xref: /netbsd-src/sys/dev/vnd.c (revision 5442314cf240a44fa261cd6bb97009c2adb01e90)
1 /*	$NetBSD: vnd.c,v 1.289 2023/05/19 15:42:43 mlelstv Exp $	*/
2 
3 /*-
4  * Copyright (c) 1996, 1997, 1998, 2008, 2020 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 1.289 2023/05/19 15:42:43 mlelstv 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/fstrans.h>
118 #include <sys/file.h>
119 #include <sys/uio.h>
120 #include <sys/conf.h>
121 #include <sys/kauth.h>
122 #include <sys/module.h>
123 #include <sys/compat_stub.h>
124 #include <sys/atomic.h>
125 
126 #include <uvm/uvm.h>
127 
128 #include <net/zlib.h>
129 
130 #include <miscfs/genfs/genfs.h>
131 #include <miscfs/specfs/specdev.h>
132 
133 #include <dev/dkvar.h>
134 #include <dev/vndvar.h>
135 
136 #include "ioconf.h"
137 
138 #if defined(VNDDEBUG) && !defined(DEBUG)
139 #define DEBUG
140 #endif
141 
142 #ifdef DEBUG
143 int dovndcluster = 1;
144 #define VDB_FOLLOW	0x01
145 #define VDB_INIT	0x02
146 #define VDB_IO		0x04
147 #define VDB_LABEL	0x08
148 int vnddebug = 0;
149 #endif
150 
151 #define vndunit(x)	DISKUNIT(x)
152 
153 struct vndxfer {
154 	struct buf vx_buf;
155 	struct vnd_softc *vx_vnd;
156 };
157 #define	VND_BUFTOXFER(bp)	((struct vndxfer *)(void *)bp)
158 
159 #define VND_GETXFER(vnd)	pool_get(&(vnd)->sc_vxpool, PR_WAITOK)
160 #define VND_PUTXFER(vnd, vx)	pool_put(&(vnd)->sc_vxpool, (vx))
161 
162 #define VNDLABELDEV(dev) \
163     (MAKEDISKDEV(major((dev)), vndunit((dev)), RAW_PART))
164 
165 #define	VND_MAXPENDING(vnd)	((vnd)->sc_maxactive * 4)
166 #define	VND_MAXPAGES(vnd)	(1024 * 1024 / PAGE_SIZE)
167 
168 
169 static void	vndclear(struct vnd_softc *, int);
170 static int	vnddoclear(struct vnd_softc *, int, int, bool);
171 static int	vndsetcred(struct vnd_softc *, kauth_cred_t);
172 static void	vndthrottle(struct vnd_softc *, struct vnode *);
173 static void	vndiodone(struct buf *);
174 #if 0
175 static void	vndshutdown(void);
176 #endif
177 
178 static void	vndgetdefaultlabel(struct vnd_softc *, struct disklabel *);
179 static void	vndgetdisklabel(dev_t, struct vnd_softc *);
180 
181 static int	vndlock(struct vnd_softc *);
182 static void	vndunlock(struct vnd_softc *);
183 #ifdef VND_COMPRESSION
184 static void	compstrategy(struct buf *, off_t);
185 static void	*vnd_alloc(void *, u_int, u_int);
186 static void	vnd_free(void *, void *);
187 #endif /* VND_COMPRESSION */
188 
189 static void	vndthread(void *);
190 static bool	vnode_has_op(const struct vnode *, int);
191 static void	handle_with_rdwr(struct vnd_softc *, const struct buf *,
192 		    struct buf *);
193 static void	handle_with_strategy(struct vnd_softc *, const struct buf *,
194 		    struct buf *);
195 static void	vnd_set_geometry(struct vnd_softc *);
196 
197 static dev_type_open(vndopen);
198 static dev_type_close(vndclose);
199 static dev_type_read(vndread);
200 static dev_type_write(vndwrite);
201 static dev_type_ioctl(vndioctl);
202 static dev_type_strategy(vndstrategy);
203 static dev_type_dump(vnddump);
204 static dev_type_size(vndsize);
205 
206 const struct bdevsw vnd_bdevsw = {
207 	.d_open = vndopen,
208 	.d_close = vndclose,
209 	.d_strategy = vndstrategy,
210 	.d_ioctl = vndioctl,
211 	.d_dump = vnddump,
212 	.d_psize = vndsize,
213 	.d_discard = nodiscard,
214 	.d_flag = D_DISK
215 };
216 
217 const struct cdevsw vnd_cdevsw = {
218 	.d_open = vndopen,
219 	.d_close = vndclose,
220 	.d_read = vndread,
221 	.d_write = vndwrite,
222 	.d_ioctl = vndioctl,
223 	.d_stop = nostop,
224 	.d_tty = notty,
225 	.d_poll = nopoll,
226 	.d_mmap = nommap,
227 	.d_kqfilter = nokqfilter,
228 	.d_discard = nodiscard,
229 	.d_flag = D_DISK
230 };
231 
232 static int	vnd_match(device_t, cfdata_t, void *);
233 static void	vnd_attach(device_t, device_t, void *);
234 static int	vnd_detach(device_t, int);
235 
236 CFATTACH_DECL3_NEW(vnd, sizeof(struct vnd_softc),
237     vnd_match, vnd_attach, vnd_detach, NULL, NULL, NULL, DVF_DETACH_SHUTDOWN);
238 
239 static struct vnd_softc	*vnd_spawn(int);
240 static int	vnd_destroy(device_t);
241 
242 static const struct	dkdriver vnddkdriver = {
243 	.d_strategy = vndstrategy,
244 	.d_minphys = minphys
245 };
246 
247 void
248 vndattach(int num)
249 {
250 	int error;
251 
252 	error = config_cfattach_attach(vnd_cd.cd_name, &vnd_ca);
253 	if (error)
254 		aprint_error("%s: unable to register cfattach, error = %d\n",
255 		    vnd_cd.cd_name, error);
256 }
257 
258 static int
259 vnd_match(device_t self, cfdata_t cfdata, void *aux)
260 {
261 
262 	return 1;
263 }
264 
265 static void
266 vnd_attach(device_t parent, device_t self, void *aux)
267 {
268 	struct vnd_softc *sc = device_private(self);
269 
270 	sc->sc_dev = self;
271 	sc->sc_comp_offsets = NULL;
272 	sc->sc_comp_buff = NULL;
273 	sc->sc_comp_decombuf = NULL;
274 	bufq_alloc(&sc->sc_tab, "disksort", BUFQ_SORT_RAWBLOCK);
275 	disk_init(&sc->sc_dkdev, device_xname(self), &vnddkdriver);
276 	if (!pmf_device_register(self, NULL, NULL))
277 		aprint_error_dev(self, "couldn't establish power handler\n");
278 }
279 
280 static int
281 vnd_detach(device_t self, int flags)
282 {
283 	int error;
284 	struct vnd_softc *sc = device_private(self);
285 
286 	if (sc->sc_flags & VNF_INITED) {
287 		error = vnddoclear(sc, 0, -1, (flags & DETACH_FORCE) != 0);
288 		if (error != 0)
289 			return error;
290 	}
291 
292 	pmf_device_deregister(self);
293 	bufq_free(sc->sc_tab);
294 	disk_destroy(&sc->sc_dkdev);
295 
296 	return 0;
297 }
298 
299 static struct vnd_softc *
300 vnd_spawn(int unit)
301 {
302 	cfdata_t cf;
303 
304 	cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
305 	cf->cf_name = vnd_cd.cd_name;
306 	cf->cf_atname = vnd_cd.cd_name;
307 	cf->cf_unit = unit;
308 	cf->cf_fstate = FSTATE_STAR;
309 
310 	return device_private(config_attach_pseudo(cf));
311 }
312 
313 static int
314 vnd_destroy(device_t dev)
315 {
316 	int error;
317 	cfdata_t cf;
318 
319 	cf = device_cfdata(dev);
320 	error = config_detach(dev, DETACH_QUIET);
321 	if (error)
322 		return error;
323 	free(cf, M_DEVBUF);
324 	return 0;
325 }
326 
327 static int
328 vndopen(dev_t dev, int flags, int mode, struct lwp *l)
329 {
330 	int unit = vndunit(dev);
331 	struct vnd_softc *sc;
332 	int error = 0, part, pmask;
333 	struct disklabel *lp;
334 
335 #ifdef DEBUG
336 	if (vnddebug & VDB_FOLLOW)
337 		printf("vndopen(0x%"PRIx64", 0x%x, 0x%x, %p)\n", dev, flags, mode, l);
338 #endif
339 	sc = device_lookup_private(&vnd_cd, unit);
340 	if (sc == NULL) {
341 		sc = vnd_spawn(unit);
342 		if (sc == NULL)
343 			return ENOMEM;
344 
345 		/* compatibility, keep disklabel after close */
346 		sc->sc_flags = VNF_KLABEL;
347 	}
348 
349 	if ((error = vndlock(sc)) != 0)
350 		return error;
351 
352 	mutex_enter(&sc->sc_dkdev.dk_openlock);
353 
354 	if ((sc->sc_flags & VNF_CLEARING) != 0) {
355 		error = ENXIO;
356 		goto done;
357 	}
358 
359 	lp = sc->sc_dkdev.dk_label;
360 
361 	part = DISKPART(dev);
362 	pmask = (1 << part);
363 
364 	if (sc->sc_dkdev.dk_nwedges != 0 && part != RAW_PART) {
365 		error = EBUSY;
366 		goto done;
367 	}
368 
369 	if (sc->sc_flags & VNF_INITED) {
370 		if ((sc->sc_dkdev.dk_openmask & ~(1<<RAW_PART)) != 0) {
371 			/*
372 			 * If any non-raw partition is open, but the disk
373 			 * has been invalidated, disallow further opens.
374 			 */
375 			if ((sc->sc_flags & VNF_VLABEL) == 0) {
376 				error = EIO;
377 				goto done;
378 			}
379 		} else {
380 			/*
381 			 * Load the partition info if not already loaded.
