xref: /freebsd/sys/geom/linux_lvm/g_linux_lvm.c (revision 8d20be1e22095c27faf8fe8b2f0d089739cc742e)
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 TUNABLE_INT("kern.geom.linux_lvm.debug", &g_llvm_debug);
83 SYSCTL_UINT(_kern_geom_linux_lvm, OID_AUTO, debug, CTLFLAG_RW, &g_llvm_debug, 0,
84     "Debug level");
85 
86 LIST_HEAD(, g_llvm_vg) vg_list;
87 
88 /*
89  * Called to notify geom when it's been opened, and for what intent
90  */
91 static int
92 g_llvm_access(struct g_provider *pp, int dr, int dw, int de)
93 {
94 	struct g_consumer *c;
95 	struct g_llvm_vg *vg;
96 	struct g_geom *gp;
97 	int error;
98 
99 	KASSERT(pp != NULL, ("%s: NULL provider", __func__));
100 	gp = pp->geom;
101 	KASSERT(gp != NULL, ("%s: NULL geom", __func__));
102 	vg = gp->softc;
103 
104 	if (vg == NULL) {
105 		/* It seems that .access can be called with negative dr,dw,dx
106 		 * in this case but I want to check for myself */
107 		G_LLVM_DEBUG(0, "access(%d, %d, %d) for %s",
108 		    dr, dw, de, pp->name);
109 
110 		/* This should only happen when geom is withered so
111 		 * allow only negative requests */
112 		KASSERT(dr <= 0 && dw <= 0 && de <= 0,
113 		    ("%s: Positive access for %s", __func__, pp->name));
114 		if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
115 			G_LLVM_DEBUG(0,
116 			    "Device %s definitely destroyed", pp->name);
117 		return (0);
118 	}
119 
120 	/* Grab an exclusive bit to propagate on our consumers on first open */
121 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
122 		de++;
123 	/* ... drop it on close */
124 	if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
125 		de--;
126 
127 	error = ENXIO;
128 	LIST_FOREACH(c, &gp->consumer, consumer) {
129 		KASSERT(c != NULL, ("%s: consumer is NULL", __func__));
130 		error = g_access(c, dr, dw, de);
131 		if (error != 0) {
132 			struct g_consumer *c2;
133 
134 			/* Backout earlier changes */
135 			LIST_FOREACH(c2, &gp->consumer, consumer) {
136 				if (c2 == c) /* all eariler components fixed */
137 					return (error);
138 				g_access(c2, -dr, -dw, -de);
139 			}
140 		}
141 	}
142 
143 	return (error);
144 }
145 
146 /*
147  * Dismantle bio_queue and destroy its components
148  */
149 static void
150 bioq_dismantle(struct bio_queue_head *bq)
151 {
152 	struct bio *b;
153 
154 	for (b = bioq_first(bq); b != NULL; b = bioq_first(bq)) {
155 		bioq_remove(bq, b);
156 		g_destroy_bio(b);
157 	}
158 }
159 
160 /*
161  * GEOM .done handler
162  * Can't use standard handler because one requested IO may
163  * fork into additional data IOs
164  */
165 static void
166 g_llvm_done(struct bio *b)
167 {
168 	struct bio *parent_b;
169 
170 	parent_b = b->bio_parent;
171 
172 	if (b->bio_error != 0) {
173 		G_LLVM_DEBUG(0, "Error %d for offset=%ju, length=%ju on %s",
174 		    b->bio_error, b->bio_offset, b->bio_length,
175 		    b->bio_to->name);
176 		if (parent_b->bio_error == 0)
177 			parent_b->bio_error = b->bio_error;
178 	}
179 
180 	parent_b->bio_inbed++;
181 	parent_b->bio_completed += b->bio_completed;
182 
183 	if (parent_b->bio_children == parent_b->bio_inbed) {
184 		parent_b->bio_completed = parent_b->bio_length;
185 		g_io_deliver(parent_b, parent_b->bio_error);
186 	}
187 	g_destroy_bio(b);
188 }
189 
190 static void
191 g_llvm_start(struct bio *bp)
192 {
193 	struct g_provider *pp;
194 	struct g_llvm_vg *vg;
195 	struct g_llvm_pv *pv;
196 	struct g_llvm_lv *lv;
197 	struct g_llvm_segment *sg;
198 	struct bio *cb;
199 	struct bio_queue_head bq;
200 	size_t chunk_size;
201 	off_t offset, length;
202 	char *addr;
203 	u_int count;
204 
205 	pp = bp->bio_to;
206 	lv = pp->private;
207 	vg = pp->geom->softc;
208 
209 	switch (bp->bio_cmd) {
210 	case BIO_READ:
211 	case BIO_WRITE:
212 	case BIO_DELETE:
213 	/* XXX BIO_GETATTR allowed? */
