xref: /freebsd/sys/dev/md/md.c (revision 2e36db147e0edeb1b213f283f9b41a8d1a902a88)
1 /*-
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD$
10  *
11  */
12 
13 /*-
14  * The following functions are based in the vn(4) driver: mdstart_swap(),
15  * mdstart_vnode(), mdcreate_swap(), mdcreate_vnode() and mddestroy(),
16  * and as such under the following copyright:
17  *
18  * Copyright (c) 1988 University of Utah.
19  * Copyright (c) 1990, 1993
20  *	The Regents of the University of California.  All rights reserved.
21  * Copyright (c) 2013 The FreeBSD Foundation
22  * All rights reserved.
23  *
24  * This code is derived from software contributed to Berkeley by
25  * the Systems Programming Group of the University of Utah Computer
26  * Science Department.
27  *
28  * Portions of this software were developed by Konstantin Belousov
29  * under sponsorship from the FreeBSD Foundation.
30  *
31  * Redistribution and use in source and binary forms, with or without
32  * modification, are permitted provided that the following conditions
33  * are met:
34  * 1. Redistributions of source code must retain the above copyright
35  *    notice, this list of conditions and the following disclaimer.
36  * 2. Redistributions in binary form must reproduce the above copyright
37  *    notice, this list of conditions and the following disclaimer in the
38  *    documentation and/or other materials provided with the distribution.
39  * 3. Neither the name of the University nor the names of its contributors
40  *    may be used to endorse or promote products derived from this software
41  *    without specific prior written permission.
42  *
43  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
44  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
45  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
46  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
47  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
48  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
49  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
50  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
51  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
52  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
53  * SUCH DAMAGE.
54  *
55  * from: Utah Hdr: vn.c 1.13 94/04/02
56  *
57  *	from: @(#)vn.c	8.6 (Berkeley) 4/1/94
58  * From: src/sys/dev/vn/vn.c,v 1.122 2000/12/16 16:06:03
59  */
60 
61 #include "opt_rootdevname.h"
62 #include "opt_geom.h"
63 #include "opt_md.h"
64 
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/bio.h>
68 #include <sys/buf.h>
69 #include <sys/conf.h>
70 #include <sys/devicestat.h>
71 #include <sys/fcntl.h>
72 #include <sys/kernel.h>
73 #include <sys/kthread.h>
74 #include <sys/limits.h>
75 #include <sys/linker.h>
76 #include <sys/lock.h>
77 #include <sys/malloc.h>
78 #include <sys/mdioctl.h>
79 #include <sys/mount.h>
80 #include <sys/mutex.h>
81 #include <sys/sx.h>
82 #include <sys/namei.h>
83 #include <sys/proc.h>
84 #include <sys/queue.h>
85 #include <sys/rwlock.h>
86 #include <sys/sbuf.h>
87 #include <sys/sched.h>
88 #include <sys/sf_buf.h>
89 #include <sys/sysctl.h>
90 #include <sys/vnode.h>
91 #include <sys/disk.h>
92 
93 #include <geom/geom.h>
94 #include <geom/geom_int.h>
95 
96 #include <vm/vm.h>
97 #include <vm/vm_param.h>
98 #include <vm/vm_object.h>
99 #include <vm/vm_page.h>
100 #include <vm/vm_pager.h>
101 #include <vm/swap_pager.h>
102 #include <vm/uma.h>
103 
104 #include <machine/bus.h>
105 
106 #define MD_MODVER 1
107 
108 #define MD_SHUTDOWN	0x10000		/* Tell worker thread to terminate. */
109 #define	MD_EXITING	0x20000		/* Worker thread is exiting. */
110 
111 #ifndef MD_NSECT
112 #define MD_NSECT (10000 * 2)
113 #endif
114 
115 static MALLOC_DEFINE(M_MD, "md_disk", "Memory Disk");
116 static MALLOC_DEFINE(M_MDSECT, "md_sectors", "Memory Disk Sectors");
117 
118 static int md_debug;
119 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0,
120     "Enable md(4) debug messages");
121 static int md_malloc_wait;
122 SYSCTL_INT(_vm, OID_AUTO, md_malloc_wait, CTLFLAG_RW, &md_malloc_wait, 0,
123     "Allow malloc to wait for memory allocations");
124 
125 #if defined(MD_ROOT) && !defined(MD_ROOT_FSTYPE)
126 #define	MD_ROOT_FSTYPE	"ufs"
127 #endif
128 
129 #if defined(MD_ROOT)
130 /*
131  * Preloaded image gets put here.
132  */
133 #if defined(MD_ROOT_SIZE)
134 /*
135  * We put the mfs_root symbol into the oldmfs section of the kernel object file.
136  * Applications that patch the object with the image can determine
137  * the size looking at the oldmfs section size within the kernel.
138  */
139 u_char mfs_root[MD_ROOT_SIZE*1024] __attribute__ ((section ("oldmfs")));
140 const int mfs_root_size = sizeof(mfs_root);
141 #else
142 extern volatile u_char __weak_symbol mfs_root;
143 extern volatile u_char __weak_symbol mfs_root_end;
144 __GLOBL(mfs_root);
145 __GLOBL(mfs_root_end);
146 #define mfs_root_size ((uintptr_t)(&mfs_root_end - &mfs_root))
147 #endif
148 #endif
149 
150 static g_init_t g_md_init;
151 static g_fini_t g_md_fini;
152 static g_start_t g_md_start;
153 static g_access_t g_md_access;
154 static void g_md_dumpconf(struct sbuf *sb, const char *indent,
155     struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp);
156 
157 static struct cdev *status_dev = NULL;
158 static struct sx md_sx;
159 static struct unrhdr *md_uh;
160 
161 static d_ioctl_t mdctlioctl;
162 
163 static struct cdevsw mdctl_cdevsw = {
164 	.d_version =	D_VERSION,
165 	.d_ioctl =	mdctlioctl,
166 	.d_name =	MD_NAME,
167 };
168 
169 struct g_class g_md_class = {
170 	.name = "MD",
171 	.version = G_VERSION,
172 	.init = g_md_init,
173 	.fini = g_md_fini,
174 	.start = g_md_start,
175 	.access = g_md_access,
176 	.dumpconf = g_md_dumpconf,
177 };
178 
179 DECLARE_GEOM_CLASS(g_md_class, g_md);
180 
181 
182 static LIST_HEAD(, md_s) md_softc_list = LIST_HEAD_INITIALIZER(md_softc_list);
183 
184 #define NINDIR	(PAGE_SIZE / sizeof(uintptr_t))
185 #define NMASK	(NINDIR-1)
186 static int nshift;
187 
188 static int md_vnode_pbuf_freecnt;
189 
190 struct indir {
191 	uintptr_t	*array;
192 	u_int		total;
193 	u_int		used;
194 	u_int		shift;
195 };
196 
197 struct md_s {
198 	int unit;
199 	LIST_ENTRY(md_s) list;
200 	struct bio_queue_head bio_queue;
201 	struct mtx queue_mtx;
202 	struct mtx stat_mtx;
203 	struct cdev *dev;
204 	enum md_types type;
205 	off_t mediasize;
206 	unsigned sectorsize;
207 	unsigned opencount;
208 	unsigned fwheads;
209 	unsigned fwsectors;
210 	char ident[32];
211 	unsigned flags;
212 	char name[20];
213 	struct proc *procp;
214 	struct g_geom *gp;
215 	struct g_provider *pp;
216 	int (*start)(struct md_s *sc, struct bio *bp);
217 	struct devstat *devstat;
218 
219 	/* MD_MALLOC related fields */
220 	struct indir *indir;
221 	uma_zone_t uma;
222 
223 	/* MD_PRELOAD related fields */
224 	u_char *pl_ptr;
225 	size_t pl_len;
226 
227 	/* MD_VNODE related fields */
228 	struct vnode *vnode;
229 	char file[PATH_MAX];
230 	char label[PATH_MAX];
231 	struct ucred *cred;
232 
233 	/* MD_SWAP related fields */
234 	vm_object_t object;
235 };
236 
237 static struct indir *
238 new_indir(u_int shift)
239 {
240 	struct indir *ip;
241 
242 	ip = malloc(sizeof *ip, M_MD, (md_malloc_wait ? M_WAITOK : M_NOWAIT)
243 	    | M_ZERO);
244 	if (ip == NULL)
245 		return (NULL);
246 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
247 	    M_MDSECT, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO);
248 	if (ip->array == NULL) {
249 		free(ip, M_MD);
250 		return (NULL);
251 	}
252 	ip->total = NINDIR;
253 	ip->shift = shift;
254 	return (ip);
255 }
256 
257 static void
258 del_indir(struct indir *ip)
259 {
260 
261 	free(ip->array, M_MDSECT);
262 	free(ip, M_MD);
263 }
264 
265 static void
266 destroy_indir(struct md_s *sc, struct indir *ip)
267 {
268 	int i;
269 
270 	for (i = 0; i < NINDIR; i++) {
271 		if (!ip->array[i])
272 			continue;
273 		if (ip->shift)
274 			destroy_indir(sc, (struct indir*)(ip->array[i]));
275 		else if (ip->array[i] > 255)
276 			uma_zfree(sc->uma, (void *)(ip->array[i]));
277 	}
278 	del_indir(ip);
279 }
280 
281 /*
282  * This function does the math and allocates the top level "indir" structure
283  * for a device of "size" sectors.