382 			 */
383 			if ((sc->sc_flags & VNF_VLABEL) == 0) {
384 				sc->sc_flags |= VNF_VLABEL;
385 				vndgetdisklabel(dev, sc);
386 			}
387 		}
388 	}
389 
390 	/* Check that the partitions exists. */
391 	if (part != RAW_PART) {
392 		if (((sc->sc_flags & VNF_INITED) == 0) ||
393 		    ((part >= lp->d_npartitions) ||
394 		     (lp->d_partitions[part].p_fstype == FS_UNUSED))) {
395 			error = ENXIO;
396 			goto done;
397 		}
398 	}
399 
400 	/* Prevent our unit from being unconfigured while open. */
401 	switch (mode) {
402 	case S_IFCHR:
403 		sc->sc_dkdev.dk_copenmask |= pmask;
404 		break;
405 
406 	case S_IFBLK:
407 		sc->sc_dkdev.dk_bopenmask |= pmask;
408 		break;
409 	}
410 	sc->sc_dkdev.dk_openmask =
411 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
412 
413  done:
414 	mutex_exit(&sc->sc_dkdev.dk_openlock);
415 	vndunlock(sc);
416 	return error;
417 }
418 
419 static int
420 vndclose(dev_t dev, int flags, int mode, struct lwp *l)
421 {
422 	int unit = vndunit(dev);
423 	struct vnd_softc *sc;
424 	int error = 0, part;
425 
426 #ifdef DEBUG
427 	if (vnddebug & VDB_FOLLOW)
428 		printf("vndclose(0x%"PRIx64", 0x%x, 0x%x, %p)\n", dev, flags, mode, l);
429 #endif
430 	sc = device_lookup_private(&vnd_cd, unit);
431 	if (sc == NULL)
432 		return ENXIO;
433 
434 	if ((error = vndlock(sc)) != 0)
435 		return error;
436 
437 	mutex_enter(&sc->sc_dkdev.dk_openlock);
438 
439 	part = DISKPART(dev);
440 
441 	/* ...that much closer to allowing unconfiguration... */
442 	switch (mode) {
443 	case S_IFCHR:
444 		sc->sc_dkdev.dk_copenmask &= ~(1 << part);
445 		break;
446 
447 	case S_IFBLK:
448 		sc->sc_dkdev.dk_bopenmask &= ~(1 << part);
449 		break;
450 	}
451 	sc->sc_dkdev.dk_openmask =
452 	    sc->sc_dkdev.dk_copenmask | sc->sc_dkdev.dk_bopenmask;
453 
454 	/* are we last opener ? */
455 	if (sc->sc_dkdev.dk_openmask == 0) {
456 		if ((sc->sc_flags & VNF_KLABEL) == 0)
457 			sc->sc_flags &= ~VNF_VLABEL;
458 	}
459 
460 	mutex_exit(&sc->sc_dkdev.dk_openlock);
461 
462 	vndunlock(sc);
463 
464 	if ((sc->sc_flags & VNF_INITED) == 0) {
465 		if ((error = vnd_destroy(sc->sc_dev)) != 0) {
466 			aprint_error_dev(sc->sc_dev,
467 			    "unable to detach instance\n");
468 			return error;
469 		}
470 	}
471 
472 	return 0;
473 }
474 
475 /*
476  * Queue the request, and wakeup the kernel thread to handle it.
477  */
478 static void
479 vndstrategy(struct buf *bp)
480 {
481 	int unit = vndunit(bp->b_dev);
482 	struct vnd_softc *vnd =
483 	    device_lookup_private(&vnd_cd, unit);
484 	struct disklabel *lp;
485 	daddr_t blkno;
486 	int s = splbio();
487 
488 	if (vnd == NULL) {
489 		bp->b_error = ENXIO;
490 		goto done;
491 	}
492 	lp = vnd->sc_dkdev.dk_label;
493 
494 	if ((vnd->sc_flags & VNF_INITED) == 0) {
495 		bp->b_error = ENXIO;
496 		goto done;
497 	}
498 
499 	/*
500 	 * The transfer must be a whole number of blocks.
501 	 */
502 	if ((bp->b_bcount % lp->d_secsize) != 0) {
503 		bp->b_error = EINVAL;
504 		goto done;
505 	}
506 
507 	/*
508 	 * check if we're read-only.
509 	 */
510 	if ((vnd->sc_flags & VNF_READONLY) && !(bp->b_flags & B_READ)) {
511 		bp->b_error = EACCES;
512 		goto done;
513 	}
514 
515 	/* If it's a nil transfer, wake up the top half now. */
516 	if (bp->b_bcount == 0) {
517 		goto done;
518 	}
519 
520 	/*
521 	 * Do bounds checking and adjust transfer.  If there's an error,
522 	 * the bounds check will flag that for us.
523 	 */
524 	if (DISKPART(bp->b_dev) == RAW_PART) {
525 		if (bounds_check_with_mediasize(bp, DEV_BSIZE,
526 		    vnd->sc_size) <= 0)
527 			goto done;
528 	} else {
529 		if (bounds_check_with_label(&vnd->sc_dkdev,
530 		    bp, vnd->sc_flags & (VNF_WLABEL|VNF_LABELLING)) <= 0)
531 			goto done;
532 	}
533 
534 	/*
535 	 * Put the block number in terms of the logical blocksize
536 	 * of the "device".
537 	 */
538 
539 	blkno = bp->b_blkno / (lp->d_secsize / DEV_BSIZE);
540 
541 	/*
542 	 * Translate the partition-relative block number to an absolute.
543 	 */
544 	if (DISKPART(bp->b_dev) != RAW_PART) {
545 		struct partition *pp;
546 
547 		pp = &vnd->sc_dkdev.dk_label->d_partitions[
548 		    DISKPART(bp->b_dev)];
549 		blkno += pp->p_offset;
550 	}
551 	bp->b_rawblkno = blkno;
552 
553 #ifdef DEBUG
554 	if (vnddebug & VDB_FOLLOW)
555 		printf("vndstrategy(%p): unit %d\n", bp, unit);
556 #endif
557 	if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
558 		/*
559 		 * Limit the number of pending requests to not exhaust
560 		 * resources needed for I/O but always allow the worker
561 		 * thread to add requests, as a wedge on vnd queues
562 		 * requests with biodone() -> dkstart() -> vndstrategy().
563 		 */
564 		if (curlwp != vnd->sc_kthread && curlwp != uvm.pagedaemon_lwp) {
565 			while (vnd->sc_pending >= VND_MAXPENDING(vnd))
566 				tsleep(&vnd->sc_pending, PRIBIO, "vndpc", 0);
567 		}
568 		vnd->sc_pending++;
569 		KASSERT(vnd->sc_pending > 0);
570 	}
571 	bufq_put(vnd->sc_tab, bp);
572 	wakeup(&vnd->sc_tab);
573 	splx(s);
574 	return;
575 
576 done:
577 	bp->b_resid = bp->b_bcount;
578 	biodone(bp);
579 	splx(s);
580 }
581 
582 static bool
583 vnode_has_strategy(struct vnd_softc *vnd)
584 {
585 	return vnode_has_op(vnd->sc_vp, VOFFSET(vop_bmap)) &&
586 	    vnode_has_op(vnd->sc_vp, VOFFSET(vop_strategy));
587 }
588 
589 /* Verify that I/O requests cannot be smaller than the
590  * smallest I/O size supported by the backend.
591  */
592 static bool
593 vnode_has_large_blocks(struct vnd_softc *vnd)
594 {
595 	u_int32_t vnd_secsize, iosize;
596 
597 	iosize = vnd->sc_iosize;
598 	vnd_secsize = vnd->sc_geom.vng_secsize;
599 
600 	return vnd_secsize % iosize != 0;
601 }
602 
603 /* XXX this function needs a reliable check to detect
604  * sparse files. Otherwise, bmap/strategy may be used
605  * and fail on non-allocated blocks. VOP_READ/VOP_WRITE
606  * works on sparse files.
607  */
608 #if notyet
609 static bool
610 vnode_strategy_probe(struct vnd_softc *vnd)
611 {
612 	int error;
613 	daddr_t nbn;
614 
615 	if (!vnode_has_strategy(vnd))
616 		return false;
617 
618 	if (vnode_has_large_blocks(vnd))
619 		return false;
620 
621 	/* Convert the first logical block number to its
622 	 * physical block number.
623 	 */
624 	error = 0;
625 	vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
626 	error = VOP_BMAP(vnd->sc_vp, 0, NULL, &nbn, NULL);
627 	VOP_UNLOCK(vnd->sc_vp);
628 
629 	/* Test if that worked. */
630 	if (error == 0 && (long)nbn == -1)
631 		return false;
632 
633 	return true;
634 }
635 #endif
636 
637 static void
638 vndthread(void *arg)
639 {
640 	struct vnd_softc *vnd = arg;
641 	int s;
642 
643 	/* Determine whether we can *use* VOP_BMAP and VOP_STRATEGY to
644 	 * directly access the backing vnode.  If we can, use these two
645 	 * operations to avoid messing with the local buffer cache.
646 	 * Otherwise fall back to regular VOP_READ/VOP_WRITE operations
647 	 * which are guaranteed to work with any file system. */
648 	if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0 &&
649 	    ! vnode_has_strategy(vnd))
650 		vnd->sc_flags |= VNF_USE_VN_RDWR;
651 
652 	/* VOP_STRATEGY can only be used if the backing vnode allows
653 	 * to access blocks as small as defined by the vnd geometry.
654 	 */
655 	if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0 &&
656 	    vnode_has_large_blocks(vnd))
657 		vnd->sc_flags |= VNF_USE_VN_RDWR;
658 
659 #ifdef DEBUG
660 	if (vnddebug & VDB_INIT)
661 		printf("vndthread: vp %p, %s\n", vnd->sc_vp,
662 		    (vnd->sc_flags & VNF_USE_VN_RDWR) == 0 ?
663 		    "using bmap/strategy operations" :
664 		    "using read/write operations");
665 #endif
666 
667 	s = splbio();
668 	vnd->sc_flags |= VNF_KTHREAD;
669 	wakeup(&vnd->sc_kthread);
670 
671 	/*
672 	 * Dequeue requests and serve them depending on the available
673 	 * vnode operations.
