xref: /freebsd/sys/dev/md/md.c (revision 52f72944b8f5abb2386eae924357dee8aea17d5b)
1 /*-
2  * SPDX-License-Identifier: (Beerware AND BSD-3-Clause)
3  *
4  * ----------------------------------------------------------------------------
5  * "THE BEER-WARE LICENSE" (Revision 42):
6  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
7  * can do whatever you want with this stuff. If we meet some day, and you think
8  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
9  * ----------------------------------------------------------------------------
10  *
11  * $FreeBSD$
12  *
13  */
14 
15 /*-
16  * The following functions are based in the vn(4) driver: mdstart_swap(),
17  * mdstart_vnode(), mdcreate_swap(), mdcreate_vnode() and mddestroy(),
18  * and as such under the following copyright:
19  *
20  * Copyright (c) 1988 University of Utah.
21  * Copyright (c) 1990, 1993
22  *	The Regents of the University of California.  All rights reserved.
23  * Copyright (c) 2013 The FreeBSD Foundation
24  * All rights reserved.
25  *
26  * This code is derived from software contributed to Berkeley by
27  * the Systems Programming Group of the University of Utah Computer
28  * Science Department.
29  *
30  * Portions of this software were developed by Konstantin Belousov
31  * under sponsorship from the FreeBSD Foundation.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  * 1. Redistributions of source code must retain the above copyright
37  *    notice, this list of conditions and the following disclaimer.
38  * 2. Redistributions in binary form must reproduce the above copyright
39  *    notice, this list of conditions and the following disclaimer in the
40  *    documentation and/or other materials provided with the distribution.
41  * 3. Neither the name of the University nor the names of its contributors
42  *    may be used to endorse or promote products derived from this software
43  *    without specific prior written permission.
44  *
45  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
46  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
47  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
48  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
49  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
50  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
51  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
52  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
53  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
54  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
55  * SUCH DAMAGE.
56  *
57  * from: Utah Hdr: vn.c 1.13 94/04/02
58  *
59  *	from: @(#)vn.c	8.6 (Berkeley) 4/1/94
60  * From: src/sys/dev/vn/vn.c,v 1.122 2000/12/16 16:06:03
61  */
62 
63 #include "opt_rootdevname.h"
64 #include "opt_geom.h"
65 #include "opt_md.h"
66 
67 #include <sys/param.h>
68 #include <sys/systm.h>
69 #include <sys/bio.h>
70 #include <sys/buf.h>
71 #include <sys/conf.h>
72 #include <sys/devicestat.h>
73 #include <sys/fcntl.h>
74 #include <sys/kernel.h>
75 #include <sys/kthread.h>
76 #include <sys/limits.h>
77 #include <sys/linker.h>
78 #include <sys/lock.h>
79 #include <sys/malloc.h>
80 #include <sys/mdioctl.h>
81 #include <sys/mount.h>
82 #include <sys/mutex.h>
83 #include <sys/sx.h>
84 #include <sys/namei.h>
85 #include <sys/proc.h>
86 #include <sys/queue.h>
87 #include <sys/rwlock.h>
88 #include <sys/sbuf.h>
89 #include <sys/sched.h>
90 #include <sys/sf_buf.h>
91 #include <sys/sysctl.h>
92 #include <sys/vnode.h>
93 #include <sys/disk.h>
94 
95 #include <geom/geom.h>
96 #include <geom/geom_int.h>
97 
98 #include <vm/vm.h>
99 #include <vm/vm_param.h>
100 #include <vm/vm_object.h>
101 #include <vm/vm_page.h>
102 #include <vm/vm_pager.h>
103 #include <vm/swap_pager.h>
104 #include <vm/uma.h>
105 
106 #include <machine/bus.h>
107 
108 #define MD_MODVER 1
109 
110 #define MD_SHUTDOWN	0x10000		/* Tell worker thread to terminate. */
111 #define	MD_EXITING	0x20000		/* Worker thread is exiting. */
112 
113 #ifndef MD_NSECT
114 #define MD_NSECT (10000 * 2)
115 #endif
116 
117 struct md_req {
118 	unsigned	md_unit;	/* unit number */
119 	enum md_types	md_type;	/* type of disk */
120 	off_t		md_mediasize;	/* size of disk in bytes */
121 	unsigned	md_sectorsize;	/* sectorsize */
122 	unsigned	md_options;	/* options */
123 	int		md_fwheads;	/* firmware heads */
124 	int		md_fwsectors;	/* firmware sectors */
125 	char		*md_file;	/* pathname of file to mount */
126 	enum uio_seg	md_file_seg;	/* location of md_file */
127 	char		*md_label;	/* label of the device (userspace) */
128 	int		*md_units;	/* pointer to units array (kernel) */
129 	size_t		md_units_nitems; /* items in md_units array */
130 };
131 
132 static MALLOC_DEFINE(M_MD, "md_disk", "Memory Disk");
133 static MALLOC_DEFINE(M_MDSECT, "md_sectors", "Memory Disk Sectors");
134 
135 static int md_debug;
136 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0,
137     "Enable md(4) debug messages");
138 static int md_malloc_wait;
139 SYSCTL_INT(_vm, OID_AUTO, md_malloc_wait, CTLFLAG_RW, &md_malloc_wait, 0,
140     "Allow malloc to wait for memory allocations");
141 
142 #if defined(MD_ROOT) && !defined(MD_ROOT_FSTYPE)
143 #define	MD_ROOT_FSTYPE	"ufs"
144 #endif
145 
146 #if defined(MD_ROOT)
147 /*
148  * Preloaded image gets put here.
149  */
150 #if defined(MD_ROOT_SIZE)
151 /*
152  * We put the mfs_root symbol into the oldmfs section of the kernel object file.
153  * Applications that patch the object with the image can determine
154  * the size looking at the oldmfs section size within the kernel.
155  */
156 u_char mfs_root[MD_ROOT_SIZE*1024] __attribute__ ((section ("oldmfs")));
157 const int mfs_root_size = sizeof(mfs_root);
158 #else
159 extern volatile u_char __weak_symbol mfs_root;
160 extern volatile u_char __weak_symbol mfs_root_end;
161 __GLOBL(mfs_root);
162 __GLOBL(mfs_root_end);
163 #define mfs_root_size ((uintptr_t)(&mfs_root_end - &mfs_root))
164 #endif
165 #endif
166 
167 static g_init_t g_md_init;
168 static g_fini_t g_md_fini;
169 static g_start_t g_md_start;
170 static g_access_t g_md_access;
171 static void g_md_dumpconf(struct sbuf *sb, const char *indent,
172     struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp);
173 
174 static struct cdev *status_dev = NULL;
175 static struct sx md_sx;
176 static struct unrhdr *md_uh;
177 
178 static d_ioctl_t mdctlioctl;
179 
180 static struct cdevsw mdctl_cdevsw = {
181 	.d_version =	D_VERSION,
182 	.d_ioctl =	mdctlioctl,
183 	.d_name =	MD_NAME,
184 };
185 
186 struct g_class g_md_class = {
187 	.name = "MD",
188 	.version = G_VERSION,
189 	.init = g_md_init,
190 	.fini = g_md_fini,
191 	.start = g_md_start,
192 	.access = g_md_access,
193 	.dumpconf = g_md_dumpconf,
194 };
195 
196 DECLARE_GEOM_CLASS(g_md_class, g_md);
197 
198 
199 static LIST_HEAD(, md_s) md_softc_list = LIST_HEAD_INITIALIZER(md_softc_list);
200 
201 #define NINDIR	(PAGE_SIZE / sizeof(uintptr_t))
202 #define NMASK	(NINDIR-1)
203 static int nshift;
204 
205 static int md_vnode_pbuf_freecnt;
206 
207 struct indir {
208 	uintptr_t	*array;
209 	u_int		total;
210 	u_int		used;
211 	u_int		shift;
212 };
213 
214 struct md_s {
215 	int unit;
216 	LIST_ENTRY(md_s) list;
217 	struct bio_queue_head bio_queue;
218 	struct mtx queue_mtx;
219 	struct mtx stat_mtx;
220 	struct cdev *dev;
221 	enum md_types type;
222 	off_t mediasize;
223 	unsigned sectorsize;
224 	unsigned opencount;
225 	unsigned fwheads;
226 	unsigned fwsectors;
227 	char ident[32];
228 	unsigned flags;
229 	char name[20];
230 	struct proc *procp;
231 	struct g_geom *gp;
232 	struct g_provider *pp;
233 	int (*start)(struct md_s *sc, struct bio *bp);
234 	struct devstat *devstat;
235 
236 	/* MD_MALLOC related fields */
237 	struct indir *indir;
238 	uma_zone_t uma;
239 
240 	/* MD_PRELOAD related fields */
241 	u_char *pl_ptr;
242 	size_t pl_len;
243 
244 	/* MD_VNODE related fields */
245 	struct vnode *vnode;
246 	char file[PATH_MAX];
247 	char label[PATH_MAX];
248 	struct ucred *cred;
249 
250 	/* MD_SWAP related fields */
251 	vm_object_t object;
252 };
253 
254 static struct indir *
255 new_indir(u_int shift)
256 {
257 	struct indir *ip;
258 
259 	ip = malloc(sizeof *ip, M_MD, (md_malloc_wait ? M_WAITOK : M_NOWAIT)
260 	    | M_ZERO);
261 	if (ip == NULL)
262 		return (NULL);
263 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
264 	    M_MDSECT, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO);
265 	if (ip->array == NULL) {
266 		free(ip, M_MD);
267 		return (NULL);
268 	}
269 	ip->total = NINDIR;
270 	ip->shift = shift;
271 	return (ip);
272 }
273 
274 static void
275 del_indir(struct indir *ip)
276 {
277 
278 	free(ip->array, M_MDSECT);
279 	free(ip, M_MD);
280 }
281 
282 static void
283 destroy_indir(struct md_s *sc, struct indir *ip)
284 {
285 	int i;
286 
287 	for (i = 0; i < NINDIR; i++) {
288 		if (!ip->array[i])
289 			continue;
290 		if (ip->shift)
291 			destroy_indir(sc, (struct indir*)(ip->array[i]));
292 		else if (ip->array[i] > 255)
293 			uma_zfree(sc->uma, (void *)(ip->array[i]));
294 	}
295 	del_indir(ip);
296 }
297 
298 /*
299  * This function does the math and allocates the top level "indir" structure
300  * for a device of "size" sectors.