284  */
285 
286 static struct indir *
287 dimension(off_t size)
288 {
289 	off_t rcnt;
290 	struct indir *ip;
291 	int layer;
292 
293 	rcnt = size;
294 	layer = 0;
295 	while (rcnt > NINDIR) {
296 		rcnt /= NINDIR;
297 		layer++;
298 	}
299 
300 	/*
301 	 * XXX: the top layer is probably not fully populated, so we allocate
302 	 * too much space for ip->array in here.
303 	 */
304 	ip = malloc(sizeof *ip, M_MD, M_WAITOK | M_ZERO);
305 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
306 	    M_MDSECT, M_WAITOK | M_ZERO);
307 	ip->total = NINDIR;
308 	ip->shift = layer * nshift;
309 	return (ip);
310 }
311 
312 /*
313  * Read a given sector
314  */
315 
316 static uintptr_t
317 s_read(struct indir *ip, off_t offset)
318 {
319 	struct indir *cip;
320 	int idx;
321 	uintptr_t up;
322 
323 	if (md_debug > 1)
324 		printf("s_read(%jd)\n", (intmax_t)offset);
325 	up = 0;
326 	for (cip = ip; cip != NULL;) {
327 		if (cip->shift) {
328 			idx = (offset >> cip->shift) & NMASK;
329 			up = cip->array[idx];
330 			cip = (struct indir *)up;
331 			continue;
332 		}
333 		idx = offset & NMASK;
334 		return (cip->array[idx]);
335 	}
336 	return (0);
337 }
338 
339 /*
340  * Write a given sector, prune the tree if the value is 0
341  */
342 
343 static int
344 s_write(struct indir *ip, off_t offset, uintptr_t ptr)
345 {
346 	struct indir *cip, *lip[10];
347 	int idx, li;
348 	uintptr_t up;
349 
350 	if (md_debug > 1)
351 		printf("s_write(%jd, %p)\n", (intmax_t)offset, (void *)ptr);
352 	up = 0;
353 	li = 0;
354 	cip = ip;
355 	for (;;) {
356 		lip[li++] = cip;
357 		if (cip->shift) {
358 			idx = (offset >> cip->shift) & NMASK;
359 			up = cip->array[idx];
360 			if (up != 0) {
361 				cip = (struct indir *)up;
362 				continue;
363 			}
364 			/* Allocate branch */
365 			cip->array[idx] =
366 			    (uintptr_t)new_indir(cip->shift - nshift);
367 			if (cip->array[idx] == 0)
368 				return (ENOSPC);
369 			cip->used++;
370 			up = cip->array[idx];
371 			cip = (struct indir *)up;
372 			continue;
373 		}
374 		/* leafnode */
375 		idx = offset & NMASK;
376 		up = cip->array[idx];
377 		if (up != 0)
378 			cip->used--;
379 		cip->array[idx] = ptr;
380 		if (ptr != 0)
381 			cip->used++;
382 		break;
383 	}
384 	if (cip->used != 0 || li == 1)
385 		return (0);
386 	li--;
387 	while (cip->used == 0 && cip != ip) {
388 		li--;
389 		idx = (offset >> lip[li]->shift) & NMASK;
390 		up = lip[li]->array[idx];
391 		KASSERT(up == (uintptr_t)cip, ("md screwed up"));
392 		del_indir(cip);
393 		lip[li]->array[idx] = 0;
394 		lip[li]->used--;
395 		cip = lip[li];
396 	}
397 	return (0);
398 }
399 
400 
401 static int
402 g_md_access(struct g_provider *pp, int r, int w, int e)
403 {
404 	struct md_s *sc;
405 
406 	sc = pp->geom->softc;
407 	if (sc == NULL) {
408 		if (r <= 0 && w <= 0 && e <= 0)
409 			return (0);
410 		return (ENXIO);
411 	}
412 	r += pp->acr;
413 	w += pp->acw;
414 	e += pp->ace;
415 	if ((sc->flags & MD_READONLY) != 0 && w > 0)
416 		return (EROFS);
417 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
418 		sc->opencount = 1;
419 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
420 		sc->opencount = 0;
421 	}
422 	return (0);
423 }
424 
425 static void
426 g_md_start(struct bio *bp)
427 {
428 	struct md_s *sc;
429 
430 	sc = bp->bio_to->geom->softc;
431 	if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE)) {
432 		mtx_lock(&sc->stat_mtx);
433 		devstat_start_transaction_bio(sc->devstat, bp);
434 		mtx_unlock(&sc->stat_mtx);
435 	}
436 	mtx_lock(&sc->queue_mtx);
437 	bioq_disksort(&sc->bio_queue, bp);
438 	mtx_unlock(&sc->queue_mtx);
439 	wakeup(sc);
440 }
441 
442 #define	MD_MALLOC_MOVE_ZERO	1
443 #define	MD_MALLOC_MOVE_FILL	2
444 #define	MD_MALLOC_MOVE_READ	3
445 #define	MD_MALLOC_MOVE_WRITE	4
446 #define	MD_MALLOC_MOVE_CMP	5
447 
448 static int
449 md_malloc_move_ma(vm_page_t **mp, int *ma_offs, unsigned sectorsize,
450     void *ptr, u_char fill, int op)
451 {
452 	struct sf_buf *sf;
453 	vm_page_t m, *mp1;
454 	char *p, first;
455 	off_t *uc;
456 	unsigned n;
457 	int error, i, ma_offs1, sz, first_read;
458 
459 	m = NULL;
460 	error = 0;
461 	sf = NULL;
462 	/* if (op == MD_MALLOC_MOVE_CMP) { gcc */
463 		first = 0;
464 		first_read = 0;
465 		uc = ptr;
466 		mp1 = *mp;
467 		ma_offs1 = *ma_offs;
468 	/* } */
469 	sched_pin();
470 	for (n = sectorsize; n != 0; n -= sz) {
471 		sz = imin(PAGE_SIZE - *ma_offs, n);
472 		if (m != **mp) {
473 			if (sf != NULL)
474 				sf_buf_free(sf);
475 			m = **mp;
476 			sf = sf_buf_alloc(m, SFB_CPUPRIVATE |
477 			    (md_malloc_wait ? 0 : SFB_NOWAIT));
478 			if (sf == NULL) {
479 				error = ENOMEM;
480 				break;
481 			}
482 		}
483 		p = (char *)sf_buf_kva(sf) + *ma_offs;
484 		switch (op) {
485 		case MD_MALLOC_MOVE_ZERO:
486 			bzero(p, sz);
487 			break;
488 		case MD_MALLOC_MOVE_FILL:
489 			memset(p, fill, sz);
490 			break;
491 		case MD_MALLOC_MOVE_READ:
492 			bcopy(ptr, p, sz);
493 			cpu_flush_dcache(p, sz);
494 			break;
495 		case MD_MALLOC_MOVE_WRITE:
496 			bcopy(p, ptr, sz);
497 			break;
498 		case MD_MALLOC_MOVE_CMP:
499 			for (i = 0; i < sz; i++, p++) {
500 				if (!first_read) {
501 					*uc = (u_char)*p;
502 					first = *p;
503 					first_read = 1;
504 				} else if (*p != first) {
505 					error = EDOOFUS;
506 					break;
507 				}
508 			}
509 			break;
510 		default:
511 			KASSERT(0, ("md_malloc_move_ma unknown op %d\n", op));
512 			break;
513 		}
514 		if (error != 0)
515 			break;
516 		*ma_offs += sz;
517 		*ma_offs %= PAGE_SIZE;
518 		if (*ma_offs == 0)
519 			(*mp)++;
520 		ptr = (char *)ptr + sz;
521 	}
522 
523 	if (sf != NULL)
524 		sf_buf_free(sf);
525 	sched_unpin();
526 	if (op == MD_MALLOC_MOVE_CMP && error != 0) {
527 		*mp = mp1;
528 		*ma_offs = ma_offs1;
529 	}
530 	return (error);
531 }
532 
533 static int
534 md_malloc_move_vlist(bus_dma_segment_t **pvlist, int *pma_offs,
535     unsigned len, void *ptr, u_char fill, int op)
536 {
537 	bus_dma_segment_t *vlist;
538 	uint8_t *p, *end, first;
539 	off_t *uc;
540 	int ma_offs, seg_len;
541 
542 	vlist = *pvlist;
543 	ma_offs = *pma_offs;
544 	uc = ptr;
545 
546 	for (; len != 0; len -= seg_len) {
547 		seg_len = imin(vlist->ds_len - ma_offs, len);
548 		p = (uint8_t *)(uintptr_t)vlist->ds_addr + ma_offs;
549 		switch (op) {
550 		case MD_MALLOC_MOVE_ZERO:
551 			bzero(p, seg_len);
552 			break;
553 		case MD_MALLOC_MOVE_FILL:
554 			memset(p, fill, seg_len);
555 			break;
556 		case MD_MALLOC_MOVE_READ:
557 			bcopy(ptr, p, seg_len);
558 			cpu_flush_dcache(p, seg_len);
559 			break;
560 		case MD_MALLOC_MOVE_WRITE:
561 			bcopy(p, ptr, seg_len);
562 			break;
563 		case MD_MALLOC_MOVE_CMP:
564 			end = p + seg_len;
565 			first = *uc = *p;
566 			/* Confirm all following bytes match the first */
567 			while (++p < end) {
568 				if (*p != first)
569 					return (EDOOFUS);
570 			}
571 			break;
572 		default:
573 			KASSERT(0, ("md_malloc_move_vlist unknown op %d\n", op));
574 			break;
575 		}
576 
577 		ma_offs += seg_len;
578 		if (ma_offs == vlist->ds_len) {
579 			ma_offs = 0;
580 			vlist++;
581 		}
582 		ptr = (uint8_t *)ptr + seg_len;
583 	}
584 	*pvlist = vlist;
585 	*pma_offs = ma_offs;
586 
587 	return (0);
588 }
589 
590 static int
591 mdstart_malloc(struct md_s *sc, struct bio *bp)
592 {
593 	u_char *dst;
594 	vm_page_t *m;
595 	bus_dma_segment_t *vlist;
