xref: /freebsd-13.1/sys/dev/md/md.c (revision efe35aec)
1 /*-
2  * SPDX-License-Identifier: (Beerware AND BSD-3-Clause)
3  *
4  * ----------------------------------------------------------------------------
5  * "THE BEER-WARE LICENSE" (Revision 42):
6  * <[email protected]> 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 on 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/uio.h>
93 #include <sys/vnode.h>
94 #include <sys/disk.h>
95 
96 #include <geom/geom.h>
97 #include <geom/geom_int.h>
98 
99 #include <vm/vm.h>
100 #include <vm/vm_param.h>
101 #include <vm/vm_object.h>
102 #include <vm/vm_page.h>
103 #include <vm/vm_pager.h>
104 #include <vm/swap_pager.h>
105 #include <vm/uma.h>
106 
107 #include <machine/bus.h>
108 
109 #define MD_MODVER 1
110 
111 #define MD_SHUTDOWN	0x10000		/* Tell worker thread to terminate. */
112 #define	MD_EXITING	0x20000		/* Worker thread is exiting. */
113 #define MD_PROVIDERGONE	0x40000		/* Safe to free the softc */
114 
115 #ifndef MD_NSECT
116 #define MD_NSECT (10000 * 2)
117 #endif
118 
119 struct md_req {
120 	unsigned	md_unit;	/* unit number */
121 	enum md_types	md_type;	/* type of disk */
122 	off_t		md_mediasize;	/* size of disk in bytes */
123 	unsigned	md_sectorsize;	/* sectorsize */
124 	unsigned	md_options;	/* options */
125 	int		md_fwheads;	/* firmware heads */
126 	int		md_fwsectors;	/* firmware sectors */
127 	char		*md_file;	/* pathname of file to mount */
128 	enum uio_seg	md_file_seg;	/* location of md_file */
129 	char		*md_label;	/* label of the device (userspace) */
130 	int		*md_units;	/* pointer to units array (kernel) */
131 	size_t		md_units_nitems; /* items in md_units array */
132 };
133 
134 #ifdef COMPAT_FREEBSD32
135 struct md_ioctl32 {
136 	unsigned	md_version;
137 	unsigned	md_unit;
138 	enum md_types	md_type;
139 	uint32_t	md_file;
140 	off_t		md_mediasize;
141 	unsigned	md_sectorsize;
142 	unsigned	md_options;
143 	uint64_t	md_base;
144 	int		md_fwheads;
145 	int		md_fwsectors;
146 	uint32_t	md_label;
147 	int		md_pad[MDNPAD];
148 } __attribute__((__packed__));
149 CTASSERT((sizeof(struct md_ioctl32)) == 436);
150 
151 #define	MDIOCATTACH_32	_IOC_NEWTYPE(MDIOCATTACH, struct md_ioctl32)
152 #define	MDIOCDETACH_32	_IOC_NEWTYPE(MDIOCDETACH, struct md_ioctl32)
153 #define	MDIOCQUERY_32	_IOC_NEWTYPE(MDIOCQUERY, struct md_ioctl32)
154 #define	MDIOCRESIZE_32	_IOC_NEWTYPE(MDIOCRESIZE, struct md_ioctl32)
155 #endif /* COMPAT_FREEBSD32 */
156 
157 static MALLOC_DEFINE(M_MD, "md_disk", "Memory Disk");
158 static MALLOC_DEFINE(M_MDSECT, "md_sectors", "Memory Disk Sectors");
159 
160 static int md_debug;
161 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0,
162     "Enable md(4) debug messages");
163 static int md_malloc_wait;
164 SYSCTL_INT(_vm, OID_AUTO, md_malloc_wait, CTLFLAG_RW, &md_malloc_wait, 0,
165     "Allow malloc to wait for memory allocations");
166 
167 #if defined(MD_ROOT) && !defined(MD_ROOT_FSTYPE)
168 #define	MD_ROOT_FSTYPE	"ufs"
169 #endif
170 
171 #if defined(MD_ROOT)
172 /*
173  * Preloaded image gets put here.
174  */
175 #if defined(MD_ROOT_SIZE)
176 /*
177  * We put the mfs_root symbol into the oldmfs section of the kernel object file.
178  * Applications that patch the object with the image can determine
179  * the size looking at the oldmfs section size within the kernel.
180  */
181 u_char mfs_root[MD_ROOT_SIZE*1024] __attribute__ ((section ("oldmfs")));
182 const int mfs_root_size = sizeof(mfs_root);
183 #elif defined(MD_ROOT_MEM)
184 /* MD region already mapped in the memory */
185 u_char *mfs_root;
186 int mfs_root_size;
187 #else
188 extern volatile u_char __weak_symbol mfs_root;
189 extern volatile u_char __weak_symbol mfs_root_end;
190 #define mfs_root_size ((uintptr_t)(&mfs_root_end - &mfs_root))
191 #endif
192 #endif
193 
194 static g_init_t g_md_init;
195 static g_fini_t g_md_fini;
196 static g_start_t g_md_start;
197 static g_access_t g_md_access;
198 static void g_md_dumpconf(struct sbuf *sb, const char *indent,
199     struct g_geom *gp, struct g_consumer *cp __unused, struct g_provider *pp);
200 static g_provgone_t g_md_providergone;
201 
202 static struct cdev *status_dev = NULL;
203 static struct sx md_sx;
204 static struct unrhdr *md_uh;
205 
206 static d_ioctl_t mdctlioctl;
207 
208 static struct cdevsw mdctl_cdevsw = {
209 	.d_version =	D_VERSION,
210 	.d_ioctl =	mdctlioctl,
211 	.d_name =	MD_NAME,
212 };
213 
214 struct g_class g_md_class = {
215 	.name = "MD",
216 	.version = G_VERSION,
217 	.init = g_md_init,
218 	.fini = g_md_fini,
219 	.start = g_md_start,
220 	.access = g_md_access,
221 	.dumpconf = g_md_dumpconf,
222 	.providergone = g_md_providergone,
223 };
224 
225 DECLARE_GEOM_CLASS(g_md_class, g_md);
226 MODULE_VERSION(geom_md, 0);
227 
228 static LIST_HEAD(, md_s) md_softc_list = LIST_HEAD_INITIALIZER(md_softc_list);
229 
230 #define NINDIR	(PAGE_SIZE / sizeof(uintptr_t))
231 #define NMASK	(NINDIR-1)
232 static int nshift;
233 
234 static uma_zone_t md_pbuf_zone;
235 
236 struct indir {
237 	uintptr_t	*array;
238 	u_int		total;
239 	u_int		used;
240 	u_int		shift;
241 };
242 
243 struct md_s {
244 	int unit;
245 	LIST_ENTRY(md_s) list;
246 	struct bio_queue_head bio_queue;
247 	struct mtx queue_mtx;
248 	struct cdev *dev;
249 	enum md_types type;
250 	off_t mediasize;
251 	unsigned sectorsize;
252 	unsigned opencount;
253 	unsigned fwheads;
254 	unsigned fwsectors;
255 	char ident[32];
256 	unsigned flags;
257 	char name[20];
258 	struct proc *procp;
259 	struct g_geom *gp;
260 	struct g_provider *pp;
261 	int (*start)(struct md_s *sc, struct bio *bp);
262 	struct devstat *devstat;
263 
264 	/* MD_MALLOC related fields */
265 	struct indir *indir;
266 	uma_zone_t uma;
267 
268 	/* MD_PRELOAD related fields */
269 	u_char *pl_ptr;
270 	size_t pl_len;
271 
272 	/* MD_VNODE related fields */
273 	struct vnode *vnode;
274 	char file[PATH_MAX];
275 	char label[PATH_MAX];
276 	struct ucred *cred;
277 
278 	/* MD_SWAP related fields */
279 	vm_object_t object;
280 };
281 
282 static struct indir *
283 new_indir(u_int shift)
284 {
285 	struct indir *ip;
286 
287 	ip = malloc(sizeof *ip, M_MD, (md_malloc_wait ? M_WAITOK : M_NOWAIT)
288 	    | M_ZERO);
289 	if (ip == NULL)
290 		return (NULL);
291 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
292 	    M_MDSECT, (md_malloc_wait ? M_WAITOK : M_NOWAIT) | M_ZERO);
293 	if (ip->array == NULL) {
294 		free(ip, M_MD);
295 		return (NULL);
296 	}
297 	ip->total = NINDIR;
298 	ip->shift = shift;
299 	return (ip);
300 }
301 
302 static void
303 del_indir(struct indir *ip)
304 {
305 
306 	free(ip->array, M_MDSECT);
307 	free(ip, M_MD);
308 }
309 
310 static void
311 destroy_indir(struct md_s *sc, struct indir *ip)
312 {
313 	int i;
314 
315 	for (i = 0; i < NINDIR; i++) {
316 		if (!ip->array[i])
317 			continue;
318 		if (ip->shift)
319 			destroy_indir(sc, (struct indir*)(ip->array[i]));
320 		else if (ip->array[i] > 255)
321 			uma_zfree(sc->uma, (void *)(ip->array[i]));
322 	}
323 	del_indir(ip);
324 }
325 
326 /*
327  * This function does the math and allocates the top level "indir" structure
328  * for a device of "size" sectors.
329  */
330 
331 static struct indir *
332 dimension(off_t size)
333 {
334 	off_t rcnt;
335 	struct indir *ip;
336 	int layer;
337 
338 	rcnt = size;
339 	layer = 0;
340 	while (rcnt > NINDIR) {
341 		rcnt /= NINDIR;
342 		layer++;
343 	}
344 
345 	/*
346 	 * XXX: the top layer is probably not fully populated, so we allocate
347 	 * too much space for ip->array in here.