674 	 */
675 	while ((vnd->sc_flags & VNF_VUNCONF) == 0) {
676 		struct vndxfer *vnx;
677 		struct buf *obp;
678 		struct buf *bp;
679 
680 		obp = bufq_get(vnd->sc_tab);
681 		if (obp == NULL) {
682 			tsleep(&vnd->sc_tab, PRIBIO, "vndbp", 0);
683 			continue;
684 		};
685 		if ((vnd->sc_flags & VNF_USE_VN_RDWR)) {
686 			KASSERT(vnd->sc_pending > 0);
687 			if (vnd->sc_pending-- == VND_MAXPENDING(vnd))
688 				wakeup(&vnd->sc_pending);
689 		}
690 		splx(s);
691 #ifdef DEBUG
692 		if (vnddebug & VDB_FOLLOW)
693 			printf("vndthread(%p)\n", obp);
694 #endif
695 
696 		if (vnd->sc_vp->v_mount == NULL) {
697 			obp->b_error = ENXIO;
698 			goto done;
699 		}
700 #ifdef VND_COMPRESSION
701 		/* handle a compressed read */
702 		if ((obp->b_flags & B_READ) != 0 && (vnd->sc_flags & VNF_COMP)) {
703 			off_t bn;
704 
705 			/* Convert to a byte offset within the file. */
706 			bn = obp->b_rawblkno *
707 			    vnd->sc_dkdev.dk_label->d_secsize;
708 
709 			compstrategy(obp, bn);
710 			goto done;
711 		}
712 #endif /* VND_COMPRESSION */
713 
714 		/*
715 		 * Allocate a header for this transfer and link it to the
716 		 * buffer
717 		 */
718 		s = splbio();
719 		vnx = VND_GETXFER(vnd);
720 		splx(s);
721 		vnx->vx_vnd = vnd;
722 
723 		s = splbio();
724 		while (vnd->sc_active >= vnd->sc_maxactive) {
725 			tsleep(&vnd->sc_tab, PRIBIO, "vndac", 0);
726 		}
727 		vnd->sc_active++;
728 		splx(s);
729 
730 		/* Instrumentation. */
731 		disk_busy(&vnd->sc_dkdev);
732 
733 		bp = &vnx->vx_buf;
734 		buf_init(bp);
735 		bp->b_flags = (obp->b_flags & (B_READ | B_PHYS | B_RAW));
736 		bp->b_oflags = obp->b_oflags;
737 		bp->b_cflags = obp->b_cflags;
738 		bp->b_iodone = vndiodone;
739 		bp->b_private = obp;
740 		bp->b_vp = vnd->sc_vp;
741 		bp->b_objlock = bp->b_vp->v_interlock;
742 		bp->b_data = obp->b_data;
743 		bp->b_bcount = obp->b_bcount;
744 		BIO_COPYPRIO(bp, obp);
745 
746 		/* Make sure the request succeeds while suspending this fs. */
747 		fstrans_start_lazy(vnd->sc_vp->v_mount);
748 
749 		/* Handle the request using the appropriate operations. */
750 		if ((vnd->sc_flags & VNF_USE_VN_RDWR) == 0)
751 			handle_with_strategy(vnd, obp, bp);
752 		else
753 			handle_with_rdwr(vnd, obp, bp);
754 
755 		fstrans_done(vnd->sc_vp->v_mount);
756 
757 		s = splbio();
758 		continue;
759 
760 done:
761 		biodone(obp);
762 		s = splbio();
763 	}
764 
765 	vnd->sc_flags &= (~VNF_KTHREAD | VNF_VUNCONF);
766 	wakeup(&vnd->sc_kthread);
767 	splx(s);
768 	kthread_exit(0);
769 }
770 
771 /*
772  * Checks if the given vnode supports the requested operation.
773  * The operation is specified the offset returned by VOFFSET.
774  *
775  * XXX The test below used to determine this is quite fragile
776  * because it relies on the file system to use genfs to specify
777  * unimplemented operations.  There might be another way to do
778  * it more cleanly.
779  */
780 static bool
781 vnode_has_op(const struct vnode *vp, int opoffset)
782 {
783 	int (*defaultp)(void *);
784 	int (*opp)(void *);
785 
786 	defaultp = vp->v_op[VOFFSET(vop_default)];
787 	opp = vp->v_op[opoffset];
788 
789 	return opp != defaultp && opp != genfs_eopnotsupp &&
790 	    opp != genfs_badop && opp != genfs_nullop;
791 }
792 
793 /*
794  * Handles the read/write request given in 'bp' using the vnode's VOP_READ
795  * and VOP_WRITE operations.
796  *
797  * 'obp' is a pointer to the original request fed to the vnd device.
798  */
799 static void
800 handle_with_rdwr(struct vnd_softc *vnd, const struct buf *obp, struct buf *bp)
801 {
802 	bool doread;
803 	off_t offset;
804 	size_t len, resid;
805 	struct vnode *vp;
806 	int npages;
807 
808 	doread = bp->b_flags & B_READ;
809 	offset = obp->b_rawblkno * vnd->sc_dkdev.dk_label->d_secsize;
810 	len = bp->b_bcount;
811 	vp = vnd->sc_vp;
812 
813 #if defined(DEBUG)
814 	if (vnddebug & VDB_IO)
815 		printf("vnd (rdwr): vp %p, %s, rawblkno 0x%" PRIx64
816 		    ", secsize %d, offset %" PRIu64
817 		    ", bcount %d\n",
818 		    vp, doread ? "read" : "write", obp->b_rawblkno,
819 		    vnd->sc_dkdev.dk_label->d_secsize, offset,
820 		    bp->b_bcount);
821 #endif
822 
823 	/* Issue the read or write operation. */
824 	bp->b_error =
825 	    vn_rdwr(doread ? UIO_READ : UIO_WRITE,
826 	    vp, bp->b_data, len, offset, UIO_SYSSPACE,
827 	    IO_ADV_ENCODE(POSIX_FADV_NOREUSE) | IO_DIRECT,
828 		vnd->sc_cred, &resid, NULL);
829 	bp->b_resid = resid;
830 
831 	/*
832 	 * Avoid caching too many pages, the vnd user
833 	 * is usually a filesystem and caches itself.
834 	 * We need some amount of caching to not hinder
835 	 * read-ahead and write-behind operations.
836 	 */
837 	npages = atomic_load_relaxed(&vp->v_uobj.uo_npages);
838 	if (npages > VND_MAXPAGES(vnd)) {
839 		rw_enter(vp->v_uobj.vmobjlock, RW_WRITER);
840 		(void) VOP_PUTPAGES(vp, 0, 0,
841 		    PGO_ALLPAGES | PGO_CLEANIT | PGO_FREE);
842 	}
843 
844 	/* We need to increase the number of outputs on the vnode if
845 	 * there was any write to it. */
846 	if (!doread) {
847 		mutex_enter(vp->v_interlock);
848 		vp->v_numoutput++;
849 		mutex_exit(vp->v_interlock);
850 	}
851 
852 	biodone(bp);
853 }
854 
855 /*
856  * Handes the read/write request given in 'bp' using the vnode's VOP_BMAP
857  * and VOP_STRATEGY operations.
858  *
859  * 'obp' is a pointer to the original request fed to the vnd device.
860  */
861 static void
862 handle_with_strategy(struct vnd_softc *vnd, const struct buf *obp,
863     struct buf *bp)
864 {
865 	int bsize, error, flags, skipped;
866 	size_t resid, sz;
867 	off_t bn, offset;
868 	struct vnode *vp;
869 	struct buf *nbp = NULL;
870 
871 	flags = obp->b_flags;
872 
873 
874 	/* convert to a byte offset within the file. */
875 	bn = obp->b_rawblkno * vnd->sc_dkdev.dk_label->d_secsize;
876 
877 	bsize = vnd->sc_vp->v_mount->mnt_stat.f_iosize;
878 	skipped = 0;
879 
880 	/*
881 	 * Break the request into bsize pieces and feed them
882 	 * sequentially using VOP_BMAP/VOP_STRATEGY.
883 	 * We do it this way to keep from flooding NFS servers if we
884 	 * are connected to an NFS file.  This places the burden on
885 	 * the client rather than the server.
886 	 */
887 	error = 0;
888 	bp->b_resid = bp->b_bcount;
889 	for (offset = 0, resid = bp->b_resid; /* true */;
890 	    resid -= sz, offset += sz) {
891 		daddr_t nbn;
892 		int off, nra;
893 
894 		nra = 0;
895 		vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
896 		error = VOP_BMAP(vnd->sc_vp, bn / bsize, &vp, &nbn, &nra);
897 		VOP_UNLOCK(vnd->sc_vp);
898 
899 		if (error == 0 && (long)nbn == -1)
900 			error = EIO;
901 
902 		/*
903 		 * If there was an error or a hole in the file...punt.
904 		 * Note that we may have to wait for any operations
905 		 * that we have already fired off before releasing
906 		 * the buffer.
907 		 *
908 		 * XXX we could deal with holes here but it would be
909 		 * a hassle (in the write case).
910 		 */
911 		if (error) {
912 			skipped += resid;
913 			break;
914 		}
915 
916 #ifdef DEBUG
917 		if (!dovndcluster)
918 			nra = 0;
919 #endif
920 
921 		off = bn % bsize;
922 		sz = MIN(((off_t)1 + nra) * bsize - off, resid);
923 #ifdef	DEBUG
924 		if (vnddebug & VDB_IO)
925 			printf("vndstrategy: vp %p/%p bn 0x%qx/0x%" PRIx64
926 			    " sz 0x%zx\n", vnd->sc_vp, vp, (long long)bn,
927 			    nbn, sz);
928 #endif
929 
930 		nbp = getiobuf(vp, true);
931 		nestiobuf_setup(bp, nbp, offset, sz);
932 		nbp->b_blkno = nbn + btodb(off);
933 
934 #if 0 /* XXX #ifdef DEBUG */
935 		if (vnddebug & VDB_IO)
936 			printf("vndstart(%ld): bp %p vp %p blkno "
937 			    "0x%" PRIx64 " flags %x addr %p cnt 0x%x\n",
938 			    (long) (vnd-vnd_softc), &nbp->vb_buf,
939 			    nbp->vb_buf.b_vp, nbp->vb_buf.b_blkno,
940 			    nbp->vb_buf.b_flags, nbp->vb_buf.b_data,
941 			    nbp->vb_buf.b_bcount);
942 #endif
943 		if (resid == sz) {
944 			break;
945 		}
946 		VOP_STRATEGY(vp, nbp);
947 		bn += sz;
948 	}
949 	if (!(flags & B_READ)) {
950 		struct vnode *w_vp;
951 		/*
952 		 * this is the last nested buf, account for
953 		 * the parent buf write too.