214 		break;
215 	default:
216 		g_io_deliver(bp, EOPNOTSUPP);
217 		return;
218 	}
219 
220 	bioq_init(&bq);
221 
222 	chunk_size = vg->vg_extentsize;
223 	addr = bp->bio_data;
224 	offset = bp->bio_offset;	/* virtual offset and length */
225 	length = bp->bio_length;
226 
227 	while (length > 0) {
228 		size_t chunk_index, in_chunk_offset, in_chunk_length;
229 
230 		pv = NULL;
231 		cb = g_clone_bio(bp);
232 		if (cb == NULL) {
233 			bioq_dismantle(&bq);
234 			if (bp->bio_error == 0)
235 				bp->bio_error = ENOMEM;
236 			g_io_deliver(bp, bp->bio_error);
237 			return;
238 		}
239 
240 		/* get the segment and the pv */
241 		if (lv->lv_sgcount == 1) {
242 			/* skip much of the calculations for a single sg */
243 			chunk_index = 0;
244 			in_chunk_offset = 0;
245 			in_chunk_length = length;
246 			sg = lv->lv_firstsg;
247 			pv = sg->sg_pv;
248 			cb->bio_offset = offset + sg->sg_pvoffset;
249 		} else {
250 			chunk_index = offset / chunk_size; /* round downwards */
251 			in_chunk_offset = offset % chunk_size;
252 			in_chunk_length =
253 			    min(length, chunk_size - in_chunk_offset);
254 
255 			/* XXX could be faster */
256 			LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
257 				if (chunk_index >= sg->sg_start &&
258 				    chunk_index <= sg->sg_end) {
259 					/* adjust chunk index for sg start */
260 					chunk_index -= sg->sg_start;
261 					pv = sg->sg_pv;
262 					break;
263 				}
264 			}
265 			cb->bio_offset =
266 			    (off_t)chunk_index * (off_t)chunk_size
267 			    + in_chunk_offset + sg->sg_pvoffset;
268 		}
269 
270 		KASSERT(pv != NULL, ("Can't find PV for chunk %zu",
271 		    chunk_index));
272 
273 		cb->bio_to = pv->pv_gprov;
274 		cb->bio_done = g_llvm_done;
275 		cb->bio_length = in_chunk_length;
276 		cb->bio_data = addr;
277 		cb->bio_caller1 = pv;
278 		bioq_disksort(&bq, cb);
279 
280 		G_LLVM_DEBUG(5,
281 		    "Mapped %s(%ju, %ju) on %s to %zu(%zu,%zu) @ %s:%ju",
282 		    bp->bio_cmd == BIO_READ ? "R" : "W",
283 		    offset, length, lv->lv_name,
284 		    chunk_index, in_chunk_offset, in_chunk_length,
285 		    pv->pv_name, cb->bio_offset);
286 
287 		addr += in_chunk_length;
288 		length -= in_chunk_length;
289 		offset += in_chunk_length;
290 	}
291 
292 	/* Fire off bio's here */
293 	count = 0;
294 	for (cb = bioq_first(&bq); cb != NULL; cb = bioq_first(&bq)) {
295 		bioq_remove(&bq, cb);
296 		pv = cb->bio_caller1;
297 		cb->bio_caller1 = NULL;
298 		G_LLVM_DEBUG(6, "firing bio to %s, offset=%ju, length=%ju",
299 		    cb->bio_to->name, cb->bio_offset, cb->bio_length);
300 		g_io_request(cb, pv->pv_gcons);
301 		count++;
302 	}
303 	if (count == 0) { /* We handled everything locally */
304 		bp->bio_completed = bp->bio_length;
305 		g_io_deliver(bp, 0);
306 	}
307 }
308 
309 static void
310 g_llvm_remove_disk(struct g_llvm_vg *vg, struct g_consumer *cp)
311 {
312 	struct g_llvm_pv *pv;
313 	struct g_llvm_lv *lv;
314 	struct g_llvm_segment *sg;
315 	int found;
316 
317 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
318 	pv = (struct g_llvm_pv *)cp->private;
319 
320 	G_LLVM_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
321 	    pv->pv_name);
322 
323 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
324 		/* Find segments that map to this disk */
325 		found = 0;
326 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
327 			if (sg->sg_pv == pv) {
328 				sg->sg_pv = NULL;
329 				lv->lv_sgactive--;
330 				found = 1;
331 				break;
332 			}
333 		}
334 		if (found) {
335 			G_LLVM_DEBUG(0, "Device %s removed.",
336 			    lv->lv_gprov->name);
337 			g_orphan_provider(lv->lv_gprov, ENXIO);
338 			lv->lv_gprov = NULL;
339 		}
340 	}
341 
342 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
343 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
