xref: /freebsd/sys/geom/linux_lvm/g_linux_lvm.c (revision d8a0fe102c0cfdfcd5b818f850eff09d8536c9bc)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Andrew Thompson <thompsa@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <sys/cdefs.h>
30 __FBSDID("$FreeBSD$");
31 
32 #include <sys/ctype.h>
33 #include <sys/param.h>
34 #include <sys/bio.h>
35 #include <sys/kernel.h>
36 #include <sys/limits.h>
37 #include <sys/malloc.h>
38 #include <sys/queue.h>
39 #include <sys/sysctl.h>
40 #include <sys/systm.h>
41 
42 #include <geom/geom.h>
43 #include <sys/endian.h>
44 
45 #include <geom/linux_lvm/g_linux_lvm.h>
46 
47 FEATURE(geom_linux_lvm, "GEOM Linux LVM partitioning support");
48 
49 /* Declare malloc(9) label */
50 static MALLOC_DEFINE(M_GLLVM, "gllvm", "GEOM_LINUX_LVM Data");
51 
52 /* GEOM class methods */
53 static g_access_t g_llvm_access;
54 static g_init_t g_llvm_init;
55 static g_orphan_t g_llvm_orphan;
56 static g_orphan_t g_llvm_taste_orphan;
57 static g_start_t g_llvm_start;
58 static g_taste_t g_llvm_taste;
59 static g_ctl_destroy_geom_t g_llvm_destroy_geom;
60 
61 static void	g_llvm_done(struct bio *);
62 static void	g_llvm_remove_disk(struct g_llvm_vg *, struct g_consumer *);
63 static int	g_llvm_activate_lv(struct g_llvm_vg *, struct g_llvm_lv *);
64 static int	g_llvm_add_disk(struct g_llvm_vg *, struct g_provider *, char *);
65 static void	g_llvm_free_vg(struct g_llvm_vg *);
66 static int	g_llvm_destroy(struct g_llvm_vg *, int);
67 static int	g_llvm_read_label(struct g_consumer *, struct g_llvm_label *);
68 static int	g_llvm_read_md(struct g_consumer *, struct g_llvm_metadata *,
69 		    struct g_llvm_label *);
70 
71 static int	llvm_label_decode(const u_char *, struct g_llvm_label *, int);
72 static int	llvm_md_decode(const u_char *, struct g_llvm_metadata *,
73 		    struct g_llvm_label *);
74 static int	llvm_textconf_decode(u_char *, int,
75 		    struct g_llvm_metadata *);
76 static int	llvm_textconf_decode_pv(char **, char *, struct g_llvm_vg *);
77 static int	llvm_textconf_decode_lv(char **, char *, struct g_llvm_vg *);
78 static int	llvm_textconf_decode_sg(char **, char *, struct g_llvm_lv *);
79 
80 SYSCTL_DECL(_kern_geom);
81 SYSCTL_NODE(_kern_geom, OID_AUTO, linux_lvm, CTLFLAG_RW, 0,
82     "GEOM_LINUX_LVM stuff");
83 static u_int g_llvm_debug = 0;
84 SYSCTL_UINT(_kern_geom_linux_lvm, OID_AUTO, debug, CTLFLAG_RWTUN, &g_llvm_debug, 0,
85     "Debug level");
86 
87 LIST_HEAD(, g_llvm_vg) vg_list;
88 
89 /*
90  * Called to notify geom when it's been opened, and for what intent
91  */
92 static int
93 g_llvm_access(struct g_provider *pp, int dr, int dw, int de)
94 {
95 	struct g_consumer *c;
96 	struct g_llvm_vg *vg;
97 	struct g_geom *gp;
98 	int error;
99 
100 	KASSERT(pp != NULL, ("%s: NULL provider", __func__));
101 	gp = pp->geom;
102 	KASSERT(gp != NULL, ("%s: NULL geom", __func__));
103 	vg = gp->softc;
104 
105 	if (vg == NULL) {
106 		/* It seems that .access can be called with negative dr,dw,dx
107 		 * in this case but I want to check for myself */
108 		G_LLVM_DEBUG(0, "access(%d, %d, %d) for %s",
109 		    dr, dw, de, pp->name);
110 
111 		/* This should only happen when geom is withered so
112 		 * allow only negative requests */
113 		KASSERT(dr <= 0 && dw <= 0 && de <= 0,
114 		    ("%s: Positive access for %s", __func__, pp->name));
115 		if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
116 			G_LLVM_DEBUG(0,
117 			    "Device %s definitely destroyed", pp->name);
118 		return (0);
119 	}
120 
121 	/* Grab an exclusive bit to propagate on our consumers on first open */
122 	if (pp->acr == 0 && pp->acw == 0 && pp->ace == 0)
123 		de++;
124 	/* ... drop it on close */
125 	if (pp->acr + dr == 0 && pp->acw + dw == 0 && pp->ace + de == 0)
126 		de--;
127 
128 	error = ENXIO;
129 	LIST_FOREACH(c, &gp->consumer, consumer) {
130 		KASSERT(c != NULL, ("%s: consumer is NULL", __func__));
131 		error = g_access(c, dr, dw, de);
132 		if (error != 0) {
133 			struct g_consumer *c2;
134 
135 			/* Backout earlier changes */
136 			LIST_FOREACH(c2, &gp->consumer, consumer) {
