xref: /freebsd/sys/geom/linux_lvm/g_linux_lvm.c (revision e30a620063b852f51e8955dd6f993680d5da6223)
1 /*-
2  * Copyright (c) 2008 Andrew Thompson <thompsa@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/ctype.h>
31 #include <sys/param.h>
32 #include <sys/bio.h>
33 #include <sys/kernel.h>
34 #include <sys/limits.h>
35 #include <sys/malloc.h>
36 #include <sys/queue.h>
37 #include <sys/sysctl.h>
38 #include <sys/systm.h>
39 
40 #include <geom/geom.h>
41 #include <sys/endian.h>
42 
43 #include <geom/linux_lvm/g_linux_lvm.h>
44 
45 FEATURE(geom_linux_lvm, "GEOM Linux LVM partitioning support");
46 
47 /* Declare malloc(9) label */
48 static MALLOC_DEFINE(M_GLLVM, "gllvm", "GEOM_LINUX_LVM Data");
49 
50 /* GEOM class methods */
51 static g_access_t g_llvm_access;
52 static g_init_t g_llvm_init;
53 static g_orphan_t g_llvm_orphan;
54 static g_orphan_t g_llvm_taste_orphan;
55 static g_start_t g_llvm_start;
56 static g_taste_t g_llvm_taste;
57 static g_ctl_destroy_geom_t g_llvm_destroy_geom;
58 
59 static void	g_llvm_done(struct bio *);
60 static void	g_llvm_remove_disk(struct g_llvm_vg *, struct g_consumer *);
61 static int	g_llvm_activate_lv(struct g_llvm_vg *, struct g_llvm_lv *);
62 static int	g_llvm_add_disk(struct g_llvm_vg *, struct g_provider *, char *);
63 static void	g_llvm_free_vg(struct g_llvm_vg *);
64 static int	g_llvm_destroy(struct g_llvm_vg *, int);
65 static int	g_llvm_read_label(struct g_consumer *, struct g_llvm_label *);
66 static int	g_llvm_read_md(struct g_consumer *, struct g_llvm_metadata *,
67 		    struct g_llvm_label *);
68 
69 static int	llvm_label_decode(const u_char *, struct g_llvm_label *, int);
70 static int	llvm_md_decode(const u_char *, struct g_llvm_metadata *,
71 		    struct g_llvm_label *);
72 static int	llvm_textconf_decode(u_char *, int,
73 		    struct g_llvm_metadata *);
74 static int	llvm_textconf_decode_pv(char **, char *, struct g_llvm_vg *);
75 static int	llvm_textconf_decode_lv(char **, char *, struct g_llvm_vg *);
76 static int	llvm_textconf_decode_sg(char **, char *, struct g_llvm_lv *);
77 
78 SYSCTL_DECL(_kern_geom);
79 SYSCTL_NODE(_kern_geom, OID_AUTO, linux_lvm, CTLFLAG_RW, 0,
80     "GEOM_LINUX_LVM stuff");
81 static u_int g_llvm_debug = 0;
82 SYSCTL_UINT(_kern_geom_linux_lvm, OID_AUTO, debug, CTLFLAG_RWTUN, &g_llvm_debug, 0,
83     "Debug level");
84 
85 LIST_HEAD(, g_llvm_vg) vg_list;
86 
87 /*
88  * Called to notify geom when it's been opened, and for what intent
89  */
90 static int
91 g_llvm_access(struct g_provider *pp, int dr, int dw, int de)
92 {
93 	struct g_consumer *c;
94 	struct g_llvm_vg *vg;
95 	struct g_geom *gp;
96 	int error;
97 
98 	KASSERT(pp != NULL, ("%s: NULL provider", __func__));
99 	gp = pp->geom;
100 	KASSERT(gp != NULL, ("%s: NULL geom", __func__));
101 	vg = gp->softc;
102 
103 	if (vg == NULL) {
104 		/* It seems that .access can be called with negative dr,dw,dx
105 		 * in this case but I want to check for myself */
106 		G_LLVM_DEBUG(0, "access(%d, %d, %d) for %s",
107 		    dr, dw, de, pp->name);
108 
109 		/* This should only happen when geom is withered so
110 		 * allow only negative requests */
111 		KASSERT(dr <= 0 && dw <= 0 && de <= 0,
112 		    ("%s: Positive access for %s", __func__, pp->name));
113 		if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
114 			G_LLVM_DEBUG(0,
115 			    "Device %s definitely destroyed", pp->name);
116 		return (0);
117 	}
118 
119 	/* Grab an exclusive bit to propagate on our consumers on first open */
120 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
121 		de++;
122 	/* ... drop it on close */
123 	if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
124 		de--;
125 
126 	error = ENXIO;
127 	LIST_FOREACH(c, &gp->consumer, consumer) {
128 		KASSERT(c != NULL, ("%s: consumer is NULL", __func__));
129 		error = g_access(c, dr, dw, de);
130 		if (error != 0) {
131 			struct g_consumer *c2;
132 
133 			/* Backout earlier changes */
134 			LIST_FOREACH(c2, &gp->consumer, consumer) {
135 				if (c2 == c) /* all eariler components fixed */