301  */
302 
303 static struct indir *
304 dimension(off_t size)
305 {
306 	off_t rcnt;
307 	struct indir *ip;
308 	int layer;
309 
310 	rcnt = size;
311 	layer = 0;
312 	while (rcnt > NINDIR) {
313 		rcnt /= NINDIR;
314 		layer++;
315 	}
316 
317 	/*
318 	 * XXX: the top layer is probably not fully populated, so we allocate
319 	 * too much space for ip->array in here.
320 	 */
321 	ip = malloc(sizeof *ip, M_MD, M_WAITOK | M_ZERO);
322 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
323 	    M_MDSECT, M_WAITOK | M_ZERO);
324 	ip->total = NINDIR;
325 	ip->shift = layer * nshift;
326 	return (ip);
327 }
328 
329 /*
330  * Read a given sector
331  */
332 
333 static uintptr_t
334 s_read(struct indir *ip, off_t offset)
335 {
336 	struct indir *cip;
337 	int idx;
338 	uintptr_t up;
339 
340 	if (md_debug > 1)
341 		printf("s_read(%jd)\n", (intmax_t)offset);
342 	up = 0;
343 	for (cip = ip; cip != NULL;) {
344 		if (cip->shift) {
345 			idx = (offset >> cip->shift) & NMASK;
346 			up = cip->array[idx];
347 			cip = (struct indir *)up;
348 			continue;
349 		}
350 		idx = offset & NMASK;
351 		return (cip->array[idx]);
352 	}
353 	return (0);
354 }
355 
356 /*
357  * Write a given sector, prune the tree if the value is 0
358  */
359 
360 static int
361 s_write(struct indir *ip, off_t offset, uintptr_t ptr)
362 {
363 	struct indir *cip, *lip[10];
364 	int idx, li;
365 	uintptr_t up;
366 
367 	if (md_debug > 1)
368 		printf("s_write(%jd, %p)\n", (intmax_t)offset, (void *)ptr);
369 	up = 0;
370 	li = 0;
371 	cip = ip;
372 	for (;;) {
373 		lip[li++] = cip;
374 		if (cip->shift) {
375 			idx = (offset >> cip->shift) & NMASK;
376 			up = cip->array[idx];
377 			if (up != 0) {
378 				cip = (struct indir *)up;
379 				continue;
380 			}
381 			/* Allocate branch */
382 			cip->array[idx] =
383 			    (uintptr_t)new_indir(cip->shift - nshift);
384 			if (cip->array[idx] == 0)
385 				return (ENOSPC);
386 			cip->used++;
387 			up = cip->array[idx];
388 			cip = (struct indir *)up;
389 			continue;
390 		}
391 		/* leafnode */
392 		idx = offset & NMASK;
393 		up = cip->array[idx];
394 		if (up != 0)
395 			cip->used--;
396 		cip->array[idx] = ptr;
397 		if (ptr != 0)
398 			cip->used++;
399 		break;
400 	}
401 	if (cip->used != 0 || li == 1)
402 		return (0);
403 	li--;
404 	while (cip->used == 0 && cip != ip) {
405 		li--;
406 		idx = (offset >> lip[li]->shift) & NMASK;
407 		up = lip[li]->array[idx];
408 		KASSERT(up == (uintptr_t)cip, ("md screwed up"));
409 		del_indir(cip);
410 		lip[li]->array[idx] = 0;
411 		lip[li]->used--;
412 		cip = lip[li];
413 	}
414 	return (0);
415 }
416 
417 
418 static int
419 g_md_access(struct g_provider *pp, int r, int w, int e)
420 {
421 	struct md_s *sc;
422 
423 	sc = pp->geom->softc;
424 	if (sc == NULL) {
425 		if (r <= 0 && w <= 0 && e <= 0)
426 			return (0);
427 		return (ENXIO);
428 	}
429 	r += pp->acr;
430 	w += pp->acw;
431 	e += pp->ace;
432 	if ((sc->flags & MD_READONLY) != 0 && w > 0)
433 		return (EROFS);
434 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
435 		sc->opencount = 1;
436 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
437 		sc->opencount = 0;
438 	}
439 	return (0);
440 }
441 
442 static void
443 g_md_start(struct bio *bp)
444 {
445 	struct md_s *sc;
446 
447 	sc = bp->bio_to->geom->softc;
448 	if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE)) {
449 		mtx_lock(&sc->stat_mtx);
450 		devstat_start_transaction_bio(sc->devstat, bp);
451 		mtx_unlock(&sc->stat_mtx);
452 	}
453 	mtx_lock(&sc->queue_mtx);
454 	bioq_disksort(&sc->bio_queue, bp);
455 	mtx_unlock(&sc->queue_mtx);
456 	wakeup(sc);
457 }
458 
459 #define	MD_MALLOC_MOVE_ZERO	1
460 #define	MD_MALLOC_MOVE_FILL	2
461 #define	MD_MALLOC_MOVE_READ	3
462 #define	MD_MALLOC_MOVE_WRITE	4
463 #define	MD_MALLOC_MOVE_CMP	5
464 
465 static int
466 md_malloc_move_ma(vm_page_t **mp, int *ma_offs, unsigned sectorsize,
467     void *ptr, u_char fill, int op)
468 {
469 	struct sf_buf *sf;
470 	vm_page_t m, *mp1;
471 	char *p, first;
472 	off_t *uc;
473 	unsigned n;
474 	int error, i, ma_offs1, sz, first_read;
475 
476 	m = NULL;
477 	error = 0;
478 	sf = NULL;
479 	/* if (op == MD_MALLOC_MOVE_CMP) { gcc */
480 		first = 0;
481 		first_read = 0;
482 		uc = ptr;
483 		mp1 = *mp;
484 		ma_offs1 = *ma_offs;
485 	/* } */
486 	sched_pin();
487 	for (n = sectorsize; n != 0; n -= sz) {
488 		sz = imin(PAGE_SIZE - *ma_offs, n);
489 		if (m != **mp) {
490 			if (sf != NULL)
491 				sf_buf_free(sf);
492 			m = **mp;
493 			sf = sf_buf_alloc(m, SFB_CPUPRIVATE |
494 			    (md_malloc_wait ? 0 : SFB_NOWAIT));
495 			if (sf == NULL) {
496 				error = ENOMEM;
497 				break;
498 			}
499 		}
500 		p = (char *)sf_buf_kva(sf) + *ma_offs;
501 		switch (op) {
502 		case MD_MALLOC_MOVE_ZERO:
503 			bzero(p, sz);
504 			break;
505 		case MD_MALLOC_MOVE_FILL:
506 			memset(p, fill, sz);
507 			break;
508 		case MD_MALLOC_MOVE_READ:
509 			bcopy(ptr, p, sz);
510 			cpu_flush_dcache(p, sz);
511 			break;
512 		case MD_MALLOC_MOVE_WRITE:
513 			bcopy(p, ptr, sz);
514 			break;
515 		case MD_MALLOC_MOVE_CMP:
516 			for (i = 0; i < sz; i++, p++) {
517 				if (!first_read) {
518 					*uc = (u_char)*p;
519 					first = *p;
520 					first_read = 1;
521 				} else if (*p != first) {
522 					error = EDOOFUS;
523 					break;
524 				}
525 			}
526 			break;
527 		default:
528 			KASSERT(0, ("md_malloc_move_ma unknown op %d\n", op));
529 			break;
530 		}
531 		if (error != 0)
532 			break;
533 		*ma_offs += sz;
534 		*ma_offs %= PAGE_SIZE;
535 		if (*ma_offs == 0)
536 			(*mp)++;
537 		ptr = (char *)ptr + sz;
538 	}
539 
540 	if (sf != NULL)
541 		sf_buf_free(sf);
542 	sched_unpin();
543 	if (op == MD_MALLOC_MOVE_CMP && error != 0) {
544 		*mp = mp1;
545 		*ma_offs = ma_offs1;
546 	}
547 	return (error);
548 }
549 
550 static int
551 md_malloc_move_vlist(bus_dma_segment_t **pvlist, int *pma_offs,
552     unsigned len, void *ptr, u_char fill, int op)
553 {
554 	bus_dma_segment_t *vlist;
555 	uint8_t *p, *end, first;
556 	off_t *uc;
557 	int ma_offs, seg_len;
558 
559 	vlist = *pvlist;
560 	ma_offs = *pma_offs;
561 	uc = ptr;
562 
563 	for (; len != 0; len -= seg_len) {
564 		seg_len = imin(vlist->ds_len - ma_offs, len);
565 		p = (uint8_t *)(uintptr_t)vlist->ds_addr + ma_offs;
566 		switch (op) {
567 		case MD_MALLOC_MOVE_ZERO:
568 			bzero(p, seg_len);
569 			break;
570 		case MD_MALLOC_MOVE_FILL:
571 			memset(p, fill, seg_len);
572 			break;
573 		case MD_MALLOC_MOVE_READ:
574 			bcopy(ptr, p, seg_len);
575 			cpu_flush_dcache(p, seg_len);
576 			break;
577 		case MD_MALLOC_MOVE_WRITE:
578 			bcopy(p, ptr, seg_len);
579 			break;
580 		case MD_MALLOC_MOVE_CMP:
581 			end = p + seg_len;
582 			first = *uc = *p;
583 			/* Confirm all following bytes match the first */
584 			while (++p < end) {
585 				if (*p != first)
586 					return (EDOOFUS);
587 			}
588 			break;
589 		default:
590 			KASSERT(0, ("md_malloc_move_vlist unknown op %d\n", op));
591 			break;
592 		}
593 
594 		ma_offs += seg_len;
595 		if (ma_offs == vlist->ds_len) {
596 			ma_offs = 0;
597 			vlist++;
598 		}
599 		ptr = (uint8_t *)ptr + seg_len;
600 	}
601 	*pvlist = vlist;
602 	*pma_offs = ma_offs;
603 
604 	return (0);
605 }
606 
607 static int
608 mdstart_malloc(struct md_s *sc, struct bio *bp)
609 {
610 	u_char *dst;
611 	vm_page_t *m;
612 	bus_dma_segment_t *vlist;