137 				if (c2 == c) /* all eariler components fixed */
138 					return (error);
139 				g_access(c2, -dr, -dw, -de);
140 			}
141 		}
142 	}
143 
144 	return (error);
145 }
146 
147 /*
148  * Dismantle bio_queue and destroy its components
149  */
150 static void
151 bioq_dismantle(struct bio_queue_head *bq)
152 {
153 	struct bio *b;
154 
155 	for (b = bioq_first(bq); b != NULL; b = bioq_first(bq)) {
156 		bioq_remove(bq, b);
157 		g_destroy_bio(b);
158 	}
159 }
160 
161 /*
162  * GEOM .done handler
163  * Can't use standard handler because one requested IO may
164  * fork into additional data IOs
165  */
166 static void
167 g_llvm_done(struct bio *b)
168 {
169 	struct bio *parent_b;
170 
171 	parent_b = b->bio_parent;
172 
173 	if (b->bio_error != 0) {
174 		G_LLVM_DEBUG(0, "Error %d for offset=%ju, length=%ju on %s",
175 		    b->bio_error, b->bio_offset, b->bio_length,
176 		    b->bio_to->name);
177 		if (parent_b->bio_error == 0)
178 			parent_b->bio_error = b->bio_error;
179 	}
180 
181 	parent_b->bio_inbed++;
182 	parent_b->bio_completed += b->bio_completed;
183 
184 	if (parent_b->bio_children == parent_b->bio_inbed) {
185 		parent_b->bio_completed = parent_b->bio_length;
186 		g_io_deliver(parent_b, parent_b->bio_error);
187 	}
188 	g_destroy_bio(b);
189 }
190 
191 static void
192 g_llvm_start(struct bio *bp)
193 {
194 	struct g_provider *pp;
195 	struct g_llvm_vg *vg;
196 	struct g_llvm_pv *pv;
197 	struct g_llvm_lv *lv;
198 	struct g_llvm_segment *sg;
199 	struct bio *cb;
200 	struct bio_queue_head bq;
201 	size_t chunk_size;
202 	off_t offset, length;
203 	char *addr;
204 	u_int count;
205 
206 	pp = bp->bio_to;
207 	lv = pp->private;
208 	vg = pp->geom->softc;
209 
210 	switch (bp->bio_cmd) {
211 	case BIO_READ:
212 	case BIO_WRITE:
213 	case BIO_DELETE:
214 	/* XXX BIO_GETATTR allowed? */
215 		break;
216 	default:
217 		g_io_deliver(bp, EOPNOTSUPP);
218 		return;
219 	}
220 
221 	bioq_init(&bq);
222 
223 	chunk_size = vg->vg_extentsize;
224 	addr = bp->bio_data;
225 	offset = bp->bio_offset;	/* virtual offset and length */
226 	length = bp->bio_length;
227 
228 	while (length > 0) {
229 		size_t chunk_index, in_chunk_offset, in_chunk_length;
230 
231 		pv = NULL;
232 		cb = g_clone_bio(bp);
233 		if (cb == NULL) {
234 			bioq_dismantle(&bq);
235 			if (bp->bio_error == 0)
236 				bp->bio_error = ENOMEM;
237 			g_io_deliver(bp, bp->bio_error);
238 			return;
239 		}
240 
241 		/* get the segment and the pv */
242 		if (lv->lv_sgcount == 1) {
243 			/* skip much of the calculations for a single sg */
244 			chunk_index = 0;
245 			in_chunk_offset = 0;
246 			in_chunk_length = length;
247 			sg = lv->lv_firstsg;
248 			pv = sg->sg_pv;
249 			cb->bio_offset = offset + sg->sg_pvoffset;
250 		} else {
251 			chunk_index = offset / chunk_size; /* round downwards */
252 			in_chunk_offset = offset % chunk_size;
253 			in_chunk_length =
254 			    min(length, chunk_size - in_chunk_offset);
255 
256 			/* XXX could be faster */
257 			LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
258 				if (chunk_index >= sg->sg_start &&
259 				    chunk_index <= sg->sg_end) {
260 					/* adjust chunk index for sg start */
261 					chunk_index -= sg->sg_start;
262 					pv = sg->sg_pv;
263 					break;
264 				}
265 			}
266 			cb->bio_offset =
267 			    (off_t)chunk_index * (off_t)chunk_size
268 			    + in_chunk_offset + sg->sg_pvoffset;
269 		}
270 
271 		KASSERT(pv != NULL, ("Can't find PV for chunk %zu",
272 		    chunk_index));
273 
274 		cb->bio_to = pv->pv_gprov;
275 		cb->bio_done = g_llvm_done;
276 		cb->bio_length = in_chunk_length;
277 		cb->bio_data = addr;
278 		cb->bio_caller1 = pv;
279 		bioq_disksort(&bq, cb);
280 
281 		G_LLVM_DEBUG(5,
282 		    "Mapped %s(%ju, %ju) on %s to %zu(%zu,%zu) @ %s:%ju",
283 		    bp->bio_cmd == BIO_READ ? "R" : "W",
284 		    offset, length, lv->lv_name,
285 		    chunk_index, in_chunk_offset, in_chunk_length,
286 		    pv->pv_name, cb->bio_offset);
287 
288 		addr += in_chunk_length;
289 		length -= in_chunk_length;
290 		offset += in_chunk_length;