136 					return (error);
137 				g_access(c2, -dr, -dw, -de);
138 			}
139 		}
140 	}
141 
142 	return (error);
143 }
144 
145 /*
146  * Dismantle bio_queue and destroy its components
147  */
148 static void
149 bioq_dismantle(struct bio_queue_head *bq)
150 {
151 	struct bio *b;
152 
153 	for (b = bioq_first(bq); b != NULL; b = bioq_first(bq)) {
154 		bioq_remove(bq, b);
155 		g_destroy_bio(b);
156 	}
157 }
158 
159 /*
160  * GEOM .done handler
161  * Can't use standard handler because one requested IO may
162  * fork into additional data IOs
163  */
164 static void
165 g_llvm_done(struct bio *b)
166 {
167 	struct bio *parent_b;
168 
169 	parent_b = b->bio_parent;
170 
171 	if (b->bio_error != 0) {
172 		G_LLVM_DEBUG(0, "Error %d for offset=%ju, length=%ju on %s",
173 		    b->bio_error, b->bio_offset, b->bio_length,
174 		    b->bio_to->name);
175 		if (parent_b->bio_error == 0)
176 			parent_b->bio_error = b->bio_error;
177 	}
178 
179 	parent_b->bio_inbed++;
180 	parent_b->bio_completed += b->bio_completed;
181 
182 	if (parent_b->bio_children == parent_b->bio_inbed) {
183 		parent_b->bio_completed = parent_b->bio_length;
184 		g_io_deliver(parent_b, parent_b->bio_error);
185 	}
186 	g_destroy_bio(b);
187 }
188 
189 static void
190 g_llvm_start(struct bio *bp)
191 {
192 	struct g_provider *pp;
193 	struct g_llvm_vg *vg;
194 	struct g_llvm_pv *pv;
195 	struct g_llvm_lv *lv;
196 	struct g_llvm_segment *sg;
197 	struct bio *cb;
198 	struct bio_queue_head bq;
199 	size_t chunk_size;
200 	off_t offset, length;
201 	char *addr;
202 	u_int count;
203 
204 	pp = bp->bio_to;
205 	lv = pp->private;
206 	vg = pp->geom->softc;
207 
208 	switch (bp->bio_cmd) {
209 	case BIO_READ:
210 	case BIO_WRITE:
211 	case BIO_DELETE:
212 	/* XXX BIO_GETATTR allowed? */
213 		break;
214 	default:
215 		g_io_deliver(bp, EOPNOTSUPP);
216 		return;
217 	}
218 
219 	bioq_init(&bq);
220 
221 	chunk_size = vg->vg_extentsize;
222 	addr = bp->bio_data;
223 	offset = bp->bio_offset;	/* virtual offset and length */
224 	length = bp->bio_length;
225 
226 	while (length > 0) {
227 		size_t chunk_index, in_chunk_offset, in_chunk_length;
228 
229 		pv = NULL;
230 		cb = g_clone_bio(bp);
231 		if (cb == NULL) {
232 			bioq_dismantle(&bq);
233 			if (bp->bio_error == 0)
234 				bp->bio_error = ENOMEM;
235 			g_io_deliver(bp, bp->bio_error);
236 			return;
237 		}
238 
239 		/* get the segment and the pv */
240 		if (lv->lv_sgcount == 1) {
241 			/* skip much of the calculations for a single sg */
242 			chunk_index = 0;
243 			in_chunk_offset = 0;
244 			in_chunk_length = length;
245 			sg = lv->lv_firstsg;
246 			pv = sg->sg_pv;
247 			cb->bio_offset = offset + sg->sg_pvoffset;
248 		} else {
249 			chunk_index = offset / chunk_size; /* round downwards */
250 			in_chunk_offset = offset % chunk_size;
251 			in_chunk_length =
252 			    min(length, chunk_size - in_chunk_offset);
253 
254 			/* XXX could be faster */
255 			LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
256 				if (chunk_index >= sg->sg_start &&
257 				    chunk_index <= sg->sg_end) {
258 					/* adjust chunk index for sg start */
259 					chunk_index -= sg->sg_start;
260 					pv = sg->sg_pv;
261 					break;
262 				}
263 			}
264 			cb->bio_offset =
265 			    (off_t)chunk_index * (off_t)chunk_size
266 			    + in_chunk_offset + sg->sg_pvoffset;
267 		}
268 
269 		KASSERT(pv != NULL, ("Can't find PV for chunk %zu",
270 		    chunk_index));
271 
272 		cb->bio_to = pv->pv_gprov;
273 		cb->bio_done = g_llvm_done;
274 		cb->bio_length = in_chunk_length;
275 		cb->bio_data = addr;
276 		cb->bio_caller1 = pv;
277 		bioq_disksort(&bq, cb);
278 
279 		G_LLVM_DEBUG(5,
280 		    "Mapped %s(%ju, %ju) on %s to %zu(%zu,%zu) @ %s:%ju",
281 		    bp->bio_cmd == BIO_READ ? "R" : "W",
282 		    offset, length, lv->lv_name,
283 		    chunk_index, in_chunk_offset, in_chunk_length,
284 		    pv->pv_name, cb->bio_offset);
285 
286 		addr += in_chunk_length;
287 		length -= in_chunk_length;
288 		offset += in_chunk_length;
289 	}
290 
291 	/* Fire off bio's here */