596 	int i, error, error1, ma_offs, notmapped;
597 	off_t secno, nsec, uc;
598 	uintptr_t sp, osp;
599 
600 	switch (bp->bio_cmd) {
601 	case BIO_READ:
602 	case BIO_WRITE:
603 	case BIO_DELETE:
604 		break;
605 	default:
606 		return (EOPNOTSUPP);
607 	}
608 
609 	notmapped = (bp->bio_flags & BIO_UNMAPPED) != 0;
610 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
611 	    (bus_dma_segment_t *)bp->bio_data : NULL;
612 	if (notmapped) {
613 		m = bp->bio_ma;
614 		ma_offs = bp->bio_ma_offset;
615 		dst = NULL;
616 		KASSERT(vlist == NULL, ("vlists cannot be unmapped"));
617 	} else if (vlist != NULL) {
618 		ma_offs = bp->bio_ma_offset;
619 		dst = NULL;
620 	} else {
621 		dst = bp->bio_data;
622 	}
623 
624 	nsec = bp->bio_length / sc->sectorsize;
625 	secno = bp->bio_offset / sc->sectorsize;
626 	error = 0;
627 	while (nsec--) {
628 		osp = s_read(sc->indir, secno);
629 		if (bp->bio_cmd == BIO_DELETE) {
630 			if (osp != 0)
631 				error = s_write(sc->indir, secno, 0);
632 		} else if (bp->bio_cmd == BIO_READ) {
633 			if (osp == 0) {
634 				if (notmapped) {
635 					error = md_malloc_move_ma(&m, &ma_offs,
636 					    sc->sectorsize, NULL, 0,
637 					    MD_MALLOC_MOVE_ZERO);
638 				} else if (vlist != NULL) {
639 					error = md_malloc_move_vlist(&vlist,
640 					    &ma_offs, sc->sectorsize, NULL, 0,
641 					    MD_MALLOC_MOVE_ZERO);
642 				} else
643 					bzero(dst, sc->sectorsize);
644 			} else if (osp <= 255) {
645 				if (notmapped) {
646 					error = md_malloc_move_ma(&m, &ma_offs,
647 					    sc->sectorsize, NULL, osp,
648 					    MD_MALLOC_MOVE_FILL);
649 				} else if (vlist != NULL) {
650 					error = md_malloc_move_vlist(&vlist,
651 					    &ma_offs, sc->sectorsize, NULL, osp,
652 					    MD_MALLOC_MOVE_FILL);
653 				} else
654 					memset(dst, osp, sc->sectorsize);
655 			} else {
656 				if (notmapped) {
657 					error = md_malloc_move_ma(&m, &ma_offs,
658 					    sc->sectorsize, (void *)osp, 0,
659 					    MD_MALLOC_MOVE_READ);
660 				} else if (vlist != NULL) {
661 					error = md_malloc_move_vlist(&vlist,
662 					    &ma_offs, sc->sectorsize,
663 					    (void *)osp, 0,
664 					    MD_MALLOC_MOVE_READ);
665 				} else {
666 					bcopy((void *)osp, dst, sc->sectorsize);
667 					cpu_flush_dcache(dst, sc->sectorsize);
668 				}
669 			}
670 			osp = 0;
671 		} else if (bp->bio_cmd == BIO_WRITE) {
672 			if (sc->flags & MD_COMPRESS) {
673 				if (notmapped) {
674 					error1 = md_malloc_move_ma(&m, &ma_offs,
675 					    sc->sectorsize, &uc, 0,
676 					    MD_MALLOC_MOVE_CMP);
677 					i = error1 == 0 ? sc->sectorsize : 0;
678 				} else if (vlist != NULL) {
679 					error1 = md_malloc_move_vlist(&vlist,
680 					    &ma_offs, sc->sectorsize, &uc, 0,
681 					    MD_MALLOC_MOVE_CMP);
682 					i = error1 == 0 ? sc->sectorsize : 0;
683 				} else {
684 					uc = dst[0];
685 					for (i = 1; i < sc->sectorsize; i++) {
686 						if (dst[i] != uc)
687 							break;
688 					}
689 				}
690 			} else {
691 				i = 0;
692 				uc = 0;
693 			}
694 			if (i == sc->sectorsize) {
695 				if (osp != uc)
696 					error = s_write(sc->indir, secno, uc);
697 			} else {
698 				if (osp <= 255) {
699 					sp = (uintptr_t)uma_zalloc(sc->uma,
700 					    md_malloc_wait ? M_WAITOK :
701 					    M_NOWAIT);
702 					if (sp == 0) {
703 						error = ENOSPC;
704 						break;
705 					}
706 					if (notmapped) {
707 						error = md_malloc_move_ma(&m,
708 						    &ma_offs, sc->sectorsize,
709 						    (void *)sp, 0,
710 						    MD_MALLOC_MOVE_WRITE);
711 					} else if (vlist != NULL) {
712 						error = md_malloc_move_vlist(
713 						    &vlist, &ma_offs,
714 						    sc->sectorsize, (void *)sp,
715 						    0, MD_MALLOC_MOVE_WRITE);
716 					} else {
717 						bcopy(dst, (void *)sp,
718 						    sc->sectorsize);
719 					}
720 					error = s_write(sc->indir, secno, sp);
721 				} else {
722 					if (notmapped) {
723 						error = md_malloc_move_ma(&m,
724 						    &ma_offs, sc->sectorsize,
725 						    (void *)osp, 0,
726 						    MD_MALLOC_MOVE_WRITE);
727 					} else if (vlist != NULL) {
728 						error = md_malloc_move_vlist(
729 						    &vlist, &ma_offs,
730 						    sc->sectorsize, (void *)osp,
731 						    0, MD_MALLOC_MOVE_WRITE);
732 					} else {
733 						bcopy(dst, (void *)osp,
734 						    sc->sectorsize);
735 					}
736 					osp = 0;
737 				}
738 			}
739 		} else {
740 			error = EOPNOTSUPP;
741 		}
742 		if (osp > 255)
743 			uma_zfree(sc->uma, (void*)osp);
744 		if (error != 0)
745 			break;
746 		secno++;
747 		if (!notmapped && vlist == NULL)
748 			dst += sc->sectorsize;
749 	}
750 	bp->bio_resid = 0;
751 	return (error);
752 }
753 
754 static void
755 mdcopyto_vlist(void *src, bus_dma_segment_t *vlist, off_t offset, off_t len)
756 {
757 	off_t seg_len;
758 
759 	while (offset >= vlist->ds_len) {
760 		offset -= vlist->ds_len;
761 		vlist++;
762 	}
763 
764 	while (len != 0) {
765 		seg_len = omin(len, vlist->ds_len - offset);
766 		bcopy(src, (void *)(uintptr_t)(vlist->ds_addr + offset),
767 		    seg_len);
768 		offset = 0;
769 		src = (uint8_t *)src + seg_len;
770 		len -= seg_len;
771 		vlist++;
772 	}
773 }
774 
775 static void
776 mdcopyfrom_vlist(bus_dma_segment_t *vlist, off_t offset, void *dst, off_t len)
777 {
778 	off_t seg_len;
779 
780 	while (offset >= vlist->ds_len) {
781 		offset -= vlist->ds_len;
782 		vlist++;
783 	}
784 
785 	while (len != 0) {
786 		seg_len = omin(len, vlist->ds_len - offset);
787 		bcopy((void *)(uintptr_t)(vlist->ds_addr + offset), dst,
788 		    seg_len);
789 		offset = 0;
790 		dst = (uint8_t *)dst + seg_len;
791 		len -= seg_len;
792 		vlist++;
793 	}
794 }
795 
796 static int
797 mdstart_preload(struct md_s *sc, struct bio *bp)
798 {
799 	uint8_t *p;
800 
801 	p = sc->pl_ptr + bp->bio_offset;
802 	switch (bp->bio_cmd) {
803 	case BIO_READ:
804 		if ((bp->bio_flags & BIO_VLIST) != 0) {
805 			mdcopyto_vlist(p, (bus_dma_segment_t *)bp->bio_data,
806 			    bp->bio_ma_offset, bp->bio_length);
807 		} else {
808 			bcopy(p, bp->bio_data, bp->bio_length);
809 		}
810 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
811 		break;
812 	case BIO_WRITE:
813 		if ((bp->bio_flags & BIO_VLIST) != 0) {
814 			mdcopyfrom_vlist((bus_dma_segment_t *)bp->bio_data,
815 			    bp->bio_ma_offset, p, bp->bio_length);
816 		} else {
817 			bcopy(bp->bio_data, p, bp->bio_length);
818 		}
819 		break;
820 	}
821 	bp->bio_resid = 0;
822 	return (0);
823 }
824 
825 static int
826 mdstart_vnode(struct md_s *sc, struct bio *bp)
827 {
828 	int error;
829 	struct uio auio;
830 	struct iovec aiov;
831 	struct iovec *piov;
832 	struct mount *mp;
833 	struct vnode *vp;
834 	struct buf *pb;
835 	bus_dma_segment_t *vlist;
836 	struct thread *td;
837 	off_t iolen, len, zerosize;
838 	int ma_offs, npages;
839 
840 	switch (bp->bio_cmd) {
841 	case BIO_READ:
842 		auio.uio_rw = UIO_READ;
843 		break;
844 	case BIO_WRITE:
845 	case BIO_DELETE:
846 		auio.uio_rw = UIO_WRITE;
847 		break;
848 	case BIO_FLUSH:
849 		break;
850 	default:
851 		return (EOPNOTSUPP);
852 	}
853 
854 	td = curthread;
855 	vp = sc->vnode;
856 	pb = NULL;
857 	piov = NULL;
858 	ma_offs = bp->bio_ma_offset;
859 	len = bp->bio_length;
860 
861 	/*
862 	 * VNODE I/O
863 	 *
864 	 * If an error occurs, we set BIO_ERROR but we do not set
865 	 * B_INVAL because (for a write anyway), the buffer is
866 	 * still valid.