291 	}
292 
293 	/* Fire off bio's here */
294 	count = 0;
295 	for (cb = bioq_first(&bq); cb != NULL; cb = bioq_first(&bq)) {
296 		bioq_remove(&bq, cb);
297 		pv = cb->bio_caller1;
298 		cb->bio_caller1 = NULL;
299 		G_LLVM_DEBUG(6, "firing bio to %s, offset=%ju, length=%ju",
300 		    cb->bio_to->name, cb->bio_offset, cb->bio_length);
301 		g_io_request(cb, pv->pv_gcons);
302 		count++;
303 	}
304 	if (count == 0) { /* We handled everything locally */
305 		bp->bio_completed = bp->bio_length;
306 		g_io_deliver(bp, 0);
307 	}
308 }
309 
310 static void
311 g_llvm_remove_disk(struct g_llvm_vg *vg, struct g_consumer *cp)
312 {
313 	struct g_llvm_pv *pv;
314 	struct g_llvm_lv *lv;
315 	struct g_llvm_segment *sg;
316 	int found;
317 
318 	KASSERT(cp != NULL, ("Non-valid disk in %s.", __func__));
319 	pv = (struct g_llvm_pv *)cp->private;
320 
321 	G_LLVM_DEBUG(0, "Disk %s removed from %s.", cp->provider->name,
322 	    pv->pv_name);
323 
324 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
325 		/* Find segments that map to this disk */
326 		found = 0;
327 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
328 			if (sg->sg_pv == pv) {
329 				sg->sg_pv = NULL;
330 				lv->lv_sgactive--;
331 				found = 1;
332 				break;
333 			}
334 		}
335 		if (found) {
336 			G_LLVM_DEBUG(0, "Device %s removed.",
337 			    lv->lv_gprov->name);
338 			g_wither_provider(lv->lv_gprov, ENXIO);
339 			lv->lv_gprov = NULL;
340 		}
341 	}
342 
343 	if (cp->acr > 0 || cp->acw > 0 || cp->ace > 0)
344 		g_access(cp, -cp->acr, -cp->acw, -cp->ace);
345 	g_detach(cp);
346 	g_destroy_consumer(cp);
347 }
348 
349 static void
350 g_llvm_orphan(struct g_consumer *cp)
351 {
352 	struct g_llvm_vg *vg;
353 	struct g_geom *gp;
354 
355 	g_topology_assert();
356 	gp = cp->geom;
357 	vg = gp->softc;
358 	if (vg == NULL)
359 		return;
360 
361 	g_llvm_remove_disk(vg, cp);
362 	g_llvm_destroy(vg, 1);
363 }
364 
365 static int
366 g_llvm_activate_lv(struct g_llvm_vg *vg, struct g_llvm_lv *lv)
367 {
368 	struct g_geom *gp;
369 	struct g_provider *pp;
370 
371 	g_topology_assert();
372 
373 	KASSERT(lv->lv_sgactive == lv->lv_sgcount, ("segment missing"));
374 
375 	gp = vg->vg_geom;
376 	pp = g_new_providerf(gp, "linux_lvm/%s-%s", vg->vg_name, lv->lv_name);
377 	pp->mediasize = vg->vg_extentsize * (off_t)lv->lv_extentcount;
378 	pp->sectorsize = vg->vg_sectorsize;
379 	g_error_provider(pp, 0);
380 	lv->lv_gprov = pp;
381 	pp->private = lv;
382 
383 	G_LLVM_DEBUG(1, "Created %s, %juM", pp->name,
384 	    pp->mediasize / (1024*1024));
385 
386 	return (0);
387 }
388 
389 static int
390 g_llvm_add_disk(struct g_llvm_vg *vg, struct g_provider *pp, char *uuid)
391 {
392 	struct g_geom *gp;
393 	struct g_consumer *cp, *fcp;
394 	struct g_llvm_pv *pv;
395 	struct g_llvm_lv *lv;
396 	struct g_llvm_segment *sg;
397 	int error;
398 
399 	g_topology_assert();
400 
401 	LIST_FOREACH(pv, &vg->vg_pvs, pv_next) {
402 		if (strcmp(pv->pv_uuid, uuid) == 0)
403 			break;	/* found it */
404 	}
405 	if (pv == NULL) {
406 		G_LLVM_DEBUG(3, "uuid %s not found in pv list", uuid);
407 		return (ENOENT);
408 	}
409 	if (pv->pv_gprov != NULL) {
410 		G_LLVM_DEBUG(0, "disk %s already initialised in %s",
411 		    pv->pv_name, vg->vg_name);
412 		return (EEXIST);
413 	}
414 
415 	pv->pv_start *= vg->vg_sectorsize;
416 	gp = vg->vg_geom;
417 	fcp = LIST_FIRST(&gp->consumer);
418 
419 	cp = g_new_consumer(gp);
420 	error = g_attach(cp, pp);
421 	G_LLVM_DEBUG(1, "Attached %s to %s at offset %ju",
422 	    pp->name, pv->pv_name, pv->pv_start);
423 
424 	if (error != 0) {
425 		G_LLVM_DEBUG(0, "cannot attach %s to %s",
426 		    pp->name, vg->vg_name);
427 		g_destroy_consumer(cp);
428 		return (error);
429 	}
430 
431 	if (fcp != NULL) {
432 		if (fcp->provider->sectorsize != pp->sectorsize) {
433 			G_LLVM_DEBUG(0, "Provider %s of %s has invalid "
434 			    "sector size (%d)", pp->name, vg->vg_name,
435 			    pp->sectorsize);
436 			return (EINVAL);
437 		}
438 		if (fcp->acr > 0 || fcp->acw || fcp->ace > 0) {
439 			/* Replicate access permissions from first "live"