344 	g_detach(cp);
345 	g_destroy_consumer(cp);
346 }
347 
348 static void
349 g_llvm_orphan(struct g_consumer *cp)
350 {
351 	struct g_llvm_vg *vg;
352 	struct g_geom *gp;
353 
354 	g_topology_assert();
355 	gp = cp->geom;
356 	vg = gp->softc;
357 	if (vg == NULL)
358 		return;
359 
360 	g_llvm_remove_disk(vg, cp);
361 	g_llvm_destroy(vg, 1);
362 }
363 
364 static int
365 g_llvm_activate_lv(struct g_llvm_vg *vg, struct g_llvm_lv *lv)
366 {
367 	struct g_geom *gp;
368 	struct g_provider *pp;
369 
370 	g_topology_assert();
371 
372 	KASSERT(lv->lv_sgactive == lv->lv_sgcount, ("segment missing"));
373 
374 	gp = vg->vg_geom;
375 	pp = g_new_providerf(gp, "linux_lvm/%s-%s", vg->vg_name, lv->lv_name);
376 	pp->mediasize = vg->vg_extentsize * (off_t)lv->lv_extentcount;
377 	pp->sectorsize = vg->vg_sectorsize;
378 	g_error_provider(pp, 0);
379 	lv->lv_gprov = pp;
380 	pp->private = lv;
381 
382 	G_LLVM_DEBUG(1, "Created %s, %juM", pp->name,
383 	    pp->mediasize / (1024*1024));
384 
385 	return (0);
386 }
387 
388 static int
389 g_llvm_add_disk(struct g_llvm_vg *vg, struct g_provider *pp, char *uuid)
390 {
391 	struct g_geom *gp;
392 	struct g_consumer *cp, *fcp;
393 	struct g_llvm_pv *pv;
394 	struct g_llvm_lv *lv;
395 	struct g_llvm_segment *sg;
396 	int error;
397 
398 	g_topology_assert();
399 
400 	LIST_FOREACH(pv, &vg->vg_pvs, pv_next) {
401 		if (strcmp(pv->pv_uuid, uuid) == 0)
402 			break;	/* found it */
403 	}
404 	if (pv == NULL) {
405 		G_LLVM_DEBUG(3, "uuid %s not found in pv list", uuid);
406 		return (ENOENT);
407 	}
408 	if (pv->pv_gprov != NULL) {
409 		G_LLVM_DEBUG(0, "disk %s already initialised in %s",
410 		    pv->pv_name, vg->vg_name);
411 		return (EEXIST);
412 	}
413 
414 	pv->pv_start *= vg->vg_sectorsize;
415 	gp = vg->vg_geom;
416 	fcp = LIST_FIRST(&gp->consumer);
417 
418 	cp = g_new_consumer(gp);
419 	error = g_attach(cp, pp);
420 	G_LLVM_DEBUG(1, "Attached %s to %s at offset %ju",
421 	    pp->name, pv->pv_name, pv->pv_start);
422 
423 	if (error != 0) {
424 		G_LLVM_DEBUG(0, "cannot attach %s to %s",
425 		    pp->name, vg->vg_name);
426 		g_destroy_consumer(cp);
427 		return (error);
428 	}
429 
430 	if (fcp != NULL) {
431 		if (fcp->provider->sectorsize != pp->sectorsize) {
432 			G_LLVM_DEBUG(0, "Provider %s of %s has invalid "
433 			    "sector size (%d)", pp->name, vg->vg_name,
434 			    pp->sectorsize);
435 			return (EINVAL);
436 		}
437 		if (fcp->acr > 0 || fcp->acw || fcp->ace > 0) {
438 			/* Replicate access permissions from first "live"
439 			 * consumer to the new one */
440 			error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
441 			if (error != 0) {
442 				g_detach(cp);
443 				g_destroy_consumer(cp);
444 				return (error);
445 			}
446 		}
447 	}
448 
449 	cp->private = pv;
450 	pv->pv_gcons = cp;
451 	pv->pv_gprov = pp;
452 
453 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
454 		/* Find segments that map to this disk */
455 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
456 			if (strcmp(sg->sg_pvname, pv->pv_name) == 0) {
457 				/* avtivate the segment */
458 				KASSERT(sg->sg_pv == NULL,
459 				    ("segment already mapped"));
460 				sg->sg_pvoffset =
461 				    (off_t)sg->sg_pvstart * vg->vg_extentsize
462 				    + pv->pv_start;
463 				sg->sg_pv = pv;
464 				lv->lv_sgactive++;
465 
466 				G_LLVM_DEBUG(2, "%s: %d to %d @ %s:%d"
467 				    " offset %ju sector %ju",
468 				    lv->lv_name, sg->sg_start, sg->sg_end,
469 				    sg->sg_pvname, sg->sg_pvstart,
470 				    sg->sg_pvoffset,
471 				    sg->sg_pvoffset / vg->vg_sectorsize);
472 			}
473 		}
474 		/* Activate any lvs waiting on this disk */
475 		if (lv->lv_gprov == NULL && lv->lv_sgactive == lv->lv_sgcount) {
476 			error = g_llvm_activate_lv(vg, lv);
477 			if (error)
478 				break;
479 		}
