xref: /freebsd/sys/dev/md/md.c (revision 0f8f86b71f022b803e99151c19db81b280f245dc)
1 /*
2  * ----------------------------------------------------------------------------
3  * "THE BEER-WARE LICENSE" (Revision 42):
4  * <phk@FreeBSD.ORG> wrote this file.  As long as you retain this notice you
5  * can do whatever you want with this stuff. If we meet some day, and you think
6  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
7  * ----------------------------------------------------------------------------
8  *
9  * $FreeBSD$
10  *
11  */
12 
13 /*
14  * The following functions are based in the vn(4) driver: mdstart_swap(),
15  * mdstart_vnode(), mdcreate_swap(), mdcreate_vnode() and mddestroy(),
16  * and as such under the following copyright:
17  *
18  * Copyright (c) 1988 University of Utah.
19  * Copyright (c) 1990, 1993
20  *	The Regents of the University of California.  All rights reserved.
21  *
22  * This code is derived from software contributed to Berkeley by
23  * the Systems Programming Group of the University of Utah Computer
24  * Science Department.
25  *
26  * Redistribution and use in source and binary forms, with or without
27  * modification, are permitted provided that the following conditions
28  * are met:
29  * 1. Redistributions of source code must retain the above copyright
30  *    notice, this list of conditions and the following disclaimer.
31  * 2. Redistributions in binary form must reproduce the above copyright
32  *    notice, this list of conditions and the following disclaimer in the
33  *    documentation and/or other materials provided with the distribution.
34  * 3. All advertising materials mentioning features or use of this software
35  *    must display the following acknowledgement:
36  *	This product includes software developed by the University of
37  *	California, Berkeley and its contributors.
38  * 4. Neither the name of the University nor the names of its contributors
39  *    may be used to endorse or promote products derived from this software
40  *    without specific prior written permission.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52  * SUCH DAMAGE.
53  *
54  * from: Utah Hdr: vn.c 1.13 94/04/02
55  *
56  *	from: @(#)vn.c	8.6 (Berkeley) 4/1/94
57  * From: src/sys/dev/vn/vn.c,v 1.122 2000/12/16 16:06:03
58  */
59 
60 #include "opt_geom.h"
61 #include "opt_md.h"
62 
63 #include <sys/param.h>
64 #include <sys/systm.h>
65 #include <sys/bio.h>
66 #include <sys/conf.h>
67 #include <sys/fcntl.h>
68 #include <sys/kernel.h>
69 #include <sys/kthread.h>
70 #include <sys/linker.h>
71 #include <sys/lock.h>
72 #include <sys/malloc.h>
73 #include <sys/mdioctl.h>
74 #include <sys/mutex.h>
75 #include <sys/namei.h>
76 #include <sys/proc.h>
77 #include <sys/queue.h>
78 #include <sys/sf_buf.h>
79 #include <sys/sysctl.h>
80 #include <sys/vnode.h>
81 
82 #include <geom/geom.h>
83 
84 #include <vm/vm.h>
85 #include <vm/vm_object.h>
86 #include <vm/vm_page.h>
87 #include <vm/vm_pager.h>
88 #include <vm/swap_pager.h>
89 #include <vm/uma.h>
90 
91 #define MD_MODVER 1
92 
93 #define MD_SHUTDOWN 0x10000	/* Tell worker thread to terminate. */
94 
95 #ifndef MD_NSECT
96 #define MD_NSECT (10000 * 2)
97 #endif
98 
99 static MALLOC_DEFINE(M_MD, "MD disk", "Memory Disk");
100 static MALLOC_DEFINE(M_MDSECT, "MD sectors", "Memory Disk Sectors");
101 
102 static int md_debug;
103 SYSCTL_INT(_debug, OID_AUTO, mddebug, CTLFLAG_RW, &md_debug, 0, "");
104 
105 #if defined(MD_ROOT) && defined(MD_ROOT_SIZE)
106 /* Image gets put here: */
107 static u_char mfs_root[MD_ROOT_SIZE*1024] = "MFS Filesystem goes here";
108 static u_char end_mfs_root[] __unused = "MFS Filesystem had better STOP here";
109 #endif
110 
111 static g_init_t md_drvinit;
112 
113 static int	mdrootready;
114 static int	mdunits;
115 static dev_t	status_dev = 0;
116 
117 static d_ioctl_t mdctlioctl;
118 
119 static struct cdevsw mdctl_cdevsw = {
120 	.d_version =	D_VERSION,
121 	.d_flags =	D_NEEDGIANT,
122 	.d_ioctl =	mdctlioctl,
123 	.d_name =	MD_NAME,
124 };
125 
126 
127 static LIST_HEAD(, md_s) md_softc_list = LIST_HEAD_INITIALIZER(&md_softc_list);
128 
129 #define NINDIR	(PAGE_SIZE / sizeof(uintptr_t))
130 #define NMASK	(NINDIR-1)
131 static int nshift;
132 
133 struct indir {
134 	uintptr_t	*array;
135 	u_int		total;
136 	u_int		used;
137 	u_int		shift;
138 };
139 
140 struct md_s {
141 	int unit;
142 	LIST_ENTRY(md_s) list;
143 	struct bio_queue_head bio_queue;
144 	struct mtx queue_mtx;
145 	dev_t dev;
146 	enum md_types type;
147 	unsigned nsect;
148 	unsigned opencount;
149 	unsigned secsize;
150 	unsigned fwheads;
151 	unsigned fwsectors;
152 	unsigned flags;
153 	char name[20];
154 	struct proc *procp;
155 	struct g_geom *gp;
156 	struct g_provider *pp;
157 
158 	/* MD_MALLOC related fields */
159 	struct indir *indir;
160 	uma_zone_t uma;
161 
162 	/* MD_PRELOAD related fields */
163 	u_char *pl_ptr;
164 	unsigned pl_len;
165 
166 	/* MD_VNODE related fields */
167 	struct vnode *vnode;
168 	struct ucred *cred;
169 
170 	/* MD_SWAP related fields */
171 	vm_object_t object;
172 	unsigned npage;
173 };
174 
175 static int mddestroy(struct md_s *sc, struct thread *td);
176 
177 static struct indir *
178 new_indir(u_int shift)
179 {
180 	struct indir *ip;
181 
182 	ip = malloc(sizeof *ip, M_MD, M_NOWAIT | M_ZERO);
183 	if (ip == NULL)
184 		return (NULL);
185 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
186 	    M_MDSECT, M_NOWAIT | M_ZERO);
187 	if (ip->array == NULL) {
188 		free(ip, M_MD);
189 		return (NULL);
190 	}
191 	ip->total = NINDIR;
192 	ip->shift = shift;
193 	return (ip);
194 }
195 
196 static void
197 del_indir(struct indir *ip)
198 {
199 
200 	free(ip->array, M_MDSECT);
201 	free(ip, M_MD);
202 }
203 
204 static void
205 destroy_indir(struct md_s *sc, struct indir *ip)
206 {
207 	int i;
208 
209 	for (i = 0; i < NINDIR; i++) {
210 		if (!ip->array[i])
211 			continue;
212 		if (ip->shift)
213 			destroy_indir(sc, (struct indir*)(ip->array[i]));
214 		else if (ip->array[i] > 255)
215 			uma_zfree(sc->uma, (void *)(ip->array[i]));
216 	}
217 	del_indir(ip);
218 }
219 
220 /*
221  * This function does the math and alloctes the top level "indir" structure
222  * for a device of "size" sectors.