348 	 */
349 	ip = malloc(sizeof *ip, M_MD, M_WAITOK | M_ZERO);
350 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
351 	    M_MDSECT, M_WAITOK | M_ZERO);
352 	ip->total = NINDIR;
353 	ip->shift = layer * nshift;
354 	return (ip);
355 }
356 
357 /*
358  * Read a given sector
359  */
360 
361 static uintptr_t
362 s_read(struct indir *ip, off_t offset)
363 {
364 	struct indir *cip;
365 	int idx;
366 	uintptr_t up;
367 
368 	if (md_debug > 1)
369 		printf("s_read(%jd)\n", (intmax_t)offset);
370 	up = 0;
371 	for (cip = ip; cip != NULL;) {
372 		if (cip->shift) {
373 			idx = (offset >> cip->shift) & NMASK;
374 			up = cip->array[idx];
375 			cip = (struct indir *)up;
376 			continue;
377 		}
378 		idx = offset & NMASK;
379 		return (cip->array[idx]);
380 	}
381 	return (0);
382 }
383 
384 /*
385  * Write a given sector, prune the tree if the value is 0
386  */
387 
388 static int
389 s_write(struct indir *ip, off_t offset, uintptr_t ptr)
390 {
391 	struct indir *cip, *lip[10];
392 	int idx, li;
393 	uintptr_t up;
394 
395 	if (md_debug > 1)
396 		printf("s_write(%jd, %p)\n", (intmax_t)offset, (void *)ptr);
397 	up = 0;
398 	li = 0;
399 	cip = ip;
400 	for (;;) {
401 		lip[li++] = cip;
402 		if (cip->shift) {
403 			idx = (offset >> cip->shift) & NMASK;
404 			up = cip->array[idx];
405 			if (up != 0) {
406 				cip = (struct indir *)up;
407 				continue;
408 			}
409 			/* Allocate branch */
410 			cip->array[idx] =
411 			    (uintptr_t)new_indir(cip->shift - nshift);
412 			if (cip->array[idx] == 0)
413 				return (ENOSPC);
414 			cip->used++;
415 			up = cip->array[idx];
416 			cip = (struct indir *)up;
417 			continue;
418 		}
419 		/* leafnode */
420 		idx = offset & NMASK;
421 		up = cip->array[idx];
422 		if (up != 0)
423 			cip->used--;
424 		cip->array[idx] = ptr;
425 		if (ptr != 0)
426 			cip->used++;
427 		break;
428 	}
429 	if (cip->used != 0 || li == 1)
430 		return (0);
431 	li--;
432 	while (cip->used == 0 && cip != ip) {
433 		li--;
434 		idx = (offset >> lip[li]->shift) & NMASK;
435 		up = lip[li]->array[idx];
436 		KASSERT(up == (uintptr_t)cip, ("md screwed up"));
437 		del_indir(cip);
438 		lip[li]->array[idx] = 0;
439 		lip[li]->used--;
440 		cip = lip[li];
441 	}
442 	return (0);
443 }
444 
445 static int
446 g_md_access(struct g_provider *pp, int r, int w, int e)
447 {
448 	struct md_s *sc;
449 
450 	sc = pp->geom->softc;
451 	if (sc == NULL) {
452 		if (r <= 0 && w <= 0 && e <= 0)
453 			return (0);
454 		return (ENXIO);
455 	}
456 	r += pp->acr;
457 	w += pp->acw;
458 	e += pp->ace;
459 	if ((sc->flags & MD_READONLY) != 0 && w > 0)
460 		return (EROFS);
461 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
462 		sc->opencount = 1;
463 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
464 		sc->opencount = 0;
465 	}
466 	return (0);
467 }
468 
469 static void
470 g_md_start(struct bio *bp)
471 {
472 	struct md_s *sc;
473 
474 	sc = bp->bio_to->geom->softc;
475 	if ((bp->bio_cmd == BIO_READ) || (bp->bio_cmd == BIO_WRITE)) {
476 		devstat_start_transaction_bio(sc->devstat, bp);
477 	}
478 	mtx_lock(&sc->queue_mtx);
479 	bioq_disksort(&sc->bio_queue, bp);
480 	wakeup(sc);
481 	mtx_unlock(&sc->queue_mtx);
482 }
483 
484 #define	MD_MALLOC_MOVE_ZERO	1
485 #define	MD_MALLOC_MOVE_FILL	2
486 #define	MD_MALLOC_MOVE_READ	3
487 #define	MD_MALLOC_MOVE_WRITE	4
488 #define	MD_MALLOC_MOVE_CMP	5
489 
490 static int
491 md_malloc_move_ma(vm_page_t **mp, int *ma_offs, unsigned sectorsize,
492     void *ptr, u_char fill, int op)
493 {
494 	struct sf_buf *sf;
495 	vm_page_t m, *mp1;
496 	char *p, first;
497 	off_t *uc;
498 	unsigned n;
499 	int error, i, ma_offs1, sz, first_read;
500 
501 	m = NULL;
502 	error = 0;
503 	sf = NULL;
504 	/* if (op == MD_MALLOC_MOVE_CMP) { gcc */
505 		first = 0;
506 		first_read = 0;
507 		uc = ptr;
508 		mp1 = *mp;
509 		ma_offs1 = *ma_offs;
510 	/* } */
511 	sched_pin();
512 	for (n = sectorsize; n != 0; n -= sz) {
513 		sz = imin(PAGE_SIZE - *ma_offs, n);
514 		if (m != **mp) {
515 			if (sf != NULL)
516 				sf_buf_free(sf);
517 			m = **mp;
518 			sf = sf_buf_alloc(m, SFB_CPUPRIVATE |
519 			    (md_malloc_wait ? 0 : SFB_NOWAIT));
520 			if (sf == NULL) {
521 				error = ENOMEM;
522 				break;
523 			}
524 		}
525 		p = (char *)sf_buf_kva(sf) + *ma_offs;
526 		switch (op) {
527 		case MD_MALLOC_MOVE_ZERO:
528 			bzero(p, sz);
529 			break;
530 		case MD_MALLOC_MOVE_FILL:
531 			memset(p, fill, sz);
532 			break;
533 		case MD_MALLOC_MOVE_READ:
534 			bcopy(ptr, p, sz);
535 			cpu_flush_dcache(p, sz);
536 			break;
537 		case MD_MALLOC_MOVE_WRITE:
538 			bcopy(p, ptr, sz);
539 			break;
540 		case MD_MALLOC_MOVE_CMP:
541 			for (i = 0; i < sz; i++, p++) {
542 				if (!first_read) {
543 					*uc = (u_char)*p;
544 					first = *p;
545 					first_read = 1;
546 				} else if (*p != first) {
547 					error = EDOOFUS;
548 					break;
549 				}
550 			}
551 			break;
552 		default:
553 			KASSERT(0, ("md_malloc_move_ma unknown op %d\n", op));
554 			break;
555 		}
556 		if (error != 0)
557 			break;
558 		*ma_offs += sz;
559 		*ma_offs %= PAGE_SIZE;
560 		if (*ma_offs == 0)
561 			(*mp)++;
562 		ptr = (char *)ptr + sz;
563 	}
564 
565 	if (sf != NULL)
566 		sf_buf_free(sf);
567 	sched_unpin();
568 	if (op == MD_MALLOC_MOVE_CMP && error != 0) {
569 		*mp = mp1;
570 		*ma_offs = ma_offs1;
571 	}
572 	return (error);
573 }
574 
575 static int
576 md_malloc_move_vlist(bus_dma_segment_t **pvlist, int *pma_offs,
577     unsigned len, void *ptr, u_char fill, int op)
578 {
579 	bus_dma_segment_t *vlist;
580 	uint8_t *p, *end, first;
581 	off_t *uc;
582 	int ma_offs, seg_len;
583 
584 	vlist = *pvlist;
585 	ma_offs = *pma_offs;
586 	uc = ptr;
587 
588 	for (; len != 0; len -= seg_len) {
589 		seg_len = imin(vlist->ds_len - ma_offs, len);
590 		p = (uint8_t *)(uintptr_t)vlist->ds_addr + ma_offs;
591 		switch (op) {
592 		case MD_MALLOC_MOVE_ZERO:
593 			bzero(p, seg_len);
594 			break;
595 		case MD_MALLOC_MOVE_FILL:
596 			memset(p, fill, seg_len);
597 			break;
598 		case MD_MALLOC_MOVE_READ:
599 			bcopy(ptr, p, seg_len);
600 			cpu_flush_dcache(p, seg_len);
601 			break;
602 		case MD_MALLOC_MOVE_WRITE:
603 			bcopy(p, ptr, seg_len);
604 			break;
605 		case MD_MALLOC_MOVE_CMP:
606 			end = p + seg_len;
607 			first = *uc = *p;
608 			/* Confirm all following bytes match the first */
609 			while (++p < end) {
610 				if (*p != first)
611 					return (EDOOFUS);
612 			}
613 			break;
614 		default:
615 			KASSERT(0, ("md_malloc_move_vlist unknown op %d\n", op));
616 			break;
617 		}
618 
619 		ma_offs += seg_len;
620 		if (ma_offs == vlist->ds_len) {
621 			ma_offs = 0;
622 			vlist++;
623 		}
624 		ptr = (uint8_t *)ptr + seg_len;
625 	}
626 	*pvlist = vlist;
627 	*pma_offs = ma_offs;
628 
629 	return (0);
630 }
631 
632 static int
633 mdstart_malloc(struct md_s *sc, struct bio *bp)
634 {
635 	u_char *dst;
636 	vm_page_t *m;
637 	bus_dma_segment_t *vlist;
638 	int i, error, error1, ma_offs, notmapped;
639 	off_t secno, nsec, uc;
640 	uintptr_t sp, osp;
641 
642 	switch (bp->bio_cmd) {
643 	case BIO_READ:
644 	case BIO_WRITE:
645 	case BIO_DELETE:
646 		break;
647 	default:
648 		return (EOPNOTSUPP);
649 	}
650 
651 	notmapped = (bp->bio_flags & BIO_UNMAPPED) != 0;
652 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
653 	    (bus_dma_segment_t *)bp->bio_data : NULL;
654 	if (notmapped) {
655 		m = bp->bio_ma;
656 		ma_offs = bp->bio_ma_offset;