954 		 * This has to be done last, so that
955 		 * fsync won't wait for this write which
956 		 * has no chance to complete before all nested bufs
957 		 * have been queued. But it has to be done
958 		 * before the last VOP_STRATEGY()
959 		 * or the call to nestiobuf_done().
960 		 */
961 		w_vp = bp->b_vp;
962 		mutex_enter(w_vp->v_interlock);
963 		w_vp->v_numoutput++;
964 		mutex_exit(w_vp->v_interlock);
965 	}
966 	KASSERT(skipped != 0 || nbp != NULL);
967 	if (skipped)
968 		nestiobuf_done(bp, skipped, error);
969 	else
970 		VOP_STRATEGY(vp, nbp);
971 }
972 
973 static void
974 vndiodone(struct buf *bp)
975 {
976 	struct vndxfer *vnx = VND_BUFTOXFER(bp);
977 	struct vnd_softc *vnd = vnx->vx_vnd;
978 	struct buf *obp = bp->b_private;
979 	int s = splbio();
980 
981 	KERNEL_LOCK(1, NULL);		/* XXXSMP */
982 	KASSERT(&vnx->vx_buf == bp);
983 	KASSERT(vnd->sc_active > 0);
984 #ifdef DEBUG
985 	if (vnddebug & VDB_IO) {
986 		printf("vndiodone1: bp %p iodone: error %d\n",
987 		    bp, bp->b_error);
988 	}
989 #endif
990 	disk_unbusy(&vnd->sc_dkdev, bp->b_bcount - bp->b_resid,
991 	    (bp->b_flags & B_READ));
992 	vnd->sc_active--;
993 	if (vnd->sc_active == 0) {
994 		wakeup(&vnd->sc_tab);
995 	}
996 	KERNEL_UNLOCK_ONE(NULL);	/* XXXSMP */
997 	splx(s);
998 	obp->b_error = bp->b_error;
999 	obp->b_resid = bp->b_resid;
1000 	buf_destroy(bp);
1001 	VND_PUTXFER(vnd, vnx);
1002 	biodone(obp);
1003 }
1004 
1005 /* ARGSUSED */
1006 static int
1007 vndread(dev_t dev, struct uio *uio, int flags)
1008 {
1009 	int unit = vndunit(dev);
1010 	struct vnd_softc *sc;
1011 
1012 #ifdef DEBUG
1013 	if (vnddebug & VDB_FOLLOW)
1014 		printf("vndread(0x%"PRIx64", %p)\n", dev, uio);
1015 #endif
1016 
1017 	sc = device_lookup_private(&vnd_cd, unit);
1018 	if (sc == NULL)
1019 		return ENXIO;
1020 
1021 	if ((sc->sc_flags & VNF_INITED) == 0)
1022 		return ENXIO;
1023 
1024 	return physio(vndstrategy, NULL, dev, B_READ, minphys, uio);
1025 }
1026 
1027 /* ARGSUSED */
1028 static int
1029 vndwrite(dev_t dev, struct uio *uio, int flags)
1030 {
1031 	int unit = vndunit(dev);
1032 	struct vnd_softc *sc;
1033 
1034 #ifdef DEBUG
1035 	if (vnddebug & VDB_FOLLOW)
1036 		printf("vndwrite(0x%"PRIx64", %p)\n", dev, uio);
1037 #endif
1038 
1039 	sc = device_lookup_private(&vnd_cd, unit);
1040 	if (sc == NULL)
1041 		return ENXIO;
1042 
1043 	if ((sc->sc_flags & VNF_INITED) == 0)
1044 		return ENXIO;
1045 
1046 	return physio(vndstrategy, NULL, dev, B_WRITE, minphys, uio);
1047 }
1048 
1049 static int
1050 vnd_cget(struct lwp *l, int unit, int *un, struct vattr *va)
1051 {
1052 	int error;
1053 	struct vnd_softc *vnd;
1054 
1055 	if (*un == -1)
1056 		*un = unit;
1057 	if (*un < 0)
1058 		return EINVAL;
1059 
1060 	vnd = device_lookup_private(&vnd_cd, *un);
1061 	if (vnd == NULL)
1062 		return -1;
1063 
1064 	if ((vnd->sc_flags & VNF_INITED) == 0)
1065 		return -1;
1066 
1067 	vn_lock(vnd->sc_vp, LK_SHARED | LK_RETRY);
1068 	error = VOP_GETATTR(vnd->sc_vp, va, l->l_cred);
1069 	VOP_UNLOCK(vnd->sc_vp);
1070 	return error;
1071 }
1072 
1073 static int
1074 vnddoclear(struct vnd_softc *vnd, int pmask, int minor, bool force)
1075 {
1076 	int error;
1077 
1078 	if ((error = vndlock(vnd)) != 0)
1079 		return error;
1080 
1081 	/*
1082 	 * Don't unconfigure if any other partitions are open
1083 	 * or if both the character and block flavors of this
1084 	 * partition are open.
1085 	 */
1086 	if (DK_BUSY(vnd, pmask) && !force) {
1087 		vndunlock(vnd);
1088 		return EBUSY;
1089 	}
1090 
1091 	/* Delete all of our wedges */
1092 	dkwedge_delall(&vnd->sc_dkdev);
1093 
1094 	/*
1095 	 * XXX vndclear() might call vndclose() implicitly;
1096 	 * release lock to avoid recursion
1097 	 *
1098 	 * Set VNF_CLEARING to prevent vndopen() from
1099 	 * sneaking in after we vndunlock().
1100 	 */
1101 	vnd->sc_flags |= VNF_CLEARING;
1102 	vndunlock(vnd);
1103 	vndclear(vnd, minor);
1104 #ifdef DEBUG
1105 	if (vnddebug & VDB_INIT)
1106 		printf("%s: CLRed\n", __func__);
1107 #endif
1108 
1109 	/* Destroy the xfer and buffer pools. */
1110 	pool_destroy(&vnd->sc_vxpool);
1111 
1112 	/* Detach the disk. */
1113 	disk_detach(&vnd->sc_dkdev);
1114 
1115 	return 0;
1116 }
1117 
1118 static int
1119 vndioctl_get(struct lwp *l, void *data, int unit, struct vattr *va)
1120 {
1121 	int error;
1122 
1123 	KASSERT(l);
1124 
1125 	/* the first member is always int vnd_unit in all the versions */
1126 	if (*(int *)data >= vnd_cd.cd_ndevs)
1127 		return ENXIO;
1128 
1129 	switch (error = vnd_cget(l, unit, (int *)data, va)) {
1130 	case -1:
1131 		/* unused is not an error */
1132 		memset(va, 0, sizeof(*va));
1133 		/*FALLTHROUGH*/
1134 	case 0:
1135 		return 0;
1136 	default:
1137 		return error;
1138 	}
1139 }
1140 
1141 /* ARGSUSED */
1142 static int
1143 vndioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1144 {
1145 	bool force;
1146 	int unit = vndunit(dev);
1147 	struct vnd_softc *vnd;
1148 	struct vnd_ioctl *vio;
1149 	struct vattr vattr;
1150 	struct pathbuf *pb;
1151 	struct vnode *vp;
1152 	int error, part, pmask;
1153 	uint64_t geomsize;
1154 	int fflags;
1155 #ifdef __HAVE_OLD_DISKLABEL
1156 	struct disklabel newlabel;
1157 #endif
1158 
1159 #ifdef DEBUG
1160 	if (vnddebug & VDB_FOLLOW)
1161 		printf("vndioctl(0x%"PRIx64", 0x%lx, %p, 0x%x, %p): unit %d\n",
1162 		    dev, cmd, data, flag, l->l_proc, unit);
1163 #endif
1164 	/* Do the get's first; they don't need initialization or verification */
1165 	switch (cmd) {
1166 	case VNDIOCGET:
1167 		if ((error = vndioctl_get(l, data, unit, &vattr)) != 0)
1168 			return error;
1169 
1170 		struct vnd_user *vnu = data;
1171 		vnu->vnu_dev = vattr.va_fsid;
1172 		vnu->vnu_ino = vattr.va_fileid;
1173 		return 0;
1174 
1175 	default:
1176 		/* First check for COMPAT_50 hook */
1177 		MODULE_HOOK_CALL(compat_vndioctl_50_hook,
1178 		    (cmd, l, data, unit, &vattr, vndioctl_get),
1179 		    enosys(), error);
1180 
1181 		/*
1182 		 * If not present, then COMPAT_30 hook also not
1183 		 * present, so just continue with checks for the
1184 		 * "write" commands
1185 		 */
1186 		if (error == ENOSYS) {
1187 			error = 0;
1188 			break;
1189 		}
1190 
1191 		/* If not already handled, try the COMPAT_30 hook */
1192 		if (error == EPASSTHROUGH)
1193 			MODULE_HOOK_CALL(compat_vndioctl_30_hook,
1194 			    (cmd, l, data, unit, &vattr, vndioctl_get),
1195 			    enosys(), error);
1196 
1197 		/* If no COMPAT_30 module, or not handled, check writes */
1198 		if (error == ENOSYS || error == EPASSTHROUGH) {
1199 			error = 0;
1200 			break;
1201 		}
1202 		return error;
1203 	}
1204 
1205 	vnd = device_lookup_private(&vnd_cd, unit);
1206 	if (vnd == NULL)
1207 		return ENXIO;
1208 	vio = (struct vnd_ioctl *)data;
1209 
1210 	/* Must be open for writes for these commands... */
1211 	switch (cmd) {
1212 	case VNDIOCSET50:
1213 	case VNDIOCCLR50:
1214 		if (!compat_vndioctl_50_hook.hooked)
1215 			return EINVAL;
1216 		/* FALLTHROUGH */
1217 	case VNDIOCSET:
1218 	case VNDIOCCLR:
1219 	case DIOCSDINFO:
1220 	case DIOCWDINFO:
1221 #ifdef __HAVE_OLD_DISKLABEL
1222 	case ODIOCSDINFO:
1223 	case ODIOCWDINFO:
1224 #endif
1225 	case DIOCKLABEL:
1226 	case DIOCWLABEL:
1227 	case DIOCCACHESYNC:
1228 		if ((flag & FWRITE) == 0)
1229 			return EBADF;
1230 	}
1231 
1232 	switch (cmd) {
1233 	case VNDIOCSET50:
1234 	case VNDIOCSET:
1235 		/* Must not be initialized */
1236 		if (vnd->sc_flags & VNF_INITED)
1237 			return EBUSY;
1238 		break;
1239 	default:
1240 		/* Must be initialized */
