xref: /netbsd-src/sys/dev/vnd.c (revision f14316bcbc544b96a93e884bc5c2b15fd60e22ae)
1 /*	$NetBSD: vnd.c,v 1.232 2014/07/25 08:10:35 dholland Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998, 2008 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1988 University of Utah.
34  * Copyright (c) 1990, 1993
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * This code is derived from software contributed to Berkeley by
38  * the Systems Programming Group of the University of Utah Computer
39  * Science Department.
40  *
41  * Redistribution and use in source and binary forms, with or without
42  * modification, are permitted provided that the following conditions
43  * are met:
44  * 1. Redistributions of source code must retain the above copyright
45  *    notice, this list of conditions and the following disclaimer.
46  * 2. Redistributions in binary form must reproduce the above copyright
47  *    notice, this list of conditions and the following disclaimer in the
48  *    documentation and/or other materials provided with the distribution.
49  * 3. Neither the name of the University nor the names of its contributors
50  *    may be used to endorse or promote products derived from this software
51  *    without specific prior written permission.
52  *
53  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
54  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
55  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
56  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
57  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
58  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
59  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
60  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
61  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
62  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
63  * SUCH DAMAGE.
64  *
65  * from: Utah $Hdr: vn.c 1.13 94/04/02$
66  *
67  *	@(#)vn.c	8.9 (Berkeley) 5/14/95
68  */
69 
70 /*
71  * Vnode disk driver.
72  *
73  * Block/character interface to a vnode.  Allows one to treat a file
74  * as a disk (e.g. build a filesystem in it, mount it, etc.).
75  *
76  * NOTE 1: If the vnode supports the VOP_BMAP and VOP_STRATEGY operations,
77  * this uses them to avoid distorting the local buffer cache.  If those
78  * block-level operations are not available, this falls back to the regular
79  * read and write calls.  Using these may distort the cache in some cases
80  * but better have the driver working than preventing it to work on file
81  * systems where the block-level operations are not implemented for
82  * whatever reason.
83  *
84  * NOTE 2: There is a security issue involved with this driver.
85  * Once mounted all access to the contents of the "mapped" file via
86  * the special file is controlled by the permissions on the special
87  * file, the protection of the mapped file is ignored (effectively,
88  * by using root credentials in all transactions).
89  *
90  * NOTE 3: Doesn't interact with leases, should it?
91  */
92 
93 #include <sys/cdefs.h>
94 __KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.232 2014/07/25 08:10:35 dholland Exp $");
95 
96 #if defined(_KERNEL_OPT)
97 #include "opt_vnd.h"
98 #include "opt_compat_netbsd.h"
99 #endif
100 
101 #include <sys/param.h>
102 #include <sys/systm.h>
103 #include <sys/namei.h>
104 #include <sys/proc.h>
105 #include <sys/kthread.h>
106 #include <sys/errno.h>
107 #include <sys/buf.h>
108 #include <sys/bufq.h>
109 #include <sys/malloc.h>
110 #include <sys/ioctl.h>
111 #include <sys/disklabel.h>
112 #include <sys/device.h>
113 #include <sys/disk.h>
114 #include <sys/stat.h>
115 #include <sys/mount.h>
116 #include <sys/vnode.h>
117 #include <sys/file.h>
118 #include <sys/uio.h>
119 #include <sys/conf.h>
120 #include <sys/kauth.h>
121 
122 #include <net/zlib.h>
123 
124 #include <miscfs/genfs/genfs.h>
125 #include <miscfs/specfs/specdev.h>
126 
127 #include <dev/dkvar.h>
128 #include <dev/vndvar.h>
129 
130 #if defined(VNDDEBUG) && !defined(DEBUG)
131 #define DEBUG
132 #endif
133 
134 #ifdef DEBUG
135 int dovndcluster = 1;
136 #define VDB_FOLLOW	0x01
137 #define VDB_INIT	0x02
138 #define VDB_IO		0x04
139 #define VDB_LABEL	0x08
140 int vnddebug = 0x00;
141 #endif
142 
143 #define vndunit(x)	DISKUNIT(x)
144 
145 struct vndxfer {
146 	struct buf vx_buf;
147 	struct vnd_softc *vx_vnd;
148 };
149 #define	VND_BUFTOXFER(bp)	((struct vndxfer *)(void *)bp)
150 
151 #define VND_GETXFER(vnd)	pool_get(&(vnd)->sc_vxpool, PR_WAITOK)
152 #define VND_PUTXFER(vnd, vx)	pool_put(&(vnd)->sc_vxpool, (vx))
153 
154 #define VNDLABELDEV(dev) \
155     (MAKEDISKDEV(major((dev)), vndunit((dev)), RAW_PART))
156 
157 #define	VND_MAXPENDING(vnd)	((vnd)->sc_maxactive * 4)
158 
159 /* called by main() at boot time */
160 void	vndattach(int);
161 
162 static void	vndclear(struct vnd_softc *, int);
163 static int	vnddoclear(struct vnd_softc *, int, int, bool);
164 static int	vndsetcred(struct vnd_softc *, kauth_cred_t);
165 static void	vndthrottle(struct vnd_softc *, struct vnode *);
166 static void	vndiodone(struct buf *);
167 #if 0
168 static void	vndshutdown(void);
169 #endif
170 
171 static void	vndgetdefaultlabel(struct vnd_softc *, struct disklabel *);
172 static void	vndgetdisklabel(dev_t, struct vnd_softc *);
173 
174 static int	vndlock(struct vnd_softc *);
175 static void	vndunlock(struct vnd_softc *);
176 #ifdef VND_COMPRESSION
177 static void	compstrategy(struct buf *, off_t);
178 static void	*vnd_alloc(void *, u_int, u_int);
179 static void	vnd_free(void *, void *);
180 #endif /* VND_COMPRESSION */
181 
182 static void	vndthread(void *);
183 static bool	vnode_has_op(const struct vnode *, int);
184 static void	handle_with_rdwr(struct vnd_softc *, const struct buf *,
185 		    struct buf *);
186 static void	handle_with_strategy(struct vnd_softc *, const struct buf *,
187 		    struct buf *);
188 static void	vnd_set_geometry(struct vnd_softc *);
189 
190 static dev_type_open(vndopen);
191 static dev_type_close(vndclose);
192 static dev_type_read(vndread);
193 static dev_type_write(vndwrite);
194 static dev_type_ioctl(vndioctl);
195 static dev_type_strategy(vndstrategy);
196 static dev_type_dump(vnddump);
197 static dev_type_size(vndsize);
198 
199 const struct bdevsw vnd_bdevsw = {
200 	.d_open = vndopen,
201 	.d_close = vndclose,
202 	.d_strategy = vndstrategy,
203 	.d_ioctl = vndioctl,
204 	.d_dump = vnddump,
205 	.d_psize = vndsize,
206 	.d_discard = nodiscard,
207 	.d_flag = D_DISK
208 };
209 
210 const struct cdevsw vnd_cdevsw = {
211 	.d_open = vndopen,
212 	.d_close = vndclose,
213 	.d_read = vndread,
214 	.d_write = vndwrite,
215 	.d_ioctl = vndioctl,
216 	.d_stop = nostop,
217 	.d_tty = notty,
218 	.d_poll = nopoll,
219 	.d_mmap = nommap,
220 	.d_kqfilter = nokqfilter,
221 	.d_discard = nodiscard,
222 	.d_flag = D_DISK
223 };
224 
225 static int	vnd_match(device_t, cfdata_t, void *);
226 static void	vnd_attach(device_t, device_t, void *);
227 static int	vnd_detach(device_t, int);
228 
229 CFATTACH_DECL3_NEW(vnd, sizeof(struct vnd_softc),
230     vnd_match, vnd_attach, vnd_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
231 extern struct cfdriver vnd_cd;
232 
233 static struct vnd_softc	*vnd_spawn(int);
234 int	vnd_destroy(device_t);
235 
236 static struct	dkdriver vnddkdriver = { vndstrategy, minphys };
237 
238 void
239 vndattach(int num)
240 {
241 	int error;
242 
243 	error = config_cfattach_attach(vnd_cd.cd_name, &vnd_ca);
244 	if (error)
245 		aprint_error("%s: unable to register cfattach\n",
246 		    vnd_cd.cd_name);
247 }
248 
249 static int
250 vnd_match(device_t self, cfdata_t cfdata, void *aux)
251 {
252 
253 	return 1;
254 }
255 
256 static void
257 vnd_attach(device_t parent, device_t self, void *aux)
258 {
259 	struct vnd_softc *sc = device_private(self);
260 
261 	sc->sc_dev = self;
262 	sc->sc_comp_offsets = NULL;
263 	sc->sc_comp_buff = NULL;
264 	sc->sc_comp_decombuf = NULL;
265 	bufq_alloc(&sc->sc_tab, "disksort", BUFQ_SORT_RAWBLOCK);
266 	disk_init(&sc->sc_dkdev, device_xname(self), &vnddkdriver);
267 	if (!pmf_device_register(self, NULL, NULL))
268 		aprint_error_dev(self, "couldn't establish power handler\n");
269 }
270 
271 static int
272 vnd_detach(device_t self, int flags)
273 {
274 	int error;
275 	struct vnd_softc *sc = device_private(self);
276 
277 	if (sc->sc_flags & VNF_INITED) {
278 		error = vnddoclear(sc, 0, -1, (flags & DETACH_FORCE) != 0);
279 		if (error != 0)
280 			return error;
281 	}
282 
283 	pmf_device_deregister(self);
284 	bufq_free(sc->sc_tab);
285 	disk_destroy(&sc->sc_dkdev);
286 
287 	return 0;
288 }
289 
290 static struct vnd_softc *
291 vnd_spawn(int unit)
292 {
293 	cfdata_t cf;
294 
295 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
296 	cf->cf_name = vnd_cd.cd_name;
297 	cf->cf_atname = vnd_cd.cd_name;
298 	cf->cf_unit = unit;
299 	cf->cf_fstate = FSTATE_STAR;
300 
301 	return device_private(config_attach_pseudo(cf));
302 }
303 
304 int
305 vnd_destroy(device_t dev)
306 {
307 	int error;
308 	cfdata_t cf;
309 
310 	cf = device_cfdata(dev);
311 	error = config_detach(dev, DETACH_QUIET);
312 	if (error)
313 		return error;
314 	free(cf, M_DEVBUF);
315 	return 0;
316 }
317 
318 static int
319 vndopen(dev_t dev, int flags, int mode, struct lwp *l)
320 {
321 	int unit = vndunit(dev);
322 	struct vnd_softc *sc;
323 	int error = 0, part, pmask;
324 	struct disklabel *lp;
325 
326 #ifdef DEBUG
327 	if (vnddebug & VDB_FOLLOW)
328 		printf("vndopen(0x%"PRIx64", 0x%x, 0x%x, %p)\n", dev, flags, mode, l);
329 #endif
330 	sc = device_lookup_private(&vnd_cd, unit);
331 	if (sc == NULL) {
332 		sc = vnd_spawn(unit);
333 		if (sc == NULL)
334 			return ENOMEM;
335 	}
336 
337 	if ((error = vndlock(sc)) != 0)
338 		return error;
339 
340 	if ((sc->sc_flags & VNF_CLEARING) != 0) {
341 		error = ENXIO;
342 		goto done;
343 	}
344 
345 	lp = sc->sc_dkdev.dk_label;
346 
347 	part = DISKPART(dev);
348 	pmask = (1 << part);
349 
350 	if (sc->sc_dkdev.dk_nwedges != 0 && part != RAW_PART) {
351 		error = EBUSY;
352 		goto done;
353 	}
354 
355 	if (sc->sc_flags & VNF_INITED) {
356 		if ((sc->sc_dkdev.dk_openmask & ~(1<<RAW_PART)) != 0) {
357 			/*
358 			 * If any non-raw partition is open, but the disk
359 			 * has been invalidated, disallow further opens.