440 			 * consumer to the new one */
441 			error = g_access(cp, fcp->acr, fcp->acw, fcp->ace);
442 			if (error != 0) {
443 				g_detach(cp);
444 				g_destroy_consumer(cp);
445 				return (error);
446 			}
447 		}
448 	}
449 
450 	cp->private = pv;
451 	pv->pv_gcons = cp;
452 	pv->pv_gprov = pp;
453 
454 	LIST_FOREACH(lv, &vg->vg_lvs, lv_next) {
455 		/* Find segments that map to this disk */
456 		LIST_FOREACH(sg, &lv->lv_segs, sg_next) {
457 			if (strcmp(sg->sg_pvname, pv->pv_name) == 0) {
458 				/* avtivate the segment */
459 				KASSERT(sg->sg_pv == NULL,
460 				    ("segment already mapped"));
461 				sg->sg_pvoffset =
462 				    (off_t)sg->sg_pvstart * vg->vg_extentsize
463 				    + pv->pv_start;
464 				sg->sg_pv = pv;
465 				lv->lv_sgactive++;
466 
467 				G_LLVM_DEBUG(2, "%s: %d to %d @ %s:%d"
468 				    " offset %ju sector %ju",
469 				    lv->lv_name, sg->sg_start, sg->sg_end,
470 				    sg->sg_pvname, sg->sg_pvstart,
471 				    sg->sg_pvoffset,
472 				    sg->sg_pvoffset / vg->vg_sectorsize);
473 			}
474 		}
475 		/* Activate any lvs waiting on this disk */
476 		if (lv->lv_gprov == NULL && lv->lv_sgactive == lv->lv_sgcount) {
477 			error = g_llvm_activate_lv(vg, lv);
478 			if (error)
479 				break;
480 		}
481 	}
482 	return (error);
483 }
484 
485 static void
486 g_llvm_init(struct g_class *mp)
487 {
488 	LIST_INIT(&vg_list);
489 }
490 
491 static void
492 g_llvm_free_vg(struct g_llvm_vg *vg)
493 {
494 	struct g_llvm_pv *pv;
495 	struct g_llvm_lv *lv;
496 	struct g_llvm_segment *sg;
497 
498 	/* Free all the structures */
499 	while ((pv = LIST_FIRST(&vg->vg_pvs)) != NULL) {
500 		LIST_REMOVE(pv, pv_next);
501 		free(pv, M_GLLVM);
502 	}
503 	while ((lv = LIST_FIRST(&vg->vg_lvs)) != NULL) {
504 		while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
505 			LIST_REMOVE(sg, sg_next);
506 			free(sg, M_GLLVM);
507 		}
508 		LIST_REMOVE(lv, lv_next);
509 		free(lv, M_GLLVM);
510 	}
511 	LIST_REMOVE(vg, vg_next);
512 	free(vg, M_GLLVM);
513 }
514 
515 static void
516 g_llvm_taste_orphan(struct g_consumer *cp)
517 {
518 
519 	KASSERT(1 == 0, ("%s called while tasting %s.", __func__,
520 	    cp->provider->name));
521 }
522 
523 static struct g_geom *
524 g_llvm_taste(struct g_class *mp, struct g_provider *pp, int flags __unused)
525 {
526 	struct g_consumer *cp;
527 	struct g_geom *gp;
528 	struct g_llvm_label ll;
529 	struct g_llvm_metadata md;
530 	struct g_llvm_vg *vg;
531 	int error;
532 
533 	bzero(&md, sizeof(md));
534 
535 	g_topology_assert();
536 	g_trace(G_T_TOPOLOGY, "%s(%s, %s)", __func__, mp->name, pp->name);
537 	gp = g_new_geomf(mp, "linux_lvm:taste");
538 	/* This orphan function should be never called. */
539 	gp->orphan = g_llvm_taste_orphan;
540 	cp = g_new_consumer(gp);
541 	g_attach(cp, pp);
542 	error = g_llvm_read_label(cp, &ll);
543 	if (!error)
544 		error = g_llvm_read_md(cp, &md, &ll);
545 	g_detach(cp);
546 	g_destroy_consumer(cp);
547 	g_destroy_geom(gp);
548 	if (error != 0)
549 		return (NULL);
550 
551 	vg = md.md_vg;
552 	if (vg->vg_geom == NULL) {
553 		/* new volume group */
554 		gp = g_new_geomf(mp, "%s", vg->vg_name);
555 		gp->start = g_llvm_start;
556 		gp->spoiled = g_llvm_orphan;
557 		gp->orphan = g_llvm_orphan;
558 		gp->access = g_llvm_access;
559 		vg->vg_sectorsize = pp->sectorsize;
560 		vg->vg_extentsize *= vg->vg_sectorsize;
561 		vg->vg_geom = gp;
562 		gp->softc = vg;
563 		G_LLVM_DEBUG(1, "Created volume %s, extent size %zuK",
564 		    vg->vg_name, vg->vg_extentsize / 1024);
565 	}
566 
567 	/* initialise this disk in the volume group */
568 	g_llvm_add_disk(vg, pp, ll.ll_uuid);
569 	return (vg->vg_geom);
570 }
571 
572 static int
573 g_llvm_destroy(struct g_llvm_vg *vg, int force)
574 {
575 	struct g_provider *pp;
576 	struct g_geom *gp;
577 
578 	g_topology_assert();
579 	if (vg == NULL)
580 		return (ENXIO);
581 	gp = vg->vg_geom;
582 
583 	LIST_FOREACH(pp, &gp->provider, provider) {
584 		if (pp->acr != 0 || pp->acw != 0 || pp->ace != 0) {
585 			G_LLVM_DEBUG(1, "Device %s is still open (r%dw%de%d)",