613 	int i, error, error1, ma_offs, notmapped;
614 	off_t secno, nsec, uc;
615 	uintptr_t sp, osp;
616 
617 	switch (bp->bio_cmd) {
618 	case BIO_READ:
619 	case BIO_WRITE:
620 	case BIO_DELETE:
621 		break;
622 	default:
623 		return (EOPNOTSUPP);
624 	}
625 
626 	notmapped = (bp->bio_flags & BIO_UNMAPPED) != 0;
627 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
628 	    (bus_dma_segment_t *)bp->bio_data : NULL;
629 	if (notmapped) {
630 		m = bp->bio_ma;
631 		ma_offs = bp->bio_ma_offset;
632 		dst = NULL;
633 		KASSERT(vlist == NULL, ("vlists cannot be unmapped"));
634 	} else if (vlist != NULL) {
635 		ma_offs = bp->bio_ma_offset;
636 		dst = NULL;
637 	} else {
638 		dst = bp->bio_data;
639 	}
640 
641 	nsec = bp->bio_length / sc->sectorsize;
642 	secno = bp->bio_offset / sc->sectorsize;
643 	error = 0;
644 	while (nsec--) {
645 		osp = s_read(sc->indir, secno);
646 		if (bp->bio_cmd == BIO_DELETE) {
647 			if (osp != 0)
648 				error = s_write(sc->indir, secno, 0);
649 		} else if (bp->bio_cmd == BIO_READ) {
650 			if (osp == 0) {
651 				if (notmapped) {
652 					error = md_malloc_move_ma(&m, &ma_offs,
653 					    sc->sectorsize, NULL, 0,
654 					    MD_MALLOC_MOVE_ZERO);
655 				} else if (vlist != NULL) {
656 					error = md_malloc_move_vlist(&vlist,
657 					    &ma_offs, sc->sectorsize, NULL, 0,
658 					    MD_MALLOC_MOVE_ZERO);
659 				} else
660 					bzero(dst, sc->sectorsize);
661 			} else if (osp <= 255) {
662 				if (notmapped) {
663 					error = md_malloc_move_ma(&m, &ma_offs,
664 					    sc->sectorsize, NULL, osp,
665 					    MD_MALLOC_MOVE_FILL);
666 				} else if (vlist != NULL) {
667 					error = md_malloc_move_vlist(&vlist,
668 					    &ma_offs, sc->sectorsize, NULL, osp,
669 					    MD_MALLOC_MOVE_FILL);
670 				} else
671 					memset(dst, osp, sc->sectorsize);
672 			} else {
673 				if (notmapped) {
674 					error = md_malloc_move_ma(&m, &ma_offs,
675 					    sc->sectorsize, (void *)osp, 0,
676 					    MD_MALLOC_MOVE_READ);
677 				} else if (vlist != NULL) {
678 					error = md_malloc_move_vlist(&vlist,
679 					    &ma_offs, sc->sectorsize,
680 					    (void *)osp, 0,
681 					    MD_MALLOC_MOVE_READ);
682 				} else {
683 					bcopy((void *)osp, dst, sc->sectorsize);
684 					cpu_flush_dcache(dst, sc->sectorsize);
685 				}
686 			}
687 			osp = 0;
688 		} else if (bp->bio_cmd == BIO_WRITE) {
689 			if (sc->flags & MD_COMPRESS) {
690 				if (notmapped) {
691 					error1 = md_malloc_move_ma(&m, &ma_offs,
692 					    sc->sectorsize, &uc, 0,
693 					    MD_MALLOC_MOVE_CMP);
694 					i = error1 == 0 ? sc->sectorsize : 0;
695 				} else if (vlist != NULL) {
696 					error1 = md_malloc_move_vlist(&vlist,
697 					    &ma_offs, sc->sectorsize, &uc, 0,
698 					    MD_MALLOC_MOVE_CMP);
699 					i = error1 == 0 ? sc->sectorsize : 0;
700 				} else {
701 					uc = dst[0];
702 					for (i = 1; i < sc->sectorsize; i++) {
703 						if (dst[i] != uc)
704 							break;
705 					}
706 				}
707 			} else {
708 				i = 0;
709 				uc = 0;
710 			}
711 			if (i == sc->sectorsize) {
712 				if (osp != uc)
713 					error = s_write(sc->indir, secno, uc);
714 			} else {
715 				if (osp <= 255) {
716 					sp = (uintptr_t)uma_zalloc(sc->uma,
717 					    md_malloc_wait ? M_WAITOK :
718 					    M_NOWAIT);
719 					if (sp == 0) {
720 						error = ENOSPC;
721 						break;
722 					}
723 					if (notmapped) {
724 						error = md_malloc_move_ma(&m,
725 						    &ma_offs, sc->sectorsize,
726 						    (void *)sp, 0,
727 						    MD_MALLOC_MOVE_WRITE);
728 					} else if (vlist != NULL) {
729 						error = md_malloc_move_vlist(
730 						    &vlist, &ma_offs,
731 						    sc->sectorsize, (void *)sp,
732 						    0, MD_MALLOC_MOVE_WRITE);
733 					} else {
734 						bcopy(dst, (void *)sp,
735 						    sc->sectorsize);
736 					}
737 					error = s_write(sc->indir, secno, sp);
738 				} else {
739 					if (notmapped) {
740 						error = md_malloc_move_ma(&m,
741 						    &ma_offs, sc->sectorsize,
742 						    (void *)osp, 0,
743 						    MD_MALLOC_MOVE_WRITE);
744 					} else if (vlist != NULL) {
745 						error = md_malloc_move_vlist(
746 						    &vlist, &ma_offs,
747 						    sc->sectorsize, (void *)osp,
748 						    0, MD_MALLOC_MOVE_WRITE);
749 					} else {
750 						bcopy(dst, (void *)osp,
751 						    sc->sectorsize);
752 					}
753 					osp = 0;
754 				}
755 			}
756 		} else {
757 			error = EOPNOTSUPP;
758 		}
759 		if (osp > 255)
760 			uma_zfree(sc->uma, (void*)osp);
761 		if (error != 0)
762 			break;
763 		secno++;
764 		if (!notmapped && vlist == NULL)
765 			dst += sc->sectorsize;
766 	}
767 	bp->bio_resid = 0;
768 	return (error);
769 }
770 
771 static void
772 mdcopyto_vlist(void *src, bus_dma_segment_t *vlist, off_t offset, off_t len)
773 {
774 	off_t seg_len;
775 
776 	while (offset >= vlist->ds_len) {
777 		offset -= vlist->ds_len;
778 		vlist++;
779 	}
780 
781 	while (len != 0) {
782 		seg_len = omin(len, vlist->ds_len - offset);
783 		bcopy(src, (void *)(uintptr_t)(vlist->ds_addr + offset),
784 		    seg_len);
785 		offset = 0;
786 		src = (uint8_t *)src + seg_len;
787 		len -= seg_len;
788 		vlist++;
789 	}
790 }
791 
792 static void
793 mdcopyfrom_vlist(bus_dma_segment_t *vlist, off_t offset, void *dst, off_t len)
794 {
795 	off_t seg_len;
796 
797 	while (offset >= vlist->ds_len) {
798 		offset -= vlist->ds_len;
799 		vlist++;
800 	}
801 
802 	while (len != 0) {
803 		seg_len = omin(len, vlist->ds_len - offset);
804 		bcopy((void *)(uintptr_t)(vlist->ds_addr + offset), dst,
805 		    seg_len);
806 		offset = 0;
807 		dst = (uint8_t *)dst + seg_len;
808 		len -= seg_len;
809 		vlist++;
810 	}
811 }
812 
813 static int
814 mdstart_preload(struct md_s *sc, struct bio *bp)
815 {
816 	uint8_t *p;
817 
818 	p = sc->pl_ptr + bp->bio_offset;
819 	switch (bp->bio_cmd) {
820 	case BIO_READ:
821 		if ((bp->bio_flags & BIO_VLIST) != 0) {
822 			mdcopyto_vlist(p, (bus_dma_segment_t *)bp->bio_data,
823 			    bp->bio_ma_offset, bp->bio_length);
824 		} else {
825 			bcopy(p, bp->bio_data, bp->bio_length);
826 		}
827 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
828 		break;
829 	case BIO_WRITE:
830 		if ((bp->bio_flags & BIO_VLIST) != 0) {
831 			mdcopyfrom_vlist((bus_dma_segment_t *)bp->bio_data,
832 			    bp->bio_ma_offset, p, bp->bio_length);
833 		} else {
834 			bcopy(bp->bio_data, p, bp->bio_length);
835 		}
836 		break;
837 	}
838 	bp->bio_resid = 0;
839 	return (0);
840 }
841 
842 static int
843 mdstart_vnode(struct md_s *sc, struct bio *bp)
844 {
845 	int error;
846 	struct uio auio;
847 	struct iovec aiov;
848 	struct iovec *piov;
849 	struct mount *mp;
850 	struct vnode *vp;
851 	struct buf *pb;
852 	bus_dma_segment_t *vlist;
853 	struct thread *td;
854 	off_t iolen, len, zerosize;
855 	int ma_offs, npages;
856 
857 	switch (bp->bio_cmd) {
858 	case BIO_READ:
859 		auio.uio_rw = UIO_READ;
860 		break;
861 	case BIO_WRITE:
862 	case BIO_DELETE:
863 		auio.uio_rw = UIO_WRITE;
864 		break;
865 	case BIO_FLUSH:
866 		break;
867 	default:
868 		return (EOPNOTSUPP);
869 	}
870 
871 	td = curthread;
872 	vp = sc->vnode;
873 	pb = NULL;
874 	piov = NULL;
875 	ma_offs = bp->bio_ma_offset;
876 	len = bp->bio_length;
877 
878 	/*
879 	 * VNODE I/O
880 	 *
881 	 * If an error occurs, we set BIO_ERROR but we do not set
882 	 * B_INVAL because (for a write anyway), the buffer is
883 	 * still valid.