867 	 */
868 
869 	if (bp->bio_cmd == BIO_FLUSH) {
870 		(void) vn_start_write(vp, &mp, V_WAIT);
871 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
872 		error = VOP_FSYNC(vp, MNT_WAIT, td);
873 		VOP_UNLOCK(vp, 0);
874 		vn_finished_write(mp);
875 		return (error);
876 	}
877 
878 	auio.uio_offset = (vm_ooffset_t)bp->bio_offset;
879 	auio.uio_resid = bp->bio_length;
880 	auio.uio_segflg = UIO_SYSSPACE;
881 	auio.uio_td = td;
882 
883 	if (bp->bio_cmd == BIO_DELETE) {
884 		/*
885 		 * Emulate BIO_DELETE by writing zeros.
886 		 */
887 		zerosize = ZERO_REGION_SIZE -
888 		    (ZERO_REGION_SIZE % sc->sectorsize);
889 		auio.uio_iovcnt = howmany(bp->bio_length, zerosize);
890 		piov = malloc(sizeof(*piov) * auio.uio_iovcnt, M_MD, M_WAITOK);
891 		auio.uio_iov = piov;
892 		while (len > 0) {
893 			piov->iov_base = __DECONST(void *, zero_region);
894 			piov->iov_len = len;
895 			if (len > zerosize)
896 				piov->iov_len = zerosize;
897 			len -= piov->iov_len;
898 			piov++;
899 		}
900 		piov = auio.uio_iov;
901 	} else if ((bp->bio_flags & BIO_VLIST) != 0) {
902 		piov = malloc(sizeof(*piov) * bp->bio_ma_n, M_MD, M_WAITOK);
903 		auio.uio_iov = piov;
904 		vlist = (bus_dma_segment_t *)bp->bio_data;
905 		while (len > 0) {
906 			piov->iov_base = (void *)(uintptr_t)(vlist->ds_addr +
907 			    ma_offs);
908 			piov->iov_len = vlist->ds_len - ma_offs;
909 			if (piov->iov_len > len)
910 				piov->iov_len = len;
911 			len -= piov->iov_len;
912 			ma_offs = 0;
913 			vlist++;
914 			piov++;
915 		}
916 		auio.uio_iovcnt = piov - auio.uio_iov;
917 		piov = auio.uio_iov;
918 	} else if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
919 		pb = getpbuf(&md_vnode_pbuf_freecnt);
920 		bp->bio_resid = len;
921 unmapped_step:
922 		npages = atop(min(MAXPHYS, round_page(len + (ma_offs &
923 		    PAGE_MASK))));
924 		iolen = min(ptoa(npages) - (ma_offs & PAGE_MASK), len);
925 		KASSERT(iolen > 0, ("zero iolen"));
926 		pmap_qenter((vm_offset_t)pb->b_data,
927 		    &bp->bio_ma[atop(ma_offs)], npages);
928 		aiov.iov_base = (void *)((vm_offset_t)pb->b_data +
929 		    (ma_offs & PAGE_MASK));
930 		aiov.iov_len = iolen;
931 		auio.uio_iov = &aiov;
932 		auio.uio_iovcnt = 1;
933 		auio.uio_resid = iolen;
934 	} else {
935 		aiov.iov_base = bp->bio_data;
936 		aiov.iov_len = bp->bio_length;
937 		auio.uio_iov = &aiov;
938 		auio.uio_iovcnt = 1;
939 	}
940 	/*
941 	 * When reading set IO_DIRECT to try to avoid double-caching
942 	 * the data.  When writing IO_DIRECT is not optimal.
943 	 */
944 	if (auio.uio_rw == UIO_READ) {
945 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
946 		error = VOP_READ(vp, &auio, IO_DIRECT, sc->cred);
947 		VOP_UNLOCK(vp, 0);
948 	} else {
949 		(void) vn_start_write(vp, &mp, V_WAIT);
950 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
951 		error = VOP_WRITE(vp, &auio, sc->flags & MD_ASYNC ? 0 : IO_SYNC,
952 		    sc->cred);
953 		VOP_UNLOCK(vp, 0);
954 		vn_finished_write(mp);
955 		if (error == 0)
956 			sc->flags &= ~MD_VERIFY;
957 	}
958 
959 	if (pb != NULL) {
960 		pmap_qremove((vm_offset_t)pb->b_data, npages);
961 		if (error == 0) {
962 			len -= iolen;
963 			bp->bio_resid -= iolen;
964 			ma_offs += iolen;
965 			if (len > 0)
966 				goto unmapped_step;
967 		}
968 		relpbuf(pb, &md_vnode_pbuf_freecnt);
969 	}
970 
971 	free(piov, M_MD);
972 	if (pb == NULL)
973 		bp->bio_resid = auio.uio_resid;
974 	return (error);
975 }
976 
977 static void
978 md_swap_page_free(vm_page_t m)
979 {
980 
981 	vm_page_xunbusy(m);
982 	vm_page_lock(m);
983 	vm_page_free(m);
984 	vm_page_unlock(m);
985 }
986 
987 static int
988 mdstart_swap(struct md_s *sc, struct bio *bp)
989 {
990 	vm_page_t m;
991 	u_char *p;
992 	vm_pindex_t i, lastp;
993 	bus_dma_segment_t *vlist;
994 	int rv, ma_offs, offs, len, lastend;
995 
996 	switch (bp->bio_cmd) {
997 	case BIO_READ:
998 	case BIO_WRITE:
999 	case BIO_DELETE:
1000 		break;
1001 	default:
1002 		return (EOPNOTSUPP);
1003 	}
1004 
1005 	p = bp->bio_data;
1006 	ma_offs = (bp->bio_flags & (BIO_UNMAPPED|BIO_VLIST)) != 0 ?
1007 	    bp->bio_ma_offset : 0;
1008 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
1009 	    (bus_dma_segment_t *)bp->bio_data : NULL;
1010 
1011 	/*
1012 	 * offs is the offset at which to start operating on the
1013 	 * next (ie, first) page.  lastp is the last page on
1014 	 * which we're going to operate.  lastend is the ending
1015 	 * position within that last page (ie, PAGE_SIZE if
1016 	 * we're operating on complete aligned pages).
1017 	 */
1018 	offs = bp->bio_offset % PAGE_SIZE;
1019 	lastp = (bp->bio_offset + bp->bio_length - 1) / PAGE_SIZE;
1020 	lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1;
1021 
1022 	rv = VM_PAGER_OK;
1023 	VM_OBJECT_WLOCK(sc->object);
1024 	vm_object_pip_add(sc->object, 1);
1025 	for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) {
1026 		len = ((i == lastp) ? lastend : PAGE_SIZE) - offs;
1027 		m = vm_page_grab(sc->object, i, VM_ALLOC_SYSTEM);
1028 		if (bp->bio_cmd == BIO_READ) {
1029 			if (m->valid == VM_PAGE_BITS_ALL)
1030 				rv = VM_PAGER_OK;
1031 			else
1032 				rv = vm_pager_get_pages(sc->object, &m, 1,
1033 				    NULL, NULL);
1034 			if (rv == VM_PAGER_ERROR) {
1035 				md_swap_page_free(m);
1036 				break;
1037 			} else if (rv == VM_PAGER_FAIL) {
1038 				/*
1039 				 * Pager does not have the page.  Zero
1040 				 * the allocated page, and mark it as
1041 				 * valid. Do not set dirty, the page
1042 				 * can be recreated if thrown out.