223  */
224 
225 static struct indir *
226 dimension(off_t size)
227 {
228 	off_t rcnt;
229 	struct indir *ip;
230 	int i, layer;
231 
232 	rcnt = size;
233 	layer = 0;
234 	while (rcnt > NINDIR) {
235 		rcnt /= NINDIR;
236 		layer++;
237 	}
238 	/* figure out log2(NINDIR) */
239 	for (i = NINDIR, nshift = -1; i; nshift++)
240 		i >>= 1;
241 
242 	/*
243 	 * XXX: the top layer is probably not fully populated, so we allocate
244 	 * too much space for ip->array in here.
245 	 */
246 	ip = malloc(sizeof *ip, M_MD, M_WAITOK | M_ZERO);
247 	ip->array = malloc(sizeof(uintptr_t) * NINDIR,
248 	    M_MDSECT, M_WAITOK | M_ZERO);
249 	ip->total = NINDIR;
250 	ip->shift = layer * nshift;
251 	return (ip);
252 }
253 
254 /*
255  * Read a given sector
256  */
257 
258 static uintptr_t
259 s_read(struct indir *ip, off_t offset)
260 {
261 	struct indir *cip;
262 	int idx;
263 	uintptr_t up;
264 
265 	if (md_debug > 1)
266 		printf("s_read(%jd)\n", (intmax_t)offset);
267 	up = 0;
268 	for (cip = ip; cip != NULL;) {
269 		if (cip->shift) {
270 			idx = (offset >> cip->shift) & NMASK;
271 			up = cip->array[idx];
272 			cip = (struct indir *)up;
273 			continue;
274 		}
275 		idx = offset & NMASK;
276 		return (cip->array[idx]);
277 	}
278 	return (0);
279 }
280 
281 /*
282  * Write a given sector, prune the tree if the value is 0
283  */
284 
285 static int
286 s_write(struct indir *ip, off_t offset, uintptr_t ptr)
287 {
288 	struct indir *cip, *lip[10];
289 	int idx, li;
290 	uintptr_t up;
291 
292 	if (md_debug > 1)
293 		printf("s_write(%jd, %p)\n", (intmax_t)offset, (void *)ptr);
294 	up = 0;
295 	li = 0;
296 	cip = ip;
297 	for (;;) {
298 		lip[li++] = cip;
299 		if (cip->shift) {
300 			idx = (offset >> cip->shift) & NMASK;
301 			up = cip->array[idx];
302 			if (up != 0) {
303 				cip = (struct indir *)up;
304 				continue;
305 			}
306 			/* Allocate branch */
307 			cip->array[idx] =
308 			    (uintptr_t)new_indir(cip->shift - nshift);
309 			if (cip->array[idx] == 0)
310 				return (ENOSPC);
311 			cip->used++;
312 			up = cip->array[idx];
313 			cip = (struct indir *)up;
314 			continue;
315 		}
316 		/* leafnode */
317 		idx = offset & NMASK;
318 		up = cip->array[idx];
319 		if (up != 0)
320 			cip->used--;
321 		cip->array[idx] = ptr;
322 		if (ptr != 0)
323 			cip->used++;
324 		break;
325 	}
326 	if (cip->used != 0 || li == 1)
327 		return (0);
328 	li--;
329 	while (cip->used == 0 && cip != ip) {
330 		li--;
331 		idx = (offset >> lip[li]->shift) & NMASK;
332 		up = lip[li]->array[idx];
333 		KASSERT(up == (uintptr_t)cip, ("md screwed up"));
334 		del_indir(cip);
335 		lip[li]->array[idx] = 0;
336 		lip[li]->used--;
337 		cip = lip[li];
338 	}
339 	return (0);
340 }
341 
342 
343 struct g_class g_md_class = {
344 	.name = "MD",
345 	.init = md_drvinit,
346 };
347 
348 static int
349 g_md_access(struct g_provider *pp, int r, int w, int e)
350 {
351 	struct md_s *sc;
352 
353 	sc = pp->geom->softc;
354 	if (sc == NULL)
355 		return (ENXIO);
356 	r += pp->acr;
357 	w += pp->acw;
358 	e += pp->ace;
359 	if ((pp->acr + pp->acw + pp->ace) == 0 && (r + w + e) > 0) {
360 		sc->opencount = 1;
361 	} else if ((pp->acr + pp->acw + pp->ace) > 0 && (r + w + e) == 0) {
362 		sc->opencount = 0;
363 	}
364 	return (0);
365 }
366 
367 static void
368 g_md_start(struct bio *bp)
369 {
370 	struct md_s *sc;
371 
372 	sc = bp->bio_to->geom->softc;