657 		dst = NULL;
658 		KASSERT(vlist == NULL, ("vlists cannot be unmapped"));
659 	} else if (vlist != NULL) {
660 		ma_offs = bp->bio_ma_offset;
661 		dst = NULL;
662 	} else {
663 		dst = bp->bio_data;
664 	}
665 
666 	nsec = bp->bio_length / sc->sectorsize;
667 	secno = bp->bio_offset / sc->sectorsize;
668 	error = 0;
669 	while (nsec--) {
670 		osp = s_read(sc->indir, secno);
671 		if (bp->bio_cmd == BIO_DELETE) {
672 			if (osp != 0)
673 				error = s_write(sc->indir, secno, 0);
674 		} else if (bp->bio_cmd == BIO_READ) {
675 			if (osp == 0) {
676 				if (notmapped) {
677 					error = md_malloc_move_ma(&m, &ma_offs,
678 					    sc->sectorsize, NULL, 0,
679 					    MD_MALLOC_MOVE_ZERO);
680 				} else if (vlist != NULL) {
681 					error = md_malloc_move_vlist(&vlist,
682 					    &ma_offs, sc->sectorsize, NULL, 0,
683 					    MD_MALLOC_MOVE_ZERO);
684 				} else
685 					bzero(dst, sc->sectorsize);
686 			} else if (osp <= 255) {
687 				if (notmapped) {
688 					error = md_malloc_move_ma(&m, &ma_offs,
689 					    sc->sectorsize, NULL, osp,
690 					    MD_MALLOC_MOVE_FILL);
691 				} else if (vlist != NULL) {
692 					error = md_malloc_move_vlist(&vlist,
693 					    &ma_offs, sc->sectorsize, NULL, osp,
694 					    MD_MALLOC_MOVE_FILL);
695 				} else
696 					memset(dst, osp, sc->sectorsize);
697 			} else {
698 				if (notmapped) {
699 					error = md_malloc_move_ma(&m, &ma_offs,
700 					    sc->sectorsize, (void *)osp, 0,
701 					    MD_MALLOC_MOVE_READ);
702 				} else if (vlist != NULL) {
703 					error = md_malloc_move_vlist(&vlist,
704 					    &ma_offs, sc->sectorsize,
705 					    (void *)osp, 0,
706 					    MD_MALLOC_MOVE_READ);
707 				} else {
708 					bcopy((void *)osp, dst, sc->sectorsize);
709 					cpu_flush_dcache(dst, sc->sectorsize);
710 				}
711 			}
712 			osp = 0;
713 		} else if (bp->bio_cmd == BIO_WRITE) {
714 			if (sc->flags & MD_COMPRESS) {
715 				if (notmapped) {
716 					error1 = md_malloc_move_ma(&m, &ma_offs,
717 					    sc->sectorsize, &uc, 0,
718 					    MD_MALLOC_MOVE_CMP);
719 					i = error1 == 0 ? sc->sectorsize : 0;
720 				} else if (vlist != NULL) {
721 					error1 = md_malloc_move_vlist(&vlist,
722 					    &ma_offs, sc->sectorsize, &uc, 0,
723 					    MD_MALLOC_MOVE_CMP);
724 					i = error1 == 0 ? sc->sectorsize : 0;
725 				} else {
726 					uc = dst[0];
727 					for (i = 1; i < sc->sectorsize; i++) {
728 						if (dst[i] != uc)
729 							break;
730 					}
731 				}
732 			} else {
733 				i = 0;
734 				uc = 0;
735 			}
736 			if (i == sc->sectorsize) {
737 				if (osp != uc)
738 					error = s_write(sc->indir, secno, uc);
739 			} else {
740 				if (osp <= 255) {
741 					sp = (uintptr_t)uma_zalloc(sc->uma,
742 					    md_malloc_wait ? M_WAITOK :
743 					    M_NOWAIT);
744 					if (sp == 0) {
745 						error = ENOSPC;
746 						break;
747 					}
748 					if (notmapped) {
749 						error = md_malloc_move_ma(&m,
750 						    &ma_offs, sc->sectorsize,
751 						    (void *)sp, 0,
752 						    MD_MALLOC_MOVE_WRITE);
753 					} else if (vlist != NULL) {
754 						error = md_malloc_move_vlist(
755 						    &vlist, &ma_offs,
756 						    sc->sectorsize, (void *)sp,
757 						    0, MD_MALLOC_MOVE_WRITE);
758 					} else {
759 						bcopy(dst, (void *)sp,
760 						    sc->sectorsize);
761 					}
762 					error = s_write(sc->indir, secno, sp);
763 				} else {
764 					if (notmapped) {
765 						error = md_malloc_move_ma(&m,
766 						    &ma_offs, sc->sectorsize,
767 						    (void *)osp, 0,
768 						    MD_MALLOC_MOVE_WRITE);
769 					} else if (vlist != NULL) {
770 						error = md_malloc_move_vlist(
771 						    &vlist, &ma_offs,
772 						    sc->sectorsize, (void *)osp,
773 						    0, MD_MALLOC_MOVE_WRITE);
774 					} else {
775 						bcopy(dst, (void *)osp,
776 						    sc->sectorsize);
777 					}
778 					osp = 0;
779 				}
780 			}
781 		} else {
782 			error = EOPNOTSUPP;
783 		}
784 		if (osp > 255)
785 			uma_zfree(sc->uma, (void*)osp);
786 		if (error != 0)
787 			break;
788 		secno++;
789 		if (!notmapped && vlist == NULL)
790 			dst += sc->sectorsize;
791 	}
792 	bp->bio_resid = 0;
793 	return (error);
794 }
795 
796 static void
797 mdcopyto_vlist(void *src, bus_dma_segment_t *vlist, off_t offset, off_t len)
798 {
799 	off_t seg_len;
800 
801 	while (offset >= vlist->ds_len) {
802 		offset -= vlist->ds_len;
803 		vlist++;
804 	}
805 
806 	while (len != 0) {
807 		seg_len = omin(len, vlist->ds_len - offset);
808 		bcopy(src, (void *)(uintptr_t)(vlist->ds_addr + offset),
809 		    seg_len);
810 		offset = 0;
811 		src = (uint8_t *)src + seg_len;
812 		len -= seg_len;
813 		vlist++;
814 	}
815 }
816 
817 static void
818 mdcopyfrom_vlist(bus_dma_segment_t *vlist, off_t offset, void *dst, off_t len)
819 {
820 	off_t seg_len;
821 
822 	while (offset >= vlist->ds_len) {
823 		offset -= vlist->ds_len;
824 		vlist++;
825 	}
826 
827 	while (len != 0) {
828 		seg_len = omin(len, vlist->ds_len - offset);
829 		bcopy((void *)(uintptr_t)(vlist->ds_addr + offset), dst,
830 		    seg_len);
831 		offset = 0;
832 		dst = (uint8_t *)dst + seg_len;
833 		len -= seg_len;
834 		vlist++;
835 	}
836 }
837 
838 static int
839 mdstart_preload(struct md_s *sc, struct bio *bp)
840 {
841 	uint8_t *p;
842 
843 	p = sc->pl_ptr + bp->bio_offset;
844 	switch (bp->bio_cmd) {
845 	case BIO_READ:
846 		if ((bp->bio_flags & BIO_VLIST) != 0) {
847 			mdcopyto_vlist(p, (bus_dma_segment_t *)bp->bio_data,
848 			    bp->bio_ma_offset, bp->bio_length);
849 		} else {
850 			bcopy(p, bp->bio_data, bp->bio_length);
851 		}
852 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
853 		break;
854 	case BIO_WRITE:
855 		if ((bp->bio_flags & BIO_VLIST) != 0) {
856 			mdcopyfrom_vlist((bus_dma_segment_t *)bp->bio_data,
857 			    bp->bio_ma_offset, p, bp->bio_length);
858 		} else {
859 			bcopy(bp->bio_data, p, bp->bio_length);
860 		}
861 		break;
862 	}
863 	bp->bio_resid = 0;
864 	return (0);
865 }
866 
867 static int
868 mdstart_vnode(struct md_s *sc, struct bio *bp)
869 {
870 	int error;
871 	struct uio auio;
872 	struct iovec aiov;
873 	struct iovec *piov;
874 	struct mount *mp;
875 	struct vnode *vp;
876 	struct buf *pb;
877 	bus_dma_segment_t *vlist;
878 	struct thread *td;
879 	off_t iolen, iostart, len, zerosize;
880 	int ma_offs, npages;
881 
882 	switch (bp->bio_cmd) {
883 	case BIO_READ:
884 		auio.uio_rw = UIO_READ;
885 		break;
886 	case BIO_WRITE:
887 	case BIO_DELETE:
888 		auio.uio_rw = UIO_WRITE;
889 		break;
890 	case BIO_FLUSH:
891 		break;
892 	default:
893 		return (EOPNOTSUPP);
894 	}
895 
896 	td = curthread;
897 	vp = sc->vnode;
898 	pb = NULL;
899 	piov = NULL;
900 	ma_offs = bp->bio_ma_offset;
901 	len = bp->bio_length;
902 
903 	/*
904 	 * VNODE I/O
905 	 *
906 	 * If an error occurs, we set BIO_ERROR but we do not set
907 	 * B_INVAL because (for a write anyway), the buffer is
908 	 * still valid.
909 	 */
910 
911 	if (bp->bio_cmd == BIO_FLUSH) {
912 		(void) vn_start_write(vp, &mp, V_WAIT);
913 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
914 		error = VOP_FSYNC(vp, MNT_WAIT, td);
915 		VOP_UNLOCK(vp);
916 		vn_finished_write(mp);
917 		return (error);
918 	}
919 
920 	auio.uio_offset = (vm_ooffset_t)bp->bio_offset;
921 	auio.uio_resid = bp->bio_length;
922 	auio.uio_segflg = UIO_SYSSPACE;
923 	auio.uio_td = td;
924 
925 	if (bp->bio_cmd == BIO_DELETE) {
926 		/*
927 		 * Emulate BIO_DELETE by writing zeros.