292 	count = 0;
293 	for (cb = bioq_first(&bq); cb != NULL; cb = bioq_first(&bq)) {
294 		bioq_remove(&bq, cb);
295 		pv = cb->bio_caller1;
296 		cb->bio_caller1 = NULL;
297 		G_LLVM_DEBUG(6, "firing bio to %s, offset=%ju, length=%ju",
298 		    cb->bio_to->name, cb->bio_offset, cb->bio_length);
299 		g_io_request(cb, pv->pv_gcons);
300 		count++;
301 	}
302 	if (count == 0) { /* We handled everything locally */
303 		bp->bio_completed = bp->bio_length;
304 		g_io_deliver(bp, 0);
305 	}
306 }
307 
308 static void
309 g_llvm_remove_disk(struct g_llvm_vg *vg, struct g_consumer *cp)
310 {
311 	struct g_llvm_pv *pv;
312 	struct g_llvm_lv *lv;
313 	struct g_llvm_segment *sg;
314 	int found;
315 
316 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
317 	pv = (struct g_llvm_pv *)cp->private;
318 
319 	G_LLVM_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
320 	    pv->pv_name);
321 
322 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
323 		/* Find segments that map to this disk */
324 		found = 0;
325 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
326 			if (sg->sg_pv == pv) {
327 				sg->sg_pv = NULL;
328 				lv->lv_sgactive--;
329 				found = 1;
330 				break;
331 			}
332 		}
333 		if (found) {
334 			G_LLVM_DEBUG(0, "Device %s removed.",
335 			    lv->lv_gprov->name);
336 			g_orphan_provider(lv->lv_gprov, ENXIO);
337 			lv->lv_gprov = NULL;
338 		}
339 	}
340 
341 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
342 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
343 	g_detach(cp);
344 	g_destroy_consumer(cp);
345 }
346 
347 static void
348 g_llvm_orphan(struct g_consumer *cp)
349 {
350 	struct g_llvm_vg *vg;
351 	struct g_geom *gp;
352 
353 	g_topology_assert();
354 	gp = cp->geom;
355 	vg = gp->softc;
356 	if (vg == NULL)
357 		return;
358 
359 	g_llvm_remove_disk(vg, cp);
360 	g_llvm_destroy(vg, 1);
361 }
362 
363 static int
364 g_llvm_activate_lv(struct g_llvm_vg *vg, struct g_llvm_lv *lv)
365 {
366 	struct g_geom *gp;
367 	struct g_provider *pp;
368 
369 	g_topology_assert();
370 
371 	KASSERT(lv->lv_sgactive == lv->lv_sgcount, ("segment missing"));
372 
373 	gp = vg->vg_geom;
374 	pp = g_new_providerf(gp, "linux_lvm/%s-%s", vg->vg_name, lv->lv_name);
375 	pp->mediasize = vg->vg_extentsize * (off_t)lv->lv_extentcount;
376 	pp->sectorsize = vg->vg_sectorsize;
377 	g_error_provider(pp, 0);
378 	lv->lv_gprov = pp;
379 	pp->private = lv;
380 
381 	G_LLVM_DEBUG(1, "Created %s, %juM", pp->name,
382 	    pp->mediasize / (1024*1024));
383 
384 	return (0);
385 }
386 
387 static int
388 g_llvm_add_disk(struct g_llvm_vg *vg, struct g_provider *pp, char *uuid)
389 {
390 	struct g_geom *gp;
391 	struct g_consumer *cp, *fcp;
392 	struct g_llvm_pv *pv;
393 	struct g_llvm_lv *lv;
394 	struct g_llvm_segment *sg;
395 	int error;
396 
397 	g_topology_assert();
398 
399 	LIST_FOREACH(pv, &vg->vg_pvs, pv_next) {
400 		if (strcmp(pv->pv_uuid, uuid) == 0)
401 			break;	/* found it */
402 	}
403 	if (pv == NULL) {
404 		G_LLVM_DEBUG(3, "uuid %s not found in pv list", uuid);
405 		return (ENOENT);
406 	}
407 	if (pv->pv_gprov != NULL) {
408 		G_LLVM_DEBUG(0, "disk %s already initialised in %s",
409 		    pv->pv_name, vg->vg_name);
410 		return (EEXIST);
411 	}
412 
413 	pv->pv_start *= vg->vg_sectorsize;
414 	gp = vg->vg_geom;
415 	fcp = LIST_FIRST(&gp->consumer);
416 
417 	cp = g_new_consumer(gp);
418 	error = g_attach(cp, pp);
419 	G_LLVM_DEBUG(1, "Attached %s to %s at offset %ju",
420 	    pp->name, pv->pv_name, pv->pv_start);
421 
422 	if (error != 0) {
423 		G_LLVM_DEBUG(0, "cannot attach %s to %s",
424 		    pp->name, vg->vg_name);
425 		g_destroy_consumer(cp);
426 		return (error);
427 	}
428 
429 	if (fcp != NULL) {
430 		if (fcp->provider->sectorsize != pp->sectorsize) {
431 			G_LLVM_DEBUG(0, "Provider %s of %s has invalid "
432 			    "sector size (%d)", pp->name, vg->vg_name,
433 			    pp->sectorsize);
434 			return (EINVAL);
435 		}
436 		if (fcp->acr > 0 || fcp->acw || fcp->ace > 0) {
437 			/* Replicate access permissions from first "live"