373 
374 	bp->bio_pblkno = bp->bio_offset / sc->secsize;
375 	bp->bio_bcount = bp->bio_length;
376 	mtx_lock(&sc->queue_mtx);
377 	bioq_disksort(&sc->bio_queue, bp);
378 	mtx_unlock(&sc->queue_mtx);
379 
380 	wakeup(sc);
381 }
382 
383 DECLARE_GEOM_CLASS(g_md_class, g_md);
384 
385 
386 static int
387 mdstart_malloc(struct md_s *sc, struct bio *bp)
388 {
389 	int i, error;
390 	u_char *dst;
391 	unsigned secno, nsec, uc;
392 	uintptr_t sp, osp;
393 
394 	nsec = bp->bio_bcount / sc->secsize;
395 	secno = bp->bio_pblkno;
396 	dst = bp->bio_data;
397 	error = 0;
398 	while (nsec--) {
399 		osp = s_read(sc->indir, secno);
400 		if (bp->bio_cmd == BIO_DELETE) {
401 			if (osp != 0)
402 				error = s_write(sc->indir, secno, 0);
403 		} else if (bp->bio_cmd == BIO_READ) {
404 			if (osp == 0)
405 				bzero(dst, sc->secsize);
406 			else if (osp <= 255)
407 				for (i = 0; i < sc->secsize; i++)
408 					dst[i] = osp;
409 			else
410 				bcopy((void *)osp, dst, sc->secsize);
411 			osp = 0;
412 		} else if (bp->bio_cmd == BIO_WRITE) {
413 			if (sc->flags & MD_COMPRESS) {
414 				uc = dst[0];
415 				for (i = 1; i < sc->secsize; i++)
416 					if (dst[i] != uc)
417 						break;
418 			} else {
419 				i = 0;
420 				uc = 0;
421 			}
422 			if (i == sc->secsize) {
423 				if (osp != uc)
424 					error = s_write(sc->indir, secno, uc);
425 			} else {
426 				if (osp <= 255) {
427 					sp = (uintptr_t) uma_zalloc(
428 					    sc->uma, M_NOWAIT);
429 					if (sp == 0) {
430 						error = ENOSPC;
431 						break;
432 					}
433 					bcopy(dst, (void *)sp, sc->secsize);
434 					error = s_write(sc->indir, secno, sp);
435 				} else {
436 					bcopy(dst, (void *)osp, sc->secsize);
437 					osp = 0;
438 				}
439 			}
440 		} else {
441 			error = EOPNOTSUPP;
442 		}
443 		if (osp > 255)
444 			uma_zfree(sc->uma, (void*)osp);
445 		if (error)
446 			break;
447 		secno++;
448 		dst += sc->secsize;
449 	}
450 	bp->bio_resid = 0;
451 	return (error);
452 }
453 
454 static int
455 mdstart_preload(struct md_s *sc, struct bio *bp)
456 {
457 
458 	if (bp->bio_cmd == BIO_DELETE) {
459 	} else if (bp->bio_cmd == BIO_READ) {
460 		bcopy(sc->pl_ptr + (bp->bio_pblkno << DEV_BSHIFT), bp->bio_data, bp->bio_bcount);
461 	} else {
462 		bcopy(bp->bio_data, sc->pl_ptr + (bp->bio_pblkno << DEV_BSHIFT), bp->bio_bcount);
463 	}
464 	bp->bio_resid = 0;
465 	return (0);
466 }
467 
468 static int
469 mdstart_vnode(struct md_s *sc, struct bio *bp)
470 {
471 	int error;
472 	struct uio auio;
473 	struct iovec aiov;
474 	struct mount *mp;
475 
476 	/*
477 	 * VNODE I/O
478 	 *
479 	 * If an error occurs, we set BIO_ERROR but we do not set
480 	 * B_INVAL because (for a write anyway), the buffer is
481 	 * still valid.
482 	 */
483 
484 	bzero(&auio, sizeof(auio));
485 
486 	aiov.iov_base = bp->bio_data;
487 	aiov.iov_len = bp->bio_bcount;
488 	auio.uio_iov = &aiov;
489 	auio.uio_iovcnt = 1;
490 	auio.uio_offset = (vm_ooffset_t)bp->bio_pblkno * sc->secsize;
491 	auio.uio_segflg = UIO_SYSSPACE;
492 	if(bp->bio_cmd == BIO_READ)
493 		auio.uio_rw = UIO_READ;
494 	else if(bp->bio_cmd == BIO_WRITE)
495 		auio.uio_rw = UIO_WRITE;
496 	else
497 		panic("wrong BIO_OP in mdstart_vnode");
498 	auio.uio_resid = bp->bio_bcount;
499 	auio.uio_td = curthread;
500 	/*
501 	 * When reading set IO_DIRECT to try to avoid double-caching
502 	 * the data.  When writing IO_DIRECT is not optimal.
