++) {
1259 			/*
1260 			 * Don't wipe out port specific hack (such as
1261 			 * dos partition hack of i386 port).
1262 			 */
1263 			if (lp->d_partitions[i].p_fstype != FS_UNUSED)
1264 				continue;
1265 
1266 			lp->d_partitions[i].p_size = lp->d_secperunit;
1267 			lp->d_partitions[i].p_offset = 0;
1268 			lp->d_partitions[i].p_fstype = FS_BSDFFS;
1269 		}
1270 
1271 		strncpy(lp->d_packname, "default label",
1272 		    sizeof(lp->d_packname));
1273 
1274 		lp->d_checksum = dkcksum(lp);
1275 	}
1276 }
1277 
1278 /*
1279  * Wait interruptibly for an exclusive lock.
1280  *
1281  * XXX
1282  * Several drivers do this; it should be abstracted and made MP-safe.
1283  */
1284 static int
1285 vndlock(sc)
1286 	struct vnd_softc *sc;
1287 {
1288 	int error;
1289 
1290 	while ((sc->sc_flags & VNF_LOCKED) != 0) {
1291 		sc->sc_flags |= VNF_WANTED;
1292 		if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0)
1293 			return (error);
1294 	}
1295 	sc->sc_flags |= VNF_LOCKED;
1296 	return (0);
1297 }
1298 
1299 /*
1300  * Unlock and wake up any waiters.
1301  */
1302 static void
1303 vndunlock(sc)
1304 	struct vnd_softc *sc;
1305 {
1306 
1307 	sc->sc_flags &= ~VNF_LOCKED;
1308 	if ((sc->sc_flags & VNF_WANTED) != 0) {
1309 		sc->sc_flags &= ~VNF_WANTED;
1310 		wakeup(sc);
1311 	}
1312 }
1313