360 			 */
361 			if ((sc->sc_flags & VNF_VLABEL) == 0) {
362 				error = EIO;
363 				goto done;
364 			}
365 		} else {
366 			/*
367 			 * Load the partition info if not already loaded.
368 			 */
369 			if ((sc->sc_flags & VNF_VLABEL) == 0) {
370 				sc->sc_flags |= VNF_VLABEL;
371 				vndgetdisklabel(dev, sc);
372 			}
373 		}
374 	}
375 
376 	/* Check that the partitions exists. */
377 	if (part != RAW_PART) {
378 		if (((sc->sc_flags & VNF_INITED) == 0) ||
379 		    ((part >= lp->d_npartitions) ||
380 		     (lp->d_partitions[part].p_fstype == FS_UNUSED))) {
381 			error = ENXIO;
382 			goto done;
383 		}
384 	}
385 
386 	/* Prevent our unit from being unconfigured while open. */
387 	switch (mode) {
388 	case S_IFCHR:
389 		sc->sc_dkdev.dk_copenmask |= pmask;
390 		break;
391 
392 	case S_IFBLK:
393 		sc->sc_dkdev.dk_bopenmask |= pmask;
394 		break;
395 	}
396 	sc->sc_dkdev.dk_openmask =
397 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
398 
399  done:
400 	vndunlock(sc);
401 	return error;
402 }
403 
404 static int
405 vndclose(dev_t dev, int flags, int mode, struct lwp *l)
406 {
407 	int unit = vndunit(dev);
408 	struct vnd_softc *sc;
409 	int error = 0, part;
410 
411 #ifdef DEBUG
412 	if (vnddebug & VDB_FOLLOW)
413 		printf("vndclose(0x%"PRIx64", 0x%x, 0x%x, %p)\n", dev, flags, mode, l);
414 #endif
415 	sc = device_lookup_private(&vnd_cd, unit);
416 	if (sc == NULL)
417 		return ENXIO;
418 
419 	if ((error = vndlock(sc)) != 0)
420 		return error;
421 
422 	part = DISKPART(dev);
423 
424 	/* ...that much closer to allowing unconfiguration... */
425 	switch (mode) {
426 	case S_IFCHR:
427 		sc->sc_dkdev.dk_copenmask &= ~(1 << part);
428 		break;
429 
430 	case S_IFBLK:
431 		sc->sc_dkdev.dk_bopenmask &= ~(1 << part);
432 		break;
433 	}
434 	sc->sc_dkdev.dk_openmask =
435 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
436 
437 	vndunlock(sc);
438 
439 	if ((sc->sc_flags & VNF_INITED) == 0) {
440 		if ((error = vnd_destroy(sc->sc_dev)) != 0) {
441 			aprint_error_dev(sc->sc_dev,
442 			    "unable to detach instance\n");
443 			return error;
444 		}
445 	}
446 
447 	return 0;
448 }
449 
450 /*
451  * Queue the request, and wakeup the kernel thread to handle it.
452  */
453 static void
454 vndstrategy(struct buf *bp)
455 {
456 	int unit = vndunit(bp->b_dev);
457 	struct vnd_softc *vnd =
458 	    device_lookup_private(&vnd_cd, unit);
459 	struct disklabel *lp;
460 	daddr_t blkno;
461 	int s = splbio();
462 
463 	if (vnd == NULL) {
464 		bp->b_error = ENXIO;
465 		goto done;
466 	}
467 	lp = vnd->sc_dkdev.dk_label;
468 
469 	if ((vnd->sc_flags & VNF_INITED) == 0) {
470 		bp->b_error = ENXIO;
471 		goto done;
472 	}
473 
474 	/*
475 	 * The transfer must be a whole number of blocks.
476 	 */
477 	if ((bp->b_bcount % lp->d_secsize) != 0) {
478 		bp->b_error = EINVAL;
479 		goto done;
480 	}
481 
482 	/*
483 	 * check if we're read-only.
484 	 */
485 	if ((vnd->sc_flags & VNF_READONLY) && !(bp->b_flags & B_READ)) {
486 		bp->b_error = EACCES;
487 		goto done;
488 	}
489 
490 	/* If it's a nil transfer, wake up the top half now. */
491 	if (bp->b_bcount == 0) {
492 		goto done;
493 	}
494 
495 	/*
496 	 * Do bounds checking and adjust transfer.  If there's an error,
497 	 * the bounds check will flag that for us.
498 	 */
499 	if (DISKPART(bp->b_dev) == RAW_PART) {
500 		if (bounds_check_with_mediasize(bp, DEV_BSIZE,
501 		    vnd->sc_size) <= 0)
502 			goto done;
503 	} else {
504 		if (bounds_check_with_label(&vnd->sc_dkdev,
505 		    bp, vnd->sc_flags & (VNF_WLABEL|VNF_LABELLING)) <= 0)
506 			goto done;
507 	}
508 
509 	/*
510 	 * Put the block number in terms of the logical blocksize
511 	 * of the "device".
512 	 */
513 
514 	blkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
515 
516 	/*
517 	 * Translate the partition-relative block number to an absolute.
518 	 */
519 	if (DISKPART(bp->b_dev) != RAW_PART) {
520 		struct partition *pp;
521 
522 		pp = &vnd->sc_dkdev.dk_label->d_partitions[
523 		    DISKPART(bp->b_dev)];
524 		blkno += pp->p_offset;
525 	}
526 	bp->b_rawblkno = blkno;
527 
528 #ifdef DEBUG
529 	if (vnddebug & VDB_FOLLOW)
530 		printf("vndstrategy(%p): unit %d\n", bp, unit);
531 #endif
532 	if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
533 		KASSERT(vnd->sc_pending >= 0 &&
534 		    vnd->sc_pending <= VND_MAXPENDING(vnd));
535 		while (vnd->sc_pending == VND_MAXPENDING(vnd))
536 			tsleep(&vnd->sc_pending, PRIBIO, "vndpc", 0);
537 		vnd->sc_pending++;
538 	}
539 	bufq_put(vnd->sc_tab, bp);
540 	wakeup(&vnd->sc_tab);
541 	splx(s);
542 	return;
543 
544 done:
545 	bp->b_resid = bp->b_bcount;
546 	biodone(bp);
547 	splx(s);
548 }
549 
550 static bool
551 vnode_has_strategy(struct vnd_softc *vnd)
552 {
553 	return vnode_has_op(vnd->sc_vp, VOFFSET(vop_bmap)) &&
554 	    vnode_has_op(vnd->sc_vp, VOFFSET(vop_strategy));
555 }
556 
557 /* XXX this function needs a reliable check to detect
558  * sparse files. Otherwise, bmap/strategy may be used
559  * and fail on non-allocated blocks. VOP_READ/VOP_WRITE
560  * works on sparse files.
561  */
562 #if notyet
563 static bool
564 vnode_strategy_probe(struct vnd_softc *vnd)
565 {
566 	int error;
567 	daddr_t nbn;
568 
569 	if (!vnode_has_strategy(vnd))
570 		return false;
571 
572 	/* Convert the first logical block number to its
573 	 * physical block number.
574 	 */
575 	error = 0;
576 	vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
577 	error = VOP_BMAP(vnd->sc_vp, 0, NULL, &nbn, NULL);
578 	VOP_UNLOCK(vnd->sc_vp);
579 
580 	/* Test if that worked. */
581 	if (error == 0 && (long)nbn == -1)
582 		return false;
583 
584 	return true;
585 }
586 #endif
587 
588 static void
589 vndthread(void *arg)
590 {
591 	struct vnd_softc *vnd = arg;
592 	int s;
593 
594 	/* Determine whether we can *use* VOP_BMAP and VOP_STRATEGY to
595 	 * directly access the backing vnode.  If we can, use these two
596 	 * operations to avoid messing with the local buffer cache.