480 	}
481 	return (error);
482 }
483 
484 static void
485 g_llvm_init(struct g_class *mp)
486 {
487 	LIST_INIT(&vg_list);
488 }
489 
490 static void
491 g_llvm_free_vg(struct g_llvm_vg *vg)
492 {
493 	struct g_llvm_pv *pv;
494 	struct g_llvm_lv *lv;
495 	struct g_llvm_segment *sg;
496 
497 	/* Free all the structures */
498 	while ((pv = LIST_FIRST(&vg->vg_pvs)) != NULL) {
499 		LIST_REMOVE(pv, pv_next);
500 		free(pv, M_GLLVM);
501 	}
502 	while ((lv = LIST_FIRST(&vg->vg_lvs)) != NULL) {
503 		while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
504 			LIST_REMOVE(sg, sg_next);
505 			free(sg, M_GLLVM);
506 		}
507 		LIST_REMOVE(lv, lv_next);
508 		free(lv, M_GLLVM);
509 	}
510 	LIST_REMOVE(vg, vg_next);
511 	free(vg, M_GLLVM);
512 }
513 
514 static void
515 g_llvm_taste_orphan(struct g_consumer *cp)
516 {
517 
518 	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
519 	    cp->provider->name));
520 }
521 
522 static struct g_geom *
523 g_llvm_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
524 {
525 	struct g_consumer *cp;
526 	struct g_geom *gp;
527 	struct g_llvm_label ll;
528 	struct g_llvm_metadata md;
529 	struct g_llvm_vg *vg;
530 	int error;
531 
532 	bzero(&md, sizeof(md));
533 
534 	g_topology_assert();
535 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
536 	gp = g_new_geomf(mp, "linux_lvm:taste");
537 	/* This orphan function should be never called. */
538 	gp->orphan = g_llvm_taste_orphan;
539 	cp = g_new_consumer(gp);
540 	g_attach(cp, pp);
541 	error = g_llvm_read_label(cp, &ll);
542 	if (!error)
543 		error = g_llvm_read_md(cp, &md, &ll);
544 	g_detach(cp);
545 	g_destroy_consumer(cp);
546 	g_destroy_geom(gp);
547 	if (error != 0)
548 		return (NULL);
549 
550 	vg = md.md_vg;
551 	if (vg->vg_geom == NULL) {
552 		/* new volume group */
553 		gp = g_new_geomf(mp, "%s", vg->vg_name);
554 		gp->start = g_llvm_start;
555 		gp->spoiled = g_llvm_orphan;
556 		gp->orphan = g_llvm_orphan;
557 		gp->access = g_llvm_access;
558 		vg->vg_sectorsize = pp->sectorsize;
559 		vg->vg_extentsize *= vg->vg_sectorsize;
560 		vg->vg_geom = gp;
561 		gp->softc = vg;
562 		G_LLVM_DEBUG(1, "Created volume %s, extent size %zuK",
563 		    vg->vg_name, vg->vg_extentsize / 1024);
564 	}
565 
566 	/* initialise this disk in the volume group */
567 	g_llvm_add_disk(vg, pp, ll.ll_uuid);
568 	return (vg->vg_geom);
569 }
570 
571 static int
572 g_llvm_destroy(struct g_llvm_vg *vg, int force)
573 {
574 	struct g_provider *pp;
575 	struct g_geom *gp;
576 
577 	g_topology_assert();
578 	if (vg == NULL)
579 		return (ENXIO);
580 	gp = vg->vg_geom;
581 
582 	LIST_FOREACH(pp, &gp->provider, provider) {
583 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) {
584 			G_LLVM_DEBUG(1, "Device %s is still open (r%dw%de%d)",
585 			    pp->name, pp->acr, pp->acw, pp->ace);
586 			if (!force)
587 				return (EBUSY);
588 		}
589 	}
590 
591 	g_llvm_free_vg(gp->softc);
592 	gp->softc = NULL;
593 	g_wither_geom(gp, ENXIO);
594 	return (0);
595 }
596 
597 static int
598 g_llvm_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
599     struct g_geom *gp)
600 {
601 	struct g_llvm_vg *vg;
602 
603 	vg = gp->softc;
604 	return (g_llvm_destroy(vg, 0));
605 }
606 
607 int
608 g_llvm_read_label(struct g_consumer *cp, struct g_llvm_label *ll)
609 {
610 	struct g_provider *pp;
611 	u_char *buf;
612 	int i, error = 0;
613 
614 	g_topology_assert();
615 
616 	/* The LVM label is stored on the first four sectors */
617 	error = g_access(cp, 1, 0, 0);
618 	if (error != 0)
619 		return (error);
620 	pp = cp->provider;
621 	g_topology_unlock();
622 	buf = g_read_data(cp, 0, pp->sectorsize * 4, &error);
623 	g_topology_lock();
624 	g_access(cp, -1, 0, 0);
625 	if (buf == NULL) {
626 		G_LLVM_DEBUG(1, "Cannot read metadata from %s (error=%d)",