503 	 */
504 	if (bp->bio_cmd == BIO_READ) {
505 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY, curthread);
506 		error = VOP_READ(sc->vnode, &auio, IO_DIRECT, sc->cred);
507 		VOP_UNLOCK(sc->vnode, 0, curthread);
508 	} else {
509 		(void) vn_start_write(sc->vnode, &mp, V_WAIT);
510 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY, curthread);
511 		error = VOP_WRITE(sc->vnode, &auio,
512 		    sc->flags & MD_ASYNC ? 0 : IO_SYNC, sc->cred);
513 		VOP_UNLOCK(sc->vnode, 0, curthread);
514 		vn_finished_write(mp);
515 	}
516 	bp->bio_resid = auio.uio_resid;
517 	return (error);
518 }
519 
520 static int
521 mdstart_swap(struct md_s *sc, struct bio *bp)
522 {
523 	struct sf_buf *sf;
524 	int i, rv;
525 	int offs, len, lastp, lastend;
526 	vm_page_t m;
527 	u_char *p;
528 
529 	p = bp->bio_data;
530 
531 	/*
532 	 * offs is the ofset at whih to start operating on the
533 	 * next (ie, first) page.  lastp is the last page on
534 	 * which we're going to operate.  lastend is the ending
535 	 * position within that last page (ie, PAGE_SIZE if
536 	 * we're operating on complete aligned pages).
537 	 */
538 	offs = bp->bio_offset % PAGE_SIZE;
539 	lastp = (bp->bio_offset + bp->bio_length - 1) / PAGE_SIZE;
540 	lastend = (bp->bio_offset + bp->bio_length - 1) % PAGE_SIZE + 1;
541 
542 	VM_OBJECT_LOCK(sc->object);
543 	vm_object_pip_add(sc->object, 1);
544 	for (i = bp->bio_offset / PAGE_SIZE; i <= lastp; i++) {
545 		len = ((i == lastp) ? lastend : PAGE_SIZE) - offs;
546 
547 		m = vm_page_grab(sc->object, i,
548 		    VM_ALLOC_NORMAL|VM_ALLOC_RETRY);
549 		VM_OBJECT_UNLOCK(sc->object);
550 		sf = sf_buf_alloc(m);
551 		VM_OBJECT_LOCK(sc->object);
552 		if (bp->bio_cmd == BIO_READ) {
553 			if (m->valid != VM_PAGE_BITS_ALL)
554 				rv = vm_pager_get_pages(sc->object, &m, 1, 0);
555 			bcopy((void *)(sf_buf_kva(sf) + offs), p, len);
556 		} else if (bp->bio_cmd == BIO_WRITE) {
557 			if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL)
558 				rv = vm_pager_get_pages(sc->object, &m, 1, 0);
559 			bcopy(p, (void *)(sf_buf_kva(sf) + offs), len);
560 			m->valid = VM_PAGE_BITS_ALL;
561 #if 0
562 		} else if (bp->bio_cmd == BIO_DELETE) {
563 			if (len != PAGE_SIZE && m->valid != VM_PAGE_BITS_ALL)
564 				rv = vm_pager_get_pages(sc->object, &m, 1, 0);
565 			bzero((void *)(sf_buf_kva(sf) + offs), len);
566 			vm_page_dirty(m);
567 			m->valid = VM_PAGE_BITS_ALL;
568 #endif
569 		}
570 		sf_buf_free(sf);
571 		vm_page_lock_queues();
572 		vm_page_wakeup(m);
573 		vm_page_activate(m);
574 		if (bp->bio_cmd == BIO_WRITE)
575 			vm_page_dirty(m);
576 		vm_page_unlock_queues();
577 
578 		/* Actions on further pages start at offset 0 */
579 		p += PAGE_SIZE - offs;
580 		offs = 0;
581 #if 0
582 if (bootverbose || bp->bio_offset / PAGE_SIZE < 17)
583 printf("wire_count %d busy %d flags %x hold_count %d act_count %d queue %d valid %d dirty %d @ %d\n",
584     m->wire_count, m->busy,
585     m->flags, m->hold_count, m->act_count, m->queue, m->valid, m->dirty, i);
586 #endif
587 	}
588 	vm_object_pip_subtract(sc->object, 1);
589 	vm_object_set_writeable_dirty(sc->object);
590 	VM_OBJECT_UNLOCK(sc->object);
591 	return (0);
592 }
593 
594 static void
595 md_kthread(void *arg)
596 {
597 	struct md_s *sc;
598 	struct bio *bp;
599 	int error, hasgiant;
600 
601 	sc = arg;
602 	curthread->td_base_pri = PRIBIO;
603 
604 	switch (sc->type) {
605 	case MD_VNODE:
606 		mtx_lock(&Giant);
607 		hasgiant = 1;
608 		break;
609 	case MD_MALLOC:
610 	case MD_PRELOAD:
611 	case MD_SWAP:
612 	default:
613 		hasgiant = 0;
614 		break;
615 	}
616 
617 	for (;;) {
618 		mtx_lock(&sc->queue_mtx);
619 		bp = bioq_first(&sc->bio_queue);
620 		if (bp)
621 			bioq_remove(&sc->bio_queue, bp);
622 		if (!bp) {
623 			if (sc->flags & MD_SHUTDOWN) {
624 				mtx_unlock(&sc->queue_mtx);
625 				sc->procp = NULL;
626 				wakeup(&sc->procp);
627 				if (hasgiant)
628 					mtx_unlock(&Giant);
629 				kthread_exit(0);
630 			}
631 			msleep(sc, &sc->queue_mtx, PRIBIO | PDROP, "mdwait", 0);