884 	 */
885 
886 	if (bp->bio_cmd == BIO_FLUSH) {
887 		(void) vn_start_write(vp, &mp, V_WAIT);
888 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
889 		error = VOP_FSYNC(vp, MNT_WAIT, td);
890 		VOP_UNLOCK(vp, 0);
891 		vn_finished_write(mp);
892 		return (error);
893 	}
894 
895 	auio.uio_offset = (vm_ooffset_t)bp->bio_offset;
896 	auio.uio_resid = bp->bio_length;
897 	auio.uio_segflg = UIO_SYSSPACE;
898 	auio.uio_td = td;
899 
900 	if (bp->bio_cmd == BIO_DELETE) {
901 		/*
902 		 * Emulate BIO_DELETE by writing zeros.
903 		 */
904 		zerosize = ZERO_REGION_SIZE -
905 		    (ZERO_REGION_SIZE % sc->sectorsize);
906 		auio.uio_iovcnt = howmany(bp->bio_length, zerosize);
907 		piov = malloc(sizeof(*piov) * auio.uio_iovcnt, M_MD, M_WAITOK);
908 		auio.uio_iov = piov;
909 		while (len > 0) {
910 			piov->iov_base = __DECONST(void *, zero_region);
911 			piov->iov_len = len;
912 			if (len > zerosize)
913 				piov->iov_len = zerosize;
914 			len -= piov->iov_len;
915 			piov++;
916 		}
917 		piov = auio.uio_iov;
918 	} else if ((bp->bio_flags & BIO_VLIST) != 0) {
919 		piov = malloc(sizeof(*piov) * bp->bio_ma_n, M_MD, M_WAITOK);
920 		auio.uio_iov = piov;
921 		vlist = (bus_dma_segment_t *)bp->bio_data;
922 		while (len > 0) {
923 			piov->iov_base = (void *)(uintptr_t)(vlist->ds_addr +
924 			    ma_offs);
925 			piov->iov_len = vlist->ds_len - ma_offs;
926 			if (piov->iov_len > len)
927 				piov->iov_len = len;
928 			len -= piov->iov_len;
929 			ma_offs = 0;
930 			vlist++;
931 			piov++;
932 		}
933 		auio.uio_iovcnt = piov - auio.uio_iov;
934 		piov = auio.uio_iov;
935 	} else if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
936 		pb = getpbuf(&md_vnode_pbuf_freecnt);
937 		bp->bio_resid = len;
938 unmapped_step:
939 		npages = atop(min(MAXPHYS, round_page(len + (ma_offs &
940 		    PAGE_MASK))));
941 		iolen = min(ptoa(npages) - (ma_offs & PAGE_MASK), len);
942 		KASSERT(iolen > 0, ("zero iolen"));
943 		pmap_qenter((vm_offset_t)pb->b_data,
944 		    &bp->bio_ma[atop(ma_offs)], npages);
945 		aiov.iov_base = (void *)((vm_offset_t)pb->b_data +
946 		    (ma_offs & PAGE_MASK));
947 		aiov.iov_len = iolen;
948 		auio.uio_iov = &aiov;
949 		auio.uio_iovcnt = 1;
950 		auio.uio_resid = iolen;
951 	} else {
952 		aiov.iov_base = bp->bio_data;
953 		aiov.iov_len = bp->bio_length;
954 		auio.uio_iov = &aiov;
955 		auio.uio_iovcnt = 1;
956 	}
957 	/*
958 	 * When reading set IO_DIRECT to try to avoid double-caching
959 	 * the data.  When writing IO_DIRECT is not optimal.
960 	 */
961 	if (auio.uio_rw == UIO_READ) {
962 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
963 		error = VOP_READ(vp, &auio, IO_DIRECT, sc->cred);
964 		VOP_UNLOCK(vp, 0);
965 	} else {
966 		(void) vn_start_write(vp, &mp, V_WAIT);
967 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
968 		error = VOP_WRITE(vp, &auio, sc->flags & MD_ASYNC ? 0 : IO_SYNC,
969 		    sc->cred);
970 		VOP_UNLOCK(vp, 0);
971 		vn_finished_write(mp);
972 		if (error == 0)
973 			sc->flags &= ~MD_VERIFY;
974 	}
975 
976 	if (pb != NULL) {
977 		pmap_qremove((vm_offset_t)pb->b_data, npages);
978 		if (error == 0) {
979 			len -= iolen;
980 			bp->bio_resid -= iolen;
981 			ma_offs += iolen;
982 			if (len > 0)
983 				goto unmapped_step;
984 		}
985 		relpbuf(pb, &md_vnode_pbuf_freecnt);
986 	}
987 
988 	free(piov, M_MD);
989 	if (pb == NULL)
990 		bp->bio_resid = auio.uio_resid;
991 	return (error);
992 }
993 
994 static void
995 md_swap_page_free(vm_page_t m)
996 {
997 
998 	vm_page_xunbusy(m);
999 	vm_page_lock(m);
1000 	vm_page_free(m);
1001 	vm_page_unlock(m);
1002 }
1003 
1004 static int
1005 mdstart_swap(struct md_s *sc, struct bio *bp)
1006 {
1007 	vm_page_t m;
1008 	u_char *p;
1009 	vm_pindex_t i, lastp;
1010 	bus_dma_segment_t *vlist;
1011 	int rv, ma_offs, offs, len, lastend;
1012 
1013 	switch (bp->bio_cmd) {
1014 	case BIO_READ:
1015 	case BIO_WRITE:
1016 	case BIO_DELETE:
1017 		break;
1018 	default:
1019 		return (EOPNOTSUPP);
1020 	}
1021 
1022 	p = bp->bio_data;
1023 	ma_offs = (bp->bio_flags & (BIO_UNMAPPED|BIO_VLIST)) != 0 ?
1024 	    bp->bio_ma_offset : 0;
1025 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
1026 	    (bus_dma_segment_t *)bp->bio_data : NULL;
1027 
1028 	/*
1029 	 * offs is the offset at which to start operating on the
1030 	 * next (ie, first) page.  lastp is the last page on
1031 	 * which we're going to operate.  lastend is the ending
1032 	 * position within that last page (ie, PAGE_SIZE if
1033 	 * we're operating on complete aligned pages).
1034 	 */
1035 	offs = bp->bio_offset % PAGE_SIZE;
1036 	lastp = (bp->bio_offset + bp->bio_length - 1) / PAGE_SIZE;
1037 	lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1;
1038 
1039 	rv = VM_PAGER_OK;
1040 	VM_OBJECT_WLOCK(sc->object);
1041 	vm_object_pip_add(sc->object, 1);
1042 	for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) {
1043 		len = ((i == lastp) ? lastend : PAGE_SIZE) - offs;
1044 		m = vm_page_grab(sc->object, i, VM_ALLOC_SYSTEM);
1045 		if (bp->bio_cmd == BIO_READ) {
1046 			if (m->valid == VM_PAGE_BITS_ALL)
1047 				rv = VM_PAGER_OK;
1048 			else
1049 				rv = vm_pager_get_pages(sc->object, &m, 1,
1050 				    NULL, NULL);
1051 			if (rv == VM_PAGER_ERROR) {
1052 				md_swap_page_free(m);
1053 				break;
1054 			} else if (rv == VM_PAGER_FAIL) {
1055 				/*
1056 				 * Pager does not have the page.  Zero
1057 				 * the allocated page, and mark it as
1058 				 * valid. Do not set dirty, the page
1059 				 * can be recreated if thrown out.