627 		    pp->name, error);
628 		return (error);
629 	}
630 
631 	/* Search the four sectors for the LVM label. */
632 	for (i = 0; i < 4; i++) {
633 		error = llvm_label_decode(&buf[i * pp->sectorsize], ll, i);
634 		if (error == 0)
635 			break;	/* found it */
636 	}
637 	g_free(buf);
638 	return (error);
639 }
640 
641 int
642 g_llvm_read_md(struct g_consumer *cp, struct g_llvm_metadata *md,
643     struct g_llvm_label *ll)
644 {
645 	struct g_provider *pp;
646 	u_char *buf;
647 	int error;
648 	int size;
649 
650 	g_topology_assert();
651 
652 	error = g_access(cp, 1, 0, 0);
653 	if (error != 0)
654 		return (error);
655 	pp = cp->provider;
656 	g_topology_unlock();
657 	buf = g_read_data(cp, ll->ll_md_offset, pp->sectorsize, &error);
658 	g_topology_lock();
659 	g_access(cp, -1, 0, 0);
660 	if (buf == NULL) {
661 		G_LLVM_DEBUG(0, "Cannot read metadata from %s (error=%d)",
662 		    cp->provider->name, error);
663 		return (error);
664 	}
665 
666 	error = llvm_md_decode(buf, md, ll);
667 	g_free(buf);
668 	if (error != 0) {
669 		return (error);
670 	}
671 
672 	G_LLVM_DEBUG(1, "reading LVM2 config @ %s:%ju", pp->name,
673 		    ll->ll_md_offset + md->md_reloffset);
674 	error = g_access(cp, 1, 0, 0);
675 	if (error != 0)
676 		return (error);
677 	pp = cp->provider;
678 	g_topology_unlock();
679 	/* round up to the nearest sector */
680 	size = md->md_relsize +
681 	    (pp->sectorsize - md->md_relsize % pp->sectorsize);
682 	buf = g_read_data(cp, ll->ll_md_offset + md->md_reloffset, size, &error);
683 	g_topology_lock();
684 	g_access(cp, -1, 0, 0);
685 	if (buf == NULL) {
686 		G_LLVM_DEBUG(0, "Cannot read LVM2 config from %s (error=%d)",
687 		    pp->name, error);
688 		return (error);
689 	}
690 	buf[md->md_relsize] = '\0';
691 	G_LLVM_DEBUG(10, "LVM config:\n%s\n", buf);
692 	error = llvm_textconf_decode(buf, md->md_relsize, md);
693 	g_free(buf);
694 
695 	return (error);
696 }
697 
698 static int
699 llvm_label_decode(const u_char *data, struct g_llvm_label *ll, int sector)
700 {
701 	uint64_t off;
702 	char *uuid;
703 
704 	/* Magic string */
705 	if (bcmp("LABELONE", data , 8) != 0)
706 		return (EINVAL);
707 
708 	/* We only support LVM2 text format */
709 	if (bcmp("LVM2 001", data + 24, 8) != 0) {
710 		G_LLVM_DEBUG(0, "Unsupported LVM format");
711 		return (EINVAL);
712 	}
713 
714 	ll->ll_sector = le64dec(data + 8);
715 	ll->ll_crc = le32dec(data + 16);
716 	ll->ll_offset = le32dec(data + 20);
717 
718 	if (ll->ll_sector != sector) {
719 		G_LLVM_DEBUG(0, "Expected sector %ju, found at %d",
720 		    ll->ll_sector, sector);
721 		return (EINVAL);
722 	}
723 
724 	off = ll->ll_offset;
725 	/*
726 	 * convert the binary uuid to string format, the format is
727 	 * xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx (6-4-4-4-4-4-6)
728 	 */
729 	uuid = ll->ll_uuid;
730 	bcopy(data + off, uuid, 6);
731 	off += 6;
732 	uuid += 6;
733 	*uuid++ = '-';
734 	for (int i = 0; i < 5; i++) {
735 		bcopy(data + off, uuid, 4);
736 		off += 4;
737 		uuid += 4;
738 		*uuid++ = '-';
739 	}
740 	bcopy(data + off, uuid, 6);
741 	off += 6;
742 	uuid += 6;
743 	*uuid++ = '\0';
744 
745 	ll->ll_size = le64dec(data + off);
746 	off += 8;
747 	ll->ll_pestart = le64dec(data + off);
748 	off += 16;
749 
750 	/* Only one data section is supported */
751 	if (le64dec(data + off) != 0) {
752 		G_LLVM_DEBUG(0, "Only one data section supported");
753 		return (EINVAL);
754 	}
755 
756 	off += 16;
757 	ll->ll_md_offset = le64dec(data + off);
758 	off += 8;
759 	ll->ll_md_size = le64dec(data + off);
760 	off += 8;
761 
762 	G_LLVM_DEBUG(1, "LVM metadata: offset=%ju, size=%ju", ll->ll_md_offset,
763 	    ll->ll_md_size);
764 
765 	/* Only one data section is supported */
766 	if (le64dec(data + off) != 0) {
767 		G_LLVM_DEBUG(0, "Only one metadata section supported");