928 		 */
929 		zerosize = ZERO_REGION_SIZE -
930 		    (ZERO_REGION_SIZE % sc->sectorsize);
931 		auio.uio_iovcnt = howmany(bp->bio_length, zerosize);
932 		piov = malloc(sizeof(*piov) * auio.uio_iovcnt, M_MD, M_WAITOK);
933 		auio.uio_iov = piov;
934 		while (len > 0) {
935 			piov->iov_base = __DECONST(void *, zero_region);
936 			piov->iov_len = len;
937 			if (len > zerosize)
938 				piov->iov_len = zerosize;
939 			len -= piov->iov_len;
940 			piov++;
941 		}
942 		piov = auio.uio_iov;
943 	} else if ((bp->bio_flags & BIO_VLIST) != 0) {
944 		piov = malloc(sizeof(*piov) * bp->bio_ma_n, M_MD, M_WAITOK);
945 		auio.uio_iov = piov;
946 		vlist = (bus_dma_segment_t *)bp->bio_data;
947 		while (len > 0) {
948 			piov->iov_base = (void *)(uintptr_t)(vlist->ds_addr +
949 			    ma_offs);
950 			piov->iov_len = vlist->ds_len - ma_offs;
951 			if (piov->iov_len > len)
952 				piov->iov_len = len;
953 			len -= piov->iov_len;
954 			ma_offs = 0;
955 			vlist++;
956 			piov++;
957 		}
958 		auio.uio_iovcnt = piov - auio.uio_iov;
959 		piov = auio.uio_iov;
960 	} else if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
961 		pb = uma_zalloc(md_pbuf_zone, M_WAITOK);
962 		MPASS((pb->b_flags & B_MAXPHYS) != 0);
963 		bp->bio_resid = len;
964 unmapped_step:
965 		npages = atop(min(maxphys, round_page(len + (ma_offs &
966 		    PAGE_MASK))));
967 		iolen = min(ptoa(npages) - (ma_offs & PAGE_MASK), len);
968 		KASSERT(iolen > 0, ("zero iolen"));
969 		pmap_qenter((vm_offset_t)pb->b_data,
970 		    &bp->bio_ma[atop(ma_offs)], npages);
971 		aiov.iov_base = (void *)((vm_offset_t)pb->b_data +
972 		    (ma_offs & PAGE_MASK));
973 		aiov.iov_len = iolen;
974 		auio.uio_iov = &aiov;
975 		auio.uio_iovcnt = 1;
976 		auio.uio_resid = iolen;
977 	} else {
978 		aiov.iov_base = bp->bio_data;
979 		aiov.iov_len = bp->bio_length;
980 		auio.uio_iov = &aiov;
981 		auio.uio_iovcnt = 1;
982 	}
983 	iostart = auio.uio_offset;
984 	if (auio.uio_rw == UIO_READ) {
985 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
986 		error = VOP_READ(vp, &auio, 0, sc->cred);
987 		VOP_UNLOCK(vp);
988 	} else {
989 		(void) vn_start_write(vp, &mp, V_WAIT);
990 		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
991 		error = VOP_WRITE(vp, &auio, sc->flags & MD_ASYNC ? 0 : IO_SYNC,
992 		    sc->cred);
993 		VOP_UNLOCK(vp);
994 		vn_finished_write(mp);
995 		if (error == 0)
996 			sc->flags &= ~MD_VERIFY;
997 	}
998 
999 	/* When MD_CACHE is set, try to avoid double-caching the data. */
1000 	if (error == 0 && (sc->flags & MD_CACHE) == 0)
1001 		VOP_ADVISE(vp, iostart, auio.uio_offset - 1,
1002 		    POSIX_FADV_DONTNEED);
1003 
1004 	if (pb != NULL) {
1005 		pmap_qremove((vm_offset_t)pb->b_data, npages);
1006 		if (error == 0) {
1007 			len -= iolen;
1008 			bp->bio_resid -= iolen;
1009 			ma_offs += iolen;
1010 			if (len > 0)
1011 				goto unmapped_step;
1012 		}
1013 		uma_zfree(md_pbuf_zone, pb);
1014 	} else {
1015 		bp->bio_resid = auio.uio_resid;
1016 	}
1017 
1018 	free(piov, M_MD);
1019 	return (error);
1020 }
1021 
1022 static int
1023 mdstart_swap(struct md_s *sc, struct bio *bp)
1024 {
1025 	vm_page_t m;
1026 	u_char *p;
1027 	vm_pindex_t i, lastp;
1028 	bus_dma_segment_t *vlist;
1029 	int rv, ma_offs, offs, len, lastend;
1030 
1031 	switch (bp->bio_cmd) {
1032 	case BIO_READ:
1033 	case BIO_WRITE:
1034 	case BIO_DELETE:
1035 		break;
1036 	default:
1037 		return (EOPNOTSUPP);
1038 	}
1039 
1040 	p = bp->bio_data;
1041 	ma_offs = (bp->bio_flags & (BIO_UNMAPPED|BIO_VLIST)) != 0 ?
1042 	    bp->bio_ma_offset : 0;
1043 	vlist = (bp->bio_flags & BIO_VLIST) != 0 ?
1044 	    (bus_dma_segment_t *)bp->bio_data : NULL;
1045 
1046 	/*
1047 	 * offs is the offset at which to start operating on the
1048 	 * next (ie, first) page.  lastp is the last page on
1049 	 * which we're going to operate.  lastend is the ending
1050 	 * position within that last page (ie, PAGE_SIZE if
1051 	 * we're operating on complete aligned pages).
1052 	 */
1053 	offs = bp->bio_offset % PAGE_SIZE;
1054 	lastp = (bp->bio_offset + bp->bio_length - 1) / PAGE_SIZE;
1055 	lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1;
1056 
1057 	rv = VM_PAGER_OK;
1058 	vm_object_pip_add(sc->object, 1);
1059 	for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) {
1060 		len = ((i == lastp) ? lastend : PAGE_SIZE) - offs;
1061 		m = vm_page_grab_unlocked(sc->object, i, VM_ALLOC_SYSTEM);
1062 		if (bp->bio_cmd == BIO_READ) {
1063 			if (vm_page_all_valid(m))
1064 				rv = VM_PAGER_OK;
1065 			else
1066 				rv = vm_pager_get_pages(sc->object, &m, 1,
1067 				    NULL, NULL);
1068 			if (rv == VM_PAGER_ERROR) {
1069 				VM_OBJECT_WLOCK(sc->object);
1070 				vm_page_free(m);
1071 				VM_OBJECT_WUNLOCK(sc->object);
1072 				break;
1073 			} else if (rv == VM_PAGER_FAIL) {
1074 				/*
1075 				 * Pager does not have the page.  Zero
1076 				 * the allocated page, and mark it as
1077 				 * valid. Do not set dirty, the page
1078 				 * can be recreated if thrown out.
1079 				 */
1080 				pmap_zero_page(m);
1081 				vm_page_valid(m);
1082 			}
1083 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1084 				pmap_copy_pages(&m, offs, bp->bio_ma,
1085 				    ma_offs, len);
1086 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1087 				physcopyout_vlist(VM_PAGE_TO_PHYS(m) + offs,
1088 				    vlist, ma_offs, len);
1089 				cpu_flush_dcache(p, len);
1090 			} else {
1091 				physcopyout(VM_PAGE_TO_PHYS(m) + offs, p, len);
1092 				cpu_flush_dcache(p, len);
1093 			}
1094 		} else if (bp->bio_cmd == BIO_WRITE) {
1095 			if (len == PAGE_SIZE || vm_page_all_valid(m))
1096 				rv = VM_PAGER_OK;
1097 			else
1098 				rv = vm_pager_get_pages(sc->object, &m, 1,
1099 				    NULL, NULL);
1100 			if (rv == VM_PAGER_ERROR) {
1101 				VM_OBJECT_WLOCK(sc->object);
1102 				vm_page_free(m);
1103 				VM_OBJECT_WUNLOCK(sc->object);
1104 				break;
1105 			} else if (rv == VM_PAGER_FAIL)
1106 				pmap_zero_page(m);
1107 
1108 			if ((bp->bio_flags & BIO_UNMAPPED) != 0) {
1109 				pmap_copy_pages(bp->bio_ma, ma_offs, &m,
1110 				    offs, len);
1111 			} else if ((bp->bio_flags & BIO_VLIST) != 0) {
1112 				physcopyin_vlist(vlist, ma_offs,
1113 				    VM_PAGE_TO_PHYS(m) + offs, len);
1114 			} else {
1115 				physcopyin(p, VM_PAGE_TO_PHYS(m) + offs, len);
1116 			}
1117 
1118 			vm_page_valid(m);
1119 			vm_page_set_dirty(m);
1120 		} else if (bp->bio_cmd == BIO_DELETE) {
1121 			if (len == PAGE_SIZE || vm_page_all_valid(m))
1122 				rv = VM_PAGER_OK;
1123 			else
1124 				rv = vm_pager_get_pages(sc->object, &m, 1,
1125 				    NULL, NULL);
1126 			VM_OBJECT_WLOCK(sc->object);
1127 			if (rv == VM_PAGER_ERROR) {
1128 				vm_page_free(m);
1129 				VM_OBJECT_WUNLOCK(sc->object);
1130 				break;
1131 			} else if (rv == VM_PAGER_FAIL) {
1132 				vm_page_free(m);
1133 				m = NULL;
1134 			} else {
1135 				/* Page is valid. */
1136 				if (len != PAGE_SIZE) {
1137 					pmap_zero_page_area(m, offs, len);
1138 					vm_page_set_dirty(m);
1139 				} else {
1140 					vm_pager_page_unswapped(m);
1141 					vm_page_free(m);
1142 					m = NULL;
1143 				}
1144 			}
1145 			VM_OBJECT_WUNLOCK(sc->object);
1146 		}
1147 		if (m != NULL) {
1148 			/*
1149 			 * The page may be deactivated prior to setting
1150 			 * PGA_REFERENCED, but in this case it will be
1151 			 * reactivated by the page daemon.