586 			    pp->name, pp->acr, pp->acw, pp->ace);
587 			if (!force)
588 				return (EBUSY);
589 		}
590 	}
591 
592 	g_llvm_free_vg(gp->softc);
593 	gp->softc = NULL;
594 	g_wither_geom(gp, ENXIO);
595 	return (0);
596 }
597 
598 static int
599 g_llvm_destroy_geom(struct gctl_req *req __unused, struct g_class *mp __unused,
600     struct g_geom *gp)
601 {
602 	struct g_llvm_vg *vg;
603 
604 	vg = gp->softc;
605 	return (g_llvm_destroy(vg, 0));
606 }
607 
608 int
609 g_llvm_read_label(struct g_consumer *cp, struct g_llvm_label *ll)
610 {
611 	struct g_provider *pp;
612 	u_char *buf;
613 	int i, error = 0;
614 
615 	g_topology_assert();
616 
617 	/* The LVM label is stored on the first four sectors */
618 	error = g_access(cp, 1, 0, 0);
619 	if (error != 0)
620 		return (error);
621 	pp = cp->provider;
622 	g_topology_unlock();
623 	buf = g_read_data(cp, 0, pp->sectorsize * 4, &error);
624 	g_topology_lock();
625 	g_access(cp, -1, 0, 0);
626 	if (buf == NULL) {
627 		G_LLVM_DEBUG(1, "Cannot read metadata from %s (error=%d)",
628 		    pp->name, error);
629 		return (error);
630 	}
631 
632 	/* Search the four sectors for the LVM label. */
633 	for (i = 0; i < 4; i++) {
634 		error = llvm_label_decode(&buf[i * pp->sectorsize], ll, i);
635 		if (error == 0)
636 			break;	/* found it */
637 	}
638 	g_free(buf);
639 	return (error);
640 }
641 
642 int
643 g_llvm_read_md(struct g_consumer *cp, struct g_llvm_metadata *md,
644     struct g_llvm_label *ll)
645 {
646 	struct g_provider *pp;
647 	u_char *buf;
648 	int error;
649 	int size;
650 
651 	g_topology_assert();
652 
653 	error = g_access(cp, 1, 0, 0);
654 	if (error != 0)
655 		return (error);
656 	pp = cp->provider;
657 	g_topology_unlock();
658 	buf = g_read_data(cp, ll->ll_md_offset, pp->sectorsize, &error);
659 	g_topology_lock();
660 	g_access(cp, -1, 0, 0);
661 	if (buf == NULL) {
662 		G_LLVM_DEBUG(0, "Cannot read metadata from %s (error=%d)",
663 		    cp->provider->name, error);
664 		return (error);
665 	}
666 
667 	error = llvm_md_decode(buf, md, ll);
668 	g_free(buf);
669 	if (error != 0) {
670 		return (error);
671 	}
672 
673 	G_LLVM_DEBUG(1, "reading LVM2 config @ %s:%ju", pp->name,
674 		    ll->ll_md_offset + md->md_reloffset);
675 	error = g_access(cp, 1, 0, 0);
676 	if (error != 0)
677 		return (error);
678 	pp = cp->provider;
679 	g_topology_unlock();
680 	/* round up to the nearest sector */
681 	size = md->md_relsize +
682 	    (pp->sectorsize - md->md_relsize % pp->sectorsize);
683 	buf = g_read_data(cp, ll->ll_md_offset + md->md_reloffset, size, &error);
684 	g_topology_lock();
685 	g_access(cp, -1, 0, 0);
686 	if (buf == NULL) {
687 		G_LLVM_DEBUG(0, "Cannot read LVM2 config from %s (error=%d)",
688 		    pp->name, error);
689 		return (error);
690 	}
691 	buf[md->md_relsize] = '\0';
692 	G_LLVM_DEBUG(10, "LVM config:\n%s\n", buf);
693 	error = llvm_textconf_decode(buf, md->md_relsize, md);
694 	g_free(buf);
695 
696 	return (error);
697 }
698 
699 static int
700 llvm_label_decode(const u_char *data, struct g_llvm_label *ll, int sector)
701 {
702 	uint64_t off;
703 	char *uuid;
704 
705 	/* Magic string */
706 	if (bcmp("LABELONE", data , 8) != 0)
707 		return (EINVAL);
708 
709 	/* We only support LVM2 text format */
710 	if (bcmp("LVM2 001", data + 24, 8) != 0) {
711 		G_LLVM_DEBUG(0, "Unsupported LVM format");
712 		return (EINVAL);
713 	}
714 
715 	ll->ll_sector = le64dec(data + 8);
716 	ll->ll_crc = le32dec(data + 16);
717 	ll->ll_offset = le32dec(data + 20);
718 
719 	if (ll->ll_sector != sector) {
720 		G_LLVM_DEBUG(0, "Expected sector %ju, found at %d",
721 		    ll->ll_sector, sector);
722 		return (EINVAL);
723 	}
724 
725 	off = ll->ll_offset;
726 	/*
727 	 * convert the binary uuid to string format, the format is
728 	 * xxxxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxxxx (6-4-4-4-4-4-6)
729 	 */
730 	uuid = ll->ll_uuid;
731 	bcopy(data + off, uuid, 6);
732 	off += 6;
733 	uuid += 6;
734 	*uuid++ = '-';
735 	for (int i = 0; i < 5; i++) {
736 		bcopy(data + off, uuid, 4);
737 		off += 4;