438 			 * consumer to the new one */
439 			error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
440 			if (error != 0) {
441 				g_detach(cp);
442 				g_destroy_consumer(cp);
443 				return (error);
444 			}
445 		}
446 	}
447 
448 	cp->private = pv;
449 	pv->pv_gcons = cp;
450 	pv->pv_gprov = pp;
451 
452 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
453 		/* Find segments that map to this disk */
454 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
455 			if (strcmp(sg->sg_pvname, pv->pv_name) == 0) {
456 				/* avtivate the segment */
457 				KASSERT(sg->sg_pv == NULL,
458 				    ("segment already mapped"));
459 				sg->sg_pvoffset =
460 				    (off_t)sg->sg_pvstart * vg->vg_extentsize
461 				    + pv->pv_start;
462 				sg->sg_pv = pv;
463 				lv->lv_sgactive++;
464 
465 				G_LLVM_DEBUG(2, "%s: %d to %d @ %s:%d"
466 				    " offset %ju sector %ju",
467 				    lv->lv_name, sg->sg_start, sg->sg_end,
468 				    sg->sg_pvname, sg->sg_pvstart,
469 				    sg->sg_pvoffset,
470 				    sg->sg_pvoffset / vg->vg_sectorsize);
471 			}
472 		}
473 		/* Activate any lvs waiting on this disk */
474 		if (lv->lv_gprov == NULL && lv->lv_sgactive == lv->lv_sgcount) {
475 			error = g_llvm_activate_lv(vg, lv);
476 			if (error)
477 				break;
478 		}
479 	}
480 	return (error);
481 }
482 
483 static void
484 g_llvm_init(struct g_class *mp)
485 {
486 	LIST_INIT(&vg_list);
487 }
488 
489 static void
490 g_llvm_free_vg(struct g_llvm_vg *vg)
491 {
492 	struct g_llvm_pv *pv;
493 	struct g_llvm_lv *lv;
494 	struct g_llvm_segment *sg;
495 
496 	/* Free all the structures */
497 	while ((pv = LIST_FIRST(&vg->vg_pvs)) != NULL) {
498 		LIST_REMOVE(pv, pv_next);
499 		free(pv, M_GLLVM);
500 	}
501 	while ((lv = LIST_FIRST(&vg->vg_lvs)) != NULL) {
502 		while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
503 			LIST_REMOVE(sg, sg_next);
504 			free(sg, M_GLLVM);
505 		}
506 		LIST_REMOVE(lv, lv_next);
507 		free(lv, M_GLLVM);
508 	}
509 	LIST_REMOVE(vg, vg_next);
510 	free(vg, M_GLLVM);
511 }
512 
513 static void
514 g_llvm_taste_orphan(struct g_consumer *cp)
515 {
516 
517 	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
518 	    cp->provider->name));
519 }
520 
521 static struct g_geom *
522 g_llvm_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
523 {
524 	struct g_consumer *cp;
525 	struct g_geom *gp;
526 	struct g_llvm_label ll;
527 	struct g_llvm_metadata md;
528 	struct g_llvm_vg *vg;
529 	int error;
530 
531 	bzero(&md, sizeof(md));
532 
533 	g_topology_assert();
534 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
535 	gp = g_new_geomf(mp, "linux_lvm:taste");
536 	/* This orphan function should be never called. */
537 	gp->orphan = g_llvm_taste_orphan;
538 	cp = g_new_consumer(gp);
539 	g_attach(cp, pp);
540 	error = g_llvm_read_label(cp, &ll);
541 	if (!error)
542 		error = g_llvm_read_md(cp, &md, &ll);
543 	g_detach(cp);
544 	g_destroy_consumer(cp);
545 	g_destroy_geom(gp);
546 	if (error != 0)
547 		return (NULL);
548 
549 	vg = md.md_vg;
550 	if (vg->vg_geom == NULL) {
551 		/* new volume group */
552 		gp = g_new_geomf(mp, "%s", vg->vg_name);
553 		gp->start = g_llvm_start;
554 		gp->spoiled = g_llvm_orphan;
555 		gp->orphan = g_llvm_orphan;
556 		gp->access = g_llvm_access;
557 		vg->vg_sectorsize = pp->sectorsize;
558 		vg->vg_extentsize *= vg->vg_sectorsize;
559 		vg->vg_geom = gp;
560 		gp->softc = vg;
561 		G_LLVM_DEBUG(1, "Created volume %s, extent size %zuK",
562 		    vg->vg_name, vg->vg_extentsize / 1024);
563 	}
564 
565 	/* initialise this disk in the volume group */
566 	g_llvm_add_disk(vg, pp, ll.ll_uuid);
567 	return (vg->vg_geom);
568 }
569 
570 static int
571 g_llvm_destroy(struct g_llvm_vg *vg, int force)
572 {
573 	struct g_provider *pp;
574 	struct g_geom *gp;
575 
576 	g_topology_assert();
577 	if (vg == NULL)
578 		return (ENXIO);
579 	gp = vg->vg_geom;
580 
581 	LIST_FOREACH(pp, &gp->provider, provider) {
582 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) {
583 			G_LLVM_DEBUG(1, "Device %s is still open (r%dw%de%d)",