597 	 * Otherwise fall back to regular VOP_READ/VOP_WRITE operations
598 	 * which are guaranteed to work with any file system. */
599 	if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0 &&
600 	    ! vnode_has_strategy(vnd))
601 		vnd->sc_flags |= VNF_USE_VN_RDWR;
602 
603 #ifdef DEBUG
604 	if (vnddebug & VDB_INIT)
605 		printf("vndthread: vp %p, %s\n", vnd->sc_vp,
606 		    (vnd->sc_flags & VNF_USE_VN_RDWR) == 0 ?
607 		    "using bmap/strategy operations" :
608 		    "using read/write operations");
609 #endif
610 
611 	s = splbio();
612 	vnd->sc_flags |= VNF_KTHREAD;
613 	wakeup(&vnd->sc_kthread);
614 
615 	/*
616 	 * Dequeue requests and serve them depending on the available
617 	 * vnode operations.
618 	 */
619 	while ((vnd->sc_flags & VNF_VUNCONF) == 0) {
620 		struct vndxfer *vnx;
621 		struct buf *obp;
622 		struct buf *bp;
623 
624 		obp = bufq_get(vnd->sc_tab);
625 		if (obp == NULL) {
626 			tsleep(&vnd->sc_tab, PRIBIO, "vndbp", 0);
627 			continue;
628 		};
629 		if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
630 			KASSERT(vnd->sc_pending > 0 &&
631 			    vnd->sc_pending <= VND_MAXPENDING(vnd));
632 			if (vnd->sc_pending-- == VND_MAXPENDING(vnd))
633 				wakeup(&vnd->sc_pending);
634 		}
635 		splx(s);
636 #ifdef DEBUG
637 		if (vnddebug & VDB_FOLLOW)
638 			printf("vndthread(%p)\n", obp);
639 #endif
640 
641 		if (vnd->sc_vp->v_mount == NULL) {
642 			obp->b_error = ENXIO;
643 			goto done;
644 		}
645 #ifdef VND_COMPRESSION
646 		/* handle a compressed read */
647 		if ((obp->b_flags & B_READ) != 0 && (vnd->sc_flags & VNF_COMP)) {
648 			off_t bn;
649 
650 			/* Convert to a byte offset within the file. */
651 			bn = obp->b_rawblkno *
652 			    vnd->sc_dkdev.dk_label->d_secsize;
653 
654 			compstrategy(obp, bn);
655 			goto done;
656 		}
657 #endif /* VND_COMPRESSION */
658 
659 		/*
660 		 * Allocate a header for this transfer and link it to the
661 		 * buffer
662 		 */
663 		s = splbio();
664 		vnx = VND_GETXFER(vnd);
665 		splx(s);
666 		vnx->vx_vnd = vnd;
667 
668 		s = splbio();
669 		while (vnd->sc_active >= vnd->sc_maxactive) {
670 			tsleep(&vnd->sc_tab, PRIBIO, "vndac", 0);
671 		}
672 		vnd->sc_active++;
673 		splx(s);
674 
675 		/* Instrumentation. */
676 		disk_busy(&vnd->sc_dkdev);
677 
678 		bp = &vnx->vx_buf;
679 		buf_init(bp);
680 		bp->b_flags = (obp->b_flags & B_READ);
681 		bp->b_oflags = obp->b_oflags;
682 		bp->b_cflags = obp->b_cflags;
683 		bp->b_iodone = vndiodone;
684 		bp->b_private = obp;
685 		bp->b_vp = vnd->sc_vp;
686 		bp->b_objlock = bp->b_vp->v_interlock;
687 		bp->b_data = obp->b_data;
688 		bp->b_bcount = obp->b_bcount;
689 		BIO_COPYPRIO(bp, obp);
690 
691 		/* Handle the request using the appropriate operations. */
692 		if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0)
693 			handle_with_strategy(vnd, obp, bp);
694 		else
695 			handle_with_rdwr(vnd, obp, bp);
696 
697 		s = splbio();
698 		continue;
699 
700 done:
701 		biodone(obp);
702 		s = splbio();
703 	}
704 
705 	vnd->sc_flags &= (~VNF_KTHREAD | VNF_VUNCONF);
706 	wakeup(&vnd->sc_kthread);
707 	splx(s);
708 	kthread_exit(0);
709 }
710 
711 /*
712  * Checks if the given vnode supports the requested operation.
713  * The operation is specified the offset returned by VOFFSET.
714  *
715  * XXX The test below used to determine this is quite fragile
716  * because it relies on the file system to use genfs to specify
717  * unimplemented operations.  There might be another way to do
718  * it more cleanly.
719  */
720 static bool
721 vnode_has_op(const struct vnode *vp, int opoffset)
722 {
723 	int (*defaultp)(void *);
724 	int (*opp)(void *);
725 
726 	defaultp = vp->v_op[VOFFSET(vop_default)];
727 	opp = vp->v_op[opoffset];
728 
729 	return opp != defaultp && opp != genfs_eopnotsupp &&
730 	    opp != genfs_badop && opp != genfs_nullop;
731 }
732 
733 /*
734  * Handes the read/write request given in 'bp' using the vnode's VOP_READ
735  * and VOP_WRITE operations.
736  *
737  * 'obp' is a pointer to the original request fed to the vnd device.
738  */
739 static void
740 handle_with_rdwr(struct vnd_softc *vnd, const struct buf *obp, struct buf *bp)
741 {
742 	bool doread;
743 	off_t offset;
744 	size_t len, resid;
745 	struct vnode *vp;
746 
747 	doread = bp->b_flags & B_READ;
748 	offset = obp->b_rawblkno * vnd->sc_dkdev.dk_label->d_secsize;
749 	len = bp->b_bcount;
750 	vp = vnd->sc_vp;
751 
752 #if defined(DEBUG)
753 	if (vnddebug & VDB_IO)
754 		printf("vnd (rdwr): vp %p, %s, rawblkno 0x%" PRIx64
755 		    ", secsize %d, offset %" PRIu64
756 		    ", bcount %d\n",
757 		    vp, doread ? "read" : "write", obp->b_rawblkno,
758 		    vnd->sc_dkdev.dk_label->d_secsize, offset,
759 		    bp->b_bcount);
760 #endif
761 
762 	/* Issue the read or write operation. */
763 	bp->b_error =
764 	    vn_rdwr(doread ? UIO_READ : UIO_WRITE,
765 	    vp, bp->b_data, len, offset, UIO_SYSSPACE,
766 	    IO_ADV_ENCODE(POSIX_FADV_NOREUSE), vnd->sc_cred, &resid, NULL);
767 	bp->b_resid = resid;
768 
769 	mutex_enter(vp->v_interlock);
770 	(void) VOP_PUTPAGES(vp, 0, 0,
771 	    PGO_ALLPAGES | PGO_CLEANIT | PGO_FREE | PGO_SYNCIO);
772 
773 	/* We need to increase the number of outputs on the vnode if
774 	 * there was any write to it. */
775 	if (!doread) {
776 		mutex_enter(vp->v_interlock);
777 		vp->v_numoutput++;
778 		mutex_exit(vp->v_interlock);
779 	}
780 
781 	biodone(bp);
782 }
783 
784 /*
785  * Handes the read/write request given in 'bp' using the vnode's VOP_BMAP
786  * and VOP_STRATEGY operations.
787  *
788  * 'obp' is a pointer to the original request fed to the vnd device.
789  */
790 static void
791 handle_with_strategy(struct vnd_softc *vnd, const struct buf *obp,
792     struct buf *bp)
793 {
794 	int bsize, error, flags, skipped;
795 	size_t resid, sz;
796 	off_t bn, offset;
797 	struct vnode *vp;
798 
799 	flags = obp->b_flags;
800 
801 	if (!(flags & B_READ)) {
802 		vp = bp->b_vp;
803 		mutex_enter(vp->v_interlock);
804 		vp->v_numoutput++;
805 		mutex_exit(vp->v_interlock);
806 	}
807 
808 	/* convert to a byte offset within the file. */
809 	bn = obp->b_rawblkno * vnd->sc_dkdev.dk_label->d_secsize;
810 
811 	bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize;
812 	skipped = 0;
813 
814 	/*
815 	 * Break the request into bsize pieces and feed them
816 	 * sequentially using VOP_BMAP/VOP_STRATEGY.
817 	 * We do it this way to keep from flooding NFS servers if we
818 	 * are connected to an NFS file.  This places the burden on
819 	 * the client rather than the server.
820 	 */
821 	error = 0;
822 	bp->b_resid = bp->b_bcount;
823 	for (offset = 0, resid = bp->b_resid; resid;
824 	    resid -= sz, offset += sz) {
825 		struct buf *nbp;
826 		daddr_t nbn;
827 		int off, nra;
828 
829 		nra = 0;
830 		vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
831 		error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra);
832 		VOP_UNLOCK(vnd->sc_vp);
833 
834 		if (error == 0 && (long)nbn == -1)
835 			error = EIO;
836 
837 		/*
838 		 * If there was an error or a hole in the file...punt.
839 		 * Note that we may have to wait for any operations
840 		 * that we have already fired off before releasing
841 		 * the buffer.
842 		 *
843 		 * XXX we could deal with holes here but it would be
844 		 * a hassle (in the write case).