1043 				 */
1044 				pmap_zero_page(m);
1045 				m->valid = VM_PAGE_BITS_ALL;
1046 			}
1047 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1048 				pmap_copy_pages(&m, offs, bp->bio_ma,
1049 				    ma_offs, len);
1050 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1051 				physcopyout_vlist(VM_PAGE_TO_PHYS(m) + offs,
1052 				    vlist, ma_offs, len);
1053 				cpu_flush_dcache(p, len);
1054 			} else {
1055 				physcopyout(VM_PAGE_TO_PHYS(m) + offs, p, len);
1056 				cpu_flush_dcache(p, len);
1057 			}
1058 		} else if (bp->bio_cmd == BIO_WRITE) {
1059 			if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL)
1060 				rv = VM_PAGER_OK;
1061 			else
1062 				rv = vm_pager_get_pages(sc->object, &m, 1,
1063 				    NULL, NULL);
1064 			if (rv == VM_PAGER_ERROR) {
1065 				md_swap_page_free(m);
1066 				break;
1067 			} else if (rv == VM_PAGER_FAIL)
1068 				pmap_zero_page(m);
1069 
1070 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1071 				pmap_copy_pages(bp->bio_ma, ma_offs, &m,
1072 				    offs, len);
1073 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1074 				physcopyin_vlist(vlist, ma_offs,
1075 				    VM_PAGE_TO_PHYS(m) + offs, len);
1076 			} else {
1077 				physcopyin(p, VM_PAGE_TO_PHYS(m) + offs, len);
1078 			}
1079 
1080 			m->valid = VM_PAGE_BITS_ALL;
1081 			if (m->dirty != VM_PAGE_BITS_ALL) {
1082 				vm_page_dirty(m);
1083 				vm_pager_page_unswapped(m);
1084 			}
1085 		} else if (bp->bio_cmd == BIO_DELETE) {
1086 			if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL)
1087 				rv = VM_PAGER_OK;
1088 			else
1089 				rv = vm_pager_get_pages(sc->object, &m, 1,
1090 				    NULL, NULL);
1091 			if (rv == VM_PAGER_ERROR) {
1092 				md_swap_page_free(m);
1093 				break;
1094 			} else if (rv == VM_PAGER_FAIL) {
1095 				md_swap_page_free(m);
1096 				m = NULL;
1097 			} else {
1098 				/* Page is valid. */
1099 				if (len != PAGE_SIZE) {
1100 					pmap_zero_page_area(m, offs, len);
1101 					if (m->dirty != VM_PAGE_BITS_ALL) {
1102 						vm_page_dirty(m);
1103 						vm_pager_page_unswapped(m);
1104 					}
1105 				} else {
1106 					vm_pager_page_unswapped(m);
1107 					md_swap_page_free(m);
1108 					m = NULL;
1109 				}
1110 			}
1111 		}
1112 		if (m != NULL) {
1113 			vm_page_xunbusy(m);
1114 			vm_page_lock(m);
1115 			if (vm_page_active(m))
1116 				vm_page_reference(m);
1117 			else
1118 				vm_page_activate(m);
1119 			vm_page_unlock(m);
1120 		}
1121 
1122 		/* Actions on further pages start at offset 0 */
1123 		p += PAGE_SIZE - offs;
1124 		offs = 0;
1125 		ma_offs += len;
1126 	}
1127 	vm_object_pip_wakeup(sc->object);
1128 	VM_OBJECT_WUNLOCK(sc->object);
1129 	return (rv != VM_PAGER_ERROR ? 0 : ENOSPC);
1130 }
1131 
1132 static int
1133 mdstart_null(struct md_s *sc, struct bio *bp)
1134 {
1135 
1136 	switch (bp->bio_cmd) {
1137 	case BIO_READ:
1138 		bzero(bp->bio_data, bp->bio_length);
1139 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
1140 		break;
1141 	case BIO_WRITE:
1142 		break;
1143 	}
1144 	bp->bio_resid = 0;
1145 	return (0);
1146 }
1147 
1148 static void
1149 md_kthread(void *arg)
1150 {
1151 	struct md_s *sc;
1152 	struct bio *bp;
1153 	int error;
1154 
1155 	sc = arg;
1156 	thread_lock(curthread);
1157 	sched_prio(curthread, PRIBIO);
1158 	thread_unlock(curthread);
1159 	if (sc->type == MD_VNODE)
1160 		curthread->td_pflags |= TDP_NORUNNINGBUF;
1161 
1162 	for (;;) {
1163 		mtx_lock(&sc->queue_mtx);
1164 		if (sc->flags & MD_SHUTDOWN) {
1165 			sc->flags |= MD_EXITING;
1166 			mtx_unlock(&sc->queue_mtx);
1167 			kproc_exit(0);
1168 		}
1169 		bp = bioq_takefirst(&sc->bio_queue);
1170 		if (!bp) {
1171 			msleep(sc, &sc->queue_mtx, PRIBIO | PDROP, "mdwait", 0);
1172 			continue;
1173 		}
1174 		mtx_unlock(&sc->queue_mtx);
1175 		if (bp->bio_cmd == BIO_GETATTR) {
1176 			int isv = ((sc->flags & MD_VERIFY) != 0);
1177 
1178 			if ((sc->fwsectors && sc->fwheads &&
1179 			    (g_handleattr_int(bp, "GEOM::fwsectors",
1180 			    sc->fwsectors) ||
1181 			    g_handleattr_int(bp, "GEOM::fwheads",
1182 			    sc->fwheads))) ||
1183 			    g_handleattr_int(bp, "GEOM::candelete", 1))
1184 				error = -1;
1185 			else if (sc->ident[0] != '\0' &&
1186 			    g_handleattr_str(bp, "GEOM::ident", sc->ident))
1187 				error = -1;
1188 			else if (g_handleattr_int(bp, "MNT::verified", isv))
1189 				error = -1;
1190 			else
1191 				error = EOPNOTSUPP;
1192 		} else {
1193 			error = sc->start(sc, bp);
1194 		}
1195 
1196 		if (error != -1) {
1197 			bp->bio_completed = bp->bio_length;
1198 			if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE))
1199 				devstat_end_transaction_bio(sc->devstat, bp);
1200 			g_io_deliver(bp, error);
1201 		}
1202 	}
1203 }
1204 
1205 static struct md_s *
1206 mdfind(int unit)
1207 {
1208 	struct md_s *sc;
1209 
1210 	LIST_FOREACH(sc, &md_softc_list, list) {
1211 		if (sc->unit == unit)
1212 			break;
1213 	}
1214 	return (sc);
1215 }
1216 
1217 static struct md_s *
1218 mdnew(int unit, int *errp, enum md_types type)
1219 {
1220 	struct md_s *sc;
1221 	int error;
1222 
1223 	*errp = 0;
1224 	if (unit == -1)
1225 		unit = alloc_unr(md_uh);
1226 	else
1227 		unit = alloc_unr_specific(md_uh, unit);
1228 
1229 	if (unit == -1) {
1230 		*errp = EBUSY;
1231 		return (NULL);
1232 	}
1233 
1234 	sc = (struct md_s *)malloc(sizeof *sc, M_MD, M_WAITOK | M_ZERO);
1235 	sc->type = type;
1236 	bioq_init(&sc->bio_queue);
1237 	mtx_init(&sc->queue_mtx, "md bio queue", NULL, MTX_DEF);
1238 	mtx_init(&sc->stat_mtx, "md stat", NULL, MTX_DEF);
1239 	sc->unit = unit;
1240 	sprintf(sc->name, "md%d", unit);
1241 	LIST_INSERT_HEAD(&md_softc_list, sc, list);
1242 	error = kproc_create(md_kthread, sc, &sc->procp, 0, 0,"%s", sc->name);
1243 	if (error == 0)
1244 		return (sc);
1245 	LIST_REMOVE(sc, list);
1246 	mtx_destroy(&sc->stat_mtx);
1247 	mtx_destroy(&sc->queue_mtx);
1248 	free_unr(md_uh, sc->unit);
1249 	free(sc, M_MD);
1250 	*errp = error;
1251 	return (NULL);
1252 }
1253 
1254 static void
1255 mdinit(struct md_s *sc)
1256 {
1257 	struct g_geom *gp;
1258 	struct g_provider *pp;
1259 
1260 	g_topology_lock();
1261 	gp = g_new_geomf(&g_md_class, "md%d", sc->unit);
1262 	gp->softc = sc;
1263 	pp = g_new_providerf(gp, "md%d", sc->unit);
1264 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
1265 	pp->mediasize = sc->mediasize;
1266 	pp->sectorsize = sc->sectorsize;
1267 	switch (sc->type) {
1268 	case MD_MALLOC:
1269 	case MD_VNODE:
1270 	case MD_SWAP:
1271 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
1272 		break;
1273 	case MD_PRELOAD:
1274 	case MD_NULL:
1275 		break;
1276 	}
1277 	sc->gp = gp;
1278 	sc->pp = pp;
1279 	g_error_provider(pp, 0);
1280 	g_topology_unlock();
1281 	sc->devstat = devstat_new_entry("md", sc->unit, sc->sectorsize,
1282 	    DEVSTAT_ALL_SUPPORTED, DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
1283 }
1284 
1285 static int
1286 mdcreate_malloc(struct md_s *sc, struct md_ioctl *mdio)
1287 {
1288 	uintptr_t sp;
1289 	int error;
1290 	off_t u;
1291 
1292 	error = 0;
1293 	if (mdio->md_options & ~(MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE))
1294 		return (EINVAL);
1295 	if (mdio->md_sectorsize != 0 && !powerof2(mdio->md_sectorsize))
1296 		return (EINVAL);
1297 	/* Compression doesn't make sense if we have reserved space */
1298 	if (mdio->md_options & MD_RESERVE)
1299 		mdio->md_options &= ~MD_COMPRESS;
1300 	if (mdio->md_fwsectors != 0)
1301 		sc->fwsectors = mdio->md_fwsectors;
1302 	if (mdio->md_fwheads != 0)
1303 		sc->fwheads = mdio->md_fwheads;
1304 	sc->flags = mdio->md_options & (MD_COMPRESS | MD_FORCE);
1305 	sc->indir = dimension(sc->mediasize / sc->sectorsize);
1306 	sc->uma = uma_zcreate(sc->name, sc->sectorsize, NULL, NULL, NULL, NULL,
1307 	    0x1ff, 0);
1308 	if (mdio->md_options & MD_RESERVE) {
1309 		off_t nsectors;
1310 
1311 		nsectors = sc->mediasize / sc->sectorsize;
1312 		for (u = 0; u < nsectors; u++) {
1313 			sp = (uintptr_t)uma_zalloc(sc->uma, (md_malloc_wait ?