1152 			 */
1153 			if (vm_page_active(m))
1154 				vm_page_reference(m);
1155 			else
1156 				vm_page_activate(m);
1157 			vm_page_xunbusy(m);
1158 		}
1159 
1160 		/* Actions on further pages start at offset 0 */
1161 		p += PAGE_SIZE - offs;
1162 		offs = 0;
1163 		ma_offs += len;
1164 	}
1165 	vm_object_pip_wakeup(sc->object);
1166 	return (rv != VM_PAGER_ERROR ? 0 : ENOSPC);
1167 }
1168 
1169 static int
1170 mdstart_null(struct md_s *sc, struct bio *bp)
1171 {
1172 
1173 	switch (bp->bio_cmd) {
1174 	case BIO_READ:
1175 		bzero(bp->bio_data, bp->bio_length);
1176 		cpu_flush_dcache(bp->bio_data, bp->bio_length);
1177 		break;
1178 	case BIO_WRITE:
1179 		break;
1180 	}
1181 	bp->bio_resid = 0;
1182 	return (0);
1183 }
1184 
1185 static void
1186 md_handleattr(struct md_s *sc, struct bio *bp)
1187 {
1188 	if (sc->fwsectors && sc->fwheads &&
1189 	    (g_handleattr_int(bp, "GEOM::fwsectors", sc->fwsectors) != 0 ||
1190 	    g_handleattr_int(bp, "GEOM::fwheads", sc->fwheads) != 0))
1191 		return;
1192 	if (g_handleattr_int(bp, "GEOM::candelete", 1) != 0)
1193 		return;
1194 	if (sc->ident[0] != '\0' &&
1195 	    g_handleattr_str(bp, "GEOM::ident", sc->ident) != 0)
1196 		return;
1197 	if (g_handleattr_int(bp, "MNT::verified", (sc->flags & MD_VERIFY) != 0))
1198 		return;
1199 	g_io_deliver(bp, EOPNOTSUPP);
1200 }
1201 
1202 static void
1203 md_kthread(void *arg)
1204 {
1205 	struct md_s *sc;
1206 	struct bio *bp;
1207 	int error;
1208 
1209 	sc = arg;
1210 	thread_lock(curthread);
1211 	sched_prio(curthread, PRIBIO);
1212 	thread_unlock(curthread);
1213 	if (sc->type == MD_VNODE)
1214 		curthread->td_pflags |= TDP_NORUNNINGBUF;
1215 
1216 	for (;;) {
1217 		mtx_lock(&sc->queue_mtx);
1218 		if (sc->flags & MD_SHUTDOWN) {
1219 			sc->flags |= MD_EXITING;
1220 			mtx_unlock(&sc->queue_mtx);
1221 			kproc_exit(0);
1222 		}
1223 		bp = bioq_takefirst(&sc->bio_queue);
1224 		if (!bp) {
1225 			msleep(sc, &sc->queue_mtx, PRIBIO | PDROP, "mdwait", 0);
1226 			continue;
1227 		}
1228 		mtx_unlock(&sc->queue_mtx);
1229 		if (bp->bio_cmd == BIO_GETATTR) {
1230 			md_handleattr(sc, bp);
1231 		} else {
1232 			error = sc->start(sc, bp);
1233 			if (bp->bio_cmd == BIO_READ || bp->bio_cmd == BIO_WRITE) {
1234 				/*
1235 				 * Devstat uses (bio_bcount, bio_resid) for
1236 				 * determining the length of the completed part
1237 				 * of the i/o.  g_io_deliver() will translate
1238 				 * from bio_completed to that, but it also
1239 				 * destroys the bio so we must do our own
1240 				 * translation.
1241 				 */
1242 				bp->bio_bcount = bp->bio_length;
1243 				devstat_end_transaction_bio(sc->devstat, bp);
1244 			}
1245 			bp->bio_completed = bp->bio_length - bp->bio_resid;
1246 			g_io_deliver(bp, error);
1247 		}
1248 	}
1249 }
1250 
1251 static struct md_s *
1252 mdfind(int unit)
1253 {
1254 	struct md_s *sc;
1255 
1256 	LIST_FOREACH(sc, &md_softc_list, list) {
1257 		if (sc->unit == unit)
1258 			break;
1259 	}
1260 	return (sc);
1261 }
1262 
1263 static struct md_s *
1264 mdnew(int unit, int *errp, enum md_types type)
1265 {
1266 	struct md_s *sc;
1267 	int error;
1268 
1269 	*errp = 0;
1270 	if (unit == -1)
1271 		unit = alloc_unr(md_uh);
1272 	else
1273 		unit = alloc_unr_specific(md_uh, unit);
1274 
1275 	if (unit == -1) {
1276 		*errp = EBUSY;
1277 		return (NULL);
1278 	}
1279 
1280 	sc = (struct md_s *)malloc(sizeof *sc, M_MD, M_WAITOK | M_ZERO);
1281 	sc->type = type;
1282 	bioq_init(&sc->bio_queue);
1283 	mtx_init(&sc->queue_mtx, "md bio queue", NULL, MTX_DEF);
1284 	sc->unit = unit;
1285 	sprintf(sc->name, "md%d", unit);
1286 	LIST_INSERT_HEAD(&md_softc_list, sc, list);
1287 	error = kproc_create(md_kthread, sc, &sc->procp, 0, 0,"%s", sc->name);
1288 	if (error == 0)
1289 		return (sc);
1290 	LIST_REMOVE(sc, list);
1291 	mtx_destroy(&sc->queue_mtx);
1292 	free_unr(md_uh, sc->unit);
1293 	free(sc, M_MD);
1294 	*errp = error;
1295 	return (NULL);
1296 }
1297 
1298 static void
1299 mdinit(struct md_s *sc)
1300 {
1301 	struct g_geom *gp;
1302 	struct g_provider *pp;
1303 
1304 	g_topology_lock();
1305 	gp = g_new_geomf(&g_md_class, "md%d", sc->unit);
1306 	gp->softc = sc;
1307 	pp = g_new_providerf(gp, "md%d", sc->unit);
1308 	devstat_remove_entry(pp->stat);
1309 	pp->stat = NULL;
1310 	pp->flags |= G_PF_DIRECT_SEND | G_PF_DIRECT_RECEIVE;
1311 	pp->mediasize = sc->mediasize;
1312 	pp->sectorsize = sc->sectorsize;
1313 	switch (sc->type) {
1314 	case MD_MALLOC:
1315 	case MD_VNODE:
1316 	case MD_SWAP:
1317 		pp->flags |= G_PF_ACCEPT_UNMAPPED;
1318 		break;
1319 	case MD_PRELOAD:
1320 	case MD_NULL:
1321 		break;
1322 	}
1323 	sc->gp = gp;
1324 	sc->pp = pp;
1325 	sc->devstat = devstat_new_entry("md", sc->unit, sc->sectorsize,
1326 	    DEVSTAT_ALL_SUPPORTED, DEVSTAT_TYPE_DIRECT, DEVSTAT_PRIORITY_MAX);
1327 	sc->devstat->id = pp;
1328 	g_error_provider(pp, 0);
1329 	g_topology_unlock();
1330 }
1331 
1332 static int
1333 mdcreate_malloc(struct md_s *sc, struct md_req *mdr)
1334 {
1335 	uintptr_t sp;
1336 	int error;
1337 	off_t u;
1338 
1339 	error = 0;
1340 	if (mdr->md_options & ~(MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE))
1341 		return (EINVAL);
1342 	if (mdr->md_sectorsize != 0 && !powerof2(mdr->md_sectorsize))
1343 		return (EINVAL);
1344 	/* Compression doesn't make sense if we have reserved space */
1345 	if (mdr->md_options & MD_RESERVE)
1346 		mdr->md_options &= ~MD_COMPRESS;
1347 	if (mdr->md_fwsectors != 0)
1348 		sc->fwsectors = mdr->md_fwsectors;
1349 	if (mdr->md_fwheads != 0)
1350 		sc->fwheads = mdr->md_fwheads;
1351 	sc->flags = mdr->md_options & (MD_COMPRESS | MD_FORCE);
1352 	sc->indir = dimension(sc->mediasize / sc->sectorsize);
1353 	sc->uma = uma_zcreate(sc->name, sc->sectorsize, NULL, NULL, NULL, NULL,
1354 	    0x1ff, 0);
1355 	if (mdr->md_options & MD_RESERVE) {
1356 		off_t nsectors;
1357 
1358 		nsectors = sc->mediasize / sc->sectorsize;
1359 		for (u = 0; u < nsectors; u++) {
1360 			sp = (uintptr_t)uma_zalloc(sc->uma, (md_malloc_wait ?
1361 			    M_WAITOK : M_NOWAIT) | M_ZERO);
1362 			if (sp != 0)
1363 				error = s_write(sc->indir, u, sp);
1364 			else
1365 				error = ENOMEM;
1366 			if (error != 0)
1367 				break;
1368 		}
1369 	}
1370 	return (error);
1371 }
1372 
1373 static int
1374 mdsetcred(struct md_s *sc, struct ucred *cred)
1375 {
1376 	char *tmpbuf;
1377 	int error = 0;
1378 
1379 	/*
1380 	 * Set credits in our softc
1381 	 */
1382 
1383 	if (sc->cred)
1384 		crfree(sc->cred);
1385 	sc->cred = crhold(cred);
1386 
1387 	/*
1388 	 * Horrible kludge to establish credentials for NFS  XXX.
1389 	 */
1390 
1391 	if (sc->vnode) {
1392 		struct uio auio;
1393 		struct iovec aiov;
1394 
1395 		tmpbuf = malloc(sc->sectorsize, M_TEMP, M_WAITOK);
1396 		bzero(&auio, sizeof(auio));
1397 
1398 		aiov.iov_base = tmpbuf;
1399 		aiov.iov_len = sc->sectorsize;
1400 		auio.uio_iov = &aiov;
1401 		auio.uio_iovcnt = 1;
1402 		auio.uio_offset = 0;
1403 		auio.uio_rw = UIO_READ;
1404 		auio.uio_segflg = UIO_SYSSPACE;
1405 		auio.uio_resid = aiov.iov_len;
1406 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1407 		error = VOP_READ(sc->vnode, &auio, 0, sc->cred);
1408 		VOP_UNLOCK(sc->vnode);
1409 		free(tmpbuf, M_TEMP);
1410 	}
1411 	return (error);
1412 }
1413 
1414 static int
1415 mdcreate_vnode(struct md_s *sc, struct md_req *mdr, struct thread *td)
1416 {
1417 	struct vattr vattr;
1418 	struct nameidata nd;
1419 	char *fname;
1420 	int error, flags;
1421 
1422 	fname = mdr->md_file;
1423 	if (mdr->md_file_seg == UIO_USERSPACE) {
1424 		error = copyinstr(fname, sc->file, sizeof(sc->file), NULL);
1425 		if (error != 0)
1426 			return (error);
1427 	} else if (mdr->md_file_seg == UIO_SYSSPACE)
1428 		strlcpy(sc->file, fname, sizeof(sc->file));
1429 	else
1430 		return (EDOOFUS);
1431 
1432 	/*
1433 	 * If the user specified that this is a read only device, don't
1434 	 * set the FWRITE mask before trying to open the backing store.