845 		 */
846 		if (error) {
847 			skipped += resid;
848 			break;
849 		}
850 
851 #ifdef DEBUG
852 		if (!dovndcluster)
853 			nra = 0;
854 #endif
855 
856 		off = bn % bsize;
857 		sz = MIN(((off_t)1 + nra) * bsize - off, resid);
858 #ifdef	DEBUG
859 		if (vnddebug & VDB_IO)
860 			printf("vndstrategy: vp %p/%p bn 0x%qx/0x%" PRIx64
861 			    " sz 0x%zx\n", vnd->sc_vp, vp, (long long)bn,
862 			    nbn, sz);
863 #endif
864 
865 		nbp = getiobuf(vp, true);
866 		nestiobuf_setup(bp, nbp, offset, sz);
867 		nbp->b_blkno = nbn + btodb(off);
868 
869 #if 0 /* XXX #ifdef DEBUG */
870 		if (vnddebug & VDB_IO)
871 			printf("vndstart(%ld): bp %p vp %p blkno "
872 			    "0x%" PRIx64 " flags %x addr %p cnt 0x%x\n",
873 			    (long) (vnd-vnd_softc), &nbp->vb_buf,
874 			    nbp->vb_buf.b_vp, nbp->vb_buf.b_blkno,
875 			    nbp->vb_buf.b_flags, nbp->vb_buf.b_data,
876 			    nbp->vb_buf.b_bcount);
877 #endif
878 		VOP_STRATEGY(vp, nbp);
879 		bn += sz;
880 	}
881 	nestiobuf_done(bp, skipped, error);
882 }
883 
884 static void
885 vndiodone(struct buf *bp)
886 {
887 	struct vndxfer *vnx = VND_BUFTOXFER(bp);
888 	struct vnd_softc *vnd = vnx->vx_vnd;
889 	struct buf *obp = bp->b_private;
890 	int s = splbio();
891 
892 	KASSERT(&vnx->vx_buf == bp);
893 	KASSERT(vnd->sc_active > 0);
894 #ifdef DEBUG
895 	if (vnddebug & VDB_IO) {
896 		printf("vndiodone1: bp %p iodone: error %d\n",
897 		    bp, bp->b_error);
898 	}
899 #endif
900 	disk_unbusy(&vnd->sc_dkdev, bp->b_bcount - bp->b_resid,
901 	    (bp->b_flags & B_READ));
902 	vnd->sc_active--;
903 	if (vnd->sc_active == 0) {
904 		wakeup(&vnd->sc_tab);
905 	}
906 	splx(s);
907 	obp->b_error = bp->b_error;
908 	obp->b_resid = bp->b_resid;
909 	buf_destroy(bp);
910 	VND_PUTXFER(vnd, vnx);
911 	biodone(obp);
912 }
913 
914 /* ARGSUSED */
915 static int
916 vndread(dev_t dev, struct uio *uio, int flags)
917 {
918 	int unit = vndunit(dev);
919 	struct vnd_softc *sc;
920 
921 #ifdef DEBUG
922 	if (vnddebug & VDB_FOLLOW)
923 		printf("vndread(0x%"PRIx64", %p)\n", dev, uio);
924 #endif
925 
926 	sc = device_lookup_private(&vnd_cd, unit);
927 	if (sc == NULL)
928 		return ENXIO;
929 
930 	if ((sc->sc_flags & VNF_INITED) == 0)
931 		return ENXIO;
932 
933 	return physio(vndstrategy, NULL, dev, B_READ, minphys, uio);
934 }
935 
936 /* ARGSUSED */
937 static int
938 vndwrite(dev_t dev, struct uio *uio, int flags)
939 {
940 	int unit = vndunit(dev);
941 	struct vnd_softc *sc;
942 
943 #ifdef DEBUG
944 	if (vnddebug & VDB_FOLLOW)
945 		printf("vndwrite(0x%"PRIx64", %p)\n", dev, uio);
946 #endif
947 
948 	sc = device_lookup_private(&vnd_cd, unit);
949 	if (sc == NULL)
950 		return ENXIO;
951 
952 	if ((sc->sc_flags & VNF_INITED) == 0)
953 		return ENXIO;
954 
955 	return physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio);
956 }
957 
958 static int
959 vnd_cget(struct lwp *l, int unit, int *un, struct vattr *va)
960 {
961 	int error;
962 	struct vnd_softc *vnd;
963 
964 	if (*un == -1)
965 		*un = unit;
966 	if (*un < 0)
967 		return EINVAL;
968 
969 	vnd = device_lookup_private(&vnd_cd, *un);
970 	if (vnd == NULL)
971 		return -1;
972 
973 	if ((vnd->sc_flags & VNF_INITED) == 0)
974 		return -1;
975 
976 	vn_lock(vnd->sc_vp, LK_SHARED | LK_RETRY);
977 	error = VOP_GETATTR(vnd->sc_vp, va, l->l_cred);
978 	VOP_UNLOCK(vnd->sc_vp);
979 	return error;
980 }
981 
982 static int
983 vnddoclear(struct vnd_softc *vnd, int pmask, int minor, bool force)
984 {
985 	int error;
986 
987 	if ((error = vndlock(vnd)) != 0)
988 		return error;
989 
990 	/*
991 	 * Don't unconfigure if any other partitions are open
992 	 * or if both the character and block flavors of this
993 	 * partition are open.
994 	 */
995 	if (DK_BUSY(vnd, pmask) && !force) {
996 		vndunlock(vnd);
997 		return EBUSY;
998 	}
999 
1000 	/* Delete all of our wedges */
1001 	dkwedge_delall(&vnd->sc_dkdev);
1002 
1003 	/*
1004 	 * XXX vndclear() might call vndclose() implicitly;
1005 	 * release lock to avoid recursion
1006 	 *
1007 	 * Set VNF_CLEARING to prevent vndopen() from
1008 	 * sneaking in after we vndunlock().
1009 	 */
1010 	vnd->sc_flags |= VNF_CLEARING;
1011 	vndunlock(vnd);
1012 	vndclear(vnd, minor);
1013 #ifdef DEBUG
1014 	if (vnddebug & VDB_INIT)
1015 		printf("vndioctl: CLRed\n");
1016 #endif
1017 
1018 	/* Destroy the xfer and buffer pools. */
1019 	pool_destroy(&vnd->sc_vxpool);
1020 
1021 	/* Detach the disk. */
1022 	disk_detach(&vnd->sc_dkdev);
1023 
1024 	return 0;
1025 }
1026 
1027 /* ARGSUSED */
1028 static int
1029 vndioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1030 {
1031 	bool force;
1032 	int unit = vndunit(dev);
1033 	struct vnd_softc *vnd;
1034 	struct vnd_ioctl *vio;
1035 	struct vattr vattr;
1036 	struct pathbuf *pb;
1037 	struct nameidata nd;
1038 	int error, part, pmask;
1039 	uint64_t geomsize;
1040 	int fflags;
1041 #ifdef __HAVE_OLD_DISKLABEL
1042 	struct disklabel newlabel;
1043 #endif
1044 	struct dkwedge_info *dkw;
1045 	struct dkwedge_list *dkwl;
1046 
1047 #ifdef DEBUG
1048 	if (vnddebug & VDB_FOLLOW)
1049 		printf("vndioctl(0x%"PRIx64", 0x%lx, %p, 0x%x, %p): unit %d\n",
1050 		    dev, cmd, data, flag, l->l_proc, unit);
1051 #endif
1052 	vnd = device_lookup_private(&vnd_cd, unit);
1053 	if (vnd == NULL &&
1054 #ifdef COMPAT_30
1055 	    cmd != VNDIOCGET30 &&
1056 #endif
1057 #ifdef COMPAT_50
1058 	    cmd != VNDIOCGET50 &&
1059 #endif
1060 	    cmd != VNDIOCGET)
1061 		return ENXIO;
1062 	vio = (struct vnd_ioctl *)data;
1063 
1064 	error = disk_ioctl(&vnd->sc_dkdev, cmd, data, flag, l);
1065 	if (error != EPASSTHROUGH)
1066 		return (error);
1067 
1068 	/* Must be open for writes for these commands... */
1069 	switch (cmd) {
1070 	case VNDIOCSET:
1071 	case VNDIOCCLR:
1072 #ifdef COMPAT_50
1073 	case VNDIOCSET50:
1074 	case VNDIOCCLR50:
1075 #endif
1076 	case DIOCSDINFO:
1077 	case DIOCWDINFO:
1078 #ifdef __HAVE_OLD_DISKLABEL
1079 	case ODIOCSDINFO:
1080 	case ODIOCWDINFO:
1081 #endif
1082 	case DIOCKLABEL:
1083 	case DIOCWLABEL:
1084 		if ((flag & FWRITE) == 0)
1085 			return EBADF;
1086 	}
1087 
1088 	/* Must be initialized for these... */
1089 	switch (cmd) {
1090 	case VNDIOCCLR:
1091 #ifdef VNDIOCCLR50
1092 	case VNDIOCCLR50:
1093 #endif
1094 	case DIOCGDINFO:
1095 	case DIOCSDINFO:
1096 	case DIOCWDINFO:
1097 	case DIOCGPART:
1098 	case DIOCKLABEL:
1099 	case DIOCWLABEL:
1100 	case DIOCGDEFLABEL:
1101 	case DIOCCACHESYNC:
1102 #ifdef __HAVE_OLD_DISKLABEL
1103 	case ODIOCGDINFO:
1104 	case ODIOCSDINFO:
1105 	case ODIOCWDINFO:
1106 	case ODIOCGDEFLABEL:
1107 #endif
1108 		if ((vnd->sc_flags & VNF_INITED) == 0)
1109 			return ENXIO;
1110 	}
1111 
1112 	switch (cmd) {
1113 #ifdef VNDIOCSET50
1114 	case VNDIOCSET50:
1115 #endif
1116 	case VNDIOCSET:
1117 		if (vnd->sc_flags & VNF_INITED)
1118 			return EBUSY;
1119 
1120 		if ((error = vndlock(vnd)) != 0)
1121 			return error;
1122 
1123 		fflags = FREAD;
1124 		if ((vio->vnd_flags & VNDIOF_READONLY) == 0)
1125 			fflags |= FWRITE;
1126 		error = pathbuf_copyin(vio->vnd_file, &pb);
1127 		if (error) {
1128 			goto unlock_and_exit;
1129 		}
1130 		NDINIT(&nd, LOOKUP, FOLLOW, pb);
1131 		if ((error = vn_open(&nd, fflags, 0)) != 0) {
1132 			pathbuf_destroy(pb);
1133 			goto unlock_and_exit;
1134 		}
1135 		KASSERT(l);
1136 		error = VOP_GETATTR(nd.ni_vp, &vattr, l->l_cred);
1137 		if (!error && nd.ni_vp->v_type != VREG)
1138 			error = EOPNOTSUPP;
1139 		if (!error && vattr.va_bytes < vattr.va_size)
1140 			/* File is definitely sparse, use vn_rdwr() */
1141 			vnd->sc_flags |= VNF_USE_VN_RDWR;
1142 		if (error) {
1143 			VOP_UNLOCK(nd.ni_vp);
1144 			goto close_and_exit;
1145 		}
1146 
1147 		/* If using a compressed file, initialize its info */
1148 		/* (or abort with an error if kernel has no compression) */
1149 		if (vio->vnd_flags & VNF_COMP) {
1150 #ifdef VND_COMPRESSION
1151 			struct vnd_comp_header *ch;
1152 			int i;
1153 			u_int32_t comp_size;
1154 			u_int32_t comp_maxsize;
1155 
1156 			/* allocate space for compresed file header */
1157 			ch = malloc(sizeof(struct vnd_comp_header),
1158 			M_TEMP, M_WAITOK);
1159 
1160 			/* read compressed file header */
1161 			error = vn_rdwr(UIO_READ, nd.ni_vp, (void *)ch,
1162 			  sizeof(struct vnd_comp_header), 0, UIO_SYSSPACE,
1163 			  IO_UNIT|IO_NODELOCKED, l->l_cred, NULL, NULL);
1164 			if (error) {
1165 				free(ch, M_TEMP);
1166 				VOP_UNLOCK(nd.ni_vp);
1167 				goto close_and_exit;
1168 			}
1169 
1170 			/* save some header info */
1171 			vnd->sc_comp_blksz = ntohl(ch->block_size);
1172 			/* note last offset is the file byte size */
1173 			vnd->sc_comp_numoffs = ntohl(ch->num_blocks)+1;
1174 			free(ch, M_TEMP);
1175 			if (vnd->sc_comp_blksz == 0 ||
1176 			    vnd->sc_comp_blksz % DEV_BSIZE !=0) {
1177 				VOP_UNLOCK(nd.ni_vp);
1178 				error = EINVAL;
1179 				goto close_and_exit;
1180 			}
1181 			if (sizeof(struct vnd_comp_header) +
1182 			  sizeof(u_int64_t) * vnd->sc_comp_numoffs >
1183 			  vattr.va_size) {
1184 				VOP_UNLOCK(nd.ni_vp);
1185 				error = EINVAL;
1186 				goto close_and_exit;
1187 			}
1188 
1189 			/* set decompressed file size */
1190 			vattr.va_size =
1191 			    ((u_quad_t)vnd->sc_comp_numoffs - 1) *
1192 			     (u_quad_t)vnd->sc_comp_blksz;
1193 
1194 			/* allocate space for all the compressed offsets */
1195 			vnd->sc_comp_offsets =
1196 			malloc(sizeof(u_int64_t) * vnd->sc_comp_numoffs,
1197 			M_DEVBUF, M_WAITOK);
1198 
1199 			/* read in the offsets */
1200 			error = vn_rdwr(UIO_READ, nd.ni_vp,
1201 			  (void *)vnd->sc_comp_offsets,
1202 			  sizeof(u_int64_t) * vnd->sc_comp_numoffs,
1203 			  sizeof(struct vnd_comp_header), UIO_SYSSPACE,
1204 			  IO_UNIT|IO_NODELOCKED, l->l_cred, NULL, NULL);
1205 			if (error) {
1206 				VOP_UNLOCK(nd.ni_vp);
1207 				goto close_and_exit;
1208 			}
1209 			/*
1210 			 * find largest block size (used for allocation limit).
1211 			 * Also convert offset to native byte order.
1212 			 */
1213 			comp_maxsize = 0;
1214 			for (i = 0; i < vnd->sc_comp_numoffs - 1; i++) {
1215 				vnd->sc_comp_offsets[i] =
1216 				  be64toh(vnd->sc_comp_offsets[i]);
1217 				comp_size = be64toh(vnd->sc_comp_offsets[i + 1])
1218 				  - vnd->sc_comp_offsets[i];
1219 				if (comp_size > comp_maxsize)
1220 					comp_maxsize = comp_size;
1221 			}
1222 			vnd->sc_comp_offsets[vnd->sc_comp_numoffs - 1] =
1223 			  be64toh(vnd->sc_comp_offsets[vnd->sc_comp_numoffs - 1]);
1224 
1225 			/* create compressed data buffer */
1226 			vnd->sc_comp_buff = malloc(comp_maxsize,
1227 			  M_DEVBUF, M_WAITOK);
1228 
1229 			/* create decompressed buffer */
1230 			vnd->sc_comp_decombuf = malloc(vnd->sc_comp_blksz,
1231 			  M_DEVBUF, M_WAITOK);
1232 			vnd->sc_comp_buffblk = -1;
1233 
1234 			/* Initialize decompress stream */
1235 			memset(&vnd->sc_comp_stream, 0, sizeof(z_stream));
1236 			vnd->sc_comp_stream.zalloc = vnd_alloc;
1237 			vnd->sc_comp_stream.zfree = vnd_free;
1238 			error = inflateInit2(&vnd->sc_comp_stream, MAX_WBITS);
1239 			if (error) {
1240 				if (vnd->sc_comp_stream.msg)
1241 					printf("vnd%d: compressed file, %s\n",
1242 					  unit, vnd->sc_comp_stream.msg);
1243 				VOP_UNLOCK(nd.ni_vp);
1244 				error = EINVAL;
1245 				goto close_and_exit;
1246 			}
1247 
1248 			vnd->sc_flags |= VNF_COMP | VNF_READONLY;
1249 #else /* !VND_COMPRESSION */
1250 			VOP_UNLOCK(nd.ni_vp);
1251 			error = EOPNOTSUPP;
1252 			goto close_and_exit;
1253 #endif /* VND_COMPRESSION */
1254 		}
1255 
1256 		VOP_UNLOCK(nd.ni_vp);
1257 		vnd->sc_vp = nd.ni_vp;
1258 		vnd->sc_size = btodb(vattr.va_size);	/* note truncation */
1259 
1260 		/*
1261 		 * Use pseudo-geometry specified.  If none was provided,
1262 		 * use "standard" Adaptec fictitious geometry.
1263 		 */
1264 		if (vio->vnd_flags & VNDIOF_HASGEOM) {
1265 
1266 			memcpy(&vnd->sc_geom, &vio->vnd_geom,
1267 			    sizeof(vio->vnd_geom));
1268 
1269 			/*
1270 			 * Sanity-check the sector size.
1271 			 * XXX Don't allow secsize < DEV_BSIZE.	 Should
1272 			 * XXX we?
1273 			 */
1274 			if (vnd->sc_geom.vng_secsize < DEV_BSIZE ||
1275 			    (vnd->sc_geom.vng_secsize % DEV_BSIZE) != 0 ||
1276 			    vnd->sc_geom.vng_ncylinders == 0 ||
1277 			    (vnd->sc_geom.vng_ntracks *
1278 			     vnd->sc_geom.vng_nsectors) == 0) {
1279 				error = EINVAL;
1280 				goto close_and_exit;
1281 			}
1282 
1283 			/*
1284 			 * Compute the size (in DEV_BSIZE blocks) specified
1285 			 * by the geometry.
1286 			 */
1287 			geomsize = (vnd->sc_geom.vng_nsectors *
1288 			    vnd->sc_geom.vng_ntracks *
1289 			    vnd->sc_geom.vng_ncylinders) *
1290 			    (vnd->sc_geom.vng_secsize / DEV_BSIZE);
1291 
1292 			/*
1293 			 * Sanity-check the size against the specified
1294 			 * geometry.
1295 			 */
1296 			if (vnd->sc_size < geomsize) {
1297 				error = EINVAL;
1298 				goto close_and_exit;
1299 			}
1300 		} else if (vnd->sc_size >= (32 * 64)) {
1301 			/*
1302 			 * Size must be at least 2048 DEV_BSIZE blocks
1303 			 * (1M) in order to use this geometry.