738 		uuid += 4;
739 		*uuid++ = '-';
740 	}
741 	bcopy(data + off, uuid, 6);
742 	off += 6;
743 	uuid += 6;
744 	*uuid++ = '\0';
745 
746 	ll->ll_size = le64dec(data + off);
747 	off += 8;
748 	ll->ll_pestart = le64dec(data + off);
749 	off += 16;
750 
751 	/* Only one data section is supported */
752 	if (le64dec(data + off) != 0) {
753 		G_LLVM_DEBUG(0, "Only one data section supported");
754 		return (EINVAL);
755 	}
756 
757 	off += 16;
758 	ll->ll_md_offset = le64dec(data + off);
759 	off += 8;
760 	ll->ll_md_size = le64dec(data + off);
761 	off += 8;
762 
763 	G_LLVM_DEBUG(1, "LVM metadata: offset=%ju, size=%ju", ll->ll_md_offset,
764 	    ll->ll_md_size);
765 
766 	/* Only one data section is supported */
767 	if (le64dec(data + off) != 0) {
768 		G_LLVM_DEBUG(0, "Only one metadata section supported");
769 		return (EINVAL);
770 	}
771 
772 	G_LLVM_DEBUG(2, "label uuid=%s", ll->ll_uuid);
773 	G_LLVM_DEBUG(2, "sector=%ju, crc=%u, offset=%u, size=%ju, pestart=%ju",
774 	    ll->ll_sector, ll->ll_crc, ll->ll_offset, ll->ll_size,
775 	    ll->ll_pestart);
776 
777 	return (0);
778 }
779 
780 static int
781 llvm_md_decode(const u_char *data, struct g_llvm_metadata *md,
782     struct g_llvm_label *ll)
783 {
784 	uint64_t off;
785 	char magic[16];
786 
787 	off = 0;
788 	md->md_csum = le32dec(data + off);
789 	off += 4;
790 	bcopy(data + off, magic, 16);
791 	off += 16;
792 	md->md_version = le32dec(data + off);
793 	off += 4;
794 	md->md_start = le64dec(data + off);
795 	off += 8;
796 	md->md_size = le64dec(data + off);
797 	off += 8;
798 
799 	if (bcmp(G_LLVM_MAGIC, magic, 16) != 0) {
800 		G_LLVM_DEBUG(0, "Incorrect md magic number");
801 		return (EINVAL);
802 	}
803 	if (md->md_version != 1) {
804 		G_LLVM_DEBUG(0, "Incorrect md version number (%u)",
805 		    md->md_version);
806 		return (EINVAL);
807 	}
808 	if (md->md_start != ll->ll_md_offset) {
809 		G_LLVM_DEBUG(0, "Incorrect md offset (%ju)", md->md_start);
810 		return (EINVAL);
811 	}
812 
813 	/* Aparently only one is ever returned */
814 	md->md_reloffset = le64dec(data + off);
815 	off += 8;
816 	md->md_relsize = le64dec(data + off);
817 	off += 16;	/* XXX skipped checksum */
818 
819 	if (le64dec(data + off) != 0) {
820 		G_LLVM_DEBUG(0, "Only one reloc supported");
821 		return (EINVAL);
822 	}
823 
824 	G_LLVM_DEBUG(3, "reloc: offset=%ju, size=%ju",
825 	    md->md_reloffset, md->md_relsize);
826 	G_LLVM_DEBUG(3, "md: version=%u, start=%ju, size=%ju",
827 	    md->md_version, md->md_start, md->md_size);
828 
829 	return (0);
830 }
831 
832 #define	GRAB_INT(key, tok1, tok2, v)					\
833 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
834 		v = strtol(tok2, &tok1, 10);				\
835 		if (tok1 == tok2)					\
836 			/* strtol did not eat any of the buffer */	\
837 			goto bad;					\
838 		continue;						\
839 	}
840 
841 #define	GRAB_STR(key, tok1, tok2, v, len)				\
842 	if (tok1 && tok2 && strncmp(tok1, key, sizeof(key)) == 0) {	\
843 		strsep(&tok2, "\"");					\
844 		if (tok2 == NULL)					\
845 			continue;					\
846 		tok1 = strsep(&tok2, "\"");				\
847 		if (tok2 == NULL)					\
848 			continue;					\
849 		strncpy(v, tok1, len);					\
850 		continue;						\
851 	}
852 
853 #define	SPLIT(key, value, str)						\
854 	key = strsep(&value, str);					\
855 	/* strip trailing whitespace on the key */			\
856 	for (char *t = key; *t != '\0'; t++)				\
857 		if (isspace(*t)) {					\
858 			*t = '\0';					\
859 			break;						\
860 		}
861 
862 static size_t
863 llvm_grab_name(char *name, const char *tok)
864 {
865 	size_t len;
866 
867 	len = 0;
868 	if (tok == NULL)
869 		return (0);
870 	if (tok[0] == '-')
871 		return (0);
872 	if (strcmp(tok, ".") == 0 || strcmp(tok, "..") == 0)
873 		return (0);
874 	while (tok[len] && (isalpha(tok[len]) || isdigit(tok[len]) ||
875 	    tok[len] == '.' || tok[len] == '_' || tok[len] == '-' ||
876 	    tok[len] == '+') && len < G_LLVM_NAMELEN - 1)
877 		len++;
878 	bcopy(tok, name, len);
879 	name[len] = '\0';
880 	return (len);
881 }
882 
883 static int