768 		return (EINVAL);
769 	}
770 
771 	G_LLVM_DEBUG(2, "label uuid=%s", ll->ll_uuid);
772 	G_LLVM_DEBUG(2, "sector=%ju, crc=%u, offset=%u, size=%ju, pestart=%ju",
773 	    ll->ll_sector, ll->ll_crc, ll->ll_offset, ll->ll_size,
774 	    ll->ll_pestart);
775 
776 	return (0);
777 }
778 
779 static int
780 llvm_md_decode(const u_char *data, struct g_llvm_metadata *md,
781     struct g_llvm_label *ll)
782 {
783 	uint64_t off;
784 	char magic[16];
785 
786 	off = 0;
787 	md->md_csum = le32dec(data + off);
788 	off += 4;
789 	bcopy(data + off, magic, 16);
790 	off += 16;
791 	md->md_version = le32dec(data + off);
792 	off += 4;
793 	md->md_start = le64dec(data + off);
794 	off += 8;
795 	md->md_size = le64dec(data + off);
796 	off += 8;
797 
798 	if (bcmp(G_LLVM_MAGIC, magic, 16) != 0) {
799 		G_LLVM_DEBUG(0, "Incorrect md magic number");
800 		return (EINVAL);
801 	}
802 	if (md->md_version != 1) {
803 		G_LLVM_DEBUG(0, "Incorrect md version number (%u)",
804 		    md->md_version);
805 		return (EINVAL);
806 	}
807 	if (md->md_start != ll->ll_md_offset) {
808 		G_LLVM_DEBUG(0, "Incorrect md offset (%ju)", md->md_start);
809 		return (EINVAL);
810 	}
811 
812 	/* Aparently only one is ever returned */
813 	md->md_reloffset = le64dec(data + off);
814 	off += 8;
815 	md->md_relsize = le64dec(data + off);
816 	off += 16;	/* XXX skipped checksum */
817 
818 	if (le64dec(data + off) != 0) {
819 		G_LLVM_DEBUG(0, "Only one reloc supported");
820 		return (EINVAL);
821 	}
822 
823 	G_LLVM_DEBUG(3, "reloc: offset=%ju, size=%ju",
824 	    md->md_reloffset, md->md_relsize);
825 	G_LLVM_DEBUG(3, "md: version=%u, start=%ju, size=%ju",
826 	    md->md_version, md->md_start, md->md_size);
827 
828 	return (0);
829 }
830 
831 #define	GRAB_INT(key, tok1, tok2, v)					\
832 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
833 		v = strtol(tok2, &tok1, 10);				\
834 		if (tok1 == tok2)					\
835 			/* strtol did not eat any of the buffer */	\
836 			goto bad;					\
837 		continue;						\
838 	}
839 
840 #define	GRAB_STR(key, tok1, tok2, v, len)				\
841 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
842 		strsep(&tok2, "\"");					\
843 		if (tok2 == NULL)					\
844 			continue;					\
845 		tok1 = strsep(&tok2, "\"");				\
846 		if (tok2 == NULL)					\
847 			continue;					\
848 		strncpy(v, tok1, len);					\
849 		continue;						\
850 	}
851 
852 #define	SPLIT(key, value, str)						\
853 	key = strsep(&value, str);					\
854 	/* strip trailing whitespace on the key */			\
855 	for (char *t = key; *t != '\0'; t++)				\
856 		if (isspace(*t)) {					\
857 			*t = '\0';					\
858 			break;						\
859 		}
860 
861 static size_t
862 llvm_grab_name(char *name, const char *tok)
863 {
864 	size_t len;
865 
866 	len = 0;
867 	if (tok == NULL)
868 		return (0);
869 	if (tok[0] == '-')
870 		return (0);
871 	if (strcmp(tok, ".") == 0 || strcmp(tok, "..") == 0)
872 		return (0);
873 	while (tok[len] && (isalpha(tok[len]) || isdigit(tok[len]) ||
874 	    tok[len] == '.' || tok[len] == '_' || tok[len] == '-' ||
875 	    tok[len] == '+') && len < G_LLVM_NAMELEN - 1)
876 		len++;
877 	bcopy(tok, name, len);
878 	name[len] = '\0';
879 	return (len);
880 }
881 
882 static int
883 llvm_textconf_decode(u_char *data, int buflen, struct g_llvm_metadata *md)
884 {
885 	struct g_llvm_vg	*vg;
886 	char *buf = data;
887 	char *tok, *v;
888 	char name[G_LLVM_NAMELEN];
889 	char uuid[G_LLVM_UUIDLEN];
890 	size_t len;
891 
892 	if (buf == NULL || *buf == '\0')
893 		return (EINVAL);
894 
895 	tok = strsep(&buf, "\n");
896 	if (tok == NULL)
897 		return (EINVAL);
898 	len = llvm_grab_name(name, tok);
899 	if (len == 0)
900 		return (EINVAL);
901 
902 	/* check too see if the vg has already been loaded off another disk */
903 	LIST_FOREACH(vg, &vg_list, vg_next) {