1304 			 */
1305 			vnd->sc_geom.vng_secsize = DEV_BSIZE;
1306 			vnd->sc_geom.vng_nsectors = 32;
1307 			vnd->sc_geom.vng_ntracks = 64;
1308 			vnd->sc_geom.vng_ncylinders = vnd->sc_size / (64 * 32);
1309 		} else {
1310 			vnd->sc_geom.vng_secsize = DEV_BSIZE;
1311 			vnd->sc_geom.vng_nsectors = 1;
1312 			vnd->sc_geom.vng_ntracks = 1;
1313 			vnd->sc_geom.vng_ncylinders = vnd->sc_size;
1314 		}
1315 
1316 		vnd_set_geometry(vnd);
1317 
1318 		if (vio->vnd_flags & VNDIOF_READONLY) {
1319 			vnd->sc_flags |= VNF_READONLY;
1320 		}
1321 
1322 		if ((error = vndsetcred(vnd, l->l_cred)) != 0)
1323 			goto close_and_exit;
1324 
1325 		vndthrottle(vnd, vnd->sc_vp);
1326 		vio->vnd_osize = dbtob(vnd->sc_size);
1327 #ifdef VNDIOCSET50
1328 		if (cmd != VNDIOCSET50)
1329 #endif
1330 			vio->vnd_size = dbtob(vnd->sc_size);
1331 		vnd->sc_flags |= VNF_INITED;
1332 
1333 		/* create the kernel thread, wait for it to be up */
1334 		error = kthread_create(PRI_NONE, 0, NULL, vndthread, vnd,
1335 		    &vnd->sc_kthread, "%s", device_xname(vnd->sc_dev));
1336 		if (error)
1337 			goto close_and_exit;
1338 		while ((vnd->sc_flags & VNF_KTHREAD) == 0) {
1339 			tsleep(&vnd->sc_kthread, PRIBIO, "vndthr", 0);
1340 		}
1341 #ifdef DEBUG
1342 		if (vnddebug & VDB_INIT)
1343 			printf("vndioctl: SET vp %p size 0x%lx %d/%d/%d/%d\n",
1344 			    vnd->sc_vp, (unsigned long) vnd->sc_size,
1345 			    vnd->sc_geom.vng_secsize,
1346 			    vnd->sc_geom.vng_nsectors,
1347 			    vnd->sc_geom.vng_ntracks,
1348 			    vnd->sc_geom.vng_ncylinders);
1349 #endif
1350 
1351 		/* Attach the disk. */
1352 		disk_attach(&vnd->sc_dkdev);
1353 		disk_blocksize(&vnd->sc_dkdev, vnd->sc_geom.vng_secsize);
1354 
1355 		/* Initialize the xfer and buffer pools. */
1356 		pool_init(&vnd->sc_vxpool, sizeof(struct vndxfer), 0,
1357 		    0, 0, "vndxpl", NULL, IPL_BIO);
1358 
1359 		vndunlock(vnd);
1360 
1361 		pathbuf_destroy(pb);
1362 
1363 		/* Discover wedges on this disk */
1364 		dkwedge_discover(&vnd->sc_dkdev);
1365 
1366 		break;
1367 
1368 close_and_exit:
1369 		(void) vn_close(nd.ni_vp, fflags, l->l_cred);
1370 		pathbuf_destroy(pb);
1371 unlock_and_exit:
1372 #ifdef VND_COMPRESSION
1373 		/* free any allocated memory (for compressed file) */
1374 		if (vnd->sc_comp_offsets) {
1375 			free(vnd->sc_comp_offsets, M_DEVBUF);
1376 			vnd->sc_comp_offsets = NULL;
1377 		}
1378 		if (vnd->sc_comp_buff) {
1379 			free(vnd->sc_comp_buff, M_DEVBUF);
1380 			vnd->sc_comp_buff = NULL;
1381 		}
1382 		if (vnd->sc_comp_decombuf) {
1383 			free(vnd->sc_comp_decombuf, M_DEVBUF);
1384 			vnd->sc_comp_decombuf = NULL;
1385 		}
1386 #endif /* VND_COMPRESSION */
1387 		vndunlock(vnd);
1388 		return error;
1389 
1390 #ifdef VNDIOCCLR50
1391 	case VNDIOCCLR50:
1392 #endif
1393 	case VNDIOCCLR:
1394 		part = DISKPART(dev);
1395 		pmask = (1 << part);
1396 		force = (vio->vnd_flags & VNDIOF_FORCE) != 0;
1397 
1398 		if ((error = vnddoclear(vnd, pmask, minor(dev), force)) != 0)
1399 			return error;
1400 
1401 		break;
1402 
1403 #ifdef COMPAT_30
1404 	case VNDIOCGET30: {
1405 		struct vnd_user30 *vnu;
1406 		struct vattr va;
1407 		vnu = (struct vnd_user30 *)data;
1408 		KASSERT(l);
1409 		switch (error = vnd_cget(l, unit, &vnu->vnu_unit, &va)) {
1410 		case 0:
1411 			vnu->vnu_dev = va.va_fsid;
1412 			vnu->vnu_ino = va.va_fileid;
1413 			break;
1414 		case -1:
1415 			/* unused is not an error */
1416 			vnu->vnu_dev = 0;
1417 			vnu->vnu_ino = 0;
1418 			break;
1419 		default:
1420 			return error;
1421 		}
1422 		break;
1423 	}
1424 #endif
1425 
1426 #ifdef COMPAT_50
1427 	case VNDIOCGET50: {
1428 		struct vnd_user50 *vnu;
1429 		struct vattr va;
1430 		vnu = (struct vnd_user50 *)data;
1431 		KASSERT(l);
1432 		switch (error = vnd_cget(l, unit, &vnu->vnu_unit, &va)) {
1433 		case 0:
1434 			vnu->vnu_dev = va.va_fsid;
1435 			vnu->vnu_ino = va.va_fileid;
1436 			break;
1437 		case -1:
1438 			/* unused is not an error */
1439 			vnu->vnu_dev = 0;
1440 			vnu->vnu_ino = 0;
1441 			break;
1442 		default:
1443 			return error;
1444 		}
1445 		break;
1446 	}
1447 #endif
1448 
1449 	case VNDIOCGET: {
1450 		struct vnd_user *vnu;
1451 		struct vattr va;
1452 		vnu = (struct vnd_user *)data;
1453 		KASSERT(l);
1454 		switch (error = vnd_cget(l, unit, &vnu->vnu_unit, &va)) {
1455 		case 0:
1456 			vnu->vnu_dev = va.va_fsid;
1457 			vnu->vnu_ino = va.va_fileid;
1458 			break;
1459 		case -1:
1460 			/* unused is not an error */
1461 			vnu->vnu_dev = 0;
1462 			vnu->vnu_ino = 0;
1463 			break;
1464 		default:
1465 			return error;
1466 		}
1467 		break;
1468 	}
1469 
1470 	case DIOCGDINFO:
1471 		*(struct disklabel *)data = *(vnd->sc_dkdev.dk_label);
1472 		break;
1473 
1474 #ifdef __HAVE_OLD_DISKLABEL
1475 	case ODIOCGDINFO:
1476 		newlabel = *(vnd->sc_dkdev.dk_label);
1477 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
1478 			return ENOTTY;
1479 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
1480 		break;
1481 #endif
1482 
1483 	case DIOCGPART:
1484 		((struct partinfo *)data)->disklab = vnd->sc_dkdev.dk_label;
1485 		((struct partinfo *)data)->part =
1486 		    &vnd->sc_dkdev.dk_label->d_partitions[DISKPART(dev)];
1487 		break;
1488 
1489 	case DIOCWDINFO:
1490 	case DIOCSDINFO:
1491 #ifdef __HAVE_OLD_DISKLABEL
1492 	case ODIOCWDINFO:
1493 	case ODIOCSDINFO:
1494 #endif
1495 	{
1496 		struct disklabel *lp;
1497 
1498 		if ((error = vndlock(vnd)) != 0)
1499 			return error;
1500 
1501 		vnd->sc_flags |= VNF_LABELLING;
1502 
1503 #ifdef __HAVE_OLD_DISKLABEL
1504 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
1505 			memset(&newlabel, 0, sizeof newlabel);
1506 			memcpy(&newlabel, data, sizeof (struct olddisklabel));
1507 			lp = &newlabel;
1508 		} else
1509 #endif
1510 		lp = (struct disklabel *)data;
1511 
1512 		error = setdisklabel(vnd->sc_dkdev.dk_label,
1513 		    lp, 0, vnd->sc_dkdev.dk_cpulabel);
1514 		if (error == 0) {
1515 			if (cmd == DIOCWDINFO
1516 #ifdef __HAVE_OLD_DISKLABEL
1517 			    || cmd == ODIOCWDINFO
1518 #endif
1519 			   )
1520 				error = writedisklabel(VNDLABELDEV(dev),
1521 				    vndstrategy, vnd->sc_dkdev.dk_label,
1522 				    vnd->sc_dkdev.dk_cpulabel);
1523 		}
1524 
1525 		vnd->sc_flags &= ~VNF_LABELLING;
1526 
1527 		vndunlock(vnd);
1528 
1529 		if (error)
1530 			return error;
1531 		break;
1532 	}
1533 
1534 	case DIOCKLABEL:
1535 		if (*(int *)data != 0)
1536 			vnd->sc_flags |= VNF_KLABEL;
1537 		else
1538 			vnd->sc_flags &= ~VNF_KLABEL;
1539 		break;
1540 
1541 	case DIOCWLABEL:
1542 		if (*(int *)data != 0)
1543 			vnd->sc_flags |= VNF_WLABEL;
1544 		else
1545 			vnd->sc_flags &= ~VNF_WLABEL;
1546 		break;
1547 
1548 	case DIOCGDEFLABEL:
1549 		vndgetdefaultlabel(vnd, (struct disklabel *)data);
1550 		break;
1551 
1552 #ifdef __HAVE_OLD_DISKLABEL
1553 	case ODIOCGDEFLABEL:
1554 		vndgetdefaultlabel(vnd, &newlabel);
1555 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
1556 			return ENOTTY;
1557 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
1558 		break;
1559 #endif
1560 
1561 	case DIOCCACHESYNC:
1562 		vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1563 		error = VOP_FSYNC(vnd->sc_vp, vnd->sc_cred,
1564 		    FSYNC_WAIT | FSYNC_DATAONLY | FSYNC_CACHE, 0, 0);
1565 		VOP_UNLOCK(vnd->sc_vp);
1566 		return error;
1567 
1568 	case DIOCAWEDGE:
1569 		dkw = (void *) data;
1570 
1571 		if ((flag & FWRITE) == 0)
1572 			return EBADF;
1573 
1574 		/* If the ioctl happens here, the parent is us. */
1575 		strlcpy(dkw->dkw_parent, device_xname(vnd->sc_dev),
1576 		    sizeof(dkw->dkw_parent));
1577 		return dkwedge_add(dkw);
1578 
1579 	case DIOCDWEDGE:
1580 		dkw = (void *) data;
1581 
1582 		if ((flag & FWRITE) == 0)
1583 			return EBADF;
1584 
1585 		/* If the ioctl happens here, the parent is us. */
1586 		strlcpy(dkw->dkw_parent, device_xname(vnd->sc_dev),
1587 		    sizeof(dkw->dkw_parent));
1588 		return dkwedge_del(dkw);
1589 
1590 	case DIOCLWEDGES:
1591 		dkwl = (void *) data;
1592 
1593 		return dkwedge_list(&vnd->sc_dkdev, dkwl, l);
1594 
1595 	default:
1596 		return ENOTTY;
1597 	}
1598 
1599 	return 0;
1600 }
1601 
1602 /*
1603  * Duplicate the current processes' credentials.  Since we are called only
1604  * as the result of a SET ioctl and only root can do that, any future access
1605  * to this "disk" is essentially as root.  Note that credentials may change
1606  * if some other uid can write directly to the mapped file (NFS).