884 llvm_textconf_decode(u_char *data, int buflen, struct g_llvm_metadata *md)
885 {
886 	struct g_llvm_vg	*vg;
887 	char *buf = data;
888 	char *tok, *v;
889 	char name[G_LLVM_NAMELEN];
890 	char uuid[G_LLVM_UUIDLEN];
891 	size_t len;
892 
893 	if (buf == NULL || *buf == '\0')
894 		return (EINVAL);
895 
896 	tok = strsep(&buf, "\n");
897 	if (tok == NULL)
898 		return (EINVAL);
899 	len = llvm_grab_name(name, tok);
900 	if (len == 0)
901 		return (EINVAL);
902 
903 	/* check too see if the vg has already been loaded off another disk */
904 	LIST_FOREACH(vg, &vg_list, vg_next) {
905 		if (strcmp(vg->vg_name, name) == 0) {
906 			uuid[0] = '\0';
907 			/* grab the volume group uuid */
908 			while ((tok = strsep(&buf, "\n")) != NULL) {
909 				if (strstr(tok, "{"))
910 					break;
911 				if (strstr(tok, "=")) {
912 					SPLIT(v, tok, "=");
913 					GRAB_STR("id", v, tok, uuid,
914 					    sizeof(uuid));
915 				}
916 			}
917 			if (strcmp(vg->vg_uuid, uuid) == 0) {
918 				/* existing vg */
919 				md->md_vg = vg;
920 				return (0);
921 			}
922 			/* XXX different volume group with name clash! */
923 			G_LLVM_DEBUG(0,
924 			    "%s already exists, volume group not loaded", name);
925 			return (EINVAL);
926 		}
927 	}
928 
929 	vg = malloc(sizeof(*vg), M_GLLVM, M_NOWAIT|M_ZERO);
930 	if (vg == NULL)
931 		return (ENOMEM);
932 
933 	strncpy(vg->vg_name, name, sizeof(vg->vg_name));
934 	LIST_INIT(&vg->vg_pvs);
935 	LIST_INIT(&vg->vg_lvs);
936 
937 #define	VOL_FOREACH(func, tok, buf, p)					\
938 	while ((tok = strsep(buf, "\n")) != NULL) {			\
939 		if (strstr(tok, "{")) {					\
940 			func(buf, tok, p);				\
941 			continue;					\
942 		}							\
943 		if (strstr(tok, "}"))					\
944 			break;						\
945 	}
946 
947 	while ((tok = strsep(&buf, "\n")) != NULL) {
948 		if (strcmp(tok, "physical_volumes {") == 0) {
949 			VOL_FOREACH(llvm_textconf_decode_pv, tok, &buf, vg);
950 			continue;
951 		}
952 		if (strcmp(tok, "logical_volumes {") == 0) {
953 			VOL_FOREACH(llvm_textconf_decode_lv, tok, &buf, vg);
954 			continue;
955 		}
956 		if (strstr(tok, "{")) {
957 			G_LLVM_DEBUG(2, "unknown section %s", tok);
958 			continue;
959 		}
960 
961 		/* parse 'key = value' lines */
962 		if (strstr(tok, "=")) {
963 			SPLIT(v, tok, "=");
964 			GRAB_STR("id", v, tok, vg->vg_uuid, sizeof(vg->vg_uuid));
965 			GRAB_INT("extent_size", v, tok, vg->vg_extentsize);
966 			continue;
967 		}
968 	}
969 	/* basic checking */
970 	if (vg->vg_extentsize == 0)
971 		goto bad;
972 
973 	md->md_vg = vg;
974 	LIST_INSERT_HEAD(&vg_list, vg, vg_next);
975 	G_LLVM_DEBUG(3, "vg: name=%s uuid=%s", vg->vg_name, vg->vg_uuid);
976 	return(0);
977 
978 bad:
979 	g_llvm_free_vg(vg);
980 	return (-1);
981 }
982 #undef	VOL_FOREACH
983 
984 static int
985 llvm_textconf_decode_pv(char **buf, char *tok, struct g_llvm_vg *vg)
986 {
987 	struct g_llvm_pv	*pv;
988 	char *v;
989 	size_t len;
990 
991 	if (*buf == NULL || **buf == '\0')
992 		return (EINVAL);
993 
994 	pv = malloc(sizeof(*pv), M_GLLVM, M_NOWAIT|M_ZERO);
995 	if (pv == NULL)
996 		return (ENOMEM);
997 
998 	pv->pv_vg = vg;
999 	len = 0;
1000 	if (tok == NULL)
1001 		goto bad;
1002 	len = llvm_grab_name(pv->pv_name, tok);
1003 	if (len == 0)
1004 		goto bad;
1005 
1006 	while ((tok = strsep(buf, "\n")) != NULL) {
1007 		if (strstr(tok, "{"))
1008 			goto bad;
1009 
1010 		if (strstr(tok, "}"))
1011 			break;
1012 
1013 		/* parse 'key = value' lines */
1014 		if (strstr(tok, "=")) {
1015 			SPLIT(v, tok, "=");
1016 			GRAB_STR("id", v, tok, pv->pv_uuid, sizeof(pv->pv_uuid));
1017 			GRAB_INT("pe_start", v, tok, pv->pv_start);
1018 			GRAB_INT("pe_count", v, tok, pv->pv_count);
1019 			continue;
1020 		}
1021 	}
1022 	if (tok == NULL)
1023 		goto bad;
1024 	/* basic checking */
1025 	if (pv->pv_count == 0)
1026 		goto bad;
1027 
1028 	LIST_INSERT_HEAD(&vg->vg_pvs, pv, pv_next);
1029 	G_LLVM_DEBUG(3, "pv: name=%s uuid=%s", pv->pv_name, pv->pv_uuid);
1030 
1031 	return (0);
1032 bad:
1033 	free(pv, M_GLLVM);
1034 	return (-1);
1035 }
1036 
1037 static int
1038 llvm_textconf_decode_lv(char **buf, char *tok, struct g_llvm_vg *vg)