584 			    pp->name, pp->acr, pp->acw, pp->ace);
585 			if (!force)
586 				return (EBUSY);
587 		}
588 	}
589 
590 	g_llvm_free_vg(gp->softc);
591 	gp->softc = NULL;
592 	g_wither_geom(gp, ENXIO);
593 	return (0);
594 }
595 
596 static int
597 g_llvm_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
598     struct g_geom *gp)
599 {
600 	struct g_llvm_vg *vg;
601 
602 	vg = gp->softc;
603 	return (g_llvm_destroy(vg, 0));
604 }
605 
606 int
607 g_llvm_read_label(struct g_consumer *cp, struct g_llvm_label *ll)
608 {
609 	struct g_provider *pp;
610 	u_char *buf;
611 	int i, error = 0;
612 
613 	g_topology_assert();
614 
615 	/* The LVM label is stored on the first four sectors */
616 	error = g_access(cp, 1, 0, 0);
617 	if (error != 0)
618 		return (error);
619 	pp = cp->provider;
620 	g_topology_unlock();
621 	buf = g_read_data(cp, 0, pp->sectorsize * 4, &error);
622 	g_topology_lock();
623 	g_access(cp, -1, 0, 0);
624 	if (buf == NULL) {
625 		G_LLVM_DEBUG(1, "Cannot read metadata from %s (error=%d)",
626 		    pp->name, error);
627 		return (error);
628 	}
629 
630 	/* Search the four sectors for the LVM label. */
631 	for (i = 0; i < 4; i++) {
632 		error = llvm_label_decode(&buf[i * pp->sectorsize], ll, i);
633 		if (error == 0)
634 			break;	/* found it */
635 	}
636 	g_free(buf);
637 	return (error);
638 }
639 
640 int
641 g_llvm_read_md(struct g_consumer *cp, struct g_llvm_metadata *md,
642     struct g_llvm_label *ll)
643 {
644 	struct g_provider *pp;
645 	u_char *buf;
646 	int error;
647 	int size;
648 
649 	g_topology_assert();
650 
651 	error = g_access(cp, 1, 0, 0);
652 	if (error != 0)
653 		return (error);
654 	pp = cp->provider;
655 	g_topology_unlock();
656 	buf = g_read_data(cp, ll->ll_md_offset, pp->sectorsize, &error);
657 	g_topology_lock();
658 	g_access(cp, -1, 0, 0);
659 	if (buf == NULL) {
660 		G_LLVM_DEBUG(0, "Cannot read metadata from %s (error=%d)",
661 		    cp->provider->name, error);
662 		return (error);
663 	}
664 
665 	error = llvm_md_decode(buf, md, ll);
666 	g_free(buf);
667 	if (error != 0) {
668 		return (error);
669 	}
670 
671 	G_LLVM_DEBUG(1, "reading LVM2 config @ %s:%ju", pp->name,
672 		    ll->ll_md_offset + md->md_reloffset);
673 	error = g_access(cp, 1, 0, 0);
674 	if (error != 0)
675 		return (error);
676 	pp = cp->provider;
677 	g_topology_unlock();
678 	/* round up to the nearest sector */
679 	size = md->md_relsize +
680 	    (pp->sectorsize - md->md_relsize % pp->sectorsize);
681 	buf = g_read_data(cp, ll->ll_md_offset + md->md_reloffset, size, &error);
682 	g_topology_lock();
683 	g_access(cp, -1, 0, 0);
684 	if (buf == NULL) {
685 		G_LLVM_DEBUG(0, "Cannot read LVM2 config from %s (error=%d)",
686 		    pp->name, error);
687 		return (error);
688 	}
689 	buf[md->md_relsize] = '\0';
690 	G_LLVM_DEBUG(10, "LVM config:\n%s\n", buf);
691 	error = llvm_textconf_decode(buf, md->md_relsize, md);
692 	g_free(buf);
693 
694 	return (error);
695 }
696 
697 static int
698 llvm_label_decode(const u_char *data, struct g_llvm_label *ll, int sector)
699 {
700 	uint64_t off;
701 	char *uuid;
702 
703 	/* Magic string */
704 	if (bcmp("LABELONE", data , 8) != 0)
705 		return (EINVAL);
706 
707 	/* We only support LVM2 text format */
708 	if (bcmp("LVM2 001", data + 24, 8) != 0) {
709 		G_LLVM_DEBUG(0, "Unsupported LVM format");
710 		return (EINVAL);
711 	}
712 
713 	ll->ll_sector = le64dec(data + 8);
714 	ll->ll_crc = le32dec(data + 16);
715 	ll->ll_offset = le32dec(data + 20);
716 
717 	if (ll->ll_sector != sector) {
718 		G_LLVM_DEBUG(0, "Expected sector %ju, found at %d",
719 		    ll->ll_sector, sector);
720 		return (EINVAL);
721 	}
722 
723 	off = ll->ll_offset;
724 	/*
725 	 * convert the binary uuid to string format, the format is
726 	 * xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx (6-4-4-4-4-4-6)
727 	 */
728 	uuid = ll->ll_uuid;
729 	bcopy(data + off, uuid, 6);
730 	off += 6;
731 	uuid += 6;
732 	*uuid++ = '-';
733 	for (int i = 0; i < 5; i++) {
734 		bcopy(data + off, uuid, 4);
735 		off += 4;
736 		uuid += 4;
737 		*uuid++ = '-';