1607  */
1608 static int
1609 vndsetcred(struct vnd_softc *vnd, kauth_cred_t cred)
1610 {
1611 	struct uio auio;
1612 	struct iovec aiov;
1613 	char *tmpbuf;
1614 	int error;
1615 
1616 	vnd->sc_cred = kauth_cred_dup(cred);
1617 	tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK);
1618 
1619 	/* XXX: Horrible kludge to establish credentials for NFS */
1620 	aiov.iov_base = tmpbuf;
1621 	aiov.iov_len = min(DEV_BSIZE, dbtob(vnd->sc_size));
1622 	auio.uio_iov = &aiov;
1623 	auio.uio_iovcnt = 1;
1624 	auio.uio_offset = 0;
1625 	auio.uio_rw = UIO_READ;
1626 	auio.uio_resid = aiov.iov_len;
1627 	UIO_SETUP_SYSSPACE(&auio);
1628 	vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1629 	error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred);
1630 	if (error == 0) {
1631 		/*
1632 		 * Because vnd does all IO directly through the vnode
1633 		 * we need to flush (at least) the buffer from the above
1634 		 * VOP_READ from the buffer cache to prevent cache
1635 		 * incoherencies.  Also, be careful to write dirty
1636 		 * buffers back to stable storage.
1637 		 */
1638 		error = vinvalbuf(vnd->sc_vp, V_SAVE, vnd->sc_cred,
1639 			    curlwp, 0, 0);
1640 	}
1641 	VOP_UNLOCK(vnd->sc_vp);
1642 
1643 	free(tmpbuf, M_TEMP);
1644 	return error;
1645 }
1646 
1647 /*
1648  * Set maxactive based on FS type
1649  */
1650 static void
1651 vndthrottle(struct vnd_softc *vnd, struct vnode *vp)
1652 {
1653 
1654 	if (vp->v_tag == VT_NFS)
1655 		vnd->sc_maxactive = 2;
1656 	else
1657 		vnd->sc_maxactive = 8;
1658 
1659 	if (vnd->sc_maxactive < 1)
1660 		vnd->sc_maxactive = 1;
1661 }
1662 
1663 #if 0
1664 static void
1665 vndshutdown(void)
1666 {
1667 	struct vnd_softc *vnd;
1668 
1669 	for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++)
1670 		if (vnd->sc_flags & VNF_INITED)
1671 			vndclear(vnd);
1672 }
1673 #endif
1674 
1675 static void
1676 vndclear(struct vnd_softc *vnd, int myminor)
1677 {
1678 	struct vnode *vp = vnd->sc_vp;
1679 	int fflags = FREAD;
1680 	int bmaj, cmaj, i, mn;
1681 	int s;
1682 
1683 #ifdef DEBUG
1684 	if (vnddebug & VDB_FOLLOW)
1685 		printf("vndclear(%p): vp %p\n", vnd, vp);
1686 #endif
1687 	/* locate the major number */
1688 	bmaj = bdevsw_lookup_major(&vnd_bdevsw);
1689 	cmaj = cdevsw_lookup_major(&vnd_cdevsw);
1690 
1691 	/* Nuke the vnodes for any open instances */
1692 	for (i = 0; i < MAXPARTITIONS; i++) {
1693 		mn = DISKMINOR(device_unit(vnd->sc_dev), i);
1694 		vdevgone(bmaj, mn, mn, VBLK);
1695 		if (mn != myminor) /* XXX avoid to kill own vnode */
1696 			vdevgone(cmaj, mn, mn, VCHR);
1697 	}
1698 
1699 	if ((vnd->sc_flags & VNF_READONLY) == 0)
1700 		fflags |= FWRITE;
1701 
1702 	s = splbio();
1703 	bufq_drain(vnd->sc_tab);
1704 	splx(s);
1705 
1706 	vnd->sc_flags |= VNF_VUNCONF;
1707 	wakeup(&vnd->sc_tab);
1708 	while (vnd->sc_flags & VNF_KTHREAD)
1709 		tsleep(&vnd->sc_kthread, PRIBIO, "vnthr", 0);
1710 
1711 #ifdef VND_COMPRESSION
1712 	/* free the compressed file buffers */
1713 	if (vnd->sc_flags & VNF_COMP) {
1714 		if (vnd->sc_comp_offsets) {
1715 			free(vnd->sc_comp_offsets, M_DEVBUF);
1716 			vnd->sc_comp_offsets = NULL;
1717 		}
1718 		if (vnd->sc_comp_buff) {
1719 			free(vnd->sc_comp_buff, M_DEVBUF);
1720 			vnd->sc_comp_buff = NULL;
1721 		}
1722 		if (vnd->sc_comp_decombuf) {
1723 			free(vnd->sc_comp_decombuf, M_DEVBUF);
1724 			vnd->sc_comp_decombuf = NULL;
1725 		}
1726 	}
1727 #endif /* VND_COMPRESSION */
1728 	vnd->sc_flags &=
1729 	    ~(VNF_INITED | VNF_READONLY | VNF_VLABEL
1730 	      | VNF_VUNCONF | VNF_COMP | VNF_CLEARING);
1731 	if (vp == NULL)
1732 		panic("vndclear: null vp");
1733 	(void) vn_close(vp, fflags, vnd->sc_cred);
1734 	kauth_cred_free(vnd->sc_cred);
1735 	vnd->sc_vp = NULL;
1736 	vnd->sc_cred = NULL;
1737 	vnd->sc_size = 0;
1738 }
1739 
1740 static int
1741 vndsize(dev_t dev)
1742 {
1743 	struct vnd_softc *sc;
1744 	struct disklabel *lp;
1745 	int part, unit, omask;
1746 	int size;
1747 
1748 	unit = vndunit(dev);
1749 	sc = device_lookup_private(&vnd_cd, unit);
1750 	if (sc == NULL)
1751 		return -1;
1752 
1753 	if ((sc->sc_flags & VNF_INITED) == 0)
1754 		return -1;
1755 
1756 	part = DISKPART(dev);
1757 	omask = sc->sc_dkdev.dk_openmask & (1 << part);
1758 	lp = sc->sc_dkdev.dk_label;
1759 
1760 	if (omask == 0 && vndopen(dev, 0, S_IFBLK, curlwp))	/* XXX */
1761 		return -1;
1762 
1763 	if (lp->d_partitions[part].p_fstype != FS_SWAP)
1764 		size = -1;
1765 	else
1766 		size = lp->d_partitions[part].p_size *
1767 		    (lp->d_secsize / DEV_BSIZE);
1768 
1769 	if (omask == 0 && vndclose(dev, 0, S_IFBLK, curlwp))	/* XXX */
1770 		return -1;
1771 
1772 	return size;
1773 }
1774 
1775 static int
1776 vnddump(dev_t dev, daddr_t blkno, void *va,
1777     size_t size)
1778 {
1779 
1780 	/* Not implemented. */
1781 	return ENXIO;
1782 }
1783 
1784 static void
1785 vndgetdefaultlabel(struct vnd_softc *sc, struct disklabel *lp)
1786 {
1787 	struct vndgeom *vng = &sc->sc_geom;
1788 	struct partition *pp;
1789 
1790 	memset(lp, 0, sizeof(*lp));
1791 
1792 	lp->d_secperunit = sc->sc_size / (vng->vng_secsize / DEV_BSIZE);
1793 	lp->d_secsize = vng->vng_secsize;
1794 	lp->d_nsectors = vng->vng_nsectors;
1795 	lp->d_ntracks = vng->vng_ntracks;
1796 	lp->d_ncylinders = vng->vng_ncylinders;
1797 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
1798 
1799 	strncpy(lp->d_typename, "vnd", sizeof(lp->d_typename));
1800 	lp->d_type = DTYPE_VND;
1801 	strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
1802 	lp->d_rpm = 3600;
1803 	lp->d_interleave = 1;
1804 	lp->d_flags = 0;
1805 
1806 	pp = &lp->d_partitions[RAW_PART];
1807 	pp->p_offset = 0;
1808 	pp->p_size = lp->d_secperunit;
1809 	pp->p_fstype = FS_UNUSED;
1810 	lp->d_npartitions = RAW_PART + 1;
1811 
1812 	lp->d_magic = DISKMAGIC;
1813 	lp->d_magic2 = DISKMAGIC;
1814 	lp->d_checksum = dkcksum(lp);
1815 }
1816 
1817 /*
1818  * Read the disklabel from a vnd.  If one is not present, create a fake one.
1819  */
1820 static void
1821 vndgetdisklabel(dev_t dev, struct vnd_softc *sc)
1822 {
1823 	const char *errstring;
1824 	struct disklabel *lp = sc->sc_dkdev.dk_label;
1825 	struct cpu_disklabel *clp = sc->sc_dkdev.dk_cpulabel;
1826 	int i;
1827 
1828 	memset(clp, 0, sizeof(*clp));
1829 
1830 	vndgetdefaultlabel(sc, lp);
1831 
1832 	/*
1833 	 * Call the generic disklabel extraction routine.
1834 	 */
1835 	errstring = readdisklabel(VNDLABELDEV(dev), vndstrategy, lp, clp);
1836 	if (errstring) {
1837 		/*
1838 		 * Lack of disklabel is common, but we print the warning
1839 		 * anyway, since it might contain other useful information.
1840 		 */
1841 		aprint_normal_dev(sc->sc_dev, "%s\n", errstring);
1842 
1843 		/*
1844 		 * For historical reasons, if there's no disklabel
1845 		 * present, all partitions must be FS_BSDFFS and
1846 		 * occupy the entire disk.