1060 				 */
1061 				pmap_zero_page(m);
1062 				m->valid = VM_PAGE_BITS_ALL;
1063 			}
1064 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1065 				pmap_copy_pages(&m, offs, bp->bio_ma,
1066 				    ma_offs, len);
1067 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1068 				physcopyout_vlist(VM_PAGE_TO_PHYS(m) + offs,
1069 				    vlist, ma_offs, len);
1070 				cpu_flush_dcache(p, len);
1071 			} else {
1072 				physcopyout(VM_PAGE_TO_PHYS(m) + offs, p, len);
1073 				cpu_flush_dcache(p, len);
1074 			}
1075 		} else if (bp->bio_cmd == BIO_WRITE) {
1076 			if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL)
1077 				rv = VM_PAGER_OK;
1078 			else
1079 				rv = vm_pager_get_pages(sc->object, &m, 1,
1080 				    NULL, NULL);
1081 			if (rv == VM_PAGER_ERROR) {
1082 				md_swap_page_free(m);
1083 				break;
1084 			} else if (rv == VM_PAGER_FAIL)
1085 				pmap_zero_page(m);
1086 
1087 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1088 				pmap_copy_pages(bp->bio_ma, ma_offs, &m,
1089 				    offs, len);
1090 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1091 				physcopyin_vlist(vlist, ma_offs,
1092 				    VM_PAGE_TO_PHYS(m) + offs, len);
1093 			} else {
1094 				physcopyin(p, VM_PAGE_TO_PHYS(m) + offs, len);
1095 			}
1096 
1097 			m->valid = VM_PAGE_BITS_ALL;
1098 			if (m->dirty != VM_PAGE_BITS_ALL) {
1099 				vm_page_dirty(m);
1100 				vm_pager_page_unswapped(m);
1101 			}
1102 		} else if (bp->bio_cmd == BIO_DELETE) {
1103 			if (len == PAGE_SIZE || m->valid == VM_PAGE_BITS_ALL)
1104 				rv = VM_PAGER_OK;
1105 			else
1106 				rv = vm_pager_get_pages(sc->object, &m, 1,
1107 				    NULL, NULL);
1108 			if (rv == VM_PAGER_ERROR) {
1109 				md_swap_page_free(m);
1110 				break;
1111 			} else if (rv == VM_PAGER_FAIL) {
1112 				md_swap_page_free(m);
1113 				m = NULL;
1114 			} else {
1115 				/* Page is valid. */
1116 				if (len != PAGE_SIZE) {
1117 					pmap_zero_page_area(m, offs, len);
1118 					if (m->dirty != VM_PAGE_BITS_ALL) {
1119 						vm_page_dirty(m);
1120 						vm_pager_page_unswapped(m);
1121 					}
1122 				} else {
1123 					vm_pager_page_unswapped(m);
1124 					md_swap_page_free(m);
1125 					m = NULL;
1126 				}
1127 			}
1128 		}
1129 		if (m != NULL) {
1130 			vm_page_xunbusy(m);
1131 			vm_page_lock(m);
1132 			if (vm_page_active(m))
1133 				vm_page_reference(m);
1134 			else
1135 				vm_page_activate(m);
1136 			vm_page_unlock(m);
1137 		}
1138 
1139 		/* Actions on further pages start at offset 0 */
1140 		p += PAGE_SIZE - offs;
1141 		offs = 0;
1142 		ma_offs += len;
1143 	}
1144 	vm_object_pip_wakeup(sc->object);
1145 	VM_OBJECT_WUNLOCK(sc->object);
1146 	return (rv != VM_PAGER_ERROR ? 0 : ENOSPC);
1147 }
1148 
1149 static int
1150 mdstart_null(struct md_s *sc, struct bio *bp)
1151 {
1152 
1153 	switch (bp->bio_cmd) {
1154 	case BIO_READ:
1155 		bzero(bp->bio_data, bp->bio_length);
1156 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
1157 		break;
1158 	case BIO_WRITE:
1159 		break;
1160 	}
1161 	bp->bio_resid = 0;
1162 	return (0);
1163 }
1164 
1165 static void
1166 md_kthread(void *arg)
1167 {
1168 	struct md_s *sc;
1169 	struct bio *bp;
1170 	int error;
1171 
1172 	sc = arg;
1173 	thread_lock(curthread);
1174 	sched_prio(curthread, PRIBIO);
1175 	thread_unlock(curthread);
1176 	if (sc->type == MD_VNODE)
1177 		curthread->td_pflags |= TDP_NORUNNINGBUF;
1178 
1179 	for (;;) {
1180 		mtx_lock(&sc->queue_mtx);
1181 		if (sc->flags & MD_SHUTDOWN) {
1182 			sc->flags |= MD_EXITING;
1183 			mtx_unlock(&sc->queue_mtx);
1184 			kproc_exit(0);
1185 		}
1186 		bp = bioq_takefirst(&sc->bio_queue);
1187 		if (!bp) {
1188 			msleep(sc, &sc->queue_mtx, PRIBIO | PDROP, "mdwait", 0);
1189 			continue;
1190 		}
1191 		mtx_unlock(&sc->queue_mtx);
1192 		if (bp->bio_cmd == BIO_GETATTR) {
1193 			int isv = ((sc->flags & MD_VERIFY) != 0);
1194 
1195 			if ((sc->fwsectors && sc->fwheads &&
1196 			    (g_handleattr_int(bp, "GEOM::fwsectors",
1197 			    sc->fwsectors) ||
1198 			    g_handleattr_int(bp, "GEOM::fwheads",
1199 			    sc->fwheads))) ||
1200 			    g_handleattr_int(bp, "GEOM::candelete", 1))
1201 				error = -1;
1202 			else if (sc->ident[0] != '\0' &&
1203 			    g_handleattr_str(bp, "GEOM::ident", sc->ident))
1204 				error = -1;
1205 			else if (g_handleattr_int(bp, "MNT::verified", isv))
1206 				error = -1;
1207 			else
1208 				error = EOPNOTSUPP;
1209 		} else {
1210 			error = sc->start(sc, bp);
1211 		}
1212 
1213 		if (error != -1) {
1214 			bp->bio_completed = bp->bio_length;
1215 			if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE))
1216 				devstat_end_transaction_bio(sc->devstat, bp);
1217 			g_io_deliver(bp, error);
1218 		}
1219 	}
1220 }
1221 
1222 static struct md_s *
1223 mdfind(int unit)
1224 {
1225 	struct md_s *sc;
1226 
1227 	LIST_FOREACH(sc, &md_softc_list, list) {
1228 		if (sc->unit == unit)
1229 			break;
1230 	}
1231 	return (sc);
1232 }
1233 
1234 static struct md_s *
1235 mdnew(int unit, int *errp, enum md_types type)
1236 {
1237 	struct md_s *sc;
1238 	int error;
1239 
1240 	*errp = 0;
1241 	if (unit == -1)
1242 		unit = alloc_unr(md_uh);
1243 	else
1244 		unit = alloc_unr_specific(md_uh, unit);
1245 
1246 	if (unit == -1) {
1247 		*errp = EBUSY;
1248 		return (NULL);
1249 	}
1250 
1251 	sc = (struct md_s *)malloc(sizeof *sc, M_MD, M_WAITOK | M_ZERO);
1252 	sc->type = type;
1253 	bioq_init(&sc->bio_queue);
1254 	mtx_init(&sc->queue_mtx, "md bio queue", NULL, MTX_DEF);
1255 	mtx_init(&sc->stat_mtx, "md stat", NULL, MTX_DEF);
1256 	sc->unit = unit;
1257 	sprintf(sc->name, "md%d", unit);
1258 	LIST_INSERT_HEAD(&md_softc_list, sc, list);
1259 	error = kproc_create(md_kthread, sc, &sc->procp, 0, 0,"%s", sc->name);
1260 	if (error == 0)
1261 		return (sc);
1262 	LIST_REMOVE(sc, list);
1263 	mtx_destroy(&sc->stat_mtx);
1264 	mtx_destroy(&sc->queue_mtx);
1265 	free_unr(md_uh, sc->unit);
1266 	free(sc, M_MD);
1267 	*errp = error;
1268 	return (NULL);
1269 }
1270 
1271 static void
1272 mdinit(struct md_s *sc)
1273 {
1274 	struct g_geom *gp;
1275 	struct g_provider *pp;
1276 
1277 	g_topology_lock();
1278 	gp = g_new_geomf(&g_md_class, "md%d", sc->unit);
1279 	gp->softc = sc;
1280 	pp = g_new_providerf(gp, "md%d", sc->unit);
1281 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
1282 	pp->mediasize = sc->mediasize;
1283 	pp->sectorsize = sc->sectorsize;
1284 	switch (sc->type) {
1285 	case MD_MALLOC:
1286 	case MD_VNODE:
1287 	case MD_SWAP:
1288 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
1289 		break;
1290 	case MD_PRELOAD:
1291 	case MD_NULL:
1292 		break;
1293 	}
1294 	sc->gp = gp;
1295 	sc->pp = pp;
1296 	g_error_provider(pp, 0);
1297 	g_topology_unlock();
1298 	sc->devstat = devstat_new_entry("md", sc->unit, sc->sectorsize,
1299 	    DEVSTAT_ALL_SUPPORTED, DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
1300 }
1301 
1302 static int
1303 mdcreate_malloc(struct md_s *sc, struct md_req *mdr)
1304 {
1305 	uintptr_t sp;
1306 	int error;
1307 	off_t u;
1308 
1309 	error = 0;
1310 	if (mdr->md_options & ~(MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE))
1311 		return (EINVAL);
1312 	if (mdr->md_sectorsize != 0 && !powerof2(mdr->md_sectorsize))
1313 		return (EINVAL);
1314 	/* Compression doesn't make sense if we have reserved space */
1315 	if (mdr->md_options & MD_RESERVE)
1316 		mdr->md_options &= ~MD_COMPRESS;
1317 	if (mdr->md_fwsectors != 0)
1318 		sc->fwsectors = mdr->md_fwsectors;
1319 	if (mdr->md_fwheads != 0)
1320 		sc->fwheads = mdr->md_fwheads;
1321 	sc->flags = mdr->md_options & (MD_COMPRESS | MD_FORCE);
1322 	sc->indir = dimension(sc->mediasize / sc->sectorsize);
1323 	sc->uma = uma_zcreate(sc->name, sc->sectorsize, NULL, NULL, NULL, NULL,
1324 	    0x1ff, 0);
1325 	if (mdr->md_options & MD_RESERVE) {
1326 		off_t nsectors;
1327 
1328 		nsectors = sc->mediasize / sc->sectorsize;
1329 		for (u = 0; u < nsectors; u++) {
1330 			sp = (uintptr_t)uma_zalloc(sc->uma, (md_malloc_wait ?
1331 			    M_WAITOK : M_NOWAIT) | M_ZERO);
1332 			if (sp != 0)
1333 				error = s_write(sc->indir, u, sp);
1334 			else
1335 				error = ENOMEM;
1336 			if (error != 0)
1337 				break;
1338 		}
1339 	}
1340 	return (error);
1341 }
1342 
1343 
1344 static int
1345 mdsetcred(struct md_s *sc, struct ucred *cred)
1346 {
1347 	char *tmpbuf;
1348 	int error = 0;
1349 
1350 	/*
1351 	 * Set credits in our softc
1352 	 */
1353 
1354 	if (sc->cred)
1355 		crfree(sc->cred);
1356 	sc->cred = crhold(cred);
1357 
1358 	/*
1359 	 * Horrible kludge to establish credentials for NFS  XXX.