632 			continue;
633 		}
634 		mtx_unlock(&sc->queue_mtx);
635 		if (bp->bio_cmd == BIO_GETATTR) {
636 			if (sc->fwsectors && sc->fwheads &&
637 			    (g_handleattr_int(bp, "GEOM::fwsectors",
638 			    sc->fwsectors) ||
639 			    g_handleattr_int(bp, "GEOM::fwheads",
640 			    sc->fwheads)))
641 				error = -1;
642 			else
643 				error = EOPNOTSUPP;
644 		} else {
645 			switch (sc->type) {
646 			case MD_MALLOC:
647 				error = mdstart_malloc(sc, bp);
648 				break;
649 			case MD_PRELOAD:
650 				error = mdstart_preload(sc, bp);
651 				break;
652 			case MD_VNODE:
653 				error = mdstart_vnode(sc, bp);
654 				break;
655 			case MD_SWAP:
656 				error = mdstart_swap(sc, bp);
657 				break;
658 			default:
659 				panic("Impossible md(type)");
660 				break;
661 			}
662 		}
663 
664 		if (error != -1) {
665 			bp->bio_completed = bp->bio_length;
666 			g_io_deliver(bp, error);
667 		}
668 	}
669 }
670 
671 static struct md_s *
672 mdfind(int unit)
673 {
674 	struct md_s *sc;
675 
676 	/* XXX: LOCK(unique unit numbers) */
677 	LIST_FOREACH(sc, &md_softc_list, list) {
678 		if (sc->unit == unit)
679 			break;
680 	}
681 	/* XXX: UNLOCK(unique unit numbers) */
682 	return (sc);
683 }
684 
685 static struct md_s *
686 mdnew(int unit)
687 {
688 	struct md_s *sc;
689 	int error, max = -1;
690 
691 	/* XXX: LOCK(unique unit numbers) */
692 	LIST_FOREACH(sc, &md_softc_list, list) {
693 		if (sc->unit == unit) {
694 			/* XXX: UNLOCK(unique unit numbers) */
695 			return (NULL);
696 		}
697 		if (sc->unit > max)
698 			max = sc->unit;
699 	}
700 	if (unit == -1)
701 		unit = max + 1;
702 	sc = (struct md_s *)malloc(sizeof *sc, M_MD, M_WAITOK | M_ZERO);
703 	sc->unit = unit;
704 	bioq_init(&sc->bio_queue);
705 	mtx_init(&sc->queue_mtx, "md bio queue", NULL, MTX_DEF);
706 	sprintf(sc->name, "md%d", unit);
707 	error = kthread_create(md_kthread, sc, &sc->procp, 0, 0,"%s", sc->name);
708 	if (error) {
709 		free(sc, M_MD);
710 		return (NULL);
711 	}
712 	LIST_INSERT_HEAD(&md_softc_list, sc, list);
713 	/* XXX: UNLOCK(unique unit numbers) */
714 	return (sc);
715 }
716 
717 static void
718 mdinit(struct md_s *sc)
719 {
720 
721 	struct g_geom *gp;
722 	struct g_provider *pp;
723 
724 	DROP_GIANT();
725 	g_topology_lock();
726 	gp = g_new_geomf(&g_md_class, "md%d", sc->unit);
727 	gp->start = g_md_start;
728 	gp->access = g_md_access;
729 	gp->softc = sc;
730 	pp = g_new_providerf(gp, "md%d", sc->unit);
731 	pp->mediasize = (off_t)sc->nsect * sc->secsize;
732 	pp->sectorsize = sc->secsize;
733 	sc->gp = gp;
734 	sc->pp = pp;
735 	g_error_provider(pp, 0);
736 	g_topology_unlock();
737 	PICKUP_GIANT();
738 }
739 
740 /*
741  * XXX: we should check that the range they feed us is mapped.
742  * XXX: we should implement read-only.
743  */
744 
745 static int
746 mdcreate_preload(struct md_ioctl *mdio)
747 {
748 	struct md_s *sc;
749 
750 	if (mdio->md_size == 0)
751 		return (EINVAL);
752 	if (mdio->md_options & ~(MD_AUTOUNIT))
753 		return (EINVAL);
754 	if (mdio->md_options & MD_AUTOUNIT) {
755 		sc = mdnew(-1);
756 		if (sc == NULL)
757 			return (ENOMEM);
758 		mdio->md_unit = sc->unit;
759 	} else {
760 		sc = mdnew(mdio->md_unit);
761 		if (sc == NULL)
762 			return (EBUSY);
763 	}
764 	sc->type = MD_PRELOAD;
765 	sc->secsize = DEV_BSIZE;
766 	sc->nsect = mdio->md_size;
767 	sc->flags = mdio->md_options & MD_FORCE;
768 	/* Cast to pointer size, then to pointer to avoid warning */
769 	sc->pl_ptr = (u_char *)(uintptr_t)mdio->md_base;
770 	sc->pl_len = (mdio->md_size << DEV_BSHIFT);
771 	mdinit(sc);
772 	return (0);
773 }
774 
775 
776 static int
777 mdcreate_malloc(struct md_ioctl *mdio)
778 {
779 	struct md_s *sc;
780 	off_t u;
781 	uintptr_t sp;
782 	int error;
783 
784 	error = 0;
785 	if (mdio->md_size == 0)
786 		return (EINVAL);
787 	if (mdio->md_options & ~(MD_AUTOUNIT | MD_COMPRESS | MD_RESERVE))
788 		return (EINVAL);
789 	if (mdio->md_secsize != 0 && !powerof2(mdio->md_secsize))
790 		return (EINVAL);
791 	/* Compression doesn't make sense if we have reserved space */