904 		if (strcmp(vg->vg_name, name) == 0) {
905 			uuid[0] = '\0';
906 			/* grab the volume group uuid */
907 			while ((tok = strsep(&buf, "\n")) != NULL) {
908 				if (strstr(tok, "{"))
909 					break;
910 				if (strstr(tok, "=")) {
911 					SPLIT(v, tok, "=");
912 					GRAB_STR("id", v, tok, uuid,
913 					    sizeof(uuid));
914 				}
915 			}
916 			if (strcmp(vg->vg_uuid, uuid) == 0) {
917 				/* existing vg */
918 				md->md_vg = vg;
919 				return (0);
920 			}
921 			/* XXX different volume group with name clash! */
922 			G_LLVM_DEBUG(0,
923 			    "%s already exists, volume group not loaded", name);
924 			return (EINVAL);
925 		}
926 	}
927 
928 	vg = malloc(sizeof(*vg), M_GLLVM, M_NOWAIT|M_ZERO);
929 	if (vg == NULL)
930 		return (ENOMEM);
931 
932 	strncpy(vg->vg_name, name, sizeof(vg->vg_name));
933 	LIST_INIT(&vg->vg_pvs);
934 	LIST_INIT(&vg->vg_lvs);
935 
936 #define	VOL_FOREACH(func, tok, buf, p)					\
937 	while ((tok = strsep(buf, "\n")) != NULL) {			\
938 		if (strstr(tok, "{")) {					\
939 			func(buf, tok, p);				\
940 			continue;					\
941 		}							\
942 		if (strstr(tok, "}"))					\
943 			break;						\
944 	}
945 
946 	while ((tok = strsep(&buf, "\n")) != NULL) {
947 		if (strcmp(tok, "physical_volumes {") == 0) {
948 			VOL_FOREACH(llvm_textconf_decode_pv, tok, &buf, vg);
949 			continue;
950 		}
951 		if (strcmp(tok, "logical_volumes {") == 0) {
952 			VOL_FOREACH(llvm_textconf_decode_lv, tok, &buf, vg);
953 			continue;
954 		}
955 		if (strstr(tok, "{")) {
956 			G_LLVM_DEBUG(2, "unknown section %s", tok);
957 			continue;
958 		}
959 
960 		/* parse 'key = value' lines */
961 		if (strstr(tok, "=")) {
962 			SPLIT(v, tok, "=");
963 			GRAB_STR("id", v, tok, vg->vg_uuid, sizeof(vg->vg_uuid));
964 			GRAB_INT("extent_size", v, tok, vg->vg_extentsize);
965 			continue;
966 		}
967 	}
968 	/* basic checking */
969 	if (vg->vg_extentsize == 0)
970 		goto bad;
971 
972 	md->md_vg = vg;
973 	LIST_INSERT_HEAD(&vg_list, vg, vg_next);
974 	G_LLVM_DEBUG(3, "vg: name=%s uuid=%s", vg->vg_name, vg->vg_uuid);
975 	return(0);
976 
977 bad:
978 	g_llvm_free_vg(vg);
979 	return (-1);
980 }
981 #undef	VOL_FOREACH
982 
983 static int
984 llvm_textconf_decode_pv(char **buf, char *tok, struct g_llvm_vg *vg)
985 {
986 	struct g_llvm_pv	*pv;
987 	char *v;
988 	size_t len;
989 
990 	if (*buf == NULL || **buf == '\0')
991 		return (EINVAL);
992 
993 	pv = malloc(sizeof(*pv), M_GLLVM, M_NOWAIT|M_ZERO);
994 	if (pv == NULL)
995 		return (ENOMEM);
996 
997 	pv->pv_vg = vg;
998 	len = 0;
999 	if (tok == NULL)
1000 		goto bad;
1001 	len = llvm_grab_name(pv->pv_name, tok);
1002 	if (len == 0)
1003 		goto bad;
1004 
1005 	while ((tok = strsep(buf, "\n")) != NULL) {
1006 		if (strstr(tok, "{"))
1007 			goto bad;
1008 
1009 		if (strstr(tok, "}"))
1010 			break;
1011 
1012 		/* parse 'key = value' lines */
1013 		if (strstr(tok, "=")) {
1014 			SPLIT(v, tok, "=");
1015 			GRAB_STR("id", v, tok, pv->pv_uuid, sizeof(pv->pv_uuid));
1016 			GRAB_INT("pe_start", v, tok, pv->pv_start);
1017 			GRAB_INT("pe_count", v, tok, pv->pv_count);
1018 			continue;
1019 		}
1020 	}
1021 	if (tok == NULL)
1022 		goto bad;
1023 	/* basic checking */
1024 	if (pv->pv_count == 0)
1025 		goto bad;
1026 
1027 	LIST_INSERT_HEAD(&vg->vg_pvs, pv, pv_next);
1028 	G_LLVM_DEBUG(3, "pv: name=%s uuid=%s", pv->pv_name, pv->pv_uuid);
1029 
1030 	return (0);
1031 bad:
1032 	free(pv, M_GLLVM);
1033 	return (-1);
1034 }
1035 
1036 static int
1037 llvm_textconf_decode_lv(char **buf, char *tok, struct g_llvm_vg *vg)
1038 {
1039 	struct g_llvm_lv	*lv;
1040 	struct g_llvm_segment *sg;
1041 	char *v;
1042 	size_t len;
1043 
1044 	if (*buf == NULL || **buf == '\0')
1045 		return (EINVAL);
1046 
1047 	lv = malloc(sizeof(*lv), M_GLLVM, M_NOWAIT|M_ZERO);