1360 	 */
1361 
1362 	if (sc->vnode) {
1363 		struct uio auio;
1364 		struct iovec aiov;
1365 
1366 		tmpbuf = malloc(sc->sectorsize, M_TEMP, M_WAITOK);
1367 		bzero(&auio, sizeof(auio));
1368 
1369 		aiov.iov_base = tmpbuf;
1370 		aiov.iov_len = sc->sectorsize;
1371 		auio.uio_iov = &aiov;
1372 		auio.uio_iovcnt = 1;
1373 		auio.uio_offset = 0;
1374 		auio.uio_rw = UIO_READ;
1375 		auio.uio_segflg = UIO_SYSSPACE;
1376 		auio.uio_resid = aiov.iov_len;
1377 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1378 		error = VOP_READ(sc->vnode, &auio, 0, sc->cred);
1379 		VOP_UNLOCK(sc->vnode, 0);
1380 		free(tmpbuf, M_TEMP);
1381 	}
1382 	return (error);
1383 }
1384 
1385 static int
1386 mdcreate_vnode(struct md_s *sc, struct md_req *mdr, struct thread *td)
1387 {
1388 	struct vattr vattr;
1389 	struct nameidata nd;
1390 	char *fname;
1391 	int error, flags;
1392 
1393 	fname = mdr->md_file;
1394 	if (mdr->md_file_seg == UIO_USERSPACE) {
1395 		error = copyinstr(fname, sc->file, sizeof(sc->file), NULL);
1396 		if (error != 0)
1397 			return (error);
1398 	} else
1399 		strlcpy(sc->file, fname, sizeof(sc->file));
1400 
1401 	/*
1402 	 * If the user specified that this is a read only device, don't
1403 	 * set the FWRITE mask before trying to open the backing store.
1404 	 */
1405 	flags = FREAD | ((mdr->md_options & MD_READONLY) ? 0 : FWRITE) \
1406 	    | ((mdr->md_options & MD_VERIFY) ? O_VERIFY : 0);
1407 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, sc->file, td);
1408 	error = vn_open(&nd, &flags, 0, NULL);
1409 	if (error != 0)
1410 		return (error);
1411 	NDFREE(&nd, NDF_ONLY_PNBUF);
1412 	if (nd.ni_vp->v_type != VREG) {
1413 		error = EINVAL;
1414 		goto bad;
1415 	}
1416 	error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred);
1417 	if (error != 0)
1418 		goto bad;
1419 	if (VOP_ISLOCKED(nd.ni_vp) != LK_EXCLUSIVE) {
1420 		vn_lock(nd.ni_vp, LK_UPGRADE | LK_RETRY);
1421 		if (nd.ni_vp->v_iflag & VI_DOOMED) {
1422 			/* Forced unmount. */
1423 			error = EBADF;
1424 			goto bad;
1425 		}
1426 	}
1427 	nd.ni_vp->v_vflag |= VV_MD;
1428 	VOP_UNLOCK(nd.ni_vp, 0);
1429 
1430 	if (mdr->md_fwsectors != 0)
1431 		sc->fwsectors = mdr->md_fwsectors;
1432 	if (mdr->md_fwheads != 0)
1433 		sc->fwheads = mdr->md_fwheads;
1434 	snprintf(sc->ident, sizeof(sc->ident), "MD-DEV%ju-INO%ju",
1435 	    (uintmax_t)vattr.va_fsid, (uintmax_t)vattr.va_fileid);
1436 	sc->flags = mdr->md_options & (MD_FORCE | MD_ASYNC | MD_VERIFY);
1437 	if (!(flags & FWRITE))
1438 		sc->flags |= MD_READONLY;
1439 	sc->vnode = nd.ni_vp;
1440 
1441 	error = mdsetcred(sc, td->td_ucred);
1442 	if (error != 0) {
1443 		sc->vnode = NULL;
1444 		vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1445 		nd.ni_vp->v_vflag &= ~VV_MD;
1446 		goto bad;
1447 	}
1448 	return (0);
1449 bad:
1450 	VOP_UNLOCK(nd.ni_vp, 0);
1451 	(void)vn_close(nd.ni_vp, flags, td->td_ucred, td);
1452 	return (error);
1453 }
1454 
1455 static int
1456 mddestroy(struct md_s *sc, struct thread *td)
1457 {
1458 
1459 	if (sc->gp) {
1460 		sc->gp->softc = NULL;
1461 		g_topology_lock();
1462 		g_wither_geom(sc->gp, ENXIO);
1463 		g_topology_unlock();
1464 		sc->gp = NULL;
1465 		sc->pp = NULL;
1466 	}
1467 	if (sc->devstat) {
1468 		devstat_remove_entry(sc->devstat);
1469 		sc->devstat = NULL;
1470 	}
1471 	mtx_lock(&sc->queue_mtx);
1472 	sc->flags |= MD_SHUTDOWN;
1473 	wakeup(sc);
1474 	while (!(sc->flags & MD_EXITING))
1475 		msleep(sc->procp, &sc->queue_mtx, PRIBIO, "mddestroy", hz / 10);
1476 	mtx_unlock(&sc->queue_mtx);
1477 	mtx_destroy(&sc->stat_mtx);
1478 	mtx_destroy(&sc->queue_mtx);
1479 	if (sc->vnode != NULL) {
1480 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1481 		sc->vnode->v_vflag &= ~VV_MD;
1482 		VOP_UNLOCK(sc->vnode, 0);
1483 		(void)vn_close(sc->vnode, sc->flags & MD_READONLY ?
1484 		    FREAD : (FREAD|FWRITE), sc->cred, td);
1485 	}
1486 	if (sc->cred != NULL)
1487 		crfree(sc->cred);
1488 	if (sc->object != NULL)
1489 		vm_object_deallocate(sc->object);
1490 	if (sc->indir)
1491 		destroy_indir(sc, sc->indir);
1492 	if (sc->uma)
1493 		uma_zdestroy(sc->uma);
1494 
1495 	LIST_REMOVE(sc, list);
1496 	free_unr(md_uh, sc->unit);
1497 	free(sc, M_MD);
1498 	return (0);
1499 }
1500 
1501 static int
1502 mdresize(struct md_s *sc, struct md_req *mdr)
1503 {
1504 	int error, res;
1505 	vm_pindex_t oldpages, newpages;
1506 
1507 	switch (sc->type) {
1508 	case MD_VNODE:
1509 	case MD_NULL:
1510 		break;
1511 	case MD_SWAP:
1512 		if (mdr->md_mediasize <= 0 ||
1513 		    (mdr->md_mediasize % PAGE_SIZE) != 0)
1514 			return (EDOM);
1515 		oldpages = OFF_TO_IDX(round_page(sc->mediasize));
1516 		newpages = OFF_TO_IDX(round_page(mdr->md_mediasize));
1517 		if (newpages < oldpages) {
1518 			VM_OBJECT_WLOCK(sc->object);
1519 			vm_object_page_remove(sc->object, newpages, 0, 0);
1520 			swap_pager_freespace(sc->object, newpages,
1521 			    oldpages - newpages);
1522 			swap_release_by_cred(IDX_TO_OFF(oldpages -
1523 			    newpages), sc->cred);
1524 			sc->object->charge = IDX_TO_OFF(newpages);
1525 			sc->object->size = newpages;
1526 			VM_OBJECT_WUNLOCK(sc->object);
1527 		} else if (newpages > oldpages) {
1528 			res = swap_reserve_by_cred(IDX_TO_OFF(newpages -
1529 			    oldpages), sc->cred);
1530 			if (!res)
1531 				return (ENOMEM);
1532 			if ((mdr->md_options & MD_RESERVE) ||
1533 			    (sc->flags & MD_RESERVE)) {
1534 				error = swap_pager_reserve(sc->object,
1535 				    oldpages, newpages - oldpages);
1536 				if (error < 0) {
1537 					swap_release_by_cred(
1538 					    IDX_TO_OFF(newpages - oldpages),
1539 					    sc->cred);
1540 					return (EDOM);
1541 				}
1542 			}
1543 			VM_OBJECT_WLOCK(sc->object);
1544 			sc->object->charge = IDX_TO_OFF(newpages);
1545 			sc->object->size = newpages;
1546 			VM_OBJECT_WUNLOCK(sc->object);
1547 		}
1548 		break;
1549 	default:
1550 		return (EOPNOTSUPP);
1551 	}
1552 
1553 	sc->mediasize = mdr->md_mediasize;
1554 	g_topology_lock();
1555 	g_resize_provider(sc->pp, sc->mediasize);
1556 	g_topology_unlock();
1557 	return (0);
1558 }
1559 
1560 static int
1561 mdcreate_swap(struct md_s *sc, struct md_req *mdr, struct thread *td)
1562 {
1563 	vm_ooffset_t npage;
1564 	int error;
1565 
1566 	/*
1567 	 * Range check.  Disallow negative sizes and sizes not being
1568 	 * multiple of page size.
1569 	 */
1570 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1571 		return (EDOM);
1572 
1573 	/*
1574 	 * Allocate an OBJT_SWAP object.
1575 	 *
1576 	 * Note the truncation.