1241 		if ((vnd->sc_flags & VNF_INITED) == 0)
1242 			return ENXIO;
1243 		break;
1244 	}
1245 
1246 	error = disk_ioctl(&vnd->sc_dkdev, dev, cmd, data, flag, l);
1247 	if (error != EPASSTHROUGH)
1248 		return error;
1249 
1250 	switch (cmd) {
1251 	case VNDIOCSET50:
1252 	case VNDIOCSET:
1253 		if ((error = vndlock(vnd)) != 0)
1254 			return error;
1255 
1256 		fflags = FREAD;
1257 		if ((vio->vnd_flags & VNDIOF_READONLY) == 0)
1258 			fflags |= FWRITE;
1259 		if ((vio->vnd_flags & VNDIOF_FILEIO) != 0)
1260 			vnd->sc_flags |= VNF_USE_VN_RDWR;
1261 		error = pathbuf_copyin(vio->vnd_file, &pb);
1262 		if (error) {
1263 			goto unlock_and_exit;
1264 		}
1265 		error = vn_open(NULL, pb, 0, fflags, 0, &vp, NULL, NULL);
1266 		if (error != 0) {
1267 			pathbuf_destroy(pb);
1268 			goto unlock_and_exit;
1269 		}
1270 		KASSERT(l);
1271 		error = VOP_GETATTR(vp, &vattr, l->l_cred);
1272 		if (!error && vp->v_type != VREG)
1273 			error = EOPNOTSUPP;
1274 		if (!error && vattr.va_bytes < vattr.va_size)
1275 			/* File is definitely sparse, use vn_rdwr() */
1276 			vnd->sc_flags |= VNF_USE_VN_RDWR;
1277 		if (error) {
1278 			VOP_UNLOCK(vp);
1279 			goto close_and_exit;
1280 		}
1281 
1282 		/* If using a compressed file, initialize its info */
1283 		/* (or abort with an error if kernel has no compression) */
1284 		if (vio->vnd_flags & VNDIOF_COMP) {
1285 #ifdef VND_COMPRESSION
1286 			struct vnd_comp_header *ch;
1287 			int i;
1288 			uint32_t comp_size;
1289 			uint32_t comp_maxsize;
1290 
1291 			/* allocate space for compressed file header */
1292 			ch = malloc(sizeof(struct vnd_comp_header),
1293 			    M_TEMP, M_WAITOK);
1294 
1295 			/* read compressed file header */
1296 			error = vn_rdwr(UIO_READ, vp, (void *)ch,
1297 			    sizeof(struct vnd_comp_header), 0, UIO_SYSSPACE,
1298 			    IO_UNIT|IO_NODELOCKED, l->l_cred, NULL, NULL);
1299 			if (error) {
1300 				free(ch, M_TEMP);
1301 				VOP_UNLOCK(vp);
1302 				goto close_and_exit;
1303 			}
1304 
1305 			if (be32toh(ch->block_size) == 0 ||
1306 			    be32toh(ch->num_blocks) > UINT32_MAX - 1) {
1307 				free(ch, M_TEMP);
1308 				VOP_UNLOCK(vp);
1309 				goto close_and_exit;
1310 			}
1311 
1312 			/* save some header info */
1313 			vnd->sc_comp_blksz = be32toh(ch->block_size);
1314 			/* note last offset is the file byte size */
1315 			vnd->sc_comp_numoffs = be32toh(ch->num_blocks) + 1;
1316 			free(ch, M_TEMP);
1317 			if (!DK_DEV_BSIZE_OK(vnd->sc_comp_blksz)) {
1318 				VOP_UNLOCK(vp);
1319 				error = EINVAL;
1320 				goto close_and_exit;
1321 			}
1322 			KASSERT(0 < vnd->sc_comp_blksz);
1323 			KASSERT(0 < vnd->sc_comp_numoffs);
1324 			/*
1325 			 * @#^@!$& gcc -Wtype-limits refuses to let me
1326 			 * write SIZE_MAX/sizeof(uint64_t) < numoffs,
1327 			 * because the range of the type on amd64 makes
1328 			 * the comparisons always false.
1329 			 */
1330 #if SIZE_MAX <= UINT32_MAX*(64/CHAR_BIT)
1331 			if (SIZE_MAX/sizeof(uint64_t) < vnd->sc_comp_numoffs) {
1332 				VOP_UNLOCK(vp);
1333 				error = EINVAL;
1334 				goto close_and_exit;
1335 			}
1336 #endif
1337 			if ((vattr.va_size < sizeof(struct vnd_comp_header)) ||
1338 			    (vattr.va_size - sizeof(struct vnd_comp_header) <
1339 				sizeof(uint64_t)*vnd->sc_comp_numoffs) ||
1340 			    (UQUAD_MAX/vnd->sc_comp_blksz <
1341 				vnd->sc_comp_numoffs - 1)) {
1342 				VOP_UNLOCK(vp);
1343 				error = EINVAL;
1344 				goto close_and_exit;
1345 			}
1346 
1347 			/* set decompressed file size */
1348 			KASSERT(vnd->sc_comp_numoffs - 1 <=
1349 			    UQUAD_MAX/vnd->sc_comp_blksz);
1350 			vattr.va_size =
1351 			    ((u_quad_t)vnd->sc_comp_numoffs - 1) *
1352 			     (u_quad_t)vnd->sc_comp_blksz;
1353 
1354 			/* allocate space for all the compressed offsets */
1355 			__CTASSERT(UINT32_MAX <= UQUAD_MAX/sizeof(uint64_t));
1356 			vnd->sc_comp_offsets =
1357 			    malloc(sizeof(uint64_t) * vnd->sc_comp_numoffs,
1358 				M_DEVBUF, M_WAITOK);
1359 
1360 			/* read in the offsets */
1361 			error = vn_rdwr(UIO_READ, vp,
1362 			    (void *)vnd->sc_comp_offsets,
1363 			    sizeof(uint64_t) * vnd->sc_comp_numoffs,
1364 			    sizeof(struct vnd_comp_header), UIO_SYSSPACE,
1365 			  IO_UNIT|IO_NODELOCKED, l->l_cred, NULL, NULL);
1366 			if (error) {
1367 				VOP_UNLOCK(vp);
1368 				goto close_and_exit;
1369 			}
1370 			/*
1371 			 * find largest block size (used for allocation limit).
1372 			 * Also convert offset to native byte order.
1373 			 */
1374 			comp_maxsize = 0;
1375 			for (i = 0; i < vnd->sc_comp_numoffs - 1; i++) {
1376 				vnd->sc_comp_offsets[i] =
1377 				    be64toh(vnd->sc_comp_offsets[i]);
1378 				comp_size =
1379 				    be64toh(vnd->sc_comp_offsets[i + 1])
1380 				    - vnd->sc_comp_offsets[i];
1381 				if (comp_size > comp_maxsize)
1382 					comp_maxsize = comp_size;
1383 			}
1384 			vnd->sc_comp_offsets[vnd->sc_comp_numoffs - 1] =
1385 			    be64toh(vnd->sc_comp_offsets[vnd->sc_comp_numoffs
1386 				    - 1]);
1387 
1388 			/* create compressed data buffer */
1389 			vnd->sc_comp_buff = malloc(comp_maxsize,
1390 			    M_DEVBUF, M_WAITOK);
1391 
1392 			/* create decompressed buffer */
1393 			vnd->sc_comp_decombuf = malloc(vnd->sc_comp_blksz,
1394 			    M_DEVBUF, M_WAITOK);
1395 			vnd->sc_comp_buffblk = -1;
1396 
1397 			/* Initialize decompress stream */
1398 			memset(&vnd->sc_comp_stream, 0, sizeof(z_stream));
1399 			vnd->sc_comp_stream.zalloc = vnd_alloc;
1400 			vnd->sc_comp_stream.zfree = vnd_free;
1401 			error = inflateInit2(&vnd->sc_comp_stream, MAX_WBITS);
1402 			if (error) {
1403 				if (vnd->sc_comp_stream.msg)
1404 					printf("vnd%d: compressed file, %s\n",
1405 					    unit, vnd->sc_comp_stream.msg);
1406 				VOP_UNLOCK(vp);
1407 				error = EINVAL;
1408 				goto close_and_exit;
1409 			}
1410 
1411 			vnd->sc_flags |= VNF_COMP | VNF_READONLY;
1412 #else /* !VND_COMPRESSION */
1413 			VOP_UNLOCK(vp);
1414 			error = EOPNOTSUPP;
1415 			goto close_and_exit;
1416 #endif /* VND_COMPRESSION */
1417 		}
1418 
1419 		VOP_UNLOCK(vp);
1420 		vnd->sc_vp = vp;
1421 		vnd->sc_size = btodb(vattr.va_size);	/* note truncation */
1422 
1423 		/* get smallest I/O size for underlying device, fall back to
1424 		 * fundamental I/O size of underlying filesystem
1425 		 */
1426 		error = bdev_ioctl(vattr.va_fsid, DIOCGSECTORSIZE, &vnd->sc_iosize, FKIOCTL, l);
1427 		if (error)
1428 			vnd->sc_iosize = vnd->sc_vp->v_mount->mnt_stat.f_frsize;
1429 
1430 		/* Default I/O size to DEV_BSIZE */
1431 		if (vnd->sc_iosize == 0)
1432 			vnd->sc_iosize = DEV_BSIZE;
1433 
1434 		/*
1435 		 * Use pseudo-geometry specified.  If none was provided,
1436 		 * use "standard" Adaptec fictitious geometry.
1437 		 */
1438 		if (vio->vnd_flags & VNDIOF_HASGEOM) {
1439 
1440 			memcpy(&vnd->sc_geom, &vio->vnd_geom,
1441 			    sizeof(vio->vnd_geom));
1442 
1443 			/*
1444 			 * Sanity-check the sector size.
1445 			 */
1446 			if (!DK_DEV_BSIZE_OK(vnd->sc_geom.vng_secsize) ||
1447 			    vnd->sc_geom.vng_ntracks == 0 ||
1448 			    vnd->sc_geom.vng_nsectors == 0) {
1449 				error = EINVAL;
1450 				goto close_and_exit;
1451 			}
1452 
1453 			/*
1454 			 * Compute missing cylinder count from size
1455 			 */
1456 			if (vnd->sc_geom.vng_ncylinders == 0)
1457 				vnd->sc_geom.vng_ncylinders = vnd->sc_size / (
1458 					(vnd->sc_geom.vng_secsize / DEV_BSIZE) *
1459 					vnd->sc_geom.vng_ntracks *
1460 					vnd->sc_geom.vng_nsectors);
1461 
1462 			/*
1463 			 * Compute the size (in DEV_BSIZE blocks) specified
1464 			 * by the geometry.