738 	}
739 	bcopy(data + off, uuid, 6);
740 	off += 6;
741 	uuid += 6;
742 	*uuid++ = '\0';
743 
744 	ll->ll_size = le64dec(data + off);
745 	off += 8;
746 	ll->ll_pestart = le64dec(data + off);
747 	off += 16;
748 
749 	/* Only one data section is supported */
750 	if (le64dec(data + off) != 0) {
751 		G_LLVM_DEBUG(0, "Only one data section supported");
752 		return (EINVAL);
753 	}
754 
755 	off += 16;
756 	ll->ll_md_offset = le64dec(data + off);
757 	off += 8;
758 	ll->ll_md_size = le64dec(data + off);
759 	off += 8;
760 
761 	G_LLVM_DEBUG(1, "LVM metadata: offset=%ju, size=%ju", ll->ll_md_offset,
762 	    ll->ll_md_size);
763 
764 	/* Only one data section is supported */
765 	if (le64dec(data + off) != 0) {
766 		G_LLVM_DEBUG(0, "Only one metadata section supported");
767 		return (EINVAL);
768 	}
769 
770 	G_LLVM_DEBUG(2, "label uuid=%s", ll->ll_uuid);
771 	G_LLVM_DEBUG(2, "sector=%ju, crc=%u, offset=%u, size=%ju, pestart=%ju",
772 	    ll->ll_sector, ll->ll_crc, ll->ll_offset, ll->ll_size,
773 	    ll->ll_pestart);
774 
775 	return (0);
776 }
777 
778 static int
779 llvm_md_decode(const u_char *data, struct g_llvm_metadata *md,
780     struct g_llvm_label *ll)
781 {
782 	uint64_t off;
783 	char magic[16];
784 
785 	off = 0;
786 	md->md_csum = le32dec(data + off);
787 	off += 4;
788 	bcopy(data + off, magic, 16);
789 	off += 16;
790 	md->md_version = le32dec(data + off);
791 	off += 4;
792 	md->md_start = le64dec(data + off);
793 	off += 8;
794 	md->md_size = le64dec(data + off);
795 	off += 8;
796 
797 	if (bcmp(G_LLVM_MAGIC, magic, 16) != 0) {
798 		G_LLVM_DEBUG(0, "Incorrect md magic number");
799 		return (EINVAL);
800 	}
801 	if (md->md_version != 1) {
802 		G_LLVM_DEBUG(0, "Incorrect md version number (%u)",
803 		    md->md_version);
804 		return (EINVAL);
805 	}
806 	if (md->md_start != ll->ll_md_offset) {
807 		G_LLVM_DEBUG(0, "Incorrect md offset (%ju)", md->md_start);
808 		return (EINVAL);
809 	}
810 
811 	/* Aparently only one is ever returned */
812 	md->md_reloffset = le64dec(data + off);
813 	off += 8;
814 	md->md_relsize = le64dec(data + off);
815 	off += 16;	/* XXX skipped checksum */
816 
817 	if (le64dec(data + off) != 0) {
818 		G_LLVM_DEBUG(0, "Only one reloc supported");
819 		return (EINVAL);
820 	}
821 
822 	G_LLVM_DEBUG(3, "reloc: offset=%ju, size=%ju",
823 	    md->md_reloffset, md->md_relsize);
824 	G_LLVM_DEBUG(3, "md: version=%u, start=%ju, size=%ju",
825 	    md->md_version, md->md_start, md->md_size);
826 
827 	return (0);
828 }
829 
830 #define	GRAB_INT(key, tok1, tok2, v)					\
831 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
832 		v = strtol(tok2, &tok1, 10);				\
833 		if (tok1 == tok2)					\
834 			/* strtol did not eat any of the buffer */	\
835 			goto bad;					\
836 		continue;						\
837 	}
838 
839 #define	GRAB_STR(key, tok1, tok2, v, len)				\
840 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
841 		strsep(&tok2, "\"");					\
842 		if (tok2 == NULL)					\
843 			continue;					\
844 		tok1 = strsep(&tok2, "\"");				\
845 		if (tok2 == NULL)					\
846 			continue;					\
847 		strncpy(v, tok1, len);					\
848 		continue;						\
849 	}
850 
851 #define	SPLIT(key, value, str)						\
852 	key = strsep(&value, str);					\
853 	/* strip trailing whitespace on the key */			\
854 	for (char *t = key; *t != '\0'; t++)				\
855 		if (isspace(*t)) {					\
856 			*t = '\0';					\
857 			break;						\
858 		}
859 
860 static size_t
861 llvm_grab_name(char *name, const char *tok)
862 {
863 	size_t len;
864 
865 	len = 0;
866 	if (tok == NULL)
867 		return (0);
868 	if (tok[0] == '-')
869 		return (0);
870 	if (strcmp(tok, ".") == 0 || strcmp(tok, "..") == 0)
871 		return (0);
872 	while (tok[len] && (isalpha(tok[len]) || isdigit(tok[len]) ||
873 	    tok[len] == '.' || tok[len] == '_' || tok[len] == '-' ||
874 	    tok[len] == '+') && len < G_LLVM_NAMELEN - 1)
875 		len++;
876 	bcopy(tok, name, len);
877 	name[len] = '\0';
878 	return (len);
879 }
880 
881 static int
882 llvm_textconf_decode(u_char *data, int buflen, struct g_llvm_metadata *md)