1577 	 */
1578 
1579 	if ((mdr->md_options & MD_VERIFY) != 0)
1580 		return (EINVAL);
1581 	npage = mdr->md_mediasize / PAGE_SIZE;
1582 	if (mdr->md_fwsectors != 0)
1583 		sc->fwsectors = mdr->md_fwsectors;
1584 	if (mdr->md_fwheads != 0)
1585 		sc->fwheads = mdr->md_fwheads;
1586 	sc->object = vm_pager_allocate(OBJT_SWAP, NULL, PAGE_SIZE * npage,
1587 	    VM_PROT_DEFAULT, 0, td->td_ucred);
1588 	if (sc->object == NULL)
1589 		return (ENOMEM);
1590 	sc->flags = mdr->md_options & (MD_FORCE | MD_RESERVE);
1591 	if (mdr->md_options & MD_RESERVE) {
1592 		if (swap_pager_reserve(sc->object, 0, npage) < 0) {
1593 			error = EDOM;
1594 			goto finish;
1595 		}
1596 	}
1597 	error = mdsetcred(sc, td->td_ucred);
1598  finish:
1599 	if (error != 0) {
1600 		vm_object_deallocate(sc->object);
1601 		sc->object = NULL;
1602 	}
1603 	return (error);
1604 }
1605 
1606 static int
1607 mdcreate_null(struct md_s *sc, struct md_req *mdr, struct thread *td)
1608 {
1609 
1610 	/*
1611 	 * Range check.  Disallow negative sizes and sizes not being
1612 	 * multiple of page size.
1613 	 */
1614 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1615 		return (EDOM);
1616 
1617 	return (0);
1618 }
1619 
1620 static int
1621 kern_mdattach_locked(struct thread *td, struct md_req *mdr)
1622 {
1623 	struct md_s *sc;
1624 	unsigned sectsize;
1625 	int error, i;
1626 
1627 	sx_assert(&md_sx, SA_XLOCKED);
1628 
1629 	switch (mdr->md_type) {
1630 	case MD_MALLOC:
1631 	case MD_PRELOAD:
1632 	case MD_VNODE:
1633 	case MD_SWAP:
1634 	case MD_NULL:
1635 		break;
1636 	default:
1637 		return (EINVAL);
1638 	}
1639 	if (mdr->md_sectorsize == 0)
1640 		sectsize = DEV_BSIZE;
1641 	else
1642 		sectsize = mdr->md_sectorsize;
1643 	if (sectsize > MAXPHYS || mdr->md_mediasize < sectsize)
1644 		return (EINVAL);
1645 	if (mdr->md_options & MD_AUTOUNIT)
1646 		sc = mdnew(-1, &error, mdr->md_type);
1647 	else {
1648 		if (mdr->md_unit > INT_MAX)
1649 			return (EINVAL);
1650 		sc = mdnew(mdr->md_unit, &error, mdr->md_type);
1651 	}
1652 	if (sc == NULL)
1653 		return (error);
1654 	if (mdr->md_label != NULL)
1655 		error = copyinstr(mdr->md_label, sc->label,
1656 		    sizeof(sc->label), NULL);
1657 	if (error != 0)
1658 		goto err_after_new;
1659 	if (mdr->md_options & MD_AUTOUNIT)
1660 		mdr->md_unit = sc->unit;
1661 	sc->mediasize = mdr->md_mediasize;
1662 	sc->sectorsize = sectsize;
1663 	error = EDOOFUS;
1664 	switch (sc->type) {
1665 	case MD_MALLOC:
1666 		sc->start = mdstart_malloc;
1667 		error = mdcreate_malloc(sc, mdr);
1668 		break;
1669 	case MD_PRELOAD:
1670 		/*
1671 		 * We disallow attaching preloaded memory disks via
1672 		 * ioctl. Preloaded memory disks are automatically
1673 		 * attached in g_md_init().
1674 		 */
1675 		error = EOPNOTSUPP;
1676 		break;
1677 	case MD_VNODE:
1678 		sc->start = mdstart_vnode;
1679 		error = mdcreate_vnode(sc, mdr, td);
1680 		break;
1681 	case MD_SWAP:
1682 		sc->start = mdstart_swap;
1683 		error = mdcreate_swap(sc, mdr, td);
1684 		break;
1685 	case MD_NULL:
1686 		sc->start = mdstart_null;
1687 		error = mdcreate_null(sc, mdr, td);
1688 		break;
1689 	}
1690 err_after_new:
1691 	if (error != 0) {
1692 		mddestroy(sc, td);
1693 		return (error);
1694 	}
1695 
1696 	/* Prune off any residual fractional sector */
1697 	i = sc->mediasize % sc->sectorsize;
1698 	sc->mediasize -= i;
1699 
1700 	mdinit(sc);
1701 	return (0);
1702 }
1703 
1704 static int
1705 kern_mdattach(struct thread *td, struct md_req *mdr)
1706 {
1707 	int error;
1708 
1709 	sx_xlock(&md_sx);
1710 	error = kern_mdattach_locked(td, mdr);
1711 	sx_xunlock(&md_sx);
1712 	return (error);
1713 }
1714 
1715 static int
1716 kern_mddetach_locked(struct thread *td, struct md_req *mdr)
1717 {
1718 	struct md_s *sc;
1719 
1720 	sx_assert(&md_sx, SA_XLOCKED);
1721 
1722 	if (mdr->md_mediasize != 0 ||
1723 	    (mdr->md_options & ~MD_FORCE) != 0)
1724 		return (EINVAL);
1725 
1726 	sc = mdfind(mdr->md_unit);
1727 	if (sc == NULL)
1728 		return (ENOENT);
1729 	if (sc->opencount != 0 && !(sc->flags & MD_FORCE) &&
1730 	    !(mdr->md_options & MD_FORCE))
1731 		return (EBUSY);
1732 	return (mddestroy(sc, td));
1733 }
1734 
1735 static int
1736 kern_mddetach(struct thread *td, struct md_req *mdr)
1737 {
1738 	int error;
1739 
1740 	sx_xlock(&md_sx);
1741 	error = kern_mddetach_locked(td, mdr);
1742 	sx_xunlock(&md_sx);
1743 	return (error);
1744 }
1745 
1746 static int
1747 kern_mdresize_locked(struct md_req *mdr)
1748 {
1749 	struct md_s *sc;
1750 
1751 	sx_assert(&md_sx, SA_XLOCKED);
1752 
1753 	if ((mdr->md_options & ~(MD_FORCE | MD_RESERVE)) != 0)
1754 		return (EINVAL);
1755 
1756 	sc = mdfind(mdr->md_unit);
1757 	if (sc == NULL)
1758 		return (ENOENT);
1759 	if (mdr->md_mediasize < sc->sectorsize)
1760 		return (EINVAL);
1761 	if (mdr->md_mediasize < sc->mediasize &&
1762 	    !(sc->flags & MD_FORCE) &&
1763 	    !(mdr->md_options & MD_FORCE))
1764 		return (EBUSY);
1765 	return (mdresize(sc, mdr));
1766 }
1767 
1768 static int
1769 kern_mdresize(struct md_req *mdr)
1770 {
1771 	int error;
1772 
1773 	sx_xlock(&md_sx);
1774 	error = kern_mdresize_locked(mdr);
1775 	sx_xunlock(&md_sx);
1776 	return (error);
1777 }
1778 
1779 static int
1780 kern_mdquery_locked(struct md_req *mdr)
1781 {
1782 	struct md_s *sc;
1783 	int error;
1784 
1785 	sx_assert(&md_sx, SA_XLOCKED);
1786 
1787 	sc = mdfind(mdr->md_unit);
1788 	if (sc == NULL)
1789 		return (ENOENT);
1790 	mdr->md_type = sc->type;
1791 	mdr->md_options = sc->flags;
1792 	mdr->md_mediasize = sc->mediasize;
1793 	mdr->md_sectorsize = sc->sectorsize;
1794 	error = 0;
1795 	if (mdr->md_label != NULL) {
1796 		error = copyout(sc->label, mdr->md_label,
1797 		    strlen(sc->label) + 1);
1798 		if (error != 0)
1799 			return (error);
1800 	}
1801 	if (sc->type == MD_VNODE ||
1802 	    (sc->type == MD_PRELOAD && mdr->md_file != NULL))
1803 		error = copyout(sc->file, mdr->md_file,
1804 		    strlen(sc->file) + 1);
1805 	return (error);
1806 }
1807 
1808 static int
1809 kern_mdquery(struct md_req *mdr)
1810 {
1811 	int error;
1812 
1813 	sx_xlock(&md_sx);
1814 	error = kern_mdquery_locked(mdr);
1815 	sx_xunlock(&md_sx);
1816 	return (error);
1817 }
1818 
1819 static int
1820 kern_mdlist_locked(struct md_req *mdr)
1821 {
1822 	struct md_s *sc;
1823 	int i;
1824 
1825 	sx_assert(&md_sx, SA_XLOCKED);
1826 
1827 	/*
1828 	 * Write the number of md devices to mdr->md_units[0].
1829 	 * Write the unit number of the first (mdr->md_units_nitems - 2)
1830 	 * units to mdr->md_units[1::(mdr->md_units - 2)] and terminate the
1831 	 * list with -1.
1832 	 *
1833 	 * XXX: There is currently no mechanism to retrieve unit
1834 	 * numbers for more than (MDNPAD - 2) units.
1835 	 *
1836 	 * XXX: Due to the use of LIST_INSERT_HEAD in mdnew(), the
1837 	 * list of visible unit numbers not stable.