1465 			 */
1466 			geomsize = (int64_t)vnd->sc_geom.vng_nsectors *
1467 			    vnd->sc_geom.vng_ntracks *
1468 			    vnd->sc_geom.vng_ncylinders *
1469 			    (vnd->sc_geom.vng_secsize / DEV_BSIZE);
1470 
1471 			/*
1472 			 * Sanity-check the size against the specified
1473 			 * geometry.
1474 			 */
1475 			if (vnd->sc_size < geomsize) {
1476 				error = EINVAL;
1477 				goto close_and_exit;
1478 			}
1479 		} else if (vnd->sc_size >= (32 * 64)) {
1480 			/*
1481 			 * Size must be at least 2048 DEV_BSIZE blocks
1482 			 * (1M) in order to use this geometry.
1483 			 */
1484 			vnd->sc_geom.vng_secsize = DEV_BSIZE;
1485 			vnd->sc_geom.vng_nsectors = 32;
1486 			vnd->sc_geom.vng_ntracks = 64;
1487 			vnd->sc_geom.vng_ncylinders = vnd->sc_size / (64 * 32);
1488 		} else {
1489 			vnd->sc_geom.vng_secsize = DEV_BSIZE;
1490 			vnd->sc_geom.vng_nsectors = 1;
1491 			vnd->sc_geom.vng_ntracks = 1;
1492 			vnd->sc_geom.vng_ncylinders = vnd->sc_size;
1493 		}
1494 
1495 		vnd_set_geometry(vnd);
1496 
1497 		if (vio->vnd_flags & VNDIOF_READONLY) {
1498 			vnd->sc_flags |= VNF_READONLY;
1499 		}
1500 
1501 		if ((error = vndsetcred(vnd, l->l_cred)) != 0)
1502 			goto close_and_exit;
1503 
1504 		vndthrottle(vnd, vnd->sc_vp);
1505 		vio->vnd_osize = dbtob(vnd->sc_size);
1506 		if (cmd != VNDIOCSET50)
1507 			vio->vnd_size = dbtob(vnd->sc_size);
1508 		vnd->sc_flags |= VNF_INITED;
1509 
1510 		/* create the kernel thread, wait for it to be up */
1511 		error = kthread_create(PRI_NONE, 0, NULL, vndthread, vnd,
1512 		    &vnd->sc_kthread, "%s", device_xname(vnd->sc_dev));
1513 		if (error)
1514 			goto close_and_exit;
1515 		while ((vnd->sc_flags & VNF_KTHREAD) == 0) {
1516 			tsleep(&vnd->sc_kthread, PRIBIO, "vndthr", 0);
1517 		}
1518 #ifdef DEBUG
1519 		if (vnddebug & VDB_INIT)
1520 			printf("vndioctl: SET vp %p size 0x%lx %d/%d/%d/%d\n",
1521 			    vnd->sc_vp, (unsigned long) vnd->sc_size,
1522 			    vnd->sc_geom.vng_secsize,
1523 			    vnd->sc_geom.vng_nsectors,
1524 			    vnd->sc_geom.vng_ntracks,
1525 			    vnd->sc_geom.vng_ncylinders);
1526 #endif
1527 
1528 		/* Attach the disk. */
1529 		disk_attach(&vnd->sc_dkdev);
1530 
1531 		/* Initialize the xfer and buffer pools. */
1532 		pool_init(&vnd->sc_vxpool, sizeof(struct vndxfer), 0,
1533 		    0, 0, "vndxpl", NULL, IPL_BIO);
1534 
1535 		vndunlock(vnd);
1536 
1537 		pathbuf_destroy(pb);
1538 
1539 		/* Discover wedges on this disk */
1540 		dkwedge_discover(&vnd->sc_dkdev);
1541 
1542 		break;
1543 
1544 close_and_exit:
1545 		(void) vn_close(vp, fflags, l->l_cred);
1546 		pathbuf_destroy(pb);
1547 unlock_and_exit:
1548 #ifdef VND_COMPRESSION
1549 		/* free any allocated memory (for compressed file) */
1550 		if (vnd->sc_comp_offsets) {
1551 			free(vnd->sc_comp_offsets, M_DEVBUF);
1552 			vnd->sc_comp_offsets = NULL;
1553 		}
1554 		if (vnd->sc_comp_buff) {
1555 			free(vnd->sc_comp_buff, M_DEVBUF);
1556 			vnd->sc_comp_buff = NULL;
1557 		}
1558 		if (vnd->sc_comp_decombuf) {
1559 			free(vnd->sc_comp_decombuf, M_DEVBUF);
1560 			vnd->sc_comp_decombuf = NULL;
1561 		}
1562 #endif /* VND_COMPRESSION */
1563 		vndunlock(vnd);
1564 		return error;
1565 
1566 	case VNDIOCCLR50:
1567 	case VNDIOCCLR:
1568 		part = DISKPART(dev);
1569 		pmask = (1 << part);
1570 		force = (vio->vnd_flags & VNDIOF_FORCE) != 0;
1571 
1572 		if ((error = vnddoclear(vnd, pmask, minor(dev), force)) != 0)
1573 			return error;
1574 
1575 		break;
1576 
1577 
1578 	case DIOCWDINFO:
1579 	case DIOCSDINFO:
1580 #ifdef __HAVE_OLD_DISKLABEL
1581 	case ODIOCWDINFO:
1582 	case ODIOCSDINFO:
1583 #endif
1584 	{
1585 		struct disklabel *lp;
1586 
1587 		if ((error = vndlock(vnd)) != 0)
1588 			return error;
1589 
1590 		vnd->sc_flags |= VNF_LABELLING;
1591 
1592 #ifdef __HAVE_OLD_DISKLABEL
1593 		if (cmd == ODIOCSDINFO || cmd == ODIOCWDINFO) {
1594 			memset(&newlabel, 0, sizeof newlabel);
1595 			memcpy(&newlabel, data, sizeof (struct olddisklabel));
1596 			lp = &newlabel;
1597 		} else
1598 #endif
1599 		lp = (struct disklabel *)data;
1600 
1601 		error = setdisklabel(vnd->sc_dkdev.dk_label,
1602 		    lp, 0, vnd->sc_dkdev.dk_cpulabel);
1603 		if (error == 0) {
1604 			if (cmd == DIOCWDINFO
1605 #ifdef __HAVE_OLD_DISKLABEL
1606 			    || cmd == ODIOCWDINFO
1607 #endif
1608 			   )
1609 				error = writedisklabel(VNDLABELDEV(dev),
1610 				    vndstrategy, vnd->sc_dkdev.dk_label,
1611 				    vnd->sc_dkdev.dk_cpulabel);
1612 		}
1613 
1614 		vnd->sc_flags &= ~VNF_LABELLING;
1615 
1616 		vndunlock(vnd);
1617 
1618 		if (error)
1619 			return error;
1620 		break;
1621 	}
1622 
1623 	case DIOCKLABEL:
1624 		if (*(int *)data != 0)
1625 			vnd->sc_flags |= VNF_KLABEL;
1626 		else
1627 			vnd->sc_flags &= ~VNF_KLABEL;
1628 		break;
1629 
1630 	case DIOCWLABEL:
1631 		if (*(int *)data != 0)
1632 			vnd->sc_flags |= VNF_WLABEL;
1633 		else
1634 			vnd->sc_flags &= ~VNF_WLABEL;
1635 		break;
1636 
1637 	case DIOCGDEFLABEL:
1638 		vndgetdefaultlabel(vnd, (struct disklabel *)data);
1639 		break;
1640 
1641 #ifdef __HAVE_OLD_DISKLABEL
1642 	case ODIOCGDEFLABEL:
1643 		vndgetdefaultlabel(vnd, &newlabel);
1644 		if (newlabel.d_npartitions > OLDMAXPARTITIONS)
1645 			return ENOTTY;
1646 		memcpy(data, &newlabel, sizeof (struct olddisklabel));
1647 		break;
1648 #endif
1649 
1650 	case DIOCGSTRATEGY:
1651 	    {
1652 		struct disk_strategy *dks = (void *)data;
1653 
1654 		/* No lock needed, never changed */
1655 		strlcpy(dks->dks_name,
1656 		    bufq_getstrategyname(vnd->sc_tab),
1657 		    sizeof(dks->dks_name));
1658 		dks->dks_paramlen = 0;
1659 		break;
1660 	    }
1661 	case DIOCGCACHE:
1662 	    {
1663 		int *bits = (int *)data;
1664 		*bits |= DKCACHE_READ | DKCACHE_WRITE;
1665 		break;
1666 	    }
1667 	case DIOCCACHESYNC:
1668 		vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1669 		error = VOP_FSYNC(vnd->sc_vp, vnd->sc_cred,
1670 		    FSYNC_WAIT | FSYNC_DATAONLY | FSYNC_CACHE, 0, 0);
1671 		VOP_UNLOCK(vnd->sc_vp);
1672 		return error;
1673 
1674 	default:
1675 		return ENOTTY;
1676 	}
1677 
1678 	return 0;
1679 }
1680 
1681 /*
1682  * Duplicate the current processes' credentials.  Since we are called only
1683  * as the result of a SET ioctl and only root can do that, any future access
1684  * to this "disk" is essentially as root.  Note that credentials may change
1685  * if some other uid can write directly to the mapped file (NFS).
1686  */
1687 static int
1688 vndsetcred(struct vnd_softc *vnd, kauth_cred_t cred)
1689 {
1690 	struct uio auio;
1691 	struct iovec aiov;
1692 	char *tmpbuf;
1693 	int error;
1694 
1695 	vnd->sc_cred = kauth_cred_dup(cred);
1696 	tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK);
1697 
1698 	/* XXX: Horrible kludge to establish credentials for NFS */
1699 	aiov.iov_base = tmpbuf;
1700 	aiov.iov_len = uimin(DEV_BSIZE, dbtob(vnd->sc_size));
1701 	auio.uio_iov = &aiov;
1702 	auio.uio_iovcnt = 1;
1703 	auio.uio_offset = 0;
1704 	auio.uio_rw = UIO_READ;
1705 	auio.uio_resid = aiov.iov_len;
1706 	UIO_SETUP_SYSSPACE(&auio);
1707 	vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
1708 	error = VOP_READ(vnd->sc_vp, &auio, 0, vnd->sc_cred);
1709 	if (error == 0) {
1710 		/*
1711 		 * Because vnd does all IO directly through the vnode
1712 		 * we need to flush (at least) the buffer from the above
1713 		 * VOP_READ from the buffer cache to prevent cache
1714 		 * incoherencies.  Also, be careful to write dirty
1715 		 * buffers back to stable storage.