1847 		 */
1848 		for (i = 0; i < MAXPARTITIONS; i++) {
1849 			/*
1850 			 * Don't wipe out port specific hack (such as
1851 			 * dos partition hack of i386 port).
1852 			 */
1853 			if (lp->d_partitions[i].p_size != 0)
1854 				continue;
1855 
1856 			lp->d_partitions[i].p_size = lp->d_secperunit;
1857 			lp->d_partitions[i].p_offset = 0;
1858 			lp->d_partitions[i].p_fstype = FS_BSDFFS;
1859 		}
1860 
1861 		strncpy(lp->d_packname, "default label",
1862 		    sizeof(lp->d_packname));
1863 
1864 		lp->d_npartitions = MAXPARTITIONS;
1865 		lp->d_checksum = dkcksum(lp);
1866 	}
1867 }
1868 
1869 /*
1870  * Wait interruptibly for an exclusive lock.
1871  *
1872  * XXX
1873  * Several drivers do this; it should be abstracted and made MP-safe.
1874  */
1875 static int
1876 vndlock(struct vnd_softc *sc)
1877 {
1878 	int error;
1879 
1880 	while ((sc->sc_flags & VNF_LOCKED) != 0) {
1881 		sc->sc_flags |= VNF_WANTED;
1882 		if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0)
1883 			return error;
1884 	}
1885 	sc->sc_flags |= VNF_LOCKED;
1886 	return 0;
1887 }
1888 
1889 /*
1890  * Unlock and wake up any waiters.
1891  */
1892 static void
1893 vndunlock(struct vnd_softc *sc)
1894 {
1895 
1896 	sc->sc_flags &= ~VNF_LOCKED;
1897 	if ((sc->sc_flags & VNF_WANTED) != 0) {
1898 		sc->sc_flags &= ~VNF_WANTED;
1899 		wakeup(sc);
1900 	}
1901 }
1902 
1903 #ifdef VND_COMPRESSION
1904 /* compressed file read */
1905 static void
1906 compstrategy(struct buf *bp, off_t bn)
1907 {
1908 	int error;
1909 	int unit = vndunit(bp->b_dev);
1910 	struct vnd_softc *vnd =
1911 	    device_lookup_private(&vnd_cd, unit);
1912 	u_int32_t comp_block;
1913 	struct uio auio;
1914 	char *addr;
1915 	int s;
1916 
1917 	/* set up constants for data move */
1918 	auio.uio_rw = UIO_READ;
1919 	UIO_SETUP_SYSSPACE(&auio);
1920 
1921 	/* read, and transfer the data */
1922 	addr = bp->b_data;
1923 	bp->b_resid = bp->b_bcount;
1924 	s = splbio();
1925 	while (bp->b_resid > 0) {
1926 		unsigned length;
1927 		size_t length_in_buffer;
1928 		u_int32_t offset_in_buffer;
1929 		struct iovec aiov;
1930 
1931 		/* calculate the compressed block number */
1932 		comp_block = bn / (off_t)vnd->sc_comp_blksz;
1933 
1934 		/* check for good block number */
1935 		if (comp_block >= vnd->sc_comp_numoffs) {
1936 			bp->b_error = EINVAL;
1937 			splx(s);
1938 			return;
1939 		}
1940 
1941 		/* read in the compressed block, if not in buffer */
1942 		if (comp_block != vnd->sc_comp_buffblk) {
1943 			length = vnd->sc_comp_offsets[comp_block + 1] -
1944 			    vnd->sc_comp_offsets[comp_block];
1945 			vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1946 			error = vn_rdwr(UIO_READ, vnd->sc_vp, vnd->sc_comp_buff,
1947 			    length, vnd->sc_comp_offsets[comp_block],
1948 			    UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, vnd->sc_cred,
1949 			    NULL, NULL);
1950 			if (error) {
1951 				bp->b_error = error;
1952 				VOP_UNLOCK(vnd->sc_vp);
1953 				splx(s);
1954 				return;
1955 			}
1956 			/* uncompress the buffer */
1957 			vnd->sc_comp_stream.next_in = vnd->sc_comp_buff;
1958 			vnd->sc_comp_stream.avail_in = length;
1959 			vnd->sc_comp_stream.next_out = vnd->sc_comp_decombuf;
1960 			vnd->sc_comp_stream.avail_out = vnd->sc_comp_blksz;
1961 			inflateReset(&vnd->sc_comp_stream);
1962 			error = inflate(&vnd->sc_comp_stream, Z_FINISH);
1963 			if (error != Z_STREAM_END) {
1964 				if (vnd->sc_comp_stream.msg)
1965 					aprint_normal_dev(vnd->sc_dev,
1966 					    "compressed file, %s\n",
1967 					    vnd->sc_comp_stream.msg);
1968 				bp->b_error = EBADMSG;
1969 				VOP_UNLOCK(vnd->sc_vp);
1970 				splx(s);
1971 				return;
1972 			}
1973 			vnd->sc_comp_buffblk = comp_block;
1974 			VOP_UNLOCK(vnd->sc_vp);
1975 		}
1976 
1977 		/* transfer the usable uncompressed data */
1978 		offset_in_buffer = bn % (off_t)vnd->sc_comp_blksz;
1979 		length_in_buffer = vnd->sc_comp_blksz - offset_in_buffer;
1980 		if (length_in_buffer > bp->b_resid)
1981 			length_in_buffer = bp->b_resid;
1982 		auio.uio_iov = &aiov;
1983 		auio.uio_iovcnt = 1;
1984 		aiov.iov_base = addr;
1985 		aiov.iov_len = length_in_buffer;
1986 		auio.uio_resid = aiov.iov_len;
1987 		auio.uio_offset = 0;
1988 		error = uiomove(vnd->sc_comp_decombuf + offset_in_buffer,
1989 		    length_in_buffer, &auio);
1990 		if (error) {
1991 			bp->b_error = error;
1992 			splx(s);
1993 			return;
1994 		}
1995 
1996 		bn += length_in_buffer;
1997 		addr += length_in_buffer;
1998 		bp->b_resid -= length_in_buffer;
1999 	}
2000 	splx(s);
2001 }
2002 
2003 /* compression memory allocation routines */
2004 static void *
2005 vnd_alloc(void *aux, u_int items, u_int siz)
2006 {
2007 	return malloc(items * siz, M_TEMP, M_NOWAIT);
2008 }
2009 
2010 static void
2011 vnd_free(void *aux, void *ptr)
2012 {
2013 	free(ptr, M_TEMP);
2014 }
2015 #endif /* VND_COMPRESSION */
2016 
2017 static void
2018 vnd_set_geometry(struct vnd_softc *vnd)
2019 {
2020 	struct disk_geom *dg = &vnd->sc_dkdev.dk_geom;
2021 
2022 	memset(dg, 0, sizeof(*dg));
2023 
2024 	dg->dg_secperunit = (int64_t)vnd->sc_geom.vng_nsectors *
2025 	    vnd->sc_geom.vng_ntracks * vnd->sc_geom.vng_ncylinders;
2026 	dg->dg_secsize = vnd->sc_geom.vng_secsize;
2027 	dg->dg_nsectors = vnd->sc_geom.vng_nsectors;
2028 	dg->dg_ntracks = vnd->sc_geom.vng_ntracks;
2029 	dg->dg_ncylinders = vnd->sc_geom.vng_ncylinders;
2030 
2031 #ifdef DEBUG
2032 	if (vnddebug & VDB_LABEL) {
2033 		printf("dg->dg_secperunit: %" PRId64 "\n", dg->dg_secperunit);
2034 		printf("dg->dg_ncylinders: %u\n", dg->dg_ncylinders);
2035 	}
2036 #endif
2037 	disk_set_info(vnd->sc_dev, &vnd->sc_dkdev, NULL);
2038 }
2039 
2040 #ifdef _MODULE
2041 
2042 #include <sys/module.h>
2043 
2044 #ifdef VND_COMPRESSION
2045 #define VND_DEPENDS "zlib"
2046 #else
2047 #define VND_DEPENDS NULL
2048 #endif
2049 
2050 MODULE(MODULE_CLASS_DRIVER, vnd, VND_DEPENDS);
2051 CFDRIVER_DECL(vnd, DV_DISK, NULL);
2052 
2053 static int
2054 vnd_modcmd(modcmd_t cmd, void *arg)
2055 {
2056 	int bmajor = -1, cmajor = -1,  error = 0;
2057 
2058 	switch (cmd) {
2059 	case MODULE_CMD_INIT:
2060 		error = config_cfdriver_attach(&vnd_cd);
2061 		if (error)
2062 			break;
2063 
2064 		error = config_cfattach_attach(vnd_cd.cd_name, &vnd_ca);
2065 	        if (error) {
2066 			config_cfdriver_detach(&vnd_cd);
2067 			aprint_error("%s: unable to register cfattach\n",
2068 			    vnd_cd.cd_name);
2069 			break;
2070 		}
2071 
2072 		error = devsw_attach("vnd", &vnd_bdevsw, &bmajor,
2073 		    &vnd_cdevsw, &cmajor);
2074 		if (error) {
2075 			config_cfattach_detach(vnd_cd.cd_name, &vnd_ca);
2076 			config_cfdriver_detach(&vnd_cd);
2077 			break;
2078 		}
2079 
2080 		break;
2081 
2082 	case MODULE_CMD_FINI:
2083 		error = config_cfattach_detach(vnd_cd.cd_name, &vnd_ca);
2084 		if (error)
2085 			break;
2086 		config_cfdriver_detach(&vnd_cd);
2087 		devsw_detach(&vnd_bdevsw, &vnd_cdevsw);
2088 		break;
2089 
2090 	case MODULE_CMD_STAT:
2091 		return ENOTTY;
2092 
2093 	default:
2094 		return ENOTTY;
2095 	}
2096 
2097 	return error;
2098 }
2099 
2100 #endif
2101