1838 	 */
1839 	i = 1;
1840 	LIST_FOREACH(sc, &md_softc_list, list) {
1841 		if (i < mdr->md_units_nitems - 1)
1842 			mdr->md_units[i] = sc->unit;
1843 		i++;
1844 	}
1845 	mdr->md_units[MIN(i, mdr->md_units_nitems - 1)] = -1;
1846 	mdr->md_units[0] = i - 1;
1847 	return (0);
1848 }
1849 
1850 static int
1851 kern_mdlist(struct md_req *mdr)
1852 {
1853 	int error;
1854 
1855 	sx_xlock(&md_sx);
1856 	error = kern_mdlist_locked(mdr);
1857 	sx_xunlock(&md_sx);
1858 	return (error);
1859 }
1860 
1861 static int
1862 mdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1863     struct thread *td)
1864 {
1865 	struct md_req mdr;
1866 	struct md_ioctl *mdio;
1867 	int error;
1868 
1869 	if (md_debug)
1870 		printf("mdctlioctl(%s %lx %p %x %p)\n",
1871 			devtoname(dev), cmd, addr, flags, td);
1872 
1873 	switch (cmd) {
1874 	case MDIOCATTACH:
1875 	case MDIOCDETACH:
1876 	case MDIOCRESIZE:
1877 	case MDIOCQUERY:
1878 	case MDIOCLIST:
1879 		mdio = (struct md_ioctl *)addr;
1880 		if (mdio->md_version != MDIOVERSION)
1881 			return (EINVAL);
1882 		mdr.md_unit = mdio->md_unit;
1883 		mdr.md_type = mdio->md_type;
1884 		mdr.md_mediasize = mdio->md_mediasize;
1885 		mdr.md_sectorsize = mdio->md_sectorsize;
1886 		mdr.md_options = mdio->md_options;
1887 		mdr.md_fwheads = mdio->md_fwheads;
1888 		mdr.md_fwsectors = mdio->md_fwsectors;
1889 		mdr.md_file = mdio->md_file;
1890 		/* If the file is adjacent to the md_ioctl it's in kernel. */
1891 		if ((void *)mdio->md_file == (void *)(mdio + 1))
1892 			mdr.md_file_seg = UIO_SYSSPACE;
1893 		else
1894 			mdr.md_file_seg = UIO_USERSPACE;
1895 		mdr.md_label = mdio->md_label;
1896 		mdr.md_units = &mdio->md_pad[0];
1897 		mdr.md_units_nitems = nitems(mdio->md_pad);
1898 		break;
1899 	}
1900 
1901 	error = 0;
1902 	switch (cmd) {
1903 	case MDIOCATTACH:
1904 		error = kern_mdattach(td, &mdr);
1905 		break;
1906 	case MDIOCDETACH:
1907 		error = kern_mddetach(td, &mdr);
1908 		break;
1909 	case MDIOCRESIZE:
1910 		error = kern_mdresize(&mdr);
1911 		break;
1912 	case MDIOCQUERY:
1913 		error = kern_mdquery(&mdr);
1914 		break;
1915 	case MDIOCLIST:
1916 		error = kern_mdlist(&mdr);
1917 		break;
1918 	default:
1919 		error = ENOIOCTL;
1920 	}
1921 
1922 	switch (cmd) {
1923 	case MDIOCATTACH:
1924 	case MDIOCQUERY:
1925 		mdio->md_unit = mdr.md_unit;
1926 		mdio->md_type = mdr.md_type;
1927 		mdio->md_mediasize = mdr.md_mediasize;
1928 		mdio->md_sectorsize = mdr.md_sectorsize;
1929 		mdio->md_options = mdr.md_options;
1930 		mdio->md_fwheads = mdr.md_fwheads;
1931 		mdio->md_fwsectors = mdr.md_fwsectors;
1932 		break;
1933 	}
1934 
1935 	return (error);
1936 }
1937 
1938 static void
1939 md_preloaded(u_char *image, size_t length, const char *name)
1940 {
1941 	struct md_s *sc;
1942 	int error;
1943 
1944 	sc = mdnew(-1, &error, MD_PRELOAD);
1945 	if (sc == NULL)
1946 		return;
1947 	sc->mediasize = length;
1948 	sc->sectorsize = DEV_BSIZE;
1949 	sc->pl_ptr = image;
1950 	sc->pl_len = length;
1951 	sc->start = mdstart_preload;
1952 	if (name != NULL)
1953 		strlcpy(sc->file, name, sizeof(sc->file));
1954 #ifdef MD_ROOT
1955 	if (sc->unit == 0) {
1956 #ifndef ROOTDEVNAME
1957 		rootdevnames[0] = MD_ROOT_FSTYPE ":/dev/md0";
1958 #endif
1959 #ifdef MD_ROOT_READONLY
1960 		sc->flags |= MD_READONLY;
1961 #endif
1962 	}
1963 #endif
1964 	mdinit(sc);
1965 	if (name != NULL) {
1966 		printf("%s%d: Preloaded image <%s> %zd bytes at %p\n",
1967 		    MD_NAME, sc->unit, name, length, image);
1968 	} else {
1969 		printf("%s%d: Embedded image %zd bytes at %p\n",
1970 		    MD_NAME, sc->unit, length, image);
1971 	}
1972 }
1973 
1974 static void
1975 g_md_init(struct g_class *mp __unused)
1976 {
1977 	caddr_t mod;
1978 	u_char *ptr, *name, *type;
1979 	unsigned len;
1980 	int i;
1981 
1982 	/* figure out log2(NINDIR) */
1983 	for (i = NINDIR, nshift = -1; i; nshift++)
1984 		i >>= 1;
1985 
1986 	mod = NULL;
1987 	sx_init(&md_sx, "MD config lock");
1988 	g_topology_unlock();
1989 	md_uh = new_unrhdr(0, INT_MAX, NULL);
1990 #ifdef MD_ROOT
1991 	if (mfs_root_size != 0) {
1992 		sx_xlock(&md_sx);
1993 		md_preloaded(__DEVOLATILE(u_char *, &mfs_root), mfs_root_size,
1994 		    NULL);
1995 		sx_xunlock(&md_sx);
1996 	}
1997 #endif
1998 	/* XXX: are preload_* static or do they need Giant ? */
1999 	while ((mod = preload_search_next_name(mod)) != NULL) {
2000 		name = (char *)preload_search_info(mod, MODINFO_NAME);
2001 		if (name == NULL)
2002 			continue;
2003 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
2004 		if (type == NULL)
2005 			continue;
2006 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
2007 			continue;
2008 		ptr = preload_fetch_addr(mod);
2009 		len = preload_fetch_size(mod);
2010 		if (ptr != NULL && len != 0) {
2011 			sx_xlock(&md_sx);
2012 			md_preloaded(ptr, len, name);
2013 			sx_xunlock(&md_sx);
2014 		}
2015 	}
2016 	md_vnode_pbuf_freecnt = nswbuf / 10;
2017 	status_dev = make_dev(&mdctl_cdevsw, INT_MAX, UID_ROOT, GID_WHEEL,
2018 	    0600, MDCTL_NAME);
2019 	g_topology_lock();
2020 }
2021 
2022 static void
2023 g_md_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
2024     struct g_consumer *cp __unused, struct g_provider *pp)
2025 {
2026 	struct md_s *mp;
2027 	char *type;
2028 
2029 	mp = gp->softc;
2030 	if (mp == NULL)
2031 		return;
2032 
2033 	switch (mp->type) {
2034 	case MD_MALLOC:
2035 		type = "malloc";
2036 		break;
2037 	case MD_PRELOAD:
2038 		type = "preload";
2039 		break;
2040 	case MD_VNODE:
2041 		type = "vnode";
2042 		break;
2043 	case MD_SWAP:
2044 		type = "swap";
2045 		break;
2046 	case MD_NULL:
2047 		type = "null";
2048 		break;
2049 	default:
2050 		type = "unknown";
2051 		break;
2052 	}
2053 
2054 	if (pp != NULL) {
2055 		if (indent == NULL) {
2056 			sbuf_printf(sb, " u %d", mp->unit);
2057 			sbuf_printf(sb, " s %ju", (uintmax_t) mp->sectorsize);
2058 			sbuf_printf(sb, " f %ju", (uintmax_t) mp->fwheads);
2059 			sbuf_printf(sb, " fs %ju", (uintmax_t) mp->fwsectors);
2060 			sbuf_printf(sb, " l %ju", (uintmax_t) mp->mediasize);
2061 			sbuf_printf(sb, " t %s", type);
2062 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
2063 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0'))
2064 				sbuf_printf(sb, " file %s", mp->file);
2065 			sbuf_printf(sb, " label %s", mp->label);
2066 		} else {
2067 			sbuf_printf(sb, "%s<unit>%d</unit>\n", indent,
2068 			    mp->unit);
2069 			sbuf_printf(sb, "%s<sectorsize>%ju</sectorsize>\n",
2070 			    indent, (uintmax_t) mp->sectorsize);
2071 			sbuf_printf(sb, "%s<fwheads>%ju</fwheads>\n",
2072 			    indent, (uintmax_t) mp->fwheads);
2073 			sbuf_printf(sb, "%s<fwsectors>%ju</fwsectors>\n",
2074 			    indent, (uintmax_t) mp->fwsectors);
2075 			if (mp->ident[0] != '\0') {
2076 				sbuf_printf(sb, "%s<ident>", indent);
2077 				g_conf_printf_escaped(sb, "%s", mp->ident);
2078 				sbuf_printf(sb, "</ident>\n");
2079 			}
2080 			sbuf_printf(sb, "%s<length>%ju</length>\n",
2081 			    indent, (uintmax_t) mp->mediasize);
2082 			sbuf_printf(sb, "%s<compression>%s</compression>\n", indent,
2083 			    (mp->flags & MD_COMPRESS) == 0 ? "off": "on");
2084 			sbuf_printf(sb, "%s<access>%s</access>\n", indent,
2085 			    (mp->flags & MD_READONLY) == 0 ? "read-write":
2086 			    "read-only");
2087 			sbuf_printf(sb, "%s<type>%s</type>\n", indent,
2088 			    type);
2089 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
2090 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0')) {
2091 				sbuf_printf(sb, "%s<file>", indent);
2092 				g_conf_printf_escaped(sb, "%s", mp->file);
2093 				sbuf_printf(sb, "</file>\n");
2094 			}
2095 			sbuf_printf(sb, "%s<label>", indent);
2096 			g_conf_printf_escaped(sb, "%s", mp->label);
2097 			sbuf_printf(sb, "</label>\n");
2098 		}
2099 	}
2100 }
2101 
2102 static void
2103 g_md_fini(struct g_class *mp __unused)
2104 {
2105 
2106 	sx_destroy(&md_sx);
2107 	if (status_dev != NULL)
2108 		destroy_dev(status_dev);
2109 	delete_unrhdr(md_uh);
2110 }
2111