1435 	 */
1436 	flags = FREAD | ((mdr->md_options & MD_READONLY) ? 0 : FWRITE) \
1437 	    | ((mdr->md_options & MD_VERIFY) ? O_VERIFY : 0);
1438 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, sc->file, td);
1439 	error = vn_open(&nd, &flags, 0, NULL);
1440 	if (error != 0)
1441 		return (error);
1442 	NDFREE(&nd, NDF_ONLY_PNBUF);
1443 	if (nd.ni_vp->v_type != VREG) {
1444 		error = EINVAL;
1445 		goto bad;
1446 	}
1447 	error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred);
1448 	if (error != 0)
1449 		goto bad;
1450 	if (VOP_ISLOCKED(nd.ni_vp) != LK_EXCLUSIVE) {
1451 		vn_lock(nd.ni_vp, LK_UPGRADE | LK_RETRY);
1452 		if (VN_IS_DOOMED(nd.ni_vp)) {
1453 			/* Forced unmount. */
1454 			error = EBADF;
1455 			goto bad;
1456 		}
1457 	}
1458 	nd.ni_vp->v_vflag |= VV_MD;
1459 	VOP_UNLOCK(nd.ni_vp);
1460 
1461 	if (mdr->md_fwsectors != 0)
1462 		sc->fwsectors = mdr->md_fwsectors;
1463 	if (mdr->md_fwheads != 0)
1464 		sc->fwheads = mdr->md_fwheads;
1465 	snprintf(sc->ident, sizeof(sc->ident), "MD-DEV%ju-INO%ju",
1466 	    (uintmax_t)vattr.va_fsid, (uintmax_t)vattr.va_fileid);
1467 	sc->flags = mdr->md_options & (MD_ASYNC | MD_CACHE | MD_FORCE |
1468 	    MD_VERIFY);
1469 	if (!(flags & FWRITE))
1470 		sc->flags |= MD_READONLY;
1471 	sc->vnode = nd.ni_vp;
1472 
1473 	error = mdsetcred(sc, td->td_ucred);
1474 	if (error != 0) {
1475 		sc->vnode = NULL;
1476 		vn_lock(nd.ni_vp, LK_EXCLUSIVE | LK_RETRY);
1477 		nd.ni_vp->v_vflag &= ~VV_MD;
1478 		goto bad;
1479 	}
1480 	return (0);
1481 bad:
1482 	VOP_UNLOCK(nd.ni_vp);
1483 	(void)vn_close(nd.ni_vp, flags, td->td_ucred, td);
1484 	return (error);
1485 }
1486 
1487 static void
1488 g_md_providergone(struct g_provider *pp)
1489 {
1490 	struct md_s *sc = pp->geom->softc;
1491 
1492 	mtx_lock(&sc->queue_mtx);
1493 	sc->flags |= MD_PROVIDERGONE;
1494 	wakeup(&sc->flags);
1495 	mtx_unlock(&sc->queue_mtx);
1496 }
1497 
1498 static int
1499 mddestroy(struct md_s *sc, struct thread *td)
1500 {
1501 
1502 	if (sc->gp) {
1503 		g_topology_lock();
1504 		g_wither_geom(sc->gp, ENXIO);
1505 		g_topology_unlock();
1506 
1507 		mtx_lock(&sc->queue_mtx);
1508 		while (!(sc->flags & MD_PROVIDERGONE))
1509 			msleep(&sc->flags, &sc->queue_mtx, PRIBIO, "mddestroy", 0);
1510 		mtx_unlock(&sc->queue_mtx);
1511 	}
1512 	if (sc->devstat) {
1513 		devstat_remove_entry(sc->devstat);
1514 		sc->devstat = NULL;
1515 	}
1516 	mtx_lock(&sc->queue_mtx);
1517 	sc->flags |= MD_SHUTDOWN;
1518 	wakeup(sc);
1519 	while (!(sc->flags & MD_EXITING))
1520 		msleep(sc->procp, &sc->queue_mtx, PRIBIO, "mddestroy", hz / 10);
1521 	mtx_unlock(&sc->queue_mtx);
1522 	mtx_destroy(&sc->queue_mtx);
1523 	if (sc->vnode != NULL) {
1524 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY);
1525 		sc->vnode->v_vflag &= ~VV_MD;
1526 		VOP_UNLOCK(sc->vnode);
1527 		(void)vn_close(sc->vnode, sc->flags & MD_READONLY ?
1528 		    FREAD : (FREAD|FWRITE), sc->cred, td);
1529 	}
1530 	if (sc->cred != NULL)
1531 		crfree(sc->cred);
1532 	if (sc->object != NULL)
1533 		vm_object_deallocate(sc->object);
1534 	if (sc->indir)
1535 		destroy_indir(sc, sc->indir);
1536 	if (sc->uma)
1537 		uma_zdestroy(sc->uma);
1538 
1539 	LIST_REMOVE(sc, list);
1540 	free_unr(md_uh, sc->unit);
1541 	free(sc, M_MD);
1542 	return (0);
1543 }
1544 
1545 static int
1546 mdresize(struct md_s *sc, struct md_req *mdr)
1547 {
1548 	int error, res;
1549 	vm_pindex_t oldpages, newpages;
1550 
1551 	switch (sc->type) {
1552 	case MD_VNODE:
1553 	case MD_NULL:
1554 		break;
1555 	case MD_SWAP:
1556 		if (mdr->md_mediasize <= 0 ||
1557 		    (mdr->md_mediasize % PAGE_SIZE) != 0)
1558 			return (EDOM);
1559 		oldpages = OFF_TO_IDX(sc->mediasize);
1560 		newpages = OFF_TO_IDX(mdr->md_mediasize);
1561 		if (newpages < oldpages) {
1562 			VM_OBJECT_WLOCK(sc->object);
1563 			vm_object_page_remove(sc->object, newpages, 0, 0);
1564 			swap_release_by_cred(IDX_TO_OFF(oldpages -
1565 			    newpages), sc->cred);
1566 			sc->object->charge = IDX_TO_OFF(newpages);
1567 			sc->object->size = newpages;
1568 			VM_OBJECT_WUNLOCK(sc->object);
1569 		} else if (newpages > oldpages) {
1570 			res = swap_reserve_by_cred(IDX_TO_OFF(newpages -
1571 			    oldpages), sc->cred);
1572 			if (!res)
1573 				return (ENOMEM);
1574 			if ((mdr->md_options & MD_RESERVE) ||
1575 			    (sc->flags & MD_RESERVE)) {
1576 				error = swap_pager_reserve(sc->object,
1577 				    oldpages, newpages - oldpages);
1578 				if (error < 0) {
1579 					swap_release_by_cred(
1580 					    IDX_TO_OFF(newpages - oldpages),
1581 					    sc->cred);
1582 					return (EDOM);
1583 				}
1584 			}
1585 			VM_OBJECT_WLOCK(sc->object);
1586 			sc->object->charge = IDX_TO_OFF(newpages);
1587 			sc->object->size = newpages;
1588 			VM_OBJECT_WUNLOCK(sc->object);
1589 		}
1590 		break;
1591 	default:
1592 		return (EOPNOTSUPP);
1593 	}
1594 
1595 	sc->mediasize = mdr->md_mediasize;
1596 
1597 	g_topology_lock();
1598 	g_resize_provider(sc->pp, sc->mediasize);
1599 	g_topology_unlock();
1600 	return (0);
1601 }
1602 
1603 static int
1604 mdcreate_swap(struct md_s *sc, struct md_req *mdr, struct thread *td)
1605 {
1606 	vm_ooffset_t npage;
1607 	int error;
1608 
1609 	/*
1610 	 * Range check.  Disallow negative sizes and sizes not being
1611 	 * multiple of page size.
1612 	 */
1613 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1614 		return (EDOM);
1615 
1616 	/*
1617 	 * Allocate an OBJT_SWAP object.
1618 	 *
1619 	 * Note the truncation.
1620 	 */
1621 
1622 	if ((mdr->md_options & MD_VERIFY) != 0)
1623 		return (EINVAL);
1624 	npage = mdr->md_mediasize / PAGE_SIZE;
1625 	if (mdr->md_fwsectors != 0)
1626 		sc->fwsectors = mdr->md_fwsectors;
1627 	if (mdr->md_fwheads != 0)
1628 		sc->fwheads = mdr->md_fwheads;
1629 	sc->object = vm_pager_allocate(OBJT_SWAP, NULL, PAGE_SIZE * npage,
1630 	    VM_PROT_DEFAULT, 0, td->td_ucred);
1631 	if (sc->object == NULL)
1632 		return (ENOMEM);
1633 	sc->flags = mdr->md_options & (MD_FORCE | MD_RESERVE);
1634 	if (mdr->md_options & MD_RESERVE) {
1635 		if (swap_pager_reserve(sc->object, 0, npage) < 0) {
1636 			error = EDOM;
1637 			goto finish;
1638 		}
1639 	}
1640 	error = mdsetcred(sc, td->td_ucred);
1641  finish:
1642 	if (error != 0) {
1643 		vm_object_deallocate(sc->object);
1644 		sc->object = NULL;
1645 	}
1646 	return (error);
1647 }
1648 
1649 static int
1650 mdcreate_null(struct md_s *sc, struct md_req *mdr, struct thread *td)
1651 {
1652 
1653 	/*
1654 	 * Range check.  Disallow negative sizes and sizes not being
1655 	 * multiple of page size.