1716 		 */
1717 		error = vinvalbuf(vnd->sc_vp, V_SAVE, vnd->sc_cred,
1718 			    curlwp, 0, 0);
1719 	}
1720 	VOP_UNLOCK(vnd->sc_vp);
1721 
1722 	free(tmpbuf, M_TEMP);
1723 	return error;
1724 }
1725 
1726 /*
1727  * Set maxactive based on FS type
1728  */
1729 static void
1730 vndthrottle(struct vnd_softc *vnd, struct vnode *vp)
1731 {
1732 
1733 	if (vp->v_tag == VT_NFS)
1734 		vnd->sc_maxactive = 2;
1735 	else
1736 		vnd->sc_maxactive = 8;
1737 
1738 	if (vnd->sc_maxactive < 1)
1739 		vnd->sc_maxactive = 1;
1740 }
1741 
1742 #if 0
1743 static void
1744 vndshutdown(void)
1745 {
1746 	struct vnd_softc *vnd;
1747 
1748 	for (vnd = &vnd_softc[0]; vnd < &vnd_softc[numvnd]; vnd++)
1749 		if (vnd->sc_flags & VNF_INITED)
1750 			vndclear(vnd);
1751 }
1752 #endif
1753 
1754 static void
1755 vndclear(struct vnd_softc *vnd, int myminor)
1756 {
1757 	struct vnode *vp = vnd->sc_vp;
1758 	int fflags = FREAD;
1759 	int bmaj, cmaj, i, mn;
1760 	int s;
1761 
1762 #ifdef DEBUG
1763 	if (vnddebug & VDB_FOLLOW)
1764 		printf("vndclear(%p): vp %p\n", vnd, vp);
1765 #endif
1766 	/* locate the major number */
1767 	bmaj = bdevsw_lookup_major(&vnd_bdevsw);
1768 	cmaj = cdevsw_lookup_major(&vnd_cdevsw);
1769 
1770 	/* Nuke the vnodes for any open instances */
1771 	for (i = 0; i < MAXPARTITIONS; i++) {
1772 		mn = DISKMINOR(device_unit(vnd->sc_dev), i);
1773 		if (mn != myminor) { /* XXX avoid to kill own vnode */
1774 			vdevgone(bmaj, mn, mn, VBLK);
1775 			vdevgone(cmaj, mn, mn, VCHR);
1776 		}
1777 	}
1778 
1779 	if ((vnd->sc_flags & VNF_READONLY) == 0)
1780 		fflags |= FWRITE;
1781 
1782 	s = splbio();
1783 	bufq_drain(vnd->sc_tab);
1784 	splx(s);
1785 
1786 	vnd->sc_flags |= VNF_VUNCONF;
1787 	wakeup(&vnd->sc_tab);
1788 	while (vnd->sc_flags & VNF_KTHREAD)
1789 		tsleep(&vnd->sc_kthread, PRIBIO, "vnthr", 0);
1790 
1791 #ifdef VND_COMPRESSION
1792 	/* free the compressed file buffers */
1793 	if (vnd->sc_flags & VNF_COMP) {
1794 		if (vnd->sc_comp_offsets) {
1795 			free(vnd->sc_comp_offsets, M_DEVBUF);
1796 			vnd->sc_comp_offsets = NULL;
1797 		}
1798 		if (vnd->sc_comp_buff) {
1799 			free(vnd->sc_comp_buff, M_DEVBUF);
1800 			vnd->sc_comp_buff = NULL;
1801 		}
1802 		if (vnd->sc_comp_decombuf) {
1803 			free(vnd->sc_comp_decombuf, M_DEVBUF);
1804 			vnd->sc_comp_decombuf = NULL;
1805 		}
1806 	}
1807 #endif /* VND_COMPRESSION */
1808 	vnd->sc_flags &=
1809 	    ~(VNF_INITED | VNF_READONLY | VNF_KLABEL | VNF_VLABEL
1810 	      | VNF_VUNCONF | VNF_COMP | VNF_CLEARING);
1811 	if (vp == NULL)
1812 		panic("vndclear: null vp");
1813 	(void) vn_close(vp, fflags, vnd->sc_cred);
1814 	kauth_cred_free(vnd->sc_cred);
1815 	vnd->sc_vp = NULL;
1816 	vnd->sc_cred = NULL;
1817 	vnd->sc_size = 0;
1818 }
1819 
1820 static int
1821 vndsize(dev_t dev)
1822 {
1823 	struct vnd_softc *sc;
1824 	struct disklabel *lp;
1825 	int part, unit, omask;
1826 	int size;
1827 
1828 	unit = vndunit(dev);
1829 	sc = device_lookup_private(&vnd_cd, unit);
1830 	if (sc == NULL)
1831 		return -1;
1832 
1833 	if ((sc->sc_flags & VNF_INITED) == 0)
1834 		return -1;
1835 
1836 	part = DISKPART(dev);
1837 	omask = sc->sc_dkdev.dk_openmask & (1 << part);
1838 	lp = sc->sc_dkdev.dk_label;
1839 
1840 	if (omask == 0 && vndopen(dev, 0, S_IFBLK, curlwp))	/* XXX */
1841 		return -1;
1842 
1843 	if (lp->d_partitions[part].p_fstype != FS_SWAP)
1844 		size = -1;
1845 	else
1846 		size = lp->d_partitions[part].p_size *
1847 		    (lp->d_secsize / DEV_BSIZE);
1848 
1849 	if (omask == 0 && vndclose(dev, 0, S_IFBLK, curlwp))	/* XXX */
1850 		return -1;
1851 
1852 	return size;
1853 }
1854 
1855 static int
1856 vnddump(dev_t dev, daddr_t blkno, void *va,
1857     size_t size)
1858 {
1859 
1860 	/* Not implemented. */
1861 	return ENXIO;
1862 }
1863 
1864 static void
1865 vndgetdefaultlabel(struct vnd_softc *sc, struct disklabel *lp)
1866 {
1867 	struct vndgeom *vng = &sc->sc_geom;
1868 	struct partition *pp;
1869 	unsigned spb;
1870 
1871 	memset(lp, 0, sizeof(*lp));
1872 
1873 	spb = vng->vng_secsize / DEV_BSIZE;
1874 	if (sc->sc_size / spb > UINT32_MAX)
1875 		lp->d_secperunit = UINT32_MAX;
1876 	else
1877 		lp->d_secperunit = sc->sc_size / spb;
1878 	lp->d_secsize = vng->vng_secsize;
1879 	lp->d_nsectors = vng->vng_nsectors;
1880 	lp->d_ntracks = vng->vng_ntracks;
1881 	lp->d_ncylinders = vng->vng_ncylinders;
1882 	lp->d_secpercyl = lp->d_ntracks * lp->d_nsectors;
1883 
1884 	strncpy(lp->d_typename, "vnd", sizeof(lp->d_typename));
1885 	lp->d_type = DKTYPE_VND;
1886 	strncpy(lp->d_packname, "fictitious", sizeof(lp->d_packname));
1887 	lp->d_rpm = 3600;
1888 	lp->d_interleave = 1;
1889 	lp->d_flags = 0;
1890 
1891 	pp = &lp->d_partitions[RAW_PART];
1892 	pp->p_offset = 0;
1893 	pp->p_size = lp->d_secperunit;
1894 	pp->p_fstype = FS_UNUSED;
1895 	lp->d_npartitions = RAW_PART + 1;
1896 
1897 	lp->d_magic = DISKMAGIC;
1898 	lp->d_magic2 = DISKMAGIC;
1899 	lp->d_checksum = dkcksum(lp);
1900 }
1901 
1902 /*
1903  * Read the disklabel from a vnd.  If one is not present, create a fake one.
1904  */
1905 static void
1906 vndgetdisklabel(dev_t dev, struct vnd_softc *sc)
1907 {
1908 	const char *errstring;
1909 	struct disklabel *lp = sc->sc_dkdev.dk_label;
1910 	struct cpu_disklabel *clp = sc->sc_dkdev.dk_cpulabel;
1911 	int i;
1912 
1913 	memset(clp, 0, sizeof(*clp));
1914 
1915 	vndgetdefaultlabel(sc, lp);
1916 
1917 	/*
1918 	 * Call the generic disklabel extraction routine.
1919 	 */
1920 	errstring = readdisklabel(VNDLABELDEV(dev), vndstrategy, lp, clp);
1921 	if (errstring) {
1922 		/*
1923 		 * Lack of disklabel is common, but we print the warning
1924 		 * anyway, since it might contain other useful information.
1925 		 */
1926 		aprint_normal_dev(sc->sc_dev, "%s\n", errstring);
1927 
1928 		/*
1929 		 * For historical reasons, if there's no disklabel
1930 		 * present, all partitions must be FS_BSDFFS and
1931 		 * occupy the entire disk.
1932 		 */
1933 		for (i = 0; i < MAXPARTITIONS; i++) {
1934 			/*
1935 			 * Don't wipe out port specific hack (such as
1936 			 * dos partition hack of i386 port).
1937 			 */
1938 			if (lp->d_partitions[i].p_size != 0)
1939 				continue;
1940 
1941 			lp->d_partitions[i].p_size = lp->d_secperunit;
1942 			lp->d_partitions[i].p_offset = 0;
1943 			lp->d_partitions[i].p_fstype = FS_BSDFFS;
1944 		}
1945 
1946 		strncpy(lp->d_packname, "default label",
1947 		    sizeof(lp->d_packname));
1948 
1949 		lp->d_npartitions = MAXPARTITIONS;
1950 		lp->d_checksum = dkcksum(lp);
1951 	}
1952 }
1953 
1954 /*
1955  * Wait interruptibly for an exclusive lock.
1956  *
1957  * XXX
1958  * Several drivers do this; it should be abstracted and made MP-safe.