792 	if (mdio->md_options & MD_RESERVE)
793 		mdio->md_options &= ~MD_COMPRESS;
794 	if (mdio->md_options & MD_AUTOUNIT) {
795 		sc = mdnew(-1);
796 		if (sc == NULL)
797 			return (ENOMEM);
798 		mdio->md_unit = sc->unit;
799 	} else {
800 		sc = mdnew(mdio->md_unit);
801 		if (sc == NULL)
802 			return (EBUSY);
803 	}
804 	sc->type = MD_MALLOC;
805 	if (mdio->md_secsize != 0)
806 		sc->secsize = mdio->md_secsize;
807 	else
808 		sc->secsize = DEV_BSIZE;
809 	if (mdio->md_fwsectors != 0)
810 		sc->fwsectors = mdio->md_fwsectors;
811 	if (mdio->md_fwheads != 0)
812 		sc->fwheads = mdio->md_fwheads;
813 	sc->nsect = mdio->md_size;
814 	sc->nsect /= (sc->secsize / DEV_BSIZE);
815 	sc->flags = mdio->md_options & (MD_COMPRESS | MD_FORCE);
816 	sc->indir = dimension(sc->nsect);
817 	sc->uma = uma_zcreate(sc->name, sc->secsize,
818 	    NULL, NULL, NULL, NULL, 0x1ff, 0);
819 	if (mdio->md_options & MD_RESERVE) {
820 		for (u = 0; u < sc->nsect; u++) {
821 			sp = (uintptr_t) uma_zalloc(sc->uma, M_NOWAIT | M_ZERO);
822 			if (sp != 0)
823 				error = s_write(sc->indir, u, sp);
824 			else
825 				error = ENOMEM;
826 			if (error)
827 				break;
828 		}
829 	}
830 	if (error)  {
831 		mddestroy(sc, NULL);
832 		return (error);
833 	}
834 	mdinit(sc);
835 	if (!(mdio->md_options & MD_RESERVE))
836 		sc->pp->flags |= G_PF_CANDELETE;
837 	return (0);
838 }
839 
840 
841 static int
842 mdsetcred(struct md_s *sc, struct ucred *cred)
843 {
844 	char *tmpbuf;
845 	int error = 0;
846 
847 	/*
848 	 * Set credits in our softc
849 	 */
850 
851 	if (sc->cred)
852 		crfree(sc->cred);
853 	sc->cred = crhold(cred);
854 
855 	/*
856 	 * Horrible kludge to establish credentials for NFS  XXX.
857 	 */
858 
859 	if (sc->vnode) {
860 		struct uio auio;
861 		struct iovec aiov;
862 
863 		tmpbuf = malloc(sc->secsize, M_TEMP, M_WAITOK);
864 		bzero(&auio, sizeof(auio));
865 
866 		aiov.iov_base = tmpbuf;
867 		aiov.iov_len = sc->secsize;
868 		auio.uio_iov = &aiov;
869 		auio.uio_iovcnt = 1;
870 		auio.uio_offset = 0;
871 		auio.uio_rw = UIO_READ;
872 		auio.uio_segflg = UIO_SYSSPACE;
873 		auio.uio_resid = aiov.iov_len;
874 		vn_lock(sc->vnode, LK_EXCLUSIVE | LK_RETRY, curthread);
875 		error = VOP_READ(sc->vnode, &auio, 0, sc->cred);
876 		VOP_UNLOCK(sc->vnode, 0, curthread);
877 		free(tmpbuf, M_TEMP);
878 	}
879 	return (error);
880 }
881 
882 static int
883 mdcreate_vnode(struct md_ioctl *mdio, struct thread *td)
884 {
885 	struct md_s *sc;
886 	struct vattr vattr;
887 	struct nameidata nd;
888 	int error, flags;
889 
890 	flags = FREAD|FWRITE;
891 	NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, mdio->md_file, td);
892 	error = vn_open(&nd, &flags, 0, -1);
893 	if (error) {
894 		if (error != EACCES && error != EPERM && error != EROFS)
895 			return (error);
896 		flags &= ~FWRITE;
897 		NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, mdio->md_file, td);
898 		error = vn_open(&nd, &flags, 0, -1);
899 		if (error)
900 			return (error);
901 	}
902 	NDFREE(&nd, NDF_ONLY_PNBUF);
903 	if (nd.ni_vp->v_type != VREG ||
904 	    (error = VOP_GETATTR(nd.ni_vp, &vattr, td->td_ucred, td))) {
905 		VOP_UNLOCK(nd.ni_vp, 0, td);
906 		(void) vn_close(nd.ni_vp, flags, td->td_ucred, td);
907 		return (error ? error : EINVAL);
908 	}
909 	VOP_UNLOCK(nd.ni_vp, 0, td);
910 
911 	if (mdio->md_options & MD_AUTOUNIT) {
912 		sc = mdnew(-1);
913 		mdio->md_unit = sc->unit;
914 	} else {
915 		sc = mdnew(mdio->md_unit);
916 	}
917 	if (sc == NULL) {
918 		(void) vn_close(nd.ni_vp, flags, td->td_ucred, td);
919 		return (EBUSY);
920 	}
921 
922 	if (mdio->md_fwsectors != 0)
923 		sc->fwsectors = mdio->md_fwsectors;
924 	if (mdio->md_fwheads != 0)
925 		sc->fwheads = mdio->md_fwheads;
926 	sc->type = MD_VNODE;
927 	sc->flags = mdio->md_options & (MD_FORCE | MD_ASYNC);
928 	if (!(flags & FWRITE))
929 		sc->flags |= MD_READONLY;
930 	sc->secsize = DEV_BSIZE;
931 	sc->vnode = nd.ni_vp;
932 
933 	/*
934 	 * If the size is specified, override the file attributes.