883 {
884 	struct g_llvm_vg	*vg;
885 	char *buf = data;
886 	char *tok, *v;
887 	char name[G_LLVM_NAMELEN];
888 	char uuid[G_LLVM_UUIDLEN];
889 	size_t len;
890 
891 	if (buf == NULL || *buf == '\0')
892 		return (EINVAL);
893 
894 	tok = strsep(&buf, "\n");
895 	if (tok == NULL)
896 		return (EINVAL);
897 	len = llvm_grab_name(name, tok);
898 	if (len == 0)
899 		return (EINVAL);
900 
901 	/* check too see if the vg has already been loaded off another disk */
902 	LIST_FOREACH(vg, &vg_list, vg_next) {
903 		if (strcmp(vg->vg_name, name) == 0) {
904 			uuid[0] = '\0';
905 			/* grab the volume group uuid */
906 			while ((tok = strsep(&buf, "\n")) != NULL) {
907 				if (strstr(tok, "{"))
908 					break;
909 				if (strstr(tok, "=")) {
910 					SPLIT(v, tok, "=");
911 					GRAB_STR("id", v, tok, uuid,
912 					    sizeof(uuid));
913 				}
914 			}
915 			if (strcmp(vg->vg_uuid, uuid) == 0) {
916 				/* existing vg */
917 				md->md_vg = vg;
918 				return (0);
919 			}
920 			/* XXX different volume group with name clash! */
921 			G_LLVM_DEBUG(0,
922 			    "%s already exists, volume group not loaded", name);
923 			return (EINVAL);
924 		}
925 	}
926 
927 	vg = malloc(sizeof(*vg), M_GLLVM, M_NOWAIT|M_ZERO);
928 	if (vg == NULL)
929 		return (ENOMEM);
930 
931 	strncpy(vg->vg_name, name, sizeof(vg->vg_name));
932 	LIST_INIT(&vg->vg_pvs);
933 	LIST_INIT(&vg->vg_lvs);
934 
935 #define	VOL_FOREACH(func, tok, buf, p)					\
936 	while ((tok = strsep(buf, "\n")) != NULL) {			\
937 		if (strstr(tok, "{")) {					\
938 			func(buf, tok, p);				\
939 			continue;					\
940 		}							\
941 		if (strstr(tok, "}"))					\
942 			break;						\
943 	}
944 
945 	while ((tok = strsep(&buf, "\n")) != NULL) {
946 		if (strcmp(tok, "physical_volumes {") == 0) {
947 			VOL_FOREACH(llvm_textconf_decode_pv, tok, &buf, vg);
948 			continue;
949 		}
950 		if (strcmp(tok, "logical_volumes {") == 0) {
951 			VOL_FOREACH(llvm_textconf_decode_lv, tok, &buf, vg);
952 			continue;
953 		}
954 		if (strstr(tok, "{")) {
955 			G_LLVM_DEBUG(2, "unknown section %s", tok);
956 			continue;
957 		}
958 
959 		/* parse 'key = value' lines */
960 		if (strstr(tok, "=")) {
961 			SPLIT(v, tok, "=");
962 			GRAB_STR("id", v, tok, vg->vg_uuid, sizeof(vg->vg_uuid));
963 			GRAB_INT("extent_size", v, tok, vg->vg_extentsize);
964 			continue;
965 		}
966 	}
967 	/* basic checking */
968 	if (vg->vg_extentsize == 0)
969 		goto bad;
970 
971 	md->md_vg = vg;
972 	LIST_INSERT_HEAD(&vg_list, vg, vg_next);
973 	G_LLVM_DEBUG(3, "vg: name=%s uuid=%s", vg->vg_name, vg->vg_uuid);
974 	return(0);
975 
976 bad:
977 	g_llvm_free_vg(vg);
978 	return (-1);
979 }
980 #undef	VOL_FOREACH
981 
982 static int
983 llvm_textconf_decode_pv(char **buf, char *tok, struct g_llvm_vg *vg)
984 {
985 	struct g_llvm_pv	*pv;
986 	char *v;
987 	size_t len;
988 
989 	if (*buf == NULL || **buf == '\0')
990 		return (EINVAL);
991 
992 	pv = malloc(sizeof(*pv), M_GLLVM, M_NOWAIT|M_ZERO);
993 	if (pv == NULL)
994 		return (ENOMEM);
995 
996 	pv->pv_vg = vg;
997 	len = 0;
998 	if (tok == NULL)
999 		goto bad;
1000 	len = llvm_grab_name(pv->pv_name, tok);
1001 	if (len == 0)
1002 		goto bad;
1003 
1004 	while ((tok = strsep(buf, "\n")) != NULL) {
1005 		if (strstr(tok, "{"))
1006 			goto bad;
1007 
1008 		if (strstr(tok, "}"))
1009 			break;
1010 
1011 		/* parse 'key = value' lines */
1012 		if (strstr(tok, "=")) {
1013 			SPLIT(v, tok, "=");
1014 			GRAB_STR("id", v, tok, pv->pv_uuid, sizeof(pv->pv_uuid));
1015 			GRAB_INT("pe_start", v, tok, pv->pv_start);
1016 			GRAB_INT("pe_count", v, tok, pv->pv_count);
1017 			continue;
1018 		}
1019 	}
1020 	if (tok == NULL)
1021 		goto bad;
1022 	/* basic checking */
1023 	if (pv->pv_count == 0)
1024 		goto bad;
1025 
1026 	LIST_INSERT_HEAD(&vg->vg_pvs, pv, pv_next);
1027 	G_LLVM_DEBUG(3, "pv: name=%s uuid=%s", pv->pv_name, pv->pv_uuid);
1028 
1029 	return (0);
1030 bad:
1031 	free(pv, M_GLLVM);
1032 	return (-1);
1033 }
1034 
1035 static int
1036 llvm_textconf_decode_lv(char **buf, char *tok, struct g_llvm_vg *vg)