1048 	if (lv == NULL)
1049 		return (ENOMEM);
1050 
1051 	lv->lv_vg = vg;
1052 	LIST_INIT(&lv->lv_segs);
1053 
1054 	if (tok == NULL)
1055 		goto bad;
1056 	len = llvm_grab_name(lv->lv_name, tok);
1057 	if (len == 0)
1058 		goto bad;
1059 
1060 	while ((tok = strsep(buf, "\n")) != NULL) {
1061 		if (strstr(tok, "{")) {
1062 			if (strstr(tok, "segment")) {
1063 				llvm_textconf_decode_sg(buf, tok, lv);
1064 				continue;
1065 			} else
1066 				/* unexpected section */
1067 				goto bad;
1068 		}
1069 
1070 		if (strstr(tok, "}"))
1071 			break;
1072 
1073 		/* parse 'key = value' lines */
1074 		if (strstr(tok, "=")) {
1075 			SPLIT(v, tok, "=");
1076 			GRAB_STR("id", v, tok, lv->lv_uuid, sizeof(lv->lv_uuid));
1077 			GRAB_INT("segment_count", v, tok, lv->lv_sgcount);
1078 			continue;
1079 		}
1080 	}
1081 	if (tok == NULL)
1082 		goto bad;
1083 	if (lv->lv_sgcount == 0 || lv->lv_sgcount != lv->lv_numsegs)
1084 		/* zero or incomplete segment list */
1085 		goto bad;
1086 
1087 	/* Optimize for only one segment on the pv */
1088 	lv->lv_firstsg = LIST_FIRST(&lv->lv_segs);
1089 	LIST_INSERT_HEAD(&vg->vg_lvs, lv, lv_next);
1090 	G_LLVM_DEBUG(3, "lv: name=%s uuid=%s", lv->lv_name, lv->lv_uuid);
1091 
1092 	return (0);
1093 bad:
1094 	while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
1095 		LIST_REMOVE(sg, sg_next);
1096 		free(sg, M_GLLVM);
1097 	}
1098 	free(lv, M_GLLVM);
1099 	return (-1);
1100 }
1101 
1102 static int
1103 llvm_textconf_decode_sg(char **buf, char *tok, struct g_llvm_lv *lv)
1104 {
1105 	struct g_llvm_segment *sg;
1106 	char *v;
1107 	int count = 0;
1108 
1109 	if (*buf == NULL || **buf == '\0')
1110 		return (EINVAL);
1111 
1112 	sg = malloc(sizeof(*sg), M_GLLVM, M_NOWAIT|M_ZERO);
1113 	if (sg == NULL)
1114 		return (ENOMEM);
1115 
1116 	while ((tok = strsep(buf, "\n")) != NULL) {
1117 		/* only a single linear stripe is supported */
1118 		if (strstr(tok, "stripe_count")) {
1119 			SPLIT(v, tok, "=");
1120 			GRAB_INT("stripe_count", v, tok, count);
1121 			if (count != 1)
1122 				goto bad;
1123 		}
1124 
1125 		if (strstr(tok, "{"))
1126 			goto bad;
1127 
1128 		if (strstr(tok, "}"))
1129 			break;
1130 
1131 		if (strcmp(tok, "stripes = [") == 0) {
1132 			tok = strsep(buf, "\n");
1133 			if (tok == NULL)
1134 				goto bad;
1135 
1136 			strsep(&tok, "\"");
1137 			if (tok == NULL)
1138 				goto bad;	/* missing open quotes */
1139 			v = strsep(&tok, "\"");
1140 			if (tok == NULL)
1141 				goto bad;	/* missing close quotes */
1142 			strncpy(sg->sg_pvname, v, sizeof(sg->sg_pvname));
1143 			if (*tok != ',')
1144 				goto bad;	/* missing comma for stripe */
1145 			tok++;
1146 
1147 			sg->sg_pvstart = strtol(tok, &v, 10);
1148 			if (v == tok)
1149 				/* strtol did not eat any of the buffer */
1150 				goto bad;
1151 
1152 			continue;
1153 		}
1154 
1155 		/* parse 'key = value' lines */
1156 		if (strstr(tok, "=")) {
1157 			SPLIT(v, tok, "=");
1158 			GRAB_INT("start_extent", v, tok, sg->sg_start);
1159 			GRAB_INT("extent_count", v, tok, sg->sg_count);
1160 			continue;
1161 		}
1162 	}
1163 	if (tok == NULL)
1164 		goto bad;
1165 	/* basic checking */
1166 	if (count != 1 || sg->sg_count == 0)
1167 		goto bad;
1168 
1169 	sg->sg_end = sg->sg_start + sg->sg_count - 1;
1170 	lv->lv_numsegs++;
1171 	lv->lv_extentcount += sg->sg_count;
1172 	LIST_INSERT_HEAD(&lv->lv_segs, sg, sg_next);
1173 
1174 	return (0);
1175 bad:
1176 	free(sg, M_GLLVM);
1177 	return (-1);
1178 }
1179 #undef	GRAB_INT
1180 #undef	GRAB_STR
1181 #undef	SPLIT
1182 
1183 static struct g_class g_llvm_class = {
1184 	.name = G_LLVM_CLASS_NAME,
1185 	.version = G_VERSION,
1186 	.init = g_llvm_init,
1187 	.taste = g_llvm_taste,
1188 	.destroy_geom = g_llvm_destroy_geom
1189 };
1190 
1191 DECLARE_GEOM_CLASS(g_llvm_class, g_linux_lvm);
1192