935 	 */
936 	if (mdio->md_size)
937 		sc->nsect = mdio->md_size;
938 	else
939 		sc->nsect = vattr.va_size / sc->secsize; /* XXX: round up ? */
940 	if (sc->nsect == 0) {
941 		mddestroy(sc, td);
942 		return (EINVAL);
943 	}
944 	error = mdsetcred(sc, td->td_ucred);
945 	if (error) {
946 		mddestroy(sc, td);
947 		return (error);
948 	}
949 	mdinit(sc);
950 	return (0);
951 }
952 
953 static void
954 md_zapit(void *p, int cancel)
955 {
956 	if (cancel)
957 		return;
958 	g_wither_geom(p, ENXIO);
959 }
960 
961 static int
962 mddestroy(struct md_s *sc, struct thread *td)
963 {
964 
965 	GIANT_REQUIRED;
966 
967 	mtx_destroy(&sc->queue_mtx);
968 	if (sc->gp) {
969 		sc->gp->softc = NULL;
970 		g_waitfor_event(md_zapit, sc->gp, M_WAITOK, sc->gp, NULL);
971 		sc->gp = NULL;
972 		sc->pp = NULL;
973 	}
974 	sc->flags |= MD_SHUTDOWN;
975 	wakeup(sc);
976 	while (sc->procp != NULL)
977 		tsleep(&sc->procp, PRIBIO, "mddestroy", hz / 10);
978 	if (sc->vnode != NULL)
979 		(void)vn_close(sc->vnode, sc->flags & MD_READONLY ?
980 		    FREAD : (FREAD|FWRITE), sc->cred, td);
981 	if (sc->cred != NULL)
982 		crfree(sc->cred);
983 	if (sc->object != NULL) {
984 		vm_object_deallocate(sc->object);
985 	}
986 	if (sc->indir)
987 		destroy_indir(sc, sc->indir);
988 	if (sc->uma)
989 		uma_zdestroy(sc->uma);
990 
991 	/* XXX: LOCK(unique unit numbers) */
992 	LIST_REMOVE(sc, list);
993 	/* XXX: UNLOCK(unique unit numbers) */
994 	free(sc, M_MD);
995 	return (0);
996 }
997 
998 static int
999 mdcreate_swap(struct md_ioctl *mdio, struct thread *td)
1000 {
1001 	int error;
1002 	struct md_s *sc;
1003 
1004 	GIANT_REQUIRED;
1005 
1006 	if (mdio->md_options & MD_AUTOUNIT) {
1007 		sc = mdnew(-1);
1008 		mdio->md_unit = sc->unit;
1009 	} else {
1010 		sc = mdnew(mdio->md_unit);
1011 	}
1012 	if (sc == NULL)
1013 		return (EBUSY);
1014 
1015 	sc->type = MD_SWAP;
1016 
1017 	/*
1018 	 * Range check.  Disallow negative sizes or any size less then the
1019 	 * size of a page.  Then round to a page.
1020 	 */
1021 
1022 	if (mdio->md_size == 0) {
1023 		mddestroy(sc, td);
1024 		return (EDOM);
1025 	}
1026 
1027 	/*
1028 	 * Allocate an OBJT_SWAP object.
1029 	 *
1030 	 * sc_nsect is in units of DEV_BSIZE.
1031 	 * sc_npage is in units of PAGE_SIZE.
1032 	 *
1033 	 * Note the truncation.
1034 	 */
1035 
1036 	sc->secsize = DEV_BSIZE;
1037 	sc->npage = mdio->md_size / (PAGE_SIZE / DEV_BSIZE);
1038 	sc->nsect = sc->npage * (PAGE_SIZE / DEV_BSIZE);
1039 	if (mdio->md_fwsectors != 0)
1040 		sc->fwsectors = mdio->md_fwsectors;
1041 	if (mdio->md_fwheads != 0)
1042 		sc->fwheads = mdio->md_fwheads;
1043 	sc->object = vm_pager_allocate(OBJT_SWAP, NULL, PAGE_SIZE *
1044 	    (vm_offset_t)sc->npage, VM_PROT_DEFAULT, 0);
1045 	sc->flags = mdio->md_options & MD_FORCE;
1046 	if (mdio->md_options & MD_RESERVE) {
1047 		if (swap_pager_reserve(sc->object, 0, sc->npage) < 0) {
1048 			vm_object_deallocate(sc->object);
1049 			sc->object = NULL;
1050 			mddestroy(sc, td);
1051 			return (EDOM);
1052 		}
1053 	}
1054 	error = mdsetcred(sc, td->td_ucred);
1055 	if (error) {
1056 		mddestroy(sc, td);
1057 		return (error);
1058 	}
1059 	mdinit(sc);
1060 	if (!(mdio->md_options & MD_RESERVE))
1061 		sc->pp->flags |= G_PF_CANDELETE;
1062 	return (0);
1063 }
1064 
1065 static int
1066 mddetach(int unit, struct thread *td)
1067 {
1068 	struct md_s *sc;
1069 
1070 	sc = mdfind(unit);
1071 	if (sc == NULL)
1072 		return (ENOENT);
1073 	if (sc->opencount != 0 && !(sc->flags & MD_FORCE))
1074 		return (EBUSY);
1075 	switch(sc->type) {
1076 	case MD_VNODE:
1077 	case MD_SWAP:
1078 	case MD_MALLOC:
1079 	case MD_PRELOAD:
1080 		return (mddestroy(sc, td));
1081 	default:
1082 		return (EOPNOTSUPP);
1083 	}
1084 }
1085 
1086 static int
1087 mdctlioctl(dev_t dev, u_long cmd, caddr_t addr, int flags, struct thread *td)
1088 {
1089 	struct md_ioctl *mdio;
1090 	struct md_s *sc;
1091 	int i;
1092 
1093 	if (md_debug)
1094 		printf("mdctlioctl(%s %lx %p %x %p)\n",
1095 			devtoname(dev), cmd, addr, flags, td);
1096 
1097 	/*
1098 	 * We assert the version number in the individual ioctl
1099 	 * handlers instead of out here because (a) it is possible we
1100 	 * may add another ioctl in the future which doesn't read an
1101 	 * mdio, and (b) the correct return value for an unknown ioctl
1102 	 * is ENOIOCTL, not EINVAL.