1037 {
1038 	struct g_llvm_lv	*lv;
1039 	struct g_llvm_segment *sg;
1040 	char *v;
1041 	size_t len;
1042 
1043 	if (*buf == NULL || **buf == '\0')
1044 		return (EINVAL);
1045 
1046 	lv = malloc(sizeof(*lv), M_GLLVM, M_NOWAIT|M_ZERO);
1047 	if (lv == NULL)
1048 		return (ENOMEM);
1049 
1050 	lv->lv_vg = vg;
1051 	LIST_INIT(&lv->lv_segs);
1052 
1053 	if (tok == NULL)
1054 		goto bad;
1055 	len = llvm_grab_name(lv->lv_name, tok);
1056 	if (len == 0)
1057 		goto bad;
1058 
1059 	while ((tok = strsep(buf, "\n")) != NULL) {
1060 		if (strstr(tok, "{")) {
1061 			if (strstr(tok, "segment")) {
1062 				llvm_textconf_decode_sg(buf, tok, lv);
1063 				continue;
1064 			} else
1065 				/* unexpected section */
1066 				goto bad;
1067 		}
1068 
1069 		if (strstr(tok, "}"))
1070 			break;
1071 
1072 		/* parse 'key = value' lines */
1073 		if (strstr(tok, "=")) {
1074 			SPLIT(v, tok, "=");
1075 			GRAB_STR("id", v, tok, lv->lv_uuid, sizeof(lv->lv_uuid));
1076 			GRAB_INT("segment_count", v, tok, lv->lv_sgcount);
1077 			continue;
1078 		}
1079 	}
1080 	if (tok == NULL)
1081 		goto bad;
1082 	if (lv->lv_sgcount == 0 || lv->lv_sgcount != lv->lv_numsegs)
1083 		/* zero or incomplete segment list */
1084 		goto bad;
1085 
1086 	/* Optimize for only one segment on the pv */
1087 	lv->lv_firstsg = LIST_FIRST(&lv->lv_segs);
1088 	LIST_INSERT_HEAD(&vg->vg_lvs, lv, lv_next);
1089 	G_LLVM_DEBUG(3, "lv: name=%s uuid=%s", lv->lv_name, lv->lv_uuid);
1090 
1091 	return (0);
1092 bad:
1093 	while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
1094 		LIST_REMOVE(sg, sg_next);
1095 		free(sg, M_GLLVM);
1096 	}
1097 	free(lv, M_GLLVM);
1098 	return (-1);
1099 }
1100 
1101 static int
1102 llvm_textconf_decode_sg(char **buf, char *tok, struct g_llvm_lv *lv)
1103 {
1104 	struct g_llvm_segment *sg;
1105 	char *v;
1106 	int count = 0;
1107 
1108 	if (*buf == NULL || **buf == '\0')
1109 		return (EINVAL);
1110 
1111 	sg = malloc(sizeof(*sg), M_GLLVM, M_NOWAIT|M_ZERO);
1112 	if (sg == NULL)
1113 		return (ENOMEM);
1114 
1115 	while ((tok = strsep(buf, "\n")) != NULL) {
1116 		/* only a single linear stripe is supported */
1117 		if (strstr(tok, "stripe_count")) {
1118 			SPLIT(v, tok, "=");
1119 			GRAB_INT("stripe_count", v, tok, count);
1120 			if (count != 1)
1121 				goto bad;
1122 		}
1123 
1124 		if (strstr(tok, "{"))
1125 			goto bad;
1126 
1127 		if (strstr(tok, "}"))
1128 			break;
1129 
1130 		if (strcmp(tok, "stripes = [") == 0) {
1131 			tok = strsep(buf, "\n");
1132 			if (tok == NULL)
1133 				goto bad;
1134 
1135 			strsep(&tok, "\"");
1136 			if (tok == NULL)
1137 				goto bad;	/* missing open quotes */
1138 			v = strsep(&tok, "\"");
1139 			if (tok == NULL)
1140 				goto bad;	/* missing close quotes */
1141 			strncpy(sg->sg_pvname, v, sizeof(sg->sg_pvname));
1142 			if (*tok != ',')
1143 				goto bad;	/* missing comma for stripe */
1144 			tok++;
1145 
1146 			sg->sg_pvstart = strtol(tok, &v, 10);
1147 			if (v == tok)
1148 				/* strtol did not eat any of the buffer */
1149 				goto bad;
1150 
1151 			continue;
1152 		}
1153 
1154 		/* parse 'key = value' lines */
1155 		if (strstr(tok, "=")) {
1156 			SPLIT(v, tok, "=");
1157 			GRAB_INT("start_extent", v, tok, sg->sg_start);
1158 			GRAB_INT("extent_count", v, tok, sg->sg_count);
1159 			continue;
1160 		}
1161 	}
1162 	if (tok == NULL)
1163 		goto bad;
1164 	/* basic checking */
1165 	if (count != 1 || sg->sg_count == 0)
1166 		goto bad;
1167 
1168 	sg->sg_end = sg->sg_start + sg->sg_count - 1;
1169 	lv->lv_numsegs++;
1170 	lv->lv_extentcount += sg->sg_count;
1171 	LIST_INSERT_HEAD(&lv->lv_segs, sg, sg_next);
1172 
1173 	return (0);
1174 bad:
1175 	free(sg, M_GLLVM);
1176 	return (-1);
1177 }
1178 #undef	GRAB_INT
1179 #undef	GRAB_STR
1180 #undef	SPLIT
1181 
1182 static struct g_class g_llvm_class = {
1183 	.name = G_LLVM_CLASS_NAME,
1184 	.version = G_VERSION,
1185 	.init = g_llvm_init,
1186 	.taste = g_llvm_taste,
1187 	.destroy_geom = g_llvm_destroy_geom
1188 };
1189 
1190 DECLARE_GEOM_CLASS(g_llvm_class, g_linux_lvm);
1191