1959  */
1960 static int
1961 vndlock(struct vnd_softc *sc)
1962 {
1963 	int error;
1964 
1965 	while ((sc->sc_flags & VNF_LOCKED) != 0) {
1966 		sc->sc_flags |= VNF_WANTED;
1967 		if ((error = tsleep(sc, PRIBIO | PCATCH, "vndlck", 0)) != 0)
1968 			return error;
1969 	}
1970 	sc->sc_flags |= VNF_LOCKED;
1971 	return 0;
1972 }
1973 
1974 /*
1975  * Unlock and wake up any waiters.
1976  */
1977 static void
1978 vndunlock(struct vnd_softc *sc)
1979 {
1980 
1981 	sc->sc_flags &= ~VNF_LOCKED;
1982 	if ((sc->sc_flags & VNF_WANTED) != 0) {
1983 		sc->sc_flags &= ~VNF_WANTED;
1984 		wakeup(sc);
1985 	}
1986 }
1987 
1988 #ifdef VND_COMPRESSION
1989 /* compressed file read */
1990 static void
1991 compstrategy(struct buf *bp, off_t bn)
1992 {
1993 	int error;
1994 	int unit = vndunit(bp->b_dev);
1995 	struct vnd_softc *vnd =
1996 	    device_lookup_private(&vnd_cd, unit);
1997 	u_int32_t comp_block;
1998 	struct uio auio;
1999 	char *addr;
2000 	int s;
2001 
2002 	/* set up constants for data move */
2003 	auio.uio_rw = UIO_READ;
2004 	UIO_SETUP_SYSSPACE(&auio);
2005 
2006 	/* read, and transfer the data */
2007 	addr = bp->b_data;
2008 	bp->b_resid = bp->b_bcount;
2009 	s = splbio();
2010 	while (bp->b_resid > 0) {
2011 		unsigned length;
2012 		size_t length_in_buffer;
2013 		u_int32_t offset_in_buffer;
2014 		struct iovec aiov;
2015 
2016 		/* calculate the compressed block number */
2017 		comp_block = bn / (off_t)vnd->sc_comp_blksz;
2018 
2019 		/* check for good block number */
2020 		if (comp_block >= vnd->sc_comp_numoffs) {
2021 			bp->b_error = EINVAL;
2022 			splx(s);
2023 			return;
2024 		}
2025 
2026 		/* read in the compressed block, if not in buffer */
2027 		if (comp_block != vnd->sc_comp_buffblk) {
2028 			length = vnd->sc_comp_offsets[comp_block + 1] -
2029 			    vnd->sc_comp_offsets[comp_block];
2030 			vn_lock(vnd->sc_vp, LK_EXCLUSIVE | LK_RETRY);
2031 			error = vn_rdwr(UIO_READ, vnd->sc_vp, vnd->sc_comp_buff,
2032 			    length, vnd->sc_comp_offsets[comp_block],
2033 			    UIO_SYSSPACE, IO_NODELOCKED|IO_UNIT, vnd->sc_cred,
2034 			    NULL, NULL);
2035 			if (error) {
2036 				bp->b_error = error;
2037 				VOP_UNLOCK(vnd->sc_vp);
2038 				splx(s);
2039 				return;
2040 			}
2041 			/* uncompress the buffer */
2042 			vnd->sc_comp_stream.next_in = vnd->sc_comp_buff;
2043 			vnd->sc_comp_stream.avail_in = length;
2044 			vnd->sc_comp_stream.next_out = vnd->sc_comp_decombuf;
2045 			vnd->sc_comp_stream.avail_out = vnd->sc_comp_blksz;
2046 			inflateReset(&vnd->sc_comp_stream);
2047 			error = inflate(&vnd->sc_comp_stream, Z_FINISH);
2048 			if (error != Z_STREAM_END) {
2049 				if (vnd->sc_comp_stream.msg)
2050 					aprint_normal_dev(vnd->sc_dev,
2051 					    "compressed file, %s\n",
2052 					    vnd->sc_comp_stream.msg);
2053 				bp->b_error = EBADMSG;
2054 				VOP_UNLOCK(vnd->sc_vp);
2055 				splx(s);
2056 				return;
2057 			}
2058 			vnd->sc_comp_buffblk = comp_block;
2059 			VOP_UNLOCK(vnd->sc_vp);
2060 		}
2061 
2062 		/* transfer the usable uncompressed data */
2063 		offset_in_buffer = bn % (off_t)vnd->sc_comp_blksz;
2064 		length_in_buffer = vnd->sc_comp_blksz - offset_in_buffer;
2065 		if (length_in_buffer > bp->b_resid)
2066 			length_in_buffer = bp->b_resid;
2067 		auio.uio_iov = &aiov;
2068 		auio.uio_iovcnt = 1;
2069 		aiov.iov_base = addr;
2070 		aiov.iov_len = length_in_buffer;
2071 		auio.uio_resid = aiov.iov_len;
2072 		auio.uio_offset = 0;
2073 		error = uiomove(vnd->sc_comp_decombuf + offset_in_buffer,
2074 		    length_in_buffer, &auio);
2075 		if (error) {
2076 			bp->b_error = error;
2077 			splx(s);
2078 			return;
2079 		}
2080 
2081 		bn += length_in_buffer;
2082 		addr += length_in_buffer;
2083 		bp->b_resid -= length_in_buffer;
2084 	}
2085 	splx(s);
2086 }
2087 
2088 /* compression memory allocation routines */
2089 static void *
2090 vnd_alloc(void *aux, u_int items, u_int siz)
2091 {
2092 	return malloc(items * siz, M_TEMP, M_NOWAIT);
2093 }
2094 
2095 static void
2096 vnd_free(void *aux, void *ptr)
2097 {
2098 	free(ptr, M_TEMP);
2099 }
2100 #endif /* VND_COMPRESSION */
2101 
2102 static void
2103 vnd_set_geometry(struct vnd_softc *vnd)
2104 {
2105 	struct disk_geom *dg = &vnd->sc_dkdev.dk_geom;
2106 	unsigned spb;
2107 
2108 	memset(dg, 0, sizeof(*dg));
2109 
2110 	spb = vnd->sc_geom.vng_secsize / DEV_BSIZE;
2111 	dg->dg_secperunit = vnd->sc_size / spb;
2112 	dg->dg_secsize = vnd->sc_geom.vng_secsize;
2113 	dg->dg_nsectors = vnd->sc_geom.vng_nsectors;
2114 	dg->dg_ntracks = vnd->sc_geom.vng_ntracks;
2115 	dg->dg_ncylinders = vnd->sc_geom.vng_ncylinders;
2116 
2117 #ifdef DEBUG
2118 	if (vnddebug & VDB_LABEL) {
2119 		printf("dg->dg_secperunit: %" PRId64 "\n", dg->dg_secperunit);
2120 		printf("dg->dg_ncylinders: %u\n", dg->dg_ncylinders);
2121 	}
2122 #endif
2123 	disk_set_info(vnd->sc_dev, &vnd->sc_dkdev, NULL);
2124 }
2125 
2126 #ifdef VND_COMPRESSION
2127 #define VND_DEPENDS "zlib"
2128 #else
2129 #define VND_DEPENDS NULL
2130 #endif
2131 
2132 MODULE(MODULE_CLASS_DRIVER, vnd, VND_DEPENDS);
2133 
2134 #ifdef _MODULE
2135 int vnd_bmajor = -1, vnd_cmajor = -1;
2136 
2137 CFDRIVER_DECL(vnd, DV_DISK, NULL);
2138 #endif
2139 
2140 static int
2141 vnd_modcmd(modcmd_t cmd, void *arg)
2142 {
2143 	int error = 0;
2144 
2145 	switch (cmd) {
2146 	case MODULE_CMD_INIT:
2147 #ifdef _MODULE
2148                 /*
2149                  * Attach the {b,c}devsw's
2150                  */
2151 		error = devsw_attach("vnd", &vnd_bdevsw, &vnd_bmajor,
2152 		    &vnd_cdevsw, &vnd_cmajor);
2153 		if (error) {
2154 #ifdef DIAGNOSTIC
2155                         aprint_error("%s: unable to attach %s devsw, "
2156                             "error %d", __func__, vnd_cd.cd_name, error);
2157 #endif
2158 			break;
2159 		}
2160 
2161 		error = config_cfdriver_attach(&vnd_cd);
2162 		if (error) {
2163 			devsw_detach(&vnd_bdevsw, &vnd_cdevsw);
2164 			break;
2165 		}
2166 
2167 		error = config_cfattach_attach(vnd_cd.cd_name, &vnd_ca);
2168 	        if (error) {
2169 			config_cfdriver_detach(&vnd_cd);
2170 			devsw_detach(&vnd_bdevsw, &vnd_cdevsw);
2171 #ifdef DIAGNOSTIC
2172 			aprint_error("%s: unable to register cfattach for \n"
2173 			    "%s, error %d", __func__, vnd_cd.cd_name, error);
2174 #endif
2175 			break;
2176 		}
2177 #endif
2178 		break;
2179 
2180 	case MODULE_CMD_FINI:
2181 #ifdef _MODULE
2182                 /*
2183                  * Remove device from autoconf database
2184                  */
2185 		error = config_cfattach_detach(vnd_cd.cd_name, &vnd_ca);
2186                 if (error) {
2187 #ifdef DIAGNOSTIC
2188                         aprint_error("%s: failed to detach %s cfattach, "
2189                             "error %d\n", __func__, vnd_cd.cd_name, error);
2190 #endif
2191                         break;
2192                 }
2193                 error = config_cfdriver_detach(&vnd_cd);
2194                 if (error) {
2195                         (void)config_cfattach_attach(vnd_cd.cd_name, &vnd_ca);
2196 #ifdef DIAGNOSTIC
2197                         aprint_error("%s: failed to detach %s cfdriver, "
2198                             "error %d\n", __func__, vnd_cd.cd_name, error);
2199                         break;
2200 #endif
2201                 }
2202                 /*
2203                  * Remove {b,c}devsw's
2204                  */
2205 		devsw_detach(&vnd_bdevsw, &vnd_cdevsw);
2206 
2207 #endif
2208 		break;
2209 
2210 	case MODULE_CMD_STAT:
2211 		return ENOTTY;
2212 
2213 	default:
2214 		return ENOTTY;
2215 	}
2216 
2217 	return error;
2218 }
2219