1656 	 */
1657 	if (sc->mediasize <= 0 || (sc->mediasize % PAGE_SIZE) != 0)
1658 		return (EDOM);
1659 
1660 	return (0);
1661 }
1662 
1663 static int
1664 kern_mdattach_locked(struct thread *td, struct md_req *mdr)
1665 {
1666 	struct md_s *sc;
1667 	unsigned sectsize;
1668 	int error, i;
1669 
1670 	sx_assert(&md_sx, SA_XLOCKED);
1671 
1672 	switch (mdr->md_type) {
1673 	case MD_MALLOC:
1674 	case MD_PRELOAD:
1675 	case MD_VNODE:
1676 	case MD_SWAP:
1677 	case MD_NULL:
1678 		break;
1679 	default:
1680 		return (EINVAL);
1681 	}
1682 	if (mdr->md_sectorsize == 0)
1683 		sectsize = DEV_BSIZE;
1684 	else
1685 		sectsize = mdr->md_sectorsize;
1686 	if (sectsize > maxphys || mdr->md_mediasize < sectsize)
1687 		return (EINVAL);
1688 	if (mdr->md_options & MD_AUTOUNIT)
1689 		sc = mdnew(-1, &error, mdr->md_type);
1690 	else {
1691 		if (mdr->md_unit > INT_MAX)
1692 			return (EINVAL);
1693 		sc = mdnew(mdr->md_unit, &error, mdr->md_type);
1694 	}
1695 	if (sc == NULL)
1696 		return (error);
1697 	if (mdr->md_label != NULL)
1698 		error = copyinstr(mdr->md_label, sc->label,
1699 		    sizeof(sc->label), NULL);
1700 	if (error != 0)
1701 		goto err_after_new;
1702 	if (mdr->md_options & MD_AUTOUNIT)
1703 		mdr->md_unit = sc->unit;
1704 	sc->mediasize = mdr->md_mediasize;
1705 	sc->sectorsize = sectsize;
1706 	error = EDOOFUS;
1707 	switch (sc->type) {
1708 	case MD_MALLOC:
1709 		sc->start = mdstart_malloc;
1710 		error = mdcreate_malloc(sc, mdr);
1711 		break;
1712 	case MD_PRELOAD:
1713 		/*
1714 		 * We disallow attaching preloaded memory disks via
1715 		 * ioctl. Preloaded memory disks are automatically
1716 		 * attached in g_md_init().
1717 		 */
1718 		error = EOPNOTSUPP;
1719 		break;
1720 	case MD_VNODE:
1721 		sc->start = mdstart_vnode;
1722 		error = mdcreate_vnode(sc, mdr, td);
1723 		break;
1724 	case MD_SWAP:
1725 		sc->start = mdstart_swap;
1726 		error = mdcreate_swap(sc, mdr, td);
1727 		break;
1728 	case MD_NULL:
1729 		sc->start = mdstart_null;
1730 		error = mdcreate_null(sc, mdr, td);
1731 		break;
1732 	}
1733 err_after_new:
1734 	if (error != 0) {
1735 		mddestroy(sc, td);
1736 		return (error);
1737 	}
1738 
1739 	/* Prune off any residual fractional sector */
1740 	i = sc->mediasize % sc->sectorsize;
1741 	sc->mediasize -= i;
1742 
1743 	mdinit(sc);
1744 	return (0);
1745 }
1746 
1747 static int
1748 kern_mdattach(struct thread *td, struct md_req *mdr)
1749 {
1750 	int error;
1751 
1752 	sx_xlock(&md_sx);
1753 	error = kern_mdattach_locked(td, mdr);
1754 	sx_xunlock(&md_sx);
1755 	return (error);
1756 }
1757 
1758 static int
1759 kern_mddetach_locked(struct thread *td, struct md_req *mdr)
1760 {
1761 	struct md_s *sc;
1762 
1763 	sx_assert(&md_sx, SA_XLOCKED);
1764 
1765 	if (mdr->md_mediasize != 0 ||
1766 	    (mdr->md_options & ~MD_FORCE) != 0)
1767 		return (EINVAL);
1768 
1769 	sc = mdfind(mdr->md_unit);
1770 	if (sc == NULL)
1771 		return (ENOENT);
1772 	if (sc->opencount != 0 && !(sc->flags & MD_FORCE) &&
1773 	    !(mdr->md_options & MD_FORCE))
1774 		return (EBUSY);
1775 	return (mddestroy(sc, td));
1776 }
1777 
1778 static int
1779 kern_mddetach(struct thread *td, struct md_req *mdr)
1780 {
1781 	int error;
1782 
1783 	sx_xlock(&md_sx);
1784 	error = kern_mddetach_locked(td, mdr);
1785 	sx_xunlock(&md_sx);
1786 	return (error);
1787 }
1788 
1789 static int
1790 kern_mdresize_locked(struct md_req *mdr)
1791 {
1792 	struct md_s *sc;
1793 
1794 	sx_assert(&md_sx, SA_XLOCKED);
1795 
1796 	if ((mdr->md_options & ~(MD_FORCE | MD_RESERVE)) != 0)
1797 		return (EINVAL);
1798 
1799 	sc = mdfind(mdr->md_unit);
1800 	if (sc == NULL)
1801 		return (ENOENT);
1802 	if (mdr->md_mediasize < sc->sectorsize)
1803 		return (EINVAL);
1804 	mdr->md_mediasize -= mdr->md_mediasize % sc->sectorsize;
1805 	if (mdr->md_mediasize < sc->mediasize &&
1806 	    !(sc->flags & MD_FORCE) &&
1807 	    !(mdr->md_options & MD_FORCE))
1808 		return (EBUSY);
1809 	return (mdresize(sc, mdr));
1810 }
1811 
1812 static int
1813 kern_mdresize(struct md_req *mdr)
1814 {
1815 	int error;
1816 
1817 	sx_xlock(&md_sx);
1818 	error = kern_mdresize_locked(mdr);
1819 	sx_xunlock(&md_sx);
1820 	return (error);
1821 }
1822 
1823 static int
1824 kern_mdquery_locked(struct md_req *mdr)
1825 {
1826 	struct md_s *sc;
1827 	int error;
1828 
1829 	sx_assert(&md_sx, SA_XLOCKED);
1830 
1831 	sc = mdfind(mdr->md_unit);
1832 	if (sc == NULL)
1833 		return (ENOENT);
1834 	mdr->md_type = sc->type;
1835 	mdr->md_options = sc->flags;
1836 	mdr->md_mediasize = sc->mediasize;
1837 	mdr->md_sectorsize = sc->sectorsize;
1838 	error = 0;
1839 	if (mdr->md_label != NULL) {
1840 		error = copyout(sc->label, mdr->md_label,
1841 		    strlen(sc->label) + 1);
1842 		if (error != 0)
1843 			return (error);
1844 	}
1845 	if (sc->type == MD_VNODE ||
1846 	    (sc->type == MD_PRELOAD && mdr->md_file != NULL))
1847 		error = copyout(sc->file, mdr->md_file,
1848 		    strlen(sc->file) + 1);
1849 	return (error);
1850 }
1851 
1852 static int
1853 kern_mdquery(struct md_req *mdr)
1854 {
1855 	int error;
1856 
1857 	sx_xlock(&md_sx);
1858 	error = kern_mdquery_locked(mdr);
1859 	sx_xunlock(&md_sx);
1860 	return (error);
1861 }
1862 
1863 /* Copy members that are not userspace pointers. */
1864 #define	MD_IOCTL2REQ(mdio, mdr) do {					\
1865 	(mdr)->md_unit = (mdio)->md_unit;				\
1866 	(mdr)->md_type = (mdio)->md_type;				\
1867 	(mdr)->md_mediasize = (mdio)->md_mediasize;			\
1868 	(mdr)->md_sectorsize = (mdio)->md_sectorsize;			\
1869 	(mdr)->md_options = (mdio)->md_options;				\
1870 	(mdr)->md_fwheads = (mdio)->md_fwheads;				\
1871 	(mdr)->md_fwsectors = (mdio)->md_fwsectors;			\
1872 	(mdr)->md_units = &(mdio)->md_pad[0];				\
1873 	(mdr)->md_units_nitems = nitems((mdio)->md_pad);		\
1874 } while(0)
1875 
1876 /* Copy members that might have been updated */
1877 #define MD_REQ2IOCTL(mdr, mdio) do {					\
1878 	(mdio)->md_unit = (mdr)->md_unit;				\
1879 	(mdio)->md_type = (mdr)->md_type;				\
1880 	(mdio)->md_mediasize = (mdr)->md_mediasize;			\
1881 	(mdio)->md_sectorsize = (mdr)->md_sectorsize;			\
1882 	(mdio)->md_options = (mdr)->md_options;				\
1883 	(mdio)->md_fwheads = (mdr)->md_fwheads;				\
1884 	(mdio)->md_fwsectors = (mdr)->md_fwsectors;			\
1885 } while(0)
1886 
1887 static int
1888 mdctlioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flags,
1889     struct thread *td)
1890 {
1891 	struct md_req mdr;
1892 	int error;
1893 
1894 	if (md_debug)
1895 		printf("mdctlioctl(%s %lx %p %x %p)\n",
1896 			devtoname(dev), cmd, addr, flags, td);
1897 
1898 	bzero(&mdr, sizeof(mdr));
1899 	switch (cmd) {
1900 	case MDIOCATTACH:
1901 	case MDIOCDETACH:
1902 	case MDIOCRESIZE:
1903 	case MDIOCQUERY: {
1904 		struct md_ioctl *mdio = (struct md_ioctl *)addr;
1905 		if (mdio->md_version != MDIOVERSION)
1906 			return (EINVAL);
1907 		MD_IOCTL2REQ(mdio, &mdr);
1908 		mdr.md_file = mdio->md_file;
1909 		mdr.md_file_seg = UIO_USERSPACE;
1910 		/* If the file is adjacent to the md_ioctl it's in kernel. */
1911 		if ((void *)mdio->md_file == (void *)(mdio + 1))
1912 			mdr.md_file_seg = UIO_SYSSPACE;
1913 		mdr.md_label = mdio->md_label;
1914 		break;
1915 	}
1916 #ifdef COMPAT_FREEBSD32
1917 	case MDIOCATTACH_32:
1918 	case MDIOCDETACH_32:
1919 	case MDIOCRESIZE_32:
1920 	case MDIOCQUERY_32: {
1921 		struct md_ioctl32 *mdio = (struct md_ioctl32 *)addr;
1922 		if (mdio->md_version != MDIOVERSION)
1923 			return (EINVAL);
1924 		MD_IOCTL2REQ(mdio, &mdr);
1925 		mdr.md_file = (void *)(uintptr_t)mdio->md_file;
1926 		mdr.md_file_seg = UIO_USERSPACE;
1927 		mdr.md_label = (void *)(uintptr_t)mdio->md_label;
1928 		break;
1929 	}
1930 #endif
1931 	default:
1932 		/* Fall through to handler switch. */
1933 		break;
1934 	}
1935 
1936 	error = 0;
1937 	switch (cmd) {
1938 	case MDIOCATTACH:
1939 #ifdef COMPAT_FREEBSD32
1940 	case MDIOCATTACH_32:
1941 #endif
1942 		error = kern_mdattach(td, &mdr);
1943 		break;
1944 	case MDIOCDETACH:
1945 #ifdef COMPAT_FREEBSD32
1946 	case MDIOCDETACH_32:
1947 #endif
1948 		error = kern_mddetach(td, &mdr);
1949 		break;
1950 	case MDIOCRESIZE:
1951 #ifdef COMPAT_FREEBSD32
1952 	case MDIOCRESIZE_32:
1953 #endif
1954 		error = kern_mdresize(&mdr);
1955 		break;
1956 	case MDIOCQUERY:
1957 #ifdef COMPAT_FREEBSD32
1958 	case MDIOCQUERY_32:
1959 #endif
1960 		error = kern_mdquery(&mdr);
1961 		break;
1962 	default:
1963 		error = ENOIOCTL;
1964 	}
1965 
1966 	switch (cmd) {
1967 	case MDIOCATTACH:
1968 	case MDIOCQUERY: {
1969 		struct md_ioctl *mdio = (struct md_ioctl *)addr;
1970 		MD_REQ2IOCTL(&mdr, mdio);
1971 		break;
1972 	}
1973 #ifdef COMPAT_FREEBSD32
1974 	case MDIOCATTACH_32:
1975 	case MDIOCQUERY_32: {
1976 		struct md_ioctl32 *mdio = (struct md_ioctl32 *)addr;
1977 		MD_REQ2IOCTL(&mdr, mdio);
1978 		break;
1979 	}
1980 #endif
1981 	default:
1982 		/* Other commands to not alter mdr. */
1983 		break;
1984 	}
1985 
1986 	return (error);
1987 }
1988 
1989 static void
1990 md_preloaded(u_char *image, size_t length, const char *name)
1991 {
1992 	struct md_s *sc;
1993 	int error;
1994 
1995 	sc = mdnew(-1, &error, MD_PRELOAD);
1996 	if (sc == NULL)
1997 		return;
1998 	sc->mediasize = length;
1999 	sc->sectorsize = DEV_BSIZE;
2000 	sc->pl_ptr = image;
2001 	sc->pl_len = length;
2002 	sc->start = mdstart_preload;
2003 	if (name != NULL)
2004 		strlcpy(sc->file, name, sizeof(sc->file));
2005 #ifdef MD_ROOT
2006 	if (sc->unit == 0) {
2007 #ifndef ROOTDEVNAME
2008 		rootdevnames[0] = MD_ROOT_FSTYPE ":/dev/md0";
2009 #endif
2010 #ifdef MD_ROOT_READONLY
2011 		sc->flags |= MD_READONLY;
2012 #endif
2013 	}
2014 #endif
2015 	mdinit(sc);
2016 	if (name != NULL) {
2017 		printf("%s%d: Preloaded image <%s> %zd bytes at %p\n",
2018 		    MD_NAME, sc->unit, name, length, image);
2019 	} else {
2020 		printf("%s%d: Embedded image %zd bytes at %p\n",
2021 		    MD_NAME, sc->unit, length, image);
2022 	}
2023 }
2024 
2025 static void
2026 g_md_init(struct g_class *mp __unused)
2027 {
2028 	caddr_t mod;
2029 	u_char *ptr, *name, *type;
2030 	unsigned len;
2031 	int i;
2032 
2033 	/* figure out log2(NINDIR) */
2034 	for (i = NINDIR, nshift = -1; i; nshift++)
2035 		i >>= 1;
2036 
2037 	mod = NULL;
2038 	sx_init(&md_sx, "MD config lock");
2039 	g_topology_unlock();
2040 	md_uh = new_unrhdr(0, INT_MAX, NULL);
2041 #ifdef MD_ROOT
2042 	if (mfs_root_size != 0) {
2043 		sx_xlock(&md_sx);
2044 #ifdef MD_ROOT_MEM
2045 		md_preloaded(mfs_root, mfs_root_size, NULL);
2046 #else
2047 		md_preloaded(__DEVOLATILE(u_char *, &mfs_root), mfs_root_size,
2048 		    NULL);
2049 #endif
2050 		sx_xunlock(&md_sx);
2051 	}
2052 #endif
2053 	/* XXX: are preload_* static or do they need Giant ? */
2054 	while ((mod = preload_search_next_name(mod)) != NULL) {
2055 		name = (char *)preload_search_info(mod, MODINFO_NAME);
2056 		if (name == NULL)
2057 			continue;
2058 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
2059 		if (type == NULL)
2060 			continue;
2061 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
2062 			continue;
2063 		ptr = preload_fetch_addr(mod);
2064 		len = preload_fetch_size(mod);
2065 		if (ptr != NULL && len != 0) {
2066 			sx_xlock(&md_sx);
2067 			md_preloaded(ptr, len, name);
2068 			sx_xunlock(&md_sx);
2069 		}
2070 	}
2071 	md_pbuf_zone = pbuf_zsecond_create("mdpbuf", nswbuf / 10);
2072 	status_dev = make_dev(&mdctl_cdevsw, INT_MAX, UID_ROOT, GID_WHEEL,
2073 	    0600, MDCTL_NAME);
2074 	g_topology_lock();
2075 }
2076 
2077 static void
2078 g_md_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
2079     struct g_consumer *cp __unused, struct g_provider *pp)
2080 {
2081 	struct md_s *mp;
2082 	char *type;
2083 
2084 	mp = gp->softc;
2085 	if (mp == NULL)
2086 		return;
2087 
2088 	switch (mp->type) {
2089 	case MD_MALLOC:
2090 		type = "malloc";
2091 		break;
2092 	case MD_PRELOAD:
2093 		type = "preload";
2094 		break;
2095 	case MD_VNODE:
2096 		type = "vnode";
2097 		break;
2098 	case MD_SWAP:
2099 		type = "swap";
2100 		break;
2101 	case MD_NULL:
2102 		type = "null";
2103 		break;
2104 	default:
2105 		type = "unknown";
2106 		break;
2107 	}
2108 
2109 	if (pp != NULL) {
2110 		if (indent == NULL) {
2111 			sbuf_printf(sb, " u %d", mp->unit);
2112 			sbuf_printf(sb, " s %ju", (uintmax_t) mp->sectorsize);
2113 			sbuf_printf(sb, " f %ju", (uintmax_t) mp->fwheads);
2114 			sbuf_printf(sb, " fs %ju", (uintmax_t) mp->fwsectors);
2115 			sbuf_printf(sb, " l %ju", (uintmax_t) mp->mediasize);
2116 			sbuf_printf(sb, " t %s", type);
2117 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
2118 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0'))
2119 				sbuf_printf(sb, " file %s", mp->file);
2120 			sbuf_printf(sb, " label %s", mp->label);
2121 		} else {
2122 			sbuf_printf(sb, "%s<unit>%d</unit>\n", indent,
2123 			    mp->unit);
2124 			sbuf_printf(sb, "%s<sectorsize>%ju</sectorsize>\n",
2125 			    indent, (uintmax_t) mp->sectorsize);
2126 			sbuf_printf(sb, "%s<fwheads>%ju</fwheads>\n",
2127 			    indent, (uintmax_t) mp->fwheads);
2128 			sbuf_printf(sb, "%s<fwsectors>%ju</fwsectors>\n",
2129 			    indent, (uintmax_t) mp->fwsectors);
2130 			if (mp->ident[0] != '\0') {
2131 				sbuf_printf(sb, "%s<ident>", indent);
2132 				g_conf_printf_escaped(sb, "%s", mp->ident);
2133 				sbuf_printf(sb, "</ident>\n");
2134 			}
2135 			sbuf_printf(sb, "%s<length>%ju</length>\n",
2136 			    indent, (uintmax_t) mp->mediasize);
2137 			sbuf_printf(sb, "%s<compression>%s</compression>\n", indent,
2138 			    (mp->flags & MD_COMPRESS) == 0 ? "off": "on");
2139 			sbuf_printf(sb, "%s<access>%s</access>\n", indent,
2140 			    (mp->flags & MD_READONLY) == 0 ? "read-write":
2141 			    "read-only");
2142 			sbuf_printf(sb, "%s<type>%s</type>\n", indent,
2143 			    type);
2144 			if ((mp->type == MD_VNODE && mp->vnode != NULL) ||
2145 			    (mp->type == MD_PRELOAD && mp->file[0] != '\0')) {
2146 				sbuf_printf(sb, "%s<file>", indent);
2147 				g_conf_printf_escaped(sb, "%s", mp->file);
2148 				sbuf_printf(sb, "</file>\n");
2149 			}
2150 			if (mp->type == MD_VNODE)
2151 				sbuf_printf(sb, "%s<cache>%s</cache>\n", indent,
2152 				    (mp->flags & MD_CACHE) == 0 ? "off": "on");
2153 			sbuf_printf(sb, "%s<label>", indent);
2154 			g_conf_printf_escaped(sb, "%s", mp->label);
2155 			sbuf_printf(sb, "</label>\n");
2156 		}
2157 	}
2158 }
2159 
2160 static void
2161 g_md_fini(struct g_class *mp __unused)
2162 {
2163 
2164 	sx_destroy(&md_sx);
2165 	if (status_dev != NULL)
2166 		destroy_dev(status_dev);
2167 	uma_zdestroy(md_pbuf_zone);
2168 	delete_unrhdr(md_uh);
2169 }
2170