1314 			    M_WAITOK : M_NOWAIT) | M_ZERO);
1315 			if (sp != 0)
1316 				error = s_write(sc->indir, u, sp);
1317 			else
1318 				error = ENOMEM;
1319 			if (error != 0)
1320 				break;
1321 		}
1322 	}
1323 	return (error);
1324 }
1325 
1326 
1327 static int
1328 mdsetcred(struct md_s *sc, struct ucred *cred)
1329 {
1330 	char *tmpbuf;
1331 	int error = 0;
1332 
1333 	/*
1334 	 * Set credits in our softc
1335 	 */
1336 
1337 	if (sc->cred)
1338 		crfree(sc->cred);
1339 	sc->cred = crhold(cred);
1340 
1341 	/*
1342 	 * Horrible kludge to establish credentials for NFS  XXX.
1343 	 */
1344 
1345 	if (sc->vnode) {
1346 		struct uio auio;
1347 		struct iovec aiov;
1348 
1349 		tmpbuf = malloc(sc->sectorsize, M_TEMP, M_WAITOK);
1350 		bzero(&auio, sizeof(auio));
1351 
1352 		aiov.iov_base = tmpbuf;
1353 		aiov.iov_len = sc->sectorsize;
1354 		auio.uio_iov = &aiov;
1355 		auio.uio_iovcnt = 1;
1356 		auio.uio_offset = 0;
1357 		auio.uio_rw = UIO_READ;
1358 		auio.uio_segflg = UIO_SYSSPACE;
1359 		auio.uio_resid = aiov.iov_len;
1360 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1361 		error = VOP_READ(sc->vnode, &auio, 0, sc->cred);
1362 		VOP_UNLOCK(sc->vnode, 0);
1363 		free(tmpbuf, M_TEMP);
1364 	}
1365 	return (error);
1366 }
1367 
1368 static int
1369 mdcreate_vnode(struct md_s *sc, struct md_ioctl *mdio, struct thread *td)
1370 {
1371 	struct vattr vattr;
1372 	struct nameidata nd;
1373 	char *fname;
1374 	int error, flags;
1375 
1376 	/*
1377 	 * Kernel-originated requests must have the filename appended
1378 	 * to the mdio structure to protect against malicious software.
1379 	 */
1380 	fname = mdio->md_file;
1381 	if ((void *)fname != (void *)(mdio + 1)) {
1382 		error = copyinstr(fname, sc->file, sizeof(sc->file), NULL);
1383 		if (error != 0)
1384 			return (error);
1385 	} else
1386 		strlcpy(sc->file, fname, sizeof(sc->file));
1387 
1388 	/*
1389 	 * If the user specified that this is a read only device, don't
1390 	 * set the FWRITE mask before trying to open the backing store.
1391 	 */
1392 	flags = FREAD | ((mdio->md_options & MD_READONLY) ? 0 : FWRITE) \
1393 	    | ((mdio->md_options & MD_VERIFY) ? 0 : O_VERIFY);
1394 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, sc->file, td);
1395 	error = vn_open(&nd, &flags, 0, NULL);
1396 	if (error != 0)
1397 		return (error);
1398 	NDFREE(&nd, NDF_ONLY_PNBUF);
1399 	if (nd.ni_vp->v_type != VREG) {
1400 		error = EINVAL;
1401 		goto bad;
1402 	}
1403 	error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred);
1404 	if (error != 0)
1405 		goto bad;
1406 	if (VOP_ISLOCKED(nd.ni_vp) != LK_EXCLUSIVE) {
1407 		vn_lock(nd.ni_vp, LK_UPGRADE | LK_RETRY);
1408 		if (nd.ni_vp->v_iflag & VI_DOOMED) {
1409 			/* Forced unmount. */
1410 			error = EBADF;
1411 			goto bad;
1412 		}
1413 	}
1414 	nd.ni_vp->v_vflag |= VV_MD;
1415 	VOP_UNLOCK(nd.ni_vp, 0);
1416 
1417 	if (mdio->md_fwsectors != 0)
1418 		sc->fwsectors = mdio->md_fwsectors;
1419 	if (mdio->md_fwheads != 0)
1420 		sc->fwheads = mdio->md_fwheads;
1421 	snprintf(sc->ident, sizeof(sc->ident), "MD-DEV%ju-INO%ju",
1422 	    (uintmax_t)vattr.va_fsid, (uintmax_t)vattr.va_fileid);
1423 	sc->flags = mdio->md_options & (MD_FORCE | MD_ASYNC | MD_VERIFY);
1424 	if (!(flags & FWRITE))
1425 		sc->flags |= MD_READONLY;
1426 	sc->vnode = nd.ni_vp;
1427 
1428 	error = mdsetcred(sc, td->td_ucred);
1429 	if (error != 0) {
1430 		sc->vnode = NULL;
1431 		vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1432 		nd.ni_vp->v_vflag &= ~VV_MD;
1433 		goto bad;
1434 	}
1435 	return (0);
1436 bad:
1437 	VOP_UNLOCK(nd.ni_vp, 0);
1438 	(void)vn_close(nd.ni_vp, flags, td->td_ucred, td);
1439 	return (error);
1440 }
1441 
1442 static int
1443 mddestroy(struct md_s *sc, struct thread *td)
1444 {
1445 
1446 	if (sc->gp) {
1447 		sc->gp->softc = NULL;
1448 		g_topology_lock();
1449 		g_wither_geom(sc->gp, ENXIO);
1450 		g_topology_unlock();
1451 		sc->gp = NULL;
1452 		sc->pp = NULL;
1453 	}
1454 	if (sc->devstat) {
1455 		devstat_remove_entry(sc->devstat);
1456 		sc->devstat = NULL;
1457 	}
1458 	mtx_lock(&sc->queue_mtx);
1459 	sc->flags |= MD_SHUTDOWN;
1460 	wakeup(sc);
1461 	while (!(sc->flags & MD_EXITING))
1462 		msleep(sc->procp, &sc->queue_mtx, PRIBIO, "mddestroy", hz / 10);
1463 	mtx_unlock(&sc->queue_mtx);
1464 	mtx_destroy(&sc->stat_mtx);
1465 	mtx_destroy(&sc->queue_mtx);
1466 	if (sc->vnode != NULL) {
1467 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1468 		sc->vnode->v_vflag &= ~VV_MD;
1469 		VOP_UNLOCK(sc->vnode, 0);
1470 		(void)vn_close(sc->vnode, sc->flags & MD_READONLY ?