1103 	 */
1104 	mdio = (struct md_ioctl *)addr;
1105 	switch (cmd) {
1106 	case MDIOCATTACH:
1107 		if (mdio->md_version != MDIOVERSION)
1108 			return (EINVAL);
1109 		switch (mdio->md_type) {
1110 		case MD_MALLOC:
1111 			return (mdcreate_malloc(mdio));
1112 		case MD_PRELOAD:
1113 			return (mdcreate_preload(mdio));
1114 		case MD_VNODE:
1115 			return (mdcreate_vnode(mdio, td));
1116 		case MD_SWAP:
1117 			return (mdcreate_swap(mdio, td));
1118 		default:
1119 			return (EINVAL);
1120 		}
1121 	case MDIOCDETACH:
1122 		if (mdio->md_version != MDIOVERSION)
1123 			return (EINVAL);
1124 		if (mdio->md_file != NULL || mdio->md_size != 0 ||
1125 		    mdio->md_options != 0)
1126 			return (EINVAL);
1127 		return (mddetach(mdio->md_unit, td));
1128 	case MDIOCQUERY:
1129 		if (mdio->md_version != MDIOVERSION)
1130 			return (EINVAL);
1131 		sc = mdfind(mdio->md_unit);
1132 		if (sc == NULL)
1133 			return (ENOENT);
1134 		mdio->md_type = sc->type;
1135 		mdio->md_options = sc->flags;
1136 		switch (sc->type) {
1137 		case MD_MALLOC:
1138 			mdio->md_size = sc->nsect;
1139 			break;
1140 		case MD_PRELOAD:
1141 			mdio->md_size = sc->nsect;
1142 			mdio->md_base = (uint64_t)(intptr_t)sc->pl_ptr;
1143 			break;
1144 		case MD_SWAP:
1145 			mdio->md_size = sc->nsect;
1146 			break;
1147 		case MD_VNODE:
1148 			mdio->md_size = sc->nsect;
1149 			/* XXX fill this in */
1150 			mdio->md_file = NULL;
1151 			break;
1152 		}
1153 		return (0);
1154 	case MDIOCLIST:
1155 		i = 1;
1156 		LIST_FOREACH(sc, &md_softc_list, list) {
1157 			if (i == MDNPAD - 1)
1158 				mdio->md_pad[i] = -1;
1159 			else
1160 				mdio->md_pad[i++] = sc->unit;
1161 		}
1162 		mdio->md_pad[0] = i - 1;
1163 		return (0);
1164 	default:
1165 		return (ENOIOCTL);
1166 	};
1167 	return (ENOIOCTL);
1168 }
1169 
1170 static void
1171 md_preloaded(u_char *image, unsigned length)
1172 {
1173 	struct md_s *sc;
1174 
1175 	sc = mdnew(-1);
1176 	if (sc == NULL)
1177 		return;
1178 	sc->type = MD_PRELOAD;
1179 	sc->secsize = DEV_BSIZE;
1180 	sc->nsect = length / DEV_BSIZE;
1181 	sc->pl_ptr = image;
1182 	sc->pl_len = length;
1183 	if (sc->unit == 0)
1184 		mdrootready = 1;
1185 	mdinit(sc);
1186 }
1187 
1188 static void
1189 md_drvinit(struct g_class *mp __unused)
1190 {
1191 
1192 	caddr_t mod;
1193 	caddr_t c;
1194 	u_char *ptr, *name, *type;
1195 	unsigned len;
1196 
1197 	mod = NULL;
1198 	g_topology_unlock();
1199 #ifdef MD_ROOT_SIZE
1200 	md_preloaded(mfs_root, MD_ROOT_SIZE*1024);
1201 #endif
1202 	while ((mod = preload_search_next_name(mod)) != NULL) {
1203 		name = (char *)preload_search_info(mod, MODINFO_NAME);
1204 		type = (char *)preload_search_info(mod, MODINFO_TYPE);
1205 		if (name == NULL)
1206 			continue;
1207 		if (type == NULL)
1208 			continue;
1209 		if (strcmp(type, "md_image") && strcmp(type, "mfs_root"))
1210 			continue;
1211 		c = preload_search_info(mod, MODINFO_ADDR);
1212 		ptr = *(u_char **)c;
1213 		c = preload_search_info(mod, MODINFO_SIZE);
1214 		len = *(size_t *)c;
1215 		printf("%s%d: Preloaded image <%s> %d bytes at %p\n",
1216 		    MD_NAME, mdunits, name, len, ptr);
1217 		md_preloaded(ptr, len);
1218 	}
1219 	status_dev = make_dev(&mdctl_cdevsw, 0xffff00ff, UID_ROOT, GID_WHEEL,
1220 	    0600, MDCTL_NAME);
1221 	g_topology_lock();
1222 }
1223 
1224 static int
1225 md_modevent(module_t mod, int type, void *data)
1226 {
1227 	int error;
1228 	struct md_s *sc;
1229 
1230 	switch (type) {
1231 	case MOD_LOAD:
1232 		break;
1233 	case MOD_UNLOAD:
1234 		LIST_FOREACH(sc, &md_softc_list, list) {
1235 			error = mddetach(sc->unit, curthread);
1236 			if (error != 0)
1237 				return (error);
1238 		}
1239 		if (status_dev)
1240 			destroy_dev(status_dev);
1241 		status_dev = 0;
1242 		break;
1243 	default:
1244 		break;
1245 	}
1246 	return (0);
1247 }
1248 
1249 static moduledata_t md_mod = {
1250 	MD_NAME,
1251 	md_modevent,
1252 	NULL
1253 };
1254 DECLARE_MODULE(md, md_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);
1255 MODULE_VERSION(md, MD_MODVER);
1256 
1257 
1258 #ifdef MD_ROOT
1259 static void
1260 md_takeroot(void *junk)
1261 {
1262 	if (mdrootready)
1263 		rootdevnames[0] = "ufs:/dev/md0";
1264 }
1265 
1266 SYSINIT(md_root, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, md_takeroot, NULL);
1267 #endif /* MD_ROOT */
1268