1039 {
1040 	struct g_llvm_lv	*lv;
1041 	struct g_llvm_segment *sg;
1042 	char *v;
1043 	size_t len;
1044 
1045 	if (*buf == NULL || **buf == '\0')
1046 		return (EINVAL);
1047 
1048 	lv = malloc(sizeof(*lv), M_GLLVM, M_NOWAIT|M_ZERO);
1049 	if (lv == NULL)
1050 		return (ENOMEM);
1051 
1052 	lv->lv_vg = vg;
1053 	LIST_INIT(&lv->lv_segs);
1054 
1055 	if (tok == NULL)
1056 		goto bad;
1057 	len = llvm_grab_name(lv->lv_name, tok);
1058 	if (len == 0)
1059 		goto bad;
1060 
1061 	while ((tok = strsep(buf, "\n")) != NULL) {
1062 		if (strstr(tok, "{")) {
1063 			if (strstr(tok, "segment")) {
1064 				llvm_textconf_decode_sg(buf, tok, lv);
1065 				continue;
1066 			} else
1067 				/* unexpected section */
1068 				goto bad;
1069 		}
1070 
1071 		if (strstr(tok, "}"))
1072 			break;
1073 
1074 		/* parse 'key = value' lines */
1075 		if (strstr(tok, "=")) {
1076 			SPLIT(v, tok, "=");
1077 			GRAB_STR("id", v, tok, lv->lv_uuid, sizeof(lv->lv_uuid));
1078 			GRAB_INT("segment_count", v, tok, lv->lv_sgcount);
1079 			continue;
1080 		}
1081 	}
1082 	if (tok == NULL)
1083 		goto bad;
1084 	if (lv->lv_sgcount == 0 || lv->lv_sgcount != lv->lv_numsegs)
1085 		/* zero or incomplete segment list */
1086 		goto bad;
1087 
1088 	/* Optimize for only one segment on the pv */
1089 	lv->lv_firstsg = LIST_FIRST(&lv->lv_segs);
1090 	LIST_INSERT_HEAD(&vg->vg_lvs, lv, lv_next);
1091 	G_LLVM_DEBUG(3, "lv: name=%s uuid=%s", lv->lv_name, lv->lv_uuid);
1092 
1093 	return (0);
1094 bad:
1095 	while ((sg = LIST_FIRST(&lv->lv_segs)) != NULL) {
1096 		LIST_REMOVE(sg, sg_next);
1097 		free(sg, M_GLLVM);
1098 	}
1099 	free(lv, M_GLLVM);
1100 	return (-1);
1101 }
1102 
1103 static int
1104 llvm_textconf_decode_sg(char **buf, char *tok, struct g_llvm_lv *lv)
1105 {
1106 	struct g_llvm_segment *sg;
1107 	char *v;
1108 	int count = 0;
1109 
1110 	if (*buf == NULL || **buf == '\0')
1111 		return (EINVAL);
1112 
1113 	sg = malloc(sizeof(*sg), M_GLLVM, M_NOWAIT|M_ZERO);
1114 	if (sg == NULL)
1115 		return (ENOMEM);
1116 
1117 	while ((tok = strsep(buf, "\n")) != NULL) {
1118 		/* only a single linear stripe is supported */
1119 		if (strstr(tok, "stripe_count")) {
1120 			SPLIT(v, tok, "=");
1121 			GRAB_INT("stripe_count", v, tok, count);
1122 			if (count != 1)
1123 				goto bad;
1124 		}
1125 
1126 		if (strstr(tok, "{"))
1127 			goto bad;
1128 
1129 		if (strstr(tok, "}"))
1130 			break;
1131 
1132 		if (strcmp(tok, "stripes = [") == 0) {
1133 			tok = strsep(buf, "\n");
1134 			if (tok == NULL)
1135 				goto bad;
1136 
1137 			strsep(&tok, "\"");
1138 			if (tok == NULL)
1139 				goto bad;	/* missing open quotes */
1140 			v = strsep(&tok, "\"");
1141 			if (tok == NULL)
1142 				goto bad;	/* missing close quotes */
1143 			strncpy(sg->sg_pvname, v, sizeof(sg->sg_pvname));
1144 			if (*tok != ',')
1145 				goto bad;	/* missing comma for stripe */
1146 			tok++;
1147 
1148 			sg->sg_pvstart = strtol(tok, &v, 10);
1149 			if (v == tok)
1150 				/* strtol did not eat any of the buffer */
1151 				goto bad;
1152 
1153 			continue;
1154 		}
1155 
1156 		/* parse 'key = value' lines */
1157 		if (strstr(tok, "=")) {
1158 			SPLIT(v, tok, "=");
1159 			GRAB_INT("start_extent", v, tok, sg->sg_start);
1160 			GRAB_INT("extent_count", v, tok, sg->sg_count);
1161 			continue;
1162 		}
1163 	}
1164 	if (tok == NULL)
1165 		goto bad;
1166 	/* basic checking */
1167 	if (count != 1 || sg->sg_count == 0)
1168 		goto bad;
1169 
1170 	sg->sg_end = sg->sg_start + sg->sg_count - 1;
1171 	lv->lv_numsegs++;
1172 	lv->lv_extentcount += sg->sg_count;
1173 	LIST_INSERT_HEAD(&lv->lv_segs, sg, sg_next);
1174 
1175 	return (0);
1176 bad:
1177 	free(sg, M_GLLVM);
1178 	return (-1);
1179 }
1180 #undef	GRAB_INT
1181 #undef	GRAB_STR
1182 #undef	SPLIT
1183 
1184 static struct g_class g_llvm_class = {
1185 	.name = G_LLVM_CLASS_NAME,
1186 	.version = G_VERSION,
1187 	.init = g_llvm_init,
1188 	.taste = g_llvm_taste,
1189 	.destroy_geom = g_llvm_destroy_geom
1190 };
1191 
1192 DECLARE_GEOM_CLASS(g_llvm_class, g_linux_lvm);
1193