1471 		    FREAD : (FREAD|FWRITE), sc->cred, td);
1472 	}
1473 	if (sc->cred != NULL)
1474 		crfree(sc->cred);
1475 	if (sc->object != NULL)
1476 		vm_object_deallocate(sc->object);
1477 	if (sc->indir)
1478 		destroy_indir(sc, sc->indir);
1479 	if (sc->uma)
1480 		uma_zdestroy(sc->uma);
1481 
1482 	LIST_REMOVE(sc, list);
1483 	free_unr(md_uh, sc->unit);
1484 	free(sc, M_MD);
1485 	return (0);
1486 }
1487 
1488 static int
1489 mdresize(struct md_s *sc, struct md_ioctl *mdio)
1490 {
1491 	int error, res;
1492 	vm_pindex_t oldpages, newpages;
1493 
1494 	switch (sc->type) {
1495 	case MD_VNODE:
1496 	case MD_NULL:
1497 		break;
1498 	case MD_SWAP:
1499 		if (mdio->md_mediasize <= 0 ||
1500 		    (mdio->md_mediasize % PAGE_SIZE) != 0)
1501 			return (EDOM);
1502 		oldpages = OFF_TO_IDX(round_page(sc->mediasize));
1503 		newpages = OFF_TO_IDX(round_page(mdio->md_mediasize));
1504 		if (newpages < oldpages) {
1505 			VM_OBJECT_WLOCK(sc->object);
1506 			vm_object_page_remove(sc->object, newpages, 0, 0);
1507 			swap_pager_freespace(sc->object, newpages,
1508 			    oldpages - newpages);
1509 			swap_release_by_cred(IDX_TO_OFF(oldpages -
1510 			    newpages), sc->cred);
1511 			sc->object->charge = IDX_TO_OFF(newpages);
1512 			sc->object->size = newpages;
1513 			VM_OBJECT_WUNLOCK(sc->object);
1514 		} else if (newpages > oldpages) {
1515 			res = swap_reserve_by_cred(IDX_TO_OFF(newpages -
1516 			    oldpages), sc->cred);
1517 			if (!res)
1518 				return (ENOMEM);
1519 			if ((mdio->md_options & MD_RESERVE) ||
1520 			    (sc->flags & MD_RESERVE)) {
1521 				error = swap_pager_reserve(sc->object,
1522 				    oldpages, newpages - oldpages);
1523 				if (error < 0) {
1524 					swap_release_by_cred(
1525 					    IDX_TO_OFF(newpages - oldpages),
1526 					    sc->cred);
1527 					return (EDOM);
1528 				}
1529 			}
1530 			VM_OBJECT_WLOCK(sc->object);
1531 			sc->object->charge = IDX_TO_OFF(newpages);
1532 			sc->object->size = newpages;
1533 			VM_OBJECT_WUNLOCK(sc->object);
1534 		}
1535 		break;
1536 	default:
1537 		return (EOPNOTSUPP);
1538 	}
1539 
1540 	sc->mediasize = mdio->md_mediasize;
1541 	g_topology_lock();
1542 	g_resize_provider(sc->pp, sc->mediasize);
1543 	g_topology_unlock();
1544 	return (0);
1545 }
1546 
1547 static int
1548 mdcreate_swap(struct md_s *sc, struct md_ioctl *mdio, struct thread *td)
1549 {
1550 	vm_ooffset_t npage;
1551 	int error;
1552 
1553 	/*
1554 	 * Range check.  Disallow negative sizes and sizes not being
1555 	 * multiple of page size.
1556 	 */
1557 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1558 		return (EDOM);
1559 
1560 	/*
1561 	 * Allocate an OBJT_SWAP object.
1562 	 *
1563 	 * Note the truncation.
1564 	 */
1565 
1566 	if ((mdio->md_options & MD_VERIFY) != 0)
1567 		return (EINVAL);
1568 	npage = mdio->md_mediasize / PAGE_SIZE;
1569 	if (mdio->md_fwsectors != 0)
1570 		sc->fwsectors = mdio->md_fwsectors;
1571 	if (mdio->md_fwheads != 0)
1572 		sc->fwheads = mdio->md_fwheads;
1573 	sc->object = vm_pager_allocate(OBJT_SWAP, NULL, PAGE_SIZE * npage,
1574 	    VM_PROT_DEFAULT, 0, td->td_ucred);
1575 	if (sc->object == NULL)
1576 		return (ENOMEM);
1577 	sc->flags = mdio->md_options & (MD_FORCE | MD_RESERVE);
1578 	if (mdio->md_options & MD_RESERVE) {
1579 		if (swap_pager_reserve(sc->object, 0, npage) < 0) {
1580 			error = EDOM;
1581 			goto finish;
1582 		}
1583 	}
1584 	error = mdsetcred(sc, td->td_ucred);
1585  finish:
1586 	if (error != 0) {
1587 		vm_object_deallocate(sc->object);
1588 		sc->object = NULL;
1589 	}
1590 	return (error);
1591 }
1592 
1593 static int
1594 mdcreate_null(struct md_s *sc, struct md_ioctl *mdio, struct thread *td)
1595 {
1596 
1597 	/*
1598 	 * Range check.  Disallow negative sizes and sizes not being
1599 	 * multiple of page size.
1600 	 */
1601 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1602 		return (EDOM);
1603 
1604 	return (0);
1605 }
1606 
1607 static int
1608 xmdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
1609 {
1610 	struct md_ioctl *mdio;
1611 	struct md_s *sc;
1612 	int error, i;
1613 	unsigned sectsize;
1614 
1615 	if (md_debug)
1616 		printf("mdctlioctl(%s %lx %p %x %p)\n",
1617 			devtoname(dev), cmd, addr, flags, td);
1618 
1619 	mdio = (struct md_ioctl *)addr;
1620 	if (mdio->md_version != MDIOVERSION)
1621 		return (EINVAL);
1622 
1623 	/*
1624 	 * We assert the version number in the individual ioctl
1625 	 * handlers instead of out here because (a) it is possible we
1626 	 * may add another ioctl in the future which doesn't read an
1627 	 * mdio, and (b) the correct return value for an unknown ioctl
1628 	 * is ENOIOCTL, not EINVAL.
1629 	 */
1630 	error = 0;
1631 	switch (cmd) {
1632 	case MDIOCATTACH:
1633 		switch (mdio->md_type) {
1634 		case MD_MALLOC:
1635 		case MD_PRELOAD:
1636 		case MD_VNODE:
1637 		case MD_SWAP:
1638 		case MD_NULL:
1639 			break;
1640 		default:
1641 			return (EINVAL);
1642 		}
1643 		if (mdio->md_sectorsize == 0)
1644 			sectsize = DEV_BSIZE;
1645 		else
1646 			sectsize = mdio->md_sectorsize;
1647 		if (sectsize > MAXPHYS || mdio->md_mediasize < sectsize)
1648 			return (EINVAL);
1649 		if (mdio->md_options & MD_AUTOUNIT)
1650 			sc = mdnew(-1, &error, mdio->md_type);
1651 		else {
1652 			if (mdio->md_unit > INT_MAX)
1653 				return (EINVAL);
1654 			sc = mdnew(mdio->md_unit, &error, mdio->md_type);
1655 		}
1656 		if (sc == NULL)
1657 			return (error);
1658 		if (mdio->md_label != NULL)
1659 			error = copyinstr(mdio->md_label, sc->label,
1660 			    sizeof(sc->label), NULL);
1661 		if (error != 0)
1662 			goto err_after_new;
1663 		if (mdio->md_options & MD_AUTOUNIT)
1664 			mdio->md_unit = sc->unit;
1665 		sc->mediasize = mdio->md_mediasize;
1666 		sc->sectorsize = sectsize;
1667 		error = EDOOFUS;
1668 		switch (sc->type) {
1669 		case MD_MALLOC:
1670 			sc->start = mdstart_malloc;
1671 			error = mdcreate_malloc(sc, mdio);
1672 			break;
1673 		case MD_PRELOAD:
1674 			/*
1675 			 * We disallow attaching preloaded memory disks via
1676 			 * ioctl. Preloaded memory disks are automatically
1677 			 * attached in g_md_init().
1678 			 */
1679 			error = EOPNOTSUPP;
1680 			break;
1681 		case MD_VNODE:
1682 			sc->start = mdstart_vnode;
1683 			error = mdcreate_vnode(sc, mdio, td);
1684 			break;
1685 		case MD_SWAP:
1686 			sc->start = mdstart_swap;
1687 			error = mdcreate_swap(sc, mdio, td);
1688 			break;
1689 		case MD_NULL:
1690 			sc->start = mdstart_null;
1691 			error = mdcreate_null(sc, mdio, td);
1692 			break;
1693 		}
1694 err_after_new:
1695 		if (error != 0) {
1696 			mddestroy(sc, td);
1697 			return (error);
1698 		}
1699 
1700 		/* Prune off any residual fractional sector */
1701 		i = sc->mediasize % sc->sectorsize;
1702 		sc->mediasize -= i;
1703 
1704 		mdinit(sc);
1705 		return (0);
1706 	case MDIOCDETACH:
1707 		if (mdio->md_mediasize != 0 ||
1708 		    (mdio->md_options & ~MD_FORCE) != 0)
1709 			return (EINVAL);
1710 
1711 		sc = mdfind(mdio->md_unit);
1712 		if (sc == NULL)
1713 			return (ENOENT);
1714 		if (sc->opencount != 0 && !(sc->flags & MD_FORCE) &&
1715 		    !(mdio->md_options & MD_FORCE))
1716 			return (EBUSY);
1717 		return (mddestroy(sc, td));
1718 	case MDIOCRESIZE:
1719 		if ((mdio->md_options & ~(MD_FORCE | MD_RESERVE)) != 0)
1720 			return (EINVAL);
1721 
1722 		sc = mdfind(mdio->md_unit);
1723 		if (sc == NULL)
1724 			return (ENOENT);
1725 		if (mdio->md_mediasize < sc->sectorsize)
1726 			return (EINVAL);
1727 		if (mdio->md_mediasize < sc->mediasize &&
1728 		    !(sc->flags & MD_FORCE) &&
1729 		    !(mdio->md_options & MD_FORCE))
1730 			return (EBUSY);
1731 		return (mdresize(sc, mdio));
1732 	case MDIOCQUERY:
1733 		sc = mdfind(mdio->md_unit);
1734 		if (sc == NULL)
1735 			return (ENOENT);
1736 		mdio->md_type = sc->type;
1737 		mdio->md_options = sc->flags;
1738 		mdio->md_mediasize = sc->mediasize;
1739 		mdio->md_sectorsize = sc->sectorsize;
1740 		error = 0;
1741 		if (mdio->md_label != NULL) {
1742 			error = copyout(sc->label, mdio->md_label,
1743 			    strlen(sc->label) + 1);
1744 		}
1745 		if (sc->type == MD_VNODE ||
1746 		    (sc->type == MD_PRELOAD && mdio->md_file != NULL))
1747 			error = copyout(sc->file, mdio->md_file,
1748 			    strlen(sc->file) + 1);
1749 		return (error);
1750 	case MDIOCLIST:
1751 		i = 1;
1752 		LIST_FOREACH(sc, &md_softc_list, list) {
1753 			if (i == MDNPAD - 1)
1754 				mdio->md_pad[i] = -1;
1755 			else
1756 				mdio->md_pad[i++] = sc->unit;
1757 		}
1758 		mdio->md_pad[0] = i - 1;
1759 		return (0);
1760 	default:
1761 		return (ENOIOCTL);
1762 	};
1763 }
1764 
1765 static int
1766 mdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
1767 {
1768 	int error;
1769 
1770 	sx_xlock(&md_sx);
1771 	error = xmdctlioctl(dev, cmd, addr, flags, td);
1772 	sx_xunlock(&md_sx);
1773 	return (error);
1774 }
1775 
1776 static void
1777 md_preloaded(u_char *image, size_t length, const char *name)
1778 {
1779 	struct md_s *sc;
1780 	int error;
1781 
1782 	sc = mdnew(-1, &error, MD_PRELOAD);
1783 	if (sc == NULL)
1784 		return;
1785 	sc->mediasize = length;
1786 	sc->sectorsize = DEV_BSIZE;
1787 	sc->pl_ptr = image;
1788 	sc->pl_len = length;
1789 	sc->start = mdstart_preload;
1790 	if (name != NULL)
1791 		strlcpy(sc->file, name, sizeof(sc->file));
1792 #if defined(MD_ROOT) && !defined(ROOTDEVNAME)
1793 	if (sc->unit == 0)
1794 		rootdevnames[0] = MD_ROOT_FSTYPE ":/dev/md0";
1795 #endif
1796 	mdinit(sc);
1797 	if (name != NULL) {
1798 		printf("%s%d: Preloaded image <%s> %zd bytes at %p\n",
1799 		    MD_NAME, sc->unit, name, length, image);
1800 	} else {
1801 		printf("%s%d: Embedded image %zd bytes at %p\n",
1802 		    MD_NAME, sc->unit, length, image);
1803 	}
1804 }
1805 
1806 static void
1807 g_md_init(struct g_class *mp __unused)
1808 {
1809 	caddr_t mod;
1810 	u_char *ptr, *name, *type;
1811 	unsigned len;
1812 	int i;
1813 
1814 	/* figure out log2(NINDIR) */
1815 	for (i = NINDIR, nshift = -1; i; nshift++)
1816 		i >>= 1;
1817 
1818 	mod = NULL;
1819 	sx_init(&md_sx, "MD config lock");
1820 	g_topology_unlock();
1821 	md_uh = new_unrhdr(0, INT_MAX, NULL);
1822 #ifdef MD_ROOT
1823 	if (mfs_root_size != 0) {
1824 		sx_xlock(&md_sx);
1825 		md_preloaded(__DEVOLATILE(u_char *, &mfs_root), mfs_root_size,
1826 		    NULL);
1827 		sx_xunlock(&md_sx);
1828 	}
1829 #endif
1830 	/* XXX: are preload_* static or do they need Giant ? */
1831 	while ((mod = preload_search_next_name(mod)) != NULL) {
1832 		name = (char *)preload_search_info(mod, MODINFO_NAME);
1833 		if (name == NULL)
1834 			continue;
1835 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
1836 		if (type == NULL)
1837 			continue;
1838 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
1839 			continue;
1840 		ptr = preload_fetch_addr(mod);
1841 		len = preload_fetch_size(mod);
1842 		if (ptr != NULL && len != 0) {
1843 			sx_xlock(&md_sx);
1844 			md_preloaded(ptr, len, name);
1845 			sx_xunlock(&md_sx);
1846 		}
1847 	}
1848 	md_vnode_pbuf_freecnt = nswbuf / 10;
1849 	status_dev = make_dev(&mdctl_cdevsw, INT_MAX, UID_ROOT, GID_WHEEL,
1850 	    0600, MDCTL_NAME);
1851 	g_topology_lock();
1852 }
1853 
1854 static void
1855 g_md_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
1856     struct g_consumer *cp __unused, struct g_provider *pp)
1857 {
1858 	struct md_s *mp;
1859 	char *type;
1860 
1861 	mp = gp->softc;
1862 	if (mp == NULL)
1863 		return;
1864 
1865 	switch (mp->type) {
1866 	case MD_MALLOC:
1867 		type = "malloc";
1868 		break;
1869 	case MD_PRELOAD:
1870 		type = "preload";
1871 		break;
1872 	case MD_VNODE:
1873 		type = "vnode";
1874 		break;
1875 	case MD_SWAP:
1876 		type = "swap";
1877 		break;
1878 	case MD_NULL:
1879 		type = "null";
1880 		break;
1881 	default:
1882 		type = "unknown";
1883 		break;
1884 	}
1885 
1886 	if (pp != NULL) {
1887 		if (indent == NULL) {
1888 			sbuf_printf(sb, " u %d", mp->unit);
1889 			sbuf_printf(sb, " s %ju", (uintmax_t) mp->sectorsize);
1890 			sbuf_printf(sb, " f %ju", (uintmax_t) mp->fwheads);
1891 			sbuf_printf(sb, " fs %ju", (uintmax_t) mp->fwsectors);
1892 			sbuf_printf(sb, " l %ju", (uintmax_t) mp->mediasize);
1893 			sbuf_printf(sb, " t %s", type);
1894 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
1895 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0'))
1896 				sbuf_printf(sb, " file %s", mp->file);
1897 			sbuf_printf(sb, " label %s", mp->label);
1898 		} else {
1899 			sbuf_printf(sb, "%s<unit>%d</unit>\n", indent,
1900 			    mp->unit);
1901 			sbuf_printf(sb, "%s<sectorsize>%ju</sectorsize>\n",
1902 			    indent, (uintmax_t) mp->sectorsize);
1903 			sbuf_printf(sb, "%s<fwheads>%ju</fwheads>\n",
1904 			    indent, (uintmax_t) mp->fwheads);
1905 			sbuf_printf(sb, "%s<fwsectors>%ju</fwsectors>\n",
1906 			    indent, (uintmax_t) mp->fwsectors);
1907 			if (mp->ident[0] != '\0') {
1908 				sbuf_printf(sb, "%s<ident>", indent);
1909 				g_conf_printf_escaped(sb, "%s", mp->ident);
1910 				sbuf_printf(sb, "</ident>\n");
1911 			}
1912 			sbuf_printf(sb, "%s<length>%ju</length>\n",
1913 			    indent, (uintmax_t) mp->mediasize);
1914 			sbuf_printf(sb, "%s<compression>%s</compression>\n", indent,
1915 			    (mp->flags & MD_COMPRESS) == 0 ? "off": "on");
1916 			sbuf_printf(sb, "%s<access>%s</access>\n", indent,
1917 			    (mp->flags & MD_READONLY) == 0 ? "read-write":
1918 			    "read-only");
1919 			sbuf_printf(sb, "%s<type>%s</type>\n", indent,
1920 			    type);
1921 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
1922 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0')) {
1923 				sbuf_printf(sb, "%s<file>", indent);
1924 				g_conf_printf_escaped(sb, "%s", mp->file);
1925 				sbuf_printf(sb, "</file>\n");
1926 			}
1927 			sbuf_printf(sb, "%s<label>", indent);
1928 			g_conf_printf_escaped(sb, "%s", mp->label);
1929 			sbuf_printf(sb, "</label>\n");
1930 		}
1931 	}
1932 }
1933 
1934 static void
1935 g_md_fini(struct g_class *mp __unused)
1936 {
1937 
1938 	sx_destroy(&md_sx);
1939 	if (status_dev != NULL)
1940 		destroy_dev(status_dev);
1941 	delete_unrhdr(md_uh);
1942 }
1943